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In Vitro Modulation of Rat Liver Glyoxalase II Activity

Description: Glyoxylase II (Glo II, E.C. 3.1.2.6) catalyzes the hydrolysis of S-D-Lactoylglutathione (SLG) to D-Lactate and glutathione. This is the rate limiting step in the conversion of methylglyoxal to D-Lactate. The purpose of the present study was to determine whether or not a relationship exists between some naturally occuring metabolites and in vivo modulation of Glo II. We have observed a non-competitive inhibition (~ 45%) of Glo II in crude preparation of rat liver by GTP (0.3 mM). A factor (apparently protein),devoid of Glo II,when reconstituted with the purified Glo II, enhanced Glo II activity. This coordinate activation and inhibition of Glo II suggest a mechanism whereby SLG levels can be modulated in vivo.
Date: August 1988
Creator: Mbamalu, Godwin E.
Partner: UNT Libraries

The Preferred Oboe Vibrato: An Analysis of Pitch Modulation and Intensity Level Modulation

Description: The purpose of this study was to determine the pitch and intensity level characteristics found in the vibrati of preferred oboe players whose vibrato was ranked by a panel of experts. The investigation also sought to discover factors that distinguish the preferred oboe vibrato from vibrato that is less preferred.
Date: December 1996
Creator: Remley, Jon Stephen
Partner: UNT Libraries

Injection-locked composite lasers for mm-wave modulation : LDRD 117819 final report.

Description: This report summarizes a 3-year LDRD program at Sandia National Laboratories exploring mutual injection locking of composite-cavity lasers for enhanced modulation responses. The program focused on developing a fundamental understanding of the frequency enhancement previously demonstrated for optically injection locked lasers. This was then applied to the development of a theoretical description of strongly coupled laser microsystems. This understanding was validated experimentally with a novel 'photonic lab bench on a chip'.
Date: September 1, 2010
Creator: Wendt, Joel Robert; Vawter, Gregory Allen; Raring, James; Tauke-Pedretti, Anna; Alford, Charles Fred (Sandia Staffing Alliance, LLC, Albuquerque, NM); Skogen, Erik J. et al.
Partner: UNT Libraries Government Documents Department

Sub-picosecond optical switching with a negative index metamaterial

Description: Development of all-optical signal processing, eliminating the performance and cost penalties of optical-electrical-optical conversion, is important for continu,ing advances in Terabits/sec (Tb/s) communications.' Optical nonlinearities are generally weak, traditionally requiring long-path, large-area devicesl,2 or very high-Q, narrow-band resonator structures.3 Optical metamaterials offer unique capabilities for optical-optical interactions. Here we report 600 femtosecond (fs) all-optical modulation using a fIShnet (2D-perforated metallamorphous-Si (a-Si)/metal film stack) negative-index meta material with a structurally tunable broad-band response near 1.2 {micro}m. Over 20% modulation (experimentally limited) is achieved in a path length of only 116 nm by photo-excitation of carriers in the a-Si layer. This has the potential for Tb/s aU-optical communication and will lead to other novel, compact, tunable sub-picosecond (ps) photonic devices.
Date: January 1, 2009
Creator: Dani, Keshav M; Upadhya, Prashant C & Zahyum, Ku
Partner: UNT Libraries Government Documents Department

A General Purpose Log Counting Rate Meter Model B

Description: Abstract: This report is a brief description of a general purpose logarithmic counting rate meter developed at the Knolls Atomic Power Laboratory. The theory of operation and the circuit design are discussed. The use of a diode as a logarithmic element in the integrating circuit allows extremely accurate counting rate determinations over a five decade range.
Date: November 1, 1954
Creator: Stone, R. S. & Wade, E. J.
Partner: UNT Libraries Government Documents Department

Novel ultrasound scintillator

Description: This development project addressed the need for a faster, less expensive method of transmission ultrasound. It utilized the principle of frustrated total internal reflection to transduce acoustic pressure into optical modulation. These data were acquired an entire 2D plane at a time. This report described the modeling and verification of a final sensor design.
Date: February 9, 1999
Creator: Ashby, E; Ciarlo, D; Kallman, J S & Thomas, G
Partner: UNT Libraries Government Documents Department

Multiplexed gas spectroscopy using tunable VCSELs

Description: Detection and identification of gas species using tunable laser diode laser absorption spectroscopy has been performed using vertical cavity surface emitting lasers (VCSEL). Two detection methods are compared: direct absorbance and wavelength modulation spectroscopy (WMS). In the first, the output of a DC-based laser is directly monitored to detect for any quench at the targeted specie wavelength. In the latter, the emission wavelength of the laser is modulated by applying a sinusoidal component on the drive current of frequency {omega}, and measuring the harmonics component (2{omega}) of the photo-detected current. This method shows a better sensitivity measured as signal to noise ratio, and is less susceptible to interference effects such as scattering or fouling. Gas detection was initially performed at room temperature and atmospheric conditions using VCSELs of emission wavelength 763 nm for oxygen and 1392 nm for water, scanning over a range of approximately 10 nm, sufficient to cover 5-10 gas specific absorption lines that enable identification and quantization of gas composition. The amplitude and frequency modulation parameters were optimized for each detected gas species, by performing two dimensional sweeps for both tuning current and either amplitude or frequency, respectively. We found that the highest detected signal is observed for a wavelength modulation amplitude equal to the width of the gas absorbance lines, in good agreement with theoretical calculations, and for modulation frequencies below the time response of the lasers (<50KHz). In conclusion, we will discuss limit of detection studies and further implementation and packaging of VCSELs in diode arrays for continuous and simultaneous monitoring of multiple species in gaseous mixtures.
Date: April 10, 2012
Creator: Bond, T; Bond, S; McCarrick, J; Zumstein, J; Chang, A; Moran, B et al.
Partner: UNT Libraries Government Documents Department

Key Schemes and Modulation Techniques in the Development Sections of First Movements in Sonata-Allegro Form of Piano Sonatas by Haydn

Description: Sections of Haydn's piano sonatas chosen for study have been analyzed to determine the composer's technique in modulation and the key schemes resulting from these modulations, and to discover the consistent patterns and exceptional patterns in these sonata movements as a group. As revealed in this analysis, Haydn is consistent in that the key scheme patterns of several development sections are identical. Also modulations, as categorized according to key relationships, are often accomplished by the same or similar procedures. However, there are important and interesting exceptions to these consistent practices which add variety and seem to contribute to Haydn's growth as a composer
Date: August 1974
Creator: Phillips, Kathryn Elaine
Partner: UNT Libraries

Stress Pulse-Trains from Multiple Reflection at a Zone of Many Discontinuities: a Notation for Machine Solution

Description: Abstract: "Presented in this report is a numerical method by which may be calculated the amplitudes of the trains of pulses that result when a single simple stress pulse encounters a zone of many abrupt discontinuities in a slender rod. The notational scheme employed enables the system of multitudes of individual progagating waves to be studied in terms of analogous number sets which may be mechanically generated. The notational concept and related operational rules, described in this report, have been used to program the problem for solution with the IBM 704 computer. The program is briefly discussed. Illustrative examples were computed for rods of two to ten discontinuities. These were compared with a pulse reflected in a rod of an unlimited number of steps."
Date: August 1962
Creator: Reed, R. P.
Partner: UNT Libraries Government Documents Department

Characterization of electron clouds in the Cornell Electron Storage Ring Test Accelerator using TE-wave transmission

Description: A relatively new technique for measuring the electron cloud density in storage rings has been developed and successfully demonstrated [S. De Santis, J.M. Byrd, F. Caspers, A. Krasnykh, T. Kroyer, M.T.F. Pivi, and K.G. Sonnad, Phys. Rev. Lett. 100, 094801 (2008).]. We present the experimental results of a systematic application of this technique at the Cornell Electron Storage Ring Test Accelerator. The technique is based on the phase modulation of the TE mode transmitted in a synchrotron beam pipe caused by the periodic variation of the density of electron plasma. Because of the relatively simple hardware requirements, this method has become increasingly popular and has been since successfully implemented in several machines. While the principles of this technique are straightforward, quantitative derivation of the electron cloud density from the measurement requires consideration of several effects, which we address in detail.
Date: January 2, 2010
Creator: De Santis, S.; Byrd, J. M.; Billing, M.; Palmer, M.; Sikora, J. & Carlson, B.
Partner: UNT Libraries Government Documents Department

Chromaticity measurement using a continuous head-tail kicking technique

Description: In the classical head-tail chromaticity measurement technique, a single large kick is applied transversely to the beam. The resulting phase difference between the head and the tail is measured and the chromaticity extracted. In the continuous head-tail kicking technique, a very small transverse kick is applied to the beam and the asymptotic phase difference between the head and the tail is found to be a function of chromaticity. The advantage of this method is that since the tune tracker PLL already supplies the small transverse kicks, no extra modulation is required.
Date: June 1, 2007
Creator: Tan, C.Y.; /Fermilab; Ranjbar, V.H. & /Tech-X, Boulder
Partner: UNT Libraries Government Documents Department

Constraints on inelastic dark matter from XENON10

Description: It has been suggested that dark matter particles which scatter inelastically from detector target nuclei could explain the apparent incompatibility of the DAMA modulation signal (interpreted as evidence for particle dark matter) with the null results from CDMS-II and XENON10. Among the predictions of inelastically interacting dark matter are a suppression of low-energy events, and a population of nuclear recoil events at higher nuclear recoil equivalent energies. This is in stark contrast to the well-known expectation of a falling exponential spectrum for the case of elastic interactions. We present a new analysis of XENON10 dark matter search data extending to E{sub nr} = 75 keV nuclear recoil equivalent energy. Our results exclude a significant region of previously allowed parameter space in the model of inelastically interacting dark matter. In particular, it is found that dark matter particle masses m{sub x} {approx}> 150 GeV are disfavored.
Date: November 23, 2009
Creator: Angle, J; Aprile, E; Arneodo, F; Baudis, L; Bernstein, A; Bolozdynya, A et al.
Partner: UNT Libraries Government Documents Department

Terahertz metamaterials

Description: In this paper we present our recent developments in terahertz (THz) metamaterials and devices. Planar THz metamaterials and their complementary structures fabricated on suitable substrates have shown electric resonant response, which causes the band-pass or band-stop property in THz transmission and reflection. The operational frequency can be further tuned up to 20% upon photoexcitation of an integrated semiconductor region in the splitring resonators as the metamaterial elements. On the other hand, the use of semiconductors as metamaterial substrates enables dynamical control of metamaterial resonances through photoexcitation, and reducing the substrate carrier lifetime further enables an ultrafast switching recovery. The metamaterial resonances can also be actively controlled by application of a voltage bias when they are fabricated on semiconductor substrates with appropriate doping concentration and thickness. Using this electrically driven approach, THz modulation depth up to 80% and modulation speed of 2 MHz at room temperature have been demonstrated, which suggests practical THz applications.
Date: January 1, 2009
Creator: Chen, Hou-tong; Taylor, Antoineete J; Azad, Abul K & O' Hara, John F
Partner: UNT Libraries Government Documents Department

Fearful Faces do Not Lead to Faster Attentional Deployment in Individuals with Elevated Psychopathic Traits

Description: This article discusses a gaze-cueing experiment in which the predictivity of a gaze-cue was manipulated to assess the degree to which individuals with elevated psychopathic traits can use contextual information.
Date: June 30, 2017
Creator: Hoppenbrouwers, Sylvo S.; Munneke, Jaap; Kooiman, Karen A.; Little, Bethany; Neumann, Craig S. & Theeuwes, Jan
Partner: UNT College of Arts and Sciences

A Comparison of Photoresist Resolution Metrics using 193 nm and EUV Lithography

Description: Image blur due to chemical amplification represents a fundamental limit to photoresist performance and manifests itself in many aspects of lithographic performance. Substantial progress has been made in linking image blur with simple resolution metrics using EUV lithography. In this presentation, they examine performance of 193 nm resist and EUV resist systems using modulation transfer function, corner rounding, and other resolution metrics. In particular, they focus on cross-comparisons in which selected EUV and 193 nm resist are evaluated using both EUV and 193 nm lithography. Simulation methods linking 193 nm and EUV performance will be described as well. Results from simulation indicate that image blur in current generation 193 nm photoresists is comparable to that of many EUV resists, but that ultra-low diffusion materials designs used in very high resolution EUV resists can result in substantially lower blur. In addition to detailing correlations between EUV and 193 nm experimental methods, they discuss their utility in assessing performance needs of future generation photoresists.
Date: August 20, 2007
Creator: Jones, Juanita; Pathak, Piyush; Wallow, Thomas; LaFontaine, Bruno; Deng, Yunfei; Kim, Ryoung-han et al.
Partner: UNT Libraries Government Documents Department

Preliminary Studies of a Phase Modulation Technique for Measuring Chromaticity

Description: The classical method for measuring chromaticity is to slowly modulate the RF frequency and then measuring the betatron tune excursion. The technique that is discussed in this paper modulates instead the phase of the RF and then the chromaticity is obtained by phase demodulating the betatron tune. However, this technique requires knowledge of the betatron frequency in real time in order for the phase to be demodulated. Fortunately, the Tevatron has a tune tracker based on the phase locked loop principle which fits this requirement. A preliminary study with this technique has showed that it is a promising method for doing continuous chromaticity measurement and raises the possibility of doing successful chromaticity feedback with it.
Date: April 1, 2006
Creator: Tan, Cheng-Yang
Partner: UNT Libraries Government Documents Department

Chromaticity tracking using a phase modulation technique

Description: In the classical chromaticity measurement technique, chromaticity is measured by measuring the change in betatron tune as the RF frequency is varied. This paper will describe a novel way of measuring chromaticity: we will phase modulate the RF with a known sine wave and then phase demodulate the betatron frequency. The result is a line in Fourier space which corresponds to the frequency of our sine wave modulation. The peak of this sine wave is proportional to chromaticity. For this technique to work, a tune tracker PLL system is required because it supplies the betatron carrier frequency. This method has been tested in the Tevatron and we will show the results here.
Date: June 1, 2007
Creator: Tan, C.Y.
Partner: UNT Libraries Government Documents Department

Chromaticity tracking with a phase modulation/demodulation technique in the Tevatron

Description: The Tevatron chromaticity tracker (CT) has been successfully commissioned and is now operational. The basic idea behind the CT is that when the phase of the Tevatron RF is slowly modulated, the beam momentum is also modulated. This momentum modulation is coupled transversely via chromaticity to manifest as a phase modulation on the betatron tune. And so by phase demodulating the betatron tune, the chromaticity can be recovered. However, for the phase demodulation to be successful, it is critical that the betatron tune be a coherent signal that can be easily picked up by a phase detector. This is easily done because the Tevatron has a phase locked loop based tune tracker which coherently excites the beam at the betatron tune.
Date: January 1, 2009
Creator: Tan, C.Y.
Partner: UNT Libraries Government Documents Department

The Tevatron Chromaticity tracker

Description: The Tevatron chromaticity tracker (CT) has been successfully commissioned and is now operational. The basic idea behind the CT is that when the phase of the Tevatron RF is slowly modulated, the beam momentum is also modulated. This momentum modulation is coupled transversely via chromaticity to manifest as a phase modulation on the betatron tune. Thus by phase demodulating the betatron tune, the chromaticity can be recovered. However, for the phase demodulation to be successful, it is critical that the betatron tune be a coherent signal that can be easily picked up by a phase detector. This is easily done because the Tevatron has a phase locked loop (PLL) based tune tracker which coherently excites the beam at the betatron tune.
Date: December 1, 2008
Creator: Tan, Cheng-Yang
Partner: UNT Libraries Government Documents Department