WorldWideScience
1

Multilayer reflective coatings for extreme-ultraviolet lithography  

Energy Technology Data Exchange (ETDEWEB)

Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These ...

1998-03-10

2

Multi-mirror system, 2. Application of inverse Compton Scattering for lithography X-ray sources  

Energy Technology Data Exchange (ETDEWEB)

A brilliant X ray source is proposed for lithography instruments with use of a multi-mirror system. The inverse Compton scattering between the stored electron beam in the storage ring and the stored photon beam in the multi-mirror system, is applied for the X-ray generation. (author)

2000-07-01

3

Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)  

Energy Technology Data Exchange (ETDEWEB)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The fabrication method has ...

2006-06-15

4

Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)  

International Nuclear Information System (INIS)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The fabrication method has ...

2006-06-01

5

Lithography Production Techniques for next Generations of Microelectronics  

CERN Document Server

Lithography Production Techniques for next Generations of Microelectronics

1992-01-01

6

Focused ion beam lithography for rapid prototyping of metallic films  

International Nuclear Information System (INIS)

We present FIB-lithography methods for rapid and cost-effective prototyping of metal structures covering the deep-submicron- to the millimeter-range in a single lithography cycle. Focused ion beam (FIB) systems are widely used in semiconductor industry and research facilities for both analytical testing and prototyping. A typical application is to apply electrical contact to micron-sized sensors/particles by FIB induced metal deposition. However, as for E-beam lithography, patterning times for large area bonding pads are unacceptably long, resulting in cost-intensive prototyping. In this work, we optimized FIB lithography processing for negative and positive imaging mode to form metallic structures for large-areas down do the sub-100 nm range. For negative lithography features are defined by implanting Ga"+-ions into a commercial photo resist, without affecting ...

2010-03-21

7

Reflectance, Optical Properties, and Stability of Molybdenum/Strontium and Molybdenum/Yttrium Multilayer Mirrors  

Energy Technology Data Exchange (ETDEWEB)

The motivation of this work is to develop high reflectance normal-incidence multilayer mirrors in the 8-12 nm wavelength region for applications in astronomy and extreme ultraviolet lithography. To achieve this goal, Mo/Sr and Mo/Y multilayers were studied. These multilayers were deposited with a UHV magnetron sputtering system and their reflectances were measured with synchrotron radiation. High normal-incidence reflectances of 23% at 8.8 nm, 40.8% at 9.4 nm, and 48.3% at 10.5 nm were achieved. However, the reflectance of Mo/Sr multilayers decreased rapidly after exposure to air. Attempts to use thin layers of carbon to passivate the surface of Mo/Sr multilayers were unsuccessful. Experimental results on the refractive index {tilde n} = 1-{delta} + i{beta} of yttrium and molybdenum in the 50-1300 eV energy region are reported in this work. This is the first time ever that values on the refractive index of yttrium are ...

2002-09-01

8

Remote Sensor Systems for Unmanned Planetary Missions  

Science.gov (United States)

instrument is shown in Figure 4-9 The incoming radiation is focused onto ...... An early rocket-borne ultraviolet spectrometer of the Ebert type by ...

9

A proposed linac cavity rf drive system for the Los Alamos extreme ultraviolet free-electron laser  

Energy Technology Data Exchange (ETDEWEB)

Since 1979, scientists and engineers at the Los Alamos National Laboratory have designed, constructed, and operated a radio-frequency (RF) linac free-electron laser (FEL) at wavelengths from 9 to 45 /mu/m. Coupled with success of other research centers investigating wavelengths from the visible to far-infrared, Los Alamos is now proposing a vacuum-ultraviolet and soft x-ray (referred to henceforth as extreme ultraviolet, (XUV)) FEL oscillator/Self-Amplified Spontaneous Emission amplifier with beam energies ranging from 100 MeV to 1 GeV. This paper will focus on the first milestone of the proposed Los Alamos XUV project, i.e., a 250-MeV linac with approximately 50 mA of average current, producing photons with wavelengths below 1000 /angstrom/. 3 refs., 3 figs.

1989-01-01

10

Electron beam, ion beam, X-ray optical techniques for fabricating surface-acoustic-wave and thin-film optical devices  

International Nuclear Information System (INIS)

Most surface-acoustic-wave and thin-film optical devices are made by the planar fabrication process. The exposure of the pattern in the polymer film is the first and most crucial step in ensuring desired device geometry, dimensional control, and freedom from pattern distortion. The methods of exposing the polymer film include: optical projection, conventional contact printing, conformable photomask contact printing, holographic recording, scanning electron beam lithography, projection electron lithography, and x-ray lithography. In this paper scanning electron beam lithography, conformable photomask contact printing, holographic recording, and x-ray lithography are discussed. In the last section, ion beam etching of relief structures is discussed.

11

Characteristics of lanthanides in pyrochemical systems observed by electrochemical and spectrophotometric measurements  

Energy Technology Data Exchange (ETDEWEB)

As research for the chemical properties of lanthanide molecules in the dry system, electrochemical and ultraviolet-visible optical measurements on the chloride molten salt system have been conducted at Research Reactor Institute, Kyoto University. The reduction behavior of Ln(III)-Ln(0) and Ln(II) are measured on La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Yb by the cyclic voltammetry. The molar absorption coefficients of the f-f transition are measured by the measurement of ultraviolet-visible absorption spectra on Pr, Nd, Ho and Gd. From the comparison of the optical data between wet and dry systems, the characteristics of photon absorption are discussed in the molten salt. (H. Katsuta)

2001-12-01

12

Lamp system for uniform semiconductor wafer heating  

Energy Technology Data Exchange (ETDEWEB)

A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

2001-01-01

13

Excimer Projection Lithography at 193-nm Wavelength  

Science.gov (United States)

... Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB. Personal Author(s) : Rothschild, M. ; Ehrlich, DJ. ...

14

Electrochemical characterisation of patterned carbon nanotube electrodes on silane modified silicon  

Energy Technology Data Exchange (ETDEWEB)

Previously we have used atomic force anodisation lithography, with a self-assembled monolayer of hexadecyltrichlorosilane as a resist, to pattern silicon oxide nanostructures onto a p-type silicon (1 0 0) substrate. A condensation reaction was used to immobilise carbon nanotubes with high carboxylic acid functionality directly to the silicon oxide. A further condensation reaction using this surface attached the molecule ferrocenemethanol to the bound nanotubes. These new nanostructures were used as electrodes to observe the oxidation and reduction of ferrocene. However, because the small currents measured are near the detection limits of the electrochemical system used, important electrode kinetics could not to be obtained. A scribing approach made larger regions of oxidised silicon leading to the creation of larger scale patterned arrangements of carbon nanotubes allowing measurement of important electrochemical parameters such as electrode ...

2008-07-20

15

Endomicroscopy imaging of epithelial structures using tissue autofluorescence  

Science.gov (United States)

We explore autofluorescence endomicroscopy as a potential tool for real-time visualization of epithelial tissue microstructure and organization in a clinical setting. The design parameters are explored using two experimental systems--an Olympus Medical Systems Corp. stand-alone clinical prototype probe, and a custom built bench-top rigid fiber conduit prototype. Both systems entail ultraviolet excitation at 266 nm and/or 325 nm using compact laser sources. Preliminary results using ex vivo animal and human tissue specimens suggest that this technology can be translated toward in vivo application to address the need for real-time histology.

2011-04-01

16

Lasing below 200 nm in the NIJI-IV compact storage-ring-based free electron laser  

International Nuclear Information System (INIS)

Laser gain of the NIJI-IV compact storage-ring-based Free Electron Laser (FEL) system at AIST reached #approx#9% at 200 nm for an average beam current of 16.3 mA. In addition to such a drastic gain enhancement, improvement of the laser-cavity performance has led to successful FEL lasing in the vacuum ultraviolet below 200 nm even in a compact system. Temporal and spectral characteristics of the NIJI-IV FEL were examined around 200 nm. FEL performance will be briefly discussed from the application point of view.

2004-08-01

17

Optimization of band gap of photonic crystals fabricated by holographic lithography  

Science.gov (United States)

Generally the photonic band gap (PBG) is a multi-variable function of several parameters related to the shape and size of the dielectric columns of photonic crystals (PhCs), and a time-consuming step-by-step scanning process for each parameter has to be used to find their best combination yielding maximum PBG. In this letter, the widely used Nelder-Mead simplex algorithm is introduced to optimize these parameters simultaneously to find a larger PBG for a new kind of two-dimensional (2D) hexagonal GaAs-Air PhC. This structure can be conveniently produced by the single-exposure holographic lithography, and the specific holographic design is also systematically investigated. This study reveals that the band gaps of PhCs made by holographic lithography may be widened by introducing irregularity of the columns and lowering the symmetry of the structure.

2008-01-01

18

The wavelength dependence of ultraviolet enhanced reactivation in a mammalian cell-virus system  

International Nuclear Information System (INIS)

The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).

19

Solid-state ozone synthesis by energetic ions  

International Nuclear Information System (INIS)

We have synthesized ozone by irradiating thin solid films of oxygen and oxygen-water mixtures with 100 keV protons, motivated by recent reports of condensed O_3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by reflectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-component (O, O_2 and O_3) model that successfully explains the fluence dependence of ozone production.

1999-08-02

21

Evolution of ultraviolet dwarfs  

Science.gov (United States)

UV dwarf star evolution, using central and gap star models emphasizing photoneutrino emission

1969-01-01

22

Detection of H2 Emission from Mira B in UV Spectra from the Hubble Space Telescope  

CERN Document Server

We present ultraviolet spectra of Mira's companion star from the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). The companion is generally assumed to be a white dwarf surrounded by an accretion disk fed by Mira's wind, which dominates the UV emission from the system. The STIS UV spectrum is dominated by numerous, narrow H2 lines fluoresced by H I Ly-alpha, which were not detected in any of the numerous observations of Mira B by the International Ultraviolet Explorer (IUE). The high temperature lines detected by IUE (e.g., C IV 1550) still exist in the STIS spectrum but with dramatically lower fluxes. The continuum fluxes in the STIS spectra are also much lower, being more than an order of magnitude lower than ever observed by IUE, and also an order of magnitude lower than fluxes observed in more recent HST Faint Object Camera objective prism spectra from 1995. Thus, the ...

2001-01-01

23

rf-driven ion sources for industrial applications (invited) (abstract)  

Science.gov (United States)

The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory have been developing rf-driven ion sources for the last two decades. These sources are being used to generate both positive and negative ion beams. Some of these sources are operating in particle accelerators such as the Spallation Neutron Source (SNS) at Oak Ridge, while others are being employed in various industrial ion beam systems. There are four areas where the rf-driven ion sources are commonly used in industry. (1) In semiconductor manufacturing, rf-driven sources have found important applications in plasma etching, ion beam implantation, and ion beam lithography. (2) In material analysis and surface modification, miniature rf-ion sources can be found in focused ion beam systems. They can provide ion beams of essentially any element in the Periodic Table. The newly developed combined rf ion-electron beam unit improves greatly the ...

2008-02-15

24

Determination of molar extinction coefficients #epsilon#_m(Ce"4"+) of Ce"4"+-Ce"3"+ dosimetric system  

International Nuclear Information System (INIS)

#epsilon#_m(Ce"4"+) values of the ceric-cereus system have been measured and the experimental procedure is described. Both routine titration method and electrochemical measurement were used. Some interference factors, such as ultraviolet, acidity and temperature, were studied as well. The temperature coefficient of #epsilon#_m(Ce"4"+) value in this experiment is about -0.1% degree C"-"1. A statistic analysis was made for 24 experimental values of #epsilon#_m(Ce"4"+) and a Gaussian distribution was found. Ultimately, an average molar extinction coefficient of 553.2 +- 1.3 m"2#centre dot#mol"-"1 was obtained at #approx#320 nm in 0.4 mol/L H_2SO_4 system, with a relative standard deviation of 0.24% (95% confidence level) and a total uncertainty of 1.5%.

1996-01-01

25

What Can a Dual beam Really Do?  

International Nuclear Information System (INIS)

Full Text: Smallstage Dualbeam (SDB) systems, that is a Focussed Ion Beam column coupled with a SEM column, have been around for about five years now. There impact on the Semiconductor industry has been enormous, with virtually every lab having a SDB to produce, characterise and analyse cross sections and TEM samples on the Nano-scale. But what about other industries? What else can SDB system be used for? The SEM column in itself is a very powerful tool for sample characterisation, modification and analysis. An electron beam from a Tungsten or Thermal Field Emission source has enough current to allow sophisticated patterns to be created in photo-resist samples, a process known as lithography. The current is also high enough to allow for a process known as Electron Beam Induced Deposition (EBID), where the beam interacts with an introduced gas and material is deposited in a controlled manner on the sample. With the addition ...

2005-08-16

26

Quadrant anode image sensor  

Science.gov (United States)

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, approx. =10 ..mu.., allows individual MCP channels to be distinguished. (AIP)

1976-11-01

27

Quadrant anode image sensor  

International Nuclear Information System (INIS)

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, approx. =10 #mu#, allows individual MCP channels to be distinguished.

9472-01-01

28

Design considerations for the magnetic system of a prototype x-ray free electron laser  

Energy Technology Data Exchange (ETDEWEB)

A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

1997-04-01

29

Construction and development of a UV free electron laser under the cooperation of Nihon U, KEK, PNC, ETL and Tohoku U  

Energy Technology Data Exchange (ETDEWEB)

The construction and the development of a UV free electron laser have been started under the cooperation of Nihon U, KEK, PNC, ETL and Tohaku U. The project requires a 100MeV S-band electron linear accelerator to expand the oscillation of FEL using fundamental mode to the UV region. The injection system consists of a thermionic RF-gun with a LaB cathode and an {alpha} magnet for magnetic bunching. We are studying to reduce the back-bombardment electrons to realize the macropulse length of 20{mu}sec. Electron beams, up to the energy of 100MeV, are injected into the optical oscillators. Changing the accelerating energy and/or undulator parameters, this system will cover the range from infrared to ultraviolet for the applications in various fields.

1995-12-31

30

Microfabricated polyester conical microwells for cell culture applications.  

Science.gov (United States)

Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing ...

2011-05-26

31

Suppression of pitting corrosion with passive film modification on type 304 stainless steel by ultra-violet light irradiation; Shigaikoshosha ni yoru Type 304 stainless ko no fudotai himaku kaishitsu to koshoku yokusei  

Energy Technology Data Exchange (ETDEWEB)

In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light irradiation. On the other hand, ...

1998-06-20

32

Photosynthetic Response of Seagrasses to Ultraviolet-A Radiation and the Influence of Visible Light Intensity 1  

UK PubMed Central (United Kingdom)

Inhibition of photosynthesis by ultraviolet-A radiation (UV-A, 315-380 nanometers) was examined in three marine angiosperms: Halophila engelmannii Aschers, Halodule wrightii...Full Text Available

1982-02-01

33

Stabilizing effect of the electron-beam self-fields on the phase-space trajectory in a self-amplified spontaneous emission free-electron laser operating in ultraviolet and x-ray spectral ranges  

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction grows exponentially.

2004-02-28

34

Exploring the binding of the strong organic acceptor F{sub 4}TCNQ to coinage metals  

Energy Technology Data Exchange (ETDEWEB)

Organic/metal interface properties are of high interest for the application of molecular (sub)monolayers to modify surface properties. They are applied for, e.g., molecular electronics, chemical sensing, or the tuning of injection barriers in organic electronic devices. We present a joint theoretical and experimental study of F{sub 4}TCNQ adsorbed on Cu(111). The electronic and structural properties were determined by ultraviolet photoelectron spectroscopy (UPS) and X-ray standing wave (XSW) measurements. To better understand the complex process of binding, we modelled the system using density-functional theory. We find forward-donation from the lone pairs of the molecule into metallic states and back-donation from the metal into the LUMO of the molecule. The data on Cu(111) are compared to F4TCNQ on Au(111) and Ag(111) as well as to investigations of pyrenetetraone on various coinage metals.

2008-07-01

35

Broad-linewidth laser absorption measurements of oxygen between 211 and 235nm at high temperatures  

British Library Electronic Table of Contents (United Kingdom)

Absorption coefficient data are presented for molecular oxygen at temperatures between 1100 and 2000K and discrete wavelengths between 211 and 235nm. Measurements were made behind reflected shock waves using broad-linewidth ultraviolet laser radiation generated from a frequency-quadrupled, tunable, pulsed Ti:Sapphire laser. Test mixtures consisting of 15% O"2, 15% He and balance Ar were used to minimize the influence of vibrational relaxation on the reflected shock temperature. The experimental results are in good agreement with theoretical calculations and confirm that discrete features from the Schumann-Runge system dominate between 211 and 235nm at temperatures higher than 1100K.

2011-01-01

36

A novel electrochemical alkylation of aniline with methanol over Zn/Cu salts modified kaolin  

British Library Electronic Table of Contents (United Kingdom)

A novel liquid phase alkylation of aniline with methanol over Zn/Cu salts modified kaolin assisted with a pair of porous carbon electrode in slurry-bed reactor under constant current intensity, room temperature and atmospheric pressure was reported. The Zn/Cu salts modified kaolin catalysts were synthesized and characterized by infrared spectrometer (IR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), which showed that the transition metals were completely supported on kaolins structure and formed a pored one. The effect parameters, such as initial pH, electrolysis time, metal ratio with kaolin and salts composition in this electrochemical catalytic system, were studied. The procedure was inspected by ultraviolet-visible spectrum (UV-vis), and the product distributi...

2008-01-01

37

Tunable single-wavelength semiconductor lasers  

Energy Technology Data Exchange (ETDEWEB)

This dissertation deals with both the theoretical and the technological aspects of monolithic tunable lasers, and the experimental techniques for opto-electronic integration. In the theoretical part, the principles and limitations of wavelength tuning and spectral linewidth reduction in monolithic semiconductor lasers are described, with coupled distributed feedback-Fabry Perot (DFB-FP) lasers and long DFB lasers as examples. Stepwise tuning of wavelength over tens of nanometers and continuous tuning over the range of a mode spacing are shown to be possible. Spatial hole burning is found to affect the spectral linewidth of lasers involving strong active gratings. On the technological side, one of the major issues is the fabrication of flexible gratings. Direct-writing techniques, such as focused ion beam (FIB) implantation and e-beam lithography, provide the resolution, flexibility and accuracy that conventional holographic lithography lacks. ...

1988-01-01

38

Focused ion beam fabrication and properties of nanoscale Josephson junctions for sensors and other applications  

International Nuclear Information System (INIS)

The methods of superconducting device fabrication by lithography and multilevel processing usually require a number of processing steps with lithographic resolution and alignment adequate for the scale of the device be fabricated. As an alternative, the focused ion beam (FIB) microscope is increasingly being used directly to fabricate devices. A major advantage of using a FIB compared to other lithography methods is its flexibility and high resolution. It allows in-situ, milling (#propor to#5 nm at a beam current of 1 pA) to a variety of depths, and imaging (2 nm) of the sample. In this paper we describe our development of junction fabrication techniques using the FIB and their application in creating a range of potential sensor devices and quantum electronics applications. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2005-03-01

41

The distribution of Lyman-limit absorption systems during and after reionization  

CERN Document Server

Lyman-limit absorption systems can play many important roles during and after cosmological reionization. Unfortunately, due to the prohibitively large dynamic range required, it is impossible to self-consistently include these systems in cosmological simulations. Using fast and versatile semi-numeric simulations, we systematically explore the spatial distribution of absorption systems during and following reionization. We self-calibrate the resulting number of absorbers to the mean free path (mfp) of the ionizing ultraviolet background (UVB), and present results at a given mfp and neutral hydrogen fraction. We use a simple optical depth criterion to identify the locations of absorbers. Our approach is fairly robust to uncertainties such as missing subgrid structure. Unlike at lower redshifts where the UVB is relatively uniform, at higher redshifts the fluctuations in the UVB and the HII morphology of ...

2010-01-01

42

Laser-assisted solar cell metallization processing. Quarterly report, September 13-December 12, 1983  

Energy Technology Data Exchange (ETDEWEB)

The Westinghouse Electric Corporation has undertaken to investigate, develop, and characterize laser-assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high-efficiency solar cells. Two basic techniques for metal deposition will be investigated, as follows: (1) photochemical decomposition of liquid or gas phase organometallic compounds utilizing either a focused, CW ultraviolet laser (System 1) or a mask and ultraviolet flood illumination, such as that provided by a repetitively pulsed, defocused excimer laser (System 2), for pattern definition, and (2) thermal deposition of metals from organometallic solutions or vapors utilizing a focused, CW laser beam as a local heat source to draw the metallization pattern. The purpose of this contract is to investigate the various existing laser-assisted film deposition techniques in order to ...

1984-01-16

43

An in vitro model to test relative antioxidant potential: Ultraviolet-induced lipid peroxidation in liposomes  

International Nuclear Information System (INIS)

Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipid peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing antioxidant effectiveness, ...

44

Modeling paraxial wave propagation in free-electron laser oscillators  

International Nuclear Information System (INIS)

Modeling free-electron laser (FEL) oscillators requires calculation of both the light-beam interaction within the undulator and the light propagation outside the undulator. We have developed a paraxial optical propagation code that can be combined with various existing models of gain media, for example, Genesis 1.3 for FELs, to model oscillators with full paraxial wave propagation within the resonator. A flexible scripting interface is used both to describe the optical resonator and to control the codes for propagation and amplification. To illustrate its capabilities, we numerically investigate two significantly different FEL oscillators: the free-electron laser for infrared experiments (FELIX) system and the vacuum-ultraviolet (VUV)-FEL oscillator of the proposed high-gain fourth generation light source. For the FELIX system, we find that diffraction losses are a considerable part of the single-pass cavity loss (at a ...

2006-11-01

45

Vacuum ultraviolet radiometry of xenon positive column discharges  

Energy Technology Data Exchange (ETDEWEB)

In order to judge the potential fluorescent lamp applications of various low-pressure positive column discharges it is necessary to measure the absolute power emitted in the ultraviolet region of the spectrum. For rare-gas discharges the principle emission occurs in the vacuum ultraviolet so that it is difficult to measure the radiant emittance (power per unit area) of the resonance radiation by standard methods. Two independent techniques are discussed for measuring the radiant emittance of positive column discharges in the vacuum ultraviolet. These techniques are used to study xenon positive column discharges at the resonance wavelength of 147 nm. The first method relies on the measurement of the resonance level density by absorption techniques. The effective decay rate of the resonance level is then determined by the simulation of resonance radiation transport. These two quantities are combined to yield the radiant ...

1995-10-01

46

f 07821-6004-R0-00 RESEARCH PROGRAM ON HOLOGRAPHIC - NASA ...  

Science.gov (United States)

in a KDP crystal fed with red light from a Q-s_tched ruby laser. One reason for interest in holograms made with ultraviolet ...

47

Test and Evaluation of Liquid Polymers for Use in Army ...  

Science.gov (United States)

... The addition of 0.5 pphr of fine thermal carbon black to the polymers gave good resistance to 500 hours of ultraviolet (UV) xposure in a Weather ...

1972-10-01

48

Photoconductive ultraviolet detectors based on ZnO films  

British Library Electronic Table of Contents (United Kingdom)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8mA, and a slow photoresponse with a rise time of 5min and a decay time of 7min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the d...

2006-01-01

49

Using light to bioactivate surfaces: A new way of creating oriented, active immunobiosensors  

International Nuclear Information System (INIS)

Ultraviolet light can be used to immobilize biomolecules onto thiol reactive surfaces in order to, e.g., make biosensors. The mechanism involves light-induced formation of free, reactive thiol groups in disulphide containing molecules. This technology allows for the creation of arrays of biomolecules with a high degree of reproducibility, circumventing the need for often expensive nano/micro-dispensing technologies. The ultimate size of the immobilized spots is defined by the focal area of the UV beam. Light-induced immobilization has the added benefit that the immobilized molecules will be spatially oriented and covalently bound to the surface. In this paper, we demonstrate the utility of a sensor array created with the new sensor technology when integrated into a microfluidic system. Protein arrays made using light-induced immobilization showed successful antigen/antibody binding in a flow cell allowing the visualisation of real time binding ...

2007-12-15

50

Investigations of the green- and infrared-stimulated luminescence using the recuperation effect  

Energy Technology Data Exchange (ETDEWEB)

We used the recuperation effect (see also 'Recuperation of infrared stimulated luminescence of feldspars' in this issue) for investigating the connection between infrared- and greenlight-stimulated luminescence (IRSL and GLSL) of feldspars by performing a 'double-bleach recuperation' experiment. A diode system was used for infrared (IR) stimulation, and a filtered-light unit for greenlight (GL) stimulation. Powdered feldspar samples (2 mg each) of known chemical characterisation from a mineral collection were used. After beta-irradiation with 180 Gy and storage in the dark for several weeks feldspar aliquots were bleached down to a residual level of {approx}1% of the initial level, first with IR and subsequently with GL. For both stimulations, detection of the stimulated luminescence was carried out in the near ultraviolet region (around 260-360 nm, peaked at 340 nm). Other aliquots were bleached in reverse ...

2000-12-15

51

Investigations of the green- and infrared-stimulated luminescence using the recuperation effect  

International Nuclear Information System (INIS)

We used the recuperation effect (see also 'Recuperation of infrared stimulated luminescence of feldspars' in this issue) for investigating the connection between infrared- and greenlight-stimulated luminescence (IRSL and GLSL) of feldspars by performing a 'double-bleach recuperation' experiment. A diode system was used for infrared (IR) stimulation, and a filtered-light unit for greenlight (GL) stimulation. Powdered feldspar samples (2 mg each) of known chemical characterisation from a mineral collection were used. After beta-irradiation with 180 Gy and storage in the dark for several weeks feldspar aliquots were bleached down to a residual level of #approx#1% of the initial level, first with IR and subsequently with GL. For both stimulations, detection of the stimulated luminescence was carried out in the near ultraviolet region (around 260-360 nm, peaked at 340 nm). Other aliquots were bleached in reverse order (1st GL, 2nd IR). These ...

2000-12-15

52

Industrial applications of the Jefferson Lab high-power free-electron laser  

International Nuclear Information System (INIS)

In partnership with the US Navy, high-technology corporations, and research universities, Jefferson Lab is building a superconducting radio-frequency (SRF) accelerator-driven free-electron laser (FEL) and is outfitting an FEL user facility. This first fourth-generation light source - a 1 kW, 3 #mu#m infrared (IR) laser - is the first step in a program to develop high-average-power SRF-based IR and ultraviolet (UV) FELs for multiple manufacturing applications as well as for defense-related applied research and basic scientific research. This initial FEL will be driven by a 42 MeV, 5 m A recirculating SRF linac similar to the much larger SRF linac in Jefferson Lab's 4 GeV, 200 #mu#A Continuous Electron Beam Accelerator Facility (CEBAF). The FEL is expected to demonstrate 75% energy recovery. Its linac will be cooled by the existing CEBAF cryogenic system. At Jefferson Lab, an infrastructure of facilities and people already supports the advance of ...

1998-09-02

53

Curing of natural rubber and epoxy adhesive  

International Nuclear Information System (INIS)

Low molecular weight epoxy resin based on diglycidyl ether of bisphenol A was synthesized and mixed at constant percentages with natural rubber. The rubber epoxy system was cured with various types of curing agents such as ethylene diamine, maleic anhydride as well as the prepared resole phenol formaldehyde. A study of the photo-induced crosslinking of the prepared elastic adhesives and film samples was carried out by exposure to ultraviolet lamp (300 w) for 2 weeks at 20 deg. C. Samples containing ethylene diamine were cured at 25 + - 1 deg. C. for 24 h while samples containing maleic anhydride or resole phenol formaldehyde resins were thermally cured at 150-170 deg. C. for 10 min. Cured adhesive compositions were tested mechanically and physically and evaluated as wood adhesives. While hardness, chemical resistance as well as heat stability of the prepared cured film sample were investigated. The obtained data indicate that the highest epoxy ...

2001-06-01

54

Adiabatic interpretation of particle creation in a de Sitter universe  

Energy Technology Data Exchange (ETDEWEB)

The choice of vacuum state for a quantum scalar field propagating in a de Sitter spacetime (massive and arbitrarily coupled to the gravitational field) is discussed. The problem of finite-time initial conditions for the mode functions is analyzed, as well as how these determine the vacuum state of the quantum system. The principle guiding the choice of vacuum state is the following: one wants the vacuum contribution to the energy-momentum tensor to contain all the ultraviolet divergent terms, so that the particle creation terms are finite, and covariantly conserved. There is a suitable set of modes (instantaneous adiabatic basis) in which this splitting of the expectation value of the energy-momentum tensor can be carried out. Numerical results are presented for different finite-time initial conditions (m = 0.6, {zeta} = 1/6). The nature of the particle creation effect is described and its relationship to the concept of a horizon crossing time ...

1998-06-10

55

Simulation of High Power Deposition on Target Materials: Applications in Magnetic, Inertial Fusion, and High Power Plasma Lithography Devices  

International Nuclear Information System (INIS)

High power and particle deposition on target materials are encountered in many applications including magnetic and inertial fusion devices, nuclear and high energy physics applications, and laser and discharge produced plasma devices. Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the Tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination.

2006-01-01

56

Large-area metallic photonic lattices for military applications.  

Energy Technology Data Exchange (ETDEWEB)

In this project we developed photonic crystal modeling capability and fabrication technology that is scaleable to large area. An intelligent optimization code was developed to find the optimal structure for the desired spectral response. In terms of fabrication, an exhaustive survey of fabrication techniques that would meet the large area requirement was reduced to Deep X-ray Lithography (DXRL) and nano-imprint. Using DXRL, we fabricated a gold logpile photonic crystal in the <100> plane. For the nano-imprint technique, we fabricated a cubic array of gold squares. These two examples also represent two classes of metallic photonic crystal topologies, the connected network and cermet arrangement.

2007-11-01

57

Simultaneous ultraviolet spectrophotometric determination of nitrate and nitrite in water  

Energy Technology Data Exchange (ETDEWEB)

A rapid and accurate method for the direct simultaneous determination of nitrate and nitrite is proposed. The method is applied to the determination of nitrate and nitrite in rainwater and wastewater without preliminary separation. The determinations are performed by a CPA matrix method with ultraviolet spectrophotometric detection. The results obtained are in agreement with those obtained by conventional methods for the determination of nitrate and nitrite.

1991-02-01

58

Electronic structure of the Ru(0001) surface  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the electronic structure of ruthenium. Synchrotron radiation in the range from 15 to 45 eV and angle-resolved ultraviolet photoemission are used to map the energies of the electronic states. The Fermi surface of Ru is determined using angle-resolved ultraviolet photoemission spectroscopy. The experimental results are compared with calculated photoemission spectra obtained within the framework of the one-step model of photoemission. (author)

2000-03-13

59

Effect of UV radiation on the killer phenotype in the wine yeast-saccharomycetes and spontaneous variation of this character  

International Nuclear Information System (INIS)

Spontaneous and ultraviolet-induced changeabilities of wine yeasts from the killer state to sensitive one have been studied. Observed often spontaneous changes of killer and neutral phenotypes under laboratory store conditions as well as high mutation frequency of genetic elements responsible for the killer indication on ultraviolet irradiation testify that often encounterability in nature and in the production of sensitive yeasts is attributed to high frequency of mutation changes of the killer and neutral phenotypes to the sensitive state.

60

Absolute absorption of ozone in the midinfrared  

Energy Technology Data Exchange (ETDEWEB)

The absolute absorption of ozone in the midinfrared has been measured relative to 253.7-nm ultraviolet absorption to an accuracy of 1% using a Bruker Fourier transform spectrometer. These new results agree with previous measurements by diode laser measurements after the latter are corrected for more recent infrared calculations and ultraviolet cross sections. They also agree with a determination based on refractive index measurements in the infrared. 16 refs., 4 figs., 3 tabs.

1992-12-20

61

Selective absorption of ultraviolet laser energy by human atherosclerotic plaque treated with tetracycline  

Energy Technology Data Exchange (ETDEWEB)

Tetracycline is an antibiotic that absorbs ultraviolet light at 355 nm and preferentially binds to atherosclerotic plaque both in vitro and in vivo. Tetracycline-treated human cadaveric aorta was compared with untreated aorta using several techniques: absorptive spectrophotometry; and tissue uptake of radiolabeled tetracycline, which showed 4-fold greater uptake by atheroma than by normal vessel. In addition, intravenous tetracycline administered to patients undergoing vascular surgery demonstrated characteristic fluorescence in surgically excised diseased arteries. Because of tetracycline's unique properties, the authors exposed tetracycline-treated and untreated aorta to ultraviolet laser radiation at a wavelength of 355 nm. They found enhanced ablation of tetracycline-treated atheroma compared with untreated atheroma. The plaque ablation caused by ultraviolet laser radiation was twice as extensive in ...

1985-05-01

62

Methods and results for calibration and track separation of a GEM based TPC using an UV-laser  

Energy Technology Data Exchange (ETDEWEB)

In the last 30 years high energy physics could write an impressive story of success. Since the introduction of the Standard Model (SM), it has met every experimental test. However the final confirmation has to prove the mechanism of electroweak symmetry breaking, which could not be confirmed yet. The most favored theory, which includes the introduction of a Higgs field, could not be verified experimentally. Furthermore there is clear evidence, that the SM is only a low energy description of nature and its principles, as the SM describes only 4 % of the known matter in the universe. There are two different approaches in accelerator driven high energy physics to clarify the open questions. The Large Hadron Collider (LHC) have a good opportunity to measure some of the missing pieces with its high center of mass energy. The International Linear Collider (ILC) will then measure their parameters with high precision. To guarantee this high precision the detectors have to be able to identify ...

2008-12-15

63

Contact lens disinfection by ultraviolet light  

Energy Technology Data Exchange (ETDEWEB)

A 253.7-nm ultraviolet light with an intensity of 1,100 microW/cm2 was tested for its germicidal activity against contact lenses and storage solutions contaminated with various corneal pathogens. The exposure time necessary to reduce a concentration of organisms from 10(6)/ml to less than 10/ml was 30 seconds for Staphylococcus aureus, 60 seconds for Pseudomonas aeruginosa, and 84 seconds for Candida albicans. The time necessary to sterilize a suspension of 10(4)/ml Acanthamoeba polyphaga was less than three minutes with this technique. Four brands of soft contact lenses were exposed to ultraviolet light for over eight hours without changing their appearance, comfort, or refraction.

1989-12-15

64

UV renormalons in QCD and their phenomenological implications  

International Nuclear Information System (INIS)

I report on some recent work done in collaboration with E. de Rafael on the connection between ultraviolet renormalons in QCD and Nambu-Jona-Lasinio-like Lagrangians as its effective description at low energies. (orig.)

1998-05-01

65

The Goddard Library - Goddard Projects Directory - NASA  

Science.gov (United States)

Oct 2, 2007 ... The Payload combines some of the most sensitive particle sensors .... provide state-of-the-art measurements of incoming x-ray, ultraviolet, .... It will be launched into a low-Earth orbit on a Delta 7320 rocket in September 2004. ...

66

Sunbed use during adolescence and early adulthood is associated with increased risk of early-onset melanoma  

UK PubMed Central (United Kingdom)

Sunbed use is associated with increased risk of melanoma. Younger people might be more susceptible to the carcinogenic effects of ultraviolet radiation. We investigated the association between...Full Text Available

2011-05-01

67

Simultaneous Reactivation of Ultraviolet Damage in Xanthium Leaves 1  

UK PubMed Central (United Kingdom)

Experiments on Xanthium leaf discs were carried out to determine whether concomitant photoreactivation could be detected and if so, to compare its effects with photoreactivation due...Full Text Available

1969-12-01

68

Simulation study of chiral two dimensional ultraviolet (2DUV) spectroscopy of the protein backbone  

UK PubMed Central (United Kingdom)

Amide n –π* and π-π* excitations around 200 nm are prominent spectroscopic...Full Text Available

2010-06-09

69

Photoelectron spectroscopy of carbonyls: benzoic acid and its derivatives  

Energy Technology Data Exchange (ETDEWEB)

The ultraviolet photoelectron spectra of benzoic acid and 20 of its derivatives are presented. The low-energy regions of these spectra are deconvoluted and assigned using chemical substitution effects. 5 figures, 3 tables.

1981-01-01

70

Photoconductive ultraviolet detectors based on ZnO films  

Energy Technology Data Exchange (ETDEWEB)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant {tau} obtained from the curve fitting represents the ...

2006-12-15

71

Photoconductive ultraviolet detectors based on ZnO films  

International Nuclear Information System (INIS)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant #tau# obtained from the curve fitting represents the ...

2006-12-15

72

Lack of adequate sun protection for children with oculocutaneous albinism in South Africa  

UK PubMed Central (United Kingdom)

BackgroundChildhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the...Full Text Available

73

In vitro and in vivo estrogenicity of UV screens.  

UK PubMed Central (United Kingdom)

Ultraviolet (UV) screens are increasingly used as a result of growing concern about UV radiation and skin cancer; they are also added to cosmetics and other products for light stability. Recent data...Full Text Available

2001-03-01

74

Chemoprevention of Nonmelanoma Skin Cancer With Celecoxib: A Randomized, Double-Blind, Placebo-Controlled Trial  

UK PubMed Central (United Kingdom)

BackgroundPreclinical studies indicate that the enzyme cyclooxygenase 2 plays an important role in ultraviolet-induced skin cancers. We evaluated the efficacy and safety of celecoxib,...Full Text Available

2010-12-15

75

A rational vision of stratospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

This work deals with a rational vision of stratospheric ozone including the threats on ozone layer, the verifications and the fears. After a recalling on the ozone layer history, the authors treats the question of the ultraviolets particularly the beneficial effects. Then an explanation of the ozone layer decrease is given. (O.L.). 29 refs., 6 figs.

1995-03-01

76

Transmission electron microscopy characterisation of permalloy elements fabricated by focussed ion beam lithography  

International Nuclear Information System (INIS)

20 nm thick permalloy elements, with dimensions of 500 x 500 nm"2 and 1000 x 200 nm"2, have been fabricated on 50 nm thick silicon nitride substrate by milling using a focussed ion beam (FIB) microscope. The dose of ion beam used for the milling was varied in order to achieve the best definition for the milled areas. The FIB milled elements were characterised physically by atomic force microscopy (AFM) and bright field transmission electron microscopy (TEM) and magnetically by Fresnel imaging on a TEM modified for magnetic imaging. The FIB milled elements were found to have a more irregular edge and lower magnetic fields for events such as vortex annihilation when compared to elements of the same dimensions fabricated by conventional electron beam microscopy (EBL).

2006-02-22

77

Proximity effect correction of a laser lithography process for photomask fabrication  

Energy Technology Data Exchange (ETDEWEB)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-07-01

78

Proximity effect correction of a laser lithography process for photomask fabrication  

International Nuclear Information System (INIS)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-11-04

79

Fast Beam Intensity Measurements for the LHC  

CERN Document Server

Particle accelerators are constructed and operated for a wide variety of applications. In particle physics - the branch of physics that studies the elementary constituents of matter and forces between them - high energy accelerators are used to look deep into the structure of matter. Medical particle accelerators are used for example in medicine to treat tumours [31], in imaging techniques such as Positron Emission Tomography (PET) [24], or for the radio-isotopes production. They also serve in many other industrial branches, e.g. geology, radiocarbon dating [39], molecular complex spectroscopy, lithography, food preservation etc. The eld of accelerator technology draws knowledge and expertise from a wide range of scientic disciplines and uses the latest technical knowledge. The incomplete list of covered disciplines includes mathematics, physics, electronics, computing, electromagnetic eld technology, microwave technology, cryogenics, vacuum technology, special ...

2010-01-01

80

Total skin electron beam therapy followed by adjuvant psoralen/ultraviolet-a light in the management of patients with T1 and T2 cutaneous T-cell lymphoma (mycosis fungoides)  

International Nuclear Information System (INIS)

Purpose: Patients with mycosis fungoides [cutaneous T-cell lymphoma (CTCL)] may benefit from adjuvant therapy after completing total skin electron beam therapy (TSEBT). We report the results for (T1(T2)) CTCL patients treated with adjuvant oral psoralen plus ultraviolet light (PUVA) with respect to overall survival (OS), disease-free survival (DFS), salvage of recurrence, and toxicity. Methods and Materials: Between 1974 and 1993, TSEBT was administered to a total of 213 patients with CTCL. Records were reviewed retrospectively, and a total of 114 patients were identified as having T1 or T2 disease. Radiotherapy was provided via a 6-MeV linac to a total of 36 Gy, 1 Gy/day, 4 days/week, for 9 weeks. Beginning in 1988, patients were offered adjuvant PUVA within 2 months of completing TSEBT. This was started at 0.5-2 J/m"2, 1-2 treatments/week, with a taper over 3-6 months. Therapy then continued once per month. There were 39 T1 and 75 T2 patients. Six T1 (15%) and ...

1997-07-15

81

The correlation between accelerated and field corrosion tests performed in carbon steel and weathering steel coupons, coated and non-coated; Correlacao entre ensaios acelerados e ensaios de campo em corpos-de-provas de aco carbono e aco patinavel, sem e com revestimento  

Energy Technology Data Exchange (ETDEWEB)

The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM D-714 and ASTM-1654 standards to rank them. ...

2002-07-01

82

Scientific Assessment of Ozone Depletion: 2002. Pursuant to Article 6 of the Montreal Protocol on Substances that Deplete the Ozone Layer  

Science.gov (United States)

Since the Scientific Assessment of Ozone Depletion: 1998, numerous laboratory investigations, atmospheric observations, and theoretical and modeling studies have produced new key findings and have strengthened overall understanding of the ozone layer and its effect on ultraviolet (UV) radiation. These advances are highlighted in the following summary of the current understanding of the impact of human activities and natural phenomena on the ozone layer and the coupling of the ozone layer and the climate system. In the troposphere (i.e., lower atmosphere), observations show that the total combined effective abundance of ozone-depleting compounds continues to decline slowly from the peak that occurred in 1992-1994. Total chlorine is declining, while bromine from industrial halons is still increasing, albeit at a slower rate than was occurring previously (and as reported in the 1998 Assessment). Analyses of air trapped in snow since the late 19th ...

2003-01-01

83

Automated ARXPS goniometer/diffractometer. Final report, April 1995--March 1997  

Energy Technology Data Exchange (ETDEWEB)

This award provided for an automated computer-controlled goniometer/diffractometer/manipulator with hot and cold stages and data acquisition system that was interfaced with the high resolution Scienta ESCA-300 X-ray photoelectron spectrometer at Lehigh University. The automation allows angular dependent X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) data to be accurately and rapidly collected without the very time-consuming and labor-intensive manual method that was previously required. It also provides for automated multi-sample analyses, collecting both wide survey scans and selected binding energy range analyses, with complete computer control and data storage. This allows 24 hour data collection without requiring the continuous presence of operators. The overall result is a greater productivity for the XPS laboratory, approximately doubling the output of the laboratory. While the automated ...

1998-07-01

84

Novel silicon fabrication process for high-aspect-ratio micromachined parts  

Energy Technology Data Exchange (ETDEWEB)

Bulk micromachining generally refers to processes involving wet chemical etching of structures formed out of the silicon substrate and so is limited to fairly large, crude structures. Surface micromachining allows intricate patterning of thin films of polysilicon and other materials to form essentially two-dimensional layered parts (since the thickness of the parts is limited by the thickness of the deposited films). There is a third type of micromachining in which the part is formed by filling a mold which was defined by photolithographic means. Historically micromachining molds have been formed in some sort of photopolymer, be it with x-ray lithography (``LIGA``) or more conventional UV lithography, with the aim of producing piece parts. Recently, however, several groups including ours at Sandia have independently come up with the idea of forming the mold for mechanical parts by etching into the silicon substrate itself. In Sandia`s mold ...

1995-08-01

85

In-situ measurement of epithelial tissue optical properties: Development and implementation of diffuse reflectance spectroscopy techniques  

Science.gov (United States)

Cancer is a severe threat to human health. Early detection is considered the best way to increase the chance for survival. While the traditional cancer detection method, biopsy, is invasive, noninvasive optical diagnostic techniques are revolutionizing the way that cancer is diagnosed. Reflectance spectroscopy is one of these optical spectroscopy techniques showing promise as a diagnostic tool for pre-cancer detection. When a neoplasia occurs in tissue, morphologic and biochemical changes happen in the tissue, which in turn results in the change of optical properties and reflectance spectroscopy. Therefore, a pre-cancer can be detected by extracting optical properties from reflectance spectroscopy. This dissertation described the construction of a fiberoptic based reflectance system and the development of a series of modeling studies. This research is aimed at establishing an improved understanding of the optical properties of mucosal tissues by analyzing ...

2009-01-01

86

Ultraviolet radiation for the sterilization of contact lenses  

Energy Technology Data Exchange (ETDEWEB)

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally ...

1990-10-01

87

Ultraviolet radiation for the sterilization of contact lenses  

International Nuclear Information System (INIS)

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally ...

88

Extreme Ultraviolet Emission from Abell 4059  

CERN Document Server

We present the results of a search for Extreme Ultraviolet emission in A4059, a cluster with an X-ray emitting cluster gas. Our analysis of Extreme Ultraviolet Explorer (EUVE) Deep Survey observations of this cluster shows that it is associated with diffuse EUV emission. Outside the central 2 arcmin radius the entire EUV emission detected is explained by the low energy tail of the X-ray emitting gas. Within the central 2 arcmin region of the cluster we find a deficit of EUV emission compared to that expected from the X-ray gas. This flux deficit is discussed in the context of the cluster's cooling flow. The results derived for A4059 are compared to EUVE results obtained for other clusters such as Coma, Virgo, A1795, and A2199. As part of the study we have carried out a detailed investigation of the stability of the EUVE Deep Survey detector background. Based on long integrations of blank sky over 27 months we disprove claims of substantial time ...

2000-01-01

89

Ultraviolet-B Phototoxicity and Hypothetical Photomelanomagenesis: Intraocular and Crystalline Lens Photoprotection  

British Library Electronic Table of Contents (United Kingdom)

Purpose Ultraviolet-B (UV-B) radiation can cause phototoxic macular injuries in young people who have been sunbathing but not sungazing and in welders. Welders have a reportedly increased risk of uveal melanoma. We analyze phakic and pseudophakic risks for solar and welding arc UV-B exposure. Design Optical radiation measurement, analysis, and perspective. Methods Spectral transmittances were measured for UV-transmitting, UV-blocking, and blue-blocking intraocular lenses (IOLs). The photoprotective performances of crystalline and intraocular lenses were analyzed using relevant epidemiologic and laboratory data and action spectra for acute retinal phototoxicity and melanoma photocarcinogenesis. Results Crystalline lens UV-B retinal protection is deficient in children and young adults, incre...

2010-01-01

90

Ultraviolet detectors based on ZnO films by thermal oxidation of Zn metallic films  

British Library Electronic Table of Contents (United Kingdom)

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 ?C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.

2008-01-01

91

Thin-film UV detectors based on hydrogenated amorphous silicon and its alloys  

Energy Technology Data Exchange (ETDEWEB)

Thin film ultraviolet detectors based on hydrogenated amorphous silicon alloys are realized with different diode structures (PIN, NIP, PN, and NP). The PIN and NIP detectors exhibit higher sensitivity in the ultraviolet spectrum and a significant lower dark current in comparison to the PN or NP structures. The best detector performance was achieved with a 33 nm thick PIN diode. This detector shows a maximum of quantum efficiency of 36.3% at a wavelength of 310 nm. By varying the thickness of the semi-transparent Ag front contact the selectivity of the detectors with the quantum efficiency peak at 320 nm can be adjusted. Thus, the spectral sensitivity of the detector shifts from a broad UV to a selective UV-B spectrum. (orig.)

2001-05-16

92

The VOISE Algorithm: a Versatile Tool for Automatic Segmentation of Astronomical Images  

CERN Document Server

The auroras on Jupiter and Saturn can be studied with a high sensitivity and resolution by the Hubble Space Telescope (HST) ultraviolet (UV) and far-ultraviolet (FUV) Space Telescope spectrograph (STIS) and Advanced Camera for Surveys (ACS) instruments. We present results of automatic detection and segmentation of Jupiter's auroral emissions as observed by HST ACS instrument with VOronoi Image SEgmentation (VOISE). VOISE is a dynamic algorithm for partitioning the underlying pixel grid of an image into regions according to a prescribed homogeneity criterion. The algorithm consists of an iterative procedure that dynamically constructs a tessellation of the image plane based on a Voronoi Diagram, until the intensity of the underlying image within each region is classified as homogeneous. The computed tessellations allow the extraction of quantitative information about the auroral features such as mean intensity, latitudinal and longitudinal ...

2009-01-01

93

Synthesis of ultraviolet curable encapsulating adhesives and their package applications for organic optoelectronic devices  

British Library Electronic Table of Contents (United Kingdom)

With conventional heating process, ultraviolet (UV) illumination, and microwave irradiation, we have successfully synthesized UV curable encapsulating adhesives with excellent gas barrier capabilities, good adhesive strength, moderate hardness, and high refractive indices. The experimental results manifest that the physical properties of lab-made encapsulating adhesives are highly dependent on their chemical structures and synthetic procedure. We also discover that the encapsulating adhesive prepared by microwave irradiation (i.e. encapsulating adhesive VI-MW) exhibits better adhesive strength and higher gas resistance than those prepared by conventional heating process and UV illumination. Furthermore, encapsulating adhesive VI-MW has also been applied for the package of organic light emi...

2011-01-01

94

Liquid chromatography with ultraviolet and dual parallel mass spectrometric detection for analysis of vitamin D in retail fortified orange juice  

British Library Electronic Table of Contents (United Kingdom)

Samples of vitamin D fortified orange juice obtained from retail food stores were analyzed for vitamin D3 content using a method developed by combining the best features of two AOAC methods. Detection by ultraviolet absorption at 265nm was compared to detection by selected ion monitoring (SIM) using atmospheric pressure chemical ionization (APCI) mass spectrometry (MS). Furthermore, an ion trap (IT) mass spectrometer was employed in a 'dual parallel MS' arrangement to simultaneously obtain qualitative APCI-ITMS data. The method was applied to 33 samples of 3 national American orange juice brands and 7 samples of 5 other American brands collected using a statistically designed sampling plan as part of the National Food and Nutrient Analysis Program to provide values for the USDA National Nu...

2011-01-01

95

FUV and X-ray absorption in the Warm-Hot Intergalactic Medium  

CERN Document Server

The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the concepts behind WHIM absorption line measurements of H I and high ions such as O VI, O VII, and O VIII in the far-ultraviolet and X-ray band. We review results of recent WHIM absorption line studies carried out with UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss their implications for our knowledge of the WHIM.

2008-01-01

96

Detection of Free-Living Amoebae in Some Water Sources and its Control by Ultraviolet- Radiation  

International Nuclear Information System (INIS)

Among the numerous free-living amoebae (FLA) of soil and water habitats, certain species belonging to two genera Acanthamoeba and Naegleria are facultative parasites of man.They cause disease called primary amoebic meningoencephalitis where history of contact with water was recorded in most of the cases especially with Naegleria species. The present work aimed to search for presence of free-living amoebae in the water and trials for its control by Ultraviolet-radiation (UV-radiation). Samples from different water sources were examined for the presence of free-living amoebae. These samples were cultured on non-nutrient agar streaked with bacteria. Amoebae were detected and identified by means of their morphological characters. Twelve positive cases of one hundred and twenty examined samples could be detected. The positive samples were exposed to different doses of UV-radiation for different times.

97

Composition and method for encapsulating photovoltaic devices  

Energy Technology Data Exchange (ETDEWEB)

A composition and method for encapsulating a photovoltaic device which minimizes discoloration of the encapsulant. The composition includes an ethylene-vinyl acetate encapsulant, a curing agent, an optional ultraviolet light stabilizer, and/or an optional antioxidant. The curing agent is preferably 1,1-di-(t-butylperoxy)-3,3,5-trimethylcyclohexane; the ultraviolet light stabilizer is bis-(N-octyloxy-tetramethyl) piperidinyl sebacate and the antioxidant is selected from the group consisting of tris (2,4-di-tert-butylphenyl) phosphite, tetrakis methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, and 2,2'-ethylidene bis(4,6-di-t-butylphenyl) fluorophosponite. The composition is applied to a solar cell then cured. The cured product contains a minimal concentration of curing-generated chromophores and resists UV-induced degradation.

2000-01-01

98

P-LIGA: 3D-integration of microstructures with curved surfaces by deep ion irradiation  

International Nuclear Information System (INIS)

Using the advantage that the projected range of ions in matter is sharply limited, a new technique for the production of three-dimensional microstructures has been developed. Based on the P-LIGA technique (Proton-Lithographie, Galvanoformung, Abformung) this process allows the generation of structures with surfaces of almost any shape having a root mean square roughness of about #lambda#/50 for visible light wavelengths. An ion beam with diameters between 2 and 50 #mu#m is directly writing the structures and the shape is varied by geometrical manipulation of the sample in three axes during the exposure. Practically, structures have been written using protons with an energy of 1.8 MeV in a provisional experimental setup with beam diameters of 10 and 50 #mu#m, respectively. After irradiation, the parts exposed were dissolved in a liquid developer without affecting the nonirradiated parts. The shape and the rms roughness of the resulting structures were estimated by ...

1998-04-01

99

Microfabrication processes for high-T_c superconducting films  

International Nuclear Information System (INIS)

Microfabrication processes for Y-Ba-Cu-O films have been investigated, using ion-beam techniques. High-T_c superconducting lines as narrow as 0.8 #mu#m have been fabricated from epitaxial YBa_2Cu_3O_7 _- _y films by Ar ion-beam etching (IBE), combined with focused ion-beam (FIB) lithography. The resulting lines, 1.3 #mu#m wide and 2 mm long, showed a zero resistance temperature of 81 K and a critical current density of 1.9 x 10"4 A/cm"2 at 77.3 K. Maskless etching was carried out using 130-keV au"+ focused ion-beam (FIB) with a 0.1-#mu#m-diameter beam. A 50-nm-thick film was patterned into 0.3-#mu#m-wide lines at a dose of 5 x "1"6 ions/cm"2. In comparison with Ar IBE, Cl_2 reactive ion-beam etching (RIBE) exhibited an enhancement effect in sputtering yield. Ion implantation with 300-keV Si"+ "+ FIB also indicated the possibility to produce submicrometer patterns by selectively modifying film properties from superconductive to normal or insulting.

100

Micro-strip metal foil detectors for the beam profile monitoring  

Energy Technology Data Exchange (ETDEWEB)

The Micro-strip Metal Foil Detectors (MMFD) designed and used for the Beam Profile Monitoring (BPM) are discussed. The results obtained for the MMFDs produced by different technologies are presented. The MMFD deposited onto the 20 {mu}m thick Si-wafer has been used for the BPM of the 32 MeV alpha-particle beam at the MPIfK (Heidelberg) Tandem generator. Another MMFD with totally removed Si-wafer at the working area has been applied for the on-line X-ray BPM at the HASYLAB (DESY). One may conclude that the developed technology of the micro-strip metal detector manufacturing allows to provide non-destructive measurement of X-ray intensity distribution over area of up to 50 mm{sup 2} with an accuracy of 10-20 {mu}m with a possibility of its improvement by a factor 5. A sub-micron position resolution is expected by applying electron lithography for the strip pattern production.

2005-07-01

101

Manipulation of inverted and direct opals by a focused ion beam scanning electron microscope (FIB SEM)  

International Nuclear Information System (INIS)

Focused ion beam (FIB) milling techniques are presented aiming at the manipulation of both tin dioxide (SnO_2) inverted opals and polystyrene (PS) direct opals. Different SnO_2 opals are considered in order to estimate the regularity of their bulk after the production. A SnO_2 mesoporous monolith is FIB micromachined to make it suitable for optical applications. PS direct opals are structured by FIB milling at different scales. Ordered arrays of PS opals are modified by selectively removing a single sphere. In performing this task, we discuss the effects on the FIB milling due to the gas-assisted enhanced etching and to the binding of the nearest neighbours. Techniques to achieve imaging of PS opals in absence of a conductive coating are also brought up. Furthermore, isolated PS spheres are drilled with or without enhanced etching in order to produce controlled defects on them. The FIB-assisted manipulations we show may find potential applications in the field of photonic crystals, ...

2008-08-01

102

Focused ion beam processes for high-T/sub c/ superconductors  

International Nuclear Information System (INIS)

Focused ion beam (FIB) processes have been developed for Y--Ba--Cu--O superconductor films. A Y--Cu liquid metal ion source has been fabricated, using a Y_6_7 --Cu_3_3 eutectic alloy as the ion source. As-sputtered Y--Ba--Cu--O film etch rate ratios to GaAs(100) and Si(100) substrates are 0.28 and 1.4 for 130-keV Au"+ FIB ion etching, respectively. Y--Ba--Cu--O submicron patterns have been demonstrated by using FIB lithography and Cl_2 reactive ion beam etching. Moreover, a Y--Ba--Cu--O superconducting line with 4-#mu#m linewidth has been fabricated by annealing an as-sputtered Y--Ba--Cu--O line pattern. T/sub c/ control of Y--Ba--Cu--O film has been achieved by 200-keV Ne"+, using conventional ion implantation and 300 keV Si"+"+ FIB ion implantation.

103

Focused ion beam machined nanostructures depth profiled by macrochannelling ion beam analysis  

International Nuclear Information System (INIS)

High aspect ratio sub-#mu#m periodic structures fabricated by focused ion beam (FIB) lithography have been characterised by Rutherford backscattering spectrometry (RBS) using the macrochannelling technique. The technique overcomes the limitations of complementary techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM), which can provide images with sub-#mu#m resolution of just the surface features and not of the deep sub-surface structures, without destructive cross sectioning of the sample. Here RBS macrochannelling with a 2 MeV He"+ ion beam is used to analyse a diffraction grating fabricated by FIB milling an array of 100 nm wide trenches in a 300 nm thick Ag film on a Si substrate. Using the surface structure imaged by SEM and AFM as a starting point, a numerical model for the RBS spectrum from the grating is fitted to the experimental spectrum as a function of the sub-surface structure. This process allows the width of the ...

2006-08-01

104

The plasma generated and photons emitted in an oil-lubricated sliding contact  

International Nuclear Information System (INIS)

Intensive work has long been going on to find out the unknown origin that sets off curious tribo-physicochemical phenomena and that causes various kinds of problems in oil-lubricated sliding contacts in mechanical and processing systems. The strange tribochemical reaction is one of the such curious chemical phenomena observed in the degradation of perfluoropolyether (PFPE) lubricating oil film in a hard disk drive. Plasma (triboplasma) (Nakayama and Mirza 2006 Tribol. Trans. 49 17) would be one of the most probable origins of the problems if it were generated sufficiently intensely in oil-lubricated sliding contacts, as it is in such a highly energetic state. The generation of plasma was predicted in both dry and oil-lubricated sliding (Nakayama 1997 Japan. J. Tribol. 42 1077, Nakayama 2004 Surf. Coat. Technol. 188-189 599). However, plasma generation in industrially important oil-lubricated contacts has not yet been proven, though it has been found in dry sliding ...

2007-02-21

105

Temperature dependence of the performance of ultraviolet detectors  

Energy Technology Data Exchange (ETDEWEB)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric ...

2003-08-21

106

Temperature dependence of the performance of ultraviolet detectors  

International Nuclear Information System (INIS)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric ...

2003-08-21

107

Spectrophotometric technique quantitatively determines NaMBT inhibitor in ethylene glycol-water solutions  

Science.gov (United States)

Spectrophotometric method, using a ratio-recording ultraviolet-absorption spectrophotometer, permits analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to detect extremely small concentrations of mercaptobenzothiazole.

1967-01-01

108

S179D prolactin diminishes the effects of UV light on epidermal gamma delta T cells  

UK PubMed Central (United Kingdom)

Epidermal gamma delta T cells (γδ T) and Langerhans cells (LC) are immune cells altered by exposure to ultraviolet radiation (UVB), a powerful stressor resulting in immune suppression....Full Text Available

2008-01-02

109

Rayleigh Scattering in Rare Gas Liquids  

CERN Document Server

The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.

2002-01-01

110

Ozone layer  

Energy Technology Data Exchange (ETDEWEB)

Governments around the world will soon make decisions on policies that could determine the fate of the ozone layer-the Earth's shield from harmful ultraviolet radiation. The Vienna Convention for the Protection of the Ozone Layer, signed on March 22, 1985, created a framework for scientific cooperation and information exchange that will form the basis for a protocol for controlling substances thought to threaten the ozone layer. As of mid-1987, 29 countries had signed the Convention, including the major producers and users of chlorofluorocarbons (CFCs), the most important of suspect chemicals.

1987-12-01

111

Conductive, spin-cast carbon films from polyacrylonitrile  

Energy Technology Data Exchange (ETDEWEB)

Polyacrylonitrile films have been spin cast and pyrolyzed to produce thin (500--1500 A) carbon films. These films have higher electrical conductivities than films produced by other methods at similar temperatures. The conductivity can be varied by at least four orders of magnitude by changing the pyrolysis temperature. Ultraviolet, infrared, and Raman spectroscopies were used to investigate the chemical structure of the films during different stages of processing.

1987-05-18

112

Clinical translation of ultraviolet autofluorescence microscopy towards endomicroscopy for early detection of cancer  

Science.gov (United States)

The non-invasiveness of autofluorescence technology may reduce sampling error and time delay for histopathology diagnosis. We establish biophotonic methods and guidelines to visualize and interpret early epithelial tissue changes that signify disease. Flexible and rigid fiber endomicroscopy instrumentation design parameters feasible for translation towards clinical use are in development.

2010-12-01

113

Calculation of general p-adic Feynman amplitude  

Energy Technology Data Exchange (ETDEWEB)

The general n-point massless p-adic Feynman amplitude with arbitrary parameters of analytic regularization for each line is calculated. This result is presented in the form of a sum over hierarchies of a given graph. The structure of ultraviolet and infrared divergences of p-adic Feynman amplitudes is characterized and the star-triangle uniqueness identity in the p-adic case is derived. (orig.).

1992-10-01

114

Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions  

International Nuclear Information System (INIS)

Ultraviolet (UV) upconversion (UC) luminescence in Yb3+/Er3+-codoped yttrium oxide (Y2O3) nanocrystals can be enhanced by orders of magnitude via tridoping further with Li+ ions under diode laser excitation of 970 nm. Sensitized three-photon UC radiations at 390 and 409 nm, corresponding to the 4G11/2?4I15/2 and 4H9/2?4I15/2 of Er3+ ions, respectively, present an enhancement time of about 33 times, which is larger than the 24 times enhancement for the UC green radiation. The UV UC radiation at 320 nm that corresponds to the 2P3/2?4I15/2 of Er3+ ions has also been greatly enhanced. Theoretical calculations interpret that all the observed enhancement times of UV UC radiations arise from the prolonged lifetimes of their intermediate states.

2009-03-01

115

Ultraviolet radiation in Finland  

Energy Technology Data Exchange (ETDEWEB)

Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s ...

1996-12-31

116

Space nuclear power requirements for ozone layer modification  

International Nuclear Information System (INIS)

This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O_3) in the Earth's atmosphere is estimated to be about 4.7 x 10"3"7 molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 x 10"3"1 molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time #approx# 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O_2 (leading to production of atomic oxygen, which can combine with O_2 to form O_3) than in ozone ...

1992-01-13

117

Second Byurakan spectral sky survey. II. Results for region centered on alpha 09h50m, delta +55 deg 00 arcmin  

Energy Technology Data Exchange (ETDEWEB)

The second list of objects in the Second Biurakan Spectral Sky Survey of the region centered on alpha 09h50m, delta +55 deg 00 arcmin is given. The list contains data on 110 objects and galaxies of a peculiar physical nature and 24 blue stars. The observations were made with the 40-52 arcsec Schmidt telescope of the Biurakan Astrophysical Observatory with a set of three objective prisms using Kodak IIIaJ and IIIaF emulsions sensitized in nitrogen. The area is found to contain 20 quasar candidates and four Seyfert galaxies, 27 blue stellar objects, 24 galaxies with an appreciable ultraviolet continuum, and 39 emission galaxies without appreciable ultraviolet radiation. The surface brightness of the quasars and Seyferts on the considered area down to the limiting magnitude 19.5 M is more than 1.5 per square degree with allowance for the already known quasars. The surface density of emission galaxies is about four per square degree. 7 references.

1984-07-01

118

Photobiological activity of marmesin (5-B-hydroxyisopropyl-4-5 dihydrofurocoumarin) in Chinese hamster V79 cells  

Energy Technology Data Exchange (ETDEWEB)

Marmesin was isolated from the medicinal plant, Afraegle paniculata. Its cytotoxicity and mutagenicity in Chinese hamster V79 cells when sensitized to near ultraviolet (NUV) and long wavelength ultraviolet light or black light (BL) were assayed. Marmesin was extremely cytotoxic in the dark. This cytotoxicity was photoenhanced in NUV and BL; the photoenhanced lethality being higher in NUV than in BL. The LD/sub 50/ of marmesin under NUV and BL photosensitization were 0.002 ..mu..M and (0.012 ..mu..M), respectively. In the absence of NUV and BL, marmesin's LD/sub 50/ was 0.013 ..mu..M.NUV and BL without marmesin were not significantly cytotoxic at the fluence rates of 0.29 W/m/sup 2/ and 4.2 W/m/sup 2/, respectively, for up to 20 min. In contrast to the observed high cytotoxicity of marmesin, its mutagenicity at the HGPRT locus (Asub(z)Gsup(r)) was weak. The implication of this result in the high incidence of skin cancer in Nigeria in ...

1983-10-01

119

Observation of the Far-ultraviolet Continuum Background with SPEAR/FIMS  

CERN Document Server

We present the general properties of the far-ultraviolet (FUV; 1370-1720A) continuum background over most of the sky, obtained with the Spectroscopy of Plasma Evolution from Astrophysical Radiation instrument (SPEAR, also known as FIMS), flown aboard the STSAT-1 satellite mission. We find that the diffuse FUV continuum intensity is well correlated with N_{HI}, 100 $\\mu$m, and H-alpha intensities but anti-correlated with soft X-ray. The strongest correlation is with the H-alpha emission, and the correlation of the diffuse background with the direct stellar flux is weaker than the correlation with other parameters. The continuum spectra are relatively flat. However, a weak softening of the FUV spectra toward some sight lines, mostly at high Galactic latitudes, is found not only in direct-stellar but also in diffuse background spectra. The diffuse background is relatively softer that the direct stellar spectrum. We also find that the diffuse FUV background averaged ...

2010-01-01

120

Mitochondrial genetic damage induced in yeast by a photoactivated furocoumarin in combination with ethidium bromide or ultraviolet light  

International Nuclear Information System (INIS)

Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of 'petite' mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or #gamma# rays. EB in combination with 3 CPs also resulted in an enhanced production of 'petite' mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the 'petite' mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of 'petite' mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with #gamma# rays produced no enhancement in 'petite' ...

121

Low-temperature synthesis and room temperature ultraviolet lasing of nanocrystalline ZnO films  

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline ZnO films were fabricated via a simple method involving the oxidation of Zn films at a remarkably low temperature of 380 C. X-ray diffraction study confirmed that the Zn films were completely oxidized even at the low temperature of 380 C and the ZnO films fabricated were of polycrystalline wurtzite structure. Room temperature optical pumping using a frequency-quintupled Q-switched Nd:YAG laser ({lambda}=213 nm) exhibited that sharp peaks at around 3.12 eV emerged above excitation powers of {proportional_to}7 MW/cm{sup 2}, demonstrating lasing in the ZnO films. These results represent that the process is a simple, promising approach for fabricating ZnO of sufficient optical performance for use as ultraviolet (UV) light emitters and an alternative UV laser source; both are key components in short-wavelength photonic devices. (orig.)

2005-02-01

122

FT-IR spectroscopic studies of polycyclic aromatic hydrocarbons  

International Nuclear Information System (INIS)

Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared absorption coefficients instead of those at the temperature of interest because of ...

1990-04-01

123

Vibrational Circular Dichroism: A developing spectroscopic technique for peptide and protein conformational studies  

International Nuclear Information System (INIS)

Electronic circular dichroism (ECD) of the n-#pi# and #pi# -#pi# transitions of the amide groups in the ultraviolet has become an indispensable tool for qualitative characterization of proteins in solution. Since the existence of such a spectrum (that is, of natural optical activity) comes from the three dimensional interaction of the chromophores in the molecule, CD is exquisitely sensitive to molecular conformation. However, in proteins, the amide transitions available in the near UV are limited in number and are broads and overlapping. Interactions among them yield information about the polymeric backbone, but since such amide electronic excitation are relatively delocalized, the resulting

1996-11-01

124

Ultraviolet Complete Electroweak Model Without a Higgs Particle  

CERN Document Server

An electroweak model with running coupling constants described by an energy dependent entire function is utraviolet complete and avoids unitarity violations for energies above 1 TeV. The action contains no physical scalar fields and no Higgs particle and the physical electroweak model fields are local and satisfy microcausality. The $W$ and $Z$ masses are compatible with a symmetry breaking $SU(2)_L\\times U(1)_Y \\rightarrow U(1)_{\\rm em}$, which retains a massless photon. The vertex couplings possess an energy scale $\\Lambda_W > 1$ TeV predicting scattering amplitudes that can be tested at the LHC.

2010-01-01

125

Two-Loop Virtual Corrections to Drell-Yan Production at order alpha_s alpha^3  

CERN Document Server

The Drell-Yan mechanism for the production of lepton pairs is one of the most basic processes for physics studies at hadron colliders. It is therefore important to have accurate theoretical predictions. In this work we compute the two-loop virtual mixed QCD x QED corrections to Drell-Yan production. We evaluate the Feynman diagrams by decomposing the amplitudes into a set of known master integrals and their coefficients, which allows us to derive an analytical result. We also perform a detailed study of the ultraviolet and infrared structure of the two-loop amplitude and the corresponding poles in epsilon.

2011-01-01

126

Tunable VUV generation by anti-Stokes stimulated Raman conversion of XeCl laser radiation  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on the results of experiments into efficient higher-order anti-Stokes Raman conversion of tunable short-pulse XeCl laser radiation. The maximum output energy of the pumping laser, in which the radiation of a frequency-doubled dye laser is amplified by two XeCl laser amplifiers, is 55 mJ with a pulse duration of 1 ns FWHM. Using hydrogen gas as a Raman medium, a series of anti-Stokes lines up to the 12th order (121.5 nm) is generated in the vacuum ultraviolet (VUV) region. 16 references.

1987-06-01

127

Spectroscopy of color centers in yttrium-aluminium perovskite crystals  

International Nuclear Information System (INIS)

The color centers, which are generated in yttrium-aluminium perovskite (YAP):Nd(1 at.%) and YAP:Er(50 at.%) crystals under the influence of ultraviolet and #gamma#-irradiation, have been studied by absorption spectroscopy. The generated color centers are both stable and transient at room temperature. It is shown that the transient color centers are mainly responsible for the decrease of laser generation efficiency of Nd:YAP and YAP:Er irradiated crystals, although physical mechanisms leading to efficiency decrease are different in these materials. (orig.)

1998-07-24

128

Photoluminescence and cathodoluminescence properties of Tb3+ activated Sr3AlO4F emitting-color tunable phosphor  

British Library Electronic Table of Contents (United Kingdom)

Tb3+-activated Sr3AlO4F phosphors were synthesized by a high-temperature solid-state reaction method. The investigation of photoluminescence and cathodoluminescence indicates that these phosphors can be effectively excited by ultraviolet light and low-voltage electron beam. The phosphors exhibit a tunable-green emission. The luminescence behaviors are explained by the site occupancy of Tb3+ ions in the host crystal and the cross-relaxation of 5D3 to 5D4 state.

2011-01-01

129

Photoluminescence and cathodoluminescence properties of Tb3+ activated Sr3AlO4F emitting-color tunable phosphor  

Science.gov (United States)

Tb3+-activated Sr3AlO4F phosphors were synthesized by a high-temperature solid-state reaction method. The investigation of photoluminescence and cathodoluminescence indicates that these phosphors can be effectively excited by ultraviolet light and low-voltage electron beam. The phosphors exhibit a tunable-green emission. The luminescence behaviors are explained by the site occupancy of Tb3+ ions in the host crystal and the cross-relaxation of 5D3 to 5D4 state.

2011-03-01

130

Photochemical generation of E' centre from Si-H in amorphous SiO2 under pulsed ultraviolet laser radiation  

CERN Document Server

In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si-H rupture, while the growth and the saturation of the defects are conditioned by their concurrent annealing due to reaction with mobile hydrogen arising from the same precursor. A rate equation is proposed to model the kinetics of the defects and tested on experimental data.

2006-01-01

131

Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation  

Energy Technology Data Exchange (ETDEWEB)

Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined.

1984-01-01

132

Optimum plasma conditions for the efficient high-order harmonic generation in platinum plasma  

International Nuclear Information System (INIS)

We studied the optimum plasma conditions that are required for efficient high-order harmonic generation in platinum plume. Harmonics up to the 49th order (?=16.32 nm) are analyzed under various conditions of laser-plasma interaction. Time-resolved ultraviolet spectra of platinum plasma at both optimum and nonoptimum conditions of harmonic generation are presented. We calculated the ionization states of the plasma, free electron density, and singly charged ion density at different prepulse intensities and compared them with experimental results.

2007-06-01

133

Emission Line Spectra in the Soft X-Ray Region 20-75 (Angstrom)  

Energy Technology Data Exchange (ETDEWEB)

As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.

2002-06-18

134

FORMATION EPOCHS, STAR FORMATION HISTORIES, AND SIZES OF MASSIVE EARLY-TYPE GALAXIES IN CLUSTER AND FIELD ENVIRONMENTS AT z = 1.2: INSIGHTS FROM THE REST-FRAME ULTRAVIOLET  

International Nuclear Information System (INIS)

We derive stellar masses, ages, and star formation histories (SFHs) of massive early-type galaxies in the z = 1.237 RDCS1252.9-2927 cluster and compare them with those measured in a similarly mass-selected sample of field contemporaries drawn from the Great Observatories Origin Deep Survey South Field. Robust estimates of these parameters are obtained by comparing a large grid of composite stellar population models with 8-9 band photometry in the rest-frame near-ultraviolet, optical, and IR, thus sampling the entire relevant domain of emission of the different stellar populations. Additionally, we present new, deep U-band photometry of both fields, giving access to the critical far-ultraviolet rest frame, in order to empirically constrain the dependence of the most recent star formation processes on the environment. We also analyze the morphological properties of both samples to examine the dependence of their scaling relations on their mass ...

2010-01-20

135

Sub-0.1 #mu#m line fabrication by Focused ion beam and columnar structural Se-Ge resist  

International Nuclear Information System (INIS)

As a method to enhance the sensitivity (S) of an inorganic resist for focused-ion-beam (FIB), lithography, sub-0.1 #mu#m patterning properties of a columnar structural #alpha#-Se_7_5Ge_2_5 resist have been investigated using 30 keV low-energy Ga"+-FIB exposure and CF_4 reactive-ion etching (RIE). development. The Se_7_5Ge_2_5 thin films were 60 .deg. and 80 .deg. -obliquely deposited on Si substrate and parts of the films were annealed for several minutes at the glass transition temperature (T_g=#approx#220 .deg. C). Columnar structures with the angles of approximately 40 .deg. and 65 .deg. are observed in 60 .deg. and 80 .deg. -obliquely deposited films, respectively, and they disappear after annealing. Despite the disappearance of the columnar structures, a critical decrease in thickness is not observed. For the FIB exposures with a beam diameter of #approx#0.1#mu#m and around the threshold dose, the negative-type fine patterns with linewidth of about ...

1998-11-01

136

Microfabrication processes for high-T sub c superconducting films  

Energy Technology Data Exchange (ETDEWEB)

Microfabrication processes for Y-Ba-Cu-O films have been investigated, using ion-beam techniques. High-{Tc} superconducting lines as narrow as 0.8 {mu}m have been fabricated from epitaxial YBa{sub 2}Cu{sub 3}O{sub 7 {minus} {ital y}} films by Ar ion-beam etching (IBE), combined with focused ion-beam (FIB) lithography. The resulting lines, 1.3 {mu}m wide and 2 mm long, showed a zero resistance temperature of 81 K and a critical current density of 1.9 {times} 10{sup 4} A/cm{sup 2} at 77.3 K. Maskless etching was carried out using 130-keV au{sup +} focused ion-beam (FIB) with a 0.1-{mu}m-diameter beam. A 50-nm-thick film was patterned into 0.3-{mu}m-wide lines at a dose of 5 {times} {sup 16} ions/cm{sup 2}. In comparison with Ar IBE, Cl{sub 2} reactive ion-beam etching (RIBE) exhibited an enhancement effect in sputtering yield. Ion implantation with 300-keV Si{sup + +} FIB also indicated the possibility to produce submicrometer patterns by selectively modifying film ...

1989-12-01

138

Wastewater treatment; Abwasserreinigung  

Energy Technology Data Exchange (ETDEWEB)

The methods introduced for the field of cleaning waste water can be classified under various processes. Chemical oxidation is done with ozone, hydrogen peroxide and ultraviolet irradiation with subsequent biological decomposition. Another method is ultra-filtration with recovery of valuable materials or waste water ponds with algae biomass to decompose ammonium compounds, nitrates and phosphates. (EF) [Deutsch] Die auf dem Gebiet der Abwasserreinigung vorgestellten Methoden kann man in verschiedene Verfahren einordnen. Die chemische Oxidation erfolgt mit Ozon, Wasserstoff-Peroxid, UV Bestrahlung und anschliessenden biologischen Abbau. Eine andere Methode ist die Ultrafiltration mit Rueckgewinnung von Wertstoffen oder Abwasserteiche mit Algenbiomasse zum Abbau von Ammoniumverbindungen, Nitraten und Phosphaten. (EF)

1994-11-01

139

Use of polarized light microscopy in porcine reproductive technologies  

British Library Electronic Table of Contents (United Kingdom)

The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted...

2011-01-01

140

Upper bound for a three-photon excitation cross section in atomic argon in the ultraviolet regime  

International Nuclear Information System (INIS)

A scheme of evaluating a generalized three-photon excitation cross section #sigma#/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p"6 "1S_0 state to the 3p"54s'[1/2]_1"0 state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of #DELTA##lambda#/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is #sigma#/sub (3)/ = 1.414 x 10/sup -80/ cm"6 s"2. .AE.

8800-01-01

141

UV inactivation: Combined effects of UV radiation and xenobiotics in two strains of Saccharomyces  

International Nuclear Information System (INIS)

The effects of eight chemicals on the inactivation rate of ultraviolet radiation on the colony building capabilities of two strains of Saccharomyces cervisae - a wild type strain and a mutant deficient in excision repair - were studied. The insecticide methoxychlor, the herbicide 2,4-dichlorophenoxyacetic acid, the fungicide pentachlorophenol and its metabolite tetrachlorohydroquinone, as well as the chemicals acrylonitrile and 2,3-dichloro-1-propene have no significant impact on the effects of UV radiation in Saccharomyces cerevisae. Depending on the concentration, trichloroethylene increases the sensitivity to UV radiation. The herbicide paraquat provides efficient protection against UV radiation at concentrations where a toxic effect cannot be observed even without UV. The results were rather similar for both strains. (orig.).

142

UPS fine structures of highest occupied band in vanadyl-phthalocyanine ultrathin film  

Energy Technology Data Exchange (ETDEWEB)

Ultraviolet photoelectron spectra were measured for vanadyl phthalocyanine (VOPc) ultrathin films prepared on graphite to study effects of the molecular orientation and the electric dipole layer on the organic electronic states. VOPc has a permanent electric dipole perpendicular to the molecular plane, hence a well-defined electric dipole layer could be intentionally prepared by using the oriented monolayer. The observed binding-energy difference of the highest occupied molecular orbital (HOMO) bands between the oriented monolayer and the double layer was found to agree with the vacuum level shift, leading to a conclusion that the molecular energy level with respect to the substrate Fermi level is changed when the molecule is in the electric dipole layer.

2005-06-15

143

Survival of gas phase amino acids and nucleobases in space radiation conditions  

CERN Document Server

We present experimental studies on the photoionization and photodissociation processes (photodestruction) of gaseous amino acids and nucleobases in interstellar and interplanetary radiation conditions analogs. The measurements have been undertaken at the Brazilian Synchrotron Light Laboratory (LNLS), employing vacuum ultraviolet (VUV) and soft X-ray photons. The experimental set up basically consists of a time-of-flight mass spectrometer kept under high vacuum conditions. Mass spectra were obtained using photoelectron photoion coincidence technique. We have shown that the amino acids are effectively more destroyed (up to 70-80%) by the stellar radiation than the nucleobases, mainly in the VUV. Since polycyclic aromatic hydrocarbons have the same survival capability and seem to be ubiquitous in the ISM, it is not unreasonable to predict that nucleobases could survive in the interstellar medium and/or in comets, even as a stable cation.

2008-01-01

144

Specific features and mechanisms of photoluminescence of nanostructured silicon carbide films grown on silicon in vacuum  

British Library Electronic Table of Contents (United Kingdom)

The light-emitting properties of cubic silicon carbide films grown by vacuum vapor phase epitaxy on Si(100) and Si(111) substrates under conditions of decreased growth temperatures (T gr ? 900?700?C) have been discussed. Structural investigations have revealed a nanocrystalline structure and, simultaneously, a homogeneity of the phase composition of the grown 3C-SiC films. Photoluminescence spectra of these structures under excitation of the electronic subsystem by a helium-cadmium laser (?excit = 325 nm) are characterized by a rather intense luminescence band with the maximum shifted toward the ultraviolet (?3 eV) region of the spectral range. It has been found that the integral curve of photoluminescence at low temperatures of measurements is split into a set of Lorentzian components. Th...

2011-01-01

145

Signatures of extra dimensions at e{gamma} and {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

The authors study the processes {gamma}e {r{underscore}arrow} {gamma}e and {gamma}{gamma} {r{underscore}arrow} {gamma}{gamma}, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory, the cross sections obtained for these processes at the Next Linear Collider (NLC), with the e{gamma} an {gamma}{gamma} options, deviate from the predictions of the Standard Model significantly. The results suggest that, for typical proposed NLC energies and luminosities, the predictions of WSQG can be tested in the range 1 TeV {approx{underscore}lt} M{sub S} {approx{underscore}lt} 10 TeV, making e{gamma} an {gamma}{gamma} colliders important tools for probing WSQG.

2000-01-26

146

Schottky barrier modulation on silicon nanowires  

Science.gov (United States)

Oxide charge on the sidewalls of SiO{sub 2} embedded silicon wires with 20x20 nm{sup 2} cross section is shown to influence the Schottky barrier height for Pd{sub 2}Si/Si junctions positioned on the end surfaces of the wires. Compared with results on planar silicon surfaces, the electron barrier height is 0.3 eV lower for wires investigated as fabricated. By increasing the oxide charge through irradiation by ultraviolet light, the electron barrier decreases by an additional 0.15 eV and the hole barrier correspondingly increases by about the same amount. The phenomenon is explained by assuming an oxide charge density in the range of 10{sup 12} cm{sup -2}.

2007-03-26

147

Positive effects of UV radiation on a calanoid copepod in a transparent lake: do competition, predation or food availability play a role?  

British Library Electronic Table of Contents (United Kingdom)

Zooplankton tolerant to ultraviolet radiation (UVR) could be indirectly affected by UVR through interactions with UV-sensitive species in the same ecosystem. In Lake Giles, Pennsylvania, USA, the calanoid copepod Leptodiaptomus minutus is more UVR tolerant than the cohabiting species Daphnia catawba and Cyclops scutifer. We asked whether L. minutus is affected by UV-induced mortality of a food competitor (D. catawba) or a predator of its nauplii (C. scutifer). We conducted two in situ enclosure experiments with six treatments: L. minutus alone, L . minutus + Daphnia and L. minutus + Cyclops in the presence and absence of UVR. There were few differences in survival among treatments in Experiment 1, which had enhanced food and a cumulative UVR (320 nm) dose of 9.3 kJ m-2. In Experiment 2, wh...

2006-01-01

148

Photosensitization by drugs. [Ultraviolet radiation  

Science.gov (United States)

uv irradiation (365 nm) of air-saturated methanol solutions of 20 drugs absorbing in the 300 to 400 nm region gave rise to oxygen uptake, as determined with a polarographic oxygen electrode. The drugs were tested for photosensitizing capability by either a Type I (free radical) or a Type II (single molecular oxygen) mechanism. This testing was done by the inclusion of either acrylamide or 2,5-dimethylfuran in the irradiated drug solution, with observation of the subsequent polymerization or oxidation, respectively. Phenothiazine and thiazide derivatives appear capable of photosensitization by both mechanisms; promethazine, trifluoperazine, and furosemide show relatively high reactivity. Diazepam (weak), hexachlorophene, aminacrine, pyrilamine, tetracycline, demeclocyline, quinine, and anthracene (strong) react only by a Type II mechanism, with a photosensitizing efficiency increasing in the order given. A correlation appears to exist with reports of in vivo photosensitivity.

1977-09-01

149

Photohemolytic potency of tetracyclines  

Energy Technology Data Exchange (ETDEWEB)

Hemolysis induced by long-wave ultraviolet radiation (UVA) and 8 different commercial tetracycline derivatives was studied in a model using human red blood cells. Demethylchlortetracycline and doxycycline were shown to have pronounced hemolytic properties causing 88% and 85% hemolysis, respectively, at a concentration of 50 micrograms/ml and 72 J/ cm2 of UVA. Tetracycline, oxytetracycline, and chlortetracycline caused maximally 18% hemolysis at 200 micrograms/ml and lymecycline only 7% at 100 micrograms/ml. Methacycline showed intermediate hemolytic effect of 36% at 200 micrograms/ml. Minocycline had no hemolytic effect whatsoever. These experimental data correlate very well with clinical reports and comparative phototoxicity trials in humans. Photohemolysis may thus be of value for predicting tetracycline phototoxicity.

1985-04-01

150

Mechanism of the accumulation effect in laser damage to polymers: appearance of microdamage due to an ionization absorption wave  

Energy Technology Data Exchange (ETDEWEB)

An investigation was made of the accumulation of laser damage to transparent polymers irradiated with nanosecond pulses from neodymium and ruby lasers. The damage was investigated by the method of scattering and luminescence in the visible and near ultraviolet parts of the spectrum. It was established that there were two stages in laser damage by repeated irradiation with pulses of intensity below the single-shot damage threshold. An absorbing defect evolved during the first stage in such a way as to create a thermal instability in the surrounding matrix. During the second stage this thermal instability caused spatial growth of laser damage because of propagation of an ionization-inducing absorption wave with a front traveling at the rate governed by the electron component of the thermal conductivity.

1984-04-01

151

Luminescence properties of Ca- and Yb-codoped SiAlON phosphors  

International Nuclear Information System (INIS)

Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.

2008-01-15

152

Low temperature deposition and characterization of TiO{sub 2} photocatalytic film through cold spray  

Energy Technology Data Exchange (ETDEWEB)

Cold spray was employed as a novel low temperature approach to deposit titanium dioxide (TiO{sub 2}) photocatalytic film. The film microstructure was characterized using X-ray diffraction and scanning electron microscopy. The photocatalytic performance was examined through acetaldehyde degradation under ultraviolet illumination. Results showed that TiO{sub 2} film was successfully deposited on substrate surface through cold spray. The film thickness reached up to 15 {mu}m. The film presented a rough surface and porous structure. Owing to the low temperature of spray powder, no phase and particle size changes occurred to TiO{sub 2} during deposition. It was found that the cold-sprayed TiO{sub 2} film was active for photodegradation of acetaldehyde.

2008-04-30

153

Kinetics of the methylparathion hydrolysis in aqueous medium; Cinetica de la hidrolisis del metilparation en medio acuoso  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of alkaline hydrolysis of methylparathion was studied at different temperatures (0-50 Centigrade) in the p H range of 8-12 by ultraviolet-visible absorption spectroscopy. Optimum p H and wavelength conditions were defined to carry out the simultaneous determination of methylparathion and one of its hydrolysis product, paranitrophenol, in buffered aqueous medium. Based on the experimental data and the mathematical equation of the kinetics, a rate constant (k) of first-order and an activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author) activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author)

1997-12-31

154

Investigating the Ultraviolet Properties of Gravity with a Wilsonian Renormalization Group Equation  

CERN Document Server

We review and extend in several directions recent results on the asymptotic safety approach to quantum gravity. The central issue in this approach is the search of a Fixed Point having suitable properties, and the tool that is used is a type of Wilsonian renormalization group equation. We begin by discussing various cutoff schemes, i.e. ways of implementing the Wilsonian cutoff procedure. We compare the beta functions of the gravitational couplings obtained with different schemes, studying first the contribution of matter fields and then the so-called Einstein-Hilbert truncation, where only the cosmological constant and Newton's constant are retained. In this context we make connection with old results, in particular we reproduce the results of the epsilon expansion and the perturbative one loop divergences. We then apply the Renormalization Group to higher derivative gravity. In the case of a general action quadratic in curvature we recover, within certain approximations, the known ...

2008-01-01

155

Intrinsic fluorescence of the amniotic fluid  

International Nuclear Information System (INIS)

The intrinsic fluorescence of clear amniotic fluid from third-trimester pregnancy is reported. The fluorescence intensity peaked at 405 nm when excited by ultraviolet light in the range of 310 to 360 nm. All of the 33 samples tested fluoresced, and their emission spectrum had the same shape, varying only in magnitude. Changing sample temperature (20 to 50 C) and sample pH (7.2 to 7.7) had little effect on the emission spectrum. The same fluorescence, with higher intensity, was observed when some newborn urine was tested. The fluorescence of amniotic fluid may provide a new tool to determine fetal age, fetal organ maturation, and fetal distress. (author).

1981-01-01

156

High power testing of a 17 GHz photocathode RF gun  

Energy Technology Data Exchange (ETDEWEB)

The authors report experimental results on a high gradient 17 GHz RF photocathode gun. The photocathode RF gun is a novel electron beam source intended to meet the requirements set by future high-energy linear colliders and next generation free electron lasers. A coupled pair of pillbox TM{sub 010}-like resonators is excited by sidewall coupled microwaves at 17 GHz. A picosecond ultraviolet laser pulse illuminates one wall of the structure at the axis of symmetry. Electrons are released by the photoelectric effect and are accelerated by the electric field of the microwaves in the cavity. The high frequency of operation raises the RF breakdown limit allowing strong electric fields to be used. In turn, the intense fields result in rapid acceleration of the electrons to relativistic speeds and reduced space charge induced emittance growth.

1996-12-31

157

Green synthesis of iron nanoparticles and their application as a Fenton-like catalyst for the degradation of aqueous cationic and anionic dyes  

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

2011-01-01

158

Extended Conjugation in Polyaniline Like Structure Prepared by Plasma Polymerization Suitable for Optoelectronic Applications  

British Library Electronic Table of Contents (United Kingdom)

Plasma polymerization of aniline is carried out in a radiofrequency plasma reactor and the effect of polymerization time is examined in the structural, optical and optoelectronic properties of deposited films. Conjugated structures of polyaniline like films are obtained with unique and broad optical absorption band in the ultraviolet and entire visible region. The width of the absorption band increases and hence the optical band gap decreases with polymerization time. The optical constants are extracted by Swanepoel method and the optical dispersion parameters are determined by employing the Wemple-DiDomenico single oscillator model. The films exhibit similar thermal stability in air and argon atmosphere in the region of interest for optoelectronic applications. The photoluminescence study...

2011-01-01

159

Conceptual design of industrial free electron laser using superconducting accelerator  

International Nuclear Information System (INIS)

Paper presents conceptual design of free electron laser (FEL) complex for industrial applications. The FEL complex consists of three. FEL oscillators with the optical output spanning the infrared (IR) and ultraviolet (UV) wave-lengths (#lambda# = 0.3...20 #mu#m) and with the average output power 10 - 20 kW. The driving beam for the FELs is produced by a superconducting accelerator. The electron beam is transported to the FELs via three beam lines (125 MeV and 2 x 250 MeV). Peculiar feature of the proposed complex is a high efficiency of the. FEL oscillators, up to 20 %. This becomes possible due to the use of quasi-continuous electron beam and the use of the time-dependent undulator tapering.

1995-08-21

160

Clinical and experimental studies of octocrylene's allergenic potency  

British Library Electronic Table of Contents (United Kingdom)

Background. Reports of positive patch test and photopatch test reactions to the chemical ultraviolet filter octocrylene have increased during the last decade. Little is known about the reason for octocrylene's allergenic activity. Objectives. To present and discuss the results of patch tests and photopatch tests with octocrylene, and to investigate the possible cause of its allergenic properties. Methods. Results of patch tests and photopatch tests with octocrylene in patients with adverse skin reactions to sunscreen products and/or ketoprofen were collected. The allergenic potency of octocrylene was investigated in the murine local lymph node assay (LLNA). Chemical reactivity assays were used to mimic octocrylene's interaction with biomolecules. Results. We report 23 cases of positive tes...

2011-01-01

161

Chemical transformations of organic matter during the composting of wood industry wastes (residues); Transformacoes quimicas da materia organica durante a compostagem de residuos da industria madeireira  

Energy Technology Data Exchange (ETDEWEB)

Composting of sawdust and paper mill sludge, using a 'Kneer' process reactor, was studied in an attempt to elaborate upon organic matter transformation during the process and to define parameters to measure the compost maturity level. Temperature, electron paramagnetic resonance data, ash and C, H, N and S contents, and a spectroscopic method using ultraviolet-visible (UV-VIS) for alkaline (pH = 8.5) and solid samples was used to study the maturity of the compost samples. These parameters were measured in 6 humic acids extracted from the compost samples during 29 days. The results of this work show that the 'Kneer' process is efficient in transforming ligno-celulitic residues in a short time (29 days), into an organic fertilizer material with application perspectives (author)

2004-06-01

162

Bonding and microstructural stability in Ni55Ti45 studied by experimental and theoretical methods  

Energy Technology Data Exchange (ETDEWEB)

Spiral orbit tribometry friction tests performed on Ni-rich Ni55Ti45 titanium ball bearings indicate that this alloy is a promising candidate for future aerospace bearing applications. Microstructural characterization of the bearing specimens was performed using transmission electron microscopy and energy dispersive spectroscopy, with NiTi, Ni4Ti3, Ni3Ti, and Ni2Ti4Ox phases identified within the microstructure of the alloy. Density functional theory was applied to predict the electronic structure of the NixTiy phases, including the band structure and site projected density of states. Ultraviolet photoemission spectroscopy was used to verify the density of states results from the density functional theory calculations, with good agreement observed between experiment and theory.

2010-11-25

163

Asphalt emulsion sealing of uranium mill tailings. 1980 annual report  

International Nuclear Information System (INIS)

Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

164

Application of asphalt emulsion seals to uranium mill tailings  

International Nuclear Information System (INIS)

Studies of asphalt emulsion sealants have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to less than background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and conpacted, overburden was applied over the seal to protect the seal from ultraviolet degradation. 14 figures.

165

Anisotropic forming of magnetic powders mixed with ultraviolet resin; Shigaisen koka jushi wo mochiita jisei funmatsu no haiko seikei  

Energy Technology Data Exchange (ETDEWEB)

For the purpose of solving the limitations such as shape and dimension for magnetic compact fabricated by conventional anisotropic forming under magnetic orienting field, the feasibility of a new magnetic forming process was studied. Ferrite powder mixed with UV resin was compacted in the die mold and followed by alignment under the magnetic field. Effects of viscosity of UV resin and forming condition on magnetic characteristics of the compact was investigated. Maximum degree of alignment for the ferrite powder reached to 0.826. It was predicted that the proposed method had make it possible to fabricate a high performance magnet having the anisotropic alignment of the magnetic powder. The UV resin is desirable to have low viscosity, good properties such as formability and configuration stability for the compact and also parting- ability between the metal mold and the compact. (author)

1999-01-15

166

Amperometric biosensor for hydrogen peroxide based on horseradish peroxidase onto gold nanowires and TiO2 nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

An electrochemical biosensor for determination of hydrogen peroxide (H2O2) was fabricated, based on the electrostatic immobilization of horseradish peroxidase (HRP) with one-dimensional gold nanowires (Au NWs) and TiO2 nanoparticles (nano-TiO2) on a gold electrode. The nano-TiO2 can give a biocompatible microenvironment and compact film, and the Au NWs can provide fast electron transferring rate and greatly add the amount of HRP molecules immobilized on the electrode surface. Au NWs were characterized by ultraviolet?visible spectra and transmission electron microscope. The electrode modification process was probed by cyclic voltammetry and electrochemical impedance spectroscopy. Chronoamperometry was used to study the electrochemical performance of the resulting biosensor. Under optimal co...

2011-01-01

167

AlxGa1-xN/GaN multi-quantum-well ultraviolet detector based on p-i-n heterostructures  

British Library Electronic Table of Contents (United Kingdom)

We report on characterization of a set of AlGaN/GaN multiple-quantum-well (MQW) photodetectors. The model structure used in the calculation is the p-i-n heterojunction with 20 AlGaN/GaN MQW structures in i-region. The MQW structures have 2nm GaN quantum well width and 15nm AlxGa1-xN barrier width. The cutoff wavelength of the MQW photodetectors can be tuned by adjusting the well width and barrier height. Including the polarization field effects, on increasing Al mole fraction, the transition energy decreases, the total noise increases, and the responsivity has a red shift, and so the detectivity decreases and has a red shift.

2009-01-01

168

Advanced oxidation process based on ozone/electron beam irradiation for treating groundwater  

International Nuclear Information System (INIS)

There are several methods of generating OH free radicals from ozone and/or hydrogen peroxide and ultraviolet light. They all have in common that the OH free radicals originate in one single source only whereas in the combination of ozone with ionizing radiation two simultaneous working sources for the OH free radicals exist. The resulting higher OH free radical concentration makes this process especially apt for the remediation of low level contaminated groundwater as for example trichloroethylene (TCE) contamination in the sub-ppm range. A cost comparison between O_3/UV and O_3/electron beam for remediation of a groundwater contaminated with 100 ppb TCE indicated that for a throughput of about 5 million gallons/day the O_3/electron beam process is more cost-effective. (authors).

169

Some relationships between ultraviolet light and heme-protein-induced peroxidative lipid breakdown in liposomes, as reflected by fluorescence changes: the effect of negative surface charge  

International Nuclear Information System (INIS)

The water soluble, photolabile nitrene precursor, azidonaphthalene-2,7-disulfonic acid (ANDS) was encapsulated in small unilamellar, isoelectric (egg PC) or negatively charged (egg PC + dihexadecylphosphate) liposomes. The individual and combined effects of heme-proteins and UV irradiation on the fluorescence of these vesicles under aerobic conditions were studied. Consistent with the catalytic action of heme-proteins on lipid peroxidation and peroxide decomposition, addition of cytochrome c (positively charged) or catalase (negatively charged) to the vesicles elicited immediate formation of a fluorescence band at 470 nm, characteristic of Schiff bases that form from aldehyde byproducts of decomposing hydroperoxides. Ultraviolet irradiation of liposomes caused no significant changes in the fluorescence spectrum, in spite of the radiolysis of ANDS inside the vesicles with consequent formation of nitrene radicals. When isoelectric vesicles were irradiated with UV ...

170

Physical, biochemical and physiological effects of ultraviolet radiation on Brassica napus and Phaseolus vulgaris  

International Nuclear Information System (INIS)

In order to follow some of the changes induced by ultraviolet-B (UV-B, 280-320 nm) radiation in Phaseolus vulgaris and Brassica napus, experiments were designed to localize sites of changes in leaves and to correlate some of the physiological and biochemical changes with penetration of UV-B radiation. B.napus was exposed to 8.9 kJ m"-"2 day"-"1 biologically effective UV-B radiation (UV-B_B_E). The penetration of UV-B radiation into the leaf was followed using a quartz fibre optic microprobe. Monochromatic radiation at 310 nm was decreased by ca 50 and 34% in the adaxial and abaxial epidermis, respectively, in plants not exposed to UV-B, whereas the radiation was decreased by ca 70 and 42%, respectively, in the same region in UV-treated plants. Polychromatic radiation showed a wavelength dependent change mainly for the collimated radiation. The results correlated with the distribution of phenolic compounds analysed from 40 #mu#m paradermal leaf sections. The first ...

1991-11-05

171

Photoresponsivity of ultraviolet detectors based on In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloys  

Energy Technology Data Exchange (ETDEWEB)

We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 {mu}m In{sub x}Al{sub y}Ga{sub 1-x-y}N alloy grown on 0.5-1.0 {mu}m GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the In{sub x}Al{sub y}Ga{sub 1-x-y}N detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The ...

2000-08-07

172

Photoresponsivity of ultraviolet detectors based on In_xAl_yGa_1_-_x_-_yN quaternary alloys  

International Nuclear Information System (INIS)

We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on In_xAl_yGa_1_-_x_-_yN quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 #mu#m In_xAl_yGa_1_-_x_-_yN alloy grown on 0.5-1.0 #mu#m GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the In_xAl_yGa_1_-_x_-_yN detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the In_xAl_yGa_1_-_x_-_yN quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The advantages of In_xAl_yGa_1_-_x_-_yN quaternary over ...

2000-08-07

173

Ozone Layer Observations  

Science.gov (United States)

The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV ...

2002-01-01

174

Organ culture of mammalian skin and the effects of ultraviolet light and testosterone on melanocyte morphology and function  

Science.gov (United States)

Scrotal skin of black Long-Evans rats and human thigh skin were maintained in vitro as organ cultures for as long as 14 days, and examined histologically using the combined skin splitting and Dopa techniques. Selected rat skin cultures received testosterone in the culture medium and/or were irradiated with ultraviolet light (290 to 320 nm uvl). With increased time in culture, scrotal melanocytes round up and there is an increase in epidermal pigmentation. Human skin behaves similarly; after eight days in vitro human melanocytes also become rounded, but remain strongly Dopa-positive. Addition of exogenous testosterone to cultured rat skin maintains dendritic morphology of melanocytes, but cell body size is still reduced. uvl irradiation stimulates melanocytes in rat skin cultures, maintaining their dendritic morphology and increasing epidermal and dermal pigmentation. Cultured skin receiving both uvl and testosterone illustrates a synergistic effect. Electron ...

1978-05-01

175

Measurement of the population densities in Gd atomic vapor using diode laser absorption spectroscopy in UV transitions  

International Nuclear Information System (INIS)

We report on the ultraviolet laser absorption spectroscopy of atomic Gd at 394-554 nm where two transition lines are place very closely by using a frequency-doubled beam of external-cavity diode laser (ECDL). One is from 999.121 to 26337.071 cm-1 and the other from 0 to 25337.755 cm-1. If two transition lines are placed closely within a continuous fine tuning range, the real-time measurement of the atomic excitation temperature is possible without any significant time consumption because at least two transition lines originating from different low-lying energy levels need to be investigated for the Boltzmann-plot. Since the spectral difference between the two transitions is only about 0.195 cm-1 (5.85 GHz), it is possible to record both the absorption spectra simultaneously as shown in Fig. 1. But the transition probabilities (or oscillator strengths) of these lines have not been measured accurately yet to the best of our knowledge. We report on the newly measured ...

2003-11-07

176

Growth-related variations in the glycosaminoglycan synthesis of ultraviolet light-induced murine cutaneous fibrosarcoma cells  

Energy Technology Data Exchange (ETDEWEB)

Glycosaminoglycan synthesis was studied in cell populations of ultraviolet light-induced murine cutaneous fibrosarcoma cells under conditions of varying growth rates in vitro. After labeling with the precursors, /sup 3/H-glucosamine and /sup 35/SO/sub 4/, sulfated glycosaminoglycans recoverable by direct proteolysis of the culture monolayers increased approximately 5-fold on a per cell basis from sparsely populated, exponential cell cultures (greater than 85% of cells in S, G2, or M phases) to stationary cultures inhibited by high cell density (greater than 50% of cells in G1). Within this cell surface-associated material, the relative ratio of heparan sulfate to the chondroitin sulfates was approximately 60/40% under conditions of exponential growth; in the growth-arrested cultures, the reverse ratio was found. The substratum attached material, obtained from the flask surface after ethyl glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid ...

1985-08-01

177

Benzene molecule is destroyed by ultraviolet and soft X-rays in circumstellar environment  

International Nuclear Information System (INIS)

Benzene molecules , present in the proto-planetary nebula CRL 618, are ionized and dissociated by ultraviolet (UV) and X-ray photons originated from the hot central star and by its fast wind. Ionic species and free radicals produced by these processes can lead to the formation of new organic molecules. The aim of this work is to study the photoionization and photodissociation processes of the benzene molecule, using synchrotron radiation and time-of-flight mass spectrometry. Mass spectra were recorded at different energies corresponding to the vacuum UV (21.21 eV) and soft X-ray (282-310 eV) spectral regions. The production of ions from the benzene dissociative photoionization is here quantified, indicating that C_6H_6 is more efficiently fragmented by soft X-ray than UV radiation, where 50% of the ionized benzene molecules survive to UV dissociation while only about 4% resist to C-rays. Partial ion yields of H and small hydrocarbons, such as C_2H_2"+, C_3H_3"+, ...

179

X-ray and UV-light irradiation effects on oxide superconducting thin films  

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 by the irradiation. From these results we can find that irradiation with the X-ray ...

180

Upper bound for a three-photon excitation cross section in atomic argon in the ultraviolet regime  

Energy Technology Data Exchange (ETDEWEB)

A scheme of evaluating a generalized three-photon excitation cross section sigma/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p/sup 6/ /sup 1/S/sub 0/ state to the 3p/sup 5/4s'(1/2)/sub 1//sup 0/ state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of ..delta..lambda/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is sigma/sub (3)/ = 1.414 x 10/sup -80/ cm/sup 6/ s/sup 2/. .AE

1989-04-15

181

The non-constant slope of the CIV Baldwin effect in NGC 4151  

CERN Document Server

The relationship between the emission line equivalent width and the continuum luminosity, so called the Baldwin effect, plays an important role in studying the broad line region physics of AGNs. Using the archived ultraviolet spectra obtained by IUE, HST and HUT in 1978-2002, we investigated the intrinsic CIV Baldwin effect of a best-studied Seyfert 1 galaxy NGC 4151. Both its continuum flux and CIV emission line flux varied about two orders of magnitude in more than two decades, making it one of the best targets for studying the slope variation of the Baldwin effect. We fitted the CIV line profile of the 490 archived UV spectra of NGC 4151 with a same model consisting of a few Gaussian components, and derived the slope in the log-log plot for the total flux of CIV emission line against the UV continuum flux in different observation epochs.We found that the slope is not constant for NGC 4151, varying from 0.58 in the highest flux epoch to 0.83 in the lowest flux ...

2006-01-01

182

The Cross-Calibration of Swift-BAT and Fermi-GBM via Correlative Spectral Analysis of GRBs  

CERN Document Server

We report on recent inter-calibration studies featuring Swift's Burst Alert Telescope (BAT) and Fermi's Gamma-ray Burst Monitor (GBM) based upon correlated observations of GRBs 080804 and 080810, via their resultant joint spectral analysis. Swift's intrinsic multi-wavelength instrumentation and dynamical response complement Fermi's superior energy range. The addition of BAT's spectral response will (i) facilitate in-orbit GBM detector response calibration, (ii) augment Fermi's low energy sensitivity, (iii) enable ground-based follow-up efforts of Fermi GRBs, and (iv) help identify a subset of GRBs discovered via off-line GBM data analysis, for an annual estimate of ~30 GRBs. The synergy of BAT and GBM augments previous successful joint spectral fit efforts by enabling the study of peak photon energies (Epeak), while leveraging the over eleven energy decades afforded by Fermi's Large Area Telescope (LAT), in conjunction with Swift's X-Ray (XRT) and ...

2009-01-01

183

Study on wavelength shortening and upgrading of the free electron laser (FEL)  

International Nuclear Information System (INIS)

This study is a task of ''Comprehensive study'' in ''nuclear energy basic technology research'', which is promoted under cooperation of four research institutes. The Electrotechnical Laboratory conducted, in 1991 in the first period of colaboration, on successful oscillation at visible region (598 nm) as the first case in Japan, construction of small type accumulation ring NIJI-IV for FEL, successful oscillation of visible range from 595 to 488 nm by installing optical krystron with maximum frequency in the world, and successful emittance lowering of accumulation beam by wide improvement of the ring. In the optical resonator, studies on minute loss measuring technique and on recovery from mirror deterioration were promoted. In the second period started from fiscal year of 1994, studies on FEL oscillation technique in short wavelength and upgrading of FEL corresponding to a frontier area were started, to succeed an oscillation experiment at 350 nm in ultraviolet ...

184

Studies on the Evolution of Silver Nanoparticles in Micelle by UV-Photoactivation  

Energy Technology Data Exchange (ETDEWEB)

Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the evolution of nanoparticles from different silver compounds have ...

2003-12-15

185

Structural transformations in Sc/Si multilayers irradiated by EUVlasers  

Energy Technology Data Exchange (ETDEWEB)

Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers adjacent tothe substrateremained intact even ...

2007-08-21

186

Semirelativistic technique for k#centre dot#p calculations: Optical properties of Pd and Pt  

International Nuclear Information System (INIS)

A semirelativistic two-component extended linear augmented plane-wave k#centre dot#p method is described. In order to ensure a high accuracy of the k#centre dot#p method, it is necessary to include into the radial-basis set, which is used for the augmentation of the plane waves, functions that are neither solutions of the Schrodinger equation nor their energy derivatives. The usual scalar relativistic procedure, which is nonlinear in energy, is not applicable to such basis sets. As an alternative, we suggest an approximation to the Foldy-Wouthuysen Hamiltonian that produces an explicitly Hermitean matrix in the augmented plane wave representation. The technique is applied to the calculation of the full dielectric matrix and optical properties of palladium and platinum metals over the photon energy region up to 100 eV. Special attention is paid to the far ultraviolet absorption by the excitations of semicore Pd 4p and Pt 5p and 4f states. A strong effect of local ...

2001-06-15

187

Seiberg duality and e+e- experiments  

Energy Technology Data Exchange (ETDEWEB)

Seiberg duality in supersymmetric gauge theories is the claim that two different theories describe the same physics in the infrared limit. However, one cannot easily work out physical quantities in strongly coupled theories and hence it has been difficult to compare the physics of the electric and magnetic theories. In order to gain more insight into the equivalence of two theories, we study the ''e{sup +}e{sup -}'' cross sections into ''hadrons'' for both theories in the superconformal window. We describe a technique which allows us to compute the cross sections exactly in the infrared limit. They are indeed equal in the low-energy limit and the equality is guaranteed because of the anomaly matching condition. The ultraviolet behavior of the total ''e{sup +}e{sup -}'' cross section is different for the two theories. We comment on proposed nonsupersymmetric ...

1998-10-02

188

Probing the Origins of the CIV and Fe Kalpha Baldwin Effect  

CERN Document Server

We use UV/optical and X-ray observations of 272 radio-quiet Type 1 AGNs and quasars to investigate the CIV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths, continuum monochromatic luminosities, and alpha_ox, which characterizes the relative X-ray to UV brightness. The equivalent width of the CIV 1549 emission line is correlated with both alpha_ox and luminosity. We find that by regressing l_UV with EW(CIV) and alpha_ox, we can obtain tighter correlations than by regressing l_UV with only EW(CIV). Both correlation and regression analyses imply that l_UV is not the only factor controlling the changes of EW(CIV); alpha_ox (or, equivalently, the soft X-ray emission) plays a fundamental role in the formation and ...

2009-01-01

189

Potassium deposition on a thiophene-terminated alkanethiol monolayer  

International Nuclear Information System (INIS)

Potassium deposition in ultrahigh vacuum on 12-(3-thienyl)dodecanethiol monolayers assembled on gold surfaces has been investigated using X-ray and ultraviolet photoelectron spectroscopies (XPS and UPS). Angle-resolved XPS indicates that initially deposited potassium penetrates the self-assembled monolayer (SAM) and diffuses to the SAM/Au interface. Even after large metal doses, the presence of thiophene ring valence electronic states in the UPS spectra confirms that most of the thiophene rings (at the SAM/vacuum interface) are not covered by potassium. The binding energy shifts of the thiophene ring valence states and the C1s and thiophene S2p peaks, referenced to the Fermi level, are due to the work function changes of the gold substrate. This indicates that these electronic states are pinned to the vacuum level, in contrast to the thiolate S2p orbital, which is pinned to the Fermi level. For large potassium doses, the appearance of new features in the UPS ...

2009-05-01

190

Photoconducting properties of ultraviolet detectors based on GaN and Al{sub 1{minus}x}Ga{sub x}N films grown by ECR-MBE  

Energy Technology Data Exchange (ETDEWEB)

GaN and Al{sub 1{minus}x}Ga{sub x}N films were grown by the method of ECR-MBE. Absorption constants as a function of wavelength were determined from transmission measurements. Photoconducting detectors were fabricated from these films and characterized in terms of their spectral response and photoconductive gain. Mobility-lifetime products were determined from the measurement of photoconductive gain. The resistivity and mobility-lifetime products of the films were varied from 10--10{sup 9} ohm-cm and 10{sup {minus}3}--10{sup {minus}8} cm{sup 2}/V respectively by changing the microwave power in the ECR discharge from 20--60 watts. The change in the mobility-lifetime product is attributed to change in the lifetimes of the photogenerated carriers. This assumption is supported by direct measurement of detector response times. Finally, the authors report for the first time, the detection of alpha particles using GaN detectors.

1997-12-31

191

Photoconducting properties of ultraviolet detectors based on GaN and Al_1_-_xGa_xN films grown by ECR-MBE  

International Nuclear Information System (INIS)

GaN and Al_1_-_xGa_xN films were grown by the method of ECR-MBE. Absorption constants as a function of wavelength were determined from transmission measurements. Photoconducting detectors were fabricated from these films and characterized in terms of their spectral response and photoconductive gain. Mobility-lifetime products were determined from the measurement of photoconductive gain. The resistivity and mobility-lifetime products of the films were varied from 10--10"9 ohm-cm and 10"-"3--10"-"8 cm"2/V respectively by changing the microwave power in the ECR discharge from 20--60 watts. The change in the mobility-lifetime product is attributed to change in the lifetimes of the photogenerated carriers. This assumption is supported by direct measurement of detector response times. Finally, the authors report for the first time, the detection of alpha particles using GaN detectors.

1996-12-02

192

Observation of multiorder coherent Raman sidebands in solid hydrogen film  

Energy Technology Data Exchange (ETDEWEB)

We investigated the Raman coherence characteristics of a solid hydrogen film deposited on a sapphire substrate held at 5.3 K. Using Raman coherence prepared with two single-frequency pulsed lasers, we generated the multiorder coherent Raman sidebands in solid hydrogen film. The highorder Raman sidebands were obtained under strong pumping intensities (>= 230 MW/cm{sup 2}). The generated anti-Stokes(AS)-Raman sidebands extend from the ultraviolet (292 nm for the AS5 band) to the visible (565 nm for the AS1 band) region. The multiorder Raman sideband generation is found to be due to the parametric coupling of pump and coupling lasers. The frequency conversion efficiency from pumping beams to the first AS-Raman sideband shows a maximum (14 %) at a pumping intensity of 360 MW/cm{sup 2}. From an experiment that makes the multimode probe beam beat with the prepared Raman coherence, we found that the prepared Raman coherence replicates the probe beam to its Raman ...

2004-07-15

193

Observation of multiorder coherent Raman sidebands in solid hydrogen film  

International Nuclear Information System (INIS)

We investigated the Raman coherence characteristics of a solid hydrogen film deposited on a sapphire substrate held at 5.3 K. Using Raman coherence prepared with two single-frequency pulsed lasers, we generated the multiorder coherent Raman sidebands in solid hydrogen film. The highorder Raman sidebands were obtained under strong pumping intensities (? 230 MW/cm2). The generated anti-Stokes(AS)-Raman sidebands extend from the ultraviolet (292 nm for the AS5 band) to the visible (565 nm for the AS1 band) region. The multiorder Raman sideband generation is found to be due to the parametric coupling of pump and coupling lasers. The frequency conversion efficiency from pumping beams to the first AS-Raman sideband shows a maximum (14 %) at a pumping intensity of 360 MW/cm2. From an experiment that makes the multimode probe beam beat with the prepared Raman coherence, we found that the prepared Raman coherence replicates the probe beam to its Raman sidebands.

2004-07-01

194

Mercury-free fluorescent lighting  

Energy Technology Data Exchange (ETDEWEB)

A brief comparative review of possible mercury free fluorescent lighting technologies is presented, including rare-gas positive column discharges, molecular discharges, and dielectric barrier discharges. Detailed experimental results on xenon positive column discharges will then be considered. In order to judge whether xenon-based discharges are a viable UV source it is necessary to measure the radiant emittance (power per unit area) for the vacuum ultraviolet (VUV) resonance xenon emission at 147 nm. Two techniques to determine the VUV radiant emittance have been developed and applied to xenon discharges. One method combines the measured resonance level density using absorption spectroscopy and a calculation of the trapped decay rate for the resonance radiation to arrive at the radiant emittance at 147 nm. A second method utilizes a direct measurement of the radiance (power per unit area per unit solid angle) at 147 nm using a calibrated VUV photodiode, and a ...

1996-05-01

195

Matrix-assisted laser desorption fourier transform mass spectrometry for biological compounds  

Science.gov (United States)

The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated that matrix-assisted ...

1990-01-01

196

Luminescence properties of europium and terbium activated yttrium niobium/tantalate phosphors under VUV-UV excitation  

International Nuclear Information System (INIS)

Various compositions of Y(Ta,Nb)O4:Eu3+,Tb3+ with different Nb and activator concentrations have been investigated under UV and VUV excitation. Some compounds with very strong emission under VUV excitation were found. Such phosphors could be proposed as very good emissive materials for Displays and Lightings. The growing interest in luminescence spectroscopy of rare earth ions in the vacuum ultraviolet (VUV) and the visible (VIS) spectral range is due to industrial demands for new applications. YTaO4 and YNbO4 phosphors are a perspective class of efficient materials that are generally used in X-ray intensifying screens. These phosphors exhibit satisfying luminescence whenever excited by UV light, cathode radiation or X ray. However, to our knowledge, no work has been published on the VUV-excited luminescence for Eu3+ and Tb3+ double activated yttrium niobate and yttrium tantalate based phosphors. In this paper, the VUV-UV PL and PLE spectra of Eu3+ and/or Tb3+ ion ...

197

Light-Powered Molecular Engineering : a new technology for medical safety applications  

DEFF Research Database (Denmark)

We present a new photonic technology and demonstrate that it allows for precise immobilisation of biomolecules to sensor surfaces. The technology secures spatially controlled molecular immobilisation since immobilisation of each molecule to a support surface can be limited to the focal point of the ultraviolet (UV) beam, as small as a few micrometers. We can immobilise molecules according to any pattern, from classical microarrays to diffraction patterns creating unique watermarking safety patterns. Given that suitable protein markers exists for all relevant diseases it is entirely feasible to test for a range of disease indicators (antigens and other markers) in a single test. Few micrometer spotsize allows for a virtually unlimited number of protein spots in a multipotent microarray. This new technology produces radically new photonics based microarray sensing technology and watermarking and has clear potential for biomedical, bioelectronic, surface chemistry, ...

2007-01-01

198

Isolation and characterization of humic acids from peat soil  

International Nuclear Information System (INIS)

In this study, two different humic acids extracted from England and China peat soil, as well as three purified products extracted from commercially available humic acids [Fluka (Fluka, Neu-Ulm, Germany, Alfa (Alfa Aesar, Ward Hill, USA) and Aldrich (Aldrich-Chemical Co, Gillingham-Dorset)] were obtained respectively with the modified IHSS (International humic substances society) procedure. The chemical and structural information of these humic acids were characterized by some techniques, such as elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and electropotential titration. UV-Vis spectra, infrared spectra, values for elemental composition and the contents of carboxyls, phenolic hydroxyls and total acidities of these humic acids were acquired. It is indicated that all these humic acids are different in the aspect of chemical structure, respectively, and these humic acids would be used for the ...

2009-05-01

199

Influence of duration and rate of pulse rise of the applied voltage on ozone concentration in the barrier glow discharge  

International Nuclear Information System (INIS)

The barrier glow discharge between two planar electrodes, covered with dielectric, is studied under high-voltage pulsed power supply. Wide applications of such type of discharges, in particular, for ozone production, stimulated a number of investigations in this direction. In this work we investigated the dependence of ozone concentration on the duration and the rate of pulse rise of the applied voltage. The thyristor converter circuit with the shortening of input pulses on the base of the saturable throttle was used for the realization of this task. The output pulses with amplitude up to 15 kV, repetition frequency of 1 kHz, pulse duration of 0.3 #mu#s (or 7 #mu#s) and the rate of pulse rise of 0.1 #mu#s were generated with this scheme. Measurements of the ozone concentration produced in the air mixture have shown that its value increased by factor two with variation of the rate of pulse rise from 0.5 #mu#s to 0.1 #mu#s (for pulse duration of 7 #mu#s). The dependence of the ozone ...

2005-09-06

200

Genotoxic effects of sunlight-activated waste waters  

Energy Technology Data Exchange (ETDEWEB)

Natural sunlight induces a genotoxic response in cultured CHO cells pre-treated with shale oil retort process water. Near ultraviolet light (NUV) component of the solar spectrum is the apparent radiation responsible for photoactivation. Cultured human skin fibroblasts are acutely sensitive to the genotoxic effects of photoactivated process water. The mutagenic potential of photoactivated process water in human cells is the same as that witnessed for an equivalent killing dose of the potent skin carcinogen FUV. DNA repair processes are involved in modulating genotoxic effects of this photo-induced process. The exact magnitude of the potential health-related and environmental risks resulting from photoactivation of retort process waters and other oil shale by-products is unassessed at this time. Our demonstration that a significant rate of mutation occurs in cultured human cells exposed to high dilutions of process waters and fluences of NUV comparable to that ...

1981-01-01

201

Generational Structure of Models with Dynamical Symmetry Breaking  

CERN Document Server

In models with dynamical electroweak symmetry breaking, this breaking is normally communicated to quarks and leptons by a set of vector bosons with masses generated via sequential breaking of a larger gauge symmetry. In reasonably ultraviolet-complete theories of this type, the number of stages of breaking of the larger gauge symmetry is usually equal to the observed number of quark and lepton generations, $N_{gen.}=3$. Here we investigate the general question of how the construction and properties of these models depend on $N_{gen.}$, regarded as a variable. We build and analyze models with illustrative values of $N_{gen.}$ different from 3 (namely, $N_{gen.}=1,2,4$) that exhibit the necessary sequential symmetry breaking down to a strongly coupled sector that dynamically breaks electroweak symmetry. Our results for variable $N_{gen.}$ show that one can robustly obtain, for this latter sector, a theory with a gauge coupling that is large but slowly running, ...

2010-01-01

202

Free-Electron Lasers: Present Status and Future Prospects  

Energy Technology Data Exchange (ETDEWEB)

Free-electron lasers as scientific instruments are reviewed. The present status and future prospects are delineated with attention drawn to the size, complexity, availability, and performance capability of this new tool. The Free-Electron Laser (FEL) was proposed by John Madey in 1970 (1), although earlier work, relevant to the concept, had been performed by Motz (2) and by Phillips (3). Experimental demonstration was achieved by Madey, et. al. in 1975 and 1976 (4). Since that time, FELs of diverse configurations have been operated at several laboratories around the world. At present, FEL development is focused in two directions: in constructing reliable FELs for scientific research and in extending FEL capability to vacuum ultra-violet (VUV) and even shorter wavelengths. In this article we shall only very briefly review the principles of an FEL, putting emphasis on those aspects that limit performance, after which we shall discuss the applications, present status ...

1990-05-01

203

Electronic structure and proton spin-lattice relaxation in PdH  

International Nuclear Information System (INIS)

We report a detailed augmented-plane-wave energy-band study and wave-function analysis of stoichiometric PdH which shows that, even though the Fermi surface of PdH is qualitatively similar to that of silver, the simple ''proton model'' is not valid. Instead, the screening of the proton in PdH is found to be larger than in an isolated H atom due, in part, to the formation of a H-Pd bonding band below the bottom of the d-band complex. This result, which is in qualitative agreement with Switendick's earlier calculation, is confirmed by ultraviolet photoemission experiments. A partial density-of-states (DOS) analysis in the energy range spanned by the six valence and conduction bands reveals the quantitative details of the bonding mechanism between the Pd and H constituents. At the Fermi energy, the high Pd d to H s DOS ratio approx. 10.3 is found to be far higher than expected in silver, despite the fact that the Fermi-surface geometry is similar. The field-induced ...

204

Effects of gamma irradiation on medicinal plants and spices (2): Piper cubeba, piper nigrum, piper retrofractum, amomum cardamomum, and myristica fragrans  

Energy Technology Data Exchange (ETDEWEB)

Effects of gamma irradiation on essential oils of five medicinal plants i.e. dried seeds of piper cubeba(cubeb), piper nigrum(black pepper), piper retrofractum, amomum cardamomum(cardamom) and myristica fragrans(mace), packed in low density polyethylene bag of 0.13 mm thickness have been investigated. After being irradiated at doses of 5 and 10 kGy, a part of the samples was analysed, and the rest were stored for six months at temperature of 30 +- 2 degC, and humidity ranging from 70 to 95%. The essential oil characteristics of control, irradiated and six month stored samples were analysed using infrared and ultraviolet spectrophotometers, HPLC, GLC and refractometer. Other parameters observed were moisture content and essential oil content of the samples. Results showed that irradiation up to a dose of 10 kGy do not give any significant effect on these parameters. Significant changes were only found in the essential oil content of piper cubeba, caused by storage ...

1983-12-01

205

Effect of V-shaped defects on structural and optical properties of AlGaN/InGaN multiple quantum wells  

International Nuclear Information System (INIS)

We have investigated the correlation between V-shaped defect formation and the optical properties of AlGaN/(In)GaN multiple quantum wells (MQWs) grown under different growth conditions and then demonstrated the characteristics of fabricated ultraviolet (UV) light emitting diodes (LEDs). From the temperature-dependent photoluminescence (PL) measurement, the internal quantum efficiency for 300 K was obtained as 43.6% for a sample with a low density of V-defects in a MQW and 13.7% for a sample with a high density of V-defects. The carrier lifetime based on the time resolved PL measurement at room temperature was 0.32 ns for a sample with a high density of V-defects and 1.26 ns for a sample with a low density of V-defects. And we also found that the density of V-defects affected the external quantum efficiency and wall plug efficiency of the fabricated UV LEDs. (fast track communication)

2008-07-07

206

Edge filter and fringe imaging for laser Doppler wind speed measurement  

Science.gov (United States)

Optical measurement of the Doppler shift of laser backscatter, using a near-IR, visible, or ultraviolet laser, is potentially more robust and field reliable than coherent, heterodyne measurement with an IR laser. The direct measurement of the displacement of Fabry-Perot interference fringes is possible, but entails expensive, technically challenging, imaging detectors. The 'edge technique' permits Doppler shift measurements with relatively simple detectors and detector electronics, and has been implemented with Fabry-Perot etalons and with atomic line filters. Simple analytical models of the fringe imaging and edge detection techniques are presented, permitting ready calculation of the potential performance of either, for various atmospheric conditions and for various lidar hardware configurations. The predictions of the analytical models are confirmed by computer models, which in turn allow more detailed considerations of complicating factors such as solar ...

1997-08-01

207

Comparative action spectrum for ultraviolet light killing of mouse melanocytes from different genetic coat color backgrounds  

International Nuclear Information System (INIS)

The photobiology of mouse melanocyte lines with different pigment genotypes was studied by measuring colony-forming ability after irradiation. The cell lines were wild-type black (melan-a) and the mutants brown (melan-b) and albino (melan-c). Four lamps emitting various UV wavelengths were used. These were germicidal (UVC, 200-280 nm), 82.3% output at 254 nm, TL01 (UVB, 280-320 nm), 64.2% at 310-311 nm, FS20, broadband with peak output at 312 nm and Alisun-S (UVA, 320-400 nm), broadband with peak output at 350-354 nm. Appropriate filtration reduced the contaminating UVC to nonlethal levels for the longer waverange lamps. It is clear from these studies that, in pigment cells, monochromatic results cannot predict polychromatic responses and that cell death from solar irradiations is a complex phenomenon that depends on more than DNA damage. (author).

1997-01-01

208

A fluorescent aminolipid from a green photosynthetic bacterium  

Energy Technology Data Exchange (ETDEWEB)

A preliminary chemical characterization is presented of phosphate-free aminolipids isolation from Chlorobium limicola f. thiosulfatophilum. The lipid contains no phosphorus, glycerol, sugar, ornithine, or lysine. Ultraviolet absorption and fluorescence spectra indicate that the amino moiety of the lipid is an aromatic heterocyclic compound. Infrared spectra indicate that the lipid is a secondary or tertiary amide, and gas chromatograhic analysis of the hydrolyzed lipid shows that for each 1100 g of lipid, 1 mol of myristic acid (C/sub 14:0/) is linked in an amide bond. Acid hydrolysis of the lipid yields two fluorescent substances, A (ninhydrine positive) and B (negative), in addition to myristic acid. Proton nuclear magnetic resonance (NMR) studies indicate that substance A contains a butyl groups attached to a conjugated ring carbon, two equivalent ethyl groups attached to one or two nitrogen atoms, and two downfield protons (8.4 ppm), perhaps attached to a ring ...

1983-04-12

209

The CMS RPC system overview  

CERN Document Server

The CMS RPC system overview

2010-01-01

211

Handbook on decision support systems  

CERN Document Server

Handbook on decision support systems

2007-01-01

212

Floating systems - Atkins  

Wastenet

...Floating systems - Atkins storage and offloading units (FPSOs). ...

214

Bose-Einstein condensation in nonlinear system  

CERN Document Server

Bose-Einstein condensation in nonlinear system

2011-01-01

215

Collaborative systems and multiagent systems  

CERN Document Server

This paper presents some basic elements regarding the domain of the collaborative systems, a domain of maximum actuality and also the multiagent systems, developed as a result of a sound study on the one-agent systems.

2009-01-01

219

An outline of the fuelling machine electrical instrumentation and controls  

International Nuclear Information System (INIS)

An outline of the instrumentation and control systems associated with fuelling machines is given. The control systems such as hydraulic system, oil hydraulic system, electric control system and the remote control systems have been discussed in detail. The difference between RAPP and MAPP fuel handling control systems has been explained. A computer based system for the Narora fuel handling control system is also discussed. (S.K.K.).

221

Two and 8-azido photoaffinity probes. 2. Studies on the binding process of 2-5A synthetase by photosensitive ATP analogues  

International Nuclear Information System (INIS)

The photoaffinity probes [#gamma#-"3"2P]2-azidoATP (2-N_3ATP) and [#alpha#-"3"2P]8-azido-ATP (8-N_3ATP) were used to investigate the binding of ATP to highly purified 2-5A synthetase. 2-N_3APT and 8-N_3ATP are substrates for 2-5A synthetase. In this study the authors show that 2- and 8-N_3ATP are competitive inhibitors of the enzymatic conversion of ATP to 2-5A. Ultraviolet irradiation results in the photoinsertion of 2-N_3ATP and 8-N_3ATP into the enzyme. The covalent photoinsertion of [#alpha#-"3"2P]8-N_3ATP into the 2-5A synthetase is proportional to the inactivation of the enzyme as UV irradiation is increased. Photolabeling of 2-5A synthetase is saturated at 1.5 mM 2-N_3ATP and 2.0 mM 8-N_3ATP. Computer analysis of the curvilinear Scatchard plots of the 2-5A synthetase suggest the presence of high-affinity and low-affinity binding sites that may correspond to the acceptor and the 2'-adenylation sites of the enzyme. The competition of nucleotides for the ...

222

Toxicity of ultraviolet-irradiated halothane in mice  

Energy Technology Data Exchange (ETDEWEB)

One such agent is the widely used anesthetic, halothane. To study the toxicity of u.v. decomposed halothane, mice were exposed to anesthetic concentrations (1.3%) of non- and u.v.-irradiated halothane in oxygen for 90 min. Halothane sleeping times increased from 14.3 min to 72.5 min. Microsomal mixed function oxidase activity decreased, as shown by prolonged pentobarbital sleeping times 1 day after exposure to halothane and irradiated halothane (54.6 min and 149.1 min, respectively, as compared to a 34.6-min control). Quantitative and qualitative differences were found in the amount of (/sup 14/C)-pentobarbital metabolites excreted by u.v. irradiated halothane-exposed mice compared to either oxygen or non-irradiated halothane-exposed groups. In addition, serum glutamic-oxalacetic transaminase (SGOT) of irradiated halothane-exposed mice increased to 233% of the control values, and serum glutamic-pyruvic transaminase (SGPT) were 377% of control values. No significant changes in SGOT or ...

1982-01-01

223

Three novel mutations responsible for Cockayne syndrome group A  

International Nuclear Information System (INIS)

Cockayne syndrome (CS) is a rare autosomal recessive disease, which shows diverse clinical symptoms such as photosensitivity, severe mental retardation and developmental defects. CS cells are hypersensitive to killing by ultraviolet (UV)-irradiation and defective in transcription-coupled repair. Two genetic complementation groups in CS (CS-A and CS-B) have been identified. We analyzed mutations of the CSA gene in 5 CS-A patients and identified 3 types of mutations. Four unrelated CS-A patients (CS2OS, CS2AW, Nps2 and CS2SE) had a deletion including exon 4, suggesting that there is a founder effect on the CSA mutation in Japanese CS-A patients. Patient CS2SE was a compound heterozygote for this deletion and an amino acid substitution at the 106th glutamine to proline (Q106P) in the WD-40 repeat motif of the CSA protein, which resulted in a defective nucleotide excision repair. Patient Mps1 had a large deletion in the upstream region including exon 1 of the CSA gene. ...

2003-02-01

224

The earth is warming up while the sky is getting a chill; La terre se rechauffe, le ciel a un coup de froid  

Energy Technology Data Exchange (ETDEWEB)

The phenomenon of global warming, its causes and implications for the future, and the relationship between global warming and the depletion of the ozone layer are discussed. The Shindell model of the greenhouse effect, which is responsible for planetary warming, also contributes to the high altitude thinning of the ozone layer. While greenhouse gas emissions contribute to retaining infrared radiation, thus warming the surface of the earth, their effect is reduced at stratospheric altitudes resulting in reduced temperatures in this region. At this altitude temperatures can reach minus 90 degrees C, creating a whirlwind effect, with ice crystals forming at the heart of the vortex, causing the surface to accelerate chemical reactions which in turn leads to destruction of ozone. Although since the signing of the Montreal Protocol in 1987 the industrialized countries have significantly reduced their emissions of refrigerating gas (chlorofluorocarbons or CFC), which were considered to have ...

2001-03-01

225

The Sorcerer II Global Ocean Sampling Expedition: Expanding theUniverse of Protein Families  

Energy Technology Data Exchange (ETDEWEB)

Metagenomics projects based on shotgun sequencing of populations of micro-organisms yield insight into protein families. We used sequence similarity clustering to explore proteins with a comprehensive dataset consisting of sequences from available databases together with 6.12 million proteins predicted from an assembly of 7.7 million Global Ocean Sampling (GOS) sequences. The GOS dataset covers nearly all known prokaryotic protein families. A total of 3,995 medium- and large-sized clusters consisting of only GOS sequences are identified, out of which 1,700 have no detectable homology to known families. The GOS-only clusters contain a higher than expected proportion of sequences of viral origin, thus reflecting a poor sampling of viral diversity until now. Protein domain distributions in the GOS dataset and current protein databases show distinct biases. Several protein domains that were previously categorized as kingdom specific are shown to have GOS examples in other kingdoms. About ...

2006-03-23

226

Synthesis, crystal structure and photoluminescence of Eu-#alpha#-SiAlON  

International Nuclear Information System (INIS)

Eu-#alpha#-SiAlON (Eu_m_/_2Si_1_2_-_m_-_nAl_m_+_nO_nN_1_6_-_n) was synthesized with nominal compositions having small m and n values, by firing the powder mixture of Eu_2Si_5N_8, #alpha#-Si_3N_4, AlN, and Al_2O_3 at 1900 "oC for 6 h under 1 MPa nitrogen atmosphere. The ratio of the oxidation state of Eu"2"+/Eu"3"+ was estimated from the X-ray absorption fine structure (XAFS) measurement. The observed X-ray absorption near edge spectrum (XANES) showed that the Eu ion in Eu-#alpha#-SiAlON was mainly in divalent state but also coexisted with a small amount of Eu in the trivalent state. The crystal structure of Eu-#alpha#-SiAlON was refined by the Rietveld analysis of the X-ray powder diffraction patterns. The lattice constants of the samples increased with increasing m and n values. The excitation band of Eu-#alpha#-SiAlON ranged from the ultraviolet to the visible light region and a broad emission band centered at about 590 nm were observed. The emission intensity ...

2010-08-20

227

Studies of aerosol formation in power plant plumes - II. Secondary aerosol formation in the Navajo generating station plume  

Energy Technology Data Exchange (ETDEWEB)

Aerosol and gas measurements were made with the University of Minnesota Mobile Laboratory (UMML) during the VISTTA programme near Page, Arizona. The UMML was stationed on Zilnez Mesa approx. 65 km east of the Navajo coal-fired power plant. Measurements were made both in and out of the power plant plume and were made during the day and night. Measured parameters included aerosol size distributions, Aitken nuclei count, ozone and sulphur dioxide concentrations, the aerosol light scattering coefficient, and meteorological parameters including ultraviolet radiation intensity. Concentrations of NO and NO/SUB/x were occasionally measured. Data show clear evidence of gas-to-particle conversion in the plume with aerosol volume being added in the 0.01 MUm - 0.32 MUm dia. range and new particles being formed. The observed excess aerosol volume depends strongly upon the SO/SUB/2 concentrations and the time of day with none observed in plume parcels which were not exposed to ...

1981-01-01

228

Scaling method for fast Monte Carlo simulation of diffuse reflectance spectra from multilayered turbid media  

Science.gov (United States)

A scaling Monte Carlo method has been developed to calculate diffuse reflectance from multilayered media with a wide range of optical properties in the ultraviolet-visible wavelength range. This multilayered scaling method employs the photon trajectory information generated from a single baseline Monte Carlo simulation of a homogeneous medium to scale the exit distance and exit weight of photons for a new set of optical properties in the multilayered medium. The scaling method is particularly suited to simulating diffuse reflectance spectra or creating a Monte Carlo database to extract optical properties of layered media, both of which are demonstrated in this paper. Particularly, it was found that the root-mean-square error (RMSE) between scaled diffuse reflectance, for which the anisotropy factor and refractive index in the baseline simulation were, respectively, 0.9 and 1.338, and independently simulated diffuse reflectance was less than or equal to 5% for ...

2007-04-01

229

Real-time optical modelling and investigation of inorganic nano-layer growth onto flexible polymeric substrates  

Energy Technology Data Exchange (ETDEWEB)

A major factor for the achievement of the desirable performance, efficiency and lifetime of flexible organic electronic devices is the optimization of the encapsulation layers that protect the device active layers by atmospheric gas molecule permeation. The active layers consisted of small molecule and/or polymer organic semiconductors as well as the organic conductors need to be encapsulated into a transparent medium that will provide the necessary protection and maintain their charge generation and transport characteristics. The encapsulation layers are generally consisted of inorganic thin films (silicon oxide-SiO{sub x} and aluminium oxide-AlO{sub x}) deposited onto the polymeric substrates, such as PolyEthylene Terephthalate (PET). In this work, in situ and real-time Spectroscopic Ellipsometry in the ultraviolet spectral region has been implemented in order to investigate the growth of inorganic SiO{sub x} and AlO{sub x} nano-layers onto PET flexible polymeric ...

2010-01-15

230

Photodegradation and photostabilization of weathered wood flour filled polyethylene composites  

Science.gov (United States)

Wood plastic composites (WPCs) have gained popularity as building materials because of their usefulness in replacing solid wood in a variety of applications. These composites are promoted as being low-maintenance, high-durability products. However, it has been shown that WPCs exposed to weathering may experience a color change and/or loss in mechanical properties. An important requirement for building materials used in outdoor applications is the retention of their aesthetic qualities and mechanical properties during service life. Therefore, it is critical to understand the photodegradation mechanisms of WPCs exposed to UV radiation and to develop approaches to stabilize these composites against ultraviolet light. In this dissertation, the surface chemistries of weathered composites (both unstabilized and stabilized) as well as the effect of weathering on the color fade and the retention of mechanical properties were characterized. Since different methods of ...

2003-01-01

231

PROBING THE ORIGINS OF THE C IV AND Fe K? BALDWIN EFFECTS  

International Nuclear Information System (INIS)

We use UV/optical and X-ray observations of 272 radio-quiet Type 1 active galactic nuclei and quasars to investigate the C IV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths (EWs), continuum monochromatic luminosities, and ?ox, which characterizes the relative X-ray to UV brightness. The EW of the C IV ?1549 emission line is correlated with both ?ox and luminosity. We find that by regressing l?(2500 A) with EW(C IV) and ?ox, we can obtain tighter correlations than by regressing l?(2500 A) with only EW(C IV). Both correlation and regression analyses imply that l?(2500 A) is not the only factor controlling the changes of EW(C IV); ?ox (or, equivalently, the soft X-ray emission) plays a fundamental role in the ...

2009-09-01

232

Luminescent properties of Eu3+-activated Sr3B2SiO8: A red-emitting phosphor for white light-emitting diodes  

International Nuclear Information System (INIS)

Single-phased Sr3B2SiO8:Eu3+ phosphor was prepared by a solid-state method at 1020 oC. The luminescence spectra showed that Sr3B2SiO8:Eu3+ phosphor can be effectively excited by near ultraviolet light (393 nm) and blue light (464 nm). When excited at 393 or 464 nm Sr3B2SiO8:Eu3+ exhibited the main emission peaks at 611 and 620 nm, which resulted from the supersensitive 5D0#->#7F2 transition of Eu3+. The luminescence intensity of Sr3B2SiO8:Eu3+ at 611 and 620 nm reached the maximum when the doping content of Eu3+ was 4.5 mol%. Its chromaticity coordinates (0.646, 0.354) were very close to the NTSC standard values (0.67, 0.33). Thus, Sr3B2SiO8:Eu3+ is considered to be an efficient red-emitting phosphor for long-UV InGaN-based light-emitting diodes. - Highlights: ? Sr3B2SiO8:Eu3+ was synthesized using solid-state reaction method for the first time. ? The phosphor can be efficiently excited by the near-UV chips and gives strong red emission. ? The phosphor is a ...

2011-07-01

233

Lifetime measurements of singlet ungerade states in isotopic molecular nitrogen  

International Nuclear Information System (INIS)

Full text: In the upper layers of the Earth's atmosphere, molecular nitrogen absorbs the extreme ultraviolet (XUV) solar radiation. The absorption is associated with dipole-allowed excitation of states of singlet ungerade symmetry ("1#SIGMA#"+_u and "1#PI#_u), which are known to undergo predissociation due to coupling with a mainfold of "1#PI#_u states. We determined new N_2 isotopic lifetimes of many "1#SIGMA#"+_u and "1#PI#_u states via line broadening measurements in the frequency domain. Ultrahigh resolution XUV + UV ionization spectra were recorded (bandwidth #approx# 250 MHz, resolving power 10"7), from which the natural linewidth, i.e. lifetime, was determined. These lifetimes provide new information about the predissociation of the singlet ungerade states in N_2. Tunable narrowband XUV radiation was produced by successively pulsed amplification of cw dye laser radiation, frequency doubling the pulsed visible laser beam into the UV and frequency tripling the ...

2004-07-19

234

Investigation of ultrafast photothermal surface expansion and diffusivity in GaAs via laser-induced dynamic gratings  

Energy Technology Data Exchange (ETDEWEB)

This thesis details the first direct ultrafast measurements of the dynamic thermal expansion of a surface and the temperature dependent surface thermal diffusivity using a two-color reflection transient grating technique. Studies were performed on p-type, n-type, and undoped GaAs(100) samples over a wide range of temperatures. By utilizing a 90 fs ultraviolet probe with visible excitation beams, the effects of interband saturation and carrier dynamics become negligible; thus lattice expansion due to heating and subsequent contraction caused by cooling provided the dominant influence on the probe. At room temperature a rise due to thermal expansion was observed, corresponding to a maximum net displacement of {approximately} 1 {Angstrom} at 32 ps. The diffracted signal was composed of two components, thermal expansion of the surface and heat flow away from the surface, thus allowing a determination of the rate of expansion as well as the surface thermal diffusivity, ...

1992-04-01

235

Interface engineering in chalcopyrite thin film solar devices  

Energy Technology Data Exchange (ETDEWEB)

Successful interface engineering requires compositional and electronic material characterization as a prerequisite for understanding and intentionally generating interfaces in photovoltaic devices. The paper gives an overview with several examples, all referring to Cu(In,Ga)(S,Se){sub 2} ('CIGSSe')-based solar cells, with an emphasis on characterization using highly specialized methods, such as elastic recoil detection analysis, X-ray emission spectroscopy and photoelectron spectroscopy using synchrotron and ultraviolet light for excitation, inverse photoemission spectroscopy and Kelvin probe force microscopy. First, the determination of the depth profile of the band gap energy E{sub g} in the absorber layer is demonstrated. The modification of E{sub g} towards both interfaces is discussed in terms of beneficial electronic effects. Next, the interface between absorber and buffer layers with alternative and promising non-toxic materials is ...

2006-06-15

236

Identification of a nucleoside triphosphate binding site on calf thymus RNA polymerase II  

Energy Technology Data Exchange (ETDEWEB)

A nucleoside triphosphate binding site on calf thymus RNA polymerase II was identified by using photoaffinity analogues of adenosine 5'-triphosphate and guanosine 5'-triphosphate. Both radiolabeled 8-azidoadenosine 5'-triphosphate (8-N3ATP) and radiolabeled 8-azidoguanosine 5'-triphosphate (8-N3GTP) bound to a single polypeptide of this enzyme. This polypeptide has a molecular mass of 37 kilodaltons and an isoelectric point of 5.4. Ultraviolet (UV) irradiation was necessary for photolabeling to occur. In addition, no labeling occurred when the probe was prephotolyzed or when the enzyme was inactivated. Furthermore, photolabeling of the enzyme could be decreased by preincubation with natural substrates. To provide evidence that the radiolabeled polypeptide forms a part of the domain of the nucleoside triphosphate binding site, experiments were performed using unlabeled 8-N3ATP. Although this unlabeled analogue was not a substrate ...

1986-01-14

237

Growth and characterization of new semi-organic L-proline strontium chloride monohydrate single crystals  

International Nuclear Information System (INIS)

The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate (L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) A, b=12.4530(5) A, c=15.2432(5) A and space group P2_12_12_1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 "oC using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different temperatures in the ...

2011-01-01

238

Facile synthesis and the sensitized luminescence of europium ions-doped titanate nanowires  

International Nuclear Information System (INIS)

Europium (Eu) ions-doped titanate nanowires were synthesized via a sol-gel-hydrothermal chemistry and they were found to be roll multilayered trititanate-type nanowires intercalated with Eu3+ and alkali ions. The average diameter was about 20 nm for nanowires synthesized in NaOH solution and about 10 nm for nanowires synthesized in KOH solution. Under ultraviolet excitation the nanowires showed bright red emission corresponding to 5D0-7Fj of Eu3+ ions at room temperature, which was attributed to the non-radiative energy transfer from the surrounding Ti-O octahedral nanosheets to the central Eu3+ ions in interlayer. The luminescent properties of nanowires were influenced by the type of co-intercalated alkali ions, doping degree, hydrothermal and annealing temperatures. The intensity ratio of 5D0-7F2 to 5D0-7F1 of titanate nanowires intercalated with Eu3+ and Na+ ions was higher than that of titanate nanowires intercalated with Eu3+ and K+ ions. The emission ...

2009-04-15

239

Exposure of Finnish population to solar UV radiation and consequent carcinogenic effects  

Energy Technology Data Exchange (ETDEWEB)

Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV doses received by different groups of Finnish population. Also, an ...

1996-12-31

240

Effective laser luminescence of nanocomposites Eu(TTA)2(Ph3PO)2NO3-polyvinylpyrrolidone  

International Nuclear Information System (INIS)

Thin films (1-10 ?m thickness) of nanocomposites (NC) based on organic coordinated compound (OCC) Eu(TTA)2(Ph3PO)2NO3 (where TTA is thenoyl trifluoroacetonate (C8H5F3O2S), Ph3PO - triphenylphosphine (C6H5PO) and polymer-polyvinylpyrrolidone ((C6H9NO)n) (PVP)) were obtained by chemical methods and with different molar ratios into organic polymer matrix. NC have been characterized by measurements of optical transmission, excitation spectra of photoluminescence (PL) and photoluminescence of NC at different concentrations of Eu(TTA)2(Ph3PO)2NO3 in NC. In the optical transmission of NC, the characteristic parameters of NC such as threshold absorbance, dependence on the concentration of the organic coordinated compound in NC, etc., have been determined The displacement of threshold absorption to infrared is observed with increasing of the concentration of the coordination material in NC. The excitation spectrum of photoluminescence of NC led the range from 200 to 400 nm energy at which takes ...

2011-07-07

241

An ultraviolet-inducible adenosine-adenosine cross-link reflects the catalytic structure of the Tetrahymena ribozyme  

Energy Technology Data Exchange (ETDEWEB)

When a shortened enzymatic version of the Tetrahymena self-splicing intervening sequence (IVS) RNA is placed under catalytic conditions and irradiated at 254 nm, a covalent cross-link forms with high efficiency. The position of the cross-link was mapped by using three independent methods: RNase H digestion, primer extension with reverse transcriptase, and partial hydrolysis of end-labeled RNA. The cross-link is chemically unusual in that it joins two adenosines, A57 and A95. Formation of this cross-link depends upon the identity and concentration of divalent cations present and upon heat-cool renaturation of the IVS in a manner that parallels conditions required for optimal catalytic activity. Furthermore, cross-linking requires the presence of sequences within the core structure, which is conserved among group I intervening sequences and necessary for catalytic activity. Together these correlations suggest that a common folded structure permits cross-linking and catalytic activity. ...

1990-06-12

242

Amplified spontaneous emission from ZnO in n-ZnO/ZnO nanodots-SiO_2 composite/p-AlGaN heterojunction light-emitting diodes  

International Nuclear Information System (INIS)

This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at #lambda##approx#380 nm in the n-ZnO/ZnO nanodots-SiO_2 composite/p- Al_0_._1_2Ga_0_._8_8N heterojunction light-emitting diode. A SiO_2 layer embedded with ZnO nanodots was prepared on the p-type Al_0_._1_2Ga_0_._8_8N using spin-on coating of SiO_2 nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO_2 composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO_2 matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO_2 composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated ...

2009-04-22

243

ARM AND INTERARM STAR FORMATION IN SPIRAL GALAXIES  

International Nuclear Information System (INIS)

We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 #mu#m) emission allow us to identify 'arm regions' that should correspond to regions of stellar mass density enhancements. The two grand-design spirals show a clear two-armed structure, while NGC 6946 is more complex. We examine these arm and interarm regions, looking at maps that trace recent star formation-far-ultraviolet (GALEX NGS) and 24 #mu#m emission (Spitzer SINGS)-and cold gas-CO (HERACLES) and H I (THINGS). We find the star formation tracers and CO more concentrated in the spiral arms than the stellar 3.6 #mu#m flux. If we define the spiral arms as the 25% highest pixels in the filtered 3.6 #mu#m images, we find that the majority (60%) of star formation tracers occur in the interarm regions; this result persists qualitatively even when considering the potential impact ...

2010-12-10

244

Specification of the steel sheet for the 300 GeV magnet system  

CERN Document Server

Specification of the steel sheet for the 300 GeV magnet system

1971-01-01

245

Randomized Algorithms for Analysis and Control of Uncertain Systems  

CERN Document Server

Randomized Algorithms for Analysis and Control of Uncertain Systems

2005-01-01

246

RF System for Compact Medical Proton Synchrotron  

CERN Document Server

RF System for Compact Medical Proton Synchrotron

2004-01-01

247

None - TDGLOBAL - NASA  

Science.gov (United States)

vibration Isolation system for the camera. ... to further define the response of the camera vibration isolation system. These ...

248

Multi-Harmonic RF Control System for J-PARC RCS  

CERN Document Server

Multi-Harmonic RF Control System for J-PARC RCS

2003-01-01

249

Java Mission Evaluation Workstation System  

Science.gov (United States)

The Java Mission Evaluation Workstation System (JMEWS) is a collection of applications designed to

2006-01-01

250

Input-output stability for accelerometer control systems  

Science.gov (United States)

It is shown that, although accelerometer control systems are not well-posed in the sense of Salamon,

1991-01-01

252

Camouflage Visualization  

Science.gov (United States)

... AAMHERST SYSTEMS INC. CAMOUFLAGE VISUALIZATION FINAL REPORT ... A AMHERST SYSTEMS INC. CAMOUFLAGE VISUALIZATION ...

1992-04-07

253

Beam Diagnostic System for High Intensity Proton Linac at KAERI  

CERN Document Server

Beam Diagnostic System for High Intensity Proton Linac at KAERI

2003-01-01

254

Knowledge systems for management and modelling of energy systems  

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is to survey the potential of knowledge systems for the management and modelling of energy systems. The paper starts with a short introduction to knowledge systems. The essence of knowledge systems is summarized and described in terms of modelling. Additionally the application of knowledge systems is compared with the use of conventional software on the one hand and human reasoning on the other. Next, research topics which are important in connection with technological applications of knowledge systems are reviewed. This paper follows with a review of knowledge system applications in the field of energy systems and ends with conclusions on the state of the art and required research and development.

1990-01-01

255

European Space Agency announces contest to "Name the Cluster Quartet"  

Science.gov (United States)

1. Contest rules The European Space Agency (ESA) is launching a public competition to find the most suitable names for its four Cluster II space weather satellites. The quartet, which are currently known as flight models 5, 6, 7 and 8, are scheduled for launch from Baikonur Space Centre in Kazakhstan in June and July 2000. Professor Roger Bonnet, ESA Director of Science Programme, announced the competition for the first time to the European Delegations on the occasion of the Science Programme Committee (SPC) meeting held in Paris on 21-22 February 2000. The competition is open to people of all the ESA member states (*). Each entry should include a set of FOUR names (places, people, or things from history, mythology, or fiction, but NOT living persons). Contestants should also describe in a few sentences why their chosen names would be appropriate for the four Cluster II satellites. The winners will be those which are considered most suitable and relevant for the Cluster II mission. ...

2000-02-01

256

Study of Japanese electrodynamic-suspension maglev systems  

Energy Technology Data Exchange (ETDEWEB)

This report presents the results of a study of the Japanese MLU magnetic-levitation (maglev) system. The development of the MLU system is reviewed, and the dynamic circuit model then is introduced and applied to the figure-eight-shaped null-flux coil suspension system. Three different types of figure-eight-shaped null-flux suspension systems are discussed in detail: (1) the figure-eight-shaped null-flux coil suspension system without cross-connection; (2) the combined suspension and guidance system; and (3) the combined propulsion, levitation, and guidance system. The electrodynamic-suspension maglev systems developed in Japan seem to be very promising and could result in a commercial application in the near future.

1994-04-01

257

General Disclaimer One or more of the Following Statements may ...  

Science.gov (United States)

Aug 3, 2011 ... System (NASS) and the NERVA Effluent Purification System ... Effluent Purification System (NEPS). 7.4.2.2. Requirements ...

258

FINAL REPORT CONTINUOUS SCANNING METEOROLOGICAL CAMERA SYSTEM FOR ...  

Science.gov (United States)

was deemed adequate and a cooling system designed utilizing the Melcor CP2-15- 10B thermoelectric module. Wall temperature achieved with this system was - 36 ...

259

Development of grid-connected photovoltaic systems  

International Nuclear Information System (INIS)

The activities and the policy in the Netherlands regarding the development of the title systems since 1990 are briefly outlined, focusing on the use of PV-systems in buildings. 5 figs., 1 tab.

260

DESIGN OF A CONVECTIVE COOLING SYSTEM FOR A MACH 6 - NASA ...  

Science.gov (United States)

Figure 23 presented detailed layout of the cooling system designed for the Mach 6 hypersonic- transport. The distribution system consisted of thin-wall ...

261

Attributes of Interactive Online Health Information Systems  

UK PubMed Central (United Kingdom)

The development of online communication systems related to prevention, decision making, and coping with cancer has outpaced theoretical attention to the attributes that appeal to system...Full Text Available

262

An Artificial Immune System-Inspired Multiobjective ...  

Science.gov (United States)

... BFS Breadth-First Search BIS Biological Immune System CCNA Cisco-Certified Network Associate CDIS Computer Defense Immune System ...

2007-03-01

263

Acid Waste Equipment on Environmental Expert  

Wastenet

...Systems by IPEX Enfield electrofusion acid waste systems give you the proven corrosion resistance of polypropylene, along with our patented, state-of-the-art electrofusion system....

264

Load calculation and system evaluation for electric vehicle climate control  

Energy Technology Data Exchange (ETDEWEB)

This paper presents an analysis of the applicability of alternative systems for electric vehicle (EV) heating and air conditioning (HVAC). The paper consists of two parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can provide the desired cooling and heating in EVs. These systems are ranked according to their overall weight The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation. The system with the minimum overall weight is considered to be the best, because minimum vehicle weight decreases the energy required for propulsion, and therefore increases the vehicle range. Three systems are considered as the best choices for EV HVAC. These are, vapor compression, ice ...

1994-09-12

265

RADIAL DISTRIBUTION OF STARS, GAS AND DUST IN SINGS GALAXIES. I. SURFACE PHOTOMETRY AND MORPHOLOGY  

International Nuclear Information System (INIS)

We present ultraviolet through far-infrared (FIR) surface brightness profiles for the 75 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS). The imagery used to measure the profiles includes Galaxy Evolution Explorer UV data, optical images from Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and Sloan Digital Sky Survey, near-IR data from Two Micron All Sky Survey, and mid- and FIR images from Spitzer. Along with the radial profiles, we also provide multi-wavelength asymptotic magnitudes and several nonparametric indicators of galaxy morphology: the concentration index (C 42), the asymmetry (A), the Gini coefficient (G), and the normalized second-order moment of the brightest 20% of the galaxy's flux (M-bar20). In this paper, the first of a series, we describe the technical aspects regarding the surface photometry, and present a basic analysis of the global and structural properties of the SINGS galaxies at different ...

2009-10-01

266

Experimental and theoretical studies of nuclear generation of ozone and its photolysis into singlet delta oxygen  

International Nuclear Information System (INIS)

A series of measurements of O_3 yield in nuclear induced O_2 and O_2-SF_6 discharges created by bombardment with energetic particles from the "1"0B(n,#alpha#)"7Li reaction are reported. Continuous irradiation at dose ratios of 10"1"5-10"1"7 eV.cm"-"3.s"-"1 and pulsed irradiation (approx.10 ms FWHM) at a peak dose rate of approx.10"2"0 eV.cm"-"3.s"-"1 were conducted. At the lower dose rates, SF_6 addition generally increased the ozone yield, which at the high dose rates, SF_6 addition decreased the observed ozone concentration. A numerical model was developed and applied to experimental conditions. The steady-state ozone concentration was found to be limited by the reaction O_3"- + O_3 #-># 2O_2 + O_2"-. A simplified analytical model of steady-state conditions was used to predict model sensitivity to various parameters. In addition to dose rate effects, pressure and temperature effect on ozone production were discussed. The present study was extended to noble gas (He, Ne, and Ar)-O_2 ...

268

Tachyons and the instability of physical systems  

International Nuclear Information System (INIS)

The problem on the ratio between the instability of physical systems and tachyons is discussed. It is shown that the tachyons participation in the real physical process of the system rearranging does not contradict any principles. It is noted that the tachyons constitute the most significant element of the systems, identifying the instability relative to the phase transition into the stable state.

278

FUEL CELL AND FUEL CELL SYSTEM  

J-STORE (Japan)

Full Text Available

2008-12-12

282

Development of contact scanner for Wolsung NPP alarm and annunciation system.  

Science.gov (United States)

Contact scanner system in Wolsung NPP(model ESE-1565) is an early '70 equipment, so most of components are obsolete. To make it 100% compatible, PCBs for this system is the main object of the study. Most of components used in the system are not available ...

1995-01-01

285

COST ESTIMATING SYSTEMS FOR REMEDIAL ACTION PROJECTS  

Science.gov (United States)

This paper details the ongoing collaboration between the U.S. EPA and the U.S. Army Corps of Engineers in the development of complementary micro-computer based cost estimating systems for hazardous waste remediations. he U.S. EPA system, "Remedial Action Cost Estimating System" (...

290

48 CFR 252.215-7002 - Cost estimating system requirements.  

Science.gov (United States)

... 2010-10-01 false Cost estimating system requirements. 252...Clauses 252.215-7002 Cost estimating system requirements. As...use the following clause: Cost Estimating System Requirements (DEC...

2010-10-01

291

Transformational Satellite (TSAT) Communications Systems. ...  

Science.gov (United States)

... The seven existing space/airborne programs are the Defense Satellite Com- munications System (DSCS), Milstar, communications re- lay ...

2007-07-01

292

System integration of pattern recognition, adaptive aided, upper limb prostheses  

Science.gov (United States)

The requirements for successful integration of a computer aided control system for multi degree of

1975-01-01

293

Sunflower power system test report topical report, nov. - 19 dec. 1962  

Science.gov (United States)

Sunflower power conversion system development test program

1964-01-01

294

Sunflower power conversion system quarterly report, mar. - may 1963  

Science.gov (United States)

Sunflower 3 kW mercury Rankine power conversion system

1963-01-01

295

Prospects of robotics research in the field of remote handling systems  

International Nuclear Information System (INIS)

The main trends of research carried out in remote handling systems in the fields of ergonomy, robotics and reliability are presented.

296

Particle-Sizing System for Scanning Electron Microscope ...  

Science.gov (United States)

... THESIS PARTICLE-SIZING SYSTEM FOR SCANNING ELECTRON MICROSCOPE IMAGES OF SOLID-PROPELLANT COMBUSTION EXHAUST ...

1991-03-01

297

Overview on some functional issues related to the uninterrupible power systems design  

CERN Document Server

Overview on some functional issues related to the uninterrupible power systems design

1989-01-01

298

NASA/BAE SYSTEMS SpaceWire Effort  

Science.gov (United States)

This paper discusses the state of the NASA and BAE SYSTEMS developments of SpaceWire. NASA has

2003-01-01

299

MINEQL-PC. Chemical Equilibrium Composition of Aqueous Systems  

Energy Technology Data Exchange (ETDEWEB)

MINEQL is a subroutine package to calculate equilibrium composition of an aqueous system, accounting for mass transfer.

1986-11-21

300

JFACC Afloat  

Science.gov (United States)

... 9 Integrated Battle Management System Data Link Architecture Common Mission Planring System MILSTAR and SATCOMs Common Aviation ...

1993-05-17

301

Integrated Reconfigurable Intelligent Systems (IRIS) for ...  

Science.gov (United States)

... They comprise of a power model for the representation of the electric system, a fluid model that represents the cooling fluid flow, three layers of ...

2009-10-31

302

Evaluation of the Reformation of Navy Personally Procured ...  

Science.gov (United States)

... POVs) overseas when space was available. ... information management system launched in 2004. ... Personally Procured Transportation (PPT) system ...

2010-12-01

304

DARPA Program Composition for Embedded Systems (PCES) ...  

Science.gov (United States)

... Title : DARPA Program Composition for Embedded Systems (PCES) Program Capstone Demonstration Video (Postprint) (CD-ROM). ...

2005-09-01

305

Chiral dynamics of few-nucleon systems  

Energy Technology Data Exchange (ETDEWEB)

I discuss some recent developments in chiral effective field theory for few-nucleon systems.

2008-06-01

306

Adaptive System and Method for Responding to Computer ...  

Science.gov (United States)

Page 1. Adaptive system and method for responding to computer network security attacks Abstract A dynamic network security ...

2002-07-11

307

A Generalized Simulation Model for Reservoir System ...  

Science.gov (United States)

... Hydropower analysis may include run-of-river, peaking, and pumped storage plants as well as system power operation. ...

1992-03-01

308

A Computer Vision System forAnalyzing Images of Rough Hardwood Lumber  

Science.gov (United States)

... In this paper research aimed at creating a computer vision system to power such an optimal edging and ... ...

309

Waste monitoring system for effluents  

Energy Technology Data Exchange (ETDEWEB)

The waste monitoring system in use at Los Alamos National Laboratory`s Plutonium Facility, TA-55, is a computer-based system that proves real-time information on industrial effluents. Remote computers monitor discharge events and data moves from one system to another via a local area network. This report describes the history, system design, summary, instrumentation list, displays, trending screens, and layout of the waste monitoring system.

1995-07-01

310

Studies on a new kind of fuzzy power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

This paper is concerned with the application of a new fuzzy inference method to the design of fuzzy power system stabilizer. Based on Truth-Value-Flow-Inference (TVFI), a fuzzy logic controlled power system stabilizer is proposed to enhance the stability of power system with weak or negative damping. The design of the proposed fuzzy power system stabilizer is presented. Numerical simulation results are presented and compared with two other kinds of fuzzy power system stabilizers. (author)

1998-12-31

311

Real time control of micro-machine system using micro-computer based fuzzy logic power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

A micro-computer based fuzzy logic power system stabilizer is applied to a micro-machine system to investigate its efficiency in real time control. The stabilizing signal is determined by using measured speed or real power signals at every sampling time to damp the system oscillations. The results show the proposed stabilizer improves the system damping effectively subject to various types of disturbances.

1994-12-01

312

Power system stabilizer in the electric power system; Stabilizator systemowy w systemie elektroenergetycznym  

Energy Technology Data Exchange (ETDEWEB)

A mathematical model of the multi machine electric power system to analyse its dynamics has been worked out. The effectivity of the power system stabilizer developed in the one machine system has been tested by means of this model. The influence of the arrangement of the stabilizers on the stability of the electric power system has also been investigated. High damping of electromechanical transient processes has been achieved. 7 refs., 1 tab., 5 figs.

1994-12-31

313

Coordinated stabilization of a multimachine power system  

Energy Technology Data Exchange (ETDEWEB)

The paper presents a sequential procedure for coordinated stabilization of a multimachine power system with arbitrary complexity of the system model. The most effective machine to be equipped with a power system stabilizer is identified using eigenvalue analysis. The selection is based on the sensitivity of critical eigenvalues to increases in the coefficient of a damping term which is inserted in each equation of motion, in succession. The method is applied to a three-machine system and simulation studies show appreciable improvements in the small disturbance stability of the system.

1984-03-01

314

Combined heuristic with fuzzy system to transmission system expansion planning  

Energy Technology Data Exchange (ETDEWEB)

A heuristic algorithm that employs fuzzy logic is proposed to the power system transmission expansion planning problem. The algorithm is based on the divide to conquer strategy, which is controlled by the fuzzy system. The algorithm provides high quality solutions with the use of fuzzy decision making, which is based on nondeterministic criteria to guide the search. The fuzzy system provides a self-adjusting mechanism that eliminates the manual adjustment of parameters to each system being solved. (author)

2011-01-15

315

A predictive integrated voltage regulator and power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

An integrated voltage regulator and power system stabilizer based on one step ahead prediction is presented. The fixed parameter predictive control scheme is shown capable of providing consistently good voltage response and contribution to system damping over a wide range of operating conditions and system configuration. This is in contrast to the case with conventional automatic voltage regulator and power system stabilizer where performance varies widely with the operating situation and can even cause system instability. (author)

1995-04-01

316

The year 2000 embedded systems problem to maintain the safety of nuclear installations  

International Nuclear Information System (INIS)

The Y2K problem may impact on nuclear installations in a number of ways because embedded systems are used in nuclear routine operation, monitoring and control system. The very simplest embedded systems are capable of performing only a single function or set of functions to meet a single predetermined purpose. In more complex systems the functioning of the embedded system is determined by an application program that enables the embedded system to be used for a particular purpose in a specific application. The simplest devices consist of a single microprocessor which may itself be packaged with other chips in a hybrid system or Application Specific Integrated Circuit (ASIC). Its input comes from a detector or sensor and its output goes to a switch or activator which may start or stop the operation of a positioning motors or, by operating a ...

1999-02-01

317

Performance of Integrated Systems of Automated Roller Shade Systems and Daylight Responsive Dimming Systems  

Energy Technology Data Exchange (ETDEWEB)

Daylight responsive dimming systems have been used in few buildings to date because they require improvements to improve reliability. The key underlying factor contributing to poor performance is the variability of the ratio of the photosensor signal to daylight workplane illuminance in accordance with sun position, sky condition, and fenestration condition. Therefore, this paper describes the integrated systems between automated roller shade systems and daylight responsive dimming systems with an improved closed-loop proportional control algorithm, and the relative performance of the integrated systems and single systems. The concept of the improved closed-loop proportional control algorithm for the integrated systems is to predict the varying correlation of photosensor signal to daylight workplane illuminance according to roller shade ...

2010-07-08

318

Design modifications in radiation monitoring system at Tarapur Atomic Power Station 3 and 4  

International Nuclear Information System (INIS)

Inputs on radiological conditions forms the basis of implementation of effective exposure control to plant personnel in nuclear power station. Radiation monitoring system provides this input to the plant operator as well as to health physics group. Several design modifications have been incorporated in the Radiation Monitoring System at Tarapur Atomic Power Station (TAPS 3 and 4) over the similar systems at Kakrapar Atomic Power Station (KAPS) and Kaiga Generating Station (KGS). The radiological monitoring systems installed at TAPS unit 3 and 4 includes on line Radiation Data Acquisition System (RADAS), Emergency sampling system, effluent monitoring system and environmental monitoring system. The design changes and the versatile use of these systems are presented in this paper. (author)

2006-11-13

319

Thermodynamic analysis of a hybrid geothermal heat pump system  

British Library Electronic Table of Contents (United Kingdom)

A thermodynamic analysis of a hybrid geothermal heat pump system is carried out. Mass, energy, and exergy balances are applied to the system, which has a cooling tower as a heat rejection unit, and system performance is evaluated in terms of coefficient of performance and exergy efficiency. The heating coefficient of performance for the overall system is found to be 5.34, while the corresponding exergy efficiency is 63.4%. The effect of ambient temperature on the exergy destruction and exergy efficiency is investigated for the system components. The results indicate that the performance of hybrid geothermal heat pump systems is superior to air-source heat pumps.

2011-01-01

320

Factors that can influence the economic feasibility of stand-alone and grid-connected photovoltaic systems: case studies using the software AVES-F  

International Nuclear Information System (INIS)

This paper presents case studies of economic feasibility of solar photovoltaic systems using the software AVES-F (Analysis of Economic Feasibility of Photovoltaic Systems), developed by the authors, considering cases of stand-alone and grid-connected systems. The software takes into account several factors that can influence the economic feasibility of these kind of systems, like load to be supplied, distance to the grid, the use regime of the system, applied subsidies and others. The main goal of this paper is to analyze some of these factors and to observe how they can affect the economics of PV systems for electricity generation. (authors)

2004-06-07

321

Electronic system hardening methodology  

International Nuclear Information System (INIS)

The notion of hardened systems can be found in several applications (nuclear power plants, alarm systems, research installations..). Their development correspond to the functional necessity to take into account a specific radiative environment. The starting point of each hardening study is the definition of the radiative environmental constraints representative of the application. In addition to these external constraints, the specific functional characteristics of each system are considered: control or interface systems in nuclear industry, in-board control systems, remote handling systems, etc. This paper summarizes the methodology followed according to the experience gained in previous studies and anticipating the future needs. (J.S.). 6 refs., 5 figs.

322

Development of a motion analysis system using acceleration sensors for tennis and its evaluations  

British Library Electronic Table of Contents (United Kingdom)

The term biological motion is often used by researchers studying the patterns of movement generated by living forms and in sports. We studied a pattern recognition system of motion in sport using biological motion data. Biological motion data are acquired using a 3D motion capture system. However, 3D motion capture systems are very expensive. In this article, a biological motion capture system was built using acceleration sensors. Our proposed system uses the technique of Gaussian fitting and regression analysis. We tested our proposed system in pattern recognition of outdoor tennis and its evaluations.

2011-01-01

323

Power system stabilizer design based on the pole assignment technique for SIMO systems. [Single-input multi-input  

Energy Technology Data Exchange (ETDEWEB)

A new power system stabilizer (PSS) design method for single-machine infinite-bus systems is developed. This design method not only assigns the poles corresponding to the electro-mechanical oscillation modes in the system, but also located other system poles in suitable places in the s-plane. The design procedure is used first to translate a PSS design problem to an equivalent constant output feedback controller design problem for a single-input multi-output (SIMO) system. Then, a new algorithm developed in this paper is applied to design a constant output feedback controller to achieve the desired closed-loop system pole locations. Finally, the controller gains are transferred back to the parameters in the PSS. The extension of the method to multi-machine power systems is also illustrated. (Author).

1991-12-01

324

Navy Occupational Health Information Management System (NOHIMS). System/Functional Manager's guide  

Energy Technology Data Exchange (ETDEWEB)

This guide is intended to provide the necessary guidance to successfully manage the NAVMED Navy Occupational Health Information Management System (NOHIMS) at NAVMED sites and the NAVSEA Occupational Safety and Health Record Keeping System (OSHRKS) at NAVSEA sites. Outlines procedures to manage system operations, procedures to resolve hardware, software and communications problems, and procedures outside the realm of system operations that are required for a successful system. This guide is intended for the System and Functional Managers use. The System Manager is the individual designated to provide overall ADP management to the entire local configuration. Usually responsible for file backup, daily operations of the CPU, security, supplies, equipment, operating software and technical ADP guidance to the local functional users.

1987-04-01

325

Instrumentation/control systems for small- to medium-size steel-making plants; Tekko setsubi chusho plant no keisoku seigyo system  

Energy Technology Data Exchange (ETDEWEB)

Fuji Electric has realized highly reliable and functional control systems by the dispersion type control system FOCUS, which uses the controller (ICS-2000) enjoying good reputation in controlling industrial plants for a long time and a personal computer with high windows operability, the former for controlling and the latter for MHI responsible for monitoring. The smelting process in a steel-making plant needs a highly reliable system for advanced control to ensure continuous operation. Fuji Electric delivered the FOCUS system to Kubota in 1998, as the smelting furnace instrumentation/control system for the cupola furnace. The system has been in service smoothly. Moreover, a total of four control systems have been delivered, 2 for steel-making furnaces and the other 2 for continuous casting. (NEDO)

1999-01-10

326

Development of Reliability Data Management System (RDMS) for safety systems of PHWR type plants  

International Nuclear Information System (INIS)

The Reliability Data Management System (RDMS) for safety systems of PHWR type plants has been developed and utilized in the reliability analysis of the special safety systems of Wolsong Unit 1 with plant overhaul period lengthened. The RDMS is developed for the periodic efficient reliability analysis of the safety systems of Wolsong Unit 1. In addition, this system provides the function of analyzing the effects on safety system unavailability if the test period of a test procedure changes as well as the function of optimizing the test periods of safety-related test procedures. The RDMS can be utilized in handling the requests of the regulatory institute actively with regard to the reliability validation of safety systems.

1999-10-01

327

Application of drive systems for mine haulage systems  

Energy Technology Data Exchange (ETDEWEB)

There are many different types of open pit mining operations around the world, and the challenge for any drive system manufacturer is to produce a system(s) that will work satisfactorily in these mines. Several factors must be considered such as vehicle speed requirements, available engine horsepower, mine rolling resistance, grades, grade lengths, payload, and tire sizes. How well a particular drive system performs depends on the size, weight, and available tractive/retarding effort. In addition to performance, the system must also have an operating cost that will be acceptable over the life of the equipment. Today the choice of drive systems is not only between mechanical and electrical drives, but also within these categories are the different manufacturers. Regardless of how the power is provided to the rear wheels, the job must be accomplished reliably and at an acceptable ...

1989-01-01

328

Adaptive power-system stabilizer based on turbine governor control  

Energy Technology Data Exchange (ETDEWEB)

A novel adaptive stabilizer, called an Adaptive Governor Power System Stabilizer (AGPSS), which operated on the governor turbine system, was described. There has been extensive research on adaptive excitation control of generators in power systems with the goal of achieving better dynamic performance. AGPSS tracks the frequency and damping of oscillations in a power system, and adjusts to ensure that there is always sufficient damping in the system. There is no interaction between stabilizers on different generating units, and each one acts independently, consuming oscillation energy locally. These stabilizers are easy to design and this facilitates their use in multimachine systems. Results obtained by nonlinear simulation of a single-machine and a three-machine power system were discussed, illustrating the effectiveness of the stabilizers ...

1994-12-31

329

Vehicle tracking systems  

Energy Technology Data Exchange (ETDEWEB)

Several systems have been developed to accomplish vehicle location. The systems consist of three types: Dead Reckoning, Satellite, and LORAN C. If the information is to be sent back to a central location, some type of radiocommunication system is needed. One can use the existing voice radio or add a radio system just for transmitting the data.

1987-01-01

330

Using decoupled characteristic in the synthesis of stabilizers in multimachine systems  

Energy Technology Data Exchange (ETDEWEB)

A decoupled characteristic between the damping of a specific swing mode and the stabilizer gain of the corresponding machine in multimachine power systems is identified. Using this decoupled characteristic a power system stabilizer (PSS) synthesis approach which is based on the phase compensation concept is verified on a 9-machine system and the dynamic performance of this system is significantly improved. This method is proved to be effective, simple and it can provide useful guidance for the PSS field tuning.

1987-02-01

331

Standardization charts for cost-benefit analysis of biogas systems: case study in Jordan  

Energy Technology Data Exchange (ETDEWEB)

This paper establishes a standardization procedure in which results are presented in ready-to-use charts for the economic evaluation of biogas plants. It is hoped this work will alleviate controversial reports on cost-effectiveness of biogas systems. Also, it is found that these systems are the most economic among renewable energy systems using a standardized procedure for their comparison augmented by the generated spider diagrams wherein most probable costing production values for each system are directly compared. (author).

1990-01-01

332

Semi-automatic system for designing operations in a face  

Energy Technology Data Exchange (ETDEWEB)

A semi-automatic system which considers operation in a face by monitoring technological parameters of an extraction vehicle and a longwall conveyor is examined. The system records in tabular form the location, progress made, operating and down time of an extraction vehicle and operating and down time of the conveyor. A description of the operating principle system and systems for arrangement of the remote sensing and central recording device are presented. (Note: extraction vehicle not identified: LTN)

1980-01-01

333

Proton beam therapy control system  

Energy Technology Data Exchange (ETDEWEB)

A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

2010-09-21

334

Proceedings of the international topical meeting on remote systems and robotics in hostile environments  

International Nuclear Information System (INIS)

This book contains the proceedings of the International Topical Meeting on Remote Systems and Robotics in Hostile Environments. It is organized under the following sessions: Worldwide Applications Overview; Operating Mobile Systems; Sensors and Control Systems; Space Applications; Reactor Operations and Surveillance; Remote Equipment for Hazardous Operations; Future Mobile System; Mining and Construction Operations; Special Applications; Hot Cell Applications; Processing; Reactor Operations and Maintenance; Decontamination and Waste Handling; Remote Handling Development and Demonstration.

335

Problems and solutions of the IFSMTF power and switch system  

Energy Technology Data Exchange (ETDEWEB)

Solutions have been found for the problems encountered with the coil power and switching systems of the International Fusion Superconducting Magnet Test Facility (IFSMTF). The coil power system provides the filtered dc sources (+- 12 V dc; 25,000 A) for charging and discharging the coils of the IFSMTF experiment. The switching system provides the means of transferring the coil current into a dump resistor when a rapid discharge of a coil is required due to a coil failure (quench) or other system abnormalities.

1985-01-01

336

Off peak geothermal heat pump storage system  

Energy Technology Data Exchange (ETDEWEB)

The basic design of a system installed in the Columbus, Ohio Zoo is described. The distribution system is described in detail. The control system is microprocessor controlled, with about 50 monitoring points. Preliminary evaluations have indicated that the system can operate with an overall coefficient of performance in excess of 3.5. 1 figure.

1986-03-01

337

Instrumentation and control improvements at Experimental Breeder Reactor II  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe instrumentation and control (I C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I C systems of the next generation of liquid metal reactor (LMR) plants.

1993-01-01

338

Instrumentation and control improvements at Experimental Breeder Reactor II  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe instrumentation and control (I&C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I&C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I&C systems of the next generation of liquid metal reactor (LMR) plants.

1993-03-01

339

Impact of computers in radiography: the advent of digital radiography, part-2  

International Nuclear Information System (INIS)

Computed radiography (CR) systems use a photostimulable phosphor plate enclosed in a cassette. In CR, image acquisition is a two-stage process wherein image capture and image read out are done separately. Direct digital radiography (DR) systems, on the other hand, use detectors that have a combined image capture and image read out capability. DR systems are also called as DDR or ddR systems by some vendors. This article focuses on DR systems

2008-08-01

340

Embedded computer systems for control applications in EBR-II  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe the embedded computer systems approach taken at Experimental Breeder Reactor II (EBR-II) for non-safety related systems. The hardware and software structures for typical embedded systems are presented The embedded systems development process is described. Three examples are given which illustrate typical embedded computer applications in EBR-II.

1993-01-01

341

Diversity and Multiplexing Tradeoff in the Uplink of Cellular Systems with Linear MMSE Receiver  

CERN Document Server

In this paper, we extend the diversity and multiplexing tradeoff (DMT) analysis from point-to-point channels to cellular systems to evaluate the impact of inter-cell interference on the system reliability and efficiency. Fundamental tradeoff among diversity order, multiplexing gain and inter-cell interference intensity is characterized to reveal the capability of multiple antennas in cellular systems. And the detrimental effects of the inter-cell interference on the system performance of diversity and multiplexing is presented and analyzed.

2011-01-01

342

Distributed multiprocessor system runs on 68000-based VME bus hardware  

Energy Technology Data Exchange (ETDEWEB)

Using the Philips DRM distributed real-time multiprocessing system, designers can implement high-performance computer systems using VME hardware and the C programming language. The system provides a virtual-processing environment in which several 68000 CPUs share the workload. There are no centralized components, and tasks can be assumed by the rest of a system in the event of an individual processor's failure.

1984-04-19

343

Current ventilation and air conditioning systems and strategies  

Energy Technology Data Exchange (ETDEWEB)

The report examines common ventilation and air conditioning systems and strategies for both domestic and commercial buildings; and covers issues such as energy conservation, indoor air quality and occupant comfort. Drawing data from many countries in Europe and the United States of America, various natural, mechanical and air conditioning systems were compared using criteria such as climate, level of occupant interaction, and level of system comfort. This classification system is evaluated and seen as a valuable framework for further research. (U.K.)

1994-02-01

344

Control and monitoring of solar thermal systems with networked embedded systems  

Energy Technology Data Exchange (ETDEWEB)

Within this paper the potentialities of using networked embedded systems will be discussed. New embedded hardware with network connectivity allows remote administration and software updates of solar thermal system controllers via internet. System self analysis helps to minimize breakdown times by sending email and SMS to request maintenance staff. (orig.)

2004-07-01

345

Continuous emission monitoring -- Data acquisition and handling system for management  

Energy Technology Data Exchange (ETDEWEB)

This paper describes New York State Electric and Gas Corporation`s concept for a comprehensive, centrally located data system for management of their continuous emission monitoring systems (CEMS) data. The topics of the paper include the power system`s mix of generating units; data reporting requirements; data base management; nitrogen oxides compliance tracking; sulfur dioxide, nitrogen oxides, carbon dioxide and flow monitoring; and allowance tracking.

1995-09-01

346

Conceptual requirements for large fusion experiment control, data, robotics, and management systems  

International Nuclear Information System (INIS)

The conceptual system requirements for the control, data, robotics, and project management (CDRM) system for the next generation of fusion experiments are developed by drawing on the success of the Tara control and data system. The requirements are described in terms of an integrated but separable matrix of well-defined interfaces among the various systems and subsystems. The study stresses modularity, performance, cost effectiveness, and exportability.

1987-05-11

347

Comparison of three methods of remote metering of electrical energy: Telephone line, fiber optic, and radio packet. Final report, June 1995--August 1995  

Energy Technology Data Exchange (ETDEWEB)

This report deals with the selection of a data communication system for a remote metering system. It covers the following three types of systems: fiber optic, telephone line, and radio packet. It provides a methodology for selecting a communication system for a given remote metering system and a method for comparing costs.

1998-07-01

348

CORIS[sup (TM)]: A knowledge based system for pitting corrosion. CORIS trademark : Wissensbasiertes System zur Lochkorrosion  

Energy Technology Data Exchange (ETDEWEB)

A knowledge based system for pitting corrosion is presented. It can be used for material selection for specific pitting corrosion conditions or to check the suitability of a chosen material. The user can enter his own knowledge. The expert system is an integration of traditional expert system technology and neural networks. (orig.)

1993-10-01

349

Applications of interval matrices in power system stabilizer design  

Energy Technology Data Exchange (ETDEWEB)

In this paper the robust stability analysis of a single machine infinite bus system is investigated using interval matrix theory. Specifically the parameters of the power system stabilizer are considered as uncertainties in the system A matrix. The range of these parameters for which the system is Hurwitz stable is then found using interval matrix theory. (Author)

1997-03-01

350

Application of power system stabilizers and static VAR compensators on a longitudinal power system  

Energy Technology Data Exchange (ETDEWEB)

Dynamic stability improvement of a longitudinal power system using a power system stabilizer (PSS) and a static VAR compensator (SVC) is reported in this paper. An analytical approach is developed for the determination of PSS parameters. Results from time domain simulations indicate that the PSS and the SVC are very effective in damping system oscillations.

1988-11-01

351

An approach to software quality assurance for robotic inspection systems  

International Nuclear Information System (INIS)

Software quality assurance (SQA) for robotic systems used in nuclear waste applications is vital to ensure that the systems operate safely and reliably and pose a minimum risk to humans and the environment. This paper describes the SQA approach for the control and data acquisition system for a robotic system being developed for remote surveillance and inspection of underground storage tanks (UST) at the Hanford Site.

1993-11-14

352

caCORE version 3: Implementation of a model driven, service-oriented architecture for semantic interoperability  

UK PubMed Central (United Kingdom)

One of the requirements for a federated information system is interoperability, the ability of one computer system to access and use the resources of another system. This feature is particularly...Full Text Available

2008-02-01

353

Transgenesis in Xenopus using the Sleeping Beauty transposon system  

UK PubMed Central (United Kingdom)

Transposon-based integration systems have been widely used for genetic manipulation of invertebrate and plant model systems. In the past decade, these powerful tools have begun to be used in...Full Text Available

2009-07-01

354

Target organs and systems: methodologies to assess immune system function.  

UK PubMed Central (United Kingdom)

Immunotoxicity encompasses both reduced and heightened immune function. Diverse chemicals can impair functioning of the immune system. Both monographs and books have been devoted to detailed descriptions...Full Text Available

1998-04-01

355

TPC magnet cryogenic system  

Energy Technology Data Exchange (ETDEWEB)

The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various ...

1980-03-01

356

Survey of Flue Gas Desulfurization Systems: Bruce Mansfield Station, Pennsylvania Power Co.  

Science.gov (United States)

This report gives the results of a survey of operational flue gas desulfurization (FGD) systems on coal-fired utility boilers in the United States. The FGD systems installed on Units 1 and 2 at the Bruce Mansfield Station of the Pennsylvania Power Company...

1979-01-01

357

Software Configuration Management Plan for the Sodium Removal System  

Energy Technology Data Exchange (ETDEWEB)

This document establishers the Software Configuration Management Plan (SCMP) for the software associated with the control system of the Sodium Removal System (SRS) located in the Interim Examination and Maintenance (IEM Cell) Facility of the FFTF Flux Test.

2000-03-06

358

SUBMIT TO: AM105 CONFERENCE TITLE: Earth Observing Systems VI - NASA  

Science.gov (United States)

BAE SYSTEMS Infrared Imaging Systems. MS 209. 2 Forbes Road. Lexington, MA 02421 -7306. (781) 863-3762. (781) 863-4809 (fax) ken.overoye @lmco.com ...

359

Reliability assessment of embedded digital system using multi-state function  

Energy Technology Data Exchange (ETDEWEB)

This work describes a combinatorial model for estimating the reliability of the embedded digital system by means of multi-state function. This model includes a coverage model for fault-handling techniques implemented in digital systems. The fault-handling techniques make it difficult for many types of components in digital system to be treated as binary state, good or bad. The multi-state function provides a complete analysis of multi-state systems as which the digital systems can be regarded. Through adaptation of software operational profile flow to multi-state function, the HW/SW interaction is also considered for estimation of the reliability of digital system. Using this model, we evaluate the reliability of one board controller in a digital system, Interposing Logic System (ILS), which is installed in YGN nuclear ...

2006-03-15

360

Recent progress towards development of effective systemic chemotherapy for the treatment of malignant brain tumors  

UK PubMed Central (United Kingdom)

Systemic chemotherapy has been relatively ineffective in the treatment of malignant brain tumors even though systemic chemotherapy drugs are small molecules that can readily extravasate across the porous...Full Text Available

361

Proton storage ring (PSR) diagnostics and control system  

Energy Technology Data Exchange (ETDEWEB)

When any new accelerator or storage ring is built that advances the state of the art, the diagnostic system becomes extremely important in tuning the facility to full specification. This paper will discuss the various diagnostic devices planned or under construction for the PSR and their connection into the control system.

1983-01-01

362

Potential of plant genetic systems for monitoring and screening mutagens  

UK PubMed Central (United Kingdom)

Plants have too long been ignored as useful screening and monitoring systems of environmental mutagens. However, there are about a dozen reliable, some even unique, plant genetic systems that can increase...Full Text Available

1978-12-01

363

OPTIMIZATION OF COMBINED SEWER OVERFLOW CONTROL SYSTEMS  

Science.gov (United States)

The highly variable and intermittent pollutant concentrations and flowrates associated with wet-weather events in combined sewersheds necessitates the use of storage-treatment systems to control pollution.An optimized combined-sewer-overflow (CSO) control system requires a manage...

364

Magnetic mirror fusion systems: Characteristics and distinctive features  

Energy Technology Data Exchange (ETDEWEB)

A tutorial account is given of the main characteristics and distinctive features of conceptual magnetic fusion systems employing the magnetic mirror principle. These features are related to the potential advantages that mirror-based fusion systems may exhibit for the generation of economic fusion power.

1987-08-10

365

LAW ON WASTE MANAGEMENT  

Wastenet

1 to the operator of a waste collective system by an agreement or contract. The conditions for the ...Fees of the waste collective system are subject to the supervision of the authority responsible for market surveillance. ...The operator of waste collection system collects wastes from producers and holder and transports these to a collection

366

Incorporating a Language/Action Design Perspective into a Computer-Based Psychiatric Alerting System  

UK PubMed Central (United Kingdom)

User acceptance of a computer system depends on a number of factors, including broad social and professional concerns regarding the system's impact on the work environment. This observation is especially...Full Text Available

1989-11-08

367

Gamuts in nuclear medicine  

Energy Technology Data Exchange (ETDEWEB)

This book provides differential diagnostic possibilities of specific scan abnormalities in one volume for easy reference. This book is organized by organ systems and covers the central nervous system, the endocrine, skeletal, pulmonary, gastrointestinal, genitourinary, and cardiovascular systems. The gamuts are designed to teach differential diagnosis and to assist in the actual interpretation of patient slides.

1983-01-01

368

FFTF reactor assembly system technology  

Science.gov (United States)

An overview is presented of the FFTF reactor and plant together with descriptions of core components, core internals, core system, primary and secondary control rod system, reactor instrumentation, reactor vessel and closure head, and supporting test programs. (DG)

1975-11-13

369

FFTF reactor assembly system technology  

International Nuclear Information System (INIS)

An overview is presented of the FFTF reactor and plant together with descriptions of core components, core internals, core system, primary and secondary control rod system, reactor instrumentation, reactor vessel and closure head, and supporting test programs.

1976-03-13

370

Electrostatic probe vacuum system for TCA BR tokamak  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the technical design and performance of the diagnostic system installed in the tokamak TCABR to measure parameters of the plasma edge. The system consists of four Langmuir probes under remote control. (author)

1999-12-01

371

Development of the high-tension distribution line design support system; Koatsu gaisen sekkei shien system no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

The 'high-tension distribution line design support system' was developed for the 'work design support system'. This support system is composed of the work outline editor for preparing work details and facility data and the inference engine for preparing practical design plans, and can check system conditions such as voltage drop and deviation from technical standards automatically. The work outline editor takes charge of selection of work items, selective input of system information, and setting of some conditions such as pole position and reserved load onto a system diagram. The inference engine provides the design plan automatically based on the information inputted by the editor. For the design of high-tension distribution line, such various factors as local condition and load sharing of distribution ...

2000-02-10

372

Computerised, remote monitoring systems for underground coal mines  

Energy Technology Data Exchange (ETDEWEB)

This report presents a study on the use of computerised, continuous remote monitoring systems for fire and explosive atmosphere safety in underground coal mines. The effects of these systems on the safety level in mines are investigated, and the relationship between mine safety regulations and computerised, continuous, remote monitoring is analysed.

1983-03-01

373

Complete programming documentation for ECIP expansion of existing Energy Monitoring and Control System (EMCS), Fort Leonard Wood, Missouri  

Science.gov (United States)

The objective of this project is to reduce energy consumption in 203 buildings by providing a new EMCS (Energy Monitoring Control System) to control and monitor systems.

1993-12-01

374

Comparison of the UHF Follow-on and MILSTAR Satellite Communication Systems.  

Science.gov (United States)

The author compares the UHF Follow-on and MILSTAR satellite communication systems. The comparison uses an analytical hierarchy process. Although the two systems have been tasked with different missions, a comparison of cost, capability, and orbit is condu...

1991-01-01

375

Comparison of the Maturation of the Adrenergic and Serotonergic Neurotransmitter Systems in the Brain: Implications for Differential Drug Effects on Juveniles and Adults  

UK PubMed Central (United Kingdom)

Our understanding of the development of neurotransmitter systems in the central nervous system has increased greatly over the past three decades and it has become apparent that drug effects...Full Text Available

2007-04-15

376

Closing the loop In Practice to Assure the Desired Performance  

UK PubMed Central (United Kingdom)

A closed loop control process assures that a system performs within control limits. In closed loop control, the system's output feeds back directly to change the system's inputs. We describe an approach...Full Text Available

2008-01-01

377

Beam-forming system for electrostatic accelerator  

International Nuclear Information System (INIS)

A simple beam-forming system is described for the electrostatic accelerator of the Scientific-Research Institute of Nuclear Physics of Moscow State University. The system allows the beam to be focused on targets at various distances for a conductor potential of from 1 to 4 MV and beam currents of up to 35 #mu# A.

1988-01-01

378

Algebraic analysis of the electromagnetic wave interaction with the two-level system with two-fold degenerated states  

Energy Technology Data Exchange (ETDEWEB)

Algebraic properties of the analytical model, describing electro-magnetic weak interaction with the two-level system with two-fold degenerate state are considered. The expressions for the coherent states and Green function of the system are obtained.

1989-04-20

379

A Pragmatic Approach to Implementing Best Practices for Clinical Decision Support Systems in Computerized Provider Order Entry Systems  

UK PubMed Central (United Kingdom)

Incorporation of clinical decision support (CDS) capabilities is required to realize the greatest benefits from computerized provider order entry (CPOE) systems. Discussions at a conference on CDS in...Full Text Available

2007-01-01

380

A Picture Archiving and Communication System Module for Radiology  

UK PubMed Central (United Kingdom)

This paper presents the design and implementation of a clinical picture archiving and communication system (PACS) module within the radiology department of a 700-bed teaching hospital. The system is...Full Text Available

1988-11-09

381

A Computer Vision System for Automated Grading of Rough Hardwood Lumber Using a Knowledge-Based Approach  

Science.gov (United States)

... in this paper is aimed at developing a computer vision system that will be used to automatically grade rough hardwood lumber. The purpose of the computer vision system is to locate and identify grading def...

382

48 CFR 228.370 - Additional clauses.  

Science.gov (United States)

...Acquisition Regulations System 3 2010-10-01...Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF...assumption of risk for transportation by conveyance on...Missiles, and Space Launch Vehicles,...

2010-10-01

383

Synthesis, characterization and optical properties of a high NIR reflecting yellow inorganic pigment: Mo"6"+ doped Y_2Ce_2O_7 as a cool colorant  

International Nuclear Information System (INIS)

Full text: Pigments possessing the ability to confer high solar reflectance have received considerable attention in recent years. The inorganic class of NIR reflective pigments are mainly metal oxides and are primarily employed in two applications: (i) visual camouflage and (ii) reducing heat build up. More than half of the solar radiation consists of near-infrared radiation (52%), the remaining being 43% visible light and 5% ultraviolet radiation. Over heating due to solar radiation negatively affects comfort in the built environment and contributes substantially to electrical consumption for air conditioning and release of green house gases. A pigment which has strong reflections in the NIR region (780-2500 nm) can be referred to as a 'cool' pigment. However, most of the NIR reflective inorganic pigments particularly yellow (eg. cadmium yellow, lead chromate, chrome titanate yellow etc.) contain toxic metals and hence their consumption is being limited. Replacing ...

2010-11-24

384

System reliability of timber structures with ductile behaviour  

British Library Electronic Table of Contents (United Kingdom)

The present paper considers the evaluation of timber structures with the focus on robustness due to connection ductility. The robustness analysis is based on the structural reliability framework applied to a simplified mechanical system. The structural timber system is depicted as a parallel system. An evaluation method of the ductile behaviour is introduced. For different ductile behaviours, the system reliability is estimated based on Monte Carlo simulation. A correlation between the strength of the structural elements is introduced. The results indicate that the reliability of a structural timber system can be significantly increased due to the ductile behavior.

2011-01-01

385

Operational Experience with LHC Collimation  

CERN Document Server

A first sub-set of the collimation system has been installed for the 2008 first beam commissioning of the LHC. It included 88 collimators around the ring and the two injection lines. Each collimator has two jaws for which must be controlled and monitored with high precision. The LHC collimation system was put into operation from July to October 2008. The installed system is described and first results from system operation without and with beam are presented. It is shown that the LHC collimation system achieved the specified accuracy and reproducibility of jaw positioning. Next steps in collimation commissioning are described and planned system upgrades for high beam intensities are outlined.

2009-01-01

386

MTF analysis of the near-real time neutron radiography facility at MURR  

International Nuclear Information System (INIS)

Several neutron radiography systems designed to view transient processes on a real-time basis have been developed. With the advent of these different real-time systems comes the necessity to develop a means to quantitatively evaluate and compare these systems. A suitable method for measuring the resolution capabilities of the image-forming system is the determination of the modulation transfer function (MTF). The MTF is a measure of an imaging system's ability to reproduce the spatial frequencies present in an image. The system in use at the University of Missouri Research Reactor is described. (Auth.).

1981-12-01

387

LCLS XTOD Tunnel Vacuum System (XVTS)  

Energy Technology Data Exchange (ETDEWEB)

The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.

2005-11-04

388

Eccentric conical fastening system  

Energy Technology Data Exchange (ETDEWEB)

Fastening systems for parts that endure high vibration shear loads have traditionally been difficult or expensive to produce. This application describes a fastening system with multiple conical surfaces and eccentric offsets. The novel conical fastener system allows parts to be assembled with reduced tolerance controls at interface features while improving alignment precision. The eccentric conical fastening system is particularly well suited for assemblies with high shear loads in high vibration/shock environments, and/or for systems that have extremely precise pointing requirements.

2008-11-25

389

Development of test procedures for benchmarking components in renewable energy systems applications, in particular energy storage systems  

Energy Technology Data Exchange (ETDEWEB)

Renewable energy systems (RES) are unique among energy supply systems because their performance and design depends entirely on the location and climatic conditions. As a result of design options, user requirements and local climatic conditions, there are enormous variations between RES. This paper describes a method how to evaluate the data on monitored renewable energy systems (RES) in such a way that the operating conditions and performance of individual components and the system as a whole can be analysed and compared. It shows how categories of similar use can be defined and recommendations for each category can be made to assist in the selection of the most suitable products. (orig.)

2004-07-01

390

Design of self-tuning PID power system stabilizer for multimachine power systems  

Energy Technology Data Exchange (ETDEWEB)

A self-tuning PID (proportional-integral-derivative) power system stabilizer (PSS) is presented for improving the dynamic stability of a multimachine power system over a wide range of operating conditions. In order to maintain good damping characteristic when there is a drastic change in system operating condition, the gain settings are adapted in real time based on the continuously measured system inputs and outputs. The proposed self-tuning stabilizer has a decentralized structure and only local measurements within each generating units are required for the adaptation process. The effectiveness of the proposed stabilizer is demonstrated by an example.

1988-08-01

391

Design of LQ-PSS for Power System Stability Enhancement using GA  

Energy Technology Data Exchange (ETDEWEB)

This paper proposes the design of LQ-PSS (linear quadratic power system stabilizer) for improving power system stability using genetic algorithm(GA). We are turned weighting matrices of LQ-PSS using GA. To evaluate the usefulness of the proposed method, we performed the nonlinear simulation on a single machine infinite system. As results on a single machine infinite system. As results of the simulation, the proposed method shows the better control performance than CPSS(conventional power system stabilizer) in terms of settling time and damping effects. (author). 7 refs., 7 figs., 3 tabs.

2001-07-01

392

Analysis on Fault for the Underground Cable Systems at Home  

Energy Technology Data Exchange (ETDEWEB)

Many power apparatus and underground cable systems have been constructed since 1970 in korea. Recently, as the needs for underground T and D systems increase rapidly, any fault on the systems causes enormous economic losses in our society. Thus, this paper described. (1) Survey on the amount and the increasing rates of the underground cable systems at home and abroad. (2) Survey on fault data for the underground cables and joints at home and abroad.From the analysis on fault data, we analyzed the cause of fault and classified the typical fault mode for the underground cable systems. (author). 5 refs., 3 figs., 11 tabs.

1999-05-01

393

Waterjet Cutting System Adds Value to Titanium Parts.  

Science.gov (United States)

... Accession Number : ADD815206. Title : Waterjet Cutting System Adds Value to Titanium Parts. Descriptive Note : Journal article. Corporate Author : ...

1998-03-01

394

VOLUME I11 IMISSION SYSTEM PERFORMANCE - NASA Technical Report ...  

Science.gov (United States)

Nov 8, 2010 ... Ihring Mission 11, the radiation dosimetry measurement system functioned normally and provided data on the Earth's trapped radiation belts ...

395

Unmanned Systems Update. SPAWAR Systems Center ...  

Science.gov (United States)

... Multi-robot Operator Control ... Way-point navigation (UUV performing lawn-mower ... Funded by JIEDDO to improve operation of EOD robots ...

2011-03-16

396

Tri-Service DoD Partnership Delivers Standard Product to ...  

Science.gov (United States)

... This coordinated proposal was presented to the Threat System Working Group (TSWG) (then called the Threat System Investment Working Group ...

2011-05-14

397

Tools and methods for implementing the control systems on the Mirror Fusion Test Facility  

Energy Technology Data Exchange (ETDEWEB)

Installation of the major hardware subsystems for MFTF is nearing completion. These subsystems include the Fusion Chamber System, the eighty KV Neutral Beam System, the Superconducting Magnet System, and the Personnel Safety System. The Local Controls group has undertaken a uniform aproach to implementing the control systems for all of these hardware subsystems. This approach has two major aspects: (1) to provide a stand-alone computer control system with a remote, portable terminal so that computer control can be provided at the site of the hardware for initial testing, (2) to provide hardware simulators so that the complicated MFTF computer control system can be tested independent of the hardware. The software and hardware tools which were developed to carry out this plan will be described. Our experiences with bringing up subsystems ...

1981-09-29

398

The Numerical Weather Prediction System at the Italian Air ...  

Science.gov (United States)

... Title : The Numerical Weather Prediction System at the Italian Air Force Weather Service: Impact of Non-Conventional Observations and Increased ...

2004-06-01

399

The Johns Hopkins Hospital Network  

UK PubMed Central (United Kingdom)

The Johns Hopkins Hospital has initiated an ambitious program to apply modern technologies to the development of a new, comprehensive clinical information system. One component of this system is a...Full Text Available

1985-11-13

400

The Goddard Library - Goddard Projects Directory - NASA  

Science.gov (United States)

Oct 2, 2007 ... Other payloads included the Orbiter Experiments Autonomous Supporting Instrumentation System-1 (OASIS-1), a cooling system designed for ...

401

Technology for Large Space Systems - NASA Technical Reports Server  

Science.gov (United States)

(AIM PAPER 81-1628). Three different examples will be given to illustrate how a ...... Power System (PS), and a Science Applications and Space Platform ...

402

Study, Design and Fabricate a Cold Crucible System  

Science.gov (United States)

... to changes in some of the system parameters by means of figures which show the two standard isotherme and two slightly distorted isotherms. ...

1975-03-31

403

Single-pole switching schemes for EHV transmission systems  

Energy Technology Data Exchange (ETDEWEB)

Recognizing that a high percentage of transmission-line faults are single-phase to earth and temporary in nature, provides the impetus for considering single-pole switching as a means to enhance the reliability of EHV transmission systems. The effectiveness of single-pole switching schemes is largely determined by the speed with which the secondary arcs extinguish, and hence allow system restoration. Simulation techniques that enable better prediction of the faulted-system response are of obvious importance to the design and assessment of the various single-pole switching scheme applications. In this thesis, digital methods are developed to enable the faulted response of EHV systems to be simulated for a variety of different single-pole switching schemes. These include conventional single-pole switching, the hybrid method of autoreclosure, the neutral switched reactor, and the High Speed Grounding ...

1986-01-01

404

Security features of a nuclear material accounting system  

Energy Technology Data Exchange (ETDEWEB)

The Los Alamos Nuclear Material Accounting and Safeguards System (MASS) is a near-real-time accountability system for bulk materials, discrete items, and material undergoing dynamic processing. MASS has evolved from an eighty-column card based process control system to a very sophisticated computer system. The security of the MASS computer system is provide through various access controls. There are two kinds of access control to be addressed. They are physical access control to the hardware which make up the system, and access control to the software. There are many features which provide a measure of security to the hardware that will be discussed. Access to the software is controlled by a security password. Access to various transaction activities in the system is controlled through the level of MASS user privilege. Details of MASS user ...

1988-01-01

405

Robotic Waterjet System - NASA  

Science.gov (United States)

Mar 2, 2011 ... United Technology spun off a new company, Waterjet Systems, to commercialize and market the technology. The resulting ARMS (Automated ...

406

RESEARCH STUDY OF THE VORTEX VALVE FOR - NASA Technical Reports Server  

Science.gov (United States)

Vortex Valve Flow Characteristics. Basic Circuit Schematic. System Test Installation. Flight-Weight Design of SITVC System. Staged Vortex Valve SITVC ...

407

RESEARCH MEMORANDUM - NASA Technical Report Server (NTRS)  

Science.gov (United States)

lytical Comparison of Turbine-Blade Cooling System Designed for a. TurboJet Engine Operat- at Supersonic Speed and Altitude. I1 -. Air-C~Oling Systems. ...

408

Proposal for the award of a blanket purchase contract for the supply of electronics subracks for the CERN accelerator control system  

CERN Document Server

Proposal for the award of a blanket purchase contract for the supply of electronics subracks for the CERN accelerator control system

2010-01-01

409

Power Management for Real-Time Systems  

Science.gov (United States)

... CycleSim models an IBM PowerPC 405GP system-on-a-chip and includes a cycle-accurate, event-based power model of the processor core and ...

2004-07-01

410

Postpartum spontaneous colonic perforation due to antiphospholipid syndrome  

UK PubMed Central (United Kingdom)

The antiphospholipid syndrome (APS) is a multi-systemic disease being characterized by the presence of antiphospholipid antibodies that involves both arterial and venous systems resulting in arterial...Full Text Available

2009-01-28

411

Possible Computer Vision Systems and Automated or Computer-Aided ...  

Science.gov (United States)

Jun 16, 2011 ... The research is part of a team effort to help the hardwood sawmill industry automate with computer vision systems, and computer-aided or ...

412

Physiology of the Autonomic Nervous System  

UK PubMed Central (United Kingdom)

This manuscript discusses the physiology of the autonomic nervous system (ANS). The following topics are presented: regulation of activity; efferent pathways; sympathetic and parasympathetic divisions;...Full Text Available

2007-08-15

413

OPERATIONS AND FURLOUGHS UNDER A GOVERNMENT - NASA  

Science.gov (United States)

Apr 7, 2011 ... You cannot be in any type of pay status (e.g., annual leave, sick leave, .... Retirement System (FERS) and the Civil Service Retirement System ...

414

NAME=\\  

Wastenet

... Waste Collection Systems Products and Equipment Find and compare a variety of waste collection systems products and equipment on the world's largest environmental industry portal. View product ...

415

NAME=\\  

Wastenet

...Systems, UWA investigating rate uplift effects of shallow foundation systems associated with high voltage transmission line support towers. This work was funded by National Grid, ...

416

Military Base Closures and Affected Defense Department Civil ...  

Science.gov (United States)

... System (CSRS) and the Federal Employees Retirement System (FERS). ... retirement, thrift savings plan, annual and sick leave, severance pay and ...

2006-03-07

417

INJECTABLE IN SITU CROSS-LINKING HYDROGELS FOR LOCAL ANTIFUNGAL THERAPY  

UK PubMed Central (United Kingdom)

Invasive fungal infections can be devastating, particularly in immunocompromised patients, and difficult to treat with systemic drugs. Furthermore, systemic administration of those medications...Full Text Available

2010-02-01

418

Guidance and Control System for an Autonomous Vehicle  

Science.gov (United States)

... operational AUV and Unmanned Underwater Vehicle (UUV) ... by Brooks with land-based robots [BROOKS 88 ... system for a mobile land robot called ...

1990-06-01

419

Geographic information systems: their use in environmental epidemiologic research.  

UK PubMed Central (United Kingdom)

Advances in geographic information system (GIS) technology, developed by geographers, provide new opportunities for environmental epidemiologists to study associations between environmental exposures...Full Text Available

1997-06-01

420

Genomic view of the evolution of the complement system  

UK PubMed Central (United Kingdom)

The recent accumulation of genomic information of many representative animals has made it possible to trace the evolution of the complement system based on the presence or absence of each complement...Full Text Available

2006-09-01

421

Fuel assemblies inspection system - (SICOM)  

Energy Technology Data Exchange (ETDEWEB)

An inspection system was developed for spent fuel assemblies of PWR so that to check their general state, perform dimensional control and measure oxide layer thickness of peripheral rods. (orig./HP)

1995-12-31

422

Existence of a complex closed trajectory in a three-dimensional dynamical system  

British Library Electronic Table of Contents (United Kingdom)

The DN-tracking method is used to prove the existence of a closed trajectory in a quadratic system of ordinary differential equations in three dimensions.

2011-01-01

423

Environmental Impact Analysis Process. Final Environmental ...  

Science.gov (United States)

... Abstract : The United States Air Force (USAF) currently operates the Milstar satellite system to provide Military Satellite Communication Systems ...

2001-02-15

424

Energy-conscious air-side design: Phase 1 of energy use minimization  

Science.gov (United States)

Of the many energy-conservation options available to the design engineer, a system-management approach is recommended as one that will effect maximum benefits to the owner. Systems management includes energy-conscious consideration of design criteria, design details, installation, testing and balancing, and operation. It requires the informed participation of the design engineer, contractor, testing and balancing (TAB) engineer, and owner/operator. Within limits, almost every component of HVAC systems offers an opportunity to conserve energy. Many of these impact energy determinants such as system static pressure, system total air flow, or the quantity of outside air. A few design considerations for energy conservation in a simple system and the impact that the TAB work has on these are illustrated. Particular attention is devoted to the energy impact of ...

1981-01-01

425

Electronics in mining symposium  

Energy Technology Data Exchange (ETDEWEB)

The symposium reviewed the use of electronics in mining today. Subjects covered include control systems; remote sensing; telemetry; data transmission; microprocessors and transportation systems. 15 papers have been abstracted separately.

1984-01-01

426

Electromagnetic Effects Requirements for Systems.  

Science.gov (United States)

This standard establishes requirements, verification criteria, and contractor tasks for electromagnetic effects protection of airborne, ground, and support systems. These effects include electromagnetic compatibility, electromagnetic interference, lightni...

1993-01-01

427

Effective Software Reuse in an Embedded Realtime System  

Science.gov (United States)

... Many of the functions required of the SMB are JANAP-128,-JINTACCS). The SMB can also get similar to other military message processing systems ...

1993-02-01

428

ELECTRIC AND GALVANOMAGNETIC PROPERTIES OF ...  

Science.gov (United States)

... Abstract : The electric resistance in weak (diluted) solid solutions of the Pd-Ag and Fe-W systems, as wellAS THE Hall effect in a Pd-Ag system ...

1961-06-27

429

Diesel engine systems for underground coal mines  

Energy Technology Data Exchange (ETDEWEB)

This standard specifies requirements for the flameproofing and the limiting of surface temperature and exhaust emission control of diesel engine systems for use in underground coal mines.

1988-01-01

430

Development of contact scanner for Wolsung NPP alarm and annunciation system  

Energy Technology Data Exchange (ETDEWEB)

Contact scanner system in Wolsung NPP(model ESE-1565) is early `70 equipment so most of components are obsolete. To make 100% compatible PCBs for this system is main object of the study. Most of components used in the system are now not available in the electric market, furthermore original system maker no longer supplies spare parts. System supplier(AECL) quoted lots of money than general PCBs prices in case of spare PCBs are re-marked by canada maker. Contents and scope of the study are specifications research and system analysis, improvements of repairability and reliability, circuit design and simulations using computer aided tools(CAE), make arbitrary mechanical contacts signal generator for test system. Now the long-run test of home made PCBs are conducting at Wolsung NPP. (author). 20 refs., 42 figs.

1995-12-31

431

Development of New Ground Inspection Techniques for the ...  

Science.gov (United States)

Integration of Eddy Current probes with MAUS scanning system has been demonstrated to produce scan rates of 36 sqft/hour. System will be designed to ...

432

Dendritic Cells in Systemic Lupus Erythematosus  

UK PubMed Central (United Kingdom)

Systemic lupus erythematosus (SLE) persists as a chronic inflammatory autoimmune disease and is characterized by the production of autoantibodies and immune complexes that affects multiple organs....Full Text Available

2010-04-01

433

Computer Vision Hardware System for Automating Rough Mills of Furniture Plants  

Science.gov (United States)

... company. To automate this initial cutup requires a computer vision system that can locate and identify surface defects ... ...

434

Centers of Research Excellence in Science and Technology  

Science.gov (United States)

... 4? Program History 5? Center for Advanced Materials and Smart Structures 6? Center for Systems ... Systems 14? Center for Photonic Materials Research 15? Synthesis, Manufacturing and Characterization ...

435

Best Practices: Better Support of Weapon System Program ...  

Science.gov (United States)

... acquisition process has produced weapons that are ... F/A-22 Raptor, Space-Based Infrared System ... occur because DOD's weapon programs do ...

2005-11-01

436

Automated Pharmacy Patient Medication Profiling System  

UK PubMed Central (United Kingdom)

The Systems Development Group and the Pharmacy Service of the Washington D.C. VAMC are involved in automating the administrative and clinical data requirements of a satellite out-patient pharmacy....Full Text Available

1981-11-04

437

Assessment of information impacts in power system security against malicious attacks in a general framework  

International Nuclear Information System (INIS)

In the analysis of power systems security, recently a new concern related to possible malicious attacks caught much attention. Coordination among different transmission system operators (TSO) in an interconnected power system to counteract such attacks has become an important problem. This paper presents a general framework for describing the physical, cyber and decision-making aspects of the problem and their interrelations; within this framework, an analytic tool for the assessment of information impacts in handling on-line security after a malicious attack is proposed and discussed. The model is based on the socially rational multi-agent systems and the equilibrium of a fictitious play is considered to analyze the impacts of various levels of information available to the interconnected system operators on the outcomes of the decision-making process under attack. A 34-buses test ...

2009-06-01

438

Approaches to the evaluation of chemical-induced immunotoxicity.  

UK PubMed Central (United Kingdom)

The immune system plays a crucial role in maintaining health; however, accumulating evidence indicates that this system can be the target for immunotoxic effects caused by a variety of chemicals including...Full Text Available

1995-12-01

439

Aircraft Survivability: Protecting and Integrating Air and Space ...  

Science.gov (United States)

... reliability of fiber optics in preference over space-based systems. ... STC web site at www.aiaa.org/tc ... and improve lethalities of US weapon systems 3 ...

2011-05-15

440

Agricultural production systems and environmental health.  

UK PubMed Central (United Kingdom)

By the turn of the century, American farmers and ranchers will be producing food and fiber through the application of highly sophisticated systems that involve a broad spectrum of relevant factors--from...Full Text Available

1990-06-01

441

Advanced synchronous luminescence system  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.

1997-01-01

442

A highly integrated trigger and readout system for a silicon micro-strip detector installed at the CERN Omega spectrometer  

CERN Document Server

A highly integrated trigger and readout system for a silicon micro-strip detector installed at the CERN Omega spectrometer

1991-01-01

443

A feedforward architecture accounts for rapid categorization  

UK PubMed Central (United Kingdom)

Primates are remarkably good at recognizing objects. The level of performance of their visual system and its robustness to image degradations still surpasses the best computer vision systems despite...Full Text Available

2007-04-10

444

A Study on the Power System Stabilizer Design using Object-Oriented Method  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we have designed power system stabilizer (PSS) using object-oriented method. There are several types of power system stabilizer, A proportional-integral (PI) controller is very simple for practical implementation. Therefore it has been widely employed by the industry. The methods of obtaining the gains (Ki,Kp) of PI controller are root-locus method and sub-optimal regulator approach. But these methods are cannot be applicable to nonlinear system and faulted power system. So we proposed a new method which can be applied to nonlinear system by numerical analysis method. The method of dynamic system simulation by numerical method is very difficult and complex. We proposed flexible simulation method for complex power system analysis using object-oriented programming (OOP) and applied to PI controller design. (author). 7 refs., 14 ...

1999-06-01

445

A PC-Based Imaging System for the Naval Postgraduate ...  

Science.gov (United States)

... 1 I3a TYPE OF REPORT 1 3b TIME COVERED ... Measured by this standard the system provides good results; it ... did not fully meet all the standards or ...

1989-09-01

446

A DNA recombinant database management system.  

UK PubMed Central (United Kingdom)

A set of computer programs is described which constitutes a clone database management system. Maintenance of the database and the stocks of material is designed to be under the control of one person...Full Text Available

1983-07-11

447

A Computer Vision System for Inspection of Light Emitting ...  

Science.gov (United States)

... Accession Number : ADD801284. Title : A Computer Vision System for Inspection of Light Emitting Diodes. Descriptive Note : Conference paper,. ...

1986-06-01

448

Solar energy utilization and microcomputer control in the greenhouse builk curing and drying solar system  

Energy Technology Data Exchange (ETDEWEB)

Three agricultural applications in a specially designed greenhouse solar system functioning as a multi-purpose solar air collector for crop production and curing/drying processes are examined. An automated hydroponic crop production system is proposed for the greenhouse solar system. Design criteria of the proposed system and its utilization of solar energy for root-zone warming are presented and discussed. Based upon limited testing of the hydroponic system considered, hydroponic production of greenhouse crops is believed reasonable to complement the year-round use of the greenhouse solar system. The hardware/software design features of a microcomputer-based control system applied in the greenhouse solar barn are presented and discussed. On-line management and utilization of incident solar energy by the microcomputer ...

1987-01-01

449

Report on commissioned business for fiscal 1997. Development of new power storage system for cells and development of technology for distributed power storage (research for a zinc/air cell system for automobiles); 1997 nendo itaku gyomu hokokusho. Shingata denchi denryoku chozo system kaihatsu bunsangata denryoku chozo gijutsu kaihatsu (denki jidoshayo aen kuki denchi system chosa)  

Energy Technology Data Exchange (ETDEWEB)

Concerning the above, it is discussed whether such a system is feasible in Japan. A zinc/air cell system requires some special plants for zinc regeneration, etc. It is necessary to build a zinc refining plant and to install dozens of electrode replacing facilities in an area dozens of kilometers in diameter with the plant at the center. For such a system to be functional, there have to be several tens of thousands of automobile users in a limited area. In Japan, so large a number will not be found anywhere even if the appeal is directed to those in the postal service and electric utilities. There will be no economic success in Japan, different from in Germany. As for the economic comparison between a zinc/air cell system and natural gas system, the two will be equivalent to each other as far as the use of the quick filling stations for the natural gas automobiles remains as it is. ...

1998-03-01

450

Comparison of power system stabilizer design using H{sub {infinity}} optimization and {mu}-synthesis approach  

Energy Technology Data Exchange (ETDEWEB)

Power system operating conditions vary with system configurations and loading conditions. Coefficients in nominal system model change in a complex manner with different operating point and so does system dynamic behavior. With the aid of unstructured and structured uncertainty descriptions, the worst system variations can be estimated and formulated into two different uncertainty models in frequency domain; multiplicative unstructured uncertainty in the form of transfer function and structured uncertainty with the parametric uncertainty description. The uncertainty descriptions are then incorporated into system nominal model to perform H{sub {infinity}} and {mu} based robust power system stabilizer (PSS) design. Both approaches to the PSS design enable the power system to remain stable over a wide range of ...

1995-11-01

451

An adaptive self-optimizing power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

A self-optimizing pole-shifting control algorithm has been developed for an adaptive power system stabilizer (APSS) to improve its dynamic performance and autonomous operation. The proposed algorithm deals with the system frequency and time domain characteristics simultaneously to guarantee stability and to enhance the performance of the closed-loop system. The mechanism of discrete control system control limits influencing the closed loop system behaviour is studied. Short-term behaviour is studied by introducing the concept of a short-term behaviour index. With the introduction of dynamic control limits, an effective discrete control system design method is proposed. A PSS oriented power system dynamics simulation package (PSDSP) has been developed. Using the PSDSP, simulation studies were performed with the proposed APSS applied to a ...

1994-01-01

454

Towards a dissipativity framework for power system stabilizer design  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a dissipativity-based framework for the study of low-frequency oscillations in power systems and for power system stabilizer design. This framework leads to a robust controller design formulation, amenable to both H{sub {infinity}} and QFT tools. An illustrating numerical example presents QFT based design for a widely used benchmark two area, four machine power system.

1996-11-01

456

The national nuclear material tracking system. A Korea's countermeasure against nuclear terrorism  

International Nuclear Information System (INIS)

Since nuclear terrorism has been identified as a real threat, the Korean government has earnestly developed elementary technologies and sub-systems for establishing an integrated defensive system against nuclear terrorism, which is based on the concept of defense-in-depth. This paper introduces the gist and implications of the studies that have been conducted in building the national nuclear material tracking system for preventing and intercepting the illicit trafficking and transporting of nuclear material in Korea. (orig.)

2011-07-01

460

Progress of magnetic-suspension systems and magnetic bearings in the USSR  

International Nuclear Information System (INIS)

This paper traces the development and progress of magnetic suspension systems and magnetic bearings in the USSR. The paper describes magnetic bearings for turbomachines, magnetic suspension systems for vibration isolation, some special measuring devices, wind tunnels, and other applications. The design, principles of operation, and dynamic characteristics of the system are presented.

1992-05-01

462

Power fluidics for ventilation control  

International Nuclear Information System (INIS)

... amplification exhaust systems fluidic control devices gloveboxes pressure

1984-11-28

464

Non-polluting cogeneration  

Energy Technology Data Exchange (ETDEWEB)

HEW is operating one of the biggest district heating networks of the Federal Republic of Germany. The paper discusses a number of projects which in recent years have been engaged in extensive air pollution abatement measures to make district heating an environmentally compatible energy source. Emphasis is placed on the hot gas cleanup system of block 2 of the harbor power plant. The system is the first of its kind to have realized an SCR system connected with the desulfurization system for industrial denitrification purposes.

1988-01-01

466

Methods for increasing the stability and reliability of combined energy systems. Sposoby povysheniya ustoychivost i nadezhnosti ob'yedinennykh energosistem  

Energy Technology Data Exchange (ETDEWEB)

An increase in the stability and reliability of a combined power system (OES) is achieved through using a control panel (PA) and regulation systems. A substantial part of the works published in this collection of works is used in the combined power systems of the Urals, the Northwest and Central Asia.

1983-01-01

467

Methodology to assess the effects of magnetohydrodynamic electromagnetic pulse (MHD-EMP) on power systems  

International Nuclear Information System (INIS)

This paper summarizes a method to evaluate the possible effects of magnetohydrodynamic-electromagnetic pulse (MHD-EMP) on power systems. This method is based on the approach adapted to study the impact of geomagnetic storms on power systems. The paper highlights the similarities and differences between the two phenomena. Also presented are areas of concern which are anticipated from MHD-EMP on the overall system operation. 12 refs., 1 fig.

1986-01-01

469

Implementation and laboratory test results for an adaptive Power System Stabilizer based on linear optimal control  

Energy Technology Data Exchange (ETDEWEB)

Implementation of an adaptive power system stabilizer (PSS) based on linear optimal control is described in this paper. The generator is identified in real time, and a special 3rd order discrete Riccati equation is solved in each sample interval. Because the output of the generator is fed back directly, the controller can track the system very fast. Experimental studies on a physical model of a power system demonstrate the effectiveness of the proposed adaptive optimal controller.

1990-12-01

472

Geothermal heat-pump systems of heat supply  

International Nuclear Information System (INIS)

The data on the multilayer operation of the objects, located in the climatic conditions of the central area of Russia and equipped with the geothermal heat-pumping systems of the heat supply are presented. The results of the analytical studies on evaluating the geothermal heat-pumping systems of the heat supply integration efficiency into the structure of the energy supply system, prevailing in the country, are presented

2004-06-01

473

Fluidic programmer for nuclear engine application  

International Nuclear Information System (INIS)

... fluidic control devices performance reactor control systems space propulsion

476

Energy storage systems program report for FY1996  

Energy Technology Data Exchange (ETDEWEB)

Sandia National Laboratories, New Mexico, conducts the Energy Storage Systems Program, which is sponsored by the US Department of Energy`s Office of Utility Technologies. The goal of this program is to assist industry in developing cost-effective energy storage systems as a resource option by 2000. Sandia is responsible for the engineering analyses, contracted development, and testing of energy storage systems for stationary applications. This report details the technical achievements realized during fiscal year 1996.

1997-05-01

477

Elimination of ``memory`` from sample handling and inlet system of a mass spectrometer  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a method for preparing the sample handling and inlet system of a mass spectrometer for analysis of a subsequent sample following analysis of a previous sample comprising the flushing of the system interior with supercritical CO{sub 2} and venting the interior. The method eliminates the effect of system ``memory`` on the subsequent analysis, especially following persistent samples such as xenon and krypton.

1991-05-08

478

Effect of the PVC system?s topology on the dielectric losses in the region of strong electric fields  

British Library Electronic Table of Contents (United Kingdom)

The electrophysical characteristics of the electric cable?s transition into a state of a heterogenic polymer system due to a wire?s explosion were examined. Using cyclic heating-cooling of the composite, the changes in its topology were observed. The latter makes it possible to regulate the dielectric characteristics of the system.

2011-01-01

479

Effect of a pumped storage plant on the generation reliability of the Taiwan power system  

Energy Technology Data Exchange (ETDEWEB)

A novel approach to the reliability analysis of a power system with both hydro and pumped storage plants is presented in this paper. The proposed method is based on the concept of peak shaving for the hydro and pumped storage units. Different values of the stored energy of the pumped storage units are employed to demonstrate their effect on the generation reliability of a power system. The proposed scheme has been applied successfully to the reliability analysis of Taiwan power system.

1986-05-01

489

Brain Basics  

Medline Plus

... related to changes in the anatomy, physiology, and chemistry of the nervous system. When the brain cannot ...

491

An intelligent management system for corporate information- calculating network development  

CERN Document Server

An approach to solving the problem of managerial control quality improvement corporate information-calculating networks (CICN) is proposed. The approach is based on the concept of a flexible toolkit. A macro-model, system-science and system-engineering models of an intelligent managerial control system (IMCS) for CICN development are considered as well as its dynamics. The practical opportunity of IMCS implementation is assessed. (5 refs).

2001-01-01

492

A multi-micro-computer based dual-rate self-tuning power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

A dual-rate self-tuning control technique, in which the system identification and control calculation are performed separately, is proposed in this paper. This greatly increases the control rate. A self-tuning power system stabilizer (DSPSS) making use of this technique is developed and implemented using multi-micro-computers. Simulation and experimental results with DSPSS show that the increase in the control rate can considerably improve the system performance.

1987-09-01