WorldWideScience
1

Heat transfer augmentation using a magnetic fluid under the influence of a line dipole  

Energy Technology Data Exchange (ETDEWEB)

Ferrofluids have promising potential for heat transfer applications, since advective transport in a ferrofluid can be readily controlled by using an external magnetic field. However, unlike conventional free or forced convection, ferrohydrodynamic convection is not yet well characterized. A full understanding of the relationship between an imposed magnetic field, the resulting ferrofluid flow, and the temperature distribution is a prerequisite for the proper design and implementation of applications involving thermomagnetic convection. The literature variously assumes constant magnetic fields, does not completely represent the variation in the imposed field, or its descriptions are inaccurate, since the fields do not comply with the Maxwell's equations of electromagnetism. We address this by simulating two-dimensional forced convection heat transfer in a channel with a ...

2004-04-01

2

Heat transfer augmentation using a magnetic fluid under the influence of a line dipole  

International Nuclear Information System (INIS)

Ferrofluids have promising potential for heat transfer applications, since advective transport in a ferrofluid can be readily controlled by using an external magnetic field. However, unlike conventional free or forced convection, ferrohydrodynamic convection is not yet well characterized. A full understanding of the relationship between an imposed magnetic field, the resulting ferrofluid flow, and the temperature distribution is a prerequisite for the proper design and implementation of applications involving thermomagnetic convection. The literature variously assumes constant magnetic fields, does not completely represent the variation in the imposed field, or its descriptions are inaccurate, since the fields do not comply with the Maxwell's equations of electromagnetism. We address this by simulating two-dimensional forced convection heat transfer in a channel with a ferrofluid ...

2004-04-01

3

Refrigerator operating experience on whole body MRI magnet systems  

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 refrigerator test ...

1985-08-01

4

Direct conversion of fusion energy into the electric one in the 'Dragon' magnetic confinement system  

International Nuclear Information System (INIS)

It is shown that recuperator in which the thermal energy of particles is transformed into electric oue under drift in crossed fields is naturally coupled with dragontype magnetic confinement system, so the recuperation process can be initiated in the dragon magnetic field. A number of questions occuring under analysis of recuperator-dragon system is considered, including the dynamics of particle transfer to the recuperator, the share of particles entering the recuperator, the effect of rotational transform and the recuperation efficiency.

5

Magnetic resonance studies of photosynthetic reaction centers and porphyrins  

Science.gov (United States)

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

1989-11-01

6

Heat transfer of lithium single-phase flow and helium-lithium two-phase flow in a circular channel under transverse magnetic field  

Energy Technology Data Exchange (ETDEWEB)

Characteristics of pressure drop and heat transfer have been investigated for a lithium single-phase flow and a helium-lithium two-phase flow in a horizontal conducting circular channel in the presence of a uniform transverse magnetic field up to 1.4 T as related to the lithium cooling for magnetic-confinement fusion reactors. By the application of the magnetic field to the lithium single-phase flow, remarkable heat transfer enhancement has been observed at the top wall due to the suppression of the mixed convection occurring in the low Peclet number range, while appreciable heat transfer deterioration appeared in the high Peclet number range. It has been confirmed that the helium-lithium two-phase flow can reduce the high magnetohydrodynamic (MHD) pressure drop in a lithium single-phase flow, and it can provide much better heat transfer ...

1998-09-01

7

Fault diagnosis of roller bearing using fuzzy classifier and histogram features with focus on automatic rule learning  

British Library Electronic Table of Contents (United Kingdom)

Roller bearing is one of the most widely used elements in rotary machines. Condition monitoring of such elements is conceived as pattern recognition problem. Pattern recognition has three main phases: feature extraction, feature selection and feature classification. Histogram features can be used for fault diagnosis of roller bearing. This paper presents the use of decision tree for selecting best few histogram features (bin ranges) that will discriminate the fault conditions of the bearing from given train samples. These features are extracted from vibration signals. A rule set is formed from the extracted features and fed to a fuzzy classifier. The rule set necessary for building the fuzzy classifier is obtained largely by intuition and domain knowledge. This paper also presents the usag...

2011-01-01

8

Spacetime constraints on accreting black holes  

International Nuclear Information System (INIS)

We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting plasma in a differentially rotating flow. We take a first principles approach, highlighting the constraint that limits the generation and amplification of radial magnetic fields, stemming from the transfer of energy from mechanical to magnetic form. Because the energy transferred in magnetic form is ultimately constrained by gravitational potential energy or Killing energy, the spin dependence of the latter allows us to derive spin-dependent constraints on the success of the accreting plasma to expel its angular momentum. We find an inverse relationship between this ability and black hole spin. If this radial ...

2009-06-15

9

Evaluation of magnetization transfer ratios for breast tissues and breast diseases  

Energy Technology Data Exchange (ETDEWEB)

To determine MTRs for normal structures and benign diseases in the breast two-dimensional magnetization transfer imaging was performed in 62 patients and in 3 young female volunteers. With regard to the MTRs of measurements in the normal breast tissues, fat tissues which is close to simple cysts in MTRs show little transfer of longitudinal magnetization. MTRs of the muscles was 15.15{+-}6.22%, which exceeded those of breast parenchyma. The breast parenchyma didn`t show the change of MTR value due to the difference of patient age and due to variable amount of fat and fibrous tissues. Breast parenchyma in the two young volunteers clearly showed biphasic change of MTR values in accordance with the menstrual cycle; little transfer value was due to hydration in the postovulatory period and high transfer value was due to dehydration in the preovulatory period. In the ...

1997-03-01

10

How the Performance of a Superconducting Magnet is affected by theConnection between a small cooler and the Magnet  

Energy Technology Data Exchange (ETDEWEB)

As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; (1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and (2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: (1) whether the cooler must be used to cool down the magnet from room temperature, (2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the ...

2005-09-08

11

Magnetic refrigeration: the promise and the problems  

Energy Technology Data Exchange (ETDEWEB)

Magnetic refrigeration uses the temperature- and field-dependence of the entropy of some magnetic materials to accomplish cooling. Because of the intrinsically high efficiency of the magnetization and demagnetization process and because of the potential for excellent heat transfer between solids and fluids, magnetic refrigerators promise to have higher efficiency than existing gas-cycle refrigerators. Many ground-based and space-based applications could benefit significantly from the cost savings implied by higher efficiency. Other attributes of these devices are high reliability and low volume and mass per unit cooling power. The development of these refrigerators is underway at several places around the world, including the Los Alamos National Laboratory. The progress to date has been encouraging but some problems have been clearly identified. The arguments for high efficiency and ...

1984-01-01

12

Industrial production of RHIC magnets  

Energy Technology Data Exchange (ETDEWEB)

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

1996-07-01

13

Tidal spin-up and magnetic braking in cataclysmic variables  

International Nuclear Information System (INIS)

Based on proposed models for the tidal spin-up and magnetic braking of stars with a convective outer envelope, it is suggested that the rotation of secondaries in cataclysmic variables is not necessarily synchronized with the orbital revolution. This may provide an explanation for the observed large range in the mass transfer rate (at the same orbital period) of cataclysmic variables above the period gap. (author).

14

Superconducting magnetic system with the controllable inductance of a winding  

International Nuclear Information System (INIS)

The experimental superconducting magnetic system of 0.5 MJ energy storage is described. The step variation of the winding inductance provides a control by the discharge current at the energy output on a high-ohmic load. The voltage on a load is 45 kV at the current 1100 A under the controllable discharge conditions. The energy transfer coefficient constitutes 0,76 under the maximum-to-minimal current ratio equal to 1.3. 7 refs., 3 figs., 2 tabs.

15

Combined effect of magnetic field and thermal dispersion on a non-darcy mixed convection  

British Library Electronic Table of Contents (United Kingdom)

This paper is devoted to investigate the influences of thermal dispersion and magnetic field on a hot semi-infinite vertical porous plate embedded in a saturated Darcy-Forchheimer-Brinkman porous medium. The coefficient of thermal diffusivity has been assumed to be the sum of the molecular diffusivity and the dynamic diffusivity due to mechanical dispersion. The effects of transverse magnetic field parameter (Hartmann number Ha), Reynolds number Re (different velocities), Prandtl number Pr (different types of fluids) and dispersion parameter on the wall shear stress and the heat transfer rate are discussed.

2011-01-01

16

Mathematical analysis of DNA histograms from asynchronous and synchronous cell populations  

Science.gov (United States)

A technique is presented for the analyss of DNA histograms which is an extension of earlier discrete Gaussian summing methods. It alleviates the problems encountered with previous methods by extending the S-phase portions of the distribution under the G/sub 1/ and G/sub 2/ + M peaks. The resuts obtained by this method for the fraction of cells in the G/sub 1/, S, and G/sub 2/ + M phases of the life cycle are compared with autoradiographic results. With one or two exceptions which are discussed, agreement between autoradiography and the analytical method is good.

1977-01-01

17

On the disrupted magnetic braking model for the period gap of cataclysmic variables  

International Nuclear Information System (INIS)

The disrupted magnetic braking theory for the period gap of cataclysmic variable systems is used to study the binary evolution of low-mass main-sequence-like stars with white dwarf companions. The model is able to reproduce the observed location and width of the gap provided that the average mass transfer rates above the upper edge of the gap are greater than about 1.9 x 10 to the -9th solar masses/yr. For the case of angular momentum loss by magnetic braking, the slope of the mass transfer rate with respect to orbital period is shown to range from 3.4 to 3.7. For the evolutionary sequences considered, the He-3 abundance at the surface of the secondary exceeds 0.0015 after the complete mixing phase, resulting in modifications in the nuclear burning development of nova explosions. 31 refs.

18

Combined effect of magnetic field and heat absorption on unsteady free convection and heat transfer flow in a micropolar fluid past a semi-infinite moving plate with viscous dissipation using element free Galerkin method  

British Library Electronic Table of Contents (United Kingdom)

The fully developed electrically conducting micropolar fluid flow and heat transfer along a semi-infinite vertical porous moving plate is studied including the effect of viscous heating and in the presence of a magnetic field applied transversely to the direction of the flow. The Darcy-Brinkman-Forchheimer model which includes the effects of boundary and inertia forces is employed. The differential equations governing the problem have been transformed by a similarity transformation into a system of non-dimensional differential equations which are solved numerically by element free Galerkin method. Profiles for velocity, microrotation and temperature are presented for a wide range of plate velocity, viscosity ratio, Darcy number, Forchhimer number, magnetic field parameter, heat absorption ...

2010-01-01

19

The effects of radiation on unsteady mhd convective heat transfer past a semi-infinite vertical porous moving surface with variable suction  

Scientific Electronic Library Online (English)

Abstract in english Numerical solutions for the effects of radiation on a MHD convective heat transfer past a semi-infinite porous plate with a magnetic field are obtained. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The magnetic field acts perpendicular to the porous surface which absorbs the fluid with a suction velocity varying with time. The gov (more) erning equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation technique and then are solved numerically by using the shooting method. The effects of the various parameters on the velocity, temperature profiles as well as the surface skin-friction and surface heat transfer are illustrated graphically.

2008-12-01

20

Studies on magnetohydrodynamic flow characteristics and heat transfer of liquid metal two-phase flow cooling systems for a magnetically confined fusion reactor  

Energy Technology Data Exchange (ETDEWEB)

Liquid metal cooling for the first wall and blanket of a magnetic confinement fusion reactor has various advantages. However, it has the disadvantages of large magnetohydrodynamic pressure drops and heat transfer deterioration under a strong magnetic field. Thus, the present authors have proposed cooling with a helium-lithium annular mist flow as well as the cooling with a liquid metal boiling flow, and as fundamental studies, investigated the effect of a magnetic field on the flow characteristics and heat transfer of liquid metal two-phase systems since the 1970s. In the present paper we summarize the important findings obtained from our experimental studies for (i) an air-mercury stratified flow in a horizontal rectangular channel, (ii) a helium-lithium annular mist flow in a horizontal rectangular channel, (iii) the mercury pool boiling on a horizontal surface, and (iv) ...

1995-03-01

21

Studies on magnetohydrodynamic flow characteristics and heat transfer of liquid metal two-phase flow cooling systems for a magnetically confined fusion reactor  

International Nuclear Information System (INIS)

Liquid metal cooling for the first wall and blanket of a magnetic confinement fusion reactor has various advantages. However, it has the disadvantages of large magnetohydrodynamic pressure drops and heat transfer deterioration under a strong magnetic field. Thus, the present authors have proposed cooling with a helium-lithium annular mist flow as well as the cooling with a liquid metal boiling flow, and as fundamental studies, investigated the effect of a magnetic field on the flow characteristics and heat transfer of liquid metal two-phase systems since the 1970s. In the present paper we summarize the important findings obtained from our experimental studies for (i) an air-mercury stratified flow in a horizontal rectangular channel, (ii) a helium-lithium annular mist flow in a horizontal rectangular channel, (iii) the mercury pool boiling on a horizontal surface, and (iv) ...

22

Measurements of K-shell x-ray production cross sections and K to L and M-shell radiative vacancy transfer probabilities for Nd, Eu, Gd, Dy and Ho at excitation with 59.5 keV photons in an external magnetic field  

International Nuclear Information System (INIS)

The effect of the #+-# 0.75 T external magnetic field on the K_#alpha#_1, K_#alpha#_2, K_#beta#_'_1 and K_#beta#_'_2 x-ray production cross sections and radiative vacancy transfer probabilities from K-shell to L2 and L3 subshells and M-shell for ferromagnetic Nd, Gd and Dy and paramagnetic Eu and Ho have been investigated, using the 59.5 keV incident photons. K-shell fluorescence yields and K x-ray intensity ratios for these elements have been determined in the external magnetic field also. The K x-rays from different targets were detected using a high-resolution Si(Li) semiconductor detector. For B = 0, the present experimental results were compared with the experimental and theoretical data in the literature. The results show that K-shell fluorescence parameters such as photoionization cross section, fluorescence yield, radiation rates, vacancy transfer probabilities and spectral linewidth can change ...

2006-06-19

23

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

International Nuclear Information System (INIS)

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

2008-03-01

24

DFT study of structure?properties correlations in [MnTPP][TCNE] quasi-one-dimensional molecular magnets  

British Library Electronic Table of Contents (United Kingdom)

We report the first band structure calculations of the quasi-one-dimensional [MnTPP][TCNE] compounds (TPP?=?meso-tetraphenylporphyrinato, TCNE?=?tetracyanoethylene), based on Density Functional Theory (DFT) methods, in order to interpret the magnetic ordering in these prototypic systems. We compare and contrast the results of broken-symmetry DFT calculations for extended systems, with periodic boundary conditions, and for finite systems, magnetic dimers modeling the actual molecular magnets. By varying systematically the main angles, we are able to determine the geometry dependence of the exchange interaction. Structure?properties correlations in these charge-transfer salts reveal the determinant role of the Mn-(N?C)TCNE bond angle on the strength of the ferrimagnetic coupling between the ...

2011-01-01

25

AUTOMATED TECHNOLOGY KNOWLEDGE BASE  

Science.gov (United States)

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

26

A novel semidry flue gas desulfurization process with the magnetically fluidized bed reactor.  

Science.gov (United States)

The magnetically fluidized bed (MFB) was used as the reactor in a novel semidry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency. Experiments in a laboratory-scale apparatus were conducted to reveal the effects of approach to adiabatic saturation temperature, Ca/S molar ratio and applied magnetic field intensity on SO(2) removal. Results showed that SO(2) removal efficiency can be obviously enhanced by decreasing approach to adiabatic saturation temperature, increasing Ca/S molar ratio, or increasing applied magnetic field intensity. At a magnetic field intensity of 300Oe and a Ca/S molar ratio of 1.0, the desulfurization efficiency (excluding desulfurization efficiency in the fabric filter) was over 80%, while spent sorbent appeared in the form of dry powder. With the SEM, XRD and EDX research, it can be found that the increase of DC magnetic field ...

2009-03-18

27

Heat transfer and hydraulics of liquid metal-gas two-phase magnetohydrodynamic flow  

International Nuclear Information System (INIS)

Local properties and heat transfer have been investigated in a NaK-nitrogen two-phase flow in a vertical tube under transverse magnetic field. An objective two-phase flow regime identification was also carried out systematically, using the probability distribution function of two-phase electromagnetic flowmeter signals. The application of a magnetic field was bound to bring about a drastic change in the void fraction profile, i.e., asymmetric profile perpendicular to the field direction. This effect was more remarkably observed in bubbly flows. The magnetic field was also observed to decrease the number of bubbles, by promoting the agglomeration of small bubbles into larger ones and also break-up of large slugs, and, thus, to shift the flow regime boundaries. It has been also shown that the two-phase Nusselt number increases in bubbly flows, while it decreases in slug flows. This trend however reduces ...

1986-08-01

28

Magnetization transfer contrast effect on multislice fast spin echo  

Energy Technology Data Exchange (ETDEWEB)

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

1994-03-01

29

A numerical solution of unsteady MHD convection heat and mass transfer past a semi-infinite vertical porous moving plate using element free Galerkin method  

British Library Electronic Table of Contents (United Kingdom)

In this paper, the unsteady MHD free convection heat and mass transfer of viscous fluid flowing through a Darcian porous regime adjacent to a moving vertical semi-infinite plate under Soret and Dufour effect have been examined. Viscous dissipation effects are included in the energy equation. A uniform magnetic field is applied transversely to the direction of the flow. The differential equations governing the problem have been transformed by a similarity transformation into a system of non-dimensional differential equations which are solved numerically by element free Galerkin method. The influence of Grashof number (Gr), magnetic parameter (M), heat absorption parameter (Q), permeability parameter (K), Schmidt number (Sc), Soret number (Sr), and Dufour number (Du) on the velocity, tempera...

2010-01-01

30

Spectrograph for free-electron laser experiments  

International Nuclear Information System (INIS)

The design and construction of a Browne-Buechner type round pole face magnetic electron spectrograph is described. The design is based on the first order transfer properties of the bending magnet including the focal surface, dispersion, magnification and resolution. Second order aberrations are compared wit numerical ray tracing results using measured field data to simulate the magnet. The numerical results are also compared with floating wire measurements on the system. Agreement is within one part in 10"4. Data extraction from the instrument is done with an array of copper detectors placed along the focal surface. The spectrograph has been successfully employed in free-electron laser (FEL) experiments for over a year.

1983-03-21

31

PET/MRI hybrid imaging: devices and initial results  

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...

2008-01-01

32

Magnetic braking of collapsing interstellar clouds  

International Nuclear Information System (INIS)

The purpose of this investigation is to show that resource to anisotropic compression along a magnetic field is not a necessary condition for star formation within large collapsing interstellar gas clouds. Although such a scenario would certainly eliminate the magnetic field and angular momentum problems associated with isotropically collapsing clouds, it is believed there is sufficient observational theoretical evidence to warrant the present study of magnetically braked, isotropically collapsing gas clouds. It is not attempted to disprove the hypothesis of anisotropic compression, but to offer instead, a reasonable alternative. Angular momentum transfer from magnetically braked, cool interstellar gas clouds of 10"2, 10"3 and 10"4 times the mass of the sun is examined. Magnetic torques acting on a contracting, rotating cloud, permeated by a frozen-in ...

33

The magnetopause  

Energy Technology Data Exchange (ETDEWEB)

A review of theoretical and observational research on the magnetopause during 1987-1990. Starting with recent work on magnetic reconnection, the review proceeds to magnetopause surface wave phenomena, including the controversy over the role of solar wind pressure pulses in the coupling process and in the mimicking of flux transfer events signatures, and finishes with the magnetopause structure and associated wave phenomena. Recent advances in computer modeling of the magnetopause and the pertinent processes are also discussed. 108 refs.

1991-01-01

34

Suppression of the transverse scattering amplitude in /sup 207/Pb  

Energy Technology Data Exchange (ETDEWEB)

Transverse form factors have been extracted for the low-lying neutron hole (particle) states of /sup 207/Pb from inelastic-electron-scattering data. A systematic, multipolarity-and momentum-transfer-independent quenching of approx.55% in the transverse amplitude is observed when compared with single particle predictions for both electric and magnetic transitions. The magnitude of the observed effect is not readily explained by our present theoretical understanding of this nucleus.

1980-07-14

35

Problems and solutions of the IFSMTF power and switch system  

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

36

Effects of transverse magnetic field, Prandtl number and Reynolds number on non-Darcy mixed convective flow of an incompressible viscous fluid past a porous vertical flat plate in a saturated porous medium  

Energy Technology Data Exchange (ETDEWEB)

The effect of transverse magnetic field parameter (Hartmann number, Ha) Reynolds number (Re) and Prandtl number (Pr) on the mixed convection flow past a semi-infinite vertical porous plate in a non-Darcian porous medium with variable viscosity and porosity, viscous dissipation and fluid-solid thermal conductivity ratio in the presence of plate transpiration (lateral mass flux) is investigated theoretically and numerically using Keller`s implicit finite difference scheme. It is shown that the Harmann number acts as a retarding force and increases the momentum boundary layer thickness, analogous to the flow against a positive pressure gradient, simultaneously decreasing local skin friction (shear stress). The heat transfer rate is however enhanced by the magnetic field (for positive values of the Eckert number) since the fluid is heated and temperature gradients become reduced between the fluid and the plate, with important ...

1997-01-01

37

An investigation into flow regimes for two-phase helium flow  

Energy Technology Data Exchange (ETDEWEB)

The Tevatron accelerator at Fermilab incorporates long two-phase helium passages. During magnet design, the generalized flow map of Baker was used to predict homogeneous flow. Longer than expected magnet time constants led to this investigation. The importance of predicting the flow regime has been amplified with the advent of non-horizontal accelerator designs. A test setup was constructed at Fermilab to investigate two-phase helium flow regimes for conditions practical in accelerator designs. The setup consisted of a standard Tevatron satellite refrigerator, subcooling dewar, heater, 35 m long transfer line, and a specialized end box. A knife blade on the midplane of the transfer line diverted the flow from the upper and lower halves of the pipe to separate vessels in the end box. The amount of liquid above and below the plane was measured at various total mass flow rates and liquid percentages. The ...

1987-10-01

38

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-01-01

39

CRC handbook of physical properties of rocks. Volume III  

Energy Technology Data Exchange (ETDEWEB)

This book presents topics on: Density of rocks and minerals, includes histograms of density ranges; elastic constants of minerals, elastic moduli, thermal properties; inelastic properties, strength and rheology for rocks and minerals, rock mechanics and friction, and stress-strain relations; radioactivity, decay constants and heat production of isotope systems in geology; seismic attenuation, in rocks, minerals, and the earth, with application to oil exploration and terrestrial studies; and index.

1984-01-01

40

PET/MRI hybrid imaging: devices and initial results  

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 even at high ...

2008-06-01

41

Anomalous tensor magnetic moments and form factors of the proton in the self-consistent chiral quark-soliton model  

Science.gov (United States)

We investigate the form factors of the chiral-odd nucleon matrix element of the tensor current. In particular, we aim at the anomalous tensor magnetic form factors of the nucleon within the framework of the SU(3) and SU(2) chiral quark-soliton model. We consider 1/N{sub c} rotational corrections and linear effects of SU(3) symmetry breaking with the symmetry-conserving quantization employed. We first obtain the results of the anomalous tensor magnetic moments for the up and down quarks: {kappa}{sub T}{sup u}=3.56 and {kappa}{sub T}{sup d}=1.83, respectively. The strange anomalous tensor magnetic moment is yielded to be {kappa}{sub T}{sup s}=0.2{approx}-0.2, that is compatible with zero. We also calculate the corresponding form factors {kappa}{sub T}{sup q}(Q{sup 2}) up to a momentum transfer Q{sup 2{<=}}1 GeV{sup 2} at a renormalization scale of 0.36 GeV{sup 2}.

2010-09-01

42

A facile method for the room-temperature synthesis of water-soluble magnetic Fe3O4 nanoparticles: Combination of in situ synthesis and decomposition of polymer hydrogel  

British Library Electronic Table of Contents (United Kingdom)

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...

2011-01-01

44

Unsteady MHD micro polar flow and heat transfer over a vertical porous moving plate with variable suction  

Energy Technology Data Exchange (ETDEWEB)

The unsteady two-dimensional laminar flow of a viscous incompressible electrically conducting micro polar fluid via a porous medium past a semi-infinite vertical porous moving plate in the presence of a transverse magnetic field is studied. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micro polar fluid with a suction velocity varying with time. The effects of material parameters on the velocity and temperature fields across the boundary layer are investigated. The method of solution can be applied for small perturbation approximation. Numerical results of velocity and temperature distributions of micro polar fluids are compared with the corresponding flow problems for a Newtonian fluid. (author)

2001-07-01

45

The effect of neutrals on the performance of plasma opening switches  

Energy Technology Data Exchange (ETDEWEB)

The authors address the question of the limitations on voltage and current transfer to loads in magnetic storage systems utilizing microsecond conduction time plasma opening switches. They propose that the limitation of performance results from neutral atoms that are not entrained into the ionized material that is driven by the magnetic field of the rising generator current. Evidence in support of this proposition is gathered from experiments performed on the Ace-4 and Hawk generators. They set forth a theory to describe the effect of neutrals on the electrical performance of plasma opening switches. The neutral gas is assumed to be present in the region between the moving plasma mass and the generator, primarily in the region in which the plasma is injected initially. The essential elements of the theory are a weak photoionization source to seed the gas with a low concentration of electrons, and joule heating accompanied ...

1996-12-31

46

Precise Determination of the Neutron Magnetic Form Factor to Higher Q{sup 2}  

Energy Technology Data Exchange (ETDEWEB)

The neutron elastic magnetic form factor G{sub M}{sup n} has been extracted from quasielastic scattering from deuterium in the CEBAF Large Acceptance Spectrometer, CLAS [B. Mecking et al., Nucl. Inst. and Meth. A 503 (2003) 513]. The kinematic coverage of the measurement is continuous over a broad range, extending from below 1 GeV{sup 2} to nearly 5 GeV{sup 2} in four-momentum transfer squared. High precision is achieved by employing a ratio technique in which most uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Preliminary results are shown with statistical errors only.

2005-06-13

47

Precise Determination of the Neutron Magnetic Form Factor to Higher Q"2  

International Nuclear Information System (INIS)

The neutron elastic magnetic form factor G_M"n has been extracted from quasielastic scattering from deuterium in the CEBAF Large Acceptance Spectrometer, CLAS [B. Mecking et al., Nucl. Inst. and Meth. A 503 (2003) 513]. The kinematic coverage of the measurement is continuous over a broad range, extending from below 1 GeV"2 to nearly 5 GeV"2 in four-momentum transfer squared. High precision is achieved by employing a ratio technique in which most uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Preliminary results are shown with statistical errors only.

2005-06-13

48

BOUNDARY LAYER FLOW AND DOUBLE DIFFUSION OVER AN UNSTEADY STRETCHING SURFACE WITH HALL EFFECT  

British Library Electronic Table of Contents (United Kingdom)

The present investigation is concerned with the effect of Hall currents on boundary layer flow, and heat and mass transfer of an electrically conducting fluid over an unsteady stretching sheet in the presence of a strong magnetic field. The electron-atom collision frequency is assumed to be relatively high, so that the Hall effect is assumed to exist, while the induced magnetic field is neglected. The governing time-dependent boundary layer equations for momentum, thermal energy, and concentration are reduced using a similarity transformation to a set of coupled ordinary differential equations. The similarity ordinary differential equations are then solved numerically by the successive linearization method together with the Chebyshev pseudo-spectral collocation method. Effects of the Prand...

2011-01-01

49

Influence of chemical reaction and thermal radiation on the heat and mass transfer in MHD micropolar flow over a vertical moving porous plate in a porous medium with heat generation  

British Library Electronic Table of Contents (United Kingdom)

An analysis is presented for the effects of chemical reaction and thermal radiation on hydromagnetic free convection heat and mass transfer for a micropolar fluid via a porous medium bounded by a semi-infinite vertical porous plate in the presence of heat generation. The plate moves with a constant velocity in the longitudinal direction and the free stream velocity follows an exponentially small perturbation law. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micropolar fluid with a suction velocity varying with time. Analytical expressions are computed numerically. Numerical calculations are carried out the purpose of the discussion of the results which are shown on graphs and the effects of the various dimensionless parameters entering into the p...

2009-01-01

50

The coil of the MBI bending magnets for the LHC injection transfer lines  

CERN Document Server

All MBI bending magnets in each of the two LHC injection transfer lines will be powered in series. The limited output voltage of existing power converters lead to an unusual coil design avoiding external return bus-bars by combining two overlapping half-coils, electrically separated, with 3 1/2 turns each in a monolithic structure. The voltage between turns in one coil can reach up-to 3.6 kV. The coil has been designed with particular care for obtaining high interturn and ground insulation. Flux-free soldering of connections with plug-in cone sleeves is applied, allowing to execute water cooled current connections as prolongation of the coil conductor. Epoxy compound polymerization in the impregnation mould is obtained by passing overheated water in regulated cycles through the water circuit of the coil conductor. We describe the design basics as well as various test results of pre-series and series produced coils. (4 refs).

2002-01-01

51

Programmed improvements of the alternating gradient synchrotron complex at Brookhaven National Laboratory, Upton, New York. Environmental assessment  

Energy Technology Data Exchange (ETDEWEB)

The purpose and need for DOE to undertake the actions described in this document are to improve the efficiency of the Alternating Gradient Synchrotron (AGS) complex. Benefits would include optimization of the AGS scientific program, increased high-energy and nuclear physics experimentation, improved health and safety conditions for workers and users, reduced impact on the environment and the general public, energy conservation, decreased generation of hazardous and radioactive wastes, and completion of actions required to permit the AGS to be the injector to the Relativistic Heavy Ion Collider (RHIC)., Improved efficiency is defined as increasing the AGS`s capabilities to capture and accelerate the proton intensity transferred to the AGS from the AGS booster. Improved capture of beam intensity would reduce the beam losses which equate to lost scientific opportunity for study and increased potential for radiation doses to workers and the general public. The action ...

1994-03-01

52

Changes of magnetization transfer ratio according to rat brain development  

International Nuclear Information System (INIS)

We assessed the age-related changes in magnetization transfer ratio (MTR) value and the ratio of water content in rat brain (frontal lobe and pons) during normal development. All studies were done on 42 normal Wistar rats. MTR was calculated by using the equation (M_o_f_f-M_o_n)/M_o_f_f, where M_o_f_f and M_o_n were the measured signal intensities on the conventional and MT-prepared SPGR images, respectively. The ratios of water content were measured by comparing the wet weight with the dry weight of the frontal lobe and the pons, which were extracted from a rat brain soon after MTR measurements. The ratio of water content was calculated by using the equation 100 x (wet weight-dry weight)/wet weight (%). The ratio of water content decreased markedly during the first 30 days, but the decrease was very slight there after both in the frontal lobe and the pons. The change in MTR was similar to that of the ratio of water content, though the ...

53

Spectroscopy of neutron-rich Fe isotopes populated in the "6"4Ni+"2"3"8U reaction  

International Nuclear Information System (INIS)

The neutron-rich Fe isotopes from A=61 to 66 were studied through multinucleon transfer reactions by bombarding a "2"3"8U target with a 400 MeV "6"4Ni beam. Unambiguous identification of prompt #gamma# rays belonging to each nucleus was achieved using coincidence relationships with the ions detected in a high-acceptance magnetic spectrometer. The new data extend our knowledge of the level structure of Fe isotopes, which is discussed in terms of the systematics of the region and compared with large-scale shell-model calculations.

2007-09-01

54

Encapsulated magnetite particles for biomedical application  

International Nuclear Information System (INIS)

The process of miniemulsification allows the generation of small, homogeneous, and stable droplets containing monomer or polymer precursors and magnetite which are then transferred by polymer reactions to the final polymer latexes, keeping their particular identity without serious exchange kinetics involved. It is shown that the miniemulsion process can excellently be used for the formulation of polymer-coated magnetic nanoparticles which can further be used for biomedical applications. The use of high shear, appropriate surfactants, and the addition of a hydrophobe in order to suppress the influence of Ostwald ripening are key factors for the formation of the small and stable droplets in miniemulsion and will be discussed. Two different approaches based on miniemulsion processes for the encapsulation of magnetite into polymer particles will be presented in detail.

2003-04-23

55

The role of 5-quark components on the nucleon form factors  

Energy Technology Data Exchange (ETDEWEB)

The covariant quark model is shown to allow a phenomenological description of the neutron electric form factor, G{sub E}{sup n}(Q{sup 2}), in the impulse approximation, provided that the wave function contains minor ({approx}3%) admixtures of the lowest energy sea-quark configurations. While that form factor is not very sensitive to whether the q{sup -} in the qqqqq{sup -} component is in the P-state or in the S-state, the calculated nucleon magnetic form factors are much closer to the empirical values in the case of the former configuration. In the case of the electric form factor of the proton, G{sub E}{sup p}(Q{sup 2}) a zero appears in the impulse approximation close to 10 GeV{sup 2}, when the q{sup -} is in the P-state. That configuration, which may be interpreted as a pion loop ('cloud') fluctuation, also leads to a clearly better description of the nucleon magnetic moments. When the amplitude of the sea-quark admixtures ...

2007-07-15

56

Measurement of the N{yields}{delta}{sup +}(1232) Transition at High-Momentum Transfer by {pi}{sup 0} Electroproduction  

Science.gov (United States)

We report a new measurement of the exclusive electroproduction reaction {gamma}*p{yields}{pi}{sup 0}p to explore the evolution from soft nonperturbative physics to hard processes via the Q{sup 2} dependence of the magnetic (M{sub 1+}), electric (E{sub 1+}), and scalar (S{sub 1+}) multipoles in the N{yields}{delta} transition. 9000 differential cross section data points cover W from threshold to 1.4 GeV/c{sup 2}, 4{pi} center-of-mass solid angle, and Q{sup 2} from 3 to 6 GeV{sup 2}/c{sup 2}, the highest yet achieved. It is found that the magnetic form factor G{sub M}* decreases with Q{sup 2} more steeply than the proton magnetic form factor, the ratio E{sub 1+}/M{sub 1+} is small and negative, indicating strong helicity nonconservation, and the ratio S{sub 1+}/M{sub 1+} is negative, while its magnitude increases with Q{sup 2}.

2006-09-15

58

Fractionation of combined heat and radiation in asynchronous CHO cells. II. The role of cell-cycle redistribution  

Science.gov (United States)

Asynchronous Chinese hamster ovary (CHO) cells treated with conditioning hyperthermia (10 min at 45/sup 0/C) followed immediately by x irradiation with 4 Gy at room temperature display a decreased radiation response when either irradiated, or heated and irradiated again 24 h later. In addition, conditioning by 4 Gy of x radiation alone followed at 24 h by the combined heat and radiation treatment als resulted in a larger radiation D/sub 0/. Since the differential cell-cycle responses to heat- and x-ray-induced lethality are well established for CHO cells, the potential role of cell-cycle redistribution in the observed radiation desensitization was investigated by flow cytometry. At 24 h after the combined treatment, the fraction of the cells found in the G/sub 2/ + M portion of the DNA histograms was about three times that of the controls and there was a concomitant reduction in both the G/sub 1/ and S fractions. Similar observations were made after the ...

1979-11-01

59

Magnetism of the Ni(110) and Ni(100) surfaces: local-spin-density-functional calculations using the thin-slab linearized augmented-plane-wave method  

International Nuclear Information System (INIS)

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

60

Liquid-metal flow in a sharp elbow in a uniform transverse magnetic field  

Science.gov (United States)

In the self-cooling blankets of the Tokamak fusion reactor, a liquid metal, namely liquid lithium, is pumped through a system of ducts to transfer heat and capture neutrons. One of the blanket designs proposed in Argonne National Laboratory's Blanket Comparison and Selection study uses a combination of poloidal and toroidal ducts in order to maximize heat transfer while minimizing net pressure drop. In the design, the poloidal and toroidal ducts meet at sharp, abrupt corners. They were modelled as two identical, straight, semi-infinite, thin-walled, rectangular ducts with 45{degree} miters and joined at a 90{degree} angle in the plane of a strong, uniform magnetic field. While in the toroidal containment vessel (i.e. the blanket), the liquid lithium is subjected to a large electromagnetic body force due to the presence of a strong magnetic field. This body force so dominates the flow as to make ...

1989-01-01

61

Magnetic Levitation of MC3T3 Osteoblast Cells as a Ground-Based Simulation of Microgravity  

UK PubMed Central (United Kingdom)

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

2009-11-01

62

Refining the Magnetic Forming Capability.  

Science.gov (United States)

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

1972-04-01

64

BIOMAGNETIC RESPONSE OF SIMPLE BIOLOGICAL ...  

Science.gov (United States)

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

1970-01-01

65

/22k : - NASA Technical Reports Server  

Science.gov (United States)

in pulse applications such as magnetic forming. ... In magnetic-forming electric circuitry, the ..... Aspects of Electrohydraulic land Magnetic Forming. ...

66

Interaction of 8 MeV /sup 12/C with /sup 88/Sr; neutron transfer, inelastic scattering and spin alignment of the 2/sup +/ state of /sup 12/C  

Energy Technology Data Exchange (ETDEWEB)

Using a Q3D magnetic spectrometer the elastic and inelastic scattering of /sup 12/C on /sup 88/Sr and the neutron pick-up (/sup 12/C, /sup 13/C) has been studied. The spin alignment of the inelastically excited 2/sup +/ state of /sup 12/C (4.43 MeV) has been deduced from the line shapes broadened by the ..gamma..-decay in flight. Thus for each m-substate a full angular distribution was obtained. The m = 1 substate shows a shifted interference minimum, which is explained by the different strength of the Coulomb and nuclear amplitudes in the m-substates. The analysis of the data on elastic scattering, inelastic scattering, alignment and the neutron transfer can be described consistently with one choice of the optical model parameters.

1982-04-01

67

MAGNETIC RESONANCE IMAGING DEVICE  

J-STORE (Japan)

Full Text Available

2010-08-31

68

The effects of temperature dependent viscosity and thermal conductivity on unsteady MHD convective heat transfer past a semi-infinite vertical porous moving plate with variable suction  

British Library Electronic Table of Contents (United Kingdom)

In this article, we studied the effects of variable viscosity and thermal conductivity on an unsteady two-dimensional laminar flow of a viscous incompressible conducting fluid past a semi-infinite vertical porous moving plate taking into account the effect of a magnetic field in the presence of variable suction. The fluid viscosity is assumed to vary as an inverse linear function of temperature but the thermal conductivity is assumed to vary as a linear function of temperature. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The governing equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation ...

2007-01-01

69

Spectroscopy of neutron-rich {sup 59-63}Mn isotopes  

Science.gov (United States)

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.

2008-08-15

70

Spectroscopy of neutron-rich "5"9"-"6"3Mn isotopes  

International Nuclear Information System (INIS)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a "2"3"8U target with a beam of "7"0Zn at an energy of E_l_a_b=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.

2008-08-01

71

Nano photonic sensors for microdamage detection : an exploratory simulation.  

Energy Technology Data Exchange (ETDEWEB)

Nano photonic materials are synthetically manufactured crystals at the nano scale with the target of creating a microstructure with a special electro-magnetic periodicity. Such nano photonic materials have the ability to control light propagation and thus are capable of creating photonic bandgaps in the frequency domain. We propose using nano photonic crystals as sensors to detect microdamage in composite materials. We demonstrate using a simulation model that a nano photonic sensor attached to a composite bar experiences a significant change in its bandgap profile when damage is induced in the composite bar. The model predicts the frequency response of the nano photonic sensor using the transfer matrix method. A damage metric to evaluate the change in the frequency response is developed. Successful developments of nano photonic sensors allow damage identification at scales not attainable using current sensing technologies.

2005-04-01

72

Large Eddy Simulation for Heat Transfer Prediction in a Gas ...  

Science.gov (United States)

... turbine blade heat-transfer and study the heat-transfer augmentation in idealized geometry and its ... responsible for heat transfer augmentation. ...

2007-03-30

74

Tissue Heterogeneity in IMRT Dose Calculation for Lung Cancer  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the gamma function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the l...

2011-01-01

75

The LCG PI project: using interfaces for physics data analysis  

CERN Document Server

In the context of the LHC computing grid (LCG) project, the applications area develops and maintains that part of the physics applications software and associated infrastructure that is shared among the LHC experiments. The "physicist interface" (PI) project of the LCG application area encompasses the interfaces and tools by which physicists will directly use the software, providing implementations based on agreed standards like the analysis systems subsystem (AIDA) interfaces for data analysis. In collaboration with users from the experiments, work has started with implementing the AIDA interfaces for (binned and unbinned) histogramming, fitting and minimization as well as manipulation of tuples. These implementations have been developed by re-using existing packages either directly or by using a (thin) layer of wrappers. In addition, bindings of these interfaces to the Python interpreted language have been done using the dictionary subsystem of the LCG ...

2005-01-01

76

The LCG PI project using interfaces for physics data analysis  

CERN Document Server

In the context of the LHC Computing Grid (LCG) project, the Applications Area develops and maintains that part of the physics applications software and associated infrastructure that is shared among the LHC experiments. The "Physicist Interface" (PI) project of the LCG Application Area encompasses the interfaces and tools by which physicists will directly use the software, providing implementations based on agreed standards like the AIDA interfaces for data analysis. In collaboration with users from the experiments, work has started with implementing the AIDA interfaces for (binned and unbinned) histogramming, fitting and minimization as well as manipulation of tuples. These implementations have been developed by re-using existing packages either directly or by using a (thin) layer of wrappers. In addition, bindings of these interfaces to the Python interpreted language have been done using the dictionary subsystem of the LCG-AA/SEAL project. The actual status and ...

2004-01-01

77

Quantitative 1-123 IMP SPECT, MR imaging, and neuropsychologic testing in AIDS dementia  

International Nuclear Information System (INIS)

The authors have performed I-123 IMP single- photon emission CT (SPECT) brain imaging on seven mildly demented patients with acquired immunodeficiency syndrome (AIDS) and on seven normal subjects. Pixel-intensity histograms have been analyzed for the fraction of pixels in the lowest quartile of the intensity range. This fraction (F) averaged 17.7% (standard deviation [SD] = 4.3) in the AIDS group and 12.6 (SD = 4.7) in the normal group (P <.05). Regression analysis of neuropsychological testing (NPT) scores vs F yielded a correlation coefficient of.71. The presence or degree of atrophy did not correlate with F or NPT scores.

78

Health effects of the Chernobyl accident  

Energy Technology Data Exchange (ETDEWEB)

The results of nine years of study of the 237 patients who suffered from acute radiation syndrome (ARS) as a consequence of the Chernobyl accident are reported. Thirty-eight of these patients have died, 28 in the acute period in 1986, 5 in 1987-90 and 5 in 1992-93. The reasons for death show no clear tendencies. They include: gangrene of the lung, organic disease of the brain and spinal chord, hypoplasia of haematopoeisis, coronary heart disease, sarcoma and an automobile accident. Investigations have been carried out on an annual obligatory basis of the patients` haemopoietic, immune, nervous and endocrine systems. An analysis of the data is presented. Histograms are included showing the incidence of digestive tract, nervous system, respiratory and cardiovascular disorders, the frequency and degree of disablement and serum prolactin concentration. The types of skin damage sustained by 39 of the patients are listed. (6 figures, 3 tables). (UK).

1995-12-31

79

Specification of the steel sheet for the 300 GeV magnet system  

CERN Document Server

Specification of the steel sheet for the 300 GeV magnet system

1971-01-01

80

Radial Halbach Magnetic Bearings  

Science.gov (United States)

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

2009-01-01

81

Magnetic phase transition in UPd_2Si_2  

International Nuclear Information System (INIS)

... fields magnetic moments neel temperature neutron diffraction order-disorder

82

Magnetic forming of resistive materials  

Science.gov (United States)

Necessary theoretical foundation is given for the treatment of magnetic stresses applied to

1969-01-01

83

Magnetic forming coil design and development summary report  

Science.gov (United States)

Magnetic forming coil design and development

1964-01-01

85

Large scale magnetic field measurements and mapping  

CERN Document Server

Large scale magnetic field measurements and mapping

1984-01-01

86

ELECTRICAL AND DIAGNOSTIC ASPECTS OF ELECTROHYDRAULIC AND MAGNETIC FORMING  

Science.gov (United States)

Discussion of an electrohydraulic and magnetic forming process

1963-01-01

88

New MR techniques in diagnostic imaging of joints; Neue MRT-Techniken in der Gelenkdiagnostik  

Energy Technology Data Exchange (ETDEWEB)

Already, MR Imaging is superior in diagnostic imaging of joints in many cases; however, there have been recent developments, which are the subjects of this paper. With gradient-echo sequences acquired in 3D technique, it is possible to produce high-resolution images of joints in acceptable scantime, because gradient-echo sequences are less time-consuming than convential SE sequences. With the acquisition of two echoes, phase difference between water and fat protons have to be considered. 3D Imaging is capable of displaying complex pathology in a superior way, which should be useful in preoperative planning. Tissue contrast is altered by fat saturation or magnetization transfer in order to achieve better conspicuity of lesions. Although diagnostic value of some of these options is not yet clear and further clinical studies are needed, they are a promising possibility for improving MR Imaging of the joints. (orig.) [Deutsch] In der ...

1993-12-31

89

Magnetic separation of antibiotics by electrochemical magnetic seeding  

Energy Technology Data Exchange (ETDEWEB)

Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of ...

2009-03-01

90

Fish Research Project Oregon; Aspects of Life History and Production of Juvenile Oncorhynchus Mykiss in the Grande Ronde River Basin, Northeast Oregon, 1995-1999 Summary Report.  

Energy Technology Data Exchange (ETDEWEB)

Rotary screw traps, located at four sites in the Grande Ronde River basin, were used to characterize aspects of early life history exhibited by juvenile Onchorhychus mykiss during migration years 1995-99. The Lostine, Catherine Creek and upper Grande Ronde traps captured fish as they migrated out of spawning areas into valley rearing habitats. The Grande Ronde Valley trap captured fish as they left valley habitats downstream of Catherine Creek and upper Grande Ronde River rearing habitats. Dispersal downstream of spawning areas was most evident in fall and spring, but movement occurred during all seasons that the traps were fished. Seaward migration occurred primarily in spring when O. mykiss smolts left overwintering area located in both spawning area and valley habitats. Migration patterns exhibited by O. mykiss suggest that Grande Ronde Valley habitats are used for overwintering and should be considered critical rearing habitat. We were unable to positively differentiate anadromous ...

2001-07-01

91

Stability and disturbance of large dc superconducting magnets  

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet ...

1981-11-11

93

Magnetic braking of the rotation of molecular cloud cores  

International Nuclear Information System (INIS)

We investigate the magnetic braking of the core of an axisymmetric cloud whose rotation axis is parallel to the mean direction of the magnetic field. (author).

94

LHC magnet alignment  

CERN Document Server

Checks are performed on the alignment of the magnets in the LHC tunnel. It is vital that each magnet is placed exactly where it has been designed so that the path of the beam is precisely controlled.

2007-01-01

95

Conjugate Heat Transfer Predictions of a Combustor ...  

Science.gov (United States)

... To maximise heat transfer rates, many heatshield designs make use of heat transfer augmentation devices such as large numbers of pin-fin ...

2003-03-01

96

Augmentation of heat and mass transfer  

Energy Technology Data Exchange (ETDEWEB)

This is the first text and reference book to be devoted completely to the very important and timely subject of heat transfer augmentation. This book is of equal appeal to both researchers and designers of heat transfer equipment.

1986-01-01

97

Density separation of materials by using magnetic fluids  

Energy Technology Data Exchange (ETDEWEB)

The magnetic fluid is a colloidal suspension of magnetite in kerosene, prepared by a low-cost process. Separation is accomplished in an open trough filled with magnetic fluid. A magnetic field is established in the fluid, by energizing an electromagnet having poles on each side of the trough. Due to the design of the magnet poles and air gaps, the magnetic field is strongest at the bottom, about 10,000 oersteds, and uniformly decreases in strength to about 2000 oersteds at the top of the fluid. Therefore, the magnetic field gradient increases with depth. The magnetic force attracts the entire separation medium (magnetic fluid) creating a reaction force of equal magnitude and acting in the opposite direction. This reaction created within a magnetic fluid/magnetic field combination ...

1980-03-01

98

Physical and optical properties of rare earth cobalt magnets  

Energy Technology Data Exchange (ETDEWEB)

Rare Earth Cobalt (REC) permanent magnets have unique properties that permit solutions to some optical tasks that cannot be accomplished with conventional magnets. A review of design and of performance characteristics of these magnets includes an analytical description of the three dimensional fringe fields of REC quadrupoles.

1980-08-01

104

METHOD OF FORMING THIN MAGNETIC FILM  

J-STORE (Japan)

Full Text Available

2007-10-04

110

Time-Dependent 2D Modeling of Magnetron Plasma Torch in Turbulent Flow  

International Nuclear Information System (INIS)

A theoretical model is presented to describe the electromagnetic, heat transfer and fluid flow phenomena within a magnetron plasma torch and in the resultant plume, by using a commercial computational fluid dynamics (CFD) code FLUENT. Specific calculations are presented for a pure argon system (i.e., an argon plasma discharging into an argon environment), operated in a turbulent mode. An important finding of this work is that the external axial magnetic field (AMF) may have a significant effect on the behavior of arc plasma and thus affects the resulting plume. The AMF impels the plasma to retract axially and expand radially. As a result, the plasma intensity distribution on the cross section of torch seems to be more uniform. Numerical results also show that with AMF, the highest plasma temperature decreases and the anode arc root moves upstream significantly, while the current density distribution at the anode is more concentrated with a ...

2008-06-01

111

The runaway instability of thick discs around black holes. II. Non constant angular momentum discs  

CERN Document Server

We present results from a comprehensive number of relativistic, time-dependent, axisymmetric simulations of the runaway instability of non-constant angular momentum thick discs around black holes. This second paper extends earlier results where only constant angular momentum discs were considered. All relevant aspects of the theory of stationary thick discs around rotating black holes, necessary to build the initial state in our simulations, are presented in great detail. The angular momentum of the discs is assumed to increase outwards with the radial distance according to a power law. The main simplifying assumptions of our approach are not to include magnetic fields and self-gravity in the discs. Furthermore, the dynamics of the spacetime is accounted for by computing the transfer of mass and angular momentum from the disc to the black hole through the event horizon : the evolution of the central black hole is assumed to follow a sequence of ...

2004-01-01

112

Stability analysis of forced-flow cooled superconducting coil; Numerical simulation on multiple stability. Kyosei reikyaku gata chodendo coil no anteisei kaiseki; Taju anteisei no simulation  

Energy Technology Data Exchange (ETDEWEB)

The stability of a forced-flow cooled superconducting coil is investigated by use of the numerical simulation. The numerical code to integrate the simultaneous partial differential system composed of the 1 D hydrodynamic equations and the 1 D thermal conduction equation has been developed and stability margins are evaluated as functions of coolant mass flow rate, operation current and imposed magnetic field. The results of computations show that the stability margin is multi-valued with respect to these operation parameters, as expected from the experimental results. It is also shown that the appearance of the first unstable regime is closely related to the existance of the stagnant region located at the upstream side of the heated zone and that the second stable regime appears because the heat transfer is appreciably enhanced by the induced backflow due to the thermal expansion of coolant. 13 refs., 13 figs., 1 tab.

1990-06-25

113

Oxidation, volatilization, and redistribution of molybdenum from TZM alloy in air  

Energy Technology Data Exchange (ETDEWEB)

The excellent high temperature strength and thermal conductivity of molybdenum-base alloys provide attractive features for components in advanced magnetic and inertial fusion devices. Refractory metal alloys react readily with oxygen and other gases. Oxidized molybdenum in turn is susceptible to losses from volatile molybdenum trioxide species, MoO{sub 3}(m), in air and the hydroxide, MoO{sub 2}(OH){sub 2}, formed from water vapor. Transport of radioactivity by the volatilization, migration, and re-deposition of these volatile species during a potential accident involving a loss of vacuum or inert environment represents a safety issue. In this report the authors present experimental results on the oxidation, volatilization and re-deposition of molybdenum from TZM in flowing air between 400 and 800 C. These results are compared with calculations obtained from a vaporization mass transfer model using chemical thermodynamic data for vapor ...

2000-01-01

114

Oxidation, Volatilization, and Redistribution of Molybdenum from TZM Alloy in Air  

Energy Technology Data Exchange (ETDEWEB)

The excellent high temperature strength and thermal conductivity of molybdenum-base alloys provide attractive features for components in advanced magnetic and inertial fusion devices. Refractory metal alloys react readily with oxygen and other gases. Oxidized molybdenum in turn is susceptible to losses from volatile molybdenum trioxide species, (MoO3)m, in air and the hydroxide, MoO2(OH)2, formed from water vapor. Transport of radioactivity by the volatilization, migration, and re-deposition of these volatile species during a potential accident involving a loss of vacuum or inert environment represents a safety issue. In this report we present experimental results on the oxidation, volatilization and re-deposition of molybdenum from TZM in flowing air between 400 and 800°C. These results are compared with calculations obtained from a vaporization mass transfer model using chemical thermodynamic data for vapor pressures of MoO3(g) over ...

2000-01-01

115

New dioxomolybdenum(VI) complexes with tridentate dibasic ONO donor schiff bases  

International Nuclear Information System (INIS)

Several dioxomolybdenum(VI) complexes of the schiff bases derived from salicylaldehyde, 2-hydroxy-1-naphthaldehyde, o-hydroxyacetophenone or pyridoxal and o-aminobenzylalcohol, o-aminophenol, o-hydroxybenzylamine, o-hydroxy(methylbenzyl)amine or 3-amino-2-naphthoic acid have been synthesized and characterized by elemental analysis, electrical conductance, molecular weight, IR and electronic spectral and magnetic susceptibility measurements. The schiff bases behave as dibasic, tridentate ligands and coordinate through ONO donor system forming complexes of the type MoO_2L.X (where LH_2=schiff base, X=H_2O or Ch_3OH). The compounds MoO_2L.Ch_3OH react with 2,2'-dipyridyl to form heterochelates of the type MoO_2L.dipyridyl. The complexes are non-electrolytes, monomers, diamagnetic and possess a cis-MoO_2 structure. The complexes exhibit a ligand-to-metal charge-transfer transition around 25000 cm"-"1. The complexes MoO_2L.X and MoO_2L.dipyridyl are ...

116

Diagnosis of breast cancer with MR imaging using the magnetization transfer contrast and a newly-developed breast surface coil for the supine position  

Energy Technology Data Exchange (ETDEWEB)

We developed a new breast surface coil for the supine position. The subjects consisted of 9 patients with breast cancer varying from 46 to 60 years of age (average: 52). The cancer image of the SPGR (CE+) method was compared with that of the FSMTC (MTC-SPGR (CE+)) method and that of the FSMTC (MTC-SPGR with fat-saturation (CE+)) method in the sagittal section after injection of Gd-DTPA (0.1 mmol/kg). Quantitative analyses were performed before and after injection of Gd-DTPA in 6 patients. Three patients were excluded from the quantitative analyses owing to the clear detection of tumors in the fat tissue. Signal intensity measurements were systematically performed in each region of interest (ROI), i.e. the cancer lesion, the surrounding mammary gland. Statistical analyses showed significant differences between the lesions using the FSMTC (MTC-SPGR (CE+)), and the FSMTC (MTC-SPGR with fat-saturation (CE+)) methods and the lesions using the SPGR (CE+) method after injection of contrast ...

1998-09-01

117

Design of the ZTH vacuum liner  

Energy Technology Data Exchange (ETDEWEB)

The current status of the ZTH vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4 m major radius and a 40 cm minor radius. Operating parameters which drive the vacuum vessel mechanical design include a 300 C bakeout temperature, an armour support system capable of withstanding 25 kV, a high toroidal resistance, 1250 kPa magnetic loading, a 10 minute cycle time, and high positional accuracy with respect to the conducting shell. The vacuum vessel design features which satisfy the operating parameters are defined. The liner is constructed of Inconel 625 and has a geometry which alternates sections of thin walled bellows with rigid ribs. These composite sections span between pairs of the 16 diagnostic stations to complete the torus. The ...

1987-01-01

118

Data Compression on Zero Suppressed High Energy Physics Data  

CERN Document Server

Future High Energy Physics experiments will produce unprecedented data volumes (up to 1 GB/s [1]). In most cases it will be impossible to analyse these data in real time and they will have to be stored on durable mostly magnetic linear media (e.g. tapes) for later analysis. This threatens to become a major cost factor for the running of these experiments. Here we present some ideas developed together with the Institute of Computer Graphics, Department for Algorithms and Programming on how this volume and the related cost can be reduced significantly. The algorithms presented are not general ones but aimed in particular to physics experiments data. Taking advantage of the knowledge of the data they are highly superior to general ones (Huffman, LZW, arithmetic coding) both in compression rate but more importantly in speed as to keep up with the output rate to modern tape drives. Above standard algorithms are, however, used after the data have been ...

1996-01-01

119

Cyclopalladated 2-phenyldihydrooxazole complexes with ethylenediamine, 2,2?-bipyridine, and bridging acetate ligands  

British Library Electronic Table of Contents (United Kingdom)

The 1H NMR, electronic absorption, and luminescence spectra, as well as voltammograms of the reduction and oxidation of the complexes [Pd(C?N)(N?N)]ClO4 and [Pd(C?N)(?-OOCCH3)]2 [where (C?N)? is deprotonated 2-phenyl-4,5-dihydro-1,3-oxazole, and N?N is ethylenediamine or 2,2?-bipyridine (bpy)] were compared. Magnetic nonequivalence of protons in the dihydrooxazole ring and upfield shift of the corresponding signals were observed as a result of anisotropic effect of the ring current in palladated phenyl substituents in the [Pd(C?N)(?-OOCCH3)]2 complex having a C 2 symmetry. One-electron reduction wave of [Pd(C?N)bpy]+ was assigned to ligand-centered electron transfer to the ?* orbital of 2,2?-bipyridine, and two oxidation waves of [Pd(C?N)(?-OOCCH3)]2 were attributed to successive one-elect...

2011-01-01

120

Characterization and reactivity of Fe3O4/FeMnOx core/shell nanoparticles for methylene blue discoloration with H2O2  

British Library Electronic Table of Contents (United Kingdom)

A magnetic core/shell Fe3O4/FeMnOx catalyst was prepared by a simple oxidation-precipitation method. The catalyst was characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry. The characterization studies verified that Fe3O4 core was coated with a layer of Fe-Mn oxide. The Fe3O4/FeMnOx was found to be an effective and stable heterogeneous catalyst for the discoloration of methylene blue (MB) in aqueous solution by H2O2. The high catalytic activity is due to the FeMnOx shell, which not only increased the surface hydroxyl groups, but also enhanced the interfacial electron transfer. The discoloration of MB could be due to the decomposition of H2O2 into ?OH ...

2011-01-01

124

ASME proceedings of the 31. national heat transfer conference: Volume 2. HTD-Volume 324  

Energy Technology Data Exchange (ETDEWEB)

This volume is divided into the following sections: (1) fundamentals of convection heat transfer; (2) fundamentals of heat transfer with impinging jets; and (3) fundamentals of heat transfer augmentation. Separate abstracts were prepared for most papers in this volume.

1996-12-31

125

NASA TECH BRIEF  

Science.gov (United States)

Magnetic Forming Studies. The use of transient high magnetic-field devices has made possible the generation of very large accurately ...

127

Magnetic properties of single crystalline RE_2PdSi_3 intermetallic compounds  

International Nuclear Information System (INIS)

... susceptibility magnetization magnetoresistance monocrystals order-disorder

128

Finite Element Analysis of Magnetoelastic Plate Problems.  

Science.gov (United States)

... in the design of such devices as fusion reactors, magnetohydrodynamic generators, magnetically levitated vehicles, magnetic forming devices, and ...

1981-08-01

129

Design of a kW, DC Magnetically Contained Electrothermal ...  

Science.gov (United States)

... magnetic containment field lines which is zero on the center line of the toroidal containment tube and increases in magnitude with ...

1988-07-01

130

An investigation of the decoupling effects in a magnetic forming beryllium coil assembly.  

Science.gov (United States)

Decoupling force exerted by magnetic forming Be coil assembly on metallic plate during forming

1968-01-01

132

Safe Type of Transference for Spent Fuel  

International Science & Technology Center (ISTC)

Safe Transference of Spent Fuel Assemblies from Near-Reactor Storage Pools to Long-term "Dry" Storage

133

Cryogenic liquid transfer termination apparatus  

International Nuclear Information System (INIS)

Apparatus for termination of cryogenic liquid transfer from a liquid supply container to a storage-dispensing container is disclosed.

134

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

International Nuclear Information System (INIS)

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

1992-05-01

135

International Symposium on Magnetic Suspension Technology. Part 2  

International Nuclear Information System (INIS)

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

1991-08-19

136

Simplified fusion power plant costing. A general prognosis and call for `new think`  

Energy Technology Data Exchange (ETDEWEB)

A top-level costing model is developed and used to project the cost of electricity (COE) (in mills per kilo watt-hour) expected from conceptual fusion power plants. Application is restricted to magnetic fusion energy (MFE) concepts. These costs are estimated parametrically in terms of the mass of the fusion-power-core (FPC) heater, the power required to sustain a reacting deuterium-tritium plasma, the heat transport/transfer system that delivers the fusion power to the balance of plant (BOP), and the BOP needed to convert the fusion heat to electrical power. Although the highly integrated (simplified) cost-estimating relationships (CERs) used to express COE in terms of FPC mass power density (MPD) [in kilowatt(electric) per tonne] and the engineering gain Q{sub E} (inverse of fraction of gross electric power recirculated to the fusion power plant) apply primarily to MFE approaches to fusion power, the costing gauge thus results is generally ...

1995-03-01

137

Quasi-ternary nanoparticle superlattices through nanoparticle design  

Energy Technology Data Exchange (ETDEWEB)

Individual nanoscale building blocks exhibit a wide range of size-dependent properties, since their size can be tuned over known characteristic length scales of bulk materials. In the last several years, the possibility of combining different materials in the form of two and three component nanoparticles (NPs) has been extensively explored. Also multi-component materials can be obtained via self-assembly of NPs from their binary colloidal mixtures. These new nanocrystal solids may possess tunable collective properties that originate from interactions between size and composition controlled building blocks. Exchange coupling between neighboring NPs of magnetically soft and hard materials enhances the magnetic energy product of the nanocomposite material. Randomly mixed solids of small and large semiconducting CdSe NPs revealed enhancement of photoluminescence intensity of large semiconductor particles accompanied by quenching of ...

2007-06-19

138

Quantum molecular dynamics and molecular interactions studied by NMR and INS[Nuclear magnetic resonance; Proton tunnelling; Hydrogen bond  

Energy Technology Data Exchange (ETDEWEB)

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 ...

2002-07-01

139

Dayside auroral activity and magnetospheric boundary layer phenomena  

Energy Technology Data Exchange (ETDEWEB)

Selected case studies of auroral structure/activity observed at different local times on the dayside are presented and discussed in the context of electrodynamic coupling between the different magnetospheric boundary regions and the ionosphere. The first case addresses the question of the auroral signatures of the two boundary regions referred to as cusp and cleft/LLBL. Combined ground-based and satellite data reveal the different latitudinal zones of auroral forms/particle precipitation/field-aligned current and the relationship with the respective magnetospheric plasma populations, i.e. CPS, BPS, LLBL, and the plasma mantle. Midday auroral breakup events and the related ionospheric ion drift and magnetic observations show many of the features that have been predicted to be ionospheric signatures of flux transfer events. An alternative explanation that has been proposed by others, i.e. ionospheric effect of magnetopause perturbations excited ...

1990-07-01

140

Tissue Heterogeneity in IMRT Dose Calculation for Lung Cancer  

International Nuclear Information System (INIS)

The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the ? function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the lung and in the tumor area. These differences are not always in DVH of the lung, although the Wilcoxon test indicated significant differences in 2 of 4 patients. Disagreement in the ...

2011-01-01

141

Simulations in statistical physics and biology: some applications  

CERN Document Server

One of the most active areas of physics in the last decades has been that of critical phenomena, and Monte Carlo simulations have played an important role as a guide for the validation and prediction of system properties close to the critical points. The kind of phase transitions occurring for the Betts lattice (lattice constructed removing 1/7 of the sites from the triangular lattice) have been studied before with the Potts model for the values q=3, ferromagnetic and antiferromagnetic regime. Here, we add up to this research line the ferromagnetic case for q=4 and 5. In the first case, the critical exponents are estimated for the second order transition, whereas for the latter case the histogram method is applied for the occurring first order transition. Additionally, Domany's Monte Carlo based clustering technique mainly used to group genes similar in their expression levels is reviewed. Finally, a control theory tool --an adaptive observer-- is applied to ...

2006-01-01

142

Design of a magnetic braking system  

International Nuclear Information System (INIS)

A non-contact method, using magnetic drag force principle, was proposed to design the braking systems to improve the shortcomings of the conventional braking systems. The extensive literature detailing all aspects of the magnetic braking is briefly reviewed, however little of this refers specifically to upright magnetic braking system, which is useful for industries. One of the major issues to design upright magnetic system is to find out the magnetic flux. The changing magnetic flux induces eddy currents in the conductor. These currents dissipate energy in the conductor and generate drag force to slow down the motion. Therefore, a finite element model is developed to analyze the phenomena of magnetic flux density when air gap and materials of track are varied. The verification shows the predicted magnetic flux is within ...

2006-09-01

143

Magnetization reversal phenomena and domain wall behaviours in nanostructured magnetic systems  

International Nuclear Information System (INIS)

Several recent experiments on micro- (or nano-) structured samples of ferromagnetic materials are introduced. Magnetization reversal phenomena are investigated on submicron wire samples of trilayer structure using the giant magnetoresistance effect. Domain wall movements are sensitively monitored by resistivity measurements and the velocity of propagation is determined. The contribution of domain wall to the resistivity is argued from the results on artificially designed samples of a spring-magnet system. In circular dots of permalloy, the existence of vortex magnetization is confirmed and the reversal of the vortex core magnetization is studied from magnetic force microscopy measurements. (author)

2001-09-23

144

Magnetic fluctuation measurement in Sino United Spherical Tokamak plasma  

International Nuclear Information System (INIS)

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

2007-07-01

145

Literature and patent searches on the subject of controllable heat transfer. Final report. Literatur- und Patentrecherche zum Thema Schaltbarer Waermedurchgang. Abschlussbericht  

Energy Technology Data Exchange (ETDEWEB)

The possibility of switching the heat transfer consists of varying heat transfer surfaces and making the heat transfer temporarily more intensive. Heat tubes prove to be particularly suitable, which must be exposed to a heat carrier fluid or removed from its effect for switching the heat transfer. This report gives a survey of the possibilities of switching heat flows and for making the heat transfer more intensive. Further, the report contains a survey of patents limited to heat transfer in the fields of cooling internal combustion engines and exhaust systems. (orig.) With 17 figs., 183 refs.

1989-01-01

146

Three-dimensional simulation study of compact toroid plasmoid injection into magnetized plasmas  

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional dynamics of a compact toroid (CT) plasmoid, which is injected into a magnetized target plasma region is investigated by using magnetohydrodynamic (MHD) numerical simulations. It is found that the process of the CT penetration into this region is much more complicated than what has been analyzed so far by using a conducting sphere (CS) model. The injected CT suffers from a tilting instability, which grows with the similar time scale as the CT penetration. The instability is accompanied by magnetic reconnection between the CT magnetic field and the target magnetic field, which disrupts the magnetic configuration of the CT. Magnetic reconnection plays a role to supply the high density plasma initially confined in the CT magnetic field into the target region. Also, the penetration depth of the CT high density plasma is ...

1999-04-01

147

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-02-21

148

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

International Nuclear Information System (INIS)

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

2009-02-21

149

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

International Nuclear Information System (INIS)

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

2005-04-01

150

Magnetic properties of materials  

Energy Technology Data Exchange (ETDEWEB)

A number of interactions between magnetic fields and matter is reviewed. The resulting forces range in magnitude from the very large, obtained in high-energy fields, to the weak ones caused by the magnetostriction of ferromagnets. The fundamentals of these interactions are highlighted, and the examples discussed are forces on dipoles, particle alignment, magnetostrictive forces, magnetic forming, magnetic stirring, levitation melting, and magnetic pulsing of tool steels. (orig.)

2000-08-15

151

Magnetic flocculation and filtration  

Energy Technology Data Exchange (ETDEWEB)

A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

1996-10-01

152

Transfer of chemical elements to breast milk  

International Nuclear Information System (INIS)

The project is intended to yield information on the transfer factors describing the transfer of ingested radionuclides to breast milk for the following elements: antimony, cerium, chromium, cobalt, gallium, lanthanum, molybdenum, niobium, radium, ruthenium, silver, thorium, titanium, and uranium. Those yet unknown or poorly known transfer factors are required in order to be able to develop a reliable model for description and assessment of the transfer of the radionuclides and the possibly resulting hazardous doses to infants, and for subsequent formulation of recommendations for radiological protection of the population. (orig./CB)

1999-08-01

153

Technetium transfer from soil to plants  

International Nuclear Information System (INIS)

Technetium transfer from soil to edible parts of various agricultural plants is studied with application of the "9"5"mTc radioactive tracer. The samples of agricultural plants were grown on andesol typical for Japan soil. The technetium transfer factor to edible parts of cultivated lettuce was higher as compared to non foliate cultures. Relative low transfer factor were observed for fruit and pod like plants. the transfer factors for root crops were of intermediate value

154

Heat transfer augmentation in rod bundles near grid spacers  

International Nuclear Information System (INIS)

Heat transfer augmentation by straight grid spacers in rod bundles is studied for single phase flow and for post critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single phase flow is also examined. Governing heat transfer mechanisms are analyzed, and predictive formulations are established. For single phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. 18 refs.

1980-01-01

155

Convective heat transfer in annular flow  

International Nuclear Information System (INIS)

Several aspects of heat transfer at the annular two phase flow regime are considered. Nucleate boiling is supposed to be absent. Theoretical solutions for cases of laminar and turbulent flow in the liquid film, respectively, are considered, when steam presence does not effect the heat transfer. Heat transfer in annular flows is also considered, where steam phase consists totally or partially of the so-called incondensable gas. In this case steam phase can be a considerable resistance to heat transfer.

1980-01-01

156

Advances in enhanced heat transfer: 1987  

Energy Technology Data Exchange (ETDEWEB)

This book contains nine selections. Some of the titles are: High Heat-Flux, Forced-Convection Heat Transfer for Tubes with Twisted-Tape Inserts; Heat Transfer Augmentation by Interrupted Surfaces - Experimental Consideration; Turbulent Flow Heat Transfer from Externally Roughened Tubes in Axial Flow in Concentric Pipe Heat Exchangers; and Heat Transfer Enhancement of Turbulent Flow in Pipes with an Internal Circular Rib.

1987-01-01

157

Advances in enhanced heat transfer: 1987  

International Nuclear Information System (INIS)

This book contains nine selections. Some of the titles are: High Heat-Flux, Forced-Convection Heat Transfer for Tubes with Twisted-Tape Inserts; Heat Transfer Augmentation by Interrupted Surfaces - Experimental Consideration; Turbulent Flow Heat Transfer from Externally Roughened Tubes in Axial Flow in Concentric Pipe Heat Exchangers; and Heat Transfer Enhancement of Turbulent Flow in Pipes with an Internal Circular Rib.

1987-08-09

158

The effective longitudinal dielectric constant for plasmas in inhomogeneous magnetic fields  

Scientific Electronic Library Online (English)

Abstract in english We present a detailed derivation of the effective dielectric constant to be used in the dispersion relation for electrostatic waves in the case of a plasma immersed in a inhomogeneous magnetic field, with inhomogeneity perpendicular to the direction of the magnetic field.

2004-09-01

159

Magnetic mirror fusion systems: Characteristics and distinctive features  

Energy Technology Data Exchange (ETDEWEB)

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

1987-08-10

160

Magnetic fields of x-ray pulsars  

Energy Technology Data Exchange (ETDEWEB)

An analytic model of magnetic torques applied to an accreting neutron star is employed to evaluate the magnetic dipole moments of x-ray pulsars. A new type of close binary system containing a neutron star is suggested.

1982-09-01

161

Magnetic excitations studied with time-of-flight spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

An introduction to time-of-flight neutron spectroscopy is presented in the context of the study of magnetic materials. Examples are taken from the class of rare earth and actinide magnetic materials known as `strongly correlated electron` systems. (author) 11 figs., 24 refs.

1996-11-01

162

Eddy Current Inspection of Mildly Ferromagnetic Tubing.  

Science.gov (United States)

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

1984-01-01

163

Active magnetic regenerator  

Energy Technology Data Exchange (ETDEWEB)

The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

1982-01-01

164

Proton Transfer Reactivity of Large Multiply Charged Ions  

UK PubMed Central (United Kingdom)

Charge-charge interactions dramatically influence the dissociation and proton transfer reactivity of large multiply protonated ions. In combination with tandem mass spectrometry, proton transfer...Full Text Available

1996-08-01

165

Nanocrystalline permanent magnets with enhanced properties  

International Nuclear Information System (INIS)

Parameters of permanent magnets result from the combination of intrinsic properties such as saturation magnetization, magnetic exchange, and magnetocrystalline energy, as well as microstructural parameters such as phase structure, grain size, and orientation. Reduction of grain size into nanocrystalline regime (#approx# 50 nm) leads to the enhanced remanence which derives from ferromagnetic exchange coupling between highly refined grains. In this study the fundamental phenomena, quantities, and structure parameters, which define nanophase permanent magnets are presented and discussed. The theoretical considerations are confronted with experimental data for nanocrystalline Sm-Fe-N type permanent magnets. (author)

2001-09-23

166

Untitled - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Principle advantages of magnetic forming for part manufacture appear to lie ... to be an area of great potential for the magnetic forming process. We have a ...

167

Symptoms of the musculoskeletal system and exposure to magnetic fields in an aluminium plant.  

UK PubMed Central (United Kingdom)

OBJECTIVE--The study was performed to examine the influence of the exposure to magnetic fields in the potrooms of an electrolysis plant on the occurrence of musculoskeletal symptoms among the employees....Full Text Available

1995-08-01

168

Progress on the Design and Fabrication of the MICE Focusing Magnets  

Energy Technology Data Exchange (ETDEWEB)

The Muon Ionization Cooling Experiment (MICE) focusing solenoid magnets focus the muon beam within the MICE cooling channel on a liquid or solid absorber that is within the warm bore of solenoid. The focusing magnet has a warm bore of 470 mm. his magnet consists of two coils 210-mm long that is separated by an aluminum mandrel that is 200 mm long. Each of the coils has its own leads. The coils may be operated in either the non-flip mode (solenoid mode with both coils at the same polarity) or the lip mode (quadrupole focusing mode where both coils are at opposite polarity). This report describes the focusing solenoid magnet design that will be built by the vendor. The progress on the construction of the first of the focusing magnets will also be discussed in this report. Ultimately three of these magnets will be built. These magnets will be ...

2009-10-19

169

Possible observation of the coexistence of superconductivity and long-range magnetic order in NdRh_4B_4  

International Nuclear Information System (INIS)

The ternary rare earth compound NdRh_4B_4 has been studied by means of critical field, low temperature heat capacity, and static magnetic susceptibility measurements. Features in the upper critical field and heat capacity data at 1.31 K and 0.89 K suggest the occurrence of long-range magnetic order in the superconducting state. The temperature dependence of the static magnetic susceptibility follows a Curie-Weiss law with an effective magnetic moment #mu#sub(eff) = 3.58 +- 0.05 #mu#sub(B) and a Curie-Weiss temperature thetasub(p) = -6.2 +- 1.0 K between 20 K and room temperature. However, magnetization vs. applied magnetic field isotherms suggest the development of a ferromagnetic component in the Nd"3"+ magnetization at low temperatures. (author).

1979-01-01

170

PLASMA JET WELDING, COATING, AND CUTTING: AN ...  

Science.gov (United States)

... 31. New electric forming methods offer potentials for light metals; magnetic forming and plasma forming. ... 3, 25 Magnetic Forming ..... ...

1963-02-01

171

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-07-15

172

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

International Nuclear Information System (INIS)

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

2008-07-01

173

Mechanism of viscosity effect on magnetic island rotation  

Energy Technology Data Exchange (ETDEWEB)

It is shown that plasma viscosity does not influence the magnetic island rotation directly. Nevertheless, it leads to nonstationarity of the plasma velocity. This nonstationarity is the reason of the viscosity effect on island rotation. (author)

2000-04-01

174

Magnetic Properties of Ni Nanoparticles Embedded in ...  

Science.gov (United States)

... M(TH) in applied magnetic fields up to ± 7 T and for temperatures ranging from 2 to 300 K. The superparamagnetic (SPM) behavior of these metallic ...

2011-05-14

175

Localization of small magnets against a noisy background  

Science.gov (United States)

Effective localization of small magnets against a noisy, real world background can involve various methods to first identify the magnetic fields produced by the magnet of interest, then to filter out background noise, and then to analyze the available magnetic field data to localize the magnet. Here we discuss low cost techniques which allow localization of small magnets with field strengths in the milliGauss range against real world background fields in the range of hundreds of mG, which may be fluctuating by up to tens of mG. Such techniques allow magnet tracking to be used to localize catheters in place of more invasive and expensive methods, e.g. fluoroscopy, for a variety of applications, including drug infusion with peripherally inserted central catheters (PICCs), laser ablation (TMR, PTMR) and introduction of pacemaker leads.

2001-05-01

176

Hypoxia and Magnetic Therapy for Personnel Radiation Protection  

International Science & Technology Center (ISTC)

Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries

177

Geometry effects in the pulsed magnetization of high-temperature superconductor bulk parts  

International Nuclear Information System (INIS)

The dynamic response of cylindrical and ring-shaped YBaCuO bulk parts to pulsed magnetic fields is calculated by using small sets of finite elements. Some comparisons with experimental results are provided, and they give confidence in the modelling of the superconducting properties. Transient magnetizations as a function of time and space as well as shapes and absolute values of trapped magnetic flux profiles are presented. The influence of the sample geometry is investigated for different millisecond pulsed magnetization processes. Results are reported for different radial thicknesses and heights, different pulse durations, peak magnetic fields and pulse sequences with and without stepwise cooling. Comparisons concerning the achievable trapped magnetic field and flux are made, and implications for the use of high-temperature superconductor bulk parts as ...

2005-02-01

178
179

Formulation development and evaluation of metronidazole magnetic nanosuspension as a magnetic-targeted and polymeric-controlled drug delivery system  

Energy Technology Data Exchange (ETDEWEB)

A nanosuspension of magnetically tagged metronidazole was developed by the solvent displacement method coupled with ultrasonication and was evaluated for its physicochemical properties. The drug release from metronidazole magnetic nanosuspension at pH 1.2 and 7.0 shows maximum correlation coefficient for zero order and Higuchi model, respectively. The anthelmintic activity of the formulated metronidazole magnetic nanosuspension was evaluated on Indian earthworms (Pheretima poi). Metronidazole magnetic nanosuspension at a dose of 10 and 50 mg/ml shortened by 31% and 34%, respectively, the mean time to death of the earthworms when compared against a non-magnetic metronidazole suspension. Thus, the developed metronidazole magnetic nanosuspension showed potent, controlled and targeted drug action and might be a good therapeutic avenue in combating infectious GI ...

2009-05-15

180

Evaluation of Commercial Magnetic Descalers.  

Science.gov (United States)

With the increased costs of maintaining boilers and chillers entrepreneurs around the country have offered magnetic and similar devices to facilities as viable alternatives to their maintenance program. This report gives a brief history of some of the pre...

1984-01-01

181

Develop Magnetic Coil Design and Manufacturing Capability.  

Science.gov (United States)

... design, and manufacturing knowledge have been acquired and used to develop an 'in-house' capability for the fabrication of magnetic forming coils ...

1974-11-01

183

CONTRACT: NAS 8-11811 DESIGN, DEVELOPMENT, MANUFACTURE, AND ...  

Science.gov (United States)

has been generally related to magnetic forming. One of the methods suggested was the following: A "pancake" magnetic coil is placed over a thin aluminum ...

184

Application of the grazing angle polarized neutron reflectometry to study the magnetism in thin films and stratified media  

Energy Technology Data Exchange (ETDEWEB)

From optical point of view and due to the magnetic interaction of the cold neutrons with the unpaired electron shell, magnetic materials hae a neutron spin-dependent refractive index n[sup +] [spin up] and n[sup -] [spin down]. Magnetic media such as Fe, Co and Ni react like birefringent uniaxial crystals in ordinary optica. n[sup +] and n[sup -] are the equivalent of the ordinary and extraordinary refractive indices. The specular reflection of spin polarized neutrons which is due to the discontinuity of the magnetic induction at the surface of the ferromagnet is a sensitive probe of surface and interface magnetism. We shall first give the background of the art of polarized neutron optics. Secondly, some recent examples from surface and interface magnetism will be given to illustrate the power of this technique such as the magnetic coupling ...

1992-12-01

185

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-01-15

186

An Advance in Superconducting Magnet Technology Opens the Door...  

Science.gov (United States)

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

2011-08-20

187

Preparation of covalently modified organic-inorganic composite nanoparticles and their interfacial electron transfer researches  

CERN Document Server

Preparation of covalently modified organic-inorganic composite nanoparticles and their interfacial electron transfer researches

1998-01-01

188

PROCEEDINGS OF THE 1966 HEAT TRANSFER AND FLUID ...  

Science.gov (United States)

... mass of gray gas by thermal radiation; An experimental study of the turbulent wake behind a cone at M = 5; Heat transfer augmentation by steady ...

189

NASA Technical Paper 3487 ... - NASA Technical Reports Server  

Science.gov (United States)

heat transfer augmentation was found to increase with decreasing length scale but no optimum length scale was found. Heat transfer augmentation due to turbu- ...

190

Fundamental study of heat transfer augmentation of tube inside surface by cascade smooth surface-turbulence promoters  

Science.gov (United States)

Fundamental study of heat transfer augmentation of tube inside surface by cascade smooth surface-turbulence promoters

1987-03-01

191

First ion beam transfered from the SPS to the LHC  

CERN Multimedia

An ion beam has been successfully transfered from the SPS to the LHC for the first time on 12 November 2007.

2007-01-01

192

Coordination of U"4"+ in the complex U(P_2W_1_7O_6_1)"1"6"-_2 in solid state and in aqueous solution  

International Nuclear Information System (INIS)

The aim of this work is to understand the reasons for the selectivity shown in the complexation by unsaturated heteropolyanions (HPA) of actinides (An) which are oxidized to the number +IV. Different studies have been carried out, both in solution and in solid state, on P_2W_1_7O_6_1"1"0"- and its complexes with Zn"2"+, UO_2"2"+, Ce"4"+, Th"4"+ and U"4"+ to characterize the nature of the complexation site offered to the cation. Among the actinides(IV), the U"4"+ ion has been selected due to its singular spectroscopic and magnetic properties. An initial series of studies, in solution, using NMR"3"1P has thus enabled us to characterize these complexes and to compare them to those formed with the complexing agent PW_1_1O_3_9"8"-. This body of data allows to identify an identical complexation site for both ligands. An analysis of the NMR"3"1P spectrum of U(P_2W_1_7O_6_1)_2"1"6"- has shown a plane of symmetry passing through the actinide and enables us to confirm the ...

1996-09-01

193

Magnetic properties of a SmNiSn single crystal  

Energy Technology Data Exchange (ETDEWEB)

The magnetic properties of a single crystal of SmNiSn with the orthorhombic {epsilon}-TiNiSi-type crystal structure have been investigated by magnetic susceptibility, magnetization and electrical resistivity measurements from 1.5 K to room temperature. Two anomalies have been found in the magnetic susceptibility, indicating an antiferromagnetic phase transition at T{sub N}=9.4 K and a second transition at 4.4 K. A large magnetic anisotropy has been found at low temperatures in the temperature and field dependencies of magnetic susceptibility and magnetization. Below 80 K, the easy axis of the magnetization is the c-axis. At T=2.0 K, the c-axis magnetization curve exhibits metamagnetic-like behavior at H{sub c}=42 kOe and reaches 0.54 emu/g at H=55 kOe, whereas for the a- and b-axis the ...

2003-04-01

194

Development of magnetic drive packless valves for commercial purpose  

Energy Technology Data Exchange (ETDEWEB)

A study on development of magnetic drive packless valves for commercial purpose showed the results as follows; 1. Study on the radial rays effecting to the permanent magnets -Measurement of the strength of Nd-magnets according to irradiation of radial rays. 2. Effects of temperature on the magnetic driving device -Temperature dependency of the Nd-casting magnets. -Effects of temperature on the heat releasing fins of high-temperature valve. 3. Optimization of torque -Arranging method of permanent magnets -Measuring method and results of torque. 4. Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Calculation and design for the flat circular plates under pressure of the magnetic power transmitting device -Design, manufacture and test for the pressure-resisting ...

1995-09-01

195

Challenges in fabrication of 180deg magnet chamber  

International Nuclear Information System (INIS)

180 deg magnet chamber is used in Folded Tandem Ion Accelerator for passage and 180 deg bending of ion beam. The chamber is placed between 180 deg terminal magnet (Electro-magnet), which is used for bending, and analysing the beams. Magnet with a particular magnetic field strength bends ions of only specified mass energy product through a precise path. There is also a space limitation in the direction of magnetic field. Both of them require the magnet chamber to be of a close tolerance. Accuracy of center distance between inlet and outlet port of the magnet chamber has to be at par with the concentricity of high energy and low energy beam line. To achieve this we started the fabrication of magnet chamber by following two methods: a) Circular rolling and bending of rectangular tube for 180 deg sector ...

2006-11-01

196

AC loss measurements of model and full size 50mm SSC collider dipole magnets at Fermilab  

Energy Technology Data Exchange (ETDEWEB)

Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5m long model magnets and eight 15m long full scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500, to 5000 Amps for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle are digitally integrated to yield the energy loss per cycle. Measurement reproducibility is typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar ...

1992-09-01

197

Pairing effects in nucleon transfer reactions in the system sup 144 Sm+ sup 88 Sr at 4. 7 MeV/u  

Energy Technology Data Exchange (ETDEWEB)

Proton and neutron transfer populating low-lying states have been studied in the system {sup 144}Sm+{sup 88}Sr at an energy below the Coulomb barrier. The experimental cross sections for the single proton transfer are well reproduced by DWBA-calculations using spectroscopic information from light ion reactions. The two-proton transfer appears enhanced relative to the uncorrelated sequential transfer of single protons. The same holds for the transfer of proton pairs, the enhancement is kept for the second pair. This is interpreted as a supercurrent between two superfluid nuclear proton-pair wave functions: More mass and charge is transported per time unit in pairs than by single nucleons. Neutron transfer is observed with large cross sections and is found to contribute to the energy loss observed in the transfer reactions. For mixed ...

1990-05-01

198

Pairing effects in nucleon transfer reactions in the system "1"4"4Sm+"8"8Sr at 4.7 MeV/u  

International Nuclear Information System (INIS)

Proton and neutron transfer populating low-lying states have been studied in the system "1"4"4Sm+"8"8Sr at an energy below the Coulomb barrier. The experimental cross sections for the single proton transfer are well reproduced by DWBA-calculations using spectroscopic information from light ion reactions. The two-proton transfer appears enhanced relative to the uncorrelated sequential transfer of single protons. The same holds for the transfer of proton pairs, the enhancement is kept for the second pair. This is interpreted as a supercurrent between two superfluid nuclear proton-pair wave functions: More mass and charge is transported per time unit in pairs than by single nucleons. Neutron transfer is observed with large cross sections and is found to contribute to the energy loss observed in the transfer reactions. For mixed proton-neutron ...

199

Augmentation of heat transfer in heat conductive medium by electro-hydrodynamic effect  

Energy Technology Data Exchange (ETDEWEB)

A method of augmenting heat transfer in the interior of a fluid or from the interface of a solid in contact to a fluid by utilizing electro hydrodynamic (EHD) phenomena has the following advantages: the heat transfer can be effected by using a relatively small, light-weight high voltage source and some simple structural members; no vibration and noise are generated; the method has a control function to control heat transfer by adjustment of field and voltage; and this method is effective in cost-saving. It is mass transfer by the electric force caused by interaction between true charges or polarized charges in a fluid and external electric filed that plays an important role in most of such heat transfer augmentation methods by EHD. Examples of heat transfer augmentation by EHD phenomena include electricaly induced convection, contribution of EHD effect to heat ...

1988-04-20

202

The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)  

International Nuclear Information System (INIS)

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but ...

203

THE APPLICATION OF STEEP PULSE CURRENTS TO THE ...  

Science.gov (United States)

... Title : THE APPLICATION OF STEEP PULSE CURRENTS TO THE ELECTROHYDRAULIC AND MAGNETIC FORMING OF METALS. ...

1966-04-01

210

Recovery Effects of a 180?mT Static Magnetic Field on Bone Mineral Density of Osteoporotic Lumbar Vertebrae in Ovariectomized Rats  

UK PubMed Central (United Kingdom)

The effects of a moderate-intensity static magnetic field (SMF) on osteoporosis of the lumbar vertebrae were studied in ovariectomized rats. A small disc magnet (maximum magnetic flux density 180 mT)...Full Text Available

2011-01-01

211

QCCM - Center for NMR Quantum Information Processing  

Science.gov (United States)

... decoherence. Descriptors : *QUANTUM COMPUTING, NUCLEAR MAGNETIC RESONANCE, JOSEPHSON JUNCTIONS. Subject ...

2011-02-16

212

Perpendicular magnetic anisotropy of ultrathin FeCo alloy films on Pd(0 0 1) surface: First principles study  

International Nuclear Information System (INIS)

Using the full potential linearized augmented plane wave (FLAPW) method, thickness dependent magnetic anisotropy of ultrathin FeCo alloy films in the range of 1 monolayer (ML) to 5 ML coverage on Pd(0 0 1) surface has been explored. We have found that the FeCo alloy films have close to half metallic state and well-known surface enhancement in thin film magnetism is observed in Fe atom, whereas the Co has rather stable magnetic moment. However, the largest magnetic moment in Fe and Co is found at 1 ML thickness. Interestingly, it has been observed that the interface magnetic moments of Fe and Co are almost the same as those of surface elements. The similar trend exists in orbital magnetic moment. This indicates that the strong hybridization between interface FeCo alloy and Pd gives rise to the large magnetic moment. Theoretically calculated ...

2009-06-01

214

Optimization of soft magnetic properties in Fe-B and Fe-B-Si amorphous alloys obtained by melt spinning method  

International Nuclear Information System (INIS)

In the present paper the progress of optimization of soft magnetic properties have been studied by applying different experimental techniques (magnetic measurements, electric measurements, X-ray analysis, and high-resolution electron microscopy observation). It has been shown that an increase in magnetic permeability after optimization annealing can be mainly attributed to annealing out of microvoids. (author)

2001-09-23

215

NASA Technical Reports Server - Magnetic forming coil design and ...  

Science.gov (United States)

Site Error There's a problem with your browser or settings. ...

220

Magnetic forming studies  

Science.gov (United States)

Elastodynamic approach to measuring stress-strain relationship of uniaxially stressed wire, and

1967-01-01

222

Magnetic excitations in amorphous ferromagnets  

Science.gov (United States)

Neutron scattering techniques have been used to measure the static structure and magnetic excitations in amorphous magnets. Sum rules and computer models are used to discuss the relationship between the static disorder and the shape of the excitation spectrum. Polarized beam measurements of chi''(Q,E) are compared to analytical theories and computer calculations for the magnetic excitations in amorphous ferromagnets.

1978-03-01

223

Magnetic electronic lenses, quadrupole and octupole for microsystem electron beam techniques  

International Nuclear Information System (INIS)

The MOS-technology allows to make tiny electronic lenses for multibeam electron systems. In the paper results of research and principles of designing of tiny magnetic electron lenses are submitted. Electronic lenses with a nonconventional configuration of tiny magnetic circuit and electronic lenses with coincident electric and magnetic fields in nonconventional tiny performance are considered

2006-09-01

227

Influence of rotation and magnetic field on the minimum mass of a main-sequence star  

Energy Technology Data Exchange (ETDEWEB)

The influence of rigid-body and differential rotation and of a fine-scale chaotic magnetic field and a poloidal magnetic field on the minimum mass of a main-sequence star is investigated. It is shown that rotation and a magnetic field with an energy equal to 10--20% of the star's gravitational energy increase the minimum mass of a main-sequence star by 1.5--2 times.

1980-11-01

244

A STUDY TO DETERMINE THE DEFORMATION ...  

Science.gov (United States)

... crystals and polycrystals. Nevertheless, explosive forming, magnetic forming, etc., are all high-strain-rate processes that ...

1963-04-01

245

A HELICAL MAGNET DESIGN FOR RHIC.  

Energy Technology Data Exchange (ETDEWEB)

Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. Specifications are for low current superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A magnet meeting the requirements has been developed that uses a small diameter cable wound into helical grooves machined into a thick-walled aluminum cylinder.

1997-05-12

246

Smith-Purcell radiation in the highly relativistic regime  

International Nuclear Information System (INIS)

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

1995-08-21

247

Model of blood-brain transfer of oxygen explains nonlinear flow-metabolism coupling during stimulation of visual cortex.  

DEFF Research Database (Denmark)

The coupling between cerebral metabolic rate of oxygen (CMRO2) and blood flow (CBF) in response to visual stimulation was evaluated by means of a model of oxygen delivery. The model predicted a nonlinear relationship between stimulus-evoked changes of oxygen consumption and blood flow. The magnitude of the CMRO2/CBF ratio index (IO2) was used to indicate the degree of flow-metabolism coupling prevailing in specific areas of the brain during physiological stimulation. Therefore, the index provided a measure of the blood oxygenation level dependent (BOLD) magnetic resonance contrast. To evaluate the changes of IO2 in response to visual stimulation, the model was applied to the effect of a changing flicker rate of a visual stimulus on the magnitudes of CBF, CMRO2, and oxygen diffusion capacity, in the human brain. Positron emission tomography (PET) was used to measure the CBF and the CMRO2 in 12 healthy volunteers who viewed a cross-hair (baseline) or a yellow-blue ...

2000-01-01

248

Experimental Study of Hypernuclei Electroproduction by High Precision Spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Jlab experiment E01-011, carried out in 2005 in JLab Hall C, is the second generation of the hypernuclear spectroscopy experiments by the (e,e{prime}K{sup +}) reaction. The (e,e{prime}K{sup +}) reaction is complimentary to the associated production reactions (K{sup -},{pi}{sup -}), ({pi}{sup +},K{sup +}) since, due to a larger momentum transfer to a hyperon, excitations of both spin-non-flip and spin-flip states are possible. The experiment uses high quality and continuous primary electron beam to produce neutron rich hypernuclei on various targets by the electroproduction. The experimental setup consists of splitter magnet, high resolution kaon spectrometer (HKS) and electron spectrometer (Enge) implemented in new configuration, the so called 'Tilt Method'. Production data was taken on multiple targets: CH{sub 2}, {sup 6}Li, {sup 7}Li, {sup 9}Be, {sup 10}B, {sup 12}C and {sup 28}Si. In present study the analysis of CH{sub 2}, ...

2009-12-01

249

Crystalline electric field of the rare-earth nickelates RniO{sub 3} (R = Pr, ND, Sm, Eu, and Pr{sub 1-x}La{sub x},0 {le} X {le} 0.7) determined by inelastic neutron scattering.  

Energy Technology Data Exchange (ETDEWEB)

The rare-earth based nickelates RNiO{sub 3} (R = Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R{sup 3+} site within the electronic ground-state J multiplet (for R = Pr, Nd, and Pr{sub 1-x}La{sub x}) as well as within the two lowest-lying J multiplets (for R = Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF ...

1999-12-01

250

Crystalline electric field of the rare-earth nickelates RNiO{sub 3} (R=Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) determined by inelastic neutron scattering  

Energy Technology Data Exchange (ETDEWEB)

The rare-earth based nickelates RNiO{sub 3} (R=Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R{sup 3+} site within the electronic ground-state J multiplet (for R=Pr, Nd, and Pr{sub 1-x}La{sub x}) as well as within the two lowest-lying J multiplets (for R=Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF ...

1999-12-01

251

Crystalline electric field of the rare-earth nickelates RNiO_3 (R=Pr, Nd, Sm, Eu, and Pr_1_-_xLa_x, 0#<=#x#<=#0.7) determined by inelastic neutron scattering  

International Nuclear Information System (INIS)

The rare-earth based nickelates RNiO_3 (R=Pr, Nd, Sm, Eu, and Pr_1_-_xLa_x, 0#<=#x#<=#0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R"3"+ site within the electronic ground-state J multiplet (for R=Pr, Nd, and Pr_1_-_xLa_x) as well as within the two lowest-lying J multiplets (for R=Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF parameters in an effective point charge ...

1999-12-01

252

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-11-01

254

Transfer of lead through the rats intestinal wall  

International Nuclear Information System (INIS)

... females in vitro intestines lead 203 mucous membranes radionuclide kinetics

260

Organizational structure and technology transfer  

International Nuclear Information System (INIS)

... administrative procedures developing countries economic development nuclear

1982-11-01

264

Heat transfer problems in high temperature heat exchangers  

International Nuclear Information System (INIS)

This paper deals with construction types of high temperature heat exchangers, their circulation loops and temperature differences. Most attention is given to gas dynamics, convective heat transfer, convection and radiant heat transfer interaction in high temperature heat exchangers. The ways of heat transfer augmentation and efficient heat exchanger construction are discussed.

1986-01-01

265

Heat transfer  

Energy Technology Data Exchange (ETDEWEB)

Heat transfer has emerged as a leading-edge technology supporting the rapid pace of developments in science and engineering ranging from energy production to electronic cooling. Subjects covered at the 6th UK National Conference on heat transfer held at Edinburgh from 15-16 September 1999 include: convection; boiling and evaporation; condensation; numerical techniques; heat exchangers; radiation and combustion; conduction; two-phase flow and heat transfer augmentation. Fifteen of the papers are abstracted here.

1999-07-01

268

Experimental investigation for fluid flow and heat transfer in a rotating tube with twisted-tape inserts  

Energy Technology Data Exchange (ETDEWEB)

Experimental investigation was carried out for friction factor and heat transfer coefficient in the case of a rotating tube with a twisted-tape insert for heat transfer augmentation. The data obtained were compared with existing data for a stationary tube with a twisted-tape insert. It has been observed that the enhancement in heat transfer offsets the rise in friction factor due to rotation, with respect to a plain tube under stationary conditions. A correlation has been proposed for the data obtained.

1995-04-01

270

Magnetocaloric and magnetoresistance studies of GdPd{sub 2}Si  

Energy Technology Data Exchange (ETDEWEB)

The compound GdPd{sub 2}Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition ...

2001-01-22

271

Magnetocaloric and magnetoresistance studies of GdPd_2Si  

International Nuclear Information System (INIS)

The compound GdPd_2Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition ...

2001-01-22

272

Magnetic separation anxiety  

International Nuclear Information System (INIS)

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

1992-01-01

273

High-mode-number ballooning modes in a heliotron/torsatron system: 1, Local magnetic shear  

Energy Technology Data Exchange (ETDEWEB)

The characteristics of the local magnetic shear, a quantity associated with high-mode-number ballooning mode stability, are considered in heliotron/torsatron devices that have a large Shafranov shift. The local magnetic shear is shown to vanish even in the stellarator-like region in which the global magnetic shear is positive. The reason for this is that the degree of the local compression of the poloidal magnetic field on the outer side of the torus, which maintains the toroidal force balance, is reduced in the stellarator-like region of global magnetic shear because the global rotational transform in heliotron/torsatron systems is a radially increasing function. This vanishing of the local magnetic shear is a universal property in heliotron/torsatron systems with a large Shafranov shift since it results from toroidal force balance in the stellarator-like ...

1996-05-01

274

Effect of the induced magnetic field on peristaltic flow of a couple stress fluid  

Science.gov (United States)

We have analyzed the MHD flow of a conducting couple stress fluid in a slit channel with rhythmically contracting walls. In this analysis we are taking into account the induced magnetic field. Analytical expressions for the stream function, the magnetic force function, the axial pressure gradient, the axial induced magnetic field and the distribution of the current density across the channel are obtained using long wavelength approximation. The results for the pressure rise, the frictional force per wave length, the axial induced magnetic field and distribution of the current density across the channel have been computed numerically and the results were studied for various values of the physical parameters of interest, such as the couple stress parameter ?, the Hartmann number M, the magnetic Reynolds number R and the time averaged mean flow rate ?. Contour plots for the stream and ...

2008-06-01

275

Eddy current probe development based on a magnetic sensor array; Developpement d'un imageur magnetique pour le controle non destructif par courants de Foucault  

Energy Technology Data Exchange (ETDEWEB)

This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.

2007-06-15

276

Numerical simulation of fluid flow and heat transfer in a concentric tube heat exchanger  

International Nuclear Information System (INIS)

In this paper, numerical simulation of a concentric tube heat exchanger is presented to determine the convective heat transfer coefficient and friction factor in a smooth tube. Increasing the convective heat transfer coefficient can increase heat transfer rate in a concentric tube heat exchanger from a given tubular surface area. This can be achieved by using heat transfer augmentation devices. This work constitutes the initial phase of the numerical simulation of heat transfer from tubes employing augmentation devices, such as twisted tapes, wire-coil inserts, for heat transfer enhancement. A computational fluid dynamics (CFD) simulation tool was developed with CFX software and the results obtained from the simulations are validated with the empirical correlations for a smooth tube heat exchanger. The difficulties associated with the simulation of a heat ...

2003-05-28

277

Influence of turbulence parameters, Reynolds number, and body shape on stagnation-region heat transfer  

Energy Technology Data Exchange (ETDEWEB)

This experiment investigated the effects of free-stream turbulence intensity, length scale, Reynolds number, and leading-edge velocity gradient on stagnation-region heat transfer. Heat transfer was measured in the stagnation region of four models with elliptical leading edges downstream of five turbulence-generating grids. Stagnation-region heat transfer augmentation increased with decreasing length scale but an optimum scale was not found. A correlation was developed that fit heat transfer data for isotropic turbulence to within {+-}4 percent but did not predict data for anisotropic turbulence. Stagnation heat transfer augmentation caused by turbulence was unaffected by the velocity gradient. The data of other researchers compared well with the correlation. A method of predicting heat transfer downstream of the stagnation point was developed. 28 refs., 12 ...

1995-08-01

278

Influence of turbulence parameters, Reynolds number, and body shape on stagnation-region heat transfer  

International Nuclear Information System (INIS)

This experiment investigated the effects of free-stream turbulence intensity, length scale, Reynolds number, and leading-edge velocity gradient on stagnation-region heat transfer. Heat transfer was measured in the stagnation region of four models with elliptical leading edges downstream of five turbulence-generating grids. Stagnation-region heat transfer augmentation increased with decreasing length scale but an optimum scale was not found. A correlation was developed that fit heat transfer data for isotropic turbulence to within #+-#4 percent but did not predict data for anisotropic turbulence. Stagnation heat transfer augmentation caused by turbulence was unaffected by the velocity gradient. The data of other researchers compared well with the correlation. A method of predicting heat transfer downstream of the stagnation point was developed. 28 refs., 12 ...

1995-01-01

279

On the temperature dependence of the magnetic excitations  

International Nuclear Information System (INIS)

We compare experimental data for temperature dependence of the magnetic order parameter and the magnetic excitations (spin waves) in materials with a quenched orbital moment and a well-defined spin quantum number. It is observed that the thermal decrease of the two quantities proceeds according to the same analytical function of the type y(T)=1-cT"#epsilon# with an identical exponent #epsilon#. This power function applies not only asymptotically for T->0 but holds over a wide temperature range. The exponent #epsilon# is universal, i.e. independent of spin order type and lattice symmetry and depends only on the dimensionality of the relevant interactions and on whether the spin quantum number is integer or half-integer. The different T"#epsilon# functions are identified as representations of stable universality classes. The fact that order parameter and magnetic excitations follow the same T"#epsilon# function shows that ...

2005-07-15

280

Theory of zwitterionic molecular-based organic magnets  

British Library Electronic Table of Contents (United Kingdom)

We describe a class of organic molecular magnets based on zwitterionic molecules (betaine derivatives) possessing donor, p bridge, and acceptor groups. Using extensive electronic structure calculations we show the electronic ground-state in these systems is magnetic. In addition, we show that the large energy differences computed for the various magnetic states indicate a high Neel temperature. The quantum mechanical nature of the magnetic properties originates from the conjugated p bridge (only p electrons) in cooperation with the molecular donor-acceptor character. The exchange interactions between electron spin are strong, local, and independent on the length of the p bridge.

2011-01-01

281

Occurrence of magnetism in superconductors  

Science.gov (United States)

We discuss how magnetic phenomena affect superconductivity in simple metals, transition metals and alloys thereof, and dilute Rare-Earth alloys. It is shown both qualitatively and quantitatively that superconductors are sensitive probes for studying itinerant spin excitations, local spin excitations associated with nearly magnetic impurities, the effect of the atomic environment on the stability of local magnetic moments, and the nature of the spin order in Rare-Earth alloys. Also, we discuss how magnetic impurities can be used to study the electronic configuration which is responsible for superconductivity in Laves-phase crystals like A-15 compounds and ..beta..-W crystals, for example.

1970-12-14

282

Magnetic response of ultrathin Fe on MgO: A polarized neutron reflectometry study  

Energy Technology Data Exchange (ETDEWEB)

The magnetization of ultrathin bcc Fe films (two and three monolayers) on MgO was measured and compared with the behavior predicted for a two-dimensional ferromagnet. The experiment indicated that no hysteresis was present in the magnetization. Instead, the magnetization at low temperature was affected by a marked field cooling effect. These observations lead to the conclusion that films of Fe on MgO of such thickness exhibit superparamagnetic behavior as if they were not entirely continuous. In contrast, films thicker than five monolayers exhibit a magnetic response close to that of bulk iron.

1994-11-15

283

Magnetic properties of glasses from geothite industrial wastes recycling (FeOOH)  

International Nuclear Information System (INIS)

It has been carried out the magnetic properties determination for high iron oxide content glasses series obtained from a geothite red mud waste from the zinc hydrometallurgy and dolomite and glass cullet as main raw materials. It has been determined the magnetic susceptibility and magnetization values for the glasses here investigated. The results suggest that the magnetic behaviour are depending on the glass chemical composition, so that glasses can be differently classified like ferrimagnetic, ferromagnetic, superparamagnetic and paramagnetic. (Author) 6 refs.

284

Magnetic fluctuations in paramagnetic Mn{sub 0.81}Ni{sub 0.19}  

Energy Technology Data Exchange (ETDEWEB)

Magnetic fluctuations present in the paramagnetic Mn{sub 0.81}Ni{sub 0.19} system have been investigated by measuring inelastic magnetic neutron scattering from a single crystal at temperatures of 450, 585 and 700 K. Antiferromagnetic correlations are observed to be present at all the temperatures studied. The spectral width of the magnetic scattering has been observed to increase with temperature, while the spatial range of the magnetic correlations is seen to decrease as the temperature is raised. The wave-vector-dependent susceptibility is found to follow a Curie-Weiss law near the (1 0 0) position, in agreement with theoretical predictions.

2006-11-15

285

Hydromagnetic rotational braking of magnetic stars  

International Nuclear Information System (INIS)

It is suggested that the magnetic Ap stars can be rotationally decelerated to long periods by the braking action of the associated magnetic field on time scales of order 10"7--10"1"0 years depending on whether the star's dipole field is aligned perpendicular or parallel to the rotation axis. Rotation includes a toroidal magnetic field in the plasma surrounding a star, and the accompanying magnetic stresses produce a net torque acting to despin the star. These results indicate that it is not necessary to postulate mass loss or mass accretion for this purely hydromagnetic braking effect.

286

Correlation between Magnetic Field Quality and mechanical components of the Large Hadron Collider Main Dipoles  

CERN Document Server

The homogeneity of the magnetic field in the LHC dipoles strongly depends on the correct position of the superconducting cables: this is related to the quality of the dipole components, such as the dimension of the coil spacers (copper wedges), of the cable and of the collars. The performance in operational conditions is also affected by the magnetization of the cables. In this work, we analyse the measurements of these quantities during the production of the 1276 LHC dipoles, their trends, and the relation to the measured magnetic field. A novel mtehod to locate electrical shorts based on the analysis of magnetic measurements is also presented, and applications to 15 dipoles reascued during the production is given.

2006-01-01

287

Nonlinear dynamics of heat transfer enhancement using eddy promoters  

Science.gov (United States)

This investigation concerns the nonlinear dynamics of heat transfer from a surface using an upstream eddy promoter. A numerical model is developed for the coupled fluid flow and heat transfer process based on a modified MacCormack scheme. Numerical simulations are carried out to determine the response and heat transfer enhancement due to the promoter. The average heat transfer from a cavity floor is seen to be increased by a factor of approximately five over the unpromoted'' flow. Another interesting feature of the study is the nonlinear viscous flow dynamics from the cylinder-wall interaction which differ significantly from the familiar cylinder-free stream patterns.

1994-02-01

288

Nonlinear dynamics of heat transfer enhancement using eddy promoters  

Energy Technology Data Exchange (ETDEWEB)

This investigation concerns the nonlinear dynamics of heat transfer from a surface using an upstream eddy promoter. A numerical model is developed for the coupled fluid flow and heat transfer process based on a modified MacCormack scheme. Numerical simulations are carried out to determine the response and heat transfer enhancement due to the promoter. The average heat transfer from a cavity floor is seen to be increased by a factor of approximately five over the unpromoted'' flow. Another interesting feature of the study is the nonlinear viscous flow dynamics from the cylinder-wall interaction which differ significantly from the familiar cylinder-free stream patterns.

1994-02-01

289

Bibliography on augmentation of convective heat and mass transfer  

International Nuclear Information System (INIS)

Heat transfer augmentation has developed into a major specialty area in heat transfer research and development. A bibliography of world literature on augmentation is presented. The literature is classified into passive augmentation techniques, which require no external power, and active techniques, which do require external power. The fourteen techniques are grouped in terms of their application to the various modes of heat transfer. Mass transfer is included for completeness. Key words are included with each citation for technique/mode identification. The total number of publications cited is 1,967, including 75 surveys of various techniques and 42 papers on performance evaluation of passive techniques. Patents are not included as they will be the subject of a future topical report.

1979-01-01

290

Anisotropic Nd{endash}Fe{endash}B bonded magnets made from HDDR powders (invited)  

Energy Technology Data Exchange (ETDEWEB)

Anisotropic Nd{endash}Fe{endash}B magnet powders can be produced by the hydrogenationdecomposition-desorption-recombination (HDDR) process from Nd{endash}Fe@ xnB{endash}Co{endash}M ({ital M}=Ga, Zr, Nb, Hf, and Ta) alloys. The present status of those HDDR powders and the bonded magnets made from them are reviewed with regards to the powder particle size dependence of their magnetic properties, their magnetic thermal stability, and their magnetization behavior. The results of a mechanistic study on the recombination step are also presented. The magnetic properties of the anisotropic HDDR powder depend relatively little on the powder particle size. Bonded magnets with a density of {approximately}6.20 g/cm{sup 3} and a BH{sub max} of 18.5{endash}20.5 MGOe can be produced from anisotropic HDDR powders with particle sizes of below 300 {mu}m diam. ...

1996-04-01

291

Use of a convolution/superposition-based treatment planning system for dose calculations in the kilovoltage energy range  

International Nuclear Information System (INIS)

A number of procedures in diagnostic radiology and cardiology make use of long exposures to x-rays from fluoroscopy units. Although numerous studies have been performed to measure or calculate skin dose from these procedures, there have only been a handful of studies to determine the dose to the other organs. This thesis was focused on devising a method to calculate the absorbed dose to underlying tissues and organs. The work was performed in several stages. First, a commercial convolution/superposition-based treatment planning system used in radiation oncology was modified and complemented to make it usable with the low energies of x-rays used in diagnostic radiology. This required generation of energy deposition kernels in the kilovoltage energy range. The kernels were generated using the EGS4 Monte Carlo system of codes and added to the treatment planning system. The treatment planning system was then evaluated for its accuracy of calculations at low energies within homogeneous and ...

2001-03-01

292

Optimizing radiotherapy of orbital and paraorbital tumors: intensity-modulated X-ray beams vs. intensity-modulated proton beams  

International Nuclear Information System (INIS)

Purpose: This study presents a dosimetric optimization effort aiming to compare intensity-modulated (IM) X-rays and IM protons in 4 different orbital and paraorbital tumors. These are most challenging targets for standard radiotherapy due to their close relationship with the eyes and related structures. Methods and Materials: A primary orbital lymphoma, an optic nerve meningioma, a sphenoidal ridge meningioma protruding into the orbit, and a pediatric parameningeal paraorbital rhabdomyosarcoma were selected for the purpose of this study. Planning target volumes (PTVs) and organs at risk (OAR) were defined in each patient CT data set for each tumor site. IM X-ray and IM proton three-dimensional treatment plans were implemented. The following total tumor doses were prescribed: 30 Gy for the orbital lymphoma, 54 Gy for both meningiomas, and 50.4 Gy for the rhabdomyosarcoma case. Dose-volume histograms (DVHs) were obtained for all targets and OAR with both treatment ...

2000-07-01

293

Monte Carlo evaluation of the AAA treatment planning algorithm in a heterogeneous multilayer phantom and IMRT clinical treatments for an Elekta SL25 linear accelerator  

International Nuclear Information System (INIS)

The Anisotropic Analytical Algorithm (AAA) is a new pencil beam convolution/superposition algorithm proposed by Varian for photon dose calculations. The configuration of AAA depends on linear accelerator design and specifications. The purpose of this study was to investigate the accuracy of AAA for an Elekta SL25 linear accelerator for small fields and intensity modulated radiation therapy (IMRT) treatments in inhomogeneous media. The accuracy of AAA was evaluated in two studies. First, AAA was compared both with Monte Carlo (MC) and the measurements in an inhomogeneous phantom simulating lung equivalent tissues and bone ribs. The algorithm was tested under lateral electronic disequilibrium conditions, using small fields (2x2 cm"2). Good agreement was generally achieved for depth dose and profiles, with deviations generally below 3% in lung inhomogeneities and below 5% at interfaces. However, the effects of attenuation and scattering close to the bone ribs were not fully taken into ...

2007-05-01

294

Lung dose calculations at kilovoltage x-ray energies using a model-based treatment planning system  

International Nuclear Information System (INIS)

The determination of the dose to organs from diagnostic x rays has become important because of reports of radiation injury to patients from fluoroscopically guided interventional procedures. We have modified a convolution/superposition-based treatment planning system to compute the dose distribution for kilovoltage beams. We computed lung doses using this system and compared them to those calculated using the CDI3 organ dose calculation program. We also computed average lung doses from a simulated radiofrequency ablation procedure and compared our results to published doses for a similar procedure. Doses calculated using this system were an average of 20% lower for AP beams and 7% higher for PA beams than those obtained using CDI3. The ratio of the average dose to the lungs to the skin dose from the simulated ablation procedure ranged from 25% higher to 15% lower than that determined by other authors. Our results show that a treatment planning system designed for use in the megavoltage ...

2001-02-01

295

Influence of dose calculation algorithms on isotoxic dose-escalation of non-small cell lung cancer radiotherapy  

International Nuclear Information System (INIS)

Background and purpose: A series of phase I/II clinical trials are being initiated in several UK centres to explore the use of dose-escalated schedules for the treatment of non-small cell lung cancer (NSCLC). Among them the IDEAL-CRT trial (ISRCTN12155469) will investigate the introduction of individualised 'isotoxic' treatment schedules based on the relative mean lung normalised total dose (rNTDmean), an estimator related to lung toxicity. Since treatment planning will be performed using different treatment planning systems (TPSs), for the quality assurance of the trial we have carried out work to quantify the influence of dose calculation algorithms based on the determination of rNTDmean and on the choice of individualised prescription doses. Material and methods: Twenty-five patient plans with stage I, II and III NSCLC were calculated, with the same prescription dose, using the Adaptive Convolve (AC) and Collapsed Cone (CC) algorithms of the Pinnacle TPS, the pencil beam convolution ...

2010-12-01

296

Flow-system analysis of exfoliated pulmonary cells: results of initial characterization studies in hamsters  

Science.gov (United States)

This paper summarizes results of preliminary experiments to develop cytological and biochemical indicators for estimating damage to respiratory cells in test animals exposed by inhalation to toxic agents associated with nonnuclear energy production, the specific goal being the application of advanced multiparameter flow-systems technologies to the detection of early atypical cellular changes in lung epithelium. Normal Syrian hamster lung cell samples composed of histiocytes, leukocytes, macrophages, ciliated columnar cells, and epithelial cells were stained with fluorescent dyes specific for different biochemical parameters and were analyzed in liquid suspension as they flowed through a chamber intersecting a laser beam of exciting light. Multiple sensors measured the total or two-color fluorescence and light scatter on a cell-by-cell basis. Cellular parameters proportional to optical measurements (i.e., cell size, DNA content, total protein, nonspecific esterase activity, nuclear and ...

1976-01-01

297

Collapsed cone convolution and analytical anisotropic algorithm dose calculations compared to VMC++ Monte Carlo simulations in clinical cases  

International Nuclear Information System (INIS)

The purpose of this work was to study and quantify the differences in dose distributions computed with some of the newest dose calculation algorithms available in commercial planning systems. The study was done for clinical cases originally calculated with pencil beam convolution (PBC) where large density inhomogeneities were present. Three other dose algorithms were used: a pencil beam like algorithm, the anisotropic analytic algorithm (AAA), a convolution superposition algorithm, collapsed cone convolution (CCC), and a Monte Carlo program, voxel Monte Carlo (VMC++). The dose calculation algorithms were compared under static field irradiations at 6 MV and 15 MV using multileaf collimators and hard wedges where necessary. Five clinical cases were studied: three lung and two breast cases. We found that, in terms of accuracy, the CCC algorithm performed better overall than AAA compared to VMC++, but AAA remains an attractive option for routine use in the clinic due to its short ...

2007-07-07

298

Collapsed cone and analytical anisotropic algorithm dose calculations compared to VMC++ Monte Carlo simulations in clinical cases  

International Nuclear Information System (INIS)

The purpose of this work was to study and quantify the differences in dose distributions computed with some of the newest dose calculation algorithms available in commercial planning systems. The study was done for clinical cases where large density inhomogeneities were present. Three dose algorithms were used: a pencil beam like algorithm, the anisotropic analytic algorithm (AAA), a convolution superposition algorithm, collapsed cone convolution (CCC) and a Monte Carlo program, voxel Monte Carlo (VMC++). The dose calculation algorithms were compared under static field irradiations at 6 MV and 15 MV using multileaf collimators and hard wedges where necessary. Five clinical cases were studied: three lung and two breast cases. We found that the CCC algorithm performed overall better than AAA compared to VMC++, but AAA remains an attractive option for routine use in the clinic due to its short computation times. Dose differences between the different algorithms for the median value of the ...

2007-06-01

299

Can intensity-modulated radiation therapy of the paraaortic region overcome the problems of critical organ tolerance?  

International Nuclear Information System (INIS)

Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were planned to theoretically deliver 60 Gy to the PO ...

2005-03-01

300

Kondo effect and impurity-impurity interaction in (La, Ce)B_6 alloys  

International Nuclear Information System (INIS)

Measurements of the magnetic susceptibility betweeen 0.03 and 300 K and of the magnetization between 0.05 and 10 K for magnetic fields up to 60kOe have been used to investigate effects from the interaction between the conduction electrons and local magnetic moments in (Lasub(1-x)Cesub(x))B_6 alloys (0.0007<=x<=0.10). For Ce concentrations x<0.006 the data show Kondo-type single impurity behaviour at low temperatures with a transition from a magnetic to a non-magnetic regime of the Ce ions. In the magnetic regime the impurity susceptibility follows a Curie-Weiss law, and in the non-magnetic regime it varies with T"2. An external magnetic field gradually restores the free-ion behaviour of the Ce impurities. For more concentrated alloys interactions between the impurities are observed. The RKKY ...

1978-01-01

301

Development of magnetic separation system of magnetoliposomes  

Energy Technology Data Exchange (ETDEWEB)

The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe{sub 3}O{sub 4} of 20 nm in diameter was ...

2009-10-15

302

Anti-cancer drug loaded iron-gold core-shell nanoparticles (Fe@Au) for magnetic drug targeting.  

Science.gov (United States)

Magnetic drug targeting, using core-shell magnetic carrier particles loaded with anti-cancer drugs, is an emerging and significant method of cancer treatment. Gold shell-iron core nanoparticles (Fe@Au) were synthesized by the reverse micelle method with aqueous reactants, surfactant, co-surfactant and oil phase. XRD, XPS, TEM and magnetic property measurements were utilized to characterize these core-shell nanoparticles. Magnetic measurements showed that the particles were superparamagnetic at room temperature and that the saturation magnetization decreased with increasing gold concentration. The anti-cancer drug doxorubicin (DOX) was loaded onto these Fe@Au nanoparticle carriers and the drug release profiles showed that upto 25% of adsorbed drug was released in 80 h. It was found that the amine (-NH2) group of DOX binds to the gold shell. An in vitro apparatus simulating the human ...

2010-09-01

303

"1"5"1Eu-Moessbauer study of complex magnetism in Eu_2PdSi_3: Effect of Eu"2"+ substitution by Y"3"+ and of high pressure  

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 applied high pressure to the Eu_2PdSi_3 sample ...

2010-03-01

304

Augmented heat transfer in a rectangular duct with angled ribs  

Energy Technology Data Exchange (ETDEWEB)

Heat transfer augmentation in a rib-roughened duct is affected by the rib configurations, such as rib height, angle of attack, shape, rib to rib pitch, and aspect ratio of a duct. These have been the main subjects in studying the average heat transfer and the friction loss of the fully developed flow. Investigating distributions of local heat transfer coefficients and flow patterns in a duct with the rib turbulators is necessary to find the characteristics of heat transfer augmentation and to decide the optimal configurations of ribs. In the present study the numerical analyses and the mass transfer experiments are performed to understand the flow through a rib roughened duct and the heat transfer characteristics with various angles of attack of ribs. A pair of counter-rotating secondary flow in a duct has a main effect on the lateral distributions of local mass ...

1998-04-01

305

Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural  

Energy Technology Data Exchange (ETDEWEB)

A heat transfer (condenser) of a domestic freezer was tested in a vertical channel in order to study the influence of the chimney effect in the optimization of the heat transfer coefficient. The variation of the opening of the channel, position and the heating power of the heat exchanger in the heat transfer coefficient was considered. The influence of the surface emissivity on the heat transfer by thermal radiation was studied with the heat exchanger testes without paint and with black paint. The air velocity entering the channel was measured with a hot wire anemometer. In order to evaluate the chimney effect, the heat exchanger was testes in a open ambient. This situation simulates its operational conditions when installed on the freezer system. The variables collected in the experimental procedures was gathered in the form of dimensionless parameters as Nusselt, Rayleigh, Grashof and Prandtl numbers, ...

1997-07-01

306

A new method of heat transfer augmentation by means of foreign gas jet impingement in liquid bath  

International Nuclear Information System (INIS)

The authors discuss a two-phase two-component experimental system developed to study enhancement of heat transfer from a vertical chip size heater to surrounding liquid (Freon 113 or Ethanol) due to air jet impingement. Heat transfer coefficient was measured as function of jet velocity, heat flux and the distance between exit of jet tube and heated surface. The injector was placed very close to the hot surface. It was found that the heat transfer was notably enhanced with foreign gas impingement, especially in the cases of small temperature differences between wall and coolant. In fact for higher jet velocities the heat transfer coefficients tended to infinite while the temperature differences between wall and coolant were zero. The heat transfer coefficients decreased with the increasing of heat flux. High-speed camera was used to study the behaviour of the gas bubbles which play ...

1985-10-01

307

Mechanisms of heat transfer augmentaiton around the stagnation point of an impinging air jet laden with solid particles. Report 1. ; Evaluation procedure of heat transfer augmentaion due to unsteady heat conduction between laden particles and heat transfer surface. Koki niso shototsu funryu no yodomiten kinbo ni okeru dennetsu sokushin kiko. 1. ; Ryushi eno chokusetsu sesshoku netsuido ni yoru dennetsu sokushin koka no bunri hoho  

Energy Technology Data Exchange (ETDEWEB)

Several heat transfer augmentation mechanisms contribute to the heat transfer augmentation around the stagnation point in the gas-solid two-phase impinging jet flow. Among those contributions, that of heat exchange was numerically analyzed and characteristically elucidated by the unsteady direct contact heat conduction at the time of impingement between the laden particles and heat transfer surface. In other words, if the contact time is short between the particles and heat transfer surface, the former is heated by heat stored in the latter as a heat capacity. In such a region, the heat quantity to be transferred to the particles changes by not only the thermal property value (heat capacity multiplied by heat conduction coefficient) of particles but also that of heat transfer surface. Then by using several kinds of particles and heat ...

1991-05-25

308

Resistivity, Hall effect, and magnetic susceptibility of UPd_2Si_2  

International Nuclear Information System (INIS)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd_2Si_2 have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd_2Si_2 is Curie-Wiess-like along the c axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

309

Resistivity, Hall effect, and magnetic susceptibility of UPd[sub 2]Si[sub 2  

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd[sub 2]Si[sub 2] have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd[sub 2]Si[sub 2] is Curie-Wiess-like along the [ital c] axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

1993-12-15

310

Recycler model magnet test on temperature compensation for strontium ferrite  

Energy Technology Data Exchange (ETDEWEB)

The Recycler ring magnet will be made of Strontium ferrite permanent magnets. A strontium ferrite permanent magnet without compensation has a temperature coefficient of -0.2 % in dB/dT. To compensate this effect, we are utilizing 30 % Ni 70 % Fe alloy, a temperature compensation ferromagnetic material with a low Curie point. To search for optimum commercially available material and optimum condition, we made a couple of simple model magnets, and tested with several different compensating material. The test results are reported and its optimal conditions are shown. Several different configurations were tested including a possible 2 kG magnet configuration.

1995-10-01

311

Large specific absorption rates in the magnetic hyperthermia properties of metallic iron nanocubes  

CERN Document Server

We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690+-160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power.

2010-01-01

312

Itinerant magnetism of Gd_xLa_1_-_xMSi (M=Fe, Co) compounds  

International Nuclear Information System (INIS)

The magnetic properties of polycrystalline and single crystalline rare earth transition metal silicides Gd_xLa_1_-_xMSi (M =Fe, Co) were investigated. Magnetic measurements have been made in static magnetic fields up to 13 kOe and in pulsed magnetic fields up to 250 kOe in the temperature range from 4.2 to 350 K. The magnetic susceptibility in the paramagnetic state of all the investigated compounds obeys the Curie-Weiss law except for LaFeSi and LaCoSi. Increase of the La content in Gd_xLa_1_-_xFeSi compounds leads to a decrease of the Curie and Neel temperatures, which can be explained by a decrease of positive exchange interactions. (orig.).

1995-09-01

313

High Tc superconducting magnetic multivibrators for fluxgate magnetic-field sensors  

Science.gov (United States)

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

1989-09-01

314

Effect of magnet sorting using a simple resonance cancellation method on the RMS orbit distortion at the APS injector synchrotron  

Energy Technology Data Exchange (ETDEWEB)

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

1993-07-01

315

Effect of On-Chip Magnetic Shielding for TES Microcalorimeters  

British Library Electronic Table of Contents (United Kingdom)

We investigated the magnet field dependence of the X-ray pulse height and the critical current of a Ti/Au bilayer TES micro-calorimeter. The pulse height was strongly affected by the magnetic field intensity applied perpendicularly to the TES surface. We found that the critical current at zero temperature, I c0, decreased by a factor of two by applying a magnet field of ?10??T. Our data are consistent with a TES sensitivity proportional to (I/I c0)?2/3, as predicted by the Ginzburg-Landau theory. This fact implies that the shape of the R?T curve of the TES is partly determined by the critical current of the superconductor. In order to make our TES microcalorimeters less sensitive to the external magnetic field, we fabricated devices equipped with on-chip magnetic shielding. One device has ...

2008-01-01

316

Design, Performance and Series Production of Superconducting Trim Quadrupoles for the Large Hadron Collider  

CERN Document Server

The Large Hadron Collider (LHC) will be equipped with several thousands of superconducting corrector magnets. Among the largest ones are the superconducting trim quadrupoles (MQTL). These twin-aperture magnets with a total mass of up to 1700 kg have a nominal gradient of 129 T/m at 1.9 K and a magnetic length of 1.3 m. Sixty MQTL are required for the LHC, 36 operating at 1.9 K in and 24 operating at 4.5 K. The paper describes the design features, and reports the measured quench performance and magnetic field quality of the production magnets. The MQTL magnet production is shared between CERN and industry. This sharing is simplified due to the modular construction, common to all twin-aperture correctors.

2006-01-01

317

Modelling of MeV alpha particle energy transfer to lower hybrid waves  

Energy Technology Data Exchange (ETDEWEB)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. Here we calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favourable for wave amplification from alpha energy. We find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is ...

1994-05-01

318

Modelling of MeV alpha particle energy transfer to lower hybrid waves  

International Nuclear Information System (INIS)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. Here we calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favourable for wave amplification from alpha energy. We find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is ...

319

Modeling of MeV alpha particle energy transfer to lower hybrid waves  

Energy Technology Data Exchange (ETDEWEB)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. An initial analytic study was done by Fisch and Rax. Here the authors calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favorable for wave amplification from alpha energy. They find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy ...

1993-10-01

320

Heat-transfer augmentation in rod bundles near grid spacers  

International Nuclear Information System (INIS)

Heat-transfer augmentation by straight grid spacers in rod bundles is studied for single-phase flow and for post-critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single-phase flow is also examined. Governing heat-transfer mechanisms are analyzed, and predictive formulations are established. For single-phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. The effect of local velocity increasing near swirling spacer is considered. For post critical heat flux (CHF) dispersed flow, the heat transfer by thermal radiation, fin cooling, and vapor convection near the spacer are calculated. The predictions are compared with experimental data with satisfactory agreement.

1982-01-01

321

Heat and mass transfer analogy studies of binary liquid mixture in comparison with ethanol-n-heptane evaporating to air  

Energy Technology Data Exchange (ETDEWEB)

An experimental and theoretical study of heat and mass transfer analogy and a comparison of that to a binary liquid mixture evaporation is presented. Common organic solvents, ethanol and n-heptane, were used to form an alcohol - hydrocarbon mixture. Studies were carried out in a horizontal rectangular channel having air flow velocities of 0.2 - 0.9 m/s. Heat transfer coefficients were measured with a copper plate resistor and mass transfer coefficients with a square pool. The heat and mass transfer analogy is presented for a system having two evaporating compounds with a fixed value of air flow and verified by measuring and comparing mass transfer coefficients for distilled water with air flow velocities of 0.2 - 0.9 m/s. An illustrative example of the use of the theory for industrial ventilation is presented. (author)

1995-12-31

322

Energy transfer study of europium-tetracycline complexes  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work was to study the energy transfer mechanisms from the ligand to the central lanthanide ion of tetracycline-europium (Tc-Eu) complex. The absorption spectra of a EuCl{sub 3}.H{sub 2}O solution was measured and absorption cross-section of Eu{sup 3+} was estimated. The observed overlap predicts a resonant energy transfer from Tetracycline to Eu{sup 3+}. The microscopic parameter of energy transfer was obtained using the overlap integral calculation considering a dipole-dipole energy transfer mechanism and results were compared considering an energy transfer by exchange. In this work, we report also the optical properties of Tc-Eu complex when urea hydrogen peroxide is added to the aqueous solution.

2007-01-15

323

Condensation heat transfer in a steam-water stratified flow  

Energy Technology Data Exchange (ETDEWEB)

Fundamental phenomena of condensation heat transfer at a steam-water interface have been studied related to the thermo-hydrodynamics of the emergency core cooling system for light water reactors. In this study temperature fluctuations near the interface and in the liquid phase were measured using fine thermocouples for a saturated steam-subcooled water co-current stratified two-phase flow in a nearly horizontal rectangular channel, and heat transfer coefficients were determined experimentally. The values of the condensation heat transfer coefficients in this experiment are from 6 to 40 kW/m{sup 2}K. In the regions of high Reynolds numbers, as the steam Reynolds numbers become larger, the average interfacial heat transfer coefficients tend to increase. The corelations of Nusselt numbers were obtained from the heat transfer data. (author)

1999-07-01

324

Condensation heat transfer in a steam-water stratified flow  

International Nuclear Information System (INIS)

Fundamental phenomena of condensation heat transfer at a steam-water interface have been studied related to the thermo-hydrodynamics of the emergency core cooling system for light water reactors. In this study temperature fluctuations near the interface and in the liquid phase were measured using fine thermocouples for a saturated steam-subcooled water co-current stratified two-phase flow in a nearly horizontal rectangular channel, and heat transfer coefficients were determined experimentally. The values of the condensation heat transfer coefficients in this experiment are from 6 to 40 kW/m"2K. In the regions of high Reynolds numbers, as the steam Reynolds numbers become larger, the average interfacial heat transfer coefficients tend to increase. The corelations of Nusselt numbers were obtained from the heat transfer data. (author)

1999-04-19

325

A metal matrix for heat transfer enhancement during phase-change processes  

Energy Technology Data Exchange (ETDEWEB)

A metal matrix is inserted into a phase-change material to enhance the heat transfer during phase-change processes. The metal matrix tends to act like a heat transfer fin from the heated or cooled surface and to increase the effective thermal conductivity of the phase-change fluid. The scope of the study involves numerically modeling the heat transfer to and from constant-temperature cylindrical tubes surrounded by water during the freezing and melting processes. Comparisons of heat transfer with and without the metal matrix are made, with different porosities and densities of the metal matrix being examined. The results of this study are discussed in terms of the effectiveness of the metal matrix as a heat transfer enhancement device.

1994-12-31

326

Observation and control of hepatic specimens with MRI and MRS; Beobachtung und Kontrolle von Fixiervorgaengen in Leberpraeparaten mittels MRT und MRS  

Energy Technology Data Exchange (ETDEWEB)

Purpose: The purpose of this study was to observe the process of fixation in liver specimens non-invasively by means of magnetic resonance. The fixation process of several formaldehyde-containing solutions was monitored with MRI and MRS at two different temperatures. Materials and Methods: Liver specimens were conserved in aqueous fixative solutions containing formaldehyde concentrations of 0.7, 1.8, 4 and 7.2% and at different temperatures of 5 C and 20 C. MRI was performed with T1-, T2- and PD-weighted TSE sequences, a 2D FLASH-sequence with and without magnetization transfer, and a FISP 3D-sequence on a clinical 1.5 Tesla MR whole-body unit, and MRS with {sup 1}H-spectroscopic methods (STEAM-sequence) on a 3 Tesla MR whole-body unit. Results: The diffusion of formaldehyde into the tissue was best identified on PD- and T1-weighted images as a band under the liver surface with increasing thickness, penetrating especially ...

2004-04-01

327

Treatment of low-frequency pulsating magnetic field on amorphous alloy Fe_7_8Si_9B_1_3  

International Nuclear Information System (INIS)

Effect of low-frequency pulsating magnetic field on the microstructure and magnetic properties of amorphous alloy Fe_7_8Si_9B_1_3 were investigated. The temperature rise induced by the treatment was measured by a non-contact infrared thermometer. The crystallization behavior and microstructure of specimens were studied by Moessbauer spectroscopy and transmission electron microscope (TEM). Magnetic properties of the specimens were investigated by alternating gradient magnetometer (AGM). The results show that the low-frequency pulsating magnetic field can promote the single-phase crystallization of amorphous alloy Fe_7_8Si_9B_1_3. The frequency, f of applied field is from 10 to 40 Hz, magnetic field, H is from 0.02 to 0.04 T and treatment duration, t is from 180-300 s. The volume fraction of crystallization phase (#alpha#-Fe(Si), the grain size, 2-10 nm) is 3-7%. The temperature rise ...

2007-07-15

328

The possible detection of magnetic monopoles and monopole tachyons  

International Nuclear Information System (INIS)

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

329

Temperature dependence of a twofold magnetic behaviour of a nanoscopic metal/silicon hybrid system - a comparison between Ni/Si and Co/Si  

Energy Technology Data Exchange (ETDEWEB)

The investigated hybrid nanocomposite consists of a porous silicon template with electrochemically embedded Ni or Co nanostructures and offers magnetic characteristics which can be tailored by the electrochemical process parameters during fabrication. A twofold magnetic behaviour can be observed, a first one due to the spinmagnetism at magnetic fields below the saturation magnetization of the deposited metals and a second non-saturating term at higher fields (>1 T up to 7 T) above the saturation magnetization. In case of Ni deposited within the pores this non-saturating term shows a paramagnetic characteristic and follows exactly the Curie-Weiss law, whereas for Co/porous silicon samples the temperature dependent magnetization shows some deviations from the Curie Weiss law. In this high field region a difference in the temperature dependence between Ni ...

2009-10-15

330

TPC magnet cryogenic system  

Energy Technology Data Exchange (ETDEWEB)

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

1980-03-01

331

Study of particles trapped by a magnetic field  

Science.gov (United States)

A new type of radiation which occurs when particles are accelerated in the field of a longitudinal wave and in a transverse magnetic field is studied. The characteristics of such spontaneous radiation are obtained, and the influence of collective effects on the radiation is analyzed. The application of the findings to the theory of free electron lasers is discussed. 8 references.

1986-01-01

332

Safety Implications of High-Field MRI: Actuation of Endogenous Magnetic Iron Oxides in the Human Body  

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

333

Room-temperature magnetic properties of oxy- and carbonmonoxyhemoglobin  

UK PubMed Central (United Kingdom)

The magnetic susceptibility and the density of human oxy-(HbO2) and carbonmonoxyhemoglobin (HbCO) solutions of various concentrations have been measured at room temperature, with pure water...Full Text Available

1978-10-01

334

Residential magnetic fields and childhood leukemia: a meta-analysis.  

UK PubMed Central (United Kingdom)

OBJECTIVES: This article uses meta-analysis methodology to examine the statistical consistency and importance of random variation among results of epidemiologic studies of residential magnetic field...Full Text Available

1998-12-01

335

Print sec333photoindex (256 pages)  

Science.gov (United States)

Electro-Magnet. Antenna Panels Types Simulated Hail Stone Damage A.Panel ...... X-Band Klystron Electro Magnet. 11. I I. 333-6104 AcBc. 333-6105 Color ...

336

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

UK PubMed Central (United Kingdom)

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

2010-06-07

337

Nature of magnetic coupling between Mn ions in as-grown Ga1-xMnxAs studied by x-ray magnetic circular dichroism  

International Nuclear Information System (INIS)

The magnetic properties of as-grown Ga1-xMnxAs have been investigated by the systematic temperature and magnetic field dependent soft x-ray magnetic circular dichroism (XMCD) measurements in the Mn L2,3 absorption edge region. The XMCD intensity at high temperatures obeys the Curie-Weiss law, but residual spin magnetic moment appears already around 100 K, significantly above Curie temperature (Tc), suggesting that short-range ferromagnetic correlations are developed significantly above Tc. The high-field magnetic susceptibility becomes T-independent below TC, indicating that the AF interaction between the substitutional Mn (Mnsub and interstitial Mn (Mnint) ions, which becomes strong as the Mn concentration x increases, exists and that the amount of the Mnint affects Tc. The present experimental findings should give valuable insight into the inhomogeneous ...

2009-07-01

338

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

UK PubMed Central (United Kingdom)

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

1997-03-01

339

Magnetic and structural investigation of magnetic thin films with obliquely deposited underlayers  

CERN Document Server

An in-plane uniaxial magnetic anisotropy has been observed in thin Co films normally deposited onto obliquely sputtered Ta and Pt underlayers. Associated with this anisotropy is an augmented easy axis coercivity. The in-plane easy axis is, in most cases, perpendicular to the incident deposition plane. Microstructural results indicate that grains are well connected along the magnetic easy axis but are separated by long continuous voids along the hard axis, which is ascribed to a geometric shadowing effect due to the oblique incidence deposition of the underlayer. Hence, the magnetic anisotropy mimics the film growth anisotropy. It is therefore believed that the observed magnetic properties are due to magnetostatic shape anisotropy effects. In-plane coercivity and anisotropy field are shown to increase with underlayer deposition angle, underlayer thickness and magnetic layer ...

2002-01-01

340

Magnetic and chemical changes in marine sediments  

Energy Technology Data Exchange (ETDEWEB)

A considerable amount of chemical knowledge of marine sediments has been acquired in recent years but has not yet been utilized by paleomagnetists. On the other hand, geochemists are often unaware of the usefulness of numerous magnetic techniques. In this review we try to bridge this gap, and in particular, we outline many of the chemical and magnetic principles that should allow paleomagnetists to better identify and undertand chemical changes that affect the magnetic properties of marine sediments. The chemical principles include those for distinguishing the four major sources of sediments (continental, biological, authigenic/hydrogenous, volcanic/hydrothermal) from one another by determining elemental abundance distributions, as well as for investigating the stabilities of mineral phases relative to changes in pE and pH. The magnetic principles include the effects of authigenesis and diagenesis on ...

1980-05-01

341

Longitudinally and circumferentially directed movements of the left ventricle studied by cardiovascular magnetic resonance phase contrast velocity mapping  

UK PubMed Central (United Kingdom)

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

342

Long-lived states to sustain hyperpolarized magnetization  

UK PubMed Central (United Kingdom)

Major breakthroughs have recently been reported that can help overcome two inherent drawbacks of NMR: the lack of sensitivity and the limited memory of longitudinal magnetization. Dynamic nuclear polarization...Full Text Available

2009-11-03

343

Functional pools of oxidative and glycolytic fibers in human muscle observed by 31P magnetic resonance spectroscopy during exercise.  

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

1987-12-01

344

Epidemiological appraisal of studies of residential exposure to power frequency magnetic fields and adult cancers.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To appraise epidemiological evidence of the purported association between residential exposure to power frequency magnetic fields and adult cancers. METHODS: Literature review and epidemiological...Full Text Available

1996-08-01

345

Epidemiologic studies of electric and magnetic fields and cancer: strategies for extending knowledge.  

UK PubMed Central (United Kingdom)

Epidemiologic research concerning electric and magnetic fields in relation to cancer has focused on the potential etiologic roles of residential exposure on childhood cancer and occupational exposure...Full Text Available

1993-12-01

346

Energetic constraints on the creation of cell membrane pores by magnetic particles.  

UK PubMed Central (United Kingdom)

Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores")....Full Text Available

1996-08-01

347

Electric and magnetic field exposures for people living near a 735-kilovolt power line.  

UK PubMed Central (United Kingdom)

The purpose of this study was to assess the effect of a 735-kV transmission line on the electric and magnetic field exposures of people living at the edge of the line's right of way. Exposure of 18...Full Text Available

1995-09-01

348

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

International Nuclear Information System (INIS)

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

349

Design of modular coils for a quasi-axisymmetric stellarator with a flexible control of the magnetic field configuration  

Energy Technology Data Exchange (ETDEWEB)

A design of the modular coil system for CHS-qa has been made for the plasma configuration '2b32' with the aspect ratio 3.2. The magnetic field strength and the major radius are 1.5 T and 1.5 m, respectively. The normal component of magnetic field produced by the modular coils is minimized on the plasma boundary to obtain the optimum coil design. We put engineering constraint on the distance between adjacent modular coils and the radius of coil curvature. The dependence of the residual normal component of the field on these conditions is examined, and the realistic values for them are selected. Additional coils to control various properties of the magnetic field configuration (the rotational transform, the magnetic well depth, etc.) have been designed and a flexibility of the magnetic field configuration is realized. For the case that the rotational transform ...

2002-08-01

350

Design and experimental results on a terawatt magnetically controlled plasma opening switch  

Energy Technology Data Exchange (ETDEWEB)

The magnetically controlled plasma opening switch (MCPOS) is an advanced plasma opening switch that utilizes magnetic fields to improve operation. Magnetic fields always dominate terawatt, pulsed power plasma opening switches. For that reason, the MCPOS uses controlled applied magnetic fields with magnitude comparable to the self-magnetic field of the storage inductor. One applied field holds the plasma in place while energy accumulates in the storage inductor, then another applied field pushes the plasma away from the cathode to allow energy to flow downstream. Over a ten month period, an MCPOS was designed, built, and tested on DECADE Module 2 at Physics International. The peak drive current was 1.8 MA in 250 ns. The output parameters were up to 1 MA into an electron beam load. The radiation temporal pulse width averaged 60 nanoseconds full-width at half-maximum. The peak load ...

1998-05-01

351

Assessment of structural changes of human teeth by low-field nuclear magnetic resonance (NMR)  

UK PubMed Central (United Kingdom)

A technique of low-field pulsed proton nuclear magnetic resonance (NMR) spin relaxation is described for assessment of age-related structural changes (dentin and pulp) of human teeth in...Full Text Available

2010-01-01

352

A case cohort study of suicide in relation to exposure to electric and magnetic fields among electrical utility workers.  

UK PubMed Central (United Kingdom)

OBJECTIVES--This case cohort study examines whether there is an association between exposure to electric and magnetic fields and suicide in a population of 21,744 male electrical utility workers from...Full Text Available

1996-01-01

353

A Helicopter-Borne Magnetic Survey over Dixie Valley Geothermal...  

Science.gov (United States)

Name U.S. Geological Survey A Helicopter-Borne Magnetic Survey over Dixie Valley Geothermal Field, Nevada: A Web Site for Distribution of Data by U. S. Geological Survey &...

2011-08-20

354

The Mechanism and the Magnitude of Flow Boiling Augmentation in Tubes with Discrete Surface Roughness Elements (III).  

Science.gov (United States)

Related to other research on the effectiveness of flow boiling heat transfer augmentation using various types of turbulators this investigation comprises a definitive study of the effect of large discrete roughness elements on heat transfer over the entir...

1972-01-01

355

Technical, TO 31R2-2FRC181-31, F Publication Transfer ...  

Science.gov (United States)

... Title : Technical, TO 31R2-2FRC181-31, F Publication Transfer Using: O'Neil & Associates' Data Supporting ESC/MSL's MILSTAR Program, MIL ...

1994-08-05

356

Stagnation region heat transfer: The influence of turbulence parameters, Reynolds number and body shape  

Science.gov (United States)

The effect of velocity gradient on stagnation region heat transfer augmentation by free stream turbulence was investigated. Heat transfer was measured in the stagnation region of four models with elliptical leading edges with ratios of major to minor axes of 1:1, 1.5:1, 2.25:1, and 3:1. Four geometrically similar, square bar, square mesh, biplane grids were used to generate free stream turbulence with different intensities and length. Heat transfer measurements were made for the following ranges of parameters: Reynolds number, based on leading edge diameter, 37,000 to 228,000; dimensionless leading edge velocity gradient, 1.20 to 1.80; turbulence intensity, 1.1 to 15.9%; and length scale to leading edge diameter ratio, 0.05 to 0.30. Stagnation point heat transfer augmentation by free stream turbulence can be predicted using a modified version of a previously developed correlation for a circular leading ...

1994-02-01

357

Semiclassical aspects of transfer reactions  

Science.gov (United States)

Semiclassical analysis of heavy ion induced transfer reactions are discussed for the quasielastic region. Some unique aspects of these reactions are shown, the variety of features which can be understood semiclassically is demonstrated, and some open problems are indicated. 28 refs., 16 figs. (LEW)

1985-01-01

358

Plasmid Transfer between Bacillus thuringiensis subsp. israelensis Strains in Laboratory Culture, River Water, and Dipteran Larvae  

UK PubMed Central (United Kingdom)

Plasmid transfer between strains of Bacillus thuringiensis subsp. israelensis was studied under a range of environmentally relevant laboratory conditions in vitro,...Full Text Available

2001-01-01

359

Laboratory simulation of a deep-ocean in-situ heat-transfer experiment  

Energy Technology Data Exchange (ETDEWEB)

The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.

1982-01-01

360

Laboratory simulation of a deep-ocean in-situ heat-transfer experiment  

International Nuclear Information System (INIS)

The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.

1982-09-22

361

Intra- and Interspecies Conjugal Transfer of Tn916-Like Elements from Lactococcus lactis In Vitro and In Vivo?  

UK PubMed Central (United Kingdom)

Tetracycline-resistant Lactococcus lactis strains originally isolated from Polish raw milk were analyzed for the ability to transfer their antibiotic resistance genes in vitro, using...Full Text Available

2009-10-01

362

Heat transfer. Fundamentals. 5. rev. ed.  

International Nuclear Information System (INIS)

This textbook contains the following main topics: Heat conductivity, convection, condensation and evaporation, radiation heat transfer and heat exchangers. It includes the physical foundations for all these aspects and many examples. (orig.)

363

Heat Transfer Augmentation in a Compact Heat Exchange Pedestal Array.  

Science.gov (United States)

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

2004-01-01

364

Heat Transfer Augmentation in Turbulent Impinging Jets.  

Science.gov (United States)

Heating and cooling by impinging jets is widely used in various engineering applications, due to the high heat transfer rates prevailing in the vicinity of the stagnation point. The authors have been able to utilize acoustically excited turbulence for the...

1979-01-01

365

Gas Turbine Blade Heat Transfer Augmentation by Impingement of Air Jets Having Various Configurations.  

Science.gov (United States)

An experimental investigation of heat transfer characteristics for various configurations of air jets impinging on the leading edge inner surface of a gas turbine blade wall is presented. Three configurations were investigated, namely a slot jet, a round ...

1970-01-01

366

Fixation Techniques for Split Anterior Tibialis Transfer in Spastic Equinovarus Feet  

UK PubMed Central (United Kingdom)

Equinovarus of the foot is the most common lower extremity deformity following traumatic brain injury. We evaluated outcomes of the split anterior tibialis tendon transfer (SPLATT) for correction of...Full Text Available

2008-10-01

367

Experimental Study of a Method of Mechanical Augmentation of Convective Heat Transfer Coefficients in Air.  

Science.gov (United States)

Scraped-surface heat transfer augmentation is proposed as a possible technique for use in improved air-cooling designs. Although it has been in common use with liquids, the technique has apparently never been used with gases. An experimental investigation...

1974-01-01

368

Creating genetically modified pigs by using nuclear transfer  

UK PubMed Central (United Kingdom)

Nuclear transfer (NT) is a procedure by which genetically identical individuals can be created. The technology of pig somatic NT, including in vitro maturation of oocytes, isolation and treatment of...Full Text Available

369

Benzene Enabling Document for Standards on Benzene Transfer and Waste Operations.  

Science.gov (United States)

On February 27, 1990, standards for Benzene were promulgated for benzene transfer and benzene waste operations. The benzene enabling document summarizes these standards. The basic purpose of the document is to assist the EPA regional enforcement personnel...

1990-01-01

370

Augmentation of heat transfer in a tube with an oscillating thin plate. Shindohen sonyu ni yoru enkannai netsudentatsu sokushin  

Energy Technology Data Exchange (ETDEWEB)

An attempt is made to augment the heat transfer efficiency by means of inserting an oscillating thin plate into a tube of the shell and tube heat exchanger. However, the heat transfer augmenting mechanism has not been fully explained. To elucidate this heat transfer augmenting mechanism, an investigation was given on the heat transfer characteristics of a tube inlet at its preliminary run area when a double-hinged oscillating thin plate is inserted in the inlet. As a result of the experiment, the heat transfer augmentation in the tube as a result of inserting the double-hinged oscillating thin plate was found effective when the preliminary inlet run area is treated as the object. However, in comparison of the effect with the heat transfer in a fully developed turbulent region, it was {eta}- 1. The result thus obtained explains that no sufficient turbulence can ...

1991-09-01

371

Variable-dispersion electron spectrometer for the SCA/FEL  

International Nuclear Information System (INIS)

A variable-dispersion electron spectrometer is being installed for use by the Stanford Superconducting Accelerator in conjunction with its Free Electron Laser program. The system has been designed to operate with electron beam energies from 20 MeV to 200 MeV, with a maximum energy resolution of 0.01% FWHM. The maximum energy acceptance is approximately #+-# 5%, as determined by the bending magnet aperture. Resolution is controlled by adjusting the focal conditions at the entrance to a 90 degree bending magnet, while the dispersion is controlled by changing the magnitude and polarity of the field in a quadrupole magnet which immediately follows the bending magnet. 4 refs., 5 figs.

1989-06-01

372

Untitled - NASA Technical Reports Server  

Science.gov (United States)

the techniques employed at present, some of which, like magnetic forming and hotdrape forming, are in experimental stages. Published October 1965. ...

373

Thermal-physical analysis of low-radioactive thermonuclear plasma in the magnetic fusion device  

International Nuclear Information System (INIS)

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

2006-09-11

375

The Effect of the Temperature to Which the Material is Heated ...  

Science.gov (United States)

... The Effect of the Temperature to Which the Material is Heated on the Process of Formation of Intermetallic Compounds in Magnetic Pulse Welding,. ...

1980-09-01

378

SELECTED LISTING OF ECHNOLOGY UTILIZATION PUBLICATIONS  

Science.gov (United States)

as magnetic forming and hot-drape forming. Details about the 25 techniques discussed incorporate the most recent improvements and ...

381

Read/write characteristics of focused-ion-beam-etched heads for perpendicular magnetic recording media  

International Nuclear Information System (INIS)

The read/write characteristics for perpendicular magnetic recording media of focused-ion-beam (FIB)-etched recording heads were investigated. It was found that the trailing edge of an FIB-etched head produces a higher gradient in the magnetic field perpendicular to the medium than a head which has not been etched. The signal-to-noise ratio of the medium increased with the FIB-etched write gap. A high-Bs and thin pole increased the magnetic field's gradient in the perpendicular direction, resulting in excellent read/write characteristics.

2001-10-01

382

Plasma flow measurement using directional Langmuir probe under weakly ion-magnetized conditions  

Energy Technology Data Exchange (ETDEWEB)

It is both experimentally and theoretically demonstrated that ion flow velocity at an arbitrary angle with respect to the magnetic field can be measured with a directional Langmuir probe. Based on the symmetry argument, we show that the effect of magnetic field on directional probe current is exactly canceled in determining the ion flow velocity, and obtain the generalized relation between flow velocity and directional probe currents valid for any flowing direction. The absolute value of the flow velocity is determined by an in situ calibration method of the probe. The applicability limit of the present method to a strongly ion-magnetized plasma is experimentally examined. (author)

2000-07-01

383

Nuclear moments of the 11/2"- isomer in "1"8"7Ir  

International Nuclear Information System (INIS)

... excited states iridium 187 isomeric nuclei magnetic fields nuclear electric

384

Nuclear moments and changes in rms-radii of neutron-deficient silver isotopes  

International Nuclear Information System (INIS)

... nuclear electric moments nuclear magnetic moments nuclear radii quadrupole

1987-03-23

385

Nuclear magnetic resonance on oriented XVTa and XXTa  

Energy Technology Data Exchange (ETDEWEB)

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

1984-08-01

386

Nature of the magnetic susceptibility of dysprosium. Paramagnetic susceptibility of dysprosium - yttrium alloys  

International Nuclear Information System (INIS)

The paramagnetic susceptibility of single crystals of dysprosium-yttirum alloys is measured in the basal plane and along the hexagonal axis. It is shown that the susceptibility of the alloys obeys the Curie-Weiss law, the effective magnetic moments allong the different directions being the same and the paramagnetic Curie temperatures being different. The difference between the paramagnetic Curie temperatures in the basal plane and along the hexagonal axis is independent of the dysprosium concentration in the alloy. As a comparison with the theoretical models of magnetic anisotropy shows, this is an indication that the magnetic anisotropy of dysprosium - yttrium alloys is of a single-ion nature.

1976-01-01

387

NMR at earth's magnetic field using para-hydrogen induced polarization  

British Library Electronic Table of Contents (United Kingdom)

A method to achieve NMR of dilute samples in the earth's magnetic field by applying para-hydrogen induced polarization is presented. Maximum achievable polarization enhancements were calculated by numerically simulating the experiment and compared to the experimental results and to the thermal equilibrium in the earth's magnetic field. Simultaneous 19F and 1H NMR detection on a sub-milliliter sample of a fluorinated alkyne at millimolar concentration (1018 nuclear spins) was realized with just one single scan. A highly resolved spectrum with a signal/noise ratio higher than 50:1 was obtained without using an auxiliary magnet or any form of radio frequency shielding.

2011-01-01

388

Methods and instruments for nondestructive testing of the anisotropy of the magnetic properties of ferromagnetic sheet materials (review)  

Energy Technology Data Exchange (ETDEWEB)

This review of methods and designs of transducers for nondestructive determination of the magnitude and nature of the anisotropy of magnetic properties (permeability, induction, coercive force, energy loss due to magnetization reversal) in local portions of ferromagnetic sheet and, in some cases, in individual parts of products. The need to measure the anisotropy is considered for two angles: for the case when the anisotropy is due to the crystallographic texture and determines the main operating characteristics of widely used sheet such as electrical steel and automobile body sheet, and for crystallographically isotropic materials, in which the anisotropy of magnetic properties as a result of mechanical stresses is a measure for determining the internal stresses.

1995-04-01

390

Magnetic structure of Ce(Ru_0_._9_6Pd_0_._0_4)_2Si_2  

International Nuclear Information System (INIS)

The magnetic structure of a tetragonal Ce(Ru_0_._9_6Pd_0_._0_4)_2Si_2 single crystal, determined by neutron diffraction measurements, is similar to that observed in Rh doped alloys. The magnetic moments are oriented and modulated along the c-axis. Here the wave vector is incommensurate: k=(0,0,0.38). At 1.5 K, the moment is estimated to about 0.3 #mu#_B. Magnetization, magnetoresistance and Hall effect measurements performed on this alloy are also reported. (orig.).

392

Magnetic resonance imaging in childhood epilepsy  

International Nuclear Information System (INIS)

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

393

Magnetic properties of oxovanadium(IV) complexes with bidentate on donor Schiff bases  

International Nuclear Information System (INIS)

(Feb 1977). Japan Syamal, A. Bombay Univ. (India). Univ. Dept. of Chemical

1977-01-01

394

Magnetic phase diagrams of the TbRh{sub 2-x}Pd{sub x}Si{sub 2} and TbRu{sub 2-x}Pd{sub x}Si{sub 2} systems  

Energy Technology Data Exchange (ETDEWEB)

The a.c. susceptibility and high field magnetization of TbRh{sub 2-x}Pd{sub x}Si{sub 2} and TbRu{sub 2-x}Pd{sub x}Si{sub 2} compounds were investigated up to 140 kOe. The (T, x) magnetic phase diagrams were determined. For both systems, an increase in the Pd content causes a decrease in the Neel temperature and changes the magnetization curves. (orig.)

1995-12-01

395

Magnetic braking in weakly ionized media  

International Nuclear Information System (INIS)

The combined magnetic braking-ambipolar diffusion problem in weakly ionized, rigidly rotating disks is studied. An analytical solution is presented for a disk whose angular velocity and magnetic yield vectors are aligned with the symmetry axis, illustrating the effects of the relative azimuthal drift of neutrals and ions. The effects of radial drift are added, commenting on the ratio of the characteristic ambipolar diffusion and magnetic braking time scales in high-mass and low-mass disks. A numerical calculation is used to show the combined action of these two processes. 31 references.

396

Magnetic Tape Pulse Width to Digital Convertor.  

Science.gov (United States)

... This is achieved by the use of a unique logic circuit employing a plurality of flip-flop devices, multivibrators and AND gates. ...

1976-12-07

397

Magnetic Properties of a Material Used to Estimate Elastic and Plastic Strains of Ferrite?Pearlite Steels  

British Library Electronic Table of Contents (United Kingdom)

The effect of elastic and plastic strains on the magnetic properties of ferrite-pearlite steels has been studied. It has been shown that the sensitivity to elastic-tensile and bending strains is four to five times greater for remnant magnetization than for coercive force. In order to determine the degree of cold plastic deformation of high-carbon steels, a two-parametric testing technique based on the use of remnant magnetization and coercive force was suggested. An MMT-2 device was recommended for measurement of the required parameters.

2005-01-01

398

Low-frequency fields - sources and exposure  

International Nuclear Information System (INIS)

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).

1993-06-01

402

Injection and extraction magnets: septa  

CERN Document Server

An accelerator has limited dynamic range: a chain of accelerators is required to reach high energy. A combination of septa and kicker magnets is frequently used to inject and extract beam from each stage. The kicker magnets typically produce rectangular field pulses with fast rise- and/or fall-times, however the field strength is relatively low. To compensate for their relatively low field strength, the kicker magnets are generally combined with electromagnetic septa. The septa provide relatively strong field strength but are either DC or slow pulsed. This paper discusses injection and extraction systems with particular emphasis on the hardware required for the septa.

2010-01-01

403

Influence of resonant US on H-NMR at application of magnetic nanoparticles  

International Nuclear Information System (INIS)

2010 [1 p.] Germany Repp, Felix El-Miladi, Nouri Hoehl, Christian Jahanbakhsh,

2010-03-21

404

From Rodinia to Gondwana: few paleo magnetic constraints; many speculations  

International Nuclear Information System (INIS)

... Trama; Montevideo (Uruguay) 70 p. GEOSCIENCES geologic history geologic

2001-11-12

408

Domain wall pining in a jointed ferromagnetic nano-wire  

Energy Technology Data Exchange (ETDEWEB)

The magnetoresistance in an FeNi submicron-structure comprising two wires of 80 and 200 nm in width connected in series was measured at 77 K. When the external magnetic field was applied parallel to the wire axis, two switching fields corresponding to the distinct coercive force of the two wires were observed. When the external magnetic field was applied at an angle of {theta}>30 deg. to the wire axis one switching field was observed, indicating simultaneous magnetization reversal in both wires. This indicates that the domain-wall trapping around the joint can be controlled systematically in terms of the direction of the external magnetic field.

2004-05-01

412

Conceptual design of a compact medical synchrotron with a hybrid magnet  

International Nuclear Information System (INIS)

English 2001 p. 178 China Iwashita, Y. Kumada, M. National Institute

2001-09-17

413

CAPACITOR DISCHARGE METAL FORMING  

Science.gov (United States)

... Report Date : JUL 1961. Pagination or Media Count : 39. Abstract : Open-ende Terms: Electrohydraulic forming, Magnetic forming. ...

1961-07-01

414

A preliminary design for a one GHz NMR spectrometer magnet  

International Nuclear Information System (INIS)

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

1993-09-20

415

A Profile of Defense Manufacturing Costs and Enabling ...  

Science.gov (United States)

... Casting Explosive forming Forging Electrohydraulic forming Extruding Magnetic forming Rolling Electroforming Drawing Powdered metal forming ...

1992-01-01

416

A GENERAL STUDY OF PROCESSES FOR THE ...  

Science.gov (United States)

... fields, materials can be subjected to energy densities exceeding those realized in high explosives, a fact which forms the basis for magnetic forming ...

1962-11-01

417

Proposal of procedures to prevent errors in radiotherapy based in learned lessons of accidental expositions; Proposta de procedimentos para evitar erros em radioterapia baseados em licoes aprendidas de exposicoes acidentais  

Energy Technology Data Exchange (ETDEWEB)

In order to consider some procedures to prevent errors in radiotherapy based in learned lessons of accidental expositions and in accordance with information contained in international reports elaborated by International Atomic Energy Agency (IAEA) and of the data base availability by the European group Radiation Oncology Safety Information System (ROSIS) on the events, a research of the occurred errors was performed. For the evaluation of the incidents a data base based in the ROSIS and added plus a parameter was created 'type of error'. All the stored data make possible the evaluation of the 839 incidents in terms of frequency of the type of error, the process of detention, the number of reached patients and the degree of severity. Of the 50 types of found errors, the type of error more frequently was 'incorrect treatment coordinate', confirmed with the data of literature and representing 28,96 por cent of the total of the incidents. The results ...

2007-07-01

418

Delayed neutron energy spectra following fast fission of "2"3"8U  

International Nuclear Information System (INIS)

Delayed neutron energy spectra have been measured for six delay-time intervals following the fast fission of "2"3"8U nuclei. The delay-time intervals span the range 0.17 to 10.2 seconds following initial fission while the measured spectra span neutron energies from 10 keV to 4 MeV. The experiment was performed utilizing the UMass/Lowell 5.5 MV Van de Graff accelerator to produce fast neutrons for inducing fission in a "2"3"8U lined fission chamber. The fission fragments were flushed via a helium jet stream to a well-shielded counting room where they were deposited onto a moving tape (magnetic audio tape) and transferred to a beta-neutron time-of-flight spectrometer. By adjusting the tape speed, composite delayed neutron time-of-flight spectra were measured for several different delay-time intervals. These measurements involved beta-neutron coincidences with "6Li-loaded glass scintillators for neutron energies from 10 keV to 450 keV and Bicron ...

419

War and Escalation in South Asia  

Science.gov (United States)

... TTP tactics, techniques, and procedures UCP Unified ... be sold or transferred to Pakistan, pursuant to ... substantial amounts of those funds being spent ...

2011-05-13

420

Ultrasonic enhancement of heat transfer on narrow surface  

Energy Technology Data Exchange (ETDEWEB)

Ultrasonic enhancement of heat transfer on a narrow surface was measured by changing the width of the surface from 8 to 0.1 mm. Ultrasonic power of 600 W with a frequency of 40 kHz was used. Heat transfer on the narrow surface without ultrasonic vibration was correlated by the experimental equation for a thin wire. The cavitation intensity was measured by the cavitation erosion loss of an aluminum foil of 15 [mu]m thickness. The effects of acoustic streaming and cavitation were separated by this measurement. Heat transfer by acoustic streaming was predicted through forced convection. Enhancement by cavitation was explained by the turbulence thermal conductivity of the microjets.

1994-06-01

421

The effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer in a pipe flow  

Science.gov (United States)

The present study investigates the effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer enhancement in a pipe flow. The constant heat flux as thermal boundary condition was adopted in the thermally developed region. The present analytical results show the heat transfer enhancement over those of a shear rate-independent thermal conductivity fluid. The heat transfer coefficient ratio (h/h{sub 0}) linearly increase with the non-dimensional average velocity difference which is the product of the shear rate-dependence of the thermal conductivity and wall-shear rate.

1996-09-01

422

Tests of Turbulators for Fire-Tube Boilers.  

Science.gov (United States)

... Originator-supplied keywords include: Turbulators, Heat transfer augmentation, Enhancement, Fire tube boilers. (Author). ...

1982-10-01

423

Technology Transfer. Volume 2  

Science.gov (United States)

... table (ASCAMP) system and the Military Strategic and Tactical Relay (Milstar) program. 10 ... Single Channel Antijam Milstar Portable Terminal ...

1992-04-01

425

Research workshop on energy conservation through enhanced heat transfer  

Science.gov (United States)

Seven papers were presented at the meeting. A separate abstract was prepared for each paper. (LCL)

1979-10-01

426

Potential gas entry into FFTF after a postulated pipe rupture  

International Nuclear Information System (INIS)

... failures fftf reactor heat transfer hydraulics loss of coolant pipes primary coolant

428

Pairing effect in the nucleon transfer processes in quasi-elastic heavy ion scattering  

International Nuclear Information System (INIS)

... range krypton 86 reactions molybdenum 92 target probability quasi-elastic

1987-04-14

429

MINEQL-PC. Chemical Equilibrium Composition of Aqueous Systems  

Energy Technology Data Exchange (ETDEWEB)

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

1986-11-21

430

Impingement-Film Heat Transfer Investigation.  

Science.gov (United States)

... Abstract : This report covers the investigation of an impingement-film cooling system designed to cool the exhaust ducts of turboshaft engines ...

1973-12-01

431

Heat transfer equipment design  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive presentation is made of state-of-the-art configurations and design methodologies for heat transfer devices applicable to industrial processes, automotive systems, air conditioning/refrigeration, cryogenics, and petrochemicals refining. Attention is given to topics in heat exchanger mechanical design, single-phase convection processes, thermal design, two-phase exchanger thermal design, heat-transfer augmentation, and rheological effects. Computerized analysis and design methodologies are presented for the range of heat transfer systems, as well as advanced methods for optimization and performance projection.

1988-01-01

432

Heat transfer augmentation in inverted annular film boiling  

International Nuclear Information System (INIS)

(Jun 1982). United States Edelman, Z. Chambre, P. Eilas, E. Naot, D. Technion,

1982-06-11

434

Excitation Energy Transfer Study of the Spatial Relationship ...  

Science.gov (United States)

... closely correlated to the amount of re- centration. The molar extinction coefficients were agent added to the enzyme. The naphtha- ...

1988-02-15

435

Convective heat transfer under unsteady impinging jets: the effect of the shape of the unsteadiness  

Science.gov (United States)

Unsteady impinging jets are systematically controlled with respect to their time dependence in order to investigate the influence of unsteadiness on the heat transfer performance. This is achieved by a special mass flow control device, which allows almost arbitrary shapes of unsteadiness to be imposed onto the impinging jet. Three different standard signals (sinusoidal, triangular, rectangular) and two specially designed signals are applied and their influence on heat transfer is determined in terms of an enhancement factor. Heat transfer augmentation up to 30% was found and could be physically explained with the help of PIV and hot-wire measurements of the flow field.

2009-10-01

436

Analysis of laminar flow and heat transfer in the entrance region of an internally finned concentric circular annular duct  

Energy Technology Data Exchange (ETDEWEB)

The concentric circular annular duct is a common geometry in many fluid flow and heat transfer devices. For the purpose of heat transfer augmentation, fins are often employed in the annular region, and such finned ducts find wide application in compact heat exchangers (5, 6). The analysis of flow and heat transfer in this geometry is, therefore, quite important from an engineering standpoint. For fully developed conditions, the problem has already been analyzed (7-10). However, no results are available for the developing flow in the entrance region. It is with this latter problem that the present paper is concerned.

1987-05-01

437

An investigation of turbulent convection heat transfer performance in spiral spring coil inserted tubes  

International Nuclear Information System (INIS)

This paper presents the results of the experimental investigation on heat transfer and fluid friction characteristics of a class of spiral spring coil used as a tube side forced convection heat transfer augmentation devices. Based on a lot of experimental data, the heat transfer correlation and fluid friction correlation revised by temperature were reached in terms of linear regression. At the same time, proper criteria were used to evaluate the economic performance of the spiral spring inserted tube according to the demand of practical application and some probing analysis were made.

1996-01-01

438

A Review of Test Medium Contamination Effects on Test ...  

Science.gov (United States)

... solid particle contamination. Solid particulate impact is a good mechanism for surface heat transfer augmentation. The aug ...

1998-01-01

439

25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection  

Science.gov (United States)

Topics covered include: Methods of Helium Injection and Removal for Heat Transfer Augmentation; The

2008-01-01

440

Use of magnetic treatment to intensify certain processes in the refining of chemical products of coking  

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

441

Stability of superconducting ISABELLE dipole magnets  

Energy Technology Data Exchange (ETDEWEB)

The concept of the minimum propagating zone (MPZ) is used to examine the causes of quenches in ISABELLE cosine theta superconducting dipole magnets. The size of disturbances large enough to exceed the MPZ and initiate quenches is estimated and compared with the size of disturbances which may be produced in the magnets. A suggestion for reducing the size of these disturbances through individual support of the coil block is outlined.

1981-04-01

442

Self-simulating motion of an ionized gas expelled by a magnetic piston  

Energy Technology Data Exchange (ETDEWEB)

The paper deals with a model in which the motion of a gas in plasma accerators and high-curent discharges in the present of a skin effect is treated as expulsion by a 'magnetic piston' under the action of surface current flow. Specifically examined is the situation where the initial gas pressure is negligible in comparison with the magnetic pressure, and the motion of the gas may be treated as a self-simulating one. A system of hydrodynamic equations of the problem is derived and integrated by Adam's method. Results are plotted and discussed.

1980-01-01

443

Search for magnetic rotation in {sup 202}Pb and {sup 203}Pb  

Energy Technology Data Exchange (ETDEWEB)

High-spin states in {sup 202}Pb and {sup 203}Pb have been investigated by in-beam {gamma}-ray spectroscopy following the reaction {sup 198}Pt({sup 9}Be,xn). A search for magnetic rotational bands in these isotopes confirmed one of the two bands previously assigned to {sup 202}Pb and revealed a new band in this isotope. No evidence for magnetic rotation has been found in {sup 203}Pb. (orig.)

2000-11-01

444

Multidipole magnetic fields for plasma confinement  

Energy Technology Data Exchange (ETDEWEB)

Plasma confinement by permanent magnets has been studied. An analytic formula for the field of a single bar magnet has been obtained. Generalization to various configurations of multidipole fields has also been found. Any two-dimensional field may now be completely described by a simple function of complex variables in closed form. Vector potential has also been obtained by integrating over a prescribed Riemann surface. The confinement of plasma by multidipole fields then becomes obvious through conservation principles.

1983-07-01

445

Methods of reducing magnetic field near the transmission lines  

International Nuclear Information System (INIS)

Due to biological effects of magnetic fields of high voltage transmission lines and induced effects on has pipe line, telecommunication system and interference with sensitive electronic equipment, many effort have been done to reduce transmission lines magnetic fields and several ideas have been introduced. In this paper we review three methods: phase split, shielded and compacted line methods. With aid of a developed software programme these methods are then applied to transmission lines and the results are analyzed.

2003-01-01

446

Mean magnetic moments of polycrystalline Ce compounds in a tetragonal crystal field  

International Nuclear Information System (INIS)

An alternative and graphical representation of the magnetic moment and the effective paramagnetic moment for polycrystalline Ce compounds with tetragonal site symmetry is described. The reduced moments can be calculated by means of standard perturbation theory. The calculated values deduced from the ground states of CeCu_2Si_2, CeRu_2Si_2, and CePd_2Si_2 polycrystals are compared with experimental magnetic moments.

447

Magnetic properties of heavy rare-earth tungstates  

International Nuclear Information System (INIS)

Measurement of the magnetic susceptibility of powder samples of heavy rare-earth (Tb, Dy, Ho, Er, Tm and Yb) tungstates have been reported in the temperature range 300 to 900 K. Curie-Weiss law behaviour has been observed for all samples. The Curie constant, paramagnetic Curie temperature and magneton number for the magnetic ions have also been evaluated for each material. (author).

1978-12-01

448

Magnetic properties of FeSi with cobalt impurities  

Energy Technology Data Exchange (ETDEWEB)

Results of experimental researches of impurity level crystals Fe1-xCoxSi are presented in this article. Magnetic properties in a temperature range up to T {<=} 1000 K are analyzed. It was established that with Co impurities increasing origin of magnetic ordering exists at low temperatures. At high temperatures a high temperature maximum of susceptibility of nominally pure iron monosilicide crystal is observed.

2010-01-01

449

Magnetic diagnostic of beta poloidal and internal inductance of plasma in the TCA/BR tokamak  

Energy Technology Data Exchange (ETDEWEB)

This report continues the studies of simplified methods, of magnetic diagnostics in application to TCA/BR tokamak. Here we study the accuracy of known formula for {beta}{sub 1} + l{sub 1}/2 determination from the poloidal magnetic field asymmetry. Errors of the diamagnetic measurements due to vibrations of the vacuum vessel are also considered. (author). 3 refs., 1 fig., 1 tab.

1996-12-31

450

Magnetic and valence transitions in CePd_2_-_xMn_xSi_2:L_I_I_I edge study  

International Nuclear Information System (INIS)

We report on solid solution CePd_2_-_xMn_xSi_2 which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.)).

451

Magnetic and valence transitions in CePd[sub 2-x]Mn[sub x]Si[sub 2]:L[sub III] edge study  

Energy Technology Data Exchange (ETDEWEB)

We report on solid solution CePd[sub 2-x]Mn[sub x]Si[sub 2] which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.))

1994-04-01

452

Kondo effect in the systems of magnetic trimers on a metal surface  

International Nuclear Information System (INIS)

Calculating the local spectral densities at magnetic adatoms, we estimate the variation in the Yosida-Kondo resonance due to the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction and the direct exchange between adatoms in systems of magnetic trimers on metal surfaces. The results show that the RKKY interaction leads to the gradual variation in Kondo temperature, and the direct exchange can be the origin of the drastic variation. (author)

2010-11-01

453

Invariant correlation functions, superconvergence sum rules, and electric-magnetic duality  

Energy Technology Data Exchange (ETDEWEB)

The gauge-invariant correlation function for the Yang-Mills field strengths is shown to admit a symmetric decomposition into electric and magnetic components. The spectral weights are seen to obey a sum rule of the superconvergence type, owing to asymptotic freedom. The close relation between the dielectric function, electric-magnetic duality, and the algebra of generalized Chern-Simons charges is illustrated for the linearized Yang-Mills-Higgs system.

1988-01-01

454

Instability of 4f and 3d magnetic moments under high pressure  

International Nuclear Information System (INIS)

The purpose of this paper is to demonstrate how recent experimental results of "1"5"1Eu and "5"7Fe high pressure Moessbauer studies in 4f and 3d metallic magnetic systems can contribute to a deeper understanding of the nature of local moment (4f) and itinerant (3d) magnetism in these systems. Special emphasis is given on the comparison of the experimental results with related theoretical models. (orig.).

455

Experimental Verification of the Hall Effect during Magnetic Reconnection in a Laboratory Plasma  

Energy Technology Data Exchange (ETDEWEB)

In this letter we report a clear and unambiguous observation of the out-of-plane quadrupole magnetic field suggested by numerical simulations in the reconnecting current sheet in the Magnetic Reconnection Experiment (MRX). Measurements show that the Hall effect is large in collisionless regime and becomes small as the collisionality increases, indicating that the Hall effect plays an important role in collisionless reconnection.

2005-06-16

456

Effect of heat treatment on the properties of Metglas foils, and laminated magnetoelectric composites made thereof  

British Library Electronic Table of Contents (United Kingdom)

Annealing of magnetostrictive Metglas foils, subsequently incorporated into laminated Metglas/Pb(Zr, Ti)O3 magnetoelectric (ME) composites, is shown to result in improved magnetic properties, as well as ME coefficients. Annealing of the foils at 350 ?C resulted in partial crystallization, without oxidation or magnetic cluster formation that would reduce the magnetization. Laminate composites made with these annealed Metglas foils had improved ME coefficients.

2011-01-01

457

Current applications of magnetic resonance in coal liquefaction research  

Energy Technology Data Exchange (ETDEWEB)

Some applications of magnetic resonance in coal liquefaction research described briefly are: (1) investigation of the nature of carbon deposits on used coal-liquefaction catalysts, (2) determination of the fate of hydrogen during coal liquefaction, and (3) observation of transient free radicals during coal pyrolysis. The first two applications make use of cross-polarization /sup 13/C magnetic resonance combined with magic angle spinning, and the third application is an electron spin resonance study. (BLM)

1982-01-01

458

Conductance quantization in ferromagnetic Ni nano-constriction  

Energy Technology Data Exchange (ETDEWEB)

The conductance in ferromagnetic Ni nano-wire is quantized in units of 2e{sup 2}/h in the absence of magnetic field, while the units switch to e{sup 2}/h in the magnetic field. The fractional units of 0.7e{sup 2}/h and 1.4e{sup 2}/h with and without magnetic field appear under the application of high bias-voltage. The spin polarization and bias-voltage play an important role in the electric conduction.

2002-02-01

459

Comment on 'Magnetic braking revisited: activities for the undergraduate laboratory'  

International Nuclear Information System (INIS)

Here, we consider a recent paper concerned with magnetic braking by induced currents (Ireson and Twidle 2008 Eur. J. Phys. 29 745-51). Our objective is to elucidate why measurement of speed in which a magnet is dropped through a non-ferromagnetic conductive tube depends on its geometry in a non-monotonic way, which was not clearly explained by the authors. (letters and comments)

2009-03-01

460

Bacterial cultivation in high magnetic fields by 7-tesla superconducting magnet; 7T chodendo magnet ni yori hasseishita kojiba ni okeru biseibutsu no baiyo  

Energy Technology Data Exchange (ETDEWEB)

Although a large number of studies on effects of magnetic fields on living organisms was reported, no definite results were obtained in many cases because the related conditions are non-uniform and uncertain, such that the uniform magnetic space is smaller than test samples, and temperature control is insufficient. Therefore, the present study developed a microorganism cultivation system that is applied with a 7-T superconducting magnet. This system has the following features: it generates homogeneous magnetic fields of 0.5 to 7 T {plus_minus} 0.5% in the space with a diameter of 100 mm and a length of 200 mm in a normal temperature bore (with a diameter of 160 mm); it can cultivate microorganisms aerobically at temperatures of 10 to 70{degree}C {plus_minus} 0.1{degree}C; it can perform the cultivation simultaneously with a control cultivation in a small magnetic field weaker than ...

1994-12-20

461

Ab initio calculations in a uniform magnetic field using periodic supercells  

Energy Technology Data Exchange (ETDEWEB)

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

2003-10-21

462

Thermal performance of solar air collectors with a passive heat transfer augmentation technique  

Energy Technology Data Exchange (ETDEWEB)

One of the main disadvantages of solar air collectors in practical applications is their relatively low efficiency. In this experimental investigation, the shape and arrangement of absorber surfaces of the collectors were reorganized to provide better heat transfer surfaces suitable for the passive heat transfer augmentation techniques. The performance of such solar air collectors with staggered absorber sheets was tested. The experimental results show that it is possible to provide 10 to 25% enhancement in the efficiency compared to the conventional solar air collectors. (authors)

2000-07-01

463

Proceedings of the 1991 ASME JSME thermal engineering joint conference  

International Nuclear Information System (INIS)

This book is organized under the following headings: Electrohydrodynamic heat transfer augmentation; Forced convection augmentation and heat transfer control; Turbulent heat transfer; Thermal problems in the environment; Energy conversion systems; Measurement, visualization, and imaging; Thermal problems in space technology; and Thermal properties.

1991-03-17

464

Off-line and on-line-monitoring of power transformers using the transfer function method  

Energy Technology Data Exchange (ETDEWEB)

The transfer function concept is well known as an additional method to evaluate the impulse test of power transformers in the test laboratory. Another application for the transfer function method is monitoring of transformers in service. Thereby, Off-line and On-line monitoring can be realized. Both kinds of monitoring are demonstrated with on-site measurements on a power transformer in service.

1996-12-31

465

Nucleon transfer contribution to the absorptive heavy ion potential by the Monte Carlo simulation method  

Energy Technology Data Exchange (ETDEWEB)

The Monte Carlo simulation method is applied to calculate the nucleon transfer part of the imaginary optical-model potential in colliding heavy ions. In the process of transfer of nucleons from one nucleus to the other, forward and backward neutrons and protons are treated separately by taking into consideration the effect of the Coulomb forces and the potential energy surfaces (driving forces). The Pauli exclusion principle is also incorporated properly in the calculation.

1988-08-08

466

Korea-IAEA Unattended Safeguards Approach on the Spent Fuel Transfer to Dry Storage in Wolsung NPP  

Energy Technology Data Exchange (ETDEWEB)

The field trial of an unattended monitoring system for SF transfer verification ended in June 2005. The system is aiming to improve the safeguards measures applied during SF transfers and reduce inspection effort currently required by the Operator, NNCA and the IAEA. They were reviewed based on its technical performance and other issues in this paper.

2006-07-01

467

Korea-IAEA Unattended Safeguards Approach on the Spent Fuel Transfer to Dry Storage in Wolsung NPP  

International Nuclear Information System (INIS)

The field trial of an unattended monitoring system for SF transfer verification ended in June 2005. The system is aiming to improve the safeguards measures applied during SF transfers and reduce inspection effort currently required by the Operator, NNCA and the IAEA. They were reviewed based on its technical performance and other issues in this paper.

2006-05-25

468

Isotopic effects on solubility-limited mass transfer  

Energy Technology Data Exchange (ETDEWEB)

In our previous theoretical analyses, solubility-limited mass transfer from waste solids applies if a species is at a constant elemental concentration in liquid at the waste surface. For an element with isotopes that decay appreciably during the time of interest, a solubility boundary condition results in a time-dependent boundary concentration of each isotope. Here we present mass-transfer equations that include the effects of isotopic decay boundary conditions. 9 refs., 1 fig.

1989-06-01

469

High temperature heat transfer augmentation  

International Nuclear Information System (INIS)

The heat transfer augmentation is reviewed in view of high temperature heat exchangers illuminating the contribution of radiative heat transfer. A number of means and/or devices are presented as well as the sophisticated concept which will be promoted to the extended applications in matured industries such as iron and steel, oir refinery, petro-chemical. It should be emphasized that the more creative and innovatory technology has to be promoted in order to stimulate and refresh the foregoing industries, recognizing the increasing importance of the energy resources.

1985-08-01

470

Heat transfer from magneto-rheological fluid dampers  

Science.gov (United States)

This paper presents a theoretical study of heat transfer from magneto-rheological fluid (MRF) dampers. A lumped system model is developed which is capable of predicting the temperature rise for any size MRF damper. As a case study example, finned and unfinned dampers are compared for automotive-size MRF dampers. The results demonstrate that heat transfer from these devices can be enhanced considerably with the use of fins.

2000-04-01

471

Heat transfer augmentation by interrupted surfaces - Experimental considerations  

International Nuclear Information System (INIS)

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

1987-08-01

472

Free convection heat and mass transfer to steady flow in a semi-infinite vertical porous medium  

Science.gov (United States)

Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively.

1988-02-01

473

Effect of ultrasonic waves on boiling heat transfer. 2  

International Nuclear Information System (INIS)

This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic steam induced by ultrasonics is a major contribution to heat transfer augmentation. (author).

1993-05-01

474

Effect of ultrasonic waves on boiling heat transfer  

Energy Technology Data Exchange (ETDEWEB)

This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic stream induced by ultrasonics is a major contribution to heat transfer augmentation. (author).

1993-07-01

475

Design and procurement report for the FFTF fuel handling systems bottom-loading transfer cask  

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) bottom-loading transfer cask (BLTC) system is designed to provide ex-vessel fuel transfers of irradiated reactor components between the reactor containment building and the LMFBR shipping cask in the reactor service building. This system is being procured from National Lead Industries, Wilmington, Delaware, under management of Aerojet Manufacturing Company.

1975-11-16

476

Bibliography of US patents on augmentation of convective heat and mass transfer  

Energy Technology Data Exchange (ETDEWEB)

Granted patents are an important source of information on the potential commercialization of augmented heat transfer technology. This report presents a bibliography of US patents pertinent to that technology. The total number of patents cited is 321. They are presented in three separate lists: by patent number, alphabetically by first inventor, and by augmentation techniques (with secondary arrangement according to mode of heat transfer).

1980-09-01

477

Air-side flow and heat transfer in compact heat exchangers: A discussion of enhancement mechanisms  

Energy Technology Data Exchange (ETDEWEB)

The behavior of air flows in complex heat exchanger passages is reviewed with a focus on the heat transfer effects of boundary-layer development, turbulence, spanwise and streamwise vortices, and wake management. Each of these flow features is discussed for the plain, wavy, and interrupted passages found in contemporary compact heat exchanger designs. Results from the literature are used to help explain the role of these mechanisms in heat transfer enhancement strategies.

1998-10-01

478

Retrospective Monte Carlo dose calculations with limited beam weight information  

International Nuclear Information System (INIS)

An important unresolved issue in outcomes analysis for lung complications is the effect of poor or completely lacking heterogeneity corrections in previously archived treatment plans. To estimate this effect, we developed a novel method based on Monte Carlo (MC) dose calculations which can be applied retrospectively to RTOG/AAPM-style archived treatment plans (ATP). We applied this method to 218 archived nonsmall cell lung cancer lung treatment plans that were originally calculated either without heterogeneity corrections or with primitive corrections. To retrospectively specify beam weights and wedges, beams were broken into Monte Carlo-generated beamlets, simulated using the VMC++ code, and mathematical optimization was used to match the archived water-based dose distributions. The derived beam weights (and any wedge effects) were then applied to Monte Carlo beamlets regenerated based on the patient computed tomography densities. Validation of the process was performed against five ...

2007-01-01

479

Incorporating an improved dose-calculation algorithm in conformal radiotherapy of lung cancer: re-evaluation of dose in normal lung tissue  

International Nuclear Information System (INIS)

Background and purpose: The low density of lung tissue causes a reduced attenuation of photons and an increased range of secondary electrons, which is inaccurately predicted by the algorithms incorporated in some commonly available treatment planning systems (TPSs). This study evaluates the differences in dose in normal lung tissue computed using a simple and a more correct algorithm. We also studied the consequences of these differences on the dose-effect relations for radiation-induced lung injury. Materials and methods: The treatment plans of 68 lung cancer patients initially produced in a TPS using a calculation model that incorporates the equivalent-pathlength (EPL) inhomogeneity-correction algorithm, were recalculated in a TPS with the convolution-superposition (CS) algorithm. The higher accuracy of the CS algorithm is well-established. Dose distributions in lung were compared using isodoses, dose-volume histograms (DVHs), the mean lung dose (MLD) and the ...

2003-10-01

480

Can intensity-modulated radiation therapy of the paraaortic region overcome the problems of critical organ tolerance?  

Energy Technology Data Exchange (ETDEWEB)

Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were planned to theoretically deliver 60 Gy to ...

2005-03-01

481

X-ray magnetic form factor of UTe  

Energy Technology Data Exchange (ETDEWEB)

A measurement of the magnetic form factor of a ferromagnetic actinide compound of UTe with circularly polarized X-rays is reported. The present geometrical configuration of the measurement gives a form factor of L(k)+0.3S(k), where L(k) and S(k) are the form factors of the orbital and the spin magnetic moment, respectively. We have combined the X-ray magnetic form factor with the neutron one which gives L(k)+2S(k) (G. Busch et al.: J. Phys. C 12 (1979) 1391), and have deduced L(k) and S(k) separately. The obtained profiles of L(k) and S(k) show that the orbital and the spin magnetic moments are spatially spread out more than those calculated for a free uranium ion. (author).

1995-07-01

482

X-ray magnetic form factor of UTe  

International Nuclear Information System (INIS)

A measurement of the magnetic form factor of a ferromagnetic actinide compound of UTe with circularly polarized X-rays is reported. The present geometrical configuration of the measurement gives a form factor of L(k)+0.3S(k), where L(k) and S(k) are the form factors of the orbital and the spin magnetic moment, respectively. We have combined the X-ray magnetic form factor with the neutron one which gives L(k)+2S(k) (G. Busch et al.: J. Phys. C 12 (1979) 1391), and have deduced L(k) and S(k) separately. The obtained profiles of L(k) and S(k) show that the orbital and the spin magnetic moments are spatially spread out more than those calculated for a free uranium ion. (author).

483

Transition-metal dimers and physical limits on magnetic anisotropy  

British Library Electronic Table of Contents (United Kingdom)

Recent advances in nanoscience have raised interest in the minimum bit size required for classical information storage. This bit size is determined by the necessity for bistability with suppressed quantum tunnelling and energy barriers that exceed ambient temperatures. In the case of magnetic information storage, much attention has centred on molecular magnets with bits consisting of about 100 atoms, magnetic uniaxial anisotropy energy barriers of about 50?K and very slow relaxation at low temperatures. Here, we draw attention to the remarkable magnetic properties of some transition-metal dimers, which have energy barriers approaching 500?K with only two atoms. The spin dynamics of these ultrasmall nanomagnets is strongly affected by a Berry phase, which arises from quasi-degen...

2007-01-01

484

The addition of trim coils to the Tandem Mirror Experiment magnet system to improve the magnetic field mapping  

International Nuclear Information System (INIS)

The mapping of the magnetic flux bundle from the center cell to the Plasma Potential Control plates (PPC) on the end fan of the Tandem Mirror Experiment Upgrade (TMX-U), was improved by the addition of trim coils (12,000 amp-turns) on each side of each end fan next to the pump beam magnetic shields. The coils' axes are oriented perpendicular to the machine centerline. These coils made the necessary corrections to the field-line mapping, while keeping the field in the nearby pump beam magnetic shield below the saturation threshold. This paper briefly describes the problem, discusses the design as it evolved, and presents the results of the field testing. A brief description of the improvement in the machine performance is also included.

485

Preliminary Calculations of the Radiation Damage of the Permanent Magnets for TRADE (TRiga Accelerator Driven Experiment)  

CERN Document Server

Monte Carlo calculations of proton irradiation of permanent magnets for the TRADE experiment have been performed. An irradiation dose of about 4´106 Gy/yr/mA has been estimated due to beam losses in normal operating conditions. Existing experimental results indicate that this irradiation level may induce a considerable demagnetization: in fact, a dose of 6´107 Gy induces a remanence loss of 0.3 % on samples of Sm2Co17 magnets, which are the most resistant type. More detailed calculations with the final design of the magnets and of the beam line are suggested, to determine if the irradiation levels allowed a reliable operation of the permanent magnets for the entire duration of the TRADE experiment. Damage and gas production rates have also been calculated; the values obtained are very low, thus confirming that the demagnetization process is in great part reversible.

2002-01-01

486

Novelty, preparation, characterization and enhancement of magnetic properties of Mn nanoferrites using safety binder (egg white)  

British Library Electronic Table of Contents (United Kingdom)

Nanocrystalline MnFe"2O"4 ferrite was prepared by using autocombustion technique (flash). The microstructure and magnetic properties are studied. The results of XRD and TEM clarified that, this ferrite is nanosized with particle size (39 nm). Magnetic measurements showed a ferromagnetic behavior with T"C = 613 K, the saturation magnetization M"s = 13.71 emu/g, remanent magnetization M"r = 0.1694 emu/g and, coercivity H"c = 25.6 Oe. Natural material, egg white used as an aqueous medium to extend prepare nanoparticles better than other chemical interesting materials.

2011-01-01

487

Magnetic beam position monitor  

Energy Technology Data Exchange (ETDEWEB)

Many nondestructive beam position monitors are known. However, these devices can not be used for DC particle beam diagnostics. We investigated a method of beam diagnostics applicable for the operative control of DC high power e-beam inside closed waveguide. A design of the detector for determination of{open_quote} center of mass {close_quote} position of DC particle beam was developed. It was shown that the monitor can be used as a nondestructive method for the beam position control in resonators. Magnetic field of the particle beam outside a resonator is used. The detector consists of the steel yokes and magnetic field sensors. The sensors measure magnetic fluxes in the steel yokes fixed outside the resonator. When the particle beam changes its position, these magnetic fluxes also change. Beam displacement sensitivity of the monitor depends on the steel yoke dimensions. The detector sensitivity is ...

1995-12-31

488

Magnetic Moments and Electromagnetic Radii of Nucleon and ?(1232) in an Extended Goldstone-Boson-Exchange Model  

International Nuclear Information System (INIS)

We derive the exchange currents of pseudoscalar, vector, and scalar mesons from Feynman diagrams, and use them to calculate the magnetic form factors of nucleon and ?(1232). The magnetic moments and electromagnetic radii are obtained by using those form factors and the parameters determined from the masses of nucleon and ?(1232). We find the magnetic moments and electromagnetic radii of nucleon and ?(1232) can be produced very well in the extended Goldstone-Boson-exchange model in which all of pseudoscalar, vector, and scalar meson nonet are included. The magnetic moments of ?(1232) are closer to experiment values and results from lattice calculation than the results obtained by the model without other mesons except for pion and sigma.

2005-01-15

489

Lorentz transmission electron microscopy investigation of magnetically patterned Co/Pt multilayers  

Energy Technology Data Exchange (ETDEWEB)

The switching behavior of magnetic patterns prepared by ion irradiation was investigated. Co/Pt multilayers with perpendicular anisotropy and large out-of-plane coercivities 5-6 kOe were grown on electron transparent SiN windows. Regularly spaced 1 micron sized regions, were magnetically pattered via ion beam irradiation through a stencil mask. Lorentz TEM was used to observe in-situ magnetization reversal processes of irradiated regions under well-defined applied magnetic fields. When the in-plane field was increased, domain wall motion was observed, resulting in the alignment of the patterns with the direction of the applied field. The switching mechanism of the in-plane patterns was by domain wall motion.

2000-08-01

490

Electromagnetic fields - introduction to relevant issues  

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 Saxony. (Uhe).

1993-06-01

491

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

Energy Technology Data Exchange (ETDEWEB)

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

1987-01-01

492

Crossover of the magnetic levels and adiabatic magnetization of the mesoscopic cluster V15  

British Library Electronic Table of Contents (United Kingdom)

The magnetic three spin-1/2 model for nanometer-scale molecular cluster V15 is analyzed with the emphasis on the origin of the mixing of different spin levels in the resonance fields that is generally important for the problem of single molecular magnets. The zero-field splitting in the ground quadruplet (two Formula Not Shown levels) is shown to depend mainly on the normal component of AS exchange meanwhile the zero-field splitting in the excited Formula Not Shown multiplet is a second order effect with respect to in-plane components of AS exchange. The normal component of the AS exchange is shown to lead to the exact crossing of the magnetic sublevels at the arbitrary direction of the field. The positions of two crossing/anticrossing points in the ground manifold depend mainly on the iso...

2006-01-01

493

Application of GIS for the evaluation of human exposure to magnetic field in the vicinity of power lines  

Energy Technology Data Exchange (ETDEWEB)

Application of the Geographic Information System (GIS) with a statistical model to evaluate the magnetic field exposure of a population from high-voltage transmission lines near residential areas is discussed, focusing on the interaction of the GIS with the statistical model. In an effort to validate the model measurements of the magnetic field, profiles were taken at two sites and these profiles have been compared with calculated values. Two conclusions have been drawn from the results: (1) the statistical model linked with the GIS is a very powerful tool for the evaluation of exposure of a population to magnetic fields, and (2) success depends on the presence of other sources of magnetic fields and on the exactness of the data used in the model. 4 refs., 5 figs.

1998-10-01

494

Time-dependent fluid flow and heat transfer around a circular heated cylinder embedded in a horizontal packed bed of spheres  

Science.gov (United States)

The present study numerically investigates the enhancement of forced convective heat transfer from a single circular cylinder embedded in a packed bed of spherical particles confined by two impermeable parallel plates. The heat transfer results from the heated cylinder, with and without the presence of a porous medium, are compared. The results show that the presence of the porous particles enhances the heat transfer from the cylinder; however, the significant heat transfer augmentation is produced at high Re due to the effect of thermal dispersion. In addition, the effect of Re on Nut is much greater than that of kr and Bi in the porous channel. It is also found that the %?p is much higher than %HTE producing from packing the empty channel.

2010-05-01

495

Fundamental study of heat transfer and flow situation around a spacer (in the case of a cylindrical rod as a spacer)  

International Nuclear Information System (INIS)

This paper describes the heat transfer augmentation and the flow situation around a single spacer (a cylindrical rod) on the heated surface of a parallel plate duct in order to examine basically the effects of the spacer in the fuel elements of a high temperature gas-cooled reactor. The ends of the cylindrical rod contact the upper and lower planes. A thermosensitive liquid crystal film is used to indicate the effective area for the heat transfer. The mean Nusselt number, which is estimated within the optional distance from the spacer to the downstream direction, peaks at a dimensionless distance of X/D = 1-3, and after that decreases gradually with the flow direction. The manner in which heat transfer corresponds to the flow situation is also examined. The horseshoe vortex, produced around the spacer, affects the wake and contributes to the increase of the local heat transfer. (author).

1988-01-01

496

Facilitated Proton Transfer by a Novel 2-Aminothiazole Derivative Across the Water/1,2-Dichloroethane Interface  

British Library Electronic Table of Contents (United Kingdom)

The behavior of proton transfer facilitated by a novel thiazole derivative, N-methyl-4-(4-phenoxyphenyl)thiazol-2-amine (MPPT), across the water/1,2-dichloroethane (1,2-DCE) interface was investigated electrochemically. The ionic partition diagram for MPPT was obtained from interpretation of the cyclic voltammograms. The apparent partition coefficient of MPPT was evaluated by the shaking-flask method under experimental conditions, while that for the protonated form of MPPT was calculated from its transfer potential obtained from the ionic partition diagram. It was suggested that the mechanism for transfer of MPPT across the water/1,2-DCE) interface depends on the pH of the aqueous phase. The parameters of the facilitated proton transfer across the water/1,2-DCE interface were evaluated as ...

2011-01-01

497

Exploring the potential energy surface for proton transfer in acetylacetone  

Energy Technology Data Exchange (ETDEWEB)

The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecular proton transfer reaction is studied using ab initio and DFT methods. The best estimate of the barrier governing proton transfer was found to be 3.4 kcal mol{sup -1} at the MP4(FC)/6-311 + G(2d,2p)//MP2(FC)/6-311 + G(2d,2p) level of theory. Six stationary points on the PES were characterized as well as the reaction paths connecting these points. Special attention paid to the pathway of intramolecular proton transfer reveals that the internal rotation of the methyl group adjacent to the carbonyl group and the proton transfer reaction are consecutive processes.

2004-11-15

498

A note on the flow and heat transfer enhancement in a channel with built-in winglet pair  

International Nuclear Information System (INIS)

Counter rotating longitudinal vortices produced by winglet in a channel are known to enhance heat transfer. In the present investigation the flow structure and heat-transfer enhancement by a winglet pair of non-zero thickness has been studied. A delta winglet pair type vortex generator is placed in a hydrodynamically developed and thermally developing laminar channel flow. Computations are done by solving the unsteady, three-dimensional, incompressible Navier-Strokes equations and energy equation using a modified Marker-and-Cell (MAC) method. The flow structure is complex and consists of main, corner and induced vortices. It is observed that as compared to a channel without winglets, the heat transfer is enhanced by 33% when single winglet is used and by 67% when a winglet pair is employed. Effects of thickness of the winglets and Reynolds number on the heat transfer augmentation are presented.

2007-04-01

499

A fundamental study of the heat transfer and flow situation around a spacer  

International Nuclear Information System (INIS)

This paper describes the heat transfer augmentation and flow situation around a single spacer (a circular cylinder) on a heated surface in a parallel plate duct in order to examine basically the effects of the spacer in the fuel elements of a High Temperature Gas-cooled Reactor. A thermosensitive liquid crystal film was used to clarify the effective region of the heat transfer. The mean Nusselt number, which was estimated within arbitrary distance from the spacer to the downstream direction, took a peak at the dimensionless distance X/D = 1 #approx# 3, and after that decreased gradually with flow direction. How heat transfer corresponds to the flow situation is also examined. The horseshoe vortex, produced around the spacer, affects the wake and contributes to the increase of the local heat transfer. (author).

1986-01-01