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1

Feasibility of anomaly detection and characterization using trans-admittance mammography with 60 × 60 electrode array  

NASA Astrophysics Data System (ADS)

Electrical impedance imaging has the potential to detect an early stage of breast cancer due to higher admittivity values compared with those of normal breast tissues. The tumor size and extent of axillary lymph node involvement are important parameters to evaluate the breast cancer survival rate. Additionally, the anomaly characterization is required to distinguish a malignant tumor from a benign tumor. In order to overcome the limitation of breast cancer detection using impedance measurement probes, we developed the high density trans-admittance mammography (TAM) system with 60 × 60 electrode array and produced trans-admittance maps obtained at several frequency pairs. We applied the anomaly detection algorithm to the high density TAM system for estimating the volume and position of breast tumor. We tested four different sizes of anomaly with three different conductivity contrasts at four different depths. From multifrequency trans-admittance maps, we can readily observe the transversal position and estimate its volume and depth. Specially, the depth estimated values were obtained accurately, which were independent to the size and conductivity contrast when applying the new formula using Laplacian of trans-admittance map. The volume estimation was dependent on the conductivity contrast between anomaly and background in the breast phantom. We characterized two testing anomalies using frequency difference trans-admittance data to eliminate the dependency of anomaly position and size. We confirmed the anomaly detection and characterization algorithm with the high density TAM system on bovine breast tissue. Both results showed the feasibility of detecting the size and position of anomaly and tissue characterization for screening the breast cancer.

Zhao, Mingkang; Wi, Hun; Lee, Eun Jung; Woo, Eung Je; In Oh, Tong

2014-10-01

2

Electrical admittance of piezoelectric parallelepipeds: application to tensorial characterization of piezoceramics  

NASA Astrophysics Data System (ADS)

This work deals with the characterization of functional properties, including determination of mechanical and electrical losses, of piezoelectric materials using only one sample and one measurement. First, the natural resonant frequencies of a piezoelectric parallelepiped are calculated and the electrical admittance is determined from calculations of the charge quantity on both electrodes of the parallelepiped. A first validation of the model is performed using a comparison with Mason's model. Results are reported for a PMN-34.5PT ceramic cube and a good agreement is found between experimental admittance measurements and their modeling. The functional properties of the PMN-34.5PT are then extracted.

Diallo, O.; Clezio, E. Le; Delaunay, T.; Bavencoffe, M.; Feuillard, G.

2014-01-01

3

Multi-dimensional admittance spectroscopy  

NASA Astrophysics Data System (ADS)

We introduce the concept of multi-dimensional admittance spectroscopy capable of characterizing thin-film diode structures in both the (standard) transversal and lateral directions. This extends the capabilities of standard admittance spectroscopy based on the model of leaky capacitor with area defined by the metal contacts. In our approach, the ac signal spreads in the lateral directions far beyond the contact area. The spreading range defines the area of the effective capacitor determining the measured capacitance and conductance. It depends on the ac signal frequency, dc bias, and various structure parameters. A phenomenological description of these dependencies here is verified numerically using our original software to model the distributed admittance via finite element circuits. We analyze the case of photovoltaic devices and show how the multi-dimensional admittance spectroscopy is sensitive to lateral nonuniformity of the system, particularly to the presence of shunts and weak diodes and their location. In addition, the proposed characterization provides information about the system lump parameters, such as sheet resistance, shunt resistance, and open circuit voltage.

Wieland, K.; Vasko, A.; Karpov, V. G.

2013-01-01

4

Reservoir characterization using wavelet transforms  

E-print Network

Automated detection of geological boundaries and determination of cyclic events controlling deposition can facilitate stratigraphic analysis and reservoir characterization. This study applies the wavelet transformation, a recent advance in signal...

Rivera Vega, Nestor

2004-09-30

5

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

6

Validation of a screening oto- admittance instrument.  

PubMed

A within-subject comparison between an American Electromedics 85R screening tympanometer and a Grason-Stadler 1723 clinical otoadmittance meter indicated equivalent results for middle-ear pressure. Tympanometer admittance readings needed to be rescaled to concur with the oto-admittance meter. Screening by acoustic reflex response using the single-intensity stimulus of the tympanometer was problematic and gave many misleading results. PMID:7159796

Wood, E J; Lutman, M E; Fernandes, M A

1982-11-01

7

Aerodynamic Admittance Function of Tall Buildings Ahsan Kareemb  

E-print Network

Aerodynamic Admittance Function of Tall Buildings Yin Zhoua Ahsan Kareemb a Malouf Engineering Int, Notre Dame, USA ABSTRACT: The aerodynamic admittance function (AAF) has been widely invoked to relate in the high frequency range were noted. KEYWORDS: Aerodynamic admittance function; Wind effects; Tall

Kareem, Ahsan

8

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

9

Coulometric differential FFT admittance voltammetry determination of Amlodipine in pharmaceutical formulation by nano-composite electrode.  

PubMed

An electrochemical detection technique based on combination of was coulometric differential fast Fourier transformation admittance voltammetry (CDFFTAV) and nano-composite film modified glassy carbon electrode was successfully applied for sensitive determination of Amlodipine. The nano-composite film was made by a mixture of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), multiwall carbon nanotube and Au nanoparticles as electrochemical mediators. Studies reveal that the irreversible oxidation of Amlodipine was highly facile on the electrode surface. The electrochemical response was established on calculation of the charge under the admittance peak, which was obtained by discrete integration of the admittance response in a selected potential range, obtained in a flow injection analysis. Once established the best operative optimum conditions, the resulting nano-composite film electrode showed a catalytic effect on the oxidation of the analyte. The response is linear in the Amlodipine concentration range of 1.0×10(-9) to 2.0×10(-7)M with a detection limit of 1.25×10(-10)M. Moreover, the proposed technique exhibited high sensitivity, fast response time (less than 6s) and long-term stability and reproducibility around 96%, and it was successfully used to the determination of Amlodipine content in the pharmaceutical formulation. PMID:25281143

Norouzi, Parviz; Gupta, Vinod Kumar; Larijani, Bagher; Rasoolipour, Solmaz; Faridbod, Farnoush; Ganjali, Mohammad R

2015-01-01

10

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

NASA Astrophysics Data System (ADS)

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.

1984-06-01

11

Measurements of reactive gaseous rocket injector admittances  

NASA Technical Reports Server (NTRS)

The paper describes the results of an experimental study of the quantitative determination of the capabilities of the combustion processes associated with coaxial gaseous propellant rocket injectors to drive combustor pressure oscillations. The data, obtained by employing the modified impedance tube technique with compressed air as the oxidizer and acetylene gas as the fuel, describe the frequency dependence of the admittance of the combined injector-combustion process. The measured data are compared with the predictions of the Feiler and Heidmann analytical model utilizing different values for the characteristic combustion time tau sub b. The values of tau sub b which result in a best fit between the measured and predicted data are indicated for different equivalence ratios. It is shown that for the coaxial injector investigated in this study the tau sub b varies between 0.7 and 1.2 msec for equivalence ratios in the range of 0.57 to 1.31. In addition, the experimental data indicate that the tested injector system could drive combustion instabilities over a frequency range that is in qualitative agreement with the predictions of the Feiler and Heidmann model.

Janardan, B. A.; Daniel, B. R.; Bell, W. A.; Zinn, B. T.

1979-01-01

12

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

13

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 6.3eV. 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

14

Characterization of Daily Wind Farm Power Fluctuations Using Wavelet Transform  

Microsoft Academic Search

With the increase of wind power installed capacities, the cost of integration is large due to the intermittent nature of wind energy. To accommodate wind farm power fluctuations, additional control measures are required. Accurate characterization of the fluctuations paves the way for optimal control design. In identifying localized characteristics of the signal, wavelet transform provides a suitable tool. Data gathered

Xiaodong Chu; Wen Zhang; Tochi Nwachukwu; Ian A. Hiskens

2008-01-01

15

Admittance survey of type 1 coronae on Venus  

Microsoft Academic Search

In this study, we analyze Magellan gravity and topography data for Type 1 coronae on Venus to estimate crustal thickness (Zc), elastic thickness (Te), and apparent depth of compensation (ZL). We examine the free-air admittance for all 103 Type 1 coronae (defined as having greater than 50% complete fracture annuli) that are resolved in the gravity data. A spatio-spectral method

Trudi Hoogenboom; Suzanne E. Smrekar; F. Scott Anderson; Greg Houseman

2004-01-01

16

Admittance Probe Measurements of Electron Temperature in the Octupole  

E-print Network

. #12;4 Fig. 1 shows the result for three cases. The gun plasma at a background pressure of 10- 6 torrAdmittance Probe Measurements of Electron Temperature in the Octupole by J.e. Sprott Plasma Studies. Briefly, it consists of placing the probe-to-plasma (sheath) impe dance across one leg of a capacitance

Sprott, Julien Clinton

17

Characterizing seismic time series using the discrete wavelet transform  

SciTech Connect

The discrete wavelet transform (DWT) has potential as a tool for supplying discriminatory attributes with which to characterize or cluster groups of seismic traces in reservoir studies. The wavelet transform has the great advantage over the Fourier transform in being able to better localize changes. The multiscale nature and structure of the DWT leads to a method of display which highlights this and allows comparison of changes in the transform with changing data. Many different sorts of wavelet exist and it is found that the quality of reconstruction of a seismic trace wavelet exist and it is found that the quality of reconstruction of a seismic trace segment, using some of the coefficients, is dependent on the choice of wavelet, which leads us to consider choosing a wavelet under a best reconstruction criterion. Location shifts, time zero uncertainties, are also shown to affect the transform, as do truncations, resampling, etc. Using real data, examples of utilizing the DWT coefficients as attributes for whole trace segments or fractional trace segments are given. Provided the DWT is applied consistently, for example with a fixed wavelet, and non-truncated data, the transform produces useful results. Care must be exercised if it is applied to data of different lengths. However, as the algorithm is refined and improved in the future, the DWT should prove increasingly useful.

Grubb, H.J.; Walden, A.T. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Mathematics] [Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Mathematics

1997-03-01

18

Admittance measurements in the quantum Hall effect regime  

NASA Astrophysics Data System (ADS)

In this work we present an admittance study of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime. We have studied several Hall bars in different contacts configurations in the frequency range 100 Hz-1 MHz. Our interpretation is based on the Landauer-Büttiker theory and takes into account both the capacitance and the topology of the coaxial cables which are connected to the sample holder. We show that we always observe losses through the capacitive impedance of the coaxial cables, except in the two contacts configuration in which the cable capacitance does not influence the admittance measurement of the sample. In this case, we measure the electrochemical capacitance of the 2DEG and show its dependence with the filling factor ?.

Hernández, C.; Consejo, C.; Chaubet, C.

2014-11-01

19

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

20

Characterization of a spontaneously transformed chicken mononuclear cell line.  

PubMed

We describe the characterization of a spontaneously transformed chicken monocytic cell line that developed as a single colony of cells in a heterophil culture that was inadvertently left in the incubator over a period of 25 days. These cells, hitherto named HTC, grow efficiently at both 37 or 41 degrees C in culture medium containing either 5% FBS or 2% chicken serum. The HTC cells are acid phosphatase positive, show expressions of both class I and class II major histocompatibility complex (MHC), CD44, K1, and K55 cell surface antigens, and engulf latex beads, produce nitrite and interleukin-6 on stimulation with bacterial lipopolysaccharide (LPS). Treatment with phorbol myristate acetate (PMA) induces respiratory burst in HTC cells and the secretion of matrix metalloproteinase (MMP) into culture medium. Using gene-specific primers and reverse transcriptase-polymerase chain reaction (RT-PCR), the presence of mRNA trancripts for interferon-gamma (IFN-gamma), interleukin-1 (IL-1), interleukin-6 (IL-6), nitric oxide synthase (NOS), matrix metalloproteinase-2 (MMP-2), and transforming growth factor-beta (TGF-beta) were detected. Lipopolysaccharide (LPS) treatment of HTC cells modulated IL-1, IL-6, IFN-gamma, NOS mRNA levels as detected by RT-PCR analyses. Using different avian tumor virus gene-specific primers and PCR, the HTC cells were positive for the presence of avian leukosis virus (ALV) and Marek's disease virus (MDV) but negative for reticuloendothelial virus (REV), chicken infectious anemia virus (CIAV), and herpes virus of turkeys (HVT). The production of ALV antigens by HTC cells was further confirmed using p27 gag protein ELISA. Collectively, these results show that the HTC cells belong to myeloid/macrophage lineage and were likely transformed by ALV and MDV but retain many interesting and useful biological activities. PMID:14522138

Rath, N C; Parcells, M S; Xie, H; Santin, E

2003-11-15

21

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

22

PID Admittance Control for an Upper Limb Exoskeleton Wen Yu, Jacob Rosen, Xiaoou Li  

E-print Network

are redundant, such as exoskeleton system. In this paper, we put both the upper-level PID admittance controlPID Admittance Control for an Upper Limb Exoskeleton Wen Yu, Jacob Rosen, Xiaoou Li Abstract-- The unique exoskeleton system (EXO-UL7) in UCSC is controlled in two levels. The lower-level uses standard

Rosen, Jacob

23

Ion-sheath admittance in cylindrical and spherical probes near the ion plasma frequency  

Microsoft Academic Search

The admittance of the ion-sheath in cylindrical and spherical probes near the ion plasma frequency has been calculated, assuming the probe is negatively polarized. An equation is derived to describe the ion motion in the sheath when the polarization applied to the probe is superimposed on a small amplitude RF signal. The admittance of the ion-sheath is derived from the

A. Dengra; V. Colomer; M. A. Hernandez

1985-01-01

24

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

25

An analytical model for admittance parameters of GaN MESFET for microwave circuit applications  

Microsoft Academic Search

An analytical model of GaN MESFET to evaluate admittance parameters is presented. Frequency dependence of the parasitic capacitances obtained by simulations has been utilized to develop the model. Results have been verified using ATLAS 2D device simulator.

Sneha Kabra; H. Kaur; S. Haldar; M. Gupta; R. S. Gupta

2007-01-01

26

48 CFR 3022.101-70 - Admittance of union representatives to DHS installations.  

Code of Federal Regulations, 2012 CFR

...HSAR) SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Basic Labor Policies 3022.101-70 Admittance...representatives to Transportation Security Administration or United States Secret Service installations and work sites is not...

2012-10-01

27

48 CFR 3022.101-70 - Admittance of union representatives to DHS installations.  

Code of Federal Regulations, 2011 CFR

...HSAR) SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Basic Labor Policies 3022.101-70 Admittance...representatives to Transportation Security Administration or United States Secret Service installations and work sites is not...

2011-10-01

28

48 CFR 3022.101-70 - Admittance of union representatives to DHS installations.  

Code of Federal Regulations, 2010 CFR

...HSAR) SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Basic Labor Policies 3022.101-70 Admittance...representatives to Transportation Security Administration or United States Secret Service installations and work sites is not...

2010-10-01

29

Electrical Properties of Metal-Silicon Nitride-Hydrogenated Amorphous Silicon Capacitor Elucidated Using Admittance Spectroscopy  

Microsoft Academic Search

Detailed admittance spectroscopy was performed on a metal-silicon nitride-hydrogenated amorphous silicon (MIAS) structure. On the basis of the properties of hydrogenated amorphous silicon (a-Si:H), three simplified equivalent circuit models under various operating conditions (accumulation, depletion and full depletion) are presented along with an alternative direct measurement method at room temperature. Admittance spectroscopy shows that the interface states density between silicon

Ming-Ta Hsieh; Jenn-Fang Chen; Kuo-Hsi Yen; Hsiao-Wen Zan; Chan-Ching Chang; Chih-Hsien Chen; Ching-Chieh Shih; Yeong-Shyang Lee

2008-01-01

30

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

31

Transport scattering time probed through rf admittance of a graphene capacitor  

Microsoft Academic Search

We have investigated electron dynamics in top gated graphene by measuring the gate admittance of a diffusive graphene capacitor in a broad frequency range as a function of carrier density. The density of states, conductivity, and diffusion constant are deduced from the low-frequency gate capacitance, its charging time, and their ratio. The admittance evolves from an rc-like to a skin-effect

E. Pallecchi; A. C. Betz; J. Chaste; G. Fève; B. Huard; T. Kontos; J.-M. Berroir; B. Plaçais

2011-01-01

32

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

33

Characterization of competent cells and early events of Agrobacterium -mediated genetic transformation in Arabidopsis thaliana  

Microsoft Academic Search

The insertion of foreign DNA in plants occurs through a complex interaction between Agrobacteria and host plant cells. The marker gene ß-glucuronidase of Escherichia coli and cytological methods were used to characterize competent cells for Agrobacterium-mediated transformation, to study early cellular events of transformation, and to identify the potential host-cell barriers that limit transformation in Arabidopsis thaliana L. Heynh. In

Rajbir S. Sangwan; Yvan Bourgeois; Spencer Brown; Gérard Vasseur; Brigitte Sangwan-Norreel

1992-01-01

34

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

35

Characterization of distribution power quality events with Fourier and wavelet transforms  

Microsoft Academic Search

It is the objective of this paper to present unique features that characterize power quality events and methodologies to extract them from recorded voltage and\\/or current waveforms using Fourier and wavelet transforms. Examples of unique features include peak amplitudes, RMS, frequency, and statistics of wavelet transform coefficients. These features are derived from well documented theories, power engineers' heuristics gained through

Surya Santoso; W. Mack Grady; Edward J. Powers; Jeff Lamoree; Siddharth C. Bhatt

2000-01-01

36

Transmission level instrument transformers and transient event recorders characterization for harmonic measurements  

Microsoft Academic Search

This paper presents a technique for laboratory characterization of instrument transformers designed for transmission level voltage and current measurements. The technique is also extended to Transient Event Recorders (TERs). The objective of the method is to determine the suitability of existing substation instrument transformers for harmonic measurements, particularly in the frequency range of 60 to 1500 Hz covering the first

A. P. S. Meliopoulos; Fan Zhang; G. J. Cokkinides; L. Coffeen; R. Burnett; J. McBride; S. Zelingher; G. Stillman

1993-01-01

37

Assessing the practicality of ATRAssessing the practicality of ATR--FTIR spectroscopy in characterizingFTIR spectroscopy in characterizing multimulti--step transformations of polypropylene surfaces and substep transformations of polypropylene surfaces and  

E-print Network

in characterizingFTIR spectroscopy in characterizing multimulti--step transformations of polypropylene surfaces and substep transformations of polypropylene surfaces and sub--surfaces:surfaces: Utility and time savings Istanbul, Turkey SUMMARSUMMARYY In transforming the physico-chemical surface properties of a polypropylene

Taralp, Alpay

38

Internal wave packet characterization from SAR images using wavelet transform modulus maxima (WTMM)  

Microsoft Academic Search

This paper addresses the problem of the characterization of oceanic internal wave packets from SAR images. Wavelet analysis provides a new strategy for examining internal wave signatures, and offers the flexibility which results from the introduction of well-suited basis functions. The continuous wavelet transform (CWT) is employed in a scale-space analysis of SAR image profiles to locate and characterize the

J. A. Rodenas; R. Garello

1998-01-01

39

CHARACTERIZATION OF LYMPHOCYTE TRANSFORMATION INDUCED BY ZINC IONS  

PubMed Central

Lymphocyte cultures from all normal human adults are stimulated by zinc ions to increase DNA and RNA synthesis and undergo blast transformation. Optimal stimulation occurs at 0.1 mM Zn++. Examination of the effects of other divalent cations reveals that 0.01 mM Hg++ also stimulates lymphocyte DNA synthesis. Ca++ and Mg++ do not affect DNA synthesis in this culture system, while Mn++, Co++, Cd++, Cu++, and Ni++ at concentrations of 10-7–10-3 M are inhibitory. DNA and RNA synthesis and blast transformation begin to increase after cultures are incubated for 2–3 days with Zn++ and these processes reach a maximum rate after 6 days. The increase in Zn++-stimulated lymphocyte DNA synthesis is prevented by rendering cells incapable of DNA-dependent RNA synthesis with actinomycin D or by blocking protein synthesis with cycloheximide or puromycin. Zn++-stimulated DNA synthesis is also partially inhibited by 5'-AMP and chloramphenicol. Zn++ must be present for the entire 6-day culture period to produce maximum stimulation of DNA synthesis. In contrast to its ability to independently stimulate DNA synthesis, 0.1 mM Zn++ inhibits DNA synthesis in phytohemagglutinin-stimulated lymphocytes and L1210 lymphoblasts. PMID:4819306

Berger, Nathan A.; Skinner, Sister Ann Marie

1974-01-01

40

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

41

Fermi level pinning at GaN-interfaces: Correlation of electrical admittance and transient spectroscopy  

SciTech Connect

In GaN layers grown by molecular beam epitaxy as well as metal organic vapor phase epitaxy significant differences were found in the appearance of deep defects detected by thermal admittance spectroscopy as compared for deep level transient spectroscopy measurements. While, thermal admittance spectroscopy measurements which were made under zero bias conditions only show thermal emissions at activation energies between 130 and 170 meV, further deep levels existing in these GaN layers were evidenced by transient spectroscopy. This discrepancy is explained by a pinning effect of the Fermi level at the metal/GaN interface induced by high a concentration of the deep levels showing up in thermal admittance spectroscopy. The authors compare their results with a GaAs:Te Schottky-diode as a reference sample. Here, both spectroscopic methods give exactly the same deep level emissions.

Witte, H.; Krtschil, A.; Lisker, M.; Rudloff, D.; Christen, J.; Krost, A.; Stutzmann, M.; Scholz, F.

2000-07-01

42

Surface plasmon resonance based sensing of different chemical and biological samples using admittance loci method  

NASA Astrophysics Data System (ADS)

The admittance loci method plays an important role in the design of multilayer thin film structures. In this paper, admittance loci method has been explored theoretically for sensing of various chemical and biological samples based on surface plasmon resonance (SPR) phenomenon. A dielectric multilayer structure consisting of a Boro silicate glass (BSG) substrate, calcium fluoride (CaF2) and zirconium dioxide (ZrO2) along with different dielectric layers has been investigated. Moreover, admittance loci as well as SPR curves of metal-dielectric multilayer structure consisting of the BSG substrate, gold metal film and various dielectric samples has been simulated in MATLAB environment. To validate the proposed simulation results, calibration curves have also been provided.

Brahmachari, Kaushik; Ghosh, Sharmila; Ray, Mina

2013-06-01

43

Synthesis and characterization of JBW structure and its thermal transformation  

SciTech Connect

In this paper, JBW zeolite prepared from Egyptian kaolin was investigated by means of XRD, IR, SEM, EDX and ion exchange of some heavy metals. Adsorption isotherms were used to investigate the structure and properties of the prepared zeolite. XRD analysis showed that the JBW was a pure crystalline phase with orthorhombic crystal symmetry. Thermal treatment showed that the JBW transformed into the It-Carn phase at 1000 Degree-Sign C through an intermediate crystalline alumino silicate phase. SEM images showed that the JBW crystallised in a cylindrical shape. However, spherical agglomerates were observed at lower magnifications. The ion exchange isotherms with Cu{sup 2+}, Ni{sup 2+} and Co{sup 2+} were found to follow a Freundlich isotherm. In addition, it shows higher affinity towards Cu{sup 2+} than other ions. - Graphical abstract: JBW zeolite structure was prepared from Egyptian kaolin and characterised. XRD analysis showed that the JBW was a pure crystalline phase with orthorhombic crystal symmetry. Thermal treatment showed that the JBW transformed into the It-Carn phase at 1000 Degree-Sign C through an intermediate crystalline alumino silicate phase. Highlights: Black-Right-Pointing-Pointer Egyptian kaolin was successfully used to prepare pure phase of JBW Structure. Black-Right-Pointing-Pointer JBW is stable till <300 Degree-Sign C. Black-Right-Pointing-Pointer JBW phase crystallizes as cylindrical shape but agglomerates in a Nano spherical shape. Black-Right-Pointing-Pointer The ion exchange isotherms of Cu{sup 2+}, Ni{sup 2+}, and Co{sup 2+} followed up Freundlich isotherm. Black-Right-Pointing-Pointer Selectivity towards Cu{sup 2+} is much higher than Co{sup 2+} or Ni{sup 2+}.

Hegazy, Eman Z., E-mail: ehegazy77@yahoo.com [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia); National research Centre, Cairo (Egypt); Kosa, Samia A., E-mail: skousah@kau.edu.sa [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia); Abd El Maksod, Islam Hamdy, E-mail: islam_9000@yahoo.com [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia); National research Centre, Cairo (Egypt)

2012-12-15

44

A biotelemetric device for measurement of left ventricular pressure-volume loops using the admittance technique in conscious, ambulatory rats  

Microsoft Academic Search

This paper presents the design, construction and testing of a device to measure pressure-volume loops in the left ventricle of conscious, ambulatory rats. Pressure is measured with a standard sensor, but volume is derived from data collected from a tetrapolar electrode catheter using a novel admittance technique. There are two main advantages of the admittance technique to measure volume. First,

Karthik Raghavan; Marc D. Feldman; John E. Porterfield; Erik R. Larson; J. Travis Jenkins; Daniel Escobedo; John A. Pearce; Jonathan W. Valvano

2011-01-01

45

Synthesis, characterization and structural transformation of a discrete tetragonal metalloprism.  

PubMed

A novel M(2)L(4) tetragonal metalloprism, [(NO(3)(-))?{Cu(2)(?-Hdpma)(4)}(NO(3))(2)](NO(3))(5) (1), was prepared from the self-assembly reaction of Cu(NO(3))(2)·3H(2)O and flexible clip-like organic ligand di(3-pyridylmethyl)amine (dpma) under acidic conditions. The cationic prismatic hollow structure of 1 hosts one nitrate anion via both metal-ligand dative bonds and electrostatic interactions. Metalloprism 1 can dissolve in water and its prismatic structure remains intact as supported by ESI-MS data. When metalloprism 1 was treated with sodium thiocyanate and sodium azide in aqueous solutions, two polymeric coordination architectures, [Cu(?-Hdpma)(2)(NCS)(2)](NO(3))(2) (2) and [Cu(?-dpma)(2)(?-1,1-N(3))(?-1,3-N(3))] (3), formed at room temperature, respectively. Polymer 2 has a two-dimensional sheet structure showing a simple rhombic 4(4)-sql topology in network connectivity, whereas polymer 3 gives a three-dimensional uninodal pcu net. The conformation of the flexible ditopic ligand is varied from a trans-trans-syn conformer in 1 to a trans-trans-anti conformer in 2 and to a trans-gauche-anti conformer in 3. The observations imply the occurrence of structural transformation from a discrete metalloprism into polymeric coordination architectures via a decoordination/rearrangement process. Magnetic studies of metalloprism 1 suggest that the two Cu(II) centers are weakly antiferromagnetically coupled. The spins communicate via the nitrate template while the Cu···O(nitrate) interactions are weak. For polymer 3, a ferromagnetically coupled system (J(2) = +17.6 cm(-1)) is operative between two Cu(II) centers bridged by end-on azidos and an antiferromagnetic coupling (J(1) = -7.7 cm(-1)) between two Cu(II) centers with end-to-end azidos. In contrast to relatively large coupling values of the reported examples, the weak ferromagnetic interaction results from insufficient spin delocalization between two Cu(II) centers. PMID:22094892

Wu, Jing-Yun; Zhong, Ming-Shiou; Chiang, Ming-Hsi; Tsai, Meng-Rong; Lai, Long-Li

2012-01-01

46

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

47

Admittance model for the shuttle remote manipulator system in four configurations. M.S. Thesis  

NASA Technical Reports Server (NTRS)

A possible scenario for robot task performance in space is to mount two small, dexterous arms to the end of the Shuttle Remote Manipulator System (SRMS). As these small robots perform tasks, the flexibility of the SRMS may cause unsuccessful task executions. In order to simulate the dynamic coupling between the SRMS and the arms, admittance models of the SRMS in four brakes locked configurations were developed. The admittance model permits calculation of the SRMS end-effector response due to end-effector disturbing forces. The model will then be used in conjunction with a Stewart Platform, a vehicle emulation system. An application of the admittance model was shown by simulating the disturbing forces using two SRMS payloads, the Dextrous Orbital Servicing System (DOSS) manipulator and DOSS carrying a 1000 lb. cylinder. Mode by mode comparisons were conducted to determine the minimum number of modes required in the admittance model while retaining dynamic fidelity. It was determined that for all four SRMS configurations studied, between 4 and 6 modes of the SRMS structure (depending on the excitation loads) were sufficient to retain tolerance of 0.01 inches and 0.01 deg. These tolerances correspond to the DOSS manipulator carrying no object. When the DOSS carries the 1000 lb. cylinder, between 15 and 20 modes were sufficient, approximately three or four times as many modes as for the unloaded case.

Papadopoulos, Loukas; Tolson, Robert H.

1993-01-01

48

Admittance estimates of mean crustal thickness and density at the Martian hemispheric dichotomy  

E-print Network

Francis Nimmo Department of Geological Sciences, University College London, London, UK Received 14 March, Mars Global Surveyor Citation: Nimmo, F., Admittance estimates of mean crustal thickness and density., 1999b]. Both Zuber et al. [2000] and Nimmo and Stevenson [2001] argue that the mean crustal thickness

Nimmo, Francis

49

Electrical Properties of MetalSilicon NitrideHydrogenated Amorphous Silicon Capacitor Elucidated Using Admittance Spectroscopy  

E-print Network

Electrical Properties of Metal­Silicon Nitride­Hydrogenated Amorphous Silicon Capacitor Elucidated online December 19, 2008) Detailed admittance spectroscopy was performed on a metal­silicon nitride­hydrogenated amorphous silicon (MIAS) structure. On the basis of the properties of hydrogenated amorphous silicon (a

50

Assessment of bronchial reactivity by forced oscillation admittance avoids the upper airway artefact  

Microsoft Academic Search

Assessment of bronchial reactivity by forced oscillation admittance avoids the upper airway artefact. R. Farre ´, M. Rotger, F. Marchal, R. Peslin, D. Navajas. #ERS Journals Ltd 1999. ABSTRACT: The forced oscillation technique (FOT) allows easy assessment of bron- chial reactivity. The use of a standard FOT generator (SG) results in changes in respiratory system resistance (DRrs,SG) which are affected

R. Farre ´; M. Rotger; F. Marchal; R. Peslin; D. Navajas

1999-01-01

51

Localized gravity/topography admittance and correlation spectra on Mars: Implications for  

E-print Network

of an elastic/plastic shell. In regions of high topography on Mars (e.g., the Tharsis rise and associated shield volcanoes), the mass-sheet (small-amplitude) approximation for the calculation of gravity from topography are not required to explain the observed admittances for the Tharsis Montes or Olympus Mons volcanoes when

Zuber, Maria

52

Admittance matrix calculations of on-chip interconnects on lossy silicon substrate using multilayer Green's function  

Microsoft Academic Search

In this paper, a simple method for computation of the shunt admittance matrix of multiconductor interconnects on a general lossy multilayer substrate at high bit rates is presented. The analysis is based on the semi-analytical Green's function approach and the recurrence relation between the coefficients of potential in n and n+1 layers. The electromagnetic concept of free charge density is

Hasan Ymeri; Bart Nauwelaers; Karen Maex; D. De Roest; S. Vandenberghe; M. Stucchi

2001-01-01

53

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

54

$(p,q)-$deformed Fibonacci and Lucas polynomials: characterization and Fourier integral transforms  

E-print Network

A full characterization of $(p,q)$-deformed Fibonacci and Lucas polynomials is given. These polynomials obey non-conventional three-term recursion relations. Their generating functions and Fourier integral transforms are explicitly computed and discussed. Relevant results known in the literature are examined as particular cases.

Mahouton Norbert Hounkonnou; Sama Arjika

2013-07-09

55

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

56

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

57

a Form of Aerodynamic Admittance for Use in Bridge Aeroelastic Analysis  

NASA Astrophysics Data System (ADS)

This paper returns to, and addresses, the question of identifying the nature of aerodynamic admittance in relation to extended-span bridges in wind. Theoretical formulations for the sectional aerodynamic forces acting upon the deck girder of a long-span bridge have conventionally been composed of the sum of two kinds of terms: aeroelastic terms and buffeting terms. The former employ frequency-dependent coefficients (``flutter derivatives'') associated with sinusoidal displacements of the structure, while the latter have typically been expressed in quasi-static terms with fixed lift, drag and moment coefficients. This inconsistency of formulation has required that at some point the buffeting terms, functions of gust velocity, be adjusted to a more compatible form through the introduction of the so-called aerodynamic admittance factors that are frequency-dependent. The present paper identifies a form of these several section-force factors as functions of the flutter derivatives themselves.

Scanlan, R. H.; Jones, N. P.

1999-10-01

58

Lithium-diffused and annealed GaAs: An admittance spectroscopy study  

Microsoft Academic Search

We study lithium-diffused and annealed GaAs by admittance spectroscopy in the frequency range 10 106 Hz and the temperature range 30 300 K. Li diffusion turns the GaAs semi-insulating but subsequent out-diffusion of Li increases the conductivity and makes the samples p type. It is demonstrated that the conduction in semi-insulating Li-diffused GaAs is due to thermally activated carriers in

H. G. Svavarsson; J. T. Gudmundsson; H. P. Gislason

2004-01-01

59

Adaptive Control of Haptic Interaction with Impedance and Admittance Type Virtual Environments  

Microsoft Academic Search

Adaptive nonlinear controllers have been proposed to improve the stability and transparency in haptic rendering. Through a separation of control and dynamic simulation, the proposed controllers can couple impedance-type haptic devices with impedance and admittance-type virtual environment simulators. The intervening dynamics of the interface, subject to stability constraints, can be replaced with an adjustable mass-damper tool within the proposed framework.

Amin Abdossalami; Shahin Sirouspour

2008-01-01

60

GHM: A generalized Hamiltonian method for passivity test of impedance\\/admittance descriptor systems  

Microsoft Academic Search

A generalized Hamiltonian method (GHM) is proposed for passivity test of descriptor systems (DSs) which describe impedance or admittance input-output responses. GHM can test passivity of DSs with any system index without minimal realization. This frequency-independent method can avoid the time-consuming system decomposition as required in many existing DS passivity test approaches. Furthermore, GHM can test systems with singular D

Chi-Un Lei; Ngai Wong; Ngai Wong

2009-01-01

61

An improved design method for asymmetric RF MEMS tunable filter utilizing admittance matrix  

Microsoft Academic Search

This paper presents a low loss 8-10GHz tunable filter using high-Q RF MEMS capacitance networks. An improved design method, which utilizes admittance matrix of the filter network, is proposed and discussed. Detail design equations for the tuning elements and coupled microstrip ?\\/2 resonators are given. Compared to previous method, this method is improved since it is applicable to not only

Cheng Tu; Jingfu Bao; Yijia Du; Wenchang Wu

2010-01-01

62

A Closed-Form Input Admittance Solution for RF and Microwave Switched Capacitor Arrays  

Microsoft Academic Search

The parallel equivalent circuit for radio-frequency and microwave single-ended switched capacitor arrays (SSCAs) is investigated. In particular, the SSCA equivalent capacitance and resistance are highlighted and predicted by new closed-form mathematic expressions. The behavior of the SSCA with the control input and frequency is also analyzed in detail. The proposed model shows that the SSCA admittance depends on frequency, integration

L. Mendes; J. C. Vaz; M. J. Rosario

2006-01-01

63

Sensor for determining the water content of oil-in-water emulsion by specific admittance measurement  

Microsoft Academic Search

It is important to know the water content of oil-in-water emulsions for applications such as oil transportation. A new on-line sensor has been designed for this purpose. The real part of the specific admittance is used for the water-content determination. A simplified Van Beck mixing law and an appropriate frequency are applied to obtain the water content without polarization effects.

Fernando García-Golding; Mario Giallorenzo; Noel Moreno; Victor Chang

1995-01-01

64

Solid-state characterization and transformation of various creatine phosphate sodium hydrates.  

PubMed

Creatine phosphate sodium (CPS) salt is a first-line cardiovascular drug for severe diastolic heart failure. The drug exists in different hydrate forms. The marketed drug form was determined as CPS·4.5H2 O (H1); however, the reference standard was supplied as CPS·6H2 O (H2). In this work, we present two newly identified hydrate forms: a thermodynamically stable low hydrate form, CPS·1.5H2 O (H3), and a pressure-sensitive transit form, CPS·7H2 O (H4). The hydrate forms were discovered through a comprehensive solid-state screening experiment and fully characterized using a range of analytical techniques including X-ray powder diffraction (XRPD), FTIR, Raman spectroscopy, hot-stage microscopy (HSM), thermogravimetric analysis, and differential scanning calorimetry. Stability tests revealed that H3 was the most stable hydrate under thermal stimulation. H4 is a pressure-sensitive hydrate and easily transforms to H2 and then H1 upon grinding. The form transformation process was closely monitored using the HSM, variable-temperature XRPD (VT-XRPD), and VT-Raman spectroscopy techniques. Specifically, the transformation of H4 to H1 is characterized in a single-crystal-to-single-crystal transformation process. The newly discovered hydrate form H3 has superior physicochemical properties than the marketed forms and is worthy of further development. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3688-3695, 2014. PMID:25223726

Xu, Yun; Jiang, Linglei; Huang, Ying; Wang, Jian-Rong; Mei, Xuefeng

2014-11-01

65

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

66

Characterization and application of fusidane antibiotic biosynethsis enzyme 3-ketosteroid-?1-dehydrogenase in steroid transformation.  

PubMed

Microbial ?(1)-dehydrogenation is one of the most important transformations in the synthesis of steroid hormones. In this study, a 3-ketosteroid-?(1)-dehydrogenase (kstD(F)) involved in fusidane antibiotic biosynthesis from Aspergillus fumigatus CICC 40167 was characterized for use in steroid transformation. KstD(F) encodes a polypeptide consisting of 637 amino acid residues. It shows 51% amino acid identity with a kstD from Thermomicrobium roseum DSM 5159. Expression of kstD(F) in Escherichia coli and Pichia pastoris showed that all kstD(F) activity is located in the cytoplasm. This indicates that it is a soluble intracytoplasmic enzyme, unlike most kstDs from bacteria, which are membrane-bound. The expression of kstD(F) was performed in P. pastoris, both intracellularly and extracelluarly. The intracellularly expressed protein displayed good activity in steroid transformation, while the extracellularly expressed protein showed nothing. Interestingly, the engineered P. pastoris KM71 (KM71(I)) and GS115 (GS115(I)) showed different transformation activities for 4-androstene-3,17-dione (AD) when kstD(F) was expressed intracellularly. Under the same conditions, KM71(I) was found capable of transforming 1.0 g/l AD to 1,4-androstadiene-3,17-dione (ADD), while GS115(I) could transform 1.5 g/l AD to both ADD and boldenone (BD). The production of BD is attributed to a 17?-hydroxysteroid dehydrogenase in P. pastoris GS115(I), which catalyzes the reversible reaction between C17-one and C17-alcohol of steroids. The conversion of AD by GS115(I) and KM71(I) may provide alternative means of preparing ADD or BD. In brief, we show here that kstD(F) is a promising enzyme in steroid ?(1)-dehydrogenation that is propitious to construct genetically engineered steroid-transforming recombinants by heterologous overexpression. PMID:22234537

Chen, Miao-Miao; Wang, Feng-Qing; Lin, Liang-Cai; Yao, Kang; Wei, Dong-Zhi

2012-10-01

67

Transformation and characterization of bovine endothelial cells after in vitro treatment with benzo(a)pyrene  

SciTech Connect

A cloned strain of bovine vascular endothelial cells with a finite in vitro lifespan was treated with the chemical carcinogen benzo(a)pyrene. Untreated cultures of this cell line senesced upon serial subcultivation and contained large non-dividing cells. In four out of eight trials, repeated subcultivation in the presence of benzo(a)pyrene produced transformed lines which appeared in cultures concomitant with the senescence of the parent cells. These lines exhibited an indefinite lifespan and a variety of altered phenotypic characteristics. Four characterized cell lines fit into two general categories. Two lines acquired an indefinite lifespan but otherwise exhibited characteristics of normal endothelial cells: contact inhibition of growth, anchorage dependence, serum requirement for growth of at least 5% fetal bovine serum, and inability to produce tumors in syngeneic hosts. In the other category, two lines acquired those characteristics normally associated with transformation: lack of contact inhibition of growth, anchorage independence, and ability to form tumors (hemangiosarcomas) in syngeneic hosts. Transformed lines lost some specialized characteristics retained by normal endothelial cells in vitro, although the ability to form hemangiosarcomas was retained by the tumorigenic cells. Finally, the two tumorigenic transformed lines have been found to contain non-random chromosomal changes: translocations of chromosome 15 and 21 and trisomy of chromosome 15. Preliminary studies have related these changes to the tumorigenicity of the cells because a non-tumorigenic line does not contain them and these alterations have also been demonstrated in the tumors caused by the injection of the tumorigenic cells.

Grinspan, J.B.

1984-01-01

68

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. PMID:23985173

2013-01-01

69

Benefits of going smart when using RF admittance (capacitance) level measurement technology  

SciTech Connect

RF Admittance, often referred to as Capacitance, has been a well accepted technology for level measurement for nearly 30 years. Certain drawbacks and limitations in the available technology have prevented it from achieving its full potential for becoming the first choice in measuring level technologies. In addition, governmental regulations such as the HON Act, OSHA 1910.119 and the Clean Air Act have created a need for re-consideration of present technology choices for measuring level. The addition of microprocessor based smart capabilities and other new developments to the existing RF technology has caused a giant step advance in the way this technology is viewed for level measurement.

Schuler, E. [Drexelbrook Engineering Co., Horsham, PA (United States)

1995-12-31

70

Meeting spill prevention regulations using RF admittance and ultrasonic level measurement technologies  

SciTech Connect

New Regulations have created liabilities and fines which far outweigh costs of spill prevention systems. These systems typically consist of high and high-high level alarms in conjunction with some final control elements and/or control interlocks. Since they are safety devices they are rarely called upon to do their job. The most important point is that alarm systems always works when something goes wrong. Compete reliability, even though they have not been called on to work for years, is essential. This presentation will explore the pros and cons of Floats, RF Admittance (Capacitance) Sensors and Ultrasonic Gap Switches. Guidelines for a complete spill prevention system will be laid out.

Bahner, M. [Drexelbrook Engineering Co., Horsham, PA (United States)

1995-12-31

71

Measuring the complex admittance of a nearly isolated graphene quantum dot  

NASA Astrophysics Data System (ADS)

We measured the radio-frequency reflection spectrum of an on-chip reflection line resonator coupled to a graphene double quantum dot (DQD), which was etched almost isolated from the reservoir and reached the low tunnel rate region. The charge stability diagram of DQD was investigated via dispersive phase and magnitude shift of the resonator with a high quality factor. Its complex admittance and low tunnel rate to the reservoir was also determined from the reflected signal of the on-chip resonator. Our method may provide a non-invasive and sensitive way of charge state readout in isolated quantum dots.

Zhang, Miao-Lei; Wei, Da; Deng, Guang-Wei; Li, Shu-Xiao; Li, Hai-Ou; Cao, Gang; Tu, Tao; Xiao, Ming; Guo, Guang-Can; Jiang, Hong-Wen; Guo, Guo-Ping

2014-08-01

72

Admittance Test and Conceptual Study of a CW Positron Source for CEBAF  

SciTech Connect

A conceptual study of a Continuous Wave (CW) positron production is presented in this paper. The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLAB) operates with a CW electron beam with a well-defined emittance, time structure and energy spread. Positrons created via bremsstrahlung photons in a high-Z target emerge with a large emittance compared to incoming electron beam. An admittance study has been performed at CEBAF to estimate the maximum beam phase space area that can be transported in the LINAC and in the Arcs. A positron source is described utilizing the CEBAF injector electron beam, and directly injecting the positrons into the CEBAF LINAC.

Golge, Serkan [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Hyde, Charles E. [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Universite Blaise Pascal, Clermont-Ferrand (France); Freyberger, Arne [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

2009-09-02

73

Compound specific stable isotope analysis (CSIA) to characterize transformation mechanisms of ?-hexachlorocyclohexane.  

PubMed

A systematic investigation of environmentally relevant transformation processes of alpha-hexachlorocyclohexane (?-HCH) was performed in order to explore the potential of compound specific stable isotope analysis (CSIA) to characterize reaction mechanisms. The carbon isotope enrichment factors (?C) for the chemical transformations of ?-HCH via direct photolysis, indirect photolysis (UV/H2O2), hydrolysis, electro-reduction or reduction by Fe(0) were quantified and compared to those previously published for biodegradation. Hydrogen abstraction by hydroxyl radicals generated by UV/H2O2 led to ?C of -1.9±0.2‰ with an apparent kinetic carbon isotope effect (AKIEC) of 1.012±0.001. Dehydrochlorination by alkaline hydrolysis yielded ?C of -7.6±0.4‰ with AKIEC of 1.048±0.003. Dechlorination either by homolytic bond cleavage in direct photolysis (?C=-2.8±0.2‰) or single-electron transfer in electro-reduction (?C=-3.8±0.4‰) corresponded to AKIEC of 1.017±0.001 and 1.023±0.003, respectively. Dichloroelimination catalyzed by Fe(0) via two-electron transfers resulted in ?C of -4.9±0.1‰. AKIEC values assuming either a concerted or a stepwise mechanism were 1.030±0.0006 and 1.015±0.0003, respectively. Contrary to biodegradation, no enantioselectivity of ?-HCH was observed in chemical reactions, which might be used to discriminate chemical and biological in situ transformations. PMID:25238192

Zhang, Ning; Bashir, Safdar; Qin, Jinyi; Schindelka, Janine; Fischer, Anko; Nijenhuis, Ivonne; Herrmann, Hartmut; Wick, Lukas Y; Richnow, Hans H

2014-09-15

74

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

75

Josephson admittance spectroscopy application for frequency analysis of broadband THz antennas  

NASA Astrophysics Data System (ADS)

Application of Josephson admittance spectroscopy for the spectral analysis of a broad-band log-periodic superconducting antenna was demonstrated at the frequency range from 50 to 700 GHz. The [001]-tilt YBa2Cu3O7-x bicrystal Josephson junctions, integrated with sinuous log-periodic YBa2Cu3O7-x antennas, were fabricated on NdGaO3 bicrystal substrates. A real part of the antenna admittance ReY(f) as a function of the frequency f was reconstructed from the modification of the dc current-voltage characteristic of the junction, induced by the antenna. Resonance features were observed in the recovered ReY(f)-spectra with a periodicity in the logarithmic frequency scale, corresponding to log-periodic geometry of the antenna. The ReY(f)-spectra, recovered by Josephson spectroscopy, were compared with the ReY(f)-spectra, obtained by CAD simulation, and both spectra were shown to be similar in their main features. A value of 23 was obtained for an effective permittivity of the NdGaO3 bicrystal substrates by fitting simulated data to those obtained from Josephson spectroscopy.

Volkov, O. Yu; Divin, Yu Yu; Gubankov, V. N.; Gundareva, I. I.; Pavlovskiy, V. V.

2010-06-01

76

A Multi-Function Force Sensing Instrument for Variable Admittance Robot Control in Retinal Microsurgery*  

PubMed Central

Robotic systems have the potential to assist vitreoretinal surgeons in extremely difficult surgical tasks inside the human eye. In addition to reducing hand tremor and improving tool positioning, a robotic assistant can provide assistive motion guidance using virtual fixtures, and incorporate real-time feedback from intraocular force sensing ophthalmic instruments to present tissue manipulation forces, that are otherwise physically imperceptible to the surgeon. This paper presents the design of an FBG-based, multi-function instrument that is capable of measuring mN-level forces at the instrument tip located inside the eye, and also the sclera contact location on the instrument shaft and the corresponding contact force. The given information is used to augment cooperatively controlled robot behavior with variable admittance control. This effectively creates an adaptive remote center-of-motion (RCM) constraint to minimize eye motion, but also allows the translation of the RCM location if the instrument is not near the retina. In addition, it provides force scaling for sclera force feedback. The calibration and validation of the multi-function force sensing instrument are presented, along with demonstration and performance assessment of the variable admittance robot control on an eye phantom. PMID:25383234

He, Xingchi; Balicki, Marcin; Gehlbach, Peter; Handa, James; Taylor, Russell; Iordachita, Iulian

2014-01-01

77

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. PMID:20816475

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

2011-01-01

78

Experimental characterization of shear transformation zones for plastic flow of bulk metallic glasses  

PubMed Central

We report experimental characterization of shear transformation zones (STZs) for plastic flow of bulk metallic glasses (BMGs) based on a newly developed cooperative shearing model [Johnson WL, Samwer K (2005) A universal criterion for plastic yielding of metallic glasses with a (T/Tg)2/3 temperature dependence. Phys Rev Lett 95: 195501]. The good agreement between experimental measurements and theoretical predictions in the STZ volumes provides compelling evidence that the plastic flow of metallic glasses occurs through cooperative shearing of unstable STZs activated by shear stresses. Moreover, the ductility of BMGs was found to intrinsically correlate with their STZ volumes. The experiments presented herein pave a way to gain a quantitative insight into the atomic-scale mechanisms of BMG mechanical behavior. PMID:18815377

Pan, D.; Inoue, A.; Sakurai, T.; Chen, M. W.

2008-01-01

79

Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) thermal vacuum testing: aspects of spectral characterization  

NASA Astrophysics Data System (ADS)

The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) represents a revolutionary step in satellite based remote sensing of atmospheric parameters. Using the combination of a Fourier Transform Spectrometer and Large Area Focal Plane Arrays, GIFTS measures incident infrared radiance with an unprecedented combination of spectral, temporal, and spatial resolution and coverage. In its regional sounding mode, it measures the infrared spectrum every 11 seconds at a spectral resolution of ~0.6 cm-1 in two spectral bands (14.6 to 8.8 ?m, 6.0 to 4.4 ?m) using two 128 × 128 detector arrays. From a geosynchronous orbit, the instrument will have the capability of taking successive measurements of such data to scan desired regions of the globe, from which thermal and gaseous concentration profiles, cloud properties, wind field profiles, and other derived products can be retrieved. Thermal vacuum testing of the GIFTS Engineering Development Unit (EDU) was performed at the Space Dynamics Laboratory in Logan Utah and completed in September 2006. With a focus on spectral characterization of the sensor, analyses of selected thermal vacuum tests are presented here.

Tobin, David C.; Revercomb, Henry E.; Taylor, Joe K.; Best, Fred A.; Knuteson, Robert O.; Smith, William L.; Elwell, John; Cantwell, Greg; Bingham, Gail; Tansock, Joe; Reisse, Robert A.; Zhou, Daniel K.

2006-12-01

80

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

81

SAW\\/LSAW COM parameter extraction from computer experiments with harmonic admittance of a periodic array of electrodes  

Microsoft Academic Search

A novel numerical method for determining the surface acoustic wave and the leaky surface acoustic wave characteristics is proposed. The Green's function method is used to simulate an infinite periodic transducer driven by a periodic voltage. We show that the coupling of modes parameters and the dispersion relation can be extracted from the change in the admittance as the periodicity

Julius Koskela; Victor P. Plessky; Martti M. Salomaa

1999-01-01

82

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. PMID:20589105

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

2010-01-01

83

Lunar Internal Structure Estimated From Local Admittance Between Gravity and Topography (Invited)  

NASA Astrophysics Data System (ADS)

A new spherical harmonic model of the lunar gravity field, complete to degree and order 100 (SGM100g), has been developed from four-way Doppler measurements of Kaguya. On nearside, a comparison of SGM100g with a previous lunar gravity models reveals a general agreement. The five principal gravity highs on Imbrium, Serenitatis, Crisium, Nectaris, and Humorum are clearly visible, as in the previous models. On farside, in contrast, the new gravity field model shows several circular signatures that correspond to topographic structures such as Moscoviense, Freundlich-Sharonov, Mendeleev, Hertzsprung, Korolev and Apollo basins that used to be identified as linear signatures in previous models. For the study of lunar basins of which diameter are comparable to lunar radius, localization by two-dimensional Fourier analysis is not appropriate. Instead, we use spectral filter of wavelet analysis. This method has an advantage to Fourier analysis that the gravity and topography models can be calculated without a loss of spectral information. This advantage is particularly important for distinguishing several compensation mechanisms of the lunar basins. New analysis reveals a difference of internal structures of basins on nearside and farside. We have classified lunar basins into Type I, Type II, and primary mascon basins. Type I basins include Korolev, Dirichlet-Jackson, and Mendeleev basins on the farside. Localized free-air gravity anomalies of Type I basins show two peaks which are representing topographic depression of the basins. Second peak has more power than expected from topography, indicating additional contribution from mass anomalies beneath basins. An agreement of second peak wavelength of topography and gravity implies genetic relationship of the central gravity high with impact process. Admittance of Type I basins show two constant plateaus. They suggests little compensation of topography. A plateau at shorter wavelength is higher than that at longer wavelength, as expected from localized topography and gravity. On the other hand,primary mascon basins on the nearside reveal the power spectrum of local gravity and topography similar to those of Type I basins. However, admittance is very different. Negative admittance and the cross sections show that the first peak of the local gravity is indeed representing broad central gravity high of primary mascon basin. Type II basins include Freundlich-Sharonov, Hertzsprung, and Orientale basins on the farside and limb. Localized free-air gravity anomalies of Type II basins show tow peaks, similar to Type I basins, while a central degree of the second peak is lower than that of the local topography, corresponding to broad central gravity high of Type II basins. In contrast to Type I basins, admittance of Type II basins show a wide variation, likely suggesting that Type II basins are transitional between farside Type I basins and primary mascon basins on the nearside. An internal structures of primary mascon basins could be inferred as an extrapolation of Type I and II basins.

Namiki, N.

2010-12-01

84

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

85

Use of Fourier transform infrared spectrometry to characterize composites and polymers  

SciTech Connect

Carbon fiber reinforced composites (CFRCs) combine the high tensile strength of carbon fibers with a highly crosslinked polymer matrix. Typically the carbon fibers are in the form of a cloth which is preimpregnated with a mixture of either unreacted monomers or partially reacted oligomers that are polymerized at high temperatures and pressures. For the product to have the desired mechanical properties, the prepreg must undergo the expected crosslinking reaction and this process is susceptible to small changes in the composition of the reactants that can occur on atmospheric exposure. In this dissertation the use of diffuse reflectance Fourier transform infrared (FT-IR) spectrometry as a means of characterizing small compositional changes occurring in epoxy and polyimide prepregs was evaluated. Prepregs were aged under similar conditions of temperature and humidity. Several methods of analyzing the spectra were investigated, ranging from the simple measurement of the ratio of two bands in the spectra to the combined use of Fourier self-deconvolution (FSD) and curve-fitting. Useful data on the epoxy polymers was obtained using each of these techniques, with the most linear plots of the spectral changes with time being obtained using combined FSD and curve-fitting. The development of several different types of step-scanning FT-IR spectrometers is described. Installation of a piezoelectric transducer (PZT) behind the movable mirror of the interferometer allows positional control to an accuracy of [+-]1.5 nm. Three coarse positioning drives, based on a dc motor, an Inchworm PZT drive, and a microstepper motor, were evaluated. Each permitted the desired level of positional accuracy, but none permitted the optical element to be stepped to the next sampling point in less than 0.5 s. The use of Fourier transforms to demodulate the sinusoidal signal from a phase-modulated interferogram was demonstrated.

Lerner, B.D.

1992-01-01

86

Parametric study and characterization of the isobaric thermomechanical transformation fatigue of nickel-rich NiTi SMA actuators  

Microsoft Academic Search

The recent development of various aerospace applications utilizing Ni-rich NiTi Shape memory Alloys (SMAs) as actuators motivated the need to characterize the cyclic response and the transformation fatigue behavior of such alloys. The fatigue life validation and certification of new designs is required in order to be implemented and used in future applications. For that purpose, a custom built fatigue

Olivier W. Bertacchini; Justin Schick; Dimitris C. Lagoudas

2009-01-01

87

Characterization and Modeling of Transformation Induced Fatigue of Shape Memory Alloy Actuators  

E-print Network

The main focus of this research is the transformation induced fatigue behavior of shape memory alloy (SMA) actuators undergoing thermally induced martensitic phase transformation. The recent development of aerospace applications employing shape...

Bertacchini, Olivier Walter

2011-02-22

88

Characterization of the Si:H network during transformation from amorphous to micro- and nanocrystalline structures  

NASA Astrophysics Data System (ADS)

Optical, structural, and electrical characterizations of the Si:H network have been performed during its changes occurred by the increasing H2 dilution to the SiH4 ensemble in hot-wire chemical vapor deposition (HWCVD). A rapid structural transformation from a mostly amorphous phase to comprehensive micro/nanocrystallinity was attained at a relatively low H2 dilution, even at a low substrate temperature, because of the associated abundance of atomic H in HWCVD. However, elevated H2 dilution induces enormous polyhydrogenation and formation of lesser dense network full of voids, mostly around the tiny micro/nanocrystallites. This highly defective grain boundary zone provides high density of electronic trapping centers and contributes significantly to the transport of carriers. The overall electrical transport in the amorphous-micro-nano-crystalline heterogeneous Si:H network has been accounted in the framework of a three-phase model comprised of amorphous and crystalline (micro- and nano-) components while the grain boundary being the third phase, separately contributing to a potential energy barrier in between. The three-phase model to the electrical phenomena of nanocrystalline structures convincingly explains the dual activation energies arising in the electrical conduction with distinguishably different temperature dependent behaviors from that occurs in the conventional amorphous matrix.

Das, Debajyoti; Bhattacharya, Koyel

2006-11-01

89

Characterization of primary human keratinocytes transformed by human papillomavirus type 18  

SciTech Connect

Primary human epithelial cells were cotransfected with pHPV-18 and pSV2neo, and cell strains were generated by selecting in G418. Southern blot analysis revealed the presence of at least one intact, integrated viral genome in these cells. FE-A cells showed altered growth properties, characterized by a change in morphology, and clonal density. Differentiation markers analyzed by Western blotting (immunoblotting), such as cytokeratins and involucrin, indicated that the cells resembled a partially differentiated epithelial population. Increased expression of the 40-kilodalton cytokeratin was observed in FE-A cells, similar to that observed in simian virus 40-immortalized human keratinocytes. Calcium and 12-O-tetradecanoyl-phorbol-13-acetate treatment induced normal epithelial cells to differentiate, whereas the human papillomavirus 18 (HPV-18)-containing keratinocytes were resistant to these signals, indicating their partially transformed nature. These cells were not able to induce tumors in nude mice over a period of up to 8 months. A second cell strain, FE-H18L, also generated by transfecting HPV-18, also exhibited an extended life span and similar alterations in morphology. Viral RNA transcribed from the early region of HPV-18 was detected in both cell strains by Northern (RNA) blot analysis. These cell strains should provide a useful model for determining the role of HPV in carcinogenesis.

Kaur, P.; McDougall, J.K. (Fred Hutchinson Cancer Research Center, Seattle, WA (USA))

1988-06-01

90

High density trans-admittance mammography development and preliminary phantom tests  

PubMed Central

Background Malignant breast tumor tissue has a significantly different electrical impedance spectrum than surrounding normal tissues. This has led to the development of impedance imaging as a supplementary or alternative method to X-ray mammography for screening and assessment of breast cancers. However low spatial resolution and poor signal to noise ratio has limited the clinical application. Methods In order to improve spatial resolution we developed a trans-admittance mammography (TAM) system including an array of 60×60 current sensing electrodes. We adopted a similar setup to X-ray mammography where the breast is situated between two holding plates. The top plate is a large solid metal electrode for applying a sinusoidal voltage over a range of frequencies from 50 Hz to 500 kHz. The bottom plate has 3600 current sensing electrodes that are kept at the ground potential. Currents are generated from the top voltage-applying electrode and spread throughout the breast, entering the TAM system through the array of current sensing electrodes on the bottom plate. The TAM system measures the exit currents through 6 switching modules connected to 600 electrodes each. Each switching module is connected to 12 ammeter channels which are switched sequentially to 50 of the 600 electrodes each measurement time. Each ammeter channel is comprised of a current-to-voltage converter, a gain amplifier, filters, an analog to digital converter, and a digital phase sensitive demodulator. Results We found an average noise level of 38 nA, amplitude stability of less than 0.2%, crosstalk of better than -60 dB and 70 dB signal to noise ratio over all channels and operating frequencies. Images were obtained in time difference and frequency difference modes in a saline phantom. Conclusion We describe the design, construction, and calibration of a high density TAM system in detail. Successful high resolution time and frequency difference images showed regions of interest with the expected admittivity changes in the frequency spectrum. PMID:23009288

2012-01-01

91

Characterization of Transformation Stasis in Low-Carbon Steels Microalloyed with B and Mo  

NASA Astrophysics Data System (ADS)

In the present study, bainite transformation kinetics was examined in low C-Mn steels with the addition of small amounts of B and Mo. This addition delays the onset of the bainite transformation. Mo addition causes transformation stasis at temperatures between 873 K and 823 K (600 °C and 550 °C) just below the bainite-start ( B s) temperature, resulting from an incomplete bainite transformation. Post-stasis transformation after a prolonged hold proceeds by the formation of ferrite with a low dislocation density, and in Mo-containing alloys, often the formation of carbides. The volume fraction at which the transformation stops is higher for lower carbon contents and lower transformation temperatures. By contrast, at 773 K (500 °C), the bainite transformation accompanying cementite precipitation occurs regardless of microalloying and is completed after shorter hold times. EDX measurement performed on the Mo-added 0.15 pct C alloy with aberration-corrected STEM revealed that segregation at the bainite/austenite interphase boundary is small for Mn and negligible for Mo in the early stages of stasis, which does not support the incomplete transformation mechanism based on the solute drag theory for the alloys used.

Furuhara, Tadashi; Tsuzumi, Kenji; Miyamoto, Goro; Amino, Takafumi; Shigesato, Genichi

2014-12-01

92

Characterization of Transformation Stasis in Low-Carbon Steels Microalloyed with B and Mo  

NASA Astrophysics Data System (ADS)

In the present study, bainite transformation kinetics was examined in low C-Mn steels with the addition of small amounts of B and Mo. This addition delays the onset of the bainite transformation. Mo addition causes transformation stasis at temperatures between 873 K and 823 K (600 °C and 550 °C) just below the bainite-start (B s) temperature, resulting from an incomplete bainite transformation. Post-stasis transformation after a prolonged hold proceeds by the formation of ferrite with a low dislocation density, and in Mo-containing alloys, often the formation of carbides. The volume fraction at which the transformation stops is higher for lower carbon contents and lower transformation temperatures. By contrast, at 773 K (500 °C), the bainite transformation accompanying cementite precipitation occurs regardless of microalloying and is completed after shorter hold times. EDX measurement performed on the Mo-added 0.15 pct C alloy with aberration-corrected STEM revealed that segregation at the bainite/austenite interphase boundary is small for Mn and negligible for Mo in the early stages of stasis, which does not support the incomplete transformation mechanism based on the solute drag theory for the alloys used.

Furuhara, Tadashi; Tsuzumi, Kenji; Miyamoto, Goro; Amino, Takafumi; Shigesato, Genichi

2014-09-01

93

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

94

Molecular cytogenetic characterization of human papillomavirus16-transformed foreskin keratinocyte cell line 16-MT.  

PubMed

Anogenital cancers are closely associated with human papillomavirus (HPV), and HPV-infected individuals, particularly those with high-grade dysplasias, are at increased risk for cervical and anal cancers. Although genomic instability has been documented in HPV-infected keratinocytes, the full spectrum of genetic changes in HPV-associated lesions has not been fully defined. To address this, we examined an HPV16-transformed foreskin keratinocyte cell line, 16-MT, by GTG-banding, spectral karyotyping (SKY), and array comparative genomic hybridization (array CGH); these analyses revealed multiple numerical, complex, and cryptic chromosome rearrangements. Based on GTG-banding, the 16-MT karyotype was interpreted as 78-83,XXY,+add(1)(p36.3),+3,+4,+5,+5,+7,+8,+i(8)(q10)x2,+10,?der(12),der(13;14)(q10;q10),+15,+16,add(19)(q13.3),+21,+21,-22[cp20]. Multicolor analysis by SKY confirmed and further characterized the anomalies identified by GTG banding. The add(1) was identified as a der(1)(1qter-->1q25::1p36.1-->1qter), the add(19) as a dup(19), and the der(12) interpreted as a der(11) involving a duplication of chromosome 11 material and rearrangement with chromosome 19. In addition, previously unidentified der(9)t(9;22), der(3)t(3;19), and der(4)t(4;9) were noted. The 16-MT cell line showed losses and gains of DNA due to unbalanced translocations and complex rearrangements of regions containing known tumor suppressor genes. Chromosomal changes in these regions might explain the increased risk of cancer associated with HPV. Also, array CGH detected copy-number gains or amplifications of chromosomes 2, 8, 10, and 11 and deletions of chromosomes 3, 4, 11, and 15. These results provide the basis for the identification of candidate oncogenes responsible for cervical and anal cancer in amplified regions, and for putative tumor suppressor genes in commonly deleted regions like 11q22-23. Furthermore, these data represent the first full characterization of the HPV-positive cell line 16-MT. PMID:16772119

McGhee, Eva M; Cotter, Philip D; Weier, Jingly F; Berline, Jennifer W; Turner, Mary A; Gormley, Mathew; Palefsky, Joel M

2006-07-01

95

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

96

Commercial production of avidin from transgenic maize: characterization of transformant, production, processing, extraction and purification  

Microsoft Academic Search

We have produced in transgenic maize seed the glycoprotein, avidin, which is native to avian, reptilian, and amphibian egg white. A transformant showing high-level expression of avidin was selected. Southern blot data revealed that four copies of the gene are present in this transformant. The foreign protein represents >2% of aqueous soluble extracted protein from populations of dry seed, a

Elizabeth E. Hood; Derrick R. Witcher; Sheila Maddock; Terry Meyer; Chris Baszczynski; Michele Bailey; Pam Flynn; James Register; Lisa Marshall; Diane Bond; Ellen Kulisek; Ann Kusnadi; Roque Evangelista; Zivko Nikolov; Cynthia Wooge; Richard J. Mehigh; Ronald Hernan; William K. Kappel; David Ritland; Chun Ping Li; John A. Howard

1997-01-01

97

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

98

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

99

Transformation and Characterization of Transgenic Plants of Solanum dulcamara L.—Incidence of Transgene Silencing  

Microsoft Academic Search

A transformation system is described for Solanum dulcamara using the supervirulentAgrobacterium tumefaciens strain 1065, carrying both the ?-glucuronidase (gus) and neomycin phosphotransferase II (npt II) genes adjacent to the right and left T-DNA borders, respectively. Leaf explants were more efficient for the production of transformed plants compared to stem explants on medium containing 50mgl?1of kanamycin sulphate. A 1:10 (v:v) dilution

I. S. Curtis; J. B. Power; P. Hedden; A. Phillips; K. C. Lowe; D. A. Ward; M. R. Davey

2000-01-01

100

An analysis of light-induced admittance changes in rod outer segments  

PubMed Central

1. Measurements were made of the time course and amplitude of the change in real part of admittance, ?G, of a suspension of frog rod outer segments, following a flash of light bleaching about 1% of the rhodopsin content of the rods. The measurements, based on the use of a specially designed marginal oscillator, covered the frequency range between 500 Hz and 17 MHz. 2. The components of response, previously described for rods prepared by a method involving exposure to strongly hypertonic sucrose solutions, are present in similar form when rods are isolated and maintained in isotonic solutions made up with equi-osmotic concentrations of NaCl and sucrose or with Na2SO4. 3. Component I, identified as a slowly developing positive ?G apparent at very low frequencies, is frequency-independent up to the characteristic frequency of admittance for the suspension, fY (about 2 MHz for rods suspended in a solution having the conductivity of Ringer solution), but decreases at still higher frequencies. 4. Component II, identified as a rapidly developing positive ?G which appears only above a critical frequency about 2·5 decades below fY, increases approximately logarithmically with frequency to reach a limiting amplitude in the region of fY. 5. The amplitude of component II, ?GII, measured in the region of fY, varies linearly with the conductivity of the suspending medium, Go, under conditions in which the conductivity of the rod interior is also a linear function of the external conductivity. The relation for a flash bleaching 1% of the rhodopsin content of the dark-adapted rod is [Formula: see text] 6. Measurements made on rods suspended in a low-conductivity solution, which has the effect of reducing the conductivity of the rod interior to about one ninth its value for rods suspended in Ringer solution, reveal a decline in component II for frequencies above 8 MHz. 7. To explain the frequency dependence of component II and its dependence on conductivity, it is proposed that component II arises from a light-induced increase in conductance of the disk membranes which obstruct the longitudinal flow of current through the rod interior except at very high frequencies. 8. The disk-membrane conductance increase for rods suspended in a solution having the conductivity of Ringer solution is calculated to be 4·3 × 10-11 mho/rhodpsin molecule bleached, a value which is similar to what has been found for ionic channels operated by membrane potential change in the nerve membrane and by synaptic transmitter in the postjunctional membrane. 9. No component of response has been observed which could be reliably attributed to a surface membrane conductance decrease of the type observed in receptor cells in the retina. PMID:4540195

Falk, G.; Fatt, P.

1973-01-01

101

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

Microsoft Academic Search

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)

Diomaris Padilla

2008-01-01

102

Automatic Enumeration and Characterization of Heterogeneous Clonal Progression in Cell Transformation  

Microsoft Academic Search

Most human tumors are clonal in origin, although the cells may be diverse in their properties. Since the tumors evolve through progressive stages over decades of time, it is possible that the conditions that induced the tumor transform many cells, but that selective overgrowth of the fastest growing lead to a clonal population of identified tumor cells. We studied the

Adam Yao; Harry Rubin

1993-01-01

103

Using wavelet transforms for ECG characterization. An on-line digital signal processing system  

Microsoft Academic Search

The rapid and objective measurement of timing intervals of the electrocardiogram (ECG) by automated systems is superior to the subjective assessment of ECG morphology. The timing interval measurements are usually made from the onset to the termination of any component of the EGG, after accurate detection of the QRS complex. This article describes a real-time system that uses wavelet transforms

J. S. Sahambi; S. N. Tandon; R. K. P. Bhatt

1997-01-01

104

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. PMID:12223765

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

1997-01-01

105

Quantum entropic characterization of Gaussian optical transformations using the replica method  

E-print Network

In spite of their very simple description in terms of rotations or symplectic transformations in phase space, quadratic Hamiltonians such as those modelling the most common Gaussian operations in quantum optics remain poorly understood in terms of entropies. For instance, determining the von Neumann entropy produced by an optical beam splitter or a two-mode squeezer is notably a hard problem, with generally no known analytical solution. Here, we overcome this difficulty by using the replica method, a tool borrowed from statistical physics and quantum field theory. We find a first application of this method to the field of quantum optics, where it enables accessing the entropic characteristics of the Bogoliubov transformation effected by a two-mode squeezer or optical amplifier. In particular, we determine the entropy produced by amplifying a binary superposition of the vacuum and an arbitrary Fock state, which yields a surprisingly simple analytical expression.

C. N. Gagatsos; A. I. Karanikas; G. Kordas; N. J. Cerf

2014-08-21

106

Characterization of phase transformation behavior in electrolytically produced indium-thallium shape memory alloy films  

SciTech Connect

Indium-thallium alloys in the range 15--38 at.% Tl were electrodeposited from a sulfate electrolyte by using pulsed current. The relationship between composition and phase structure of the alloys deposited was investigated with regard to the shape memory effect. To date there have been no reported experimental studies describing the electrodeposition of In-Tl alloys capable of undergoing such transformations. Not only did the deposited alloys exhibit the shape memory effect, but the composition-phase relationship exhibited was shown to deviate from that reported for alloys in an equilibrium condition. The results show that the temperature and the temperature interval for the transformation of the electrodeposited alloys are substantially different from those of the thermally prepared alloys. The shape recovery for the electrodeposited alloy was also confirmed.

Sonu, C.H.; O'Keefe, T.J. (Univ. of Missouri, Rolla, MO (United States))

1994-12-01

107

Open-path Fourier transform infrared spectrometry characterization of low temperature combustion gases in biomass fuels  

Microsoft Academic Search

Accurate determination of gas concentration emitted during thermal degradation (pyrolysis) of biomass in forest fires is one of the keypoints in recent research on physical-based fire spread models. However, it is a very cumbersome task not well solved by classical invasive sensors and procedures. In this work, a methodology to use open-path Fourier transform-based infrared (OP-FTIR) spectrometry has been applied

A. J. de Castro; A. M. Lerma; F. López; M. Guijarro; C. Díez; C. Hernando; J. Madrigal

2007-01-01

108

Characterizing the Moisture Content of Tea with Diffuse Reflectance Spectroscopy Using Wavelet Transform and Multivariate Analysis  

PubMed Central

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

109

Agrobacterium rhizogenes-transformed Roots of Coffee (Coffea arabica): Conditions for Long-term Proliferation, and Morphological and Molecular Characterization  

PubMed Central

Background and Aims The aims of this study were to set up proliferation conditions for hairy roots of Coffea arabica regenerated after transformation by Agrobacterium rhizogenes strain A4-RS, and to carry out the morphological and molecular characterization of hairy root clones maintained over the long term. Methods Auxin supply, light conditions and sucrose concentration were modified with the aim of establishing efficient root proliferation conditions. The morphological variability among 62 established hairy root clones was phenotyped by scanning the roots and analysing the images using ‘whinRHIZO’ software procedures. PCR analysis of integration in transformed root cells of rol and aux oncogenes from the T-DNA of the Ri plasmid was used to study the molecular variability among clones. Key Results Auxin supply was necessary to obtain and stimulate growth and branching, and IBA applied at 0·5 µm was the most efficient auxin. Significant differences were shown among the 62 clones for total root length and for the percentage of fine roots. These variables were stable across subcultures and could hence be used for efficient characterization of hairy root clones. The majority of hairy root clones (86 %) exhibited non-significant phenotype differences with non-transformed roots. Eight clones were significantly different from the non-transformed controls in that they possessed a low proportion of fine roots. Two other hairy root clones grew significantly faster than the other clones. The PCR analysis revealed a low variability in the integration of rol and aux oncogenes in transformed root cells. The TR-DNA was never integrated as aux1 and aux2 genes were not found, although rolB and rolC genes from the TL-DNA were always present. Conclusions The discovery of low morphological variability among coffee hairy roots together with the identification of morphological variables allowing easy identification of phenotypically altered clones represent two important results. They make hairy roots a possible, and efficient, tool for functional-genomic studies of coffee root genes. PMID:18316320

Alpizar, E.; Dechamp, E.; Lapeyre-Montes, F.; Guilhaumon, C.; Bertrand, B.; Jourdan, C.; Lashermes, P.; Etienne, H.

2008-01-01

110

Force Control and Nonlinear Master-Slave Force Profile to Manage an Admittance Type Multi-Fingered Haptic User Interface  

SciTech Connect

Natural movements and force feedback are important elements in using teleoperated equipment if complex and speedy manipulation tasks are to be accomplished in remote and/or hazardous environments, such as hot cells, glove boxes, decommissioning, explosives disarmament, and space to name a few. In order to achieve this end the research presented in this paper has developed an admittance type exoskeleton like multi-fingered haptic hand user interface that secures the user’s palm and provides 3-dimensional force feedback to the user’s fingertips. Atypical to conventional haptic hand user interfaces that limit themselves to integrating the human hand’s characteristics just into the system’s mechanical design this system also perpetuates that inspiration into the designed user interface’s controller. This is achieved by manifesting the property differences of manipulation and grasping activities as they pertain to the human hand into a nonlinear master-slave force relationship. The results presented in this paper show that the admittance-type system has sufficient bandwidth that it appears nearly transparent to the user when the user is in free motion and when the system is subjected to a manipulation task, increased performance is achieved using the nonlinear force relationship compared to the traditional linear scaling techniques implemented in the vast majority of systems.

Anthony L. Crawford

2012-08-01

111

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

112

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

113

Control and virus-transformed baby hamster kidney cells resistant to ethidium bromide. I. Characterization and the respiratory enzymes.  

PubMed

Cell lines resistant to ethidium bromide have been developed from cultured mammalian BHK21/C13 cells and these same cells transformed by Rous sarcoma virus (C13/B4). Cells resistant to 2 micrograms ethidium bromide per milliliter have been cloned. One clone of the control and one of the virus-transformed cell lines has been employed for characterization. The resistant cells, in the presence of 2 micrograms ethidium bromide/ml, grow at approximately the same rate as the untreated parental cells. The control cells possess a "normal" karyotype (44 chromosomes), while the corresponding ethidium bromide mutant has a reduced chromosome number of 41 and a number of translocations. The mitochondria displayed morphological alterations compared to the parental lines during the transition phase prior to the isolation of the ethidium bromide-resistant cells. The mitochondria of the ethidium bromide-resistant mutants appear somewhat enlarged with a normal morphology. The effect of ethidium bromide on selected respiratory enzymes in normal and virus-transformed ethidium bromide-resistant baby hamster kidney cells was determined. Ethidium bromide-resistant cells exhibited a depressed level of cytochrome aa3. This depression could not be reversed by growth in ethidium bromide-free media. Ethidium bromide-resistant cells possessed the same cytochrome b, c, and c1 levels per cell as their corresponding parental lines. Purified mitochondria isolated from virus-transformed ethidium bromide-resistant cells exhibited a depression in cytochrome oxidase-specific activity, while the ethidium bromide-resistant control cells did not. All cell lines studied showed a depression in NADH-ferricyanide and NADH-cytochrome c reductase-specific activities relative to their parental BHK21/C13 cells. No increase was observed in virus-transformed ethidium bromide-resistant cells. Ethidium bromide-resistant control cells exhibited a two-fold increase in oligomycin-insensitive adenosine triphosphatase activity relative to their parental cells. All of the cell lines studied possessed equivalent oligomycin-sensitive adenosine triphosphatase-specific activity except for the virus-transformed, dye-resistant mutant, whose activity was increased. PMID:6251098

Soslau, G; Zavodny, P J

1980-08-01

114

Isolation and characterization of chemically transformed pancreatic acinar cell lines from young and old mice.  

PubMed

To evaluate the role of animal age in chemically induced transformation, pancreatic cells were grown in culture 6 to 8 wk after injecting mice at either 6 or 22 mo. of age with a single dose of N-methyl-N-nitrosourea (NMU). The cell type and the frequency with which lines were obtained from aged animals paralleled the frequency and pattern of tumor induction by NMU in vivo. Outgrowth of pancreatic explants from young animals required the presence of the tumor promoter 12-otetradecanoyl-phorbol-13-acetate to establish continuously growing cell lines. Whereas NMU alone produced lines from aged mice, the promoter did not increase the frequency with which continuous lines were recovered from the aged animals. Of eight cloned cell lines (four young and four old), all had characteristics of transformed mouse pancreatic acinar cells when tested for lectin binding, lactate dehydrogenase isozyme pattern, chromosome number, and anchorage-independent growth. Cell lines derived from aged animals were slower growing and had higher chromosome numbers than lines derived from their younger counterparts. PMID:3818503

Zelinsky-Papez, K; Carter, T H; Zimmerman, J A

1987-02-01

115

Processing and characterization of transformation-toughened ceramics with strength retention to elevated temperatures. Final report  

SciTech Connect

Monolithic and three-layered Al{sub 2}O{sub 3} -- 15 vol % ZrO{sub 2} composites were fabricated by slip casting aqueous slurries. The outer and inner layers of three-layer composites contained unstabilized and partially stabilized ZrO{sub 2}, respectively. Transformation of part of the unstabilized ZrO{sub 2} led to surface compressive stresses in the outer layers. Strain gage, x-ray, indentation crack length, and strength measurements were used to determine the magnitude of residual stresses in the composites. The strength of the three-layer composites ({approx}1200 MPa) was 500--700 MPa higher than that of the monolithic outer layer composites at room temperature and 350 MPa higher at 750{degree}C. The strength differential decreased rapidly above the m {yields} t transformation temperature. Three-layered composites showed excellent damage resistance and improved reliability. Cam follower rollers were fabricated to demonstrate the applicability of this technique for making automotive components.

Cutler, R.A.; Brinkpeter, C.B. [Ceramatec, Inc., Salt Lake City, UT (United States); Vircar, A.V.; Shetty, D.K. [Univ. of Utah (United States)

1994-09-01

116

Open-path Fourier transform infrared spectrometry characterization of low temperature combustion gases in biomass fuels  

NASA Astrophysics Data System (ADS)

Accurate determination of gas concentration emitted during thermal degradation (pyrolysis) of biomass in forest fires is one of the keypoints in recent research on physical-based fire spread models. However, it is a very cumbersome task not well solved by classical invasive sensors and procedures. In this work, a methodology to use open-path Fourier transform-based infrared (OP-FTIR) spectrometry has been applied as a remote sensing technique that permits in situ, non-intrusive and simultaneous measurements. Main gaseous by-products (CO, CO 2, CH 4 and NH 3) have been measured and quantified in terms of path-integrated concentrations. Different emission ratios have been determined for the species under study. These results can help to simplify the modelling of pyrolysis processes inside the physical-based models for fire spread.

de Castro, A. J.; Lerma, A. M.; López, F.; Guijarro, M.; Díez, C.; Hernando, C.; Madrigal, J.

2007-07-01

117

Functional Characterization of the Plasmodium falciparum Chloroquine-Resistance Transporter (PfCRT) in Transformed Dictyostelium discoideum Vesicles  

PubMed Central

Background Chloroquine (CQ)-resistant Plasmodium falciparum malaria has been a global health catastrophe, yet much about the CQ resistance (CQR) mechanism remains unclear. Hallmarks of the CQR phenotype include reduced accumulation of protonated CQ as a weak base in the digestive vacuole of the erythrocyte-stage parasite, and chemosensitization of CQ-resistant (but not CQ-sensitive) P. falciparum by agents such as verapamil. Mutations in the P. falciparum CQR transporter (PfCRT) confer CQR; particularly important among these mutations is the charge-loss substitution K?T at position 76. Dictyostelium discoideum transformed with mutant PfCRT expresses key features of CQR including reduced drug accumulation and verapamil chemosensitization. Methodology and Findings We describe the isolation and characterization of PfCRT-transformed, hematin-free vesicles from D. discoideum cells. These vesicles permit assessments of drug accumulation, pH, and membrane potential that are difficult or impossible with hematin-containing digestive vacuoles from P. falciparum-infected erythrocytes. Mutant PfCRT-transformed D. discoideum vesicles show features of the CQR phenotype, and manipulations of vesicle membrane potential by agents including ionophores produce large changes of CQ accumulation that are dissociated from vesicular pH. PfCRT in its native or mutant form blunts the ability of valinomycin to reduce CQ accumulation in transformed vesicles and decreases the ability of K+ to reverse membrane potential hyperpolarization caused by valinomycin treatment. Conclusion Isolated vesicles from mutant-PfCRT-transformed D. discoideum exhibit features of the CQR phenotype, consistent with evidence that the drug resistance mechanism operates at the P. falciparum digestive vacuole membrane in malaria. Membrane potential apart from pH has a major effect on the PfCRT-mediated CQR phenotype of D. discoideum vesicles. These results support a model of PfCRT as an electrochemical potential-driven transporter in the drug/metabolite superfamily that (appropriately mutated) acts as a saturable simple carrier for the facilitated diffusion of protonated CQ. PMID:22724026

Papakrivos, Janni; Sa, Juliana M.; Wellems, Thomas E.

2012-01-01

118

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

119

Characterization of near-terahertz complementary metal-oxide semiconductor circuits using a Fourier-transform interferometer  

Optical methods for measuring of the emission spectra of oscillator circuits operating in the 400–600 GHz range are described. The emitted power from patch antennas included in the circuits is measured by placing the circuit in the source chamber of a Fourier-transform interferometric spectrometer. The results show that this optical technique is useful for measuring circuits pushing the frontier in operating frequency. The technique also allows the characterization of the circuit by measuring the power radiated in the fundamental and in the harmonics. This capability is useful for oscillator architectures designed to cancel the fundamental and use higher harmonics. The radiated power was measured using two techniques: direct measurement of the power by placing the device in front of a bolometer of known responsivity, and by comparison to the estimated power from blackbody sources. The latter technique showed that these circuits have higher emission than blackbody sources at the operating frequencies, and, therefore, offer potential spectroscopy applications.

Arenas, D. J. [Univ. of North Florida, Jacksonville, FL (United States); Shim, Dongha [Univ. of Florida, Gainesville, FL (United States); Koukis, D. I. [Univ. of Florida, Gainesville, FL (United States); Seok, Eunyoung [Univ. of Florida, Gainesville, FL and Texas Instruments, Dallas, TX (United States); Tanner, D. B. [Univ. of Florida, Gainesville, FL (United States); O, Kenneth K. [Univ. of Texas, Dallas, TX (United States)

2011-10-24

120

Comparison of Multi-Sensor Admittance Control in Joint Space and Task Space for a Seven Degree of Freedom Upper Limb Exoskeleton  

E-print Network

compared to back-driving the device. I. INTRODUCTION Integrating capabilities of humans and robotic and technological issues: (i) the exoskeleton (orthotic device) mechanism itself and its biomechanical integrationComparison of Multi-Sensor Admittance Control in Joint Space and Task Space for a Seven Degree

Rosen, Jacob

121

Bio-telemetric device for measurement of left ventricular pressure-volume loops using the admittance technique in conscious, ambulatory rats  

PubMed Central

This paper presents the design, construction and testing of a device to measure pressure volume loops in the left ventricle of conscious, ambulatory rats. Pressure is measured with a standard sensor, but volume is derived from data collected from a tetrapolar electrode catheter using a novel admittance technique. There are two main advantages of the admittance technique to measure volume. First, the contribution from the adjacent muscle can be instantaneously removed. Second, the admittance technique incorporates the nonlinear relationship between the electric field generated by the catheter and the blood volume. A low power instrument weighing 27 g was designed, which takes pressure-volume loops every 2 minutes and runs for 24 hours. Pressure-volume data are transmitted wirelessly to a base station. The device was first validated in thirteen rats with an acute preparation with 2-D echocardiography used to measure true volume. From an accuracy standpoint, the admittance technique is superior to both the conductance technique calibrated with hypertonic saline injections, and calibrated with cuvettes. The device was then tested in six rats with a 24-hour chronic preparation. Stability of the animal preparation and careful calibration are important factors affecting the success of the device. PMID:21606560

Raghavan, Karthik; Feldman, Marc D; Porterfield, John E; Larson, Erik R; Jenkins, J Travis; Escobedo, Daniel; Pearce, John A

2011-01-01

122

Proc. of the 24th IEEE Photovoltaic Specialists Conference (IEEE, New York, 1995), pp. 291-294. ADMITTANCE MEASUREMENTS ON Cu(In,Ga)Se2 POLYCRYSTALLINE THIN-  

E-print Network

State University, Ft. Collins, CO 80523, USA ABSTRACT We have measured the complex admittance Department, Oberlin College, Oberlin, OH 44074 M. Contreras, A. M. Gabor, and R. Noufi National Renewable and were usually at room temperature. Capacitance versus voltage data were used to extract effective charge

Scofield, John H.

123

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

124

Characterization of Rainwater Dissolved Organic Matter by Ultrahigh Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

NASA Astrophysics Data System (ADS)

Rainwater is a complex, heterogeneous mixture of dissolved organic matter (DOM) that remains largely uncharacterized at the molecular level. Rainwater with dissolved organic carbon values ranging from 3 to 450 ?M was collected during 40 separate rain events from 2007-2011 that included coastal and terrestrial storms based upon 36 hour back trajectories. Individual rain samples were lypholized and solvent added in preparation for analysis by negative electrospray ionization and atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). This data set is unique in that each rain event was analyzed individually and not combined allowing for unprecedented insight into rainwater DOM at the molecular level on an episodic basis. Unique elemental compositions were assigned for compounds belonging to CHO, CHOS and CHON classes. Data visualization by van Krevelen diagrams showed clear differences in coastal and terrestrial storm events with a majority of coastal storms having high H/C (1.5-2.0) relative to terrestrial storms. Further inspection of the data revealed that rainwater has relatively high O/C (1.4) and low H/C (<0.5) which suggests rainwater DOM is compositionally different than fog water, water soluble organic carbon isolated from aerosols and surface waters.

Mead, R. N.; Podgorski, D. C.; Mullaugh, K. M.; Avery, B.; Kieber, R. J.; Willey, J. D.; Cooper, W. T.

2011-12-01

125

Multi-responsive polypeptidosome: characterization, morphology transformation, and triggered drug delivery.  

PubMed

The biodegradable polymeric nanomedicines that may be integrated with multi-stimuli-sensitivity to achieve triggered or on-demand drug release kinetics are challenging for polymer therapeutics and drug delivery systems. By controlling the structure transformation of one polypeptide-b-PEO copolymer, a novel multi-responsive polypeptide-based vesicle (polypeptidosome) presents the combined sensitivity of multiple physiological and clinic-related stimuli, and both morphology and size of the polypeptidosome are changed during the triggered process. The designer polypeptide has unique structures composed of 1) light-responsive o-nitrobenzyl groups, 2) oxidizable thioether linkers, 3) photo-caged redox thiol groups on parent poly(L-cysteine), and 4) tunable conformation, which enable the polypeptidosome to have a peculiar multi-response. The anticancer drug doxorubicin can be released in a controlled or on-off manner. The combination stimuli of UV irradiation and H2 O2 oxidation induces a large effect and a lower IC50 of 3.80 ?g doxorubicin (DOX) equiv/mL compared to 5.28 ?g DOX equiv/mL of individual H2 O2 trigger. PMID:25170968

Liu, Gang; Zhou, Linzhu; Guan, Yanfei; Su, Yue; Dong, Chang-Ming

2014-10-01

126

Characterization of buried metal-molecule-metal junctions using Fourier transform infrared microspectroscopy  

NASA Astrophysics Data System (ADS)

We have devised an infrared spectromicroscopy based experimental configuration to enable structural characterization of buried molecular junctions. Our design utilizes a small mercury drop at the focal point of an infrared microscope to act as a mirror in studying metal-molecule-metal (MmM) junctions. An organic molecular monolayer is formed either directly on the mercury drop or on a thin, infrared (IR) semi-transparent layer of Au deposited onto an IR transparent, undoped silicon substrate. Following the formation of the monolayer, films on either metal can be examined independently using specular reflection spectroscopy. Furthermore, by bringing together the two monolayers, a buried molecular bilayer within the MmM junction can be characterized. Independent examination of each half of the junction prior to junction formation also allows probing any structural and/or conformational changes that occur as a result of forming the bilayer. Because our approach allows assembling and disassembling microscopic junctions by forming and withdrawing Hg drops onto the monolayer covered metal, spatial mapping of junctions can be performed simply by translating the location of the derivatized silicon wafer. Finally, the applicability of this technique for the longer-term studies of changes in molecular structure in the presence of electrical bias is discussed.

Babayco, Christopher B.; Land, Donald P.; Parikh, Atul N.; Kiehl, Richard A.

2014-09-01

127

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. PMID:24848958

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

2014-06-01

128

Purification and characterization of a novel restricted antigen expressed by normal and transformed human colonic epithelium.  

PubMed

A cell surface antigen that is expressed by normal and 95% of transformed colonic epithelium and is recognized by the monoclonal antibody A33 (Welt, S., Divgi, C. R., Real, F. X., Yeh, S. D., Garin-Chesa, P., Finstad, C. L., Sakamoto, J., Cohen, A., Sigurdson, E. R., Kemeny, N., Carswell, E. A., Oettgen, H. F., and Old, L. J. (1990) J. Clin. Oncol. 8, 1894-1906) has been purified to homogeneity from the human colonic carcinoma cell line LIM1215. The A33 protein was purified from Triton X-114 extracts of LIM1215 cells under nondenaturing conditions. These extracts were applied sequentially to Green-Sepharose HE-4BD, Mono-Q HR 10/10, Superose 12 HR 10/30, and micropreparative Brownlee Aquapore RP 300. The purification was monitored by biosensor analysis using surface plasmon resonance detection with a F(ab')2 fragment of the humanized A33 monoclonal antibody immobilized on the sensor surface and Western blot analysis following SDS-polyacrylamide gel electrophoresis (PAGE) under nonreducing conditions using humanized A33 monoclonal antibody. The purified A33 antigen has a Mr on SDS-PAGE of 43,000 under nonreducing conditions. By contrast, the purified protein displayed a Mr of approximately 180,000 under native conditions on both size exclusion chromatography and native PAGE, possibly due to the formation of a homotetramer. N-terminal amino acid sequence analysis of the purified protein identified 34 amino acid residues of a unique sequence: ISVETPQDVLRASQGKSVTLPXTYHTSXXXREGLIQWD. A polyclonal antibody was raised against a synthetic peptide corresponding to residues 2-20 of this sequence. The antipeptide serum recognized the purified protein using Western blot analysis under both nonreducing (Mr 43,000) and reducing (Mr 49,000) conditions. PMID:8810343

Catimel, B; Ritter, G; Welt, S; Old, L J; Cohen, L; Nerrie, M A; White, S J; Heath, J K; Demediuk, B; Domagala, T; Lee, F T; Scott, A M; Tu, G F; Ji, H; Moritz, R L; Simpson, R J; Burgess, A W; Nice, E C

1996-10-11

129

Bilateral Laplace Transforms on Time Scales: Convergence, Convolution, and the Characterization of Stationary Stochastic Time Series  

Microsoft Academic Search

The convergence of Laplace transforms on time scales is generalized to the bilateral case. The bilateral Laplace transform\\u000a of a signal on a time scale subsumes the continuous time bilateral Laplace transform, and the discrete time bilateral z-transform as special cases. As in the unilateral case, the regions of convergence (ROCs) time scale Laplace transforms are\\u000a determined by the time

John M. Davis; Ian A. Gravagne; Robert J. Marks II

2010-01-01

130

New way to characterize the percolation threshold of polyethylene and carbon nanotube polymer composites using Fourier transform (FT) rheology  

NASA Astrophysics Data System (ADS)

In this article, a new way to characterize the percolation threshold of polymer nanocomposites made of polyethylene (PE) with single and multi walled carbon nanotubes (SWCNTs and MWCNTs) is presented. Small and large oscillatory shear (SAOS and LAOS) experiments were performed to characterize the degree of dispersion and percolation threshold. The analysis of the stress response in the LAOS regime as a function of the applied deformation amplitude and frequency was performed using Fourier Transform (FT)-Rheology. The zero strain intrinsic nonlinear parameter, Q0(?), was calculated by extrapolation of I3/1(?0, ?) and was, used to quantify the nonlinearity measured by FT-Rheology. Interestingly, a drop in Q0 as a function of the CNT weight fraction at a fixed frequency was found that was below the percolation threshold. This was followed by, a steep rise in Q0 above the percolation threshold. Therefore, the new method based on this observation that is proposed and described with this article has the potential to lead to a better understanding of structure-property relationships in polymer nanocomposites.

Ahirwal, Deepak; Palza, Humberto; Schlatter, Guy; Wilhelm, Manfred

2014-08-01

131

Characterization of full-scale carbon contactors for siloxane removal from biogas using online Fourier transform infrared spectroscopy.  

PubMed

In this study, online Fourier transform infrared (FTIR) spectroscopy has been used to generate the first comprehensive characterization of full-scale carbon contactors for siloxane removal from biogas. Using FTIR, two clear operational regions within the exhaustion cycle were evidenced: an initial period of pseudo-steady state where the outlet siloxane concentration was consistently below the proposed siloxane limits; and a second period characterized by a progressive rise in outlet siloxane concentration during and after breakthrough. Due to the sharp breakthrough front identified, existing detection methods (which comprise field sampling coupled with laboratory-based chromatographic determination) are insufficiently responsive to define breakthrough, thus carbon contactors currently remain in service while providing limited protection to the combined heat and power engine. Integration of the exhaustion cycle to breakthrough identified average specific media capacities of 8.5-21.5 gsiloxane [Formula: see text], which are lower than that has been reported for vapour phase granular activated carbon (GAC). Further speciation of the biogas phase identified co-separation of organic compounds (alkanes and aromatics), which will inevitably reduce siloxane capacity. However, comparison of the five full-scale contactors identified that greater media capacity was accessible through operating contactors at velocities sufficient to diminish axial dispersion effects. In addition to enabling significant insight into gas phase GAC contactors, the use of FTIR for online control of GAC for siloxane removal is also presented. PMID:25413112

Hepburn, C A; Martin, B D; Simms, N; McAdam, E J

2015-01-01

132

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

133

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

134

Spectral Characterizations of the Clouds and the Earth's Radiant Energy System (CERES) Thermistor Bolometers using Fourier Transform Spectrometer (FTS) Techniques  

NASA Technical Reports Server (NTRS)

Fourier Transform Spectrometer (FTS) techniques are being used to characterize the relative spectral response, or sensitivity, of scanning thermistor bolometers in the infrared (IR) region (2 - >= 100-micrometers). The bolometers are being used in the Clouds and the Earth's Radiant Energy System (CERES) program. The CERES measurements are designed to provide precise, long term monitoring of the Earth's atmospheric radiation energy budget. The CERES instrument houses three bolometric radiometers, a total wavelength (0.3- >= 150-micrometers) sensor, a shortwave (0.3-5-micrometers) sensor, and an atmospheric window (8-12-micrometers) sensor. Accurate spectral characterization is necessary for determining filtered radiances for longwave radiometric calibrations. The CERES bolometers spectral response's are measured in the TRW FTS Vacuum Chamber Facility (FTS - VCF), which uses a FTS as the source and a cavity pyroelectric trap detector as the reference. The CERES bolometers and the cavity detector are contained in a vacuum chamber, while the FTS source is housed in a GN2 purged chamber. Due to the thermal time constant of the CERES bolometers, the FTS must be operated in a step mode. Data are acquired in 6 IR spectral bands covering the entire longwave IR region. In this paper, the TRW spectral calibration facility design and data measurement techniques are described. Two approaches are presented which convert the total channel FTS data into the final CERES spectral characterizations, producing the same calibration coefficients (within 0.1 percent). The resulting spectral response curves are shown, along with error sources in the two procedures. Finally, the impact of each spectral response curve on CERES data validation will be examined through analysis of filtered radiance values from various typical scene types.

Thornhill, K. Lee; Bitting, Herbert; Lee, Robert B., III; Paden, Jack; Pandey, Dhirendra K.; Priestley, Kory J.; Thomas, Susan; Wilson, Robert S.

1998-01-01

135

Physicochemical characterization of the thermal aging of insulating paper in power transformers  

SciTech Connect

Paper is a low-cost base material with outstanding mechanical and electrical properties, which is why it is still a key element in the insulation of electrical apparatus. Under the effect of a variety of factors including temperature, paper can substantially lose its properties, thus jeopardizing the service life of costly equipment. To remedy this situation, new so-called thermally upgraded papers are being made by certain manufacturers. A study carried out jointly by Hydro-Quebec, Electricite de France and the Ecole Nationale Superieure de Chimie de Toulouse has allowed researchers to qualify the thermal resistance of three different types of thermostable paper. These papers have been selected as being representative of what is available on the market today. The paper samples were subjected to a thermal aging test in the presence of mineral oil to represent normal conditions of operation (150 C). The thermal degradation of the paper insulation is characterized by various physicochemical methods including measurement of the degree of polymerization, determination of 2-furfural in mineral oil by HPLC as well as determination of various sugars (monosaccharides, polysaccharides and anhydrosugars) in the paper using ion chromatography. This last method allows the authors to verify the formation of cellobiose, which is the real repeat unit of cellulose, as well as that of levoglucosan, which is an anhydrosugar and a precursor of 2-furfural. The evolution of all of these parameters, measured as a function of time, has allowed them to compare the thermal resistance of various insulating papers. The results of this study seem to show that, compared to traditional kraft paper, certain paper types are more susceptible to being thermally upgraded than others. This study also allowed the authors to demonstrate that the use of an inhibitor in mineral oil (DBPC) does not seem to influence the thermal degradation of these papers.

Lessard, M.C.; Van Nifterik, L.; Masse, M. [Inst. de Recherche d`Hydro-Quebec, Varennes, Quebec (Canada); Penneau, J.F. [Electricite de France, Moret sur Loing (France). Direction des Etudes et Recherches; Grob, R. [Ecole Nationale Superieure de Chimie de Toulouse (France). Inst. National Polytechnique

1996-12-31

136

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

137

Fate of transforming deoxyribonucleic acid after uptake by competent Bacillus subtilis: phenotypic characterization of radiation-sensitive recombination-deficient mutants.  

PubMed

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. PMID:4349031

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

1973-04-01

138

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

139

[Genetic transformation of somatic cells. I. Clone of Chinese hamster cells defective in thymidine kinase and characterized by high transformation efficiency].  

PubMed

A characteristics is given of clone A238 of the Chinese hamster cells deficient in thymidine kinase (TK). The isolation procedure is described. Upon transformation with the aid of DNA of plasmids, containing thymidine kinase gene (tk-gene) of Herpes simplex virus type 1 (HSV1) clone A238 cells show frequency (7.10(-5) and efficiency (130 TK+ colonies per 1 microgram of plasmid DNA) compatible with those of mouse line LMtk- cells. Modified transformation and selection conditions of clone A238 cells expressing TK-gene of HSV1 are demonstrated. A simple method is described for discriminating somatic cells, expressing either their proper or a virus TK-gene according to the cloning efficiency of cells on the HAT medium containing thymidine in concentration 100 micrograms/ml. It is shown that at the fixed total DNA concentrations a complete replacement of the eukaryotic carrier DNA for the plasmid DNA, containing no tg gene of HSV1, decreases but only insignificantly the frequency and efficiency of transformation. PMID:2988162

Glebov, O K; Abramian, D S; Tomilin, N V

1985-04-01

140

Electrogenic transport of sodium ions in cytoplasmic and extracellular ion access channels of Na + ,K + ATPase probed by admittance measurement technique  

Microsoft Academic Search

Electrogenic movements of sodium ions in cytoplasmic and extracellular access channel of the Na+,K+-ATPase have been studied by the admittance measurement technique which allows the detection of small changes of the membrane\\u000a capacitance and conductance induced by phosphorylation of the ion pump. The measurements were carried out on a model system\\u000a consisting of a bilayer lipid membrane, to which membrane

V. S. Sokolov; A. A. Scherbakov; A. A. Lenz; Yu. A. Chizmadzhev; H.-J. Apell

2008-01-01

141

Étude par spectroscopie d'admittance et MEB de la dégradation électrique des couches minces de CuAlS{2} non dopé déposées sous vide  

Microsoft Academic Search

We have accelerated the ageing of CuAlS2 by the application of a static electrical field for different degradation times. We have investigated the admittance spectroscopy and the scanning electron microscopy to follow and understand the (mass-charge) coupled transport processes produced in the volume and on the surface of these films. The electrical constraint induces, after an incubation phase, an activated

N. Helali; B. Bouricha; B. Rezig

1998-01-01

142

Effects of bulk wave radiation on IDT admittance on 42 degrees YX-LiTaO3.  

PubMed

This paper investigates the effects of bulk acoustic wave (BAW) radiation on the admittance of interdigital transducers (IDTs) with significant internal reflections of shear horizontal (SH) type leaky surface acoustic waves (SAWs) on 42 degrees YX-LiTaO3 (42-LT). Theoretical analysis is made by using the discrete Green function theory, and synchronous one-port resonators are analyzed. It is shown that the BAW radiation significantly affects the IDT characteristics even for resonators; under certain circumstances, BAWs launched from an IDT are converted into SH-type SAWs by the strong internal reflections, and they interact with the BAWs radiated by the IDT. Then, the net amount of the radiated BAW power is highly dependent upon the number of IDT finger pairs. For the precise simulation of devices based on the SH-type SAWs with strong internal reflections, the BAW radiation should carefully be taken into consideration. If the BAW radiation is ignored, the radiated power of the SH-type SAWs may seem to be negative above the BAW cut-off frequency. PMID:11570768

Hashimoto, K; Yamaguchi, M; Kovacs, G; Wagner, K C; Ruile, W; Weigel, R

2001-09-01

143

The change in the acoustic admittance phase angle: a study in children suffering from acute otitis media.  

PubMed

Middle ear mechanics, in normal and in pathological conditions, is the subject of this research, with acoustic impedance measurements as the cornerstone. Previous studies have established the importance of admittance-phase tympanograms, mainly in frequencies higher than the conventional 226 Hz. The purpose of the present study was to record how acute otitis media (AOM) affects the middle ear system and function by evaluating the recordings of the change in phase angle parameter (deltatheta) provided by an automated tympanometer using the sweep-frequency technique. Multifrequency and conventional tympanograms were obtained from 70 children suffering from AOM on consecutive visits. Values of deltatheta from these subjects were compared to normative data previously acquired in our Department. It appears that changes in the mechanical status of the middle ear after AOM are reflected in abnormal deltatheta values, despite the normal findings of conventional tympanometry. A positive history of AOM did not seem to influence the behaviour of the middle ear. In most cases, abnormal deltatheta values coexisted with abnormal values of resonance frequency (RF), i.e. the frequency at which mass and stiffness of the middle ear are in balance, and total susceptance (deltaB) reaches 0mmhos and the converse. The deltatheta seems to be an important indicator of middle ear mechanical status that can record changes occurring in the system after AOM and undetected by low probe-tone tympanometry. PMID:11330915

Vlachou, S G; Tsakanikos, M; Douniadakis, D; Apostolopoulos, N

2001-01-01

144

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

145

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 PMID:1986255

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

1991-01-01

146

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

SciTech Connect

Spatially Resolved X-Ray Diffraction (SRXRD) has been used to identify a previously unobserved low temperature ferrite ({delta})/austenite({gamma}) 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 in a ferrite volume fraction equivalent to that in the base metal. Time Resolved X-Ray Diffraction (TRXRD) and laser dilatometry measurements during Gleeble{reg_sign} thermal simulations are performed in order to verify the existence of this low temperature phase transformation. Thermodynamic and kinetic models for phase transformations, including both local-equilibrium and para-equilibrium diffusion controlled growth, show that diffusion of substitutional alloying elements does not provide a reasonable explanation for the experimental observations. On the other hand, the diffusion of interstitial alloying elements may be rapid enough to explain this behavior. Based on both the experimental and modeling results, two mechanisms for the ''ferrite dip'' transformation, including the formation and decomposition of secondary austenite and an athermal martensitic-type transformation of ferrite to austenite, are considered.

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

2003-08-20

147

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

148

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

149

Identification and characterization of genes whose expressions are altered in rat 6 fibroblasts transformed by mutant p53(val135).  

PubMed

The wild-type tumor suppressor gene p53 is known as a transcription factor in activating or suppressing target genes that encode proteins in regulating genome stability, DNA damage, cell arrest, and apoptosis. However, the role of mutant p53 in the process of cell transformation is still unclear. Our recent work indicated that overexpression of mutant p53(val135) induced high incidence of spontaneous transformation in prolonged cultures of Rat 6 fibroblasts. In order to identify genes related to neoplastic transformation induced by the mutant p53, the p53(val135)-overexpressor R6#13-8 and its derived spontaneously transformed cell line T2 were analyzed by mRNA differential display. In a systematic screening with 80 primer sets of RT-PCR reactions, three genes were found to be differentially expressed between R6#13-8 and T2 cells. Two genes, identified as homologues of the growth factor inducible immediate-early gene Cyr61 and the human nonmuscle myosin heavy chain-B, were down-regulated in T2 cells. Interestingly, both genes were also suppressed in Rat 6 cells transformed by c-H-ras and v-myc, but not by v-src genes. The third gene is a homologue of the frizzled related protein, a gene family that acts, in some cases, as an antagonist to the Wnt signaling pathway. It is intriguing that the rat homologue of the frizzled related protein was only expressed in p53(val135)-overexpressing cells, but not in the parental Rat 6 cells. However, the same gene was also highly expressed in ras-transformed Rat 6 cells, and moderately expressed in v-src-transformed Rat 6 cells. This is the first study in which the association of mutant p53 to these three genes is revealed. Our current report may provide new clues to the role of mutant p53 in the process of cell transformation. PMID:10600527

Yam, J W; Zheng, J Y; Hsiao, W L

1999-12-20

150

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

151

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

152

Characterization of polymer nanocomposite films using quartz thickness shear mode (TSM) acoustic wave sensor  

Microsoft Academic Search

Quartz thickness shear mode (TSM) resonator is adopted to characterize the viscoelastic properties of polymer nanocomposite thin films deposited on the resonators surface. The input electric admittance of multilayer loaded TSM acoustic wave resonator is first derived using transfer matrix method by taking into account the acoustic wave impedance of the polymeric layer. Nanocomposite thin films of multi-wall carbon nanotubes

Lifeng Qin; Hongbin Cheng; Jacob M. Li; Qing-Ming Wang

2007-01-01

153

Étude par spectroscopie d'admittance et MEB de la dégradation électrique des couches minces de CuAlS{2} non dopé déposées sous vide  

NASA Astrophysics Data System (ADS)

We have accelerated the ageing of CuAlS2 by the application of a static electrical field for different degradation times. We have investigated the admittance spectroscopy and the scanning electron microscopy to follow and understand the (mass-charge) coupled transport processes produced in the volume and on the surface of these films. The electrical constraint induces, after an incubation phase, an activated decrease of the resistance, followed by a susbstantial increase correlated to the formation of an open circuit. This degradation occurs more rapidly for the films having initially a lower resistance, due to the thermal dissipation which increases considerably the temperature to about 140 °C. Admittance spectra reveal, at low frequencies, a capacitive loop related to the formation of a charge space induced by copper diffusion. Such migration develop induces the formation of copper arborescences, spreading from the cathode towards the anode. The effect of these structures on the properties of the degraded films is discussed in relation to electromigration and associated processes (whiskers, fracture, healing, bridge-building, ...). Also, we have noticed their similarity with fractal phenomena such as electrodeposition and dielectric breakdown. Nous avons accéléré le vieillissement des couches minces de CuAlS2 par l'application d'un champ électrique statique pendant des durées variables. Nous avons fait appel à la spectroscopie d'admittance et la microscopie électronique à balayage, pour suivre et comprendre les processus de transport couplé (masse- charge) qui se produisent en volume et en surface de ces couches. L'effet de la contrainte électrique s'est traduit, après une phase d'incubation, par une décroissance activée de la résistance, suivie d'une phase d'emballement reliée à la formation d'un circuit ouvert. Cette fracturation se manifeste plus rapidement pour les couches ayant initialement une faible résistance, suite à l'effet de la dissipation thermique qui peut augmenter notablement leur température (140 °C). Les spectres d'admittance révèlent, vers les basses fréquences, une boucle capacitive reliée à la formation d'une charge d'espace induite par la diffusion du cuivre. Une telle migration développe, sur la surface depuis la cathode, des arborescences de cuivre orientées vers l'anode. L'effet de ces structures sur les propriétés des couches dégradées a été discuté en mettant en cause le phénomène d'électromigration et ses mécanismes associés (whiskers, fracture, “healing", pontage, ...). De même, nous avons noté leur similarité avec des phénomènes fractals tels que l'électrodéposition ou le claquage diélectrique.

Helali, N.; Bouricha, B.; Rezig, B.

1998-07-01

154

Structure of low dielectric constant to extreme low dielectric constant SiCOH films: Fourier transform infrared spectroscopy characterization  

Microsoft Academic Search

Carbon doped oxide dielectrics comprised of Si, C, O, and H (SiCOH) have been prepared by plasma enhanced chemical vapor deposition (PECVD) from mixtures of tetramethylcyclotetrasiloxane (TMCTS) and an organic precursor. The films have been analyzed by determining their elemental composition and by Fourier transform infrared spectroscopy with deconvolution of the absorption peaks. The analysis has shown that PECVD of

Alfred Grill; Deborah A. Neumayer

2003-01-01

155

Characterization of Delhi iron pillar rust by X-ray diffraction, Fourier transform infrared spectroscopy and Mössbauer spectroscopy  

Microsoft Academic Search

Rust samples obtained from the region just below the decorative bell capital of the Delhi iron pillar (DIP) have been analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Mössbauer spectroscopy. The identification of iron hydrogen phosphate hydrate in the crystalline form by XRD was unambiguous. Very weak diffraction from the oxyhydroxides\\/oxides of iron was observed indicating that

R Balasubramaniam; A. V Ramesh Kumar

2000-01-01

156

Mutational analysis of the DEAD-box RNA helicase eIF4AII characterizes its interaction with transformation  

E-print Network

initiation. Programmed cell death 4 (Pdcd4) is a novel transformation suppressor and eIF4A-binding partner of the 43S preinitiation complex at the 5 -cap structure of mRNA, followed by scanning along the 5 to the mRNA by catalyzing the unwind- ing of mRNA secondary and tertiary structure at the cap structure

157

Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform  

Microsoft Academic Search

Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ?10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the

N. Maercklin; P. A. Bedrosian; C. Haberland; O. Ritter; T. Ryberg; M. Weber; U. Weckmann

2005-01-01

158

Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform  

Microsoft Academic Search

Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ~10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the

N. Maercklin; P. A. Bedrosian; C. Haberland; O. Ritter; T. Ryberg; M. Weber; U. Weckmann

2005-01-01

159

Characterization of Nanoscale Transformations in Polyelectrolyte Multilayers Fabricated from Plasmid DNA Using Laser Scanning Confocal Microscopy in Combination with Atomic Force Microscopy  

PubMed Central

Laser scanning confocal microscopy (LSCM) and atomic force microscopy (AFM) were used to characterize changes in nanoscale structure that occur when ultrathin polyelectrolyte multilayers (PEMs) are incubated in aqueous media. The PEMs investigated here were fabricated by the deposition of alternating layers of plasmid DNA and a hydrolytically degradable polyamine onto a precursor film composed of alternating layers of linear poly(ethylene imine) (LPEI) and sodium poly(styrene sulfonate) (SPS). Past studies of these materials in the context of gene delivery revealed transformations from a morphology that is smooth and uniform to one characterized by the formation of nanometer-scale particulate structures. We demonstrate that in-plane registration of LSCM and AFM images acquired from the same locations of films fabricated using fluorescently labeled polyelectrolytes allows the spatial distribution of individual polyelectrolyte species to be determined relative to the locations of topographic features that form during this transformation. Our results suggest that this physical transformation leads to a morphology consisting of a relatively less disturbed portion of film composed of polyamine and DNA juxtaposed over an array of particulate structures composed predominantly of LPEI and SPS. Characterization by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) microanalysis provides additional support for this interpretation. The combination of these different microscopy techniques provides insight into the structures and dynamics of these multicomponent thin films that cannot be achieved using any one method alone, and that could prove useful for the further development of these assemblies as platforms for the surface-mediated delivery of DNA. PMID:20155860

Fredin, Nathaniel J.; Flessner, Ryan M.; Jewell, Christopher M.; Bechler, Shane L.; Buck, Maren E.; Lynn, David M.

2010-01-01

160

Characterization of Delhi iron pillar rust by X-ray diÄraction, Fourier transform infrared spectroscopy and Mossbauer spectroscopy  

Microsoft Academic Search

Rust samples obtained from the region just below the decorative bell capital of the Delhi iron pillar (DIP) have been analyzed by X-ray diÄraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Mossbauer spectroscopy. The identification of iron hydrogen phosphate hydrate in the crystalline form by XRD was unambiguous. Very weak diÄraction from the oxyhydroxides\\/oxides of iron was observed indicating that

R. Balasubramaniam; A. V. Ramesh Kumar

161

In Vitro Tn7 Mutagenesis of Haemophilus influenzae Rd and Characterization of the Role of atpA in Transformation  

Microsoft Academic Search

Haemophilus influenzae Rd is a gram-negative bacterium capable of natural DNA transformation. The compe- tent state occurs naturally in late exponential growth or can be induced by a nutritional downshift or by tran- sient anaerobiosis. The genes cya, crp, topA, and sxy (tfoX) are known to function in the regulation of competence development. The phosphoenolpyruvate:carbohydrate phosphotransferase system functions to maintain

M. L. GWINN; A. E. STELLWAGEN; N. L. CRAIG; J.-F. TOMB; H. O. SMITH

1997-01-01

162

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

163

In vitro Tn7 mutagenesis of Haemophilus influenzae Rd and characterization of the role of atpA in transformation.  

PubMed Central

Haemophilus influenzae Rd is a gram-negative bacterium capable of natural DNA transformation. The competent state occurs naturally in late exponential growth or can be induced by a nutritional downshift or by transient anaerobiosis. The genes cya, crp, topA, and sxy (tfoX) are known to function in the regulation of competence development. The phosphoenolpyruvate:carbohydrate phosphotransferase system functions to maintain levels of cyclic AMP necessary for competence development but is not directly involved in regulation. The exact signal(s) for competence and the genes that mediate the signal(s) are still unknown. In an effort to find additional regulatory genes, H. influenzae Rd was mutated by using an in vitro Tn7 system and screened for mutants with a reduced ability to induce the competence-regulatory gene, comA. Insertions in atpA, a gene coding for the alpha subunit of the F1 cytoplasmic domain of the ATP synthase, reduce transformation frequencies about 20-fold and cause a significant reduction in expression of competence-regulatory genes, while the expression of constitutive competence genes is only minimally affected. In addition, we found that an insertion in atpB, which encodes the a subunit of the F0 membrane-spanning domain, has a similar effect on transformation frequencies. PMID:9393695

Gwinn, M L; Stellwagen, A E; Craig, N L; Tomb, J F; Smith, H O

1997-01-01

164

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

165

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

166

Transformer ratio enhancement experiment  

Microsoft Academic Search

Recently, a multibunch scheme for efficient acceleration based on dielectric wakefield accelerator technology was outlined in ref.[1]. In this paper we present an experimental program for the design, development and demonstration of an Enhanced Transformer Ratio Dielectric Wakefield Accelerator (ETR-DWA). The principal goal is to increase the transformer ratio R, the parameter that characterizes the energy transfer efficiency from the

A. Kanareykin; Wei Gai; J. G. Power; E. Nenasheva; A. Altmark

2003-01-01

167

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

168

Isolation and characterization of human prorenin secreted from murine cells transformed with a bovine papillomavirus-preprorenin expression vector  

SciTech Connect

The authors report the construction of a plasmid-based expression vector that carries the murine metallothionein gene promoter, the human preprorenin gene, the Tn5 phosphotransferase gene, and a complete bovine papilloma virus genome. Murine cells transformed with this vector constitutively secrete high levels of human prorenin as determined by immunoprecipitation of culture media with anti-human renin antibody and activity assays. An immunoaffinity system for the isolation of human prorenin from serum-free media, or media containing serum, was developed. Purified human prorenin is stable for months and is fully activated to enzymatically mature renin by limited tryptic digestion. This is the first example of a recombinant system leading to the isolation of research quantities of highly pure and fully activatable human prorenin.

Evans, D.B.; Weighous, T.F.; Cornette, J.C.; Tarpley, W.G.; Sharma, S.K.

1987-07-01

169

Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform  

USGS Publications Warehouse

Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

2005-01-01

170

Thermal behavior of silicone rubber-based ceramizable composites characterized by Fourier transform infrared (FT-IR) spectroscopy and microcalorimetry.  

PubMed

Ceramizable (ceramifiable) silicone rubber-based composites are commonly used for cable insulation. These materials are able to create a protective ceramic layer during fire due to the ceramization process, which occurs at high temperature. When the temperature is increased, the polymer matrix is degraded and filler particles stick together by the fluxing agent, producing a solid, continuous ceramic phase that protects the copper wire from heat and mechanical stress. Despite increasing interest in these materials that has resulted in growing applications in the cable industry, their thermal behavior and ceramization process are still insufficiently described in the literature. In this paper, the thermal behavior of ceramizable silicone rubber-based composites is studied using microcalorimetry and Fourier transform infrared spectroscopy. The analysis of the experimental data made it possible to develop complete information on the mechanism of composite ceramization. PMID:24359658

Anyszka, Rafa?; Bieli?ski, Dariusz M; J?drzejczyk, Marcin

2013-12-01

171

Characterization of hyaluronate binding proteins isolated from 3T3 and murine sarcoma virus transformed 3T3 cells  

SciTech Connect

A hyaluronic acid binding fraction was purified from the supernatant media of both 3T3 and murine sarcoma virus (MSV) transformed 3T3 cultures by hyaluronate and immunoaffinity chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved the hyaluronate affinity-purified fraction into three major protein bands of estimated molecular weight (M/sub r,e/) 70K, 66K, and 56K which contained hyaluronate binding activity and which were termed hyaluronate binding proteins (HABP). Hyaluronate affinity chromatography combined with immunoaffinity chromatography, using antibody directed against the larger HABP, allowed a 20-fold purification of HABP. Fractions isolated from 3T3 supernatant medium also contained additional binding molecules in the molecular weight range of 20K. This material was present in vanishingly small amounts and was not detected with a silver stain or with (/sup 35/S)methionine label. The three protein species isolated by hyaluronate affinity chromatography (M/sub r,e/ 70K, 66K, and 56K) were related to one another since they shared antigenic determinants and exhibited similar pI values. In isocratic conditions, HABP occurred as aggregates of up to 580 kilodaltons. Their glycoprotein nature was indicated by their incorporation of /sup 3/H-sugars. Enzyme-linked immunoadsorbent assay showed they were antigenically distinct from other hyaluronate binding proteins such as fibronectin, cartilage link protein, and the hyaluronate binding region of chondroitin sulfate proteoglycan. The results are discussed with regard both to the functional significance of hyaluronate-cell surface interactions in transformed as well as normal cells and to the relationship of HABP to other reported hyaluronate binding proteins.

Turley, E.A.; Moore, D.; Hayden, L.J.

1987-06-02

172

Suitability of the normalized difference vegetation index and the adjusted transformed soil-adjusted vegetation index for spatially characterizing loggerhead shrike habitats in North American mixed prairie  

NASA Astrophysics Data System (ADS)

Habitat loss has become one major cause of prairie loggerhead shrike population decline, which is associated with some important grassland biophysical features. However, our understanding of what and how biophysical variables can spatially characterize shrike habitats is poor. The purpose of this study is to investigate the suitability of two vegetation indices (VIs) for spatially characterizing shrike habitats in North American mixed prairies. Our research, conducted in Grasslands National Park of Canada, is based on the normalized difference vegetation index (NDVI) and the adjusted transformed soil-adjusted vegetation index (ATSAVI) as derived from both in situ measurements and SPOT imagery for three types of nesting categories at three spatial scales. Our results demonstrated that shrikes in mixed North American prairies prefer sparsely vegetated areas with a leaf area index less than 2.01 and shrub cover of around 25%. Our results also demonstrated that ATSAVI is superior to NDVI in estimating vegetation abundance and structure. Loggerhead shrikes seems to prefer habitats characterized by NDVI ranging from 0.562 to 0.616 and ATSAVI ranging from 0.319 to 0.372 with the spatial scale varying from 100 to 20 m. ATSAVI also had better performance in detecting the spatial variation of shrike habitats due to its higher sensitivity to background information.

Shen, Li; He, Yuhong; Guo, Xulin

2013-01-01

173

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

174

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

175

Modeling Transformation  

E-print Network

Modeling Transformation What does each step do? #12;Transformation Procedure #12;Transformation Procedure #12;Building Your Model Yarn = chromosomal DNA Beads = ribosomes Black velcro = plasmid DNA Green velcro = GFP gene Pink velcro

Rose, Michael R.

176

Transformation of LMTK- cells with purified HLA class I gene. VI. Serological characterization of HLA-B7 and AW24 molecules.  

PubMed

Serological characterization of HLA-B7 and HLA-AW24 class I molecules following transfection of murine LMTK- cells with purified HLA class I genes was performed using human alloantisera. Induction by murine alpha interferon of the expression of class I molecules was required to obtain unambiguous identification of these molecules which appear serologically identical to the HLA-B7 and HLA-AW24 molecules expressed at the surface of human peripheral blood lymphocytes of 20 unrelated individuals. Analysis of the transformed cells with 8 different anti-HLA class I monoclonal antibodies results in the definition of 3 separate clusters of antigenic determinants shared by all HLA class I molecules. These studies further suggest the existence of locus-specific serological reactivities associated either with the HLA-A or with the HLA-B and C gene products. PMID:6207154

Layet, C; Le Bouteiller, P P; N'guyen, C; Mercier, P; Rosa, F; Fellous, M; Caillol, D H; Jordan, B R; Lemonnier, F A

1984-09-01

177

Genetic Transformation System for a Psychrotrophic Deep-sea Bacterium: Isolation and Characterization of a Psychrotrophic Plasmid  

Microsoft Academic Search

:   A versatile system that permits genetic manipulation of a psychrotrophic deep-sea bacterium, Pseudoalteromonas sp. PS1M3, has been developed. A cryptic indigenous plasmid, pPS1M3, of 3.1 kb from the above strain was isolated and characterized.\\u000a The nucleotide sequence analysis of plasmid pPS1M3 revealed the presence of one open reading frame, and its deduced amino\\u000a acid sequence was identified as the

Yasurou Kurusu; Satoshi Yoshimura; Mitsuko Tanaka; Takamichi Nakamura; Akihiko Maruyama; Takanori Higashihara

2001-01-01

178

Characterization of the surfaces of platinum/tin oxide based catalysts by Fourier Transform Infrared Spectroscopy (FTIR)  

NASA Technical Reports Server (NTRS)

A Pt/SnO2 catalyst has been developed at NASA Langley that is effective for the oxidation of CO at room temperature (1). A mechanism has been proposed to explain the effectiveness of this catalyst (2), but most of the species involved in this mechanism have not been observed under actual catalytic conditions. A number of these species are potentially detectable by Fourier Transform Infrared Spectroscopy (FTIR), e.g., HOSnO sub x, HO sub y PtO sub z, Pt-CO, and SnHCO3. Therefore a preliminary investigation was conducted to determine what might be learned about this particular catalyst by transmission FTIR. The main advantage of FTIR for this work is that the catalyst can be examined under conditions similar to the actual catalytic conditions. This can be of critical importance since some surface species may exist only when the reaction gases are present. Another advantage of the infrared approach is that since vibrations are probed, subtle chemical details may be obtained. The main disadvantage of this approach is that FTIR is not nearly as sensitive as the Ultra High Vacuum (UHV) surface analytical techniques such as Auger, Electron Spectroscopy for Chemical Analysis (ESCA), Electron Energy Loss Spectroscopy (EELS), etc. Another problem is that the assignment of the observed infrared bands may be difficult.

Keiser, Joseph T.; Upchurch, Billy T.

1990-01-01

179

Efficient Heterologous Transformation of Chlamydomonas reinhardtii npq2 Mutant with the Zeaxanthin Epoxidase Gene Isolated and Characterized from Chlorella zofingiensis  

PubMed Central

In the violaxanthin cycle, the violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the inter-conversion between violaxanthin and zeaxanthin in both plants and green algae. The zeaxanthin epoxidase gene from the green microalga Chlorella zofingiensis (Czzep) has been isolated. This gene encodes a polypeptide of 596 amino acids. A single copy of Czzep has been found in the C. zofingiensis genome by Southern blot analysis. qPCR analysis has shown that transcript levels of Czzep were increased after zeaxanthin formation under high light conditions. The functionality of Czzep gene by heterologous genetic complementation in the Chlamydomonas mutant npq2, which lacks zeaxanthin epoxidase (ZEP) activity and accumulates zeaxanthin in all conditions, was analyzed. The Czzep gene was adequately inserted in the pSI105 vector and expressed in npq2. The positive transformants were able to efficiently convert zeaxanthin into violaxanthin, as well as to restore their maximum quantum efficiency of the PSII (Fv/Fm). These results show that Chlamydomonas can be an efficient tool for heterologous expression and metabolic engineering for biotechnological applications. PMID:23118714

Couso, Inmaculada; Cordero, Baldo F.; Vargas, Maria Angeles; Rodriguez, Herminia

2012-01-01

180

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

181

Fourier Transform Infrared Spectroscopic characterization and optimization of Pb(II) biosorption by fish (Labeo rohita) scales.  

PubMed

The present study reports the use of locally available fish (Labeo rohita) scales for Pb(II) removal from aqueous solutions under different experimental conditions. Maximum Pb(II) adsorption (196.8 mg g(-1)) occurred at pH 3.5. Pb(II) sorption was found to be pH, dose, initial metal concentration, contact time and shaking speed dependent while particle size and temperature independent. Experimental data of Pb(II) biosorption onto fish scales fitted well to Freundlich isotherm model in comparison to the model of Langmuir. The fast adsorption process in first 30 min followed by subsequent slow adsorption rate was suitably described by pseudo-second order model. In addition, this study was designed to evaluate the effect of physical and chemical pretreatments on surface properties of fish scales by the application of Fourier Transform Infrared (FTIR) Spectroscopic analysis. Physical pretreatments resulted in partial degradation of some functional groups. Alkaline pretreatments of fish scales did not have any significant influence on the nature of functional groups responsible for Pb(II) uptake, while acidic pretreatments resulted in degeneration of the most of functional groups on biosorbent cell wall. FTIR analysis confirmed the involvement of amino, carboxylic, phosphate and carbonyl groups in Pb(II) biosorption by fish scales. PMID:18242826

Nadeem, Raziya; Ansari, Tariq Mahmood; Khalid, Ahmad Mukhtar

2008-08-15

182

Molecular characterization of inhibiting biochar water-extractable substances using electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Biochar has gained significant interest worldwide for its potential use as both a carbon sequestration technique and soil amendment. Recently, research has shown that pinewood-derived biochar water extracts inhibited the growth of aquatic photosynthetic microorganisms, both prokaryotic and eukaryotic algae, while chicken litter- and peanut shell-derived biochar water extracts showed no growth inhibition. With the use of electrodialysis, the pinewood-derived biochar water extract is separated into 3 fractions (anode-isolated, center chamber retained, and cathode-isolated substances) all with varying toxic effects. Because of its ultrahigh resolution and mass precision, electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is utilized in this study to analyze biochar water extracts at a molecular level to enhance our understanding of the toxic nature of pinewood-derived biochar water extracts as compared to benign peanut shell-derived biochar water extracts. The molecular composition of pinewood-derived biochar water extracts shows unique carbohydrate ligneous components and sulfur containing condensed ligneous components that are both absent from the peanut shell water extracts and more prevalent in the anode-isolated substances. Using Kendrick mass defect analysis, we also determine that the most likely inhibitor species contain carboxyl and hydroxyl homologous series, both of which are characteristic functional groups hypothesized in our previous research for the inhibitor species. We have suggested that inhibition of aquatic photosynthetic microorganism growth is most likely due to degraded lignin-like species rich in oxygen containing functionalities. From the study conducted here, we show the potential of ultrahigh resolution FTICR-MS as a valuable analytical technique for determining whether certain biochars are safe and benign for use as carbon sequestration and soil amendment. PMID:24180747

Smith, Cameron R; Sleighter, Rachel L; Hatcher, Patrick G; Lee, James W

2013-12-01

183

Preparation and in situ Characterization of Surfaces Using Soft-Landing in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer  

SciTech Connect

Mass-selected peptide ions produced by electrospray ionization were deposited onto fluorinated self-assembled monolayer surfaces (FSAM) surfaces by soft-landing using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially designed for studying interactions of large ions with surfaces. Analysis of the modified surface was performed in situ by combining 2 keV Cs+ secondary ion mass spectrometry with FT-ICR detection of the sputtered ions (FT-ICR-SIMS). Regardless of the initial charge state of the precursor ion, the SIMS mass spectra included singly-protonated peptide fragment ions and peaks characteristic of the surfaces in all cases. In some experiments multiply-protonated peptide ions and [M+Au]+ ions were also observed upon SIMS analysis of modified surfaces. For comparison with the in situ analysis of the modified surfaces, ex situ analysis of some of the modified surfaces was performed by 25 kV Ga+ time of flight ? secondary ion mass spectrometry (ToF-SIMS). The ex situ analysis demonstrated that a significant number of soft-landed peptide ions remain charged on the surface even when exposed to air for several hours after deposition. Charge retention of soft-landed ions dramatically increases the ion yields obtained during SIMS analysis very sensitive detection of deposited material at less than 1% of monolayer coverage. Accumulation of charged species on the surface undergoes saturation due to Coulomb repulsion between charges at close to 30% coverage. We estimated that close to 1 ng of peptide could be deposited on the spot area of 4 mm2 of the FSAM surface without reaching saturation.

Alvarez, Jormarie; Cooks, Robert G.; Barlow, Stephan E.; Gaspar, Dan J.; Futrell, Jean H.; Laskin, Julia

2005-06-01

184

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 (H(2)O(2))-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 H(2)O(2) 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 H(2)O(2)-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

185

Characterization and petrophysical properties of hydrothemally altered lacustrine volcanistic rock in Geyser Valley (Kamchatka) and its transformation by weathering  

NASA Astrophysics Data System (ADS)

Work is devoted to the study of volcano sedimentary hydrothermally altered rocks in Geyser Valley (Kamchatka peninsula, Russia). The Geyser Valley is one of the most unique nature objects in Russia. There are quite large geyser fields. The valley of the river is part of the Uson-Geysernaya depression, where hydrothermal activity is very high. Besides geysers here are hot springs, mud pots and fumarols. In the late Pleistocene (about 45-35 thousand years ago) the lake was located in the site of the modern valley of the Geysernaya river, where sediments accumulated intensively. Sedimentary material came from several sources in the form of pyroclastic flows, ash falls, was supplied by permanent and temporary water streams. The total deposit thickness reached several hundred meters. In the late Pleistocene there was breakthrough of reservoir and further conditions for the lacustrine deposits formation did not arose. Later the rocks were intensively processed by thermal water. In 2007 large landslide was formed in lower part of the Geysernaya River on their left slope. Deposits of Geysernaya (Q34grn) series and Pemsovaya (Q34pmz) series were involved in landslide displacement. The headscarp was formed up to 100 m and a length of 800 m, exposing the volcano-sedimentary section of hydrothermally altered rocks - a unique opportunity for sampling and subsequent laboratory study. Thickness of lake sediments is interbedding of coarse-grain, medium-grain, fine-grain tuffites predominantly acidic composition. The study of thin sections revealed that all samples are lithoclastic and vitroclastic hydrothermally altered tuffits. Currently, the primary minerals and volcanic glass is largely replaced by clay minerals of the smectite group. Pores and cracks are made zeolites (heulandite and clinoptilolite). All this points to the low-temperature (<200 ° C) hydrothermal conditions with a pH near neutral. Tyere are acid plagioclase and quartz in most samples The high content of smectite causes high hygroscopy of deposits. Rocks are highly porous - of 37-65%, primarily low density - 0,9-1,65 g/cm3 wave velocities - from 0.74 km/s for porous to 3.42 km/sec for dense varieties. All samples are characterized by low strength characteristics: uniaxial compressive strength - 1.2 - 21.7 MPa, uniaxial tension - 0,6-4,7 MPa. By water saturation strength decreases rapidly. Soft coefficient ranges from 0.22 to 0.57. Proving to be on the land surface as a result of slope deformation, volcanic-sedimentary hydrothermally altered rocks are destroyed quickly by precipitation and temperature fluctuations Rock turned to sand, silt and clay depending on the original composition. It was found that often weathered to clayey state tuffites inherit structural and textural features of the primary species. The composition also varies: increased content of clay minerals (to 90%), decreasing the content of zeolites (not to exceed 10%). Quartz and plagioclase form sans fraction. Physical and mechanical properties vary widely: the density of the soil increases slightly up to 1,57-1,59 g/cm3 for sands, 1,2-1,79 g/cm3 for clays, porosity of 51-52% and 49-78% respectively, moisture 22-23% and 43-98/ Clays are in a state of semi-solid to fluid. The high content of smectite determines high plastic properties. Plasticity Index varies widely from 11 to 57. Cohesion and the internal friction angle obtained from shear tests also change widely. For clayey sand grip reaches 137 kPa, internal friction angle - 17 degrees. In clay grip ranges from 13 kPa to 120 kPa, and the internal friction angle - from 11 degrees to 31 degrees. Large variation of properties of the investigated soils is explained by the inhomogeneity of volcano-sedimentary formations both vertically and laterally, varying degrees of hydrothermal alteration and of weathering, fracturing and cracks filling The obtained datas can adequately characterize the volcanic-lacustrine sediments in the valley of the Geysernaya river and use them in calculations of slope stability and for and geological mapping.

Gvozdeva, Irina; Zerkal, Oleg; Samarin, Evgeny

2013-04-01

186

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

187

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.

188

Characterization of organic material in ice core samples from North America, Greenland, and Antarctica using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry  

NASA Astrophysics Data System (ADS)

Historically, it has been an analytical challenge to detect and identify the organic components present in ice cores, due to the low abundance of organic carbon. In order to detect and characterize the small amounts of organic matter in ice cores, ultra high resolution instrumentation is required. Here we report the use of ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry, coupled with electrospray ionization, to identify the molecular formulas and compound classes of organic matter in both modern and ancient ice core and glacial samples from Wyoming, Greenland, and Antarctica. A suite of 21 samples were analyzed and thousands of distinct molecular species were identified in each sample, providing clues to the nature and sources of organic matter in these regions. Major biochemical classes of compounds were detected such as lignins, tannins, carbohydrates, proteins, lipids, unsaturated hydrocarbons, and condensed aromatic compounds. We will compare the nature of the organic matter present in the samples in order to determine the differences in dominant organic compound classes and in heteroatom (nitrogen and sulfur) abundance. By analyzing these differences, it is possible to investigate the historical patterns of organic matter deposition/source, and begin to investigate the influence of climate change, volcanism, and onset of the industrial revolution on the nature of organic matter preserved in ice cores.

Catanzano, V.; Grannas, A. M.; Sleighter, R. L.; Hatcher, P. G.

2013-12-01

189

Characterization of silicon dioxide films on a 4H-SiC Si(0001) face by fourier transform infrared (FT-IR) spectroscopy and cathodoluminescence spectroscopy.  

PubMed

We used Fourier transform infrared (FT-IR) spectroscopy to characterize silicon dioxide (SiO(2)) films on a 4H-SiC(0001) Si face. We found that the peak frequency of the transverse optical (TO) phonon in SiO(2) films grown on a 4H-SiC substrate agrees well with that in SiO(2) films grown on a Si substrate, whereas the peak frequency of the longitudinal optical (LO) phonon in SiO(2) films on a 4H-SiC substrate is red-shifted by approximately 50 cm(-1) relative to that in SiO(2) films on a Si substrate. We concluded that this red-shift of the LO phonon is mainly caused by a change in inhomogeneity due to a decrease in density in the SiO(2) films. Furthermore, cathodoluminescence (CL) spectroscopy results indicated that the channel mobility of the SiC metal-oxide-semiconductor field-effect transistor (MOSFET) decreases roughly in proportion to the increase in the intensity of the CL peak at 460 and 490 nm, which is attributed to the increase in the number of oxygen vacancy centers (OVCs). FT-IR and CL spectroscopies provide us with a large amount of data on OVCs in the SiO(2) films on a 4H-SiC substrate. PMID:21513598

Yoshikawa, Masanobu; Seki, Hirohumi; Inoue, Keiko; Matsuda, Keiko; Tanahashi, Yusaku; Sako, Hideki; Nanen, Yuihiro; Kato, Muneharu; Kimoto, Tsunenobu

2011-05-01

190

Characterization of the secondary structure and thermostability of the extrinsic 16 kilodalton protein of spinach photosystem II by Fourier transform infrared spectroscopy  

NASA Astrophysics Data System (ADS)

The secondary structure and thermostability of the extrinsic 16 kDa protein of the spinach photosystem II (OEC16) were characterized in solution between 25 and 75°C using Fourier transform infrared (FTIR) spectroscopy. Quantitative analyses of the amide I band (1700-1600 cm -1) showed that the OEC16 subunit contains 34% ?-helix, 28% ?-sheet, 6% turn, and 32% disorder structures at 25°C. This structural feature differs significantly from that of OEC23 as we had reported previously (H. Zhang, Y. Ishikawa, Y. Yamamoto, R. Carpentier, FEBS Letters 426 (1998) 347-351), although both the OEC subunits are involved in regulating Ca 2+ and Cl - requirements. In addition, it was observed that the structure of OEC16 is stable at <60°C. At increased temperatures, however, thermal denaturation due to an irreversible protein aggregation occurs with a conformational transition at ?65°C. This transitional temperature is considerably higher than that (42.5°C) of the PSII reaction centers as also determined by FTIR spectroscopy (J. De Las Rivas, J. Barber, Biochemistry 36 (1997) 8897-8903). The higher thermostability of OEC16 may indicate the role of OEC16 against heat inactivation of PSII in vivo.

Zhang, H.; Yamamoto, Y.; Ishikawa, Y.; Carpentier, R.

1999-12-01

191

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

192

Wavelet transforms versus Fourier transforms  

Microsoft Academic Search

This note is a very basic introduction to wavelets. It starts with an orthogonal basis of piecewise constant functions, constructed by dilation and translation. The ``wavelet transform'' maps each $f(x)$ to its coefficients with respect to this basis. The mathematics is simple and the transform is fast (faster than the Fast Fourier Transform, which we briefly explain), but approximation by

Gilbert Strang

1993-01-01

193

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

194

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

195

On the synthesis of equivalent-circuit models for multiports characterized by frequency-dependent parameters  

Microsoft Academic Search

The synthesis of lumped-element equivalent circuits for time-domain analysis of problems with frequency-dependent parameters is of great interest in microwave theory. This paper presents a systematic approach to generate minimal-order realizations for passive microwave circuits characterized by either admittance, impedance, or scattering-parameter data. In addition, a very efficient method to ensure inherent system properties such as stability and passivity is

Roland Neumayer; Andreas Stelzer; Friedrich Haslinger; Robert Weigel

2002-01-01

196

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

197

Probabilistic predicate transformers  

Microsoft Academic Search

Probabilistic predicates generalize standard predicates over a state space; with probabilistic predicate transformers one thus reasons about imperative programs in terms of probabilistic pre- and postconditions. Probabilistic healthiness conditions generalize the standard ones, characterizing “real” probabilistic programs, and are based on a connection with an underlying relational model for probabilistic execution; in both contexts demonic nondeterminism coexists with probabilistic choice.

Carroll Morgan; Annabelle McIver; Karen Seidel

1996-01-01

198

Characterization of genetic transformation in Streptococcus oralis NCTC 11427: Expression of the pneumococcal amidase in S. oralis using a new shuttle vector  

Microsoft Academic Search

We have worked out conditions for the study of competence development and genetic transformation in Streptococcus oralis NCTC 11427 (type strain), a species that contains choline in the cell wall. The peak of competence was found at the early exponential phase of growth and the optimal conditions for transformation were achieved with shuttle plasmids prepared from S. pneumoniae or from

Concepción Ronda; José L. García; Rubens López

1988-01-01

199

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  

Microsoft Academic Search

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

T. Garcia de Oteyza; J. O. Grimalt

2006-01-01

200

Transformational Events  

ERIC Educational Resources Information Center

Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

Denning, Peter J.; Hiles, John E.

2006-01-01

201

Transformational Grammar and Cognitive Psycholinguistics.  

ERIC Educational Resources Information Center

An overview of Noam Chomsky's theories about transformational grammar and phonology is given. Since Chomsky was interested in characterizing what it is to know a language, the ways in which we demonstrate knowledge of our native language are discussed in detail. Particular emphasis is placed on describing how the transformational approach actually…

Lester, Mark

1973-01-01

202

Transformation of LMTK- cells with purified HLA class I genes. II. Serologic characterization of HLA-A3 and CW3 molecules.  

PubMed

The expression of two different HLA class I genes was observed after transformation of LMTK- cells. The corresponding class I molecules reacted differentially with monomorphic monoclonal antibodies (m.Ab). Absorption and elution studies of the human alloantibodies reacting with the transformed cells and cellular radioimmunoassay of these cells with polymorphic m.Ab resulted in the identification of HLA-A3 and CW3 molecules. These transformed cells were used to immunize C3H mice and induce the production of xenogeneic antisera, which, following absorption, showed polymorphic reactivity with human cells, suggesting that some of these sera could be used as typing reagents. PMID:6190745

Lemonnier, F A; Dubreuil, P C; Layet, C; Malissen, M; Bourel, D; Mercier, P; Jakobsen, B K; Caillol, D H; Svejgaard, A; Kourilsky, F M; Jordan, B R

1983-01-01

203

CHARACTERIZATION OF PCB (POLYCHLORINATED BIPHENYL) TRANSFORMER/CAPACITOR FLUIDS AND CORRELATION WITH PCDDS (POLYCHLORINATED DIBENZO-P-DIOXINS) AND PCDFS (POLYCHLORINATED DIBENZOFURANS) IN SOOT  

EPA Science Inventory

Dielectric fluids in transformers and capacitors often contain polychlorinated biphenyls (PCBs) or chlorobenzenes. These substances may generate polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) under certain conditions of combustion/pyrolysis. W...

204

Identification and characterization of novel competence genes comA and exbB involved in natural genetic transformation of Pseudomonas stutzeri  

Microsoft Academic Search

After transposon mutagenesis we identified a novel gene (comA) of Pseudomonas stutzeri which is essential for natural genetic transformation. The putative amino acid sequence is similar to ComA orthologs of other transformable bacteria including Neisseria gonorrhoeae (ComA), Haemophilus influenzae (Rec-2), Bacillus subtilis (ComEC) and Streptococcus pneumoniae (CelB). Downstream of comA two partially overlapping open reading frames termed exbB and exbD

Stefan Graupner; Wilfried Wackernagel

2001-01-01

205

Transforming California  

NSDL National Science Digital Library

Transforming California is a PowerPoint presentation of digital images (60.7 Mb) exploring the landforms found along the San Andreas Fault. Designed for classroom use, this slideshow provides a complementing narrative for each slide.

Mcguire, Thomas

2001-01-01

206

Transformative copy  

E-print Network

The ability to create an unlimited number of identical copies is a privilege of digital documents. What if that would not be the case, if each copy of a digital file would go along with some sort of transformation? This ...

Offenhuber, Dietmar

2008-01-01

207

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

208

Covariant Transform  

NASA Astrophysics Data System (ADS)

Dedicated to the memory of Cora Sadosky The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable or vacuum vectors which are not admissible. Covariant transform extends an applicability of the popular wavelets construction to classic examples like the Hardy space H2, Banach spaces, covariant functional calculus and many others.

Kisil, Vladimir V.

2011-03-01

209

Cotton Transformation  

Microsoft Academic Search

Cotton has been cultured in vitro for 37 years, yet even today, some of the culture difficulties that were seen when it was\\u000a first cultured, namely, a very long culture time and a limited number of cultivars that can be cultured, continue to pose\\u000a problems. These inherent tissue culture limitations have made transforming cotton an arduous process. Transforming embryogenic\\u000a callus

D. R. Duncan

210

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

211

Fourier Transform Pairs The Fourier transform transforms a function of  

E-print Network

Fourier Transform Pairs The Fourier transform transforms a function of time, f(t), into a function of frequency, F(s): F {f(t)}(s) = F(s) = Z - f(t)e- j2st dt. The inverse Fourier transform transforms a func. The inverse Fourier transform of the Fourier trans- form is the identity transform: f(t) = Z - Z - f()e- j2s

Masci, Frank

212

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

213

Transformation & Metamorphosis  

ERIC Educational Resources Information Center

The sculptures of Canadian artist Brian Jungen are a great inspiration for a lesson on creating new forms. Jungen transforms found objects into unique creations without fully concealing their original form or purpose. Frank Stella's sculpture series, including "K.132,2007" made of stainless steel and spray paint, is another great example of…

Lott, Debra

2009-01-01

214

Transforming Schools.  

ERIC Educational Resources Information Center

The authors in this book address the issues that relate to the crisis in American education and review some of the proposed solutions. To transform education, schools must be examined as social systems that are interrelated with families, communities, and the world of work. Following the introduction, section 1, "Conditions for Educational…

Cookson, Peter W., Jr., Ed.; Schneider, Barbara, Ed.

215

Transformation Optics  

NASA Astrophysics Data System (ADS)

Transformation optics applies ideas from Einstein's general theory of relativity in optical and electrical engineering for designing devices that can do the (almost) impossible: invisibility cloaking, perfect imaging, levitation, and the creation of analogues of the event horizon. This chapter gives an introduction to this field requiring minimal prerequisites.

Leonhardt, Ulf

216

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

217

Rapid characterization and identification of fatty acids in margarines using horizontal attenuate total reflectance Fourier transform infrared spectroscopy (HATR-FTIR)  

Microsoft Academic Search

Fourier transform infrared spectroscopy (FTIR) with horizontal attenuated total reflectance (HATR) coupled to multivariate\\u000a analysis was used to predict chemical composition, fatty acid profile, nutritional relationships between fatty acids, and\\u000a to identify trans fatty acids (TFA) of margarines. For model building and validation, a set of 42 margarines samples were\\u000a analyzed in terms of fatty acid profile, total fat, moisture,

Maylet Hernández-Martínez; Tzayhri Gallardo-Velázquez; Guillermo Osorio-Revilla

2010-01-01

218

DNA Sequence and Characterization ofHaemophilus influenzae dprA1, a Gene Required for Chromosomal but Not Plasmid DNA Transformation  

Microsoft Academic Search

to encode a 41.6-kDa polypeptide that was required for efficient chromosomal but not plasmid DNA transfor- mation. Analysis of the deduced amino acid sequence of DprA suggested that it may be an inner membrane protein, which is consistent with its apparent role in DNA processing during transformation. Four other open reading frames (ORFs) on the cloned DNA segment were identified.

SUREKHA KARUDAPURAM; XUMEI ZHAO; ANDGERARD J. BARCAK

1995-01-01

219

Vectors for cloning in cyanobacteria: Construction and characterization of two recombinant plasmids capable of transformation to Escherichia coli K12 and Anacystis nidulans R2  

Microsoft Academic Search

Two plasmids were constructed consisting of the E. coli vector pACYC184 and the cyanobacterial plasmid pUC1. These recombinants, designated pUC104 and pUC105, can be transformed to E. coli K12 as well as to the cyanobacterium Anacystis nidulans R2 and in both hosts they express their antibiotic markers. pUC104 and pUC105 differ with respect to the location and the orientation of

C. J. Kuhlemeier; W. E. Borrias; C. A. M. J. J. van den Hondel; G. A. van Arkel

1981-01-01

220

Isolation and Characterization of Three Streptococcus pneumoniae Transformation-Specific Loci by Use of a lacZ Reporter Insertion Vector  

Microsoft Academic Search

Although more than a dozen new proteins are produced when Streptococcus pneumoniae cells become com- petent for genetic transformation, only a few of the corresponding genes have been identified to date. To find genes responsible for the production of competence-specific proteins, a random lacZ transcriptional fusion library was constructed in S. pneumoniae by using the insertional lacZ reporter vector pEVP3.

EKATERINA V. PESTOVA; DONALD A. MORRISON

1998-01-01

221

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

222

Isolation and characterization of a bacteriophage factor that confers competence for genetic transformation to an exfoliative toxin-producing strain of Staphylococcus aureus.  

PubMed

Competence for genetic transformation in an exfoliative toxin-producing strain of Staphylococcus aureus was shown to be dependent on a virion factor that was isolated from a crude bacteriophage 80 alpha lysate. This competence-conferring factor was completely separated from infectious virus particles after either centrifugation through a neutral sucrose velocity gradient or fractionation on a Sepharose 2B gel. Since the competence-conferring factor tends to aggregate, optimal separation was obtained after treatment of the phage factor with the detergent Nonidet P-40. The competence-conferring factor had a molecular weight between 3 X 10(6) and 20 X 10(6) and an approximate sedimentation coefficient of 252. The factor was neutralized after interaction with antiserum prepared against isolated infectious 80 alpha virions. Electron microscopy of transforming cells that were exposed to isolated competence-conferring factor revealed a significant number of abnormally long and aggregated phage tail-like structures attached to the surface of recipient cells. This phenomenon was only observed in the presence of donor DNA, indicating that a phage tail-DNA-surface receptor complex might be one of the early steps in DNA-mediated transformation of S. aureus. PMID:6219953

Jackson, M P; DeSena, J; Lednicky, J; McPherson, B; Haile, R; Garrison, R G; Rogolsky, M

1983-02-01

223

Sequential cytogenetic and molecular cytogenetic characterization of an SV40T-immortalized nasopharyngeal cell line transformed by Epstein-Barr virus latent membrane protein-1 gene.  

PubMed

Cytogenetic and molecular cytogenetic analyses were performed on four sublines derived from a newly established, SV40T-immortalized nasopharyngeal (NP) cell line, NP69, with two of the sublines expressing LMP1, an Epstein-Barr virus-encoded gene. A total of seven cytogenetically related subclones were identified, all having highly complex karyotypes with massive numerical and structural rearrangements. Centromeric rearrangements in the form of isochromosomes and whole-arm translocations were prevalent. A cytogenetic sign of gene amplification [i.e., homogeneously staining region (HSR)] was detected at 1q25 in all metaphase cells analyzed. Multicolor combined binary ratio labeling fluorescence in situ hybridization (COBRA-FISH) was used to confirm the karyotypic interpretations. Furthermore, multicolor COBRA-FISH also showed that part of the HSR contained chromosome 20 material. Extensive clonal evolution could be observed by the assessment of karyotypic variation among different subclones and individual metaphase cells. The evaluation of clonal evolution enabled the identification of the temporal order of chromosome aberrations during cell immortalization and malignant transformation. A striking karyotypic similarity was found between sublines expressing LMP1 and an NP carcinoma cell line, with loss of genetic material from chromosome arm 3p being an important recurrent observation. More interestingly, the karyotypic features of NP69 were also similar to those of many epithelial malignancies. Our observations suggest that serial transformation of NP cell lines might provide a useful in vitro model for the study of the multistep neoplastic transformation of NP cells. PMID:15066322

Zhang, Hao; Tsao, Sai Wah; Jin, Charlotte; Strömbeck, Bodil; Yuen, Po Wing; Kwong, Yok-Lam; Jin, Yuesheng

2004-04-15

224

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

225

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.

226

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

227

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

228

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

229

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

230

Corn transformed  

SciTech Connect

Researchers have produced fertile corn transformed with a foreign gene that makes the plants resistant to the herbicide bialaphos. This achievement, is the first report of fertile transgenic corn in the reviewed literature, and it is the capstone of almost a decade's efforts to genetically engineer this country's most important crop. The only other major crop to be so manipulated is rice. The ability produce transgenic corn gives biologists a valuable tool to probe the whys and hows of gene expression and regulation. It may also give plant breeders a way to develop new corn varieties with a speed and predictability that would be impossible with classical breeding techniques.

Moffat, A.S.

1990-08-10

231

In-situ CIR-FTIR (cylindrical internal reflection/Fourier transform infrared) characterization of salicylate complexes at the goethite/aqueous solution interface  

SciTech Connect

The types of complexes that salicylate (2-hydroxy-benzoate) forms with the surface of goethite ({alpha}-FeOOH) in aqueous medium were studied in situ by using cylindrical internal reflection (CIR) Fourier transform infrared (FTIR) spectroscopy. Results obtained from CIR-FTIR studies were compared with adsorption isotherm experiments in order to relate the level of salicylate coverage to the nature of the surface complex. At lower surface coverages all the interfacial salicylate has a chelate structure in which one carboxylic oxygen and the ortho phenolic oxygen bind one Fe atom of the goethite surface. At higher surface coverages this chelate complex coexists with salicylate ions, which are weakly bound in the double layer.

Yost, E.C.; Tejedor-Tejedor, M.I.; Anderson, M.A. (Univ. of Wisconsin, Madison (USA))

1990-06-01

232

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

233

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

234

Special Features of Admittance in Mis Structures Based on Graded-Gap MBE n-Hg1- x Cd x Te ( x = 0.31-0.32) in a Temperature Range OF 8-300 K  

NASA Astrophysics Data System (ADS)

Admittance of MIS structures based on graded-gap n-Hg1- ? Cd ? Te ( x = 0.31-0.32) grown by molecular beam epitaxy (MBE) is investigated in a wide temperature range (8-300 K). It is shown that the temperature and frequency dependences of the differential resistance of space charge region for structures with a graded-gap layer are qualitatively similar to those for structures without a graded-gap layer. It is found that for MIS structures based on MBE n-Hg1- ? Cd ? Te ( x = 0.31-0.32), regardless of the presence of a graded-gap layer, the differential resistance of space charge region is limited by the processes of Shockley-Read generation in the temperature range of 25-100 K.

Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.; Vasil'ev, V. V.; Varavin, V. S.; Dvoretskii, S. A.; Mikhailov, N. N.; Kuz'min, V. D.; Remesnik, V. G.

2014-09-01

235

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

236

An integrated approach to characterization of microbial exudates and investigation of their role in the spatial distribution and transformations of uranium at the mineral-microbe interface  

SciTech Connect

The long-term aim of this project was to understand the role of microbiota and their polymers (EPS) in controlling the distribution and fates of contaminants in subsurface environments. Additionally, this project also focused on the identification and characterization of extracellular proteins under a variety of growth conditions. Finally, this project sought to develop and advance the use of a variety of synchrotron-based hard-x-ray techniques to address a number of different ERSP elements.

Kemner, K.M.; O'Loughlin, E.J.; Kelly, S.D.; Nealson, K.H.

2006-06-01

237

Genesis of a Cerium Oxide-Supported Gold Catalyst for CO Oxidation: Transformation of Mononuclear Gold Complexes into Clusters as Characterized by X-Ray Absorption Spectroscopy  

SciTech Connect

CeO{sub 2}-supported mononuclear gold species synthesized from Au(CH{sub 3}){sub 2}(acac) catalyzed CO oxidation at 353 K, with a turnover frequency of 6.5 x 10{sup -3} molecules of CO (Au atom s){sup -1} at CO and O{sub 2} partial pressures of 1.0 and 0.5 kPa, respectively. As the catalyst functioned in a flow reactor, the activity increased markedly so that within about 10 h the conversion of CO had increased from about 1% to almost 100%. Activated catalyst samples were characterized by X-ray absorption spectroscopy and found to incorporate clusters of gold, which increased in size, undergoing reduction, with increasing time of operation. The X-ray absorption near-edge structure spectrum of the catalyst used for the longest period was indistinguishable from that characterizing gold foil. Extended X-ray absorption fine structure data characterizing the catalyst after the longest period of operation indicated the presence of clusters of approximately 30 Au atoms each, on average. The evidence that the catalytic activity increased as the clusters grew is contrasted with earlier reports pointing to increasing activity of supported gold clusters as they were made smallerin a cluster size range largely exceeding ours.

Aguilar-Guerrero, V.; Lobo-Lapidus, R; Gates, B

2009-01-01

238

Transforming vulnerability.  

PubMed

Asian American immigrant women engaged in filial caregiving are at special risk for health problems due to complex contextual factors related to immigration, cultural traditions, and role transition. This study examines the experience of two groups of immigrant Asian American women who are caring for older parents. A total of 41 women (22 Chinese American and 19 Filipino American) were interviewed in a study based on Strauss and Corbin's grounded theory methodology. The women were determined to be loyal to their traditional culture, which included strong filial values, while adapting to a new culture. Through the struggle of meeting role expectations and coping with paradox, the women mobilized personal and family resources to transform vulnerability into strength and well-being. PMID:14596182

Jones, Patricia S; Zhang, Xinwei Esther; Meleis, Afaf I

2003-11-01

239

Characterization of photo-transformation products of the antibiotic drug Ciprofloxacin with liquid chromatography-tandem mass spectrometry in combination with accurate mass determination using an LTQ-Orbitrap.  

PubMed

The presence of pharmaceuticals, especially antibiotics, in the aquatic environment is of growing concern. Several studies have been carried out on the occurrence and environmental risk of these compounds. Ciprofloxacin (CIP), a broad-spectrum anti-microbial second-generation fluoroquinolone, is widely used in human and veterinary medicine. In this work, photo-degradation of CIP in aqueous solution using UV and xenon lamps was studied. The transformation products (TPs), created from CIP, were initially analyzed by an ion trap in the MS, MS/MS and MS(3) modes. These data were used to clarify the structures of the degradation products. Furthermore, the proposed products were confirmed by accurate mass measurement and empirical formula calculation for the molecular ions of TPs using LTQ-Orbitrap XL mass spectrometer. The degree of mineralization, the abundance of detected TPs and degradation pathways were determined. Eleven TPs were detected in the present study. TP1, which was never detected before, was structurally characterized in this work. All TPs still retained the core quinolone structure, which is responsible for the biological activity. As mineralization of CIP and its transformation products did not happen, the formation of stable TPs can be expected in waste water treatment and in surface water with further follow-up problems. PMID:24630245

Haddad, Tarek; Kümmerer, Klaus

2014-11-01

240

Characterization of crude oils at the molecular level by use of laser desorption ionization Fourier-transform ion cyclotron resonance mass spectrometry.  

PubMed

In this study, laser desorption ionization (LDI) coupled to Fourier-transform ion cyclotron resonance mass spectrometry (FTICR MS) was applied to study crude oils at the molecular level. Molecular ions were the major type of ion detected by (+) mode, and deprotonated and radical anions were the major ions observed by (-) mode LDI FTICR MS. N(1) and hydrocarbon classes were dominant in the class distribution plots obtained by (+) LDI FTICR MS, but other heteroatom classes, including O(x) and S(1), were abundant in plots obtained by (-) LDI FTICR MS. Detailed analysis of double-bond equivalence (DBE) vs carbon number plots revealed that LDI FTICR MS is more sensitive toward polyaromatic compounds than mono- or dicyclic-aromatic compounds. However, nonaromatic and aromatic O(2) compounds could be detected simultaneously. An abundance of nonaromatic O(2) compounds (presumably naphthenic acids) are correlated with total acid numbers, but O(2) compounds with condensed structures are not. Overall, this study shows that LDI FTICR MS can be successfully used to study crude oils at the molecular level. PMID:22954288

Cho, Yunju; Witt, Matthias; Kim, Young Hwan; Kim, Sunghwan

2012-10-16

241

Characterization of Inhomogeneity in Silicon Dioxide Films on 4H-Silicon Carbide Epitaxial Substrate Using a Combination of Fourier Transform Infrared and Cathodoluminescence Spectroscopy.  

PubMed

We measured the Fourier transform infrared (FT-IR) and cathodoluminescence (CL) spectra of silicon dioxide (SiO2) films grown on 4H-silicon carbide (4H-SiC) substrates and confirmed that the phonon observed at around 1150-1250 cm(-1) originates from the upper branch of the surface phonon polaritons (SPPs) in the SiO2 films and that its frequency is sensitive to the oxide thickness. The relative intensity of the upper branch of SPPs normalized by that of the transverse optical phonon (TO) tended to increase with decreasing channel mobility (CM). A comparison of the FT-IR and CL measurements shows that the relative intensity is correlated with an inhomogeneity in the SiO2-SiC interface and the CM of SiC devices. A combination of FT-IR spectroscopy and CL spectroscopy provides us with a large amount of data on the inhomogeneity, defect, and oxide thickness of SiO2 films on 4H-SiC substrates. PMID:25198339

Yoshikawa, Masanobu; Seki, Hirohumi; Inoue, Keiko; Nanen, Yuichiro; Kimoto, Tsunenobu

2014-10-01

242

EDITORIAL: Transformation optics Transformation optics  

NASA Astrophysics Data System (ADS)

Metamaterials are artificial materials with versatile properties that can be tailored to fit almost any practical need and thus go well beyond what can be obtained with `natural' materials. Recent progress in developing optical metamaterials allows unprecedented extreme control over the flow of light at both the nano- and macroscopic scales. The innovative field of transformation optics, which is enabled by metamaterials, inspired researchers to take a fresh look at the very foundations of optics and helped to create a new paradigm for the science of light. Similar to general relativity, where time and space are curved, transformation optics shows that the space for light can also be bent in an almost arbitrary way. Most importantly, the optical space can be designed and engineered, opening up the fascinating possibility of controlling the flow of light with nanometer spatial precision. This new paradigm enables a number of novel optical devices guiding how, using metamaterials, the space for light can be curved in a pre-designed and well-controlled way. Metamaterials which incorporate the innovative theories of transformation optics are pertinent to the important areas of optical cloaking, optical black holes, super-resolution imaging, and other sci-fi-like devices. One such exciting device is an electromagnetic cloak that can bend light around itself, similar to the flow of water around a stone, making invisible both the cloak and the object hidden inside. Another important application is a flat hyperlens that can magnify the nanometer-scale features of an object that cannot be resolved with conventional optics. This could revolutionize the field of optical imaging, for instance, because such a meta-lens could become a standard add-on tool for microscopes. By enabling nanoscale resolution in optical microscopy, metamaterial-based transformation optics could allow one to literally see extremely small objects with the eye, including biological cells, viruses, and possibly even DNA molecules. Light-concentrating devices, such as the optical black hole, can be used for efficient solar light collection in photovoltaic elements for renewable energy. With the dramatic advances in micro- and nanofabrication methods, we are presented with the opportunity to control light in a way that was not possible with the materials provided to us by nature. In an artificial pattern of sub-wavelength elements, the propagation of electromagnetic energy can be defined by an equivalent spatial and spectral dispersion of effective dielectric and magnetic properties. These synthetic structures, which can be fabricated with a desired spatial distribution of effective permittivity epsilon(r) and permeability ?(r), offer a unique potential to guide and control the flow of electromagnetic energy in such an engineered optical space. No longer are we constrained by the electromagnetic response of natural materials and their chemical compounds. Instead, we can tailor the shape and size of the structural units of the metamaterials, or tune their composition and morphology to provide new functionality.

Shalaev, Vladimir M.; Pendry, John

2011-02-01

243

Characterization of high rate composting of vegetable market waste using Fourier transform-infrared (FT-IR) and thermal studies in three different seasons.  

PubMed

Fourier transform-infrared (FT-IR), Thermogravimetry (TG), Differential thermal analyses (DTA) and Differential Thermogravimetric (DTG) studies of a mixture of vegetable waste, saw dust, tree leaves and cow dung for microbial activity (feedstock) and their compost were reported in three different seasons i.e. winter, spring and summer. The correlation between spectral studies and compost composition provide information regarding their stability and maturity during composting. FT-IR spectra were conferred the functional groups and their intensity and TG, DTG and DTA for wt. loss, rate of wt. loss and enthalpy change in compost. Weight loss in feedstock and compost at two different temperatures 250-350 and 350-500°C was found 38.06, 28.15% for inlet and 14.08, 25.67% for outlet zones in summer and 50.59, 29.76% for inlet and 18.08, 25.67% in outlet zones in spring season, higher (5-10%) than winter. The corresponding temperatures in DTA in the samples from inlet to outlet zone were; endotherm (100-200°C), due to dehydration, exotherm (300-320°C), due to peptidic structure loss and exotherm (449-474°C) due to the loss of polynuclear aromatic structures, which were higher by 4°C and 10-20°C and rate of wt. loss was higher by 5-10% in spring and summer season, respectively than winter season composting, reported regardless of the maturation age of the compost. Relative intensity of exotherms (300-320/449-474°C) gave the thermally more stable fractions of organic compound. Our results indicated that the rotary drum composting of organic matters in spring and summer season gave higher molecular complexity and stability than the winter season. PMID:21814814

Ali, Muntjeer; Bhatia, Akansha; Kazmi, A A; Ahmed, Naseem

2012-04-01

244

RANK ESTIMATORS FOR A TRANSFORMATION MODEL  

Microsoft Academic Search

We establish [square root]n-consistency and asymptotic normality of Han s (1987a, Journal of Econometrics 35, 191 209) estimator of the parameters characterizing the transformation function in a semiparametric transformation model. We verify a Vapnik Cervonenkis (VC) condition for the parameterizations of Box and Cox (1964, Journal of the Royal Statistical Society, Series B 34, 187 200) and Bickel and Doksum

Elena Asparouhova; Robert Golanski; Krzysztof Kasprzyk; Robert P. Sherman; Tihomir Asparouhov

2002-01-01

245

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

246

On Admissible States of Quantum Fourier Transform  

E-print Network

We present a general methodology to obtain the basis of qudits which are admissible to Quantum Fourier Transform (QFT). We first study this method for qubits to characterize the ensemble that works for the Hadamard transformation (QFT for two dimension). In this regard we identify certain incompleteness in the result of Maitra and Parashar (IJQI, 2006). Next we characterize the ensemble of qutrits for which QFT is possible. Further, some theoretical results related to higher dimensions are also discussed.

Arpita Maitra; Santanu Sarkar

2011-09-21

247

Molecular Characterization and Reactivity of Dissolved Organic Matter by High Resolution Nanospray Ionization Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS)  

NASA Astrophysics Data System (ADS)

The ultrahigh resolving power of FTICR-MS allows for the intense characterization of dissolved organic matter (DOM). DOM is the largest reactive component of the global carbon cycle, and an improved understanding of its composition is necessary to determine the transport and eventual fate of pollutants. The seasonal and spatial variations in DOM composition are investigated by taking surface water samples from five different sampling sites, four times a year. Water sampling begins at the Dismal Swamp in North Carolina, continues north up the Elizabeth River to the Chesapeake Bay, and concludes approximately ten miles off the coast in the Atlantic Ocean. DOM was extracted from the water samples using C18 extraction disks and were prepared in 50:50 methanol:water. Ammonium hydroxide was added prior to nanospray in order to solubilize the DOM as well as to increase the ionization efficiency. The samples were continuously infused into the Apollo II ion source with an Advion TriVersa NanoMate system of a Bruker 12 Tesla Apex QE FTICR-MS with resolving powers exceeding 400,000. All samples were analyzed in negative ion mode and were externally and internally calibrated prior to data analysis. Our DOM mass spectra consist of a multitude of peaks spanning the range of 200-850 m/z. Complexity is apparent from the detection of up to 20 peaks per nominal mass at nearly every mass throughout that range. A molecular formula calculator generated molecular formula matches from which van Krevelen plots were constructed for characterization purposes. A wide range of molecules were observed each containing oxygen, sulfur and nitrogen functional groups. We utilize the van Krevelen diagram to assist in clustering the molecules according to their functional group compositions. To test the hypothesis that formation of adducts to DOM serve to protect peptides from bacterial degradation, microcosm experiments were performed with a small isotopically enriched peptide, GGGR. This peptide was predicted to covalently bond to DOM via a Michael addition reaction or Schiff base formation. Following the incubation of GGGR with DOM, adduct formation was examined by FTICR-MS. Covalent binding of GGGR to DOM is a process that may reduce the bioavailability and degradation of proteins in the environment and could potentially lead to their preservation on longer time scales. FTICR-MS is clearly a powerful technique used to examine the complex composition of DOM and allow for advancements in the areas of aquatic and analytical chemistry.

Sleighter, R. L.; Hatcher, S. A.; Hatcher, P. G.

2006-12-01

248

Martensitic transformation in zirconia  

Microsoft Academic Search

Main characteristics of martensitic transformations in metals and alloys ; are described, and available data on the monoclinic-tetragonal transformation in ; ZrOâ are critically evaluated. Kinetics, thermal hysteresis, tetragonal -- ; cubic transformation, metastable high-temperature phases, and pressure and ; irradiationinduced transformation are discussed. Transformation in HfOâ is ; also briefly examined. (9 tables, 22 figures, 108 references) (DLC);

E. C. Subbarao; H. S. Maiti; K. K. Srivastava

1974-01-01

249

Analyzing Signals Fourier transform  

E-print Network

Page 1 1 Analyzing Signals Fourier transform s frequency content s linear combination of sin frequency analysis s windowed Fourier transform 6 #12;Page 4 7 Gabor Transform function to analyze window Gabor Transform Spatial domain Gabor domain b #12;Page 5 9 Gabor Transform Problems s discrete version

Sweldens, Wim

250

Efficiency of Deterministic Entanglement Transformation  

E-print Network

We prove that sufficiently many copies of a bipartite entangled pure state can always be transformed into some copies of another one with certainty by local quantum operations and classical communication. The efficiency of such a transformation is characterized by deterministic entanglement exchange rate, and it is proved to be always positive and bounded from top by the infimum of the ratios of Renyi's entropies of source state and target state. A careful analysis shows that the deterministic entanglement exchange rate cannot be increased even in the presence of catalysts. As an application, we show that there can be two incomparable states with deterministic entanglement exchange rate strictly exceeding 1.

Runyao Duan; Yuan Feng; Zhengfeng Ji; Mingsheng Ying

2004-10-06

251

On the positivity of Fourier transforms  

E-print Network

Characterizing in a constructive way the set of real functions whose Fourier transforms are positive appears to be yet an open problem. Some sufficient conditions are known but they are far from being exhaustive. We propose two constructive sets of necessary conditions for positivity of the Fourier transforms and test their ability of constraining the positivity domain. One uses analytic continuation and Jensen inequalities and the other deals with Toeplitz determinants and the Bochner theorem. Applications are discussed, including the extension to the two-dimensional Fourier-Bessel transform and the problem of positive reciprocity, i.e. positive functions with positive transforms.

Bertrand G. Giraud; Robi Peschanski

2014-05-13

252

Classification of transforms  

NASA Astrophysics Data System (ADS)

Lindsey and Suter have shown that for many transforms the transform of the convolution of two functions have the same functional form. We explain the origin of this result and derive the condition on the transformation kernel for when this should be the case. In addition we consider the general transform of the inverse and direct scale transform and obtain condition on the kernel so that the transform gives similar functional forms.

Cohen, Leon; Lindsey, Alan R.; Suter, Bruce W.

2000-12-01

253

Heterospecific transformation among cyanobacteria.  

PubMed Central

Heterospecific transformation occurred between cyanobacteria currently classified in either the genus Synechococcus or Synechocystis. Cyanobacterial strains 73109 and 6906 were capable of physiological transformation. PMID:3091578

Stevens, S E; Porter, R D

1986-01-01

254

Structural characterization and physical properties of P2O5-CaO-Na2O-TiO2 glasses by Fourier transform infrared, Raman and solid-state magic angle spinning nuclear magnetic resonance spectroscopies.  

PubMed

Phosphate-based glasses have been investigated for tissue engineering applications. This study details the properties and structural characterization of titanium ultra-phosphate glasses in the 55(P(2)O(5))-30(CaO)-(25-x)(Na(2)O)-x(TiO(2)) (0?x?5) system, which have been prepared via melt-quenching techniques. Structural characterization was achieved by a combination of X-ray diffraction (XRD), and solid-state nuclear magnetic resonance, Raman and Fourier transform infrared spectroscopies. Physical properties were also investigated using density, degradation and ion release studies; additionally, differential thermal analysis was used for thermal analysis of these glasses. The results show that with the addition of TiO(2) the density and glass transition temperature increased whereas the degradation and ion release properties are decreased. From XRD data, TiP(2)O(7) and CaP(2)O(6) were detected in 3 and 5 mol.% TiO(2)-containing glasses. Magic angle spinning nuclear magnetic resonance results confirmed that as TiO(2) is incorporated into the glass; the amount of Q(3) increases as the amount of Q(2) consequently decreases, indicating increasing polymerization of the phosphate network. Spectroscopy results also showed that the local structure of glasses changes with increasing TiO(2) content. As TiO(2) is incorporated into the glass, the phosphate connectivity increases, indicating that the addition of TiO(2) content correlates unequivocally with an increase in glass stability. PMID:21930253

Kiani, Azadeh; Hanna, John V; King, Scott P; Rees, Gregory J; Smith, Mark E; Roohpour, Nima; Salih, Vehid; Knowles, Jonathan C

2012-01-01

255

Transforming DNA Uptake Gene Orthologs Do Not Mediate Spontaneous Plasmid Transformation in Escherichia coli  

Microsoft Academic Search

Spontaneous plasmid transformation of Escherichia coli occurs on nutrient-containing agar plates. E. coli has also been reported to use double-stranded DNA (dsDNA) as a carbon source. The mechanism(s) of entry of exogenous dsDNA that allows plasmid establishment or the use of DNA as a nutrient remain(s) unknown. To further characterize plasmid transformation, we first documented the stimulation of transformation by

Dongchang Sun; Xuewu Zhang; Lingyu Wang; Marc Prudhomme; Zhixiong Xie; Bernard Martin; Jean-Pierre Claverys

2009-01-01

256

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

257

Glowing Bacteria: Transformation Efficiency  

E-print Network

took up and expressed GFP after transformation. Background: Transformation efficiency is a quantitative1 Glowing Bacteria: Transformation Efficiency Purpose: To determine how well your E. coli cells. The number represents how many cells were transformed per microgram (µg) of plasmid DNA used

Rose, Michael R.

258

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

259

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

260

Transforming human gait for signature signals characterization  

NASA Astrophysics Data System (ADS)

An integrated wireless inductive sensor is reported based on a system for monitoring human movement and body size. The proposed system senses the presence of human beings using electromagnetic field by making use of basic inductive coupling approach, hence analysing the performance of human monitoring. The amalgamation of the integrated system proposed will help in providing better services to the elderly people resided in healthcare centres. The developed sensing system is of low cost, flexible, robust, and easily implantable and capable of inductive sensing through marking signature waveforms as a result of human movements.

Arshad, Atika; Fadzil Ismail, Ahmad; Khan, Sheroz; Zahirul Alam, A. H. M.; Tasnim, Rumana; Samnan Haider, Syed; Shobaki, Mohammed M.; Shahid, Zeeshan

2013-12-01

261

Transforming America's Energy Economy Transforming America's  

E-print Network

to ensure our energy security and to mitigate the environmental consequences associated with our current outlined in this white paper are driven by energy security and climate change concerns. Energy security#12;Transforming America's Energy Economy Transforming America's Energy Economy This document

262

Arsenic(V) Reduction in Relation to Iron(III) Transformation and Molecular Characterization of the Structural and Functional Microbial Community in Sediments of a Basin-Fill Aquifer in Northern Utah  

PubMed Central

Basin-fill aquifers of the Southwestern United States are associated with elevated concentrations of arsenic (As) in groundwater. Many private domestic wells in the Cache Valley Basin, UT, have As concentrations in excess of the U.S. EPA drinking water limit. Thirteen sediment cores were collected from the center of the valley at the depth of the shallow groundwater and were sectioned into layers based on redoxmorphic features. Three of the layers, two from redox transition zones and one from a depletion zone, were used to establish microcosms. Microcosms were treated with groundwater (GW) or groundwater plus glucose (GW+G) to investigate the extent of As reduction in relation to iron (Fe) transformation and characterize the microbial community structure and function by sequencing 16S rRNA and arsenate dissimilatory reductase (arrA) genes. Under the carbon-limited conditions of the GW treatment, As reduction was independent of Fe reduction, despite the abundance of sequences related to Geobacter and Shewanella, genera that include a variety of dissimilatory iron-reducing bacteria. The addition of glucose, an electron donor and carbon source, caused substantial shifts toward domination of the bacterial community by Clostridium-related organisms, and As reduction was correlated with Fe reduction for the sediments from the redox transition zone. The arrA gene sequencing from microcosms at day 54 of incubation showed the presence of 14 unique phylotypes, none of which were related to any previously described arrA gene sequence, suggesting a unique community of dissimilatory arsenate-respiring bacteria in the Cache Valley Basin. PMID:24632255

Mirza, Babur S.; Muruganandam, Subathra; Meng, Xianyu; Sorensen, Darwin L.; Dupont, R. Ryan

2014-01-01

263

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

264

Performance measures for transform data coding.  

NASA Technical Reports Server (NTRS)

This paper develops performance criteria for evaluating transform data coding schemes under computational constraints. Computational constraints that conform with the proposed basis-restricted model give rise to suboptimal coding efficiency characterized by a rate-distortion relation R(D) similar in form to the theoretical rate-distortion function. Numerical examples of this performance measure are presented for Fourier, Walsh, Haar, and Karhunen-Loeve transforms.

Pearl, J.; Andrews, H. C.; Pratt, W. K.

1972-01-01

265

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

266

Solid State Power Transformer.  

National Technical Information Service (NTIS)

Apparatus for providing the voltage transformation functions of a conventional electrical power transformer. An AC input signal is chopped in a solid state switching converter at a frequency very much larger than the frequency of the input signal and then...

J. L. Brooks, R. I. Staab, J. C. Bowers, H. A. Nienhaus

1980-01-01

267

Landscapes of transformation  

E-print Network

This thesis aims to examine the cultural effect of transformation through the lens of procedural techniques applied to the human body and architecture. The body and architecture both operate as landscapes of transformation. ...

Ambs, Emily (Emily Kiersten)

2007-01-01

268

Metrics for enterprise transformation  

E-print Network

The objective of this thesis is to depict the role of metrics in the evolving journey of enterprise transformation. To this end, three propositions are explored: (i) metrics and measurement systems drive transformation, ...

Blackburn, Craig D. (Craig David), S. M. Massachusetts Institute of Technology

2009-01-01

269

Influence of composition of the near-surface graded-gap layer on the admittance of metal-insulator-semiconductor structures based on graded-gap MBE n-Hg1-xCdxTe in wide temperature range  

NASA Astrophysics Data System (ADS)

Influence of the CdTe content in a near-surface graded-gap layer on the admittance of MIS-structures fabricated on the basis of heteroepitaxial Hg1-xCdxTe (x = 0.22-0.23 and 0.31-0.32) films grown by molecular beam epitaxy was investigated in a wide temperature range. It is shown that a temperature drop from 77 K to 8 K results in a decrease of hysteresis of the capacitance-voltage (C-V) characteristics and a decrease of frequencies which corresponds to a high-frequency behaviour of C-V characteristics of MIS-structures based on n-HgCdTe (x = 0.22-0.23) with and without graded-gap layersand also for MIS-structures based on n-HgCdTe (x = 0.31-0.32). Temperature dependences of the resistance of the epitaxial film bulk and differential resistance of the space-charge region (SCR) in strong inversion mode were studied. The experimental results can be explained by the fact that for MIS-structures based on n-HgCdTe (x = 0.22-0.23) with the graded-gap layers and for MIS-structures based on n-HgCdTe (x = 0.31-0.32), the differential resistance of SCR is limited by Shockley-Read generation at 25-77 K. Differential resistance of SCR for MIS-structures based on n-HgCdTe (x = 0.22-0.23) without the graded-gap layers is limited by tunnelling through deep levels at 8-77 K.

Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.

2014-12-01

270

Influence of composition of the near-surface graded-gap layer on the admittance of metal-insulator-semiconductor structures based on graded-gap MBE n-Hg1-xCdxTe in wide temperature range  

NASA Astrophysics Data System (ADS)

Influence of the CdTe content in a near-surface graded-gap layer on the admittance of MIS-structures fabricated on the basis of heteroepitaxial Hg1-xCdxTe (x = 0.22-0.23 and 0.31-0.32) films grown by molecular beam epitaxy was investigated in a wide temperature range. It is shown that a temperature drop from 77 K to 8 K results in a decrease of hysteresis of the capacitance-voltage (C-V) characteristics and a decrease of frequencies which corresponds to a high-frequency behaviour of C-V characteristics of MIS-structures based on n-HgCdTe (x = 0.22-0.23) with and without graded-gap layersand also for MIS-structures based on n-HgCdTe (x = 0.31-0.32). Temperature dependences of the resistance of the epitaxial film bulk and differential resistance of the space-charge region (SCR) in strong inversion mode were studied. The experimental results can be explained by the fact that for MIS-structures based on n-HgCdTe (x = 0.22-0.23) with the graded-gap layers and for MIS-structures based on n-HgCdTe (x = 0.31-0.32), the differential resistance of SCR is limited by Shockley-Read generation at 25-77 K. Differential resistance of SCR for MIS-structures based on n-HgCdTe (x = 0.22-0.23) without the graded-gap layers is limited by tunnelling through deep levels at 8-77 K.

Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.

2014-09-01

271

Power electronics traction transformer  

Microsoft Academic Search

With the new generation of full low floor passenger trains, the constraints of weight and size on the traction transformer are becoming stronger. The ultimate target weight for the transformer is 1 kg\\/kVA. The reliability and the efficiency are also becoming more important. To address these issues, a multilevel topology using medium frequency transformers has been developed. It permits to

Nicolas Hugo; Philippe Stefanutti; Marc Pellerin; Alper Akdag

2007-01-01

272

Review article Genetic transformation  

E-print Network

Review article Genetic transformation: a short review of methods and their applications, results of phenotypic traits has been examined. Agrobacterium I biotechnology I forest tree I genetic transformation Biotechnology includes tissue culture, mo- lecular biology and genetic transformation. This field of research

Paris-Sud XI, Université de

273

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

274

Transforming Anxiety into ENERGYTM  

E-print Network

Transforming Anxiety into ENERGYTM How to Prevent Panic and Promote Productivity in Turbulent Times By Wendy Mack with contributions from Meredith Kimbell and Myron Radio #12;Transforming Anxiety into Energy, consultants, and researchers who shared their stories and expertise. 1 #12;Transforming Anxiety into Energy

Maryland, Baltimore County, University of

275

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

276

A dinuclear manganese(II) complex with the [Mn(2)(mu-O(2)CCH(3))(3)](+) core: synthesis, structure, characterization, electroinduced transformation, and catalase-like activity.  

PubMed

Reactions of Mn(II)(PF(6))(2) and Mn(II)(O(2)CCH(3))(2).4H(2)O with the tridentate facially capping ligand N,N-bis(2-pyridylmethyl)ethylamine (bpea) in ethanol solutions afforded the mononuclear [Mn(II)(bpea)](PF(6))(2) (1) and the new binuclear [Mn(2)(II,II)(mu-O(2)CCH(3))(3)(bpea)(2)](PF(6)) (2) manganese(II) compounds, respectively. Both 1 and 2 were characterized by X-ray crystallographic studies. Complex 1 crystallizes in the monoclinic system, space group P2(1)/n, with a = 11.9288(7) A, b = 22.5424(13) A, c =13.0773(7) A, alpha = 90 degrees, beta = 100.5780(10 degrees ), gamma = 90 degrees, and Z = 4. Crystals of complex 2 are orthorhombic, space group C222(1), with a = 12.5686(16) A, b = 14.4059(16) A, c = 22.515(3) A, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, and Z = 4. The three acetates bridge the two Mn(II) centers in a mu(1,3) syn-syn mode, with a Mn-Mn separation of 3.915 A. A detailed study of the electrochemical behavior of 1 and 2 in CH(3)CN medium has been made. Successive controlled potential oxidations at 0.6 and 0.9 V vs Ag/Ag(+) for a 10 mM solution of 2 allowed the selective and nearly quantitative formation of [Mn(III)(2)(mu-O)(mu-O(2)CCH(3))(2)(bpea)(2)](2+) (3) and [Mn(IV)(2)(mu-O)(2)(mu-O(2)CCH(3))(bpea)(2)](3+) (4), respectively. These results have shown that each substitution of an acetate group by an oxo group is induced by a two-electron oxidation of the corresponding dimanganese complexes. Similar transformations have been obtained if 2 is formed in situ either by direct mixing of Mn(2+) cations, bpea ligand, and CH(3)COO(-) anions with a 1:1:3 stoichiometry or by mixing of 1 and CH(3)COO(-) with a 1:1.5 stoichiometry. Associated electrochemical back-transformations were investigated. 2, 3, and the dimanganese [Mn(III)Mn(IV)(mu-O)(2)(mu-O(2)CCH(3))(bpea)(2)](2+) analogue (5) were also studied for their ability to disproportionate hydrogen peroxide. 2 is far more active compared to 3 and 5. The EPR monitoring of the catalase-like activity has shown that the same species are present in the reaction mixture albeit in slightly different proportions. 2 operates probably along a mechanism different from that of 3 and 5, and the formation of 3 competes with the disproportionation reaction catalyzed by 2. Indeed a solution of 2 exhibits the same activity as 3 for the disproportionation reaction of a second batch of H(2)O(2) indicating that 3 is formed in the course of the reaction. PMID:11925172

Romero, Isabel; Dubois, Lionel; Collomb, Marie-Noëlle; Deronzier, Alain; Latour, Jean-Marc; Pécaut, Jacques

2002-04-01

277

Frequency analysis of DC tolerant current transformers  

NASA Astrophysics Data System (ADS)

This article deals with wide frequency range behaviour of DC tolerant current transformers that are usually used in modern static energy meters. In this application current transformers must comply with European and International Standards in their accuracy and DC tolerance. Therefore, the linear DC tolerant current transformers and double core current transformers are used in this field. More details about the problems of these particular types of transformers can be found in our previous works. Although these transformers are designed mainly for power distribution network frequency (50/60 Hz), it can be interesting to understand their behaviour in wider frequency range. Based on this knowledge the new generations of energy meters with measuring quality of electric energy will be produced. This solution brings better measurement of consumption of nonlinear loads or measurement of non-sinusoidal voltage and current sources such as solar cells or fuel cells. The determination of actual power consumption in such energy meters is done using particular harmonics component of current and voltage. We measured the phase and ratio errors that are the most important parameters of current transformers, to characterize several samples of current transformers of both types.

Mlejnek, P.; Kaspar, P.

2013-09-01

278

[Natural transformation in bacteria].  

PubMed

Transformants may be formed by some bacterial species when the growing cultures are mixed. This phenomenon caused by the DNA release from bacterial cells is called natural transformation. DNA release is most likely to be mediated by cell autolysis. Both chromosomal markers and plasmids are transferred by natural transformation. The phenomenon is reproduced while growing bacteria together in sterile soil. The DNA adsorbed on sand and other soil solid particles was more resistant to DNAse action, than the free transforming DNA. Natural transformation seems to be one of the forms of the genetic exchange in bacteria in their habitats. An indirect argument for this suggestion is perfect coordination between the different steps of transformation process, at least, in some bacterial species. PMID:2185417

Kosovich, P V; Prozorov, A A

1990-01-01

279

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

280

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

281

Program Transformation in HATS  

SciTech Connect

HATS is a general purpose syntax derivation tree based transformation system in which transformation sequences are described in special purpose language. A powerful feature of this language is that unification is an explicit operation. By making unification explicit, an elegant framework arises in which to express complex application conditions which in turn enables refined control strategies to be realized. This paper gives an overview of HATS, focusing especially on the framework provided by the transformation language and its potential with respect to control and general purpose transformation.

Winter, V.L.

1999-02-24

282

An experimental study and modeling of Transformer-Coupled Toroidal Plasma processing of materials  

E-print Network

The Transformer Coupled Toroidal Plasma (TCTP) source uses a high power density plasma formed in a toroidal-shaped chamber by transformer coupling using a magnetic core. The objectives of the thesis are (1) to characterize ...

Bai, Bo, Ph. D. Massachusetts Institute of Technology

2006-01-01

283

Transformation Market Transformation is based on  

E-print Network

and reducing high insurance costs. Strategies Market Transformation's primary goal is to accelerate-powered lift trucks. When compared to typical battery-powered units, fuel cell lift trucks provide 80% lower collection and analysis by the National Renewable Energy Laboratory.1 Fuel cell-powered lift trucks offer

284

Disc piezoelectric ceramic transformers.  

PubMed

In this contribution, we present our study on disc-shaped and homogeneously poled piezoelectric ceramic transformers working in planar-extensional vibration modes. Transformers are designed with electrodes divided into wedge, axisymmetrical ring-dot, moonie, smile, or yin-yang segments. Transformation ratio, efficiency, and input and output impedances were measured for low-power signals. Transformer efficiency and transformation ratio were measured as a function of frequency and impedance load in the secondary circuit. Optimum impedance for the maximum efficiency has been found. Maximum efficiency and no-load transformation ratio can reach almost 100% and 52 for the fundamental resonance of ring-dot transformers and 98% and 67 for the second resonance of 2-segment wedge transformers. Maximum efficiency was reached at optimum impedance, which is in the range from 500 ? to 10 k?, depending on the electrode pattern and size. Fundamental vibration mode and its overtones were further studied using frequency-modulated digital holographic interferometry and by the finite element method. Complementary information has been obtained by the infrared camera visualization of surface temperature profiles at higher driving power. PMID:25004532

Erhart, Jirií; P?lpán, Petr; Dole?ek, Roman; Psota, Pavel; Lédl, Vít

2013-08-01

285

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

286

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.

Lin, Mow S. (Rocky Point, NY); Premuzic, Eugene T. (East Moriches, NY)

1999-03-23

287

Optical source transformations.  

PubMed

Transformation optics is a recently appreciated methodology for the design of complex media that control the propagation of electromagnetic and other types of waves. The transformation optical technique involves the use of coordinate transformations applied to some region of space, providing a conceptual means to redirect the flow of waves. Successfully designed devices to date have made use of transformations acting on passive space only; however, the technique can also be applied when source distributions (e.g., current and charge) are included within the space being transformed. In this paper we present examples of source transformations that illustrate the potential of these expanded transformation optical methods. In particular, using finite-element full-wave simulations, we confirm the restoration of dipole radiation patterns from both a distorted 'pin-wheel' antenna and a bent dipole partially occluded by a cylindrical scatterer. We propose the technique of source transformations as a powerful approach for antenna design, especially in relation to conformal antennas. PMID:19104551

Kundtz, N; Roberts, D A; Allen, J; Cummer, S; Smith, D R

2008-12-22

288

Fourier Transform Spectrometer  

NASA Technical Reports Server (NTRS)

Understanding the global atmospheric changes is difficult with today's current technology. However, with high resolution and nearly continuous observations from a satellite, it's possible to transform our understanding of the atmosphere. To enable the next generation of atmospheric science, a new class of orbiting atmospheric sensors is being developed. The foundation of this advanced concept is the Fourier Transform Spectrometer, or FTS.

1998-01-01

289

Transforming Dentistry through Innovation  

E-print Network

7 Transforming Dentistry through Innovation and Imagination Research Matters Faculty Highlights's practitioners and researchers through... DentistryF A C U L T Y O F TRANSFORMING DENTISTRY THROUGH INNOVATION a short time ago, were not possible. Naturally, these changes are influencing the teaching of dentistry

Barthelat, Francois

290

Deployment & Market Transformation (Brochure)  

SciTech Connect

NREL's deployment and market transformation (D and MT) activities encompass the laboratory's full range of technologies, which span the energy efficiency and renewable energy spectrum. NREL staff educates partners on how they can advance sustainable energy applications and also provides clients with best practices for reducing barriers to innovation and market transformation.

Not Available

2012-04-01

291

Transform picture coding  

Microsoft Academic Search

Picture coding by first dividing the picture into sub-pictures and then performing a linear transformation on each sub-picture cud quantizing and coding the resulting coefficients is introduced from a heuristic point of view. Various transformation, quantization, and coding strategies are discussed. A survey of all known applications of these techniques to monochromatic image coding is presented along with a summary

P. A. Wintz

1972-01-01

292

Transforming convolution and correlation  

NASA Astrophysics Data System (ADS)

We give an explicit expression for the transform of a signal in an arbitrary representation which has first been filtered in another representation. Using this formula we connect the work of Cohen for obtaining convolution and correlation theorems in arbitrary representations with the work of Lindsey and Suter for partitioning the space of integral transforms.

Cohen, Leon; Lindsey, Alan R.; Suter, Bruce W.

2001-12-01

293

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

294

Transformations Using Technology  

NSDL National Science Digital Library

The teacher can introduce the website and demonstrate the use of commands to translate, rotate, or reflect. A series of transformations can be explored to result in a specified final image. Students can then access the site and use the tool to explore transformations.

Interactivate (Shodor)

2010-03-04

295

Reconstructing finite radon transforms  

NASA Astrophysics Data System (ADS)

Reconstructing finite Radon transforms is equivalent to inverting incidence matrices, that is, matrices whose entries are zeroes or ones. We describe several methods of reconstructing Radon transforms on combinatorial structures which may be useful in statistical mechanics. Amongst these structures are experimental designs, translates of subsets in finite groups, nearest neighborhoods in grids, geometric lattices, matroids, and modular lattices.

Kung, Joseph P. S.

1988-09-01

296

CST: C state transformers  

Microsoft Academic Search

C State transformers (CST) is an expression ori- ented dialect of C designed to smoothly integrate functional programming into C based software. C State Transformers is an attempt to do for functional programming what C++ did for object oriented pro- gramming. It provides support for functional pro- gramming with a C like syntax.

John D. Ramsdell

1995-01-01

297

Transforming Health Research  

E-print Network

Transforming Health Research the first two years National Institute for Health Research Progress For Information R OCR R ef: 0 Gateway R ef: 9298 Title Transforming Health Research the first two years. Health Research Progress Report 2006-2008 National Institute for Author National Institute for Health Research

Diggle, Peter J.

298

Transformation of Anaplasma phagocytophilum  

Microsoft Academic Search

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:

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

2006-01-01

299

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

300

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

301

Transformation optics and metamaterials.  

PubMed

Underpinned by the advent of metamaterials, transformation optics offers great versatility for controlling electromagnetic waves to create materials with specially designed properties. Here we review the potential of transformation optics to create functionalities in which the optical properties can be designed almost at will. This approach can be used to engineer various optical illusion effects, such as the invisibility cloak. PMID:20414221

Chen, Huanyang; Chan, C T; Sheng, Ping

2010-05-01

302

Genetic transformation in citrus.  

PubMed

Citrus is one of the world's important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species. PMID:23983635

Donmez, Dicle; Simsek, Ozhan; Izgu, Tolga; Kacar, Yildiz Aka; Mendi, Yesim Yalcin

2013-01-01

303

Genetic Transformation in Citrus  

PubMed Central

Citrus is one of the world's important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species. PMID:23983635

Donmez, Dicle; Simsek, Ozhan; Izgu, Tolga; Aka Kacar, Yildiz; Yalcin Mendi, Yesim

2013-01-01

304

Microbial Transformations of (+)-Isomenthol by Fusarium lini and Rhizopus stolonifer.  

PubMed

Microbial transformation of (+)-isomenthol (1) by various strains of fungi was investigated. Fusarium lini has successfully converted compound 1 into a new metabolite, 5?-hydroxyisomenthol (2), and a known metabolite, 1?-hydroxyisomenthol (3), whereas incubation with Rhizopus stolonifer only yielded metabolite 3. The transformed metabolites were structurally characterized on the basis of their spectral data. PMID:21720039

Gondal, Humaira Yasmeen; Choudhary, Muhammad Iqbal; Khan, Ahmed Abbas

2011-01-01

305

Peculiarity transformation of modern economies (example of Ukraine)  

Microsoft Academic Search

Olena Slozko – PhD, Senior Research Adviser IWEIR NAS Ukraine Peculiarity transformation of modern economies (example of Ukraine) For the transformation of modern economies characterized by two features that impede the integration of world financial markets: first, large scale non-market sectors and relations, and secondly, the low information transparency. Typical is the low level of economy of Ukraine depends on

Olena Slozko

2011-01-01

306

Transformer Ratio Enhancement for Structure-Based Wakefield Acceleration  

Microsoft Academic Search

A limiting factor in the efficiency of wakefield accelerators is the fact that the transformer ratio R, the parameter that characterizes the energy transfer efficiency from the accelerating structure to the accelerated electron beam, is less than 2 for most technologically realizable beam-structure configurations. We are planning an experiment to study transformer ratio enhancement in a 13.625 GHz dielectric wakefield

A. Kanareykin; W. Gai; J. G. Power; P. Schoessow

2004-01-01

307

Performance analysis of transient detectors based on linear data transforms  

Microsoft Academic Search

The authors study the performance of detection algorithms based on linear time-frequency (or time-scale) transforms, for transient signals characterized by linear and nonlinear parametric signal models, and by a `model mismatch' representing the difference between the model and the actual signal. The transients are assumed to undergo a noninvertible linear transformation prior to the application of the detection algorithm. Examples

Benjamin Friedlander; Boaz Porat

1991-01-01

308

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

309

Special Relativity and Diagonal Transformations  

Microsoft Academic Search

We discuss the form of the special Lorentz transformation, and the corresponding transformation of the electromagnetic field, in which the transformation matrix is diagonal. We derive the diagonal form of the special Lorentz transformation directly, in a simple way, and show that it is sometimes more convenient to apply than the algebraically equivalent conventional form of the transformation. The convenience

Leonard Parker; Glenn M. Schmieg

1970-01-01

310

Properties of the Fourier Transform  

E-print Network

Properties of the Fourier Transform 24.2 Introduction ' & $ % Prerequisites Before starting to . . . #12;1. Linearity Properties of the Fourier Transform (i) If f(t), g(t) are functions with transforms F Transform of the resulting function is simply the sum of the individual Fourier Transforms. (ii) If k is any

Vickers, James

311

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

312

Information under Lorentz transformation  

E-print Network

A general form of a two-qubit system is obtained under the effect of Lorentz transformation. We investigate extensively some important classes in the context of quantum information. It is shown Lorentz transformation causes a decay of entanglement and consequently information loses. On the other hand, it generates entangled states between systems prepared initially in a separable states. The partial entangled states are more robust under Lorentz transformation than maximally entangled states. Therefore the rate of information lose is larger for maximum entangled states compared with that for partially entangled states.

N. Metwally; H. Eleuch; M. Abdel-Aty

2014-02-11

313

Some Properties of Transforms in Cultural Theory  

NASA Astrophysics Data System (ADS)

It is shown that, in certain circumstances, systems of cultural rules may be represented by doubly stochastic matrices denoted ?, called “possibility transforms,” and by certain real valued “possibility densities” ?=( ? 1, ? 2,…, ? n ) with inner product characterize a certain problem of ethnographic or ethological description as a problem of prediction, in which observations are predicted by properties of fixed points of transforms of “pure systems”, or by properties of convex combinations of such “pure systems”. Other relationships to quantum methods are noted.

Ballonoff, Paul

2010-12-01

314

Some Properties of Transforms in Culture Theory  

E-print Network

It is shown that, in certain circumstances, systems of cultural rules may be represented by doubly stochastic matrices denoted called possibility transforms, and by certain real valued possibility densities with inner product. Using such objects we may characterize a certain problem of ethnographic and ethological description as a problem of prediction, in which observations are predicted by properties of fixed points of transforms of pure systems, or by properties of convex combinations of such pure systems. That is, ethnographic description is an application of the Birkhoff theorem regarding doubly stochastic matrices on a space whose vertices are permutations.

Paul Ballonoff

2009-03-07

315

Imaging Fourier transform spectrometer  

SciTech Connect

This invention is comprised of an imaging Fourier transform spectrometer having a Fourier transform infrared spectrometer providing a series of images to a focal plane array camera. The focal plane array camera is clocked to a multiple of zero crossing occurrences as caused by a moving mirror of the Fourier transform infrared spectrometer and as detected by a laser detector such that the frame capture rate of the focal plane array camera corresponds to a multiple of the zero crossing rate of the Fourier transform infrared spectrometer. The images are transmitted to a computer for processing such that representations of the images as viewed in the light of an arbitrary spectral ``fingerprint`` pattern can be displayed on a monitor or otherwise stored and manipulated by the computer.

Bennett, C.L.

1993-09-13

316

Applying Improved Efficiency Transformers  

E-print Network

Today's business and energy conscious environment affords both producers and consumers of electric energy an opportunity to reduce costs and conserve energy through the use of improved efficiency transformers. Various design techniques...

Haggerty, N. K.; Malone, T. P.

317

Technique for lymphocyte transformation  

PubMed Central

Current techniques for lymphocyte transformation are evaluated and criticised. A simple technique, designed to meet these criticisms, is described in detail, with particular reference to lymphocyte separation and scoring methods. PMID:5697050

Pentycross, C. R.

1968-01-01

318

Fourier Transform Mass Spectrometry  

PubMed Central

This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook. PMID:21742802

Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

2011-01-01

319

Transformation inverse design  

E-print Network

We present a new technique for the design of transformation-optics devices based on large-scale optimization to achieve the optimal effective isotropic dielectric materials within prescribed index bounds, which is ...

Liu, David

320

Transformation: Women and Mathematics.  

ERIC Educational Resources Information Center

Discusses the transformation of women and mathematics and the papers contained in this special issue. Questions whether women are changed by mathematics or if mathematics can and is being changed by them. (MKR)

John-Steiner, Vera

1996-01-01

321

Series Transmission Line Transformer  

SciTech Connect

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

322

Service Enterprise Transformation  

Microsoft Academic Search

\\u000a This chapter examines the challenges in transforming a complex multi-organisational service enterprise. It builds on a review\\u000a of relevant literature and an empirical analysis of the early experience and lessons learned by industry and MoD partners\\u000a in the ATTAC (ATTAC (Availability Transformation: Tornado Aircraft Contract) is a long-term, whole-aircraft availability contract\\u000a where BAE Systems take prime responsibility to provide Tornado

Valerie Purchase; Glenn Parry; John Mills

323

Finite-Field Wavelet Transforms  

Microsoft Academic Search

Cyclic wavelet transforms, analogous to cyclic Fourier transforms, are described. Among other things, this construction allows for the development of wavelet transforms over finite fields. Potential applications of this construct in algebraic coding are discussed.

H. Vincent Poor

1995-01-01

324

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

325

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

326

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

327

Relational mentoring in clinical supervision: the transformational supervisor.  

PubMed

Effective clinical supervision naturally incorporates many elements of mentoring. In this article, we us the Mentoring Relationship Continuum (MRC) model to frame a discussion of transformational supervision. We define transformational supervision as a rich developmental relationship characterized by increasing relational reciprocity, a greater range of career and psychosocial mentoring functions, and a strong sense of collegiality. As a strong supervisory relationship approaches the transformational end of the MRC, the supervisor offers increasing levels of support, empowerment, authenticity, and reciprocity; over time, the relationship has a more interdependent, egalitarian, and communitarian character. We employ a case example to illustrate excellent transformational supervision. PMID:25220809

Johnson, W Brad; Skinner, Cessily J; Kaslow, Nadine J

2014-11-01

328

A deblocking technique for block-transform compressed image using wavelet transform modulus maxima  

Microsoft Academic Search

In this work, we introduce a deblocking algorithm for Joint Photographic Experts Group (JPEG) decoded images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect of a JPEG decoded image as: 1) small modulus maxima at block boundaries over smooth regions; 2) noise or irregular structures near strong edges; and 3)

Tai-Chiu Hsung; Daniel Pak-kong Lun; Wan-Chi Siu

1998-01-01

329

Canonical Transformations in Quantum Mechanics  

E-print Network

Quantum canonical transformations are defined algebraically outside of a Hilbert space context. This generalizes the quantum canonical transformations of Weyl and Dirac to include non-unitary transformations. The importance of non-unitary transformations for constructing solutions of the Schr\\"odinger equation is discussed. Three elementary canonical transformations are shown both to have quantum implementations as finite transformations and to generate, classically and infinitesimally, the full canonical algebra. A general canonical transformation can be realized quantum mechanically as a product of these transformations. Each transformation corresponds to a familiar tool used in solving differential equations, and the procedure of solving a differential equation is systematized by the use of the canonical transformations. Several examples are done to illustrate the use of the canonical transformations. [This is an extensively revised version of hep-th-9205080: the first third of the paper is new material; the notation has been simplified, and further discussion has been added to the remainder.

Arlen Anderson

1993-05-13

330

Transformation Nets -A Runtime Model for Transformation Languages  

E-print Network

transformation languages relieve trans- formation designers from these burdens, specification of transformation to the information provided by the transformation engine, most often just consist- ing of variable values and logging messages, but missing important information e.g., why certain parts of a transformation are actually

Hochreiter, Sepp

331

TRANSFORMATIVE LEARNING THEORY: LEARNING BY TRANSFORMING AND CHANGING  

Microsoft Academic Search

In this manuscript, Mezirow’s transformative learning theory is studied. In this context, the definition, dimensions of transformative learning, the roles of teachers and learners in transformative learning and its curricular scopes are analyzed. In the study held as analyses of the literature, the following results are reached: Transformative learning theory is formed with a synthesis of critical reflection and hermeneutics.

Burhan Akpinar

2010-01-01

332

Transformation inverse design.  

PubMed

We present a new technique for the design of transformation-optics devices based on large-scale optimization to achieve the optimal effective isotropic dielectric materials within prescribed index bounds, which is computationally cheap because transformation optics circumvents the need to solve Maxwell's equations at each step. We apply this technique to the design of multimode waveguide bends (realized experimentally in a previous paper) and mode squeezers, in which all modes are transported equally without scattering. In addition to the optimization, a key point is the identification of the correct boundary conditions to ensure reflectionless coupling to untransformed regions while allowing maximum flexibility in the optimization. Many previous authors in transformation optics used a certain kind of quasiconformal map which overconstrained the problem by requiring that the entire boundary shape be specified a priori while at the same time underconstraining the problem by employing "slipping" boundary conditions that permit unwanted interface reflections. PMID:23787612

Liu, David; Gabrielli, Lucas H; Lipson, Michal; Johnson, Steven G

2013-06-17

333

Plastid transformation in eggplant.  

PubMed

Eggplant (Solanum melongena L.) is an important vegetable crop of tropical and temperate regions of the world. Here we describe a procedure for eggplant plastid transformation, which involves preparation of explants, biolistic delivery of plastid transformation vector into green stem segments, selection procedure, and identification of the transplastomic plants. Shoot buds appear from cut ends of the stem explants following 5-6 weeks of spectinomycin selection after bombardment with the plastid transformation vector containing aadA gene as selectable marker. Transplastomic lines are obtained after the regenerated shoots are subjected to several rounds of spectinomycin selection over a period of 9 weeks. Homoplasmic transplastomic lines are further confirmed by spectinomycin and streptomycin double selection. The transplastomic technology development in this plant species will open up exciting possibilities for improving crop performance, metabolic engineering, and the use of plants as factories for producing biopharmaceuticals. PMID:24599862

Bansal, Kailash C; Singh, Ajay K

2014-01-01

334

Fourier Transform Infrared (FTIR) Spectroscopy  

E-print Network

Fourier Transform Infrared (FTIR) Spectroscopy Klaus Gerwert, Lehrstuhl fu¨r Biophysik, Ruhr Transform IR by Johannes Orphal. Fourier transform infrared (FTIR) spectroscopy is an experimental technique. Introduction The underlying principle of a Fourier transform infrared (FTIR) spectrometer is the separation

Gerwert, Klaus

335

The discrete fractional Fourier transform  

Microsoft Academic Search

We propose and consolidate a definition of the discrete fractional Fourier transform that generalizes the discrete Fourier transform (DFT) in the same sense that the continuous fractional Fourier transform generalizes the continuous ordinary Fourier transform. This definition is based on a particular set of eigenvectors of the DFT matrix, which constitutes the discrete counterpart of the set of Hermite-Gaussian functions.

Çagatay Candan; M. Alper Kutay; Haldun M. Ozaktas

2000-01-01

336

Discrete Fourier Transform Javier Montoya  

E-print Network

Discrete Fourier Transform Javier Montoya Photogrammetry and Remote Sensing ETH Zurich March 16, 2012 1 Introduction The Discrete form of the Fourier transform is known as Discrete Fourier Transform domain using the Inverse Discrete Fourier Transform (IDFT): f(x) = 1 N N-1 x=0 F(u)ej 2 N ux for u = 0, 1

Giger, Christine

337

Building an evolution transformation library  

Microsoft Academic Search

We have been developing knowledge-based tools to support the evolutionary development of specifications. Evolution is accomplished by means of evolution transformations, which are meaning-changing transformations applied to formal specifications. A sizable library of evolution transformations has been developed for our specification language, Gist. This paper assesses the results of our previous work on evolution transformations. It then describes our current

W. Lewis Johnson; Martin S. Feather

1990-01-01

338

Microbial transformation of (+)-adrenosterone.  

PubMed

The microbial transformation of (+)-adrenosterone (1) by Cephalosporium aphidicola afforded three metabolites identified as androsta-1,4-diene-3,11,17-trione (2), 17beta-hydroxyandrost-4-ene-3,11-dione (3) and 17beta-hydroxyandrosta-1,4-diene-3,11-dione (4). The fermentation of 1 with Fusarium lini also produced metabolites 2 and 4, while the fermentation with Trichothecium roseum afforded metabolite 3. The structures of transformed products were determined by spectroscopic methods. PMID:12434991

Musharraf, S Ghulam; Atta-Ur-Rahman; Choudhary, M Iqbal; Sultan, Sadia

2002-10-01

339

Optical Haar wavelet transform  

NASA Astrophysics Data System (ADS)

An optical Haar mother wavelet is created with a SEMETEX 128 X 128 magneto-optic spatial light modulator. Two techniques for dilating the mother wavelet are explored: (1) aperture stopping and (2) operating the SLM in ternary phase-amplitude mode. Discrete resolution levels of a continuous wavelet transform are obtained by optically correlating a binarized image with multiple dilations of the mother wavelet. Frequency-plane masks for the correlation process are generated suing thermoplastic holography. Experimental results are compared with a digital simulation of the wavelet transform.

Burns, Thomas J.; Fielding, Kenneth H.; Rogers, Steven K.; Pinski, Steven D.; Ruck, Dennis W.

1992-09-01

340

Plastid transformation in soybean.  

PubMed

The biotechnological potential of plastid genetic engineering has been illustrated in a limited number of higher plant species. We have developed a reproducible method to generate plastid transformants in soybean (Glycine max), a crop of major agronomic importance. The transformation vectors are delivered to embryogenic cultures by the particle gun method and selection performed using the aadA antibiotic resistance gene. Homoplasmy is established rapidly in the selected events without the need for further selection or regeneration cycles, and genes of interest can be expressed at a high level in green tissues. This is a significant step toward the commercial application of this technology. PMID:24599865

Dubald, Manuel; Tissot, Ghislaine; Pelissier, Bernard

2014-01-01

341

Dendrimer-enabled transformation of Chlamydia trachomatis.  

PubMed

Lack of a system for genetic manipulation of Chlamydia trachomatis has been a key challenge to advancing understanding the molecular genetic basis of virulence for this bacterial pathogen. We developed a non-viral, dendrimer-enabled system for transformation of this organism and used it to characterize the effects of inserting the common 7.5 kbp chlamydial plasmid into strain L2(25667R), a C. trachomatis isolate lacking it. The plasmid was cloned in pUC19 and the clone complexed to polyamidoamine dendrimers, producing ?83 nm spherical particles. Nearly confluent McCoy cell cultures were infected with L2(25667R) and reference strain L2(434). At 16 h post-infection, medium was replaced with dendrimer-plasmid complexes in medium lacking additives (L2(25667R)) or with additive-free medium alone (L2(434)). Three h later complexes/buffer were removed, and medium was replaced; cultures were harvested at various times post-transformation for analyses. Real time PCR and RT-PCR of nucleic acids from transformed cultures demonstrated plasmid replication and gene expression. A previous report indicated that one or more plasmid-encoded product govern(s) transcription of the glycogen synthase gene (glgA) in standard strains. In L2(25667R) the gene is not expressed, but transformants of that strain given the cloned chlamydial plasmid increase glgA expression, as does L2(434). The cloned plasmid is retained, replicated, and expressed in transformants over at least 5 passages, and GFP is expressed when transformed into growing L2(25667R). This transformation system will allow study of chlamydial gene function in pathogenesis. PMID:24075820

Kannan, Rangaramanujam M; Gérard, Hérve C; Mishra, Manoj K; Mao, Guangzhao; Wang, Sunxi; Hali, Mirabela; Whittum-Hudson, Judith A; Hudson, Alan P

2013-12-01

342

Facilities: NHMFL 9.4 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation: Characterization of Pine Pellet and Peanut Hull Pyrolysis of Bio-Oils by Negative-Ion Electrospray Ionization Fourier  

E-print Network

with greater than 1% relative abundance in either phase are shown. Pyrolysis of solid biomass, in this case: Characterization of Pine Pellet and Peanut Hull Pyrolysis of Bio-Oils by Negative-Ion Electrospray Ionization of nitrogen-containing species identified in the peanut hull pyrolysis oil by FT-ICR mass spectrometry

Weston, Ken

343

Using Extensible Heterogeneous Database Transformers  

Microsoft Academic Search

\\u000a Transforming a heterogeneous data model to another heterogeneous data model involves mapping of structural information and\\u000a data layout. For performing the transformation processes this paper presents a flexible and extensible approach for heterogeneous\\u000a database transformation using XML. Basics steps involved are forward transformation and reverse transformation. Between these\\u000a two steps lie two XML documents; one representing the database structure; the

F. Furman Haddix; Kalyan Pydipati

2006-01-01

344

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

345

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

346

BAM Transformations 1. Introduction  

E-print Network

into BAM code, a series of optimizing transforma­ tions is performed. The transformations performed are: (1) synonym optimization, (6) peephole optimization, and (7) determinism optimization. This chapter first definitions are useful: Definition DB: A distant branch is a branch that always transfers control

Bonaventure, Olivier

347

Teaching, Caring, and Transformation  

ERIC Educational Resources Information Center

Educator Bell Hooks acknowledged the fundamental truth that teaching, caring, and transformation are closely linked, that is, that true teaching must be accompanied by a deep level of care in order for learning to take place. No matter how young or old, no matter the subject matter, and no matter where teaching and learning take place--a…

Nieto, Sonia

2012-01-01

348

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

349

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

350

Optical Haar wavelet transform  

Microsoft Academic Search

An optical Haar mother wavelet is created with a SEMETEX 128 X 128 magneto-optic spatial light modulator. Two techniques for dilating the mother wavelet are explored: (1) aperture stopping and (2) operating the SLM in ternary phase-amplitude mode. Discrete resolution levels of a continuous wavelet transform are obtained by optically correlating a binarized image with multiple dilations of the mother

Thomas J. Burns; Kenneth H. Fielding; Steven K. Rogers; Steven D. Pinski; Dennis W. Ruck

1992-01-01

351

Transforming Education at Einstein  

E-print Network

of Albert Einstein College of Medicine of Yeshiva University #12;2 EinstEin : WintEr/spring 2012 Meet Our trANsfOrMiNg eDuCAtiON At eiNsteiN Education at Albert Einstein College of Medicine is undergoing the magazine for alumni, faculty, students, friends and supporters of Albert einstein College of Medicine

Yates, Andrew

352

Transforming projectile system  

Microsoft Academic Search

The objective of this research was to develop a framework to design a transforming projectile system that has the ability to convert from a simple projectile into a guided projectile that can perform multiple tasks depending on its payload and guiding keyboard. This projectile would be launched from existing standard platforms. Our objective is to determine which design alternative potentially

M. Chafac; K. Howell; C. Williams; J. Sexton

2010-01-01

353

Flexible Power Electronic Transformer  

Microsoft Academic Search

This paper proposes a new modular flexible power electronic transformer (FPET). The proposed FPET is flexible enough to meet future needs of power electronic centralized systems. The main feature of the FPET is the independent operation of modules each of which contains one port. Each port can be considered as input or output, because bidirectional power flow is provided. The

Mehran Sabahi; Ali Yazdanpanah Goharrizi; Seyed Hossein Hosseini; Mohammad Bagher Bana Sharifian; Gevorg B. Gharehpetian

2010-01-01

354

Program refinement by transformation  

Microsoft Academic Search

Program maintenance is simplified when the program to be modified can be viewed as an abstract algorithm to which clearly documented implementation decisions have been applied to produce an efficient realization. The Harvard Program Development System (PDS) [8] is a programming support environment that encourages users to take this view of programs. A user of the PDS creates transformations that

Thomas E. Cheatham Jr.; Glenn H. Holloway; Judy A. Townley

1981-01-01

355

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

356

Transforming American Education  

ERIC Educational Resources Information Center

In this article the authors accept as a given the National Education Technology Plan's vision of a transformed education system powered by technology such that learners receive personalized and engaging learning experiences, and where assessment, teaching, infrastructure, and productivity are redefined. The article analyzes this vision of a…

Horn, Michael B.; Mackey, Katherine

2011-01-01

357

Bacterial Transformation Lab  

NSDL National Science Digital Library

The "glowing genes" activity on this engaging website shows students the process of bacterial transformation, a specific type of genetic engineering. This online activity supplements a hands-on lab at the Dolan DNA Learning Center's Harlem DNA Lab, in which plasmids, or tiny loops of DNA that contain genes, are inserted into a harmless strain of E.coli.

Dolan DNA Learning Center * (Dolan DNA Learning Center;)

2010-05-27

358

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

359

9 (extension) " (Z transform)"  

E-print Network

10 9 (extension) (CtFT) " (Z transform)" (discrete-time aperiodic signal) (Dt n r r [ ]x n " (ROC: region of convergence)" ROC ( )X z [ ]x n #12;10-3 { }Re z { }Im z 1 X z a u n z az - - =- = = = (10.8) ( )1 0 n n az - = ROC ( )X z 1 1az- 0 1 1 n

Kovintavewat, Piya

360

Transformations: Translation (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore the translation transformation (sliding) both informally and within a coordinate system. Students select and compose shapes and manipulate the ends of a translation vector to see the effect on a translated image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

361

Transformer insulation life assessment  

Microsoft Academic Search

This paper presents novel techniques for life assessment of the insulation of the generator stepup units in power plants. Load and ambient temperatures are two important factors that influence the life of insulation in transformers. Hourly load and ambient temperatures obtained through condition monitoring are used to assess the operating profile of the equipment. Modeling techniques for estimating load factors

Kshira T. Muthanna; Abhinanda Sarkar; Kaushik Das; Kurt Waldner

2006-01-01

362

Transforming Nursery Education.  

ERIC Educational Resources Information Center

Reviews "Transforming Nursery Education" by Peter Moss and Helen Penn. Maintains that the book clarifies issues and options in child care policy in Great Britain, is highly applicable to the situation in Canada, articulates the importance of values as central to developing early childhood policy and programs, highlights the importance of learning…

Friendly, Martha

1998-01-01

363

Rainbow Fourier Transform  

NASA Technical Reports Server (NTRS)

We present a novel technique for remote sensing of cloud droplet size distributions. Polarized reflectances in the scattering angle range between 135deg and 165deg exhibit a sharply defined rainbow structure, the shape of which is determined mostly by single scattering properties of cloud particles, and therefore, can be modeled using the Mie theory. Fitting the observed rainbow with such a model (computed for a parameterized family of particle size distributions) has been used for cloud droplet size retrievals. We discovered that the relationship between the rainbow structures and the corresponding particle size distributions is deeper than it had been commonly understood. In fact, the Mie theory-derived polarized reflectance as a function of reduced scattering angle (in the rainbow angular range) and the (monodisperse) particle radius appears to be a proxy to a kernel of an integral transform (similar to the sine Fourier transform on the positive semi-axis). This approach, called the rainbow Fourier transform (RFT), allows us to accurately retrieve the shape of the droplet size distribution by the application of the corresponding inverse transform to the observed polarized rainbow. While the basis functions of the proxy-transform are not exactly orthogonal in the finite angular range, this procedure needs to be complemented by a simple regression technique, which removes the retrieval artifacts. This non-parametric approach does not require any a priori knowledge of the droplet size distribution functional shape and is computationally fast (no look-up tables, no fitting, computations are the same as for the forward modeling).

Alexandrov, Mikhail D.; Cairns, Brian; Mishchenko, Michael I.

2012-01-01

364

Microbial Transformation of TRU and Mixed Wastes: Actinide Speciation and Waste Volume Reduction  

SciTech Connect

I. To characterize the biodegradation of cellulosic materials using Fourier Transform Infrared (FTIR) Spectroscopy. II. To develop an electrochemical/spectroscopic methodology to characterize TRU waste microbial transformation III. To develop molecular models of TRU complexes in order to understand microbial transformation In all cases, objectives are designed to compliment the efforts from other team members, and will be periodically coordinated through the lead P.I. at Brookhaven National Laboratory (BNL), A.J. Francis.

Halada, Gary P.

2004-12-01

365

Canonical Transformations in Quantum Mechanics  

E-print Network

Three elementary canonical transformations are shown both to have quantum implementations as finite transformations and to generate, classically and infinitesimally, the full canonical algebra. A general canonical transformation can, in principle, be realized quantum mechanically as a product of these transformations. It is found that the intertwining of two super-Hamiltonians is equivalent to there being a canonical transformation between them. A consequence is that the procedure for solving a differential equation can be viewed as a sequence of elementary canonical transformations trivializing the super-Hamiltonian associated to the equation. It is proposed that the quantum integrability of a system is equivalent to the existence of such a sequence.

Arlen Anderson

1992-05-22

366

Quantum Canonical Transformations and Integrability: Beyond Unitary Transformations  

E-print Network

Quantum canonical transformations are defined in analogy to classical canonical transformations as changes of the phase space variables which preserve the Dirac bracket structure. In themselves, they are neither unitary nor non-unitary. A definition of quantum integrability in terms of canonical transformations is proposed which includes systems which have fewer commuting integrals of motion than degrees of freedom. The important role of non-unitary transformations in integrability is discussed.

Arlen Anderson

1993-02-15

367

Liquid Metal Transformers  

E-print Network

The room temperature liquid metal is quickly emerging as an important functional material in a variety of areas like chip cooling, 3D printing or printed electronics etc. With diverse capabilities in electrical, thermal and flowing behaviors, such fluid owns many intriguing properties that had never been anticipated before. Here, we show a group of unconventional phenomena occurring on the liquid metal objects. Through applying electrical field on the liquid metals immersed in water, a series of complex transformation behaviors such as self-assembling of a sheet of liquid metal film into a single sphere, quick mergences of separate metal droplets, controlled self-rotation and planar locomotion of liquid metal objects can be realized. Meanwhile, it was also found that two accompanying water vortexes were induced and reliably swirled near the rotating liquid metal sphere. Further, effects of the shape, size, voltage, orientation and geometries of the electrodes to control the liquid metal transformers were clar...

Sheng, Lei; Liu, Jing

2014-01-01

368

Genetic transformation in bacteria  

Microsoft Academic Search

Certain species of bacteria can become competent to take up high molecular weight DNA from the surrounding medium. DNA homologous\\u000a to resident chromosomal DNA is transported, processed and recombined with the resident DNA. There are some variations in steps\\u000a leading to transformation between Gram-positive bacteria likebiplococcus pneumoniae and Gram-negative bacteria represented byHaemophilus influenzae but the integration is by single-strand displacement

N. K. Notani; V. P. Joshi; R. P. Kanade

1984-01-01

369

Laminated piezoelectric transformer  

NASA Technical Reports Server (NTRS)

A laminated piezoelectric transformer is provided using the longitudinal vibration modes for step-up voltage conversion applications. The input portions are polarized to deform in a longitudinal plane and are bonded to an output portion. The deformation of the input portions is mechanically coupled to the output portion, which deforms in the same longitudinal direction relative to the input portion. The output portion is polarized in the thickness direction relative its electrodes, and piezoelectrically generates a stepped-up output voltage.

Vazquez Carazo, Alfredo (Inventor)

2006-01-01

370

Transformer Impedance Reflection Demonstration  

NASA Astrophysics Data System (ADS)

Questions often arise as to how a device attached to a transformer can draw power from the electrical power grid since it seems that the primary and secondary are not connected to one another. However, a closer look at how the primary and secondary are linked together magnetically and a consideration of the role of Lenz's law in this linkage may help to clear up this confusion.

Layton, William

2014-10-01

371

Multipath Transformational Development of User Interfaces with Graph Transformations  

NASA Astrophysics Data System (ADS)

In software engineering, transformational development is aimed at developing computer systems by transforming a coarse-grained specification of a system to its final code through a series of transformation steps. Transformational development is known to bring benefits such as: correctness by construction, explicit mappings between development steps, and reversibility of transformations. No comparable piece exists in the literature that provides a formal system applying transformational development in the area of user interface engineering. This chapter defines such a system. For this purpose, a mathematical system for expressing specifications and transformation rules is introduced. This system is based on graph transformations. The problem of managing the transformation rules is detailed, e.g., how to enable a developer to access, define, extend, restrict or relax, test, verify, and apply appropriate transformations. A tool supporting this development paradigm is also described and exemplified. Transformational development, applied to the development of user interfaces of interactive systems, allows reusability of design knowledge used to develop user interfaces and fosters incremental development of user interfaces by applying alternative transformations.

Limbourg, Quentin; Vanderdonckt, Jean

372

Characterization methodology for PMR-15  

NASA Technical Reports Server (NTRS)

Characterization of model compounds, monomers, resin solutions and cure cycles of PMR-15 polyimide are performed. Successful separation of various reaction products is also accomplished by liquid chromatography. The PMR-15 cure analysis is performed by fourier transform spectroscopy and gas chromatograph - mass spectrometry. Characterization receiving inspection tests for Quality Control are recommended.

Hunter, A. B.

1985-01-01

373

Optimal Bounds for Transformations of omega-Automata  

Microsoft Academic Search

In this paper we settle the complexity of some basic constructions of omega-automata theory, concerning transformations of automata characterizing the set of omega-regular languages. In particular we consider Safra's construction (for the conversion of nondeterministic B¨1chi automata into deterministic Rabin automata) and the appearance record constructions (for the transformation between different models of deterministic automata with various acceptance conditions). Extending

Christof Löding; RWTH Aachen

1999-01-01

374

LIE GENERATORS FOR SEMIGROUPS OF TRANSFORMATIONS ON A POLISH SPACE  

Microsoft Academic Search

Let X be a separable complete metric space. We characterize completely the innitesimal generators of semigroups of linear transformations in Cb(X), the bounded real-valued continuous functions on X, that are induced by strongly continuous semigroups of continuous transformations in X.I n order to do this, Cb(X) is equipped with a locally convex topology known as the strict topology.

J. R. Dorroh; J. W. Neuberger

1993-01-01

375

Fabrication and characterization of Na0.5K0.5NbO3-CuNb2O6 lead-free step-down piezoelectric transformers  

NASA Astrophysics Data System (ADS)

Lead-free (Na0.5K0.5)NbO3 (NKN) ceramics doped with 1 mol% CuNb2O6 (01CN) ceramics were prepared using the conventional mixed oxide method at a sintering temperature of 1075 °C. NKN + 1 mol% CuTa2O6 (NKN-01CN) ceramics sintered at 1075 °C exhibit excellent "hard" piezoelectric properties of kp = 40%, kt = 45%, and k33 = 57%, with ferroelectric property Ec = 23 kV/cm. The mechanical quality factor (Qm) is extraordinarily high (1933) and the temperature stability is excellent (Temperature coefficient of frequency (TCF) = -154 ppm/°C). The piezoelectric transformer (PT) was fabricated on NKN-01CN lead-free substrates, and the electrical characteristics were investigated. The devices were simplified into an equivalent circuit and analyzed using the MATLAB software package. The simulation results matched the experimental results. By reversing the input and the output, the step-down PT can be easily fabricated using a simple disk-type structure. A maximum efficiency of 93% with a voltage gain of 0.12 was measured, which was in good agreement with the simulation results (a maximum efficiency of 98.7% with a voltage gain of 0.13) for the step-down mode.

Yang, Ming-Ru; Chu, Sheng-Yuan; Chan, I.-Hao; Huang, Sheng-Kai

2011-08-01

376

Transformational Leadership, Integrity, and Power  

ERIC Educational Resources Information Center

Transformational leadership enjoys widespread appeal among student affairs professionals. National Association of Student Personnel Administrators (NASPA) and American College Personnel Association (ACPA) conferences frequently feature speakers who promote transformational leadership's two primary tenets: (1) change is the central purpose of…

Harrison, Laura M.

2011-01-01

377

Transformer Abdullah Al-Otaibi  

E-print Network

induces a changing voltage in the secondary. II. HISTORY Michael Faraday demonstrated the principle of the transformer in 1831. The transformer is used by Faraday only to demonstrate the principle of electromagnetic

Masoudi, Husain M.

378

Transformation method and wave control  

NASA Astrophysics Data System (ADS)

Transformation method provides an efficient way to control wave propagation by materials. The transformed relations for field and material during a transformation are essential to fulfill this method. We propose a systematic method to derive the transformed relations for a general physic process, the constraint conditions are obtained by considering geometrical and physical constraint during a mapping. The proposed method is applied to Navier's equation for elastodynamics, Helmholtz's equation for acoustic wave and Maxwell's equation for electromagnetic wave, the corresponding transformed relations are derived, which can be used in the framework of transformation method for wave control. We show that contrary to electromagnetic wave, the transformed relations are not uniquely determined for elastic wave and acoustic wave, so we have a freedom to choose them differently. Using the obtained transformed relations, we also provide some examples for device design, a concentrator for elastic wave, devices for illusion acoustic and illusion optics are conceived and validated by numerical simulations.

Chang, Zheng; Hu, Jin; Hu, Geng-Kai

2010-12-01

379

Transforming Content into Effective Composition.  

ERIC Educational Resources Information Center

Demonstrates key concepts of transformational generative grammar that can be applied to a discussion of the composing process. Discusses relevant linguistic concepts and selected transformational processes to illustrate how writers achieve certain effects. (RL)

Esau, Helmut

1980-01-01

380

Distinctive transforming genes in x-ray-transformed mammalian cells.  

PubMed Central

DNAs from hamster embryo cells and mouse C3H/10T1/2 cells transformed in vitro by x-irradiation into malignant cells transmit the radiation transformation phenotype by producing transformed colonies (transfectants) in two mouse recipient lines, the NIH 3T3 and C3H/101/2 cells, and in a rat cell line, the Rat-2 cells. DNAs from unirradiated cells or irradiated and visibly untransformed cells do not produce transformed colonies. The transfectants grow in agar and form tumors in nude mice. Treatment of the DNAs with restriction endonucleases prior to transfection indicates that the same transforming gene (oncogene) is present in each of the transformed mouse cells and is the same in each of the transformed hamster cells. Southern blot analysis of 3T3 or Rat-2 transfectants carrying oncogenes from radiation-transformed C3H/10T1/2 or hamster cells indicates that the oncogenes responsible for the transformation of 3T3 cells are not the Ki-ras, Ha-ras, or N-ras genes, nor are they neu, trk, raf, abl, or fms, although quick blot analysis using 11 oncogene probes detected increased transcripts of c-abl and c-fms in the 3T3 transformants containing oncogenic sequences from the x-ray-transformed C3H/10T1/2 cells. The work demonstrates that DNAs from mammalian cells transformed into malignancy by direct exposure in vitro to radiation contain genetic sequences with detectable transforming activity in three recipient cell lines. The results provide evidence that DNA is the target of radiation carcinogenesis induced at a cellular level in vitro. The experiments indicate that malignant radiogenic transformation in vitro of hamster embryo and mouse C3H/10T1/2 cells involves the activation of unique non-ras transforming genes, which heretofore have not been described. Images PMID:3027705

Borek, C; Ong, A; Mason, H

1987-01-01

381

Thin-Film Power Transformers  

NASA Technical Reports Server (NTRS)

Transformer core made of thin layers of insulating material interspersed with thin layers of ferromagnetic material. Flux-linking conductors made of thinner nonferromagnetic-conductor/insulator multilayers wrapped around core. Transformers have geometric features finer than those of transformers made in customary way by machining and mechanical pressing. In addition, some thin-film materials exhibit magnetic-flux-carrying capabilities superior to those of customary bulk transformer materials. Suitable for low-cost, high-yield mass production.

Katti, Romney R.

1995-01-01

382

Reducing losses in distribution transformers  

Microsoft Academic Search

This paper examines three methods of reducing distribution transformer losses. The first method analyzes the effects of using aluminum electromagnetic shields in a distribution transformer. The goal of placing electromagnetic shields in the distribution-transformer tank walls is to reduce the stray losses. A 500 kVA shell-type transformer was used in the experiments. The overall results presented indicate that stray losses

Juan Carlos Olivares; Yilu Liu; Jose M. Cañedo; Rafael Escarela-Pérez; Johan Driesen; Pablo Moreno

2003-01-01

383

Adaptive wavelet transforms via lifting  

Microsoft Academic Search

This paper develops two new adaptive wavelet transforms based on the lifting scheme. The lifting construction exploits a spatial-domain, prediction-error interpretation of the wavelet transform and provides a powerful framework for designing customized transforms. We use the lifting construction to adaptively tune a wavelet transform to a desired signal by optimizing data-based prediction error criteria. The performances of the new

Roger L. Claypoole; Richard G. Baraniuk; Robert D. Nowak

1998-01-01

384

Experiments on transformation thermodynamics: molding the flow of heat.  

PubMed

It was recently shown theoretically that the time-dependent heat conduction equation is form invariant under curvilinear coordinate transformations. Thus, in analogy to transformation optics, fictitious transformed space can be mapped onto (meta)materials with spatially inhomogeneous and anisotropic heat-conductivity tensors in the laboratory space. On this basis, we design, fabricate, and characterize a microstructured thermal cloak that molds the flow of heat around an object in a metal plate. This allows for transient protection of the object from heating while maintaining the same downstream heat flow as without object and cloak. PMID:23705719

Schittny, Robert; Kadic, Muamer; Guenneau, Sebastien; Wegener, Martin

2013-05-10

385

Transformer Ratio Enhancement for Structure-Based Wakefield Acceleration  

SciTech Connect

A limiting factor in the efficiency of wakefield accelerators is the fact that the transformer ratio R, the parameter that characterizes the energy transfer efficiency from the accelerating structure to the accelerated electron beam, is less than 2 for most technologically realizable beam-structure configurations. We are planning an experiment to study transformer ratio enhancement in a 13.625 GHz dielectric wakefield structure driven by a ramped bunch train. In this paper we present an experimental program for the demonstration of this Enhanced Transformer Ratio Dielectric Wakefield Accelerator (ETR-DWA)

Kanareykin, A. [Euclid Techlabs LLC, Solon OH 44139 (United States); Gai, W.; Power, J.G. [Argonne National Laboratory, Argonne IL, 60439 (United States); Schoessow, P. [Tech-X Corp., Boulder CO, 80303 (United States)

2004-12-07

386

Transformer Ratio Enhancement for Structure-Based Wakefield Acceleration  

NASA Astrophysics Data System (ADS)

A limiting factor in the efficiency of wakefield accelerators is the fact that the transformer ratio R, the parameter that characterizes the energy transfer efficiency from the accelerating structure to the accelerated electron beam, is less than 2 for most technologically realizable beam-structure configurations. We are planning an experiment to study transformer ratio enhancement in a 13.625 GHz dielectric wakefield structure driven by a ramped bunch train. In this paper we present an experimental program for the demonstration of this Enhanced Transformer Ratio Dielectric Wakefield Accelerator (ETR-DWA).

Kanareykin, A.; Gai, W.; Power, J. G.; Schoessow, P.

2004-12-01

387

Nonlocal conservation laws and related Bäcklund transformations via reciprocal transformations  

E-print Network

A set of infinitely many nonlocal conservation laws are revealed for (1+1)-dimensional evolution equations. For some special known integrable systems, say, the KdV and Dym equations, it is found that different nonlocal conservation laws can lead to same new integrable systems via reciprocal transformation. On the other hand, it can be considered as one solution of the new model obtained via reciprocal transformation(s) can be changed to different solutions of the original model. The fact indicates also that two or more different (local and nonlocal) conservation laws can be used to find implicit auto-B\\"acklund transformations via reciprocal transformation to other systems.

Sen-Yue Lou

2014-02-28

388

Enhancing Understanding of Transformation Matrices  

ERIC Educational Resources Information Center

With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…

Dick, Jonathan; Childrey, Maria

2012-01-01

389

Lightning Protection for Distribution Transformers  

Microsoft Academic Search

Usual methods of connecting arresters for the protection of distribution transformers are often inadequate. In service some transformers still flash over although the arrester, in itself, is capable of protecting the transformer with a large margin of safety. Surge current flowing to ground through the ground lead of the arrester gives rise to inductive drop and resistance drop voltages. These

A. M. Opsahl; A. S. Brookes; R. N. Southgate

1932-01-01

390

Some Special Fourier Transform Pairs  

E-print Network

Some Special Fourier Transform Pairs 24.3 Introduction ' & $ % Prerequisites Before starting period. For a non-periodic real signal f(t) with Fourier Transform F() the corresponding result is - f2): Workbook Level 2 24.3: Some Special Fourier Transform Pairs 2 #12;Wehave F()=F{e-t u(t)}= 1 1+i , so |F()|2

Vickers, James

391

Mineral insulating oil in transformers  

Microsoft Academic Search

Nearly all load bearing transformers in electric power delivery systems around the world are filled with liquid. The liquid functions both as an electrical insulation and as a heat transfer fluid. The liquid in almost all of these units is transformer oil, petroleum-based insulating oil refined specifically to meet the requirements of this application. Transformers in electric power distribution and

T. O. Rouse

1998-01-01

392

Transformational leadership and team performance  

Microsoft Academic Search

Despite transformational leadership enjoying success and attention as an exceptional leadership theory, few scholars have investigated a specific link between transformational leadership theory and team performance. As such, we discuss how transformational leadership theory can provide a framework in which to investigate a leader's impact on team performance. We posit that idealized influence\\/inspirational motivation, intellectual stimulation and individualized consideration could

Shelley D. Dionne; Francis J. Yammarino; Leanne E. Atwater; William D. Spangler

2004-01-01

393

An Interplay Between Infrared Multiphoton Dissociation Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry and Density Functional Theory Computations in the Characterization of a Tripodal Quinolin-8-Olate Gd(III) Complex  

NASA Astrophysics Data System (ADS)

A new hexadentate, tripodal 8-hydroxyquinoline based ligand (QH3) and its gadolinium(III) tris-chelated (GdQ) complex with hemicage structure was investigated by using high resolution Fourier-transform ion cyclotron resonance mass spectrometry (FTICRMS). The protonated adduct of the free ligand and its hemicage tripodal Gd(III) complex, [GdQ + H]+, were first observed in experiments of electrospray ionization (ESI) with a linear ion trap (LTQ) mass spectrometer and further investigated by using high resolution FTICRMS. Gas-phase dissociation of the protonated Gd(III) complex, by infrared multiphoton dissociation (IRMPD) FTICR MS, demonstrated a fragmentation pattern with six main product cluster ions labeled as [Fn]+ ( n = 1 up to 6). These product ions suggest the elimination of 7-amino-alkyl or 7-alkyl chains of the hemicage moiety. High resolution MS conditions allowed the elucidation of the fragmentation pattern and product ion structures along with the determination, among the isotopic pattern of Gd, of the chemical compositions of closely related species, which differ in terms of hydrogen content. Among the Gd six naturally stable isotopes, 158Gd is the most abundant, and its peak within each cluster was used as a reference for distinguishing each product ions. Computational DFT investigations were applied to give support to some hypothesis of fragmentation pathways, which could not have been easily justified on the basis of the experimental work. Furthermore, computational studies suggested the coordination geometry of the protonated parent complex and the five- and four-coordinated complexes, which derive from its fragmentation. Furthermore, experimental and computational evidences were collected about the octet spin state of the parent compound.

De Bonis, Margherita; Bianco, Giuliana; Amati, Mario; Belviso, Sandra; Cataldi, Tommaso R. I.; Lelj, Francesco

2013-04-01

394

Characterization of sulfided Mo/Al[sub 2]O[sub 3] catalysts by temperature-programmed reduction and low-temperature fourier transform infrared spectroscopy of adsorbed carbon monoxide  

SciTech Connect

Sulfided Mo/Al[sub 2]O[sub 3] catalysts were studied by temperature-programmed reduction (TPRS) and transmission infrared spectroscopy of adsorbed CO at low temperatures. Reductive elimination of nonstoichiometric and stoichiometric sulfur from edge and corner sites creates coordinatively unsaturated Mo[sup 2+] sites. C-O stretching bands at 2100 cm[sup [minus]1] and at ca. 2060-2070 cm[sup [minus]1] were attributed to CO adsorption complexes on edge and corner sites, respectively. Evidence of morphological changes of MoS[sub 2] slabs during H[sub 2] treatment at 770 K is provided. IR spectroscopy of adsorbed CO at low temperature provides unique possibilities for the characterization of sulfided catalysts. 39 refs., 8 figs., 1 tab.

Mueller, B.; Knoezinger, H. (Universitaet Muenchen (Germany)); Langeveld, A.D. van; Moulijn, J.A. (Delft Univ. of Technology (Netherlands))

1993-09-02

395

Evaluate and characterize mechanisms controlling transport, fate and effects of army smokes in an aerosol wind tunnel: Transport, transformations, fate and terrestrial ecological effects of fog oil obscurant smokes: Final report  

SciTech Connect

The terrestrial transport, chemical fate, and ecological effects of fog oil (FO) smoke obscurants 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 an exposure scenario, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of fog oil 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 three soil types. 29 refs., 35 figs., 32 tabs.

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

1989-01-01

396

Shock phase transformation and release properties of aluminum nitride  

SciTech Connect

Aluminum nitride is characterized by a non-recoverable volume phase transformation from the wurtzite (hexagonal) to the rocksalt (cubic) structure that commences about 22 GPa, accompanied by a volume strain of about 20%. A study of the manifestation of this large volume change under shock loading was made with four uniaxial strain impact experiments. Particle velocity histories of the shock and release states were obtained corresponding to impact pressures of 40 GPa, including the evolution of the shock and release waves with propagation distance. Stress-strain features characterizing aluminum nitride, including the phase transformation, were determined with numerical analysis techniques.

Kipp, M.E.; Grady, D.E.

1993-12-31

397

Microbial transformation of cycloastragenol.  

PubMed

The microbial transformation of cycloastragenol by the fungi Cunninghamella blakesleeana NRRL 1369 and Glomerella fusarioides ATCC 9552, and the bacterium Mycobacterium sp. NRRL 3805 were investigated. Both fungi mainly provided hydroxylated metabolites together with products formed by cyclization, dehydrogenation and Baeyer-Villiger oxidation resulting in a ring cleavage. The bacteria yielded only a single oxidation product, namely, 3-oxo-cycloastragenol. Structures of the metabolites were elucidated by 1-D ((1)H,(13)C), 2-D NMR (COSY, HMBC, HMQC) and HRMS analyses. PMID:23357596

Kuban, Melis; Öngen, Gaye; Khan, Ikhlas A; Bedir, Erdal

2013-04-01

398

Thermal energy transformer  

NASA Technical Reports Server (NTRS)

For use in combination with a heat engine, a thermal energy transformer is presented. It is comprised of a flux receiver having a first wall defining therein a radiation absorption cavity for converting solar flux to thermal energy, and a second wall defining an energy transfer wall for the heat engine. There is a heat pipe chamber interposed between the first and second walls having a working fluid disposed within the chamber and a wick lining the chamber for conducting the working fluid from the second wall to the first wall. Thermal energy is transferred from the radiation absorption cavity to the heat engine.

Berdahl, C. M.; Thiele, C. L. (inventors)

1979-01-01

399

A Fast Hermite Transform?  

PubMed Central

We present algorithms for fast and stable approximation of the Hermite transform of a compactly supported function on the real line, attainable via an application of a fast algebraic algorithm for computing sums associated with a three-term relation. Trade-offs between approximation in bandlimit (in the Hermite sense) and size of the support region are addressed. Numerical experiments are presented that show the feasibility and utility of our approach. Generalizations to any family of orthogonal polynomials are outlined. Applications to various problems in tomographic reconstruction, including the determination of protein structure, are discussed. PMID:20027202

Leibon, Gregory; Rockmore, Daniel N.; Park, Wooram; Taintor, Robert; Chirikjian, Gregory S.

2008-01-01

400

Bacterial Transformation Lab  

NSDL National Science Digital Library

This PDF, part of the classroom activities site by Biotechnology Education and Training Sequence Investment (BETSI), introduces the concept of recombinant DNA and a process called transformation. Here, instructors will find detailed lab instructions/diagrams that trace out the introduction of a recombinant plasmid into a foreign bacteria resulting in the "change of the bacteria's genetic make-up and traits." With the end result of the lab being a product that "glow[s] bright green," this will be a fun lab for any chemistry or biochemistry classroom. The site even playfully boasts, "[that] you will all be genetics engineers" by the end of this experiment!

2008-12-10

401

Surface catalyzed mercury transformation reactions  

NASA Astrophysics Data System (ADS)

Mercury is a known pollutant that has detrimental effect on human health and environment. The anthropogenic emissions of mercury account for 10 to 30% of worldwide mercury emissions. There is a need to control/reduce anthropogenic mercury emissions. Many mercury control technologies are available but their effectiveness is dependent on the chemical form of mercury, because different chemical forms of mercury have different physical and chemical properties. Mercury leaves the boiler in its elemental form but goes through various transformations in the post-combustion zone. There is a need to understand how fly ash and flue gas composition affect speciation, partitioning, and reactions of mercury under the full range of post-combustion zone conditions. This knowledge can then be used to predict the chemical transformation of mercury (elemental, oxidized or particulate) in the post combustion zone and thus help with the control of mercury emissions from coal-burning power plants. To accomplish this goal present study was conducted using five coal fly ashes. These ashes were characterized and their catalytic activity was compared under selected reaction conditions in a fixed bed reactor. Based on the results from these fly ash experiments, three key components (carbon, iron oxide and calcium oxide) were chosen. These three components were then used to prepare model fly ashes. Silica/alumina was used as a base for these model fly ashes. One, two or three component model fly ashes were then prepared to investigate mercury transformation reactions. The third set of experiments was performed with five different oxidation catalysts to further understand the mercury oxidation process. Based on the results of these three studies the key components were predicted for different fly ash compositions under variety of flue gas conditions. A fixed bed reactor system was used to conduct this study. In all the experiments, the inlet concentration of Hg0(g) was maintained at 35 mug/m 3 using a diffusion tube as the source of Hg0(g). All experiments were conducted using 4% O2 in nitrogen mix as a reaction gas, and other reactants (HCl, H2O and SO2, NO 2, Br2) were added as required. The fixed bed reactor was operated over a temperature range of 200 to 400°C. In each experiment, the reactor effluent was analyzed using the modified Ontario-Hydro method. After each experiment, fly ash particles were also analyzed for mercury. The results show that the ability of fly ash to adsorb and/or oxidize mercury is primarily dependent on its carbon, iron and calcium content. There can be either one or more than one key component at a particular temperature and flue gas condition. Surface area played a secondary role in effecting the mercury transformations when compared to the concentration of the key component in the fly ash. Amount carbon and surface area played a key important role in the adsorption of mercury. Increased concentration of gases in the flue gas other than oxygen and nitrogen caused decreased the amount of mercury adsorbed on carbon surface. Mercury adsorption by iron oxide primarily depended on the crystalline structure of iron oxide. alpha-iron oxide had no effect on mercury adsorption or oxidation under most of the flue gas conditions, but gamma-iron oxide adsorbed mercury under most of the flue gas conditions. Bromine is a very good oxidizing agent for mercury. But in the presence of calcium oxide containing fly ashes, all the oxidized mercury would be reduced to elemental form. Among the catalysts, it was observed that presence of free lattice chlorine in the catalyst was very important for the oxidation of mercury. But instead of using the catalyst alone, using it along with carbon may better serve the purpose by providing the adsorption surface for mercury and also some extra surface area for the reaction to occur (especially for fly ashes with low surface area).

Varanasi, Patanjali

402

Transformation by the oncogene v-fms: The effects of castanospermine on transformation-related parameters  

SciTech Connect

The effects of castanospermine on various parameters associated with transformation were examined in cells expressing the viral oncogene v-fms. Fischer rat embryo (FRE) cells transformed by the oncogene v-fms and grown in the presence of castanospermine reverted to a more normal cell morphology and accumulated fms protein within the endoplasmic reticulum. Treated cells attained contact inhibition of cell growth at a much lower cell density compared to the untreated controls. No effect of castanospermine on cell growth was observed for FRE cells transformed by a different oncogene v-fgr. Castanospermine-treated SM-FRE (v-fms transformed) cells reexpressed extracellular matrix fibronectin and exhibited an extensive actin-containing cytoskeleton similar to that of normal nontransformed FRE cells. Castanospermine treatment of SM-FRE cells resulted in a sixfold decrease in ({sup 3}H)deoxyglucose uptake compared to that of the nonreverted SM-FRE cells. Again, no effect was observed in FRE cells transformed by the oncogene v-fgr (GR-FRE). These results further characterize the reversion caused by castanospermine and indicate that cell surface expression coordinately controls anchorage independent growth, cell morphology, contact inhibition of growth, and hexose uptake.

Nichols, E.J.; Manger, R.; Hakomori, Senitiroh; Rohrschneider, L.R. (Fred Hutchinson Cancer Research Center, Seattle, WA (United States))

1987-12-01

403

Recent advances in plant transformation.  

PubMed

Plant genetic engineering has become one of the most important molecular tools in the modern molecular breeding of crops. Over the last decade, significant progress has been made in the development of new and efficient transformation methods in plants. Despite a variety of available DNA delivery methods, Agrobacterium- and biolistic-mediated transformation remain the two predominantly employed approaches. In particular, progress in Agrobacterium-mediated transformation of cereals and other recalcitrant dicot species has been quite remarkable. In the meantime, other transgenic-enabling technologies have emerged, including generation of marker-free transgenics, gene targeting, and chromosomal engineering. Although transformation of some plant species or elite germplasm remains a challenge, further advancement in transformation technology is expected because the mechanisms of governing the regeneration and transformation processes are now better understood and are being creatively applied to designing improved transformation methods or to developing new enabling technologies. PMID:21181522

Barampuram, Shyamkumar; Zhang, Zhanyuan J

2011-01-01

404

Image Transformations-Montserrat  

NASA Technical Reports Server (NTRS)

A slightly oblique digital photograph of Montserrat taken from the International Space Station was posted to Earth Observatory in December 2001. An Earth Observatory reader used widely available software to correct the oblique perspective and adjust the color. The story of how he modified the image includes step-by-step instructions that can be applied to other photographs. Photographs of Earth taken by astronauts have shaped our view of the Earth and are part of our popular culture because NASA makes them easily accessible to the public. Read the Transformations Story for more information. The original image was digital photograph number ISS002-E-9309, taken on July 9, 2001, from the International Space Station and was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth. Bill Innanen provided the transformed image and the story of how he did it.

2002-01-01

405

Energy: Energy Transformations  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Energy SciPack. It provides a conceptual and real-world understanding of how energy is transferred, from object to object and from one form of energy to another. Although the various forms of energy appear different, each can be measured in a closed system. This makes it possible to keep track of how much of one form of energy is converted into another form. Most of what goes on in the universe--from exploding stars and biological growth to the operation of machines and the motion of people--involves some form of energy being transformed into another form. The law of conservation of energy states that whenever the amount of energy in one place (or form) decreases, the amount of energy in other places (or forms) increases by the same amount. Learning Outcomes:� Recognize that there are ways to measure the amount of different kinds of energy that allow us to track how much of one form is changed into another.� Recognize that energy is conserved, meaning it is not "used up" and does not appear out of nowhere.� Give examples of transformation of energy, including recognizing the forms of energy involved.� Construct an argument against an example that claims to be a perpetual motion machine.

National Science Teachers Association (NSTA)

2006-11-01

406

Liquid Metal Transformers  

E-print Network

The room temperature liquid metal is quickly emerging as an important functional material in a variety of areas like chip cooling, 3D printing or printed electronics etc. With diverse capabilities in electrical, thermal and flowing behaviors, such fluid owns many intriguing properties that had never been anticipated before. Here, we show a group of unconventional phenomena occurring on the liquid metal objects. Through applying electrical field on the liquid metals immersed in water, a series of complex transformation behaviors such as self-assembling of a sheet of liquid metal film into a single sphere, quick mergences of separate metal droplets, controlled self-rotation and planar locomotion of liquid metal objects can be realized. Meanwhile, it was also found that two accompanying water vortexes were induced and reliably swirled near the rotating liquid metal sphere. Further, effects of the shape, size, voltage, orientation and geometries of the electrodes to control the liquid metal transformers were clarified. Such events are hard to achieve otherwise on rigid metal or conventional liquid spheres. This finding has both fundamental and practical significances which suggest a generalized way of making smart soft machine, collecting discrete metal fluids, as well as flexibly manipulating liquid metal objects including accompanying devices.

Lei Sheng; Jie Zhang; Jing Liu

2014-01-30

407

Transformational silicon electronics.  

PubMed

In today's traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 ?m), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry's most advanced high-?/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications. PMID:24476361

Rojas, Jhonathan Prieto; Torres Sevilla, Galo Andres; Ghoneim, Mohamed Tarek; Inayat, Salman Bin; Ahmed, Sally M; Hussain, Aftab Mustansir; Hussain, Muhammad Mustafa

2014-02-25

408

Physical characterization of cadmium telluride/cadmium sulfide photovoltaics: Defects, fields, and micrononuniformities  

NASA Astrophysics Data System (ADS)

Recent advances in large area thin-film photovoltaic manufacturing have raised a number of problems related to the physical parameters and processes behind the device efficiency and stability. The characteristics of interest include the defect spectra and related optical absorption, the built-in electric field distribution, the degree of lateral uniformity of the device, and the device stability. Established in this thesis is a set of techniques appropriate for the physical characterization of the above features in CdTe/CdS solar cells, addressing the issues of device spectra vs. energy (as revealed in the optical absorption, photoluminescence (PL), and admittance spectroscopy); the electric field distribution analyzed by means of bias dependent PL, and, indirectly, by capacitance measurements; device lateral resistivity and uniformity, through the phenomenon of nonlocal optical response and PL mapping; local parameter fluctuations as appear in virtually all of the above cases. The most important physical conclusions made are: energy spectra of polycrystalline CdTe based photovoltaics combine the features of crystalline materials, such as identifiable point defects, and amorphous materials, which exhibit continuous spectra of localized states; the concept of a single-defect (elemental) capacitance is for the first time defined and applied to estimate the density of states in polycrystalline p-n junctions; a phenomenon of bias-dependent PL in CdTe based photovoltaics is for the first time observed and modeled; a new phenomenon of nonlocal photovoltaic response is observed and interpreted. The results suggest several practical applications, such as: absorption and PL measurements as a diagnostic tool for monitoring the CdCl2, quality of treatments; admittance spectroscopy techniques to diagnose the material quality and degradation through its defect spectra and concentration; bias-dependent PL as a sensitive nondestructive accelerated life testing tool; nonlocal PV response as a transparent contact diagnostic tool in a finished device.

Shvydka, Diana

409

Lorentz-transformation and Galileo-transformation windows  

NASA Astrophysics Data System (ADS)

We define Lorentz-transformation windows as windows that change the direction of transmitted light rays like a Lorentz transformation. Similarly, Galileo-transformation windows change the direction of transmitted light rays like a Galileo transformation. This light-ray-direction change distorts the scene seen through such a window in the same way in which the scene would be distorted in a photo taken with a camera moving through the scene. Lorentz-transformation windows can also undo the distortion of the scene when moving at relativistic velocity relative to it. For small angles between the direction of the light rays and the direction of the velocity, Galileo-transformation windows can be realised with relatively simple telescope windows, which consist of arrays of identical micro-telescopes.

Oxburgh, Stephen; Gray, Norman; Hendry, Martin; Courtial, Johannes

2014-09-01

410

Clifford Algebra and Space-Time Transformations: Lorentz Transformation and Inertial Transformation  

E-print Network

We review the Inertial transformation and Lorentz transformation under a new context, by using Clifford Algebra or Geometric Algebra. The apparent contradiction between theses two approach is simply stems from different procedures for clock synchronization associated with different choices of the coordinates used to describe the physical world. We find the physical and coordinates components of both transformations. A important result is that in the case of Inertial transformation the physical components are exactly the Galilean transformations, but the speed of light is not c. Another interesting result is due to the fact the Lorentz transformations lead directly to physical components, and this case the speed of light is c. Finally e show that both scenarios, de-synchronization Einstein theory and synchronized theory, are all mathematically equivalent by means of Clifford Algebra Transformations.

R. de Oliveira; S. J. da Silva; V. H. G. de Campos

2013-11-25

411

LU transformation invariant operators and LU transformation invariant  

E-print Network

We proposed a concept of LU transformation invariant operators. By using this operator, arbitrary multi-qubit states LU transformation invariant and SLOCC invariant could be easily obtained. And we find that presences two kinds of invariant operators and corresponding invariants. One kind of operators yields LU invariants and the other operators results in SLOCC invariants. For three-qubit states, all independence LU transformation invariant are obtained. Furthermore, by this system method, arbitrary multi-qubit states invariants can be given.

Xin-wei Zha; Chun-min Zhang

2007-02-06

412

Genetic transformation of Ascochyta rabiei using Agrobacterium -mediated transformation  

Microsoft Academic Search

In order to study pathogenic mechanisms of the plant pathogen Ascochyta rabiei, conditions for efficient transformation using Agrobacterium-mediated transformation were investigated. Hygromycin B resistance (hph) was superior to geneticin resistance (nptII) for selecting transformants, and the hph gene was more efficiently expressed by the Aspergillus nidulans\\u000a trpC promoter than by the Cauliflower mosaic virus 35S promoter CaMV35S. Co-cultivation on solid

David White; Weidong Chen

2006-01-01

413

Microfabricated electrodynamic transformers for electromechanical power conversion  

NASA Astrophysics Data System (ADS)

This paper presents a compact power electronic device, called an ‘electrodynamic transformer (ET)’, that transfers electrical power between isolated circuits through electrodynamically coupled vibrations of a mechanical beam structure. Background motivating factors are discussed, and an equivalent circuit model of the ET is presented. A microscale (10 mm3) ET is designed, fabricated and characterized, achieving ?40% maximum efficiency. Taking advantage of the unique circuit topology of the ET equivalent circuit model, a dc/ac power inverter is then implemented with only two external components, a MOSFET and a capacitor.

Cheng, Shuo; Arnold, David P.

2013-11-01

414

Fourier transform and related integral transforms in superspace  

E-print Network

In this paper extensions of the classical Fourier, fractional Fourier and Radon transforms to superspace are studied. Previously, a Fourier transform in superspace was already studied, but with a different kernel. In this work, the fermionic part of the Fourier kernel has a natural symplectic structure, derived using a Clifford analysis approach. Several basic properties of these three transforms are studied. Using suitable generalizations of the Hermite polynomials to superspace (see [H. De Bie, F. Sommen, Hermite and Gegenbauer polynomials in superspace using Clifford analysis, J. Phys. A 40 (2007) 10441-10456]) an eigenfunction basis for the Fourier transform is constructed.

Hendrik De Bie

2008-05-13

415

Imaging Fourier Transform Spectrometer  

SciTech Connect

The operating principles of an Imaging Fourier Transform Spectrometer (IFTS) are discussed. The advantages and disadvantages of such instruments with respect to alternative imaging spectrometers are discussed. The primary advantages of the IFTS are the capacity to acquire more than an order of magnitude more spectral channels than alternative systems with more than an order of magnitude greater etendue than for alternative systems. The primary disadvantage of IFTS, or FTS in general, is the sensitivity to temporal fluctuations, either random or periodic. Data from the IRIFTS (ir IFTS) prototype instrument, sensitive in the infrared, are presented having a spectral sensitivity of 0.01 absorbance units, a spectral resolution of 6 cm{sup {minus}1} over the range 0 to 7899 cm{sup {minus}1}, and a spatial resolution of 2.5 mr.

Bennett, C.L.; Carter, M.R.; Fields, D.J.; Hernandez, J.

1993-04-14

416

Transforming Cities With Transit  

NSDL National Science Digital Library

How are cities transformed by the creation of new transit lines? How can existing transit lines be modified to create new land use opportunities for housing and commercial properties? These subjects are covered by a 172-page conference edition of a forthcoming paper from the World Bank. The paper was authored by Hiroaki Suzuki, Robert Cervero, and Kanako Iuchi. Visitors will note that the work focuses on "identifying barriers to and opportunities for effective coordination of transport infrastructure and urban development." The work takes on a number of global best practices of transit-oriented metropolises that have direct relevance to cities in developing countries and offers both analysis and suggestions for future projects. Sections here include "Lessons from Sustainable Transit-Oriented Cities," "Integrating Transit and Urban Development in Cities in the Developing World," and "Toward Sustainable Urban Futures."

Cervero, Robert.; Iuchi, Kanako; Suzuki, Hiroaki

417

Improving facilities, transforming attitudes.  

PubMed

Providing an effective healing environment for patients facing a wide range of mental health issues, while balancing their needs with security, safety, and affordability considerations, will be key area of focus at this year's Design in Mental Health (DIMH) conference and exhibition, taking place from 13-14 May at the National Motorcycle Museum in Bickenhill near Solihull. As HEJ editor, Jonathan Baillie, reports, conference speakers will include the director of estates and new business at the Priory Group; the chief executive of mental health charity, Mind; architects and designers with substantial mental healthcare experience; top academics, and service-users--all with their own perspective on the 2014 conference theme, 'Improving facilities, transforming attitudes'. PMID:24783329

Baillie, Jonathan

2014-04-01

418

Infrared transform spectral imager  

NASA Astrophysics Data System (ADS)

A dispersive transform spectral imager named FAROS (FAst Reconfigurable Optical Sensor) has been developed for high frame rate, moderate-to-high resolution hyperspectral imaging. A programmable digital micromirror array (DMA) modulator makes it possible to adjust spectral, temporal and spatial resolution in real time to achieve optimum tradeoff for dynamic monitoring requirements. The system's F/2.8 collection optics produces diffraction-limited images in the mid-wave infrared (MWIR) spectral region. The optical system is based on a proprietary dual-pass Offner configuration with a single spherical mirror and a confocal spherical diffraction grating. FAROS fulfills two functions simultaneously: one output produces two-dimensional polychromatic imagery at the full focal plane array (FPA) frame rate for fast object acquisition and tracking, while the other output operates in parallel and produces variable-resolution spectral images via Hadamard transform encoding to assist in object discrimination and classification. The current version of the FAROS spectral imager is a multispectral technology demonstrator that operates in the MWIR with a 320 x 256 pixel InSb FPA running at 478 frames per second resulting in time resolution of several tens of milliseconds per hypercube. The instrument has been tested by monitoring small-scale rocket engine firings in outdoor environments. The instrument has no macro-scale moving parts, and conforms to a robust, small-volume and lightweight package, suitable for integration with small surveillance vehicles. The technology is also applicable to multispectral/hyperspectral imaging applications in diverse areas such as atmospheric contamination monitoring, agriculture, process control, and biomedical imaging, and can be adapted for use in any spectral domain from the ultraviolet (UV) to the LWIR region.

Vujkovic-Cvijin, Pajo; Lee, Jamine; Gregor, Brian; Goldstein, Neil; Panfili, Raphael; Fox, Marsha

2012-10-01

419

Electrolytic phase transformation actuators  

NASA Astrophysics Data System (ADS)

The emerging field of materials-based actuation continues to be the focus of considerable research due to its inherent scalability and its promise to drive devices in ways that cannot be realized with conventional mechanical actuator strategies. Current approaches include electrochemically responsive conducting polymers, capacitance-driven carbon nanotubes actuators, pH responsive hydrogels, ionic polymer metal composites, electric field responsive elastomers, and field-driven electrostrictive polymers. However, simple electrochemical processes that lead to phase transformations, particularly from liquid to gas, have been virtually ignored. Although a few specialized applications have been proposed, the nature of the reactions and their implication for design, performance, and widespread applicability have not been addressed. Herein we report an electrolytic phase transformation (EPT) actuator, a device capable of producing strains surpassing 136,000% and stresses beyond 200 MPa. These performance characteristics are several orders of magnitude greater than those reported for other materials and could potentially compete with existing commercial hydraulic systems. Furthermore, unlike other materials-based systems that rely on bimorph structures to translate infinitesimally small volume changes into observable deflections, this device can direct all of its output towards linear motion. We show here that an unoptimized actuator prototype can produce volume and pressure changes close to the theoretically predicted values, with maximum stress (70 kPa) limited only by the mechanical strength of the apparatus. Expansion is very rapid and scales with applied current density. Retraction depends on the catalytic nature of the electrode, and state-of-the-art commercial fuel cell electrodes should allow rates surpassing 0.9 mL's-1.cm-2 and 370 kPa's-1.cm-2. We anticipate that this approach will provide a new direction for producing scalable, low-weight, high performance actuators that will be useful in a broad range of applications.

Cameron, Colin G.; Freund, Michael S.

2003-07-01

420

7 transformations of leadership.  

PubMed

Most developmental psychologists agree that what differentiates one leader from another is not so much philosophy of leadership, personality, or style of management. Rather, it's internal "action logic"--how a leader interprets the surroundings and reacts when his or her power or safety is challenged. Relatively few leaders, however, try to understand their action logic, and fewer still have explored the possibility of changing it. They should, because leaders who undertake this voyage of personal understanding and development can transform not only their own capabilities but also those of their companies. The authors draw on 25 years of consulting experience and collaboration with psychologist Susanne Cook-Greuter to present a typology of leadership based on the way managers personally make sense of the world around them. Rooke and Torbert classify leaders into seven distinct actionlogic categories: Opportunists, Diplomats, Experts, Achievers, Individualists, Strategists, and Alchemists-the first three associated with below-average performance, the latter four with medium to high performance. These leadership styles are not fixed, the authors say, and executives who are willing to work at developing themselves and becoming more self-aware can almost certainly move toward one of the more effective action logics. A Diplomat, for instance, can succeed through hard work and self-reflection at transforming himself into a Strategist. Few people may become Alchemists, but many will have the desire and potential to become Individualists and Strategists. Corporations that help their executives and leadership teams to examine their action logics can reap rich rewards. PMID:15807040

Rooke, David; Torbert, William R

2005-04-01

421

A study of transformations of ?-solid solution in shape-memory alloys of the Cu-Zn-Al system  

Microsoft Academic Search

Conclusions  1. The ? ? ? transformation in high-temperature decomposition of alloys of the Cu - Zn - Al system has features of diffusion\\u000a and martensitic transformations. The shapes of the crystals, their merging, and the change in the chemical composition characterize\\u000a the ? ? ? transformation as a diffusion one. The spatial distribution of rods of the ?-phase within the

I. V. Khomskaya; V. I. Zel’dovich; N. Yu. Frolova

2000-01-01

422

Fabrication and Characterization of Nanowires  

E-print Network

- dustries. In order to enhance the applicability of Shape Memory Alloys (SMAs) in systems such as Nano-Electromechanical Systems, the phase transformation behavior of SMA nanostructures should be explored. The primary focus of this work... is on the fabrication of metallic nanowires and the characterization of the phase transformation of SMA nanowires. Various metallic nanowires are fabricated through the use of the mechanical pressure injection method. The mechanical pressure injection method is a...

Phillips, Francis Randall

2011-10-21

423

Transformation plasticity in ductile solids  

SciTech Connect

Research has addressed the role of martensitic transformation plasticity in the enhancement of toughness in high-strength austenitic steels, and the enhancement of formability in multiphase low-alloy sheet steels. In the austenitic steels, optimal processing conditions have been established to achieve a significant increase in strength level, in order to investigate the interaction of strain-induced transformation with the microvoid nucleation and shear localization mechanisms operating at ultrahigh strength levels. The stress-state dependence of transformation and fracture mechanisms has been investigated in model alloys, comparing behavior in uniaxial tension and blunt-notch tension specimens. A numerical constitutive model for transformation plasticity has been reformulated to allow a more thorough analysis of transformation/fracture interactions. Processing of a new low alloy steel composition has been optimized to stabilize retained austenite by isothermal bainitic transformation after intercritical annealing. Preliminary results show a good correlation of uniform ductility with the austenite amount and stability.

Olson, G.B.

1993-02-01

424

Alchemical attention: Shaw's transformational matrix  

E-print Network

ideas. I argue for the thesis that Shaw dramatically bodies forth the idea that a human being may be transformed through the agency of an inner female principle, a principle that itself bridges the chasm between the lower nature and the higher nature... sacred idea, intended not to explain transformation but rather to catalyze, guide, and support it. Concluding thoughts concerning the nature of this transformation are presented in chapter nine. TABLE OF CONTENTS Page ABSTRACT TABLE OF CONTENTS...

Bryant, Gary Richard

2012-06-07

425

Cereal transformation through particle bombardment  

NASA Technical Reports Server (NTRS)

The review focuses on experiments that lead to stable transformation in cereals using microprojectile bombardment. The discussion of biological factors that affect transformation examines target tissues and vector systems for gene transfer. The vector systems include reporter genes, selectable markers, genes of agronomic interest, and vector constructions. Other topics include physical parameters that affect DNA delivery, selection of stably transformed cells and plant regeneration, and analysis of gene expression and transmission to the progeny.

Casas, A. M.; Kononowicz, A. K.; Bressan, R. A.; Hasegawa, P. M.; Mitchell, C. A. (Principal Investigator)

1995-01-01

426

Genetic transformation of Vitreoscilla sp  

Microsoft Academic Search

Of all the methods customarily used to transform E. coli we found only electroporation to be effective for transformation of the Gram-negative bacterium Vitreoscilla, yielding 5.105 transformants\\/?g of plasmid DNA. The conditions used were close to those described for E. coli. E. coli plasmids are stably maintained in Vitreoscilla. This is the first report of exogenous DNA transfer in Vitreoscilla

Naveen K. Navani; Meenal A. Joshi; Kanak L. Dikshit

1996-01-01

427

Discrete Pulse Transform of Images  

Microsoft Academic Search

\\u000a The Discrete Pulse Transform (DPT) of images is defined by using a new class of LULU operators on multidimensional arrays.\\u000a This transform generalizes the DPT of sequences and replicates its essential properties, e.g. total variation preservation.\\u000a Furthermore, the discrete pulses in the transform capture the contrast in the original image on the boundary of their supports.\\u000a Since images are perceived

Roumen Anguelov; Inger Fabris-rotelli

2008-01-01

428

Continuous boundary local Fourier transform  

NASA Astrophysics Data System (ADS)

The Local Fourier Transform (LFT) provides a nice tool for concentrating both a signal and its Fourier transform. But there are certain properties of this algorithm that make it unattractive for various applications. In this paper, some of these disadvantages are explored, and a new approach to localized Fourier analysis is proposed, the continuous boundary local Fourier transform (CBLFT), which attempts to correct some of these shortcomings. Results ranging from segmentation to representation cost to compression are also presented.

Larson, Brons M.; Saito, Naoki

2001-12-01

429

Tree Transducer Composition Program Transformation  

E-print Network

a specific transformation for the elimination of inter� mediate results (for so called deforestation . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Deforestation and accumulating parameters . . . . . . . . . . . . . .

Eckmiller, Rolf

430

Algorithm For Integer Cosine Transforms  

NASA Technical Reports Server (NTRS)

Algorithm computes coefficients of integer cosine transforms, containing only integer coefficients approximately proportional to floating-point coefficients of discrete cosine transforms. Used in compression of image data in blocks of N x N pixels, discrete cosine transforms involve large amounts of computation, typically amounting to 80 percent of computational load in data-compression scheme. In constructing integer approximations, competing requirements are to obtain data-compression and data-decompression performances comparable to those of corresponding descrete cosine transforms while taking advantage of simplicity afforded by integer arithmetic to reduce complexity and amount of computation.

Pollara, Fabrizio; Cheung, Kar-Ming; Shahshahani, Mehrdad

1994-01-01

431

Anthropogenic transformation of the biomes, 1700 to 2000  

E-print Network

RESEARCH PAPER Anthropogenic transformation of the biomes, 1700 to 2000 Erle C. Ellis1 *, Kees biomes (anthromes) were mapped for 1700, 1800, 1900 and 2000 using a rule-based anthrome classification- mation of terrestrial biomes was then characterized by map comparisons at century intervals. Results

Ellis, Erle C.

432

Rainbow Fourier transform Mikhail D. Alexandrov a,b,n  

E-print Network

Rainbow Fourier transform Mikhail D. Alexandrov a,b,n , Brian Cairns b , Michael I. Mishchenko b Rainbow Optical particle characterization Remote sensing a b s t r a c t We present a novel technique between 1351 and 1651 exhibit a sharply defined rainbow structure, the shape of which is determined mostly

433

Expression of transforming growth factor-?1 during diabetic renal hypertrophy  

Microsoft Academic Search

Expression of transforming growth factor-?1 during diabetic renal hypertrophy. Experimental type I diabetes mellitus is characterized by an early increase in kidney weight and glomerular volume, but changes in gene expression accompanying diabetic renal growth have not been fully elucidated. In the current study, total RNA was extracted from renal cortex and isolated glomeruli of streptozotocin-induced diabetic rats 24 hours,

Stuart J Shankland; James W Scholey; Hao Ly; Kerri Thai

1994-01-01

434

Mobius Transformations, Power Diagrams, Lombardi Drawings, and Soap Bubbles  

E-print Network

M¨obius Transformations, Power Diagrams, Lombardi Drawings, and Soap Bubbles David Eppstein Euro of degree four) has a planar Lombardi drawing We also use it to characterize the graphs of planar soap bubble clusters: they are exactly the bridgeless 3-regular planar graphs #12;Inversion through a circle

Eppstein, David

435

Mediating the Conflict between Transformative Pedagogy and Bureaucratic Practice  

ERIC Educational Resources Information Center

This article reflects on the authors' experiences during a pilot year of an innovative core curriculum at a state research university and their attempts to create a "collaborative community" characterized by transformative pedagogy. It discusses their students' and colleagues' resistance to their inventive, albeit time-consuming and sometimes…

Inderbitzin, Michelle; Storrs, Debbie A.

2008-01-01

436

Phase transformations in xerogels of mullite composition  

NASA Technical Reports Server (NTRS)

Monophasic and diphasic xerogels have been prepared as precursors for mullite (3Al2O3-2SiO2). Monophasic xerogel was synthesized from tetraethyl orthosilicate and aluminum nitrate nanohydrate and the diphasic xerogel from colloidal suspension of silica and boehmite. The chemical and structural evolutions, as a function of thermal treatment, in these two types of sol-gel derived mullite precursor powders have been characterized by DTA, TGA, X-ray diffraction, SEM and infrared spectroscopy. Monophasic xerogel transforms to an Al-Si spinel from an amorphous structure at approximately 980 C. The spinel then changes into mullite on further heating. Diphasic xerogel forms mullite at approximately 1360 C. The components of the diphasic powder react independently up to the point of mullite formation. The transformation in the monophasic powder occurs rapidly and yields strongly crystalline mullite with no other phases present. The diphasic powder, however, transforms rather slowly and contains remnants of the starting materials (alpha-Al2O3, cristobalite) even after heating at high temperatures for long times (1600 C, 6 hr). The diphasic powder could be sintered to high density but not the monophasic powder in spite of its molecular level homogeneity.

Hyatt, Mark J.; Bansal, Narottam P.

1988-01-01

437

Tripartite entanglement transformations and tensor rank  

E-print Network

Understanding the nature of multipartite entanglement is a central mission of quantum information theory. To this end, we investigate the question of tripartite entanglement convertibility. We find that there exists no easy criterion to determine whether a general tripartite transformation can be performed with a nonzero success probability and in fact, the problem is NP-hard. Our results are based on the connections between multipartite entanglement and tensor rank (also called Schmidt rank), a key concept in algebraic complexity theory. Not only does this relationship allow us to characterize the general difficulty in determining possible entanglement transformations, but it also enables us to observe the previously overlooked fact that {\\em the Schmidt rank is not an additive entanglement measure}. As a result, we improve some best known transformation rates between specific tripartite entangled states. In addition, we find obtaining the most efficient algorithm for matrix multiplication to be precisely equivalent to determining the optimal rate of conversion between the Greenberger-Horne-Zeilinger state and a triangular distribution of three Einstein-Podolsky-Rosen states.

Eric Chitambar; Runyao Duan; Yaoyun Shi

2008-05-19

438

Mitochondrial DNA Heteroplasmy in Candida glabrata after Mitochondrial Transformation ? †  

PubMed Central

Genetic manipulation of mitochondrial DNA (mtDNA) is the most direct method for investigating mtDNA, but until now, this has been achieved only in the diploid yeast Saccharomyces cerevisiae. In this study, the ATP6 gene on mtDNA of the haploid yeast Candida glabrata (Torulopsis glabrata) was deleted by biolistic transformation of DNA fragments with a recoded ARG8m mitochondrial genetic marker, flanked by homologous arms to the ATP6 gene. Transformants were identified by arginine prototrophy. However, in the transformants, the original mtDNA was not lost spontaneously, even under arginine selective pressure. Moreover, the mtDNA transformants selectively lost the transformed mtDNA under aerobic conditions. The mtDNA heteroplasmy in the transformants was characterized by PCR, quantitative PCR, and Southern blotting, showing that the heteroplasmy was relatively stable in the absence of arginine. Aerobic conditions facilitated the loss of the original mtDNA, and anaerobic conditions favored loss of the transformed mtDNA. Moreover, detailed investigations showed that increases in reactive oxygen species in mitochondria lacking ATP6, along with their equal cell division, played important roles in determining the dynamics of heteroplasmy. Based on our analysis of mtDNA heteroplasmy in C. glabrata, we were able to generate homoplasmic ?atp6 mtDNA strains. PMID:20207853

Zhou, Jingwen; Liu, Liming; Chen, Jian

2010-01-01

439

Characterizations of severely deformed and annealed copper  

E-print Network

The objectives of this study were to characterize severely plastically deformed and recrystallized oxygen free high conductivity copper, to determine texture transformation potential of Equal Channel Angular Extrusion (ECAE) and to investigate...

Haouaoui, Mohammed

2012-06-07

440

Genetic analysis of transformation in a microconidiating strain of Neurospora crassa  

Microsoft Academic Search

We have characterized Neurospora crassa transformants obtained with plasmid pDV1001 bearing the cloned catabolic dehydroquinase (qa-2+) gene (Hughes et al. 1983) and fluffy 268 host strain producing only uninucleate microconidia allowing to isolate individual transformation products. The percentage of transformed nuclei in the mycelium and their stability were determined by genetic analysis of microconidia produced on selective or non-selective medium.

Claude Rossier; Anne Pugin; Gilbert Turian

1985-01-01

441

Coordinate Transformations in Object Recognition  

ERIC Educational Resources Information Center

A basic problem of visual perception is how human beings recognize objects after spatial transformations. Three central classes of findings have to be accounted for: (a) Recognition performance varies systematically with orientation, size, and position; (b) recognition latencies are sequentially additive, suggesting analogue transformation

Graf, Markus

2006-01-01

442

Lightning Protection for Distribution Transformers  

Microsoft Academic Search

This paper presents a five year history of the results of lightning arrester protection for distribution transformers in New England where the normal ground electrode resistance is much higher than in most other parts of this country. The experience shows that the trouble rate of the protected transformers has consistently been materially less than that of those not protected, notwithstanding

T. H. Haines; C. A. Corney

1932-01-01

443

Conformal Transformations and Space Travel  

Microsoft Academic Search

Conformal transformations are applied to the motion of a space ship experiencing a constant acceleration. The role of proper time is interpreted in terms of atomic periods, and the relationship between the conformal transformations and the general theory of relativity is clarified.

Suraj N. Gupta

1961-01-01

444

Travel and Adult Transformative Learning  

ERIC Educational Resources Information Center

This phenomenological research study examines the lived experience of individual adult transformation in the context of travel. Adults throughout history have experienced profound personal and perception changes as a result of significant travel events. Transformative learning occurs through experience, crisis, and reflection, all of which are…

Lindstrom, Steven K.

2011-01-01

445

Transformative Learning: Mutinous Thoughts Revisited  

ERIC Educational Resources Information Center

The author finds himself rereading an article he wrote several years ago, in which he questioned transformative learning. He recalls some of his reasons for writing the article, and considers his present position. He reflects on the understanding of consciousness that underlies much of the literature on transformative learning, and compares it…

Newman, Michael

2014-01-01

446

Transformation of encapsulated Streptococcus pneumoniae.  

PubMed Central

We describe the high-efficiency transformation of several virulent, encapsulated isolates of Streptococcus pneumoniae. Transformation was effected by the induction of competence with competence factor and was apparently the result both of inducing noncompetent recipients and overcoming the inhibition imposed by the capsule. PMID:3782044

Yother, J; McDaniel, L S; Briles, D E

1986-01-01

447

Towards Transformative Leadership in Education  

ERIC Educational Resources Information Center

This article argues that an educational organization's type of leadership will to a very large extent determine the quality of personal transformation it instigates among its stakeholders. Focusing on the importance of transformative leadership, such leadership will be viewed as a critical and collaborative process in which school-based…

van Oord, Lodewijk

2013-01-01

448

Student Services Revitalization/Transformation  

ERIC Educational Resources Information Center

Over a two year period, a multidisciplinary team developed and implemented a plan to transform the delivery of student services at George Brown College in Toronto. It was a plan that called upon the College to fundamentally overhaul student services, but more importantly, to transform the service culture at the College through the students'…

Pipitone, Brenda; Poirer, Wayne

2011-01-01

449

Simplified Relativistic Force Transformation Equation.  

ERIC Educational Resources Information Center

A simplified relativistic force transformation equation is derived and then used to obtain the equation for the electromagnetic forces on a charged particle, calculate the electromagnetic fields due to a point charge with constant velocity, transform electromagnetic fields in general, derive the Biot-Savart law, and relate it to Coulomb's law.…

Stewart, Benjamin U.

1979-01-01

450

Real Time Pyramid Transform Architecture  

NASA Astrophysics Data System (ADS)

This paper describes an architecture for creating pyramid transforms of real time video images. A powerful preprocessor can be designed with this architecture by representing the image data in a form most suitable for the application. The Burt pyramid algorithm [1], an efficient method for transforming video images into hierarchical representation, is an example of an effective transform. A programmable version of such a preprocessor, occupying two Multibus* boards, was built at low cost using available hardware. This unit can perform the basic pyramid trans-form on 256 x 240 images in real time. More complex and/or multiple transforms can be performed at reduced data rate by passing data through the unit several times, or can be performed in real time by passing data through multiple units. Because the preprocessor is programmable, the system is easily configured to perform several different pyramid transforms, or the appropriate inverse transforms. Algorithms can be developed to reduce edge effects by modifying the edges of the image before applying the transform. The preprocessor can be programmed to insert time delays into the system, which is useful in the display of the results. Image processing system, design can be simplified by using the preprocessor to significantly reduce the computational requirements of the main processor. The proposed architecture, suitable for system integration, could lead to the availability of low cost, efficient image processing systems.

van der Wal, Gooitzen S.; Sinniger, Joseph O...

1985-12-01

451

Transformation of Wave Height Distribution  

Microsoft Academic Search

Earlier models of random wave transformation are reviewed in the first section. Then the transformation of waves, including dissipation due to breaking and bottom friction, is described by an energy flux balance model. The wave height pdf of all waves (broken and unbroken) is shown by the field data to be well described by the Rayleigh distribution everywhere. The observed

Edward B. Thornton; R. T. Guza

1983-01-01

452

Database Transformations for Biological Applications  

SciTech Connect

The goal of this project was to develop tools to facilitate data transformations between heterogeneous data sources found throughout biomedical applications. Such transformations are necessary when sharing data between different groups working on related problems as well as when querying data spread over different databases, files and software analysis packages.

Overton, C.; Davidson, S. B.; Buneman, P.; Tannen, V.

2001-04-11

453

Detrecting and Locating Partial Discharges in Transformers  

SciTech Connect

A collaborative research between the Oak Ridge National Laboratory (ORNL), the American Electric Power (AEP), the Tennessee Valley Authority (TVA), and the State of Ohio Energy Office (OEO) has been formed to conduct a feasibility study to detect and locate partial discharges (PDs) inside large transformers. The success of early detection of the PDs is necessary to avoid costly catastrophic failures that can occur if the process of PD is ignored. The detection method under this research is based on an innovative technology developed by ORNL researchers using optical methods to sense the acoustical energy produced by the PDs. ORNL researchers conducted experimental studies to detect PD using an optical fiber as an acoustic sensor capable of detecting acoustical disturbances at any point along its length. This technical approach also has the potential to locate the point at which the PD was sensed within the transformer. Several optical approaches were experimentally investigated, including interferometric detection of acoustical disturbances along the sensing fiber, light detection and ranging (LIDAR) techniques using frequency modulation continuous wave (FMCW), frequency modulated (FM) laser with a multimode fiber, FM laser with a single mode fiber, and amplitude modulated (AM) laser with a multimode fiber. The implementation of the optical fiber-based acoustic measurement technique would include installing a fiber inside a transformer allowing real-time detection of PDs and determining their locations. The fibers are nonconductive and very small (core plus cladding are diameters of 125 ?m for single-mode fibers and 230 ?m for multimode fibers). The research identified the capabilities and limitations of using optical technology to detect and locate sources of acoustical disturbances such as in PDs in large transformers. Amplitude modulation techniques showed the most promising results and deserve further research to better quantify the technique’s sensitivity and its ability to characterize a PD event. Other sensing techniques have been also identified, such as the wavelength shifting fiber optics and custom fabricated fibers with special coatings.

Shourbaji, A.; Richards, R.; Kisner, R. A.; Hardy, J.

2005-02-04

454

Fast Numerical Nonlinear Fourier Transforms  

E-print Network

The nonlinear Fourier transform, which is also known as the forward scattering transform, decomposes a periodic signal into nonlinearly interacting waves. In contrast to the common Fourier transform, these waves no longer have to be sinusoidal. Physically relevant waveforms are often available for the analysis instead. The details of the transform depend on the waveforms underlying the analysis, which in turn are specified through the implicit assumption that the signal is governed by a certain evolution equation. For example, water waves generated by the Korteweg-de Vries equation can be expressed in terms of cnoidal waves. Light waves in optical fiber governed by the nonlinear Schr\\"dinger equation (NSE) are another example. Nonlinear analogs of classic problems such as spectral analysis and filtering arise in many applications, with information transmission in optical fiber, as proposed by Yousefi and Kschischang, being a very recent one. The nonlinear Fourier transform is eminently suited to address them ...

Wahls, Sander

2014-01-01

455

Inversion of the star transform  

NASA Astrophysics Data System (ADS)

We define the star transform as a generalization of the broken ray transform introduced by us in previous work. The advantages of using the star transform include the possibility to reconstruct the absorption and the scattering coefficients of the medium separately and simultaneously (from the same data) and the possibility to utilize scattered radiation which, in the case of conventional x-ray tomography, is discarded. In this paper, we derive the star transform from physical principles, discuss its mathematical properties and analyze numerical stability of inversion. In particular, it is shown that stable inversion of the star transform can be obtained only for configurations involving odd number of rays. Several computationally-efficient inversion algorithms are derived and tested numerically.

Zhao, Fan; Schotland, John C.; Markel, Vadim A.

2014-10-01

456

Optimal oscillation-center transformations  

SciTech Connect

A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed.

Dewar, R.L.

1984-08-01

457

ENANTIOSELECTIVE MICROBIAL TRANSFORMATION OF THE PHENYLPYRAZOLE INSECTICIDE FIPRONIL IN ANOXIC SEDIMENTS  

EPA Science Inventory

Fipronil, a chiral insecticide, was biotransformed initially to fipronil sulfide in anoxic sediment slurries following a short lag period. Sediment slurries characterized as either sulfidogenic or methanogenic transformed fipronil with half-lives of approximately 35 and 40 days, ...

458

Instrument Line Shape Modeling and Correction for Off-Axis Detectors in Fourier Transform Spectrometry  

NASA Technical Reports Server (NTRS)

Spectra measured by off-axis detectors in a high-resolution Fourier transform spectrometer (FTS) are characterized by frequency scaling, asymmetry and broadening of their line shape, and self-apodization in the corresponding interferogram.

Bowman, K.; Worden, H.; Beer, R.