WorldWideScience
1

Confocal Imaging of Biological Tissues Using Second Harmonic Generation  

Energy Technology Data Exchange (ETDEWEB)

A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.

2000-03-06

2

Pharmaceutical applications of non-linear imaging  

British Library Electronic Table of Contents (United Kingdom)

Non-linear optics encompasses a range of optical phenomena, including two- and three-photon fluorescence, second harmonic generation (SHG), sum frequency generation (SFG), difference frequency generation (DFG), third harmonic generation (THG), coherent anti-Stokes Raman scattering (CARS), and stimulated Raman scattering (SRS). The combined advantages of using these phenomena for imaging complex pharmaceutical systems include chemical and structural specificities, high optical spatial and temporal resolutions, no requirement for labels, and the ability to image in an aqueous environment. These features make such imaging well suited for a wide range of pharmaceutical and biopharmaceutical investigations, including material and dosage form characterisation, dosage form digestion and drug rele...

2011-01-01

3

Analysis of even harmonics generation in an isolated electric power system  

British Library Electronic Table of Contents (United Kingdom)

Harmonics bred from loads are mainly odd order because the current waveforms have half-wave symmetry. Since the even harmonics are negligibly small, they generally are not measured in electric power systems. However, even harmonics were measured at a 500/275/154 kV substation in Hokuriku Electric Power Company after a transmission line fault was corrected. The even harmonics caused malfunctions of protective digital relays because the relays used 4th harmonics at the input filter as the automatic supervisory signal. This paper describes mechanisms of generation of the even harmonics by comparing the measured waveforms with the ATP-EMTP simulation results. Analysis of these results has clearly shown that there are three different mechanisms of generation of even harmonics. The first mechani...

2009-01-01

4

Nonlinear response of superconductors to alternating fields and currents  

Science.gov (United States)

This report discusses the following topics on superconductivity: nonlinearities in hard superconductors such as surface impedance of a type II superconductimg half space and harmonic generation and intermodulation due to alternating transport currents; and nonlinearities in superconducting weak links such as harmonic generation by a long Josephson Junction in a superconducting slab.

1997-10-08

5

Operating Manual for Single-Shot Autocorrelator  

Science.gov (United States)

... pulses by a 50/50 beamsplitter and recombined in space and in time inside a wafer of KDP crystal which generates a second harmonic of the ...

1993-01-01

6

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

International Nuclear Information System (INIS)

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

2007-06-01

7

Second harmonic generation of copper-vapor pulsed laser radiation  

Energy Technology Data Exchange (ETDEWEB)

An experimental study of second harmonic generation in a copper-vapor pulsed laser with an ADP crystal is presented. The ratio of the conversion into the second harmonic is found to depend on the average power of the exciting radiation. The maximum conversion ratio was 8.5%. Thermal self-defocusing is the main obstacle to obtaining high average powers at the double frequency.

1980-08-01

9

Shaping pulses using frequency conversion with a modulated picosecond free electron laser  

Energy Technology Data Exchange (ETDEWEB)

Computer simulations and experiments indicate that we can shape the infrared picosecond pulses of the Mark III FEL in amplitude, frequency, and phase. Strongly modulated fundamental and second harmonic pulses have been generated by operating the Mark III FEL in the regime of strong sideband growth. In this paper, we present the results of simulations and experiments for second harmonic generation with fundamental inputs from 2 to 3 {mu}m.

1995-12-31

10

Using ICCD as a fast optical switch to measure harmonic super-radiation from an optical klystron in a storage ring  

International Nuclear Information System (INIS)

An optical klystron is built in the 800 MeV electron storage ring at University of Science and Technology of China for harmonic super-radiation generation. In single bunch operation mode the repetition rate of the spontaneous radiation pulses is about 4.533 MHz, and the repetition rate of the seed laser pulses is about 3 Hz, while the radiation pulse duration is 300 ps. For measuring harmonic radiation a high on/off ratio ICCD is used as an optical switch to reject spontaneous radiation pulses of high repetition rate

2001-07-01

11

Nonlinear effect in vibroseis data; Vibroseis kiroku ni oite mitomerareru hisenkei koka  

Energy Technology Data Exchange (ETDEWEB)

This paper describes nonlinear effect recognized in Vibroseis data. Harmonics is a wave of frequency in integer factors generated in association with basic sweep vibrated by Vibroseis. Harmonics is generated because vibration in the vicinity of seismic source contains nonlinear terms. Seismic exploration using the reflection method often discusses propagation of seismic waves hypothesized as a linear phenomenon. Vibroseis data analysis, however, requires evaluation of the effect of the harmonics on accuracy. Vibroseis investigation measures may be taken by eliminating n-order harmonics by using the phase control method, and generating seismic source sweep in which the phase is shifted by 180/(n-1) each time in order to leave the basic sweep. Methods to increase the sweep length include a method to expel strain to a location outside the range ...

1997-05-27

12

Free electron laser seeded by ir laser driven high-order harmonic generation  

International Nuclear Information System (INIS)

Coherent x-ray production by a seeded free electron laser (FEL) is important for next generation synchrotron light sources. The authors examine the feasibility and features of FEL emission seeded by a high-order harmonic generation (HHG) of an infrared laser. In addition to the intrinsic FEL chirp, the longitudinal profile and spectral bandwidth of the HHG seed are modified significantly by the FEL interaction well before saturation. This smears out the original attosecond pulselet structure. The authors introduce criteria for this smearing effect on the pulselet and the stretching effect on the entire pulse. They discuss the noise issue in such a seeded FEL.

2007-01-08

13

Imaging Three Dimensional Two-Particle Correlations for Heavy-Ion Reaction Studies  

Energy Technology Data Exchange (ETDEWEB)

The authors report an extension of the source imaging method for analyzing three-dimensional sources from three-dimensional correlations. The technique consists of expanding the correlation data and the underlying source function in spherical harmonics and inverting the resulting system of one-dimensional integral equations. With this strategy, they can image the source function quickly, even with the extremely large data sets common in three-dimensional analyses.

2005-06-27

14

Utility activities that create power quality problems  

Energy Technology Data Exchange (ETDEWEB)

Power quality problems are caused by activities normal to utility operations such as maintenance outages and capacitor switching or events that are abnormal such as lightning strikes and equipment failures. Disconnection and reconnection of transmission lines and transformers can cause switching surges, and are more severe on extra high voltage transmission lines than high voltage lines. Capacitor switching can cause transients and harmonics that may affect sensitive equipment, and are the source of 3rd, 5th, 7th and 9th harmonics in the hundreds of hertz ranges. Overload, sudden loss of generating capacity and transmission line faults are typical problems affecting system stability. Fault interruptions and reclosings can cause surges in the distribution system, and lightning strikes may cause voltage surges or dips due to arrester sparkover. Blackouts, brownouts, voltage fluctuations, travelling wave overvoltages, ...

1992-02-01

15

Multi-Harmonic RF Control System for J-PARC RCS  

CERN Document Server

Multi-Harmonic RF Control System for J-PARC RCS

2003-01-01

16

Transverse velocity modulator and generator schemes based on non-collinear radiation and electron beams  

International Nuclear Information System (INIS)

New non-collinear schemes are suggested for transverse velocity modulation of electron beams and for the generation of coherent spontaneous radiation by these transversely modulated beams. It is shown that due to the non-collinearity some orders of magnitude enhancement can be achieved for the coherent spontaneous radiation (CSR) power at both the fundamental and harmonic frequencies.

2000-05-01

17

High-gain harmonic generation free electron laser seeded by few-cycle laser  

International Nuclear Information System (INIS)

Tunable output wavelength is an important character of a free electron laser (FEL). As generally understood, to alter the wavelength of a high-gain harmonic generation (HGHG) FEL laser, the seed laser must be tunable. A few-cycle, high intensity laser obtained by optical compression usually has pretty broad bandwidth in the spectral domain, which can be used as the seed laser of a HGHG and may open the possibility to approach a HGHG scheme with fully tunable wavelength. In this paper, a HGHG FEL seeded by a few-cycle laser is theoretically discussed and numerically investigated. A few-cycle seed laser significantly influences HGHG FEL performance, especially in output wavelength tuning. For a HGHG FEL seeded by a 4-cycle 786 nm laser, output wavelength tunability range up to 14.9% of the central wavelength 262 nm is observed by adjusting the resonant condition.

2008-06-07

18

Advances in Modeling of Scanning Charged-Particle-Microscopy Images  

CERN Document Server

Modeling artificial scanning electron microscope (SEM) and scanning ion microscope images has recently become important. This is because of the need to provide repeatable images with a priori determined parameters. Modeled artificial images are highly useful in the evaluation of new imaging and metrological techniques, like image-sharpness calculation, or drift-corrected image composition (DCIC). Originally, the NIST-developed artificial image generator was designed only to produce the SEM images of gold-on-carbon resolution sample for image-sharpness evaluation. Since then, the new improved version of the software was written in C++ programming language and is in the Public Domain. The current version of the software can generate arbitrary samples, any drift ...

2010-01-01

19

Spontaneous radiation decay of weakly bound system in externa field  

International Nuclear Information System (INIS)

A new channel of nonlinear ionization of quantum system in a strong laser field is discussed. The probability of spontaneous radiation decay from the ground state in a short-range potential to the final Volkov wave function, is calculated by the first order of the perturbation theory. It is shown that this process at high intensities of the laser field will be comparable with the high harmonic generation. (orig.)

2001-02-01

20

P3 flux from anisotropic point source  

International Nuclear Information System (INIS)

One-velocity angular flux of a neutron field generated by a polarly anisotropic point source in an infinite homogeneous region is calculated in P3 approximation, using the spherical harmonics operator formalism adapted to two-dimensional spherical geometry. The problem is reduced to simple algebraic equations. For weak absorption and linearly anisotropic scattering, the solution is given in closed form. (orig.).

21

Monitoring interfacial dynamics by pulsed laser techniques. [Annual report  

Energy Technology Data Exchange (ETDEWEB)

Goal was developing optical methods for study of dynamic processes at the electrode/electrolyte interface. In the past year, optical second harmonic generation was used for time-resolved measurements of thallium deposition on Cu(111). The studies of carrier dynamics in photo-excited materials have involved both steady-state and picosecond time-resolved luminescence measurements following photoexcitation of the semiconductor material.

1992-12-31

22

CRC handbook of laser science and technology. Volume 3. Optical materials, Part 1 - Nonlinear optical properties/radiation damage  

Energy Technology Data Exchange (ETDEWEB)

This book examines the nonlinear optical properties of laser materials. The physical radiation effects on laser materials are also considered. Topics considered include: nonlinear optical properties; nonlinear and harmonic generation materials; two-photon absorption; nonlinear refractive index; stimulated Raman scattering; radiation damage; crystals; and glasses.

1986-01-01

23

Optical second-harmonic generation in III-V semiconductors: Detailed formulation and computational results  

Science.gov (United States)

In an earlier paper (Phys. Rev. Lett. 66, 41 (1991)), we calculated both the dielectric constant ({epsilon}{sub {infinity}}) and the nonlinear optical susceptibilities for second-harmonic generation ({chi}{sup (2)}) in the static limit for AlP, AlAs, GaP, and GaAs in the local-density approximation with and without a self-energy correction in the form of a scissors operator,'' including local-field effects. In this paper, we expand our presentation of this calculation. Agreement with experiment to within 15% for the nonlinear susceptibility is demonstrated where experiments are available (GaP and GaAs); the dielectric constants are in no worse than 4% agreement with experiment. The virtual hole'' contributions are reformulated to avoid large numerical cancellations in the case of near degeneracies. The virtual electron'' terms dominate over the virtual hole'' terms ...

1991-12-15

24

Real time neutron radiography using a Lixi neutron imaging device  

Energy Technology Data Exchange (ETDEWEB)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Illinois. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or ...

1986-01-15

25

Real time neutron radiography using a Lixi neutron imaging device  

International Nuclear Information System (INIS)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Ill. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or ...

1986-01-01

26

Fracture imaging with converted elastic waves  

Energy Technology Data Exchange (ETDEWEB)

This paper examines the seismic signatures of discrete, finite-length fractures, and outlines an approach for elastic, prestack reverse-time imaging of discrete fractures. The results of this study highlight the importance of incorporating fracture-generated P-S converted waves into the imaging method, and presents an alternate imaging condition that can be used in elastic reverse-time imaging when a direct wave is recorded (e.g., for crosswell and VSP acquisition geometries).

2001-05-29

27

Crystal growth, structural and optical characterization of a semi-organic single crystal for frequency conversion applications  

International Nuclear Information System (INIS)

Single crystals of semi-organic L-histidine hydrobromide have been grown by slow evaporation technique from a mixture of L-histidine and hydrobromic acid in aqueous solution at ambient temperature. From high-resolution X-ray diffraction analysis, the crystalline perfection of the grown crystal has been studied. Single crystal X-ray diffraction analyses, Nuclear Magnetic Resonance spectral analysis, Thermo-Gravimetry (TG), Differential Thermal Analysis (DTA) and hardness test have been employed to characterize the as-grown crystals. The UV cutoff wavelength of the grown crystal is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics have been studied using Q switched Nd:YAG laser (#lambda#=1064 nm). The second harmonic generation conversion efficiency of the grown crystals confirms their ...

2010-12-15

28

Measurement of low-energy laser pulse duration in femtosecond range  

International Nuclear Information System (INIS)

Measurements of low-energy (#approx#10"- "1"0 J) femtosecond laser pulse durations have been carried out on the basis of second-order autocorrelation function analysis. The scheme of non collinear second harmonic generation realized in KDP crystal has been used for increasing of the measurement contrast and accuracy. Proposed scheme can be used for measurements in wide enough ranges of laser pulse durations (from tens femto seconds to hundreds picoseconds) and energies. (authors)

29

Parallel architecture for rapid image generation and analysis  

Energy Technology Data Exchange (ETDEWEB)

A multiprocessor architecture inspired by the Disney multiplane camera is proposed. For many applications, this approach produces a natural mapping of processors to objects in a scene. Such a mapping promotes parallelism and reduces the hidden-surface work with minimal interprocessor communication and low-overhead cost. Existing graphics architectures store the final picture as a monolithic entity. The architecture here stores each object's image separately. It assembles the final composite picture from component images only when the video display needs to be refreshed. This organization simplifies the work required to animate moving objects that occlude other objects. In addition, the architecture has multiple processors that generate the component images in parallel. This further shortens the time needed to create a composite picture. In addition to generating ...

1987-01-01

30

Future of X-ray phase imaging in medical imaging technology  

International Nuclear Information System (INIS)

Weakly absorbing materials, such as biological, soft tissues, can be imaged by generating contrast due to the phase shift of X-rays. In the past decade, several methods for X-ray phase imaging were proposed and demonstrated. The performance of X-ray phase imaging is attractive in the field of medical imaging technology, and its development for practical use is expected. Many methods, however, have been developed under the assumption of the use of synchrotron radiation, which is an obstacle to practical use. The method based on Talbot (-Lau) interferometry enables us to use a compact X-ray source, and its development is expected as a breakthrough for medical applications. (author)

2007-04-01

31

Interim cryo-cooler/detector report  

Energy Technology Data Exchange (ETDEWEB)

This report describes development of an electronic system designed to reduce vibration generated by a cryocooler. The diminished vibration makes it practical to use the active cooler to extract heat from a portable gamma ray detector instrument. The system was developed for a Sunpower cryocooler with an integrated counterbalance mass. The overall momentum cancellation approach is also applicable to other similar cryocoolers. The cancellation system is an assembly of several components tailored to accomplish the required vibration reduction with minimum power consumption and volume. It is designed to be powered by a 18--32 Volt battery. Up to ten harmonics of the 58.65 Hz drive frequency are controlled. In addition to the vibration cancellation, the electronic system produces the drive signal for the cryocooler and regulates the cooler temperature. The system employs a sinusoidal drive to reduce the amount of higher harmonic ...

1995-04-19

32

Infrared (IR) vs x-ray power generation in the SLAC Linac Coherent Light Source (LCLS)  

Energy Technology Data Exchange (ETDEWEB)

The LCLS, a Free-Electron Laser (FEL) designed for operation at a first harmonic energy of 300 eV ({lambda} {congruent} 40{Angstrom}) in the Self-Amplified Spontaneous Emission (SASE) regime, will utilize electron bunches compressed down to durations of <0.5ps, or lengths of <150 {mu}. It is natural to inquire whether coherent radiation of this (and longer) wavelength will constitute a significant component of the total coherent output of the FEL. In this paper a determination of a simple upper bound on the IR that can be generated by the compressed bunches is outlines. Under the assumed operating parameters of the LCLS undulator, it is shown that that IR component of the coherent output should be strongly dominated by the x-ray component.

1993-05-01

33

Frequency mixing crystal  

Energy Technology Data Exchange (ETDEWEB)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

1992-01-01

34

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

35

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 ...

36

Subject-specific, multiscale simulation of electrophysiology: a software pipeline for image-based models and application examples  

UK PubMed Central (United Kingdom)

Many simulation studies in biomedicine are based on a similar sequence of processing steps, starting from images and running through geometric model generation, assignment of tissue properties, numerical...Full Text Available

2009-06-13

37

Serial Intravascular Ultrasound Analysis of the Impact of Myocardial Bridge on Neointimal Proliferation After Coronary Stenting in Patients with Acute Myocardial Infarction  

British Library Electronic Table of Contents (United Kingdom)

Background: Mechanisms underlying the association between myocardial bridge (MB)-stenting and in-stent restenosis (ISR) are still unclear. Objective: To assess the impact of MB on ISR using intravascular ultrasound (IVUS). Methods: In the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, 100 left anterior descending artery (LAD) culprit lesions (79 treated with paclitaxel-eluting stents [PES] and 21 treated with bare metal stents) were imaged with serial IVUS immediately postprocedure and at 13 months. Results: At baseline the LAD stent extended into the MB segment beyond the culprit lesion in seven patients (MB-stent group). In the remaining 93 patients the LAD stent was implanted only in the culprit lesion without extending into t...

2010-01-01

38

Language and Music in the Musician Brain  

British Library Electronic Table of Contents (United Kingdom)

Abstract Results of numerous experiments conducted over the past 15-years by using behavioural as well as brain imaging methods have shown that musical expertise influences brain anatomy, brain functions and behaviour. The musician- brain is thus considered as a very good model of brain plasticity. Moreover, many results have demonstrated that musical expertise not only impacts on music processing but also on several aspects of speech processing including lexical pitch, sentence intonation and the metric structure of words. Conversely, recent results indicated that linguistic expertise with tone or quantity languages such as Mandarin Chinese, Thai, Finnish and Japanese, influences the processing of harmonic tones and musical intervals. We discuss possible interpretations of these findings ...

2011-01-01

39

Portal localization images using computed radiography for high-energy electron beam therapy  

Energy Technology Data Exchange (ETDEWEB)

Portal localization images for high-energy electron beam therapy are necessary to confirm the treatment field by comparing them with a simulation image obtained before treatment or portal verification images after treatment. In this study, portal localization images were acquired using the computed radiography (CR) system and bremsstrahlung X-rays generated in the electron beam irradiations. All images obtained with phantom and the irradiations of in the electron energy of 8, 10, 12 and 15 MeV were feasible for clinical use. The CR system used in this study included general diagnostic imaging cassette and storage phosphor plate, but none of other special devices. The system can usually supply portal localization images, which maintains the quality assurance of high-energy electron beam therapy. (author)

2002-09-01

40

Harmonic decomposition of orbit data for multipole analysis  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a simple analysis procedure that transforms a set of beamline orbit data into a set of harmonic orbits of first, second, and third order or higher. Each harmonic orbit can be studied individually to identify errors of the specific order with minimum interference from other orders. Effectively these are orbits caused by kicks, due to harmonic errors, propagated through linear lattice. Examples from accelerator study will be presented. The application and inherent limitations of this analysis procedure are discussed.

2005-05-01

41

Third harmonic lasing in a storage ring free-electron laser  

International Nuclear Information System (INIS)

We report the first experimental achievement of a storage ring free-electron laser (FEL) oscillation on the third harmonic in the near-infrared region. The FEL gain was evaluated as 0.029% per mA. The measured linewidth of the third-harmonic FEL was less than that of the fundamental FEL, and the measured pulse width of the third-harmonic FEL was wider than that of the fundamental FEL. A higher-harmonic FEL should be developed not only to enhance the wavelength region of the FEL but also to vary the characteristics of an FEL micropulse. (author)

2010-09-01

42

Approximate fuzzy C-means (AFCM) cluster analysis of medical magnetic resonance image (MRI) data  

International Nuclear Information System (INIS)

The authors describe the application of an approximate fuzzy C-means (AFCM) clustering algorithm as a data dimension reduction approach to medical magnetic resonance images (MRI). Image data consisted of one T1-weighted, two T2-weighted, and one T2*-weighted (magnetic susceptibility) image for each cranial study and a matrix of 10 images generated from 10 combinations of TE and TR for each body lymphoma study. All images were obtained with a 1.5 Tesla imaging system (GE Signa). Analyses were performed on over 100 MR image sets with a variety of pathologies. The cluster analysis was operated in an unsupervised mode and computational overhead was minimized by utilizing a table look-up approach without adversely affecting accuracy. Image data were first segmented into 2 coarse clusters, each of which ...

43

Parametric study of pulsed thermal bumps in supersonic boundary layer  

British Library Electronic Table of Contents (United Kingdom)

A three-dimensional numerical study is performed to explore the effect of pulsed spanwise-periodic surface thermal perturbation (also denoted as thermal bump) in a Mach 1.5 flat plate laminar boundary layer. A high-resolution upwind-biased Roe method is used with the compressive Van Leer harmonic limiter on a suitably refined mesh. The dependence of flow stability characteristics on the variation of thermal bump geometry (shape and dimension) and pulsing properties (disturbance amplitude and frequency) is assessed. It is shown that the finite-span thermal bumps generate streamwise vortices. When the thermal bump is pulsed, vortex shedding is observed, and the streamwise vorticity grows with the downstream distance. Analysis of the integrated disturbance energy indicates that the streamwise...

2011-01-01

44

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)

45

Visualization of liquid metal two-phase flow by a real time neutron radiography system  

Energy Technology Data Exchange (ETDEWEB)

In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).

1995-11-01

46

Visualization of liquid metal two-phase flow by a real time neutron radiography system  

International Nuclear Information System (INIS)

In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).

1995-01-01

47

Closing the loop in cortically-coupled computer vision: a brain-computer interface for searching image databases.  

Science.gov (United States)

We describe a closed-loop brain-computer interface that re-ranks an image database by iterating between user generated 'interest' scores and computer vision generated visual similarity measures. The interest scores are based on decoding the electroencephalographic (EEG) correlates of target detection, attentional shifts and self-monitoring processes, which result from the user paying attention to target images interspersed in rapid serial visual presentation (RSVP) sequences. The highest scored images are passed to a semi-supervised computer vision system that reorganizes the image database accordingly, using a graph-based representation that captures visual similarity between images. The system can either query the user for more information, by adaptively resampling the database to create additional RSVP sequences, or it can converge to a ...

2011-05-12

48

Synthesis, crystal structure and nonlinear optical property of Rb3V5O14  

International Nuclear Information System (INIS)

The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The crystal Rb3V5O14 crystallizes in the trigonal system with space P31m (No. 157), a=b=8.7134(12) A, c=5.2807(11) A and ?=90o, ?=90o, ?=120o, Z=1, ?=3.516 g/cm3. It is a layered structure that is very flat and strongly parallel to c. The V5O14 layer structure consists of corner-linked square and triangular pyramids. The layers are separated by Rb+ ions, which fit equally well on the V5O14 layer. The Kurtz powder SHG measurement, using 1064 nm radiation, showed that the second-harmonic generation efficiency of Rb3V5O14 is about two times that of KDP. -- Graphical abstract: The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The crystal Rb3V5O14 ...

2010-12-01

49

3-D brain CT image display for planning of craniofacial operation  

International Nuclear Information System (INIS)

The authors have been developing a 3D brain CT image display system for planning of craniofacial operations. This system helps doctors plan craniofacial operations on a graphic display (GD) terminal by rendering 3D images reconstructed from a set of slices. The authors reveal how the system generates 3D shapes of organs from given CT images and how it modifies or transforms the obtained shapes according to the user's request. The system functions now available are extraction and display of the skull and the skin, measurement of the distance between two points on the skull given through the GD terminal, and generating and eliminating a polygonal region arbitrarily given on the skull as an operative region. (Auth.).

50

Velocity control in three-phase induction motors using PIC; Controle de velocidade de motor de inducao trifasico usando PIC  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a technique for speed control three-phase induction motor using the pulse width modulation (PWM), in open loop while maintaining the tension for constant frequency. The technique is adapted from a thesis entitled 'Control of the three-phase induction motor, using discrete PWM generation, optimized and synchronized', where studies are presented aimed at their application in home appliances, to eliminate mechanical parts, replaced by low cost electronic control, thus having a significant reduction in power consumption. Initially the experiment was done with the Intel 80C31 micro controller. In this paper, the PWM modulation is implemented using a PIC micro controller, and the speed control kept a low profile, based on tables, synchronized with transitions and reduced generation of harmonics in the network. Confirmations were made using the same process of building tables, but takes ...

2009-07-01

51

Longitudinal and transverse dynamics of a free electron laser based on a storage ring of second and third generation  

International Nuclear Information System (INIS)

This work aims at improving the understanding of the dynamics of a Free Electron Laser (FEL) based on a storage ring. A new phenomenon of saturation by the electron bunch transverse dimensions is pointed out, during the FEL operation with a magnetic optics ''low emittance''. A part of this thesis work concerns the study of the longitudinal dynamics of the FEL depending on a parameter: the detuning between the pass frequency of the electrons and the back and return frequency of the laser pulse in the optical cavity. This study shows that the FEL presents a pulsed or a steady state behavior depending on the detuning. Besides, a spectro-temporal behavior of the FEL is pointed out showing the FEL pulse substructures and holes in the spectrum. Another part of this work concerns the response of the resonant FEL system, when a perturbation is applied on the gain. Under the effect of a modulation, the FEL can present a periodic or chaotic regime. The analysis of these regimes shows that a ...

52

Broad-band stigmatic spectrograph for the soft x-ray range  

International Nuclear Information System (INIS)

We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)

1998-09-30

54

INTERACTIONS OF COHERENT OPTICAL RADIATION WITH ...  

Science.gov (United States)

... and flashtube. Unfortunately, we had insufficient laser intensity to use the harmonic from a KDP crystal as a monitor. This ...

1964-08-31

56

Spherical harmonic operator method of solving the transport equation in curvilinear coordinates. Application to #gamma#-theta geometry  

International Nuclear Information System (INIS)

An explicite PN solution of the multi-dimensional homogeneous neutron transport equation is given by expanding the angular flux into a series of geometry-independent spherical harmonics operators. An algorithm is developed for representing the spherical harmonic operators in orthogonal curvilinear coordinates. The general formulae are applied to two-dimensional spherical geometry; detailed P3 formulae are given. (orig.).

57

Advantages of magnification in digital phase-contrast mammography using a practical X-ray tube  

Energy Technology Data Exchange (ETDEWEB)

Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point source results in a phase contrast too narrow for detection with CR. ...

2008-12-15

58

Native Synthetic Imaging of Smoothed Particle Hydrodynamics density fields using gridless Monte Carlo Radiative Transfer  

CERN Document Server

An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework ...

2010-01-01

59

Generation and control of sound bullets with a nonlinear acoustic lens  

UK PubMed Central (United Kingdom)

Acoustic lenses are employed in a variety of applications, from biomedical imaging and surgery to defense systems and damage detection in materials. Focused acoustic signals, for example, enable ultrasonic...Full Text Available

2010-04-20

60

Catheter Ablation for Paroxysmal Atrial Fibrillation  

Medline Plus

... catheter ablation for paroxysmal atrial fibrillation procedure utilizing 3-D mapping and rotational intracardiac echocardiography. This program is ... of the MRI scan and then there's the 3-D image, which is generated from the pixels chosen ...

61

A new method for 2D gel spot alignment: application to the analysis of large sample sets in clinical proteomics  

UK PubMed Central (United Kingdom)

BackgroundIn current comparative proteomics studies, the large number of images generated by 2D gels is currently compared using spot matching algorithms. Unfortunately, differences...Full Text Available

62

Pseudospin symmetry and the relativistic harmonic oscillator  

CERN Document Server

A generalized relativistic harmonic oscillator for spin 1/2 particles is studied. The Dirac Hamiltonian contains a scalar, $S$, and a vector, $V$, quadratic potentials in the radial coordinate, as well as a tensor potential, $U$, linear in $r$. Setting either or both combinations $\\Sigma=S+V$ and $% \\Delta=V-S$ to zero, analytical solutions for bound states of the corresponding Dirac equations are found. The eigenenergies and wave functions are presented and particular cases are discussed, devoting a special attention to the non-relativistic limit and the case $\\Sigma=0$, for which pseudospin symmetry is exact. We also show that the case $U=\\Delta=0$ is the most natural generalization of the non-relativistic harmonic oscillator. The radial node structure of the Dirac spinor is studied for several combinations of harmonic oscillator potentials, and that study allows us to explain why nuclear intruder levels cannot be ...

2004-01-01

63

On the Approach to Spherical Harmonics by Maxwell, Thomson and Tait  

CERN Document Server

We present a unified self-consistent review of the approach to spherical harmonics developed in the second half of the 19th century by Maxwell and by Thomson and Tait. We remark how this spherical coordinate-free approach straightforwardly leads to physically very important results of the theory of solid and surface harmonics which become rather tedious to work out when using spherical coordinates and associated Legendre functions. These results include, among others, the addition theorem, spherical wave expansions, the construction of the standard set of normalized spherical harmonics, Y_lm - together with their rotational properties-, and recursion relations. We provide new proofs for Maxwell's theorem, the addition theorem and Hobson's theorem, respectively, using in the latter some elementary notions of the symbolic techniques proper of the theory of invariants. Also, we give an approach based on compact vector methods ...

2008-01-01

64

Preliminary Design of ARIES-Devasthal Faint Object Spectrograph and Camera  

CERN Document Server

We present here the preliminary design of ARIES-Devasthal Faint Object Spectrograph and Camera (ADFOSC), which is a multi-mode instrument for both imaging and spectroscopy. ADFOSC is the first-generation instrument to be mounted at the axial port of the Cassegrain focus on our new 3.6m optical telescope to be installed at Devasthal, Nainital. The main design goals of the instrument are : the instrument will have capability of broad- and narrow-band imaging, low-medium resolution spectroscopy, and imaging polarimetry. The operating wavelength range will be from 360 to 1000 nm and the instrument will have remote-control capability.

2009-01-01

65

[The study of the mixing layer by the point image method].  

Science.gov (United States)

The properties of the mixing layer in dynamic systems were studied by the example of a mathematical model of the cubic image type. Its role in the generation of information and the evolution of its significance was shown. At the moment of generation, information is of zero significance, and this significance then increases. A criterion of efficiency was proposed, and the optimum moment of making a decision in creative work was determined. It was shown that the increase in the variability of the parameters of a living system upon entry into the mixing layer and its decrease upon exit can serve as objective indicators of the transition of the system from one dynamic regime (attractor) to another. PMID:12723364

66

Statistical mapping analysis of serotonin synthesis images generated in healthy volunteers using positron-emission tomography and alpha-[11C]methyl-L-tryptophan.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To assess the suitability of analyzing functional images of brain serotonin (5-HT) synthesis with statistical parametric mapping (SPM), and to investigate further possible sex-related regional...Full Text Available

2000-09-01

67

Nonlinear air-coupled emission: The signature to reveal and image microdamage in solid materials  

International Nuclear Information System (INIS)

It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.

2007-12-17

68

Harmonics in power systems of ships with electrical propulsion drives. Comparison between different converters  

Energy Technology Data Exchange (ETDEWEB)

In this report the effects of harmonics in marine power systems is discussed and a comparison is given between the most typical converter types, including pulse width modulated drives, load commutated inverters and cycloconverters. The effect of harmonic distortion on the power system equipment and loads is first briefly discussed. Special attention is given to the circumstances in the low voltage distribution system, where general load equipment is connected. In addition to the total harmonic distortion the effect of voltage deviation to the supply quality is also considered. The origin of harmonics in the load currents of the three converter types is then considered. The differences between the converters are outlined, and the most typical spectra are presented. The possible means for reducing the harmonic distortion are also studied. The solutions considered are the increasing of ...

1996-11-01

69

High-power radio frequency pulse generation and extraction based on wakefield excited by an intense charged particle beam in dielectric-loaded waveguides  

International Nuclear Information System (INIS)

Power extraction using a dielectric-loaded (DL) waveguide is a way to generate high-power radio frequency (RF) waves for future particle accelerators, especially for two-beam-acceleration. In a two-beam-acceleration scheme, a low-energy, high-current particle beam is passed through a deceleration section of waveguide (decelerator), where the power from the beam is partially transferred to trailing electromagnetic waves (wakefields); then with a properly designed RF output coupler, the power generated in the decelerator is extracted to an output waveguide, where finally the power can be transmitted and used to accelerate another usually high-energy low-current beam. The decelerator, together with the RF output coupler, is called a power extractor. At Argonne Wakefield Accelerator (AWA), we designed a 7.8GHz power extractor with a circular DL waveguide and tested it with single electron bunches and bunch trains. The output RF frequency (7.8GHz) ...

70

Steganography using wavelet compressed images  

Science.gov (United States)

Internet bandwidth is in high demand, and one way that web sites lower the amount of bandwidth they use is by compressing their site's images. This lowers the amount of bandwidth used, and makes the site load much faster. There are of course many other useful applications for compressed images. Bit Plane Complexity Segmentation (BPCS) digital picture steganography is a technique to hide data inside an image file. BPCS achieves high embedding rates with low distortion based on the theory that noise-like regions in a bit-plane can be replaced with noise-like secret data without discernible loss in image quality. This is possible because the human eye, while very good at distinguishing anomalies in areas of homogenous texture, is bad at distinguishing anomalies in visually complex areas. However, BPCS is not a robust embedding scheme, and any lossy compression usually destroys the data. Wavelet ...

2001-08-01

71

Spontaneous Radiation Emission from Short, High Field Strength Insertion Devices  

Energy Technology Data Exchange (ETDEWEB)

Since the earliest papers on undulaters were published, it has been known how to calculate the spontaneous emission spectrum from ''short'' undulaters when the magnetic field strength parameter is small compared to unity, or in ''single'' frequency sinusoidal undulaters where the magnetic field strength parameter is comparable to or larger than unity, but where the magnetic field amplitude is constant throughout the undulater. Fewer general results have been obtained in the case where the insertion device is both short, i.e., the magnetic field strength parameter changes appreciably throughout the insertion device, and the magnetic field strength is high enough that ponderomotive effects, radiation retardation, and harmonic generation are important physical phenomena. In this paper a general method is presented for calculating the radiation spectrum for short, high-field ...

2005-09-15

72

PWM applications for the electric railway traction system fed by the AC/DC dual power line  

Energy Technology Data Exchange (ETDEWEB)

The latest electronic circuit technology that can be used for the electric railway traction system fed by an AC/DC dual power line was developed. This system consists of reverse conducting GTO thyristors, microprocessors, and DSP`s. In the AC power supply line section, the line converter is controlled by PWM technology to secure a high power factor and reduce the higher harmonic generation of an input current as far as possible. The line converter and motor converter use reverse conducting GTO thyristors. Since these converters are cooled using a heat pipe cooler, they are reduced in size and weight. The electric grounding point of the main power circuit is set to the negative side of the DC line for AC and DC line sections. Therefore, the AC/DC selector switch was simplified in structure. Moreover, the DC input for the auxiliary power supply can be obtained from multiple line converters using diodes. As the result of the actual operational ...

1996-01-01

73

New intelligent monitor for CANDU type NPP  

International Nuclear Information System (INIS)

Nuclear energy provides a third of Europe's electricity with nearly no greenhouse-gas emissions. Sustained efforts are now being conducted to harmonize regulations all over Europe through WENRA and to converge on technical nuclear safety practices within the TSO network ETSON (European Technical Safety Organizations Network). In CANDU type NPP the tritiated water occurs by the neutron bombardment of deuterium. The tritiated water vapors imply health hazard (in the critical organs of the body the water presents a 10 day average biological half-life) and the early detection in nuclear plants of tritium emissions is important because the tritiated water vapors have the same characteristics as of atmospheric water vapors. By detecting tritiated vapors, the monitoring system ensures the following objectives: (a) indicates levels of tritium generally due to heavy water leakage, (b) reduces the possibility of health hazard. In order to attain this goal of safety function, ...

2009-10-12

74

The effect of patient positioning aids on PET quantification in PET/MR imaging  

British Library Electronic Table of Contents (United Kingdom)

Objectives Clinical PET/MR requires the use of patient positioning aids to immobilize and support patients for the duration of the combined examination. Ancillary immobilization devices contribute to overall attenuation of the PET signal, but are not detected with conventional MR sequences and, hence, are ignored in standard MR-based attenuation correction (MR-AC). We report on the quantitative effect of not accounting for the attenuation of patient positioning aids in combined PET/MR imaging. Methods We used phantom and patient data acquired with positioning aids on a PET/CT scanner (Biograph 16, HI-REZ) to mimic PET/MR imaging conditions. Reference CT-based attenuation maps were generated from measured (original) CT transmission images (origCT-AC). We also created MR-like attenuation map...

2011-01-01

75

Non-invasive on-line two-phase flow regime identification employing artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

A novel non-invasive approach to the on-line identification of BWR two-phase flow regimes is investigated. The proposed approach receives neutron radiography images of coolant flow recordings as its input and performs feature extraction on each image via simple and directly computable statistical operators. The extracted features are subsequently used as inputs to an ensemble of self-organizing maps whose outputs demonstrate swift and accurate classification of each image into its corresponding flow regime. The novelty of the approach lies in the use of the self-organizing map which generates the different classes by itself, according to feature similarity of the corresponding images; this contrasts traditional artificial neural networks where the user has to define both the number of distinct classes as well as to supply separate training vectors for each class.

2009-05-01

76

Imaging hypoxia in vivo by controlling the electrochemistry of copper radionuclide complexes  

British Library Electronic Table of Contents (United Kingdom)

Tissue hypoxia is a feature of cancer, heart disease and stroke, and imaging it may become clinically important. Copper-ATSM (ATSMH2 = 2,3-butanedione bis(N-methyl)thiosemicarb-azone), labelled with 60Cu, 62Cu or 64Cu, is selectively taken up in hypoxic cells in vitro and in vivo by a bioreductive mechanism, and is a prototype hypoxia imaging agent amenable to improvement. In vitro studies with several differently alkylated analogues of CuATSM show that hypoxia selectivity is a general property of complexes with two alkyl groups at the diketone backbone, offering a range of pharmacokinetic properties while retaining hypoxia selectivity. This pharmacokinetic control affords a route to development of second-generation hypoxia imaging agents with optimized properties for different clinical ap...

2007-01-01

77

Verification of electron beam therapy with storage phosphor images: Precision of field placement  

Energy Technology Data Exchange (ETDEWEB)

Portal verification images were generated from the photon contamination in electron beams produced by a linear accelerator during treatment of patients receiving high-energy electron radiation therapy (8-14 MeV). An experimental storage phosphor system was used to record the images and display them on laser-printed film. Images were obtained from four or more treatment fractions from 21 cases of head and neck cancer. Precision in field placement was estimated by determining the position of a selected anatomic landmark relative to the center of the field for each series of images. The average standard deviation in the field-position measurements was 3.8 mm. Several procedural problems were also detected and corrected after review of the verification images. The results indicate that the emphasis placed on monitoring and control of field-positioning error in ...

1990-04-01

78

Intensification of Harmonic Spontaneous Radiation with a Novel Undulator  

Science.gov (United States)

We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessive current in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K < 1, for spontaneous radiation emitted along the axis of the system. The emission at harmonics f > 1 is greatly enhanced for the approximate square-wave magnetic ...

1998-11-01

79

Characteristics of cosmic ray pole-equator anisotropy derived from spherical harmonic analysis of neutron monitor data  

International Nuclear Information System (INIS)

The spherical harmonic analysis of cosmic ray neutron data from the worldwide network neutron monitor stations during the years 1966 to 1969 was carried out. The second zonal harmonic component obtained from the analysis corresponds to the Pole-Equator anisotropy of the cosmic ray neutron intensity. Such an anisotropy makes a semiannual variation. In addition to this, it is shown that the Pole-Equator anisotropy makes a variation depending on the interplanetary magnetic field (IMF) sector polarities around the passages of the IMF sector boundary. A mechanism to interpret these results is also discussed.

1985-08-01

80

What will keep the lights on in Ontario: Responses to a policy short-circuit  

Energy Technology Data Exchange (ETDEWEB)

Ontario's electricity industry restructuring program is reviewed, with a view to identify the reasons behind the failure of deregulation which was expected to create competition, to stabilize, or even reduce, prices to consumers, and attract serious private sector investment for the construction of new generating capacity. The report painstakingly reviews the series of events which resulted in a steep rise in electricity rates during the summer of 2002, immediately after deregulation came into effect, which led to freezing retail electricity rates and related charges by the then Conservative provincial government, and the reversal of that decision by the newly-elected Liberal government in the fall of 2003, and plans to bring back retail hydro rates that reflect the cost of production. The authors provide a discussion of policy options and a series of recommendations that are expected to create incentives to reduce and shift demand, encourage the use of ...

2003-12-01

81

Safety in the forefront  

Energy Technology Data Exchange (ETDEWEB)

Safety in general and harmonization of International Maritime Organization rules on mobile offshore drilling rig operation in particular are discussed. The improvement of the industry's safety record is also discussed.

1985-02-01

82

Preliminary representation of world population by spherical harmonics.  

UK PubMed Central (United Kingdom)

The geographical arrangement of people on the surface of the earth is approximated by a mathematical equation of 361 terms. This is a convenient form for comparison with other distributions and for...Full Text Available

1992-07-15

83

Harmonized Tariff Schedule Codes Flagged with Prior Notice ...  

Science.gov (United States)

... 3004505040***, MEDICAMENTS, DOSED, VITAMINS, MULTIPLE, OTHER COMBINATIONS, FD3***. 3104100000**, CARNALLITE, SYLVITE AND OTHER CRUDE POTASSIUM SALTS, FD3**. ...

84

System suitable for use in neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

A system for real-time neutron radiography of moving objects is described. It comprise a source adapted to generate a continuous uninterrupted series of neutron pulses. Each pulse has a predetermined peak power and duration compatible with the framing times of a real-time video imaging system. A transporter moves an object to be examined to bring sequentially position selected portions of the object in the path of the pulses. Where the object itself has moving components, pulses are sequentially incident on the object. According to any dissimilarities, the object will alter the intensity of the neutrons passing therethrough. In order to record separately the changes in the neutron intensity, for each pulse, an imager is positioned to receive the neutron beam pulses which have been altered by their passage through the object and produce images indicating intensity alterations. A refrigerated beryllium ...

1990-02-07

85

System suitable for use in neutron radiography  

International Nuclear Information System (INIS)

A system for real-time neutron radiography of moving objects is described. It comprise a source adapted to generate a continuous uninterrupted series of neutron pulses. Each pulse has a predetermined peak power and duration compatible with the framing times of a real-time video imaging system. A transporter moves an object to be examined to bring sequentially position selected portions of the object in the path of the pulses. Where the object itself has moving components, pulses are sequentially incident on the object. According to any dissimilarities, the object will alter the intensity of the neutrons passing therethrough. In order to record separately the changes in the neutron intensity, for each pulse, an imager is positioned to receive the neutron beam pulses which have been altered by their passage through the object and produce images indicating intensity alterations. A refrigerated beryllium ...

1988-07-20

86

Grating-based X-ray phase imaging using multiline X-ray source  

International Nuclear Information System (INIS)

Differential phase-contrast X-ray imaging has been performed in a Talbot-Lau configuration, where a multiline X-ray source was used instead of a combination of a hard-X-ray multiple slit and a normal focus X-ray generator. When the multiple slit is used, a high aspect ratio structure is needed and slit width should be below 10 ?m for its function. The fabrication and use of such a multislit can be omitted using the presented configuration. The multiline X-ray source was developed by making grooves on a tungsten rotating anode, which was irradiated by an electron beam to generate X-rays. An array of 10?m line sources with a pitch of 30?m was formed and combined with a 4.5 ?m pitch phase grating and a 5.3 ?m pitch amplitude grating to generate differential phase contrast. With a total exposure time of 40 s, a differential phase image depicting cartilages was obtained. (author)

2009-07-01

87

The influence of scattered radiation on recording systems and quality-assurance test parameters  

International Nuclear Information System (INIS)

Scattered radiation generated in patient and imaging system has to be considered when quality-assurance tests involve dose detection or image-quality estimations. Measurement of automatic-exposure control dose can be altered by backscattering from intensifying screens of more than 10% and the equipment transmission factor can be overestimated up to a factor of 10 when only primary radiation is used. The sensitivity of intensifying screens depends on the angle of incidence of the radiation and so primary and scattered radiation are detected differently. The quality-control aspects of anti-scatter grids are discussed. (author).

1988-02-23

88

The influence of scattered radiation on recording systems and quality-assurance test parameters  

International Nuclear Information System (INIS)

Scattered radiation generated in patient and imaging system has to be considered when quality-assurance tests involve dose detection or image-quality estimations. Measurement of automatic-exposure control dose can be altered by backscattering from intensifying screens of more than 10% and the equipment transmission factor can be overestimated up to a factor of 10 when only primary radiation is used. The sensitivity of intensifying screens depends on the angle of incidence of the radiation and so primary and scattered radiation are detected differently. The quality-control aspects of anti-scatter grids are discussed. (author).

89

Models of cardiac electromechanics based on individual hearts imaging data  

British Library Electronic Table of Contents (United Kingdom)

Current multi-scale computational models of ventricular electromechanics describe the full process of cardiac contraction on both the micro- and macro- scales including: the depolarization of cardiac cells, the release of calcium from intracellular stores, tension generation by cardiac myofilaments, and mechanical contraction of the whole heart. Such models are used to reveal basic mechanisms of cardiac contraction as well as the mechanisms of cardiac dysfunction in disease conditions. In this paper, we present a methodology to construct finite element electromechanical models of ventricular contraction with anatomically accurate ventricular geometry based on magnetic resonance and diffusion tensor magnetic resonance imaging of the heart. The electromechanical model couples detailed repres...

2011-01-01

90

Awarable complexity: a study on CRT picture design based on plant images by NPP operators  

International Nuclear Information System (INIS)

Original pictures installed in the 1st and 2nd generation type central control panels (CCP) and new 'Awarable and Complex' pictures were made on personal computers and evaluated. A total 18 of actual plant operators (M=32.3, SD=10.5 years old) participated in the evaluation. The operators rated the new CRT pictures highly. The response times using the new CRT pictures were shorter than those by the original pictures. Both results suggested that the CRT picture design guidelines based on the operators' plant images were effective for improving their performance. (author)

2000-12-01

91

Maximum imaging depth of two-photon autofluorescence microscopy in epithelial tissues  

Science.gov (United States)

Endogenous fluorescence provides morphological, spectral, and lifetime contrast that can indicate disease states in tissues. Previous studies have demonstrated that two-photon autofluorescence microscopy (2PAM) can be used for noninvasive, three-dimensional imaging of epithelial tissues down to approximately 150 ?m beneath the skin surface. We report ex-vivo 2PAM images of epithelial tissue from a human tongue biopsy down to 370 ?m below the surface. At greater than 320 ?m deep, the fluorescence generated outside the focal volume degrades the image contrast to below one. We demonstrate that these imaging depths can be reached with 160 mW of laser power (2-nJ per pulse) from a conventional 80-MHz repetition rate ultrafast laser oscillator. To better understand the maximum imaging depths that we can achieve in epithelial tissues, we studied ...

2011-02-01

92

Real-time neutron monitoring method using an imaging plate  

Energy Technology Data Exchange (ETDEWEB)

A novel system for real-time radiation monitoring in reactor or accelerator facilities has been studied using an imaging plate. The authors made a feasibility study on a new neutron detection system using both photostimulated luminescence (PSL) and prompt luminescence (PL) generated in a neutron imaging plate (NIP) when the NIP is irradiated by neutrons. A readout system consisting of a semiconductor laser and a photomultiplier tube was fabricated for the purpose. It was confirmed that the system can measure both PSL and PL, where Am-Li was used as a neutron source. It may be possible to establish a new wide-range neutron monitoring system using the developed system as a PL mode normally, and as a PSL mode in case of intense neutron dose that cannot be measured in a PL mode because of saturation of the detection system. (author)

1999-07-01

93

Real-time neutron monitoring method using an imaging plate  

International Nuclear Information System (INIS)

A novel system for real-time radiation monitoring in reactor or accelerator facilities has been studied using an imaging plate. The authors made a feasibility study on a new neutron detection system using both photostimulated luminescence (PSL) and prompt luminescence (PL) generated in a neutron imaging plate (NIP) when the NIP is irradiated by neutrons. A readout system consisting of a semiconductor laser and a photomultiplier tube was fabricated for the purpose. It was confirmed that the system can measure both PSL and PL, where Am-Li was used as a neutron source. It may be possible to establish a new wide-range neutron monitoring system using the developed system as a PL mode normally, and as a PSL mode in case of intense neutron dose that cannot be measured in a PL mode because of saturation of the detection system. (author)

1999-04-19

94

Development of a Full Body CAD Dataset for Computational Modeling: A Multi-modality Approach  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study was to develop full body CAD geometry of a seated 50th percentile male. Model development was based on medical image data acquired for this study, in conjunction with extensive data from the open literature. An individual (height, 174.9?cm, weight, 78.6???0.77?kg, and age 26?years) was enrolled in the study for a period of 4?months. 72 scans across three imaging modalities (CT, MRI, and upright MRI) were collected. The whole-body dataset contains 15,622 images. Over 300 individual components representing human anatomy were generated through segmentation. While the enrolled individual served as a template, segmented data were verified against, or augmented with, data from over 75 literature sources on the average morphology of the human body. Non-Uniform Rational...

2011-01-01

95

Real time closed orbit correction system  

Energy Technology Data Exchange (ETDEWEB)

We describe a global closed orbit feedback experiment, based upon a real time harmonic analysis of both the orbit movement and the correction magnetic fields. The feedback forces the coefficients of a few harmonics near the betatron tune to vanish, and significantly improves the global orbit stability. We present the results of the experiment in the UV ring using 4 detectors and 4 trims, in which maximum observed displacement was reduced by a factor of between 3 and 4. 4 refs., 3 figs.

1989-01-01

96

Single-pass high-gain free electron laser electron beam diagnostics  

International Nuclear Information System (INIS)

Consensus reached in the last few years that fourth generation light source will most likely be a X-ray or a UV coherent source based on single-pass high-gain free electron laser (FEL), such as Self Amplified Spontaneous Emission (SASE), or seeded high-gain harmonic-generation (HGHG) free electron lasers. High-gain (>10"7) required for single-pass FEL puts great constrain on the quality of electron beam, and demands detailed distribution information of electron beam in six-dimension. The typical accelerator system for single-pass FEL consists of a photocathode RF gun injection system, a linac and magnetic bunch compressors, and a long undulator. The major challenges in beam diagnostics for single-pass FEL are to characterize the pico-seconds high-brightness electron beam in six-dimension produced by photocathode RF gun injector, and improve the stability and reliability of the photocathode RF gun injection system. Characterization of short ...

2000-11-27

97

Intensification of harmonic spontaneous radiation with a novel undulator  

International Nuclear Information System (INIS)

We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessivecurrent in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K1 is greatly enhanced for the approximate square-wave magnetic profile: the ratio of the power emitted at f=5 by the square-wave undulator to that of the sine-wave undulator is about 15 (whereas ...

1999-07-01

98

Experimental generation of non-Kolmogorov turbulence using a liquid crystal spatial light modulator  

Science.gov (United States)

Several experiments showed that the classical Kolmogorov power spectral density of the refractive-index sometimes does not properly describe the statistics of the atmosphere. In this paper we show an experimental testbed able to generate non-classical Kolmogorov turbulence by using a liquid crystal spatial light modulator. The testbed is used at Naval Postgraduate School for laboratory investigation of laser beam propagation in maritime environment where a power law different from classical Kolmogorov, 11/ 3, could be present. Applications of this testbed are ship to-ship free space optical communication, imaging and high energy laser weapons.

2011-09-01

99

Dual-energy projection radiography using condenser discharge x-ray generator and FCR. Determination of technical factors  

Energy Technology Data Exchange (ETDEWEB)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique.

1987-04-01

100

Dual-energy projection radiography using condenser discharge x-ray generator and FCR  

International Nuclear Information System (INIS)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique. (author).

1987-01-01

102

Elastic plane wave response migration  

Energy Technology Data Exchange (ETDEWEB)

Migration-based methods have been recently proposed to improve the estimation of angle-dependent reflectivity in the presence of complex structures. An anisotropic prestack reverse-time migration is developed to estimate the reflectivity as function of the local illumination angle. This migration method generates four simultaneous images which corresponds to the in-depth (local) plane-wave response for PP, PS, SP and SS reflections, and can be used in a Zoeppritz-based elastic inversion scheme. (author)

1993-07-01

103

Development of a computerized portal verification scheme for pelvic treatment fields  

International Nuclear Information System (INIS)

Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV ...

1996-09-01

104

Scatter measurements for optical cone-beam computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Both x-ray and optical cone-beam CT (CBCT) scanners are limited by scattered photons that contaminate the primary images. Transparent radiochromic gels and plastics are anticipated to produce less scattering than polymerization gels and hence result in reconstructed dose distributions with greater contrast and dynamic range. Four methods of scatter measurement were investigated to quantify scatter fractions using an in-house optical CBCT scanner. The methods consisted of generating either 'coin' shadows or primary beamlets in transmission images. The four methods generated similar results of 10% scatter fractions in gel transmission images for this particular scanner configuration with both leuco crystal violet and carbon black micelle gels. The scatter contributions were distributed as 5% from micelle gel, 2% from Teflon wall, 2% from refractive index matching ...

2009-05-01

105

Determination of time-dependent void fraction distribution in bubbly two-phase flow by a real-time neutron radiography technique  

Energy Technology Data Exchange (ETDEWEB)

Radiographic images generated by the real-time neutron radiography system (RTNR) are analyzed by customized image processing software of the determination of instantaneous void fraction distribution. The cross-sectional averaged axial void fraction profiles and the two-dimensional void fraction profiles are determined simultaneously for each image. Various flow regimes are generated to determine if the RTNR system can accurately predict the void distribution in the radial, axial, and temporal coordinates. The results show the RTNR system correctly determines the void fraction distribution for each flow regime; however, accuracy decreases with decreasing void fraction. For net water thicknesses > 1.0 cm, the accuracy decreases with increasing water thickness due to the extreme sensitivity of thermal neutron interactions with light water. Heavy water is a more suitable fluid than ...

1995-01-01

106

Neutron radiography with the cyclotron, 4  

International Nuclear Information System (INIS)

A real-time neutron radiography system was installed at the neutron radiography facility of Sumitomo Heavy Industries where a sub-compact cyclotron is used as a neutron generator and nominal neutron flux was observed as 1.1 x 10"6 n/cm"2/sec. Preliminary tests were made for various kinds of such components as collimators, scintillators, cameras and lenses and the system was chosen to give the highest quality images. Especially for the scintillator screen, screening tests were carried out for compounds of LiF/ZnS(Ag) and Gd_2O_3/ZnS(Ag) by radiographic film method. The neutron radiography image was converted to fluorescent images by means of the converter and observed by a SIT type TV camera. The video signal was directly displayed on a CRT or after processed with digital image processing devices. The characteristics of this system as for the resultant resolution are presented ...

1986-01-01

107

MTF analysis of the MURR real-time neutron radiography facility  

International Nuclear Information System (INIS)

In neutron radiography, as in other forms of NDE, it is sometimes desirable to observe dynamic events. This need has generated increased interest in real-time neutron radiography systems. As in other forms of radiography, a standard method for measuring the image forming capability of real-time systems is necessary in order to compare the various methods and systems used. A technique which has been used extensively in general photography and has been applied in the characterization of several screen-film combinations used in conventional neutron radiography is to determine the imaging system's modulation transfer function (MTF). This gives a graphical representation of the system's spatial resolution capabilities and was therefore chosen as the method for evaluation of the real-time neutron radiography facility at the University of Missouri Research Reactor (MURR). The method used was to image a ...

1982-04-01

108

Distortion-invariant color pattern recognition using multiple phase-shifted-reference-based joint transform correlation incorporating synthetic discriminant function  

Science.gov (United States)

This paper proposes a new pattern recognition system employing optical joint transform correlation (JTC) technique which offers a great number of advantages over similar digital techniques, including very fast operation, simple architecture and capability of updating the reference image in real time. The proposed JTC technique incorporates a synthetic discriminant function (SDF) of the target image estimated from different training images to make the pattern recognition performance invariant to noise and distortion. It then involves four different phase-shifted versions of the same target SDF reference image, which are individually joint transform correlated with the given input scene. When the correlation signals are combined, it produces a single cross-correlation peak corresponding to each potential target present in the given input scene. The proposed technique also includes a fringe-adjusted filter ...

2011-04-01

109

Investigation by physical methods of the possible role of telomeres in DNA in aging process  

CERN Document Server

The interaction energies between the different types of bases of a single strand of DNA molecule have been calculated. Using these original values of energies the harmonic behavior of a number of base patterns of DNA has been studied. In view of the great interest aroused by the discovery of the role of the telomere segment of the DNA in the replication process and its possible link with the aging process, we have investigated, with simple models, the harmonic behavior of the telomeric pattern of bases as well as the thermodynamic response in the biological system. With these results a conclusion on the probable role of the telomeric pattern on aging has also been drawn. Here the calculated values of harmonic frequencies of the telomeric pattern of bases and of other possible patterns show that the telomeric pattern is associated with the highest vibrational frequency among all patterns of base combinations at the ...

2003-01-01

110

Renewable energies and energy choices. Summary of the colloquium; Energies renouvelables et choix energetiques. Compte rendu du colloque  

Energy Technology Data Exchange (ETDEWEB)

This document is an executive summary of the colloquium organized by the French syndicate of renewable energies (SER) which took place at the Maison de l'UNESCO in Paris during the national debate on energies organized by the French government in spring 2003. The colloquium was organized around 6 round tables dealing with: the world perspectives and the environmental context of the contribution of renewable energies to the sustainable development (respect of Kyoto protocol commitments, contribution to the security of energy supplies, lack of large scale program of development of decentralized power generation in developing countries, lack of market tools linked with CO{sub 2} emissions, improvement of competitiveness); development of renewable energies in Europe (promotion and sustain in all European countries, obligation of supply and purchase, pricing regulation, European harmonization of practices); renewable electricity and its ...

2003-05-01

111

Inverse Bloch-oscillator: Strong Thz-photocurrent resonances at the Bloch frequency  

Energy Technology Data Exchange (ETDEWEB)

We have observed resonant changes in the current-voltage characteristics of miniband semiconductor superlattices when the Bloch frequency is resonant with a terahertz field and its harmonics: the inverse Bloch oscillator effect. The resonant feature consists of a peak in the current which grows with increasing laser intensity accompanied by a decrease of the current at the low bias side. The peak position moves linearly with the laser frequency. When the intensity is increased further the first peak starts to decrease and a second peak at about twice the voltage of the first peak is observed due to a two photon resonance. At the highest intensities we observe up to a four photon resonance. A superlattice is expected to show negative differential conductance due to the strong nonparabolicity of the miniband. In this situation the carriers should undergo Bloch oscillations with a frequency {omega}{sub B} = eEd/h. Transient Bloch oscillations of photo excited carriers ...

1995-12-31

112

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

International Nuclear Information System (INIS)

The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate (L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) A, b=12.4530(5) A, c=15.2432(5) A and space group P2_12_12_1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 "oC using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different temperatures in the frequency range 1 kHz-2 ...

2011-01-01

113

Atlas of nuclear medicine imaging  

Energy Technology Data Exchange (ETDEWEB)

An exhaustive compendium of normal and abnormal imaging is presented. The following systems and procedures are illustrated by over 2800 captioned illustrations: liver, spleen, and hepatobiliary imaging; perfusion and ventilation lung imaging; thyroid imaging; salivary gland imaging; bone imaging; brain imaging; radionuclide cisternography; blood flow studies; gallium imaging; nuclear cardiology; and renal imaging. Not included in the atlas are adrenal imaging procedures and emission computed tomography. (ERB)

1981-01-01

114

Pion-induced fission  

Energy Technology Data Exchange (ETDEWEB)

The A(..pi../sup +/,/sup 3/He)B reaction near threshold is studied in a model where the pion is absorbed by an /sup 4/He constituent of the target nucleus. The predictions of this model using harmonic oscillator cluster wave functions agree semi-quantitatively with the experimental data on the inverse reaction.

1982-03-10

115

NSF/Tokyo Report: MITI's Polymer Project  

Science.gov (United States)

... Highly-Functional Materials" was launched in JFY1996 under the New Materials field. This project was ... Bio-mimetic materials" (1) Advanced stimuli responsive materials (2) Harmonized molecular materials ...

116

Efficient Second Harmonic Conversion of Broadband High ...  

Science.gov (United States)

... Rev. Lett., vol. 42, no. 24, pp. 1625-1628, June 1979. 3 ... Trans. Plasma Science, vol. PS-10, no. 1, pp. 55-58, March 1982. ...

1989-06-23

117

Effects of introducing low-frequency harmonics in the perception of vocoded telephone speech1  

UK PubMed Central (United Kingdom)

Several studies have demonstrated that telephone use presents a challenge for most cochlear implant (CI) users, and this is attributed mainly to the narrow bandwidth (300–3400 Hz) introduced...Full Text Available

2010-09-01

118

Discrimination of Schroeder-Phase Harmonic Complexes by Normal-Hearing and Cochlear-Implant Listeners  

UK PubMed Central (United Kingdom)

The temporal fine structure (TFS) of sound contributes significantly to the perception of music and speech in noise. The evaluation of new strategies to improve TFS delivery in cochlear implants (CIs)...Full Text Available

2008-03-01

119

Structures in the Universe and Origin of Galaxies  

CERN Document Server

The analysis of images (of obtained in various ranges of the lengths of waves) of luminous objects in the Universe by means of a method of multilevel dynamic contrasting led author to the conclusions: a) the structures of all observable galaxies represents a complicated constructions which have the tendency to self-similarity and made of separate (basic) blocks, which are a coaxially tubular structures and a cartwheel-like structures; b) the majority of observable objects in the Universe are luminous butt-ends of almost invisible (of almost completely transparent) of filamentary formations which structures are seen only near to their luminous butt-ends; c) the result of analysis of images of cosmic objects show the structure of many pairs of cooperating galaxies point to opportunity of their formation at butt-ends generated in a place of break of the similar filament; d) the interacting galaxies (M 81 and M 82) show they ...

2005-01-01

120

Simulating the operation of photosensor-based lighting controls  

International Nuclear Information System (INIS)

Energy savings from the use of daylighting in commercial buildings are realized through implementation of photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate workplane illumination. The dimming level of electric lighting is based on the signal of a photosensor. Current simulation approaches for such systems are based on the questionable assumption that the signal of the photosensor is proportional to the task illuminance. This paper presents a method that simulates the performance of photosensor controls considering the acceptance angle, angular sensitivity, placement of the photosensor within a space, and color correction filter. The method is based on the multiplication of two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180- or 360-degree fisheye image of the space as ''seen'' by the photosensor. The paper ...

121

Progress and problems in the chemistry of technetium-99m tracers  

International Nuclear Information System (INIS)

The recent acceleration of effort to elucidate and explore the coordination chemistry of technetium has been prompted mainly by the need for a new generation of radiotracers in nuclear medicine, preferentially for tomograhic studies. Current approaches and their limitations in designing "9"9"mTc complexes capable of penetrating cell membranes of the target organs, and remaining there sufficiently long, are reviewed. With the predominance of Tc(V) oxo compounds, especially for brain imaging agents, new N4 and N2S2 coordinate complexes have been developed by shifting from bidentate to tetradentate ligands with a variable side chain or other adjustable reactivity. The search for myocardial imaging agents has focused on a variety of mixed ligand complexes of Tc(III) and most promising [Tc(CNR)_6]"+ complexes of Tc(I). 64 refs. (author).

122

Biological effects and physical safety aspects of NMR imaging and in vivo spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

An assessment is made of the biological effects and physical hazards of static and time-varying fields associated with the NMR devices that are being used for clinical imaging and in vivo spectroscopy. A summary is given of the current state of knowledge concerning the mechanisms of interaction and the bioeffects of these fields. Additional topics that are discussed include: (1) physical effects on pacemakers and metallic implants such as aneurysm clips, (2) human health studies related to the effects of exposure to nonionizing electromagnetic radiation, and (3) extant guidelines for limiting exposure of patients and medical personnel to the fields produced by NMR devices. On the basis of information available at the present time, it is concluded that the fields associated with the current generation of NMR devices do not pose a significant health risk in themselves. However, rigorous guidelines must be followed to avoid the physical ...

1985-08-01

123

Amplitude preserved VSP reverse time migration for angle-domain CIGs extraction  

Science.gov (United States)

An improved method of generating angle-domain common-image gathers (ADCIGs) by VSP reverse time migration (RTM) is introduced in this paper. The formula which is used to compute the receiver wavefield for VSP RTM is modified by adding an amplitude correction term in order to conveniently output amplitude-preserved ADCIGs. Compared with the surface seismic data, VSP data contains much richer wavefields. However, the direct and downgoing waves can bring about serious imaging artifacts in ADCIGs, especially the direct wave. The feasibility and validity of this method is demonstrated by both numerical and real VSP data from western China. Thus, the ADCIGs from this method can provide reliable basic data for VSP migration velocity analysis, VSP AVO/AVA analysis, and inversion.

2011-06-01

124

Nonlinear vibrations and chaos in electrostatic torsional actuators  

British Library Electronic Table of Contents (United Kingdom)

Electrostatic torsional micro-mirrors have wide spread use in different industries for diverse purposes. This paper investigates the development of superharmonics and chaotic responses in electrostatic torsional micro-mirrors near the pull-in condition. Appearance of nonlinear phenomena is investigated in models accounting for and disregarding the coupling of torsional and flexural deflections. Analysis of the system response to step and harmonic excitation reveals the appearance of DC and AC symmetry breaking. Increasing the amplitude of harmonic excitation, the response in the form of distinct superharmonics changes to a broad band response, where there is loss of periodicity and the response becomes chaotic. Accounting for flexural deflections in coupled model reduces the voltage thresh...

2011-01-01

125

Multi-megajoule Nd: glass fusion laser design  

Energy Technology Data Exchange (ETDEWEB)

New technologies make multi-megajoule glass lasers economically feasible. Laser architectures using harmonic switchout, target plane holographic injection, phase conjugation, continuous apodization and higher amplifier efficiencies have been devised. A plan for a multi-megajoule laser which can be built for an acceptable cost relies on manufacturing economies of scale and the demonstration of the new technologies presented here. These include continuous pour glass production, rapid harmonic crystal growth, switching of large blocks of power using larger capcaitors packed more economically and by using large identical parts counts.

1986-04-04

126

Harmonic oscillator representation in the theory of scattering and nuclear reactions  

Energy Technology Data Exchange (ETDEWEB)

The following questions, concerning the application of the harmonic oscillator representation (HOR) in the theory of scattering and reactions, are discussed: the formulation of the scattering theory in HOR; exact solutions of the free motion Schroedinger equation in HOR; separable expansion of the short range potentials and the calculation of the phase shifts; `isolated states` as generalization of the Wigner-von Neumann bound states embedded in continuum; a nuclear coupled channel problem in HOR; and the description of true three body scattering in HOR. As an illustration the soft dipole mode in the (11)Li nucleus is considered in a frame of the (9)Li+n+n cluster model taking into account three body continuum effects.

1995-01-01

127

Analysis of the reactive power consumption and the harmonics in the network by the non-linear electrical loads  

Energy Technology Data Exchange (ETDEWEB)

The non linear electrical loads can give rise to a number of disturbances in electrical power networks. Among them, the high consumption of relative power is to be noted and so is the several harmonic components which may be injected in the industry system and very often in the utility system. So, by using appropriate technical considerations, as well as measurements in typical special electrical loads, such negative effects are analyzed and ways of minimizing them are suggested. (author) 3 refs., 11 figs., 6 tabs.

1994-12-31

128

Focused ion beam assisted three-dimensional rock imaging at submicron scale  

Energy Technology Data Exchange (ETDEWEB)

Computation of effective flow properties of fluids in porous media based on three dimensional (3D) pore structure information has become more successful in the last few years, due to both improvements in the input data and the network models. Computed X-ray microtomography has been successful in 3D pore imaging at micron scale, which is adequate for many sandstones. For other rocks of economic interest, such as chalk and diatomite, submicron resolution is needed in order to resolve the 3D-pore structure. To achieve submicron resolution, a new method of sample serial sectioning and imaging using Focused Ion Beam (FIB) technology has been developed and 3D pore images of the pore system for diatomite and chalk have been obtained. FIB was used in the milling of layers as wide as 50 micrometers and as thin as 100 nanometers by sputtering of atoms from the sample surface. The focused ion beam, consisting of gallium ions (Ga+) ...

2003-05-09

129

The role of 3D Helical CT in the reconstructive treatment of maxillofacial cancers  

International Nuclear Information System (INIS)

Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT ...

2000-12-01

130

Evaluation of heterogeneity in thickness of passive films on pure iron by scanning electrochemical microscopy  

Energy Technology Data Exchange (ETDEWEB)

Scanning electrochemical microscopy (SECM) was applied to evaluate the heterogeneity of a passive film formed on a pure iron electrode in deaerated pH 8.4 borate solution. A probe current image of SECM was measured with a tip-generation/sub-strate-collection (TO/SC) mode in deaerated pH 8.4 borate solution containing 0.03 moldm{sup -3} Fe(CN){sub 6}{sup 4-} as a mediator. The difference in thickness of passive films formed on two iron plates at different potentials could be evaluated from the probe current image. The probe current image of the passivated iron surface with distinctive crystal grains was composed of the patch patterns, the shapes of which coincided completely with the shapes of the substrate crystal grains. The probe current flowed above the grain surface oriented to {l_brace}100{r_brace} plane was less than that above the grain surface oriented to {l_brace}110{r_brace} or ...

1999-04-01

131

Performance of a low cost solar paraboloidal dish steam generating system  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the design, development and performance characteristics of a low cost solar steam generating system which incorporates recent design and materials innovations of parabolic dish technology. The concentrator is a deep dish of rather imperfect optics, made of silvered polymer reflectors fitted in the aluminum frame of a satellite communication dish. Conventional cavity receivers tend to be inadequate for this concentrator. Semi-cavity and modified cavity receivers, thermally optimised, with the fuzzy focal image have, therefore, been investigated. Preliminary field measurements and cost, as well as performance analyses of the system, indicate a solar to steam conversion efficiency of 70-80% at 450{sup o}C and a collector system cost of Rs 8000-9000/m{sup 2} (1 US dollar = Rs, 40.0). (author)

2000-05-01

132

Expression of bacterial luciferase in eukaryotic cells  

International Nuclear Information System (INIS)

Expression of Bacterial luciferase enzyme (lux) in mammalian cells would be a powerful bioreporter protein system for in vivo imaging because eukaryotic luciferases need expensive substrates. However, only a few efforts have been made to express bacterial luciferase enzyme in mammalian cells. As the result of this, we attempted to construct bicistronic vector including two bacterial luciferase genes (LuxA and LuxB) for assessing the potential to be visualized in vitro or in vivo by optical imaging system after transfection to mammalian cells. We designed and synthesized luxA and luxB genes from Photorhabdus Luminescens. To co-express both luxA and luxB genes from a single promoter, we cloned as a bicistronic transcript fused with an internal ribosomal entry site (IRES). This bicistronic transcript was transfected by Superfect to HEK 293T cell line. We also transfected lux A and lux B vector to HEK 293T cells separately. To evaluate gene ...

2005-11-18

133

Optical Images Due to Lenses and Mirrors  

Science.gov (United States)

... Title : Optical Images Due to Lenses and Mirrors. ... Abstract : The properties of real and virtual images formed by lenses and mirrors are reviewed. ...

134
135

MAGNETIC RESONANCE IMAGING DEVICE  

J-STORE (Japan)

Full Text Available

2010-08-31

136

Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques  

International Nuclear Information System (INIS)

Positron emission tomography (PET) is a fully quantitative technology for imaging metabolic pathways and dynamic processes in vivo. Attenuation correction of raw PET data is a prerequisite for quantification and is typically based on separate transmission measurements. In PET/CT attenuation correction, however, is performed routinely based on the available CT transmission data. Recently, combined PET/magnetic resonance (MR) has been proposed as a viable alternative to PET/CT. Current concepts of PET/MRI do not include CT-like transmission sources and, therefore, alternative methods of PET attenuation correction must be found. This article reviews existing approaches to MR-based attenuation correction (MR-AC). Most groups have proposed MR-AC algorithms for brain PET studies and more recently also for torso PET/MR imaging. Most MR-AC strategies require the use of complementary MR and transmission images, or morphology ...

2009-03-01

137

Summary of the marine aerosol properties and thermal imager performance trial (MAPTIP). Professional paper  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a 1993 field experiment entitled Marine Aerosol Properties and Thermal Imager Performance Trial (MAPTIP) conducted by NATO AC/243 Panel 04/RSG.8 and 04/RSG.5 in the Dutch coastal waters. Objectives were: to improve and validate vertical marine aerosol models by providing an extensive set of aerosol and meteorological measurements, within a coastal environment at different altitudes and for a range of meteorological conditions; make aerosol and meteorological observations in the first 10 m of the ocean surface with a view to extending existing aerosol models to incorporate near-surface effects; and to assess marine boundary layer effects on thermal Imaging systems. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were utilized. This network of instrumentation has provided a comprehensive database of aerosol size distribution profiles and relevant meteorological ...

1995-08-01

138

Proceedings of clinical SPECT [single photon emission computed tomography] symposium  

International Nuclear Information System (INIS)

It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have ...

1986-09-22

139

Measuring q sub 0 using supernovae at z approx 0. 3  

Energy Technology Data Exchange (ETDEWEB)

The measurement of q{sub o} is extremely important for understanding the quantity of matter in our universe. The measurement of q{sub o} using supernovae of type Ia as standard candles is appealing because it requires less modeling than other methods using galaxies. The challenge with using supernovae to measure q{sub o} is in finding enough of them. In order to find supernovas, we have constructed a very popular f/1 camera for the 3.9m Anglo-Australian Telescope. The camera uses reducing optics that put a 17 in. {times} 17 in. field on a 1024 {times} 1024 pixel Thomson CCD. Using this system, we image to 23rd magnitude in five minutes. We have developed a software package that uses image subtraction to find supernovae that are approximately magnitude 22.4 or brighter in these images. One field can be processed every 6.6 minutes on a relatively unloaded VAX 6000-6510. We estimate that this system should find one supernova ...

1992-07-01

140

Imaging of reflection seismic and radar wavefields: Monitoring of steam-heated oil reservoirs and characterization of nuclear waste repositories  

Energy Technology Data Exchange (ETDEWEB)

A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the Cold Lake deposit. Simulations were performed during different phases of the steam stimulation process to examine the relation between reservoir ...

1994-12-31

141

SGTR Project: Separate Effect Studies for Vertical Steam Generators  

Energy Technology Data Exchange (ETDEWEB)

The SGTR project has been carried out within the fifth EURATOM Framework Programme (Contract No FIKS-CT-1999-0007). Its main objective was to provide an experimental database and to develop and/or verify models to support definition of accident management measures in the hypothetical case of a Steam Generator tube Rupture (SGTR) sequence. The project addressed both vertical and horizontal steam generator designs. This report summarises the main results obtained in the intermediate scale experimentation that addressed Western type steam generators. The specific goal of this test programme was to investigate aerosol retention in the break stage of the secondary side of a water-empty steam generator. The test matrix consisted of 12 tests that explored the influence of variables such as break type and orientation and inlet gas flow rate. This work was performed in the PECA facility of the Laboratory for ...

2003-07-01

144

Java Image I/O for VICAR, PDS, and ISIS  

Science.gov (United States)

This library, written in Java, supports input and output of images and metadata (labels) in the

2011-01-01

145

Dependence of Energy Thresholds on Laser Radiation Wavelength in Initiation of Heavy Metal Azides  

CERN Document Server

The behavior of silver and lead azides (scaly and threadlike crystals, and compacted powders) in initiation of explosive decomposition by laser pulsed radiation has been investigated. Initiation energy thresholds in irradiation at wavelengths of 1064 nm, 532 nm, 354.7 nm, 266 nm corresponding to four laser radiation harmonics have been measured. Samples both uncovered and covered with a transparent dielectric (a quartz plate) with the compressive force of up to 0.5GPa were initiated. In the transparent spectral region (the first and second laser harmonics) of the heavy metal azide matrix the effect of covering the sample surface with a plate on initiation energy threshold was insignificant, whereas, in the region of bandgap absorption (the fourth harmonic) strong dependence of the initiation threshold on whether the surface under irradiation is uncovered or covered. The results obtained have been considered with the account ...

2010-01-01

146

Critical assessment of the Schroedinger picture of quantum mechanics  

Energy Technology Data Exchange (ETDEWEB)

We provide an example in which the Heisenberg and the Schroedinger pictures of quantum mechanics give different results, thus confirming the statement of P.A.M. Dirac that the two pictures may lead to inequivalent results. We consider a one-dimensional nonrelativistic charged harmonic oscillator (frequency {omega}{sub 0} and mass m), and take into account the action of the radiation reaction and the vacuum electromagnetic forces on the charged oscillator. We show that the Heisenberg picture gives the correct value, {Dirac_h}{omega}{sub 0}/2, for the ground state energy of the harmonic oscillator in both cases of classical and quantized vacuum fields. In the case of the Schroedinger picture, considering classical vacuum fields, and using a simple calculation for the classical radiation reaction force that is valid in the limit of large mass (mc{sup 2} >> {Dirac_h}{omega}{sub 0}), we obtain the value {Dirac_h}{omega}{sub 0} for the ...

2002-12-16

147

APSTNG: Neutron interrogation for detection of nuclear and CW weapons, explosives, and drugs  

Energy Technology Data Exchange (ETDEWEB)

A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed- portal requirements for nondestructive verification of sealed munitions and detection of contraband explosives and drugs. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron inelastic scattering and fission reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from determined from detection times of the gamma-rays and alpha-particles yield a separate tomographic image ...

1992-07-01

148

A non-local approach for image super-resolution using intermodality priors ?  

UK PubMed Central (United Kingdom)

Image enhancement is of great importance in medical imaging where image resolution remains a crucial point in many image analysis algorithms. In this paper, we investigate brain hallucination...Full Text Available

2010-08-01

149

ALOS satellite imagery utilizations for safeguards  

International Nuclear Information System (INIS)

This paper introduces examples of satellite imageries analysis and utilizations for safeguards activities. Recently, many kinds of satellite imageries are available in the world i.e., high-spatial resolution, multi- and hyper-spectral, multi-function, and multi-polarization radars. The problem is that how to obtain the required information from these digital images. The Japan Aerospace Exploration Agency (JAXA) has successfully launched the Advanced Land Observing Satellite (ALOS, the nickname is 'Daichi') on 24th January, 2006. The mission objectives are cartography, regional observation, disaster monitoring etc. ALOS has three instruments, PRISM, AVNIR-2, and PALSAR, to achieve these objectives. An overview of ALOS is provided. ALOS follows the Japanese Earth Resources Satellite- 1 (JERS-1) and the Advanced Earth Observing Satellite (ADEOS) and utilizes advanced land-observing technology. ALOS is fling in a Sun-synchronous orbit with an inclination angle of 98.16 ...

2006-10-16

150

VLF wave stimulation by pulsed electron beams injected from the space shuttle  

International Nuclear Information System (INIS)

Among the investigations conducted on the space shuttle flight STS 3 March 1982 was an experiment in which a 1-keV, 100-mA electron gun was pulsed at 3.25 and 4.87 kHz. The resultant waves were measured with a broadband plasma wave receiver. At the time of flight the experimental setup was unique in that the electron beam was square wave modulated and that the shuttle offered relatively long times for in situ measurements of the ionospheric plasma response to the VLF pulsing sequences. In addition to electromagnetic response at the pulsing frequencies the waves exhibited various spectral harmonics as well as the unexpected occurrence of satellite lines around those harmonics. Both phenomena occurred with a variety of different characteristics for different pulsing sequences.

151

Saturation of relativistic Weibel instability and the formation of stationary current sheets in collisionless plasma  

International Nuclear Information System (INIS)

We have studied the features of formation and the possible stationary structures of a self-consistent magnetic field in a relativistic collisionless plasma, which are characteristic of a simple geometry of the Weibel instability that is well known in the nonrelativistic case. The universal condition is established, the growth rate is determined, and the criteria of saturation of the Weibel instability are analyzed for a broad class of anisotropic particle distribution functions (for definiteness, in application to an electron-positron plasma). A nonlinear equation of the Grad-Shafranov type describing the potential current structures is derived and its solutions are analytically studied. Special attention is paid to spatially harmonic, nonlinear current configurations with parameters determined by the properties of the initial homogeneous plasma subject to the Weibel instability. It is demonstrated that the magnetic field energy density in the obtained solutions ...

2008-12-01

152

Predicting moisture state of timber members in a continuously varying climate  

British Library Electronic Table of Contents (United Kingdom)

A prerequisite for a sensible estimate of moisture induced stresses in timber members is an accurate prediction of the members' moisture states during their service life. There are, however, an infinite number of possible moisture states for an arbitrary timber member in a natural varying climate. The naturally varying humidity is possible to describe as harmonic cycles, with different periods, superimposed. This work presents realizations of envelop curves over the possible moisture states in a timber member for some carefully chosen harmonic humidity variations. The calculations, on which the realizations were made, are based on a fully coupled transport model including a model for the influential sorption hysteresis of wood. A format containing required information suitable for assessin...

2011-01-01

153

Irreversible Performance of a Quantum Harmonic Heat Engine  

CERN Document Server

The unavoidable irreversible losses of power in a heat engine are found to be of quantum origin. Following thermodynamic tradition a model quantum heat engine operating by the Otto cycle is analyzed. The working medium of the model is composed of an ensemble of harmonic oscillators. A link is established between the quantum observables and thermodynamical variables based on the concept of canonical invariance. These quantum variables are sufficient to determine the state of the system and with it all thermodynamical variables. Conditions for optimal work, power and entropy production show that maximum power is a compromise between the quasistatic limit of adiabatic following on the compression and expansion branches and a sudden limit of very short time allocation to these branches. At high temperatures and quasistatic operating conditions the efficiency at maximum power coincides with the endoreversible result. The optimal compression ratio varies from the square ...

2006-01-01

154

Development of the SSC (Superconducting Super Collider) trim coil beam tube assembly  

Energy Technology Data Exchange (ETDEWEB)

The Superconducting Super Collider uses approx. =9600 dipole magnets. The magnets have been carefully designed to exhibit minimal magnetic field harmonics. However, because of superconductor magnetization effects, iron saturation and conductor/coil positioning errors, certain harmonic errors are possible and must be corrected by use of multipole correctors called trim coils. For the most efficient use of axial space in the magnet, and lowest possible current, a distributed internal correction coil design is planned. The trim coil assembly is secured to the beam tube, a uhv tube with special strength, size, conductivity and vacuum. The report details the SSC trim coil/beam tube assembly specifications, history, and ongoing development.

1987-01-01

155

Cluster models of light nuclei and the method of hyperspherical harmonics: Successes and challenges  

International Nuclear Information System (INIS)

Hyperspherical-harmonics method to investigate the lightest nuclei having three-cluster structure is discussed together with recent experiments. Properties of bound states and methods to explore three-body continuum are presented. The challenges created by large neutron excess and halo phenomena are highlighted. Astrophysical aspects of the "7Li + n "#-># "8Li + #gamma# reaction and the solar-boron-neutrinos problem are analyzed. Three-cluster structure of highly excited states in "8Be is shown to be responsible for extreme isospin mixing. Progress in studies of "6He- and "1"1Li-induced inclusive and exclusive nuclear reactions is demonstrated, providing information on the nature of continuum structures of Borromean nuclei.

2009-08-01

156

A fast multipole transformation for global climate calculations  

Energy Technology Data Exchange (ETDEWEB)

A fast multipole transformation is adapted to the evaluation of summations that occur in global climate calculations when transforming between spatial and spherical harmonic representations. For each summation, the timing of the fast multipole transformation scales linearly with the number of latitude gridpoints, but the timing for direct evaluations scales quadratically. In spite of a larger computational overhead, this scaling advantage renders the fast multipole method faster than direct evaluation for transformations involving greater than approximately 300 to 500 gridpoints. Convergence of the fast multipole transformation is accurate to machine precision. As the resolution in global climate calculations continues to increase, an increasingly large fraction of the computational work involves the transformation between spatial and spherical harmonic representations. The fast multipole transformation offers a significant reduction in ...

1996-01-01

157

166Ho-HA evaluation as therapeutic agent for rheumatoid arthritis treatment  

International Nuclear Information System (INIS)

Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This leads to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate "1"6"6Ho-Hydroxyapatite ("1"6"6 Ho-HA) as potential radiopharmaceutical for the symptomatic treatment of chronic and acute arthritis. Materials and Methods: Holmiun-166 was produced by irradiation of Ho_2O_3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthesized. Its labelling and quality controls follows the internationally accepted procedures. An antigen's arthritis was induced to eight New Zealand rabbits with the "1"6"6 Ho-HA radiochemical being administered thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon ...

2002-09-01

158

Radiohalogen-labeled imaging agents. 3. Compounds for measurement of brain blood flow by emission tomography  

Energy Technology Data Exchange (ETDEWEB)

The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, ...

1984-08-01

159

Radiohalogen-labeled imaging agents. 3. Compounds for measurement of brain blood flow by emission tomography  

International Nuclear Information System (INIS)

The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, ...

160

Near-surface 3D reflections seismic survey; Sanjigen senso hanshaho jishin tansa  

Energy Technology Data Exchange (ETDEWEB)

Faults are being actively investigated across Japan since the Great Hanshin-Awaji Earthquake. Discussed in this report is the application of the 3D near-surface reflection seismic survey in big cities. Data from trenching and drilling is used for the geological interpretation of the surroundings of a fault, and the reflection seismic survey is used to identify the position, etc., of the fault. In this article, when the results obtained from the experimental field are examined, it is found that the conventional 2D imaging reflection survey betrays the limit of its capability when the geological structure is complicated, that the 3D reflection seismic survey, on the contrary, is capable of high-precision imaging and, when augmented by drilling, etc., becomes capable of a more detailed interpretation, and that it also contributes effectively to the improvement of local disaster prevention in big cities. Using as the model the Tachikawa fault that ...

1997-05-27

161

Microstructural characterization of Ti-6Al-4V metal chips by focused ion beam (FIB) and transmission electron microscopy (TEM)  

Energy Technology Data Exchange (ETDEWEB)

The microstructure of the secondary deformation zone (SDZ) near the cutting surface in metal chips of Ti-6Al-4V formed during machining was investigated using focused ion beam (FIB) specimen preparation and transmission electron microscopy (TEM) imaging. Use of the FIB allowed precise extraction of the specimen across this region to reveal its inhomogeneous microstructure resulting from the non-uniform distribution of strain, strain rate, and temperature generated during the cutting process. Initial imaging from conventional TEM foil preparation revealed microstructures ranging from heavily textured to regions of fine grains. Using FIB preparation, the transverse microstructure could be interpreted as fine grains near the cutting surface which transitioned to coarse grains toward the free surface. At the cutting surface a 10 nm thick recrystallized layer was observed capping a 20 nm thick amorphous layer.

2011-01-01

162

MAPLE/HANARO type fuel element two-phase flow parameter measurement by real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is the measurement of two-phase flow parameters to support development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR). A single element finned Fuel Element Simulator was used with R134a Freon flow. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distributions were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration and the ...

2002-07-01

163

MAPLE/HANARO type fuel element two-phase flow parameter measurement by real-time neutron radiography  

International Nuclear Information System (INIS)

The objective of this work is the measurement of two-phase flow parameters to support development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR). A single element finned Fuel Element Simulator was used with R134a Freon flow. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distributions were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration and the ...

2002-08-11

164

Finned fuel element two-phase flow parameter measurements using real-time neutron radiography  

International Nuclear Information System (INIS)

The measurement of two-phase flow parameters and development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR) is discussed in this paper. A single element finned Fuel Element Simulator (FES) was used with R134a Freon as the working fluid. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distribution were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration ...

2007-04-22

165

Finned fuel element two-phase flow parameter measurements using real-time neutron radiography  

International Nuclear Information System (INIS)

The measurement of two-phase flow parameters for development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR) is discussed in this paper. A single element finned Fuel Element Simulator (FES) was used with Freon 134a as the working fluid. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer present. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distribution were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant ...

2008-02-01

166

A study of the effects of scattered radiation on radiographic quality and methods of elimination of such radiation  

International Nuclear Information System (INIS)

Many mechanical parts are subjected to stresses and strains that may eventually lead to their failure. In order to prevent the costly delays associated with equipment down-time, many parts have to be tested for weaknesses and defects when machinery is constructed or dismantled for maintenance. These procedures are known as Non-Destructive Testing (NDT) methods. Five types of non-destructive testing methods routinely used are radiographic testing, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. Out of these five techniques industrial radiography plays an important role in non-destructive testing to reveal interior defects in materials. In radiography almost two-thirds of the radiation reaching the film is scattered radiation which does not form the image of defects. Scattered radiation generated inside and outside a material has a very large effect on sensitivity of flaw detection since it ...

1998-02-01

168

Young Cypriots' perspectives of the symbolic values of smoking  

British Library Electronic Table of Contents (United Kingdom)

This paper reports the findings of a study that explores the perspectives of 25 young Cypriots regarding the symbolic values of smoking with respect to their everyday lived experiences. This study was motivated by recognising the high levels of smoking prevalence among adolescents in Cyprus and the absence of published research 'recording' their own versions of reality about smoking. Data for the study were generated from one-to-one qualitative interviews which encouraged the participants to articulate the symbolic value of smoking in their day-to-day experiences. The analysis focuses first, on the content of the embedded symbolic values of smoking (e.g. the quality of being 'cool') and second on the role of these values (e.g. used in projecting an image) in their everyday lives. A central...

2010-01-01

169

University of Michigan workscope for 1991 DOE University program in robotics for advanced reactors  

International Nuclear Information System (INIS)

The University of Michigan (UM) is a member of a team of researchers, including the universities of Florida, Texas, and Tennessee, along with Oak Ridge National Laboratory, developing robotic for hazardous environments. The goal of this research is to develop the intelligent and capable robots which can perform useful functions in the new generation of nuclear reactors currently under development. By augmenting human capabilities through remote robotics, increased safety, functionality, and reliability can be achieved. In accordance with the established lines of research responsibilities, our primary efforts during 1991 will continue to focus on the following areas: radiation imaging; mobile robot navigation; three-dimensional vision capabilities for navigation; and machine-intelligence. This report discuss work that has been and will be done in these areas.

170

Sensitization and radiation hardening of the photostimulable X-ray storage phosphor CsBr:Eu2+  

British Library Electronic Table of Contents (United Kingdom)

The X-ray storage phosphor CsBr:Eu2+ in form of needle image plates is believed to be a promising alternative to the granular BaFBr:Eu2+ with regard to PSL yield and spatial resolution. Unfortunately, CsBr:Eu2+ exhibits poor radiation hardness, which is caused by a migration of europium ions initiated by naturally existing defect centers like (Eu2+-VCs)-centers and X-ray generated MEu-centers. It will be shown that the formation of (Eu2+-O2?)-dipoles at the expense of (Eu2+-VCs)-dipoles, incorporated by thermal annealing in O2-containing and humid atmosphere, does not improve the radiation stability. There is, however, a strong improvement in the radiation hardness by codoping of CsBr:Eu2+ with lithium ions, which is accompanied by a complete suppression of the previously observed MEu-cent...

2009-01-01

171

Partial unmixing as a tool for single surface class detection and time series analysis  

British Library Electronic Table of Contents (United Kingdom)

In this paper we present the results of time series analysis for a coal mining region based on partial unmixing. We test the method also known as mixture tuned matched filtering on an eight image Landsat 5 TM and Landsat 7 ETM+ time series covering the period from 1987 to 2003. Common change detection methods often include the comparison of two interactively generated classification results, such as derived from Maximum Likelihood classification. These approaches often yield highly accurate results. However, disadvantages include a strong analyst bias and hardly repeatable results. For a quantitative monitoring of a single surface class' development over time they are often not recommendable. Our goal was to test an unbiased quantitative way to assess the development of coal surfaces, such...

2008-01-01

172

Multi-Mode Lamb Wave Arrival Time Extraction for Improved Tomographic Reconstruction  

International Nuclear Information System (INIS)

An ultrasonic signal processing technique is applied to multi-mode arrival time estimation from Lamb waveforms. The basic tool is a simplified time-scale projection called a dynamic wavelet fingerprint (DWFP) which enables direct observation of the variation of features of interest in non-stationary ultrasonic signals. The DWFP technique was used to automatically detect and evaluate each candidate through-transmitted Lamb mode. The area of the dynamic wavelet fingerprint was then used as a feature to distinguish false modes caused by noise and other interference from the true modes of interest. The set of estimated arrival times were then used as inputs for tomographic reconstruction. The Lamb wave tomography images generated with these estimated arrival times were able to indicate different defects in aluminum plates.

2005-04-09

173

Explosives detector  

Energy Technology Data Exchange (ETDEWEB)

An apparatus for non-invasively inspecting an object, such as an item of luggage, for explosives material is described. It comprises a multi-channel thermal neutron inspection system having a plurality of neutron irradiation chambers. Simultaneous operation of several channels increases the maximum system throughput several times. Each chamber has a lithium neutron source which is stimulated to neutron production by a proton beam. Beam switching magnets are energised by pulsing to divert a common proton beam to each source in turn. The initial beam is generated by a radio frequency quadrupole accelerator. The advantages of this system are very low residual source activity and controllable neutron production thereby minimising safety hazards. The irradiation chamber may contain several different gamma ray detectors to identify the elements present in explosives material. In addition, a neutron radiography imaging means may be employed to ...

1991-10-02

174

Crystallization and preliminary X-ray studies of a galactose-specific lectin from the seeds of Spatholobus parviflorus  

British Library Electronic Table of Contents (United Kingdom)

A galactose-specific seed lectin was purified from the legume Spatholobus parviflorus and crystallized using the hanging-drop vapour-diffusion technique. Thecrystals belonged to space group P1, with unit-cell parameters a = 60.998, b=60.792, c = 78.179-, = 101.32, = 91.38, = 104.32. X-ray diffraction data were collected under cryoconditions (100-K) to a resolution of 2.04- using a MAR image-plate detector system mounted on a rotating-anode X-ray (Cu-K) generator. Molecular replacement using legume-lectin coordinates as a search model gave a tetrameric structure.

2011-01-01

175

Computational mouse atlases and their application to automatic assessment of craniofacial dysmorphology caused by the Crouzon mutation Fgfr2C342Y  

British Library Electronic Table of Contents (United Kingdom)

Abstract Crouzon syndrome is characterized by premature fusion of sutures and synchondroses. Recently, the first mouse model of the syndrome was generated, having the mutation Cys342Tyr in Fgfr2c, equivalent to the most common human Crouzon/Pfeiffer syndrome mutation. In this study, a set of micro-computed tomography (CT) scannings of the skulls of wild-type mice and Crouzon mice were analysed with respect to the dysmorphology caused by Crouzon syndrome. A computational craniofacial atlas was built automatically from the set of wild-type mouse micro-CT volumes using (1) affine and (2) non-rigid image registration. Subsequently, the atlas was deformed to match each subject from the two groups of mice. The accuracy of these registrations was measured by a comparison of manually placed landma...

2007-01-01

176

Application of nuclear analytical methods in determining heavy metals in a welder's working environment  

International Nuclear Information System (INIS)

The problems are discussed of using radionuclide X-ray fluorescence analysis (the most frequently used source is "2"4"1Am) and neutron activation analysis for monitoring the chemical quality of the working environment of a welder. Elements determinable by these methods are listed and the advantages of the methods stated with regard to speed, simplicity and appropriate accuracy of measurement together with commercial availability of the instruments. Welding as a source of harmful substances is assessed by determination of the amount of chromium in aerosols generated by welding austenitic chromium-nickel steels. The described methods allow to obtain a complex image of the chemical nature of welding aerosols and to understand the mechanism of their impact on the human organism. (J.C.).

1986-01-01

177

Airbags to Martian Landers: Analyses at Sandia National Laboratories  

Energy Technology Data Exchange (ETDEWEB)

A new direction for the national laboratories is to assist US business with research and development, primarily through cooperative research and development agreements (CRADAs). Technology transfer to the private sector has been very successful as over 200 CRADAs are in place at Sandia. Because of these cooperative efforts, technology has evolved into some new areas not commonly associated with the former mission of the national laboratories. An example of this is the analysis of fabric structures. Explicit analyses and expertise in constructing parachutes led to the development of a next generation automobile airbag; which led to the construction, testing, and analysis of the Jet Propulsion Laboratory Mars Environmental Survey Lander; and finally led to the development of CAD based custom garment designs using 3D scanned images of the human body. The structural analysis of these fabric structures is described as well as a more traditional ...

1994-03-01

178

Adaptive Radiation Therapy for Localized Mesothelioma with Mediastinal Metastasis Using Helical Tomotherapy  

British Library Electronic Table of Contents (United Kingdom)

The purpose of this study was to compare 2 adaptive radiotherapy strategies with helical tomotherapy. A patient having mesothelioma with mediastinal nodes was treated using helical tomotherapy with pretreatment megavoltage CT (MVCT) imaging. Gross tumor volumes (GTVs) were outlined on every MVCT study. Two alternatives for adapting the treatment were investigated: (1) keeping the prescribed dose to the targets while reducing the dose to the OARs and (2) escalating the target dose while maintaining the original level of healthy tissue sparing. Intensity modulated radiotherapy (step-and-shoot IMRT) and 3D conformal radiotherapy (3DCRT) plans for the patient were generated and compared. The primary lesion and nodal mass regressed by 16.2% and 32.5%, respectively. Adapted GTVs and reduced plan...

2009-01-01

179

The triaxial motion in Mo isotopes  

Energy Technology Data Exchange (ETDEWEB)

The nuclear shapes of transitional Mo isotopes are calculated by means of a model based on the cranking approximation and the Strutinksy method. The recent experimental results of the high-spin spectroscopy and lifetime measurement of [sup 87]Mo are studied in detail and explained by the evolution of the [gamma]-deformation with the quasiparticle configurations. The shape calculations with the modified-harmonic-oscillator potential give a critical neutron number N [>=] 47 for the spherical shape of the Mo isotopes. (orig.)

1993-11-22

180

The triaxial motion in Mo isotopes  

International Nuclear Information System (INIS)

The nuclear shapes of transitional Mo isotopes are calculated by means of a model based on the cranking approximation and the Strutinksy method. The recent experimental results of the high-spin spectroscopy and lifetime measurement of "8"7Mo are studied in detail and explained by the evolution of the #gamma#-deformation with the quasiparticle configurations. The shape calculations with the modified-harmonic-oscillator potential give a critical neutron number N #>=# 47 for the spherical shape of the Mo isotopes. (orig.).

181

Nuclear level densities in self-consistent field approximation  

International Nuclear Information System (INIS)

The effect of two-body nature of the nuclear shell model potential on the recent numerical calculations of the nuclear level density has been examined. For the two most widely used single particle energy level schemes based on harmonic oscillator and Woods-Saxon potential, this effect is shown to significantly modify the excitation energy dependence of the level densities. (author).

1976-01-01

182

Higher harmonics of spontaneous radiation of ultrarelativistic channeled particles  

International Nuclear Information System (INIS)

The case of spontaneous radiation of channeled ultrarelativistic particles is considered when the dipolarity condition is not satisfied. The change of the particle longitudinal velocity affecting the maximum radiation frequency is included. The angular and frequency characteristics of the radiation for superhigh energies are studied for the first time. It is shown that there is an optimum energy at which the radiation density is maximum. The influence of the angle at which electrons enter a crystal and of the beam divergence on the radiation is investigated. The problem of quasichanneled particle radiation and also the radiation in axis-plane transitions are considered. (author).

1980-06-01

183

Feynman integrals and difference equations  

Energy Technology Data Exchange (ETDEWEB)

We report on the calculation of multi-loop Feynman integrals for single-scale problems by means of difference equations in Mellin space. The solution to these difference equations in terms of harmonic sums can be constructed algorithmically over difference fields, the so-called {pi}{sigma}{sup *}-fields. We test the implementation of the Mathematica package Sigma on examples from recent higher order perturbative calculations in Quantum Chromodynamics. (orig.)

2007-09-15

184

Coherent oscillator radiation  

International Nuclear Information System (INIS)

Coherent oscillator radiation is considered. A comparison is made with classical particle radiation with gauss distribution. Decay probability for coherent state in spontaneous radiation is estimated. The method suggested for describing harmonic oscillator allows to separate the effect of classical field radiation from quantum description of particle state within the framework of a self-consistent quantum mechanical problem.

1982-04-01

185

View larger image for ISS022-E-26137 - Earth Sciences and Image ...  

Science.gov (United States)

The Asarco-Mission complex (image left) is an active producer of copper and molybdenum (important in making steel and other metal alloys), ...

186

Digital processing to improve image quality in real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction ...

1985-01-01

187

Digital processing to improve image quality in real-time neutron radiography  

International Nuclear Information System (INIS)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction ...

1985-01-01

188

Advances in Imaging of Vertebral and Spinal Cord Injury  

UK PubMed Central (United Kingdom)

Background/Objectives:Imaging technology is an important part of the diagnosis and management of spinal trauma. Indications and findings in post-traumatic imaging of the vertebral...Full Text Available

2010-04-01

189

3 - NASA Technical Report Server (NTRS)  

Science.gov (United States)

performs Gaussian pyramid operation on an image performs expand pyramid operation on an image mosaic two images using 'reduce' and 'expand' pyramid ...

190

(Hadamard transform imaging)  

Science.gov (United States)

This report describes the design of, and image reconstruction capacity of a Hadamard Raman Microscopic imager. Microscopy of benzoic acid and graphite electrodes, as well as electrophoretic blotting, are described. (CBS)

1990-01-01

191

Studies on reactivity of coal surfaces at low temperature; Teion ni okeru sekitan hyomen no hannosei no kento  

Energy Technology Data Exchange (ETDEWEB)

With an objective to learn reactivity of coal at its surface, surfaces of oxidized coal samples were investigated. Miike coal was oxidized by using {sup 18}O2 in a closed loop system. As the reaction progresses, proportion of CO2 including isotopes increased rapidly as a result of oxidation of CO sites existing in the coal and the newly generated C{sup 18}O sites. The oxidizing reaction progressed via oxygen adsorbing sites generated near the surface, and oxygen containing groups. An FT-IR analysis estimated the depth of the oxidized layer to be 10{mu}m or less from particle surface. The oxidized coal was pulverized to see its surface condition. Functional groups introduced by the oxidation enter into the vicinity of the surface in a form to desorb as CO. CO2 is trapped in inner pores. The coal surface was observed by using an atomic force microscope. No observable openings in the pore structure were discerned on the surface before the ...

1996-10-28

192

Magnetic resonance imaging. Handbook and atlas; Kernspintomographie. Kompendium und Atlas  

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging (MRI) as a diagnostic imaging tool relies on the generation of magnetic fields, whereas the computerized tomography (CT) uses X-radiation. The fundamental principle of MRI is the magnetic resonance of paramagnetic atomic nuclei. These nuclei, as e.g. protons (= hydrogen nuclei), are aligned in required orientation by application of a strong magnetic field. Upon simultaneous application of an electromagnetic high-frequency field perpendicular to the axis of the basic magnetic field, and in response to periodical changing of the electromagnetic field at a given frequency, the originally aligned paramagnetic nuclei are forced into a movement similar to that of a ``whipping top``. When the resonance frequency is shut off, the nuclei return to their former, aligned positions, inducing a weak signal in a coil. The series of signals generated by multiple repetition of this process of ...

1999-10-01

193
195

Simple fractal method of assessment of histological images for application in medical diagnostics  

UK PubMed Central (United Kingdom)

We propose new method of assessment of histological images for medical diagnostics. 2-D image is preprocessed to form 1-D landscapes or 1-D signature of the image contour and then their complexity is...Full Text Available

196
203

Images of photoreceptors in living primate eyes using adaptive optics two-photon ophthalmoscopy  

UK PubMed Central (United Kingdom)

In vivo two-photon imaging through the pupil of the primate eye has the potential to become a useful tool for functional imaging of the retina. Two-photon excited fluorescence images...Full Text Available

204

Image Engine: an object-oriented multimedia database for storing, retrieving and sharing medical images and text.  

UK PubMed Central (United Kingdom)

This paper describes Image Engine, an object-oriented, microcomputer-based, multimedia database designed to facilitate the storage and retrieval of digitized biomedical still images, video, and text...Full Text Available

1993-01-01

212

Adaptive Image Processing A Computational Intelligence Perspective  

CERN Document Server

Adaptive image processing is one of the most important techniques in visual information processing, especially in early vision such as image restoration, filtering, enhancement, and segmentation. This work focuses on applications of advanced CI techniques in image processing applications

2009-01-01

213

Performance study of teleradiology network systems with CRT monitors. ROC analysis of an observation study of simulated lung nodules  

International Nuclear Information System (INIS)

To evaluate the diagnostic performance of commercially available CRT monitors used in a teleradiology system by determining the rate of detection of simulated lung nodules. Three types of CRT monitors were tested in the observation study. They had matrix sizes of 1024 x 768 (16 inches, color), 1024 x 768 (20 inches, color) and 1600 x 1125 (24 inches, black and white). Twenty chest radiographs were obtained by Fuji computed radiography (FCR) of an anthropomorphic chest phantom with ten simulated nodules on its surface. These FCR films were digitized by a film digitizer with 125 DPI (1024 x 1024 matrix sizes) and 12 bit gray scales, and the image data were transferred from Shinshu University Hospital to other hospitals where interpretation was carried out by the radiologists. Ten radiologists of three hospitals were asked to interpret independently both the original FCR films and the images shown on the CRT monitors and to indicate the presence ...

214

Chapter 14: Seismic imaging using 2- and 3-D migration  

Energy Technology Data Exchange (ETDEWEB)

Development of a number of original 3-D migration methods and algorithms is described. The computational efficiency of these algorithms is demonstrated by implementing them on vector and parallel supercomputers. Two-dimensional post-stack and pre-stack depth migration algorithms in the frequency - space domain using implicit finite difference method were also developed and implemented on a parallel computer, and adapted for applications that range from deep crustal imaging of seismic wavefields that involve wide ranging travel times and frequencies. All implicit finite difference migration algorithms were highly prallelized . The one pass 3-D post-stack depth migration algorithm was extensively used for imaging of seismic monitoring data from Cold Lake, Alberta. Experience shows that it provides the right trade-off between accuracy and computational efficiency. A new formulation of the 3-D reverse-time migration method was developed using ...

1999-09-01

215

Usefulness of Computed Tomography in pre-surgical evaluation of maxillo-facial pathology with rapid prototyping and surgical pre-planning by virtual reality  

International Nuclear Information System (INIS)

Purpose. To validate a protocol for creating virtual models to be used in the construction of solid prototypes useful for the planning-simulation of maxillo-facial surgery, in particular for very complex anatomical and pathologic problems. To optimize communications between the radiology, engineering and surgical laboratories. Methods and materials. We studied 16 patients with different clinical problems of the maxillo-facial district. Exams were performed with multidetector computed tomography (MDCT) and single slice computed tomography (SDCT) with axial scans and collimation of 0.5-2 mm, and reconstruction interval of 1 mm. Subsequently we performed 2D multiplanar reconstructions and 3D volume-rendering reconstructions. We exported the DICOM images to the engineering laboratory, to recognize and isolate the bony structures by software. With these data the solid prototypes were generated using stereolitography. To date, surgery has been ...

2005-11-01

216

Magnetic resonance imaging in childhood epilepsy  

International Nuclear Information System (INIS)

The suitability of MR imaging versus computerized tomography in observation of brain development disorders in children are compared. 13 refs.

217

Esters useful as brain imaging agents  

Energy Technology Data Exchange (ETDEWEB)

Certain radioiodine containing esters useful as brain imaging agents are disclosed. The formula of these compounds are presented.

1981-08-18

218

Esters useful as brain imaging agents  

International Nuclear Information System (INIS)

Certain radioiodine containing esters useful as brain imaging agents are disclosed. The formula of these compounds are presented.

219

Amides useful as brain imaging agents  

Energy Technology Data Exchange (ETDEWEB)

Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula

1981-07-21

220

Amides useful as brain imaging agents  

International Nuclear Information System (INIS)

Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula.

221

Image-enhancement applications at the Lawrence Livermore National Laboratory  

Energy Technology Data Exchange (ETDEWEB)

A diverse set of digital image-processing applications exists at the Lawrence Livermore National Laboratory. While many of these include some sort of image analysis or restoration, virtually all of them require image-enhancement procedures. In this paper we describe the principal image-processing facility at the Laboratory, followed by a discussion of several of the major image-processing application areas.

1982-06-01

222

An Effective Method of Image Retrieval using Image Mining Techniques  

CERN Document Server

The present research scholars are having keen interest in doing their research activities in the area of Data mining all over the world. Especially, [13]Mining Image data is the one of the essential features in this present scenario since image data plays vital role in every aspect of the system such as business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-Based Image Retrieval (CBIR) which performs retrieval based on the similarity defined in terms of extracted features with more objectiveness. The drawback in CBIR is the features of the query image alone are considered. Hence, a new technique called Image retrieval based on optimum clusters is proposed for improving user interaction with image retrieval systems by fully exploiting ...

2010-01-01

223

High-resolution beta imaging; L'imagerie beta haute resolution  

Energy Technology Data Exchange (ETDEWEB)

For many years, {beta} radioactivity has been used to label molecules and follow them in various biological processes. {beta} imaging is obtained by autoradiography. Classically made on films or on photographic emulsions, autoradiography is now supplanted by radio-imagers which are very performing. The phosphor-imager, {beta}-imager and {mu}-imager are the systems mainly used today and their operating principles and properties are compared. The great advantages of these imagers are: their rapidity to obtain results and their reliability for absolute quantification. All emitters ({beta}{sup -}, {beta}{sup -} -{gamma} and {beta}{sup +}) are detectable as well as the gamma emitters of nuclear medicine, by means of their low energy electrons ejected during y emission. Phosphor-imager is well suited to energetic tracers and large series of ...

2007-04-15

224

Eddy current signal analysis techniques for assessing degradation of support plate structures in nuclear steam generators  

Energy Technology Data Exchange (ETDEWEB)

The steam generator (SG) is one of the most critical components of the heat transfer system in nuclear generation stations. Testing the structural integrity of SG tubing and SG internals is a key element of the fitness-for-service assessments to assure the safe and continuous operation of nuclear power plants. Recent eddy current (ET) inspections of two nuclear power plants revealed degradation of some of the tube support plate (TSP) structures, which was also confirmed by visual inspection. The phenomena was described as metal loss, caused by flow-accelerated corrosion of the carbon steel trefoil support plate and varying from minor to complete loss of the ligaments. This loss of TSP ligaments results in lack of support for the adjacent tubes making them more susceptible to fretting-wear damage and fatigue cracking. A signal analysis method, based on the responses at low frequency of two types of eddy current probes, has been developed to ...

2006-07-01

225

Development and use of localized arc filament plasma actuators for high-speed flow control  

International Nuclear Information System (INIS)

The paper discusses recent results on the development of localized arc filament plasma actuators and their use in controlling high-speed and high Reynolds number jet flows. Multiple plasma actuators (up to 8) are controlled using a custom-built 8-channel high-voltage pulsed plasma generator. The plasma generator independently controls pulse repetition rate (0-200 kHz), duty cycle and phase for each individual actuator. Current and voltage measurements demonstrated the power consumption of each actuator to be quite low (20 W at 20% duty cycle). Emission spectroscopy temperature measurements in the pulsed arc filament showed rapid temperature increase over the first 10-20 ?s of arc operation, from below 1000 deg. C to up to about 2000 deg. C. At longer discharge pulse durations, 20-100 ?s, the plasma temperature levels off at approximately 2000 deg. C. Modelling calculations using an unsteady, quasi-one-dimensional arc filament model showed that ...

2007-02-07

226

Thermodynamics, lattice stability and defect structure of strontium silicides via first-principles calculations  

International Nuclear Information System (INIS)

The thermodynamics of the Sr-Si system is of fundamental importance for the understanding of eutectic modification of Al-Si alloys. At the same time, strontium silicides have recently been found to have potential applications in electronic devices. Renewed research efforts have led to a re-evaluation of the phase equilibria in this system, resulting in the discovery of previously undetected stable intermetallic compounds. In this work, we investigate the finite temperature thermodynamic properties of the stable (and metastable) Sr-Si intermetallics. The vibrational properties of the intermetallic compounds are calculated within harmonic theory, with quasi-harmonic corrections to account for the effects of thermal expansion. The total free energies of the compounds are computed considering vibrational and electronic contributions, as well as weak anharmonic corrections. The ground state of the system is predicted and compared to previous ...

2009-09-18

227

String Junctions and Holographic Interfaces  

CERN Document Server

In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles ...

2010-01-01

228

Nonlinear pulse evolution in seeded free-electron laser amplifiers and in free-electron laser cascades  

International Nuclear Information System (INIS)

The advances in laser technology have made available very short and intense laser pulses which can be used to seed a high-gain single-pass free-electron laser (FEL) amplifier. With these seed pulses, a regime of the FEL interaction where the radiation evolution is simultaneously dominated by nonlinear effects (saturation) and time-dependent effects (slippage) can be explored. This regime is characterized by the propagation of a solitary wavelike pulse where the power of the optical wave grows quadratically with time, its pulse length decreases and the spectral bandwidth increases. We analyze the interplay between the field and particle dynamics of this propagation regime which was studied before and termed super-radiance. Furthermore we analyze the properties of the strong higher-order harmonic emission from this wave and its behavior when propagating in a cascade FEL. The super-radiant pulse is indeed capable of passing through the stages of a cascade FEL and to ...

2005-08-15

229

High-efficiency RF suppression circuit for fluorescent lamp inverters using charge pump and partial smoothinf capacitors; Chagi ponpu shiki korikiritsu bubun heikatsu hoshiki wo mochiita keikoto inbatayo kochoha teigen kairo  

Energy Technology Data Exchange (ETDEWEB)

A highly efficiency partial smoothing method is proposed to be used for inverters for 40W class household fluorescent inverters. In this system, the input current from the commercial AC power source is accumulated in a capacitor with comparatively small capacity as the electric charge, and then the lamp circuit is driven by the inverter utilizing the charging voltage of the capacitor and the charging voltage of the separately prepared partial smoothing capacitor. By this method, the RF harmonic components in the supply current can be decreased to improve the power factor with no complicated feedback controlling device. In addition, comparatively small capacity coils and capacitors can be used. The structure of the circuit and the operation of this proposed method are described, and the operational characteristic of the prototype circuit and the result of analysis are shown. Furthermore, problems and improving method of the actual circuit are investigated by an ...

1997-06-20

230

Gauge invariant perturbation theory in spatially homogeneous cosmology  

International Nuclear Information System (INIS)

The perturbations of the L.R.S. class A spatially homogeneous spacetimes are treated using Hamiltonian methods in conjunction with techniques from the theory of Lie group harmonic analysis. These latter techniques lead to a simple way of handling any set of tensor equations on these background spacetimes which has the same symmetry group as the space-time metric. Once this approach is developed, the Hamiltonian formulation is used to recover in a clean way the Bonanos equations for the perturbations of the perfect fluid models of the class of spacetimes under consideration. The conserved quantities associated with the four-dimensional symmetry group are evaluated and their role in the linearized Hamiltonian dynamics is discussed. The time-dependent linear canonical transformation of the linearized vacuum gravitational phase space adapted to Moncrief's gauge invariant decomposition is described in general for these models and evaluated explicitly for a class of ...

231

Development of quality assurance requirements - an international comparison  

International Nuclear Information System (INIS)

Total quality management strategy and the worldwide introduction of the DIN/ISO 9000 (EN 29 000) series of standards have given new impetus to traditional quality assurance. The most important change must surely be seen in the holistic approach of total quality management and its strict orientation towards customer requirements and satisfaction. International codes and standards for the nuclear industry will also have to be brought into line as part of the process of harmonizing quality assurance system standards. One possible approach is simply to specify a supplementary 'delta' of nuclear-specific requirements to be appended to the broad range of conventional requirements. It is a particular feature of quality-assured procedures in Germany that product and/or component related quality requirements and quality verifications are defined in the specifications of the architect engineer so that full implementation of the requirements from the design phase through to ...

232

Emplacement technology for the direct disposal of spent fuel into deep vertical boreholes  

International Nuclear Information System (INIS)

In the early sixties it was decided to investigate salt formations on its suitability to host heat generating radioactive waste in Germany. In the reference repository concept consequently the emplacement of vitrified waste canisters in deep vertical boreholes inside a salt mine was considered whereas spent fuel should be disposed of in self shielding casks (type POLLUX) in horizontal drifts. The POLLUX casks, 65 t heavy carbon steel casks, will be laid down on the floor of a horizontal drift in one of the disposal zones to be constructed in the salt dome at the 870 m level. The space between casks and drift walls will be backfilled with crushed salt. The transport, the handling und the emplacement of POLLUX casks were subject of successfully performed demonstration and in situ tests in the nineties and resulted in an adjustment of the atomic law. The borehole disposal concept comprises the emplacement of unshielded canisters with vitrified HLW in boreholes with a ...

2008-09-01

233

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

234

Target identification of buried coated objects  

Scientific Electronic Library Online (English)

Abstract in english We consider the three dimensional electromagnetic inverse scattering problem of determining information about a buried coated object from a knowledge of the electric and magnetic fields measured on the surface of the earth corresponding to time harmonic electric dipoles as incident fields. We assume that the buried object is a perfect conductor that is (possibly) partially coated by a thin dielectric layer. No a priori assumption is made on the extent of the coating, i.e. (more) the object can be fully coated, partially coated or not coated at all. We present an algorithm based on the linear sampling method and reciprocity gap functional for reconstructing the shape of the scattering obstacle together with an estimate of the surface impedance of the coating.

2006-01-01

235

Polarized proton acceleration at the Brookhaven AGS  

Energy Technology Data Exchange (ETDEWEB)

At the conclusion of polarized proton commissioning in February 1986, protons with an average polarization of 45%, momentum of 21.7 GeV/c, and intensity of 2 x 10/sup 10/ protons per pulse, were extracted to an external polarimeter at the Brookhaven AGS. In order to maintain this polarization, five intrinsic and nearly forty imperfection depolarizing resonances had to be corrected. An apparent interaction between imperfection and intrinsic resonances occurring at very nearly the same energy was observed and the correction of imperfection resonances using ''beat'' magnetic harmonics discovered in the previous AGS commissioning run was further confirmed.

1986-01-01

236

Magnetic fluctuation measurement in Sino United Spherical Tokamak plasma  

International Nuclear Information System (INIS)

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)

2007-07-01

237

Generalized Tonnetze  

British Library Electronic Table of Contents (United Kingdom)

We study a generalization of the classical Riemannian Tonnetz to N-tone equally tempered scales (for all N) and arbitrary triads. We classify all the spaces that result. The torus turns out to be the most common possibility, especially as N grows. Other spaces include 2-simplices, tetrahedra boundaries, and the harmonic strip (in both its cylinder and Mobius band variants). The final and most exotic space we find is something we call a 'circle of tetrahedra boundaries'. These are the Tonnetze for spaces of triads which contain a tritone. They are closely related to Peck's Klein bottle Tonnetz.

2011-01-01

238

Electromagnetic characterization of superconducting radio-frequency cavities for gw detection  

International Nuclear Information System (INIS)

The electromagnetic properties of a prototype gravitational wave detector, based on two coupled superconducting microwave cavities, were tested. The radio-frequency (rf) detection system was carefully analysed. With the use of piezoelectric crystals small harmonic displacements of the cavity walls were induced and the parametric conversion of the electromagnetic field inside the cavities explored. Experimental results of bandwidth and sensitivity of the parametric converter versus stored energy and voltage applied to the piezoelectric crystal are reported. A rf control loop, developed to stabilize phase changes on signal paths, gave a 125 dBc rejection of the drive mode on a time scale of 1 h.

2004-03-07

239

A preliminary design for a one GHz NMR spectrometer magnet  

International Nuclear Information System (INIS)

The authors have performed a preliminary design for a persistent GHz NMR magnet at 23.5 T and 1.8 K operating conditions. In this paper the authors shall address the issues of realistic conductor selection, the coil design, the magnetic and mechanical analysis of the coil, and the required field uniformity. In addition, they shall describe the GHz magnet cryostat with a practical 1.8 K J-T refrigerator system. Finally vibration isolation system and field shield design and its associated field harmonics will be analyzed.

1993-09-20

241

The hydroclimatology of the United States during El Nino/Southern Oscillation  

Energy Technology Data Exchange (ETDEWEB)

Palmer Drought Severity Index (PDSI) monthly data are analyzed, building on a previous study that investigated the influence of the El Nino/Southern Oscillation (ENSO) on US streamflow. Harmonic analysis is performed using data from 1,035 selected climatological stations, allowing observation of the biennial tendency in climate data. With the middle twelve months defined as the El Nino year (0), an idealized first harmonic fit to a 24-month ENSO composite is computed for each station. By plotting the first harmonic vectors of each station, regions of similar, or coherent, response are identified. The regions identified using PDSI data represent wet conditions in the Gulf of Mexico (Gm1 and GM2) and central (C) US, and dry conditions in the Pacific northwest (PNW) and northeast (NE) US. The PNW region exhibits the strongest interrelationship between ENSO and extreme drought events. Comparing PDSI data results with other ...

1995-12-31

242

Measurement of characteristics of an infrared free-electron laser with the L-band at Osaka University  

Energy Technology Data Exchange (ETDEWEB)

Free-electron laser (FEL) experiments have been conducted with the 38-MeV L-band electron linac at the Institute of Scientific and Industrial Research, Osaka University. It is a 1.3 GHz RF linac with a thermoionic gun, and equipped with two 12th and one 6th sub-harmonic prebunchers for producing the high-intensity single-bunch beam with a charge up to 67 nC/bunch. For oscillation experiments of FEL, the gun is replaced with that with a smaller cathode area in order to reduce the emittance of the beam. The normalized emittance has been measured to be 200 {pi} mm-mrad. The linac is operated in the long-pulse mode and one of the 12th sub-harmonic bunchers and the 6th sub-harmonic buncher are operated, so that the time duration of the macropulse is 4 {mu}s and the spacing between micropulses is 9.2 ns. The length of the micropulse is 30-40 ps and the charge in each micropulse is 2 nC. The electron beam from the linac is ...

1995-12-31

243

Is the Short Distance Scale a Result of a Problem with the LMC Photometric Zero Point?  

Energy Technology Data Exchange (ETDEWEB)

I present a promising route to harmonize distance measurements based on clump giants and RR Lyrae stars. This is achieved by comparing the brightness of these distance indicators in three environments: the solar neighborhood, Galactic bulge and Large Magellanic Cloud (LMC). As a result of harmonizing the distance scales in the solar neighborhood and Baade's Window, I derive the new absolute magnitude of RR Lyrae stars, M{sub v}(RR) at [Fe/H] = -1.6 (0.59 {+-} 0.05, 0.70 {+-} 0.05). Being somewhat brighter than the statistical parallax solution, but fainter than typical results of the main sequence fitting to Hipparcos data, these values of M{sub V}(RR) favor intermediate or old ages of globular clusters. Harmonizing the distance scales in the LMC and Baade's Window, I show that the most likely distance modulus to the LMC, {mu}{sub LMC} is in the range 18.24 - 18.44. The Hubble constant of about 70 km/s/Mpc ...

2004-03-29

244

CR portal imaging; A linac graphy using storage phosphor imaging systems  

Energy Technology Data Exchange (ETDEWEB)

In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In ...

1992-07-01

245

Automatic segmentation of thoracic and pelvic CT images for radiotherapy planning using implicit anatomic knowledge and organ-specific segmentation strategies  

Energy Technology Data Exchange (ETDEWEB)

Automatic segmentation of anatomical structures in medical images is a valuable tool for efficient computer-aided radiotherapy and surgery planning and an enabling technology for dynamic adaptive radiotherapy. This paper presents the design, algorithms and validation of new software for the automatic segmentation of CT images used for radiotherapy treatment planning. A coarse to fine approach is followed that consists of presegmentation, anatomic orientation and structure segmentation. No user input or a priori information about the image content is required. In presegmentation, the body outline, the bones and lung equivalent tissue are detected. Anatomic orientation recognizes the patient's position, orientation and gender and creates an elastic mapping of the slice positions to a reference scale. Structure segmentation is divided into localization, outlining and refinement, performed by procedures with implicit ...

2008-03-21

246

Radioisotope imaging of brain tumors in two rhesus monkeys. Final report  

Energy Technology Data Exchange (ETDEWEB)

Two geriatic male rhesus monkeys were used for the radioisotope imaging in this research. Discussion of the radionuclide, materials, and method used to accomplish the neurologic examination and the results obtained, both during the procedure and confirmation of the results by necropsies were accompanied by color photos of scan images. Results were that the nuclear images provided accurate images of intracranial neoplasia.

1988-04-01

247

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

International Nuclear Information System (INIS)

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

2008-08-01

248

Utilization of CTR to measure the evolution of electron-beam microbunching in a self-amplified spontaneous emission (SASE) free-electron laser (FEL)  

International Nuclear Information System (INIS)

We report on the first measurements of the z-dependent evolution of electron-beam microbunching as revealed through coherent transition radiation (CTR) measurements in a visible self-amplified spontaneous emission free-electron laser experiment. The increase in microbunching was detected by tracking the growth of the visible CTR signals as generated from insertable metal mirrors/foils after each of the last three undulators. The same optical imaging diagnostics that were used to track the z-dependent intensity of the undulator radiation (UR) were also used to track the electron beam/CTR information. Angular distribution, beam size, and intensity data were obtained after each of the last three undulators in the five-undulator series, and spectral information was obtained after the last undulator. The exponential growth rate of the CTR was found to be very similar to that of the UR and consistent with simulations using the code GENESIS.

2002-07-01

249

Utilization of CTR to measure the evolution of electron-beam microbunching in a self-amplified spontaneous emission (SASE) free-electron laser (FEL)  

International Nuclear Information System (INIS)

We report on the first measurements of the z-dependent evolution of electron-beam microbunching as revealed through coherent transition radiation (CTR) measurements in a visible self-amplified spontaneous emission free-electron laser experiment. The increase in microbunching was detected by tracking the growth of the visible CTR signals as generated from insertable metal mirrors/foils after each of the last three undulators. The same optical imaging diagnostics that were used to track the z-dependent intensity of the undulator radiation (UR) were also used to track the electron beam/CTR information. Angular distribution, beam size, and intensity data were obtained after each of the last three undulators in the five-undulator series, and spectral information was obtained after the last undulator. The exponential growth rate of the CTR was found to be very similar to that of the UR and consistent with simulations using the code GENESIS.

2001-12-21

250

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 width at half maximum. ...

1996-12-01

251

Seismic migration and absorbing boundaries with a one-way wave system for heterogeneous media  

Energy Technology Data Exchange (ETDEWEB)

A first-order one-way wave system has been created based on characteristic analysis of the acoustic wave system and optimization of the dispersion relation. The authors demonstrate that this system is equivalent to a third-order scalar partial-differential equation which, for a homogeneous medium, reduces to a form similar to the 45{degree} paraxial wave equation. This system describes accurately waves propagating in a 2D heterogeneous medium at angles up to 75{degree}. The one-way wave system representing downgoing waves is used for a modified reverse time migration method. As a wavefield extrapolator in migration, the downgoing wave system propagates the reflection events backwards to their reflectors without scattering at the discontinuities in the velocity model. Hence, images with amplitudes proportional to reflectivity can be obtained from this migration technique. They present examples of the application of the new migration method to synthetic seismic data ...

1996-07-01

252

Noise bias in the refinement of structures derived from single particles  

Energy Technology Data Exchange (ETDEWEB)

One of the main goals in the determination of three-dimensional macromolecular structures from electron microscope images of individual molecules and complexes (single particles) is a sufficiently high spatial resolution, about 4 A, at which the interpretation with an atomic model becomes possible. To reach high resolution, an iterative refinement procedure using an expectation maximization algorithm is often used that leads to a more accurate alignment of the positional and orientational parameters for each particle. We show here the results of refinement algorithms that use a phase residual, a linear correlation coefficient, or a weighted correlation coefficient to align individual particles. The algorithms were applied to computer-generated data sets that contained projections from model structures, as well as noise. The algorithms show different degrees of over-fitting, especially at high resolution where the signal is weak. We demonstrate ...

2004-12-15

253

Free-electron laser beam  

International Nuclear Information System (INIS)

The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7#mu#m FEL beam. Cancer ...

2003-06-01

254

Fly on the wings of the sun - a study of solar-powered aircraft  

Energy Technology Data Exchange (ETDEWEB)

Solar High Altitude Powered Platform (Solar HAPP) aircraft are unmanned remote sensing vehicles designed for cruises lasting up to one year at 20-km altitude, while carrying up to 250 pounds of cameras and electrooptic sensors in an underslung payload pod. It is anticipated that real time IR and UV images of earth features may be more inexpensively and accurately obtained by this means than by the conventional geosynchronous earth resources satellites. Solar HAPPs, with wing spans of over 300 ft and weights of only 2000 lb, require ultralight composite structures with external wire bracing. Solar cells will cover both sides of the vertical wing stabilizers and wing tips, which hinge up in daytime to capture the maximum amount of sunlight. A 15-hp electric propulsion unit drives a low-rpm, large diameter propeller; power will be derived from the solar cells diurnally, and from hydrogen-oxygen fuel cells nocturnally. The fuel gases will be ...

1985-06-01

255

Effects of local texture and grain structure on the sputtering performance of tantalum  

Energy Technology Data Exchange (ETDEWEB)

Tantalum and tantalum-based thin films have gained precedence as the diffusion barrier for copper interconnects used in the latest generation of integrated circuits (ICs). The paper presents insight and observations on the covariance of texture and grain size of wrought tantalum sputtering targets and their influence on sputtering performance. Previous studies involving deposition trials of tantalum targets of varying metallurgical character had demonstrated that both grain size and textural homogeneity is critical for assuring reliable sputtering performance of tantalum. Subsequently, a model had been proposed to prescribe how localized texture bands and orientation clusters in tantalum are effectively resistant to sputter erosion. In this paper, results of atomic force microscopy (AFM) and orientation imaging microscopy (OIM{sup TM}) analyses on the eroded surface of a tantalum sputtering target are presented. Initial findings support the ...

2002-07-01

256

Automatic system for measuring dose-area product (DAP) in ROI fluoroscopy  

Energy Technology Data Exchange (ETDEWEB)

A computerized system for monitoring dose-area product (DAP) has been developed for region of interest (ROI) fluoroscopy in which patient exposure is reduced using an x-ray attenuating filter with an aperture. The system includes an IBM compatible computer which is connected through an IEEE-488 interface to an electrometer which measures the charge from a DAP ionization chamber. A digital input/output board connects the computer to the filter placement device to determine whether the filter is in or out of the beam, and to the x-ray generator to determine when the exposure is due to spot filming. The computer logs the DAP from conventional fluoroscopy, ROI fluoroscopy and spot filming separately, applying the appropriate calibration factor for each. Measured DAPs, fluoroscopic DAP rates and exposure times are displayed in real-time. The system has been installed in a GI fluoroscopic room so that the dose-reduction potential of ROI imaging can ...

1997-04-01

257

Real-time neutron coded aperture imaging: A technique for nondestructive three-dimensional imaging  

Energy Technology Data Exchange (ETDEWEB)

Neutron Coded Aperture Imaging is a nondestructive imaging technique that utilizes neutrons scattered from an object through specially designed apertures. Coded Aperture Imaging is an alternative technique to Computed Tomography for three-dimensional imaging. Coded Aperture Imaging has the advantage that all of the three-dimensional information is contained in a single image, whereas Computed Tomography requires several images or projections. This technique has been implemented by other using photographic film as an image recording medium and optical reconstruction or decoding of the images. In this work, the possibility of using a real-time neutron video camera to record the images, followed by digital decoding methodology has been investigated. Because only a small fraction of ...

1992-01-01

258

Visibility of tumor-like details in inline phase contrast mammography using quasimonochromatic X-ray sources  

Energy Technology Data Exchange (ETDEWEB)

A new generation of quasimonochromatic high-flux X-ray sources, based on the X-ray radiation produced through Compton scattering between an electron beam and a laser beam, is under development. One of the possible applications of this source is inline phase contrast mammography, based on the observation of the edge-enhancement effect that can be observed at the border of structures inside the breast in images produced using a partially or totally coherent X-ray beam. In this work we present the results of a set of simulations of inline phase contrast mammography using typical inverse Compton scattering sources parameters. The simulated sample was a tumour-like mass having spherical shape, diameter between 200 {mu}m and 5 mm, placed inside a breast-like matrix, 4 cm thick, and a standard composition of 50% glandular tissue and 50% adipose tissue. We discuss the minimum requirements for mammography using inverse Compton scattering sources and we ...

2009-09-01

259

Structural Analysis for Gold Mineralization Using Remote Sensing and Geochemical Techniques in a GIS Environment: Island of Lesvos, Hellas  

International Nuclear Information System (INIS)

Exploration for epithermal Au has been active lately in the Aegean Sea of the eastern Mediterranean Basin, both in the islands of the Quaternary arc and in those of the back-arc region. The purpose of this study was the structural mapping and analysis for a preliminary investigation of possible epithermal gold mineralization, using remotely sensed data and techniques, structural and field data, and geochemical information, for a specific area on the Island of Lesvos. Therefore, Landsat-TM and SPOT-Pan satellite images and the Digital Elevation Model (DEM) of the study area were processed digitally using spatial filtering techniques for the enhancement and recognition of the geologically significant lineaments, as well as algebraic operations with band ratios and Principal Component Analysis (PCA), for the identification of alteration zones. Statistical rose diagrams and a SCHMIDT projection Stereo Net were generated from the lineament maps and ...

2000-12-01

260

Rapid yield learning through optical defect and electrical test analysis  

Energy Technology Data Exchange (ETDEWEB)

As semiconductor device density and wafer area continue to increase, the volume of in-line and off-line data required to diagnose yield-limiting conditions is growing exponentially. To manage this data in the future, analysis tools will be required that can automatically reduce this data to useful information, e.g., by assisting the engineer in rapid root-cause diagnosis of defect generating mechanisms. In this paper, the authors describe a technology known as Spatial Signature Analysis (SSA) and its application to both optically-detected defect data as well as electrical test (e-test) bin data. The results of a validation study are summarized that demonstrate the effectiveness of the SSA approach on optical defect wafermaps through field-testing at three semiconductor manufacturing sites on ASIC, DRAM and SRAM products. This method has been extended to analyze and interpret electrical test data and to provide a pathway for correlation of this data with in-line ...

1998-02-01

261

Preliminary studies of tunnel interface response modeling using test data from underground storage facilities.  

Energy Technology Data Exchange (ETDEWEB)

In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock properties such as P-wave and ...

2010-11-01

262

Experimental studies of the turbulence structures of impinging reacting jets using time-resolved particle image velocimetry visualisation, hot wire anemometry and acoustic signal processing  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the turbulence structures of premixed impinging jets are investigated by three different experimental techniques: time-resolved particle image velocimetry (TPIV) visualisation, hot wire anemometry (HWA) and acoustic signal processing. The focus is on the TPIV, with the other two techniques providing supplementary information. The 2-D velocities of the impinging jets were obtained by TPIV. The contour maps of velocity derivatives were computed to facilitate the visualisation of the turbulence structure of the reactant part of turbulent impinging flames. Particular attention was concentrated on the turbulence structures out of the burner nozzle and their interactions with the combustion process. It was found that the contour plots are effective in visualising time-dependent structures. It is demonstrated that the derivatives of the velocity field are able to reveal many otherwise hidden turbulence patterns. Test cases were designed to facilitate easy ...

2000-12-01

263

3D Fourier synthesis of a new X-ray picture identical in projection to a previous picture  

Energy Technology Data Exchange (ETDEWEB)

A central problem in diagnostic radiology is to compare a new X-ray picture with a previous picture and from this comparison be able to decide if anatomical changes have occurred in the patient or not. It is of primary interest that these pictures are identical in projection. If not it is difficult to decide with confidence if differences between the pictures are due to anatomical changes or differences in their projection geometry. In this thesis we present a non invasive method that makes it possible to find the relative changes in the projection geometry between the exposure of a previous picture and a new picture. The method presented is based on the projection slice theorem (central section theorem). Instead of an elaborate search for a single new picture a pre-planned set of pictures are exposed from a circular orbit above the patient. By using 3D Fourier transform techniques we are able to synthesize a new X-ray picture from this set of pictures that is identical in projection ...

1993-11-01

264

The Possibility of Digital Imaging in the Diagnosis of Occlusal Caries  

UK PubMed Central (United Kingdom)

The aim of this study was to assess the possibility of digital image analysis of pit-and-fissure discoloration in order to diagnose caries. Digital images showing pit-and-fissure discoloration in 100...Full Text Available

2010-01-01

265

Selective imaging of adherent targeted ultrasound contrast agents  

UK PubMed Central (United Kingdom)

The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles...Full Text Available

2007-04-21

266

Radionuclide imaging of the acutely painful scrotum  

International Nuclear Information System (INIS)

This paper discusses the clinical application and main objective of testicular imaging. The authors present cases that represent a spectrum of the abnormalities which might be detected by testicular imaging, with special attention given to testicular torsion and the acute diseases which may mimic it clinically. Accuracy of the test is noted.

267

Quantifying the accuracy of automated structure segmentation in 4D CT images using a deformable image registration algorithm  

UK PubMed Central (United Kingdom)

Four-dimensional (4D) radiotherapy is the explicit inclusion of the temporal changes in anatomy during the imaging, planning, and delivery of radiotherapy. One key component of 4D radiotherapy planning...Full Text Available

2008-04-01

268

Performance evaluation of an automatic anatomy segmentation algorithm on repeat or four-dimensional CT images using a deformable image registration method  

UK PubMed Central (United Kingdom)

PurposeAuto-propagation of anatomical region-of-interests (ROIs) from the planning CT to daily CT is an essential step in image-guided adaptive radiotherapy. The...Full Text Available

2008-09-01

269

Nonnegative Factorization of Diffusion Tensor Images and Its Applications  

UK PubMed Central (United Kingdom)

This paper proposes a novel method for computing linear basis images from tensor-valued image data. As a generalization of the nonnegative matrix factorization, the proposed method aims to approximate...Full Text Available

2011-01-01

270

Near Infrared-Fluorescent and Magnetic Resonance Imaging Molecular Probe with High T1 Relaxivity for In Vivo Multimodal Imaging  

UK PubMed Central (United Kingdom)

A new gadolinium chelating NIR fluorescent molecular probe increases T1 relaxivity of water protons, facilitating combined optical and magnetic resonance imaging.

2010-06-07

271

MULTIMODALITY IMAGING: BEYOND PET/CT AND SPECT/CT  

UK PubMed Central (United Kingdom)

Multimodality imaging with PET/CT and SPECT/CT has become commonplace in clinical practice and in preclinical and basic medical research. Do other combinations of imaging modalities have a similar...Full Text Available

2009-09-01

272

Longitudinal assessment of lung cancer progression in the mouse using in vivo micro-CT imaging  

UK PubMed Central (United Kingdom)

Purpose: Small animal micro-CT imaging is being used increasingly in preclinical biomedical research to provide phenotypic descriptions of genomic models. Most of this imaging is coincident...Full Text Available

2010-09-01

273

Imaging of calcium transients in skeletal muscle fibers.  

UK PubMed Central (United Kingdom)

Epifluorescence images of Ca2+ transients elicited by electrical stimulation of single skeletal muscle fibers were studied with fast imaging techniques that take advantage of the large fluorescence...Full Text Available

1991-01-01

274

High speed optical coherence microscopy with autofocus adjustment and a miniaturized endoscopic imaging probe  

UK PubMed Central (United Kingdom)

Optical coherence microscopy (OCM) is a promising technique or high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging...Full Text Available

2010-03-01

275

Diagnostic radiology: An Anglo-American textbook of imaging  

Energy Technology Data Exchange (ETDEWEB)

This multiauthored text is aimed particularly toward the resident or registrar training in diagnostic radiology. This is a text book on the entire scope of diagnostic imaging. It includes techniques and imaging modalities of all the systems, head, face and neck. The book covers the entire gamut of diagnostic radiology.

1986-01-01

276

Diagnostic quality of low resolution images for tele-woundcare.  

UK PubMed Central (United Kingdom)

The use of digital wound images would allow remote consultation between patients, physicians, or other caregivers over the Internet. To evaluate the efficacy and validity of digital images for assessment...Full Text Available

1998-01-01

277

Comprehensive Quantification of Signal-to-Noise Ratio and g-Factor for Image-Based and k-Space-Based Parallel Imaging Reconstructions  

UK PubMed Central (United Kingdom)

Parallel imaging reconstructions result in spatially varying noise amplification characterized by the g-factor, precluding conventional measurements of noise from the final...Full Text Available

2008-10-01

278

Comparative evaluation of similarity measures for the rigid registration of multi-modal head images  

Energy Technology Data Exchange (ETDEWEB)

Image registrations that are based on similarity measures simply adjust the parameters of an appropriate spatial transformation model until the similarity measure reaches an optimum. The numerous similarity measures that have been proposed in the past are differently sensitive to imaging modality, image content and differences in the image content, selection of the floating and target image, partial image overlap, etc. In this paper, we evaluate and compare 12 similarity measures for the rigid registration. To study the impact of different imaging modalities on the behavior of similarity measures, we have used 16 CT/MR and 6 PET/MR image pairs with known 'gold standard' registrations. The results for the PET/MR registration and for the registration of CT to both rectified and unrectified MR ...

2007-09-21

279

Compact Image Slicing Spectrometer (ISS) for hyperspectral fluorescence microscopy  

UK PubMed Central (United Kingdom)

An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available

2009-07-20

280

CR portal imaging  

International Nuclear Information System (INIS)

In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In ...

1992-01-01

281

An Evaluation of a Computer Imaging Program to Prepare Women for Chemotherapy-related Alopecia  

UK PubMed Central (United Kingdom)

ObjectiveThis study was conducted to evaluate a computer-imaging program called HAAIR (Help with Adjustment to Alopecia by Image Recovery) that was developed to provide...Full Text Available

2010-07-01

282

A BPF-FBP tandem algorithm for image reconstruction in reverse helical cone-beam CT  

UK PubMed Central (United Kingdom)

Purpose: Reverse helical cone-beam computed tomography (CBCT) is a scanning configuration for potential applications in image-guided radiation therapy in which an accurate anatomic image...Full Text Available

2010-01-01

283

Post-mortem fetal MRI: What do we learn from it?  

International Nuclear Information System (INIS)

Post-mortem magnetic resonance (MR) imaging is of increasing interest not only as an alternative to autopsy but as a research tool to aid the interpretation and diagnosis of in utero MR images. The information from the post-mortem MR has allowed the development of imaging sequences applicable to in utero imaging and neonatal imaging. It has established brain development during gestation and has provided data on this to which in utero MR can be compared. The detail available from the post-mortem images is such that brain development can be studied in a non-invasive manner, a permanent record on the normal and abnormal areas is available and a greater understanding of developmental abnormalities is possible.

2006-02-01

284

MR imaging in neuroborreliosis of the cervical spinal cord  

Energy Technology Data Exchange (ETDEWEB)

The central nervous system is involved in 10-20% of cases in Lyme disease. The neurological symptoms, time course of the disease and imaging findings are multifaceted. We report two patients with cervical radiculitis. Magnetic resonance imaging revealed strong enhancement of the cervical nerve roots on contrast-enhanced T1-weighted images. These imaging patterns of borrelia-associated radiculitis have not been reported before. Knowledge of these imaging features may help to diagnose neuroborreliosis, which presents with non-specific symptoms. (orig.)

2004-11-01

285

Reactive ceramics of CeO{sub 2}-MO{sub x} (M=Mn, Fe, Ni, Cu) for H{sub 2} generation by two-step water splitting using concentrated solar thermal energy  

Energy Technology Data Exchange (ETDEWEB)

The addition of MO{sub x} (M: di- or tri-valent transition metal ion) into cerium dioxide (CeO{sub 2}) enhanced the ability of CeO{sub 2} for the oxygen (O{sub 2})-releasing reaction at lower temperature and swift hydrogen (H{sub 2})-generation reaction. CeO{sub 2}-MO{sub x} (M=Mn, Fe, Ni, Cu) reactive ceramics having high melting points were synthesized with the combustion method from their nitrates for solar H{sub 2} production. The prepared CeO{sub 2}-MO{sub x} samples were solid solutions between CeO{sub 2} and MO{sub x} with the fluorite structure through the X-ray diffractometry measurement. Two-step water-splitting reactions with CeO{sub 2}-MO{sub x} reactive ceramics proceeded at 1573-1773 K for the O{sub 2}-releasing step and at 1273 K for the H{sub 2}-generation step by irradiation of infrared image furnace as a solar simulator. The amounts of O{sub 2} evolved in the O{sub 2}-releasing reaction with CeO{sub ...

2007-05-15

286

The Influence Of Plasma Temperature On Wake Wave Generation  

CERN Document Server

The Influence Of Plasma Temperature On Wake Wave Generation

1992-01-01

287
288

Lithography Production Techniques for next Generations of Microelectronics  

CERN Document Server

Lithography Production Techniques for next Generations of Microelectronics

1992-01-01

289

Typhoon Aere : Image of the Day - NASA Earth Observatory  

Science.gov (United States)

Aug 25, 2004 ... The Tropical Rainfall Measuring Mission or TRMM satellite provided this image of Typhoon Aere over the western Philippine Sea as it was ...

290

The importance of radiation quality for optimisation in radiology  

UK PubMed Central (United Kingdom)

Selection of the appropriate radiation quality is an important aspect of optimisation for every clinical imaging task in radiology, since it affects both image quality and patient dose. Spreadsheet...Full Text Available

291

The Use of Medical Images in Planning and Delivery of Radiation Therapy  

UK PubMed Central (United Kingdom)

Abstract The authors provide a survey of how images are used in radiation therapy to improve the precision of radiation therapy plans, and delivery of radiation treatment. In contrast...Full Text Available

1997-09-01

292

Method for the reduction of image content redundancy in large image databases  

Energy Technology Data Exchange (ETDEWEB)

A method of increasing information content for content-based image retrieval (CBIR) systems includes the steps of providing a CBIR database, the database having an index for a plurality of stored digital images using a plurality of feature vectors, the feature vectors corresponding to distinct descriptive characteristics of the images. A visual similarity parameter value is calculated based on a degree of visual similarity between features vectors of an incoming image being considered for entry into the database and feature vectors associated with a most similar of the stored images. Based on said visual similarity parameter value it is determined whether to store or how long to store the feature vectors associated with the incoming image in the database.

2010-03-02

293

JHK and 3.3um PAH Imaging of the Starburst Ring in the Type I Seyfert Galaxy NGC 7469  

Science.gov (United States)

Imaging of NGC 7469 in the J, H, & K bands shows that the starburst 'ring' is a tight inner

1993-01-01

294

Implementation of improved interactive image analysis at the Advanced Photon Source (APC) linac.  

Energy Technology Data Exchange (ETDEWEB)

An image-analysis system, based on commercially available data visualization software (IDL [1]), allows convenient interaction with image data while still providing calculated beam parameters at a rate of up to 2 Hz. Image data are transferred from the IOC to the workstation via EPICS [2] channel access. A custom EPICS record was created in order to overcome the channel access limit of 16k bytes per array. The user can conveniently calibrate optical transition radiation (OTR) and fluorescent screens, capture background images, acquire and average a series of images, and specify several other filtering and viewing options. The images can be saved in either IDL format or APS-standard format (SDDS [3]), allowing for rapid postprocessing of image data by numerous other software tools.

1998-09-11

295

Imaging subsurface using cross-correlation  

Energy Technology Data Exchange (ETDEWEB)

This paper presents two imaging methods by using cross correlation. The one method images the subsurface by cross-correlation of the observed data and partial derivative seismograms calculated for a guessed model. The other method images the interface by use of cross-correlation of the virtual sources and the back propagated wave fields calculated from the observed data. Experimental tests show that both methods image subsurface interfaces well even if the guessed model is different from the true one. These imaging methods are reverse time migration that we perform cross-correlation as an imaging condition and have an advantage, as compared to conventional waveform inversion method, that images subsurface structure without iterative perturbation of the assumed model. (author). 18 refs., 15 figs.

1997-12-31

296

Image Analysis and Computer Vision: 1996.  

Science.gov (United States)

... Title : Image Analysis and Computer Vision: 1996. ... bibliography,. Corporate Author : MARYLAND UNIV COLLEGE PARK COMPUTER VISION LAB. ...

1997-01-01

297

Histopathological Image Analysis: A Review  

UK PubMed Central (United Kingdom)

Over the past decade, dramatic increases in computational power and improvement in image analysis algorithms have allowed the development of powerful computer-assisted analytical approaches...Full Text Available

2009-01-01

298

X-ray phase imaging using a X-ray tube with a small focal spot. Improvement of image quality in mammography  

International Nuclear Information System (INIS)

Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a ...

2002-03-01

299

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 ...

2001-01-01

300

Combining anatomy and function: the path to true image fusion  

Energy Technology Data Exchange (ETDEWEB)

Modern imaging technologies visualize different aspects of disease in a non-invasive way. Considerable progress has been made in the fusion of images from different imaging modalities using software approaches. One goal of fusion software is to align anatomical and functional images and allow improved spatial localization of abnormalities. The resulting correlation of the anatomical and functional images may clarify the nature of the abnormality and help diagnose or stage the underlying disease. Whereas successful image fusion software has been developed for the brain, only limited success has been achieved for image alignment in other parts of the body. The development and current status of alternative approaches are presented. Dual-modality imaging is described with devices where two modalities are combined and mounted ...

2001-10-01

301

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

Science.gov (United States)

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

2008-02-15

302

Submarine tsunamigenic landslides at Stromboli Volcano: characterization and estimation of recurrence time  

Science.gov (United States)

Seafloor mapping and morphometric analysis of landslide scars can provide useful insights for marine geo-hazard assessment, as demonstrated by several studies performed on different geological settings. The availability of high-resolution multibeam bathymetry and long-range side scan sonar data on the submarine portions of Stromboli Volcano allow us to map and characterize the main mass-wasting features that affect, on the whole, about the 90% of its submarine extension. In particular, two main kinds of tsunamigenic landslides have been recognized and analyzed. Large-scale sector collapses (Fig. 1) are catastrophic events that mobilize 1-2 cubic kilometers of material, generating huge tsunami waves that may affect Stromboli and propagate in surrounding areas; related hazard is not very high, as they show recurrence periods of some (or more) thousand years. Conversely, medium-scale landslides are more hazardous, as they occur at higher frequency with respect to the ...

2010-12-01

303

Nuclear medicine progress report for quarter ending March 31, 1985  

Energy Technology Data Exchange (ETDEWEB)

Radioiodinated 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPP) has been prepared as a new terminal iodophenyl-substituted fatty acid containing dimethyl-branching at the beta-position. Iodine-125-labeled DMIPP showed rapid, high myocardial uptake (min, mean % injected dose/g) in fasted rats (5, 4.67; 30, 5.06; 60, 4.79; 120, 4.37), and also exhibited high heart:blood ratios (min, ratio) 5, 3:1; 30, 12:1; 60, 12:1; 120, 13:1. These data demonstrate an unanticipated much longer myocardial residence time with DMIPP (+/sub 1/2/ 7-8 h) than observed with either the 3-monomethyl (BMIPP) analogue (+/sub 1/2/ 30-45 min) or the rapidly metabolized straight-chain (IPP) analogue (+/sub 1/2/ 10-15 min). The (/sup 123/I)DMIPP is thus an excellent candidate for clinical evaluation of regional fatty acid metabolism under conditions where the uptake of energy substrates can be assessed independent of regional blood delivery. Studies with the new activated carbon-based osmium-191/iridium-191m ...

1985-07-01

304

Estimation of a stress field in the earth`s crust using drilling-induced tensile fractures observed at well WD-1 in the Kakkonda geothermal field; Kakkonda WD-1 sei de kansokusareta drilling induced tensile fracture ni yoru chikaku oryokuba no suitei  

Energy Technology Data Exchange (ETDEWEB)

This paper describes estimation of a stress field in the earth`s crust in the Kakkonda geothermal field. Formation micro imager (FMI) logging known as a crack detecting logging was performed in the well WD-1. This FMI logging has made observation possible on cracks along well axis thought to indicate size and direction of the crust stress, and drilling-induced tensile fractures (DTF). It was verified that these DTFs are generated initially in an azimuth determined by in-situ stress (an angle up to the DTF as measured counterclockwise with due north as a starting point, expressed in {theta}) in the well`s circumferential direction. It was also confirmed that a large number of cracks incline at a certain angle to the well axis (an angle made by the well axis and the DTF, expressed in {gamma}). The DTF is a crack initially generated on well walls as a result of such tensile stresses as mud pressure and thermal stress acting on ...

1997-05-27

305

Appendix W: deep sea biophysics (microbiology and amphiped studies)  

International Nuclear Information System (INIS)

CNPT-3 is the laboratory designation of a strain of bacteria that reproduces best at deep-sea pressures. It was isolated from a sample collected at a 5800 m depth of the Pacific Ocean. This isolation was achieved from a sample that had been retrieved without warning. This year we demonstrated that there are similarly behaving bacteria that can be isolated from samples even when retrieved with decompression. The purpose of this project was to define the temperatures and pressures over which CNPT-3 can exist and function. (1) At 2"0C CNPT-3 is eurybathic from about 1000 to 6500 m, as judged from an only slightly pressure dependent generation time. (2) CNPT-3 is unquestionably barophilic at 2"0C, with doubling times of 9 hours at 580 bars and over 18 hours at 1 bar. (3) At 10"0C, reproduction is adversely affected at 1 bar to the extent that CNPT-3 becomes obligately barophilic at 10"0C. Yet reproduction is enhanced above 280 bars and occurs with a regeneration time ...

1981-04-01

306

Visible Earth: Typhoon Aere  

Science.gov (United States)

NASA's Visible Earth catalog of NASA images and animations of our home planet.

309

Theoretical study of subwavelength imaging by acoustic metamaterial slabs  

CERN Document Server

We investigate theoretically subwavelength imaging by acoustic metamaterial slabs immersed in the liquid matrix. A near-field subwavelength image formed by evanescent waves is achieved by a designed metamaterial slab with negative mass density and positive modulus. A subwavelength real image is achieved by a designed metamaterial slab with simultaneously negative mass density and modulus. These results are expected to shed some lights on designing novel devices of acoustic metamaterials.

2009-01-01

313

Possibilities of rayleigh-taylor instability measurement by X-ray phase imaging  

International Nuclear Information System (INIS)

X-ray imaging is a very useful plasma diagnostic method. A theoretical analysis of the x-ray phase imaging in the method based on Fresnel diffraction is given. The authors show it is a linear band pass filter, a property suit for Rayleigh-Taylor (R-T) instability measurement. The evaluation permits the possibility of R-T instability measurement in x-ray phase imaging

318

MR imaging of musculoskeletal trauma to the pelvis and the lower limb  

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging can be used in the trauma setting to detect fractures and associated soft tissue injuries of the musculoskeletal system. Magnetic resonance imaging complements plain radiography and CT for evaluating cancellous bone, cartilage and growth-plate injuries, and intra- and extraarticular supporting soft tissue structures. This review outlines typical applications and imaging consideration for injuries of the pelvis and lower extremity. (orig.) With 12 figs., 78 refs.

1999-03-01

320

Lead-203 for skeletal imaging  

International Nuclear Information System (INIS)

... biological variability body distribution kidneys labelled compounds lead 203

321

Knowledge-based image analysis: some aspects on the analysis of images using other types of information  

Energy Technology Data Exchange (ETDEWEB)

The computer vision approach to image analysis is discussed from two aspects. First, this approach is constrasted to the pattern recognition approach. Second, how external knowledge and information and models from other fields of science and engineering can be used for image and scene analysis is discussed. In particular, the connections between computer vision and computer graphics are pointed out.

1982-01-01

323

Introduction to Three Dimensional Reconstruction of Brain C. T. Image  

International Nuclear Information System (INIS)

The reconstruction of coronal and Sagittal Image of Brain C. T. is helpful to diagnosis of Brain. Three Dimensional Reconstruction software package allows to display three dimensional Image clerived from a series of Horizontal, Sagittal and Coronal Brain C. T. images. It useful in determine approach of operation, to define portals of deep radiation therapy.

1986-11-01

331

Fundamental study on Fuji Computed Radiography (FCR) image  

International Nuclear Information System (INIS)

Japanese (Mar 1986). Japan Tomiyoshi, Tsukasa Kakoi, Iwao Fukushima,

1986-01-01

334

Eddy current imaging  

Energy Technology Data Exchange (ETDEWEB)

Image representations have gained wide acceptance in displaying data collected during optical, ultrasonic, radiographic, and thermographic inspections. Applying imaging techniques to eddy current testing is explored in this article. The authors show that flaw interpretation and characterization are made considerably simpler when images are used to visualize the impedance changes in eddy current probes.

1993-04-01

347

A submillimeter wavelength space-based imaging radar  

Science.gov (United States)

This report considers the use of a submillimeter wavelength space-based imaging radar. The main application envisioned is midcourse decoy discrimination for strategic defense, for which it would have the capability of producing a series of images, in real time, at strategic ranges, with less than meter scale resolution and with modest power requirements. Undoubtedly, there are other applications. The requirements for a SAR and ISAR imaging radar at submillimeter wavelength are determined, and the prospect for the development of RF sources to power the radar is examined.

1988-05-01

349

X-ray imaging dose due to the digital imaging devices used in radiation therapy for patient positioning and repositioning: How to take it into account?; Les doses dues a l'imagerie numerique pour le controle de positionnement du patient en radiotherapie: comment les prendre en compte?  

Energy Technology Data Exchange (ETDEWEB)

The patient positioning and repositioning control in radiation therapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiation therapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiation therapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiation therapy treatment. (authors)

2008-12-15

350

Utilization of fractional Brownian motion in constrained least-squares restoration of medical images  

International Nuclear Information System (INIS)

Constrained least-squares techniques have been used to produce a well known class of image restoration algorithms. These techniques typically involve minimizing a linear operator on a vector representation of an image, subject to a constraint. For cases where an equality constraint is appropriate the method of Lagrange multipliers can be used to produce a restored image. In this work a fractal textural model, fractional Brownian motion, is used to represent images of interest. Using a variance fractal dimension estimator a non-linear operator, that represents the squared difference between the fractal dimension of the restored image and on a priori value is minimized, subject to the constraint that the norm of the residual between the restored image and available measurement equal the norm of the additive noise.

351

Document image retrieval with morphology-based segmentation and features combination  

Science.gov (United States)

Digital libraries need more than just a retrieval based on keywords, which can be inefficient for some applications. Thus, a document retrieval based on content of the digitized image version of the document can be a more appropriated approach. This paper discusses the retrieval of document images by means of identifying a variety of elements present in the document's image body. We propose a new strategy to identify and combine features extracted from a document image. We also consider the task of constructing an optimized feature set to improve the retrieval performance and to validate our experiments on an assorted database. Experimental results show that the proposed segmentation together with a wisely feature combination increase the overall retrieval performance. Moreover the retrieved images demonstrate the generality and effectiveness of our approach for an efficient ...

2011-01-01

352

Comparative evaluation of /sup 99m/Tc GH, /sup 99m/TcO_4, and /sup 99m/Tc DTPA as brain imaging agents  

International Nuclear Information System (INIS)

The brain imaging properties of /sup 99m/Tc glucoheptonate, /sup 99m/Tc pertechnetate, and /sup 99m/Tc DPTA are compared. Results demonstrate that optimum images are obtained at 90, 180, and 180 min., for /sup 99m/Tc GH, /sup 99m/Tc DTPA, and /sup 99m/Tc pertechnetate, respectively. The former two images are not affected by prior bone imaging with /sup 99m/Tc pyrophosphate, while /sup 99m/Tc pertechnetate images are adversely affected. /sup 99m/Tc glucoheptonate appears to be the superior agent for brain imaging, followed by /sup 99m/Tc DTPA and /sup 99m/Tc pertechnetate.

353

de Haas--van Alphen effect and Fermi surface of lutetium  

International Nuclear Information System (INIS)

We report de Haas--van Alphen measurements of the Fermi surface of lutetium at temperatures down to 0.3 K and in fields up to 150 kG in the (1010) and (1120) planes. Lutetium, having a filled 4f shell, serves as a nonmagnetic prototype of the structurally similar (hcp), trivalent, heavy rare-earth elements from Gd to Tm. The fact that no complete frequency branches were observed indicates that there are no closed pieces of the Fermi surface. We observed all but one orbit predicted by relativistic augmented-plane-wave calculations of Keeton and Loucks and by recent spin-orbit--linearized-augmented-plane-wave calculations of Tibbetts and Harmon. The data support a geometry similar to that of yttrium, and in good qualitative agreement with energy-band theory.

354

The high-density regime of kinetic-dominated loop quantum cosmology  

CERN Document Server

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These moments back-react on the trajectories of the expectation values of the state and hence alter the energy density at the bounce. This analysis is performed for isotropic loop quantum cosmology coupled to a scalar field with a small but non-zero constant potential, hence in a regime in which the kinetic energy of matter dominates. Analytic restrictions on the existence of dynamical coherent states and the meaning of semi-classicality within these systems are discussed. A numerical investigation of the trajectories of states that remain semi-classical across the bounce demonstrates that, at least for such states, the bounce persists and that its properties are similar to the standard case, in which the moments of the states are ...

2010-01-01

355

The electron cyclotron absorption diagnostic for the JET pumped divertor plasma  

International Nuclear Information System (INIS)

We present the design of a diagnostic system to measure electron cyclotron absorption at the second harmonic E-mode resonance in the JET pumped divertor plasma. The diagnostic will measure transmission as a function of frequency along one or more sightlines from which the spatial profile of the n_eT_e product will be deduced. The divertor is briefly described, and the electron cyclotron resonance physics relevant to this measurement is reviewed. The problems of measuring transmission using an oversized transmission system are discussed and the chosen measurement technique, a swept frequency interferometer using a coherent radiation source, is described. A prototype of the instrument has been assembled to test the measurement technique. Some data demonstrating the instrument's characteristics are presented. The nonresonant losses, which may affect the interpretation of the measurement, are also discussed. (orig.).

1993-03-01

356

Synchrotron radiation from electron beams in plasma-focusing channels.  

Science.gov (United States)

Spontaneous radiation emitted from relativistic electrons undergoing betatron motion in a plasma-focusing channel is analyzed, and applications to plasma wake-field accelerator experiments and to the ion-channel laser (ICL) are discussed. Important similarities and differences between a free electron laser (FEL) and an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter a(beta), which plays a role similar to that of the wiggler strength parameter in a conventional FEL. For a(beta) > or approximately 1, radiation is emitted in numerous harmonics. Furthermore, a(beta) is proportional to the amplitude of the betatron orbit, which varies for every electron in the beam. The radiation spectrum emitted from an electron beam is calculated by averaging the single-electron spectrum over the electron distribution. This leads to a frequency broadening of the radiation spectrum, which places ...

2002-05-20

357

Perturbations of Schwarzschild Black Holes in Chern-Simons Modified Gravity  

CERN Document Server

We study perturbations of a Schwarzschild black hole in Chern-Simons modified gravity. We begin by showing that Birkhoff's theorem holds for a wide family of Chern-Simons coupling functions, a scalar field present in the theory that controls the strength of the Chern-Simons correction to the Einstein-Hilbert action. After decomposing the perturbations in spherical harmonics, we study the linearized modified field equations and find that axial and polar modes are coupled, in contrast to general relativity. The divergence of the modified equations leads to the Pontryagin constraint, which forces the vanishing of the Cunningham-Price-Moncrief master function associated with axial modes. We analyze the structure of these equations and find that the appearance of the Pontryagin constraint yields an overconstrained system that does not allow for generic black hole oscillations. We illustrate this situation by studying the case characterized by a canonical choice of the ...

2007-01-01

358

Los Alamos Advanced Free-Electron Laser  

Energy Technology Data Exchange (ETDEWEB)

At Los Alamos, we are building a free-electron laser (FEL) for industrial, medical, and research applications. This FEL, which will incorporate many of the new technologies developed over the last decade, will be compact in size, robust, and user-friendly. Electrons produced by a photocathode will be accelerated to 20 MeV by a high-brightness accelerator and transported using permanent-magnet quadrupoles and dipoles. They will form an electron beam with an excellent instantaneous beam quality of 10 {pi} mm mrad in transverse emittance and 0.3% in energy spread at a peak current up to 300 A. Including operation at higher harmonics, the laser wavelength extends form 3.7 {mu}m to 0.4 {mu}m. In this paper, we will describe the project and the programs to date. 10 refs., 10 figs., 1 tab.

1991-01-01

359

Locally resonant acoustic metamaterials with 2D anisotropic effective mass density  

British Library Electronic Table of Contents (United Kingdom)

A two-dimensional (2D) lattice model with anisotropic resonant microstructures is found to provide an anisotropic band gap structure. A 2D continuum with anisotropic effective mass density is introduced to represent this lattice system. Two methods are proposed to derive the equivalent continuum. In the first method, the effective mass density of the equivalent continuum is obtained by matching the dispersion relations for harmonic waves propagating in the principal directions. The second approach employs an approximate estimation of the effective mass density by volume-averaging an effective mass that represents the resonant microstructure. For both equivalent continuum models, the effective mass density is frequency-dependent and may become negative in certain frequency ranges. Subsequen...

2011-01-01

360

High Tc superconducting magnetic multivibrators for fluxgate magnetic-field sensors  

Science.gov (United States)

Sensitive and quick-response nonlinear inductance characteristics are found for high Tc superconducting (YBa/sub 2/Cu/sub 3/O/sub 7-chi/) disk cores at 77K in which soft magnetic BH hysteresis loops are observed. Various quick response magnetic devices such as modulators, amplifiers and sensors are built using these cores. The magnetizing frequency can be set to more than 20 MHz, which is difficult for conventional ferromagnetic bulk materials such as Permalloy amorphous alloys and ferrite. New quick-response fluxgate type magnetic-field sensors are made using ac and dc voltage sources. The former is used for second-harmonic type sensors, while the latter is for voltage-output multivibrator type sensors. Stable and quick-response sensor characteristics were obtained for two-core type multivibrators.

1989-09-01

361

Gravity-wave insights to Bianchi type-IX universes  

Energy Technology Data Exchange (ETDEWEB)

Every Bianchi type-IX universe can be interpreted as a closed Friedmann universe on which is superimposed circularly polarized gravitational waves with the longest wavelength that will fit into a closed universe. In this paper, I give a new derivation of this result based on the concept of homogeneous tensor fields on the three-sphere. Every homogeneous symmetric traceless tensor field is shown to be a longest-wavelength three-sphere harmonic. Contrary to previous authors, I show that the wavelength of these gravitational waves is one-half the circumference of the universe. In order to maintain homogeneity, the gravitational waves must all have the same polarization. There are five longest-wavelength modes for each polarization. This interpretation is an {ital exact} description that is valid for every Bianchi type-IX universe---it is in no way limited to first-order perturbations of a Friedmann universe.

1991-10-15

362

Electron cyclotron current drive at {omega} approx. = {omega}{sub c} with X-mode launched from the low field side  

Energy Technology Data Exchange (ETDEWEB)

The electron cyclotron resonance layer in a tokamak, {omega}={omega}{sub c}(r), is not accessible by the extraordinary wave from the low field side, because it is shielded by a cutoff layer. However, a X-mode launched with a nonzero toroidal angle propagates at the cutoff parallel to the magnetic field and has a circular polarization. Therefore it can already at the cutoff layer interact efficiency with electrons via the Doppler shifted resonance. The driven current can be substantially higher than that driven by the second harmonic X-mode. The applicability of this current drive scheme is limited to rather low values of {omega}{sub p}{sup 2}/{omega}{sub c}{sup 2}, but may be of interest for high magnetic field devices. (author)

2000-02-01

363

Effects of velocity-dependent force on the magnetic form factors of odd-Z  

International Nuclear Information System (INIS)

We investigate the effects of the velocity-dependent force on the magnetic form factors and magnetic moments of odd-Z nuclei. The form factors are calculated with the harmonic-oscillator wavefunctions. It is found that the contributions of the velocity-dependent force manifest themselves in the very large momentum transfer region (q?4 fm-1). In the low and medium q region the contributions of the velocity-dependent force are very small compared with those without this force. However, in the high-q region the contributions of the velocity-dependent force are larger than the normal form factors. The diffraction structures beyond the existing experimental data are found after the contributions of the velocity-dependent force are included. The formula of the correction to the single particle magnetic moment due to the velocity-dependent force is reproduced exactly in the long-wavelength limit (q=0) of the M1 form factor. (authors)

2008-03-01

364

Couple stress fluid improve rub-impact rotor-bearing system - Nonlinear dynamic analysis  

British Library Electronic Table of Contents (United Kingdom)

This study performs a dynamic analysis of the rub-impact rotor supported by two couple stress fluid film journal bearings. The strong nonlinear couple stress fluid film force, nonlinear rub-impact force and nonlinear suspension (hard spring) are presented and coupled together in this study. The displacements in the horizontal and vertical directions are considered for various non-dimensional speed ratios. The numerical results show that the dynamic behaviors of the system vary with the dimensionless speed ratios, the dimensionless unbalance parameters and the dimensionless parameter, l*. Inclusive of the periodic, sub-harmonic, quasi-periodic and chaotic motions are found in this analysis. The results of this study contribute to a further understanding of the nonlinear dynamics of a rotor-...

2010-01-01

365

Construction of the maximal solution of Backus? problem in geodesy and geomagnetism  

British Library Electronic Table of Contents (United Kingdom)

The (simplified) Backus? Problem (BP) consists in finding a harmonic function u on the domain exterior to the three dimensional unit sphere S, such that u tends to zero at infinity and the norm of the gradient of u takes prescribed values g on S. Except for a change of sign, the solution is not unique in general. However, there is uniqueness of solutions in the class of functions with the additional property that the radial component of the gradient of u on S is nonpositive. This is the geodetically relevant case. If a solution u with this property exists, then u is the maximal solution of the problem (and -u the minimal one). In this paper we propose a method of successive approximations to get this particular solution of BP and prove the convergence for functions g close to a constant fu...

2011-01-01

366

Chatter resistance of non-uniform turning bars with attached dynamic absorbers—Analytical approach  

British Library Electronic Table of Contents (United Kingdom)

Forced harmonic vibration of a non-uniform elastic beam with attached dynamic vibration absorbers (DVA) is studied. Analytical approximation of the solution is obtained by the functional perturbation method (FPM). The problem has application to cutting tools operations where the resistance of the tool holder against regenerative chatter can be enhanced by optimizing the real part of the frequency response function (FRF). A test case of a beam with step-like heterogeneity and single DVA at the tip shows that the FPM solution is very accurate for up to ?40 percent deviation in both stiffness and mass density. Using the analytical results and Sims approach, optimal DVA tuning is found for each set of beam heterogeneity parameters by solving a set of nonlinear algebraic equations numer...

2010-01-01

367

Atomic density functions: atomic physics calculations analyzed with methods from quantum chemistry  

CERN Document Server

This contribution reviews a selection of findings on atomic density functions and discusses ways for reading chemical information from them. First an expression for the density function for atoms in the multi-configuration Hartree--Fock scheme is established. The spherical harmonic content of the density function and ways to restore the spherical symmetry in a general open-shell case are treated. The evaluation of the density function is illustrated in a few examples. In the second part of the paper, atomic density functions are analyzed using quantum similarity measures. The comparison of atomic density functions is shown to be useful to obtain physical and chemical information. Finally, concepts from information theory are introduced and adopted for the comparison of density functions. In particular, based on the Kullback--Leibler form, a functional is constructed that reveals the periodicity in Mendeleev's table. Finally a quantum similarity measure is ...

2011-01-01

368

A unified framework for biological evolution and stochastic quantization  

CERN Document Server

We investigate the profound relation between the equations of biological evolution and quantum mechanics by writing a biologically inspired equation for the stochastic dynamics of an ensemble of particles. Interesting behavior is observed which is related to a new type of stochastic quantization. We find that the probability distribution of the ensemble of particles can be decomposed into eigenfunctions associated to a discrete spectrum of eigenvalues. In absence of interactions between the particles, the out-of-equilibrium dynamics asymptotically relaxes towards the fundamental state. This phenomenon can be related with the Fisher theorem in biology. On the contrary, in presence of scattering processes the evolution reaches a steady state in which the distribution of the ensemble of particles is characterized by a Bose-Einstein statistics. In order to show a concrete example of this stochastic quantization we have solved explicitly the case in which the potential energy has the ...

2010-01-01

369

Subsurface imaging using the spectral polarization difference technique and NIR illumination  

Energy Technology Data Exchange (ETDEWEB)

A subsurface imaging system is utilized to test the ability of the spectral polarization difference imaging technique for deep subsurface imaging in tissues. The illumination of the system is derived from compact class III lasers in the red and NIR spectral region and, alternatively, from a white light source and selection of the appropriate illumination wavelength using band-pass optical filters. The experimental results demonstrate detection and imaging of a high-scattering object located up to 1.5 cm underneath the surface of a host chicken tissue.

1999-01-26

370

Cutaneous gallium uptake in patients with AIDS with mycobacterium avium-intracellulare septicemia  

International Nuclear Information System (INIS)

Gallium imaging is increasingly being used for the early detection of complications in patients with AIDS. A 26-year-old homosexual man who was HIV antibody positive underwent gallium imaging for investigation of possible Pneumocystis carinii pneumonia. Widespread cutaneous focal uptake was seen, which was subsequently shown to be due to mycobacterium avium-intracellulare (MAI) septicemia. This case demonstrates the importance of whole body imaging rather than imaging target areas only, the utility of gallium imaging in aiding the early detection of clinically unsuspected disease, and shows a new pattern of gallium uptake in disseminated MAI infection.

371

Myocardial imaging in patients with Kawasaki disease. Exercise stress imaging and serial studies  

Energy Technology Data Exchange (ETDEWEB)

Thallium-201 myocardial imaging was performed in 80 children with coronary arterial lesions due to Kawasaki disease in order to assess the value of serial and exercise myocardial imagings. In eight of these children, abnormalities of the image were noted. Twenty children had serial thallium studies with an interval of three to 18 months, and five of these showed changes in the image including appearance of a new perfusion defect in one patient and improvement of perfusion defects in four. These changes of the myocardial image were correlated well with coronary angiographic findings obtained within a few days of the isotope studies. It was noted that the changes of the myocardial image were more frequently observed at relatively recent period recovered from Kawasaki disease. Exercise myocardial imaging using a bicycle ergometer was performed ...

1982-06-01

372

Nonphotochemical Hole-Burning Imaging Studies of in vitro Carcinoma and Normal Cells Utilizing a Mitochondrial Specific Dye  

Energy Technology Data Exchange (ETDEWEB)

Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria due to the high lipid composition of mitochondria and the generation of a large negative membrane potential (relative to the cellular cytoplasm) for oxidative phosphorylation. Results presented for NPHB of MF680 located in the cells show significant differences between the two cell lines. The ...

2002-06-27

373

Nonphotochemical Hole-Burning Imaging Studies of In Vitro Carcinoma and Normal Cells Utilizing a Mitochondrial Specific Dye  

Energy Technology Data Exchange (ETDEWEB)

Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria due to the high lipid composition of mitochondria and the generation of a large negative membrane potential (relative to the cellular cytoplasm) for oxidative phosphorylation. Results presented for NPHB of MF680 located in the cells show significant differences between the two cell lines. The ...

2002-08-01

374

Laser: a Tool for Optimization and Enhancement of Analytical Methods  

Energy Technology Data Exchange (ETDEWEB)

In this work, we use lasers to enhance possibilities of laser desorption methods and to optimize coating procedure for capillary electrophoresis (CE). We use several different instrumental arrangements to characterize matrix-assisted laser desorption (MALD) at atmospheric pressure and in vacuum. In imaging mode, 488-nm argon-ion laser beam is deflected by two acousto-optic deflectors to scan plumes desorbed at atmospheric pressure via absorption. All absorbing species, including neutral molecules, are monitored. Interesting features, e.g. differences between the initial plume and subsequent plumes desorbed from the same spot, or the formation of two plumes from one laser shot are observed. Total plume absorbance can be correlated with the acoustic signal generated by the desorption event. A model equation for the plume velocity as a function of time is proposed. Alternatively, the use of a static laser beam for observation enables reliable ...

1997-01-01

375

Imaging-based dust sensors: equipment and methods  

Science.gov (United States)

Dust detection and control in real time, represent one of the most challenging problem in all those environments where fine and ultrafine airborne particulate solids products are present. The presence of such products can be linked to several factors, often directly related and influenced by the working-production actions performed. Independently from the causes generating dust, airborne contaminants are an occupational problem of increasing interest as they are related to a wide number of diseases. In particular, airborne dusts are well known to be associated with several classical occupational lung diseases, such as the pneumoconiosis, especially at high levels of exposure. Nowadays there is also an increasing interest in other dust related diseases, from the most serious as cancer and asthma, to those related with allergies or irritation and other illnesses, also occurring at lower levels of exposure. Among the different critical factors influencing health risk ...

2004-05-01

379

Resolution enhancement by subtraction of confocal signals taken at different pinhole sizes.  

Science.gov (United States)

Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in ...

2003-01-01

380

Magnified x-ray phase imaging using asymmetric Bragg reflection: Experiment and theory  

International Nuclear Information System (INIS)

X-ray imaging using asymmetric Bragg reflection in the hard x-ray regime opens the way to improve the spatial resolution limit below 1 #mu#m by magnifying the image before detection, simultaneously providing a strong phase contrast. A theoretical formalism of the imaging process is established. Based on this algorithm, numerical simulations are performed and demonstrate that both Fresnel propagation and Bragg diffraction contribute to contrast formation. The achievable resolution of this technique is investigated theoretically; the results obtained can be used to improve future experimental setups. Furthermore, the minimum detectable phase gradient is estimated, for comparison with other phase sensitive imaging techniques. Results from biological objects demonstrate that the technique is viable for imaging both in two and three dimensions. Refraction contrast ...

2006-08-01

381

Development of a dual-detector X-ray imaging system for phase retrieval study  

International Nuclear Information System (INIS)

Based on a recently introduced phase X-ray imaging approach, a dual-detector prototype was developed for in-line X-ray phase imaging and phase retrieval utilizing a micro-focus X-ray source and two computed radiography (CR) cassette detectors. The system was built on a horizontal optical rail to facilitate manual adjustment of the positions of the X-ray source, the sample and the detectors. The novel design of the detector-1 is essential, it detects a portion of radiation to form an attenuation image; allows the rest of radiation to reach the detector-2 to form a phase contrast image, and the two images are used to retrieve a phase map. The two detectors are balanced for optimal phase-retrieval with reasonable radiation dose to the object to be imaged. The system was examined in terms of the linearity, the fractions of the X-ray photons detected by the two ...

2007-01-01

382

Clinical trial of NMR-CT, (4). Clinical evaluation of hybrid image  

Energy Technology Data Exchange (ETDEWEB)

In our evaluation we utilized the Asahi Mark-J NMR-CT system, with a resistive vertical quadrupolar electromagnet (0.1 Tesla) and a proton resonance frequency of 4.5 MHz. Our main imaging methods are the inversion-recovery or IR, saturation-recovery, or SR, and calculated T/sub 1/. Difference, or D images, constructed by subtracting the data of the IR signal from that of the SR signal, have also been obtained in some cases. The system allows averaging of raw data. Hybrid images were constructed from two or more images to obtain clear definition of areas of interest. By using the hybrid image, several tissues of different relaxation times can be shown in the same image. Application in our study of the newly developed hybrid image indicates its importance in the detection and diagnosis of lesion, especially the detection of the differentiation ...

1985-01-01

383

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 ...

1993-12-01

384

Direct digital radiography vs conventional radiography of thoracic spine: a comparative study  

International Nuclear Information System (INIS)

Objective: An evaluation of the application of DR in thoracic spine and a comparative study of the DR with the conventional radiography. Methods: DR images and the conventional radiogram of 89 cases respectively were evaluated by 3 vice-consultant doctors and 2 chief technicians. Statistics was processed with 2 categories: (1) images were classified into grade A, B, C and condemned according to the image quality; and (2) thoracic spine are divided into upper, middle and lower portions, in which the rate of successful imaging were compared respectively. Results: The image quality of DR: 74. 1% images in grade A, 20.2% in grade B, 5.7% in grade C, and no image condemned. Conventional radiogram: 45% images in grade A, 41.6% in grade B, 11.2% in grade C, and 2.2% images condemned. The successful ...

2005-09-01

385

Ignition system  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an ignition system of an internal combustion engine which consists of: a permanent magnet supported by a rotary member of the engine adapted to rotate in synchronism with a rotary shaft of the engine; a generating coil for generating an electromotive force to produce an electric current as the permanent magnet acts on the generating coil during the rotation of the rotary member; an ignition capacitor charged by the electric current generated by the generating coil; a thyristor caused to turn on by a counter electromotive force generated by the generating coil to thereby cause the ignition capacitor to begin to discharge; and an ignition coil generating a high voltage as the ignition capacitor begins to discharge, to cause a spark discharge to take place in an ignition plug of the internal combustion ...

1986-09-16

386

Complete intersection Calabi-Yau manifolds ; 2, three generation manifolds  

CERN Document Server

Complete intersection Calabi-Yau manifolds ; 2, three generation manifolds

1988-01-01

387

Phase 2 Final Report. IAEA Safeguards: Implementation blueprint of commercial satellite imagery  

International Nuclear Information System (INIS)

This document - IAEA Safeguards: Implementation Blueprint of Commercial Satellite Imagery - constitutes the second report from SSC Satellitbild giving a structured view and solid guidelines on how to proceed with a conceivable implementation of satellite imagery to support Safeguards activities of the Agency. This Phase 2 report presents a large number of concrete recommendations regarding suggested management issues, work organisation, imagery purchasing and team building. The study has also resulted in several lists of actions and preliminary project plans with GANT schedules concerning training, hardware and software, as well as for the initial pilot studies. In both the Phase 1 and Phase 2 studies it is confirmed that the proposed concept of a relatively small Imagery Unit using high-resolution data will be a sound and feasible undertaking. Such a unit capable of performing advanced image processing as a tool for various safeguard tasks will give the Agency an ...

1989-08-01

388

Smith-Purcell radiation in the highly relativistic regime  

International Nuclear Information System (INIS)

An electron moving over the surface of a diffraction grating will transfer a part of its kinetic energy to radiation via a velocity synchronous coupling with a slow space harmonic component of the field. Since the phase velocity of a slow space harmonic is less than the speed of light, the slow components decay exponentially, or evanesce, with distance above the grating and the evanescence scale is determined by the product of the relative velocity, #beta#, the relative energy, #gamma#, and the wavelength #lambda#. Thus, in the relativistic regime, good electron - grating coupling can be maintained at beam heights that are greater than the emitted wavelength. In order to explore this regime a series of experiments have been carried out with moderately energetic beams and an experiment with the 70-MeV beam at the Accelerator Test Facility is in the planning stage. The work has two basic goals: the first is to explore the characteristics of the ...

1995-08-21

389

Fiscal 1997 report on the results of the R and D of industrial scientific technology. R and D of synergistic ceramics (R and D of corrosion prevention technology for the petroleum production system); 1997 nendo sangyo kagaku gijutsu kenkyu kaihatsu seika hokokusho. Synergy ceramics no kenkyu kaihatsu (sekiyu seisan system fushoku boshi gijutsu kenkyu kaihatsu)  

Energy Technology Data Exchange (ETDEWEB)

To heighten durability and safety of materials/parts for undersea oil drilling, the development of ceramic base materials was made by developing function harmony type process technology which harmonizes on a high grade contrary characteristics and various functions. The paper summed up the fiscal 1997 results. In the design of system formation, computational simulation technology was developed to the composite process and the diploid system. The development of multifunction simultaneous manifestation materials was trially made by the higher nano structure process. A study was made of control of microstructures of porous materials and matrix filling by the gas phase precipitation control. Proposed were selective control of grain growth from species crystals and the columnar particle orientation laminated structure of simultaneous manifestation of strength and toughness. By composite precipitation reaction control, studied were simultaneous dispersion of whisker and ...

1998-03-01

390

X-ray Phase Imaging Microscopy using a Fresnel Zone Plate and a Transmission Grating  

International Nuclear Information System (INIS)

We report on a hard X-ray phase imaging microscopy (a phase-difference microscopy) that consists of an objective and a transmission grating. The simple optical system provides a quantitative phase image, and does not need a wave field mostly coherent on the objective. Our method has a spatial resolution almost same as that of the absorption contrast microscope image obtained by removing the grating. We demonstrate how our approach provides a phase image from experimentally obtained images. Our approach is attractive for easily appending a quantitative phase-sensitive mode to normal X-ray microscopes, and has potentially broad applications in biology and material sciences.

2010-06-23

391

Tracheal images using energy subtraction Fuji computed radiography  

International Nuclear Information System (INIS)

Twenty patients with lesions in the trachea or bronchus underwent energy subtraction Fuji computed radiography (FCR). Images obtained were compared with those from conventional FCR (plain FCR). ''Very clear'' images (in which the contour of the trachea and bronchus could be clearly defined) were obtained in 12/22 (55 %) by energy subtraction FCR and in 3/22 (14 %) by plain FCR; ''clear'' images (in which the contour could be defined) in 9/22 (41 %) by energy subtraction FCR and in 18/22 (82 %) by plain FCR; and ''unclear'' images (in which the contour could not be defined) in 1/22 (5 %) by both methods. Energy subtraction FCR, as well as plain FCR, yielded high image quality for the trachea. Energy subtraction FCR was superior to plain films when tumors existed within the trachea. (Namekawa, K.).

1985-01-01

392

The Adrenal Mass: Correlation of Histopathology with Imaging  

British Library Electronic Table of Contents (United Kingdom)

Background Computed tomography (CT) and magnetic resonance (MR) imaging can help diagnose benign adrenal adenomas, but prior studies rely on nonoperative follow-up as proof of a lesion?s benign nature. We examined adrenalectomy tissues to determine if imaging characteristics correlate with histopathologic findings. Methods We retrieved data for 196 consecutive adrenalectomies in 192 patients from 2000 to 2008. Imaging results were considered to signify benign adrenal adenoma if one or more of the following was present: Hounsfield units 60% or relative contrast washout of >40%, or MR with chemical-shift imaging demonstrating loss of signal intensity on out-of-phase images. Results The sensitivity and specif...

2010-01-01

393

Real time neutron radioscopy - trends and applications  

International Nuclear Information System (INIS)

Real Time Radiography (RTR) finds extensive applications for inspection of objects on assembly lines for rapid inspection. A typical RTR widely used includes a image intensifier, CCD camera, image processor and high resolution TV monitor in addition to radiographic source. Image intensifiers used in X-radiography employ CsI as the input detector. With the increased use of neutrons as radiation source, real time neutron radiography is also being practised widely. Image intensifiers used in neutron radiography employ gadolinium as the input screen. The neutron image intensifier system at the authors laboratory essentially consists of a 9 inch Trifield image intensifier tube, motorised zoom lens, CCD camera and a high resolution TV monitor

2003-11-12

394

Position sensitive detection of individual nuclear particle scintillations using image intensifier tubes  

International Nuclear Information System (INIS)

An imaging position sensitive detector for charged particles, neutrons, X-and gamma rays has been developed. The novel feature of this scintillation imaging radiation detector is its ability to detect individual nuclear particle scintillations with a h igh degree of spatial resolution. The key elements of this detector system are a high gain, low noise image intensifier tube, a CCD camera and commercially available image processing hardware and software. This detector system is highly effective for applications such as low fluence and real time neutron radiography, mapping of radioactive contamination in nuclear reactor fuel rods, X-ray diffraction imaging, high speed autoradiography and in general position sensitive detection of nuclear radiation. Results of some of the exploratory experiments carried out using this detector system are presented in this paper. (orig.).

1996-01-01

395

Neutron imaging system for neutron tomography, radiography, and beam diagnostics  

Energy Technology Data Exchange (ETDEWEB)

A neutron imaging system (NIS) has been recently installed at the University of Texas TRIGA reactor facility. The imaging system establishes new capabilities for beam diagnostics at the Texas Cold Neutron Source (TCNS) for real-time neutron radiography (RTNR) and for neutron computed tomography (NCT) research. The NIS will also be used for other research projects. The system consists of two subsystems as follows: (1) Thomson 9-in. neutron image intensifier (NII) tube sensitive to cold, thermal, and epithermal neutrons, (2) image-processing unit consisting of vidicon camera, two high-resolution monitors, image enhancement and measurement processor, and video printer. The NIS is installed at the cold neutron beam of the TCNS for testing and cold neutron beam diagnostics.

1995-12-31

396

Magnetization transfer contrast effect on multislice fast spin echo  

Energy Technology Data Exchange (ETDEWEB)

Magnetization transfer contrast (MTC) on fast spin echo (FSE) images was evaluated in normal brain tissue as well as in brain tumors to better understand contrast of FSE images. On multislice FSE images, attenuation of the signal intensity of brain tissue due to MTC is observed. The rate of MTC (MTR) is obtained by comparing with additional single slice images. The effect of signal attenuation is greater on images with smaller interslice gap, larger number of slices, and longer echo train length. MTR of brain tumors is less than that of normal brain tissue. Among them, meningiomas have relatively high MTR, and cavernous malformation has relatively low MTR. Determination of MTC can be easily specified by obtaining multislice and single slice FSE images, and it may help differentiate brain tumors. (author).

1994-03-01

397

Field test studies of our infrared-based human temperature screening system embedded with a parallel measurement approach  

British Library Electronic Table of Contents (United Kingdom)

This paper introduces a parallel measurement approach for fast infrared-based human temperature screening suitable for use in a large public area. Our key idea is based on the combination of simple image processing algorithms, infrared technology, and human flow management. With this multidisciplinary concept, we arrange as many people as possible in a two-dimensional space in front of a thermal imaging camera and then highlight all human facial areas through simple image filtering, image morphological, and particle analysis processes. In this way, an individual's face in live thermal image can be located and the maximum facial skin temperature can be monitored and displayed. Our experiment shows a measured 1ms processing time in highlighting all human face areas. With a thermal imaging ca...

2009-01-01

398

Feasibility study of the iterative x-ray phase retrieval algorithm  

International Nuclear Information System (INIS)

An iterative phase retrieval algorithm was previously investigated for in-line x-ray phase imaging. Through detailed theoretical analysis and computer simulations, we now discuss the limitations, robustness, and efficiency of the algorithm. The iterative algorithm was proved robust against imaging noise but sensitive to the variations of several system parameters. It is also efficient in terms of calculation time. It was shown that the algorithm can be applied to phase retrieval based on one phase-contrast image and one attenuation image, or two phase-contrast images; in both cases, the two images can be obtained either by one detector in two exposures, or by two detectors in only one exposure as in the dual-detector scheme.

2009-01-01

399

Extraction methods of phase information for X-ray diffraction enhanced imaging  

Energy Technology Data Exchange (ETDEWEB)

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more ...

2007-08-21

400

Extraction methods of phase information for X-ray diffraction enhanced imaging  

International Nuclear Information System (INIS)

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of ...

2007-08-21

401

Digital radiography of pulmonary abnormalities using Fuji computed radiography (FCR)  

Energy Technology Data Exchange (ETDEWEB)

Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best ...

1991-12-01

402

Digital radiography of pulmonary abnormalities using Fuji computed radiography (FCR)  

International Nuclear Information System (INIS)

Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best practical ...

1991-01-01

403

Development of the high sensitivity real-time neutron radiography for low-flux neutron sources  

Energy Technology Data Exchange (ETDEWEB)

The authors have developed a high-sensitivity real-time neutron radiography (NR) system by the use of the low power reactor of Kinki University. The system was constructed with a high efficiency neutron-photon converter, an image intensifier and a SIT TELEVISION camera. Some digital image processing techniques were applied for improving the quality of the real-time neutron images. By the use of this system, dynamic neutron imaging was performed successfully under the condition of a weak neutron field that was about two orders of magnitude lower than that of the standard NR system. The neutron flux, calculated from the fluctuation of the neutron response of the images, was nearly equal to the value measured by the foil activation method. From this fact, the efficiency for the neutron detection of the imaging system was estimated to be almost 100%. For the purpose ...

1994-08-01

404

Development of the high sensitivity real-time neutron radiography for low-flux neutron sources  

International Nuclear Information System (INIS)

The authors have developed a high-sensitivity real-time neutron radiography (NR) system by the use of the low power reactor of Kinki University. The system was constructed with a high efficiency neutron-photon converter, an image intensifier and a SIT TELEVISION camera. Some digital image processing techniques were applied for improving the quality of the real-time neutron images. By the use of this system, dynamic neutron imaging was performed successfully under the condition of a weak neutron field that was about two orders of magnitude lower than that of the standard NR system. The neutron flux, calculated from the fluctuation of the neutron response of the images, was nearly equal to the value measured by the foil activation method. From this fact, the efficiency for the neutron detection of the imaging system was estimated to be almost 100%. For the purpose ...

1994-01-01

405

A new method of imaging particle tracks in solid state nuclear track detectors  

British Library Electronic Table of Contents (United Kingdom)

Summary Solid state nuclear track detectors are used to determine the concentration of a particles in the environment. The standard method for assessing exposed detectors involves 2D image analysis. However 3D imaging has the potential to provide additional information relating to angle as well as to differentiate clustered hit sequences and possibly energy of a particles but this could be time consuming. Here we describe a new method for rapid high-resolution 3D imaging of solid state nuclear track detectors. A `LEXT' OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) was used in confocal mode to successfully obtain 3D image data on four CR-39 plastic detectors. Three-dimensional visualization and image analysis enabled characterization of track features. This ...

2010-01-01

406

Pulmonary nodule detection of chest phantom with CRT images; Comparison with conventional radiography (film-screen system) and FCR hardcopy  

Energy Technology Data Exchange (ETDEWEB)

Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and ...

1989-08-01

407

Pulmonary nodule detection of chest phantom with CRT images  

International Nuclear Information System (INIS)

Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and ...

1989-01-01

408

X-Ray Phase Imaging for Breast Cancer Detection  

Science.gov (United States)

... Accession Number : ADA535309. Title : X-Ray Phase Imaging for Breast Cancer Detection. Descriptive Note : Annual rept. 1 Sep 2009-31 Aug 2010 ...

2010-09-01

409

Verification of MLC based real-time tumor tracking using an electronic portal imaging device  

UK PubMed Central (United Kingdom)

Purpose: The authors have developed a novel technique using an electronic portal imaging device (EPID) to verify the geometrical accuracy of delivery of dose-rate-regulated tracking (DRRT)....Full Text Available

2010-06-01

410

Technical note: A physical phantom for assessment of accuracy of deformable alignment algorithms  

International Nuclear Information System (INIS)

The purpose of this study was to investigate the feasibility of a simple deformable phantom as a QA tool for testing and validation of deformable image registration algorithms. A diagnostic thoracic imaging phantom with a deformable foam insert was used in this study. Small plastic markers were distributed through the foam to create a lattice with a measurable deformation as the ground truth data for all comparisons. The foam was compressed in the superior-inferior direction using a one-dimensional drive stage pushing a flat 'diaphragm' to create deformations similar to those from inhale and exhale states. Images were acquired at different compressions of the foam and the location of every marker was manually identified on each image volume to establish a known deformation field with a known accuracy. The markers were removed digitally from corresponding images prior to ...

2007-07-01

411

TLD assessment of mouse dosimetry during microCT imaging  

UK PubMed Central (United Kingdom)

Advances in laboratory animal imaging have provided new resources for noninvasive biomedical research. Among these technologies is microcomputed tomography (microCT) which is widely used to obtain high...Full Text Available

2008-09-01

412

Study of Stent Deployment Mechanics Using a High-Resolution X-ray Imaging Detector  

UK PubMed Central (United Kingdom)

To treat or prevent some of the 795,000 annual strokes in the U.S., self-expanding endo-vascular stents deployed under fluoroscopic image guidance are often used. Neuro-interventionalists need...Full Text Available

2011-03-01

413

Single exposure energy subtraction chest radiography in the diagnosis of pulmonary cancer  

Energy Technology Data Exchange (ETDEWEB)

A single exposure energy subtraction technique with a metal filter and an imaging plate for the Fuji Computed Radiography (FCR) system was developed for dual-energy subtraction radiography (DES) of the chest. By the use of this technique, 206 patients with suspected lung cancer were scanned in the clinical settings. The subtracted images in 200 patients, excluding six with poor image quality, were examined. Soft-tissue images (bone cancelled images) were useful in visualizing abnormality of the airway and nodules lying under the ribs; and bone images (soft-tissue cancelled images) in detecting rib metastases and the presence or absence of calcification in nodules. Additional information was acquired in 21 % (42/200). A single exposure is capable of neglecting motion artifacts. In addition, this technique may be of value in DES, which is ...

1987-03-01

414

Single exposure energy subtraction chest radiography in the diagnosis of pulmonary cancer  

International Nuclear Information System (INIS)

A single exposure energy subtraction technique with a metal filter and an imaging plate for the Fuji Computed Radiography (FCR) system was developed for dual-energy subtraction radiography (DES) of the chest. By the use of this technique, 206 patients with suspected lung cancer were scanned in the clinical settings. The subtracted images in 200 patients, excluding six with poor image quality, were examined. Soft-tissue images (bone cancelled images) were useful in visualizing abnormality of the airway and nodules lying under the ribs; and bone images (soft-tissue cancelled images) in detecting rib metastases and the presence or absence of calcification in nodules. Additional information was acquired in 21 % (42/200). A single exposure is capable of neglecting motion artifacts. In addition, this technique may be of value in DES, which is ...

1987-01-01

415

Simple device for scanning image  

CERN Document Server

The simple device for scanning image is described. It has much in common with usual TV camera, with an electron beam replaced by an optical one. After the general description of the device, we present a simple experimental illustration.

2002-01-01

416

Signal and imaging sciences workshop proceedings  

Energy Technology Data Exchange (ETDEWEB)

Papers are presented in the areas of: Medical Technologies; Non-Destructive Evaluation; Applications of Signal/Image Processing; Laser Guide Star and Adaptive Optics; Computational Electromagnetic, Acoustics and Optics; Micro-Impulse Radar Processing; Optical Applications; TANGO Space Shuttle.

1997-11-01

417

SEGMENTING CT PROSTATE IMAGES USING POPULATION AND PATIENT-SPECIFIC STATISTICS FOR RADIOTHERAPY  

UK PubMed Central (United Kingdom)

This paper presents a new deformable model using both population and patient-specific statistics to segment the prostate from CT images. There are two novelties in the proposed method. First,...Full Text Available

2009-08-07

418

Romantic and Sexual Relationships, Body Image, and Fertility in Adolescent and Young Adult Testicular Cancer Survivors: A Review of the Literature  

UK PubMed Central (United Kingdom)

This review presents a summary of existing knowledge regarding the impact of testicular cancer along four broad domains, including romantic and sexual relationships, body image, and fertility....Full Text Available

2010-08-01

419

Retinal Fundus Image Registration via Vascular Structure Graph Matching  

UK PubMed Central (United Kingdom)

Motivated by the observation that a retinal fundus image may contain some unique geometric structures within its vascular trees which can be utilized for feature matching, in this paper, we proposed...Full Text Available

2010-01-01

420

Real-Time Assessment of Cardiac Perfusion, Coronary Angiography, and Acute Intravascular Thrombi Using Dual-Channel Near-Infrared Fluorescence Imaging  

UK PubMed Central (United Kingdom)

ObjectivesWe have developed an image-guided surgery system based on invisible near-infrared (NIR) fluorescent light. Presently, the only clinically-available NIR...Full Text Available

2009-07-01

421

Radio frequency noise from an MLC: a feasibility study of the use of an MLC for linac-MR systems  

UK PubMed Central (United Kingdom)

Currently several groups are actively researching the integration of a megavoltage teletherapy unit with magnetic resonance (MR) imaging for real-time image-guided radiotherapy. The use of a...Full Text Available

2010-02-21

422

On the sensitivity of IMRT dose optimization to the mathematical form of a biological imaging-based prescription function  

UK PubMed Central (United Kingdom)

Voxel-based prescriptions of deliberately non-uniform dose distributions based on molecular imaging, so-called dose painting or theragnostic radiation therapy, require specification of a transformation...Full Text Available

2009-03-21

423

Noise Characterization of Polycrystalline Silicon Thin Film Transistors for X-ray Imagers Based on Active Pixel Architectures  

UK PubMed Central (United Kingdom)

An examination of the noise of polycrystalline silicon thin film transistors, in the context of flat panel x-ray imager development, is reported. The study was conducted in the spirit of exploring...Full Text Available

2008-01-01

424

New real-time MR image-guided surgical robotic system for minimally invasive precision surgery  

Energy Technology Data Exchange (ETDEWEB)

To investigate the usefulness of a newly developed magnetic resonance (MR) image-guided surgical robotic system for minimally invasive laparoscopic surgery. The system consists of MR image guidance [interactive scan control (ISC) imaging, three-dimensional (3-D) navigation, and preoperative planning], an MR-compatible operating table, and an MR-compatible master-slave surgical manipulator that can enter the MR gantry. Using this system, we performed in vivo experiments with MR image-guided laparoscopic puncture on three pigs. We used a mimic tumor made of agarose gel and with a diameter of approximately 2 cm. All procedures were successfully performed. The operator only advanced the probe along the guidance device of the manipulator, which was adjusted on the basis of the preoperative plan, and punctured the target while maintaining the operative field using robotic forceps. The position of the probe ...

2008-04-15

425

Multiscale registration of planning CT and daily cone beam CT images for adaptive radiation therapy  

UK PubMed Central (United Kingdom)

Adaptive radiation therapy (ART) is the incorporation of daily images in the radiotherapy treatment process so that the treatment plan can be evaluated and modified to maximize the amount of radiation...Full Text Available

2009-01-01

426

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

427

Monitoring of NK-Cell Immunotherapy using non-invasive Imaging Modalities  

UK PubMed Central (United Kingdom)

Cancer immunotherapies can be guided by cellular imaging techniques, which can identify the presence or absence of immune-cell accumulation in the tumor tissue in-vivo and in real time. This...Full Text Available

2010-08-01

428

Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare...Full Text Available

1997-03-01

429

JAtlasView: a Java atlas-viewer for browsing biomedical 3D images and atlases  

UK PubMed Central (United Kingdom)

BackgroundMany three-dimensional (3D) images are routinely collected in biomedical research and a number of digital atlases with associated anatomical and other information have...Full Text Available

430

In vivo imaging of neutrotransmitter functions in brain, heart and tumors  

Energy Technology Data Exchange (ETDEWEB)

This volume contains the proceedings of a symposium entitled In Vivo Imaging of Neurotransmitter Function in Brain, Heart, and Tumors'' held August 24--25, 1990 in Montreal Canada. The six individual papers contained herein are separately abstracted and indexed for the database.

1991-01-01

431

Human Lymphatic Architecture and Dynamic Transport Imaged Using Near-infrared Fluorescence12  

UK PubMed Central (United Kingdom)

BACKGROUND: Although the importance of lymphatic function is well recognized, the lack of real-time imaging modalities limits our understanding of its role in many diseases. In a phase...Full Text Available

432

High Contrast Near-infrared Polarized Reflectance Images of Demineralization on Tooth Buccal and Occlusal Surfaces at ?=1310-nm  

UK PubMed Central (United Kingdom)

Background and Objectives:Sound enamel manifests peak transparency in the near-IR (NIR) at 1310-nm, therefore the near-IR is ideally suited for high contrast imaging...Full Text Available

2009-03-01

433

Exploration of exposure dose optimization for pelvic examination in direct digital radiography with a phantom  

International Nuclear Information System (INIS)

Objective: To investigate the relationship between exposure dose and image quality for a direct digital radiography system and to determine the optimum exposure parameters for pelvic examination. Methods: A contrast-detail phantom CDRAD2.0 was exposed to different doses and the IQF of phantom images were calculated. The optimum exposure parameters were determined by ANOVA and SNK analysis. The image of an anthropomorphic phantom taken with optimized exposure parameters was verified using CEC image criteria. Results: The IQF of the images of CDRAD2.0 phantom was significantly different for different doses, as the exposure dose was greater than 0.61 mGy. The IQFs have no difference for different dose groups. The image quality between this optimized exposure dose and conventional exposure dose not was significantly different. Conclusion: The ...

2005-10-01

434

Evaluation of Tumor Micro-Environment in an Animal Model using a Nanoparticle Contrast Agent in Computed Tomography Imaging  

UK PubMed Central (United Kingdom)

RATIONALE AND OBJECTIVESNon-invasive longitudinal imaging of tumor vasculature could provide new insights into the development of solid tumors, facilitating efficient...Full Text Available

2011-01-01

435

Early detection of bone metastases of Ewing's sarcoma by magnetic resonance imaging  

International Nuclear Information System (INIS)

Bone metastases of an Ewing's sarcoma were detected by magnetic resonance imaging (MRI), when bone scan, CT and plain films were still normal. This is due to the ability of MRI to detect intramedullary metastases before involvement of the cortex. (Auth.).

436

Early Detection of Bronchial Lesions Using Lung Imaging Fluorescence Endoscope  

UK PubMed Central (United Kingdom)

The performance of the Lung Imaging Fluorescence Endoscope (LIFE) system was compared with conventional bronchoscopy in 158 patients: 68 patients with invasive cancer, 42 patients with abnormal sputum...Full Text Available

1999-01-01

437

Dual-channel imaging system for singlet oxygen and photosensitizer for PDT  

UK PubMed Central (United Kingdom)

A two-channel optical system has been developed to provide spatially resolved simultaneous imaging of singlet molecular oxygen (1O2) phosphorescence and photosensitizer (PS) fluorescence...Full Text Available

438

Doppler imaging using spectrally-encoded endoscopy  

UK PubMed Central (United Kingdom)

The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique...Full Text Available

2008-09-15

439

Digital image precessing for neutron television fluoroscopic system and its application to neutron computed tomography  

Energy Technology Data Exchange (ETDEWEB)

The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the ...

1984-09-01

440

Digital image precessing for neutron television fluoroscopic system and its application to neutron computed tomography  

International Nuclear Information System (INIS)

The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the ...

1984-01-01

441

Design and Implementation of an Open Source Indexing Solution for a Large Set of Radiological Reports and Images  

UK PubMed Central (United Kingdom)

This paper hopes to share the insights we experienced during designing, building, and running an indexing solution for a large set of radiological reports and images in a production environment for...Full Text Available

2007-11-01

442

Correspondence of Ultrasound Elasticity Imaging to Direct Mechanical Measurement in Aging DVT in Rats  

UK PubMed Central (United Kingdom)

Previous ultrasound elasticity imaging experiments supported a generally accepted concept that the hardness of deep venous thrombi increases with thrombus aging. Results also showed that this...Full Text Available

2005-10-01

443

Characteristics of common solid liver lesions and recommendations for diagnostic workup  

UK PubMed Central (United Kingdom)

Due to the widespread clinical use of imaging modalities such as ultrasonography, computed tomography and magnetic resonance imaging (MRI), previously unsuspected liver masses are increasingly being...Full Text Available

2009-07-14

444

Challenges of functional imaging research of pain in children  

UK PubMed Central (United Kingdom)

Functional imaging has revolutionized the neurosciences. In the pain field it has dramatically altered our understanding of how the brain undergoes significant functional, anatomical and chemical changes...Full Text Available

445

Automated 3-D method for the correction of axial artifacts in spectral-domain optical coherence tomography images  

UK PubMed Central (United Kingdom)

The 3-D spectral-domain optical coherence tomography (SD-OCT) images of the retina often do not reflect the true shape of the retina and are distorted differently along the x and y...Full Text Available

446

Antisense imaging of gene expression in the brain in vivo  

UK PubMed Central (United Kingdom)

Antisense radiopharmaceuticals could be used to image gene expression in the brain in vivo, should these polar molecules be made transportable through the blood–brain barrier....Full Text Available

2000-12-19

447

A high-speed network for cardiac image review.  

UK PubMed Central (United Kingdom)

A high-speed fiber-based network for the transmission and display of digitized full-motion cardiac images has been developed. Based on Asynchronous Transfer Mode (ATM), the network is scaleable, meaning...Full Text Available

1994-01-01

448

A comparison with result of normalized image to different template image on statistical parametric mapping of ADHD children patients  

Energy Technology Data Exchange (ETDEWEB)

We studied 64 ADHD children patients group (4 {approx} 15 ys, mean age: 8 {+-} 2.6 ys. M/F: 52/12) and 12 normal group (6 {approx} 7 ys, mean age: 9.4 {+-} 3.4 ys, M/F: 8/4) of the brain had been used to analysis of blood flow between normal and ADHD group. For analysis of Children ADHD, we used 12 children's mean brain images and made Template image of SPM99 program. In crease of blood flow (P-value 0.05), the result of normalized images to Template image to offer from SPM99 program, showed significant cluster in inter-Hemispheric and occipital Lobe, in the case of normalized images to children template image, showed inter-hemispheric and parietal lobe.

2003-06-15

449

A Software System for Data Analysis in Automated DNA?Sequencing  

UK PubMed Central (United Kingdom)

Software for gel image analysis and base-calling in fluorescence-based sequencing consisting of two primary programs, BaseFinder and GelImager, is described. BaseFinder is a framework for trace processing,...Full Text Available

1998-06-01

450

A Comparison of intra-oral digital imaging modalities: Charged Couple Device versus Storage Phosphor Plate  

UK PubMed Central (United Kingdom)

BackgroundThis in vitro study was conducted to compare the accuracy of two digital image receptors in identifying the location of tip of a fine endodontic file and radiographic apex...Full Text Available

2010-11-01

451

Understanding and predicting soot generation in turbulent non-premixed jet flames.  

Energy Technology Data Exchange (ETDEWEB)

This report documents the results of a project funded by DoD's Strategic Environmental Research and Development Program (SERDP) on the science behind development of predictive models for soot emission from gas turbine engines. Measurements of soot formation were performed in laminar flat premixed flames and turbulent non-premixed jet flames at 1 atm pressure and in turbulent liquid spray flames under representative conditions for takeoff in a gas turbine engine. The laminar flames and open jet flames used both ethylene and a prevaporized JP-8 surrogate fuel composed of n-dodecane and m-xylene. The pressurized turbulent jet flame measurements used the JP-8 surrogate fuel and compared its combustion and sooting characteristics to a world-average JP-8 fuel sample. The pressurized jet flame measurements demonstrated that the surrogate was representative of JP-8, with a somewhat higher tendency to soot formation. The premixed flame measurements revealed that flame temperature has a ...

2010-10-01

452

Time-varying magnetic fields increase cytosolic free Ca sup 2+ in HL-60 cells  

Energy Technology Data Exchange (ETDEWEB)

Electromagnetic fields have been reported to cause a variety of biological effects. It has been hypothesized that many of these phenomena are mediated by a primary effect on the concentration of cytosolic free calcium ((Ca2+)i). We investigated the effects of exposure to electromagnetic fields on (Ca2+)i in HL-60 cells using the Ca2(+)-sensitive fluorescent indicator indo-1. Indo-1-loaded cell samples were exposed to a radiofrequency electromagnetic field, a static magnetic field, and a time-varying magnetic field, which were generated by a magnetic resonance imaging (MRI) unit. We found that a 23-min exposure to all three fields, in combination, induced a significant increase in (Ca2+)i of 31 +/- 8 (SE) nM (P less than 0.01, n = 13) from a basal level of 121 +/- 8 nM. Also, cells exposed to only the time-varying magnetic field had a mean (Ca2+)i that was 34 +/- 10 nM (P less than 0.01, n = 11) higher than parallel control samples. Separate ...

1990-10-01

453

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

454

Gas-liquid flows in a microscale fractal-like branching flow network  

Energy Technology Data Exchange (ETDEWEB)

Two-phase air-water flows in a microscale fractal-like flow network were experimentally studied and results were compared to predictions from existing macroscale void fraction correlations and flow regime maps. Void fraction was assessed using (1) two-dimensional analysis of high-speed images (direct method) and (2) experimentally determined using gas velocities (indirect method). Fixed downstream-to-upstream length and width ratios of 1.4 and 0.71, respectively, characterize the five-level flow network. Channels were fabricated in a 38 mm diameter silicon disk, 250 {mu}m deep disk with a terminal channel width of 100 {mu}m. A Pyrex top allowed for flow visualization. Superficial air and water velocities through the various branch levels were varied from 0.007 m/s to 1.8 m/s and from 0.05 m/s to 0.42 m/s, respectively. Two-phase flow regime maps were generated for each level of the flow network and are well predicted by the Taitel and Dukler ...

2009-10-15

455

Gas-liquid flows in a microscale fractal-like branching flow network  

International Nuclear Information System (INIS)

Two-phase air-water flows in a microscale fractal-like flow network were experimentally studied and results were compared to predictions from existing macroscale void fraction correlations and flow regime maps. Void fraction was assessed using (1) two-dimensional analysis of high-speed images (direct method) and (2) experimentally determined using gas velocities (indirect method). Fixed downstream-to-upstream length and width ratios of 1.4 and 0.71, respectively, characterize the five-level flow network. Channels were fabricated in a 38 mm diameter silicon disk, 250 ?m deep disk with a terminal channel width of 100 ?m. A Pyrex top allowed for flow visualization. Superficial air and water velocities through the various branch levels were varied from 0.007 m/s to 1.8 m/s and from 0.05 m/s to 0.42 m/s, respectively. Two-phase flow regime maps were generated for each level of the flow network and are well predicted by the Taitel and Dukler model. ...

2009-10-01

456

Fundamental studies of coal liquefaction  

Energy Technology Data Exchange (ETDEWEB)

The authors have examined the pyrolysis of Argonne samples of Wyodak and Illinois No. 6 coal in argon, undecane, Tetralin, and water. The effects of the pyrolysis on individual particles of coal were monitored visually in a cell with diamond windows capable of operation to temperature and pressures in excess of 500{degrees}C and 3000 psi. The changes in the particles from ambient to 460{degrees}C were recorded in real time on video tape, and images were then taken from the tape record and analyzed. The study showed that in argon both coals developed tars at 350{degrees}-370{degrees}C. The tars then quickly evaporated, leaving core particles remarkably similar in size and shape to the initial particles. These observations suggest that coal does not melt nor become fully liquid when heated. Nor does the softened coal undergo crosslinking to generate coke. Rather the simple loss of volatiles leaves behind the core residue as coke. Contrary to the ...

1995-01-01

457

Efficient, intelligent systems for navigating the biological literature. Final report, September 15, 1993--September 14, 1996  

Energy Technology Data Exchange (ETDEWEB)

The biological literature is huge and increasingly moving to electronic form. By developing a variety of new techniques, it should be possible to take advantage of this huge and growing electronic store. Computers should allow one to use the literature with greater efficiency and insight to disseminate information and to advance scientific understanding. Though there is a great deal of research and development effort focused on electronic text, e.g., the Digital Libraries initiative, little attention has been paid to the diagrammatic content of documents. However, it is common knowledge among biologists, and scientists in general, that the figures in documents are of critical importance. Little work has been done to develop principles and systems for analyzing, representing, and indexing and searching the diagrammatic content of electronic documents. This has been the main thrust of this research project. The primary work in the world on the analysis of graphics in documents has been ...

1997-04-04

458

Cloning of Drosophila transcription factor Adf-1 reveals homology to Myb oncoproteins.  

Science.gov (United States)

The Drosophila sequence-specific DNA binding protein, Adf-1, is capable of activating transcription of the alcohol dehydrogenase gene, Adh, and is implicated in the transcriptional control of other developmentally regulated genes. We have cloned the cDNA encoding Adf-1 by generating specific DNA probes deduced from partial amino acid sequence of the protein. Several cDNA clones encoding an extended open reading frame were isolated from a phage lambda library. The complete amino acid sequence of Adf-1 deduced from the longest cDNA reveals structural similarities to the putative helix-turn-helix DNA binding motif of Myb and Myb-related proteins. DNA sequence analysis of genomic clones and Northern blot analysis of mRNA suggest that Adf-1 is a single-copy gene encoding a 1.9-kb transcript. Purified recombinant Adf-1 expressed in Escherichia coli binds specifically to Adf-1 recognition sites and activates transcription of a synthetic Adh promoter in vitro in a manner ...

1992-01-15

459

Characterization of a time-of-flight mass spectrometer and its applications in the study of solid surfaces; Charakterisierung eines Flugzeitmassenspektrometers und seine Anwendungen in der Festkoerperoberflaechenuntersuchung  

Energy Technology Data Exchange (ETDEWEB)

The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the ...

2006-12-21

460

DoseWatchers - A computer based X ray dose monitoring project in paediatric radiology  

International Nuclear Information System (INIS)

Full text: Introduction. Children, especially premature infants and neonates, are at a much higher risk to obtain an X ray induced disturbance of life - particularly cancer. On the one hand this is due to their longer life expectancy and on the other hand it is due to their higher cell proliferation rate. The paediatric radiology unit of the Inselspital Bern recently installed some of the most advanced X ray equipment nowadays available. It is based on the two latest digital technologies: double read computed radiography (CR) and direct digital radiography (DR). Only the implementation of these digital radiography systems permits the digital acquisition and additionally the analysis of acquired data. The systematic analysis of large amounts of biometric data and exposition data is the basis for further dose reduction and a systematic quality control (QC). Patients are increasingly critical concerning radiation exposure - especially parents regarding their children. Besides an ...

2006-11-13

461

metadata, images and captions. - The Gateway to Astronaut ...  

Science.gov (United States)

... the Zaire is not an efficient transportation link because of many rapids and falls to negotiate between Kinshasa and the port city of Matadi. ...

462

Visible Earth: Food Additives  

Science.gov (United States)

Feb 25, 2008 ... NASA's Visible Earth catalog of NASA images and animations of our home planet.

463

Using Acoustic Tomography to Monitor Deep Ocean Currents ...  

Science.gov (United States)

... 2009. Copyright belongs to the Marine Technology Society., The original document contains color images. 14. ABSTRACT ...

2010-06-01

464

Tolerance limits of X-ray image intensity  

International Nuclear Information System (INIS)

Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author).

465

Three-dimensional image display of brain tumor utilizing a modified voxel method  

Energy Technology Data Exchange (ETDEWEB)

The patch and voxel methods are representative examples of the ways in which multi-slice images may be displayed three-dimensionally by means of computer-graphics. Each of them have advantages and disadvantages and they are mutually complementary. We have developed algorithms for a modified voxel method which incorporates the advantages of the patch methods. We have applied this to the three-dimensional image display of brain tumor with excellent results. The three-dimensional reconstructions used for clinical application in this study were derived from X-ray CT images.

1988-08-01

468

Stereotactic Radiation Therapy for Brain Tumors  

Medline Plus

... acquired, which we then volumetrically fuse with the 3D image set from the MR. And by doing ...

470

Radioiodine benzodiazepines as brain imaging agents  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a radioiodinated benzodiazepine derivative. It comprises a lower alkyl group with 1-4 C-atoms and a radioactive iodine.

1992-03-17

471

Radioiodine benzodiazepines as brain imaging agents  

International Nuclear Information System (INIS)

This patent describes a radioiodinated benzodiazepine derivative. It comprises a lower alkyl group with 1-4 C-atoms and a radioactive iodine.

1990-06-25

472

RAPID DAMAGE ASSESSMENT FROM HIGH RESOLUTION IMAGERY  

Energy Technology Data Exchange (ETDEWEB)

Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.

2008-07-01

473

Prospects for lithium imaging using annular bright field scanning transmission electron microscopy: A theoretical study  

British Library Electronic Table of Contents (United Kingdom)

There is strong interest in lithium imaging, particularly because of its significance in battery materials. However, light atoms only scatter electrons weakly and atomic resolution direct imaging of lithium has proven difficult. This paper explores theoretically the conditions under which lithium columns can be expected to be directly visible using annular bright field scanning transmission electron microscopy. A detailed discussion is given of the controllable parameters and the conditions most favourable for lithium imaging.

2011-01-01

476

Phase imaging using laser-produced X-ray sources  

International Nuclear Information System (INIS)

A possible novel application of hard x-ray emitted during laser-plasma interaction was discussed. The authors established an Optical Transform Function to study the joint effect of the spectral distribution and temporal profile of the laser-produced x-ray on x-ray phase imaging. Though the laser-produced x-ray pulse duration is short and incoherent, the analysis confirms that the current x-ray phase imaging theory still holds for laser-produced x-ray phase imaging

2000-08-01

477

Particle-Sizing System for Scanning Electron Microscope ...  

Science.gov (United States)

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

1991-03-01

478

Non-traumatic thoracic emergencies: imaging and treatment of thoracic fluid collections (including pneumothorax)  

International Nuclear Information System (INIS)

Cross-sectional imaging has revolutionised the radiological diagnosis of pleural collections. Not only can the precise location and volume of a pleural effusion be established, but also features specific for the aetiology of the effusion can be demonstrated. Increasingly, radiologists are called upon to perform image-guided biopsies, aspirations and small bore chest drain placement, all of which have been shown to be safe and efficacious. Pneumothoraces occurring due to acute trauma and in an intensive care setting can also benefit from radiological input, both in terms of diagnosis and image-guided treatment. (orig.)

2002-08-01

479

Monitoring the movement of water influx subsidence in coal district by remote sensing - examples from Huainan coal district  

Energy Technology Data Exchange (ETDEWEB)

Multitemporal TM images are used to collect information about the extension and variation of water influx subsidence in coal district in order to provide a reference for the harnessing and utilization of water influx subsidence. The multitemporal TM images are used as a blended data group for the analysis of the principal components to reflect the expanding water influx subsidence in the past years. Because of the differences in the environment and imaging condition, 'unitary' order is used to enhance the 'coherence' and 'comparability' of the original TM images. 5 refs., 4 figs., 2 tabs.

2002-08-01

480

MER-DIMES : a planetary landing application of computer vision  

Science.gov (United States)

During the Mars Exploration Rovers (MER) landings, the Descent Image Motion Estimation System

2005-01-01

483

Incidental discovery of asplenia syndrome, with situs inversus and a normal heart by radionuclide biliary imaging. A case report  

International Nuclear Information System (INIS)

/sup 99m/Tc biliary imaging was performed on a 34-year-old woman who was being investigated for suspected cholelithiasis. A left-sided liver was detected. On subsequent radionuclide imaging, partial visceral situs inversus and asplenia were demonstrated. Extensive roentgenographic investigation, ECG, echocardiogram, and laparotomy confirmed the radionuclide findings. Asplenia syndrome may exist without cardiovascular abnormalities and thus be undiscovered. Radionuclide imaging is important in the diagnosis of this syndrome.

484

Imaging characterization of carbon nanotube tips modified using a focused ion beam  

International Nuclear Information System (INIS)

A carbon nanotube (CNT) tip, which assembled on the sharp end of a Si tip by dielectrophoresis, was structurally modified using focused ion beam (FIB). We described the imaging characterization of the FIB-modified CNT tip in noncontact AFM mode in terms of wear, deep trench accessibility, and imaging resolution. Compared to a conventional Si tip, the FIB-modified CNT tip was superior, especially for prolonged scanning over 10 h. We conclude that modified CNT tips have the potential to obtain high-quality images of nanoscale structures.

2007-06-15

485

Image Descriptors for Displays  

Science.gov (United States)

... 44 2. Luminance Power Spectral Density Measurements ..... 44 ... 50 4. Chrominance Power Spectral Density Measurements ..... 53 ...

1977-02-01

486

Iao: The New Adaptive Optics Visible Imaging and ...  

Science.gov (United States)

... is the sensor that converts incoming photons into a ... with CCD foundries to acquire such a sensor. ... 2007, Journal of Spacecraft and Rockets, 44, 910 ...

2008-09-01

487

Growth, Characterization and Device Development in ...  

Science.gov (United States)

... eV. In some instances the spontaneous radiation from a free electron laser system was employed to obtain images. The ...

1998-03-01

489

Development of high resolution imaging detectors for X-ray astronomy  

Energy Technology Data Exchange (ETDEWEB)

High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.

1985-03-01

490

Development of high resolution imaging detectors for X-ray astronomy  

International Nuclear Information System (INIS)

High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.

1985-01-01

491

Development of ARIES Baker-Nunn camera to a wide-field Imaging Telescope with CCD  

CERN Document Server

ARIES Baker-Nunn Schmidt telescope project is converting a Baker-Nunn satellite tracking camera for Astronomical research. Original Baker-Nunn camera produces an extremely large (5X30 degree) curved focal plane at the prime focus for photographic imaging. We present here the re-designing of the camera produces a wide (4 X 4 degree) flat field of view for CCD imaging observations, which have many scientific potentials in Astronomy. Imaging performance of the CCD camera is also estimated.

2009-01-01

492

Detection and Diagnosis of Oral Neoplasia with an Optical ...  

Science.gov (United States)

... Thus, 0CM provides the potential to image epithelial tissue with the subcellular resolution needed to assess the pathologic state of tissue. ...

493

DVRPC 2010 Digital Orthoimagery - Mr.SID County Mosaics  

Science.gov (United States)

... image overlap between adjacent tiles. Orthoimagery processed by BAE Systems....

494

Computer vision approaches to medical image analysis. Revised papers  

Energy Technology Data Exchange (ETDEWEB)

This book constitutes the thoroughly refereed post proceedings of the international workshop Computer Vision Approaches to Medical Image Analysis, CVAMIA 2006, held in Graz, Austria in May 2006 as a satellite event of the 9th European Conference on Computer Vision, EECV 2006. The 10 revised full papers and 11 revised poster papers presented together with 1 invited talk were carefully reviewed and selected from 38 submissions. The papers are organized in topical sections on clinical applications, image registration, image segmentation and analysis, and the poster session. (orig.)

2006-07-01

495

Cerebral angiography using Fuji computed radiography (FCR) system  

International Nuclear Information System (INIS)

Eighty-seven subtraction images of FCR were compared with subtraction images of conventional angiography. Although FCR images with reduced exposure dose (25 % of regular dose) and with diluted contrast material (150 mgI/ml, 50 % of usual concentration) were slightly inferior to the images of conventional angiography, most clinically important vessels were adequately visualized. As FCR has wider dynamic range and higher contrast resolution than conventional angiography, FCR may take over conventional angiography. (author).

1985-01-01

496

Burned Timber Canyon  

Science.gov (United States)

The Digital Raster Graphic (DRG) is a raster image of a scanned USGS topographic map including the collar information, georeferenced to the UTM grid....

498

A Computer Vision System forAnalyzing Images of Rough Hardwood Lumber  

Science.gov (United States)

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