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Determining Camera Gain in Room Temperature Cameras

Description: James R. Janesick provides a method for determining the amplification of a CCD or CMOS camera when only access to the raw images is provided. However, the equation that is provided ignores the contribution of dark current. For CCD or CMOS cameras that are cooled well below room temperature, this is not a problem, however, the technique needs adjustment for use with room temperature cameras. This article describes the adjustment made to the equation, and a test of this method.
Date: December 1, 2010
Creator: Cogliati, Joshua
Partner: UNT Libraries Government Documents Department

Comparison of amplified spontaneous emission pulse cleaners for use in chirped pulse amplification front end lasers

Description: We compare various schemes for removing amplified spontaneous emission from seed laser pulses. We focus on compact schemes that are compatible with fiber laser front end systems with pulse energies in the 10nJ-1{micro}J range and pulse widths in the 100fs-10ps range. Pre-pulse contrast ratios greater than 10{sup 9} have been measured.
Date: July 2, 2007
Creator: Dawson, J.; Siders, C.; Phan, H.; Kanz, V. & Barty, C.
Partner: UNT Libraries Government Documents Department

Faith in the algorithm, part 1: beyond the turing test

Description: Since the Turing test was first proposed by Alan Turing in 1950, the goal of artificial intelligence has been predicated on the ability for computers to imitate human intelligence. However, the majority of uses for the computer can be said to fall outside the domain of human abilities and it is exactly outside of this domain where computers have demonstrated their greatest contribution. Another definition for artificial intelligence is one that is not predicated on human mimicry, but instead, on human amplification, where the algorithms that are best at accomplishing this are deemed the most intelligent. This article surveys various systems that augment human and social intelligence.
Date: January 1, 2009
Creator: Rodriguez, Marko A & Pepe, Alberto
Partner: UNT Libraries Government Documents Department

Genomic Sequencing of Single Microbial Cells from Environmental Samples

Description: Recently developed techniques allow genomic DNA sequencing from single microbial cells [Lasken RS: Single-cell genomic sequencing using multiple displacement amplification, Curr Opin Microbiol 2007, 10:510-516]. Here, we focus on research strategies for putting these methods into practice in the laboratory setting. An immediate consequence of single-cell sequencing is that it provides an alternative to culturing organisms as a prerequisite for genomic sequencing. The microgram amounts of DNA required as template are amplified from a single bacterium by a method called multiple displacement amplification (MDA) avoiding the need to grow cells. The ability to sequence DNA from individual cells will likely have an immense impact on microbiology considering the vast numbers of novel organisms, which have been inaccessible unless culture-independent methods could be used. However, special approaches have been necessary to work with amplified DNA. MDA may not recover the entire genome from the single copy present in most bacteria. Also, some sequence rearrangements can occur during the DNA amplification reaction. Over the past two years many research groups have begun to use MDA, and some practical approaches to single-cell sequencing have been developed. We review the consensus that is emerging on optimum methods, reliability of amplified template, and the proper interpretation of 'composite' genomes which result from the necessity of combining data from several single-cell MDA reactions in order to complete the assembly. Preferred laboratory methods are considered on the basis of experience at several large sequencing centers where >70% of genomes are now often recovered from single cells. Methods are reviewed for preparation of bacterial fractions from environmental samples, single-cell isolation, DNA amplification by MDA, and DNA sequencing.
Date: February 1, 2008
Creator: Ishoey, Thomas; Woyke, Tanja; Stepanauskas, Ramunas; Novotny, Mark & Lasken, Roger S.
Partner: UNT Libraries Government Documents Department

Amplification of surface temperature trends and variability in thetropical atmosphere

Description: The month-to-month variability of tropical temperatures is larger in the troposphere than at the Earth's surface. This amplification behavior is similar in a range of observations and climate model simulations, and is consistent with basic theory. On multi-decadal timescales, tropospheric amplification of surface warming is a robust feature of model simulations, but occurs in only one observational dataset. Other observations show weak or even negative amplification. These results suggest that either different physical mechanisms control amplification processes on monthly and decadal timescales, and models fail to capture such behavior, or (more plausibly) that residual errors in several observational datasets used here affect their representation of long-term trends.
Date: August 11, 2005
Creator: Santer, B.D.; Wigley, T.M.L.; Mears, C.; Wentz, F.J.; Klein,S.A.; Seidel, D.J. et al.
Partner: UNT Libraries Government Documents Department

Dissecting Biological Dark Matter: Single Cell Genetic Analysis of TM7, a Rare and Uncultivated Microbe from the Human Mouth

Description: We have developed a microfluidic device that allows the isolation and genome amplification of individual microbial cells, thereby enabling organism-level genomic analysis of complex microbial ecosystems without the need for culture. This device was used to perform a directed survey of the human subgingival crevice and to isolate bacteria having rod-like morphology. Several isolated microbes had a 16S rRNA sequence that placed them in candidate phylum TM7, which has no cultivated or sequenced members. Genome amplification from individual TM7 cells allowed us to sequence and assemble >1,000 genes, providing insight into the physiology of members of this phylum. This approach enables single-cell genetic analysis of any uncultivated minority member of a microbial community.
Date: July 1, 2007
Creator: Fenner, Marsha W; Marcy, Yann; Ouverney, Cleber; Bik, Elisabeth M.; Losekann, Tina; Ivanova, Natalia et al.
Partner: UNT Libraries Government Documents Department

Pu Workshop Letter

Description: In preparation for the upcoming Pu Workshop in Livermore, CA, USA, during July 14 and 15, 2006, we have begun to give some thought as to how the meeting will be structured and what will be discussed. Below, you will find our first proposal as to the agenda and contents of the meeting. From you, we need your feedback and suggestions concerning the desirability of each aspect of our proposal. Hopefully, we will be able to converge to a format that is acceptable to all parties. First, it now appears that we will be limited to three main sessions, Friday morning (July 14), Friday afternoon (July 14) and Saturday morning (July 15). The Pu Futures Meeting will conclude on Thursday, July 13. Following a social excursion, the Russian participants will be transported from Monterey Bay to their hotel in Livermore. We anticipate that the hotel will be the Residence Inn at 1000 Airway Blvd in Livermore. However, the hotel arrangements still need to be confirmed. We expect that many of our participants will begin their travels homeward in the afternoon of Saturday, July 15 and the morning of Sunday, July 16. Associated with the three main sessions, we propose that there be three main topics. Each session will have an individual focus. Because of the limited time available, we will need to make some judicious choices concerning the focus and the speakers for each session. We will also have a poster session associated with each session, to facilitate discussions, and a rotating set of Lab Tours, to maximize participation in the tour and minimize the disruption of the speaking schedule. Presently, we are planning a tour of the Dynamical Transmission Electron Microscope (DTEM) facilities, but this is still in a preliminary stage. We estimate that for each session and topic, ...
Date: March 6, 2006
Creator: Tobin, J G; Schwartz, A J & Fluss, M
Partner: UNT Libraries Government Documents Department


Description: The influence of the active gain medium on the spectral amplitude and phase of amplified pulses in a CPA system is studied. Results from a 10-PW example based on Nd-doped mixed glasses are presented. In conclusion, this study shows that, by using spectral shaping and gain saturation in a mixed-glass amplifier, it is possible to produce 124 fs, 1.4 kJ laser pulses. One detrimental effect, the pulse distortion due to resonant amplification medium, has been investigated and its magnitude as well as its compensation calculated.
Date: November 22, 2010
Creator: Filip, C V
Partner: UNT Libraries Government Documents Department

Yttrium Calcium Oxyborate for high average power frequency doubling and OPCPA

Description: Significant progress has been achieved recently in the growth of Yttrium Calcium Oxyborate (YCOB) crystals. Boules have been grown capable of producing large aperture nonlinear crystal plates suitable for high average power frequency conversion or optical parametric chirped pulse amplification (OPCPA). With a large aperture (5.5 cm x 8.5 cm) YCOB crystal we have demonstrated a record 227 W of 523.5nm light (22.7 J/pulse, 10 Hz, 14 ns). We have also demonstrated the applicability of YCOB for 1053 nm OPCPA.
Date: June 20, 2006
Creator: Liao, Z M; Jovanovic, I; Ebbers, C A; Bayramian, A; Schaffers, K; Caird, J et al.
Partner: UNT Libraries Government Documents Department

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

An adaptive radiation model for the origin of new genefunctions

Description: The evolution of new gene functions is one of the keys to evolutionary innovation. Most novel functions result from gene duplication followed by divergence. However, the models hitherto proposed to account for this process are not fully satisfactory. The classic model of neofunctionalization holds that the two paralogous gene copies resulting from a duplication are functionally redundant, such that one of them can evolve under no functional constraints and occasionally acquire a new function. This model lacks a convincing mechanism for the new gene copies to increase in frequency in the population and survive the mutational load expected to accumulate under neutrality, before the acquisition of the rare beneficial mutations that would confer new functionality. The subfunctionalization model has been proposed as an alternative way to generate genes with altered functions. This model also assumes that new paralogous gene copies are functionally redundant and therefore neutral, but it predicts that relaxed selection will affect both gene copies such that some of the capabilities of the parent gene will disappear in one of the copies and be retained in the other. Thus, the functions originally present in a single gene will be partitioned between the two descendant copies. However, although this model can explain increases in gene number, it does not really address the main evolutionary question, which is the development of new biochemical capabilities. Recently, a new concept has been introduced into the gene evolution literature which is most likely to help solve this dilemma. The key point is to allow for a period of natural selection for the duplication per se, before new function evolves, rather than considering gene duplication to be neutral as in the previous models. Here, I suggest a new model that draws on the advantage of postulating selection for gene duplication, and proposes that bursts ...
Date: October 18, 2004
Creator: Francino, M. Pilar
Partner: UNT Libraries Government Documents Department

Wind Spires as an Alternative Energy Source

Description: This report discloses the design and development of an innovative wind tower system having an axisymmetric wind deflecting structure with a plurality of symmetrically mounted rooftop size wind turbines near the axisymmetric structure. The purpose of the wind deflecting structure is to increase the ambient wind speed that in turn results in an overall increase in the power capacity of the wind turbines. Two working prototypes were constructed and installed in the summer of 2009 and 2012 respectively. The system installed in the Summer of 2009 has a cylindrical wind deflecting structure, while the tower installed in 2012 has a spiral-shape wind deflecting structure. Each tower has 4 turbines, each rated at 1.65 KW Name-Plate-Rating. Before fabricating the full-size prototypes, computational fluid dynamic (CFD) analyses and scaled-down table-top models were used to predict the performance of the full-scale models. The performance results obtained from the full-size prototypes validated the results obtained from the computational models and those of the scaled-down models. The second prototype (spiral configuration) showed at a wind speed of 11 miles per hour (4.9 m/s) the power output of the system could reach 1,288 watt, when a typical turbine installation, with no wind deflecting structure, could produce only 200 watt by the same turbines at the same wind speed. At a wind speed of 18 miles per hour (8 m/sec), the spiral prototype produces 6,143 watt, while the power generated by the same turbines would be 1,412 watt in the absence of a wind deflecting structure under the same wind speed. Four US patents were allowed, and are in print, as the results of this project (US 7,540,706, US 7,679,209, US 7,845,904, and US 8,002,516).
Date: October 30, 2012
Creator: Majid Rashidi, Ph.D., P.E.
Partner: UNT Libraries Government Documents Department

Rotational Augmentation Disparities in the MEXICO and UAE Phase VI Experiments: Preprint

Description: Wind turbine structures and components suffer excessive loads and premature failures when key aerodynamic phenomena are not well characterized, fail to be understood, or are inaccurately predicted. Turbine blade rotational augmentation remains incompletely characterized and understood, thus limiting robust prediction for design. Pertinent rotational augmentation research including experimental, theoretical, and computational work has been pursued for some time, but large scale wind tunnel testing is a relatively recent development for investigating wind turbine blade aerodynamics. Because of their large scale and complementary nature, the MEXICO and UAE Phase VI wind tunnel experiments offer unprecedented synergies to better characterize and understand rotational augmentation of blade aerodynamics.
Date: May 1, 2010
Creator: Schreck, S.; Sant, T. & Micallef, D.
Partner: UNT Libraries Government Documents Department

Single pulse phase-control interferometric coherent anti-StokesRaman scattering spectroscopy (CARS)

Description: In coherent anti-Stokes Raman scattering spectroscopy (CARS) experiments, usually the amplitude of the signal is measured and the phase information is lost. With a polarization- and phase-controlled pulse shaping technique, the relative phase between the resonant and non-resonant CARS signals is controlled, and spectral interferometry is performed without an interferometer. Both the real and imaginary parts of the background-free resonant CARS spectrum are measured via spectral interferometry between the resonant and non-resonant signals from the same sample. The resonant signal is amplified significantly by homodyne mixing with the non-resonant signal as a local oscillator, greatly improving the detection limit.
Date: September 28, 2005
Creator: Lim, Sang-Hyun; Caster, Allison G. & Leone, Stephen R.
Partner: UNT Libraries Government Documents Department

Enzymatic Ligation Creates Discrete Multi-Nanoparticle Building Blocks for Self-Assembly

Description: Enzymatic ligation of discrete nanoparticle?DNA conjugates creates nanoparticle dimer and trimer structures in which the nanoparticles are linked by single-stranded DNA, rather than double-stranded DNA as in previous experiments. Ligation is verified by agarose gel and small-angle X-ray scattering. This capability is utilized in two ways: first to create a new class of multiparticle building blocks for nanoscale self-assembly; second to develop a system which can amplify a population of discrete nanoparticle assemblies.
Date: May 27, 2008
Creator: Claridge, Shelley A.; Mastroianni, Alexander J.; Au, Yeung B.; Liang, Huiyang W.; Micheel, Christine M.; Frechet, Jean M.J. et al.
Partner: UNT Libraries Government Documents Department

Apparatus and method for extracting power from energetic ions produced in nuclear fusion

Description: This invention is comprised of an apparatus and method of extracting power from energetic ions produced by nuclear fusion in a toroidal plasma to enhance respectively the toroidal plasma current and fusion reactivity. By injecting waves of predetermined frequency and phase traveling substantially in a selected poloidal direction within the plasma, the energetic ions become diffused in energy and space such that the energetic ions lose energy and amplify the waves. The amplified waves are further adapted to travel substantially in a selected toroidal direction to increase preferentially the energy of electrons traveling in one toroidal direction which, in turn, enhances or generates a toroidal plasma current. In an further adaptation, the amplified waves can be made to preferentially increase the energy of fuel ions within the plasma to enhance the fusion reactivity of the fuel ions. The described direct, or in situ, conversion of the energetic ion energy provides an efficient and economical means of delivering power to a fusion reactor.
Date: December 31, 1993
Creator: Fisch, N.J. & Rax, J.M.
Partner: UNT Libraries Government Documents Department

Amplification of Beam Acceleration in a Plasma by Plasma Instability

Description: Although achieving of high accelerating field in a plasma has been demonstrated experimentally, a practical use of such a scheme for building a large accelerator is questionable. A novel scheme of beam acceleration by a plasma wave is considered in this article. The scheme is based on an initial excitation of a plasma wave by a probe beam with comparatively modest intensity. This seed excitation is then amplified by plasma instability, so that the test beam which follows the probe beam with a small delay will be accelerated by the plasma wave with an amplitude significantly exceeding the initial amplitude of the wave. Because of small interaction between the synchronization beam and the plasma, such a scheme allows one to excite a plasma over large length and, consequently, to build a large accelerator.
Date: September 1, 1998
Creator: Lebedev, Valeri
Partner: UNT Libraries Government Documents Department

Electron cloud effects at positron/electron (e+/e-) machines and electron cloud diagnostics.

Description: Background electrons are ubiquitous in high-intensity particle accelerators. Under certain operating conditions, amplification of the electron cloud can occur. The beam-cloud interaction can seriously degrade the accelerator performance with effects that range from vacuum degradation to collective beam instabilities. Although electron cloud effects (ECEs) were first observed 20 years ago in a proton ring, in recent years, they have been widely observed and intensely studied in e{sup +}/e{sup -} rings. This paper will focus on describing electron cloud diagnostics, which have led to an enhanced understanding of ECEs, especially details of beam-induced multipacting and saturation of the cloud. Such experimental results can be used to provide realistic limits on key input parameters for modeling efforts.
Date: July 9, 2002
Creator: Harkay, K.; Rosenberg, R. A.; Macek, R. J.; Browman, A. & Wang, T.-S
Partner: UNT Libraries Government Documents Department

Spontaneous and amplified radiation at the initial stage of a SASE FEL.

Description: At the initial stage of a self-amplified spontaneous emission (SASE) free-electron laser (FEL), spontaneous undulator radiation in certain experimental configurations can dominate the amplified signal over an extended undulator distance. In this paper they study both the spontaneous and the amplified radiation in the framework of the paraxial wave equation and determine the transition from the dominance of spontaneous emission to exponential amplification. They compare theoretical expectations with SASE simulation codes GINGER and GENESIS.
Date: November 1, 2002
Creator: Huang, Z. & Kim, K.-J.
Partner: UNT Libraries Government Documents Department

Simulations of electron cloud build-up and saturation in the APS.

Description: In studies with positron beams in the Advanced Photon Source, a dramatic amplification was observed in the electron cloud for certain bunch current and bunch spacings. In modeling presented previously, we found qualitative agreement with the observed beam-induced multipacting condition, provided reasonable values were chosen for the secondary electron yield parameters, including the energy distribution. In this paper, we model and discuss the build-up and saturation process observed over long bunch trains at the resonance condition. Understanding this saturation mechanism in more detail may have implications for predicting electron cloud amplification, multipacting, and instabilities in future rings.
Date: June 13, 2002
Creator: Harkay, K.; Rosenberg, R.; Furman, M. & Pivi, M.
Partner: UNT Libraries Government Documents Department

The Effects of Amplification and Selected Vocal Exercises on the Perceived Vocal Health of Elementary Music Educators.

Description: The main purpose of this study was to consider the effects of amplification and vocal function exercises on the perceived vocal health of elementary music educators (N = 37) from Oklahoma (n = 11) and Texas (n = 26). Participants were assigned to the use of the ChatterVoxTM amplifier or vocal function exercises based on pretest scores on the Voice Handicap Index with Music Teacher Voice Questionnaire (VHI/MVQ). Following the 4-week study period, participants completed the posttest VHI/MVQ. The results of a one-way ANCOVA that used treatment group as the independent variable, the summed posttest scores as the dependent variable, and the summed pretest scores as the covariate or control variable indicated that there was a statistically significant difference between the adjusted means for the posttest scores, favoring the exercises group. The overall group and both treatment groups reported frequent loud voice use in work settings and in public places. The overall group and the amplification group reported hoarseness after prolonged talking. The exercises group did not report as great a problem with hoarseness after prolonged talking. Secondary purposes addressed demographic variables. Women perceived greater overall vocal difficulties than men; men frequently reported specific vocal complaints that were not commonly indicated by women. The vocal problems of women may have been associated with loud voice use. The following common vocal complaints of men may have been related to the use of falsetto while teaching: need for vocal rest, worse voices in the evening, dry throats, loss of voice, obvious pitch breaks in their singing voices, pain after singing for an extended time, and limited use of their high range. VHI/MVQ scores indicated that the study participants with 21 to 39 years of teaching experience had more vocal difficulties than other participants and indicated limited use of the low range of ...
Date: May 2008
Creator: Vincent, Lynette Susanne
Partner: UNT Libraries