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J-STORE (Japan)

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British Library Electronic Table of Contents (United Kingdom)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...

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No abstract prepared.

KoreaScience (Korea)

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J-STORE (Japan)

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors ...

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.

UK PubMed Central (United Kingdom)

ObjectiveUsing high resolution cardiovascular magnetic resonance (CMR), we aimed to detect new details of left ventricular (LV) systolic and diastolic function, to explain the twisting...Full Text Available

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.).

International Nuclear Information System (INIS)

... electron reactions electrons excitation inelastic scattering m1-transitions proton

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.

Energy Technology Data Exchange (ETDEWEB)

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

The introduction of positron emission tomography (PET)/magnetic resonance (MR) systems into medical practice in the foreseeable future may not only lead to a gain in clinical diagnosis compared to PET/computed tomography (CT) imaging due to the superior soft-tissue contrast of the MR technology but can also substantially reduce exposure of patients to ionizing radiation. On the other hand, there are also risks and health effects associated with the use of diagnostic MR devices that have to be considered carefully. This review article summarizes biophysical and biological aspects, which are of relevance for the assessment of health effects related to the exposure of patients to both ionizing radiation in PET and magnetic and electromagnetic fields in MR. On this basis, some considerations concerning the justification and optimization of PET/MR examinations are presented - as far as this is possible at ...

Energy Technology Data Exchange (ETDEWEB)

Electron paramagnetic resonance was used to investigate surface-coated magnetite-based magnetic fluids doped with TEMPOL. Two magnetic fluid samples, having magnetite nanoparticles with average diameter of 94 A and coated with different coating layers (lauric acid plus ethoxylated polyalcohol in one case and oleoylsarcosine in the other case), were doped with TEMPOL (6 mM and pH 7.4) and investigated as a function of the nanoparticle concentration. The resonance field and the resonance linewidth both scale linearly with the nanoparticle concentration.

International Nuclear Information System (INIS)

In order to examine the state of technology of all areas of magnetic suspension and to review related recent developments in sensors and controls approaches, superconducting magnet technology, and design/implementation practices, a symposium was held. The proceedings are presented. The sessions covered the areas of bearings, sensors and controls, microgravity and vibration isolation, superconductivity, manufacturing applications, wind tunnel magnetic suspension systems, magnetically levitated trains (MAGLEV), space applications, and large gap magnetic suspension systems.

Science.gov (United States)

magnet research at several national laboratories through its Advanced Accelerator Technology Program. The HEP Conductor Development Program, a collaboration among national...

International Nuclear Information System (INIS)

Several refrigerators for liquid helium and liquid nitrogen systems have been integrated successfully into IGC manufactured whole body Magnetic Resonance Imaging (MRI) magnet systems. The refrigerators have been tested in systems with magnetic fields of 0.6T to 1.5T. Tests were performed to study the effectiveness of the refrigerators, the magnetic field effects on the refrigerators, the effect of the refrigerators on the field uniformity and magnetic resonance image quality. The interface between the refrigerator and the whole body MRI magnet system cryostat was specifically designed to allow retrofit to the existing IGC magnet systems, while ensuring good heat transfer characteristics and good vibration isolation from the cryostat. The interface between the refrigerator and the cryostat and the ...

UK PubMed Central (United Kingdom)

Background/Objective:Tarlov cysts or spinal perineurial cysts are uncommon lesions. These are mostly incidental findings on magnetic resonance imaging or myelograms. The...Full Text Available

International Nuclear Information System (INIS)

English 2009 p. 41-42 Brazil Preto, Monica Santos de Moura Tavares,

Energy Technology Data Exchange (ETDEWEB)

MRI is a powerful diagnostic modality of expanding availability. Equipment and installation amount to nearly $2M per site. An important component of diagnostic efficacy is not just equipment costs but also replacement costs, which for x-ray CT amount to 14-20% of the purchase cost per year; and in the early years of that technology reached 30-50%. The authors show how design choices made during the RandD stages of MRI development have allowed them to improve system performance parameters such as data reconstruction, archiving and display speeds, computational capabilities, operator interfaces, imaging sequence flexibility and signal-to-noise levels. Over the last four years these improvements have been made at a retrofit cost well below the target of 6-7% of the purchase price per year.

UK PubMed Central (United Kingdom)

BackgroundMagnetic Resonance Imaging scanners have become ubiquitous in hospitals and high-field systems (greater than 3 Tesla) are becoming increasingly common. In light of recent...Full Text Available

UK PubMed Central (United Kingdom)

Gadolinium (Gd) based contrast agents (GBCAs) in magnetic resonance imaging (MRI) are used in daily clinical practice and appear safe in most patients; however, nephrogenic systemic fibrosis...Full Text Available

International Nuclear Information System (INIS)

Nuclear magnetic resonance results are presented for a number of NaCl-type compounds and cubic Laves-phase type compounds of uranium, neptunium, and plutonium. Special emphasis is placed on the Knight shift and spin-lattice relaxation time measurements and their interpretation in terms of localized or itinerant pictures of the 5f electrons. (author).

UK PubMed Central (United Kingdom)

A pulsed field gradient spin echo sequence has been incorporated in a nuclear magnetic resonance (NMR) imaging experiment to provide an image contrast dependent on local molecular self-diffusion. The...Full Text Available

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.

Energy Technology Data Exchange (ETDEWEB)

The introduction of CT scan and, more recently, magnetic resonance imaging, has radically changed the diagnostic approach to tumors developed in the internal auditory canal and cerebellopontine angle. CT scan with intravenous injection visualizes tumors lying in the cerebellopontine angle. Magnetic resonance imaging, especially using gadolinium, is a very accurate means for diagnosing tumors of both the auditory canal and cerebellopontine angle.

Energy Technology Data Exchange (ETDEWEB)

The Advanced Photon Source injector synchrotron is a 7-GeV positron machine with a standard alternating gradient lattice. The calculated effect of dipole magnet strength errors on the orbit distortion, simulated by Monte Carlo, was reduced by sorting pairs of magnets having the closest simulated measured strengths to reduce the driving the term of the integer resonance nearest the operating point. This method resulted in a factor of four average reduction in the rms orbit distortion when all 68 magnets were sorted at once. The simulated effect of magnet measurement experimental resolution was found to limit the actual improvement. The {Beta}-beat factors were similarly reduced by sorting the quadrupole magnets according to their gradients.

Science.gov (United States)

The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence ins...

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

Energy Technology Data Exchange (ETDEWEB)

XVTa and XXTa nuclei were oriented at low temperature as dilute impurities in Fe. The magnetic hyperfine splitting frequencies = B sub(HF)/Ih of the XVTa and XXTa ground states have been measured to be 320.45(11) and 317.552(55) MHz by using the technique of NMR-ON. Taking the known hyperfine field of Y Ta in Fe, the magnetic moments have been deduced: ( XVTa, 7/2 ) =2.270(45) and ( XXTa, 7/2 ) =2.250(45) sub(N). These values of the magnetic moments are discussed in the framework of the rotational model.

UK PubMed Central (United Kingdom)

Hypercapnia is often used as vasodilatory challenge in clinical applications and basic research. In functional magnetic resonance imaging (fMRI), elevated CO₂ is applied to derive stimulus-induced...Full Text Available

UK PubMed Central (United Kingdom)

The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI)...Full Text Available

UK PubMed Central (United Kingdom)

High resolution structural elucidation of macromolecular structure by solid-state nuclear magnetic resonance requires the preparation of uniformly aligned samples that are isotopically labeled. In...Full Text Available

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

International Nuclear Information System (INIS)

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

UK PubMed Central (United Kingdom)

Arriving at a firm diagnosis of neurosarcoidosis continues to pose serious problems, particularly when evidence of granulomatous disease outside the nervous system is lacking. The commonest mode of...Full Text Available

UK PubMed Central (United Kingdom)

Accurate and automated methods for measuring the thickness of human cerebral cortex could provide powerful tools for diagnosing and studying a variety of neurodegenerative and psychiatric disorders....Full Text Available

UK PubMed Central (United Kingdom)

The percentages of total airflows over the nasal respiratory and olfactory epithelium of female rabbits were calculated from computational fluid dynamics (CFD) simulations of steady-state inhalation....Full Text Available

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Short communication

UK PubMed Central (United Kingdom)

In this study, we aimed to demonstrate whether spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal derived from resting state functional magnetic resonance imaging (fMRI) reflect...Full Text Available

UK PubMed Central (United Kingdom)

The purpose of this study was to investigate whether genetically determined properties of muscle metabolism contribute to the exceptional physical endurance of world-class distance runners. ATP, phosphocreatine,...Full Text Available

UK PubMed Central (United Kingdom)

In Diffusion Tensor Magnetic Resonance Image (DT-MRI) processing a 2^nd order tensor has been commonly used to approximate the diffusivity function at each lattice...Full Text Available

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

UK PubMed Central (United Kingdom)

The polymorphic phase behavior of a homologous series of n-saturated 1,2-diacyl phosphatidylethanolamines was investigated by differential scanning calorimetry, 31P-nuclear magnetic resonance, and Fourier...Full Text Available

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.

British Library Electronic Table of Contents (United Kingdom)

Abstract Neurodegenerative and neurometabolic disorders may cause significant morbidity and mortality in children. Imaging is important in early diagnosis of metabolic disorders and in determining the extent of brain injury. Especially after the development of new techniques such as diffusion-weighted magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), neuroimaging plays more important role in the diagnosis and management of these disorders. In these disorders, usually a mutation causes a clinically significant block in one or more metabolic pathways. This blockage usually results in either a deficiency of the product or in an accumulation of substrate with damage induced by either storage or toxicity. The presenting symptoms are usually nonspecific. In some of the ...

International Nuclear Information System (INIS)

In Nuclear Magnetic Resonance (NMR) imaging, contrast is dependent on the emission of radiofrequency waves by atomic nuclei, balanced by several parameters. The high information content of NMR images is due to the multiplicity of its parameters. However, this advantage introduces a difficulty in the interpretation of the contrast. There are three contrast parameters for each tissue: hydrogen nuclei density; relaxation time T1; relaxation time T2. Contrast may be enhanced towards any of these parameters by increasing the emission of radiowaves by atomic nuclei using particular pulse sequences.

Science.gov (United States)

During the period covered by this report research has been concerned with the study of photo-induced electron transfer reactions from porphyrins to acceptor molecules with time-resolved Electron Paramagnetic Resonance (EPR) methods. Excited-state electron transfer reactions are of importance from a fundamental point of view and in connection with applications in homogeneous and heterogeneous photosensitization, photopolymerization, and solar energy conversions. For this reason, the study of photo-induced electron transfer reactions is of considerable interest.

International Nuclear Information System (INIS)

Electron cyclotron resonance heating (ECH) in BPX is planned as a possible upgrade to supplement the baseline ion cyclotron resonance frequency (ICRF) system. Eventual implementation primarily depends on the development of the required source technology. ECH offers important technical advantages over ICRF: High radio-frequency (FR) power density can be transmitted through ports (P/A >#approx# 100 MW/M"2), and the antenna need not be in contact with the plasma for efficient coupling. In particular, low-field side, linearly polarized (O-mode) power injection will suffice. By controlling the N spectrum, or by steering the antenna, the power deposition profile can be controlled during ramping of the magnetic field even with a fixed frequency source. Because of the possibility of localized power deposition, ECH is a natural candidate for controlling magnetrohydrodynamic (MHD) activity. Sawtooth ...

International Nuclear Information System (INIS)

This paper discusses the possible detection of magnetic monopoles and monopole tachyons. Topics considered include insects, astrophysics, general relativity theory, plants, and biotechnology. The paper was presented at an international symposium on non-conventional energy technology.

International Nuclear Information System (INIS)

This introductory paper surveys potential sources of electric magnetic, and electro-magnetic fields. Various cases are discussed to exemplify the total frequency range: nuclear magnetic resonance tomography, high-voltage transmission lines, transformer stations, effect lighting balls, military transmitters, transmitter towers of the Postal Services and other operators, mobile radiotelephone equipment, large broadcasting transmitters, radar radiation, high-frequency heat therapy. There is evidence suggesting that electric, magnetic and electro-magnetic fields may possibly represent a certain nuisance or health hazard even at field strength occuring in equipment used for every-day-life purposes, with an emphasis on their possible actions and effects in children and adolescents. The author discusses, in conclusion, the aerial equipment ordinance issued by Lower ...

International Nuclear Information System (INIS)

This paper reports that only a few years ago superconducting magnetic separation was viewed as the next major market for superconducting magnets. The first commercial units had been installed, worked flawlessly, and demonstrated real economic viability. The potential market was seen as quite large, and many people believed that superconducting magnetic separation would soon show the same rapid growth that MRI had demonstrated after its initial success. These hopes even prompted IGC, one of the top MRI magnet builders, to form a separate division devoted to magnetic separation. Despite the existence of Magstream, IGC has not been overly active in the market. As a technology that has applications from the clay on the Earth to the soil on the moon, superconducting magnetic separation has yet to become widely used.

Energy Technology Data Exchange (ETDEWEB)

We propose a novel method for ultrasensitive isotope analysis that combines magnetic mass selection, resonant charge-exchange neutralization, and resonant laser ionizaion. Our method attains high isotopic abundance selectivity by means of continuous multistage separation of ions stored in a small ring. For the environmentally interesting case of /sup 90/Sr versus /sup 88/Sr we estimate that sensitivity better than 10/sup -15/ for a throughput of 10/sup 13/ atoms/sec and an efficiency (after the ion source) greater than 10% are readily achievable.

Science.gov (United States)

A systematic study of the Bragg nuclear resonant reflectivity from periodic multilayers in the energy and time domains is presented. Using the kinematical approach of the general reflectivity theory we describe the basic features of the time evolution of the reflected wave after a pulsed excitation of resonant multilayers by synchrotron radiation. Effects of the collective excitation have been examined such as the shift of quantum beat phases, the interplay between electronic and nuclear subsystem excitations depending on their relative position in a multilayer, the energy and time evolution of standing waves inside a resonant multilayer, and their influence on the reflectivity spectra. The exact expression for the reflectivity by a thin resonant layer placed inside a multilayer structure has been derived. The observed shift of the delayed reflectivity Bragg peak relative to the prompt peak is explained ...

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The results of the investigations show that magnetic treatment is a quite practical and effective method of intensifying certain technological processes in the coking industry. Magnetic treatment was utilized for improving the production of ammonium sulfate, refining of the naphthalene fraction, removal of sludge from wash oil in the benzol division, and the treatment of tar before fractionation. 2 references, 3 tables.

International Nuclear Information System (INIS)

Extraskeletal Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are widely regarded as clinically and histologically identical tumors which consist of small blue round cells. Extraskeletal ESs/PNETs usually occur in the deep soft tissues of the paraspinal region, chest wall, or lower extremities. However, superficially located cases, so-called cutaneous ESs/PNETs, are exceedingly rare, and the vast majority of the reported cases present as a single small mass. We present magnetic resonance imaging (MRI) findings and clinical course of a unique case of primary cutaneous ES/PNET presenting as numerous huge masses with severe ulceration on them. (orig.)

International Nuclear Information System (INIS)

Magnetic resonance imaging has proven an invaluable method in the diagnosis of joint diseases associated with osteonecrotic, inflammatory, traumatic and degenerative processes. At the clinical level, it has an important role in decisions about the method of treatment and evaluations of the therapeutic success. When the merits of MRT are balanced against those of conventional radiography including tomography and CT, which both ensure better spatial resolution in the visualisation of cortical and spongy bone structures, it becomes quite evident that MRT must not be regarded as an alternative method of imaging but as one that can be used additionally to obtain the most information for the diagnosis of arthropathy. The question as to whether new pulse sequences (snap shots) or invasive techniques like intra-articular injection of paramagnetic substances (MR arthrography) are likely to become routine procedures in the detection of joint diseases ...

International Nuclear Information System (INIS)

Fetal MRI examines non-invasively the unborn fetus. Ultrafast MRI sequences effectively suppress fetal motion. Multiple case reports and studies have shown that fetal MRI is particularly helpful in the evaluation of the central nervous system. The high contrast-to-noise ratio, the high spatial resolution, the multiplanar capabilities, the large field of view and the simultaneous visualisation of fetal and maternal structures have proven to be advantageous. Fetal MRI is particularly helpful in the evaluation of the normal and pathological development of the brain. Despite the fact that no side effects have been reported or are to be expected, the use of MRI during pregnancy is still limited to the second and third trimester of pregnancy. Magnetic resonance imaging contrast media are not to be used as it passes the placenta. Ultrasound remains the primary screening modality for fetal pathology; fetal MRI can serve as an adjunct or second-line ...

International Nuclear Information System (INIS)

Twenty-three patients with intracranial meningiomas were examined by means of magnetic resonance tomography (MRT). In 13 patients the paramagnetic contrast medium gadolinium DTPA was used. Meningiomas show only slight changes in signal intensity compared with brain in the spin-echo mode, the greatest contrast being found on photon density images (TR 1600 ms, TE 35 ms). In T1 images more than 50% of the patients showed a low signal margin between tumour and brain. Hyperostosis of the calvarium is easily recognised, but MRT is unreliable for showing tumour calcification. After intravenous injection of gadolinium DTPA, there was marked homogeneous uptake in the meningiomas. These signs are useful for the diagnosis of a meningioma by MRT. (orig.).

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

Assessment of the roles of the carboxyl-terminal #beta#146 histidyl residues in the alkaline Bohr effect in human and normal adult hemoglobin by high-resolution proton nuclear magnetic resonance spectroscopy requires assignment of the resonances corresponding to these residues. By a careful spectroscopic study of human normal adult hemoglobin, enzymatically prepared des(His146#beta#)-hemoglobin, and the mutant hemoglobins Cowtown (#beta#146His #-># Leu) and York (#beta#146His #-># Pro), the authors have resolved some of these conflicting results. By a close incremental variation of pH over a wide range in chloride-free 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid buffer, a single resonance has been found to be consistently missing in the proton nuclear magnetic resonance spectra of these hemoglobin variants. The results indicate that the ...

UK PubMed Central (United Kingdom)

Multiple memory systems are involved in parallel processing of spatial information during navigation. A series of studies have distinguished between hippocampus-dependent ‘spatial’ navigation,...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Cardiac tumours may display diverse symptoms through potential involvement of any structure of the heart. We describe a case of a highly malignant thymoma with involvement of different cardiac structures with important haemodynamic compromise. With the high sensitivity of transthoracic echocardiography for detection of intracardiac masses, computed tomography and magnetic resonance add essential structural preoperative information on the tumour and surrounding tissue as vessels, pleura, lung and mediastinum.

Energy Technology Data Exchange (ETDEWEB)

Positron emission tomography (PET) and magnetic resonance imaging (MRI) studies were performed on a case of neuro-Behcet's syndrome. In accordance with the clinical signs, FDG PET (using /sup 18/F-labeled 2-F-2'-desoxyglucose) revealed disseminated storage defects in the cerebrum and cerebellum. Focal regions of enhanced signal intensity were demonstrated in the parietal white matter of the cerebrum in T2-weighted images and in the brain stem by MRI. (orig.).

International Nuclear Information System (INIS)

We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.).

UK PubMed Central (United Kingdom)

To assess which specific morphologic features, enhancement patterns, or pharmacokinetic parameters on breast Magnetic Resonance Imaging (MRI) could predict a false-negative outcome of Proton...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The method of double microwave--radio-frequency resonance has been used to obtain spectra of the 2/sub 11/reverse arrow2/sub 12/ and 3/sub 21/reverse arrow3/sub 22/ transitions in HCOOD, DCOOH, and HCOOH molecules. The constants of the quadrupole bond of the deuterons have been determined, magnetic interactions being taken into acocunt. A comparison with results of previous studies is given.

International Nuclear Information System (INIS)

A review of the information on the electron and phonon spectra in the A-15 compounds and Chevrel phase superconductors obtained from nuclear magnetic resonance, heat capacity, and Moessbauer effect experiments is presented. Relationships of the Fermi energy electrons and the soft phonons to the strength of the electron-phonon interaction are discussed.

Energy Technology Data Exchange (ETDEWEB)

We have measured, by {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR), the percent deuteration, the tacticity and the purity of several polymers and one solvent used in the preparation of microcellular foams. The percent deuteration was measured for polystyrene, polyacrylonitrile and polyethylene. The tacticities of polystyrene and polyacrylonitrile were determined. The purity and degradation products of polyacrylonitrile and maleic anhydride were examined. This report documents the experimental procedures and results of these measurements.

CERN Document Server

Observations show the ubiquitous presence of propagating magnetohydrodynamic (MHD) kink waves in the solar atmosphere. Waves and flows are often observed simultaneously. Due to plasma inhomogeneity in the perpendicular direction to the magnetic field, kink waves are spatially damped by resonant absorption. The presence of flow may affect the wave spatial damping. Here, we investigate the effect of longitudinal background flow on the propagation and spatial damping of resonant kink waves in transversely nonuniform magnetic flux tubes. We combine approximate analytical theory with numerical investigation. The analytical theory uses the thin tube (TT) and thin boundary (TB) approximations to obtain expressions for the wavelength and the damping length. Numerically, we verify the previously obtained analytical expressions by means of the full solution of the resistive MHD eigenvalue problem beyond the TT ...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

High-intensity contact ultrasound (HICU) under MRI guidance may provide minimally invasive treatment of endocavitary digestive tumors in the esophagus, colon or rectum. In this study, a miniature receive-only coil was integrated into an endoscopic ultrasound applicator to offer high-resolution MRI guidance of thermotherapy. A cylindrical plastic support with an incorporated single element flat transducer (9.45 MHz, water cooling tip) was made and equipped with a rectangular RF loop coil surrounding the active element. The integrated coil provided significantly higher sensitivity than a four-element extracorporeal phased array coil, and the standard deviation of the MR thermometry (SDT) improved up to a factor of 7 at 10 mm depth in tissue. High-resolution morphological images (T1w-TFE and IR-T1w-TSE with a voxel size of 0.25 x 0.25 x 3 mm3) and accurate thermometry data (the PRFS method with a voxel size of 0.5 x 0.5 x 5 mm3, 2.2 s/image, 0.3 deg. C voxel-wise SDT) were acquired in an ...

Science.gov (United States)

Recent proposals have shown that a quantum degenerate gas of alkaline earth atoms can be used for a number of novel quantum computing and quantum simulation experiments. Strontium is a good candidate for such experiments because it can be controlled with high precision, as demonstrated in recent atomic clock experiments. Unfortunately, the small scattering length of strontium is not amenable to evaporative cooling techniques that are used to reach quantum degeneracy. Furthermore, increasing the scattering length of alkaline earths with a magnetic Feshbach resonance is not possible due to their spinless electronic ground state configuration. However, recent theoretical and experimental work suggests the possibility of changing scattering lengths in alkaline earths with laser light. Using this optical Feshbach resonance near strontium's narrow ^1S0->^3P1 intercombination transition might allow its scattering length to be ...

Energy Technology Data Exchange (ETDEWEB)

RHIC 8 cm aperture dipole magnets and quadrupole cold masses are being built for Brookhaven National Laboratory (BNL) by Northrop Grumman Corporation at a production rate of one dipole magnet and two quadrupole cold masses per day. This work was preceded by a lengthy Technology Transfer effort which is described elsewhere. This paper describes the tooling which is being used for the construction effort, the production operations at each workstation, and also the use of trend plots of critical construction parameters as a tool for monitoring performance in production. A report on the improvements to production labor since the start of the programs is also provided. The magnet and cold mass designs, and magnetic test results are described in more detail in a separate paper.

International Nuclear Information System (INIS)

Structure and magnetic properties of UNi_1_0_-_xFe_xSi_2 intermetallics and "2"9Si nuclear magnetic resonance (NMR) in UNi_1_0Si_2 are investigated in a wide temperature range. Solid solutions in the exactly single-phase tetragonal form, ThMn_1_2 type, exist for x<2. The Ni and Fe atoms occupy the 8(f), 8(i) and 8(j) positions statistically, whereas the U atoms occupy the 2(a) and the Si atoms the 8(j) sites. The lattice parameters roughly follow Vegard's law. The magnetic susceptibility does not exhibit Curie-Weiss behaviour and, at about 630 K, an anomaly in the temperature dependence is observed. At low temperature, other anomalies are observed at 32 K and 45 K, for x=0.5 and 1.0 respectively. These low temperature anomalies are probably connected with magnetic ordering of a ferromagnetic character, whereas that at 630 K might result from the superparamagnetic state of Ni. Two ...

International Nuclear Information System (INIS)

Superconducting magnetic and inertial energy pulsed power systems are being developed for future theta-pinch, Tokamak, and laser fusion applications. The short term requirements for these applications are discussed along with present day accomplishments. Areas requiring a research and development effort are examined in detail. Subjects discussed include stresses, energy loss factors, conductor metallurgy, cryogenic requirements, and electrical limitations of superconducting magnetic storage systems; costs, applications, and present technology of homopolar systems; and switching problems associated with both systems.

International Nuclear Information System (INIS)

The authors compared unenhanced and contrast-enhanced fast MRI and Computerized Tomography in the detection of liver metastases. Eleven patients with single or multiple hepatic lesions (42 in all) were submitted to V and magnetic resonance studies; T1- and T2- weighted TSE, T2-weighted TSE with fat suppression, unenhanced breath-hold TFE and early or delayed enhanced breath-hold TFE images were acquired with a 1.5 T superconductive magnet (Philips NT). The quantitative analysis of all magnetic resonance images was performed for contrast/noise ratio (CNR) and number of detected lesions; magnetic resonance and Computerized Tomography images were also compared qualitatively for lesion conspicuity, anatomical structure identification and artifacts. The results were compared with Student's test. Early enhanced breath-hold TFE was statistically ...

Energy Technology Data Exchange (ETDEWEB)

The author briefly discusses definition of terms, gives an introduction to measurement techniques and describes the characteristics of various low-frequency fields and their causes using typical examples: natural electric fields (thunderstroms), natural magnetic fields, technical electric constant fields (urban transportation, households), static magnetic fields (urban transportation, nuclear magnetic resonance imaging), technical electric alternating fields (high-voltage transmission lines, households), and magnetic alternating fields (high-voltage transmission lines). The author discusses both occupational exposure and that of the general public while underpinning his statements by numerous tables, measurement diagrams and charts. (Uhe) [Deutsch] Nach einer kurzen Diskussion der Begriffsdefinitionen und einer Einfuehrung in die Messtechnik werden die Charakteristika verschiedener ...

International Nuclear Information System (INIS)

The isostructural uranium monopnictides and monochalcogenides have become prototype systems in actinide research with respect to their unusual magnetic properties. We have investigated the origins in the electronic structure of the variation in magnetic behavior as the degree of 5f-electron localization changes from localized to itinerant on going up the pnictogen or chalcogen column, thus decreasing the U-U separation. We have applied a synthesis of: (1) A phenomenological theory of orbitally driven magnetic ordering which includes both the hybridization-induced and the RKKY exchange interactions on an equal footing, and (2) Ab initio electronic structure calculations, based on the linear-muffin-tin-orbital method, allowing a first-principles evaluation of the parameters entering the model Hamiltonian. We have investigated systematically characteristic trends and changes of the 5f-state resonance ...

International Nuclear Information System (INIS)

We examined whether proton magnetic resonance spectroscopy (MRS) could provide accurate information on histological grade and cell proliferation in astrocytomas. We studied 23 patients with astrocytomas: five grade II, 10 grade III and eight with grade IV (glioblastoma multiforme). We performed proton MRS and determined the Ki-67 labeling index (LI), a tumour proliferation marker, in the same areas of the astrocytomas, and examined the statistical relationship between proton MRS and Ki-67 LI. The N-acetylaspartate (NAA)/creatine-phosphocreatine (Cr) and NAA/choline (Cho)-containing compound ratios were always significantly lower and the Cho/Cr ratios significantly higher than those for normal brain. The Cho/Cr ratio correlated positively and the NAA/Cho ratio inversely with Ki-67 LI. These findings suggest that the Cho signal in proton MRS reflects cellular proliferation. In Kaplan-Meier survival analysis, there was no significant difference ...

International Nuclear Information System (INIS)

Central Nervous System (CNS) involvement, whether primary by the Human Immunodeficiency Virus - HIV - itself, or secondary (toxoplasmosis or lymphoma) is remarkably frequent in AIDS, in 40 to 70% of cases, depending upon the author. In order to study the natural history of this illness, a cohort of 25 asymptomatic seropositive patients have been established. Every 6 months these patients undergo biological and clinical examinations, as well as Magnetic Resonance brain scans. After two examinations at a 6 month's interval, the first results are reported. Out of these 25 cases, 9 present anomalies: One patient with diffuse cerebral atrophy and 8 others with high signal intensity areas on T2 weighted sequences, like those of the Multiple Sclerosis. No relationship could be demonstrated between the existence of these lesions and various criteria such as age, sex, risk factors and T4 cells count. The nature of these lesions is not lear. They ...

International Nuclear Information System (INIS)

Artifical valve prostheses are often regarded as a contraindication for magnetic resonance imaging (MRI), although preliminary in vitro studies suggested, that patients with these metallic implants might safely undergo MR examination. This study reports on the experience with a group of 89 patients with 100 heart valve prostheses who were examined by spin-echo MR and gradient-echo MR. MR examination was performed in all patients without complications. The spin-echo sequence showed advantages in the depiction of anatomical structures like paravalvular abcesses. Anatomical structures adjacent to the artificial valve were clearly visivle and the metal components of the valves showes no or only small artifacts. Artifacts were accentuated when using gradient-echo sequences. Gradient-echo sequences provided valuable information regarding the presence of valvular insufficiency. Physiological valvular regurgitation was easy to differentiate from ...

International Nuclear Information System (INIS)

Fourteen patients with cervical hip fractures were treated with internal fixation using titanium screws. The femoral head vitality was evaluated with "9"9Tc"m-MDP scintigraphy and scintimetry within 2 weeks postoperatively and by serial low field magnetic resonance imaging (MR). Two patients with reduced radionuclide uptake (femoral head ratio =# 1.0), MR revealed a focal decrease of the signal intensity in the femoral head or neck at 2, 3 and 7 months after fracture, respectively. The radiographs in one of these patients were normal at 7 months after fracture. The second one showed signs of necrosis at 16 months and the last one developed delayed/non-union. With a non-ferromagnetic osteosynthesis the healing course after femoral neck fracture can be studied with low field MR equipment without disturbing artifacts. The time period between ischaemia and definite abnormalities on MR may embrace several months. (orig.).

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We have investigated CeTSi{sub 3} and CeTGe{sub 3} (T = Rh and Ir) by measuring the magnetic susceptibility, specific heat, electrical resistivity, the resonant inverse photoemission (RIPES) and M{sub IV,V} x-ray absorption spectra (XAS). The germanides showed a very weak Kondo effect, but the silicides exhibited a negatively large Weiss temperature (approx. = -130 K) and a lnT dependence of magnetic resistivity above 100 K, suggesting that they are a Kondo-lattice compound with a high Kondo temperature T{sub K} (approx. = 100 K). The Curie-Weiss law suggests that Ce atoms in these compounds remain close to 3+ down to about 150 K in spite of their high T{sub K}. In general, both RIPES and M{sub IV,V} XAS support their apparently stable valency. (author)

International Nuclear Information System (INIS)

Cardiac disease research relies increasingly on small animal models and non-invasive imaging methods such as positron emission tomography (PET) and magnetic resonance imaging (MRI). Delayed enhancement magnetic resonance imaging (DE-MRI) using gadolinium-based contrast agents appear to be a visualizing infracted myocardium with high spatial resolution. Polar map (or bull's-eye image) was used to determination of the myocardial infarction area. Polar map is a comprehensive interpretation of the left ventricle. The infarct size was computed as the fraction of the total polar map areas. The threshold was computed as the percentage of mean intensity of the normal region. In other study, 50% predefined threshold value in varying range (30?70%) was most commonly use. However, predefined threshold value isn't acceptance in all case. The purpose of this study was to investigate methodological approach for ...

British Library Electronic Table of Contents (United Kingdom)

The current paper continues the analysis of a completely novel method of fluid manipulation technology in micro-fluidics systems, inspired by nature, namely by the mechanisms found in ciliates. More information on this subject can be found at http://www.hitech-projects.com/euprojects/artic/. In order to simulate the drag forces acting on an array of artificial cilia, we have developed a computer code that is based on fundamental solutions of Stokes flow in a semi-infinite domain. The actuation mechanism consists of a bi-directional rotating excitation magnetic field. The magnetization induced by the magnetic field was calculated in a separate routine based on the Integral Nonlinear Equations Approach with 1D discretization of wire (cilium). Time averaged x-coordinate mass flow rates, strea...

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Vibrational dephasing in condensed phases is studied from both a theoretical and experimental standpoint. A theory is presented which describes the dynamics of motional or exchange processes in weakly perturbed systems. This general formalism, which has been previously used to describe motional narrowing in magnetic resonance, is applied to vibrational spectroscopy. The model treats the case of a high frequency vibration anharmonically coupled to a low-frequency vibration. Intermolecular exchange of low frequency vibrational quanta results in a temperature dependent broadening and frequency shift of the high frequency vibration. Analysis of experimental data by this model yields both the exchange rates and the anharmonic couplings.

DEFF Research Database (Denmark)

We propose to encode a register of quantum bits in different collective electron spin wave excitations in a solid medium. Coupling to spins is enabled by locating them in the vicinity of a superconducting transmission line cavity, and making use of their strong collective coupling to the quantized radiation field. The transformation between different spin waves is achieved by applying gradient magnetic fields across the sample, while a Cooper pair box, resonant with the cavity field, may be used to carry out one- and two-qubit gate operations.

British Library Electronic Table of Contents (United Kingdom)

We have prepared a series of novel gemini surfactants having ester bonds in their structures. These surfactants possess two identical hydrophilic polyethylene glycol moieties, two hydrophobic alkyl group moieties, and an anionic spacer. The structures of these compounds were confirmed through infrared and nuclear magnetic resonance spectroscopic and elemental analyses. The novel gemini surfactants exhibit excellent surface activity in terms of their surface tension, low-foaming, wetting power, and fluorescence properties. The presence of the ester linkages made these structures cleavable surfactants.

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To expand the information base on molecular accessibility in solvent swelled coal, Argonne Premium Coal Samples (APCS) were swelled in polar, basic solvents before and after moisture loss and upon air oxidation. So far studies have been reported on the changes in pore size distribution as a function of temperature when polar basic swelling solvents are used. Additional studies employing EPR spin probe techniques performed on the breaking up of the hydrogen bonding between bedding planes were later confirmed by magnetic resonance imaging at Argonne National Lab and the University of Illinois.

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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.)

International Nuclear Information System (INIS)

In order to understand the physical processes concerned with the selective heating by ion cyclotron resonance and with the subsequent collection of heated particles, experiments were carried out with the extraction of lithium samples, enriched with "6Li isotopes. Probe and integral extractors allow to collect enriched Li at the end of the selective heating region. Surface density distribution on the collector and local isotopic content of lithium are measured, as a function of the screen height and the retarding potential. Dependence of the collected amount of lithium and of its isotopic content on the value of the magnetic field is also measured. 4 figs., 2 tabs., 5 refs.

International Nuclear Information System (INIS)

A 3"1/_2-year-old child developed unilateral diaphragmatic paralysis after chest drain insertion. Plain chest X-ray demonstrated paravertebral positioning of the chest-tube tip, and magnetic resonance imaging revealed hematomas in the region of the chest-tube tip and the phrenic nerve fibers. The trauma to the phrenic nerve was apparently secondary to malposition of the chest tube. This is a rare complication and has been reported mainly in neonates. Radiologists should notify the treating physicians that the correct position of a chest drain tip is at least 2 cm distant from the vertebrae. (orig.)

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Purpose: Hormonal activity causes breast volume to change during the menstrual cycle. One possible cause of this volume change is thought to be due to water retention or oedema within the tissues. We used magnetic resonance imaging (MRI) to study the variation in breast volume and {sup 1}H Magnetic Resonance Spectroscopy (MRS) to measure T{sub 2} relaxation times which are known to increase with increasing tissue water content. We hypothesised that an increase in breast volume will elevate T{sub 2} relaxation due to the presence of an increased water content within the breast. T{sub 2} Relaxation time and volume were studied in fifteen control subjects and in a cohort of eight patients with cyclical mastalgia in order to determine whether changes in breast volume and T{sub 2} relaxation times differed in controls and patients during menses, ovulation and premenses. Method: Breast volume was determined ...

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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 ...

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Horizontal vibrations of elevator cars mainly occur because a car swings as roller guides installed at corners of a car frame move on a winding guide rail at high speeds. Rider comfort in high speed elevators is worsened by these vibrations. Conventional active dampers suppressing horizontal vibrations using ac servo motors make cars heavier so driving power becomes larger, and they are not easily applied to existing elevators. An active damping control method suited to super-high-speed elevators is which can solve these problems. The method suppresses vibrations by generating only enough magnetic force needed to suppress them only when vibrations of the car franc are produced. The vibrations are detected using acceleration detectors and magnets installed on left and right sides of the car frame. A computer simulator was made to analyze phenomena of car vibrations and to verify effects of the proposed magnetic damping ...

International Nuclear Information System (INIS)

Superparamagnetic MFe23+O4 (M=Mn2+, Fe2+ and Co2+) inverse spinel ferrite (ISF) nanoparticles with narrow size distribution having average diameters of 6-8 nm were synthesized by a diol reduction of organic metals and the surface was modified to be hydrophilic by coating with succimer. Magnetic resonance imaging (MRI) contrast enhancement by dipolar coupling defined interactions between the synthesized ISFs and protons in the bulk water was investigated with initial susceptibility, magnetization and anisotropy of the succimer-coated ISFs. The relaxivity ratios, r2/r1, for MnFe2O4, Fe3O4 and CoFe2O4 were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T2 contrast agents for MRI.

CERN Document Server

Each of the two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7.86 microseconds, and rise and fall times of less than 900 ns and 3 microseconds, respectively. A kicker magnet system consists of four 5 Ohm transmission line magnets with matching terminating resistors, four 5 Ohm Pulse Forming Networks (PFN) and two Resonant Charging Power Supplies (RCPS). Nine PFNs, together with associated switch tanks, and dump switch terminating resistors have been built at TRIUMF and all have been tested at high voltage (54 kV) to ensure that the performance is within specification. This paper describes the HV measurements, compares these results with low voltage measurements and analyses the pulse performance of the PFNs. The measurements are compared with results from PSpice simulations and small discrepancies between the predictions and measurements are ...

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As a part of the program at the Lawrence Livermore National Laboratory (LLNL) in induction-linac free-electron laser (IFEL) research, we are conducting a variety of activities addressing the unique requirements imposed on IFEL wiggler systems. We are actively developing improved dc iron-core electromagnetic wiggler designs to attain higher peak fields, greater tunability, and lower random error levels. We are pursuing specialized control systems, such as magnetic-field and beam-position controllers, which can relax requirements on the wiggler itself. We are also pursuing basic studies to establish the effect of radiation on permanent magnets.

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The Magnet Test Facility at Fermilab tests a variety of full-scale and model superconducting magnets for both R and D and production. As the design characteristics and test requirements of these magnets vary widely, the magnet test stand must accommodate a wide range of Data Acquisition (DAQ) and Control requirements. Such a system must provide several functions, which includes: quench detection, quench protection, power supply control, quench characterization, and slow DAQ of temperature, mechanical strain gauge, liquid helium level, etc. The system must also provide cryogenic valve control, process instrumentation monitoring, and process interlock logic associated with the test stand. A DAQ and Control system architecture that provides the functionality described above has been designed, fabricated, and put into operation. This system utilizes a modular approach that provides both extensibility and ...

International Nuclear Information System (INIS)

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs.

International Nuclear Information System (INIS)

... range magnetic fields magnetic susceptibility magnetization neutron diffraction

International Nuclear Information System (INIS)

Microwave Electron Cyclotron Resonance (ECR) Plasma assisted Chemical Vapor Deposition (CVD) technology has been used to prepare Si_3N_4 films, which were analyzed by using infrared (IR) transmission spectroscopy and XPS. The analysis results show that with the increase of the deposition temperature, the H content decrease, and the densification of the film increases. When the temperature is up to 360 degree C, the stoichiometrical rate of Si:N is close to 0.75. The protective property of Si_3N_4 films is also examined

International Nuclear Information System (INIS)

The marked difference between the intra- and extracellular "3"1P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the "3"1P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethylphosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the "3"1P NMR resonances to shift to lower frequency in a manner ...

International Nuclear Information System (INIS)

The present article outlines major features of the free electron laser (FEL) and reviews research and development of FEL. Relations among the oscillation frequency, electron beam parameters and wiggler parameters, the physical mechanism of amplification and the physical process of saturation are discussed to identify the difference between FEL and other lasers. The report also outlines techniques for accelerators which are used to generate high-quality, high-energy electron beams required for FEL experiments. Techniques to achieve a short wavelength, high output and high efficiency, and applications of FEL are also discussed. FEL consists of an electron accelerator, wiggler and optical resonator. In FEL, electron beams with a relativistic energy interact resonantly with an electromagnetic field to generate coherent electromagnetic waves. Unlike conventional lasers, FEL does not surfer from restrictions on its oscillation frequency associated ...

International Nuclear Information System (INIS)

Results of self-consistent local-spin-density-functional calculations are reported for the first time for the Ni(110) surface, represented by one-, three-, and five-layer slabs. Calculations for one- and five-layer slabs of Ni(100) are also reported. The behavior of the surface magnetization with varying slab thickness elucidates the nature and origin of the surface magnetic moment. We predict a 13% enhancement of the Ni(110) surface magnetic moment compared to the bulk value. For the Ni(100) surface, we find a smaller surface enhancement about 7%, compared to bulk, which agrees with the results of Jepsen et al. The enhancement of surface magnetic moments on Ni(100) and Ni(110) surfaces is attributed to s-d dehybridization at the surface and to the presence of electrostatic shifts required to maintain layer-by-layer charge neutrality. We find that the total d-electron charge is the same in each layer, ...

British Library Electronic Table of Contents (United Kingdom)

MRI (Magnetic resonance imaging) has been widely used in the diagnosis of primary carpal tunnel syndrome (CTS). However, it has had limited clinical application in diagnosing persistent or recurrent CTS. We aimed to investigate the efficacy of this imaging modality in patients who had previously undergone open carpal tunnel release without relief of symptoms, and assess the correlation of MRI with intra-operative findings upon re-exploration. MRI studies were performed on 17 wrists (16 patients) presenting with recurrent/persistent symptoms and signs of CTS in whom repeat nerve conduction studies were also performed. Surgical re-exploration was undertaken on 16 wrists in which a 100% correlation was noted between MRI and intra-operative findings of an incompletely released or re-grown tran...

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...

Energy Technology Data Exchange (ETDEWEB)

Results of discrete element method (DEM) simulation and magnetic resonance imaging (MRI) experiments are compared for monodisperse granular materials flowing in a half-filled horizontal rotating cylinder. Because opacity is not a problem for MRI, a long cylinder with an aspect ratio {approximately}7 was used and the flow in a thin transverse slice near the center was studied. The particles were mustard seeds and the ratio of cylinder diameter to particle diameter was approximately 50. The parameters compared were dynamic angle of repose, velocity field in a plane perpendicular to the cylinder axis, and velocity fluctuations at rotation rates up to 30 rpm. The agreement between DEM and MRI was good when the friction coefficient and nonsphericity were adjusted in the simulation for the best fit. {copyright} {ital 1998 American Institute of Physics.}

British Library Electronic Table of Contents (United Kingdom)

Incongruent auditory and visual stimuli can elicit audiovisual illusions such as the McGurk effect where visual /ka/ and auditory /pa/ fuse into another percept such as/ta/. In the present study, human brain activity was measured with adaptation functional magnetic resonance imaging to investigate which brain areas support such audiovisual illusions. Subjects viewed trains of four movies beginning with three congruent /pa/ stimuli to induce adaptation. The fourth stimulus could be (i) another congruent /pa/, (ii) a congruent /ka/, (iii) an incongruent stimulus that evokes the McGurk effect in susceptible individuals (lips /ka/ voice /pa/), or (iv) the converse combination that does not cause the McGurk effect (lips /pa/ voice/ ka/). This paradigm was predicted to show increased release fro...

International Nuclear Information System (INIS)

We provide a brief review of our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in two most important dilute nitride systems-Ga(In)NAs grown on GaAs substrates and Ga(Al,In)NP grown on Si and GaP substrates. These results have led to the identification of defect complexes in the alloys, involving intrinsic defects such as As_G_a antisites and Ga_i self-interstitials. They have also shed light on formation mechanisms of the defects and on their role in non-radiative carrier recombination that is harmful to the performance of potential optoelectronic and photonic devices based on these dilute nitrides.

British Library Electronic Table of Contents (United Kingdom)

Chemical modification of poly(?-caprolactone) PCL by oxidation with potassium permanganate in solution was investigated. According to the data obtained from Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance 1H NMR, after the oxidation reactions the PCL chains exhibited new functional groups (vinyl and hydroxyl) and possible intermolecular recombination, producing an oxidized-polycaprolactone (PCL-OX). Solution viscometry indicated that degradation also occurred during the oxidation reactions (30% drop in viscosity average molecular weight was detected). Differential scanning calorimetry (DSC) also indicated that PCL was chemically modified and degraded. The successive self-nucleation/annealing (SSA) treatment confirmed that a reduction (or interruption) in line...

International Nuclear Information System (INIS)

17 patients with chronic aortic dissection were examined by MRI. In 12 patients, comparison between gradient echo sequences and SE sequences was possible. Gradient echo sequences, unlike SE sequences, permitted evaluation of flow in the true and false lumen, reliable differentiation between thrombus and flowing blood and clear delination of the intimal flap. An additional comparison between transoesophageal ultrasound and MRT in 15 patients showed significant advantages in favour of MRI. In three patients MRI was able to detect more proximal origins of the dissection. Moreover, MRI allowed evaluation of the major aortic branches and their relation to the dissection; this was not possible with ultrasound. MRI plays an important role in the follow-up of chronic aortic dissections. (orig.).

British Library Electronic Table of Contents (United Kingdom)

Perceptions of sensation and pain in healthy people are believed to be the net result of sensory input and descending modulation from brainstem and cortical regions depending on emotional and cognitive factors. Here, the influence of attention on neural activity in the spinal cord during thermal sensory stimulation of the hand was investigated with functional magnetic resonance imaging by systematically varying the participants' attention focus across and within repeated studies. Attention states included (1) attention to the stimulus by rating the sensation and (2) attention away from the stimulus by performing various mental tasks of watching a movie and identifying characters, detecting the direction of coherently moving dots within a randomly moving visual field and answering mentally-...

International Nuclear Information System (INIS)

Because of the superior tissue contrast, high spatial resolution, and multiplanar capabilities, fetal magnetic resonance imaging (MRI) can depict fetal brain pathologies with high accuracy. Pathological fetal brain development may result from malformations or acquired conditions. Differentiation of these etiologies is important with respect to managing the actual pregnancy or counseling future pregnancies. As a widened ventricular system is a common hallmark of both maldevelopment and acquired conditions, it may cause problems in the differential diagnosis. Fetal MRI can provide detailed morphological information, which allows refinement of the diagnosis of ventricular enlargement in a large number of cases. Systematic work-up of morphological details that may be recognized on MR images provides an approach for achieving a correct diagnosis in cases of ventricle enlargement. (orig.)

International Nuclear Information System (INIS)

Purpose. We report a case of Ewing's sarcoma in the right distal femur in a 6-year-old male to demonstrate how dynamic contrast-enhanced magnetic resonance imaging (DEMRI) findings predicted histopathology. Materials and methods. DEMRI was performed at presentation and during and after completion of chemotherapy and radiation therapy. Histopathologic studies were done at presentation, at 77 weeks (20 weeks after a pathological fracture), and from the en bloc resection at 104 weeks. Results. DEMRI predicted the early tumor response, absence of tumor recurrence, presence of necrosis and lack of fracture healing, confirmed by histopathology. Conclusion. DEMRI is a clinically useful tool in managing Ewing's sarcoma. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Two cases of focal nodular hyperplasia (FNH), in which ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MR) studies detected an atypical hemorrhagic pattern associated with an intrahepatic arterio venous malformation (AVM) around the growths, are presented. In both cases, histology demonstrated a very early regenerative stage and necrotic-hemorrhagic areas within the lesions. In these cases, the analysis of radiological findings, surgical specimens and histology seemed to confirm the pathogenetic hypothesis suggested by Wanless: in normal liver parenchyma, a ``blood steal`` phenomenon due to congenital or acquired intrahepatic AVM could cause ischemic damage, appearing as a hemorrhagic necrotic area, the extent of which depends on the degree of residual portal supply. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The early diagnosis of such disorders is of major importance because, in most cases, severe consequences can only be averted by early treatment. The value of magnetic resonance imaging (MRI) in many orthopaedic and traumatological conditions is generally accepted. The value of MRI in this particular field is illustrated by typical case reports on common clinical problems [Deutsch] Der Fruehdiagnose von Erkrankungen des Kindes- und Jugendalters kommt grosse Bedeutung zu, da oftmals nur durch eine daraus resultierende Fruehbehandlung schwerwiegende Folgen vermieden werden koennen. Die Kernspintomographie (Magnetresonanztomographie=MRT) ist in zahlreichen orthopaedischen-traumatologischen Fragestellungen bereits etabliert. An ausgewaehlten Fallbeispielen haeufiger klinischer Problemstellungen soll in der vorliegenden Arbeit der Stellenwert der MRT dargestellt werden. (orig.)

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Brain tumor was diagnosed by computer tomography or magnetic resonance imaging in 100 children aged 0 to 19 years. They consecutively underwent primary surgical treatment during the years 1984 to 1988. Non-neoplastic lesions and operations for residual tumors are not included. 54 tumors were localized supratentorially. 72% of these were benign og low grade malignancies. 46 tumors had an infratentorial localication. 59% of these were high grade malignancies. Children tolerate major-neurosurgical procedures better than adults and restitution is usually favourable. 42 children with high grade malignancies underwent postoperative radiotherpy. Per- and postoperative mortality in this series was 1%. 80 children are alive. 62 of these are in excellent condition after a median observation time of 40 months. 10 refs.

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The available experimental data on the specific heat, magnetic susceptibility, magnetization, valence, NMR Knight shift and relaxation rate, and the quadrupolar moment of YbPd_2Si_2 are examined within the framework of the single-ion Anderson model. Such an analysis has previously given excellent agreement between theory and experiment for numerous other light heavy-fermion compounds, where crystalline fields do not play a dominant role. For YbPd_2Si_2, substantial crystalline-field splittings make difficult a quantitative comparison with existing exact solutions of the Anderson model. Inconsistencies with the interpretation that a nearly degenerate ground quadruplet determines the low-temperature thermodynamics are pointed out. It is concluded that at least three of the four Kramers doublets participate in the low-T properties. These three doublets should have a splitting of the order of the Kondo temperature, i.e., about 100 K. A simple ...

International Nuclear Information System (INIS)

Three dimensional data of brain from the formalin-fixed fetuses were collected without isolation, by the 4.7 tesla super high magnetic field MRI and the developmental process of the cerebral parenchyma was studied by 3D images. Subjects were 13 fetal brain and MRI was performed using 3D-steady-state free precession sequence. The isolated brain is very soft and fragile and is deformed by its weight at the imaging. However 3D-MRI can be obtained without isolation, and the deformation is remarkably small. The subependymal germinal matrix layer did not be observed in 7 weeks-old fetus, appeared at 9 weeks-old and increased gradually. Then it rapidly reduced from 28 weeks-old. The volume calculated, from 3D-MRI, increased rapidly from 9 weeks-old to 23 weeks-old, and reached the maximum (2.346 mm"3) at 23 weeks-old. The relation between fetal ages and volume of cerebral ventricle also showed similar pattern. This method will be useful to examine the development of the ...

Science.gov (United States)

Besides the multifunctionality, another equally important aspect of nanoparticles is their engineerability to control the geometrical and chemical properties during fabrication. In this work, we exploited this aspect to define asymmetric surface chemistry of an iron oxide nanosphere by controlling the topology of ligand expression on its surface resulting in a particle with two faces, one displaying only amines and the other only thiols. Specifically, amine-functionalized iron oxide nanospheres were attached on a solid support via a crosslinker containing a disulfide bridge. Liberation of the nanosphere using thiolytic cleavage created thiols on the portion of the particle's surface that interacted with the solid support. Employing a solid-phase strategy and a step-by-step addition of particles, the two unique faces on the same nanosphere served as fittings to assemble them into linear nano-chains. Assembly of chains with various lengths and aspect ratios was controlled by the size and ...

International Nuclear Information System (INIS)

This work describes the theoretical basis for a new concept rotating magnetic tensor gradiometer. The rotating gradiometer consists of an approximately axial or transverse gradiometer which is made to rotate about a perpendicular axis so that the direction of sensitivity is continually changing. It is demonstrated for the first time that the rotation separates gradient components of progressively higher-order in the frequency domain and enables absolute-value measurements of all components of the first-order magnetic gradient tensor, even if the magnetic sensors comprising the gradiometer are intrinsically incapable of absolute-value detection. In addition, the rotating gradiometer concept has a number of other advantages: the gradiometer imbalance is no longer directly determined by the engineering precision, the DC and low-frequency performance of the instrument is not limited by the performance of the detectors in these ...

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A generic reactor model is used to examine the economic viability of electricity generation by magnetic fusion. The simple model uses components which are representative of those used in previous reactor studies of deuterium-tritium burning tokamaks, stellarators, bumpy tori, reverse field pinches and tandem mirrors. Conservative costing assumptions are made. The generic reactor is not a tokamak but rather it is intended to emphasize what is common to all magnetic fusion reactors. The reactor uses a superconducting toroidal coil set to produce the dominant magnetic field. To this extent it is a less good approximation to systems, such as the reversed field pinch in which the main field is produced by a plasma current. The main output of the study is the cost of electricity as a function of the weight and size of the fusion core - blanket, shield, structure and coils. The model shows that a 1200 MW/sub e/ power plant with a ...

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... parameters magnetic fields magnetic properties magnetization monocrystals

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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 ...

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The wavefunction of a particle extends into the classically forbidden barrier region of the potential energy surface. The consequence of this partial delocalisation is the phenomenon of quantum tunnelling, an effect which enables a particle to penetrate a potential barrier of magnitude greater than the energy of the particle. The tunnelling probability is an exponential function of the particle mass. The effect is therefore an important contribution to the behaviour of light atoms, in particular the proton. The hydrogen bond has long been appreciated to be an essential component of many biological and chemical systems, and the proton transfer reaction in the hydrogen bond is fundamental to many of these processes. The proton behaviour in the hydrogen bonds of benzoic acid, acetylacetone and calix-4-arene has been studied. A variety of techniques, both experimental and computational, were adopted for the study of the three hydrogen bonded systems. The complementary spectroscopic ...

International Nuclear Information System (INIS)

Early white matter (WM) injury affects brain maturation in preterm infants as revealed by diffusion tensor imaging and volumetric magnetic resonance (MR) imaging at term postmenstrual age (PMA). The aim of the study was to assess quantitatively brain maturation in preterm infants with and without milder forms of WM damage (punctate WM lesions, PWML) using conventional MRI. Brain development was quantitatively assessed using a previously validated scoring system (total maturation score, TMS) which utilizes four parameters (progressive myelination and cortical infolding, progressive involution of glial cell migration bands and germinal matrix tissue). PWML were defined as foci of increased signal on T1-weighted images and decreased signal on T2-weighted images with no evidence of cystic degeneration. A group of 22 preterm infants with PWML at term PMA (PWML group) were compared with 22 matched controls with a normal MR appearance. The two groups ...

International Nuclear Information System (INIS)

Purpose: To assess the relationship between large intracranial vessel occlusive vasculopathy (vasculopathy) and radiation therapy, and to clarify the clinical efficacy of magnetic resonance (MR) imaging in the diagnosis and screening of the vasculopathy. Methods and Materials: We retrospectively evaluated the medical records and serial MR images for 32 pediatric patients, in whom radiation therapy had been given to fields including the circle of Willis and major cerebral arteries. All children had periodically undergone follow-up neurologic assessment and MR imaging examinations at Kanagawa Children's Medical Center for more than one year after radiation therapy (range 1.3-14 years). Patients who had not remained free of tumor progression up to the time of final evaluation were excluded. Results: Vasculopathy developed in 6 of 32 patients 2-13 years after radiation therapy. Three of them presented with transient ischemic attacks (TIA) and the ...

DEFF Research Database (Denmark)

Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of vision in very young infants and in infants with brain damage. We examined 15 preterm infants, 12 children suspected of having a cerebral visual impairment and 10 children with a normal visual system, all of whom were either spontaneously asleep or sedated with chloral hydrate. Cortical response to stroboscopic light stimulation could be demonstrated in all technically acceptable data sets from children with a post-menstrual age (PMA) of > 41 weeks, but not in younger infants. Children < 60 weeks PMA showed either a blood oxygenation level-dependent (BOLD) signal increase or decrease, while all older children showed a signal decrease. The activated ...

International Nuclear Information System (INIS)

Background: Early detection of cholangiocarcinoma (CC) is very difficult, especially in patients with primary sclerosing cholangitis (PSC) who are at increased risk of developing CC. Purpose: To evaluate "1H magnetic resonance spectroscopy ("1H-MRS) of bile as a diagnostic marker for CC in patients with and without PSC. Material and Methods: The institutional review board approved the study, and all patients gave informed consent. Bile from 49 patients was sampled and investigated using "1H-MRS. MR spectra of bile samples from 45 patients (18 female; age range 22-87 years, mean age 57 years) were analyzed both conventionally and using computerized multivariate analysis. Sixteen of the patients had CC, 18 had PSC, and 11 had other benign findings. Results: The spectra of bile from CC patients differed from the benign group in the levels of phosphatidylcholine, bile acids, lipid, and cholesterol. It was possible to distinguish CC from benign ...

International Nuclear Information System (INIS)

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

Science.gov (United States)

Giant magnetoresistance (GMR) has been used with Eddy current testing to detect small defects not only in thin film structures but also in multilayered metallic structures. This work detected small scratches in the thin film under the surface where these defects were unable to be inspected or monitored by regular testing. In addition, rotational GMR magnetic sensor based Eddy current probes were used for detecting buried corner cracks at the edge of holes in metallic structures. The results of this study proved that giant magnetoresistance is very powerful and effective to sense the magnetic field, which is the result from the perturbation of the Eddy currents caused by a defect. This method can be used for quality control of metallization layers on silicon wafer and to detect cracks in thick structures such as cracks in aging aircraft.

Energy Technology Data Exchange (ETDEWEB)

A concept of direct energy recovery system applying an alternating or rotating magnetic field is proposed for a negative-ion-based neutral beam injection system (NNB) to heat a plasma and/or drive a plasma current in a fusion reactor. Nearly same amounts of residual positive and negative hydrogen-isotope ion beams with beam energy of {approx}1 MeV are produced in an NNB using a gas neutralizing cell. Consequently, a recovered energy is obtained directly in the form of ac electric power, if these positive- and negative-ion beams are alternated or rotated and introduced to two or more recovery electrodes in turn by an alternating or rotating magnetic field. This concept will greatly reduce a technological difficulty in regeneration of a recovered electric energy with such a very high voltage. (author).

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

International Nuclear Information System (INIS)

The polycrystalline samples of Y_2_-_xHo_xO_3 (0.10#<=#x#<=#1.80) were synthesized by ceramic technology. The X-ray powder diffraction data were collected and the crystal structures were refined by the Rietveld method for the samples Y_2_-_xHo_xO_3 (x=0.00, 0.20, 0.40, 1.20, 1.80, 2.00). Holmium ions Ho"3"+ were randomly distributed over two cationic sites 8b and 24d in the space group Ia3 in all refined structures. Cation-anion-cation bonds important for superexchange interaction were determined. Magnetic susceptibility measurements were done by the Faraday method in the temperature range 290 to 620 K and a behaviour in accordance with the Curie-Weiss law was obtained. The molar Curie's constants linearly depend on concentration. The effective magnetic moments of Ho"3"+ ions were smaller than the free ion value. The Curie-Weiss paramagnetic temperatures indicated antiferromagnetic interaction. The gram ion ...

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This document reports on the work done by the Separations Science and Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April-September 1993. This effort is mainly concerned with developing the TRUEX process for removing and concentrating actinides from acidic waste streams contaminated with transuranic (TRU) elements. The objectives of TRUEX processing are to recover valuable TRU elements and to lower disposal costs for the nonTRU waste product of the process. Other projects are underway with the objective of developing (1) evaporation technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process, (2) treatment schemes for liquid wastes stored or being generated at Argonne, (3) a process based on sorbing modified TRUEX solvent on magnetic beads to be used for separation of contaminants from radioactive ...

International Nuclear Information System (INIS)

Complete text of publication follows. In order to extend the capabilities of the electron cyclotron resonance (ECR) ion source (ECRIS) of ATOMKI it has been transformed into a special plasma facility [1,2]. The transformation is reversible and was simply done by changing several main components of the ion source by new ones, namely: the hexapole magnet, the plasma chamber and the microwave source. The basic requirements of the transformation were: (1) most parts of the present ECRIS should be used in the new assembly in the same way and (2) the transformation time between the two operation modes should not be more than 2-3 days (in both directions). The following sub-systems are used identically in both configurations: solenoid coils, vacuum system, gas dosing system, ovens, probes. The extraction optics and beam transport system can also be used in the new configuration to check the components and charge-state of the plasma. A new, large, but ...

UK PubMed Central (United Kingdom)

Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances...Full Text Available

DEFF Research Database (Denmark)

The blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal response to neural stimulation is influenced by many factors that are unrelated to the stimulus. These factors are physiological, such as the resting venous cerebral blood volume (CBV(v)) and vessel size, as well as experimental, such as pulse sequence and static magnetic field strength (B(0)). Thus, it is difficult to compare task-induced fMRI signals across subjects, field strengths, and pulse sequences. This problem can be overcome by normalizing the neural activity-induced BOLD fMRI response by a global hypercapnia-induced BOLD signal. To demonstrate the effectiveness of the BOLD normalization approach, gradient-echo BOLD fMRI at 1.5, 4, and 7 T and spin-echo BOLD fMRI at 4 T were performed in human subjects. For neural stimulation, subjects performed sequential finger movements at 2 Hz, while for global stimulation, ...

Science.gov (United States)

The purpose of this study was to develop a simple motion measurement system with magnetic resonance (MR) compatibility and safety. The motion measurement system proposed here can measure 5-DoF motion signals without deteriorating the MR images, and it has no effect on the intense and homogeneous main magnetic field, the temporal-gradient magnetic field (which varies rapidly with time), the transceiver radio frequency (RF) coil, and the RF pulse during MR data acquisition. A three-axis accelerometer and a two-axis gyroscope were used to measure 5-DoF motion signals, and Velcro was used to attach a sensor module to a finger or wrist. To minimize the interference between the MR imaging system and the motion measurement system, nonmagnetic materials were used for all electric circuit components in an MR shield room. To remove the effect of RF pulse, an amplifier, modulation circuit, and power supply were ...

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The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers parts of the second and third year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas: precision test of parity-invariance violation in resonance neutron scattering at LANSCE/LANL; parity violation measurements using charged-particle resonances in A = 20--40 targets and the A = 4 system at TUNL; chaotic behavior in the nuclei {sup 30}P and {sup 34}Cl from studies of eigenvalue fluctuations in nuclear level schemes; search for anomalies in the level density (pairing phase transition) in 1f-2p shell nuclei using GEANIE at LANSCE/LANL; parity-conserving time-reversal noninvariance tests using {sup 166}Ho ...

Science.gov (United States)

... Title : Refining the Magnetic Forming Capability. ... Abstract : The purpose of this project was to refine the in-house magnetic forming capability. ...

Science.gov (United States)

... Examples include magnetic forming tools, magnetic shielding, magnetohydrodynamic propulsion systems, and various magnetic containment ...

Energy Technology Data Exchange (ETDEWEB)

Pinta is a system for segmentation and visualization of anatomical structures obtained from serial sections reconstructed from magnetic resonance imaging. The system approaches the segmentation problem by assigning each volumetric region to an anatomical structure. This is accomplished by satisfying constraints at the pixel level, slice level, and volumetric level. Each slice is represented by an attributed graph, where nodes correspond to regions and links correspond to the relations between regions. These regions are obtained by grouping pixels based on similarity and proximity. The slice level attributed graphs are then coerced to form a volumetric attributed graph, where volumetric consistency can be verified. The main novelty of our approach is in the use of the volumetric graph to ensure consistency from symbolic representations obtained from individual slices. In this fashion, the system allows errors to be made at the slice level, yet ...

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A 52-year-old woman had a history of left hearing loss for 5 years. An acoustic neurinoma with 3.2 cm in diameter was diagnosed and treated with gamma-knife radiosurgery (19 Gy of marginal dose) 1 year and 4 months ago. She developed headache, nausea, and visual disturbance 1 month prior to admission. Slight left facial palsy appeared after radiosurgery. Magnetic resonance imaging demonstrated the tumor with central necrosis in the left cerebellopontine angle cistern, increasing in size to 3.5 cm in diameter, and hydrocephalus. Tumor removal was performed incompletely, because of the fibrous appearance of the tumor and severe adherence with the surrounding cerebellar tissue. Facial palsy did not worsen after surgery. Since the hydrocephalus was not resolved, a right ventriculo-peritoneal shunt was inserted. The clinical course in this case suggests that tumor removal followed by radiosurgery was an approximately effective treatment for large ...

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The structural change of the (100-x)(0.6Li[sub 2]S[center dot]0.4SiS[sub 2])centre dotxLi[sub 3]PO[sub 4] oxysulfide glassesduring crystallization was analyzed by means of solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The unique tetrahedral units of SiO[sub n]S[sub 4-n] (n=1,2,3) and PO[sub n]S[sub 4-n] (n=1,2,3) present in the glass samples vanished and the SiS[sub 4], PS[sub 4], SiO[sub 4] units increased with proceeding of the crystallization process. Nonbridging sulfur and oxygen atoms decreased while bridging oxygens and S[sup 2-] increased with proceeding of the crystallization process. Large structural difference between the glass and the corresponding crystallized sample explained the high stability against crystallization found in the oxysulfide glass with the composition of X=5. (author)

International Nuclear Information System (INIS)

The solid-pseudopapillary tumor (SPT) of the pancreas is a rare type of exocrine pancreatic neoplasm. SPT predominantly affects young women and female children, and is usually discovered incidentally. This tumor is generally benign with a low incidence of malignancy. A 13-year-old girl was admitted to the hospital with a few weeks' history of mild abdominal pain and jaundice. On physical examination, there was no palpable mass. The laboratory tests showed increased SR, CRP, high bilirubin, amylase and lipase serum levels. Ultrasound imaging revealed a solid lesion in the region of the pancreatic head. On MRI, precise tumor localization in the head of the pancreas with pancreatic duct dilatation and compression of the common bile duct were visualized. Pancreaticoduodenectomy and cholecystectomy was performed with good clinical outcome. Microscopic and immunohistochemical studies indicated that tumor cells were typical of SPT without any signs of malignancy. After surgical treatment, the ...

International Nuclear Information System (INIS)

The aim of this study was to evaluate typical magnetic resonance imaging (MRI) findings in early rheumatic diseases manifesting at the soft tissues of the hand using a retrospective analysis. A total of 186 MRI examinations of patients with clinical suspicion of a rheumatic disease were evaluated in a consensus reading by two experienced radiologists. All imaging patterns were assessed with respect to their type and localization. Under blinded and non-blinded conditions diagnoses were correlated with final clinical diagnosis. The most frequent diagnoses were rheumatoid arthritis (RA, 45.7%) and psoriatic arthritis (PsA, 15.6%). The mean correlation between clinical and MRI diagnosis (r) was 0.75 in blinded and 0.853 in non-blinded reading (p <0.001). The following extra-articular imaging patterns were found: synovitis (59.1%), tendovaginitis (91.4%), dactylitis (14.5%), and bone marrow edema (18.3%). Only dactylitis was specific for a ...

British Library Electronic Table of Contents (United Kingdom)

A series of new non-discoid chiral copper(ii)-salen type complexes, [Cu((4-CnH2n+1O)2salen)], n = 14, 16, 18 and salen = N,N'-cyclohexane bis (salicylideneiminato), containing 4-substituted alkoxy tails in the side aromatic rings and a cyclohexane spacer, have been prepared and their mesogenic properties investigated. The compounds were characterised by Fourier transform infra-red spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, UV-vis spectroscopy and fast atom bombardment mass spectrometry. Mesomorphic properties of these compounds were studied by polarising optical microscopy, differential scanning calorimetry and X-ray diffraction (XRD). The ligands are non-mesogenic but the complexes exhibited enantiotropic rectangular columnar mesophases (Colr) with extended temperat...

DEFF Research Database (Denmark)

The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation and residual movement artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other effects are typically modelled as an autoregressive (AR) process. In this paper, we propose an alternative approach: Nuisance Variable Regression (NVR). By inclusion of confounding effects in a general linear model (GLM), we first confirm that the spatial distribution of the various fMRI noise sources is similar to what has already been described in the ...

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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 was monitored continuously with 3-D ...

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We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.) [Deutsch] Die Befunde von drei Patienten mit intrakranieller Tuberkulose (intrakranielle Miliartuberkulose, Meningitis tuberculosa, Neuritis und Tuberkulome) in der Magnetresonanztomographie (MRT) wurden mit der Computertomographie (CT) verglichen. Sowohl die MRT als auch die CT wurden nativ und nach Kontrastmittelgabe durchgefuehrt. Die MRT zeigte sich im Nachweis von Granulomen insbesondere im Bereich des Hirnstamms ueberlegen. Ebenso wurde ein hoeherer Bildkontrast bei der Darstellung der Meningitis beobachtet. Eine ...

International Nuclear Information System (INIS)

Magnetic resonance (MR) images of 18 cases of hilar cholangiocarcinoma were evaluated to compare the effectiveness of Gd-DTPA with that of high dose contrast enhancement computed tomography (HCE-CT) in detecting the primary tumor. The primary tumor was demonstrated as having slightly low intensity compared with liver parenchyma and high intensity compared with the delated bile duct on T1-weighted images. In contrast, MRI using Gd-DTPA, which was carried out in five cases, revealed intense enhancement of the tumor. As the differentiation between cholangiocarcinoma and dilated bile duct was difficult, it was concluded that the use of Gd-DTPA improves the efficacy of MRI in diagnosing cholangiocarcinoma. Gd-DTPA was also effective in differentiating the growth pattern of the tumor: the infiltrating type was demonstrated as thickening of the wall of the bile duct, the polypoid type as a soft tissue mass in the bile duct. Contrast MRI study is ...

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The lipid obtained by the toluene extraction of a dried raw Atlanta sewage sludge by the Soxhlet method, was pyrolyzed over activated alumina at atmospheric pressure. A range of weight hourly space velocities (WHSV) from 0.22-1.60/h and a range of temperatures from 400-480[degree]C were selected. A 70 wt % yield of light liquid hydrocarbons was obtained at a WHSV of 0.46/h and 450[degree]C. The sulfur and nitrogen contents of the pyrolysis products were much lower than products from direct liquefaction of sludge. Infrared spectra and [sup 13]C nuclear magnetic resonance confirmed the absence of carbonyl groups in the products. Gas chromatography showed a uniform hydrocarbon chain length distribution across the C[sub 7] to C[sub 17] mass range. The gas product consisted mainly of carbon dioxide and hydrocarbons. Lauric acid was used as a model to study the decarboxylation. The effects of catalyst loading and catalyst moisture content were ...

Energy Technology Data Exchange (ETDEWEB)

The interaction of cis-diamminediaquoplatinum(II) nitrate with adenosylcobalamin and a series of alkylcobalamins was studied by carbon-13 nuclear magnetic resonance spectroscopy and by electronic spectroscopy. With these cobalamins cis-(Pt(NH/sub 3/)/sub 2/(OH/sub 2/)/sub 2/)/sup 2 +/ forms adducts in which N(3) of the 5,6-methylbenzimidazole moiety is co-ordinated to platinum(II) rather than to cobalt(III) of the corrin. The chemical shifts of the 5'-methylene carbon of adenosylcobalamin-platinum adduct and of the Co-methyl carbon of the methylcobalamin-platinum adduct are characteristic of these cobalamins in the base-off form. Furthermore, these cobalamin-platinum complexes have visible spectra identical to those of the cobalamins in acidic solution. The /sup 13/C NMR spectrum of the adenosylcobalamin-platinum complex suggests the presence of a second adduct in which platinum(II) complexes are co-ordinated to both the N(3) of the ...

International Nuclear Information System (INIS)

Ewing's sarcoma is a highly malignant neoplasm of the bone whose origin is still uncertain. A strong relationship exists between Ewing's sarcoma and tumors of neural origin (Ewing family of tumors). Ewing's sarcoma must be distinguished from other round-cell tumors like lymphoma and neuroblastoma and also must be differentiated from osteogenic sarcomas. On plain radiographs, Ewing's sarcoma appears as a lytic or mixed lytic-sclerotic, rarely as predominantly sclerotic lesion with margins Lodwick grade III. It is located primarily in the diaphyseal and metadiaphyseal regions of the long bones of the lower extremities. A large soft tissue tumor is usually present. Magnetic resonance imaging is the imaging modality of choice to evaluate the extent of the primary lesion, to monitor the response to neoadjuvant chemotherapy and to follow up non-resected Ewing's sarcomas. Bone scintigraphy is necessary to detect skeletal metastasis, and "2"0"1thallium ...

DEFF Research Database (Denmark)

The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly to both the results of the contrast sensitivity test ...

International Nuclear Information System (INIS)

Partially purified UDPgalactosyltransferase (EC 2.4.1.22) from bovine milk has been used to synthesize millimolar amounts of compounds such as Gal#beta#(1#->#4)Glc, Gal#beta#(1#->#4)GlcNAc-#beta#-hexanolamine, and Gal#beta#(1#->#4)-GlcNAc#beta#(1#->#4)GlcNAc. The same method has been used to prepare similar compounds containing "1"3C-enriched galactopyranosyl moieties. Gal#beta#(1#->#4)GlcNAc-#beta#-hexanolamine was also synthesized in a solid-phase system in which the GlcNAc-#beta#-hexanolamine glycoside was covalently linked to agarose beads. At pH 7.0 and at 1 to 5 mM Mn"2"+"+ the yields of the galactosyl saccharides are greater than 90% by using 10% excess of UDPGal donor. The use of a 90% enriched [1-"1"3C]galactosyl residue allowed the determination of the most abundant conformer about the galactopyranosyl-glycoside linkage by analysis of the carbon-carbon coupling constants from Cl to Gal to the C3', C4', and C5' of GlcNAc or Glc. 3 figures, 1 table.

International Nuclear Information System (INIS)

Early effects of boron neutron capture therapy (BNCT) on malignant glioma are characterized by reduction of the enhancement area and regression of the peritumoral edema radiologically. The aim of this study was to investigate the early histological changes of tumors and inflammatory cells after BNCT in the rat brain. Rats were treated with BNCT using boronophenylalanine (BPA) 7 days after implantation of C6 glioma cells. The tumors were assessed with magnetic resonance imaging and histopathological examination at 4 days after BNCT. The mean tumor volumes were 39#+-#2 mm"3 in the BNCT group and 134#+-#18 mm"3 in the control group. In the BNCT group, tumor cells showed a less pleomorphic appearance with atypical nuclei and mitotic figures. The Ki-67 labeling index was 6.5%#+-#4.7% in the BNCT and 35%#+-#3.8% in the control group. The reactions of the inflammatory cells were examined with ED-1 as macrophage marker and OX42 as microglia marker. ...

International Nuclear Information System (INIS)

Five cases diagnosed as extraosseous Ewing's sarcoma (EES) during a 15 year period, and the relevant literature, were reviewed. The diagnosis in these cases was difficult to confirm, mainly because the distinction between the osseous form of Ewing's sarcoma (OES) and either periosteal reactions or direct tumour invasion into adjacent bone by EES was often unclear. The literature suggests that other authors have also encountered difficulties. The authors believe that many cases reported as EES are likely to have been OES. This distinction has some importance, as the two conditions are usually treated in differing ways. The following criteria are proposed for the diagnosis of primary EES: (i) no evidence of bony involvement on magnetic resonance imaging; (ii) no evidence of increased uptake in bone or periosteum adjacent to the tumour on static isotope bone scan images; (iii) a small round cell tumour with no differentiating features on light ...

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 suitability for frequency conversion applications.

International Nuclear Information System (INIS)

CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous ...

International Nuclear Information System (INIS)

The authors present a comparison between the diagnostic accuracy of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) in the articular pathologies of the knee. CT and MRI were performed in 30 patients who subsequently underwent surgery. CT and MRI results were compared on three bases: technique, definition of normal anatomy, and diagnostic accuracy. CT allowed a standardization of the technique, while MRI was superior in defining normal anatomy - especially in the study of capsulo-ligamentous structures. In all cases the use of both CT and MRI allowed a correct diagnosis, showing the site, extent and gravity of the lesion. CT proved to be superior to MRI in 4 cases, while MRI corrected CT diagnosis in 11 cases; in 15 patients both techniques had the same diagnostic accuracy. Meniscal tears were better identified by CT, while MRI was superior in the detection of ligamentous lesions and in the characterization of PVNS and tendinitis ...

International Nuclear Information System (INIS)

In addition to the usual circularly symmetric TM/sub 010/ mode used to accelerate particles in an rf linac, there is a large number of modes with cos phi or sin phi dependence, for example the TM/sub 1xx/ modes. These latter modes possess a uniform magnetic (dipole) field near the axis of symmetry and therefore can deflect the beam away from the axis. Any portion of an accelerated beam that is off-axis will drive these modes, so that subsequent portions of the beam will be deflected. This deflected beam will then resonantly drive the same modes in downstream cavities, so that still later portions of the beam will be more severely deflected, and so on. In this paper are reported the results of numerical simulations of this so-called cumulative beam-breakup instability. The simulation assumes that only the TM/sub 110/ mode acts to deflect the beam, and further assumes that this mode does not couple from one accelerating cavity to the next.

Energy Technology Data Exchange (ETDEWEB)

A beta microprobe was successfully applied to monitor arterial input function for quantification of regional cerebral blood flow (rCBF) in the monkey brain with {sup 15}O-water and positron emission tomography (PET). The sensitivity of the probe was approximately 0.83 to 1.67 cps/kBq/ml depending on the studies. A preliminary study was performed to find a suitable use and to evaluate the performance of the system and data analysis procedure. The results showed that dispersion correction of measured input function was unnecessary if microprobes were connected directly to the arterial catheter. Then multiple CBF measurements were done in three monkeys under anesthesia. Identical regions of interest were placed with the aid of magnetic resonance imaging (MRI) of each monkey and rCBF values were estimated. Estimated rCBFs were reproducible for several measurements. The mean CBF value for a pentobarbital anesthetized monkey was 46.0 ml/min/100 g ...

Energy Technology Data Exchange (ETDEWEB)

Integration of positron emission tomography (PET) and magnetic resonance (MR) has become a topic of increasing interest to the imaging community over the past two years. In this text, the authors attempt to distinguish facts from fiction concerning such integrated systems. Analysis of existing information of combined imaging on existing brain PET/MR systems and imaging experience with PET-computed tomography (CT) is reviewed. Various types of system integration of PET and MR are discussed with completely independent systems on one hand and completely integrated systems with the possibility of simultaneous data acquisition on the other hand. Furthermore, it is discussed, what simultaneous data acquisition with nuclear imaging systems combined with MR or CT really means, as technical simultaneity may not be relevant in light of the pharmacokinetics of the nuclear tracers used. The authors conclude that combining PET/MR is an interesting research ...

International Nuclear Information System (INIS)

There has been a good deal of interest in the sialon system of ceramics in recent years due to their combination of important engineering properties #beta# including strength, hardness, low thermal expansion and good thermal shock resistance. #beta#-sialon (Si_6_-_zAl_zO_zN_8_-_z ;0Magnetic Resonance techniques in determining the nature of intermediate phases which occur. 9 refs., 1 tab., 1 fig.

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging (MRI) of the lung is challenging because of substantial drawbacks. However, lung pathologies that are associated with increased attenuation values in CT enhance visualization in MRI: proton density is increased and tissue-air interfaces, resulting in susceptibility artifacts, are reduced in pneumonia, pneumonitis, edema, and carcinoma. On the other hand, many lung diseases result in shortness of breath, so that patients cannot hold their breath for long periods. Therefore, fast imaging techniques are required which should also allow for high spatial resolution so that small lesions can be detected. Calcifications and air pockets within lesions are not readily recognized with MRI. Thin section CT is standard for the diagnosis of pneumonia. With parallel imaging techniques, MRI examination of the lungs can be performed with short periods of breath holding, which allow for sub-centimeter resolution in the z-axis. ...

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 in a single gantry. The use of existing scanner technology ensures that no compromises are made in the clinical efficacy of ...

International Nuclear Information System (INIS)

Doubly-excited 2s-12p-13pnp autoionizing resonance series of Ne atom as well as autoionizing resonances in the 2s region of Na and Mg atoms have been studied with monochromatized synchrotron radiation. Use of charge-separated photoion-yield method allowed us to detect these weak resonances in a clarified way in the yield curves of doubly-charged ions. The observed resonance states have been interpreted with the help of MCDF calculations, and the decay processes of these resonance states are discussed briefly.

British Library Electronic Table of Contents (United Kingdom)

Resonant scattering of atoms with formation of the Feshbach resonance in the presence of a laser radiation coupling the levels of two bound atoms (a molecule) is considered. The laser field leads to a second resonance in scattering and broadening of resonances, which facilitates the possibility of experimental observation of asymmetry of the total scattering cross-section arising because of interference between resonant and potential scatterings. The effects associated with interference of the two channels of decay of a bound system of two atoms (a molecule) in the laser field are studied. An expression is obtained for the scattering length in collision of two cold atoms in the field of laser radiation.

Science.gov (United States)

Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly

Science.gov (United States)