UK PubMed Central (United Kingdom)

Quantitative probing of heterogeneous regions in muscle is feasible with phosphorus-31 magnetic resonance spectroscopy because of the differentiation of metabolic patterns of glycolytic and oxidative...Full Text Available

J-STORE (Japan)

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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)

This paper describes a new technique that can be used to study chloroplast volume regulation in vivo. Nuclear magnetic resonance spectroscopy was used to measure relative amounts of chloroplast water...Full Text Available

UK PubMed Central (United Kingdom)

Prostatic neoplasms are not uniformly distributed within the prostate volume. With recent developments in three-dimensional intensity-modulated and imageguided radiation therapy, it is possible to treat...Full Text Available

International Nuclear Information System (INIS)

The long and resource intensive process of drug discovery and development is confronted with the basic challenge of providing effective and safe therapies at reasonably low costs. The better the mechanism of a disease is known, the higher the probability to find an appropriate therapy. Also, the better and earlier a disease can be diagnosed and characterized, the higher the chance to be able to interfere in this process with a chemical entity. This reasoning sets the framework for the use of imaging in drug discovery. We discuss the relevance of magnetic resonance imaging and spectroscopy to derive anatomical, functional, metabolic and target-related information in the context of pharmacological research in vivo. (author)

KoreaScience (Korea)

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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...

UK PubMed Central (United Kingdom)

We have employed both ³¹P nuclear magnetic resonance spectroscopy and two intracellular fluorescent pH indicator dyes to monitor the pH of the vacuole and cytoplasm of suspension-cultured...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Gamma-aminobutyric acid type A receptor-associated protein (GABARAP) belongs to a family of small ubiquitin-like adaptor proteins implicated in intracellular vesicle trafficking and autophagy. We have used diffusion-ordered nuclear magnetic resonance spectroscopy to study the temperature and concentration dependence of the diffusion properties of GABARAP. Our data suggest the presence of distinct conformational states and provide support for self-association of GABARAP molecules. Assuming a monomer-dimer equilibrium, a temperature-dependent dissociation constant could be derived. Based on a temperature series of {sup 1}H{sup 15}N heteronuclear single quantum coherence nuclear magnetic resonance spectra, we propose residues potentially involved in GABARAP self-interaction. The possible biological significance of these observations is discussed with respect to alternative scenarios of ...

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 that can be operated ...

Energy Technology Data Exchange (ETDEWEB)

Trichlorfon is an organophosphorus insecticide, which is extensively being used for protection of fruit crops. Trichlorfon is a thermal labile compound, which cannot be easily determined by gas chromatography (GC) and has no suitable group for sensitive detection by high performance liquid chromatography (HPLC). In this study, a {sup 31}P nuclear magnetic resonance ({sup 31}P NMR) has been described for monitoring of trichlorfon without any separation step. The quantitative works of {sup 31}P NMR spectroscopy has been performed in the presence of an internal standard (hexamethylphosphoramide). Limit of detection (LOD) for this method has been found to be 55 mg L{sup -1}, without any sample preparation, and the linear working range was 150-5500 mg L{sup -1}. Relative standard deviation (R.S.D.%) of the method for three replicates within and between days was obtained {<=}9%. The average recovery efficiency was ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

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.

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 ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

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Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclear multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of protonated and nonprotonated carbons, respectively. S. Staurosporeus was found to utilize ...

International Nuclear Information System (INIS)

Hybrid organic-inorganic coatings with phosphonate functionalities have been synthesized and evaluated as prospective surface treatments for magnesium materials. These coatings have been processed via a sol-gel route by hydrolysis and condensation of a mixture of diethylphosphonatoethyltriethoxy-silane and tetraethoxy-silane with variable molar ratios. The coatings morphology and the surface chemistry at the coating/substrate interface have been characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, "3"1P nuclear magnetic resonance spectroscopy, and time-of-flight secondary ion mass spectrometry. The corrosion protection performance of the coatings deposited on magnesium alloy AZ31B has been examined by a group of electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, a scanning Kelvin ...

International Nuclear Information System (INIS)

A dense silica glass was prepared by consolidating a highly dispersed silicic acid powder (particle size 1H magic-angle spinning (MAS) NMR confirmed an increase in hydroxyl groups in the sample prepared by SPS relative to that of the conventional SiO2 reference glass. Aside from the comparably high water content, we conclude from the similarity of the IR-reflectance and the 29Si MAS NMR spectra of the SPS sample and the corresponding spectra of the conventionally prepared silica glass, that the short- and medium-range order is virtually the same in both materials. Raman spectroscopy, however, suggests that the number of three- and four-membered rings is significantly smaller in the SPS sample compared to the conventionally prepared sample. Based on these results we conclude that it is possible to prepare glasses by compacting amorphous powders by the SPS process. The SPS process may therefore enable the preparation of glasses with compositions inaccessible by ...

UK PubMed Central (United Kingdom)

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

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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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...

Energy Technology Data Exchange (ETDEWEB)

Electron spin resonance spectroscopy can provide a powerful approach to the study of radiation effects in biological materials. This memorandum gives an overview of current and future research. (author).

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.

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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 ...

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 ...

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,

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

International Nuclear Information System (INIS)

The authors present differential scanning calorimetry (DSC) and in situ Moessbauer spectroscopy results for Metglas ribbons, to which different heat treatments were made. The Curie temperature of the amorphous phase is determined and the evolution of the magnetic field of this phase is studied as a function of temperature

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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)

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A series of 2-alkylthiopyrine-4-carbothioamides were synthesized, and their anti-fungal potency was tested. The chemical structures were proved by infrared spectroscopy (IR) and {sup 1}H nuclear magnetic resonance ({sup 1}H-NMR) data and by elemental analysis. The minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) assessment were used for the estimation of potential activity in vitro. The study comprising 21 clinical isolates of fungi showed that two compounds exhibited fair inhibitory activity against some yeasts and dermatophytes. Selective fungistatic activity against non-dermatophytes (MIC = 3.12-25.0 {mu}g/mL) was found also in another compound. None of the above compounds showed inhibitory activity against non-dermatophyte filamentous fungi. Microbiological activity of 2-alkylthiopyridine-4-carbothioamides appears to be mainly related to hydrophobicity of alkyl in position 2. (authors). ...

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.

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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.

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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 ...

International Nuclear Information System (INIS)

Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d"76s"2"4F_9_/_2#->#5d"76s6p"6F_1_1_/_2 at 351.5nm were measured for "1"8"2"-"1"8"9Ir, "1"8"6Ir"m and the stable "1"9"1","1"9"3Ir. The nuclear magnetic moments #mu#_I and the spectroscopic quadrupole moments Q_s were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of #mu#_I was experimentally determined for the first time for the ...

DEFF Research Database (Denmark)

We present a theoretical study of the resonant interaction between dynamical localized states (discrete breathers) and linear electromagnetic excitations (EE's) in Josephson junction ladders. By making use of direct numerical simulations we find that such an interaction manifests itself by resonant steps and various sharp switchings (voltage jumps) in the current-voltage characteristics. Moreover, the power of ac oscillations away from the breather center (the breather tail) displays singularities as the externally applied dc bias decreases. All these features may be mapped to the spectrum of EE's that has been derived analytically and numerically. Using an improved analysis of the breather tail, a spectroscopy of the EE's is developed, The nature of breather instability driven by localized EE's is established.

International Nuclear Information System (INIS)

With "1"5"1Eu-Moessbauer spectroscopy and other methods the complex magnetic properties of Eu_2PdSi_3, arising from the two crystallographically different lattice sites of the Eu"2"+ ions, have been already studied. Here we study the impact of magnetic dilution of the magnetic Eu"2"+ sites by non-magnetic Y"3"+ ions. A previous specific heat study has found reduced magnetic ordering temperatures with strong indication of disorder effects like in magnetic spin glasses. Here we provide from "1"5"1Eu-Moessbauer spectroscopy detailed information of the impact of Y"3"+ substitution on the magnetic properties of the two lattice sites, well distinguishable in the "1"5"1Eu-spectra. Since the substitution of the larger Eu"2"+ ions by the smaller Y"3"+ ions is connected with a lattice contraction, we also ...

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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 affinity and temporal course of functional fields in middle and posterior superior temporal cortex for the categorization of complex sounds was examined using functional magnetic resonance imaging...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)

Early detection of precancerous tissue has significantly improved survival of most cancers including colorectal cancer (CRC). Animal models designed to study the early stages of cancer are valuable...Full Text Available

UK PubMed Central (United Kingdom)

Background and purposeRadial head fractures are common, and may be associated with other injuries of clinical importance. We present the results of a standard additional MRI scan...Full Text Available

UK PubMed Central (United Kingdom)

Pericardial fat necrosis is an infrequent cause of acute chest pain and this can mimic acute myocardial infarction and acute pericarditis. We describe here a patient with the magnetic resonance imaging...Full Text Available

International Nuclear Information System (INIS)

English Mar 1998 p. 278 France Omura, M. Aida, N. Sekido, K. Kakehi,

UK PubMed Central (United Kingdom)

Using 31P-nuclear magnetic resonance, we studied the relationship between myocardial high-energy phosphate content and flux values for the creatine kinase reaction in the living rat under inotropic...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.

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.

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The authors report the findings of Aicardi syndrome, a disease of unknown etiology composed of multiple spasms, chorioretinal lacunae and agenesis of the corpus callosum. They present a case of Aicardi syndrome with characteristic clinical presentation and magnetic resonance imaging findings. The disease, despite being considered rare, has characteristic imaging findings. Over the past years magnetic resonance imaging has improved its ability in demonstrating other findings besides agenesis of the corpus callosum, making the radiologist's role very important in the diagnostic suspicion of this disease. (author)

Energy Technology Data Exchange (ETDEWEB)

This thesis describes the analysis of the semileptonic decay D{sup 0} {yields} {bar K}{sup 0} {pi}{sup -} {mu}{sup +}{nu} using FOCUS data. FOCUS is a fixed target experiment at Fermilab that studies the physics of the charm quark. Particles containing charm are produced by photon-gluon fusion from the collision of a photon beam on a BeO target. The experiment is characterized by excellent vertex resolution and particle identification. The spectrometer consists of three systems for track reconstruction (two silicon systems and one multiwire proportional chamber system) and two magnets of opposite polarity. The polarity of the magnet is such that the events of e{sup +}e{sup -} pairs produced in the target (which constitutes the main background) travel through a central opening in the detectors without interactions. Particle momentum is measured from the deflection angle in the magnets. Three multicell Cerenkov counters are ...

International Nuclear Information System (INIS)

Normal state nuclear magnetic resonance studies of the La_3In, La_3Tl compounds have been made in order to investigate the origin of the large temperature-dependent magnetic susceptibility. It is possible to analyse the different contributions to the susceptibility using Knight-shift and relaxation time T_1 measurements of In"1"1"5 and Tl"2"0"5 nuclei. The exchange enhancement of the spin-susceptibility chisub(pd) is of the same order as that found in A-15 compounds and the strong temperature-dependence of chi(T) is attributed to the presence of a peak in the electronic density of states near the Fermi level. The variation of the Knight-shift in the ternary alloys La_3Xsub(1-y)Xsub(y)sup(') is analogous to that observed in the corresponding La_3X phases, on the other hand the Knight-shift in the carbides La_3XC is temperature independent. (author).

British Library Electronic Table of Contents (United Kingdom)

The physicochemical properties of binary lipid mixtures of diether C25,25 lipids and dipalmitoyl-L-a-phosphatidylcholine (DPPC) were studied using photon correlation, fluorescence and electron paramagnetic resonance spectroscopy, and transmission electron microscopy. These two types of lipids can be mixed at all molar ratios to form unilamellar and multilamellar liposomes. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatrien in mixed liposomes indicates that the abrupt changes in order parameter in the hydrophobic part of bilayer membranes made of DPPC lipids disappears with increasing mol%C25,25 lipids. Electron paramagnetic resonance spectroscopy shows that at temperatures below 50^oC, the interfacial regions of membrane bilayer of mixed liposomes is more fluid than for pure DPPC lipo...

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 ...

Energy Technology Data Exchange (ETDEWEB)

Proton magnetic resonance spectroscopy (MRS) measures concentrations of metabolites in vivo and provides a powerful method for identifying tumours. MRS has not entered routine clinical use partly due to the difficulty of analysing the spectra. To create a straightforward method for interpreting short-echo-time MRS of childhood cerebellar tumours. Single-voxel MRS (1.5-T Siemens Symphony NUM4, TR/TE 1,500/30 ms) was performed at presentation in 30 children with cerebellar tumours. The MRS results were analysed for comparison with histological diagnosis. Peak heights for N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mIns) were determined and receiver operator characteristic curves used to select ratios that best discriminated between the tumour types. The method was implemented by a group of clinicians and scientists, blinded to the results. A total of 27 MRS studies met the quality control ...

Energy Technology Data Exchange (ETDEWEB)

A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of {sup 137}Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the exchangers were irradiated with a {sup 60}Co source to a total ...

Energy Technology Data Exchange (ETDEWEB)

Changes in the phosphate metabolism of the transplanted SCCVII (squamous cell carcinoma VII) tumor were studied before and after irradiation using in vivo [sup 31]P-magnetic resonance spectroscopy (MRS). Phosphocreatine (PCr), [gamma]-, [alpha]-, [beta]-ATP, inorganic phosphate (Pi), phosphomonoester (PME), and phosphodiester (PDE) were detected in [sup 31]P-MR spectra of tumor tissues. The curve fitting method was employed for calculating each peak of [sup 31]P-MR spectra (PCr, [beta]-ATP, Pi, PME, PDE). The values of PCr, PCr/Pi, [beta]-ATP/Pi and pH decreased in proportion to the growth of tumor, whereas that of Pi, PME and PDE increased. But the changes of [beta]-ATP were minimal in degree. Based on the fact that the ratio of PCr/Pi highly correlated with tumor volume and showed the most remarkable change among various parameters, it might be the useful index for the tumor growth. Because the phospholipid metabolite PME ...

Energy Technology Data Exchange (ETDEWEB)

The rate of the oxygen-exchange reaction in an aqueous solution of a heterocyclic oxygen compound, 2,4,6-trimethylpyrylium perchlorate, was quantitated. The /sup 18/O isotope effect in /sup 13/C NMR spectroscopy affords a direct, continuous, and relatively simple analysis of the reaction and was used to obtain data on the incorporation of /sup 18/O from solvent H/sub 2//sup 18/O into the pyrylium salt. Due to the low solubility of this salt in aqueous solutions, 2,4,6-trimethyl(2-/sup 13/C)pyrylium perchlorate and 2,4,6-trimethyl(2,6-/sup 13/C/sub 2/)pyrylium perchlorate were synthesized to facilitate the acquisition of the data on an NTC-200 spectrometer operating at 50.31 MHz. Upon incorporation of /sup 18/O into the pyrylium salt, the /sup 13/C NMR signal of the directly bonded carbon atom is shifted upfield 0.038 ppm. A /sup 13/C isotope effect is also detected in the doubly /sup 13/C-enriched pyrylium salt where the /sup 13/C NMR signal for /sup 13/C-O-/sup ...

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)

The structure of the layers formed on a silver electrode by the adsorption of pyridine, Cl"-, CN"- and SO_4"2"- is discussed. A comparison of the amount of the species adsorbed with their Raman spectra shows that there is no simple relation between the species concentration and the enhancement of the Raman intensity. Furthermore, the inhomogeneity of the layers is shown by Raman microscopy observations. These results lead the authors to propose the formation of a new species stabilized in the colloidal silver layer. The Raman enhancement could be explained by the existence of a resonance effect. (Auth.).

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.

British Library Electronic Table of Contents (United Kingdom)

Inspired by the recent realizations of quantum dot (QD)-DNA conjugation, we study the spectral density of a magnetic impurity coupled to a mesoscopic semiconducting host. Using a combination of exact diagonalization technique and an analytic approach, we demonstrate that various types of resonances occur according to the relative position of impurity levels (IL) with respect to the host levels (HL). While the usual Coulomb peaks appear when the IL lie inside a band gap, with IL approaching HL and hybridization activated, they shift nonlinearly with the repulsion strength and even undergo splitting for a strong hybridization. When IL merge into HL, multiple resonances of a comblike structure are found along with a parity effect.

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.).

CERN Document Server

We explore a planar GaAs/AlAs photonic microcavity using pump-probe spectroscopy. Free carriers are excited in the GaAs with short pump pulses. The time-resolved reflectivity is spectrally resolved short probe pulses. We show experimentally that the cavity resonance and its width depend on the dynamic refractive index of both the lambda-slab and the lambda/4 GaAs mirrors. We clearly observe a double exponential relaxation of both the the cavity resonance and its width, which is due to the different recombination timescales in the lambda-slab and the mirrors. In particular, the relaxation time due to the GaAs mirrors approaches the photon storage time of the cavity, a regime for which nonlinear effects have been predicted. The strongly non-single exponential behavior of the resonance and the width is in excellent agreement to a transfer-matrix model taking into account two recombination times. The change ...

International Nuclear Information System (INIS)

The future use of single-molecule magnets in applications will require the ability to control and manipulate the spin state and magnetization of the magnets by external means. There are different approaches to this control, one being the modification of the magnets by adsorption of small ligand molecules. In this paper we use iron phthalocyanine supported by an Au(111) surface as a model compound and demonstrate, using x-ray photoelectron spectroscopy and density functional theory, that the spin state of the molecule can be tuned to different values (S #approx# 0, 1/2, 1) by adsorption of ammonia, pyridine, carbon monoxide or nitric oxide on the iron ion. The interaction also leads to electronic decoupling of the iron phthalocyanine from the Au(111) support. (fast track communication)

British Library Electronic Table of Contents (United Kingdom)

Samples of Fe78B13Si9 (Metglas 2605 TCA) and Fe77Cr2B16Si5 (Metglas 2605 S3A) were exposed to pulsed excimer laser irradiation at repetition rates of 15, 25 and 50Hz. The occurrence of out-of-plane magnetic anisotropy, changes in the average hyperfine magnetic field and width of the hyperfine field distribution were evidenced by transmission Mossbauer spectroscopy. The variation of the recoilless fraction with laser processing parameters was derived from the simultaneous recording of Mossbauer spectra using a stainless steel etalon as a dual absorber. Conclusions on the onset of long-range magnetic order were formulated.

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.

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)

The quality of molecular dynamics (MD) simulations of proteins depends critically on the biomolecular force field that is used. Such force fields are defined by force-field parameter sets, which are generally determined and improved through calibration of properties of small molecules against experimental or theoretical data. By application to large molecules such as proteins, a new force-field parameter set can be validated. We report two 3.5 ns molecular dynamics simulations of hen egg white lysozyme in water applying the widely used GROMOS force-field parameter set 43A1 and a new set 45A3. The two MD ensembles are evaluated against NMR spectroscopic data NOE atom-atom distance bounds, {sup 3}J{sub NH{alpha}} and {sup 3}J{sub {alpha}}{sub {beta}} coupling constants, and {sup 1}5N relaxation data. It is shown that the two sets reproduce structural properties about equally well. The 45A3 ensemble fulfills the atom-atom distance bounds derived from NMR spectroscopy ...

Energy Technology Data Exchange (ETDEWEB)

He ions incident at grazing angles on Cu(110) and Ni(110) surfaces are neutralised into triplet and singlet states, of which the 3p, 3d and 4d upper states are accessible to optical spectroscopy. In the energy range from 500 eV to 15 keV no significant energy dependence of the relative intensities of singlet and triplet lines was observed for scattering on Cu(110). The intensities from Ni(110) are higher and the singlet to triplet intensity ratio of the 3d to 2p transition is about 6% smaller than that from Cu(110). The results can be explained well by assuming resonant charge capture into excited He and intermediate formation of negative He/sup -/ states.

International Nuclear Information System (INIS)

"1"7"5Ta and "1"7"7Ta nuclei were oriented at low temperature as dilute impurities in Fe. The magnetic hyperfine splitting frequencies #nu#="+#mu#B sub(HF)/Ih"+ of the "1"7"5Ta and "1"7"7Ta 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 "1"8"1Ta in Fe, the magneticmoments have been deduced: "+#mu#("1"7"5Ta, 7/2"+)"+=2.270(45) and "+#mu#("1"7"7Ta, 7/2"+)"+=2.250(45)#mu# sub(N). These values of the magnetic moments are discussed in the framework of the rotational model. (author).

International Nuclear Information System (INIS)

Formation of the soft magnetic nanostructure in amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloy due to heat treatment is studied by the Moessbauer, differential scanning calorimetry, and X-ray diffraction techniques. Annealing at temperatures 520-580 "oC leads to the formation of extremely soft nanocrystalline alloy as revealed by the rf-Moessbauer measurements. The superparamagnetic behaviour was observed for the alloy annealed at 620-640 "oC. At higher annealing temperatures good soft magnetic properties deteriorate. (author)

Science.gov (United States)

We present evidence for the creation of an exchange spring in an antiferromagnet due to exchange coupling to a ferromagnet. X-ray magnetic linear dichroism spectroscopy on single crystal Co/NiO(001) shows that a partial domain wall is wound up at the surface of the antiferromagnet when the adjacent ferromagnet is rotated by a magnetic field. We determine the interface exchange stiffness and the antiferromagnetic domain wall energy from the field dependence of the direction of the antiferromagnetic axis, the antiferromagnetic pendant to a ferromagnetic hysteresis loop. The existence of a planar antiferromagnetic domain wall, proven by our measurement, is a key assumption of most exchange bias models.

British Library Electronic Table of Contents (United Kingdom)

Fe-doped TiO2 hollow spheres (Fe-THs) were synthesized by sol?gel process using carbon spheres as templates. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV?vis diffuse reflectance spectrum (DRS), N2 adsorption?desorption isotherms, Electron paramagnetic resonance (EPR) spectroscopy and Photoluminescence emission spectroscopy (PL). UV?vis spectra showed that Fe3+ doping could extend the absorption edge to the visible region. EPR spectra showed that Fe3+ was incorporated into the crystal lattice of TiO2, which could inhibit the recombination of photo-induced electron?hole pairs and improve the photocatalytic activity. The photocatalytic activities of the prepared samples were evaluated for the degradation of dye Reactive Brillia...

International Nuclear Information System (INIS)

Cavity ringdown spectroscopy (CRDS) with continuous-wave (cw) laser excitation has added high frequency resolution to the ability of CRDS being used for the absolute quantification of trace-level species present in many chemical processes. Cavity dithering technique has easily resolved the problem of resonant coupling of a cw laser light into a high-finesse cavity. The present study addresses the potential uncertainty involved in such cw-CRDS techniques incorporating the cavity mirror motion, i.e., the doppler frequency shift of a probe light inside the cavity. In the high-resolution spectroscopic work of megahertz-accuracy, even the influence of intracavity doppler effect may become significant.

Energy Technology Data Exchange (ETDEWEB)

Optical Isotope shift measurements have been performed for the {sup 240f,242f}Am fission isomers to test the stability of nuclear deformation as function of the neutron number. The method is based on resonance ionization spectroscopy (RIS) in a buffer gas cell with fission detection of the ionization process. The {sup 240f,242f}Am fission isomers have been produced by {sup 242}Pu(p, 3n), {sup 242}Pu(d, 2n) reactions, respectively. Relative isotope shift ratios X{sub exp}{sup 242f}(500 nm)=IS{sup 242f,241}/IS{sup 243,241}=41.4(8) and X{sub exp}{sup 240f}(500 nm)=IS{sup 240f,241}/IS{sup 243,241}=39.2(8) were measured. From these ratios a small difference {delta}{beta}{sub 2}{sup 242f,240f}=0.0076(14) of the deformation parameter {beta}{sub 2} can be deduced assuming that the isotope shift between the reference isotopes {sup 241,243}Am is caused by a pure volume change. (orig.)

Science.gov (United States)

MAGNETIC FORMING .............. MAGNETIC INDUCTION ............ MAGNETIC MATERIALS ............ MAGNETIC MEASUREMENT .......... MAGNETIC PERMEABILITY . ...

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)

Free Electron Laser (FEL) with wide wavelength tunability has been developed and used for various applications. We report the structural-changes in P-ion-implanted diamond when we can achieve resonant excitation of the vibrations of specific bonds in the lattice of target (P-C) by using FEL. The change of property was analyzed by SIMS and Raman spectroscopy. After 5.8 #mu#m-FEL irradiation, we observed the crystallization of amorphous structure which was induced by P-ion-implantation. These results indicated the FEL annealing of diamond at room temperature. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

CERN Document Server

We report an uncertainty evaluation of an optical lattice clock based on the $^1S_0\\leftrightarrow^3P_0$ transition in the bosonic isotope $^{174}$Yb by use of magnetically induced spectroscopy. The absolute frequency of the $^1S_0\\leftrightarrow^3P_0$ transition has been determined through comparisons with optical and microwave standards at NIST. The weighted mean of the evaluations is $\

Energy Technology Data Exchange (ETDEWEB)

High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu{sub 2}O{sub 3} as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.

British Library Electronic Table of Contents (United Kingdom)

High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723K by using Eu2O3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.

Energy Technology Data Exchange (ETDEWEB)

Piezoelectric ceramics for acoustic applications have been prepared by mixing the piezoelectric phase Pb{sub 1-1.5x}La{sub x}{open_square}{sub x/2}(Ti{sub 1-y}Zr{sub y})O{sub 3} (PLZT) with variable fractions of Al{sub 2}O{sub 3}. The samples are in form of pellets and polarized at high temperature. After thermal treatment, X-ray diffraction and scanning electron microscopy have been used to determine the phase and morphological modifications. The morphotropic PLZT initial phase disproportionates into modified PLZT and ZrO{sub 2} phases. Using electrical impedance spectroscopy, the resonance frequencies of the composite system have been determined and analyzed. As the Al{sub 2}O{sub 3} volume fractions increase, the resonance frequency and the amplitude of the electrical response both decrease. An interpretation of the role of Al{sub 2}O{sub 3} additions is proposed in terms of phase and microstructure modifications. Using ...

International Nuclear Information System (INIS)

Using the full potential linearized augmented plane wave (FLAPW) method, the magnetic properties of two-dimensional Ru and Rh monolayers (MLs) on a NiAl(001) surface have been investigated. It has been found that free standing one monolayer Ru and Rh films have ferromagnetic ground state with magnetic moments of 2.21 and 1.48 #mu#_B, respectively. The ferromagnetism is still observed even on a Ni terminated NiAl(001) surface, while no magnetic state is found on an Al terminated surface. The calculated magnetic moments of Ru and Rh atoms are 1.56 and 0.88 #mu#_B, respectively. In addition, an induced magnetic moment in surface Ni is observed. It has been found that the free standing Ru film has perpendicular magnetization to the film surface with a magnetocrystalline anisotropy (MCA) energy of 0.66 meV/atom, while an in-plane MCA energy of 0.37 meV/atom is ...

International Nuclear Information System (INIS)

Magnetic properties of the Al1-xGaxFeO3 family of oxides crystallizing in a non-centrosymmetric space group have been investigated in detail along with structural aspects by employing X-ray and neutron diffraction, Moessbauer spectroscopy and other techniques. The study has revealed the occurrence of several interesting features related to unit cell parameters, site disorder and ionic size. Using first-principles density functional theory based calculations, we have attempted to understand how magnetic ordering and related properties in these oxides depend sensitively on disorder at the cation site. The origin and tendency of cations to disorder and the associated properties are traced to the local structure and ionic sizes. -- Graphical abstract: We have studied both experimentally and theoretically the important role of disorder at the cation site on magnetic and related properties of the Al1-xGaxFeO3 ...

International Nuclear Information System (INIS)

Ge pre-amorphisation step is used to reduce the high diffusivity and the transient-enhanced diffusion of boron implanted in silicon. The aim of the process is to obtain shallow P"+N junctions. The pre-amorphisation step was performed under different conditions (in ambient temperature and in nitrogen). Following the rapid thermal annealing step, end of range (EOR) defects appear at the amorphous-crystalline interface. These defects could influence the electrical characteristics of the P"+N junctions. An experimental study concerning three samples has been performed without and under a magnetic field of 800 G. The magnetic susceptibility was essentially observed in the case of the reverse current. The impact of the magnetic field, studied by varying the sample temperature, permits us to show an increase of the magnetic susceptibility when the defects present in such structures are electrically active. ...

Energy Technology Data Exchange (ETDEWEB)

Bremstrahlung Isochromat Spectroscopy (BIS). The XES spectra were collected using a Specs electron gun for the excitation and the XES 350 grating monochromator and channel plate system from Scienta as the photon detection. Spectra were collected in 'normal mode,' where the electron gun kinetic energy (KE) and the energy position of the center of the channel plate were both fixed and the energy distribution in the photon (hv) spectrum was derived from the intensities distributed across the channel plate detector in the energy dispersal direction. The polycrystalline Ce sample was oxidized by exposure to air at ambient pressures. After introduction to the ultra-high vacuum system, the oxidized sample was bombarded with Ar, to clean the topmost surface region and stabilize the surface and near surface regions. Although CeO{sub 2} would be the thermodynamically preferred composition in an oxygen rich environment, the combination of a vacuum ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The method of proton magnetic resonance (PMR) has been used to study the mechanism of reaction of complexing of paramagnetic Pr/sup 3 +/ ion with ethylenediaminetetra acetic acid (EDTA). The influence of medium acidity (pH5-12), EDTA/Pr ratio varying from 1 to 50, Pr/sup 3 +/ ion concentration (from 5x10/sup -3/ to 3x10/sup -1/ g-ion/l) and temperature (8-98 deg C) on chemical shifts and broadening of signals of EDTA molecule protons is investigated. Data on ratio of components, coordination and stability of forming complexes are obtained. The existence of two types of complexes with the Pr/EDTA ratio equal to 1:1 and 1:2 has been found. Equimolecular complex (1:1) is stable all over the studied temperature interval in contrast to the complex 1:2 for which at 50 deg C fast extrasphere exchange (Pr EDTA)EDTA * + EDTA/sup 0/ reversible (PrEDTA)EDTA/sup 0/ + EDTA * is observed, while at t=98 deg C intrasphere exchange (PrEDTA)EDTA * reversible ...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Magnetic resonance imaging (MRI) was used to evaluate 22 histological proven peripheral nerve sheath tumors, approximately two-thirds of which arose in the lower extremity. The histologic distribution was as follows: 12 schwannomas, 7 neurofibromas, and 3 malignant peripheral nerve sheath tumors (2 of which occurred in patients with neurofibromatosis). Most lesions demonstrated an intermediate to moderately bright signal on T_1-weighted images and were minimally inhomogeneous. All lesions were moderately bright on T_2-weighted images, again with variable inhomogeneity. The extent of the tumor was best assessed on proton-density- and T_2-weighted images. Smooth margins were noted in 19 lesions. Of the 3 remaining lesions, 2 were malignant (but had been subjected to biopsy prior to MRI), and the other lesion was a plexiform neurofibroma. MRI accurately determined the relationship between the lesions and the adjacent neurovascular structures and ...

Energy Technology Data Exchange (ETDEWEB)

The effect of the external pH on the intracellular pH in mung bean (Vigna mungo (L.) Hepper) root-tip cells was investigated with the T P nuclear magnetic resonance (NMR) method. The T P NMR spectra showed three peaks caused by cytoplasmic G-6-P, cytoplasmic Psub(i) and vacuolar Psub(i). The cytoplasmic and vacuolar pHs could be determined by comparing the Psub(i) chemical shifts with the titration curve. When the external pH was changed over a range from pH 3 to 10, the cytoplasmic pH showed smaller changes than the vacuolar pH, suggesting that the former is regulated more strictly than the latter. The H -ATPase inhibitor, DCCD, caused the breakdown of the mechanism that regulates the intracellular pH. H -ATPase appears to have an important part in the regulation of the intracellular pH.

Energy Technology Data Exchange (ETDEWEB)

Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration ...

Energy Technology Data Exchange (ETDEWEB)

The authors present a guide to the imaging of facial fractures. It is illustrated with conventional radiographs and computed tomograms; the magnetic resonance images primarily suggest the potential applications of this technique. This book provides a source of imaging information on facial trauma. A section on pertinent anatomy is followed by a systematic discussion of the common isolated and complex facial fractures. Perspectives are offered on some commonly seen but infrequently described relationships, such as the tripod-LeFort II association. Consideration is also given to related soft-tissue injuries. The book includes a brief chapter on the type and utility of supplementary imaging studies in the evaluation of those intracranial injuries that may occur concurrently.

Energy Technology Data Exchange (ETDEWEB)

It is shown that pure NQR can be utilized as a platform for quantum computing without applying a high external magnetic field. By exciting each resonance transition between quadrupole energy levels with two radio-frequency fields differing in phase and direction, the double degeneracy of the spin energy spectrum in an electric field gradient is removed. As an example, in the case of I=7/2 (nuclei {sup 133}Cs or {sup 123}Sb) the energy spectrum has eight levels which can be used as three qubits. (orig.)

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The atlas presents sequences of MRI sections parallel to the orbito-meatal plane in children from birth through the age of sixteen years. Each child was studied horizontally and sagitally and three-dimensional brain images were reconstructed to facilitate accurate identification of sulci and gyri. The images show crucial aspects of brain development such as the constancy of the brain stem and primitive brain from birth onward; the development of the telencephalon, characterized by deepening of sulci and growth of the cerebral cortex surface; and the different stages of white matter myelinization.

British Library Electronic Table of Contents (United Kingdom)

Magnetic resonance (MR) imaging and histopathology were used to diagnose an articular process synovial myxoma in a dog. On MR images, the tumor was characterized by distortion of the left L1-L2 articular process, widening of the articular process joint, and the presence of a mass contiguous with the synovium of the articular process that displaced the spinal cord. The tumor was T2-hyperintense, T1-hypointense, relative to muscle, and had mild contrast enhancement. The MR features of articular process synovial myxoma may be distinct from other diseases of the articular process joint.

International Nuclear Information System (INIS)

A 37-year-old military mechanic presented to our institution with a chronic history of a slowly enlarging left elbow antecubital fossa mass. There was no history of other chronic illness or trauma. Magnetic resonance imaging (MRI) and excisional biopsy revealed fatty villi and synovial inflammation within the left bicipitoradial bursa, consistent with lipoma arborescens. Four years later the patient presented with a 6-month history of swelling at the antecubital fossa of the opposite elbow. Diagnostic computed tomography and MRI examinations were performed. The surgical and pathologic findings confirmed the imaging diagnosis of lipoma arborescens at the right bicipitoradial bursa. (orig.)

Science.gov (United States)

Renal arteriovenous fistula or pseudoaneurysms developing after invasive procedures are either asymptomatic or show only transient symptoms. We describe here a case of symptomatic renal artery pseudoaneurysm that presented with gross hematuria and azotemia. The pseudoaneurysm of renal artery was diagnosed by ultrasonography and abdominal magnetic resonance imaging (MRI), and it was successfully treated by percutaneous transcatheter coil embolization. A high index of suspicion is essential for the early diagnosis and treatment of delayed gross hematuria in patients with history of percutaneous nephrostomy. PMID:17180737

International Nuclear Information System (INIS)

The thickness dependent magnetic properties of artificially prepared ultrathin body-centered cubic Ni films have been explored using the all electron full potential linearized augmented plane wave (FLAPW) method. We have considered two types of BCC Ni(001) films: (i) pure BCC Ni(001) and (ii) Au capped BCC Ni(001) in the range from 1 monolayer (ML) to 4 ML of Au capping coverage. The average magnetic moment of pure BCC Ni(001) is about 0.63 #mu#_B and a typical surface enhancement is found with a magnetic moment of 0.78 #mu#_B. In the presence of an Au capping layer, the magnetic moment of interface Ni is strongly suppressed to approximately 0.5 #mu#_B and this causes a reduction of average magnetic moment. Nevertheless, the Au adlayer has no meaningful induced magnetic moment. The BCC pure Ni(001) films always have in-plane magnetization up ...

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We propose and demonstrate a facile room-temperature synthetic method for obtaining water-soluble magnetic Fe3O4 nanoparticles (NPs) by combining the in situ synthesis and decomposition of a magnetic polymer hydrogel. The Fe3O4 NPs with average diameters of 6.3-8.3nm were synthesized in a cross-linked polyacrylamide (PAAm) hydrogel by coprecipitating iron ions. The decomposition of the magnetic polymer hydrogel by an aqueous solution of sodium hydroxide led to the transfer of Fe3O4 NPs into the aqueous medium. The NPs can be dispersed stably in water for more than three months. The Fe3O4 NPs were characterized by X-ray photoelectron spectra (XPS), X-ray powder diffraction (XRD), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The saturation magn...

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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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We synthesized Fe3O4Gg nanocomposites through a combination of solvothermal, hydrothermal, and chemical redox reactions. Characterization of the resulting samples by X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning and transmission electron microscopy, and magnetic measurement is reported. Compared to Fe3O4g nanocomposites, the Fe3O4Gg nanocomposites showed enhanced antibacterial activity. The Fe3O4Gg nanocomposites were able to almost entirely prevent growth of Escherichia coli when the concentration of Ag nanoparticles was 10mg/mL. Antibacterial activity of the Fe3O4Gg nanocomposites was maintained for more than 40h at 37^oC. The intermediate carbon layer not only protects magnetic core, but also improves the dispersion and antibacterial activity of the...

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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 ...

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Silver silica nanocomposites were obtained by the sol-gel technique using tetraethyl orthosilicate (TEOS) and silver nitrate (AgNO{sub 3}) as precursors. The silver nitrate concentration was varied for obtaining composites with different nanoparticle sizes. The structural and microstructural properties were determined by x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopic (XPS) studies were done for determining the chemical states of silver in the silica matrix. For the lowest AgNO{sub 3} concentration, monodispersed and spherical Ag crystallites, with an average diameter of 5 nm, were obtained. Grain growth and an increase in size distribution was observed for higher concentrations. The occurrence of surface plasmon resonance (SPR) bands and their evolution in the size range 5-10 nm is studied. For decreasing nanoparticle size, a redshift and ...

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Superparamagnetic MFe{sub 2}{sup 3+}O{sub 4} (M=Mn{sup 2+}, Fe{sup 2+} and Co{sup 2+}) 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, r{sub 2}/r{sub 1}, for MnFe{sub 2}O{sub 4}, Fe{sub 3}O{sub 4} and CoFe{sub 2}O{sub 4} were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T{sub 2} contrast agents for MRI.

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 this very early stage. ...

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Recent developments in solid-state radio frequency (RF) power technologies allow for the practical consideration of RF heated plasmas for space propulsion. These technologies permit the use of any electrical power source, de-couple the power and propellant sources, and allow for the effcient use of both the propellant mass and power. Effcient use of the propellant is obtained by expelling the rocket exhaust at the highest possible velocity, which can be orders of magnitude higher than those achieved in chemical rockets. Handling the hot plasma exhaust requires the use of magnetic nozzles, and the basic physics of ion detachment from the magnetic eld is discussed. The plasma can be generated by RF using helicon waves to heat electrons. Further direct heating of the ions helps to reduce the line radiation losses, and the magnetic geometry is tailored to allow ion cyclotron resonance heating. RF eld and ...

International Nuclear Information System (INIS)

In previous work, on cooling from 300 K to 10 K the elastic moduli for both #alpha#- and #delta#-Pu dropped 30%. This large change may reflect effects of 5f-electron localization. In this work, the elastic moduli at ambient temperature of several Pu-Ga alloys were measured using resonant ultrasound spectroscopy (RUS). The strong temperature dependence of the bulk and shear modulus and the temperature independence of Poisson's ratio was confirmed and the upper temperature limit for #alpha#-Pu was extended to 360 K. Measurements of the time dependence of the shear moduli of Pu and Pu-2.36 at.% Ga were determined with high precision as a function of time and temperature. Using a model for time dependence of point defects, we determined the exponential time constant at ambient temperature for such variations. The low temperature results are consistent with Fluss .

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In CsCdBr{sub 3}, Tm{sup 3+} substitutes for Cd{sup 2+}. It predominately forms symmetric dimer centers and single-ion centers, both of trigonal symmetry. The energy level schemes of both centers were determined by EPR and site-selective laser spectroscopy. To describe the spectra term dependent crystal-field parameters were deduced on the basis of a microscopic model taking into account the local lattice deformation induced by the impurity centers and the quasi-resonant virtual scattering of intrinsic lattice excitations by the Tm{sup 3+} ions. (orig.) 22 refs.

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Yb3+?Tm3+ codoped tellurite glasses containing silver nanoparticles (NPs) were synthesized and characterized using transmission electron microscopy and optical techniques. The samples? composition and the nucleation of NPs were investigated using electron diffraction and energy dispersive spectroscopy. For the optical experiments, the samples were excited using a diode laser operating at 980?nm, in resonance with the Yb3+ transition 2F7/2?2F5/2. Photoluminescence (PL) bands corresponding to Tm3+ transitions were observed at 480, 650, and 800?nm due to the Yb3+? Tm3+ energy transfer. PL enhancement was achieved by heat-treatment of the samples at 325?C during different time intervals. The growth of the PL bands correlates with the increase of the silver NPs concentration. The relevant mecha...

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Crystal field calculation and electron paramagnetic resonance (EPR) have been performed on zircon-type materials Nd:YMO{sub 4} (M=V, As, P). Simulation of the energy level schemes has been carried out and the wave functions composition and g tensor principal values associated to the first sub-level of the {sup 4}I{sub 9/2} manifold were calculated. A rather good correlation is obtained between crystal field calculations and the EPR measurements. Furthermore, some extra lines observed by optical spectroscopy (absorption and emission) also appear on the EPR spectra and a correlation between the two spectroscopies indicates that Nd{sup 3+}-Nd{sup 3+} exchange and dipolar interactions occur in the zircon family, even at very low doping content (less than 8 x 10{sup 19} Nd{sup 3+} ions cm{sup -3}). Nd{sup 3+}-Nd{sup 3+} pairs at distances 3.9, 5.9 and 6.3 A have been identified. (orig.) 13 refs.

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Nanocrystalline zeolites with discrete crystal sizes of less than 100 nm have different properties relative to zeolites with larger crystal sizes. Nanocrystalline zeolites have improved mass transfer properties and very large internal and external surface areas that can be exploited for many different applications. The additional external surface active sites and the improved mass transfer properties of nanocrystalline zeolites offer significant advantages for selective catalytic reduction (SCR) catalysis with ammonia as a reductant in coal-fired power plants relative to current zeolite based SCR catalysts. Nanocrystalline NaY was synthesized with a crystal size of 15-20 nm and was thoroughly characterized using x-ray diffraction, electron paramagnetic resonance spectroscopy, nitrogen adsorption isotherms and Fourier Transform Infrared (FT-IR) spectroscopy. Copper ions were exchanged into nanocrystalline NaY to increase the ...

International Nuclear Information System (INIS)

The ternary stannides RE_3Ru_4Sn_1_3 (RE = La, Ce, Pr, Nd) were obtained by arc-melting of the elements. The polycrystalline samples were characterized by powder X-ray diffraction. The structures of three compounds were refined from single-crystal diffractometer data: Yb_3Rh_4Sn_1_3 type, Pm anti 3n, a = 977.74(3) pm, wR2 = 0.0379, 280 F"2 values for La_3Ru_4Sn_1_3, a = 971.34(9) pm, wR2 = 0.0333, 274 F"2 values for Ce_3Ru_4Sn_1_3, a = 970.68(8) pm, wR2 = 0.0262, 272 F"2 values for Nd_3Ru_4Sn_1_3 with 13 variables per refinement. The structures consist of three-dimensional networks of condensed RuSn_6_/_2 trigonal prisms with the RE (CN 16) and Sn2 (CN 12) atoms in two different types of cavities of the networks. The two crystallographically independent tin sites have been resolved by "1"1"9Sn Moessbauer spectroscopy. Temperature-dependent magnetic susceptibility measurements of Ce_3Ru_4Sn_1_3 gave a reduced magnetic moment ...

International Nuclear Information System (INIS)

Nanocrystalline samples of Fe_8_0Mo_2_0 and Fe_5_0Mo_5_0 alloys were prepared by the mechanical milling method. The structure, lattice parameters, and crystallite size were determined by the X-ray diffraction. The magnetic properties of the milled products were determined by the Moessbauer spectroscopy. It was observed that in the case of the Fe_8_0Mo_2_0 alloy a solid solution of Mo in Fe was formed with the lattice parameters of the Fe increasing from 0.28659 nm to 0.29240 nm and the crystallite size decreasing from 250 nm to 20 nm. In the case of the Fe_5_0Mo_5_0 alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the milling process, but the crystallite size decreased from 200 to 15 nm. Moessbauer spectra revealed different magnetic phases in the machanosynthesized Fe_Mo samples. In the case of the Fe_8_0Mo_2_0 alloy, the spectrum for the milled mixture indicated the formation of ...

Science.gov (United States)

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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)

The utility of recording Raman spectroscopy under liquid nitrogen, a technique we call Raman Under Nitrogen (RUN), is demonstrated for ferrocene, uranocene and thorocene. Using RUN, low temperature (liquid nitrogen cooled) Raman spectra for these compounds exhibit higher resolution than previous studies and new vibrational features are reported. The first Raman spectra of crystalline uranocene at 77 K are reported using excitation from argon (5145 ) and krypton (6764 ) ion lasers. The spectra obtained showed bands corresponding to vibrational transitions at 212, 236, 259, 379, 753, 897, 1500, and 3042 cm-1 , assigned to ring-metal-ring stretching, ring-metal tilting, out-of-plane CCC bending, in-plane CCC bending, ring-breathing, C-H bending, CC stretching and CH stretching, respectively. The assigned vibrational bands are compared to those of uranocene in THF and thorocene. All vibrational frequencies of the ligands, except the 259 cm-1 out-of-plane CCC bending ...

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Objective To investigate value of magnetic resonance cholangiopancreatography (MRCP) using oral diluted gadolinium (Gd)-diethylenetriamine penta-acetic acid (DTPA) as negative contrast materials in diagnosis of juxtapapillary duodenal diverticulum with atypical imaging features. Methods Nineteen patients with juxtapapillary duodenal diverticula of which imaging findings were atypical underwent MRCP using oral diluted Gd-DTPA as negative contrast materials after conventional MRCP without any oral contrast materials. Results Twenty diverticula were revealed in the 19 patients. At conventional MRCP, the diverticula appeared as rounded lesion with high signal intensity. After oral administration of diluted Gd-DTPA, they disappeared at MRCP. These entities were diagnosed as duodenal diverticula...

British Library Electronic Table of Contents (United Kingdom)

There is evidence that aged normal subjects have more difficulty in achieving automaticity than young subjects. The underlying central neural mechanism for this phenomenon is unclear. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the effect of normal ageing on automaticity. Aged healthy subjects were asked to practice self-initiated, self-paced, memorized sequential finger movements with different complexity until they could perform the tasks automatically. Automaticity was evaluated by having subjects perform a secondary task simultaneously with the sequential movements. Although it took more time, most aged subjects eventually performed the tasks automatically at the same level as the young subjects. Functional MRI results showed that, for bot...

CERN Document Server

We have monitored a Type II outburst of the Be/X-ray binary MXB 0656-072 in a series of pointed RXTE observations during October through December 2003. The source spectrum shows a cyclotron resonance scattering feature at 32.8 +/- 0.5 keV, corresponding to a magnetic field strength of (3.67 +/- 0.06) x 10^12 G and is stable through the outburst and over the pulsar spin phase. The pulsar, with an average pulse period of 160.4 +/- 0.4 s, shows a spin-up of 0.45 s over the duration of the outburst. From optical data, the source distance is estimated to be 3.9 +/- 0.1 kpc and this is used to estimate the X-ray luminosity and a theoretical prediction of the pulsar spin-up during the outburst.

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Study Type - Therapy (case series)Level of Evidence 4 OBJECTIVE To present our experience of retroperitoneoscopic partial adrenalectomy (RPA) for small adrenal tumours, as with modern imaging methods small adrenal lesions are being diagnosed more commonly, and retroperitoneoscopic adrenal surgery for small adrenal tumours (PATIENTS AND METHODS We retrospectively reviewed the records of 389 consecutive retroperitoneoscopic adrenalectomies from September 2005 to December 2008, 88 of which were small adrenal tumours and treated by RPA. Ultrasonography and computed tomography (CT) were used in all patients before RPA, and magnetic resonance imaging or positron emission tomography/CT in some patients. We used RPA for adrenal tumours and total adrenalectomy for adrenal cancer. During the surgery...

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.

International Nuclear Information System (INIS)

We studied age-related microstructural changes in the subcortical white matter from adolescence to middle age in 16 healthy male subjects (age range: 12 to 47 years) using diffusion-weighted magnetic resonance (MR) imaging (DWI). Mean diffusivity (MD) of subcortical white matter was mapped onto the overlying cortical surface using our original method. The mean MD values within 76 cortical regions were measured using atlas-based gray matter segmentation and then correlated with age. A significant negative correlation with age was observed in subcortical MD values in several cortical regions, primarily over the bilateral temporal and occipital lobes. Our results demonstrated subcortical microstructural change in postadolescence that may reflect continuing myelination. (author)

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Aim To determine the fate and clinical implication of large (?2cm), non-hypervascular nodules depicted on magnetic resonance imaging (MRI) in the cirrhotic liver. Materials and methods In 21 patients with cirrhosis (14 hepatitis B, two ethanol abuse, four cryptogenic, one Wilson's disease), 25 large (?2cm in the longest dimension) non-hypervascular nodules were identified on dynamic MRI. The implications for diagnosis of the initial size, contour, and signal characteristics on MRI in addition to patients' age and cause of cirrhosis were assessed in our analysis. Results Twelve (75%) out of 16 lesions were malignant or potentially-malignant from 14 hepatitis B patients, while seven (78%) of the nine lesions from other patients were benign (p=0.016). The mean age of the patients who ha...

International Nuclear Information System (INIS)

The aim of this review is to evaluate the role of inflammatory spine disease in patients with chronic back pain. The contribution of imaging modalities for the diagnostic evaluation of back pain is discussed. A systematic literature search based on the classification of seronegative spondyloarthropathies and rheumatoid arthritis was performed. The results of this search and the experiences in a large collective of rheumatological patients are analyzed. The prevalence of rheumatoid arthritis (1-2%) is comparable to that of spondyloarthropathies (1.9%). The etiology of these entities is not fully elucidated. Magnetic resonance imaging is increasingly used for early detection and surveillance of therapy with TNF-#alpha# antagonists. Bone marrow edema, which is only detectable with MRI, represents an early sign of inflammation. Therapy with TNF-#alpha# antagonists is based on clinical and laboratory criteria, and signs of inflammation in MRI. MRI ...

DEFF Research Database (Denmark)

The determination of conformational preferences in unfolded and disordered proteins is an important challenge in structural biology. We here describe an algorithm to optimize energy functions for the simulation of unfolded proteins. The procedure is based on the maximum likelihood principle and employs a fast and efficient gradient descent method to find the set of parameters of the energy function that best explain the experimental data. We first validate the method by using synthetic reference data, and subsequently apply the algorithms to data from nuclear magnetic resonance spin-labeling experiments on the Delta 131 Delta fragment of Staphylococcal nuclease. A significant strength of the procedure that we present is that it directly uses experimental data to optimize the energy parameters, without relying on the availability of high resolution structures. The procedure is fully general and can be applied to a range of experimental data and ...

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Summary Humans discount the value of future rewards over time. Here we show using functional magnetic resonance imaging (fMRI) and neural coupling analyses that episodic future thinking reduces the rate of delay discounting through a modulation of neural decision-making and episodic future thinking networks. In addition to a standard control condition, real subject-specific episodic event cues were presented during a delay discounting task. Spontaneous episodic imagery during cue processing predicted how much subjects changed their preferences toward more future-minded choice behavior. Neural valuation signals in the anterior cingulate cortex and functional coupling of this region with hippocampus and amygdala predicted the degree to which future thinking modulated individual preference fu...

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There are no specific diagnostic tests or a gold standard method for measuring disease activity and outcome in spondyloarthropathies (SpA). Many different methods have been developed to assess the signs and symptoms in SpA. The aim of this study was to evaluate the value of scintigraphy, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Bath Ankilosing Spondylitis Disease Activity Index (BASDAI) in the evaluation of disease activity in early axial SpA diagnosed with magnetic resonance imaging (MRI). Thirty early MRI-positive axial SpA patients (23 males, 7 females) with a median age of 35 (18?55) years and a median duration of inflammatory low back pain of 24 (8?60) months were included in the study. In the patients with sacroiliitis, the sensitivity, specificity, and pos...

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.

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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.

British Library Electronic Table of Contents (United Kingdom)

Nuclear magnetic resonance (NMR) techniques coupled with multivariate data analysis were used to conduct monitoring of biochemical changes of black raspberry fruits at different stages of maturation and under various extraction and NMR dissolution solvent conditions: extraction with 50% methanol and D"2O as an NMR dissolution solvent, extraction with 50% methanol and 50% methanol-d"4 as an NMR dissolution solvent, and extraction with 100% ethyl acetate and 100% methanol-d"4 as an NMR dissolution solvent. Partial least-squares discriminant analysis reliably distinguished black raspberry fruits according to the maturation stage, whereby the relative levels of various compounds such as amino acids, organic acids, sugars and phenolic compounds were compared using analysis of variance. Sucrose ...

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 ...

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Laser spectroscopy measurements have been performed on neutron deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d{sup 7}6s{sup 24}F{sub 9/2} {sup {yields}} 5d{sup 7}6s6p {sup 6}F{sub 11/2} at 351.5 nm have been studied for the {sup 182-189}Ir, {sup 186}Ir{sup 1}m and {sup 191,193}Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the HFS measurements and the changes of the mean square charge radii from the IS measurements. A large mean square charge radius change between {sup 187}Ir and {sup 186}Ir and between {sup 186}Ir{sup 1}m and {sup 186}Ir{sup 1}g has been observed.

International Nuclear Information System (INIS)

Laser spectroscopy measurements have been performed on neutron-deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d"76s"2 "4F_9_/_2#->#5d"76s6p "6F_1_1_/_2 have been studied for the "1"8"2"-"1"8"9Ir, "1"8"0Ir"m and "1"9"1","1"9"3Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the hyperfine splitting measurements and the changes of the mean square charge radii from the isotope shift measurements. A large deformation change between "1"8"7Ir and "1"8"6Ir and between "1"8"6Ir"m and "1"8"6Ir"g has been observed.

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... parameters magnetic fields magnetic properties magnetization monocrystals

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The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a {sup 238}U target with a beam of {sup 70}Zn at an energy of E{sub lab}=460 MeV. Prompt {gamma} rays measured by the CLARA array have been identified unambiguously for each nucleus, using coincidence relationships with ions detected in the high-acceptance magnetic spectrometer PRISMA. The new data extends the knowledge of the low-lying level structure of Mn isotopes, which is discussed in terms of the systematics of the region. Results are compared with large-scale shell-model calculations using different effective interactions and valence spaces.

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The z-phase, existing between 35% and 70% U in Pu, belongs to the high-density phases seen from the point of view of systematics of allotropic modifications of Pu metal. Despite the volume per actinide atom only slightly higher than for a-Pu, it magnetic susceptibility is much higher than for a-Pu and exceeds even the d-Pu value. Similarly, the Sommerfeld coefficient g>40mJ/mol Pu K2 exceeds the experimental d-Pu value. The data confirm that the volume is not the primary control parameter affecting the situation around the Fermi level of common Pu phases and they point against the traditional belief that they are essentially narrow 5f band systems. Electronic structure calculations suggest that the 5f states of Pu have slightly lower occupancy comparing with d-Pu. A tendency to the 5f loca...

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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)

Background: Malformations of cortical development vary in neuronal maturity and level of functioning. Purpose: To characterize regional relative cerebral blood volume (rCBV) and difference in first moment transit time (TTfm) in polymicrogyria and cortical tubers using magnetic resonance (MR) perfusion imaging. Material and Methods: MR imaging and dynamic T2*-weighted MR perfusion imaging were performed in 13 patients with tuberous sclerosis complex, 10 with polymicrogyria, and 18 controls with developmental delay but no macroscopic brain abnormality. Regions of interest were placed in cortical tubers or polymicrogyric cortex and in the contralateral normal-appearing side in patients with malformations. In 'control' subjects, regions of interest were placed in the frontal and parietal lobes in both hemispheres. The rCBV and TTfm of the tuber/contralateral side (rCBVRTSC and TTFMTSC) as well as those of the polymicrogyria/contralateral side ...

International Nuclear Information System (INIS)

Aim: To evaluate magnetic resonance cholangiography (MRC) with high-resolution dynamic gadolinium-enhanced magnetic resonance imaging (MRI) in determining the imaging features of hilar cholangiocarcinoma that relate to tumour extent and influence resectability. Materials and methods: Twenty-six patients that underwent resection were reviewed. Tumour location and extent, lobar atrophy, the degree of portal vein and hepatic artery involvement were recorded. The findings were correlated with surgical and histopathological findings. Results: Biliary assessment was concordant in 14 and discordant in eight of 14 stented and four of 12 non-stented patients. In 63/82 veins and 43/74 arteries results were fully concordant. The mean sensitivity, specificity, positive and negative predictive values (PPV, NPV) in predicting involvement of the main portal vein (MPV) at surgery were 83.3, 100, 100, and 92.5%; of the ...

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The objective was to characterize imaging findings of benign notochordal cell tumors (BNCTs). Clinical and imaging data for 9 benign notochordal cell tumors in 7 patients were reviewed retrospectively. Conventional radiographs (n = 9), bone scintigrams (n = 2), computed tomographic images (n = 7), and magnetic resonance images (n = 8) were reviewed. Eight of the 9 lesions were stained with hematoxylin-eosin and microscopically examined. There were 3 male and 4 female patients with an age range of 22 to 55 years (average age, 44 years). Two patients had two lesions at different sites. The lesions involved the cervical spine in 4 patients, the lumbar spine in 2, the sacrum in 2, and the coccyx in 1. The most common symptom was mild pain. The lesions of 2 patients were found incidentally during imaging studies for unrelated conditions. Five patients underwent surgical procedures. One patient died of surgical complications. All other patients have ...

International Nuclear Information System (INIS)

The results of a combined investigation of splat-quenched Fe-Csub(x) (x<0.05) alloys by resistivity, X-ray diffraction and Moessbauer spectroscopy are presented. The residual resistivity increases linearly with the carbon content (#DELTA#rho=5#mu##OMEGA#cm/at.%) with a slope identical to that observed in the dilute ferritic phase. X-ray diffraction reveals the presence of a martensite structure in addition to a small fraction of residual austenite; the dependence of the a and c lattice parameters on xsub(c) agrees with earlier measurements. A detailed investigation of the relative reflexion intensities shows that the as-quenched martensites consist of a mixing of massive martensite and tetragonal martensite for low carbon content and of tetragonal martensite only for xsub(c) approximately 0.05. The Moessbauer spectra reveal 3 or 4 magnetically non equivalent iron sites. From a detailed analysis of the intensity dependence of the subspectra ...

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Professor Richard H. Dalitz passed away on January 13, 2006. He was almost 81 years old and his outstanding contributions are intimately connected to some of the major breakthroughs of the 20th century in particle and nuclear physics. These outstanding contributions go beyond the Dalitz Plot, Dalitz Pair and CDD poles that bear his name. He pioneered the theoretical study of strange baryon resonances, of baryon spectroscopy in the quark model, and of hypernuclei, to all of which he made lasting contributions. His formulation of the ''{theta} - {tau} puzzle'' led to the discovery that parity is not a symmetry of the weak interactions. A brief scientific evaluation of Dalitz's major contributions to particle and nuclear physics is hereby presented, followed by the first comprehensive list of his scientific publications, as assembled from several sources. The list is divided into two categories: the ...

Energy Technology Data Exchange (ETDEWEB)

The knowledge shown in this work of the relationships between the oxidation stage of chromium, molybdenum and tungsten and their catalytic activity in some hydrocarbon reactions was achieved by the combination of separate investigations of reduction properties and the catalytic activity of the catalysts concerned. To characterize the electronic state of the reduced surfaces, X-ray photo-electronic spectroscopy was mainly used, supplemented by electron spin resonance. The catalyst activity was measured in conventional apparatus (flow, pulse and gradient-free reactors). (orig.) [Deutsch] Die in dieser Arbeit dargestellten Erkenntnisse ueber die Zusammenhaenge zwischen der Oxidationsstufe von Chrom, Molybdaen und Wolfram und ihrer katalytischen Aktivitaet in einigen Kohlenwasserstoffreaktionen wurden durch die Kombination getrennter Untersuchungen ueber Reduktionseigenschaften und katalytische Aktivitaet der betreffenden Katalysatoren erzielt. ...

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Isotope shift measurements have been performed for the {sup 242{ital f}}Am fission isomer with target production rates of only a few per second. The method is based on resonance ionization spectroscopy (RIS) in a buffer gas cell with radioactive decay detection of the ionization process (RADRIS). A relative isotope shift ratio X{sub {ital exp}}=IS{sup 242{ital f},241}/IS{sup 243,241}=41.7{plus_minus}0.9 has been measured for the 500.02 nm transition corresponding to a nuclear parameter A{sup 242{ital f},241}=(5.4{plus_minus}0.3) fm{sup 2}. A preliminary analysis of the quadrupole moment based on the deformed Fermi model of the nuclear charge distribution results in Q{sub 20}=35.9{plus_minus}1.1({sup +0.3}{sub {minus}0.7}) {sub model} eb. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

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Point-contact (PC) investigations on the title compound in the normal and superconducting (SC) state (T{sub c}{approx_equal}10.6 K) are presented. The T-dependence of two SC gaps in TmNi{sub 2}B{sub 2}C determined by Andreev-reflection spectroscopy deviates from the BCS behavior in displaying a maximum at about T{sub c}/2. Additional evidence for the presence of a 2nd gap half as large as the main gap is given. For the first time ''reentrant'' features were found in the Andreev-reflection spectra measured in magnetic fields. The PC spectroscopy of the fermion-boson interaction in TmNi{sub 2}B{sub 2}C reveals a pronounced phonon maximum at 9.5 meV and a more smeared one around 15 meV, while at higher energies the PC spectra are almost featureless. Additionally, the intense peak slightly above 3 meV observed in the PC spectra of TmNi{sub 2}B{sub 2}C, is presumably caused by ...

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 ...