WorldWideScience
1

OPTICAL FIBRE ARRAY MANUFACTURE (OFAM)  

Environmental Research Database

Objectives1. The study of the automatic alignment of electrically charged optical fibres.~%~~%~2. The design and construction of a prototype system for assembly of the fibres.~%~~%~3. The fabrication of a proof-of-principle 4-by-4 fibre array.~%~~%~4. The test and characterisation of the prototype fibre bundle in terms of translational and angular positioning accuracy.~%~~%~5. A paper design of a full-scale automated system.~%~~%~6. Enable commercial exploitation.~%~DescriptionThis multidisciplinary programme aims to investigate and develop an 'adventurous' process for manufacturing 2-D optical fibre arrays, with at least an order of magnitude improvement in the positional and angular tolerances of the mono-mode fibres compared to conventional techniques. Manufacturable, dense 2-D optical fibre arrays are essential ...

2002-01-31

2

The frontal weapon of the termite Armitermes euamignathus Silvestri (Isoptera, Termitidae, Nasutitermitinae)  

Scientific Electronic Library Online (English)

Abstract in english Frontal weapon is the term used to designate the apparatus consisting of frontal gland and associated structures that participate in the chemical defense of termite soldiers. The ultra structure of the frontal gland and the scanning microscopy of the soldier head was investigated in the termite Amiitermes euamignathus Silvestri, 1901.Campaniform sensilla was not observed but there were 80 to100 sensory bristles around the frontal pore. The glandular epithelium shows only (more) class 1 cells according 10 the classification of NOIROT & QUENNEDEY (1974, 1991). The glandular cells are characterized by apical microvilli, a basal labyrinth and a large quantity of smooth endoplasmic reticulum which forms dense zones throughout the cytoplasm. The secretion is concentrated mainly in the basal pole of the cell and consists of large lipid droplets. The secretory epithelium is covered by a thick apical cuticle composed of a thin ...

2001-06-01

3

Pd based membrane reactor for ultra pure hydrogen production through the dry reforming of methane. Experimental and modeling studies  

British Library Electronic Table of Contents (United Kingdom)

A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...

2011-01-01

4

Advanced Neutron Source: Plant Design Requirements  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents ...

1990-07-01

5

The cluster structure of the inner crust of neutron stars in the Hartree-Fock-Bogoliubov approach  

CERN Document Server

We analyse how the structure of the inner curst is influenced by the pairing correlations. The inner-crust matter, formed by nuclear clusters immersed in a superfluid neutron gas and ultra-relativistic electrons, is treated in the Wigner-Seitz approximation. The properties of the Wigner-Seitz cells, i.e., their neutron to proton ratio and their radius at a given baryonic density, are obtained from the energy minimization at beta equilibrium. To obtain the binding energy of baryonic matter we perform Skyrme-HFB calculations with zero-range density-dependent pairing forces of various intensities. We find that the Wigner-Seitz cells have much smaller numbers of protons compared to previous calculations. For the dense cells the binding energy of the configurations with small proton numbers do not converge to a well-defined minimum value which precludes the determination of their structure. We show that for these cells there is a significant ...

2011-01-01

8

Conceptual Design of Superconducting Quadrupole Arrays for the Heavy-Ion Fusion  

CERN Document Server

Conceptual Design of Superconducting Quadrupole Arrays for the Heavy-Ion Fusion

1999-01-01

9

Using Gamma-Ray Burst Prompt Emission to Probe Relativistic Shock Acceleration  

CERN Document Server

It is widely accepted that the prompt transient signal in the 10 keV - 10 GeV band from gamma-ray bursts (GRBs) arises from multiple shocks internal to the ultra-relativistic expansion. The detailed understanding of the dissipation and accompanying acceleration at these shocks is a currently topical subject. This paper explores the relationship between GRB prompt emission spectra and the electron (or ion) acceleration properties at the relativistic shocks that pertain to GRB models. The focus is on the array of possible high-energy power-law indices in accelerated populations, highlighting how spectra above 1 MeV can probe the field obliquity in GRB internal shocks, and the character of hydromagnetic turbulence in their environs. It is emphasized that diffusive shock acceleration theory generates no canonical spectrum at relativistic MHD discontinuities. This diversity is commensurate with the significant range of spectral indices discerned in ...

2010-01-01

10

Future limits on isotropic Lorentz violation in the photon sector from UHECRs and TeV gamma rays  

CERN Document Server

Present and future ultra-high-energy-cosmic-ray facilities (e.g., the Pierre Auger Observatory with South and North components) and TeV-gamma-ray telescope arrays (e.g., HESS/VERITAS and CTA) have the potential to set stringent indirect bounds on the nine Lorentz-violating parameters of nonbirefringent modified Maxwell theory minimally coupled to standard Dirac theory. Theoretically, the most interesting case is isotropic Lorentz violation, which is described by a single parameter [taken to vanish for the case of the standard Lorentz-invariant theory]. It appears possible to obtain in the future an upper (lower) indirect bound on this single isotropic Lorentz-violating parameter at the +10^{-21} (-10^{-17}) level. Comparison is made with existing and future direct bounds from laboratory experiments. The possible physics implications of upper bounds at the 10^{-21} level are also briefly discussed.

2011-01-01

11

Advanced Neutron Source: Plant Design Requirements. Revision 4  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents ...

1990-07-01

12

Demonstrating leadership inside and out : green building project trains employees, educates clients  

Energy Technology Data Exchange (ETDEWEB)

This article described a full-scale green renovation project undertaken by a construction management firm in Newton, Massachusetts. Chapman Construction and Design began renovating its own office building in late 2007 and completed it in September 2008. The firm set out to achieve LEED Platinum certification from the United States Green Building Council. The project involved energy saving modifications to its mechanical systems; replacing plumbing fixtures with high efficiency alternatives to reduce water consumption by at least 40 per cent; installing skylights and additional windows to allow more natural light into the interior space; salvaging doors, lighting, metal studs and masonry whenever possible; and using sustainable products such as recyclable carpets, tiles and low-VOC paint. The main feature of the renovation was a new 47 kW (DC) photovoltaic (PV) solar power array installed on the rooftop. The PV array includes 208 panels and a ...

2009-01-15

13

Ultra-thin lithium micro-batteries. Performances and applications; Microaccumulateurs ultra minces au lithium. Performances et applications  

Energy Technology Data Exchange (ETDEWEB)

This short paper (abstract) describes the characteristics and performances of prototypes of ultra-thin lithium micro-batteries (thickness < 0.2 mm) which can be incorporated into microelectronic circuits. (J.S.)

1996-12-31

14

Ultra High Strength Beta Titanium Alloy for Fasteners.  

Science.gov (United States)

... Accession Number : ADD151811. Title : Ultra High Strength Beta Titanium Alloy for Fasteners. Descriptive Note : Journal article,. ...

15

Analysis of low-level computer vision algorithms for implementation on a very large scale integrated (VLSI) processor array  

Energy Technology Data Exchange (ETDEWEB)

In a recent paper, Lowry (1981) described an architecture for a computer vision rectangular processor array that is suitable for VLSI implementation. In this paper the authors review that architecture, discuss extensions to it and present results of an array simulator applied to vision algorithms. They also present an algorithm for re-routing an array with bad processors into a working subset of the array, making it feasible to implement a large array on one wafer-sized chip. 7 references.

1982-01-01

20

Fostering the commercialization of ultra capacitors  

Energy Technology Data Exchange (ETDEWEB)

This document presents the activity of KiloFarad International (KFI), a trade association for the promotion of the interests of the international ultra-capacitor industry through education and representation. KFI provides a forum for the ultra-capacitor industry to work on non-competitive activities (standards, working groups, test procedures etc..). The rest of the document presents some informations about ultra-capacitors technology and some advanced applications in the automotive and telecommunication industries. (J.S.)

2004-07-01

22

High-speed surface temperature measurements on plasma facing materials for fusion applications  

International Nuclear Information System (INIS)

For the lifetime evaluation of plasma facing materials in fusion experimental machines, it is essential to investigate their surface behavior and their temperature responses during an off-normal event such as the plasma disruptions. An infrared thermometer with a sampling speed as fast as 1x10"-"6 s/data, namely, the high-speed infrared thermometer (HSIR), has been developed by the National Research Laboratory of Metrology in Japan. To evaluate an applicability of the newly developed HSIR on the surface temperature measurement of plasma facing materials, high heat flux beam irradiation experiments have been performed with three different materials under the surface heat fluxes up to 170 MW/m"2 for 0.04 s in a hydrogen ion beam test facility at the Japan Atomic Energy Research Institute. As for the results, HSIR can be applicable for measuring the surface temperature responses of the armor tile materials with a little modification. It is also confirmed that surface temperatures measured ...

23

A technique for determining the spatial and temporal distributions of surface fluxes of heat and moisture over the Southern Great Plains Cloud and Radiation Testbed  

Energy Technology Data Exchange (ETDEWEB)

Land surface parameterization schemes such as the Simple Biosphere Model (SiB2) have found considerable use in climate simulation models, where they provide lower boundary conditions in the form of surface sensible and latent heat fluxes. A methodology is described to apply models of this type at high resolution, using data from the Department of Energy{close_quote}s Cloud and Radiation Testbed in Oklahoma and Kansas, to determine the spatial variations of heat fluxes over the domain and to determine area-weighted flux averages for use in single-column model studies. Data from a dense array of meteorological instruments are interpolated to provide the wind, temperature, vapor pressure, radiation, and precipitation values needed by SiB2. The state of the vegetation is characterized through the use of the normalized difference vegetation index determined from satellites. The performance of the SiB2 model is evaluated by comparing its predictions ...

1998-03-01

24

Inelastic x-ray scattering of dense solid oxygen: Evidence for intermolecular bonding  

UK PubMed Central (United Kingdom)

The detailing of the intermolecular interactions in dense solid oxygen is essential for an understanding of the rich polymorphism and remarkable properties of this element at high pressure. Synchrotron...Full Text Available

2008-08-19

25

Through Weld Inspection of Wrought Stainless Steel Piping Using Phased Arrays  

Energy Technology Data Exchange (ETDEWEB)

Outline: Discuss far-side weld problem and phased array techniques applied. Describe laboratory work on flawed piping specimens using L- and S-wave arrays and provide synopsis of results. Discuss conclusions ofr capability of phased array as applied to austenitic welds. Research Approach: Evaluate phased arrays on unifornly-welded piping specimens. Apply best methods to non-uniform welds. Correlate acoustic responses as function of weld microstructures.

2004-12-31

26

Evaluation of phased array UT conditions using ultrasonic visualization technique  

International Nuclear Information System (INIS)

Phased array provides many advantages over conventional ultrasonic testing method, but phased array has also limitations. This paper describes typical results of the experimental sound field analysis generated from the array probe. A photo-elastic ultrasonic visualization technique was applied in this study. The sound fields of shear wave generated from the array probe was equivalent to that from the fixed angle probe. (author)

2008-07-01

27

Heat Transfer Augmentation in a Compact Heat Exchange Pedestal Array.  

Science.gov (United States)

A compact heat exchanger pedestal array for augmenting heat transfer in a machine is disclosed. The compact heat exchanger pedestal array includes a wall having first and second surfaces. The first surface faces a heated flow path and the second surface p...

2004-01-01

28

MILSTAR's flexible substrate solar array: Lessons learned, addendum  

Science.gov (United States)

MILSTAR's Flexible Substrate Solar Array (FSSA) is an evolutionary development of the lightweight, flexible substrate design pioneered at Lockheed during the seventies. Many of the features of the design are related to the Solar Array Flight Experiment (SAFE), flown on STS-41D in 1984. FSSA development has created a substantial technology base for future flexible substrate solar arrays such as the array for the Space Station Freedom. Lessons learned during the development of the FSSA can and should be applied to the Freedom array and other future flexible substrate designs.

1990-01-01

29

A Method for Accurate in silico modeling of Ultrasound Transducer Arrays  

UK PubMed Central (United Kingdom)

This paper presents a new approach to improve the in silico modeling of ultrasound transducer arrays. While current simulation tools accurately predict the theoretical element...Full Text Available

2009-05-01

32

Determination of Proper Peaking Time for Ultra Lege detector at Medium Energies  

International Nuclear Information System (INIS)

Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.

2008-08-25

36

Iterative Dense Correspondence Correction Through Bundle Adjustment Feedback-Based Error Detection  

Energy Technology Data Exchange (ETDEWEB)

A novel method to detect and correct inaccuracies in a set of unconstrained dense correspondences between two images is presented. Starting with a robust, general-purpose dense correspondence algorithm, an initial pose estimate and dense 3D scene reconstruction are obtained and bundle-adjusted. Reprojection errors are then computed for each correspondence pair, which is used as a metric to distinguish high and low-error correspondences. An affine neighborhood-based coarse-to-fine iterative search algorithm is then applied only on the high-error correspondences to correct their positions. Such an error detection and correction mechanism is novel for unconstrained dense correspondences, for example not obtained through epipolar geometry-based guided matching. Results indicate that correspondences in regions with issues such as occlusions, repetitive patterns and moving objects can be identified and ...

2009-11-23

37

The I3I Model; Identifying Cultural Determinants of Information ...  

Science.gov (United States)

... Information behavior in dynamic group work contexts: Interwoven situational awareness, dense social networks and contested collaboration in ...

2009-06-01

38

Enterprise Command, Control, and Design: Bridging C2 ...  

Science.gov (United States)

... Information behavior in dynamic group work contexts: interwoven situational awareness, dense social networks and contested collaboration in ...

2011-05-14

39

Dynamic Phenotypic Clustering in Noisy Ecosystems  

UK PubMed Central (United Kingdom)

In natural ecosystems, hundreds of species typically share the same environment and are connected by a dense network of interactions such as predation or competition for resources. Much is known about...Full Text Available

2011-03-01

40

54 - IGS  

Science.gov (United States)

Eight units (low-power model Z-12's) were purchased, all for installation at continuously- operating stations in the Los Angeles prototype Dense GPS ...

41

Technical evaluation of Solar Cells, Inc., CdTe module and array at NREL  

Energy Technology Data Exchange (ETDEWEB)

The Engineering and Technology Validation Team at the National Renewable Energy Laboratory (NREL) conducts in-situ technical evaluations of polycrystalline thin-film photovoltaic (PV) modules and arrays. This paper focuses on the technical evaluation of Solar Cells, Inc., (SCI) cadmium telluride (CdTe) module and array performance by attempting to correlate individual module and array performance. This is done by examining the performance and stability of the modules and array over a period of more than one year. Temperature coefficients for module and array parameters (P{sub max}, V{sub oc}, V{sub max}, I{sub sc}, I{sub max}) are also calculated.

1996-05-01

42

Acoustic band gaps in arrays of neutral inclusions  

British Library Electronic Table of Contents (United Kingdom)

We analyse numerically the acoustic stop band properties of an array of orthotropic coated cylinders whose elastic parameters are deduced from a geometric transform [H. Chen, C.T. Chan, Acoustic cloaking in three dimensions using acoustic metamaterials, Appl. Phys. Lett. 91 (2007) 183518]. We find that whereas a single coated inclusion is acoustically neutral at any frequency, an array of them might display some stop bands. More precisely, an array of freely vibrating coated voids is always neutral, whereas an array of clamped coated inclusions might display a zero frequency stop band. Interestingly, an array of radially symmetric coated inclusions behaves as local Helmholtz resonators, for which the eigenfield within each cloak is obtained in closed form, leading to a frequency estimate a...

2010-01-01

43

Dynamical evolution and molecular abundances of interstellar clouds  

International Nuclear Information System (INIS)

Dynamical models are presented that start with interstellar gas in an initial diffuse state and consider their gravitational collapse and the formation of dense cores. Frozen-in tangled magnetic fields are included to mimic forces that might oppose gravitational contraction and whose effectiveness may increase with increasing core densities. Results suggest the possibility that dense cloud cores may be dynamically evolving ephemeral objects, such that their lifespan at a given core density decreases as that density increases. 66 refs.

44

Safety analysis practices for the dense storage of RBMK spent fuel and improved technology for the long term storage of spent fuel in water pools  

International Nuclear Information System (INIS)

The paper discusses the safety problems connected with the conversion to dense storage of RBMK-1000 spent fuel in reactor cooling pools and independent storage facilities. Recourse to dense storage has been made for a number of reasons, among which are the absence of spent fuel shipments from the nuclear power plant site, prolongation of storage time and a partial change in storage conditions. Increasing the storage density per unit volume of the storage facility and turning to new technical procedures (as against the basic design) call for further investigation of safety problems. The safety assessment of the dense storage mode includes: (1) Selecting a list of initiating events for design basis and unforeseeable accidents; (2) Assessing dense storage safety under normal as well as design basis accident conditions; (3) Safety analysis and development of measures to compensate for unforeseen accidents. ...

1995-08-01

45

chipD: a web tool to design oligonucleotide probes for high-density tiling arrays  

UK PubMed Central (United Kingdom)

chipD is a web server that facilitates design of DNA oligonucleotide probes for high-density tiling arrays, which can be used in a number of genomic applications such as ChIP-chip or gene-expression...Full Text Available

2010-07-01

46

WIRE-SPEC-003 Wide-Field Infrared Explorer ... - sunland - NASA  

Science.gov (United States)

Oct 20, 1997 ... The following requirements apply to the solar array: ..... housings will be coated with material meeting the program's outgassing requirements. ... The solar array temperature testing requirements will be determined by analysis. .... The ADS also generates attitude products for the project and science team. ...

47

Volume 2- Technical Approach - IMAGE Science Center - NASA  

Science.gov (United States)

Power system analysis shows the output from the solar arrays varies as a function .... Each array corresponds to a raw image browse product, which is generated by .... low outgassing, ability to withstand long-term exposure to the space ...

48

Seismicity and Stress Changes Subsequent to Destress Blasting at the Galena Mine and Implications for Stress Control Strategies.  

Science.gov (United States)

Destress blasting is commonly used as a stress control technique at the Galena Mine, Wallace, Idaho, where the U.S. Bureau of Mines maintains a cooperative research program with the mine operators (ASARCO). A digital seismic array and an array of borehole...

1993-01-01

49

Nuclear magnetic resonance imaging of hepatic focal injuries with phased array antennae surface: apnoea or high resolution imagery?  

International Nuclear Information System (INIS)

French English ... Orig. Title Imagerie IRM des lesions focales hepatiques avec les antennes de surface en reseau phase (phased array): apnee ou imagerie haute resolution?.

1995-10-26

50

Multi-focal optical-resolution photoacoustic microscopy in vivo  

UK PubMed Central (United Kingdom)

Although ultrasound arrays were exploited in photoacoustic imaging to improve imaging speed, ultrasound-array-based optical-resolution photoacoustic microscopy (OR-PAM) has never been achieved...Full Text Available

2011-04-01

52

Fast, Scalable, Bayesian Spike Identification for Multi-Electrode Arrays  

UK PubMed Central (United Kingdom)

We present an algorithm to identify individual neural spikes observed on high-density multi-electrode arrays (MEAs). Our method can distinguish large numbers of distinct neural units, even when spikes...Full Text Available

53

Dose verification of helical tomotherapy intensity modulated radiation therapy planning using 2D-array ion chambers  

UK PubMed Central (United Kingdom)

Purpose:To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers, and to develop an efficient way to validate the dose delivered...Full Text Available

54

Binary Pseudo-Random Gratings and Arrays for Calibration of Modulation Transfer Function of Surface Profilometers  

Energy Technology Data Exchange (ETDEWEB)

In the present work, we describe application of binary pseudo-random gratings (BPRG) and arrays (BPRA) as effective 1D and 2D test surfaces suitable for calibration of different surface profilometers, including a number of interferometric microscopes and scatterometers.

2009-06-17

55

Superconducting Switchable Circulator  

Science.gov (United States)

... as time delay shifters for large-area phased arrays in military (MILSTAR) as well as commercial (Sky phone and other satellite communication) systems, ...

56

Programmed Assembly of Quantum-Dot Arrays on DNA Templates: Hardware for Quantum Computing?  

Energy Technology Data Exchange (ETDEWEB)

This paper reports progress in the fabrication and characterization of an array of 1nm-scale colloidal particles (i.e., quantum-dot array) that can be operated to execute nontrivial and innovative computations, possibly including quantum logic. We discuss the actual fabrication of 2-nm metal clusters as an example of possible quantum dot implementation. Innovative and unconventional paradigms underlie the different stages of this work. For example, regular array geometry is achieved by directing appropriately derivatized metal clusters to preselected locations along a stretched strand of an engineered DNA sequence.

2001-03-23

57

Optical Processing and Control  

Science.gov (United States)

... the application of an acousto- optical tunable filter ... Couplers for Large Switch-Array Applications ... Symmetric Integrated Optic X Junction," Electronics ...

1994-01-01

58

Magnetometer towed array. Innovative Technology Summary Report  

Energy Technology Data Exchange (ETDEWEB)

This document contains information on the above-mentioned technology, including description, applicability, cost, and performance data.

1999-09-01

59

Multi-spectral schottky barrier infrared radiation detection array  

Energy Technology Data Exchange (ETDEWEB)

A multi-spectral Schottky barrier infrared detector array in which individual pixels of radiation from a remote radiating object are detected by two or more Schottky barrier infrared radiation detectors each having a different spectral response so as to provide a ''color'' discrimination for the array.

1983-12-27

60

Multi-spectral schottky barrier infrared radiation detection array  

International Nuclear Information System (INIS)

A multi-spectral Schottky barrier infrared detector array in which individual pixels of radiation from a remote radiating object are detected by two or more Schottky barrier infrared radiation detectors each having a different spectral response so as to provide a ''color'' discrimination for the array.

61

In-beam conversion electron spectroscopy using the SACRED array  

International Nuclear Information System (INIS)

Conversion electron studies of medium-heavy to heavy nuclear mass systems are important where the internal conversion process begins to dominate over gamma-ray emission. The use of a segmented detector array sensitive to conversion electrons has been used to study multiple conversion electron cascades from nuclear transitions. The application of the silicon array for conversion electron detection (SACRED) for in-beam measurements has successfully been implemented. (orig.). With 2 figs.

62

Effect of wind turbine array establishment at the Overgaard manor on whooper swan; Effekten paa sangsvane ved etablering af en vindmoellepark ved Overgaard gods  

Energy Technology Data Exchange (ETDEWEB)

Whooper swans habitat in the coastal regions of Denmark can be affected by wind turbine arrays on the coast. The planned array consists of 55 wind turbines very close to the swan breeding area. A possibility of moving the swans away from the windmill area would be to spread the preferred swan feeds (rape, potatoes) outside their present breeding ground. (EG) 14 refs.

1998-06-01

63

PV Conversion Technologies, Session: OPV, Sensitized, Seed (Presentation)  

Energy Technology Data Exchange (ETDEWEB)

The NREL Sensitized Solar Cell (SSC) Core Program supports the Solar America Initiative by: (1) targeting new devices and processes for commercialization by 2015 that are less expensive, more efficient, highly reliable, and environmentally benign; (2) collaborating with DOE OS/BES to conduct basic research targeting breakthroughs in key areas, such as ultra-high efficiency and/or ultra-low cost materials and devices.

2008-04-01

64

Intramolecular Form Factor in Dense Polymer Systems: Systematic Deviations from the Debye formula  

CERN Document Server

We discuss theoretically and numerically the intramolecular form factor $F(q)$ in dense polymer systems. Following Flory's ideality hypothesis, chains in the melt adopt Gaussian configurations and their form factor is supposed to be given by Debye's formula. At striking variance to this, we obtain noticeable (up to 20%) non-monotonic deviations which can be traced back to the incompressibility of dense polymer solutions beyond a local scale. The Kratky plot ($q^2F(q)$ {\\it vs.} wavevector $q$) does not exhibit the plateau expected for Gaussian chains in the intermediate $q$-range. One rather finds a significant decrease according to the correction $\\delta(F^{-1}(q)) = q^3/32\\rho$ that only depends on the concentration $\\rho$ of the solution, but neither on the persistence length or the interaction strength.

2007-01-01

65

Dense and diffuse gas in dynamically active clouds  

CERN Document Server

We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical evolution. We then allow the same gas immediately to undergo further such formation and dispersion cycles. The chemistry of the dense gas in subsequent cycles is similar to that of the first, and a limit cycle is reached quickly (2 - 3 cycles). Enhancement of hydrocarbon abundances during a specific period of evolution is the strongest indicator of previous dynamical history. The molecular content of the diffuse background gas in the molecular cloud is expected to be strongly enhanced by the core formation and dispersion process. Such enhancement may remain for as long as 0.5 Myr. The frequency of repetitive core formation should strongly determine the level of background molecular enhancement. We also convolve the ...

2006-01-01

66

Applications of the phased array technique; Anwendungsmoeglichkeiten der Gruppenstrahlertechnik  

Energy Technology Data Exchange (ETDEWEB)

The application of the phased array technique was limited to heavy and thick wall components as present in the nuclear industry. With the improvement of the equipment and probes other application areas are now open for the phased array technique, e.g. the inspection of the turbine blade root, weld inspection in a wall thickness range between 12 and 40 mm, inspection of aircraft components, inspection of spot welds or inspection of concretes. The aim of the use of phased array techniques has not been changed related to the first applications, i.e. the adaptation of the sound beam to the geometry by steering the angel of incidence or the skewing angle as well as the focussing of sound fields. Due to the fact, that the new applications of the phased array techniques in some cases don't leave the laboratories for the time being, the examples of this contribution will focus applications with ...

1999-07-01

67

MR evaluation of rectal carcinoma: pelvic phased-array coil versus endorectal-pelvic phased-array coil  

Energy Technology Data Exchange (ETDEWEB)

To compare the accuracy of MR imaging using an endorectal-pelvic and a pelvic phased-array coil for preoperative local staging of rectal carcinoma. To determine preoperative staging, 38 patients with rectal carcinoma underwent MR imaging. All patients were examined with both an endorectal-pelvic and a pelvic phased-array coil. All underwent surgery and staging was pathologically confirmed. Two radiologists blinded to pathologic stage analyzed perirectal invasion and perirectal node metastasis, and scored according to a four-point scale. Radiologic and pathologic findings were correlated. Receiver operating characteristic (ROC) analysis of Wilcoxon statistic (W values) was used to compare diagnostic accuracy between the two different MR methods. Interobserver variation was measured using {kappa} statistics. For perirectal invasion, T1WI endorectal-pelvic phased-array coil images (reader 1:0. 854, reader 2:0.818) showed ...

1998-10-01

68

Synchronous orbit performance of Hughes Aircraft Company solar arrays - update  

Energy Technology Data Exchange (ETDEWEB)

The synchronous orbit performance of Hughes Aircraft Company solar arrays is presented and compared with the results of ground based predictions for orbital durations of almost 11 years. Performances of the Intelsat IV*, IVA*, and Telesat (Anik) solar arrays are detailed. This paper is an update of the in-orbit performances previously reported in 1976 (1). The in-space performance data indicate solar array power degradation of 16.7 percent for Intelsat IV F-2 after 130 months in orbit, and 13.0 percent for Telesat F-1 after 85 months in orbit. The predicted output of each of these solar arrays is within 2 percent of the actual in-orbit performance of these systems. The Intelsat IV F-2 experienced the 4 August 1972 solar flare. The ability to accurately predict the performance of solar arrays within telemetry accuracy is demonstrated. This ability combines the electrical measurements ...

1982-08-01

69

Array coil probe: Final report  

Energy Technology Data Exchange (ETDEWEB)

Nuclear steam generator tubes have become flawed in ways that challenge conventional eddy current probes. In response to the shortcomings of conventional probes, array probes have been developed to improve measurement capabilities. However, the commercially available array probes have exhibited several weaknesses that offset the advantages and limit the applications in steam generator inspections. A primary weakness is the relatively high rate of probe failure coupled with the high unit cost for each probe. This can be costly for a utility in the time lost for probe replacement and increased radiation exposure in addition to the probe costs. Other weaknesses which make array probes undesirable for routine use are: poor mechanical and electrical characteristics; difficulty in operation and calibration; and incomplete coverage of the tube circumference. Several prototype array probes have been built to ...

1987-03-01

70

Transformation of human osteoblast cells to the tumorigenic phenotype by depleted uranium-uranyl chloride.  

UK PubMed Central (United Kingdom)

Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term...Full Text Available

1998-08-01

71

Problem-centric Organization and Visualization of Patient Imaging and Clinical Data  

UK PubMed Central (United Kingdom)

A patient’s electronic medical record contains a large amount of unstructured textual information. As patient records become increasingly dense owing to an aging population and increased occurrence...Full Text Available

2009-03-01

72

Novel Multilocus Measure of Linkage Disequilibrium to Estimate Past Effective Population Size  

UK PubMed Central (United Kingdom)

Linkage disequilibrium (LD) between densely spaced, polymorphic genetic markers in humans and other species contains information about historical population size. Inferring past population size is of...Full Text Available

2003-04-01

73

Interhemispheric Interactions between the Human Primary Somatosensory Cortices  

UK PubMed Central (United Kingdom)

In the somatosensory domain it is still unclear at which processing stage information reaches the opposite hemispheres. Due to dense transcallosal connections, the secondary somatosensory cortex (S2)...Full Text Available

74

Genome-wide detection and characterization of positive selection in human populations  

UK PubMed Central (United Kingdom)

With the advent of dense maps of human genetic variation, it is now possible to detect positive natural selection across the human genome. Here we report an analysis of over 3 million polymorphisms...Full Text Available

2007-10-18

75

GNF - Wilson Inlet  

Wastenet

... The costal plain still supports Jarrah (Eucalyptus marginata ) forest, dense woodlands, coastal heath and diverse swamplands. Many species of plants are endemic. 20 species of mammals and 12 species of introduced mammals including with feral pigs, rabbits and foxes of particular concern....

76

Finding Dense Clusters via "Low Rank + Sparse" Decomposition  

CERN Document Server

Finding "densely connected clusters" in a graph is in general an important and well studied problem in the literature \\cite{Schaeffer}. It has various applications in pattern recognition, social networking and data mining \\cite{Duda,Mishra}. Recently, Ames and Vavasis have suggested a novel method for finding cliques in a graph by using convex optimization over the adjacency matrix of the graph \\cite{Ames, Ames2}. Also, there has been recent advances in decomposing a given matrix into its "low rank" and "sparse" components \\cite{Candes, Chandra}. In this paper, inspired by these results, we view "densely connected clusters" as imperfect cliques, where imperfections correspond missing edges, which are relatively sparse. We analyze the problem in a probabilistic setting and aim to detect disjointly planted clusters. Our main result basically suggests that, one can find \\emph{dense} clusters in a graph, as long as the ...

2011-01-01

77

Evolutionary conservation of a microbody targeting signal that targets proteins to peroxisomes, glyoxysomes, and glycosomes  

UK PubMed Central (United Kingdom)

Peroxisomes, glyoxysomes, glycosomes, and hydrogenosomes have each been classified as microbodies, i.e., subcellular organelles with an electron-dense matrix that is bound by a single membrane. We investigated...Full Text Available

1991-09-01

78

Effects of ambient temperature and scrotal fleece cover on scrotal and testicular temperatures in rams.  

UK PubMed Central (United Kingdom)

The objective was to determine scrotal and testicular temperatures in rams and how they are affected by ambient temperature (10 degrees C vs 25 degrees C) and scrotal fleece (densely fleeced vs shaved)....Full Text Available

1999-04-01

79

Cytochemical localisation and characterisation of proteoglycans (glycosaminoglycans) in the epithelial-stromal interface of the seminal vesicle of the guinea pig.  

UK PubMed Central (United Kingdom)

The proteoglycans (PGs) in the guinea pig seminal vesicle were demonstrated ultrastructurally by both cuprolinic blue (CB) and ruthenium red (RR) staining. The PGs appeared as electron-dense granules...Full Text Available

1992-02-01

80

CENTRAL CORNEAL OPACIFICATION RESULTING FROM RECENT CHEMOTHERAPY IN CORNEAL DONORS  

UK PubMed Central (United Kingdom)

PurposeOcular surface disease following penetrating keratoplasty has been shown to increase patient morbidity and adversely affect graft survival. Five cases of dense central subepithelial...Full Text Available

2007-12-01

81

A Marker-Dense Physical Map of the Bradyrhizobium japonicum Genome  

UK PubMed Central (United Kingdom)

Bacterial artificial chromosome (BAC) clones are effective mapping and sequencing reagents for use with a wide variety of small and large genomes. This report describes the development of a physical...Full Text Available

2001-08-01

82

Quantum Secure Direct Communication with Four-Particle Genuine Entangled State and Dense Coding  

Science.gov (United States)

A quantum secure direct communication scheme using dense coding is proposed. At first, the sender (Alice) prepares four-particle genuine entangled states and shares them with the receiver (Bob) by sending two particles in each entangled state to him. Secondly, Alice encodes secret information by performing the unitary transformations on her particles and transmits them to Bob. Finally, Bob performs the joint measurements on his particles to decode the secret information. The two-step security test guarantees the security of communication.

2009-07-01

83

Non-catalytic and catalytic wet air oxidation of pharmaceuticals in ultra-pure and natural waters  

British Library Electronic Table of Contents (United Kingdom)

A wet air oxidation (WAO) process was applied to four selected pharmaceuticals (metoprolol, naproxen, amoxicillin, and phenacetin) individually dissolved in ultra-pure water, varying the temperature and oxygen pressure. Due to the moderate (amoxicillin) or low (metoprolol, naproxen, and phenacetin) efficiency found in the oxidation of these pollutants, a catalytic wet air oxidation (CWAO) process was then tested using a platinum catalyst supported on multi-walled carbon nanotubes (CNT). In this CWAO process, the pharmaceuticals were dissolved together in ultra-pure water and in four natural water matrices-a reservoir water, a groundwater, and two waters from different municipal wastewater treatment plants. On the basis of the measurements of their removals, a discussion is given of the inf...

2011-01-01

84

Machinability of magnesium alloy in ultra-precision diamond cutting  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with an experimental study of ultra-precision diamond cutting of magnesium alloy (AZ31). In order to investigate the machinability such as the cutting force and the surface integrity and understand the problems in a micro cutting, the experiments on the diamond cutting of magnesium alloy and pure aluminum with an ultra-precision turning machine has been carried out. The machinability of magnesium alloy was compared with that of pure aluminum and discussed. Consequently, both the thrust force component and the surface roughness obtained by cutting of magnesium alloy became larger than that of pure aluminum. It was also found that the inclusions or the defects in the work material caused to generate the scratches on the finished surface and influenced the integrity of mirror surface. (orig.)

2003-07-01

85

Identification of oxidation states of ultra-trace elements by radiation detection  

International Nuclear Information System (INIS)

The determination of the oxidation state of ultra-trace elements in the environment, especially in the case of actinides, is of importance in many ways. Speciation techniques using radiation may comprise methods based on the detection of the nuclear and atomic radiations emitted in radioactive decay or methods using external sources of excitation. In the former instance, information can be obtained from the energy and intensity of radiation, but at present the partition method is still the most commonly used, although its reliability is questionable. Excitation with intense laser beams, as is currently being used for trace element analysis in photoacoustic and thermal lensing spectroscopic techniques, could conceivably be applied under suitable conditions to ultra-trace elements with a sensitivity approaching that of the radiochemical methods.

1989-11-01

86

Free-electron laser driven by the LBNL laser-plasma accelerator  

Energy Technology Data Exchange (ETDEWEB)

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

2008-08-04

87

Corrosion resistance of Ultra-Low-Carbon 19% Cr-11% Ni stainless steel for nuclear fuel reprocessing plants in nitric acid  

International Nuclear Information System (INIS)

An Ultra-Low-Carbon 19% Cr-11% Ni Stainless Steels used in nuclear fuel reprocessing plants where highly corrosion resistance in nitric acid is required has been developed. This steel has optimized the chemistry composition to decrease inclusions and deformation-induced martensitic transformation. The formation of deformation-induced martensite has the potential danger of accelerating corrosion in nitric acid. In this paper, effects of cold reduction and martensitic transformation on corrosion resistance of Ultra-Low-Carbon Stainless Steels in nitric acid are discussed. The developed steel showed excellent corrosion resistance during long-term exposure to nitric acid. (author).

88

A numerical study of ultra-short-pulse reflectometry  

Energy Technology Data Exchange (ETDEWEB)

Ultra-short-pulse reflectometry is studied by means of the numerical integration of a one-dimensional full-wave equation for ordinary modes propagating in a plasma. The numerical calculations illustrate the potential of using the reflection of ultra-short-pulse, microwaves as an effective probe of the density profile even in the presence of significant density fluctuations. The difference in time delays of differing frequency components of the microwaves can be used to deduce the density profile. The modification of the reflected pulses in the presence of density fluctuations is examined and can be understood based on considerations of Bragg resonance. A simple and effective profile-reconstruction algorithm using the zero-crossings of the reflected pulse and subsequent Abel inversion is demonstrated. The robustness of the profile reconstruction algorithm in the presence of a sufficiently small amplitude density perturbation is assessed.

1994-05-01

89

Low concentration ratio solar array for low Earth orbit multi-100 kW application. Volume 1: Design, analysis and development tests. Final Report  

Energy Technology Data Exchange (ETDEWEB)

A preliminary design effort directed toward a low concentration ratio photovoltaic array system capable of delivering multihundred kilowatts (300 kW to 1000 kW range) in low earth orbit is described. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of .25 sq. m. The structural analysis and design trades leading to the baseline design are discussed. It describes the configuration, as well as optical, thermal and electrical performance ...

1983-07-01

90

Viscoelastic locally resonant double negative metamaterials with controllable effective density and elasticity  

British Library Electronic Table of Contents (United Kingdom)

A metamaterial that is composed of solid viscoelastic elements with controllable properties is proposed in this Letter. This enables an adaptable and general acoustic metamaterial to be practically realised. An array of masses with a single elastic connection to a supporting viscoelastic structure, such as one that is dynamically equivalent to an array of Helmholtz resonators, only provides a system with negative effective mass. A local active control scheme applied to each of these masses can emulate additional elastic connections to the supporting structure. An array of masses with a suitable local control scheme can provide both the negative effective stiffness and mass required for negative refraction. The tuneable feedback control parameters determine the characteristics of the region...

2010-01-01

91

Variational relevance vector machine for classification and regression problems with multidimensional feature arrays  

British Library Electronic Table of Contents (United Kingdom)

Problems of classification and regression estimation in which objects are represented by multidimensional arrays of features are considered. Many practical statements can be reduced to such problems, for example, the popular approach to the description of images as a set of patches and a set of descriptors in each patch or the description of an object in the form of a set of distances from it to certain support objects selected based on a set of features. For solving problems concerning the objects thus described, a generalization of the relevance vector model is proposed. In this generalization, specific regularization coefficients are defined for each dimension of the multidimensional array of the object description; the resultant regularization coefficient for a given element in the mul...

2011-01-01

92

Semantic network array processor and its applications to image understanding  

Energy Technology Data Exchange (ETDEWEB)

The problems in computer vision range from edge detection and segmentation at the lowest level to the problem of cognition at the highest level. This correspondence describes the organization and operation of a semantic network array processor (SNAP) as applicable to high level computer vision problems. The architecture consists of an array of identical cells each containing a content addressable memory, microprogram control, and a communication unit. The applications discussed in this paper are the two general techniques, discrete relaxation and dynamic programming. While the discrete relaxation is discussed with reference to scene labeling and edge interpretation, the dynamic programming is tuned for stereo.

1987-01-01

93

Ultra high field magnetic resonance imaging  

International Nuclear Information System (INIS)

Understanding human brain function, brain development and brain dysfunction is one of the great challenges of the twenty first century. Biomedical imaging has now run up against a number of technical constraints that are exposing limits to its potential. In order to overcome the current limits to high-field magnetic resonance cerebral imaging (MRI) and unleash its fullest potential, the Cea has built NeuroSpin, an ultra-high-field neuroimaging facility at its Saclay centre (in the Essonne). NeuroSpin already boasts three fully operational MRI systems. The first is a 3-tesla high-field system and the second is a very-high-field 7-tesla system, both of which are dedicated to clinical studies and investigations in humans, while the third is an ultra-high-field 17.65-tesla system designed for studies on small animals. In 2011, NeuroSpin will be commissioning an 11.7-tesla ultra-high-field system of unprecedented power that is ...

94

System Design and Applications of the Ultra Small ... - GLTRS - NASA  

Science.gov (United States)

The advanced technologies of Ka-Band systems such as high gain spot .... sometimes used based on link requirements for a specific application. .... received at NASA LeRC from a Ku-band satellite and retransmitted to the USAT at Ka-Band. .... and to the Office of Management and Budget, Paperwork Reduction Project ...

95

Railgun. Challenge to ultra-high speed; Railgun. Chokosoku eno chosen  

Energy Technology Data Exchange (ETDEWEB)

A railgun has an armature driven between two rail-like conductors. In other words, it is a linear drive device system that drives airframes by using the Lorentz`s force. The system is expected as a next-generation high-speed transport means, or as a means to create such ultimate fields as ultra-high pressures, ultra-high temperatures, and ultra-ferromagnetic fields. This paper is a report on investigations on the relevant technological trends as surveyed by the investigation committee at the Institute of Electrical Engineers of Japan using research reports published inside and outside the country. The reported themes cover explanations from the construction to the pulse power supply that forms the core of the technology, problems in switching, recent status of research and development, and to application fields. Compatibility in the high-level electrical and mechanical performances demanded in the railgun is not as easy as ...

1995-09-12

96

Mesozoic Era of relativistic heavy ion physics and beyond.  

Science.gov (United States)

In order to understand how matter 15 billion years ago in the form of quarks, gluons and leptons at a temperature of 2 (times) 10(sup 12) (degrees)K evolved to become today's Universe, the goal of relativistic and ultra-relativistic heavy ion physics is t...

1994-01-01

97

Breaking the 1000-gene barrier for Mimivirus using ultra-deep genome and transcriptome sequencing  

UK PubMed Central (United Kingdom)

BackgroundMimivirus, a giant dsDNA virus infecting Acanthamoeba, is the prototype of the mimiviridae family, the latest addition to the family of the nucleocytoplasmic...Full Text Available

98

Telomeres in cancer and ageing  

UK PubMed Central (United Kingdom)

Telomeres protect the chromosome ends from unscheduled DNA repair and degradation. Telomeres are heterochromatic domains composed of repetitive DNA (TTAGGG repeats) bound to an array of specialized...Full Text Available

2011-01-12

100

Some effects of packaging materials on critical arrays of fissile materials  

International Nuclear Information System (INIS)

(1977). United States Thomas, JT Tang, JS Oak Ridge National Lab., TN San

1977-11-27

101

Probe-Flaw Interactions with Eddy Current Array Probes  

Science.gov (United States)

... The development of various modeling methods for conventional eddy current probes (absolute, differential, two-port, etc.) has led to a general ...

102

Main MenuPg  

Science.gov (United States)

Previous experimental data and theoretical analysis have demonstrated that ... products of a technological process) but also other contaminants. ..... Thorough outgassing of solar array surfaces may result in significant decrease of arc ...

103

Effector Glycosyltransferases in Legionella  

UK PubMed Central (United Kingdom)

Legionella causes severe pneumonia in humans. The pathogen produces an array of effectors, which interfere with host cell functions. Among them are the glucosyltransferases Lgt1, Lgt2...Full Text Available

104

Directory of NSF-Supported UFE Projects  

Science.gov (United States)

... .13 Teaching the Materials Science, Engineering, and Field Aspects of Concrete ... Gate Arrays. . . . . . . . . . . . . . .15 Materials Science Concepts for Introductory Courses in ...

105

DOE Solar Decathlon: News Blog  

Science.gov (United States)

shading trellis. This array powers all of the electric appliances, including an oven, cooktop, dishwasher, clothes washer and dryer, home entertainment systems (television and...

2011-09-04

106

Contamination Effects of Satellite Material Outgassing ...  

Science.gov (United States)

... A detailed analysis of QCM errors is ... Surface Effects of Satellite Outgassing Products." AIAA Journal ... 9. Rauschenbach, H. S. Solar Cell Array Design ...

1990-12-01

107

Bacterial chemoreceptors: high-performance signaling in networked arrays  

UK PubMed Central (United Kingdom)

Chemoreceptors are crucial components in the bacterial sensory systems that mediate chemotaxis. Chemotactic responses exhibit exquisite sensitivity, extensive dynamic range and precise adaptation....Full Text Available

2008-01-01

108

A Study on TOFD Inspection Using Phased Array Ultrasonic Technique  

Energy Technology Data Exchange (ETDEWEB)

The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in thick component such as the pressure ...

2005-08-15

109

Spectroscopy of Neutron-Rich Nuclei with the CLARA-PRISMA Setup  

International Nuclear Information System (INIS)

The CLARA-PRISMA setup, composed of an array of 25 Clover detectors placed at the target position of the magnetic spectrometer PRISMA, has recently concluded its campaign to study the structure of moderately neutron-rich nuclei. In this contribution, results obtained in the vicinity of the doubly-magic nucleus "4"8Ca are presented, together with results obtained for the heavy iron isotopes. The perspectives offered by the forthcoming operation of the AGATA Demonstrator Array coupled to PRISMA are also discussed. (author)

2009-03-01

110

Single chip linear array picture processor  

Energy Technology Data Exchange (ETDEWEB)

A CMOS programmable picture processor with its own photodiode array is presented. The circuit is novel in that it includes an instruction set that permits most low-level picture processing operations. The chip is a parallel machine with a processing unit for each picture element. Images are binarized and are processed line by line. An experimental chip has been designed and is under fabrication. 2 references.

1983-01-01

111

Numerical methods for matrix computations using arrays of processors. Final report, 15 August 1983-15 October 1986  

Energy Technology Data Exchange (ETDEWEB)

The basic objective of this project was to consider a large class of matrix computations with particular emphasis on algorithms that can be implemented on arrays of processors. In particular, methods useful for sparse matrix computations were investigated. These computations arise in a variety of applications such as the solution of partial differential equations by multigrid methods and in the fitting of geodetic data. Some of the methods developed have already found their use on some of the newly developed architectures.

1987-04-30

112

Heat transfer augmentation by interrupted surfaces - Experimental considerations  

International Nuclear Information System (INIS)

An experimental study was undertaken to determine for the turbulent regime the heat transfer and fluid flow characteristics of a heat exchange array of unperforated, and perforated brass plates with 33% of the plate area open. In both cases, the plates were aligned parallel to the flow direction. For the flow conditions examined, the results showed enhancement of heat transfer and friction factor for the perforated array.

1987-08-01

113

A modeling and experimental study of flue gas desulfurization in a dense phase tower.  

Science.gov (United States)

We used a dense phase tower as the reactor in a novel semi-dry flue gas desulfurization process to achieve a high desulfurization efficiency of over 95% when the Ca/S molar ratio reaches 1.3. Pilot-scale experiments were conducted for choosing the parameters of the full-scale reactor. Results show that with an increase in the flue gas flow rate the rate of the pressure drop in the dense phase tower also increases, however, the rate of the temperature drop decreases in the non-load hot gas. We chose a water flow rate of 0.6 kg/min to minimize the approach to adiabatic saturation temperature difference and maximize the desulfurization efficiency. To study the flue gas characteristics under different processing parameters, we simulated the desulfurization process in the reactor. The simulated data matched very well with the experimental data. We also found that with an increase in the Ca/S molar ratio, the differences between the simulation and ...

2011-03-05

114

TLD array for precise dose measurements in stereotactic radiation techniques  

International Nuclear Information System (INIS)

We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full ...

1996-12-01

115

Low concentration ratio solar array for low Earth orbit multi-100kW application. Volume 2: Drawings. Final Report  

Energy Technology Data Exchange (ETDEWEB)

A preliminary design effort directed toward a low concentration ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 100 kW range) in low Earth orbit is described. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. Drawings for the preliminary design configuration and for the test hardware that was fabricated for design evaluation and test are ...

1982-07-01

116

Adaptive and mobile ground sensor array.  

Energy Technology Data Exchange (ETDEWEB)

The goal of this LDRD was to demonstrate the use of robotic vehicles for deploying and autonomously reconfiguring seismic and acoustic sensor arrays with high (centimeter) accuracy to obtain enhancement of our capability to locate and characterize remote targets. The capability to accurately place sensors and then retrieve and reconfigure them allows sensors to be placed in phased arrays in an initial monitoring configuration and then to be reconfigured in an array tuned to the specific frequencies and directions of the selected target. This report reviews the findings and accomplishments achieved during this three-year project. This project successfully demonstrated autonomous deployment and retrieval of a payload package with an accuracy of a few centimeters using differential global positioning system (GPS) signals. It developed an autonomous, multisensor, temporally aligned, radio-frequency communication and signal ...

2003-12-01

117

Workshop on dense granular flows  

Environmental Research Database

ObjectivesThe objective of this meeting will be to interface the two ends of the particulate flow spectrum - those working to understand the fundamentals of granular flows and those attempting to control particulate flows in an industrial setting - to develop solutions to the complex problems presented by dense granular flows. We will aim~%~~%~to provide a forum for the interface between practical users of particulate technology and the developers of theories for understanding granular flow;~%~to present [continued...]DescriptionIn practical situations such as those met in industry where segregation and mixing are important, understanding particulate flows is complex due to the presence of polydispersity, anisotropy and complex grain morphology. In attempting to model such systems, many of these features are generally ignored, except perhaps through empirical parameter fitting. Developing a theory to include these effects is a considerable ...

2009-01-08

118

The Formation of the Low-sized High Density Plasma Structures in the Self-maintained Plasma-beam Discharge  

International Nuclear Information System (INIS)

The opportunity of use self-maintained plasma-beam discharge in an extended pulsing plasma diode of low pressure for making powerful sources of the soft X-rays is investigated. Conditions of formation of the self-maintained plasma-beam discharge are determined. The mode of making of dense high-temperature plasma on the basis of stannum ions in the discharge is shown. The stannum ions are used as a working element of a radiation sources at pulsing power of electron beam P?10...100 MW. Results of the examination on formation of the dense (np?1016 cm3), small sizes (le?100 eV in conditions of working material evaporation from the anode are given. The total contribution of energy to the discharge has made W < 20 J.

2006-01-01

119

Nanoporous YSZ film in electrolyte membrane of Micro-Solid Oxide Fuel Cell  

International Nuclear Information System (INIS)

Yttria stabilized zirconia (YSZ) with 8 mol% Y was deposited by reactive magnetron sputtering onto oxidized (100) silicon substrates. It was possible to switch film texture from (111) to (200) by applying a strong RF substrate bias. Transmission electron microscopy showed that the film deposited under bias is porous and exhibits nanoscaled grains, whereas the film deposited without bias is dense and columnar. The ionic conductivity as a function of temperature revealed an activation energy of 1.04 eV. The mechanical stress could be tuned to low values by thermal post-annealing. Using the dense (111) film as electrolyte layer, and the porous (200) film as an interlayer to a porous Pt anode, an open circuit voltage of 0.85 V was obtained in a micro machined fuel cell structure.

2010-06-01

120

Long Range Correlation in Granular Shear Flow II: Theoretical Implications  

CERN Document Server

Numerical simulations are used to test the kinetic theory constitutive relations of inertial granular shear flow. These predictions are shown to be accurate in the dilute regime, where only binary collisions are relevant, but underestimate the measured value in the dense regime, where force networks of size $\\xi$ are present. The discrepancy in the dense regime is due to non-collisional forces that we measure directly in our simulations and arise from elastic deformations of the force networks. We model the non-collisional stress by summing over all paths that elastic waves travel through force networks. This results in an analytical theory that successfully predicts the stress tensor over the entire inertial regime without any adjustable parameters.

2006-01-01

121

Grain mantles: The impact on grain evolution and selective extinction  

International Nuclear Information System (INIS)

Depletion studies are used to infer the presence of mantles and to constrain grain evolutionary models in the diffuse interstellar medium. The presence of these mantles appears to be important in the evolution of the grains inside diffuse as well as dense clouds. In dense clouds where the element-to-element abundances sometimes differ from those found in diffuse clouds, empirical relationships are starting to emerge between gas abundances and various types of peculiar selective extinction. These peculiar extinction curves may be the results of nonvolatile mantle formation on grain cores or may reflect chemical differences due to variations in the intrinsic metalicity from one cloud to another. A simple model of the time evolution of a parcel of gas and dust as observed by the depletion of two elements is presented. Different studies of grain evolution and selective extinction are discussed and compared.

1989-12-01

122

Half-period optical pulse generation using a free-electron laser  

Energy Technology Data Exchange (ETDEWEB)

Recently there has been growth, in interest in non-equilibrium interaction of half-period long optical pulses with matter. To date the optical pulses have been produced by chopping out a half-period long segment from a longer pulse using a semiconductor switch driven by a femtosecond laser. In this paper we present new methods for producing tunable ultra-short optical pulses as short as half an optical period using a free-electron laser driven by electron bunches with a duration a fraction of an optical period. Two different methods relying on the production of coherent spontaneous emission will be described. In the first method we show that when a train of ultra-short optical pulses as short as one half period. We present calculations which show that the small signal gain is unimportant in the early stages of radiation build up in the cavity when the startup process is dominated by coherent spontaneous emission. To support our proposed method ...

1995-12-31

123

Ultra-thin {sup 242m}Am fuel elements in nuclear reactors  

Energy Technology Data Exchange (ETDEWEB)

There is a growing interest in using {sup 242m}Am as a nuclear fuel. The advantages of {sup 242m}Am as a nuclear fuel derive from the fact that {sup 242m}Am has the highest thermal fission cross section. The thermal capture cross section is relatively low and the number of neutrons per thermal fission is high. These nuclear properties make it possible to obtain nuclear criticality with ultra-thin fuel elements. The possibility of having ultra-thin fuel elements enables the use of these fission products directly, without the necessity of converting their energy to heat, as is done in conventional reactors. There are three options of using such highly energetic and highly ionized fission products. - Using the fission products themselves for ionic propulsion. - Using the fission products in an MHD generator, in order to obtain electricity directly. - Using the fission products to heat a gas up to a high temperature for propulsion purposes. In this ...

2000-12-01

124

Ultra-high pressure water jet: Baseline report  

International Nuclear Information System (INIS)

The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of ...

1997-07-01

125

Phantom and animal imaging studies using PLS synchrotron X-rays  

CERN Document Server

Ultra-high resolution radiographs can be obtained using synchrotron X-rays. A collaboration team consisting of K-JIST, POSTECH and YUMC has recently commissioned a new beamline (5C1) at Pohang Light Source (PLS) in Korea for medical applications using phase contrast radiology. Relatively simple image acquisition systems were set up on 5C1 beamline, and imaging studies were performed for resolution test patterns, mammographic phantom, and animals. Resolution test patterns and mammographic phantom images showed much better image resolution and quality with the 5C1 imaging system than the mammography system. Both fish and mouse images with 5C1 imaging system also showed much better image resolution with great details of organs and anatomy compared to those obtained with a conventional mammography system. A simple and inexpensive ultra-high resolution imaging system on 5C1 beamline was successfully implemented. The authors were able to acquire ...

2001-01-01

126

Investigation on boron transient enhanced diffusion induced by the advanced P{sup +}/N ultra-shallow junction fabrication processes  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P{sup +}/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B{sup +} and BF{sub 2}{sup +} ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF{sub 3} as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit ...

2005-08-01

127

Investigation on boron transient enhanced diffusion induced by the advanced P"+/N ultra-shallow junction fabrication processes  

International Nuclear Information System (INIS)

In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P"+/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B"+ and BF_2"+ ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF_3 as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit coming from PLAD ...

2005-08-01

128

H_2 emission arises outside photodissociation regions in ultra-luminous infrared galaxies  

CERN Document Server

Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen observed at mid-infrared wavelengths are not affected by dust obscuration, leaving unresolved the source of excitation of this emission. Here I report an analysis of archival Spitzer Space Telescope data on ultra-luminous infrared galaxies and demonstrate that star formation regions are buried inside optically thick clouds of gas and dust, so that dust obscuration affects star-formation indicators but not molecular hydrogen. I thereby establish that the emission of H_2 is not co-spatial with the buried starburst activity and originates outside the obscured regions. This is rather surprising in light of the standard view that H_2 emission is directly associated with star-formation activity. Instead, I propose ...

2010-01-01

129

Effects of DC gate and drain bias stresses on the degradation of excimer laser crystallized polysilicon thin film transistors  

Energy Technology Data Exchange (ETDEWEB)

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V{sub GS} = V{sub DS}/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted ...

2005-01-01

130

Effects of DC gate and drain bias stresses on the degradation of excimer laser crystallized polysilicon thin film transistors  

International Nuclear Information System (INIS)

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V_G_S = V_D_S/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted in ...

2005-01-01

131

Development of a fine and ultra-fine group cell calculation code SLAROM-UF for fast reactor analyses  

International Nuclear Information System (INIS)

A cell calculation code SLAROM-UF has been developed for fast reactor analyses to produce effective cross sections with high accuracy in practical computing time, taking full advantage of fine and ultra-fine group calculation schemes. The fine group calculation covers the whole energy range in a maximum of 900-group structure. The structure is finer above 52.5 keV with a minimum lethargy width of 0.008. The ultra-fine group calculation solves the slowing down equation below 52.5 keV to treat resonance structures directly and precisely including resonance interference effects. Effective cross sections obtained in the two calculations are combined to produce effective cross sections over the entire energy range. Calculation accuracy and improvements from conventional 70-group cell calculation results were investigated through comparisons with reference values obtained with continuous energy Monte Carlo calculations. It was confirmed that ...

2006-08-01

132

The Fermilab Advanced Computer Program multi-array processor system (ACPMAPS): A site oriented supercomputer for theoretical physics  

Energy Technology Data Exchange (ETDEWEB)

The ACP Multi-Array Processor System (ACPMAPS) is a highly cost effective, local memory parallel computer designed for floating point intensive grid based problems. The processing nodes of the system are single board array processors based on the FORTRAN and C programmable Weitek XL chip set. The nodes are connected by a network of very high bandwidth 16 port crossbar switches. The architecture is designed to achieve the highest possible cost effectiveness while maintaining a high level of programmability. The primary application of the machine at Fermilab will be lattice gauge theory. The hardware is supported by a transparent site oriented software system called CANOPY which shields theorist users from the underlying node structure. 4 refs., 2 figs.

1988-08-01

133

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

Energy Technology Data Exchange (ETDEWEB)

Highly ordered arrays of Ni nanoholes and Fe{sub 20}Ni{sub 80} antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.

2008-07-15

134

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

International Nuclear Information System (INIS)

Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.

2008-07-01

135

Long range ordering in self-assembled Ni arrays on patterned Si  

Energy Technology Data Exchange (ETDEWEB)

We have succeeded in aligning self-assembled structures by using a lithographically defined stripe. The 140 nm wide by 100 nm high SiO{sub 2} strip is shown to guide the assembly of 500 nm latex spheres so that spheres are aligned along the strip and are in registration on either side of the strip. This method can be used to increase long-range ordering in magnetic storage systems without compromising the density. Inverse sphere Ni arrays were made by electrodeposition through the latex template. We also show that the hexagonal symmetry of the resulting inverse sphere Ni arrays can be simulated using the approach presented below.

2007-09-15

136

Long range ordering in self-assembled Ni arrays on patterned Si  

International Nuclear Information System (INIS)

We have succeeded in aligning self-assembled structures by using a lithographically defined stripe. The 140 nm wide by 100 nm high SiO_2 strip is shown to guide the assembly of 500 nm latex spheres so that spheres are aligned along the strip and are in registration on either side of the strip. This method can be used to increase long-range ordering in magnetic storage systems without compromising the density. Inverse sphere Ni arrays were made by electrodeposition through the latex template. We also show that the hexagonal symmetry of the resulting inverse sphere Ni arrays can be simulated using the approach presented below.

2007-09-01

137

Long range ordering in self-assembled Ni arrays on patterned Si  

British Library Electronic Table of Contents (United Kingdom)

We have succeeded in aligning self-assembled structures by using a lithographically defined stripe. The 140nm wide by 100nm high SiO2 strip is shown to guide the assembly of 500nm latex spheres so that spheres are aligned along the strip and are in registration on either side of the strip. This method can be used to increase long-range ordering in magnetic storage systems without compromising the density. Inverse sphere Ni arrays were made by electrodeposition through the latex template. We also show that the hexagonal symmetry of the resulting inverse sphere Ni arrays can be simulated using the approach presented below.

2007-01-01

138

Dynamically focussed array  

Energy Technology Data Exchange (ETDEWEB)

An array of sonic transducers, useful for medical ultrasonic imaging, has individual sections thereof separately coupled for forming separate beams of sonic energy which converge, respectively, to separate foci along a common axis of the beams. The ratio of the diameter of the radiating aperture of the array relative to a wavelength of the sonic energy is chosen to provide a moderate degree of focusing so that the depth of field at one focus blends with the depth of field of the next focus. Thereby, there is formed a continuous region of substantially uniform intensity of sonic radiation along the common beam axis. Circuitry is provided for selecting one or more specific foci dependent on the bounds of a selected region to be insonified. Upon reception of sonic energy, circuitry is provided for selecting one or more specific foci as a function of the time of travel of an echo from a subject being observed to approximate a continuously varying ...

1981-07-07

139

A simple model for predicting the flux distribution through the focal plane of a multifaceted concentrator solar furnace  

Energy Technology Data Exchange (ETDEWEB)

The authors describe a small doubly reflecting research furnace. Its optical components, a heliostat and a concentrating array of hexagonal-in-plan-form mirrors, focus sunlight at the aperture of a cavity receiver. A perfect paraboloid of revolution would have given higher concentration ratios. But large paraboloids are difficult to make and manipulate. Small hexagons are convenient and can be close packed. Spherical mirrors centered on a sphere simplified construction and were economical. In this note they use a simple model to describe the radial distribution of the normal flux at the focus of such an array. A schematic representation of a cross section of the concentrator mirror array in a plane which includes its axis is shown.

1984-02-01

140

Ultrashallow P{sup +}/N junction formation by plasma ion implantation  

Energy Technology Data Exchange (ETDEWEB)

We investigated the electrical characteristics and the junction depth of ultra-shallow junctions formed by using the plasma-doping method. Compared with ultra-low energy boron-ion implantation at 500 eV, the junctions formed with the plasma-doping process exhibited shallow junction depths and low sheet resistances. The junction depths of the plasma-doped samples were 150 A and 330 A after annealing for 10 s at 900 .deg. C and 950 .deg. C, respectively. For the same junction depth, the sheet resistance of the B{sub 2}H{sub 6} plasma-doped sample was an order of magnitude less than that of the 500-eV B-ion implanted sample. Cross-sectional transmission electron microscopy and deep level transient spectroscopy showed that the defects formed by the B{sub 2}H{sub 6} plasma-doping process could be removed by annealing at 950 .deg. C for 10 s. The scaling of metal-oxide-semiconductor field-effect-transistor (MOSFET) device channel lengths for ...

2000-12-01

141

Ultrashallow P"+/N junction formation by plasma ion implantation  

International Nuclear Information System (INIS)

We investigated the electrical characteristics and the junction depth of ultra-shallow junctions formed by using the plasma-doping method. Compared with ultra-low energy boron-ion implantation at 500 eV, the junctions formed with the plasma-doping process exhibited shallow junction depths and low sheet resistances. The junction depths of the plasma-doped samples were 150 A and 330 A after annealing for 10 s at 900 .deg. C and 950 .deg. C, respectively. For the same junction depth, the sheet resistance of the B_2H_6 plasma-doped sample was an order of magnitude less than that of the 500-eV B-ion implanted sample. Cross-sectional transmission electron microscopy and deep level transient spectroscopy showed that the defects formed by the B_2H_6 plasma-doping process could be removed by annealing at 950 .deg. C for 10 s. The scaling of metal-oxide-semiconductor field-effect-transistor (MOSFET) device channel lengths for high-speed application ...

2000-12-01

142

Sealant Research for solid oxide fuel cells  

International Nuclear Information System (INIS)

The objective of this work is to develop sealing materials for solid oxide fuel cells (SOFCs). A suitable sealant must form strong, dense bonds with SOFC components, be chemically and mechanically compatible with the components, be stable at 1000 degrees C in the operating environment of the SOFC (H_2 and H_2O on the anode side, O_2 on the cathode side), and must be nonconductive.

1992-07-01

143

Process in Plasma Research at IPJ and IPPLM, POLAND  

International Nuclear Information System (INIS)

The most important results of theoretical and experimental studies of plasmas, which have been achieved at the IPJ in Swierk and IPPLM in Warsaw recently, are presented. Studies of physical phenomena in PF discharges, development of diagnostic techniques and research on new plasma technologies, as performed at IPJ, have been summarized. Studies of dense magnetized plasmas, investigation of physics and applications of laser-produced plasmas; and research on the development of advanced diagnostic techniques for the EUROATOM fusion program, as performed at IPPLM, are also described.

2006-01-01

144

Molecular dynamics simulation of nanoctrystalline nickel: structure and mechanical properties  

Energy Technology Data Exchange (ETDEWEB)

Molecular dynamics computer simulations of a dense nanocrystalline Nickel sample are performed on the parallel Cray T3 (EPFL-Lausanne). The sample contains 50 grains with an average size of 3 nm. By perturbing the relaxed configuration elastic and plastic properties are studied. (author) 1 fig., 1 ref.

1996-10-01

145

Methods of investigation of nuclear matter under the conditions characteristics for transition to quark-gluon plasma  

International Nuclear Information System (INIS)

Features of deep inelastic nuclear reactions proceeding on dense fluctuations of nuclear matter (fluctons) are briefly considered. Fluctons, which can be many-quark bags or drops of quark-gluon plasma, are studied. Their properties are discussed, viz., characteristic parameters of nuclear matter inside a flucton - temperature and density close to the critical values for a phase transition. These values can be reached or exceeded if the flucton-flucton collision events are separated. The separation method is discussed

2002-11-01

146

Electromagnetic effects in relativistic electron beam plasma interactions  

Energy Technology Data Exchange (ETDEWEB)

Electromagnetic effects excited by intense relativistic electron beams in plasmas are investigated using a two-dimensional particle code. The simulations with dense beams show large magnetic fields excited by the Weibel instability as well as sizeable electromagnetic radiation over a significant range of frequencies. The possible relevance of beam plasma instabilities to the laser acceleration of particles is briefly discussed. 6 refs., 4 figs.

1985-02-13

147

Breakdown and discharges in dense gases governed by runaway electrons  

Energy Technology Data Exchange (ETDEWEB)

The phenomenon of runaway electrons (REs) at high values of the ratio field intensity/gas number density {ital E}/{ital N} and {ital N} up to the Loshmidt number {ital N}{sub {ital L}}{approx_equal}2.7{times}10{sup 19} cm{sup {minus}3} is described. REs are shown to govern the breakdown and discharges at such condition. {copyright} {ital 1996 American Institute of Physics.}

1996-03-01

148

Ab initio calculations in a uniform magnetic field using periodic supercells  

Energy Technology Data Exchange (ETDEWEB)

We present a formulation of ab initio electronic structure calculations in a finite magnetic field, which retains the simplicity and efficiency of techniques widely used in first principles molecular dynamics simulations, based on plane-wave basis sets and Fourier transforms. In addition we discuss results obtained with this method for the energy spectrum of interacting electrons in quantum wells, and for the electronic properties of dense fluid deuterium in a uniform magnetic field.

2003-10-21

149

Theoretical Standard Model Rates of Proton to Neutron Conversions Near Metallic Hydride Surfaces  

CERN Document Server

The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are determined in part by the collective plasma modes of the participating charged particles, e.g. electrons and protons. The radiation energy required for such low energy nuclear reactions may be supplied by the applied voltage required to push a strong charged current across a metallic hydride surface employed as a cathode within a chemical cell. The electroweak rates of the resulting ultra low momentum neutron production are computed from these considerations.

2006-01-01

150

Tailor die quenching in hot stamping for producing ultra-high strength steel formed parts having strength distribution  

British Library Electronic Table of Contents (United Kingdom)

Tailor die quenching in the hot stamping of quenchable steel sheets was developed to produce ultra-high strength steel formed parts having strength distribution. Local portions of the heated sheet were quenched by holding grooved tools at the bottom dead centre during the stamping. Non-contact portions were generated in the sheet by grooving the tools, and thus the strength in the contact portions is high owing to the quenching and that in the non-contact portions is low owing to the lack of the quenching. Hat-shaped products having a tensile strength of approximately 1.5GPa only at four corners were formed.

2010-01-01

151

Simulation of the filtration mechanism of hyaluronic acid in total knee prosthesis  

Energy Technology Data Exchange (ETDEWEB)

Polyethylene (UHMWPE) wear in current knee prosthesis causes prosthesis loosening after no more than 15 years. In this work, a steady state one-dimensional lubrication model with non- Newtonian fluid, porous elastic layer on tibial component, ultra-filtration mechanism of fluid and some features of the surface roughness is studied through a numerical technique based on the Finite Element Method. The results show that the UHMWPE stiffness makes difficult the lubrication mechanism of the artificial joint and promotes abrasive and fatigue wear. Nevertheless, the use of compliant porous materials on the tibial component could reduce friction and wear. Moreover, the ultra-filtration mechanism promotes efficiency on the joint.

2007-11-15

152

Separation of rubidium from irradiated aluminum-encapsulated uranium  

International Nuclear Information System (INIS)

A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.

1993-05-01

153

Separation of rubidium from irradiated aluminum-encapsulated uranium  

Energy Technology Data Exchange (ETDEWEB)

A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.

1982-01-01

154

Production and characterization of ultrafine WC powders  

International Nuclear Information System (INIS)

The conventional Calzination-Reduction-Carburization (CRC) process offers the potential to manufacture commercial WC powders with median SEM grain sizes below 0.5 pm (ultra fine grades). Strict process control and a high degree of automation have led to increased powder uniformity and high lot-to-lot reliability. The high potential and flexibility of the CRC process is shown by the development of tailor made WC powders with regard to subsequent alloy manufacturing. R and D powders have successfully been processed in full-scale units exhibiting SEM grain sizes of 0.15 - 0.20 pm. This paper discusses the powder characteristics of various ultra fine WC powder grades, stemming from the conventional CRC process. Analytical characterization include also field-emission SEM, bright field TEM, EDX analysis and XRD-line broadening. (author)

2001-05-01

155

Mechanical properties and structure of low-alloy ultra-high strength steels  

Energy Technology Data Exchange (ETDEWEB)

Mechanical properties of P-LDHA and V-ROL N steels of the Czech production are compared with other ultra-high strength steels produced in the world. The most important results can be summarized into following points: 1. Optimally heat treated P-LDHA steel exhibits substantially better strength characteristics then the V-ROL N steel. 2. Optimal tempering temperature of the P-LDHA steel is 300 C. 3. Basic mechanical properties of P-LDHA steel belong to the top of the UHS steels ranking and are well comparable with those of American 300 M steel. 4. In the low-cycle fatigue region, the P-LDHA steel exhibits slightly better fatigue resistance then the 300 M steel. On the other hand, the high-cycle fatigue resistance of 300 M steel is slightly better then that of the P-LDHA steel. (orig.)

2000-07-01

156

Hydrogen transport and embrittlement in 300 M and AerMet100 ultra high strength steels  

Energy Technology Data Exchange (ETDEWEB)

This paper describes how hydrogen transport affects the severity of hydrogen embrittlement in 300 M and AerMet100 ultra high strength steels. Slow strain rate tests were carried out on specimens coated with electrodeposited cadmium and aluminium-based SermeTel 1140/962. Hydrogen diffusivities were measured using two-cell permeation and galvanostatic charging methods and values of 8.0 x 10{sup -8} and 1.0 x 10{sup -9} cm{sup 2} s{sup -1} were obtained for 300 M and AerMet100, respectively. A two-dimensional diffusion model was used to predict the hydrogen distributions in the SSR specimens at the time of failure. The superior embrittlement resistance of AerMet100 was attributed to reverted austenite forming around martensite laths during tempering.

2010-05-15

157

Development of Ultra-Fast Silicon Switches for Active X-Band High Power RF Compression Systems  

Energy Technology Data Exchange (ETDEWEB)

We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.

2006-03-06

158

Design and fabrication of large ultra-thin PIN detector with membrane stress deviation  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the design of large thin PIN detector with a membrane stress avoidance configuration is proposed, and the related device fabrication process is developed. Ultra-thin PIN detector {approx} 1.13 cm{sup 2} in area is fabricated on a thin ( {approx} 35{mu}m) silicon membrane, and characterized. Detector performance improvement has been successfully demonstrated. With the membrane stress avoidance design, the improved detector exhibits a leakage of 6nA, which is at least 5 times lower than that of detector of identical junction area. The new detector features a full depleted capacitance of 110 pF, and a FWHM of 40.86 keV energy resolution for 5.486 MeV alpha particle spectrography.

2010-09-15

159

Aerogels from Unaltered Bacterial Cellulose: Application of scCO2 Drying for the Preparation of Shaped, Ultra-Lightweight Cellulosic Aerogels  

British Library Electronic Table of Contents (United Kingdom)

Bacterial cellulose produced by the gram-negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra-lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 degreeC and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg cm-3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open-porous network structure that consists of a comparatively high percentage of large mesopores and small...

2010-01-01

160

When autophagy meets viruses: a double-edged sword with functions in defense and offense  

UK PubMed Central (United Kingdom)

Autophagy is a ubiquitous catabolic process that ensures organism’s well-being by sequestering a wide array of undesired intracellular constituents into double-membrane vesicles termed...Full Text Available

2010-12-01

161

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 ...

2007-12-15

162

Use of Microelectrode Arrays to Directly Measure Diffusion of ...  

Science.gov (United States)

... F.; Murray, R. W. J. Am. Chem. ... 14. Thackeray, J. W.; White, H. S.; Wrighton, M. SJ Phys. ... Dr. James S. Murday (1) Dr. Harold H. Singerman (i) ...

1990-05-16

163

The mitochondrial p53 pathway  

UK PubMed Central (United Kingdom)

p53 is one of the most mutated tumor suppressors in human cancers and as such has been intensively studied for a long time. p53 is a major orchestrator of the cellular response to a broad array...Full Text Available

2009-05-01

164

Temporal Interactions during Paired-Electrode Stimulation in Two Retinal Prosthesis Subjects  

UK PubMed Central (United Kingdom)

Purpose.Since 2002, six blind patients have undergone implantation of an epiretinal 4 × 4 electrode array designed to directly stimulate the remaining cells of the retina...Full Text Available

2011-01-01

165

TIARA: A large solid angle silicon array for direct reaction studies with radioactive beams  

International Nuclear Information System (INIS)

A compact, quasi-4? position sensitive silicon array, TIARA, designed to study direct reactions induced by radioactive beams in inverse kinematics is described here. The Transfer and Inelastic All-angle Reaction Array (TIARA) consists of 8 resistive charge division detectors forming an octagonal barrel around the target and a set of double-sided silicon-strip annular detectors positioned at each end of the barrel. The detector was coupled to the ?-ray array EXOGAM and the spectrometer VAMOS at the GANIL Laboratory to demonstrate the potential of such an apparatus with radioactive beams. The 14N(d,p)15N reaction, well known in direct kinematics, has been carried out in inverse kinematics for that purpose. The observation of the 15N ground state and excited states at 7.16 and 7.86 MeV is presented here as well as the comparison of the measured proton angular distributions with DWBA calculations. Transferred l-values are in ...

2010-03-11

166

Subacute neuropathological effects of microplanar beams of x-rays from a synchrotron wiggler.  

UK PubMed Central (United Kingdom)

Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and...Full Text Available

1995-09-12

167

Study of the Photon Strength Functions for Gadolinium Isotopes with the DANCE Array  

Science.gov (United States)

The gadolinium isotopes are interesting for reactor applications as well as for medicine and astrophysics. The gadolinium isotopes have some of the largest neutron capture cross sections. As a consequence they are used in the control rod in reactor fuel assembly. From the basic science point of view, there are seven stable isotopes of gadolinium with varying degrees of deformation. Therefore they provide a good testing ground for the study of deformation dependent structure such as the scissors mode. Decay gamma rays following neutron capture on Gd isotopes are detected by the DANCE array, which is located at flight path 14 at the Lujan Neutron Scattering Center at Los Alamos National Laboratory. The high segmentation and close packing of the detector array enable gamma-ray multiplicity measurements. The calorimetric properties of the DANCE array coupled with the neutron time-of-flight technique enables one to gate on a ...

2009-03-10

168

Shared versus specialized glycinergic spinal interneurons in axial motor circuits of larval zebrafish  

UK PubMed Central (United Kingdom)

The neuronal networks in spinal cord can produce a diverse array of motor behaviors. In aquatic vertebrates such as fishes and tadpoles, these include escape behaviors, swimming across a range...Full Text Available

2008-11-26

169

Semiconductor Radiation Detectors with Frisch Collars and Collimators for Gamma Ray Spectroscopy and Imaging  

Energy Technology Data Exchange (ETDEWEB)

To study CdZnTe as a high energy resolution gamma ray detector with a novel new design, and to build a detector array from the new detector design

2006-12-04

170

Reciprocal Silencing, Transcriptional Bias and Functional Divergence of Homeologs in Polyploid Cotton (Gossypium)  

UK PubMed Central (United Kingdom)

Polyploidy is an important force in the evolution of flowering plants. Genomic merger and doubling induce an extensive array of genomic effects, including immediate and long-term alterations in the...Full Text Available

2009-06-01

171

Real-time neutron beam monitor  

Energy Technology Data Exchange (ETDEWEB)

An array of multiwire proportional counters has been employed to image, in 'real-time', a collimated neutron beam produced at an electron linac facility. Test results are presented, along with a discussion of the advantages of this technique.

1983-06-15

172

Pulmonary metabolism of foreign compounds: its role in metabolic activation.  

UK PubMed Central (United Kingdom)

The lung has the potential of metabolizing many foreign chemicals to a vast array of metabolites with different pharmacological and toxicological properties. Because many chemicals require metabolic...Full Text Available

1990-04-01

173

Photovoltaic lighting for outdoor telephone booth  

Energy Technology Data Exchange (ETDEWEB)

A free standing outdoor telephone booth is provided with a photovoltaic (PV) array, one or more rechargeable storage batteries and electrical control circuit which includes a temperature compensated control for limiting the supply of electrical energy from the PV array to the rechargeable battery to avoid over charging the battery, an ambient light (solar insolation) sensing circuit for controlling the electrical lamp load, to turn the lamp ON during dark ambient and OFF during light ambient conditions. In addition, the total discharge limit of the storage battery is controlled to a safe operating limit and a means is disclosed to power a fluorescent lamp at energy conserving intensities with energy derived from the rechargeable storage battery. The lamp control circuitry is preferably constituted by a high frequency power inverter with regulated output power to energize a low wattage fluorescent lamp and to dim the fluorescent lamp when the ...

1984-04-03

174

Parallel Arrays of Geometric Nanowells for Assembling Curtains of DNA with Controlled Lateral Dispersion  

UK PubMed Central (United Kingdom)

The analysis of individual molecules is evolving into an important tool for biological research, and presents conceptually new ways of approaching experimental design strategies. However, more...Full Text Available

2008-10-07

175

Molecular and clinico-pathological markers in rectal cancer: a tissue micro-array study  

UK PubMed Central (United Kingdom)

AimsThe aims of the study were to study the effect of pre-operative treatment on the expression of tumour-related proteins and to correlate the expression of these...Full Text Available

2009-02-01

176

Methyl Jasmonate Induces Traumatic Resin Ducts, Terpenoid Resin Biosynthesis, and Terpenoid Accumulation in Developing Xylem of Norway Spruce Stems1  

UK PubMed Central (United Kingdom)

Norway spruce (Picea abies L. Karst) produces an oleoresin characterized by a diverse array of terpenoids, monoterpenoids, sesquiterpenoids, and diterpene resin acids that can protect...Full Text Available

2002-07-01

177

Membrane protein biosensing with plasmonic nanopore arrays and pore-spanning lipid membranes  

UK PubMed Central (United Kingdom)

Integration of solid-state biosensors and lipid bilayer membranes is important for membrane protein research and drug discovery. In these sensors, it is critical that the solid-state sensing...Full Text Available

2010-01-01

178

Magnetic resonance imaging of the hip with a pelvic phased-array surface coil: a technical note  

Energy Technology Data Exchange (ETDEWEB)

Objective. The aim of this study was to assess the capability of high-resolution images obtained with a commercially available pelvic phased-array surface coil to demonstrate normal hip anatomy. Design. We retrospectively analyzed the oblique coronal magnetic resonance (MR) images of hips of 36 consecutive patients acquired on a 1.5-T clinical imager using a pelvic phased-array coil as a receiver, a 16-20 cm field of view, and 5 mm slice thickness. Patients. Thirty-six patients were studied, age 15-81 years. There were 20 males and 16 females. Results and conclusions. The articular cartilage, cortex, superior labrum, and iliofemoral ligament were well visualized on proton density weighted fat saturation (PDF) images. The femoral and obturator vessels, obturator nerve, and various muscles were easily seen on T1-weighted images. High-resolution imaging of the hip is achievable in a reasonable amount of time using newer ...

1998-02-01

179

Lymph node staging in cervical carcinoma: Results of high resolution MRT with phased-array coil  

International Nuclear Information System (INIS)

Purpose: To determine the diagnostic value of high resolution MR imaging with a circularly polarised (c.p.) body phased-array coil for the staging of pelvic lymph nodes in cervical carcinoma. Material and methods: 42 patients with histologically proven carcinoma of the cervix were studied on a 1.5 T scanner by using a c.p. body phased-array coil. The imaging protocol included T_2-weighted turbo-spin-echo (TSE) and T_1-weighted spin-echo sequences pre and post IV application of Gd-DTPA; slice thickness was 5-7 mm and pixel size 0.53 mm"2. Lymph nodes with a diameter of #>=#8 mm were considered to have metastatic involvement. MR imaging results were compared with histopathologic findings. Results: MR imaging showed enlarged lymph nodes (#>=# 8 mm) in 16 of 18 patients with histologic proof of lymph node metastases (sensitivity 89%). In 22 of 24 cases MR findings were true negative (specificity 92%). Diagnostic accuracy was 91%. Conclusion: ...

180

LED Arrays as Cost Effective and Efficient Light Sources for Widefield Microscopy  

UK PubMed Central (United Kingdom)

New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission...Full Text Available

181

Global Analysis of the General Stress Response of Bacillus subtilis  

UK PubMed Central (United Kingdom)

Gene arrays containing all currently known open reading frames of Bacillus subtilis were used to examine the general stress response of Bacillus. By proteomics, transcriptional...Full Text Available

2001-10-01

182

Gene expression analysis after low dose ionising radiation exposure of the developing organism  

International Nuclear Information System (INIS)

Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two ...

2007-09-01

183

Fish schooling as a basis for vertical axis wind turbine farm design  

International Nuclear Information System (INIS)

Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement ...

2010-09-01

184

Enhanced defect detection and sizing accuracy using matrix phased array ultrasonic tools  

Energy Technology Data Exchange (ETDEWEB)

Although ultrasonic testing inspection technology and tools have improved significantly, there is still a need for more reliable detection, monitoring, and accurate sizing of crack-like and planar defects, complex corrosion damage, and detection of secondary features within deformed pipe. Ultrasonic two dimensional (2D) matrix phased array technology offers some unique advantages that make the technology promising for improving detection and sizing of pipeline flaws resulting from welding or from in-service damage. Ultrasonic modeling and simulation has been conducted to evaluate the detection and sizing capabilities of 2D matrix arrays for various pipeline inspection concepts. Simulations have been performed using both flexible and rigid array probes. Inspection concepts using rigid probes were evaluated for inspections from both the outside and inside pipe surfaces, while flexible probes were evaluated primarily for ...

2009-07-01

185

Effect of rib height and pitch of the thermal performance of a passage disturbed by detached solid ribs  

Energy Technology Data Exchange (ETDEWEB)

Laser holographic interferometry and pressure measurements are presented for the effects of rib-to-duct height ratio (H/2B), rib pitch-to-height ratio (Pi/H), and Reynolds number (Re) on the spatially periodic-fully developed turbulent heat transfer and friction in a rectangular duct of width-to-height ratio of 4:1 with an array of ribs detached from one wall at a clearance to rib-height ratio of 0.38. The ranges of H/2B, Pi/H, and Re examined were 0.13 to 0.26, 7 to 13, and 5 {times} 10{sup 3} to 5 {times} 10{sup 4}, respectively. The difference in the H/2B dependence of the thermal performance between the detached and attached solid-rib array is documented H/2B = 0.17 and Pi/H = 10 are found to provide the best thermal performance for the range of parameters tested. Compact heat transfer and friction correlations are developed. Additionally, it is found that heat transfer augmentation with a detached solid-rib array is ...

1998-07-01

186

Current state of methodology on hemoglobin oximetry in tissues.  

Science.gov (United States)

Photon migration provides sensitive tissue oximetry in which the optical pathlength is known. Phase array gives the precise location of a subnanomolar amount of hidden absorber in highly scattering medium. PMID:8079713

1994-01-01

187

Crassulacean Acid Metabolism and Epiphytism Linked to Adaptive Radiations in the Orchidaceae1[OA  

UK PubMed Central (United Kingdom)

Species of the large family Orchidaceae display a spectacular array of adaptations and rapid speciations that are linked to several innovative features, including specialized pollination syndromes,...Full Text Available

2009-04-01

188

Construction and Application of a Zebrafish Array CGH Platform  

UK PubMed Central (United Kingdom)

The zebrafish is emerging as a prominent model system for studying the genetics of human development and disease. Genetic alterations that underlie each mutant model can exist in the form of...Full Text Available

2009-02-01

189

Anchoring of a Single Molecular Rotor and Its Array on Metal Surfaces using Molecular Design and Self-Assembly  

UK PubMed Central (United Kingdom)

Functionalizing of single molecules on surfaces has manifested great potential for bottom-up construction of complex devices on a molecular scale. We discuss the growth mechanism for the initial layers...Full Text Available

190

A study on heat-transfer enhancement by a square-rod array in an impinging jet system  

Energy Technology Data Exchange (ETDEWEB)

An impinging jet is a widely used technique for realizing high heat-transfer rates between a fluid and a surface. However, the area of enhanced heat transfer is limited to the neighborhood of the stagnation point. In this study, heat transfer is augmented remote from the stagnation point in an impinging plane jet system by a rod array located near the wall. Each square rod in the array was positioned normal to the flow direction and parallel to the flat plate surface. The distance between the nozzle and the flat plate (H) and the spacing between the rods and the flat plate surface (C) were changed to find the optimum values. The largest heat-transfer augmentation was obtained for C = 1 mm, H/B = 10, where the jet nozzle width is B. In this case, the heat-transfer coefficient averaged over an area 2B from the stagnation point is about 1.6 times greater compared to that without a rod array.

1996-07-01

191

A real-time neutron beam monitor  

International Nuclear Information System (INIS)

An array of multiwire proportional counters has been employed to image, in 'real-time', a collimated neutron beam produced at an electron linac facility. Test results are presented, along with a discussion of the advantages of this technique. (orig.).

1983-06-01

192

A novel custom high density-comparative genomic hybridization array detects common rearrangements as well as deep intronic mutations in dystrophinopathies  

UK PubMed Central (United Kingdom)

BackgroundThe commonest pathogenic DMD changes are intragenic deletions/duplications which make up to 78% of all cases and point mutations (roughly 20%) detectable...Full Text Available

193

The 8{pi}LP Project: A 4{pi} light charged particle detection array at LNL  

Energy Technology Data Exchange (ETDEWEB)

A 4{pi} detection system sensitive to light charged particles is being developed at the Laboratori Nazionali di Legnaro (LNL) for the study of reaction mechanisms at energies up to 20 AMeV. The array consists of 262 {Delta}E-E telescopes covering 90% of 4{pi}. Each telescope is made of a 300 {mu}m passivated silicon detector and a 15 mm (or 5 mm) CsI(Tl) crystal read by a photodiode. The system will be operational in the Spring of 1997 and the first experiments will run in the second half of 1997.

1996-12-31

194

Single-shot diffusion-weighted echo-planar imaging of normal and cirrhotic livers using a phased-array multicoil  

Energy Technology Data Exchange (ETDEWEB)

Single-shot spin-echo diffusion-weighted echo-planar imaging using a phased-array multicoil was performed to distinguish between normal and cirrhotic livers. Sets of 6 images with different b-value were acquired with breath-holding. Significant differences were observed between controls and cirrhosis cases in the signal ratios when the b-value was 383 s/mm{sup 2}, and apparent diffusion coefficients. (orig.)

1998-07-01

195

SEU hardening of field programmable gate arrays (EPGAS) for space applications and device characterization  

International Nuclear Information System (INIS)

Field Programmable Gate Arrays (FPGAs) are being used in space applications because of attractive attributes: good density, moderate speed, low cost, and quick turn-around time. However, these devices are susceptible to Single Event Upsets (SEUs). An approach using triple modular redundancy (TMR) and feedback was developed for flip-flop hardening in these devices. Test data showed excellent results for this circuit topology. Total dose and Single Event Effect (SEE) testing have been performed on recently released technologies. Failures are analyzed and test methodology is discussed.

1994-07-18

196

Photoluminescence of manganese- and copper-doped CdS nanowires  

Energy Technology Data Exchange (ETDEWEB)

Arrays of CdS:Mn{sup 2+}:Cu{sup +} micro- and nanowires grown in polycarbonate ion-track templates exhibit photoluminescence in the spectral domain ranging from 500 to 800 nm at room temperature. A comparison with similar CdS and CdS:Mn{sup 2+} wire arrays is presented. The individual contributions to the emission spectra of Cu{sup +} and Mn{sup 2+} ions in the CdS matrix are explained using their energy level schemes. Also SEM, EDX and EPR data are given for these wires. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2005-02-01

197

Photoluminescence of manganese- and copper-doped CdS nanowires  

International Nuclear Information System (INIS)

Arrays of CdS:Mn"2"+:Cu"+ micro- and nanowires grown in polycarbonate ion-track templates exhibit photoluminescence in the spectral domain ranging from 500 to 800 nm at room temperature. A comparison with similar CdS and CdS:Mn"2"+ wire arrays is presented. The individual contributions to the emission spectra of Cu"+ and Mn"2"+ ions in the CdS matrix are explained using their energy level schemes. Also SEM, EDX and EPR data are given for these wires. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2005-02-01

198

Low cost, low power, high sensitivity, real time neutron detection microsystem  

International Nuclear Information System (INIS)

A Si array neutron detector is proposed based on commercial CCD and CMOS sensor technology coupled with a thin film neutron conversion coating. System sensitivity is estimated for a baseline device containing a single array and various schemes to increase detection probability by simple area scaling and stacking are discussed. Some possible use scenarios are discussed involving static and moving sources. Likely neutron source fluxes for weapons grade and commercial grade nuclear material are estimated along with expected intensities of cosmic background neutrons which would establish a noise floor to detection limits.

2002-10-10

199

In-beam #gamma#-ray spectroscopy of fast beams at the NSCL  

International Nuclear Information System (INIS)

With the development of an array of highly-segmented germanium detectors, it now becomes possible to perform in-flight #gamma#-ray spectroscopy experiments on intermediate energy beams with unprecedented #gamma#-ray energy resolution. Presented in this report are examples of two techniques in which SeGA, the most highly-segmented operational germanium array for in-flight spectroscopy with fast beams, was used for the detection of #gamma# rays. SeGA used in conjunction with a high-resolution magnetic spectrograph (S800) to detect the reaction residues in coincidence represents a powerful combination for in-beam #gamma#-ray studies.

2004-04-05

200

High-power continuous wave 690 nm AlGaInP laser-diode arrays  

Energy Technology Data Exchange (ETDEWEB)

High-power diode laser arrays emitting at 690 nm have been developed for solid-state laser pumping. The laser diode bars (fill factor [approx]0.7) have been fabricated from single quantum well AlGaInP-based heterostructures. Using silicon microchannel heatsinks, a record high 360 W/cm[sup 2] per emitting aperture is achieved under continuous wave operation.

1995-03-06

201

Cosmological surveys with the Australian Square Kilometre Array Pathfinder  

CERN Document Server

This is a design study into the capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) in performing a full-sky low redshift neutral hydrogen survey, termed WALLABY, and the potential cosmological constraints one can attain from measurement of the matter power spectrum. We find that the full sky survey will likely attain 600,000 redshifts which, when combined with expected Planck CMB data, will constrain the Dark Energy equation of state to 20%, for the first time making cosmological constraints from radio observations competitive with the best existing optical surveys.

2011-01-01

202

Air Shower Events of High-Energy Cosmic Rays Measured at Seoul, South Korea  

Science.gov (United States)

The COsmic ray Research and Education Array (COREA) collaboration has installed an array of six detector stations at two high schools in and near Seoul, Korea for measurement of air-shower events from high-energy cosmic rays. Three stations are installed at each site, where each station consists of four plastic scintillation detectors covering an area of 2m2. In this presentation, we report the currenst status of the COREA project, describing the experimental equipment and measurement of coincident events.

2011-09-01

203

Special phased array applications for pipeline girth weld inspections  

Energy Technology Data Exchange (ETDEWEB)

Pipeline automated ultrasonic testing (AUT) uses fully automated equipment that travels around a pipe on a welding band in a linear scan to allow array pulses to provide ultrasound information on weld zones. Pipeline AUT is also used for zone discrimination as well as with special calibration blocks, dual gate output displays, and rapid defect sizing. AUT allows for the inspection of welds soon after completion, and can save construction costs by process control when combined with engineering critical assessment (ECA) to minimize rejection rates. Ultrasonic phased arrays (UPA) use an array of elements that are all individually wired, pulsed, and time-shifted. Elements are pulsed in groups of approximately 16 elements at a time for pipeline welds. Phased arrays can be used to combine electronic scanning, sectorial scanning and precision focusing to give a practical combination of displays. Optimum angles ...

2004-07-01

204

In-situ examination of turbine components (blade roots, rotor steeple grooves and disk-blade rim attachments) of low-pressure steam turbine, using phased array technology  

Energy Technology Data Exchange (ETDEWEB)

A feasibility study test and 3 field trials were performed at Darlington NGS in 1996, 1999 and 2000 on ABB LP turbines. The scope of these trials was to commission in-situ automatic phased array systems capable to inspect blade roots and rotor steeples of L-0 and L-1 rows. GE disk-blade rim attachments were inspected at Bruce B nuclear station, in fall of 1999. The automated ultrasonic phased array technology is capable of high-speed rate and reliable detection and sizing. The capability demonstration was performed on mock-ups and reference blocks, using EDM notches. A custom built UT simulation software: Imagine 3D interfaces with SimScan to generates the spreadsheets/charts with target and probe coordinates and ultrasonic path and angles (refracted and skew) to hit the reference target. Examination of L-0 blade and rotor steeple grooves was performed with 2 phased array systems under networking. Data analysis was done in ...

2000-07-01

205

The implementation of SOMO (SOlution MOdeller) in the UltraScan analytical ultracentrifugation data analysis suite: enhanced capabilities allow the reliable hydrodynamic modeling of virtually any kind of biomacromolecule  

UK PubMed Central (United Kingdom)

The interpretation of solution hydrodynamic data in terms of macromolecular structural parameters is not a straightforward task. Over the years, several approaches have been developed to cope...Full Text Available

2010-02-01

206

Steel microstructure engineering for large diameter tubes; Engenharia de microestrutura de acos para tubos de grande diametro  

Energy Technology Data Exchange (ETDEWEB)

High and ultra-high strength steels for pipelines are produced by properly handling the steel microstructure. The metallurgical principles involved in the microstructure control are presented, with emphasis on TMCP processing, that comprises conventional controlled rolling followed by accelerated cooling. (author)

2008-05-15

207

SLAROM-UF: Ultra fine group cell calculation code for fast reactor  

International Nuclear Information System (INIS)

A cell calculation code SLAROM-UF was developed to improve calculation accuracy of effective cross sections for various fast reactor types. SLAROM-UF has a capability to calculate effective cross sections in ultra fine groups of about 100,000 below 50keV and in fine groups above the energy (maximum 900 groups). Resonance interaction among the fuel, the coolant, and the structure materials can be treated accurately even in a heterogeneous cell structure. Temperature can be set up freely in a cell by the ultra fine group calculation. Improvement in nuclear characteristics was observed in the analysis of JUPITER critical experiment, as 0.1% for criticality, 4% for sodium void reactivity, several % for radial reaction rate distribution, when SLAROM-UF was used instead of the typical cell calculation code. The effect of the ultra fine group calculation is remarkable in the non-leakage term of sodium void reactivity, and that of ...

208

Non-Linear Dose-Response Relationships in Biology, Toxicology and Medicine - An International Conference  

Energy Technology Data Exchange (ETDEWEB)

Conference abstract book contains seven sections: Plenary-4 abstracts; Chemical-9 abstracts; Radiation-7 abstracts; Ultra Low Doses and Medicine-6 abstracts; Biomedical-11 abstracts; Risk Assessment-5 abstracts and Poster Sessions-25 abstracts. Each abstract was provided by the author/presenter participating in the conference.

2002-05-28

209

New designs for Ultra High High-Power Single Transverse Mode Cw fibre lasers  

International Nuclear Information System (INIS)

Overcoming the limiting constraints of stimulated Raman scattering (SRS) and stimulated Brilluoin scattering (SBS) poses serious fibre design challenges for increasing the output power of optical amplifiers and lasers. New fibre amplifier designs are proposed to break out of these limitations to reach several kWs CW powers. (Author)

2009-04-01

210

Nanophotonic components utilizing channel plasmon polaritons  

Science.gov (United States)

Channel plasmon polaritons (CPPs) propagating along the bottom of subwavelength grooves cut into a metal surface were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realisation of ultra-compact photonic components. Here, the results of our investigations of CPP guiding by V-grooves cut into gold are presented, demonstrating efficient large-angle bending and splitting of radiation as well as waveguide-ring resonators and Bragg grating filters.

2008-08-01

211

Method of defining features on materials with a femtosecond laser  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to a pulsed laser ablation method of metals and/or dielectric films from the surface of a wafer, printed circuit board or a hybrid substrate. By utilizing a high-energy ultra-short pulses of laser light, such a method can be used to manufacture electronic circuits and/or electro-mechanical assemblies without affecting the material adjacent to the ablation zone.

2006-05-23

212

In situ spectroscopic and corrosion studies of ultra-thin gradient plasma polymer layers on zinc  

International Nuclear Information System (INIS)

By means of an audio frequency plasma polymerisation ultra-thin gradient plasma polymer layers were deposited on zinc and zinc-coated iron. The aim was to generate an interfacial polymeric layer which bonds to an oxidised metal as well as to a subsequently applied organic coating and acts as an interfacial barrier layer for ions and water. Surface modifications were done in an in situ plasma cell with infrared reflection absorption spectroscopy (IRRAS). The zinc surface was first activated by an oxygen plasma to provide a freshly oxidised and contamination free oxide surface. The intermediate stages of the surface reactions could be revealed. Carbon dioxide molecules as oxidation products adsorbed on the growing zinc oxide and were desorbed at a later stage. An organosilicon plasma polymer was deposited directly on top of the oxide layer from a hexamethyldisilane (HMDS) plasma. Afterwards a cyclohexene (CHEX)/hexamethyldisilane co-plasma polymer was deposited. The ...

2003-07-15

213

Determination of heavy metals in welders' working environment using nuclear analytical methods  

International Nuclear Information System (INIS)

Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed. (author).

1985-01-01

214

Determination of heavy metals in welders' working environment using nuclear analytical methods  

Energy Technology Data Exchange (ETDEWEB)

Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed.

1985-01-03

215

Determination of [sup 99]Tc in sea water at ultra low levels  

Energy Technology Data Exchange (ETDEWEB)

A method based on the collection of [sup 99]Tc from 500 l sea water samples by anion exchange and further extraction of TcO[sub 4][sup -] into 5% triisooctylamine-xylene has been improved to include a decontamination factor 6.5x10[sup 5] for uranium. The detection limit for [sup 99]Tc is thereby reduced to 3 mBq/m[sup 3].

1994-01-20

216

A Theory of Laser Induced Nuclear Reaction in Single Atoms  

International Nuclear Information System (INIS)

An 'electron-bridge' mechanism of nuclear reaction in an atom or ion by ultra-intense laser fields is presented. A preliminary estimate of the intensity dependence of the rate of disintegration reaction of deuteron nucleus in deuterium atom is made for 800 nm laser fields. For intensities below 5x1021 W/cm2, the rate of disintegration by the 'electron-bridge' mechanism is found to be small, but it rises sharply and becomes large already for ?1022 W/cm2.

2010-02-02

217

Towards a Better Understanding of Large Scale Network Models  

CERN Document Server

Connectivity and capacity are two fundamental properties of wireless multi-hop networks. The scalability of these properties has been a primary concern for which asymptotic analysis is a useful tool. Three related but logically distinct network models are often considered in the asymptotic analysis, i.e. the dense network model, the extended network model and the infinite network model, which consider respectively a network deployed in a finite area with a sufficiently large node density, a network deployed in a sufficiently large area with a fixed node density, and a network deployed in $\\Re^{2}$ with a sufficiently large node density. The infinite network model originated from continuum percolation theory and asymptotic results obtained from the infinite network model have often been applied to the dense and extended networks. In this paper, through two case studies related to network connectivity on the expected number of isolated nodes and ...

2010-01-01

218

Test plan for Geo-Cleanse{reg_sign} demonstration (in situ destruction of dense non-aqueous phase liquid (DNAPL))  

Energy Technology Data Exchange (ETDEWEB)

Soils and groundwater beneath an abandoned process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLs, or dense non-aqueous phase liquids. Technologies targeted at the efficient characterization or removal of DNAPL are not currently proven. For example, most DNAPL studies rely on traditional soil and water sampling and the fortuitous observation of immiscible solvent. Once DNAPL is identified, soil excavation (which is only applicable to small contained spill sites) is the only proven cleanup method. New cleanup approaches based ...

1996-09-01

219

Hydrogenolysis reactions characteristics of deashed coal under low temperature; Teionka ni okeru dakkai shoritan no suisoka bunkai hanno tokusei  

Energy Technology Data Exchange (ETDEWEB)

In relation to coal liquefaction, the effect of inorganic minerals on liquefaction reactivity and the effect of hydrofluoric acid (HF) treatment on organic molecular structure of coals were studied by demineralization of low-rank coals in HCl or HF solution. In experiment, Taiheiyo coal specimen was deashed in HCl solution at 25-70{degree}C for 6 hours while agitating, and in addition, deashed in HF solution. Hydrogenolysis of the deashed coal specimen was conducted using tetralin or methylnaphthalene as solvent under initial hydrogen pressure of 1.96MPa at reaction temperature of 693K for 60min. The experimental results are as follows. The ash content of Taiheiyo coal hardly offers catalysis in hydrogenolysis reaction. Carboxyl group increases in demineralization of coal because of breakage of bridged bonds. Organic structure of coal changes by demineralization in dense HF solution. Change in organic structure of coal by demineralization in ...

1996-10-28

220

High Velocity Molecular Outflows In Massive Cluster Forming Region G10.6-0.4  

CERN Document Server

We report the arcsecond resolution SMA observations of the $^{12}$CO (2-1) transition in the massive cluster forming region G10.6-0.4. In these observations, the high velocity $^{12}$CO emission is resolved into individual outflow systems, which have a typical size scale of a few arcseconds. These molecular outflows are energetic, and are interacting with the ambient molecular gas. By inspecting the shock signatures traced by CH$_{3}$OH, SiO, and HCN emissions, we suggest that abundant star formation activities are distributed over the entire 0.5 pc scale dense molecular envelope. The star formation efficiency over one global free-fall timescale (of the 0.5 pc molecular envelope, $\\sim$10$^{5}$ years) is about a few percent. The total energy feedback of these high velocity outflows is higher than 10$^{47}$ erg, which is comparable to the total kinetic energy in the rotational motion of the dense molecular envelope. From order-of-magnitude ...

2010-01-01

221

A computational fluid dynamics investigation of fluid flow in a dense medium plasma reactor  

International Nuclear Information System (INIS)

Computational fluid dynamics are applied to the study of three-dimensional fluid flow in a dense medium plasma reactor (DMPR) under different operating conditions. Reaction mechanisms and rates for the removal of methyl t-butyl ether (MTBE) in a DMPR are developed from experimental data to determine the plasma volume, the rate of interphase mass transfer and the photolysis rate of MTBE via UV emission from the plasma. The simulations utilize the plasma volume determined from the kinetic data to show that the volume of fluid in contact with the plasma in the DMPR only constitutes a maximum of approximately 10% of the fluid intended to be cycled through the plasma tubules. The simulations also predict appreciable pressure gradients on the surface of the pin electrodes, resulting in a small discharge area located away from the region in which the electric field strength is a maximum. This result has been confirmed indirectly through observation in that the pin ...

2007-01-21

222

New methods of production of titanium alloy ingots  

International Nuclear Information System (INIS)

Production of titanium alloys from the mixture containing large amounts of metallurgy wastes is very promising. It is shown that unlimited possibilities of the waste material use in the mixture (up to 100%) are provided by garnissage melting, the size of the cast being limited only by that of the vessel. With garnissage being used as a consumed electrode the metal is refined from hydrogen and the blank ingots to serve as consumed electrodes in electro-slag remelting are chemically homogeneous. The ingots thus obtained have dense structure, rather fine grain homogeneous chemical composition, are no less pure than those obtained by vacuum arc remelting and provide for economic savings.

223

Method of forming and assembly of parts  

Energy Technology Data Exchange (ETDEWEB)

A method of assembling two or more parts together that may be metal, ceramic, metal and ceramic parts, or parts that have different CTE. Individual parts are formed and sintered from particles that leave a network of interconnecting porosity in each sintered part. The separate parts are assembled together and then a fill material is infiltrated into the assembled, sintered parts using a method such as capillary action, gravity, and/or pressure. The assembly is then cured to yield a bonded and fully or near-fully dense part that has the desired physical and mechanical properties for the part's intended purpose. Structural strength may be added to the parts by the inclusion of fibrous materials.

2010-12-28

224

Interpretation of EXAFS data from laser shock compressed plasmas  

Energy Technology Data Exchange (ETDEWEB)

Measurements on laser shock compressed aluminium using the EXAFS (Extended X-ray Absorption Fine Structure) technique on the Al K-edge are described. Two methods of analysis of this data were used for the determination of density: the standard EXAFS technique using Fourier transforms and curve fitting, and a method based on a bandstructure calculation of the absorption spectra as a function of compression. These two techniques give results which are in fairly good agreement with each other and also with a hydrodynamic simulation of the experiment. The ion correlation parameter is estimated and shows that two-sided laser irradiation of aluminium foils produces a dense plasma which is strongly coupled. (author).

1989-01-01

225

A simplified approach to the drying of solids in a batch fluidised bed  

Scientific Electronic Library Online (English)

Abstract in english A simplified model for drying solids in the constant rate period in a batch fluidised bed was developed.It assumes the bed to be divided into dense and bubble phases with heat and mass transfer between the phases.The model predicts the constant-rate drying period, provided the fluid bed shape and material characteristics are known.The model is compared with experimental data reported in the literature covering a wide range of materials, gas flow rates, column diameters, m (more) aterial hold-ups, air temperatures and humidities.Model predictions compare satisfactorily with the experimental data.

2002-07-01

226

TEM characterization of Al/Al{sub 2}O{sub 3} composite fabricated by reactive metal infiltration  

Energy Technology Data Exchange (ETDEWEB)

The microstructure of Al/{alpha}-Al{sub 2}0{sub 3} composites made by infiltrating Al into dense mullite preforms has been characterized using transmission electron microscopy. Observations revealed that the formation of the Al/Al{sub 2}0{sub 3} composites involves three stages. Initially, Al infiltrates into a dense mullite preform through grain boundary diffusion, and reacts with mullite at grain boundaries to form a partial reaction zone. Then, a complete reaction takes place in the reaction region between the partial reaction zone and the full reaction zone to convert the dense mullite preform to a composite of {alpha}-Al{sub 2}0{sub 3} (matrix) and an Al-Si phase (thin channels). Finally, the reduced Si from the reaction diffuses out of the Al/Al{sub 2}0{sub 3} composite through the metal channels, whereas Al from the molten Al pool is continuously drawn to the reaction region until the mullite preform is consumed or ...

1994-12-31

227

Effects of strong and electromagnetic correlations on neutrino interactions in dense matter  

Energy Technology Data Exchange (ETDEWEB)

An extensive study of the effects of correlations on both charged and neutral current weak interaction rates in dense matter is performed. Both strong and electromagnetic correlations are considered. The propagation of particle-hole interactions in the medium plays an important role in determining the neutrino mean free paths. The effects due to Pauli blocking and density, spin, and isospin correlations in the medium significantly reduce the neutrino cross sections. As a result of the lack of experimental information at high density, these correlations are necessarily model dependent. For example, spin correlations in nonrelativistic models are found to lead to larger suppressions of neutrino cross sections compared to those of relativistic models. This is due to the tendency of the nonrelativistic models to develop spin instabilities. Notwithstanding the above caveats, and the differences between nonrelativistic and relativistic approaches such as the spin- and ...

1999-05-01

228

Effects of ion-induced electron emission on magnetron plasma instabilities  

International Nuclear Information System (INIS)

Some magnetron sputtering systems experience rapid oscillations in the current and voltage of the plasma discharge after several hours when equipped with certain targets. These oscillations often lead to the plasma becoming extinguished, a condition known as ''flame-out.'' This article details the study of two 90% W--10% Ti magnetron targets which differed in density. The higher density targets sometimes experienced flame-out after approximately 3 h of sputtering. The less dense material could be sputtered for the entire 15 h life of the target. Scanning electron microscopy pictures and atomic composition depth profiles were obtained using Auger electron spectroscopy. In addition, a Colutron-based ion source with a high vacuum system was used to measure ion-induced secondary electron emission coefficients as a function of energy, ion specie, and gas coverage. Analysis of the sample from the group that suffers flame-out showed large regions of pure titanium in the ...

229

Field investigation of a wake structure downwind of a VAWT in a windfarm array  

Energy Technology Data Exchange (ETDEWEB)

The effects of upwind turbine wakes on the performance of a FloWind 17-m VAWT were investigated through a series of field experiments conducted at the FloWind windfarm on Cameron Ridge, Tehachapi, California. The field experiment was conducted within a VAWT array consisting of more than nine VAWTs with separations 3D crosswised by 8D downwind (where D is the turbine diameter) in a staggered configuration. The array is the upwind three rows of VAWTS in a total of six rows that are on top of the Cameron Ridge plateau. The terrain features in the vicinity are reasonably regular, with an upslope of 7 deg on the average; however, several local irregularities are present. The annual hourly averaged wind speed exceeds 8 m/s at the site. The wind field and the power-outputs of nine turbines within the array were measured with wind sensors and power transducers. Nine Gill propeller and 18 Maximum cup anemometers and one direction ...

1987-10-01

230

Array coil probe design optimization  

International Nuclear Information System (INIS)

To overcome the limitations of conventional bobbin style eddy-current probes, it has become common practice to perform some portion of a steam generator tube inspection program with array coil probes. Typically, eight surface-riding pancake coils are utilized in a probe head, either as eight independent coils (8 x 1) or in a parallel combination of four serially connected coils (4 x 4). The advantages of the array coils are improved sensitivity to intergranular attack (IGA), reduced interference from tube denting, and improved sensitivity to circumferential cracking. The current status of commercially available probes is such that several weaknesses in array coils have limited the widespread application of this technology. Task S 301-6 was conceived to address each of the weaknesses in order to produce a more reliable and cost-effective probe. The emphasis was on reliability, since the cost associated with downtime for a ...

1987-07-01

231

3D time-of-flight MR angiography of the intracranial vessels: optimization of the technique with water excitation, parallel acquisition, eight-channel phased-array head coil and low-dose contrast administration  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study is three folds: to compare the eight-channel phased-array and standard circularly polarized (CP) head coils in visualiazation of the intracranial vessels, to compare the three-dimentional (3D) time-of-flight (TOF) MR angiography (MRA) techniques, and to define the effects of parallel imaging in 3D TOF MRA. Fifteen healthy volunteers underwent 3D TOF MRA of the intracranial vessels using eight-channel phased-array and CP standard head coils. The following MRA techniques were obtained on each volunteer: (1) conventional 3D TOF MRA with magnetization transfer; (2) 3D TOF MRA with water excitation for background suppression; and (3) low-dose (0.5 ml) gadolinium-enhanced 3D TOF MRA with water excitation. Results are demonstrating that water excitation is a valuable background suppression technique, especially when applied with an eight-channel phased-array head coil. For central and proximal portions of the ...

2004-11-01

232

{sup 252}Cf-source-driven frequency analysis measurements with subcritical arrays of PWR fuel pins  

Energy Technology Data Exchange (ETDEWEB)

Experiments with fresh PWR fuel assemblies were performed to assess the {sup 252}Cf-source-driven frequency analysis method for measuring the subcriticality of spent fuel. The measurements at the Babcox and Wilcox Critical Experiments Facility mocked up between 17x17 fuel pins (single assembly) and a full array of 4961 fuel pins (about 17 fuel assemblies) in borated water with a fixed B concentration. For the full array, the B content of the water was varied from 1511 at delayed criticality to 4303 ppM. Measurements were done for various source-detector-fuel pin configurations; they showed high sensitivity of frequency analysis parameters to B content and fissile mass. Parameters such as auto and cross power spectral densities can be calculated directly by a more general model of the Monte Carlo code (MCNP-DSP). Calculation-measurement comparisons are presented. This model permits the validation of neutron and gamma ray transport calculational ...

1996-08-01

233

Video Analysis Transputer Array (VATA)  

Energy Technology Data Exchange (ETDEWEB)

This paper presents (a) an overview of the Inmos transputer and its use in parallel arrays for image processing, (b) a functional block-level description of IBM-AT-compatible boards for signal/image processing research using transputers with reconfigurable interconnection topologies, and (c) an overview of the OCCAM and C programming tools for placing parallel algorithms onto such a processor. The hardware consists of two custom printed-circuit boards (and two commercially available boards) within an IBM-AT host. The first provides a flexible input/output interface between a general-purpose high-speed input-data bus and the transputer array. The second contains 32 transputers and 4 programmable crossbar-switch interconnection chips. Several copies of the second board can be cascaded (or even partially-unpopulated) to provide for an arbitrary number of transputer chips. Each one of these boards will perform about 128 million Whetstones or, for ...

1988-08-19

234

Partial top dielectric stack distributed Bragg reflectors for red vertical cavity surface emitting laser arrays  

Energy Technology Data Exchange (ETDEWEB)

Room temperature continuous wave operation of red ([lambda][sub 0] [approximately] 660 nm) vertical cavity surface emitting laser arrays is reported. The 1 [times] 64 arrays have a pitch of 100 [mu]m with device diameters of 15 [mu]m with device diameters of 15 [mu]m. Grown by metalorganic vapor phase epitaxy, the devices consist of an AlGaInP strained quantum well optical cavity active region surrounded by AlGaAs distributed Bragg reflectors (DBR's). The top coupling DBR includes a partial dielectric stack, deposited after implanted device fabrication. All 64 devices operation simultaneously with peak output powers >0.45 mW, threshold current <1.5 mA, and threshold voltages [<=] 2.7 V. The differential quantum efficiencies exceed 10%.

1994-12-01

235

Optical Modelling of the HFI Instrument on Board the Planck Surveyor  

Science.gov (United States)

The PLANCK SURVEYOR is a European Space Agency satellite mission to image the very faint anisotropies in the temperature of the Cosmic Microwave Background (CMB) radiation. Maynooth is actively participating in an international collaboration of scientists involved with the optical design of the High Frequency Instrument (HFI). This paper outlines research which has been undertaken in Maynooth concerned with numerical modelling of the optical characteristics of the multi-frequency array of detectors making up the HFI instrument. In the study the commercial software package ZEMAX was used to model the coupling of the focal plane HFI detectors to the PLANCK telescope. This package is particularly useful in the optical design of PLANCK because of the powerful optimisation features of the software. It is thus possible to readily determine the optimum positioning of the detectors in the focal plane of the telescope. Although the package is based on a numerical ray ...

1999-07-01

236

Nanostructuring the graphite basal plane by focused ion beam patterning and oxygen etching  

International Nuclear Information System (INIS)

Ga"+ focused ion beam (FIB) patterning was used to structure highly oriented pyrolytic graphite surfaces with square, periodic arrays of amorphous carbon defects (mesh sizes: 300 nm-2 #mu#m). Controlled oxygen etching of these arrays leads to matrices of uniform, orientationally aligned, nm-sized, hexagonal holes. The properties of the resulting hole assembly (hole depths and lateral hole dimensions) have been investigated by means of atomic force microscopy, scanning electron microscopy and FIB sectioning. The hole dimensions and uniformity both depend on the FIB parameters and etching conditions. Etching temperatures from 500 to 700 deg. C were applied. Initial etch rates of up to 10"6 C s"-"1 per individual hole were observed when using oxygen pressures of 200 mbar. For an etch temperature of 590 deg. C the rate of etching of individual holes was found to depend measurably on the inter-hole separation. This confirms that the associated ...

2006-12-14

237

Forced laminar convection in an array of stacked plates  

Energy Technology Data Exchange (ETDEWEB)

A numerical study of laminar flow and heat transfer in an array of stacked rectangular plates is presented. The array is placed in a uniform stream, and the plates are subjected to a constant surface heat flux. This flow configuration is relevant to a number of practical heat transfer devices with finned surfaces. The computations were performed using a finite volume solution of the steady, two-dimensional Navier-Stokes equations and energy equation. A numerical scheme that reduces numerical diffusion is used to discretize the equations. The dominant feature of the flow is the separation, and subsequent reattachment of, the boundary layer, which takes place at Reynolds numbers greater than about 75. The separation first occurs downstream of the leading edge of the plate; then as Re increases, the separation point moves upstream and remains fixed at the leading edge, and the reattachment length increases linearly with Re. The appearance and ...

1994-04-01

238

Detection of explosives  

Energy Technology Data Exchange (ETDEWEB)

An analyser for detecting explosives has at least one neutron source and a plurality of gamma ray detectors. An article to be analysed is moved adjacent the source and detectors and is subjected to neutrons which generate gamma rays from any nitrogen in the article. The gamma rays are detected and analysed to determine the nitrogen concentration within the article. In order to achieve an area of uniform detection there are a plurality of detectors equidistant both from the or each source and from the article to be analysed. In order to avoid a decrease in sensitivity away from the source(s) and detectors there may be a second opposing array of source(s) and detectors on the opposite side of the article. For greatest uniformity of detection, a source in one array opposes a detector in the other array and vice versa. Transmission of radiation from the analyser is kept at safe levels by enclosing the analyser within shielding ...

1991-03-13

239

Decoupling of uranium metal with borated plaster using /sup 252/Cf nose analysis methods  

Energy Technology Data Exchange (ETDEWEB)

The use of borated plaster to isolate uranium (93.2 wt % /sup 235/U) metal was studied in a series of subcritical experiments with uranium metal cylinders (7.0 in. diam, 2.0 in. thick) and slabs (approx.1.4 x approx.5.4 x approx.10.1 in. dimensions). In the cylindrical experiments, the thickness of borated plaster was varied up to 10 in. and the subcriticality measured using the /sup 252/Cf-source-driven neutron noise analysis method. In the experiments with the uranium slabs, an array of slabs 3 wide and 8 high was assembled in steps to demonstrate the subcriticality of this array with 3.75-in.-thick borated plaster as an isolating material between all uranium slabs. In the slab experiments, both noise analysis and source neutron multiplication measurements were performed. Before assembly of the slab array the presence of boron in the plaster was verified by neutron transmission and gamma-ray spectrometry measurements.

1985-01-01

240

Blending of nanoscale and microscale in uniform large-area sculptured thin-film architectures  

CERN Document Server

The combination of large thickness ($>3$ $\\mu$m), large--area uniformity (75 mm diameter), high growth rate (up to 0.4 $\\mu$m/min) in assemblies of complex--shaped nanowires on lithographically defined patterns has been achieved for the first time. The nanoscale and the microscale have thus been blended together in sculptured thin films with transverse architectures. SiO$_x$ ($x\\approx 2$) nanowires were grown by electron--beam evaporation onto silicon substrates both with and without photoresist lines (1--D arrays) and checkerboard (2--D arrays) patterns. Atomic self--shadowing due to oblique--angle deposition enables the nanowires to grow continuously, to change direction abruptly, and to maintain constant cross--sectional diameter. The selective growth of nanowire assemblies on the top surfaces of both 1--D and 2--D arrays can be understood and predicted using simple geometrical shadowing equations.

2003-01-01

241

Beam Test of a Prototype Detector Array for the PoGO Astronomical Hard X-Ray/Soft Gamma-Ray Polarimeter  

CERN Document Server

Polarization measurements in the X-ray and gamma-ray energy range can provide crucial information on massive compact objects such as black holes and neutron stars. The Polarized Gamma-ray Observer (PoGO) is a new balloon-borne instrument designed to measure polarization from astrophysical objects in the 30-100 keV range, under development by an international collaboration with members from United States, Japan, Sweden and France. To examine PoGO's capability, a beam test of a simplified prototype detector array was conducted at the Argonne National Laboratory Advanced Photon Source. The detector array consisted of seven plastic scintillators, and was irradiated by polarized photon beams at 60, 73, and 83 keV. The data showed a clear polarization signal, with a measured modulation factor of $0.42 \\pm 0.01$. This was successfully reproduced at the 10% level by the computer simulation package Geant4 after modifications to its implementation of ...

2005-01-01

242

Ultrathin coatings of nanoporous materials as property enhancements for advanced functional materials  

International Nuclear Information System (INIS)

This report summarizes the findings of a five-month LDRD project funded through Sandia's NTM Investment Area. The project was aimed at providing the foundation for the development of advanced functional materials through the application of ultrathin coatings of microporous or mesoporous materials onto the surface of substrates such as silicon wafers. Prior art teaches that layers of microporous materials such as zeolites may be applied as, e.g., sensor platforms or gas separation membranes. These layers, however, are typically several microns to several hundred microns thick. For many potential applications, vast improvements in the response of a device could be realized if the thickness of the porous layer were reduced to tens of nanometers. However, a basic understanding of how to synthesize or fabricate such ultra-thin layers is lacking. This report describes traditional and novel approaches to the growth of layers of microporous materials on silicon wafers. The ...

243

Technologies for high speed rolling and control of gauge in cold tandem mill for ultra-thin gauge strip; Gokuusu reikan atsuenki ni okeru kosoku atsuen gijutsu oyobi itaatsu seigyo gijutsu  

Energy Technology Data Exchange (ETDEWEB)

This paper describes high speed rolling and gauge control in cold tandem mill for ultra-thin gauge strip at the Chiba Works of Kawasaki Steel Corporation. To improve the plate-out property of rolling oil, cationic polymeric coagulant was prepared. Rolling oil with cohesion independent of inorganic inclusions or phosphatide was developed, to improve the lubrication for cold rolling, remarkably. In addition, a low-cost Ti-enhanced work roll having high wear resistance and excellent grindability was developed. Rolling can be conducted at the optimal rolling roughness and operation can be performed at the highest rolling speed independent of the rolling treatment amount. Rolling speed at 2800 m/min was confirmed by developing the rolling oil with excellent lubrication and the work roll having high wear resistance. For the improvement of strip thickness accuracy at the steady state rolling, use of the backup roll as roller bearing was more effective rather than the ...

1996-09-01

244

Studies of ultra-low energy electron-molecule collisions using very-high-n Rydberg atoms  

International Nuclear Information System (INIS)

Potassium atoms in selected high-lying np Rydberg states (80 #<=# n #<=# 400) are being used as a tool to examine electron-polar molecule collisions at ultra-low energies (#approx#80 #mu#eV - 1 meV). This energy regime has not been investigated previously and is of interest because the corresponding electron de Broglie wavelength is large, #approx#1300 - 330 Angstrom, and because the collision time is comparable to the period of molecular rotation. A variety of target molecules has been studied, including simple rotors such as HF, and more complex species such as NH_3, CH_3I, CH_2Br_2 and C_6H_5NO_2. These targets encompass a range of dipole moments and rotational behavior, but analysis of the data shows that in each case the cross section #sigma#(#epsilon#) for rotationally-inelastic electron-polar molecule scattering varies approximately as 1/#epsilon# where #epsilon# is the electron energy. Such threshold behavior is not predicted by the Born approximation ...

1993-05-16

245

Point defect engineering in preamorphized silicon enriched with fluorine  

International Nuclear Information System (INIS)

Fluorine is known to have a beneficial role for the B diffusion reduction in preamorphized Si, and is promising for the realization of ultra-shallow junctions. Thus, we studied the F incorporation in Si during the solid phase epitaxy (SPE) process, pointing out the effects of the implanted F energy and fluence and the role played by the possible presence of dopants. The incorporation of fluorine proceeds by F segregation at the amorphous-crystalline interface, with a kinetics driven by the SPE rate. In fact, the quicker the SPE rate, the higher is the F fluence retained. Moreover, we demonstrated that F incorporated in Si layers does not appreciably affect the Is emission from spatially separated end-of-range (EOR) defects. The modification, induced by the presence of F, of the point defect density (Is and Vs) was also studied by means of B and Sb spike layers, used as local markers for Is and Vs, respectively. We showed that F is not only able to completely ...

2006-12-01

246

Oxygen stabilization induced enhancement in superconducting characteristics of high-Tc oxides  

International Nuclear Information System (INIS)

In an attempt to enhance the electrical and mechanical properties of the high temperature superconducting oxides, high T(sub c) composites were prepared composed of the 123 compounds and AgO. The presence of extra oxygen due to the decomposition of AgO at high temperature is found to stabilize the superconducting 123 phase. Ag is found to serve as clean flux for grain growth and precipitates as pinning center. Consequently, almost two orders of magnitude enhancement in critical current densities were also observed in these composites. In addition, these composites also show much improvement in workability and shape formation. On the other hand, proper oxygen treatment of Y5Ba6Cu11Oy was found to possibly stabilize superconducting phase with T(sub c) near 250 K. I-V, ac susceptibility, and electrical resistivity measurements indicate the existence of this ultra high T(sub c) phase in this compound. Detailed structure, microstructure, electrical, magnetic and thermal ...

1991-01-01

247

Modelisation of boron diffusion from ultra-low-energy implantation in crystalline silicon  

Energy Technology Data Exchange (ETDEWEB)

We have investigated and modeled the boron diffusion in silicon following ultra-low-energy implantation (500 eV). It is well known that reducing implant energies is an effective way to eliminate transient enhanced diffusion due to the excess of interstitials from the implant. However, for sub-keV B implants diffusion remains enhanced. This enhancement is linked to the presence of a silicon boride layer located at the silicon surface which creates interstitials. This phenomenon is named 'boron enhanced diffusion' (BED). The BED effect is of obvious interest since it counteracts the advantage obtained by reducing the ion implantation energy. For these reasons, we have investigated the diffusion of low-energy boron implanted in crystalline silicon and tested a complete simulation program, which takes into account the effect of boron precipitation and the effect of the silicon boride layer as a source of self-interstitials. Experimental results have ...

2003-12-31

248

Leading research on supermetal. Part 1. Large-scale materials (iron system); Super metal no sendo kenkyu. 1. Ogata sozai (tetsukei)  

Energy Technology Data Exchange (ETDEWEB)

Supermetal with critical characteristics is under advanced investigation for further improvement of metal materials. Although iron is most frequently used as structural material among various metals, it should be used more carefully and effectively because of resource limitation and global environmental problem. It is essential to draw various excellent properties much more from iron and to improve recyclability. In particular, the best way to meet these requirements is achievement of more fine structure and higher purity. Since the lowest crystalline grain size is now limited to nearly 10{mu}m, metallic structure composed of grains below 1{mu}m is expected by mesoscopic control. Various methods have been studied to achieve ultra-fine crystalline structure, and study of precise heat treatment control and ultra-strength metallurgy is required. Heat treatment in magnetic field and layered structure by mechanical alloying are also promising. ...

1996-03-01

249

High-energy cosmic-ray nuclei from high- and low-luminosity gamma-ray bursts and implications for multi-messenger astronomy  

CERN Document Server

Gamma-ray burst (GRB) is one of the candidates of high-energy cosmic-ray acceleration sites. They may be also ultra-high-energy (above 3 EeV) cosmic-ray (UHECR) sources. In this paper, we discuss possibilities and implications of high-energy cosmic-ray acceleration in GRBs. (1) First, we show that not only protons but also heavier nuclei can be accelerated up to ultra-high energies in both usual high-luminosity (HL) and low-luminosity (LL) GRBs by using the Geant4. LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population, and we investigate cosmic-ray acceleration in LL GRBs in detail. (2) Second, we discuss implications of the GRB-UHECR hypothesis (and Hypernova-UHECR hypothesis) to cosmic-ray astronomy. HL GRBs and LL GRBs will lead to different source number densities as UHECR sources, so that the determination of the number density of UHECR sources and strength of the mean extragalactic ...

2008-01-01

250

High Angular Resolution Imaging Spectroscopy of the Galactic Ultra-Compact HII Region K3-50A  

CERN Document Server

Gemini North adaptive optics imaging spectroscopy is presented for the Galactic ultra-compact HII (UCHII) region K3-50A. Data were obtained in the K-band using the Near-infrared Integral Field Spectrograph (NIFS) behind the facility adaptive optics module ALTAIR in natural guide star mode. The NIFS data cube reveals a complex spatial morphology across the 0.1 pc scale of the 3'' UCHII region. Comparison of the nebular emission to Cloudy ionization models shows that the central source must have an effective temperature between about 37000 K and 45000 K with preferred values near 40000 K. Evidence is presented for sharp density variations in the nebula which are interpreted as a clearing of material nearest the central source. High excitation lines of FeIII and SeIV show that the ionization of the nebula clearly changes with distance from the central source. A double lobed kinematic signature (+/- 25 kms) is evident in the Br gamma line map which may be related to ...

2009-01-01

251

Fundamentals for remote structural health monitoring of wind turbine blades - a pre-project. Annex D - Full-scale test of wind turbine blade, using sensors and NDT  

Energy Technology Data Exchange (ETDEWEB)

A 19.1 metre wind turbine blade was subjected to static tests. The purpose of the test series was to verify the abilities of different types of sensors to detect damage in wind turbine blades. Prior to each of the static test-series an artificial damage was made on the blade. The damage made for each test-series was surveyed during each series by acoustic emission, fiber optic micro bend displacement transducers and strain gauges. The propagation of the damage was determined by use of ultra sonic and X-ray surveillance during stops in the test series. By use of acoustic emission it was possible to measure damage propagation before the propagation was of visible size. By use of fiber optic micro bend displacement transducers and strain gauges it was possible to measure minor damage propagation. By use of both ultra sonic, and X-ray NDT-equipment it were possible to determine the size of propagated damage. (au)

2002-05-01

252

Electrical properties of ultra-thin oxynitrided layer using N{sub 2}O plasma in inductively coupled plasma chemical vapor deposition for non-volatile memory on glass  

Energy Technology Data Exchange (ETDEWEB)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics demonstrated that the ...

2007-06-04

253

Electrical properties of ultra-thin oxynitrided layer using N_2O plasma in inductively coupled plasma chemical vapor deposition for non-volatile memory on glass  

International Nuclear Information System (INIS)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics demonstrated that the ...

2007-06-04

254

Effect of V and W addition on the high temperature strength properties of 12%Cr-15%Mn austenitic steels. 12%Cr-15%Mn austenite ko no ondo kyodo ni oyobosu V to W tenka no eikyo  

Energy Technology Data Exchange (ETDEWEB)

Experimental discussions were given on effect of V and W addition on the high temperature strength properties of 12% Cr-15% Mn austenite steels. The test samples were added with W at 0% to 3.5% and V at 0% to 0.5% in addition to C and N, and were given aging treatment or solution treatment. This paper describes the following matters on the results of high-temperature strength measurements and structural observation: A remarkable trend was observed that M23 Cb type carbides precipitate in the aging treatment, wherein aging hardening appears prominently which is attributable to ultra-fine deposits of vanadium nitride (VN) in the V-added material; the V addition is very effective in increasing the high-temperature tensile strength and creep fracture strength as compared with single W addition, wherein the said carbides that accelerate the precipitation as a result of the V addition make a large contribution, in addition to that by ultra-fine VN ...

1992-11-01

255

Determination of the specific heat petroleum derivates; Determinacao do calor especifico de derivados ultrapesados de petroleo  

Energy Technology Data Exchange (ETDEWEB)

In the development of the specific mathematical modeling for heavy and ultra heavy petroleum fractions in a molecular distiller is very important the definition of physical and chemical parameters as density and specific heat of the mixture, the enthalpy of vaporization, among others, since they are used in the energy balance. Information on these properties and their variation with temperature are found in the open literature for mixture with few components (simple mixtures). However, for multicomponent solutions consisting of complex mixtures such as oil and its heavy and ultraheavy fractions, available data are few, or are limited to low temperatures. The specific heat is an important property in the energy balance. This property can be measured by Differential Scanning Calorimetry (DSC), which gives results with great sensitivity and accuracy. This paper presents the variation of specific heat with the temperature of ultra-heavy oil ...

2008-07-01

256

Conversion of a plasma enhanced chemical vapor deposited silicon-carbon-nitride thin film at ultra-low temperature by oxygen plasma  

Energy Technology Data Exchange (ETDEWEB)

In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray photoelectron spectroscopy is reported for both the as-deposited and ...

2008-01-30

257

Coherent Electromagnetic Processes in Ultra-Peripheral Heavy-Ion Collisions  

CERN Document Server

We report measurements for coherent rho^0 production, AuAu->AuAu rho^0, and coherent rho^0 and e^+e^- pair production accompanied by mutual nuclear Coulomb excitation, AuAu->Au*Au* rho^0 and AuAuee, in ultra-peripheral relativistic gold-gold collisions (UPC). We discuss transverse momentum, mass, and rapidity distributions. The two photon-process of e^+e^- pair production is an important probe of strong field QED because of the large coupling Z*alpha=0.6. At sqrt{s}=200GeV, the e^+e^- production cross section agrees with lowest order QED calculations. The cross sections for coherent rho^0 production at sqrt{s}=130 and 200GeV are in agreement with theoretical predictions. The calculations for both, coherent e^+e^- and rho^0 production treat nuclear excitation as independent process.

2004-01-01

258

Catalytic-adsorptive stripping voltammetric determination of ultra-trace iridium(III). Application to fresh- and sea-water  

British Library Electronic Table of Contents (United Kingdom)

An extremely sensitive stripping voltammetric procedure for ultra-trace determination of iridium(III) is reported. The method is based on the interfacial accumulation of the iridium(III)-CTAB complex onto the glassy carbon electrode, followed by the catalytic reduction of the adsorbed complex in the presence of bromate. 0.3molL^-^1 acetate buffer pH 4.7+6.9x10^-^2molL^-^1 NaBrO3+2.7x10^-^5molL^-^1 cetyltrimethylammonium bromide (CTAB)+0.2molL^-^1 KCl was employed as the supporting electrolyte. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403 and Fresh Water NIST-SRM 1643d. The accuracy, expressed as relative error e%, was satisfactory, being lower than 6%, while precision as repeatability, expressed as relative standard deviat...

2011-01-01

259

Analysis of algorithms for ultra high speed relays for the protection of high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

The object of this research is the evaluation of the performance of ultra high speed relays (UHSR's) used for protection of a-c transmission lines. For purposes of this report, these are relays whose response time is less than a quarter of a cycle of the 60 Hz wave (i.e. 4.167 ms.). To identify relaying schemes that may comply with this definition, a literature survey was undertaken. The selected relays were studied in detail and modeled on a digital computer. A theoretical description of these relays is presented. Records of real transient data as well as of simulated data were used as input to the digital models of relays. The real data were recorded by means of monitoring stations connected to the Florida Power and Light Company transmission lines. The simulated data were obtained by modeling the relevant parts of the utility's transmission system using a University of British Columbia simplified version of the well known Electromagnetic ...

1984-01-01

260

A new application of MRT of the lung using ultra-shot turbo spin echo sequences (UTSE)  

International Nuclear Information System (INIS)

T_2 weighted ultra-short turbo spin echo sequences were used in five individuals with variations in echo times, delayed triggering and echo intervals. To reduce movement artifacts all examinations were carried out with ECG and respiratory triggering. The sequences giving optimal image quality were then employed in 19 patients having various pulmonary abnormalities. Image resolutions, artifacts, image contrasts and diagnostic value were then judged by two observers and compared with CT. In the first study, a diastole-triggered UTSE sequence with the shortest echo proved optimal (T_E=90 ms, T_R=2-4 s, echo=9 ms, turbo factor=19). In the patient series studied, MRT was inferior to CT with regard to resolution and number of artifacts, but better in respect of contrast and diagnostic value. Using UTSE of the lung, MRT can produce images of good quality. Compared with CT, contrast is better with MRT, offering diagnostic advantages for MRT. (orig./MG).

261

A comparative study on ultra-shallow junction formation using co-implantation with fluorine or carbon in pre-amorphized silicon  

Energy Technology Data Exchange (ETDEWEB)

The main driver in ultra-shallow formation for the 65 nm technology node and beyond is to find solutions that both reduce boron transient enhanced diffusion and can be integrated in the CMOS process flow. To this end, many studies have recently focused on using co-doping techniques with fluorine and most recently with carbon. In most cases, one or both of these is co-implanted with a dopant specie in pre-amorphized silicon. In this work, we show a comparative study of fluorine or carbon co-implanted with low-energy boron to form source and drain extension junctions for PMOS devices. We will show that by a systematic optimization of germanium, boron, fluorine or carbon energies and doses, spike annealing technology can be extended to the 65 nm node. These results will be used to discuss how the different formed junctions offer potential solutions for either low-power or high-performance PMOS device fabrication.

2005-12-05

262

"Mtrack 2.0": An ultra-scale tracking algorithm for low-resolution overhead imagery  

Energy Technology Data Exchange (ETDEWEB)

Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery is very desirable. Typically, this imagery has many thousands of pixels on a side and is characterized by lower resolutions (e.g. {approx}0.5 meters/pixel to {approx}2.0 meters/pixel) and lower frame rates (e.g. {approx} sub-Hz to several Hz). We describe our ultra-scale capable implementation of a multiple-vehicle tracking algorithm for overhead persistent surveillance imagery. This work builds upon an earlier report, where now the algorithm has been modified for improved performance and has been substantially improved to handle much larger datasets in a much shorter time.

2008-09-26

263

Vertical array receptions of the Heard Island transmissions  

Energy Technology Data Exchange (ETDEWEB)

The Heard Island Feasibility Test (HIFT) demonstrated that coded acoustic signals could be detected at ranges up to 18,000 km with currently available source technology. This paper describes one component of the HIFT where a large aperture vertical line array was deployed to record the signals transmitted from Heard Island. We have performed four analysis Of the VLA receptions, of the Heard Island signals. All four suggest the presence of higher order modes. The frequency- vertical wavenumber analysis and the modal beamforming indicate that mode 3 has the highest amplitude while the modal fitting suggests that made 5--6 are largest. It is difficult to resolve the differences since the SNR at the VLA, nearly 18,000 km with a transmission loss of around 145 dB, is quite low. Individual arrivals could not be distinguished because of the long integration time necessitated by the low SNR.

1993-03-23

264

The Micro-X Imaging Spectrometer Instrument  

Science.gov (United States)

The Micro-X instrument is a NASA funded, rocket borne X-ray imaging spectrometer planned for launch in January 2011. An array of Transition Edge Sensors (TESs) will observe incoming photons in the 0.2-3 keV energy band with an energy resolution of 2-4 eV at 1 keV. This will be a substantial improvement over current non-dispersive detectors for X-ray spectroscopy of extended sources and will be the first demonstration of a TES-based microcalorimeter in space. The TESs will utilize the 50 mK stage of an Adiabatic Demagnetization Refrigerator (ADR) as a heat sink, and will be read out by a SQUID time division multiplexer. X-rays will be focused onto the TES array of 128 pixels on a 600 micron pitch by a conically approximated Wolter optic with an effective area of 200 cm2. The spectrometer will have a field of view of 11.8 arcmin. We describe the design and development progress of the instrument.

2010-01-01

265

The Australian Geographic Team Marsupial solar-powered car  

Energy Technology Data Exchange (ETDEWEB)

As in all vehicles of this type, low weight and aerodynamic drag must be achieved without compromising safety, and in an extremely rugged structure. This has been done by using a chrome-molybdenum steel space-frame, surrounded by a Kevlar/foam sandwich body shell. The solar panel wing, which uses a laminar flow section to obtain low drag, does not tilt except when the vehicle is stationary. A high degree of redundancy is built into the vehicle; for example there are two motors and transmissions, the solar array is divided into seven parallel sub-arrays, and the power electronics is multiply redundant. Built entirely in the garage of a suburban house, the Australian Geographic Team Marsupial car cost less than US$50,000 to construct.

1988-01-01

266

Stability of modulation transfer function calibration of surface profilometers using binary pseudo-random gratings and arrays with nonideal groove shapes  

Energy Technology Data Exchange (ETDEWEB)

The major problem of measurement of a power spectral density (PSD) distribution of surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments, which tends to distort the PSD at higher spatial frequencies. The special mathematical properties of binary pseudo-random patterns make them an ideal basis for developing MTF calibration test surfaces. Two-dimensional binary pseudo-random arrays (BPRAs) have been fabricated and used for the MTF calibration of the MicroMap{trademark}-570 interferometric microscope with all available objectives. An investigation into the effects of fabrication imperfections on the quality of the MTF calibration and a procedure for accounting for such imperfections are presented.

2010-03-31

267

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

Energy Technology Data Exchange (ETDEWEB)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of {approx}10{sup 4} or more is required to detect the magnetic scattering of this material.

2009-02-21

268

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

International Nuclear Information System (INIS)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of ?104 or more is required to detect the magnetic scattering of this material.

2009-02-21

269

Lymph node staging in cervical carcinoma: Results of high resolution MRT with phased-array coil; Lymphknotenstaging beim Zervixkarzinom: Ergebnisse der hochaufloesenden Magnetresonanztomographie (MRT) mit einer Phased-Array-Koerperspule  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To determine the diagnostic value of high resolution MR imaging with a circularly polarised (c.p.) body phased-array coil for the staging of pelvic lymph nodes in cervical carcinoma. Material and methods: 42 patients with histologically proven carcinoma of the cervix were studied on a 1.5 T scanner by using a c.p. body phased-array coil. The imaging protocol included T{sub 2}-weighted turbo-spin-echo (TSE) and T{sub 1}-weighted spin-echo sequences pre and post IV application of Gd-DTPA; slice thickness was 5-7 mm and pixel size 0.53 mm{sup 2}. Lymph nodes with a diameter of {>=}8 mm were considered to have metastatic involvement. MR imaging results were compared with histopathologic findings. Results: MR imaging showed enlarged lymph nodes ({>=} 8 mm) in 16 of 18 patients with histologic proof of lymph node metastases (sensitivity 89%). In 22 of 24 cases MR findings were true negative (specificity 92%). Diagnostic accuracy was ...

1997-03-01

270

International Lens Design Conference, Monterey, CA, June 11-14, 1990, Proceedings  

Energy Technology Data Exchange (ETDEWEB)

The present conference on lens design encompasses physical and geometrical optics, diffractive optics, the optimization of optical design, software packages, ray tracing, the use of artificial intelligence, the achromatization of materials, zoom optics, microoptics and GRIN lenses, and IR lens design. Specific issues addressed include diffraction-performance calculations in lens design, the optimization of the optical transfer function, a rank-down method for automatic lens design, applications of quadric surfaces, the correction of aberrations by using HOEs in UV and visible imaging systems, and an all-refractive telescope for intersatellite communications. Also addressed are automation techniques for optics manufacturing, all-reflective phased-array imaging telescopes, the thermal aberration analysis of a Nd:YAG laser, the analysis of illumination systems, athermalized FLIR optics, and the design of array systems using shared symmetry.

1990-01-01

271

High channel density wavelength division multiplexer with defined diffracting means positioning  

Energy Technology Data Exchange (ETDEWEB)

A wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges.

1990-01-01

272

Gas sensor arrays (electronic noses) and their combination with trap techniques  

Energy Technology Data Exchange (ETDEWEB)

In the food, chemical and safety industry there is a demand for gas detectors for process control applications, like quality control of food or leakage control in chemical plants. Gas sensor array systems have the potential to be used in this areas, with the advantage of being also affordable systems compared to other systems like gaschromatographs (GC) or infrared detectors (NIR, FTIR). One of the main drawbacks of the gas sensors is their response to non interesting ambient factors like temperature, pressure and humidity. Metal oxide sensors (MOS) have a low ambient temperature and pressure dependency. Some of them (SnO + dopands) have some sensitivity to humidity. In many cases the response of the sensors is often non-linear, which implies a concentration dependant pattern of the samples. (orig.)

2001-07-01

273

Development of a new #gamma#-ray detector for PEM applications  

International Nuclear Information System (INIS)

The authors are developing a high specificity detector for detecting the increased metabolic rate of breast tumors. Positron emission mammography (PEM) provides a highly efficient, high spatial resolution positron imaging system. PMT plays a very important role in PEM detectors, because most of the systems consist of scintillator arrays coupled with PMT. Our detector is composed of 20 x 20 arrays of 2 mm x 2 mm x 20 mm of Bi_4Ge_3O_1_2 (BGO) scintillators and a novel flat panel position-sensitive PMT (FP-PS-PMT)-Hamamatsu R8400-00-M256. Spatial resolutions of 2.0 mm FWHW and energy resolutions of 23% FWHM are achieved. (authors)

2007-05-01

274

Design of a GaAs/Ge solar array for unmanned aerial vehicles  

Energy Technology Data Exchange (ETDEWEB)

Unmanned Aerial Vehicles (UAV) are being proposed for many applications including surveillance, mapping and atmospheric studies. These applications require a lightweight, low speed, medium to long duration airplane. Due to the weight, speed, and altitude constraints imposed on such aircraft, solar array generated electric power is a viable alternative to air-breathing engines. Development of such aircraft is currently being funded under the Environmental Research Aircraft and Sensor Technology (ERAST) program. NASA Lewis Research Center (LeRC) is currently building a Solar Electric Airplane to demonstrate UAV technology. This aircraft utilizes high efficiency Applied Solar Energy Corporation (ASEC) GaAs/Ge space solar cells. The cells have been provided by the Air Force through the ManTech Office. Expected completion of the plane is early 1995, with the airplane currently undergoing flight testing using battery power.

1995-03-01

275

Deep subsurface structure modeling based on microtremor and earthquake observation. Applicability of microtremor array measurements at the Kashiwazaki-Kariwa Nuclear Power Station  

International Nuclear Information System (INIS)

During the 2007 Niigataken Chuetsu-oki earthquake, strong ground motion with the peak acceleration of 680 cm/s/s which was larger than that of the empirical prediction was recorded at the base mat of the No.1 reactor building of Kashiwazaki-Kariwa Nuclear Power Station (NPS). Furthermore, in the Kashiwazaki-Kariwa NPS, over twice difference of 680 vs. 322 cm/s/s of peak acceleration between the No.1 and the No.6 reactor buildings was observed on the base mat. From the results of recent research, it is suggested that the deep sedimentary layers can be one of the important factors to elucidate these phenomena. In this study, at first, the applicability of microtremor array measurements for estimation of deep S-wave velocity structure (#approx#Vs=3 km/s layer) are discussed. Vertical microtremors were observed in three arrays at the Kashiwazaki-Kariwa NPS with the maximum station spacings of 3.04 km, 1.49 km and 0.75 km, respectively. The Rayleigh ...

2010-05-01

276

Comparison of the channel coupling array and CRC methods for a realistic nuclear transfer-reaction model  

International Nuclear Information System (INIS)

Using a realistic three-body model, angular distributions for the "1"6O(d,p)"1"7O(1/2"+) reaction, based on the channel coupling array (CCA) theory and various forms of the coupled reaction channel (CRC) method are compared. Despite the different forms and theoretical foundations of these methods, they yield similar angular distributions, within the bound state approximations used herein. The expected breaking of time reversal inveriance in the approximated CCA theory is quite small over most of the angular range. Of all the methods used, coupling effects in the forward directions are largest for the post form of the CRC, indicating that it is the least reliable of the CRC forms for fitting data. (Auth.).

277

Adaptive Waveform Correlation Detectors for Arrays: Algorithms for Autonomous Calibration  

Energy Technology Data Exchange (ETDEWEB)

Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the individual channel correlation traces to achieve significant ...

2009-07-23

278

Acoustic metamaterials for new two-dimensional sonic devices  

Energy Technology Data Exchange (ETDEWEB)

It has been shown that two-dimensional arrays of rigid or fluidlike cylinders in a fluid or a gas define, in the limit of large wavelengths, a class of acoustic metamaterials whose effective parameters (sound velocity and density) can be tailored up to a certain limit. This work goes a step further by considering arrays of solid cylinders in which the elastic properties of cylinders are taken into account. We have also treated mixtures of two different elastic cylinders. It is shown that both effects broaden the range of acoustic parameters available for designing metamaterials. For example, it is predicted that metamaterials with perfect matching of impedance with air are now possible by using aerogel and rigid cylinders equally distributed in a square lattice. As a potential application of the proposed metamaterial, we present a gradient index lens for airborne sound (i.e. a sonic Wood lens) whose functionality is demonstrated by multiple ...

2007-09-15

279

A tomography system at the thermal neutron column of the ENEA Casaccia TRIGA reactor  

Energy Technology Data Exchange (ETDEWEB)

The developed system is intended for use at a collimated thermal neutron beam with a flux of about 10{sup 6} n/cm{sup 2} s. The system works with a cooled CCD array (192 x 165 pixels) and an intensifier for light from a NE426 scintillator with traditional optical coupling. A fine mechanical regulation system allows an accurate positioning of the tomographer, also ensuring the alignment of the CCD array with the rotation and translation axes. The acquisition of 200 projections is carried out in about 30 min with a reconstruction time (40 min max) depending on the reconstruction-matrix order. Radiography and tomography of significant objects are illustrated. The reconstruction algorithm, including spatial and temporal inhomogeneity corrections and filters, was tested with good results for projections up to 512 x 512 pixels. (orig.)

2002-07-01

280

A tomography system at the thermal neutron column of the ENEA Casaccia TRIGA reactor  

International Nuclear Information System (INIS)

The developed system is intended for use at a collimated thermal neutron beam with a flux of about 10"6 n/cm"2 s. The system works with a cooled CCD array (192 x 165 pixels) and an intensifier for light from a NE426 scintillator with traditional optical coupling. A fine mechanical regulation system allows an accurate positioning of the tomographer, also ensuring the alignment of the CCD array with the rotation and translation axes. The acquisition of 200 projections is carried out in about 30 min with a reconstruction time (40 min max) depending on the reconstruction-matrix order. Radiography and tomography of significant objects are illustrated. The reconstruction algorithm, including spatial and temporal inhomogeneity corrections and filters, was tested with good results for projections up to 512 x 512 pixels. (orig.)

281

A program for passively tracking a target using an array of sensors  

Energy Technology Data Exchange (ETDEWEB)

The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.

1993-01-01

282

A ZnO nanowire array film with stable highly water-repellent properties  

Energy Technology Data Exchange (ETDEWEB)

Highly water-repellent surfaces have been prepared from arrayed nanowires of zinc oxide (ZnO) by a treatment with stearic acid. The layers are electrochemically deposited on a nanocrystalline seed layer from an oxygenated aqueous zinc chloride solution. An advancing contact angle (CA) as high as 176{sup 0} is obtained with a very small hysteresis {approx}1{sup 0}. These results, supplemented by infrared spectroscopy, show that the stearic acid forms a very well-packed self-assembled monolayer. The CA measurements show a very good stability of the treated surface even when exposed to harsh conditions or long-term ambient illumination.

2007-09-12

283

A Combinatorial Library of Micro-Topographies and Chemical Compositions for Tailored Surface Wettability  

British Library Electronic Table of Contents (United Kingdom)

Abstract Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X-=-1-m and...

2011-01-01

284

{sup 242m}Am fueled nuclear battery  

Energy Technology Data Exchange (ETDEWEB)

A nuclear battery based on the direct energy conversion of the fission products is presented. Such energy conversion is possible by using a nuclear reactor with ultra-thin fuel elements of 0.2 {mu}m of {sup 242m}Am. The amount of nuclear fuel is 376 g and the dimensions of the battery are 2.4x2.4x2.4 m{sup 3} (including the vacuum spacing), with a BeO moderator and Be electrodes. The total power of the reactor is 10.6 MW and the electrical power is 0.652 MW.

2004-10-01

285

Ultra-thin {sup 242m}Am fuel elements in nuclear reactors. II  

Energy Technology Data Exchange (ETDEWEB)

There is growing interest in using {sup 242m}Am as a nuclear fuel for space reactors and nuclear batteries. In this paper, we discuss different {sup 242m}Am enrichments, as well as fuel weight requirements, to produce a critical reactor. It was found that relatively low enrichments of {sup 242m}Am, about 10 w/o, are enough to guarantee criticality. Such low enrichments might eliminate the need for a {sup 242m}Am enrichment process. It was also found that the best results for low {sup 242m}Am requirements are obtained with a moderator to fuel volume ratio of 10,000.

2004-04-21

286

Star Formation in the Outer Disks of Spiral Galaxies  

Science.gov (United States)

This is a study done in collaboration with Deidre Hunter at Lowell Observatory studying star formation in two luminous spiral galaxies NGC 801 and UGC 2885. We used ultra-deep H? images taken at the KPNO 2.1 m telescope. We compare these data to stellar images at various wavelengths and to HI maps to determine the extent of star formation activity into the outer disk in these galaxies and its relationship to the gas and older stars. TW is grateful for an REU internship during the summer of 2010 at Northern Arizona University, funded by NSF through grant AST-1004107.

2011-01-01

287

Simulation on energy deposition process due to anisotropic fast electron transport in high density plasma  

International Nuclear Information System (INIS)

Energy deposition process by relativistic fast electrons produced by ultra-intense laser pulses is discussed. The process is calculated with a two dimensional Fokker-Planck simulation code including binary and collective collisions coupled with electromagnetic field. We focused on Velocity Distribution Function (VDF) dependence in the simulation. The results show that the spread angle of the fast electrons distribution affects energy deposition area and deposited energy is concentrated in the vicinity of the propagation axis of the fast electrons. It may be also suggested that self-pinch effect of a fast electron beam causes large deposition energy. (author)

2008-03-01

288

Problems and approach to geological disposal of radioactive waste  

International Nuclear Information System (INIS)

This feature articles described a concept and technical problems of geological disposal of high-level radioactive waste in the civil engineering. It consists of six papers such as the present statues and subjects of geological disposal by KITAYAMA Kazumi, the diastrophism, igneous activity, and upheaval and erosion by YAMAZAKI Haruo, the groundwater flow and evaluation of nuclear transfer by IJIRI Yuji, evaluation of alteration of cement materials in the ultra-long period by HAGA Kazuko, The Mizunami Underground Research Laboratory in course of construction by SAKAMAKI Masanori, and interview of the ninetieth president of JSCE (Japan Society of Civil Engineers), he places his hope on JSCE and civil engineers by KISHI Kiyoshi. (S.Y.)

2006-11-01

289

Orthophosphoric acid interactions with ultrastable zeolite Y: Infrared and NMR studies  

Energy Technology Data Exchange (ETDEWEB)

Zeolite Y is the active component of most commercial cracking catalysts. Interaction of H[sub 3]PO[sub 4] with extraframework aluminum of ultra-stable zeolite (USY) leads to the formation of different types of aluminum phosphates, while there is no indication of the formation of SAPO zeotype structures. The total acidity of USY slightly decreases upon the H[sub 3]PO[sub 4] treatment, while the maximum in the distribution of acid strength is shifted to milder acidities. Dealumination of the zeolite and creation of POH sites associated with AIPO[sub 4] are responsible for the modifications observed. 37 refs., 8 figs., 3 tabs.

1994-01-01

290

Multilayer ultra high gradient insulator technology  

Energy Technology Data Exchange (ETDEWEB)

We are investigating a novel insulator concept which involves the use of alternating layers of conductors and insulators with periods less than 1 mm. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present our ongoing studies investigating the degradation of the breakdown electric field resulting from surface roughness, the effect of gas pressure, and the performance of the insulator structure under bi-polar stress. Further, we present our initial modeling studies.

1998-03-27

291

Improved formability of ultra high strength steels through local heat treatment  

Energy Technology Data Exchange (ETDEWEB)

In this paper it is described how a martensitic steel sheet with tensile strength of 1400 MPa is heat treated locally. The sheet is then formed in the heat treated regions in a way that would be impossible with the untreated material. Mechanical properties and forming limit diagrams of the heat treated material are determined and the forming operations are simulated, which shows that the method can be used by designers. Although the method has been known for decades, it remains to be industrialised and the work presented here is to be seen as a contribution to this development. (orig.)

2005-07-01

292

Enhancement of Heat and Mass Transfer in Mechanically Contstrained Ultra Thin Films  

Energy Technology Data Exchange (ETDEWEB)

Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of absorption and desorption systems can be ...

2005-01-01

293

Direct dark matter identification with a hybrid detection technique  

CERN Document Server

In the quest to understand the ultimate nature of WIMPs, we propose the use of a hybrid detection technique: cylinders filled with liquefied noble gasses, acting as targets, are immersed inside a tank of Gd-doped ultra-pure water that provides an active and efficient veto against neutrons. The evaluation of the background rejection capabilities and physics potential of this instrument have been carried out through a full GEANT4 simulation, assuming the detector will be located at the Canfranc underground laboratory (in the Spanish Pyrenees). Our results compare very favourably with existing or planned experiments in the field. This technique is scalable and will allow to reach target masses of few tonnes in the next future.

2008-01-01

294

Coverage and large scale anisotropies estimation methods for the Pierre Auger Observatory  

Energy Technology Data Exchange (ETDEWEB)

When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new method, developed for the Auger Observatory, based on a smooth estimate of the zenith angle distribution obtained from the data itself (which is essentially unchanged in the case of the presence of a large scale anisotropy pattern). We also study the sensitivity of several methods to detect large-scale anisotropies in the cosmic ray arrival direction distribution : Rayleigh analysis, dipole fitting and angular power spectrum estimation.

2005-07-01

295

Cosmic no hair for collapsing universes  

Energy Technology Data Exchange (ETDEWEB)

It is shown that all contracting, spatially homogeneous, orthogonal Bianchi cosmologies that are sourced by an ultra-stiff fluid with an arbitrary and, in general, varying equation of state asymptote to the spatially flat and isotropic universe in the neighbourhood of the big crunch singularity. This result is employed to investigate the asymptotic dynamics of a collapsing Bianchi type IX universe sourced by a scalar field rolling down a steep, negative exponential potential. A toroidally compactified version of M*-theory that leads to such a potential is discussed and it is shown that the isotropic attractor solution for a collapsing Bianchi type IX universe is supersymmetric when interpreted in an 11-dimensional context.

2006-05-21

296

Chloranilic acid as complex forming reagent for the ultra trace analysis of elements by adsorptive stripping voltammetry; Chloranilsaeure als Komplexbildner fuer die Ultraspurenanalyse von Elementen durch Adsorptions-Stripping-Voltammetrie  

Energy Technology Data Exchange (ETDEWEB)

It is reported about the adsorptive stripping voltammetric determination of uranium, antimony, tin, vanadium and molybdenum using chloranilic acid as complex forming reagent. The determination limits are in the l{sup 1}-range. (orig.) [Deutsch] Es wird ueber die Bestimmung von Uran, Antimon, Zinn, Vanadium und Molybdaen durch Adsorptions-Stripping-Voltammetrie mit Chloranilsaeure als Komplexbildner berichtet. Die Bestimmungsgrenzen liegen im ng l{sup -1} Bereich. (orig.)

1996-12-01

297

Ultra high vacuum test setup for electron gun  

Energy Technology Data Exchange (ETDEWEB)

Ultra High Vacuum (UHV) test setup for electron gun testing has been developed. The development of next generation light sources and accelerators require development of klystron as a radio frequency power source, and in turn electron gun. This UHV electron gun test setup can be used to test the electron guns ranging from high average current, quasi-continuous wave to high peak current, single pulse etc. An electron gun has been designed, fabricated, assembled and tested for insulation up to 80 kV under the programme to develop high power klystron for future accelerators. Further testing includes the electron emission parameters characterization of the cathode, as it determines the development of a reliable and efficient electron gun with high electron emission current and high life time as well. This needs a clean ultra high vacuum to study these parameters particularly at high emission current. The cathode emission current, work function and ...

2008-05-01

298

Spin-resolved magnetic studies of focused ion beam etched nano-sized magnetic structures  

International Nuclear Information System (INIS)

Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We report on new, spin-resolved magnetic microstructures, such as magnetic 'C' states and magnetic vortices, found at surfaces of ...

2005-04-01

299

Pressurized electroosmotic dewatering (PED) of fine coal suspensions  

Science.gov (United States)

Current dewatering methods for ultra-fine coal suspensions are inadequate and usually require subsequent expensive thermal drying. This unique dewatering method is based on pressurized electroosmosis, the movement of water by an electrical field through a porous medium, under modest pressure, e.g., 110 psi. More ultra-fine coal can be utilized since an effective dewatering process can be realized by combining known filtration techniques with electroosmosis. The dewatering efficiency can be significantly improved, the residual moisture of the cake can be substantially reduced and handling problems can be eliminated. Bench-scale testing is being used to optimize the parameters which influence pressurized electroosmotic dewatering (PED) of ultra-fine coal suspensions. Particle size distribution is being addressed to obtain a maximum density for a given pressure such that pore saturation is maintained allowing electroosmosis to ...

1985-01-01

300

Feasibility of ultra-low-dose multislice CT colonography for the detection of colorectal lesions: preliminary experience  

Energy Technology Data Exchange (ETDEWEB)

Our objective was to evaluate the feasibility of ultra-low-dose scanning for multislice CT colonography in the detection of colorectal lesions. Twenty-seven patients (14 men, 13 women) with clinical indication for conventional colonoscopy were recruited. Multislice spiral CT (Somatom Plus 4 Volume Zoom, Siemens, Germany) examinations were performed after standard oral colonoscopic preparation and colonic distension with room air. Images were acquired using 2.5-mm collimation, 3.0-mm slice thickness, standard reconstruction kernel, 140 kVp, and 10 mAs. Supine and prone acquisitions were obtained in all patients. Images were analyzed on a workstation by two gastrointestinal radiologists. Conventional colonoscopy was performed on the same day in all patients and represented the standard of reference. Total radiation exposure was also calculated. All colorectal cancers were correctly identified at CT colonography (9 of 9, sensitivity 100%). The CT colonography also ...

2003-06-01

301

Ultrafast photoinduced electron transfer reactions in supramolecular arrays: From charge separation and storage to molecular switches  

Science.gov (United States)

Photoinduced charge separation reactions form the basis for energy storage processes in both natural and artificial photosynthesis. Moreover, rapid reversible photoinduced electron transfer reactions are a class of photophysical phenomena that can be exploited to develop schemes for optical switching. Examples from each of these fields are discussed.

1992-01-01

302

Transport Properties of Doubly Periodic Arrays of Circular Cylinders and Optimal Design Problems  

Science.gov (United States)

We solve an R -linear problem for a multiple-connected circular domain in a class of doubly periodic functions in analytic form by a method of functional equations. This problem models transport properties of two-dimensional composite materials made from a collection of disks embedded in an otherwise uniform host.

2001-07-01

303

Transport Properties of Doubly Periodic Arrays of Circular Cylinders and Optimal Design Problems  

International Nuclear Information System (INIS)

We solve an R -linear problem for a multiple-connected circular domain in a class of doubly periodic functions in analytic form by a method of functional equations. This problem models transport properties of two-dimensional composite materials made from a collection of disks embedded in an otherwise uniform host.

2001-01-01

304

Technique for preliminary analysis and sizing of photovoltaic - thermal (PV-T) systems and associated components  

Energy Technology Data Exchange (ETDEWEB)

Design considerations of a combined photovoltaic-thermal (PV-T) system for a particular site and application must include thermal and electrical tradeoffs. A simplified technique for determining preliminary design and economic analyses would minimize costly computer simulation and indicate feasibility. To that end, nomographs that size an array to meet a specific annual load and determine the subsequent cost savings have been developed, and are presented in this paper.

1983-06-01

305

Reactivity of aliphatic amines toward platinum(II) complexes  

Energy Technology Data Exchange (ETDEWEB)

Reaction kinetics for the displacement of 5-aminoquinoline (5-Aq) and diethyl sulfide (SEt{sub 2}) from cis-[PtPh{sub 2}(CO)(L)] (L = 5-Aq or SEt{sub 2}) by aliphatic amines was measured for a wide array of amines. Reaction products were characterized by IR and NMR spectroscopies and crystalk structures of selected products were reported. Steric effects on the substitutions were discussed.

1994-08-31

306

Quantitative imaging of turbulent and reacting flows  

Energy Technology Data Exchange (ETDEWEB)

Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection strategies which provide ...

1993-12-01

307

New concept to optimize emergency diagnoses in patients with multiple injuries  

International Nuclear Information System (INIS)

To optimize the emergency care of patients with multiple injuries, a special emergency room with integrated radiological equipment has been developed. It consists of a linear array of a computed tomography system, a mobile C-arm with an integrated scattered radiation grid for conventional films and a C-arm fluorographic system. The intent is to avoid delay caused by transport and repositioning of the patient. It enables all necessary diagnostic procedures to be performed within a minimal amount of time. (orig./MG).

308

Massive parallel generation of indistinguishable single photons via the polaritonic superfluid to Mott-insulator quantum phase transition  

International Nuclear Information System (INIS)

We study the possibility of utilizing the superfluid to Mott-insulator quantum phase transition in an array of quantum well exciton-polariton traps to generate indistinguishable single photons in a massive parallel fashion. By means of analytical and numerical methods, the device operations and system properties are examined using realistic experimental parameters. Such a deterministic, massive parallel generation may find new applications in photonic quantum information processing.

2010-12-01

309

Layout 1 - NASA  

Science.gov (United States)

The solar array wings were deployed by swinging two half-blanket boxes open from a folded hinge launch position .... pure-water by-product of the shuttle's fuel cell power generators because ..... outgassing limits, flammability limits, ... Foale fills a water microbiology bag for in-flight analysis. ...

310

Heat exchange in a multi-cavity volumetric solar receiver  

Energy Technology Data Exchange (ETDEWEB)

The concept of a multi-cavity volumetric solar receiver is very attractive for the profitability of certain of its characteristics such as high efficiency and economy. The absorber is based on a pack of small ceramic cavities which intercept and absorb the inherent high solar flux reflected from an array of mirrors. Atmospheric air acts as a coolant medium when it is drawn through the pack. A model for an overall heat transfer performance of the receiver is given and numerically solved.

1991-01-01

311

Field Investigation of a Wake Structure Downwind of a VAWT (Vertical-Axis Wind Turbine) in a Wind Farm Array.  

Science.gov (United States)

The effects of upwind turbine wakes on the performance of a FloWind 17-m vertical-axis wind turbine (VAWT) were investigated through a series of field experiments conducted at the FloWind wind farm on Cameron Ridge, Tehachapi, California. From the field m...

1988-01-01

312

Electrical properties of retinal electrode interface  

Science.gov (United States)

A critical element of a retinal prosthesis is the stimulating electrode array, which is placed in close proximity to the retina. It is via this retinal-electrode interface that a retinal prosthesis electrically stimulates nerve cells to produce the perception of light. The impedance load seen by the current driver consists of the tissue resistance and the complex electrode impedance. The results in this paper show that the tissue resistance of the retina is significantly greater than that of the vitreous humor in the eye. Circuit models of the electrode-retina interface are used to parameterize the different contributors to the overall impedance.

2007-03-01

313

Detecting and Genotyping Escherichia coli O157:H7 using multiplexed PCR and nucleic acid microarrays  

Energy Technology Data Exchange (ETDEWEB)

Rapid detection and characterization of food borne pathogens such as Escherichia coli O157:H7 is crucial for epidemiological investigations and food safety surveillance. As an alternative to conventional technologies, we examined the sensitivity and specificity of nucleic acid microarrays for detecting and genotyping E. coli O157:H7. The array was composed of oligonucleotide probes (25-30 mer) complementary to four virulence loci (intimin, Shiga-like toxins I and II, and hemolysin A). Target DNA was amplified from whole cells or from purified DNA via single or multiplexed polymerase chain reaction (PCR), and PCR products were hybridized to the array without further modification or purification. The array was 32-fold more sensitive than gel electrophoresis and capable of detecting amplification products from < 1 cell equivalent of genomic DNA (1 fg). Immunomagnetic capture, PCR and a microarray were subsequently used ...

2000-12-01

314

Cross Entropy Approximation of Structured Covariance Matrices  

CERN Document Server

We apply two variations of the principle of Minimum Cross Entropy (the Kullback information measure) to fit parameterized probability density models to observed data densities. For an array beamforming problem with P incident narrowband point sources, N > P sensors, and colored noise, both approaches yield eigenvector fitting methods similar to that of the MUSIC algorithm[1]. Furthermore, the corresponding cross-entropies are related to the MDL model order selection criterion[2].

2006-01-01

315

Comparative transcriptional pathway bioinformatic analysis of dietary restriction, Sir2, p53 and resveratrol life span extension in Drosophila  

UK PubMed Central (United Kingdom)

A multiple comparison approach using whole genome transcriptional arrays was used to identify genes and pathways involved in calorie restriction/dietary restriction (DR) life span extension in Drosophila....Full Text Available

2011-03-15

316

Binary Pseudo-Random Gratings and Arrays for Calibration of Modulation Transfer Functions of Surface Profilometers  

Energy Technology Data Exchange (ETDEWEB)

A technique for precise measurement of the modulation transfer function (MTF), suitable for characterization of a broad class of surface profilometers, is investigated in detail. The technique suggested in [Proc. SPIE 7077-7, (2007), Opt. Eng. 47(7), 073602-1-5 (2008)]is based on use of binary pseudo-random (BPR) gratings and arrays as standard MTF test surfaces. Unlike most conventional test surfaces, BPR gratings and arrays possess white-noise-like inherent power spectral densities (PSD), allowing the direct determination of the one- and two-dimensional MTF, respectively, with a sensitivity uniform over the entire spatial frequency range of a profiler. In the cited work, a one dimensional realization of the suggested method based on use of BPR gratings has been demonstrated. Here, a high-confidence of the MTF calibration technique is demonstrated via cross comparison measurements of a number of two dimensional BPR arrays ...

2009-09-11

317

Pre-Flight Development of the PoGOLite Pathfinder  

International Nuclear Information System (INIS)

The Polarized Gamma-ray Observer (PoGOLite) is a balloon-borne instrument that will measure gamma-ray polarization in the energy range 25-80 keV from astronomical sources such as pulsars, accretion discs and jets from active galactic nuclei. The two additional parameters provided by such observations, polarization angle and degree, will allow these objects to be studied in a new way, providing information about their emission mechanisms and geometries. The instrument measures azimuthal scattering angles of photons within a close packed array of phoswich detector cells (PDCs) based on coincident detection of Compton scattering and photoelectric absorption. Each PDC comprises three different scintillating components and combines photon detection, active collimation and bottom anticoincidence into one single unit. The three parts are viewed by a photomultiplier tube (PMT) and pulse shape discrimination is used to identify signals from dierent parts. Surrounding the ...

318

ZrO_2/O' sialon composites containing mixed additives  

International Nuclear Information System (INIS)

Mixed additions of Sm_2O_3 and Y_2O_3 were used in the formation of zirconia-containing O'-sialon composites, where Sm_2O_3 was used for the purpose of densification and Y_2O_3 for zirconia stabilization. Dense ZrO_2/O' -sialon composites were produced at 1500 deg C. by sintering in nitrogen for 4 hours. Tetragonal zirconia remained in the product and t#->#m transformation was observed when the sample was ground into powder. However, the improvement in fracture toughness was not significant and this was attributed to the weakened transformability of the tetragonal zirconia phase in the nitrogen-based materials. 18 refs., 4 tabs., 2 figs.

319

Zirconium for superior corrosion resistance  

International Nuclear Information System (INIS)

Zirconium is a transition element located along with sister elements titanium and hafnium in Group IVB of the periodic table. It is grayish white metal, with a density somewhat less than carbon steel. Zirconium is the ninth most common metallic element in the earth's crust, and is more abundant than zinc, lead, nickel, or even copper. Zirconium is exceptionally resistant to corrosion by many common acids and alkalis. It is resistant to most organic acids, such as formic, acetic, lactic, and oxalic acids. It also has a high resistance to localized forms of corrosion, such as pitting, crevice corrosion, and stress corrosion cracking. Its corrosion resistance is caused by the formation of a dense, tenaciously adherent, chemically inert oxide film on the surface. This oxide film protects the base metal from both chemical and mechanical attack at temperatures up to about 400 C (750 F). This article describes zirconium's formability, machinability, corrosion resistance, ...

320

Wear and machining of engineering ceramics by abrasive waterjets  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this investigation was to simulate a machining front from an abrasive waterjet and its movements in a ceramic material. Wear factors affecting the abrasive waterjet nozzle were also to be established. Therefore, a low inclination angle (9[degree]) was used between the nozzle and test sample, simulating a moving machine front. A standard nozzle with an inner diameter of 0.76 mm was used in the test, and it was placed close to the samples. The outer diameter of the abrasive nozzle was 9.5 mm. The high wear rate from abrasive waterjets makes it possible to machine hard ceramics-including dense alumina, titanium boride, silicon nitride, and composites-at high machining speeds.

1993-08-01

321

Ultrastructure of the spermatozoon of the digenean Cricocephalus albus (Kuhl & van Hasselt, 1822) Looss, 1899 (Platyhelminthes, Pronocephaloidea, Pronocephalidae), parasite of ''the hawksbill sea turtle''Eretmochelys imbricata (Linnaeus, 1766) in Senegal  

British Library Electronic Table of Contents (United Kingdom)

The mature spermatozoon of Cricocephalus albus is filiform, tapered at both ends and shows the following features: 2 axonemes of different lengths presenting the 9+''1'' trepaxonematan pattern, 2 bundles of parallel cortical microtubules, a mitochondrion and a nucleus. Nevertheless, the particularity of the spermatozoon of C. albus is its anterior extremity with an apical electron-dense material associated with extramembranar ornamentation, a cytoplasmic dorsolateral expansion and spine-like bodies. To our knowledge, such an anterior extremity of the spermatozoon has not previously been described from a species of the superfamily Pronocephaloidea. Our study provides new data on the mature gamete of C. albus in order to improve our understanding of the pronocephaloidean phylogenetic relatio...

2011-01-01

322

The rapid nitriding of Al alloys with the controlling of plasma power density and pretreatments  

Energy Technology Data Exchange (ETDEWEB)

The properties of AlN make this material very attractive for optical, electronic, and tribological application. Also, if the AlN could be formed on the Al surface to enhance its surface properties, Al could be applied for the lightening of machine parts. However, a dense oxide film exists on the surface of Al, which prevents the formation of the Al nitride even during plasma nitriding and plasma coating process. In this study, plasma nitriding has been tried to form an AlN layer on Al after the surface activation processes. During the plasma nitriding, the density of the nitrogen ions was amplified by means of controlling the power of the Al substrates. The film thickness, microstructural features and the mechanical properties such as hardness and wear properties of the AlN layer were examined as a function of the process parameters of pretreatment and plasma nitriding

2010-05-15

323

The Nuclear Outflow in NGC 2110  

CERN Document Server

We present a HST/STIS spectroscopic and optical/radio imaging study of the Seyfert NGC 2110 aiming to measure the dynamics and understand the nature of the nuclear outflow in the galaxy. Previous HST studies have revealed the presence of a linear structure in the Narrow-Line Region (NLR) aligned with the radio jet. We show that this structure is strongly accelerated, probably by the jet, but is unlikely to be entrained in the jet flow. The ionisation properties of this structure are consistent with photoionisation of dusty, dense gas by the active nucleus. We present a plausible geometrical model for the NLR, bringing together various components of the nuclear environment of the galaxy. We highlight the importance of the circum-nuclear disc in determining the appearance of the emission line gas and the morphology of the jet. From the dynamics of the emission line gas, we place constraints on the accelerating mechanism of the outflow and discuss the relative ...

2010-01-01

324

Tetracycline ulcers of the oesophagus  

Energy Technology Data Exchange (ETDEWEB)

Two cases of tetracycline ulcers of the oesophagus are reported and compared with thirteen other cases from the literature. In most cases, the patients had taken their capsules with little or no fluid just before going to bed. Some hours later they developed retrosternal pain that was intensified by swallowing. Endoscopy showed sharply demarcated greyish-white areas of mucosal damage which represented layers of stratified squamous cells, separated by oedema, and a dense neutrophilic infiltration of the lamina propria and the muscularis mucosa. Roentgenology was unsuitable to detect the lesions. They healed without complications within one to six weeks. Prolonged retention of the capsules in the oesophagus is thought to cause the mucosal damage. Patients on oral tetracycline or doxycycline treatment should therefore be instructed to take their capsules with a meal or with copious water and not just before going to bed.

1981-11-01

325

Study on the structural evolution of modified phenol-formaldehyde resin adhesive for the high-temperature bonding of graphite  

International Nuclear Information System (INIS)

A novel adhesive for carbon materials composed of phenol-formaldehyde resin, boron carbide and fumed silica, was prepared. The adhesive property of graphite joints bonded by the above adhesive treated at high-temperatures was tested. Results showed that the adhesive was found to have outstanding high-temperature bonding properties for graphite. The adhesive structure was dense and uniform even after the graphite joints were heat-treated at 1500 deg. C. Bonding strength was 17.1 MPa. The evolution of adhesive structure was investigated. The results indicated that the addition of the secondary additive, fumed silica, improved the bonding performance greatly. Borosilicate phase with better stability was formed during the heat-treatment process, and the volume shrinkage was restrained effectively, which was responsible for the satisfactory high-temperature bonding performance of graphite.

2006-01-01

326

Spin-down of protostars through gravitational torques  

British Library Electronic Table of Contents (United Kingdom)

Abstract Young protostars embedded in circumstellar discs accrete from an angular momentum rich mass reservoir. Without some braking mechanism, all stars should be spinning at or near breakup velocity. In this paper, we perform simulations of the self-gravitational collapse of an isothermal cloud using the orion adaptive-mesh refinement code and investigate the role that gravitational torques might play in the spin-down of the dense central object. While magnetic effects likely dominate for low-mass stars, high-mass and Population III stars might be less well magnetized. We find that gravitational torques alone prevent the central object from spinning up to more than half of its breakup velocity, because higher rotation rates lead to bar-like deformations that enable efficient angular mome...

2011-01-01

327

Some preliminary views of plasma interaction: electromagnetic-launch systems  

Energy Technology Data Exchange (ETDEWEB)

This discussion outlines a few areas of fundamental research which appear vital for progress in developing advanced propulsion concepts using dc railgun thrusters. We have placed emphasis on the following: (1) dense plasma and high current density influences on changes in microstructure and properties of conventional rail conductors such as Cu, Al, and W alloys or composites; (2) the influences described in (1) on more advanced high temperature, microstrain resistant, materials such as amorphous tungsten; (3) location, description and temporal evolution of current, magnetic field, and losses during intense plasma-current field interactions with conductors; and (4) composite materials and sequentially sectioned structures for more efficient EM dc launcher configuration.

1982-07-14

328

Sintering and properties of #beta#"p"r"i"m"e-sialon with a nitrogen-rich Y_2O_3 sintering aid  

International Nuclear Information System (INIS)

The synthesis of dense sintered sialon with external additives selected from the system Y_2O_3-AlN-SiO_2 is reported. The highest density (3.21 g/cm"3) was achieved at 1750 degrees C at 90 min of sintering with 5 wt% additive. The degree of sialon substitution increased with the amount of liquid; the YSiO_2N crystalline phase formed concurrently. Strength degradation occurred above 1000 degrees C. The fracture toughness of the material sintered with a lower amount of sintering aid remained relatively unchanged to 1200 degrees C. The material with more additive exhibited decreased toughness above 1000 degrees C.

329

Single-step mineralization of woodpile chitosan scaffolds with improved cell compatibility  

British Library Electronic Table of Contents (United Kingdom)

Abstract A facile and efficient single-step mineralization approach was exploited for achieving nanoscopic hydroxyapatite (HAP) crystal layer in chitosan porous matrix, wherein a mixed water-ethanol solvent was used to control the growth of minerals. The crystallographic structure, morphology, and mechanical properties of the scaffold were analyzed with XRD, FTIR, environmental scanning electric microscopy (ESEM), TEM, and compression tests. The behaviors and responses of MC3T3-E1 pre-osteoblast cells on the scaffolds were studied as well. The results showed that the scaffolds kept woodpile structure with predefined and controlled hierarchical structure after mineralization. The inorganic phase in the mineralized chitosan scaffolds was determined as pure rod-like HAP, which settled densely...

2011-01-01

330

Significance of microstructure for a MOCVD-grown YSZ thin film gas sensor  

Energy Technology Data Exchange (ETDEWEB)

The authors report the fabrication and characterization of a low temperature (200--400 C) thin film gas sensor constructed from a MOCVD-grown yttria-stabilized zirconia (YSZ) layer sandwiched between two platinum thin film electrodes. A reproducible gas-sensing response is produced by applying a cyclic voltage which generates voltammograms with gas-specific current peaks and shapes. Growth conditions are optimized for preparing YSZ films having dense microstructures, low leakage currents, and maximum ion conductivities. In particular, the effect of growth temperature on film morphology and texture is discussed and related to the electrical and gas-sensing properties of the thin film sensor device.

1996-11-01

331

Serotonin Inhibits Protein Feeding in the Blow Fly, Phormia regina (Meigen)  

British Library Electronic Table of Contents (United Kingdom)

Serotonin is an important signaling molecule involved in the control of feeding in flies and other animals. In this study, a potential neurohemal release site for serotonin and the effects of exogenous serotonin on protein feeding were examined in the black blow fly, Phormia regina. A dense network of varicose neural processes exhibiting serotonin-like immunoreactivity was identified on the dorsal region of the thoracico-abdominal ganglion in P. regina. This dorsal region of the central nervous system is a likely site for the release of serotonin into the hemolymph. Circulating serotonin may have multiple systemic effects on fly physiology, including modulating or regulating feeding related processes and diuresis. Injections of exogenous serotonin reduced protein meal size in female flies ...

2009-01-01

332

Rondonia Deforestation (WMS)  

Science.gov (United States)

Throughout much of the 1980s, deforestation in Brazil eliminated more than 15,000 square kilometers (9000 square miles) of forest per year. Data gathered by several satellites in the Landsat series of spacecraft shows enormous tracts of forest disappearing in Rondonia, Brazil from 1975 through 2001. The human phenomenon of deforestation starts, especially in the dense tropical forests of Brazil, when systematic cutting of a road opens new territory to potential deforestation by penetrating into new areas. Clearing of vegetation along the sides of those roads then tends to fan out to create a pattern akin to a fish skeleton. As new paths appear in the woods, more areas become vulnerable. Finally, the spaces between the skeletal bones fall to defoliation.

2005-02-17

333

Renormalization of Polygon Exchange Maps arising from Corner Percolation  

CERN Document Server

We describe a 2 parameter family of polygon exchange transformations parameterized by points in a square. Whenever the two parameters are irrational, the polygon exchange has periodic orbits of arbitrarily large period. We show that for almost all parameters, the polygon exchange map has the property that almost every point is periodic. However, there is a dense set of irrational parameters for which this fails. By choosing parameters carefully, the measure of non-periodic points can be made arbitrarily close to full measure. These results are powered by a notion of renormalization which holds in a more general setting. Namely, we consider a renormalization of tilings arising from the Corner Percolation Model.

2011-01-01

334

Recycling and ?re-hydration? of degassed magma inducing transient dissolution/crystallization events at Stromboli (Italy)  

British Library Electronic Table of Contents (United Kingdom)

Intrusive degassing and recycling of degassed and dense magma at depth have been proposed for a long time at Stromboli. The brief explosive event that occurred at the summit craters on 9 January 2005 threw out bombs and lapilli that could be good candidates to illustrate recycling of shallow degassed magma at depth. We present an extensive data set on both the textures and the mineral, bulk rock and glassy matrix chemistry of the ?9 Jan? products. The latter have the common shoshonitic?basaltic bulk composition of lavas and scoriae issued from typical strombolian activity. In contrast they differ by the heterogeneous chemistry of their matrix glasses and their crystal textures that testify to crystal dissolution event(s) just prior magma crystallization upon ascent and eruption. Comparison...

2008-01-01

335

Rapid self-assembly of Ni nanodots on Si substrate covered by a less-adhesive and heat-accumulated SiO_2 layers  

International Nuclear Information System (INIS)

Rapid self-aggregation of Ni nanodots on Si substrate covered with a thin SiO_2 buffered layer is investigated. The Ni nanodots can hardly self-aggregate on highly heat-dissipated Si substrate with a thermal conductivity of 148 W/m K. Adding a 200-A-thick SiO_2 buffer with an ultralow thermal conductivity of 1.35 W/m K prevents the formation of NiSi_2 compounds, enhances the heat accumulation, and releases the adhesion at Ni/Si interface, which greatly accelerates the self-assembly of Ni nanodots. Dense Ni nanodots with size and density of 30 nm and 7x10"1"0 cm"-"2, respectively, can be formatted after rapid thermal annealing at 850 deg. C for 22 s.

2006-08-14

336

Rapid optical variability of TeV blazars  

British Library Electronic Table of Contents (United Kingdom)

Abstract In this first systematic attempt to characterize the intranight optical variability (INOV) of TeV-detected blazars, we have monitored a well-defined set of nine TeV blazars on total 26 nights during 2004-10. In this R- or V-band-monitoring programme only one blazar was monitored per night and the minimum duration was close to 4-h, the average being 5.3 h per night. Using the CCD for strictly simultaneous photometry of the blazar and nearby reference stars (N-star photometry), an INOV detection threshold of -1-2-per cent was achieved in the densely sampled differential light curves derived from our data. We have further expanded the sample by including another 13 TeV blazars, taking advantage of the availability in the literature of INOV data, including those published earlier in o...

2011-01-01

337

Protective nitride formation on stainless steel alloys for proton exchange membrane fuel cell bipolar plates  

British Library Electronic Table of Contents (United Kingdom)

Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr2N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr...

2007-01-01

338

Programmed cell death during pigment gland formation in Gossypium hirsutum leaves  

British Library Electronic Table of Contents (United Kingdom)

Abstract Ultrastructural studies have shown that the formation of pigment glands in Gossypium hirsutum L. leaves is a lysigenous process, originating from a cluster of cells in the ground meristem. Various techniques were used here to investigate whether programmed cell death (PCD) plays a critical role in this developmental process. Nuclei of internal cells in the pigment gland-forming tissue were TUNEL-positive and DAPI-negative, suggesting that DNA cleavage is an early event and complete DNA degradation is a late event. Smeared bands and a lack of laddering after gel electrophoresis indicate that DNA cleavage is random. Ultrastructurally, secretory cells in the pigment glands become distorted, nuclei are densely stained, and chromosomes become condensed until completely degraded at late...

2010-01-01

339

Preparation and Characterization of a Novel Polyamide Charged Mosaic Membrane  

British Library Electronic Table of Contents (United Kingdom)

A novel composite charged mosaic membrane (CCMM) was prepared via interfacial polymerization (IP) of polyamine [poly(epichlorohydrin amine)] and trimesoyl chloride (TMC) on the polyethersulfone (PES) support. Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and water contact angle analysis were applied to characterize the resulted CCMM. The FT-IR spectrum indicates that TMC reacts sufficiently with polyamine. ESEM and AFM pictures show that the IP process produces a dense selective layer on the support membrane. The water contact angle of the CCMM is smaller than that of the substrate membrane because of the cross-linked hydrophilic polyamine network. Several factors affecting the IP reaction and the performan...

2010-01-01

340

Photobioreactor for cultivation and real-time, in-situ measurement of O2 and CO2 exchange rates, growth dynamics, and of chlorophyll fluorescence emission of photoautotrophic microorganisms  

British Library Electronic Table of Contents (United Kingdom)

A detailed knowledge about the dynamics of phytoplanktonic photosynthesis and respiration is crucial for the determination of primary productivity in open oceans as well as for biotechnological applications. The dynamics are best studied in photobioreactors that are able to simulate natural conditions in such, that light can be modulated not only diurnally but also mimicking effects of solar elevation angle from sunrise to sunset, variable cloudiness, light modulation in refractory sun flecks due to water waves, or light intermittence due to turbulent flow in dense suspensions. In addition, high performance photobioreactors ought to be able to monitor in real time photosynthetic and respiratory activities as well as culture growth. Here, we demonstrate performance of a newly designed bench...

2009-01-01

341

On the problem of magnitude calibration of palaeoearthquakes  

British Library Electronic Table of Contents (United Kingdom)

Some factors affecting the accuracy of magnitude calibration of palaeoearthquakes are discussed. The general problem is illustrated by two case studies. First, the 2003 strong earthquake in the Altai region (Russia-Mongolia border), which has generated co-seismic surface faulting is considered. An analysis is conducted to determine how accurately its magnitude could be defined after 2000 years based on surface faulting parameters, retrieved when future palaeoearthquake studies are launched. This example demonstrates that accurate evaluation of magnitude is possible if specific regional seismotectonic features are taken into account and surface faulting parameters are measured over a dense grid. Next, the Muya earthquake that occurred in the Baikal seismic region in 1957 is studied with res...

2011-01-01

342

Numerical Algorithms for Two-Dimensional Dry Granular Flow with Deformable Elastic Grain  

Energy Technology Data Exchange (ETDEWEB)

The authors consider the dynamics of interacting elastic disks in the plane. This is an experimentally realizable two-dimensional model of dry granular flow where the stresses can be visualized using the photoelastic effect. As the elastic disks move in a vacuum, they interact through collisions with each other and with the surrounding geometry. Because of the finite propagation speed of deformations inside each grain it can be difficult to capture computationally even simple experiments involving just a few interacting grains. The goal of this project is to improve our ability to simulate dense granular flow in complex geometry. They begin this process by reviewing some past work, how they can improve upon previous work. the focus of this project is on capturing the elastic dynamics of each grain in an approximate, computationally tractable, model that can be coupled to a molecular dynamics scheme.

2005-08-11

343

New High-Pressure Excitations in Parahydrogen  

Energy Technology Data Exchange (ETDEWEB)

Raman and infrared spectroscopy of para-H{sub 2} to pressures in excess of 200GPa and to 8K using new ultrapure synthetic diamond anvils reveals numerous new vibrational excitations in the three high-pressure phases. Highly resolved Raman-active librons indicate differences in orientational ordering between phasesII and III, including evidence for changes within phaseII. The librons in phaseIII are strongly pressure dependent and reflect a substantial increase in ordering with pressure. Multiple vibrons in all three phases (I, II, and III) are observed. The results place new bounds on predicted crystal structures and dynamics of the dense molecular solid. {copyright} {ital 1997} {ital The American Physical Society}

1998-01-01

344

Multiparty controlled quantum secure direct communication using Greenberger Horne Zeilinger state  

Science.gov (United States)

Based on the idea of dense coding of three-photon entangled state and qubit transmission in blocks, we present a multiparty controlled quantum secret direct communication scheme by using Greenberger Horne Zeilinger state. In the present scheme, the sender transmits three bits of secret message to the receiver directly and the secret message can only be recovered by the receiver under the permission of all the controllers. All three-photon entangled states are used to transmit the secret message except those chosen for eavesdropping check and the present scheme has a high source capacity because Greenberger Horne Zeilinger state forms a large Hilbert space.

2006-10-01

345

Ionizing feedback from massive stars in massive clusters: fake bubbles and untriggered star formation  

British Library Electronic Table of Contents (United Kingdom)

Abstract We use Smoothed Particle Hydrodynamics to simulate the formation of a massive (106-M-) stellar cluster system formed from the gravitational collapse of a turbulent molecular cloud. We investigate the hierarchical clustering properties of our model system and we study the influence of the photoionizing radiation produced by the system's multiple O-type stars on the evolution of the protocluster. We find that dense gas near the ionizing sources prevents the radiation from eroding the filaments in which most of the star formation occurs and that instead, ionized gas fills pre-existing voids and bubbles originally created by the turbulent velocity field.

2011-01-01

346

Introduction to Big Bang nucleosynthesis: open and closed models, anisotropies  

Energy Technology Data Exchange (ETDEWEB)

A variety of observations suggest that the Universe had a hot dense origin and that the pregalactic composition of the Universe was determined by nuclear reactions that occurred in the first few minutes. There is no unique hot Big Bang theory, but the simplest version produces a primeval chemical composition that is in good qualitative agreement with the abundances deduced from observation. Whether or not any Big Bang theory will provide quantitative agreement with observations depends on a variety of factors in elementary particle physics (number and masses of stable or long-lived particles, half-life of neutron, structure of grand unified theories) and from observational astronomy (present mean baryon density of the Universe, the Hubble constant and deceleration parameter). The influence of these factors on the abundances is discussed, as is the effect of departures from homogeneity and isotropy in the early Universe.

1982-10-15

347

In-medium reduction of the \\eta' mass in \\sqrt{s_NN} = 200 GeV Au+Au collisions  

CERN Document Server

A reduction of the mass of the \\eta'(958) meson may indicate the restoration of the UA(1) symmetry in a hot and dense hadronic matter, corresponding to the return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a combined PHENIX and STAR data set on the intercept parameter of the two-pion Bose-Einstein correlation functions, as measuremed in \\sqrt{s_NN} = 200 GeV Au+Au collisions at RHIC. To describe this combined PHENIX and STAR dataset, an in-medium \\eta' mass reduction of at least 200 MeV is needed, at the 99.9 % confidence level in a broad model class of resonance multiplicities. Energy, system size and centrality dependence of the observed effect is also discussed.

2011-01-01

348

High-throughput screening of microscale pitted substrate topographies for enhanced nonviral transfection efficiency in primary human fibroblasts  

British Library Electronic Table of Contents (United Kingdom)

Optimization of nonviral gene delivery typically focuses on the design of particulate carriers that are endowed with desirable membrane targeting, internalization, and endosomal escape properties. Topographical control of cell transfectability, however, remains a largely unexplored parameter. Emerging literature has highlighted the influence of cell-topography interactions on modulation of many cell phenotypes, including protein expression and cytoskeletal behaviors implicated in endocytosis. Using high-throughput screening of primary human dermal fibroblasts cultured on a combinatorial library of microscale topographies, we have demonstrated an improvement in nonviral transfection efficiency for cells cultured on dense micropit patterns compared to smooth substrates, as verified with flow...

2011-01-01

349

High-tension corona controlled ozone generator for environment protection  

International Nuclear Information System (INIS)

Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O_3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.

2010-02-01

350

High dielectric constant ceramics for ion-electron sources  

Energy Technology Data Exchange (ETDEWEB)

Ferroelectric disks, coated with proper electrodes, can easily produce a dense plasma cloud when excited with a high-voltage pulse. This plasma can be a source of either electrons or ions depending on the sign of the extracting field set in front of the disk. We present the behavior of the disks operating at high frequency as emitters of both electrons and ions in two experimental configurations: (a) without and (b) with two screening grids. These two screening grids are inserted when the plasma must be confined within the cathode region. The system is capable of providing ion pulses of a few hundred milliamperes, whose length can range from a hundred nanoseconds to dozen microseconds. The electron pulses of energetic electrons have typically an amplitude higher than a couple of amperes. Tests at MHz repetition rate were positive as for stable operation.

2002-08-21

351

Fabrication of Dense -SiAlON Ceramics with ZrO2 Additions Via a Rapid Reaction-Bonding and Postsintering Route  

British Library Electronic Table of Contents (United Kingdom)

Rapid nitridation was used to fabricate reaction-bonded and postsintered -Si6-ZAlZOZN8-Z (Z=1) ceramics with monoclinic ZrO2 added to the starting powder. Thermo-gravimetric analysis revealed that the addition of ZrO2 reduced the starting temperature of the main nitridation reaction. Using a reaction-bonding route with heating rates of 5, 10, and 20C/min, to fabricate -SiAlON ceramics without ZrO2 resulted in unreacted silicon that bled out of the specimens and the Z=1 composition samples did not maintain the original green compact morphology. On the other hand, no such bleeding of melted silicon was observed for samples with ZrO2 additions and the samples following nitridation maintained the original green morphology. The microstructure and mechanical properties of samples produced by rap...

2011-01-01

352

Experimental modelling of thermal consolidation effects around a high level waste repository  

International Nuclear Information System (INIS)

This report summarizes the results of a research programme which involves the development of a laboratory experimental facility for the simulation and study of hydro-thermo-mechanical processes in saturated geomaterials with low permeability. The experimentation involves a synthetic cement based porous material made of cement grout which possesses permeabilities in the range of dense unfractured sandstones or shale. Specially manufactured pore-pressure transducers were installed within the cylindrical block at locations adjacent to a plane free boundary. The block was saturated with the periodic application of a vacuum. In its saturated state the plane boundary of the block was subjected to heating via a circular heater the temperature of which was maintained constant. The resulting pore pressure generation along with temperature at these locations was monitored continuously. The results of a series of experiments are documented and further extensions to the ...

353

Evapotranspiration estimation using the Landsat-5 Thematic Mapper image over the Gyungan watershed in Korea  

British Library Electronic Table of Contents (United Kingdom)

Even if there have been efforts to validate remote-sensing-based energy balance models, which provide evapotranspiration (ET) maps over a large spatial scale, few studies have been conducted to validate their performance in Korea. In this study, surface energy balance fluxes including ET were estimated and inter-compared with two different models using the Landsat-5 Thematic Mapper (TM) image over a watershed scale in Korea. While there were larger spatial discrepancies for net radiation, soil heat and sensible heat fluxes on a pixel-by-pixel basis between the two models, relatively smaller spatial discrepancies for the latent heat flux and daily ET were detected. The spatial discrepancies for the daily ET were larger in low topography and dense vegetation ranges. Despite the different par...

2011-01-01

354

Environmentally conscious sintered glass-ceramics  

Energy Technology Data Exchange (ETDEWEB)

Sintered glass-ceramics have been produced using municipal incinerator solid residues and glass cullet or an inert waste, from feldspars processing, as sintering aids. The capability of three different mixtures, either previously vitrified or not, to be sintered was investigated by means of linear shrinkage, water absorption and bulk density measurements, and by X-ray diffraction analysis and scanning electron microscopy observations. Particular attention has been addressed to the study of particle size effect on the sintering process. The conclusions that can be drawn from the experimental study are that the preliminary vitrification step is essential in order to obtain a dense sintered glass-ceramic product in the 850-1050 C temperature range developing silicate crystalline phases. The optimal powder particle size that confers a good densification degree was found to be < 45 {mu}m. (orig.)

2002-07-01

355

Electrorheological RayleighTaylor instability at the interface between a porous layer and thin shell with poorly conducting couple stress fluid  

British Library Electronic Table of Contents (United Kingdom)

This paper is concerned with the study of the Electrorheological RayleighTaylor instability (ERTI) at the interface between a densely packed saturated poorly conducting couple stress porous layer accelerated by a lighter poorly conducting couple stress fluid in a thin shell in the presence of a transverse electric field and laser radiation. A simple theory based on fully developed flow approximations is used to derive the dispersion relation for the growth rate of ERTI. The cutoff and the maximum wave numbers and the corresponding maximum frequencies are obtained. It is shown that the effects of couple stress parameter and the electric field reduce the growth rate considerably compared to a non-conducting fluid in the absence of an electric field. These are favorable to control the surface...

2011-01-01

356

Elastic properties, hardness and indentation fracture toughness of #beta#-sialons  

International Nuclear Information System (INIS)

Dense samples of #beta#-sialons (with z from 1 to 4) were pressuressly sintered for different time (15-240 minutes) and at relatively low temperature of 1600 C using single-phase #beta#-sialon powders synthesized by combustion nitridation. The samples were characterized using ultrasonic method for determination of elastic properties (E,G,#mu#). Also, hardness by Knoop and fracture toughness by Vickers indentation microfracture method was estimated. With increasing z number Young's modulus decreases from 293 to 179 GPa. Simultaneously Poisson ratio increases by about 30%. The highest values of hardness and fracture toughness were obtained for sialon with z equal to 1. (orig.).

1993-10-04

357

Effects of manganese doping on properties of sol-gel derived biphasic calcium phosphate ceramics  

British Library Electronic Table of Contents (United Kingdom)

We have investigated the effect of manganese (Mn) doping on properties of nanosized biphasic calcium phosphate powders and their dense bodies. Manganese levels of 0.6, 1.3, 1.9, 4.3, 7.0 and 11.9at.% were successfully incorporated into biphasic calcium phosphate via a sol-gel route. The prepared powders were calcined at temperatures of 500-1200^oC. The X-ray diffraction analysis revealed that a mix phase comprising of hydroxyapatite and @b-tricalcium phosphate were present, however the content of each phases in the structure was affected by the Mn content. The studies found that the largest portion of @b-tricalcium phosphate was detected at 4.3at.% Mn doping. The incorporation of Mn has also greatly increased the crystallinity of the biphasic calcium phosphate powder due to progressive den...

2011-01-01

358

Dimensional stability, optical and elastic properties of MgAl{sub 2}O{sub 4} spinel irradiated in FFTF to very high exposures  

Energy Technology Data Exchange (ETDEWEB)

Stoichiometric MgAl{sub 2}O{sub 4} spinel specimens irradiated in FFTF-MOTA at temperatures between 385 and 750C to fluences ranging from 2.2 to 24.9 {times} 10{sup 22}n cm{sup {minus}2} (E>0.1 MeV) darken significantly, but do not develop any significant loss in weight or change in dimensions. Similar behavior was observed in both single crystal and fully dense polycrystalline specimens. Measurements of elastic constants by an ultrasonic technique show that no measurable changes occur as a result of the irradiation. These and other results confirm the stability of this material for fusion application as an electrical insulator.

1993-10-01

359

Development of a support system for hydraulic maniford block design. Yuatsu manifold block yo sekkei shien system no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a newly developed software for manifold block design. Manifold block has become indispensable as an important component part to hydraulic systems since the 1970 {prime} s. However, its design is complicated and difficult. The reasons are firstly that hydraulic circuits have to be densely placed and secondary there is no means to correct a failure in the design or manufacture. Considering these points, the experiments of design engineers and the habitual design processes are analyzed, and a support system for manifold block design was developed by using a super-mini computer. With this system, the correctness of a design became to be proved. The software is easy to operate, and it can retrieve past design data, and it is extendible to the production line. 4 refs., 7 figs., 4 tabs.

1990-11-15

360

Correlation effects in partially ionized mass asymmetric electron-hole plasmas  

CERN Document Server

The effects of strong Coulomb correlations in dense three-dimensional electron-hole plasmas are studied by means of unbiased direct path integral Monte Carlo simulations. The formation and dissociation of bound states, such as excitons and bi-excitons is analyzed and the density-temperature region of their appearance is identified. At high density, the Mott transition to the fully ionized metallic state (electron-hole liquid) is detected. Particular attention is paid to the influence of the hole to electron mass ratio $M$ on the properties of the plasma. Above a critical value of about M=80 formation of a hole Coulomb crystal was recently verified [Phys. Rev. Lett. {\\bf 95}, 235006 (2005)] which is supported by additional results. Results are related to the excitonic phase diagram of intermediate valent Tm[Se,Te], where large values of $M$ have been observed experimentally.

2007-01-01

361

Combining innovative technology demonstrations with dense nonaqueous phase liquids cleanup  

Energy Technology Data Exchange (ETDEWEB)

Radioactively contaminated acidic aqueous wastes and organic liquids were discharged to the soil column at three disposal sites within the 200 West Area of the Hanford Site, Washington. As a result, a portion of the underlying groundwater is contaminated with carbon tetrachloride several orders of magnitude above the maximum contaminant level accepted for a drinking water supply. Treatability testing and cleanup actions have been initiated to remove the contamination from both the unsaturated soils to minimize further groundwater contamination and the groundwater itself. To expedite cleanup, innovative technologies for (1) drilling, (2) site characterization, (3) monitoring, (4) well field development, and (5) contaminant treatment are being demonstrated and subsequently used where possible to improve the rates and cost savings associated with the removal of carbon tetrachloride from the soils and groundwater.

1993-05-01

362

Chemistry of dense clumps near moving Herbig-Haro objects  

British Library Electronic Table of Contents (United Kingdom)

Abstract Localized regions of enhanced emission from HCO+, NH3 and other species near Herbig-Haro objects (HHOs) have been interpreted as arising in a photochemistry stimulated by the HHO radiation on high-density quiescent clumps in molecular clouds. Static models of this process have been successful in accounting for the variety of molecular species arising ahead of the jet; however, recent observations show that the enhanced molecular emission is widespread along the jet as well as ahead. Hence, a realistic model must take into account the movement of the radiation field past the clump. It was previously unclear as to whether the short interaction time between the clump and the HHO in a moving source model would allow molecules such as HCO+ to reach high enough levels, and to survive fo...

2011-01-01

363

Characterising and reducing seizure wear of inconel and incoloy superalloys in a sliding contact  

British Library Electronic Table of Contents (United Kingdom)

Superalloys, such as Inconels and Incoloys, are extensively used where high strength is a requirement. However, where these materials are required to slide against one another, particularly with poor or no lubrication, high friction levels and seizure are commonly seen to occur, which can cause component failure. In this work seizure characteristics of three superalloys (Inconel 718 and Incoloys 945 and 945X) were investigated, uncoated, coated with Armoloy (a hard, thin, dense chrome coating with a micro-nodular surface texture) and plasma nitrided in dry sliding conditions. A rig purpose built for initiating seizure was used. It involves sliding a ball against a disc at constant speed while the load is increased. Tests are designed to last less than one rotation so that the wear scar can...

2011-01-01

364

Bubble nucleation, growth and coalescence during the 1997 Vulcanian explosions of Soufriere Hills Volcano, Montserrat  

British Library Electronic Table of Contents (United Kingdom)

Soufriere Hills Volcano had two periods of repetitive Vulcanian activity in 1997. Each explosion discharged the contents of the upper 0.5-2km of the conduit as pyroclastic flows and fallout: frothy pumices from a deep, gas-rich zone, lava and breadcrust bombs from a degassed lava plug, and dense pumices from a transition zone. Vesicles constitute 1-66vol.% of breadcrust bombs and 24-79% of pumices, all those larger than a few tens of m being interconnected. Small vesicles (few hundreds of m) in pumices are interpreted as pre-dating explosion, implying pre-explosive conduit porosities up to 55%. About a sixth of large vesicles in pumices, and all those in breadcrust bombs, are angular voids formed by syn-explosive fracturing of amphibole phenocrysts. An intermediate-sized vesicle population...

2010-01-01

365

Automated motion estimation of root responses to sucrose in two Arabidopsis thaliana genotypes using confocal microscopy  

British Library Electronic Table of Contents (United Kingdom)

Root growth is a highly dynamic process influenced by genetic background and environment. This paper reports the development of R scripts that enable root growth kinematic analysis that complements a new motion analysis tool: PlantVis. Root growth of Arabidopsis thaliana expressing a plasma membrane targeted GFP (C24 and Columbia 35S:LTI6b-EGFP) was imaged using time-lapse confocal laser scanning microscopy. Displacement of individual pixels in the time-lapse sequences was estimated automatically by PlantVis, producing dense motion vector fields. R scripts were developed to extract kinematic growth parameters and report displacement to ?0.1 pixel. In contrast to other currently available tools, Plantvis-R delivered root velocity profiles without interpolation or averaging across the root s...

2011-01-01

366

A superconductor to superfluid phase transition in liquid metallic hydrogen  

CERN Document Server

Although hydrogen is the simplest of atoms, it does not form the simplest of solids or liquids. Quantum effects in these phases are considerable (a consequence of the light proton mass) and they have a demonstrable and often puzzling influence on many physical properties, including spatial order. To date, the structure of dense hydrogen remains experimentally elusive. Recent studies of the melting curve of hydrogen indicate that at high (but experimentally accessible) pressures, compressed hydrogen will adopt a liquid state, even at low temperatures. In reaching this phase, hydrogen is also projected to pass through an insulator-to-metal transition. This raises the possibility of new state of matter: a near ground-state liquid metal, and its ordered states in the quantum domain. Ordered quantum fluids are traditionally categorized as superconductors or superfluids; these respective systems feature dissipationless electrical currents or mass flow. Here we report an ...

2004-01-01

367

A principle of charged particle trapping by RF electromagnetic field in the spherical cavity  

Energy Technology Data Exchange (ETDEWEB)

A new principle of particle trapping in the simple spherical cavity using both electric and magnetic components of radiofrequency electromagnetic field is proposed. The electric component of H {sub 12} oscillating mode drives the fast particle oscillations, while the magnetic component synchronously bends the trajectories to the cavity center. A specially developed theory of particle stability predicts dense and energetic electron cluster in the trap. Numerical simulations of particle dynamics in the complete electromagnetic field taking into account both space charge and particle-induced magnetic field are in good agreement with the analytic results, giving a density of 2.6*10{sup 1} electrons/cm{sup 3} and an average kinetic energy of around 30 keV at an operating frequency of 3 GHz. Being used at lower frequency, spherical cavity can trap protons and heavier ions too, but with lower density and kinetic energy.

2005-11-21

368

A novel approach for measuring the radial distribution of charge in a heavy ion track  

International Nuclear Information System (INIS)

The energy deposited by the passage of a single, energetic, heavy-ion through a semiconductor produces dense electron-hole (eh) pair concentrations near the ion trajectory. The size, shape, and charge density of an ion track represent critical parameters for many models of single event phenomena. The authors describe the design and uses of possible semiconductor test structures for measuring the initial radial distribution of charge and subsequent charge transport in a high energy, heavy-ion track. Numerical simulations show how the test structure can resolve different radial distributions of charge within an ion track. The test structure simulations also show the importance of accurately representing ion track structure in single event effects simulations.

1994-07-18

369

Study of silicon damage caused by ultra-low energy boron implantation  

International Nuclear Information System (INIS)

Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross section transmission microscopy (XTEM) as ...

370

Swelling/shrinkage of compacted and natural clayey soils; Retrait/gonflement des sols argileux compacts et naturels  

Energy Technology Data Exchange (ETDEWEB)

This thesis presents an experimental study performed on compacted loose and natural dense expansive soils using osmotic odometers. Several successive cycles were applied under three different low constant vertical net stresses. The loose soil presents a significant shrinkage accumulation while the dense one produces the swelling accumulation during the suction cycles. The suction cycles induced an equilibrium stage which indicates an elastic behaviour of the samples. At the end of suction cycles, a loading/unloading test was performed at the constant suctions for both materials. The mechanical parameters, i.e. the virgin compression index lambda(s), the apparent pre-consolidation stress p0(s) and the elastic compression index values lambda are completely dependent on the followed stress paths. The whole experimental results made it possible to define the yielding surfaces: suction limit between micro and macrostructure (Lm/M), loading collapse ...

2007-12-15

371

Suspension and solution plasma spraying of finely structured layers: potential application to SOFCs  

International Nuclear Information System (INIS)

Suspension direct current plasma spraying allows achieving finely structured coatings whose thickness is between few tens and few hundreds of micrometres. Drops (200-300 ?m in diameter) or liquid jets are mechanically injected in the plasma jet. With radial injection they are rapidly (a few ?s) fragmented into droplets (a few ?m in diameter). The latter are vaporized (in a few ?s) and the solid particles contained in suspension droplets are accelerated and melted by the plasma jet. As in conventional plasma spraying (CPS), much smaller splats (with diameters between 0.2 and 3 ?m and thicknesses between 30 and 200 nm) are arranged in layers up to form the coating. The low inertia of particles requires spray distances between 40 and 60 mm which induces plasma heat fluxes up to 22 MW m-2 participating in coating densification. Even more than in CPS, the plasma jet fluctuations, particularly for plasmas containing di-atomic gases, perturb drops penetration and fragmentation. It has been ...

2007-04-21

372

Spectroscopic investigation of the charge dynamics of heavy ions penetrating solid and gaseous targets  

Energy Technology Data Exchange (ETDEWEB)

This thesis presents the study of the slowing down process of fast heavy ions inside matter. In the framework of this research, the influence of the target density on the stopping process is investigated. Experiments on the interaction of {sup 48}Ca{sup 6+}-{sup 48}Ca{sup 10+} and {sup 26}Mg{sup 5+} ion beams with initial energies of 11.4 MeV/u and 5.9 MeV/u with solid and gaseous targets have been carried out. A novel diagnostic method, X-ray spectroscopy of K-shell projectile radiation, is used to determine the ion charge state in relation to its velocity during the penetration of fast heavy ions inside the stopping material. A spatially resolved analysis of the projectile and target radiation in solids is achieved for the first time. The application of low-density silica aerogels as stopping media provided a stretching of the ion stopping length by 20 - 100 times in comparison with solid quartz. The Doppler Effect observed on the projectile K-shell spectra is used to calculate the ...

2007-01-15

373

PROGRESS IN BEAM FOCUSING AND COMPRESSION FOR WARM-DENSE MATTER EXPERIMENTS  

Energy Technology Data Exchange (ETDEWEB)

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using spacecharge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has beendemonstrated in the Neutralized Drift Compression Experiment (NDCX) with controlledramps and forced neutralization. Using an injected 30-mA K+ ion beam with initialkinetic energy 0.3 MeV, axial compression leading to ~;;50-fold current amplification andsimultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss the status of several improvements to our Neutralized Drift Compression Experiment and associated beam diagnostics that are under development to reach the necessary higher beam intensities, including: (1) greater axial ...

2008-09-25

374

High resolution electron microscopy of interfaces in fcc materials  

Energy Technology Data Exchange (ETDEWEB)

Modern high-resolution electron microscopy (HREM) instruments, which are capable of a point-to-point resolution of better than 0.2 nm, have allowed atomic-scale observations of a variety of internal interfaces. The application of the HREM technique to fcc model systems for the purpose of addressing a number of interface issues will be examined in this paper. Atomic structure observations for heterophase interfaces of metal/metal and metal/metal-oxide systems as well as HREM studies of grain boundaries in NiO and Au will be discussed with emphasis on generic structural features and the role of the interface plane. Comparisons between observed interface structures and atomistic computer modeling results have shown agreements for some interfaces, as well as certain differences in others. A number of structural features are common to both metal and oxide grain boundaries, as well as certain heterophase boundaries. Of particular importance in close-packed solids appears to be the tendency ...

1990-08-01

375

Herschel observations in the ultracompact HII region Mon R2: Water in dense Photon-dominated regions (PDRs)  

CERN Document Server

Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds 13CO, C18O, o-H2-18O, HCO+, CS, CH, and NH have been used to derive the physical and chemical conditions in the PDR, in particular the water abundance. The 13CO, C18O, o-H2-18O, HCO+ and CS observations are well described assuming that the emission is coming from a dense (n=5E6 cm-3, N(H2)>1E22 cm-2) layer of molecular gas around the UC HII. Based on our o-H2-18O observations, we estimate an o-H2O abundance of ~2E-8. This is the average ortho-water abundance in the PDR. Additional H2-18O and/or water lines are required to derive the water abundance profile. A lower density envelope (n~1E5 cm-3, N(H2)=2-5E22 cm-2) is responsible for the absorption in the NH 1_1-0_2 line. The emission of the CH ground state triplet is coming ...

2010-01-01

376

Halogens for negative ion beams and ion-ion plasmas  

International Nuclear Information System (INIS)

Negative ions have attractive features as drivers for inertial confinement fusion, because they will avoid electron cloud effects, and could be efficiently photodetached to neutrals after the final focus, which could also be beneficial in heating warm dense matter targets. The halogens have large electron affinities, and thus should be able to produce high current densities of relatively robust negative ions. Recent experiments comparing chlorine beams to argon beams using the same source, extraction optics, and diagnostics have demonstrated that Cl"- beams can be produced with similar emittance to Ar"+ beams, and with about 34 the current density from the same configuration. The observed effective beam temperature of about 13eV, and the similarity of current densities show that negative halogen beams can meet the current density and emittance requirements of heavy ion fusion. The near equivalence of the Cl"- and Cl"++Cl_2"+ current densities reaching the Faraday ...

2007-07-01

377

Estimates of the hydrologic impact of drilling water on core samples taken from partially saturated densely welded tuff  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this work is to determine the extent to which drill water might be expected to be imbibed by core samples taken from densely welded tuff. In a related experimental study conducted in G-Tunnel, drill water imbibition by the core samples was observed to be minimal. Calculations were carried out with the TOUGH code with the intent of corroborating the imbibition observations. Due to the absence of hydrologic data pertaining directly to G-Tunnel welded tuff, it was necessary to apply data from a similar formation. Because the moisture retention curve was not available for imbibition conditions, the drainage curve was applied to the model. The poor agreement between the observed and calculated imbibition data is attributed primarily to the inappropriateness of the drainage curve. Also significant is the value of absolute permeability (k) assumed in the model. Provided that the semi-log plot of the drainage and imbibition moisture retention curves are ...

1987-09-01

378

Diagnostic value of immediate CT after chemoembolization in patients with hepatocellular carcinoma: comparison with 2-3 week delayed CT  

Energy Technology Data Exchange (ETDEWEB)

Lipiodol CT is a important modality for the diagnosis of hepatocellular carcinoma and compared is usually performed at 2-3 week after Lipiodol injection. Therefore, we assessed and the diagnostic value and merits of immediate CT after chemoembolization from there of 2-3 week delayed Lipiodol CT. Thirty three cases of chemoembolization which were performed both immediate CT after chemoembolization and 2-3 week delayed Lipiodol CT were reviewed retrospectively. They were divided into four grades according to pattern of lipiodol uptake by three radiologists. The diagnostic value of immediate Lipiodol CT was compared to delayed Lipiodol CT. Grade 0 was two cases(3.0%) and Grade 1 was seven cases(21.2%). In the cases of Grade 2(23/33, 69.7%), tumor uptake could be dishing wished from parenchymal uptake of Lipiodol by its density and pattern, Tumor uptake showed dense and homogeneous pattern, but parenchymal uptake revealed less dense and ...

1995-08-15

379

Bonding of WC with an iron aluminide (FeAl) intermetallic  

Energy Technology Data Exchange (ETDEWEB)

FeAl, which has high oxidation and sulfidation resistance, was shown to be thermodynamically compatible with WC. Calculations indicate that soly. of WC in liq. Fe-40at.%Al at 1450 C is about 2 at.%. Since liquid FeAl wets WC very well, the WC/FeAl system lends itself to liquid-phase sintering, resulting in close to theoretical densities. Almost fully dense cermets with 20.6 wt% FeAl binder were produced. With one-step infiltration, 98% dense cermets with only 7 wt% FeAl binder were fabricated. RT bend strengths and fracture toughness for WC-20.6 wt% FeAl reached 1680 MPa and 22 MPa{center_dot}m{sup 1/2}. Ductile binder fracture was observed on the fracture surfaces. Pores containing oxide inclusions were found, suggesting that improvements in processing are likely to further improve the mechanical properties. Insufficient process control may explain why WC/FeAlNi cermets did not show improved mechanical properties, although Ni strengthens FeAl. ...

1996-08-01

380

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

381

Useful vacancies: Positron beam interrogation of fluorine-vacancy complexes in semiconductor device structures  

Energy Technology Data Exchange (ETDEWEB)

The formation, migration and agglomeration in silicon of fluorine-vacancy complexes have been monitored by single-detector Doppler broadening spectroscopy. After electronics engineers found that fluorine ion implantation effectively eliminated the transient-enhanced diffusion of dopants in the creation of ultra-shallow junctions, a vital step in the further miniaturization of device structures, positron beams have played a pivotal role in providing an insight into the mechanisms underlying this phenomenon, being able to detect FV complexes in implanted and annealed samples. Secondary Ion Mass Spectrometry has provided complementary information on fluorine concentrations so that the nature of the F{sub m}V{sub n} complexes can be further assessed. New results on Si and SiGe structures are presented.

2008-10-31

382

Untersuchungen zur Anwendung von UHPFRC-Tubbingen bei der zweischaligen Tunnelbauweise  

British Library Electronic Table of Contents (United Kingdom)

Faserbewehrter Beton wird heute zunehmend auch bei Tunnelbauwerken (Tunnelinnenschalen, Tubbinge) eingesetzt. Wesentliche Vorteile sind das hohe Tragvermogen, das daraus entstehende Einsparungspotential an herkommlicher stabformiger Bewehrung (Biegebewehrung, Bugelbewehrung in der Randzone), die Aufnahme von Spaltzugbeanspruchungen durch die Fasern, Rissbreitenbegrenzung, erhohte Dauerhaftigkeit, verbesserter Brandwiderstand (insbesondere bei Verwendung von Kunststofffasern), Optimierung der Arbeitsablaufe etc. Neue Entwicklungen in der Betontechnologie haben in den letzten Jahrzehnten den faserbewehrten ultrahochfesten Beton (engl. UHPFRC - Ultra High Performance Fibre Reinforced Concrete) hervorgebracht. Im Rahmen dieser Arbeit wird der Einsatz des ultrahochfesten, stahlfaserbewehrten Be...

2010-01-01

383

Ultratrace determination in high purity molybdenum and tungsten with ion chromatographic trace-matrix-separation. Pt. 2; Ultra trace analysis using ion chromatography. Ultraspurenanalytik in hochreinem Molybdaen und Wolfram mit ionenchromatographischer Spuren-Matrix-Trennung. Tl. 2; Ionenchromatographische Ultraspurenanalyse  

Energy Technology Data Exchange (ETDEWEB)

The use of high-performance ion exchangers allows a trace-matrix-separation (SMT) directly followed by an ion chromatographic (IC) separation of the analytes. Based on the principles described in Part 1, a combined procedure IC-SMT-IC for metallic impurities in Mo and W is presented. Up to 12 metal traces (Fe, Cu, Pb, Zn, Ni, Co, Cd, Ca, Mn, Sr, Mg and Ba) can be determined in one run with 35 min. A special method for traces of U and Th is also given. Detection limits are typically 10-100 ng g{sup -1} in the metal sample. (author). 14 refs.; 10 figs.; 6 tabs.

1992-01-31

384

Ultra high strength beta titanium alloy for fasteners  

International Nuclear Information System (INIS)

A new high strength titanium alloy has been developed primarily intended for fastener applications. While Ti-6Al-4V is used extensively as a fastener alloy in the aerospace industry, its shear strength allowable is limited to 655 MPa (95 ksi). For higher shear strength requirements, various steels or nickel-based alloys are used (up to 860 MPa (125 ksi)), but with the attendant density penalty. This new alloy is intended to provide the 860 MPa shear strength at roughly a 40% weight savings. After screening various alloy systems, the optimum chemistry has been selected as follows: Ti-6.0V-6.2Mo-5.7Fe-3Al. In light of its 125 ksi shear strength goal, the alloy has been designated TIMETAL reg-sign 125.

1993-02-21

385

The investigations on K and L X-ray fluorescence parameters of gold compounds  

British Library Electronic Table of Contents (United Kingdom)

The study aimed to determine the chemical effects on the K and L X-ray intensity ratios and the K and L X-ray production cross sections for gold compounds. The K shell fluorescence yields and L shell average yields were also investigated. The samples were excited by 59.5keV ?-rays from an 241Am annular radioactive source and 123.6keV ?-rays from a 57Co annular radioactive source. K and L X-rays emitted from samples were counted by an Ultra-LEGe detector with a resolution of 0.150keV at 5.9keV. The experimental values were compared with theoretical, the semi-empirical and other experimental values.

2010-01-01

386

Self-organization and electrical properties of Head-to-Tail poly(3-hexylthiophene) in Langmuir-Blodgett films  

Energy Technology Data Exchange (ETDEWEB)

The conductive ultra thin films were fabricated from mixed monolayers containing stearic acid and Head-to-Tail poly(3-alkylthiophene). These films exhibited well-defined layered structures as determined by optical absorption and X-ray diffraction measurements. The UV-Vis absorption spectra of these films showed lower energy absorption shifts of 48 nm from that of the random poly(3-alkylthiophene)/stearic acid LB films. The blue shift of absorption maximum of the LB film is attributed to the increase of {pi}-conjugation length caused by no steric hindrance of alkyl side chains. The conductivity of the Head-to-Tail poly(3-hexylthiophene)/stearic acid LB films was greatly improved in the range of 67-100 S/cm. (orig.)

1997-01-01

387

Pulsed laser deposition of titanium-carbonitride thin films  

Energy Technology Data Exchange (ETDEWEB)

The goal of this research program is to determine whether pulsed laser deposition is an effective alternative method for growing TiCN thin films. Pulsed laser deposition (PLD) is chosen because of its well-documented capability for growing uniform, stoichiometric films in ultra-high vacuum or gaseous environments. Processing of thin films by PLD is also achieved at relatively low temperatures compared with CVD processing. Given these attributes, the primary objectives in this article are to determine whether nitrogen may be readily incorporated into films resulting from the laser-ablation of TiC in an N{sub 2} environment, determine what effect nitrogen has on mechanical properties, and determine whether nitrogen incorporation is strongly influenced by processes unrelated to laser deposition (e.g., thermally-activated surface reactions).

1997-05-15

388

Potential of AMS for Quantifying Long-Lived Reaction Products  

International Nuclear Information System (INIS)

Accelerator mass spectrometry (AMS) represents a powerful technique for the detection of long-lived radionuclides through ultra-low isotope ratio measurements. In many cases, counting atoms rather than decays yields much higher sensitivities. The potential of AMS will be demonstrated on typical radionuclides of interest with half-lives between some tens of years up to a hundred million years. The precise measurement of the 27Al(n,2n)26Al excitation function will be exemplified. Lack of information exists for a list of nuclides as pointed out by nuclear data requests. A brief overview on detection limits and some applications for selected long-lived radionuclides is given.

2005-05-24

389

Photodegradation of flupentixol in aqueous solution under irradiation at 254nm: Identification of the photoproducts generated  

British Library Electronic Table of Contents (United Kingdom)

After irradiation at 254nm of aqueous solutions of the antipsychotic drug flupentixol, the structures of the photodegradation products were determined by ultra high performance liquid-chromatography linked to mass spectrometry. Fragmentation patterns of the parent ions were established on a hybrid linear ion trap-orbitrap mass spectrometer allowing accurate mass measurements of both parent and daughter ions. This allowed to propose plausible structures for the main photolysis products of flupentixol. A total of nine photoproducts were detected after irradiation of the drug. The main photoproduct is generated following the addition of a hydroxyl group on the double bond adjacent to the thioxanthene ring. Secondary photoproducts were also observed.

2010-01-01

390

Optimized pre-amorphization conditions for the formation of highly activated ultra shallow junctions in silicon-on insulator  

International Nuclear Information System (INIS)

Pre-amorphization of ultrashallow implanted boron in Silicon-on-insulator is optimized to produce an abrupt box-like doping profile with negligible electrical deactivation and significantly reduced transient enhanced diffusion. The effect is achieved by positioning the as-implanted amorphous/crystalline interface close to the buried oxide interface, to minimize interstitials whilst leaving a single-crystal seed to support solid-phase epitaxy. Based on a simple physical model of our results, we estimate that the interface between the Si overlayer and the buried oxide is an efficient interstitial sink with a recombination length of the order of 10nm or less under our experimental conditions. (author)

2008-12-01

391

On the parameterization of the roughness length for the air-sea interface in free convection for the coastal site Tarapur, India  

International Nuclear Information System (INIS)

The roughness length at air-sea interface during free convection (Z0fc) is mainly related to the convective velocity (w) rather than the friction velocity (u). The parameterization of Z0fc with (w)2/g as proposed by Abdella and D'Alessio (2003) is evaluated. It is shown that the field measurements at MM Lab, Tarapur Maharashtra Site (TMS) coastal site using Metek GmbH, Ultra sonic anemometers are consistent with the proposed formula. In order to avoid self-correlation by using u, a new parameterization of w with ?u and ?v and gustiness parameter as given by Fairall et al. (1996) is used. The mean values of w and Z0fc estimated using new parameterization were observed to be 0.97 m/s and 2.3E-4 m respectively for the year 2009 at TMS. (author)

2010-05-13

392

Non-destructive Imaging of Individual Bio-Molecules  

CERN Document Server

Radiation damage is considered to be the major problem that still prevents imaging an individual biological molecule for structural analysis. So far, all known mapping techniques using sufficient short wave-length radiation, be it X-rays or high energy electrons, circumvent this problem by averaging over many molecules. Averaging, however, leaves conformational details uncovered. Even the anticipated use of ultra-short but extremely bright X-ray bursts of a Free Electron Laser shall afford averaging over 10^6 molecules to arrive at atomic resolution. Here we present direct experimental evidence for non-destructive imaging of individual DNA molecules. In fact, we show that DNA withstands coherent low energy electron radiation with deBroglie wavelength in the Angstrom regime despite a vast dose of 10^8 electrons/nm^2 accumulated over more than one hour.

2009-01-01

393

Near term and future alternative clean vehicle technologies  

Energy Technology Data Exchange (ETDEWEB)

Availability of a natural gas-powered van that meets California`s ultra low emission vehicle requirements and has a 300-km range was reported. A similar van with an electric system giving a range of 240 km was also within sight. Regarding the limitations of electric batteries it was suggested that a super capacitor may allow systems to achieve higher energy densities; a refuelable zinc-air battery could be considered for vehicle use. While the prospect for emissions improvement of gasoline vehicles has clearly improved in recent years, the relative costs of infrastructure, vehicle and fuel for the the alternative fuels compared with gasoline demonstrate the difficulty the alternative fuels have in taking market share from gasoline. For the next decade, gasoline, propane and CNG are expected to be the dominant fuels for vehicles. After that, the leading fuel will be the one that has been most extensively researched and developed during the decade. 17 refs.

1994-12-31

394

Mesodynamics in the SARS nucleocapsid measured by NMR field cycling  

Energy Technology Data Exchange (ETDEWEB)

Protein motions on all timescales faster than molecular tumbling are encoded in the spectral density. The dissection of complex protein dynamics is typically performed using relaxation rates determined at high and ultra-high field. Here we expand this range of the spectral density to low fields through field cycling using the nucleocapsid protein of the SARS coronavirus as a model system. The field-cycling approach enables site-specific measurements of R{sub 1} at low fields with the sensitivity and resolution of a high-field magnet. These data, together with high-field relaxation and heteronuclear NOE, provide evidence for correlated rigid-body motions of the entire {beta}-hairpin, and corresponding motions of adjacent loops with a time constant of 0.8 ns (mesodynamics). MD simulations substantiate these findings and provide direct verification of the time scale and collective nature of these motions.

2009-09-15

395

Manganese oxide nanowires, films, and membranes and methods of making  

Energy Technology Data Exchange (ETDEWEB)

Nanowires, films, and membranes comprising ordered porous manganese oxide-based octahedral molecular sieves, and methods of making, are disclosed. A single crystal ultra-long nanowire includes an ordered porous manganese oxide-based octahedral molecular sieve, and has an average length greater than about 10 micrometers and an average diameter of about 5 nanometers to about 100 nanometers. A film comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is stacked on a surface of a substrate, wherein the nanowires of each layer are substantially axially aligned. A free standing membrane comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is aggregately stacked, and wherein the nanowires of each layer are substantially axially aligned.

2008-10-21

396

Ionically conductive thin polymer films prepared by plasma polymerization. Pt. 7. Preparation and characterization of solid polymer electrolyte having fixed carboxylic acid groups with single mobile species  

Energy Technology Data Exchange (ETDEWEB)

Ultra-thin, uniform, pinhole-free solid polymer electrolyte films having a fixed carboxylic ester group of approximately 1 {mu}m thickness were prepared by polymerization of methyl acrylate and tris(2-methoxyethoxy)vinylsilane in a glow discharge plasma. The carboxylic ester group of the plasma polymer were transformed to lithium carboxylate groups by treatment with lithium iodide. This process give a single lithium ion conductive film. These solid polymer electrolyte films showed ionic conductivities of the order of 10{sup -8} S cm{sup -1} (10{sup 4} {omega} cm{sup 2} resistance per unit area) at room temperature. (orig.).

1990-08-01

397

Influence of Population III stars on cosmic chemical evolution  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT New observations from the Hubble Ultra Deep Field suggest that the star formation rate at Formula Not Shown drops off faster than previously thought. Using a newly determined star formation rate for the normal mode of Population II/I (PopII/I) stars, including this new constraint, we compute the Thomson scattering optical depth and find a result that is marginally consistent with Wilkinson Microwave Anisotropy Probe 5 results. We also reconsider the role of Population III (PopIII) stars in light of cosmological and stellar evolution constraints. While this input may be needed for reionization, we show that it is essential in order to account for cosmic chemical evolution in the early universe. We investigate the consequences of PopIII stars on the local metallicity distribution fu...

2009-01-01

398

Improved recovery demonstration for Williston basin carbonates. Quarterly technical progress report, October 1, 1995--December 31, 1995  

Science.gov (United States)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional and multi-component seismic area is being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in-place will result in additional oil production by primary and enhanced recovery processes.

1996-02-01

399

Improved recovery demonstration for Williston basin carbonates. Annual report, June 10, 1994--June 9, 1995  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.

1995-09-01

400

Improved recovery demonstration for Williston Basin carbonates. Annual report, June 10, 1995--June 9, 1996  

Science.gov (United States)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.

1996-09-01

401

Identification of fatigue damage in cortical bone by diffraction enhanced imaging  

International Nuclear Information System (INIS)

In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.

2005-08-11

402

Hot dip galvanised dual phase steels for automotive applications  

Energy Technology Data Exchange (ETDEWEB)

The automotive industry desires to optimize safety and lightweight construction for the production of cars and trucks. The resulting task for steel suppliers is to make steel grades available that can fulfil these requirements. Different projects have shown optimistic outlooks for optimization of safety and reduction of the weight of automobile bodies by using different high strength and ultra high strength steels. In the last group the dual phase steels play the lead. In recent years different steel grades have been developed and optimized for these applications. On one hand developing the mechanical properties as well as joining and forming of dual phase steels is one of the first steps. On the other hand different coated surfaces for various applications of dual phase steels is another step. Starting with characteristic production conditions for cold rolled hot dip galvanised dual phase steels, the mechanical properties for joining and forming will be deduced ...

2005-07-01

403

High-throughput proteomics of breast carcinoma cells: a focus on FTICR-MS  

Energy Technology Data Exchange (ETDEWEB)

Discovery of better biomarkers for diagnosis, prognosis, and therapy-response prediction is the most critical task of a scientific quest aimed at developing newly designed, tailor-made therapies for patients with cancer. Consequently, a proteome wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.

2008-06-05

404

High-temperature property data: Ferrous alloys  

Energy Technology Data Exchange (ETDEWEB)

In this book over 250 alloys are organized by AISI number into 10 major sections: Irons, Carbon Steels, Alloy Steels, Low Alloy Constructional Steels, Ultra High Strength Steels, Tool Steels, Maraging Steels, Wrought Stainless Steels, Heat Resistnat Casting Alloys, and Iron Based Rought Superalloys. Each alloy record lists the designation, specifications, UNS number, composition, product forms and a comment on the high-temperature properties and applications. Referenced data is then given for physical properties such as density, specific heat, thermal conductivity, thermal expansion, electrical conductivity, Poisson's ratio, moduli of elasticity and rigidity, etc. Mechanical properties follow, and include tensile properties, shearing and bearing properties, impact properties, creep, stress rupture and stress relaxation and fatigue properties. The last part of the alloy record gives other effects of temperature, such as hot hardness, corrosion, and growth.

1987-01-01

405

High-Throughput Screening of Drugs of Abuse in Urine by Supported Liquid?Liquid Extraction and UHPLC Coupled to Tandem MS  

British Library Electronic Table of Contents (United Kingdom)

A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...

2009-01-01

406

Friction in ultra-thin conjunction of valve seals of pressurised metered dose inhalers  

British Library Electronic Table of Contents (United Kingdom)

In many drug dispensing devices, such as syringes and inhalers, an elatomeric gasket is used to prevent the formulation from leaking from the chamber. During device actuation, the seal is subjected to friction, which in turn causes its deformation and can cause unintentional leakage, thus dose variability. Additionally, friction of seal is responsible for a host of potential problems such undue effort required for actuation and potential wear. The mechanism of friction generation in the seal conjunction is complex, arising from adhesion of rubber in contact with the moving interface, viscous action of a thin film of fluid and deformation of seal asperities. Therefore, the first step in understanding the conjunctional behaviour of rubber seals is a fundamental study of mechanisms of frictio...

2010-01-01

407

Empirical regularities of order placement in the Chinese stock market  

CERN Document Server

Using ultra-high-frequency data extracted from the order flows of 23 stocks traded on the Shenzhen Stock Exchange, we study the empirical regularities of order placement in the opening call auction, cool period and continuous auction. The distributions of relative logarithmic prices against reference prices in the three time periods are qualitatively the same with quantitative discrepancies. The order placement behavior is asymmetric between buyers and sellers and between the inside-the-book orders and outside-the-book orders. In addition, the conditional distributions of relative prices in the continuous auction are independent of the bid-ask spread and volatility. These findings are crucial to build an empirical behavioral microscopic model based on order flows for Chinese stocks.

2007-01-01

408

Embedded systems for vacuum control at PEFP  

International Nuclear Information System (INIS)

Development of a front end system for a high energy proton accelerator is in progress at Korea Atomic Energy Research Institute (KAERI) for basic science and industrial applications. The proper vacuum components has been installed and operated successfully between ion source and RFQ. The reliable operation of the accelerator has been completed at vacuum system in the high and ultra high vacuum range under operating conditions. Proper control system for the vacuum instruments, based on PC operated by Windows, has been designed and constructed by control group at PAL. As PC operated by windows with inherent instability does not proper, embedded system can be replaced for reliable operation system, such as VME system operated by vxWorks.

2005-05-26

409

Effects of C-60 fullerenes and carbon nanotubes on marine mussels.  

Environmental Research Database

Objectives1. We will use reduction of lysosomal stability as an indicator of cell injury induced by C-60 fullerenes and carbon nanotubes in the liver analogue or digestive gland (hepatopancreas) of marine mussels. Molluscan hepatopancreatic digestive cells are key to normal function and are a sensitive key interface with the environment. Reduction of lysosomal stability is mechanistically linked with impaired health of the whole animal. 2. We will also test the hepatopancreatic digestive cells for evide [continued...]DescriptionNanotechnology is a major innovative scientific and economic growth area, which may present a variety of hazards for environmental and human health. The surface properties and very small size of nanoparticles and nanotubes provides surfaces that may bind and transport toxic chemical pollutants, as well as possibly being toxic in their own right by generating reactive oxygen species (ROS). There is a wealth of evidence for the harmful effects of nanoscale ...

2008-01-25

410

Double plasma mirror for ultrahigh temporal contrast ultra-intense laser pulses  

International Nuclear Information System (INIS)

We present and characterize a very efficient optical device that employs the plasma mirror technique to increase the contrast of high-power laser systems. Contrast improvements higher than 104 with 50% transmission are shown to be routinely achieved on a typical 10 TW laser system when the pulse is reflected on two consecutive plasma mirrors. Used at the end of the laser system, this double plasma mirror preserves the spatial profile of the initial beam, is unaffected by shot-to-shot fluctuations, and is suitable for most high peak power laser systems. We use the generation of high-order harmonics as an effective test for the contrast improvement produced by the double plasma mirrors. (authors)

411

Development of In-Service Inspection system for heat transfer tubes in the primary pressurized water cooler in the HTTR  

International Nuclear Information System (INIS)

The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

1999-08-22

412

Development of In-Service Inspection system for heat transfer tubes in the primary pressurized water cooler in the HTTR  

Energy Technology Data Exchange (ETDEWEB)

The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

1999-08-01

413

COSY synchrotron and storage ring for medium energy physics  

Energy Technology Data Exchange (ETDEWEB)

At present the cooler synchrotron COSY a synchrotron and storage ring for medium energy physics is being commissioned at Juelich. The construction of the ring was finished during September 1992. The cooler ring will deliver protons in the momentum range from 270 to 3300 MeV/c. The phase density of the circulating protons will be increased with electron cooling at injection and with stochastic cooling at momenta between 1500 and 3300 MeV/c. High luminosity internal experiments as well as high resolution external experiments will be possible. Details of the lattice, to match the different ion optical requirements for cooling, acceleration, internal experiments and ultra-slow extraction will be discussed. An overview of the performance of the ion sources, the injector cyclotron, the ring, the injection beamline are given. The realization status of the extraction beamlines to the external experimental area is given. The experience on the commissioning of the cooler ...

1993-01-01

414

Boron-enhanced-diffusion of boron: The limiting factor for ultra-shallow junctions  

Energy Technology Data Exchange (ETDEWEB)

Reducing implant energy is an effective way to eliminate transient enhanced diffusion (TED) due to excess interstitials from the implant. It is shown that TED from a fixed Si dose implanted at energies from 0.5 to 20 keV into boron doping-superlattices decreases linearly with decreasing Si ion range, virtually disappearing at sub-keV energies. However, for sub-keV B implants diffusion remains enhanced and x{sub j} is limited to {ge} 100 nm at 1,050 C. The authors term this enhancement, which arises in the presence of B atomic concentrations at the surface of {approx} 6%, Boron-Enhanced-Diffusion (BED).

1997-12-01

415

Biological and morphological characterization of human neonatal fibroblast cell culture B-HNF-1  

British Library Electronic Table of Contents (United Kingdom)

In the present study, human neonatal fibroblasts were isolated from a two-month-old human male. The purpose of the present investigation was the analysis of the morphology (light and transmission electron microscopy), karyotype and growth characteristics of the human neonatal fibroblast cell culture B-HNF-1. Moreover, STR typing and mitochondrial DNA amplification and sequencing was also performed. Analysis of chromosomes count showed that B-HNF-1 cell culture is diploid and has normal male karyotype 46, XY, which was stable during cultivation. The transmission electron microscopy demonstrated the ultra-structure of the B-HNF-1 cells; they have typical morphological features of proteosynthesis-active cells. Large number of fibroblasts bearing different shapes and surface characteristics ad...

2010-01-01

416

Validating eddy current array probes for inspecting steam generator tubes  

International Nuclear Information System (INIS)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves based on signal-to-noise studies using ...

1997-11-16

417

Validating eddy current array probes for inspecting steam generator tubes  

Energy Technology Data Exchange (ETDEWEB)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves based on signal-to-noise studies using ...

1997-07-01

418

Ultrasonic Phased Array Implementation of the Inside Diameter Creeping Wave Sizing Method  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a technique for implementing the ultrasonic inside diameter (ID) creeping wave technique for detection and sizing ID connected defects using a phased array ultrasonic system. The technique uses multiple focal laws to produce the examination modes. The first focal law is designed to create a shear wave nominally at the critical angle for mode conversion to a longitudinal wave at the ID of a part, thus creating a creeping wave. This focal law is focused at the ID to improve sensitivity. The rest of the laws are designed to create tandem sound paths that progress up a vertical surface directly above the focal point of the creeping wave generation point. When a defect on the inner surface is detected with the creeping wave, the height of the defect can be measured from the response of a set of tandem laws without readjusting the position of the probe. Results from standard one-inch long notches of varying depths are presented.

2006-05-01

419

Superfluid 4He interferometer operating near 2 K  

International Nuclear Information System (INIS)

We report the observation of quantum interference in superfluid 4He. The interferometer, an analog of a dc-superconducting quantum interference device (SQUID), employs a recently reported phenomenon wherein superfluid 4He exhibits Josephson frequency oscillations in an array of submicron apertures. An interference pattern is generated by reorienting the loop of the superfluid 'SQUID' with respect to the Earth's rotation vector, thereby varying the rotation flux in the loop. The experiment is performed at 2 K, a temperature 2000 times higher than previously achieved with superfluid 3He. We find that the interference exists not only when the aperture array current-phase relation is a sinusoidal function characteristic of the Josephson effect, but also at lower temperatures where it is linear and oscillations occur by phase slips. The modest requirements for the interferometer (2 K cryogenics and fabrication of apertures at the level of 100 nm) ...

2006-09-01

420

Small, efficient thermophotovoltaic power supply. Final report, 21 February 1997--21 February 1999  

Energy Technology Data Exchange (ETDEWEB)

The objective of this contract is to design and build a small, lightweight, stand-alone thermophotovoltaic electric generator, capable of at least 100 Watts useful output for charging 24V batteries. The prototype generator built consists of a pre-mixed burner, a cylindrical selective emitter mantle surrounded by six silicon photovoltaic concentrator arrays. The arrays are cooled with forced-air heat exchangers using self-powered fans. The generator, operated at 117,00 W (40,000 BTU/hr) of fuel input rate, produces 122 W of electrical power at 1.0% of efficiency. The cooling and pre-mix fans consume 35 W of electrical power resulting in a net 85 Watts of electrical output for charging batteries. The generator`s output is capable of continuous charging five 12/24V batteries over 10 hours with a 9.07 Kg (20 lbs.) of propane gas.

1999-04-23

421

Radiation effects on MOS devices and radiation-hard CMOS technologies  

International Nuclear Information System (INIS)

Total-dose irradiation seriously damages MOS devices and their circuit performance. Threshold voltage shifts, transconductance degradation and increase in off-state leakage current are generally observed for irradiated devices. These instabilities are essentially due to positive and/or negative charge trapping in SiO_2 and interface trap generation at the SiO_2/Si interface. Radiation hardening of CMOS VLSIs is to eliminate these trapping effects, and for this purpose, special considerations for fabrication processes and layout design are necessary. In this paper, basic mechanisms for radiation-induced charge trapping and related effects on MOS devices are reviewed. Also discussed are radiation-hardening technologies from both fabrication-process and layout-design viewpoints. Using these technologies, 1 #mu#m radiation-hard CMOS gate arrays have been successfully developed. Experimental data taken for 2k-gate test chips indicate that radiation hardness of these ...

422

Optimizing electrical load pattern in Kuwait using grid connected photovoltaic systems  

International Nuclear Information System (INIS)

Grid connected photovoltaic systems is one of the most promising applications of photovoltaic systems. These systems are employed in applications where utility service is already available. In this case, there is no need for battery storage because grid power may be used to supplement photovoltaic systems (PV) when the load exceeds available PV generation. The load receives electricity from both the photovoltaic array and the utility grid. In this system, the load is the total electrical energy consumption. The main objective of the present work is to optimize the electrical load pattern in Kuwait using grid connected PV systems. In this situation, the electric load demand can be satisfied from both the photovoltaic array and the utility grid. The performance of grid connected photovoltaic systems in the Kuwait climate has been evaluated. It was found that the peak load matches the maximum incident solar radiation in Kuwait, which would ...

2004-03-01

423

Optimization of Valve Disc Using Orthogonal Array and Kriging Model  

Science.gov (United States)

A butterfly valve is a type of flow control device, typically used to regulate a fluid flowing. Currently, FEA is often used to predict the safety in the design of valve disc. Also, the study about the affection of butterfly valve's disc to the valve flow characteristics by using CFD has been done by many researchers. Along with the development of computer technique, design and analysis of computer experiments has becoming more and more important in engineering design and optimization. Hereinto Kriging model is one popular analysis approach for the purpose of creating a cheap ``meta-model'' as a surrogate to a computationally expensive simulation model. In this paper, the numerical analysis considered the strength, pressure loss coefficient and weight of valve disc simultaneously is investigated to improve the shape of a traditional butterfly valve disc. Firstly, an initial model of butterfly valve is made to evaluate the performance of the valve disc by using CFD and FEM. Then several ...

2008-10-01

424

Natural fracture characterization using passive seismic illumination  

Energy Technology Data Exchange (ETDEWEB)

The presence of natural fractures in reservoir rock can significantly enhance gas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas for subsequent higher resolution active seismic imaging. Current practices for estimating fracture properties before the acquisition of surface seismic data are usually based on the assumed geology and tectonics of the region, and empirical or fracture mechanics-based relationships between stratigraphic curvature and fracturing. The objective of this research is to investigate the potential of multicomponent surface sensor arrays, and passive seismic sources in the form of local earthquakes to identify and characterize potential fractured gas reservoirs located near ...

2003-01-08

425

Natural convection cooling of a close-packed array of AGR fuel pins surrounded by graphite debris  

International Nuclear Information System (INIS)

Certain postulated faults during refuelling of AGRs may give rise to compacted fuel and graphite sleeve debris. This debris must be maintained below some safe limiting temperature. As part of a programme to assess the benefits of natural convection in cooling such debris in a region experiencing no forced cooling, a simple geometry incorporating typical debris has been studied both experimentally and by prediction. The experiment comprised an array of electrically heated fuel rods mounted co-axially in a closed cylindrical vessel and surrounded by fragments of graphite. The vessel was cooled on its cylindrical surface, the ends being insulated. Rods and vessel wall were thermocoupled. Tests covered a range of temperature and pressures in both CO_2 and N_2. Significant natural convection heat removal was demonstrated, particularly at high pressure. Predictions utilising the PHOENICS code agreed well with measured temperatures over a wide range of test conditions. ...

426

MEMS-based Speckle Spectrometer  

CERN Document Server

We describe a new concept for a MEMS-based active spatial filter for astronomical spectroscopy. The goal of this device is to allow the use of a diffraction-limited spectrometer on a seeing limited observation at improved throughput over a comparable seeing-limited spectrometer, thus reducing the size and cost of the spectrometer by a factor proportional to r0/D (For the case of a 10 meter telescope this size reduction will be approximately a factor of 25 to 50). We use a fiber-based integral field unit (IFU) that incorporates an active MEMS mirror array to feed an astronomical spectrograph. A fast camera is used in parallel to sense speckle images at a spatial resolution of lambda/D and at a temporal frequency greater than that of atmospheric fluctuations. The MEMS mirror-array is used as an active shutter to feed speckle images above a preset intensity threshold to the spectrometer, thereby increasing the signal-to-noise ratio (SNR) of the ...

2006-01-01

427

Lifetimes of superdeformed nuclei in the mass region A {approx}150 with the Eurogam multidetector array; Durees de vie de noyaux superdeformes de la region de masse A {approx}150 mesurees avec le multicompteur Eurogam  

Energy Technology Data Exchange (ETDEWEB)

This work concerns the study of the nuclear superdeformation phenomenon in the rare earth region (A {approx} 150). The superdeformed (SD) states in Gadolinium and Dysprosium isotopes were produced via heavy-ion induced reactions and studied with the (EUROGAM EUROpean GAmma-ray Microscope) gamma multidetector array. Precise level attenuation method (DSAM). From the derived quadrupole moments, we find large differences in deformation between the yrast bands in neighbour nuclei explained in terms of the case of nuclei corresponding to an axis ratio of 2:1, the shell gaps are not fixed at a specific particle number and deformation. Furthermore the present results indicate that the deformations associated with identical bands are different supporting the picture that mass and deformation changes tend to compensate in SB bands with the same moments of inertia. (author). 114 refs.

1996-05-13

428

Integration and Testing of the Micro-X Rocket Payload  

Science.gov (United States)

The Micro-X instrument is a rocket borne, X-ray imaging spectrometer planned for launch in October 2011. An array of 128 Transition Edge Sensors (TESs) on a 600 micron pitch will observe incoming photons in the 0.2-3 keV energy band with an energy resolution of 2-4 eV at 1 keV. X-rays will be focused onto the TES array by a conically approximated Wolter optic with an effective area of 300 cm^2 giving the instrument a field of view of 11.8 arcmin. This performance will constitute a substantial improvement over current non-dispersive detectors for X-ray spectroscopy of extended sources and will be the first demonstration of a TES-based microcalorimeter in space. The TESs will utilize the 50 mK stage of an Adiabatic Demagnetization Refrigerator (ADR) as a heat bath, and will be read out by a SQUID time division multiplexer. The first flight of the Micro-X instrument will observe the Puppis A supernova remnant. Future targets include the core of ...

2011-05-01

429

Integrated microelectrode arrays for trace-metal analysis of aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

Stripping Voltammetry (SV) at microelectrodes has gained increased interest in the analysis of aqueous solutions due to its ability to analyze low concentrations (ppb) of electroactive metallic species in solution. Existing integrated circuit (IC) technology allows the inexpensive fabrication of microelectrodes with dimensions on the order of microns and with a high degree of uniformity and reproducibility. Additional circuitry, both multiplexing and signal conditioning, can be placed directly onto the sensor offering increased sensitivity and flexibility. Multi-element electrochemical sensors containing arrays of Pt, Au, and Ag electrodes and capable of individual measurement through built-in multiplexing or simultaneous measurement at the appropriate potential ranges for each individual electrode were fabricated using existing 2 micron IC technology. Results of simultaneous measurements of low concentrations of Cd, Pb, Cu, As, and Hg in solution indicate that ...

1995-12-31

430

INDUCIBLE RNAi-MEDIATED GENE SILENCING USING NANOSTRUCTURED GENE DELIVERY ARRAYS  

Energy Technology Data Exchange (ETDEWEB)

RNA interference has become a powerful biological tool over the last decade. In this study, a tetracycline-inducible shRNA vector system was designed for silencing CFP expression and delivered alongside the yfp marker gene into Chinese hamster ovary cells using impalefection on spatially indexed vertically aligned carbon nanofiber arrays (VACNFs). The VACNF architecture provided simultaneous delivery of multiple genes, subsequent adherence and proliferation of interfaced cells, and repeated monitoring of single cells over time. Following impalefection and tetracycline induction, 53.1% 10.4% of impalefected cells were fully silenced by the inducible CFP-silencing shRNA vector. Additionally, efficient CFP-silencing was observed in single cells among a population of cells that remained CFP-expressing. This effective transient expression system enables rapid analysis of gene silencing effects using RNAi in single cells and cell populations.

2008-01-01

431

IECEC '91; Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, Boston, MA, Aug. 4-9, 1991. Vol. 2 - Aerospace power systems, conversion technologies  

International Nuclear Information System (INIS)

The present volume on energy and the environment discusses space power requirements, space power systems, space power systems hardware, space radioisotope systems, space solar arrays, space solar cells, space station power, and terrestrial applications of aerospace technology. Attention is given to NASA future space power requirements and issues, the design of a battery charger for the NASA EOS Space Platform, in situ carbon dioxide fixation on Mars, and a preliminary design update of the CRAF/Cassini Power Subsystem. Topics addressed include concentrator testing using projected images, solar power satellites and demonstraton platforms from nonterrestrial materials, a mass sensitivity analysis of lunar orbiting beam power systems, and a power-beaming-based infrastructure for space power. Also discussed are fiber-optic sensors for aerospace electrical measurements, the preliminary design of a mobile lunar power supply, advanced power systems for EOS, and Air Force ...

1991-08-03

432

Fatigue crack detection in aircraft skin structures using eddy current array technique  

International Nuclear Information System (INIS)

Detection of fatigue damage cracks in aircraft skin structures is an ongoing NDT challenge. Cracks growing rate is difficult to predict, and for this reason, it is important to detect them as soon as possible to avoid a catastrophic break. Eddy current methods are known and well-accepted techniques which are relatively simple to carry out. However, with conventional inspection of airframe structures using standard driver-pickup eddy current probes, it is difficult to detect small fatigue cracks initiated in the second layer of the skin and in the shadow region at fastener holes. Such difficulty is related to fasteners length and their spacing which reduces test sensitivity. This report explains the development of improved eddy current probe/technique to detect and visualize fatigue cracks in fasteners. In this study, an eddy current array probe was evaluated and new coil design was suggested. Several tests were conducted on an A-300 circumferential joint sample ...

2004-01-01

433

Electronically tunable semiconductor laser (ETL) based on silica Bragg reflectors  

Science.gov (United States)

We will report on a new type of tunable semiconductor laser, which is based on the electronic selection of one Bragg grating among an array of such gratings in silica. The device that we have built operates at 120 Mb/s but extension to 1 Gb/s for Gigabit-Ethernet applications would be straightforward. In comparison with tunable semiconductor lasers using gratings in the III-V materials, silica gratings offer two significant advantages: 1-wavelength stability and predictability, 2-the ability to phusically overlap many gratings in a compact space in order to enable the selection of a large number of wavelengths for wavelength division multiplexed communications systems. The time required to chagne the wavelength in our laser has not been measured for lack of the necessary electronics but it is expected to be in the microsecond range on the basis of a straightforward calculation. The robust all solid-state nature of our device and its expected microsecond ...

2003-12-01

434

Development of a high performance air heater through use of an evacuated tube cover design  

Science.gov (United States)

Development of a high performance air heater through use of an evacuated tube cover design is described. The cover design utilizes evacuated fluorescent light tubes laid parallel in a close packed array to form an inner transparent glazing over a conventional metal absorber plate with flow behind the plate. A tempered flat glass plate was used as an outer glazing. Both clear and infrared reflective (IR) tubes were investigated. Solar transmittance tests indicate that the clear tube array has a higher transmittance than two flat sheets of low-iron glass. The IR coating produced substantial transmittance loss. Thermal conductance tests indicate that the tubes behave similar to two flat glass sheets with a vacuum in between. The IR reflective coating was only marginally effective at reducing heat conductance. Final prototype designs are presented along with collector performance estimates.

1980-01-01

435

Determination of 40 synthetic food colors in drinks and candies by high-performance liquid chromatography using a short column with photodiode array detection  

British Library Electronic Table of Contents (United Kingdom)

Forty synthetic food colors were determined in drinks and candies by reversed-phase high-performance liquid chromatography with photodiode array detection. The following food colors were analyzed within 19min using a short analytical column (50mmx4.6mm i.d., 1.8mm) at 50degreeC with gradient elution: Ponceau 6R, Tartrazine, Fast yellow AB, Amaranth, Indigotine, Naphthol yellow S, Chrysoine, Ponceau 4R, Sunset yellow FCF, Red 10B, Orange G, Acid violet 7, Brilliant black PN, Allura red AC, Yellow 2G, Red 2G, Uranine, Fast red E, Green S, Ponceau 2R, Azorubine, Orange I, Quinoline yellow, Martius yellow, Ponceau SX, Ponceau 3R, Fast green FCF, Eosine, Brilliant blue FCF, Orange II, Orange RN, Acid blue 1, Erythrosine, Amido black 10B, Acid red 52, Patent blue V, Acid green 9, Phloxine B, Ben...

2008-01-01

436

Calibration of the modulation transfer function of surface profilometers with binary pseudo-random test standards: expanding the application range  

Energy Technology Data Exchange (ETDEWEB)

A modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays [Proc. SPIE 7077-7 (2007), Opt. Eng. 47, 073602 (2008)] has been proven to be an effective MTF calibration method for a number of interferometric microscopes and a scatterometer [Nucl. Instr. and Meth. A616, 172 (2010)]. Here we report on a further expansion of the application range of the method. We describe the MTF calibration of a 6 inch phase shifting Fizeau interferometer. Beyond providing a direct measurement of the interferometer's MTF, tests with a BPR array surface have revealed an asymmetry in the instrument's data processing algorithm that fundamentally limits its bandwidth. Moreover, the tests have illustrated the effects of the instrument's detrending and filtering procedures on power spectral density measurements. The details of the development of a BPR test sample suitable for calibration of ...

2011-03-14

437

Calibration of the modulation transfer function of surface profilometers with binary pseudo-random test standards: Expanding the application range  

Energy Technology Data Exchange (ETDEWEB)

A modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays [Proc. SPIE 7077-7 (2007), Opt. Eng. 47(7), 073602-1-5 (2008)] has been proven to be an effective MTF calibration method for a number of interferometric microscopes and a scatterometer [Nucl. Instr. and Meth. A 616, 172-82 (2010]. Here we report on a significant expansion of the application range of the method. We describe the MTF calibration of a 6 inch phase shifting Fizeau interferometer. Beyond providing a direct measurement of the interferometer's MTF, tests with a BPR array surface have revealed an asymmetry in the instrument's data processing algorithm that fundamentally limits its bandwidth. Moreover, the tests have illustrated the effects of the instrument's detrending and filtering procedures on power spectral density measurements. The details of the development of a BPR test sample suitable for ...

2010-07-26

438

Binary pseudo-random gratings and arrays for calibration of the modulation transfer function of surface profilometers: recent developments  

Energy Technology Data Exchange (ETDEWEB)

The major problem of measurement of a power spectral density (PSD) distribution of the surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF tends to distort the PSD at higher spatial frequencies. It has been suggested [Proc. SPIE 7077-7, (2007), Opt. Eng. 47 (7), 073602-1-5 (2008)] that the instrumental MTF of a surface profiler can be precisely measured using standard test surfaces based on binary pseudo-random (BPR) patterns. In the cited work, a one dimensional (1D) realization of the suggested method based on use of BPR gratings has been demonstrated. Here, we present recent achievements made in fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. The 2D BPRAs were used as standard test surfaces for 2D MTF calibration of the MicromapTM-570 interferometric microscope with all available objectives. The effects of ...

2009-07-07

439

BIMA Array Observations of the Highly Unusual SiO Maser Source with a Bipolar Nebulosity, IRAS 19312+1950  

CERN Document Server

We report the results of mapping observations of the bipolar nebula with SiO maser emission, IRAS 19312+1950, in the CO (J=1-0 and J=2-1), 13CO (J=1-0 and J=2-1), C18O (J=1-0), CS (J=2-1), SO (J_K=3_2-2_1) and HCO+ (J=3-2) lines with the Berkeley-Illinois-Maryland Association array. Evolutional status of this source has been evoking a controversy since its discovery, though SiO maser sources are usually identified as late-type stars with active mass loss. In line profiles, two kinematical components are found as reported in previous single-dish observations: a broad pedestal component and a narrow component. Spatio-kinetic properties of a broad component region traced by 12CO lines are roughly explained by a simple spherical outflow model with a typical expanding velocity of an AGB star, though some properties of the broad component region still conflict with properties of a typical AGB spherical outflow. A narrow component region apparently exhibits a bipolar ...

2005-01-01

440

An actively stimulating net panel and rope array inside a model cod-end to increase juvenile red seabream escapement  

British Library Electronic Table of Contents (United Kingdom)

One method of increasing juvenile fish escapement from net cod-ends is to encourage fish to approach the netting by placing an active stimulating device (ASD) in the cod-end. Two types of ASD were tested inside model cod-ends to generate variable visual stimuli. One was a free-end flag-like net panel and the other consisted of an array of free-ended ropes. Escape responses of juvenile red seabream were observed in a circulating water channel using a cod-end fitted with the ASD, and they were compared with responses to conventional polyethylene multi-ply, high-contrast cod-ends with and without ASD made from either 28- or 43-mm mesh under three light conditions. With the ASD attached, the retention rate was significantly lower, 20%, than for conventional cod-ends except in dim light with 28...

2010-01-01

441

Aircraft  

Energy Technology Data Exchange (ETDEWEB)

This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can ...

1998-09-22

442

The lateral hypothalamus as integrator of metabolic and environmental needs: From electrical self-stimulation to opto-genetics  

British Library Electronic Table of Contents (United Kingdom)

As one of the evolutionary oldest parts of the brain, the diencephalon evolved to harmonize changing environmental conditions with the internal state for survival of the individual and the species. The pioneering work of physiologists and psychologists around the middle of the last century clearly demonstrated that the hypothalamus is crucial for the display of motivated behaviors, culminating in the discovery of electrical self-stimulation behavior and providing the first neurological hint accounting for the concepts of reinforcement and reward. Here we review recent progress in understanding the role of the lateral hypothalamic area in the control of ingestive behavior and the regulation of energy balance. With its vast array of interoceptive and exteroceptive afferent inputs and its equ...

2011-01-01

443

The High-Redshift Neutral Hydrogen Signature of an Anisotropic Matter Power Spectrum  

CERN Document Server

An anisotropic power spectrum will have a clear signature in the 21cm radiation from high- redshift hydrogen. We calculate the expected power spectrum of the intensity fluctuations in neutral hydrogen from before the epoch of reionization, and predict the accuracy to which future experiments could constrain a quadrupole anisotropy in the power spectrum. We find that the Square Kilometer Array will have marginal detection abilities for this signal at z~17 if the process of reionization has not yet started; reionization could enhance the detectability substantially. Pushing to higher redshifts and higher sensitivity will allow highly precise (percent level) measurements of anisotropy.

2011-01-01

444

Simulation of DNA electrophoresis through microstructures  

British Library Electronic Table of Contents (United Kingdom)

The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E 25 V/cm for the mobility of l-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the electric field and the DNA lengths. The model and the associated phase diagram described here provide an expl...

2007-01-01

445

Scaling and performance of a 3-D radiation hydrodynamics code on message-passing parallel computers: final report  

Energy Technology Data Exchange (ETDEWEB)

This report details an investigation into the efficacy of two approaches to solving the radiation diffusion equation within a radiation hydrodynamic simulation. Because leading-edge scientific computing platforms have evolved from large single-node vector processors to parallel aggregates containing tens to thousands of individual CPU's, the ability of an algorithm to maintain high compute efficiency when distributed over a large array of nodes is critically important. The viability of an algorithm thus hinges upon the tripartite question of numerical accuracy, total time to solution, and parallel efficiency.

1999-10-28

446

SKA in VLBI Impact on Studies of Small Scale Structures in Active Galactic Nuclei  

CERN Document Server

We discuss the advantages which the next generation interferometer SKA (the Square Kilometer Array) will bring for Very Long Baseline Interferometry (VLBI) at centimeter wavelengths. With a sensitivity to micro-Jy level flux density, a brightness temperature limit of about 10.000 K, and an expected dynamic range in future VLBI maps of better than 1.000.000, the impact of SKA on the research of compact extragalactic radio sources and their energetic jets will be very strong. We discuss some consequences, including a possible combination of SKA with future space VLBI missions.

1999-01-01

447

New England Wind Forum: A Wind Powering America Project, Newsletter #5 -- January 2010, Wind and Hydropower Technologies Program (WHTP)  

Energy Technology Data Exchange (ETDEWEB)

Wind Powering America program launched the New England Wind Forum (NEWF) in 2005 to provide a single comprehensive source of up-to-date, Web-based information on a broad array of wind energy issues pertaining to New England. The NEWF newsletter provides New England stakeholders with updates on wind energy development in the region. In addition to regional updates, Issue #5 offers an interview with Angus King, former governor of Maine and co-founder of Independence Wind.

2010-01-01

448

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

449

High-power CW operation of AlGaInP laser-diode array at 640 nm  

Science.gov (United States)

Visible-emitting high-power laser bars are investigated at an emission wavelength of 640 nm. AlGaInP/GaInP, single tensile-strained quantum well, separate confinement heterostructures are fabricated into one cm long laser bars using a 0.7 fill factor. The low threshold current of the diode, combined with the aggressive heatsinking of a silicon microchannel cooler has resulted in more than 12 W of continuous wave output power.

1995-02-01

450

Envelope correlation in (N, N) MIMO antenna array from scattering parameters  

DEFF Research Database (Denmark)

A simple closed-form equation to calculate the envelope correlation between any two receiver or transmitter antennas in a multi-input multi-output (MIMO) system of an arbitrary number of elements is derived. The equation uses the scattering parameters obtained at the antenna feed point to calculate the envelope correlation coefficient. This approach has the advantage that it does not require knowledge of the antenna radiation pattern. Numerical data that include conductor and permittivity loss are shown to validate the approach. Using the scattering parameters for calculating the envelope correlation is less laborious and relatively cheaper, as compared to the radiation pattern approach.

2006-01-01

451

Electron Beam and Gamma Radiolysis of Solid-State Metoclopramide  

British Library Electronic Table of Contents (United Kingdom)

Purpose Study the radiolysis of solid-state metoclopramide hydrochloride at various absorbed doses. Elucidate the structure of the degradation products to gain information on the radiolysis mechanisms. Methods Solid-state metoclopramide samples were irradiated at several doses with gamma rays and high-energy electrons to evaluate the influence of the dose rate. High-performance liquid chromatography with a diode array detector was used to measure the chemical potency as a function of the absorbed dose and to quantify the degradation products. The characterization of degradation products was performed by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Results The degradation of solid-state metoclopramide after irradiation was negligible. No qualitati...

2006-01-01

452

Electrical properties of retinal-electrode interface.  

Science.gov (United States)

A critical element of a retinal prosthesis is the stimulating electrode array, which is placed in close proximity to the retina. It is via this retinal-electrode interface that a retinal prosthesis electrically stimulates nerve cells to produce the perception of light. The impedance load seen by the current driver consists of the tissue resistance and the complex electrode impedance. The results in this paper show that the tissue resistance of the retina is significantly greater than that of the vitreous humor in the eye. Circuit models of the electrode-retina interface are used to parameterize the different contributors to the overall impedance. PMID:17325413

2007-02-20

453

Ecosystem restoration versus reclamation: the value of managing for biodiversity  

Energy Technology Data Exchange (ETDEWEB)

The importance of ecosystem restoration to land reclamation is discussed. If a plant community is to be self sustaining, natural diversity processes provide a useful model for restoration. Biodiversity is important for utilitarian, ecological, and ethical/aesthetic reasons. Issues that must be considered include sampling and management scales, the separate richness of the diverse array of species playing a role in ecosystem productivity and stability, and natural trends in diversity. Ecological restoration comprises two fundamental activities: management for some pre-disturbance level of biodiversity and the combination of species in a manner that is essentially experimental. Endeavours to restore biological diversity are a useful method of experimenting with the factors that control ecosystem structure and function. 21 refs.

1991-06-01

454

Development of conductive nanotemplates on ZnSe  

International Nuclear Information System (INIS)

We demonstrate the possibility to fabricate arrays of pores oriented perpendicular and parallel to the top surface of the ZnSe nanotemplate. The control of material conductivity allows one to produce porous ZnSe samples with the mean pore diameter and characteristic skeleton wall thickness from several hundreds of nanometers to about 15 nm. In addition, electrochemical treatment of ZnSe single crystals using photoresist masks allows one to prepare buried porous structures with pores directed parallel to the top template surface, which is especially important for photonic applications.

2011-07-07

455

Development of a helium-cooled divertor concept: design-related requirements on materials and fabrication technology  

International Nuclear Information System (INIS)

Within the framework of the EU power plant conceptual study (PPCS), a modular He-cooled divertor concept with integrated pin array (HEMP) is being developed at the Forschungszentrum Karlsruhe. The design goal is to achieve a high heat flux of at least about 10-15 MW/m"2, which is proposed for a near-term reactor model like DEMO. The development and optimization of the divertor concept require a close link between the main issues: design, analyses, materials and fabrication technology, and experiments with feedbacks between them to be accounted for. Design-specific requirements on materials and fabrication issues will be discussed.

2004-08-01

456

Design of a 2 T multipole wiggler insertion device for the SRS  

International Nuclear Information System (INIS)

Two new identical insertion devices have been designed for the Daresbury SRS. They are 2T permanent-magnet multipole wigglers that will provide high flux in the X-ray region. This paper describes the magnetic and mechanical design of the arrays of steel pole pieces and permanent-magnet blocks. Also given is the engineering design of the support structure that will cope with the very large forces present while maintaining high levels of precision in gap setting and parallelism. The engineering design has been fully assessed using finite-element techniques to predict the deflections of critical parts of the structure. These two devices are due to be installed into the SRS by the end of 1998.

1998-05-01

457

Controllable growth and magnetic properties of nickel nanoclusters electrodeposited on the ZnO nanorod template  

International Nuclear Information System (INIS)

The ZnO nanorods were used as a template to fabricate nickel nanoclusters by electrodeposition. The ZnO nanorod arrays act as a nano-semiconductor electrode for depositing metallic and magnetic nickel nanoclusters. The growth sites of Ni nanoclusters could be controlled by adjusting the applied potential. Under -1.15 V the Ni nanoclusters could be grown on the tips of ZnO nanorods. On increasing the potential to be more negative the ZnO nanorods were covered by Ni nanoclusters. The magnetic properties of the electrodeposited Ni nanoclusters also evolved with the applied potentials.

2009-12-09

458

Biomass production in Florida  

Energy Technology Data Exchange (ETDEWEB)

Florida posseses climatic, land, and water resources favorable for abundant biomass production. Therefore, a statewide program has been initiated to determine adapted species for the available array of production sites. Plant resources under investigation include woody, aquatic, grasses, hydrocarbon, and root crop species. The goal is to produce a continuous stream of biomass for the various biofuel conversion options. Preliminary yields from energy cropping experiments range from about 10 to nearly 90 metric tons per hectare per year, depending on the crop and the production systems employed. (Refs. 15).

1981-08-01

459

The Infrared Camera (IRC) for the ASTRO-F infrared astronomical satellite  

Science.gov (United States)

The Infrared Camera (IRC) is one of the scientific focal plane instruments on board the ASTRO-F infrared astronomical satellite. The IRC is designed for wide field imaging and slit-less spectroscopic observations at near- and mid-infrared wavelengths. The IRC consists of three channels; NIR, MIR-S and MIR-L, each of which covers wavelengths of 2-5, 5-12 and 12-26 micron, respectively. All channels adopt compact refractive optical designs. Large format array detectors (a InSb 512 x 412 array and two Si:As IBC 256 x 256 arrays) are employed. Each channel has 10 x 10 arcminutes wide FOV with diffraction-limited angular resolution of 70cm aperture of the liquid helium cooled telescope at wavelengths over 5 micron. A 6-position filter wheel is placed at the aperture stop in each channel, and has three band-pass filters, two grisms/prisms and a mask for dark current measurements. The 5 sigma sensitivity of one pointed observation ...

2004-01-01

460

Low Frequency Phased Array Techniques for Crack Detection in Cast Austenitic Piping Welds: A Feasibility Study  

Energy Technology Data Exchange (ETDEWEB)

Studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington have focused on developing and evaluating the reliability of nondestructive testing (NDT) approaches for coarse-grained stainless steel reactor components. The objective of this work is to provide information to the United States Nuclear Regulatory Commission (NRC) on the utility, effectiveness and limitation of NDT techniques as related to inservice testing of primary system piping components in pressurized water reactors. We examined cast stainless steel pipe specimens containing thermal and mechanical fatigue cracks located close to the weld roots and having inner and outer diameter surface geometrical conditions that simulate several water reactor primary piping configurations. In addition, segments of vintage centrifugally cast piping were examined to characterize the inherent acoustic noise and scattering caused by grain structures and to determine the consistency of ultrasonic responses ...

2007-01-01

461

Experiments in High-Frequency Imaging of the 2004 M6.0 Parkfield Earthquake  

Science.gov (United States)

We attempt to image the rupture propagation of the 2004 M6.0 Parkfield earthquake by analyzing records from the USGS Parkfield seismic array (UPSAR) and other strong-motion stations. The UPSAR array consists of 12 stations distributed over about one square kilometer at a distance of 10~km from the San Andreas fault near Parkfield, California. We employ a method that uses reverse time migration to stack the seismograms at back-projected locations along the fault. We use waveform cross-correlation to align the initial P-wave arrivals and correct for small static time shifts in the records. This forces a coherent image at the hypocenter at the quake origin time. Initial results at later time steps show some evidence of the expected rupture propagation to the north. However, the resolution of the back-projection is limited by the small aperture of the UPSAR array. Records from other strong-motion stations can improve the ...

2006-12-01

462

Eddy current array probe for detection of surface breaking cracks in the extrados of feeder bends  

Energy Technology Data Exchange (ETDEWEB)

A new eddy current array probe has been implemented as a straightforward and promising technique for detection of outer diameter (OD) surface-breaking cracks on the extrados of feeder bends. The design is based on previous work performed at AECL, which had demonstrated that eddy current probes with laterally displaced transmit-receive coils can overcome some of the limitations of inspecting ferritic steel components for surface-breaking cracks. The Feeder Integrity Joint Program-CANDU Owners Group Inc. (FIJP-COG) Non-Destructive Evaluation (NDE) Team members commissioned AECL to work in collaboration with the probe manufacturer ZETEC, to develop a field usable eddy current array probe. The objective was to acquire a technique with the following capabilities: fast scanning non-contact inspection technique for surface breaking discontinuities; full inspection of the bend extrados OD surface in a single scan; ability to inspect first and second ...

2006-07-01

463

Eddy current array probe for detection of surface breaking cracks in the extrados of feeder bends  

International Nuclear Information System (INIS)

A new eddy current array probe has been implemented as a straightforward and promising technique for detection of outer diameter (OD) surface-breaking cracks on the extrados of feeder bends. The design is based on previous work performed at AECL, which had demonstrated that eddy current probes with laterally displaced transmit-receive coils can overcome some of the limitations of inspecting ferritic steel components for surface-breaking cracks. The Feeder Integrity Joint Program-CANDU Owners Group Inc. (FIJP-COG) Non-Destructive Evaluation (NDE) Team members commissioned AECL to work in collaboration with the probe manufacturer ZETEC, to develop a field usable eddy current array probe. The objective was to acquire a technique with the following capabilities: fast scanning non-contact inspection technique for surface breaking discontinuities; full inspection of the bend extrados OD surface in a single scan; ability to inspect first and second ...

2005-11-20

464

Determination of Shear Properties in the Upper Seafloor Using Seismo-acoustic Interface Waves  

Energy Technology Data Exchange (ETDEWEB)

This thesis develops methods for recording and analysis of seismo-acoustic interface waves for determination of shear wave velocity as a function of depth and includes this in standard refraction seismic surveying. It investigates different techniques for estimation of dispersion characteristics of the interface waves and demonstrates that multi sensor spectral estimation techniques improve the dispersion estimates. The dispersion estimate of the fundamental interface wave mode is used as input to an object function for a model based linearized inversion. The inversion scheme provides an estimate of the shear wave velocity as a function of depth. Three field surveys were performed. Data were acquired with a standard bottom deployed refraction seismic hydrophone array containing 24 or 48 receivers, with a receiver spacing of 2.5 m. Explosive charges were used as sources. The recording time was increased from 0.5 to 8 s, compared to standard refraction seismic ...

1998-12-31

465

Weld metal as strong as base metal?; Schweisszusatzwerkstoffe koennen/muessen nicht immer die Anforderungen der Grundwerkstoffe erfuellen  

Energy Technology Data Exchange (ETDEWEB)

The development of new steels is always a challenge for the manufacturer of filler metals. In many cases it is obvious that some properties of the base metal cannot be fulfilled with matching filler metals. In some cases, dissimilar filler metals can solve the problem in some cases, there is no chance to meet the requirements of the base metal (for example yield strengths of new ultra high strength steels). This paper deals with different kinds of new steels and the requirements for the weld metal with examples from motor car industry (Mangan Austenite), crane (Ultra high strength steels), earthmoving machinery (Wear-resistant steels) and offshore (Supermartensitic steels). Specific problems will be discussed and best solutions will be highlighted. These examples make clear that the success of new kinds of steels in the market depends on solving the joining problems of these steels. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [German] ...

2007-07-15

466

Ultra-high temperature strength properties on Mod.9Cr-1Mo steel  

Energy Technology Data Exchange (ETDEWEB)

A sodium-water reaction drove from the single tube break in steam generator of FBR might overheat labor tubes rapidly under internal pressure loadings. If the temperature of tube wall becomes too high, it has to be evaluated that the stress of tube does not exceed the material strength limit to prevent the propagation of tube rupture. This study clarified the tensile and creep properties of Mod.9Cr-1Mo steel at ultra-high temperature which will be used in evaluation of the tube burst by sodium-water reaction. The strain rates for tensile test are from 10%/min to 10%/sec, and creep-rupture time is maximum 277sec. The range of test temperature is 700degC to 1300degC. The main results obtained were as follows; (1) The evaluation data on the relationship between tensile strength and strain rate and creep-rupture strength in shorter time on Mod.9Cr-1Mo steel were acquired. (2) Short-term mechanical properties of Mod.9Cr-1Mo steel were evaluated based on the results of ...

2000-03-01

467

Ultra-fast charge transfer in organic electronic materials and at hybrid interfaces studied using the core-hole clock technique  

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} The use of resonant photoemission in its 'core-hole clock' expression for the study of the dynamical charge transfer across hybrid organic-inorganic interfaces and for the intermolecular charge transfer in the bulk of organic thin films is reviewed. {yields} The electronic coupling to the substrate and the efficiency of charge transport across hybrid interfaces is different for individual electronic subsystems of the molecular adsorbate. {yields} The intermolecular charge transfer in the bulk of discotic liquid crystals occurs on the order of a few femtoseconds and is faster than expected from the macroscopic charge transport characteristics of the material. -- Abstract: The focus of this brief review is the use of resonant photoemission in its 'core-hole clock' expression for the study of two important problems relevant for the field of organic electronics: the dynamical charge transfer across hybrid organic-inorganic ...

2011-01-15

468

Status and potential of materials development as reflected in steels for the automotive industry; Stand und Potential der Werkstoffentwicklung am Beispiel der Staehle fuer die Automobilindustrie  

Energy Technology Data Exchange (ETDEWEB)

The high-strength and ultra high-strength steels developed and produced by Thyssen Krupp Stahl make a major contribution to automotive lightweighting. Proven and newly-developed coatings are used to meet increasingly important corrosion protection requirements. Design for materials, optimized forming and joining processes and the use of modern simulation techniques help to exploit the potential of the new steels. Future development work will focus on reducing the density of steels without compromising their well-known advantages - in particular their strength. The use of high-strength and ultra high-strength steels in the automotive industry is on the increase. Steel will remain the material of choice for auto manufacture, above all due to its potential for cost-efficient lightweight construction and its full recyclability. (orig.) [German] Einen wesentlichen Beitrag zum Leichtbau im Automobil leisten die von Thyssen Krupp Stahl entwickelten ...

1999-04-01

469

Rapid laser fluorometric method for the determination of uranium in soil, ultrabasic rock, plant ash, coal fly ash and red mud samples  

International Nuclear Information System (INIS)

A simple and rapid laser fluorometric determination of trace and ultra trace level of uranium in a wide variety of low uranium content materials like soil, basic and ultra basic rocks, plant ash, coal fly ash and red mud samples is described. Interference studies of some common major, minor and trace elements likely to be present in different geological materials on uranium fluorescence are studied using different fluorescence enhancing reagents like sodium pyrophosphate, orthophosphoric acid, penta sodium tri-polyphosphate and sodium hexametaphosphate. The accurate determination of very low uranium content samples which are rich in iron, manganese and calcium, is possible only after the selective separation of uranium. Conditions suitable for the quantitative single step extraction of 25 ng to 20 #mu#g uranium with tri-n-octylphosphine oxide and single step quantitative stripping with dilute neutral sodium pyrophosphate, which also acts as ...

1999-10-01

470

Potent, selective and cell penetrant inhibitors of SF-1 by functional ultra-high-throughput screening.  

Science.gov (United States)

The steroidogenic factor 1 (SF-1, also known as NR5A1) is a transcription factor belonging to the nuclear receptor superfamily. Whereas most of the members of this family have been extensively characterized, the therapeutic potential and pharmacology of SF-1 still remains elusive. Described here is the identification and characterization of selective inhibitory chemical probes of SF-1 by a rational ultra-high-throughput screening (uHTS) strategy. A set of 64,908 compounds from the National Institute of Health's Molecular Libraries Small Molecule Repository was screened in a transactivation cell-based assay employing a chimeric SF-1 construct. Two analogous isoquinolinones, ethyl 2-[2-[2-(2,3-dihydro-1,4-benzodioxin-7-ylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate (SID7969543) and ethyl 2-[2-[2-(1,3-benzodioxol-5-ylmethylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate and (SID7970631), were identified as potent submicromolar inhibitors, yielding ...

2008-03-11

471

Issues on boron electrical activation in silicon: Experiments on boron clusters and shallow junctions formation  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive understanding of dopant activation mechanisms in crystalline Si is required in order to form shallow junctions. In this paper, we will review several experimental assessments on boron clustering and novel methods to form shallow junctions. Boron marker-layer structures have been used to investigate the fundamental aspects of formation and ripening boron-interstitial clusters (BICs) and their influence on the associated transient enhanced diffusion (TED). The samples were damaged by Si implants at different doses in the sub-amorphizing range and annealed at high temperatures. We found that BICs act as a sink for interstitials at supersaturations values S(t)>10{sup 4}. This implies that silicon self-interstitial defects are the primary source of interstitials driving TED, and that BICs act as a secondary 'buffer' for the interstitial supersaturation. These clusters are less sensitive to the ripening process than pure interstitial clusters do, so ...

2002-01-01

472

High performance polymer electrolyte fuel cells with ultra-low Pt loading electrodes prepared by dual ion-beam assisted deposition  

International Nuclear Information System (INIS)

Ultra-low pure Pt-based electrodes (0.04-0.12 mg_P_t/cm"2) were prepared by dual ion-beam assisted deposition (dual IBAD) method on the surface of a non-catalyzed gas diffusion layer (GDL) substrate. Film thicknesses ranged between 250 and 750 A, these are compared with a control, a conventional Pt/C (1.0 mg_P_t_(_M_E_A_)/cm"2, E-TEK). The IBAD electrode constituted a significantly different morphology, where low density Pt deposits (largely amorphous) were formed with varying depths of penetration into the gas diffusion layer, exhibiting a gradual change towards increasing crystalline character (from 250 to 750 A). Mass specific power density of 0.297 g_P_t/kW is reported with 250 A IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V. This is contrasted with the commercial MEA with a loading of 1 mg_P_t_(_M_E_A_)/cm"2 where mass specific power density obtained was 1.18 g_P_t/kW (at 0.65 V), a value typical of current state of the ...

2006-06-05

473

Experimental study of lipiodol ultra-fluid. On its signal intensity in MR imaging  

Energy Technology Data Exchange (ETDEWEB)

Lipiodol Ultra-Fluid (Lipiodol) is widely applied in the transcatheter arterial embolization (TAE). We studied signal intensity, the T1 relaxation time and the T2 relaxation time of Lipiodol itself using Siemens Magnetom H15-2 T (1.5 Tesla) and Magnetom M10 (1.0 Tesla). Lipiodol showed higher signal intensity than saline solution on the T1-weighted images (short TR, short TE technique in spin echo method). On the T2-weighted images (long TR, long TE technique in spin echo method), Lipiodol showed lower signal intensity than saline solution. The T1 relaxation time of Lipiodol, measured at 1.0 T, was 201 msec and 218 msec at 1.5 T. The T2 relaxation time of Lipiodol, measured at 1.0 T, was 127 msec; and 167 msec at 1.5 T. The signal intensity of Lipiodol at 1.0 T was higher than the intensity at 1.5 T. Shorter T1 relaxation time of Lipiodol at 1.0 T is probably responsible for the higher intensity at 1.0 T. When MRI is performed after TAE with Lipiodol, the signal ...

1988-11-01

474

Enhanced activity and interfacial durability study of ultra low Pt based electrocatalysts prepared by ion beam assisted deposition (IBAD) method  

International Nuclear Information System (INIS)

Ultra low loading noble metal (0.04-0.12 mg_P_t/cm"2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 g_P_t/kW with 250 A thick IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V in contrast to the state of the art power density of 1.18 g_P_t/kW using 1 mg_P_t_(_M_E_A_)/cm"2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface by means of ...

2009-11-01

475

Edge biasing in the WEGA stellarator  

Energy Technology Data Exchange (ETDEWEB)

The WEGA stellarator is used to confine low temperature, overdense (densities exceeding the cut-off density of the heating wave) plasmas by magnetic fields in the range of B=50-500 mT. Microwave heating systems are used to ignite gas discharges using hydrogen, helium, neon or argon as working gases. The produced plasmas have been analyzed using Langmuir and emissive probes, a single-channel interferometer and ultra-high resolution Doppler spectroscopy. For a typical argon discharge in the low field operation, B=56 mT, the maximum electron density is n{sub e}{proportional_to}10{sup 18} m{sup -3} with temperatures in the range of T=4-12 eV. The plasma parameters are determined by using Langmuir probes and are cross-checked with interferometry. It is demonstrated within this work that the joint use of emissive probes and ultra-high resolution Doppler spectroscopy allows a precise measurement of the radial electric field. The focus of this work is ...

2009-02-27

476

Development of a dedicated ethanol ultra-low emission vehicle (ULEV) system design  

Energy Technology Data Exchange (ETDEWEB)

The objective of this 3.5 year project is to develop a commercially competitive vehicle powered by ethanol (or ethanol blend) that can meet California`s ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes a system design study completed after six months of effort on this project. The design study resulted in recommendations for ethanol-fuel blends that shall be tested for engine low-temperature cold-start performance and other criteria. The study also describes three changes to the engine, and two other changes to the vehicle to improve low-temperature starting, efficiency, and emissions. ...

1995-02-01

477

Challenges in environmental radiological surveillance around nuclear facilities  

International Nuclear Information System (INIS)

To accomplish the environmental radiological surveillance need of India's ambitious nuclear power programme, Health Physics Division is infusing new technologies and improved analytical techniques for day to day measurements of various radionuclides in different environmental matrices. It is essential to have techniques for measuring the concentration of radionuclides just above the background level since the discharges from the nuclear facilities are very low i.e. in the range of 5-10% of the prescribed discharge limits by the regulatory bodies. In view of developing ultra-sensitive techniques, the aim of ongoing programmes of the division is to meet the challenges of measuring ultra trace level of radioactivity by adopting state of art new instrumentation and improved sample processing techniques. This will allow us to measure the lowest level of radioactivity (3H, 90Sr, 137Cs, 239+240Pu, etc.) in the environment and thereby estimating the ...

2007-06-05

478

Analysis and design of an ultra-high-temperature, hydrogen-fueled MHD generator as an open cycle power supply  

Energy Technology Data Exchange (ETDEWEB)

The theoretical analysis of a partially-ionized hydrogen gas flow (gas temperatures of approximately 10,000 to 20,000 K) through a particular class of magnetohydrodynamic (MHD) generators and the preliminary design of these MHD generators as open cycle, electric power supplies are performed. Analysis of the gas flow through these ultra-high temperature MHD generators requires a coupled gas dynamics/radiative heat transfer solution. Gas dynamics are modeled by a set of quasi-one-dimensional, nonlinear differential equations which account for friction, convective and radiative heat transfer and the interaction between the ionized gas and applied magnetic field. Radiative heat transfer is modeled using non-gray, absorbing-emitting two- and three-dimensional P-1 approximations which permit an arbitrary variation of the spectral absorption coefficient with frequency. Gas dynamics and radiative heat transfer are coupled through the energy equation, and through the ...

1990-01-01

479

Winter study of power plant effects  

Energy Technology Data Exchange (ETDEWEB)

As a part of DOE's Meteorological Effects of Thermal Energy Releases (METER) program a field study was undertaken at the Bowen Electric Generating Plant (Plant Bowen) in December 1979. The study was a joint endeavor of Battelle Pacific Northwest Laboratories (PNL), Pennsylvania State University (PSU), and Oak Ridge National Laboratory (ORNL) with the main objective of determining the effects of the plant's smokestack effluents on aerosol characteristics and precipitation chemistry. Other objectives included studies of cooling tower temperature and humidity (T/h) plumes and drift drop concentrations. Conducted over a period of three weeks, the study involved an instrumented aircraft, pilot balloons, a tethered balloon system, a dense network of wetfall chemistry collectors and numerous ground- and tower-based meteorological instruments. Rainfall samples collected during the precipitation event of December 13, 1979, revealed some evidence of plume ...

1980-10-01

480

Thermodynamics and stability of the mixed-conducting Sr-Fe-Co-O system.  

Energy Technology Data Exchange (ETDEWEB)

Mixed-conducting Sr-Fe-Co oxides have potential applications in dense ceramic membranes for high-purity oxygen separation and/or methane conversion to produce syngas (CO + H{sub 2}), because of their combined high electronic/ionic conductivity and significant oxygen permeability. We studied the crystal structure and microstructure of the system in X-ray diffraction experiments and by using scanning electron microscopy, respectively. Thermogravimetric analysis was conducted on the SrFeCo{sub 0.5}O{sub x} sample in environments of various oxygen partial pressures (pO{sub 2}). Conductivity increased while weight decreased with increasing temperature. Activation energy decreased while conductivity increased with increasing pO{sub 2}. The pO{sub 2}-dependent conducting behavior of the SrFeCo{sub 0.5}O{sub x} system can be understood by considering the trivalent-to-divalent transition of transition-metal ions.

1999-04-28

481

The viscous overstability, nonlinear wavetrains, and finescale structure in dense planetary rings  

CERN Document Server

This paper addresses the fine-scale axisymmetric structure exhibited in Saturn's A and B-rings. We aim to explain both the periodic microstructure on 150-220m, revealed by the Cassini UVIS and RSS instruments, and the irregular variations in brightness on 1-10km, reported by the Cassini ISS. We propose that the former structures correspond to the peaks and troughs of the nonlinear wavetrains that form naturally in a viscously overstable disk. The latter variations on longer scales may correspond to modulations and defects in the wavetrains' amplitudes and wavelength. We explore these ideas using a simple hydrodynamical model which captures the correct qualitative behaviour of a disk of inelastically colliding particles, while also permitting us to make progress with analytic and semi-analytic techniques. Specifically, we calculate a family of travelling nonlinear density waves and determine their stability properties. Detailed numerical simulations that confirm our basic results will ...

2009-01-01

482

The corrosion resistance of alloy 800  

International Nuclear Information System (INIS)

Basic studies of the oxidation resistance of Fe-Cr binary and Fe-Cr-Ni ternary alloys in pure oxygen have shown that the excellent corrosion resistance of Alloy 800 is explicable in terms of the low defect concentrations and diffusion rates in the oxide forming on alloys of this composition in sufficiently oxidising environments. The performance of Alloy 800 in environments of particular importance to nuclear power generation is briefly reviewed to determine to what extent ideas derived from the basic studies of Fe-Cr-Ni ternary alloys are borne out in practice. The good corrosion resistance of Alloy 800 in steam and CO_2 and, to some extent, in molten salt environments is in agreement with the behaviour of ternary alloys in oxygen. Minor aliovalent alloying additions are only expected to have a significant effect on the oxidation resistance of Alloy 800 if they favour the formation of breakthrough duplex oxidation. In impure helium and liquid sodium dense coherent ...

483

The construction of earthquake damage estimation system for city gas supply system  

Energy Technology Data Exchange (ETDEWEB)

The regular occurrence of large-scale earthquakes in Japan necessitates the use of earthquake disaster prevention systems that focus on gathering damage information on gas supply facilities immediately after an earthquake strikes and minimizing the damage. This paper discussed the development of an earthquake damage estimation system for city gas pipelines that can show damage information in real-time by using earthquake records obtained from densely deployed earthquake observation networks and the most advanced telecommunication and information technologies. The paper summarized the earthquake damage estimation system (EDES) and Toho Gas disaster prevention measures. Specific topics that were discussed included the Toho Gas supply method; earthquake countermeasures; construction of computer systems; normal and emergency operation of EDES; and verification of functions in actual earthquakes. It was concluded that when there is an emergency, the EDES functions as an ...

2010-07-01

484

Study of porous silicon morphologies for electron transport  

International Nuclear Information System (INIS)

Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous silicon is still a ...

1993-05-17

485

Pullout behavior of steel fibers from cement-based composites  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive experimental program on pullout tests of steel fibers from cement based matrices is described. A specially designed single fiber pullout apparatus was used to provide a quantitative determination of interfacial properties that are relevant to toughening brittle materials through fiber reinforcement. The parameters investigated included a specially designed high strength cement based matrix called Densified Small Particles system (DSP), a conventional mortar matrix, fiber embedment length, and the fiber volume fraction. The mediums from which the fiber was pulled included a control mortar mix without fibers, a mortar mix with 3, and 6 percent fibers by volume. The results indicate that: (1) the dense DSP matrix has significantly improved interfacial properties as compared to the conventional mortar matrix. (2) Increasing the fiber embedment length and the fiber volume fraction in the cement matrix increase the peak pullout load and the pullout work. ...

1997-06-01

486

Mullite long fibres prepared by sol-gel method using water solvent systems  

Energy Technology Data Exchange (ETDEWEB)

Mullite long fibres, which are a candidate for high temperature applications were prepared by sol-gel method from water solvent systems. They were synthesized from three different combinations of raw materials as follows: (1):Al(O{sub 1}C{sub 3}H{sub 7}){sub 3}, Al-nitrate and Si(OC{sub 2}H{sub 5}){sub 4} (TEOS), (2):Al metal, Al-chloride and TEOS, (3):Al metal, Al-nitrate and TEOS. In the methods (1) and (2), very fine SiO{sub 2} aerosol particles were also used partially replacing TEOS. The prepared solutions were condensed and examined the spinability by a hand drawing method. Dense and crack free mullite fibres were prepared from the methods (1) and (3) by firing up to 1100 C. Whereas the fibres prepared from the method (2) were less SiO{sub 2} than mullite composition and were porous by the firing due to evaporation of residual Cl ions at high temperature. (orig.) 10 refs.

1997-12-31

487

Is the Supernova Remnant RX J1713.7-3946 a Hadronic Cosmic Ray Accelerator ?  

CERN Document Server

The non-thermal supernova remnant RX J1713.7-3946 (G347.3-0.5) has recently been shown to be a site of cosmic ray (CR) electron acceleration to TeV energies (Muraishi et al. 2000). Here we present evidence that this remnant is also accelerating CR nuclei. Such nuclei can interact with ambient interstellar gas to produce high energy gamma-rays via the decay of neutral pions. We associate the unidentified EGRET GeV gamma- ray source 3EG J1714-3857 with a massive (~3*10 5 Mo) and dense (~500 nucleons cm -3) molecular cloud interacting with RX J1713.7-3946. Direct evidence for such interaction is provided by observations of the lowest two rotational transitions of CO in the cloud; as in other clear cases of interaction, the CO(J=2-1)/CO(J=1-0) ratio is significantly enhanced. Since the cloud is of low radio and X-ray brightness, CR electrons cannot be responsible for the bulk of its GeV emission there. A picture thus emerges where both electrons and nuclei are being ...

2001-01-01

488

Fast Flooding over Manhattan  

CERN Document Server

We consider a Mobile Ad-hoc NETwork (MANET) formed by n agents that move at speed V according to the Manhattan Random-Way Point model over a square region of side length L. The resulting stationary (agent) spatial probability distribution is far to be uniform: the average density over the "central zone" is asymptotically higher than that over the "suburb". Agents exchange data iff they are at distance at most R within each other. We study the flooding time of this MANET: the number of time steps required to broadcast a message from one source agent to all agents of the network in the stationary phase. We prove the first asymptotical upper bound on the flooding time. This bound holds with high probability, it is a decreasing function of R and V, and it is tight for a wide and relevant range of the network parameters (i.e. L, R and V). A consequence of our result is that flooding over the sparse and highly-disconnected suburb can be as fast as flooding over the dense ...

2010-01-01

489

Environmental strategy for energy: hydrogen fuel cell bus for Brazil  

Energy Technology Data Exchange (ETDEWEB)

One of the most densely populated urban regions in the world is the Sao Paulo Metropolitan region (SPMR) in the State of Sao Paulo, Brazil. Air pollution is a real problem, mainly caused by vehicle exhaust fumes. The air pollution abatement measures adopted in the SPMR, such as the addition of ethanol to gasoline, the use of cars running on pure alcohol, the restrictions in the circulation of vehicles and the utilization of electronic fuel injection and catalyst have had a positive effect on the environment. The 25,000 buses and approximately 400,000 trucks, all operating on diesel, have not been affected by these measures, and it is believed that SPMR is the ideal location for testing new vehicular pollution reduction technologies. A project to this effect was launched by the Ministry of Mines and Energy in conjunction with a host of other partners, and it involved the operation of a fuel cell bus using hydrogen produced by electrolysis. The project was divided ...

2001-06-01

490

Distribution of activation energies for impurity hopping in amorphous metals  

Energy Technology Data Exchange (ETDEWEB)

The distribution of activation energies ..delta.. for classical over-the-barrier hopping is computed for a model amorphous metal. The spread in ..delta.. is determined by the variation in equilibrium-site and saddle-point sizes for the assumed model of dense random packing (DRP) of soft spheres. The size distribution is related to the radial distribution function in a manner which reproduces recent numerical results for the interstitials in DRP models. Size (distance) variation in general is related to energy variation by the form of the potential energy V(r). We show, however, that the distribution of equilibrium-site energies can be related directly to the impurity-induced lattice expansion and bulk modulus without detailed knowledge of V(r). The form of V(r) is necessary for the saddle-point distribution, and we estimate this using simple analytic expressions which fit the observed lattice expansion and impurity (hydrogen) vibrational frequency. The effects of a ...

1983-02-15

491

Cobalt, titanium or cerium oxide protective coatings for the nickel cathode of the molten carbonate fuel cells; Revetements protecteurs a base d'oxyde de cobalt, de titane ou de cerium pour la cathode de nickel des piles a combustible a carbonates fondus  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to combine the MCFC cathode Li{sub x}Ni{sub 1-x}O properties to those of the protective coatings of LiCoO{sub 2}, Li{sub 2}TiO{sub 3} or of CeO{sub 2}, less soluble in the molten carbonates. In the cases of LiCoO{sub 2}, have been carried out by controlled potential coulometry in aqueous solution, a deposition of Co{sub 3}O{sub 4} on dense Ni. The cobalt oxide reacts rapidly in the Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} medium at 650 C to give LiCoO{sub 2}, a spinel cubic phase revealed by Raman spectroscopy. (O.M.)

2003-10-15

492

COLLISIONAL AND LUMINOSITY EVOLUTION OF A DEBRIS DISK: THE CASE OF HD 12039  

International Nuclear Information System (INIS)

Extrasolar debris disks that are bright enough to be observed are dense enough to be collision-dominated; i.e., the small grains that produce their infrared excess have collisional lifetimes shorter than their Poynting-Robertson decay times. This paper describes a numerical code for the modeling of such disks, including accretion and gravitational stirring as well as disruptive collisions. A constraint relating the mass of a debris disk and the sizes of the largest embedded bodies to its luminosity is demonstrated. The collisional code is applied to the debris disk around HD 12039, which has been intensively observed by the Spitzer Space Telescope. The evolution in time of the disk's luminosity is computed for a range of initial disk masses and planetesimal sizes. The luminosity at a given age depends on both the initial disk mass and the initial size of the planetesimals. Luminosity decays more rapidly for massive disks due to the combination of collisional ...

2010-10-20

493

Bullets in a Core Collapse Supernova Remnant The Vela Remnant  

CERN Document Server

We use two-dimensional hydrodynamical simulations to investigate the properties of dense ejecta clumps (bullets) in a core collapse supernova remnant, motivated by the observation of protrusions probably caused by clumps in the Vela supernova remnant. The ejecta, with an inner flat and an outer steep power law density distribution, were assumed to freely expand into an ambient medium with a constant density, $\\sim 0.1$ H atoms cm$^{-3}$ for the case of Vela. At an age of $10^4$ yr, the reverse shock front is expected to have moved back to the center of the remnant. Ejecta clumps with an initial density contrast $\\chi \\sim 100$ relative to their surroundings are found to be rapidly fragmented and decelerated. In order to cause a pronounced protrusion on the blast wave, as observed in the Vela remnant, $\\chi \\sim 1000$ may be required. In this case, the clump should be near the inflection point in the ejecta density profile, at an ejecta velocity $\\sim 3000 ...

2001-01-01

494

An alternative explanation of the COBE data  

Energy Technology Data Exchange (ETDEWEB)

The COBE data on cosmic background radiation (CBR) isotropy and spectrum are generally considered to be explicable only in the context of the Big Bang theory and to be confirmation of that theory. However, this data can also be explained by an alternative, non-Big Bang model which hypothesizes an intergalactic radio-absorbing and scattering medium. Dense, force-free magnetic filaments generated by quasars, active galactic nuclei and Herbig-Haro objects can remain stable in the intergalactic medium for many Gy. They will be opaque to radiation with wavelengths longer than 100--400 microns, and essentially transparent to shorter wavelengths. They are thus capable of thermalizing and isotropizing the cosmic background radiation, and of accounting for the observed decrease of radio luminosity of galaxies within increasing distance from earth. A simple, inhomogeneous model of such an absorbing medium can reproduce both the isotropy and spectrum of the CBR within the ...

1994-12-31

495

Ab initio Stellar Astrophysics: Reliable Modeling of Cool White Dwarf Atmospheres  

CERN Document Server

Over the last decade {\\it ab initio} modeling of material properties has become widespread in diverse fields of research. It has proved to be a powerful tool for predicting various properties of matter under extreme conditions. We apply modern computational chemistry and materials science methods, including density functional theory (DFT), to solve lingering problems in the modeling of the dense atmospheres of cool white dwarfs ($T_{\\rm eff}\\rm <7000 \\, K$). Our work on the revision and improvements of the absorption mechanisms in the hydrogen and helium dominated atmospheres resulted in a new set of atmosphere models. By inclusion of the Ly-$\\rm \\alpha$ red wing opacity we successfully fitted the entire spectral energy distributions of known cool DA stars. In the subsequent work we fitted the majority of the coolest stars with hydrogen-rich models. This finding challenges our understanding of the spectral evolution of cool white dwarfs. We discuss a few ...

2010-01-01

496

A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro  

Energy Technology Data Exchange (ETDEWEB)

Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region (l {element_of} [65{sup o}, 85{sup o}]). For the Cygnus region, the flux is twice the predicted value. This ...

2008-05-14

497

3-dimensional observations of atmospheric variables during the field campaign COPS  

Energy Technology Data Exchange (ETDEWEB)

The Convective and Orographically-induced Precipitation Study (COPS) has the aim to advance the quality of forecasts of orographically-induced precipitation in complex terrain. COPS is a Research and Development Project of the World Weather Research Program and considered to be one of the largest field campaigns on quantitative precipitation forecasting that has been performed so far. A network of state-of-the-art active and passive remote sensing systems was combined with in total 10 airborne platforms, Meteosat rapid scans and dense networks of standard meteorological instruments during the three months long field phase (June-August, 2007) in south-western Germany/eastern France to observe atmospheric variables in the three spatial dimensions and in time. By the University of Hohenheim, two novel ground-based mobile scanning lidar systems were deployed: a scanning rotational Raman lidar which provides combined measurements of the field of atmospheric temperature ...

2008-05-01