A method for the approximate calculation of the neutron physical lifetime of absorber materials with several absorbing nuclides was developed, and the lifetimes of various materials were determined as a function of the layer thickness. A crude economic comparison gives a survey on the favorable ...

... FLUORESCENT LIFETIME MEASUREMENTS OF RARE EARTH ELEMENTS ... vii Page 10. FLUORESCENT LIFETIME MEASUREMENTS ...

... Accession Number : ADA229865. Title : Fluorescent Lifetime Measurements of Rare Earth Elements in Gallium Arsenide. ...

The objective of the project was to establish the feasibility of extending the lifetime of fuel elements for the Ford Nuclear Reactor (FNR) by replacing current aluminide fuel with silicide fuel comprising a heavier uranium loading but with the same fissile enrichment of 19.5 wt% {sup 235}U. The project has focused on fuel designs where burnable ...

A solar collector unit is described including a corrugated absorber element coated with a reflectively selective coating; a plurality of thin, low mass, low thermal conductivity, thermal isolating elements for supporting the absorber element; and an insulation medium spaced from and generally ...

Fact sheet describing NREL CSP Program capabilities in the area of advanced reflector and absorber materials: evaluating performance, determining degradation rates and lifetime, and developing new coatings.

... 20 If the incoming electromagnetic wave is represented by ... metallic resonant absorber elements leading to an ... A tunable Continuous Wave (CW) and ...

The key elements of the Muon Ionization Cooling Experiment (MICE) cooling channel are the absorbers that are a part of the MICE absorber focus coil modules (AFC modules). The boundaries of room temperature solid absorbers are well defined. The density of most solid absorber materials is also ...

A BeO moderated reactor using slightly enriched uranium oxide as fuel was studied by the pulsed neutron source technique. The neutron lifetime was measured in two different cores without refiector, then attempts were made at the measurement of great negative reactivities introduced into the reactor under the following forms: decrease of the volume of the unreflected ...

... BG = Background Absorbance; AA = Atomic Absorbance. ... BG = Background Absorbance; AA = Atomic Absorbance. 3.6 Figure 3. Irregular Peak Profiles. ...

An incident radiation absorber/reflector assembly has a mounting housing to which is adjustably secured an absorber body and a reflector element. An entrance opening, aligned with the reflector element, is formed within the body. The entrance opening is c...

... ELEMENTS, INCLUDING STRONGLY ABSORBING TRACES, WERE ELIMINATED BY A PRELIMINARY MULTIELEMENT ANALYSIS AND A ...

Room-temperature recombination dynamics has been investigated in a large set of different Cu(In,Ga)Se2 absorber films and compared to the electrical device characteristics of the respective solar cell modules. For a given cell preparation process, a characteristic relation between the low-injection minority-carrier lifetime of the ...

... of the transition's upper and lower level lifetimes. ... and the self-absorbed integrated emission of the ... hydrogen lines from the Balmer series appear in ...

for extended lifetimes. We have begun evaluation of several new UV-screened polycarbonate sheet glazing constructions. This has involved interactions with several major...

An activator has a base on which is mounted an elastically deformable micromechanical element that has a section that is free to be displaced toward the base. An absorber of radioactively emitted particles is formed on the base or the displaceable section of the deformable element and a source is formed on the other of the displaceable ...

Building construction having at least one wall with an inner surface and an outer surface is described. A heat energy absorbing member is disposed outwardly of the outer surface for absorbing solar heat energy. Heat radiating members are disposed inwardly of the inner surface, and heat transfer elements extend through the wall. The ...

Large-Scale Fluid-Structure Modeling Approaches. Structure. Finite elements. Fluid. Boundary elements; Finite elements with absorbing boundary ...

This work gives a methodology for analyzing matroids with random element weights, with emphasis placed on independent, exponentially distributed element weights. The minimum weight basic element in such a structure is shown to be an absorbing state in a M...

... One of the two negative shunt inductors of inverter k01 can be absorbed into the shunt resonator inductance, while the other can be absorbed into a ...

... selectively absorb elements or compounds. Therefore, zeolites are highly useful as catalysts, molecular sieves, absorbants, or ion exchange materials. ...

Applying element specific drive-in treatments before the microwave reflection photo-conductive decay (�-PCD) analysis recombination centers can be assigned to metallic contaminants, which have a degrading influence on the recombination lifetime (?). Element specific information can further be obtained by variation of the injection ...

The Light Water Breeder Reactor (LWBR) was designed for a lifetime of 18,000 EFPH. Fuel element design was based on performance evaluations demonstrating adequacy for the design lifetime. Continued operation of LWBR beyond design lifetime required re-eval...

The method, algorithm and PRAKGER computer code complex used for calculating the lifetime of a heterogeneous reactor core with regular lattice of control elements are described. The method is based on the effective homogenization of a heterogeneous reacto...

From the present cosmic abundance of the light elements, one can obtain a lifetime bounds of LSP. From the consideration of deuterium, we obtain {tau}{sub {chi}}{>=}10{sup 6} s.

Lifetime measurements of the excited states of three GaAs semiconductors doped with the rare earth elements Erbium (Er), Praseodymium (Pr), and Thulium (Tm) has been studied using a pulsed nitrogen laser and germanium detector. The measurements were made ...

A measurement of the lifetime and capture rate of negative muons in various elements is reported. The timing system was calibrated in terms of the accurately known positive muon lifetime. The values obtained are in reasonable agreement with previous experimental data, and have a comparable accuracy. (auth)

Marginally trapped neutrons are a major source of systematic errors in storage experiments with ultra-cold neutrons (UCN): their energies slightly exceed the trapping potential and their storage lifetimes are of the same order of magnitude as the neutron ?-decay lifetime to be measured. Hence, they have to be removed before the actual neutron storage ...

The effectiveness of a three-element dynamic absorber and of dual dynamic absorbers in reducing the transmissibility across a simple spring-mass system at resonance has been investigated and shown to be considerably greater than that of the conventional d...

A metamaterial absorber for the terahertz regime: Design, fabrication and characterization Hu Tao1, USA. Contributed equally to this work. Willie.Padilla@bc.edu Abstract: We present a metamaterial coefficient = 2000 cm-1. These metamaterials are promising candidates as absorbing elements for thermally

The positron annihilation lifetimes of He-ion-irradiated Fe samples were measured by a pulsed positron beam technique. The relative thickness of the surface oxidation layer was measured by Auger microprobe measurements. Unirradiated samples with different surface oxidation layer thicknesses had very similar second lifetime component intensities, indicating ...

The Army Package Power Reactor (APPR-1) is currently operating with a control rod which contains a boron-bearing neutron absorber section, This component is a welded rectangular parallelepiped, in which the side consist of rolled austenitic stainless steel-clad presents details describing the design of the absorber section, selection of materials, ...

The reactor transfer function of HIFAR was measured at low power and compared with the calculated response to determine the prompt neutron lifetime. Lifetime values in the range 600 to 800 microseconds, depending on the position of absorbers within the core and reflector, were ob tained with an estimated error of less than 100 ...

A solar collector is disclosed comprised of a frame and a plurality of tubular collector elements. Each collector element is comprised of an outer transparent tube, a metallic absorber tube, and an intermediate transparent tube which encloses the absorber tube. The absorber tube is coated with ...

We present the design of a planar metamaterial absorber based on lumped elements, which shows a wide-band polarization-insensitive and wide-angle strong absorption. This absorber consists of metal electric resonators, the dielectric substrate, the metal film and lumped elements. The simulated ...

A coupler is described for absorber rods being suspended during operation of nuclear reactors which includes plurality of actuating elements being movable for individually and jointly releasing the coupler, the movement of each of the actuating elements for releasing the coupler being independently controllable.

In order to realize any of these potential fuel cycle cost savings from the fabrication of fewer, heavier loaded elements, the characteristics of the potential suitable burnable absorbers must be well understood. Boron and cadmium are the two leading cand...

... uncertainty in dynamic systems; Abstracts from ... ELEMENT ANALYSIS, VIBRATION ISOLATORS, SHOCK ABSORBERS, ABSTRACTS ...

... Abstract : The study of adsorbed enzyme properties serves not only as a method for modeling separate elements of biomembrane structure, but ...

... The absorption characteristics of the stack were simulated using COMSOL finite element modeling and theoretical analysis performed using ...

in power measurement applications, electromagnetic wave guides are sometimes ..... That is, the same equations apply in the duct and in the absorber ...

... Title : Electromagnetic Radiation Detector Utilizing an Electromagnetic Radiation Absorbing Element in a Mach-Zehnder Interferometer ...

The root cause of shifts was due to the type of adhesive used on the strain gage elements, which enabled moisture to be absorbed in the gage. ...

The positron lifetime technique of monitoring absorbed moisture is applied to several composites, including graphite/polymides which are candidates for high-temperature (over 260 C) applications. The experimental setup is a conventional fast-slow coincidence system wherein the positron lifetime is measured with respect to a reference ...

The Solar Heating and Lighting Program has set the goal of reducing the cost of solar water heating systems by at least 50%. An attractive approach to such large cost reduction is to replace glass and metal parts with less-expensive, lighter-weight, more-integrated polymeric components. The key challenge with polymers is to maintain performance and assure requisite durability for extended ...

Based on Hinode SOT/NFI observations with greatly improved spatial and temporal resolution and polarization sensitivity, the lifestory of the intranetwork (IN) magnetic elements are explored in a solar quiet region. A total of 2282 IN elements are followed from their appearance to disappearance and their fluxes measured. By tracing individual IN ...

Disclosed are a method and apparatus for regulating and shutting down a gas cooled nuclear reactor having a bed of spherical fuel elements, wherein regulation of the reactor is accomplished by a first set of absorber rods in the side reflector of the reactor, partial shutdown is achieved by a second set of absorber rods movable in the ...

A radiant surface combustor is disclosed that is comprised of a porous combustor element in close heat transfer relation with a heat transfer surface for absorbing radiant heat energy from the combustor element.

A radiant surface combustor is described comprising a porous combustor element in close heat transfer relation with a heat transfer surface for absorbing radiant heat energy from the combustor element.

An optical element for filtering infrared light for use in a radiometer is disclosed wherein at least one metalorganic infrared absorbing dye is at least partially dissolved homogeniously throughout a molded optical plastic.

Arrays of such cylinders allow greater freedom in the geometry ... and passes through the FSB elements. Because each element absorbs only in a ...

A novel composite neutronic reactor control element is offered. The element comprises a multiplicity of sections arranged in end-to-end relationship, each of the sections having a markedly different neutron-reactive characteristic. For example, a three-section control element could contain absorber, ...

We study the influence of pump current and absorber bias voltage on the pulse width and frequency of sustained pulsation in GaN-based multisection laser diodes. The observed frequencies and pulse widths range from 1.5 to 4.5 GHz and 90 to 18 ps, respectively. Negative absorber bias is found to reduce the pulsation frequency and increase the pulse width. ...

Metallic fuel elements irradiated in EBR-II at temperatures significantly higher than design, causing liquid phase attack of the cladding, were subsequently irradiated at normal operating temperatures to first breach. The fuel element lifetime was compared to that for elements not subjected to the over-temperature ...

Electric dipole matrix elements for 6p-nd, n=5, 6, 7, transitions in cesium are calculated using a relativistic all-order method. The resulting matrix elements are used to evaluate 5d lifetimes and 6p polarizabilities. The data are compared with experimental lifetime and polarizability measurements made by ...

A technique is presented for calculating the dose or energy absorbed in a material from a knowledge of the ..gamma.. radiation field and the composition of the material. The absorbed dose per unit exposure for various elements and the absorbed dose as a function of material composition and photon energy are ...

There is a need to calculate loss rates when trapped Van Allen radiation encounters inert orbiting material such as planetary rings and satellites. An analytic expression for the probability of a hit in a bounce encounter is available for all cases where the absorber is spherical and the particles are gyrotropically distributed on a cylindrical flux tube. The hit probability ...

There is a need to calculate loss rates when trapped Van Allen radiation encounters inert orbiting material such as planetary rings and satellites. An analytic expression for the probability of a hit in a bounce encounter is available for all cases where the absorber is spherical and the particles are gyrotropically distributed on a cylindrical flux tube. The hit probability ...

A vertex chamber for MAC was proposed to increase precision in the measurement of the B hadron and tau lepton lifetimes. Thin-walled aluminized mylar drift tubes were used for detector elements. A study of radiation hardness was conducted under the condit...

In the boundary element (BE) solution of wave propagation, infinite absorbing elements are introduced to minimize diffractions from truncated edges of models. This leads to a significant simplification and reduction of computational effort, especially for 3-D problems. The infinite Be absorbing boundary condition ...

This report describes current operations necessary to monitor an RD program element. It is written from the viewpoint of a Program Element Monitor (PEM). It includes activities performed by a PEM and information exchanged with a PEM during the lifetime of...

Improvements were made in both electrode technology and ceramic conductor quality to increase significantly the lifetime and thermal cycling capability of electrically conducting ceramic heater elements. These elements were operated in vacuum, inert and r...

Methyl chloride (MC) is the major natural source of chlorine in the stratosphere. Production has a seasonal cycle which couples with the shorter lifetime of tropospheric MC to produce nonuniform global mixing. As an absorber of infrared radiation, MC is o...

A huge amount of oxytetracycline (OTC) is used in aquaculture worldwide. Since it is poorly absorbed by the gastrointestinal system and has a relatively long lifetime, it is necessary to study its occurrence, distribution, transport, and fate in the associated environmental waters, its impact on th...

The present invention generally relates to luminescent and/or optically absorbing compositions and/or precursors to those compositions, including solid films incorporating these compositions/precursors, exhibiting increased luminescent lifetimes, quantum ...

The optoacoustic technique shows promise for pollution monitoring due to its small size and high sensitivity. This technique is fundamentally different from most spectroscopy in that absorbed energy is measured indirectly as a pressure change in the surrounding gas. Not all the a...

A huge amount of oxytetracycline (OTC) is used in aquaculture worldwide. Since it is poorly absorbed by the gastrointestinal system and has a long lifetime, it is an important task to monitor its distribution and fate in the marine environment and its impact on human and the biosphere. A portable ...

This paper presents an optimal design of a magnetorheological (MR) shock absorber based on finite element analysis. The MR shock absorber is constrained in a specific volume and the optimization problem identifies geometric dimensions of the shock absorber that minimize a multi-objective function. The objective ...

. Perfectly Matched Layers (PMLs) and an absorbing boundary condition are used to damp waves interacting of the electromagnetic interrogation problems introduced in [3]. Here we use perfectly matched layers (PMLs) as absorbing of interest. We use Perfectly Matched Layers to absorb incident waves without reflection and damp the ...

The concepts of radiation exposure dose, absorbed dose, and biological dose resulting from ionizing particles are reviewed. The units used in radiation measurements are defined, and the concept of electronic equilibrium is discussed. The Bragg-Gray cavity relation ls used to calculate the absorbed dose from measured ionlzation and to relate the ...

An absorber element is disclosed for the absorption of solar energy, which serves also as a heat exchanger for ambient air and forms the skin of a roof, wherein the outside facing surface of the element is substantially identical in appearance with that of a conventional roof covered with tiles or slates, and wherein the ...

A new dynamic vibration absorber combining a translational-type absorber and a rotational-type absorber is proposed for isolation of beam vibration under point or distributed harmonic excitation. Finite element analysis and Euler Bernouli beam theory are used for evaluation of the performance of vibration isolation ...

A wall element, comprising a solar collector which is arranged between two panes and which comprises a number of rotatable absorber plates is described. One side of the absorber plates is provided with a non-selective black coating and the other side is provided with a selective, heat-reflective layer. The absorber ...

The technique of measuring absorbed energy in accelerator elements under approximately 4.2 K helium temperatures is described. The distributions of absorbed energy have been measured in a model of magnet iron yoke at its irradiation with 2.55 GeV protons ...

Fuel, fertile material and/or absorber material containing particles for fuel and/or absorber elements in nuclear reactors are coated by a process comprising introducing thermally cleavable gases into the reaction space heated to an operating temperature of a fluidized bed unit provided with a gas inlet nozzle cooled with a cooling ...

Radiation damage to cryocooled protein crystals during x-ray structure determination has become an inherent part of macromolecular diffraction data collection at third-generation synchrotrons. Generally, radiation damage is an undesirable component of the experiment and can result in erroneous structural detail in the final model. The characterization of radiation damage thus has become an ...

We have previously demonstrated that phosphorescence lifetime imaging (PLI) allows for unbiased determination of absolute oxygen levels in homogeneously absorbing/scattering media. We computationally show that tomographic PLI can perform equally well in heterogeneous environments relying only on surface measurements of phosphorescence. PMID:18414531

Control rod materials, designs, and fabrication processes were compared for their relative economics. Control rod lifetime data were calculated with a simple approximation of nuclear worth depreciation. These data were used in conjunction with the estimated fabrication costs to determine the cost of using several absorber materials in a typical ...

The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about ...

Various solid state lasers such as Cr:LISAF, Yb:YAG, Nd:Vanadate, Ti:sapphire and Nd:YAG have in common a long lifetime of the laser level, which results in a tendency to Q-switching rather than pure mode-locking. These lasers are being used in a linear or ring cavity for intracavity sensing applications (displacements, rotation, electric and magnetic fields), and for ...

We have measured the emission lifetime of bacteriorhodopsin at physiological temperatures to be 15 +/- 3 ps using a technique which employs a mode-locked dye laser, a sum frequency light gate, and a continuous flow system. We observe no concentration dependence of the lifetime over the range of 1.1 X 10(-4) M to 1.0 X 10(-5) M. We conclude that the ...

CONTENTS: Analysis of the Finite Element Radiation Model Cone for Antenna Modeling; Accuracy of the Finite Element Method with Second Order Absorbing Boundary Conditions for the Solution of Aperture Radiation Problems; The FEMAX Finite Element Package for...

The fluorescence lifetime value of tryptophan residues varies by more than a factor of 100 in different proteins and is determined by several factors, which include solvent exposure and interactions with other elements of the protein matrix. Because of the variety of different elements that can alter the lifetime ...

The fluorescence lifetime value of tryptophan residues varies by more than a factor of 100 in different proteins and is determined by several factors, which include solvent exposure and interactions with other elements of the protein matrix. Because of the variety of different elements that can alter the lifetime ...

A finite-element Galerkin formulation has been developed to study attenuation of transverse magnetic (TM) waves propagating in two-dimensional S-curved ducts with absorbing walls. In the frequency range where the duct diameter and electromagnetic wave len...

The use of inorganic absorbers for the removal of a number of specified elements from aqueous waste streams has been studied. A worldwide review of the literature on the subject has been carried out and a number of processes identified at various stages o...

Infrared absorbing, air-bridge, structures are anticipated to be used in the next generation of ferroelectric uncooled infrared detectors. These structures will consist of resonant cavities with an absorbing bridge element, which contains the ferroelectri...

Infrared absorbing air-bridge structures are anticipated to be used in the next generation of ferroelectric uncooled infrared detectors. These structures will consist of resonant cavities with an absorbing bridge element, which contains the ferroelectric ...

During the course of normal operation, a particle accelerator can produce radionuclides in the adjacent soil and in the beam line elements through the interactions of accelerated particles and/or secondary particles produced in the beam absorbers, targets...

An approach to the development of a mathematical model for calculating heat release in absorbing rods of HTGR control elements using the HGR-50 reactor as an example is presented. On the basis of results of neutron-physical calculations of the reactor wit...

Thin-film photovoltaic (PV) technologies led by CdTe and Cu(In,Ga)Se2 (CIGS) are enjoying growing market share, due to their high performance and cost competitiveness, in the quest for renewable energy for the future. However the reliance on non-earth abundant elements tellurium and indium in these technologies presents a potential obstacle to ultimate terawatt deployment. We ...

Optical bistability in two-segment diode lasers with inhomogeneous injection is considered. Analytical solution of the rate-equation model gives a simple bistability condition. Slower carrier recombination in the absorber relative to the gain region is required for bistability when the gain and the absorber optical cross sections are equal. Carrier ...

Electric-dipole matrix elements for ns-n{sup '}p, nd-n{sup '}p, and 6d-4f transitions in Rb are calculated using a relativistic all-order method. A third-order calculation is also carried out for these matrix elements to evaluate the importance of the high-order many-body perturbation theory contributions. The all-order matrix ...

... behavior showed the difference between specimens depending on the alloying elements; vacancy migration temperature for pure Fe, Fe-5% Cr ...

... presented. Crystal doping methods used include boron ion implantation, diborane gas, and elemental gallium doping. ...

Large stars that are big and hot enough to fuse simple elements into heavier metals have shorter lifetimes, because they burn out of fuel faster. ...

We have conducted an experimental test at our XACT facility using an x-ray microcalorimeter with Ta/Au absorber and neutron transmutation doped germanium thermal sensor. The test was aimed at measuring the percentage of energy effectively thermalized after absorption of x-ray photons in superconducting tantalum. Moreover, in general, possible formation of long living ...

The author has compared the trap model to the absorber model by numerically simulating the responses of semiconductor lasers containing traps or absorbers with or without external optical feedback at low to moderate levels. He has discussed dependence of intensity oscillation frequency, onset of self-sustained pulsations and damping rate of relaxation ...