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Sample records for beam tracing method

  1. Reconstruction of Sound Source Pressures in an Enclosure Using the Phased Beam Tracing Method

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Ih, Jeong-Guon

    2009-01-01

    Source identification in an enclosure is not an easy task due to complicated wave interference and wall reflections, in particular, at mid-high frequencies. In this study, a phased beam tracing method was applied to the reconstruction of source pressures inside an enclosure at medium frequencies...... all the pressure histories at the field points, source-observer relations can be constructed in a matrix-vector form for each frequency. By multiplying the measured field data with the pseudo-inverse of the calculated transfer function, one obtains the distribution of source pressure. An omni....... First, surfaces of an extended source are divided into reasonably small segments. From each source segment, one beam is projected into the field and all emitted beams are traced. Radiated beams from the source reach array sensors after traveling various paths including the wall reflections. Collecting...

  2. Effects of source and receiver locations in predicting room transfer functions by a phased beam tracing method

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Ih, Jeong-Guon

    2012-01-01

    The accuracy of a phased beam tracing method in predicting transfer functions is investigated with a special focus on the positions of the source and receiver. Simulated transfer functions for various source-receiver pairs using the phased beam tracing method were compared with analytical Green’s...

  3. SYSTEMATIC ERROR REDUCTION: NON-TILTED REFERENCE BEAM METHOD FOR LONG TRACE PROFILER.

    Energy Technology Data Exchange (ETDEWEB)

    QIAN,S.; QIAN, K.; HONG, Y.; SENG, L.; HO, T.; TAKACS, P.

    2007-08-25

    Systematic error in the Long Trace Profiler (LTP) has become the major error source as measurement accuracy enters the nanoradian and nanometer regime. Great efforts have been made to reduce the systematic error at a number of synchrotron radiation laboratories around the world. Generally, the LTP reference beam has to be tilted away from the optical axis in order to avoid fringe overlap between the sample and reference beams. However, a tilted reference beam will result in considerable systematic error due to optical system imperfections, which is difficult to correct. Six methods of implementing a non-tilted reference beam in the LTP are introduced: (1) application of an external precision angle device to measure and remove slide pitch error without a reference beam, (2) independent slide pitch test by use of not tilted reference beam, (3) non-tilted reference test combined with tilted sample, (4) penta-prism scanning mode without a reference beam correction, (5) non-tilted reference using a second optical head, and (6) alternate switching of data acquisition between the sample and reference beams. With a non-tilted reference method, the measurement accuracy can be improved significantly. Some measurement results are presented. Systematic error in the sample beam arm is not addressed in this paper and should be treated separately.

  4. Phased Beam Tracing Method Using the Reflection Coefficient Calculated from the Absorption Coefficient

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Ih, Jeong-Guon; Rindel, Jens Holger

    The phased beam tracing method (PBTM) is a technique which can calculate the pressure impulse response instead of energy impulse response, by taking the phase information into account. Inclusion of the phase information can extend the application of beam tracing technique to the mid frequency range...... in spite of the fact that the usual assumptions of geometric acoustics still hold. In the calculation of pressure impulse response, it is essential to have the reflection characteristics of the surfaces in the enclosed space. There is a method to obtain the reflection coefficient of the surface using...... the measured surface impedance. However, it is not always possible to get the measured impedance data of the surface, so that a practical way of getting reflection characteristics is needed. Generally, in the architectural acoustics field, the absorption coefficients have been employed in the...

  5. A Study on the Characteristics of Phased Beam Tracing Method for the Acoustic Simulation of an Enclosure at Mid Frequencies

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Rindel, Jens Holger

    2006-01-01

    the phased method is advantageous compared to the conventional ray/beam tracing method: accurate prediction of early part of impulse response, better agreement with measured data, lower and extendable frequency range. This means that the technique can be employed in calculating the sound quality......High frequency acoustic analysis of an enclosure has been dealt with by geometrical acoustic techniques and low frequency response can be estimated by modal methods; however, mid frequency range has been a grey zone. The phased beam tracing method (PBTM) is one of the mid-frequency techniques...

  6. A numerical method for the ray-tracing of polarized beams

    International Nuclear Information System (INIS)

    A numerical method for solving the Thomas-BMT differential equation of spin motion is presented. It has been implemented in the ray-tracing code Zgoubi. This is illustrated by ray-tracing in the spectrometer SPES 2 and multiturn tracing of resonant depolarization in the synchrotron Saturne. (author) 7 refs.; 6 figs.; 1 tab

  7. A new method of measurement of trace elements by using particle beams

    International Nuclear Information System (INIS)

    A new method of measurement of light elements by using the particle beam from an accelerator was developed. This paper reports on the results of analyses of N-15 and O-18. The tandem accelerator of University of Tokyo was used to accelerate proton beam. The energy of protons was determined from the excitation curves of elastic scattering by N-15, O-18 and O-16. The scattering by O-16 was background count. Therefore, The measurement was made at the energy of small background and large true counting. Biological samples were examined. The linearity of counts with the concentration of N-15 and O-18 was confirmed. The cells which contain glycine (O-18, 71.8 percent) and methionine (N-15, 95 percent) were analyzed. The peaks of N-15 and O-18 were well separated from teh peaks by N-14 and O-16. The natural amounts of N-15 in adenine and O-18 in glucose were also measured. The resonance reaction method of measurement by using particle beam was developed. (Kato, T.)

  8. A new method of measuring the poloidal magnetic and radial electric fields in a tokamak using a laser-accelerated ion-beam trace probe.

    Science.gov (United States)

    Yang, X Y; Chen, Y H; Lin, C; Wang, L; Xu, M; Wang, X G; Xiao, C J

    2014-11-01

    Both the poloidal magnetic field (Bp) and radial electric field (Er) are significant in magnetic confinement devices. In this paper, a new method was proposed to diagnose both Bp and Er at the same time, which was named Laser-accelerated Ion-beam Trace Probe (LITP). This method based on the laser-accelerated ion beam, which has three properties: large energy spread, short pulse lengths, and multiple charge states. LITP can provide the 1D profiles, or 2D images of both Bp and Er. In this paper, we present the basic principle and some preliminary theoretical results. PMID:25430336

  9. An Approximate Treatment of Reflection Coefficient in the Phased Beam Tracing Method for the Simulation of Enclosed Sound Fields at Medium Frequencies

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Ih, Jeong-Guon; Rindel, Jens Holger

    2008-01-01

    surface and the complex wave number for describing the propagation characteristics. In this study, two types of approximate real reflection coefficients derived from the measured absorption coefficient were tested for a practical applicability. As a test example, pressure impulse responses and energy......The phased beam tracing method (PBTM) was suggested as a medium-frequency simulation technique for the calculation of impulse response, although main assumptions of geometric acoustics still hold. The phased method needs the reflection coefficient for characterizing the acoustic property of a...

  10. Advanced simulations of x-ray beam propagation through CRL transfocators using ray-tracing and wavefront propagation methods

    DEFF Research Database (Denmark)

    Baltser, Jana; Bergbäck Knudsen, Erik; Vickery, Anette;

    2011-01-01

    Compound refractive lenses (CRL) are widely used to manipulate synchrotron radiation beams. Accurate modelling of X-ray beam propagation through individual lenses and through "transfocators" composed of a large number of CRLs is of high importance, since it allows for comprehensive optimization o...

  11. Consideration of Wall Reflection and Diffraction in the Room Acoustic Prediction Using the Phased Beam Tracing Method

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2007-01-01

    diffraction is integrated into, the present method can even deal with the low to mid frequency range, which has been considered as the typical territory for the wave based methods for a long time. The capability of calculating a room transfer function enables this method to be used in the analysis, design...... suggestions are the use of approximated reflection coefficient and the integration with the theory of diffraction. This study aimed to improve the precision of the present method in mid frequency range and extend the applicability to the low frequency below Schroeder cutoff frequency. Because this method is...

  12. Status of multi-beam long trace-profiler development

    Science.gov (United States)

    Gubarev, Mikhail V.; Merthe, Daniel J.; Kilaru, Kiranmayee; Kester, Thomas; Ramsey, Brian; McKinney, Wayne R.; Takacs, Peter Z.; Dahir, A.; Yashchuk, Valeriy V.

    2013-09-01

    The multi-beam long trace profiler (MB-LTP) is under development at NASA's Marshall Space Flight Center. The traditional LTPs scans the surface under the test by a single laser beam directly measuring the surface figure slope errors. While capable of exceptional surface slope accuracy, the LTP single beam scanning has slow measuring speed. Metrology efficiency can be increased by replacing the single laser beam with multiple beams that can scan a section of the test surface at a single instance. The increase in speed with such a system would be almost proportional to the number of laser beams. The progress for a multi-beam long trace profiler development is presented.

  13. Documentation for TRACE: an interactive beam-transport code

    International Nuclear Information System (INIS)

    TRACE is an interactive, first-order, beam-dynamics computer program. TRACE includes space-charge forces and mathematical models for a number of beamline elements not commonly found in beam-transport codes, such as permanent-magnet quadrupoles, rf quadrupoles, rf gaps, accelerator columns, and accelerator tanks. TRACE provides an immediate graphic display of calculative results, has a powerful and easy-to-use command procedure, includes eight different types of beam-matching or -fitting capabilities, and contains its own internal HELP package. This report describes the models and equations used for each of the transport elements, the fitting procedures, and the space-charge/emittance calculations, and provides detailed instruction for using the code

  14. Process tracing methods: foundation and guidelines

    DEFF Research Database (Denmark)

    Beach, Derek; Pedersen, Rasmus Brun

    Derek Beach and Rasmus Brun Pedersen have written the first practical guide for using process tracing in social science research. The book introduces a more refined definition of what process tracing methods are, differentiating it into three variants, showing the uses and limitations of each. This...... develops a set of tools for how the three variants of process tracing methods can be used in research, introducing a set of practical guidelines for each stage of the research process (working with theories, developing empirical tests, working with evidence, and case selection strategies, nesting case...

  15. Development of Multi-Beam Long Trace Profiler

    Science.gov (United States)

    Kilaru, Kiranmayee; Merthe, Daniel J.; Ali, Zulfiqar; Gubarev, Mikhail V.; Kester, Thomas; McKinney, Wayne R.; Takacs, Peter Z.; Yashchuk, Valeriy V.

    2011-01-01

    In order to fulfill the angular resolution requirements and make the performance goals for future NASA missions feasible, it is crucial to develop instruments capable of fast and precise figure metrology of x-ray optical elements for further correction of the surface errors. The Long Trace Profilometer (LTP) is an instrument widely used for measuring the surface figure of grazing incidence X-ray mirrors. In the case of replicated optics designed for x-ray astronomy applications, such as mirrors and the corresponding mandrels have a cylindrical shape and their tangential profile is parabolic or hyperbolic. Modern LTPs have sub-microradian accuracy, but the measuring speed is very low, because the profilometer measures surface figure point by point using a single laser beam. The measurement rate can be significantly improved by replacing the single optical beam with multiple beams. The goal of this study is to demonstrate the viability of multi-beam metrology as a way of significantly improving the quality and affordability of replicated x-ray optics. The multi-beam LTP would allow one- and two-dimensional scanning with sub-microradian resolution and a measurement rate of about ten times faster compared to the current LTP. The design details of the instrument's optical layout and the status of optical tests will be presented.

  16. Trace element fingerprinting of jewellery rubies by external beam PIXE

    International Nuclear Information System (INIS)

    External beam PIXE analysis allows the non-destructive in situ characterisation of gemstones mounted on jewellery pieces. This technique was used for the determination of the geographical origin of 64 rubies set on a high-valued necklace. The trace element content of these gemstones was measured and compared to that of a set of rubies of known sources. Multivariate statistical processing of the results allowed us to infer the provenance of rubies: one comes from Thailand/Cambodia deposit while the remaining are attributed to Burma. This highlights the complementary capabilities of PIXE and conventional geological observations

  17. Trace element fingerprinting of jewellery rubies by external beam PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Calligaro, T. E-mail: calli@culture.nl; Poirot, J.-P.; Querre, G

    1999-04-02

    External beam PIXE analysis allows the non-destructive in situ characterisation of gemstones mounted on jewellery pieces. This technique was used for the determination of the geographical origin of 64 rubies set on a high-valued necklace. The trace element content of these gemstones was measured and compared to that of a set of rubies of known sources. Multivariate statistical processing of the results allowed us to infer the provenance of rubies: one comes from Thailand/Cambodia deposit while the remaining are attributed to Burma. This highlights the complementary capabilities of PIXE and conventional geological observations.

  18. Trace element fingerprinting of jewellery rubies by external beam PIXE

    Science.gov (United States)

    Calligaro, T.; Poirot, J.-P.; Querré, G.

    1999-04-01

    External beam PIXE analysis allows the non-destructive in situ characterisation of gemstones mounted on jewellery pieces. This technique was used for the determination of the geographical origin of 64 rubies set on a high-valued necklace. The trace element content of these gemstones was measured and compared to that of a set of rubies of known sources. Multivariate statistical processing of the results allowed us to infer the provenance of rubies : one comes from Thailand/Cambodia deposit while the remaining are attributed to Burma. This highlights the complementary capabilities of PIXE and conventional gemological observations.

  19. Two-Dimensional Beam Tracing from Visibility Diagrams for Real-Time Acoustic Rendering

    Directory of Open Access Journals (Sweden)

    Antonacci F

    2010-01-01

    Full Text Available We present an extension of the fast beam-tracing method presented in the work of Antonacci et al. (2008 for the simulation of acoustic propagation in reverberant environments that accounts for diffraction and diffusion. More specifically, we show how visibility maps are suitable for modeling propagation phenomena more complex than specular reflections. We also show how the beam-tree lookup for path tracing can be entirely performed on visibility maps as well. We then contextualize such method to the two different cases of channel (point-to-point rendering using a headset, and the rendering of a wave field based on arrays of speakers. Finally, we provide some experimental results and comparisons with real data to show the effectiveness and the accuracy of the approach in simulating the soundfield in an environment.

  20. Two-Dimensional Beam Tracing from Visibility Diagrams for Real-Time Acoustic Rendering

    Science.gov (United States)

    Antonacci (Eurasip Member), F.; Sarti (Eurasip Member), A.; Tubaro (Eurasip Member), S.

    2010-12-01

    We present an extension of the fast beam-tracing method presented in the work of Antonacci et al. (2008) for the simulation of acoustic propagation in reverberant environments that accounts for diffraction and diffusion. More specifically, we show how visibility maps are suitable for modeling propagation phenomena more complex than specular reflections. We also show how the beam-tree lookup for path tracing can be entirely performed on visibility maps as well. We then contextualize such method to the two different cases of channel (point-to-point) rendering using a headset, and the rendering of a wave field based on arrays of speakers. Finally, we provide some experimental results and comparisons with real data to show the effectiveness and the accuracy of the approach in simulating the soundfield in an environment.

  1. Modeling of reverberation in shallow-water based on the beam tracing theory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A reverberation intensity model and a reverberation series model in shallow-water based on the beam tracing theory were presented.The brief theoretical deduction to compute reverberation intensity was given,and the results were compatible with the measured data. The reverberation series simulation method was built and its characteristics were tested with the measured data and other results that had been verified.The studies show that the reverberation intensity model can be used to forecast shallow-water...

  2. Method of electron beam investigation

    Directory of Open Access Journals (Sweden)

    М. V. Derenovsky

    1967-12-01

    Full Text Available In this article the possibility of electron beam testing by a modified method of moving right edge is considered. The description of the working set made for the continuous indication of radial current density distribution on an oscilloscope is given. As an exemple the results of beam measurement under continuous operation are presented.

  3. X-ray trace element analysis with positive ion beams

    International Nuclear Information System (INIS)

    A new trace element analysis having the advantage that many elements may be detected in a single measurement, based on positive charged particle induced X-ray florescence and on the production of X-rays by heavy ions, is described. Because of the large cross-sections for the production of discrete X-ray and the low yield of continuum radiation, positive charged particle X-ray florescence is a competitive, fast, analytic tool. In the experiment a beam of positive charged particles from an accelerator was directed toward a target. X-rays induced by the bombardment were detected by a Si(Li) detector the ouput from which was amplified and sorted in a multichannel analyzer. For rapid data handling and analysis, the multichannel analyzer or ADC unit was connected to an on-line computer. A large variety of targets prepared in collaboration with the oceanographers have been studied and spectra obtained for different particles having the same velocity are presented to show that the yield of discrete X-rays increases at least as rapidly as Z2. While protons of several MeV appear to be already competitive further advantage may be gained by heavy ions at lower energies since the continuum is reduced while the peak ''signals'' retain strength due to the Z2 dependence. (S.B.)

  4. Method for splitting low power laser beams

    Energy Technology Data Exchange (ETDEWEB)

    Pierscionek, B.K. (University of Melbourne, Optometry Department, Parkville, Victoria 3052, Australia (AU))

    1990-04-01

    A new method for producing parallel rays from a laser beam using a cylindrical lens and pinholes is presented. This method can produce a greater number of emergent rays than using a {ital beam} {ital splitter}.

  5. Combined radioactivation methods in determining trace elements

    International Nuclear Information System (INIS)

    The authors have devised a method of radioactivation analysis (RAA) for determining 32 elements by NAA, proton-activation analysis (PAA), and emission spectral analysis (ESA). Here they examine element distributions in certain plants by NAA, PAA, and DAA (deuteron activation analysis) as described elsewhere. The results are compared with those from activation analysis (AA) and ESA. The authors used five species of medicinal plant: Plantago Major L, Salvia officinalis L., Artemisia absinthium L., Alhagi Persarum, and Eremurus. They used referenced methods for preparing the samples, irradiating them in the reactor or cyclotron, and measuring the radioactivity. The γ-ray spectra for the activated samples from all the plants gave peaks representing 24Na, 42K, 56Mn, 140La, 82Br, 124Sb, 46Sc, 59Fe, 198Au, 139Ce, 153Sm, 86Rb, 65Zn, 60Co, and 147MSn. The concentrations of Fe, Sb, Sn, Zn, Rb, Co were determined when the irradiated samples have been kept for 10 days. To determine Ca, Fe, Ti, Cu, Zn, and Sr, ash disks were irradiated by proton and deuteron beams in a cyclotron, where they recorded radiation from the 48Sc, 56Co, 48V, 65Zn, 67Ga, 88Y. The conclusions are that all these plants and the parts of them accumulate the elements in different ways

  6. Improved beam propagation method equations.

    Science.gov (United States)

    Nichelatti, E; Pozzi, G

    1998-01-01

    Improved beam propagation method (BPM) equations are derived for the general case of arbitrary refractive-index spatial distributions. It is shown that in the paraxial approximation the discrete equations admit an analytical solution for the propagation of a paraxial spherical wave, which converges to the analytical solution of the paraxial Helmholtz equation. The generalized Kirchhoff-Fresnel diffraction integral between the object and the image planes can be derived, with its coefficients expressed in terms of the standard ABCD matrix. This result allows the substitution, in the case of an unaberrated system, of the many numerical steps with a single analytical step. We compared the predictions of the standard and improved BPM equations by considering the cases of a Maxwell fish-eye and of a Luneburg lens. PMID:18268554

  7. Method for removing trace pollutants from aqueous solutions

    Science.gov (United States)

    Silver, G.L.

    A method of substantially removing a trace metallic contaminant from a liquid containing the same comprises: adding an oxidizing agent to a liquid containing a trace amount of a metallic contaminant of a concentration of up to about 0.1 ppM, and separating the homogeneously precipitated product from the liquid.

  8. The trace minimization method for the symmetric generalized eigenvalue problem

    Science.gov (United States)

    Sameh, Ahmed; Tong, Zhanye

    2000-11-01

    In this paper, the trace minimization method for the generalized symmetric eigenvalue problems proposed by Sameh and Wisniewski [35] is reviewed. Convergence of an inexact trace minimization algorithm is established and a variant of the algorithm that uses expanding subspaces is introduced and compared with the block Jacobi-Davidson algorithm.

  9. Trace element analysis of placentas of alcoholics and controls with external beam PIXE

    International Nuclear Information System (INIS)

    External beam PIXE analysis with a proton beam of 2.4 MeV was used to study trace element concentrations in human placentas. The aim was to check the suitability of PIXE analysis regarding soft tissue samples. The elements of interest (Fe, Cu, Zn, Se, Br, Rb, and Sr) were easily detected. A comparison was made with placental samples of alcoholics and controls to determine whether trace element concentrations in the placenta play a role in the pathogenesis of fetal alcohol syndrome. (author)

  10. A Non-invasive Method of Tracing Spiral Tips

    Institute of Scientific and Technical Information of China (English)

    王凯; 毛晓明; 欧阳颀

    2001-01-01

    A new method is developed to trace the tip of spiral waves in an excitable medium. The information of a spiraltip movement is obtained from only six probes. This method can trace the tip of a simple rotating spiral as wellas a complex spiral tip movement. More importantly, it can be used to distinguish between a spiral and a targetwave. The method is checked with data by experiments and numerical simulations, and found to be successful.

  11. Standardization of C-14 by tracing method

    International Nuclear Information System (INIS)

    The standardization of a 14C radioactive solution by means of the efficiency tracing technique is described. The 14C is a beta pure emitter with endpoint energy of 156 keV decaying to the ground state of 14N. The activity measurement was performed in a 4πβ-γ coincidence system, measuring the pure beta emitter mixed with a beta gamma emitter, which provides the beta detection efficiency. The radionuclide 60Co, which decays by beta particle followed by two gamma rays, was used as tracer and the efficiency was obtained by selecting the 1173 keV plus 1332 keV total energy absorption peak at the gamma channel. Known aliquots of the tracer, previously standardized by 4πβ (PC)-γ coincidence, were mixed with known aliquots of 14C. The sources of 14C + 60Co were prepared by dropping known aliquots from each radioactive solution. The events were registered by a Software Coincidence System (SCS). The activity of the solution was determined by using the extrapolation technique, changing the beta efficiency by pulse height discrimination. In order to determine the final activity, a Monte Carlo simulation was used to calculate the extrapolation curve. All the uncertainties involved were treated rigorously, by means of the covariance analysis methodology. Measurements using a HIDEX, a commercial liquid scintillator system, were carried out and the results were compared with the tracing technique, showing a good agreement. (author)

  12. METHOD OF ELECTRON BEAM PROCESSING

    DEFF Research Database (Denmark)

    2003-01-01

    As a rule, electron beam welding takes place in a vacuum. However, this means that the workpieces in question have to be placed in a vacuum chamber and have to be removed therefrom after welding. This is time−consuming and a serious limitation of a process the greatest advantage of which is the...... option of welding workpieces of large thicknesses. Therefore the idea is to guide the electron beam (2) to the workpiece via a hollow wire, said wire thereby acting as a prolongation of the vacuum chamber (4) down to workpiece. Thus, a workpiece need not be placed inside the vacuum chamber, thereby...... exploiting the potential of electron beam processing to a greater degree than previously possible, for example by means of electron beam welding...

  13. Development of visual beam adjustment method for cyclotron

    International Nuclear Information System (INIS)

    We have developed a computer-based visual assistance system for JAERI AVF cyclotron operation. This system provides a CRT display about the cyclotron beam trajectories, feasible setting regions (FSRs), and search traces designed to improve beam parameter adjustment. As a result of the test in actual operation, it was realized that simulated beam trajectories and FSRs nearly agree with actual beam conditions. (author)

  14. Trace element mapping in Parkinsonian brain by quantitative ion beam microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barapatre, Nirav, E-mail: barapatre@physik.uni-leipzig.d [Nukleare Festkoerperphysik, Universitaet Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Morawski, Markus [Paul-Flechsig-Institut fuer Hirnforschung, Universitaet Leipzig, Jahnalle 59, 04109 Leipzig (Germany); Butz, Tilman; Reinert, Tilo [Nukleare Festkoerperphysik, Universitaet Leipzig, Linnestr. 5, 04103 Leipzig (Germany)

    2010-06-15

    The role of iron in the pathogenesis of the Parkinson's disease (PD) is a current subject of research in Neurochemistry, since an abnormal increase in iron is reported in the substantia nigra (SN) of Parkinsonian patients. A severe loss of the cells containing dopamine in the SN in the PD has also drawn attention towards the function of a browny-black pigment called neuromelanin, which accumulates predominantly in these dopaminergic neurons. The neuromelanin has an ability to chelate metal ions, which, in free state, may cause considerable damage to cells by reacting with their lipid-rich membranes. However, it could also potentiate free radical production if it releases the bound metal ions. The highly sensitive and non-destructive micro-PIXE method suits best to quantify and map the trace elements in the SN. The accuracy in charge measurement for such microanalysis studies is of utmost importance for quantitative analysis. Since a Faraday cup is usually placed behind the thin biological sample to measure the charge, the primary and the secondary electrons, knocked out from the sample by traversing ion beam, hamper an exact charge determination. Hence, a new non-interceptive technique was developed for precise charge measurement and for continuous monitoring of beam current.

  15. Trace element mapping in Parkinsonian brain by quantitative ion beam microscopy

    International Nuclear Information System (INIS)

    The role of iron in the pathogenesis of the Parkinson's disease (PD) is a current subject of research in Neurochemistry, since an abnormal increase in iron is reported in the substantia nigra (SN) of Parkinsonian patients. A severe loss of the cells containing dopamine in the SN in the PD has also drawn attention towards the function of a browny-black pigment called neuromelanin, which accumulates predominantly in these dopaminergic neurons. The neuromelanin has an ability to chelate metal ions, which, in free state, may cause considerable damage to cells by reacting with their lipid-rich membranes. However, it could also potentiate free radical production if it releases the bound metal ions. The highly sensitive and non-destructive micro-PIXE method suits best to quantify and map the trace elements in the SN. The accuracy in charge measurement for such microanalysis studies is of utmost importance for quantitative analysis. Since a Faraday cup is usually placed behind the thin biological sample to measure the charge, the primary and the secondary electrons, knocked out from the sample by traversing ion beam, hamper an exact charge determination. Hence, a new non-interceptive technique was developed for precise charge measurement and for continuous monitoring of beam current.

  16. Ion Beam Energy Calibration Method for Accelerator

    International Nuclear Information System (INIS)

    Ion beam energy calibration methods, i e : nuclear reaction method, magnetic field method and calorimeter method were elaborated and studied from its advantage and disadvantage in this paper. Ion beam energy calibration method for accelerator using the method of magnetic field on 3 MV Tandem Accelerator have been carried out at Tiara, JAERI, Japan. The result showed that the energy of ion beam current is 43.56 keV. The result of study conclude that nuclear reaction method generally used to calibrate ion beam energy at the accelerator of energy larger than 2 MeV, calorimetric method for the accelerator electron including linac, magnetic field method for all particle type of accelerator. (author)

  17. Particle beam injector system and method

    Science.gov (United States)

    Guethlein, Gary

    2013-06-18

    Methods and devices enable coupling of a charged particle beam to a radio frequency quadrupole accelerator. Coupling of the charged particle beam is accomplished, at least in-part, by relying on of sensitivity of the input phase space acceptance of the radio frequency quadrupole to the angle of the input charged particle beam. A first electric field across a beam deflector deflects the particle beam at an angle that is beyond the acceptance angle of the radio frequency quadrupole. By momentarily reversing or reducing the established electric field, a narrow portion of the charged particle beam is deflected at an angle within the acceptance angle of the radio frequency quadrupole. In another configuration, beam is directed at an angle within the acceptance angle of the radio frequency quadrupole by the first electric field and is deflected beyond the acceptance angle of the radio frequency quadrupole due to the second electric field.

  18. Ion beam sputter implantation method

    International Nuclear Information System (INIS)

    By means of ion beam atomizing or sputtering an integrally composed coating, the composition of which continuously changes from 100% of the substrate to 100% of the coating, can be surfaced on a substrate (e.g. molten quartz on plastic lenses). In order to do this in the facility there is directed a primary beam of accelerated noble gas ions on a target from the group of the following materials: SiO2, Al2O3, Corning Glass 7070, Corning Glass 7740 or borosilicate glass. The particles leaving the target are directed on the substrate by means of an acceleration potential of up to 10 KV. There may, however, be coated also metal layers (Ni, Co) on a mylar film resulting in a semireflecting metal film. (RW)

  19. Dynamic vacuum analysis for APS high heat flux beamline front ends using optical ray-tracing simulation methods

    International Nuclear Information System (INIS)

    The high-power and high-flux x-ray beams produced by third generation synchrotron radiation sources such as the Advanced Photon Source (APS) can cause significantly high gas desorption rates on beamline front-end components if beam missteering occurs. The effect of this gas desorption needs to be understood for dynamic vacuum analysis. To simulate beam missteering conditions, optical ray-tracing methods have been employed. The results of the ray-tracing analysis have been entered into a system-oriented vacuum program to provide dynamic vacuum calculations for determination of pumping requirements for the beamline front-ends. The APS will provide several types of synchrotron radiation sources, for example, undulators, wigglers, and bending magnets. For the purpose of this study, the wiggler source was chosen as a ''worst case'' scenario due to its high photon flux, high beam power, and relatively large beam cross section

  20. Dynamic vacuum analysis for APS high heat flux beamline front ends using optical ray-tracing simulation methods

    International Nuclear Information System (INIS)

    The high-power and high-flux x-ray beams produced by third generation synchrotron radiation sources such as the Advanced Photon Source (APS) can cause significantly high gas desorption rates on beamline front-end components if beam missteering occurs. The effect of this gas desorption needs to be understood for dynamic vacuum analysis. To simulate beam missteering conditions, optical ray-tracing methods have been employed. The results of the ray-tracing analysis have been entered into a system-oriented vacuum program to provide dynamic vacuum calculations for determination of pumping requirements for the beamline front-ends. The APS will provide several types of synchrotron radiation sources, for example, undulators, wigglers, and bending magnets. For the purpose of this study, the wiggler source was chosen as a worst case scenario due to its high photon flux, high beam power, and relatively large beam cross section

  1. EQUAL OPTICAL PATH BEAM SPLITTERS BY USE OF AMPLITUDE-SPLITTING AND WAVEFRONT-SPLITTING METHODS FOR PENCIL BEAM INTERFEROMETER.

    Energy Technology Data Exchange (ETDEWEB)

    QIAN,S.TAKACS,P.

    2003-08-03

    A beam splitter to create two separated parallel beams is a critical unit of a pencil beam interferometer, for example the long trace profiler (LTP). The operating principle of the beam splitter can be based upon either amplitude-splitting (AS) or wavefront-splitting (WS). For precision measurements with the LTP, an equal optical path system with two parallel beams is desired. Frequency drift of the light source in a non-equal optical path system will cause the interference fringes to drift. An equal optical path prism beam splitter with an amplitude-splitting (AS-EBS) beam splitter and a phase shift beam splitter with a wavefront-splitting (WS-PSBS) are introduced. These beam splitters are well suited to the stability requirement for a pencil beam interferometer due to the characteristics of monolithic structure and equal optical path. Several techniques to produce WS-PSBS by hand are presented. In addition, the WS-PSBS using double thin plates, made from microscope cover plates, has great advantages of economy, convenience, availability and ease of adjustment over other beam splitting methods. Comparison of stability measurements made with the AS-EBS, WS-PSBS, and other beam splitters is presented.

  2. Trace determination of sulfur and beryllium by activation in an oxygen-18 ion beam

    International Nuclear Information System (INIS)

    A novel method for determining traces of sulfur and beryllium is described. The reaction 32S(18O,t)47V is selective if using a 39 MeV 18O6+ beam. The detection limit is 3 ppm in an iron matrix and a precision of +-15% has been achieved for samples with 15 to 20 ppm sulfur. In the case of beryllium determination, two reactions were studied, namely 9Be(18O,2α)19O and 9Be(18O,d)25Na. At 25 MeV 18O5+, the first reaction is completely selective and yields a 5 ng detection limit for a 5 minutes irradiation. Boron is a nuclear interference when using the second reaction which yields a 110 ng detection limit in the same conditions. An irradiation chamber has been constructed that allows to decrease these limits. The technique was tested by analyzing two standard materials (NBS-SRM 394 and IRSID 508-1) whose sulfur content is certified. The results obtained by analyzing a biological sample (NBS-SRM 1571) for sulfur and a metallic sample Cu-Be for beryllium, are discussed

  3. Intradermal Alcian-Blue Injection Method to Trace Acupuncture Meridians

    OpenAIRE

    Baeckkyoung Sung; Min-Su Kim; Vyacheslav Ogay; Dae-In Kang; Kwang-Sup Soh

    2008-01-01

    Objective : In this article, we report on the intradermal Alcian blue staining method for tracing the meridians of acupuncture. Methods : 1% Alcian blue solution was injected into acupoints by using a 0.5mL insulin syringe with a 31-gauge needle, then the skin was incised and was observed under a stereoscopic microscope. The specimens were examined by using immunohistochemical methods and were observed under a confocal laser scanning microscope. Results : A threadlike structure, which w...

  4. Recent advances in chemical engineering. Tracers and tracing methods

    International Nuclear Information System (INIS)

    The first congress on 'tracers and tracing methods' has taken place in Nancy in November 1998. It has been a successful national event with more than 100 participants and 65 presentations. The applications of radiotracers in different industries have been studied. The target participants were the researchers, engineers and technologists of various industrial and research sectors

  5. Simplified method for trace anomaly calculations in d≤6

    International Nuclear Information System (INIS)

    We discuss a simplified method for computing trace anomalies in dimensions d≤6. It is known that in the quantum mechanical approach trace anomalies in d dimensions are given by a (d/2+1)-loop computation in an auxiliary 1D sigma model with arbitrary geometry. We show how one can obtain the same information using a simpler (d/2)-loop calculation on an arbitrary geometry supplemented by a (d/2+1)-loop calculation on the simplified geometry of a maximally symmetric space

  6. Development of visual beam adjustment method for cyclotron

    International Nuclear Information System (INIS)

    We have developed a computer-based visual assistance system for JAERI AVF-cyclotron operation. This system provides a CRT display about the cyclotron beam trajectories, feasible setting regions (FSR's), and search traces designed to enhance beam parameter adjustment. As a result of the test in actual operation, it was realized that simulated beam trajectories and FSR's were nearly agreeable with actual beam condition in the axial injection block and the extraction block. (author)

  7. Simulation of radiation damping in rings, using stepwise ray-tracing methods

    International Nuclear Information System (INIS)

    The ray-tracing code Zgoubi computes particle trajectories in arbitrary magnetic and/or electric field maps or analytical field models. It includes a built-in fitting procedure, spin tracking, many Monte Carlo processes. The accuracy of the integration method makes it an efficient tool for multi-turn tracking in periodic machines. Energy loss by synchrotron radiation, based on Monte Carlo techniques, had been introduced in Zgoubi in the early 2000s for studies regarding the linear collider beam delivery system. However, only recently has this Monte Carlo tool been used for systematic beam dynamics and spin diffusion studies in rings, including the eRHIC electron-ion collider project at the Brookhaven National Laboratory. Some beam dynamics aspects of this recent use of Zgoubi capabilities, including considerations of accuracy as well as further benchmarking in the presence of synchrotron radiation in rings, are reported here

  8. Simulation of radiation damping in rings, using stepwise ray-tracing methods

    Science.gov (United States)

    Méot, F.

    2015-06-01

    The ray-tracing code Zgoubi computes particle trajectories in arbitrary magnetic and/or electric field maps or analytical field models. It includes a built-in fitting procedure, spin tracking, many Monte Carlo processes. The accuracy of the integration method makes it an efficient tool for multi-turn tracking in periodic machines. Energy loss by synchrotron radiation, based on Monte Carlo techniques, had been introduced in Zgoubi in the early 2000s for studies regarding the linear collider beam delivery system. However, only recently has this Monte Carlo tool been used for systematic beam dynamics and spin diffusion studies in rings, including the eRHIC electron-ion collider project at the Brookhaven National Laboratory. Some beam dynamics aspects of this recent use of Zgoubi capabilities, including considerations of accuracy as well as further benchmarking in the presence of synchrotron radiation in rings, are reported here.

  9. Simulation of radiation damping in rings, using stepwise ray-tracing methods

    International Nuclear Information System (INIS)

    The ray-tracing code Zgoubi computes particle trajectories in arbitrary magnetic and/or electric field maps or analytical field models. It includes a built-in fitting procedure, spin tracking many Monte Carlo processes. The accuracy of the integration method makes it an efficient tool for multi-turn tracking in periodic machines. Energy loss by synchrotron radiation, based on Monte Carlo techniques, had been introduced in Zgoubi in the early 2000s for studies regarding the linear collider beam delivery system. However, only recently has this Monte Carlo tool been used for systematic beam dynamics and spin diffusion studies in rings, including eRHIC electron-ion collider project at the Brookhaven National Laboratory. Some beam dynamics aspects of this recent use of Zgoubi capabilities, including considerations of accuracy as well as further benchmarking in the presence of synchrotron radiation in rings, are reported here

  10. Effective beam method for element concentrations

    International Nuclear Information System (INIS)

    A method to evaluate chemical element concentrations in samples by generating an effective polychromatic beam using as initial input real monochromatic beam data is presented. There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s)

  11. Effective beam method for element concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Tolhurst, Thomas; Barbi, Mauricio, E-mail: barbi@uregina.ca [University of Regina (Canada); Tokaryk, Tim [Royal Saskatchewan Museum (Canada)

    2015-01-29

    A method to evaluate chemical element concentrations in samples by generating an effective polychromatic beam using as initial input real monochromatic beam data is presented. There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s)

  12. Method for charged particle beam acceleration

    International Nuclear Information System (INIS)

    The method of charged particle beam acceleration based on its resonance interaction with electromagnetic field of travelling wave is suggested. The electron beam is injected into waveguide in which longitudinal magnetic field and electromagnetic wave are excited. With the purpose of reducing HF-power losses in the waveguide walls, the azimuthal particle motion is synchronized with azimuthal change of longitudinal component of electric field of the accelerating electromagnetic wave. The suggested method permits to increase the efficiency and shunting resistance of the accelerating waveguide by reducing its boundary surface

  13. AIR CONVECTION NOISE OF PENCIL-BEAM INTERFERMETER FOR LONG TRACE PROFILER.

    Energy Technology Data Exchange (ETDEWEB)

    YASHCHUK, V.V.; IRICK, S.C.; MACDOWELL, A.A.; MCKINNEY, W.R.; TAKACS, P.Z.

    2006-08-14

    In this work, we investigate the effect of air convection on laser-beam pointing noise essential for the long trace profiler (LTP). We describe this pointing error with noise power density (NPD) frequency distributions. It is shown that the NPD spectra due to air convection have a very characteristic form. In the range of frequencies from {approx}0.05 Hz to {approx}0.5 Hz, the spectra can be modeled with an inverse-power-law function. Depending on the intensity of air convection that is controlled with a resistive heater of 100 to 150 mW along a one-meter-long optical path, the power index lies between 2 and 3 at an overall rms noise of {approx}0.5 to 1 microradian. The efficiency of suppression of the convection noise by blowing air across the beam optical path is also discussed. Air-blowing leads to a white-noise-like spectrum. Air blowing was applied to the reference channel of an LTP allowing demonstration of the contribution of air convection noise to the LTP reference beam. The ability to change (with the blowing technique presented) the spectral characteristics of the beam pointing noise due to air convection allows one to investigate the contribution of the convection effect, and thus make corrections to the power spectral density spectra measured with the LTP.

  14. Ray tracing studies of a complete plane grating monochromator beam line

    International Nuclear Information System (INIS)

    Optical design of a plane grating monochromator beam line for X-ray spectroscopic studies to be installed on Indus-1 is studied using ray tracing technique. The main components of the beam line are pre- and post-elliptical mirrors and the plane mirror-grating dispersing system. The ideal position of the optical components are decided by using our analytical formulation of the Riemer's kinetic principle for reflecting synchrotron radiation onto the same spot of the dispersing grating. The program is developed indigenously and can be used on a PC. The tangent error and micro roughness of the mirrors is explicitly accounted for in the program. The wavelength dependent absorption of radiation at the different reflecting surfaces is also included for calculations of the optical throughput. The dependence of the final image line shape and resolution on various beam line parameters is calculated. The results are useful in deciding the tolerances of the various beam line components and their positions. (author). 8 figs., 4 tabs., 13 refs., 1 appendix

  15. Application of the radioreagent method for trace determinatior of lead

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, A.M.; Saiki, M.; Lima, F.W. (Comissao Nacional de Energia Nuclear de Brasil, Sao Paulo)

    1985-02-01

    A radioagent method of analysis was developed and applied to the determination of trace quantities of lead in several types of samples. The method is based on the extraction of radioactive cobalt, displaced by lead from the cobalt chelate of ethylenediaminetetraacetate labelled with sup(60)Co, into a tetracycline-benzyl alcohol solution. The radioactivity of the released cobalt, extracted into the organic phase, is proportional to the lead concentration. Interference caused by some elements was eliminated by means of a previous separation of lead using dithizone. The method was applied for lead determination in aerosol samples, gasoline and samples from the International Atomic Energy Agency, e.g. simulated-air filter (Air-3), fresh water (W-3), dried animal whole blood (A-2) and calcined animal bone (A-3/1). The sensitivity, accuracy and precision of the method were also studied.

  16. Knowledge rule base for the beam optics program TRACE 3-D

    International Nuclear Information System (INIS)

    An expert system type of knowledge rule base has been developed for the input parameters used by the particle beam transport program TRACE 3-D. The goal has been to provide the program's user with adequate on-screen information to allow him to initially set up a problem with minimal open-quotes off-lineclose quotes calculations. The focus of this work has been in developing rules for the parameters which define the beam line transport elements. Ten global parameters, the particle mass and charge, beam energy, etc., are used to provide open-quotes expertclose quotes estimates of lower and upper limits for each of the transport element parameters. For example, the limits for the field strength of the quadrupole element are based on a water-cooled, iron-core electromagnet with dimensions derived from practical engineering constraints, and the upper limit for the effective length is scaled with the particle momenta so that initially parallel trajectories do not cross the axis inside the magnet. Limits for the quadrupole doublet and triplet parameters incorporate these rules and additional rules based on stable FODO lattices and bidirectional focusing requirements. The structure of the rule base is outlined and examples for the quadrupole singlet, doublet and triplet are described. The rule base has been implemented within the Shell for Particle Accelerator Related Codes (SPARC) graphical user interface (GUI)

  17. Effective beam method for element concentrations.

    Science.gov (United States)

    Tolhurst, Thomas; Barbi, Mauricio; Tokaryk, Tim

    2015-03-01

    There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s). PMID:25723941

  18. Octree ray tracing method for complicated reactor geometry

    International Nuclear Information System (INIS)

    This paper presents the new approach to ray tracing for nuclear reactor neutron transport computer simulation analysis. This method is aimed for Monte-Carlo methods as well as for deterministic neutron transport methods. Special attention is attended for reactor core composed of a set of material zones with complicate geometrical boundaries. The method consists of two phase: an octree map generation and then tracing many random rays using this map. The octree map is generated for a given region consisting of zones, formed by typical geometrical bodies with given parameters. For the map generation process, we use Monte-Carlo type of input describing the bodies and zones. Map generation is designed for all typical kind of bodies we have to do with in reactors. By now, spheres and cylinders are implemented. For each body, we must specify whether we want to discretize it or to preserve analytical calculation and curvature. Having an octree generated, we can launch rays. With a given ray, we traverse it through all the octree volumes, each on its turn. Traversing the current volume, we check the intersection points between the ray and three planes. Since we have intersection points with the planes sorted along the ray's direction, we can track the sequence of 0-7 numbered positions of sub-volumes one passed by, one after another. Having this sequence of position obtained, we traverse each of these sub-volumes respectively to the obtained sequence. Method works for 3-D space in general case. Simple 2-D numerical benchmark is given to demonstrate the advantage of new approach

  19. A MODIFIED COMPRESSION TECHNIQUE FOR TRACE DATA USING DICTIONARY METHOD

    Directory of Open Access Journals (Sweden)

    R.AGALYA

    2015-04-01

    Full Text Available In VLSI design circuits, System-On-Chip consumes more area due to huge data volume in the hardware. In order to reduce that constraint, the size of the trace buffer should be maintained constant. The trace data should be compressed to acquire huge amount of data. To compress those data several conventional techniques has been followed. Here in the proposed system, an approach called Look-Up-Table based dictionary compression method for System-On-Chip is used. It implements dictionary in such way that the most of the test vector frequencies are calculated which is to compress the test data in an efficient manner. This compression technique holds three different test vectors of all zero’s, one’s and X’s value where most of benchmark circuitry frequency can be captured. This technique is implemented in those circuits using hardware description language and it is verified by XILINX Spartan-3E to know utilization of devices. Hence, it achieves more compression ratio with less area overhead without loss of data.

  20. Cluster beam sources. Part 1. Methods of cluster beams generation

    Directory of Open Access Journals (Sweden)

    A.Ju. Karpenko

    2012-10-01

    Full Text Available The short review on cluster beams generation is proposed. The basic types of cluster sources are considered and the processes leading to cluster formation are analyzed. The parameters, that affects the work of cluster sources are presented.

  1. Cluster beam sources. Part 1. Methods of cluster beams generation

    OpenAIRE

    A.Ju. Karpenko; V.A. Baturin

    2012-01-01

    The short review on cluster beams generation is proposed. The basic types of cluster sources are considered and the processes leading to cluster formation are analyzed. The parameters, that affects the work of cluster sources are presented.

  2. Nuclear analytical methods for trace element studies in calcified tissues

    International Nuclear Information System (INIS)

    Full text: Various nuclear analytical methods have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the 19F(p,ag)16O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues, enamel, dentine, cement, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Microprobe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelodentin junction

  3. Trace element content and magnetic properties of commercial HOPG samples studied by ion beam microscopy and SQUID magnetometry

    Directory of Open Access Journals (Sweden)

    D. Spemann

    2014-10-01

    Full Text Available In this study, the impurity concentration and magnetic response of nine highly oriented pyrolytic graphite (HOPG samples with different grades and from different providers were determined using ion beam microscopy and SQUID magnetometry. Apart from sideface contaminations in the as-received state, bulk contamination of the samples in most cases consists of disk-shaped micron-sized particles made of Ti and V with an additional Fe contamination around the grain perimeter. The saturation magnetization typically increases with Fe concentration, however, there is no simple correlation between Fe content and magnetic moment. The saturation magnetization of one, respectively six, out of nine samples clearly exceeds the maximum contribution from pure Fe or Fe3C. For most samples the temperature dependence of the remanence decreases linearly with T – a dependence found previously for defect-induced magnetism (DIM in HOPG. We conclude that apart from magnetic impurities, additional contribution to the ferromagnetic magnetization exists in pristine HOPG in agreement with previous studies. A comparative study between the results of ion beam microscopy and the commonly used EDX analysis shows clearly that EDX is not a reliable method for quantitative trace elemental analysis in graphite, clarifying weaknesses and discrepancies in the element concentrations given in the recent literature.

  4. Ray-tracing simulations of spherical Johann diffraction spectrometer for in-beam X-ray experiments

    International Nuclear Information System (INIS)

    The results of the Monte-Carlo ray-tracing simulations for a Johann-type Bragg spectrometer with spherically curved-crystal designed to detect the X-rays from a fast-moving source are reported. These calculations were performed to optimize the X-ray spectrometer to be used at the gas-target installed at ion storage ring for high-resolution X-ray experiments. In particular, the two-dimensional distributions of detected photons were studied using the Monte-Carlo method both for the stationary and moving X-ray sources, taking into account a detailed description of X-ray source and X-ray diffraction on the crystal as well as a role of the Doppler effect for in-beam experiments. The origin of the asymmetry of observed X-ray profiles was discussed in detail and the procedure to derive a precise (sub-eV) X-ray transition energy for such asymmetric profiles was proposed. The results are important for the investigations of 1s2p3P2→1s2s3S1 intrashell transition in excited He-like uranium ions in in-beam X-ray experiments

  5. Computing the laser beam path in optical cavities: a geometric Newton's method based approach

    CERN Document Server

    Cuccato, Davide; Ortolan, Antonello; Beghi, Alessandro

    2015-01-01

    In the last decade, increasing attention has been drawn to high precision optical experiments, which push resolution and accuracy of the measured quantities beyond their current limits. This challenge requires to place optical elements (e.g. mirrors, lenses, etc.) and to steer light beams with sub-nanometer precision. Existing methods for beam direction computing in resonators, e.g. iterative ray tracing or generalized ray transfer matrices, are either computationally expensive or rely on overparametrized models of optical elements. By exploiting Fermat's principle, we develop a novel method to compute the steady-state beam configurations in resonant optical cavities formed by spherical mirrors, as a function of mirror positions and curvature radii. The proposed procedure is based on the geometric Newton method on matrix manifold, a tool with second order convergence rate that relies on a second order model of the cavity optical length. As we avoid coordinates to parametrize the beam position on mirror surfac...

  6. A new method for automated discontinuity trace mapping on rock mass 3D surface model

    Science.gov (United States)

    Li, Xiaojun; Chen, Jianqin; Zhu, Hehua

    2016-04-01

    This paper presents an automated discontinuity trace mapping method on a 3D surface model of rock mass. Feature points of discontinuity traces are first detected using the Normal Tensor Voting Theory, which is robust to noisy point cloud data. Discontinuity traces are then extracted from feature points in four steps: (1) trace feature point grouping, (2) trace segment growth, (3) trace segment connection, and (4) redundant trace segment removal. A sensitivity analysis is conducted to identify optimal values for the parameters used in the proposed method. The optimal triangular mesh element size is between 5 cm and 6 cm; the angle threshold in the trace segment growth step is between 70° and 90°; the angle threshold in the trace segment connection step is between 50° and 70°, and the distance threshold should be at least 15 times the mean triangular mesh element size. The method is applied to the excavation face trace mapping of a drill-and-blast tunnel. The results show that the proposed discontinuity trace mapping method is fast and effective and could be used as a supplement to traditional direct measurement of discontinuity traces.

  7. AMS method for depth profiling of trace elements concentration in materials - Construction and applications

    Science.gov (United States)

    Stan-Sion, C.; Enachescu, M.

    2015-10-01

    The need to investigate the behavior of solid state materials on the impact/retention/repulsion/contamination/impregnation with special trace elements or radioactive elements has driven us to develop a modified Accelerator Mass Spectrometry (AMS) analyzing method that is able to perform the measurement of the concentration depth profile of an element in a host material. This upgraded method that we call AMS-depth profiling method (AMS-DP) measures continuously the concentration of a trace element in a given sample material as a function of the depth from the surface (e.g., tritium in carbon, deuterium in tungsten, etc.). However, in order to perform depth profiling, common AMS facilities have to undergo several changes: a new replaceable sample target-holder has to be constructed to accept small plates of solid material as samples; their position has to be adjusted in the focus point of the sputter beam; crater rim effects of the produced hole in the sample have to be avoided or removed from the registered events in the detector; suitable reference samples have to be prepared and used for calibration. All procedures are presented in the paper together with several applications.

  8. Intradermal Alcian-Blue Injection Method to Trace Acupuncture Meridians

    Directory of Open Access Journals (Sweden)

    Baeckkyoung Sung

    2008-06-01

    Full Text Available Objective : In this article, we report on the intradermal Alcian blue staining method for tracing the meridians of acupuncture. Methods : 1% Alcian blue solution was injected into acupoints by using a 0.5mL insulin syringe with a 31-gauge needle, then the skin was incised and was observed under a stereoscopic microscope. The specimens were examined by using immunohistochemical methods and were observed under a confocal laser scanning microscope. Results : A threadlike structure, which was visualized with Alcian blue, existed in dermis layer and proceeded to hypodermis. In this structure, characteristic alignments of rod- shaped nuclei and 1-2μm sized DNA granules were observed. Furthermore, abundant blood capillary plexuses, peripheral nerve endings, and a corpusclelike structure(about 300μm in diameter were visualized in the skin tissues of acupoints. Conclusion : It was concluded that the specific threadlike and corpuscle-like structures corresponded to superficial Bonghan duct and corpuscle, respectively.

  9. Integrated method for the measurement of trace atmospheric bases

    Directory of Open Access Journals (Sweden)

    D. Key

    2011-09-01

    Full Text Available Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  10. Integrated method for the measurement of trace nitrogenous atmospheric bases

    Science.gov (United States)

    Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.

    2011-12-01

    Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace, atmospheric, gaseous nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications (e.g., methylamine, 1 pptv; ethylamine, 2 pptv; morpholine, 1 pptv; aniline, 1 pptv; hydrazine, 0.1 pptv; methylhydrazine, 2 pptv), as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  11. Integrated method for the measurement of trace atmospheric bases

    Science.gov (United States)

    Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.

    2011-09-01

    Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  12. Optimal control methods for vertical and horizontal beam dynamics

    International Nuclear Information System (INIS)

    An application of the Macro Fiber Composite (MFC) actuators for damping of a composite beam is presented in this paper. The effectiveness of vibration reduction by a selected control method is tested for vertical and horizontal position of the beam. The original model has been studied numerically by using Galerkin's discretisation method. The numerical results for the vertical and horizontal beams are compared.

  13. Automated method of tracing proton tracks in nuclear emulsions

    International Nuclear Information System (INIS)

    The low performance of the manual recognition of proton-recoil tracks in nuclear emulsions has limited its application to energy spectrum measurement of a pulsed neutron source. We developed an automated microscope system to trace proton-recoil tracks in nuclear emulsions. Given a start point on the proton track of interest, the microscope system can automatically trace and record the entire track using an image processing algorithm. Tests indicate that no interaction of the operator is needed in tracing the entire track. This automated microscope greatly reduces the labor of the operator and increases the efficiency of track data collection in nuclear emulsion

  14. Automated method of tracing proton tracks in nuclear emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, Jin-lu, E-mail: rjl@mail.ustc.edu.cn [Northwest Institute of Nuclear Technology, P.O. box 69-9, Xi’an, Shaanxi 710024 (China); Li, Hong-yun; Song, Ji-wen [Northwest Institute of Nuclear Technology, P.O. box 69-9, Xi’an, Shaanxi 710024 (China); Zhang, Jian-fu, E-mail: zhang_jianfu@163.com [Northwest Institute of Nuclear Technology, P.O. box 69-9, Xi’an, Shaanxi 710024 (China); Academy of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Chen, Liang; Zhang, Zhong-bing; Liu, Jin-liang; Liu, Lin-yue [Northwest Institute of Nuclear Technology, P.O. box 69-9, Xi’an, Shaanxi 710024 (China)

    2015-07-21

    The low performance of the manual recognition of proton-recoil tracks in nuclear emulsions has limited its application to energy spectrum measurement of a pulsed neutron source. We developed an automated microscope system to trace proton-recoil tracks in nuclear emulsions. Given a start point on the proton track of interest, the microscope system can automatically trace and record the entire track using an image processing algorithm. Tests indicate that no interaction of the operator is needed in tracing the entire track. This automated microscope greatly reduces the labor of the operator and increases the efficiency of track data collection in nuclear emulsion.

  15. Initial alignment method for free space optics laser beam

    Science.gov (United States)

    Shimada, Yuta; Tashiro, Yuki; Izumi, Kiyotaka; Yoshida, Koichi; Tsujimura, Takeshi

    2016-08-01

    The authors have newly proposed and constructed an active free space optics transmission system. It is equipped with a motor driven laser emitting mechanism and positioning photodiodes, and it transmits a collimated thin laser beam and accurately steers the laser beam direction. It is necessary to introduce the laser beam within sensible range of the receiver in advance of laser beam tracking control. This paper studies an estimation method of laser reaching point for initial laser beam alignment. Distributed photodiodes detect laser luminescence at respective position, and the optical axis of laser beam is analytically presumed based on the Gaussian beam optics. Computer simulation evaluates the accuracy of the proposed estimation methods, and results disclose that the methods help us to guide the laser beam to a distant receiver.

  16. Determination of trace amount of SDS surfactant by Oxtractionspectrophotometric method

    International Nuclear Information System (INIS)

    Complete text of publication follows. Sodium dodecylsulfate (SDS) is linear surfactant that widely used in detergent formulations such as dishwashing liquids, hair and body shampoos etc. Various analytical techniques have been reported for the determination of SDS including capillary electrophoresis/mass spectrometry (Y. Tanaka et al., Bunseki Kagaku Abstract, 1998, Vol. 47. No. 9.), turbidimetry (M. L. Fielden et al., Journal of Colloid and Interface Science, 198 (1998), 261-265.). and polarographic method. (S. Hiromiti, et al., Japan Analyst, 38(1989), 288-291.). A simple, sensitive extraction-spectrophotometric method for determination of trace amounts of sodium dodecyl sulfate (SDS) is reported.The (SDS--OTB+) ion-pair in buffered media is quantitatively extracted into di-chloromethane and its absorbance is measured at 625 nm in room temperature.The effect of different variables such as solvent, volume of extractant, volume of cationic reagent, pH, shaking time is investigated and optimum conditions for quantitative extraction of SDS is obtained. Linear calibration curve over the SDS concentration range of 0.14 μg mL-1 and regression coefficient of 0.9996 is obtained.The relative standard deviation (RSD) of seven replicate determinations of SDS concentrations of 0.2 μg mL-1 , 1 μg mL-1 and 4 μg mL-1 is 3.75%, 1.84% and 0.63% respectively. The detection limit of the method is 8.91 ng mL-1.The amount of SDS in Karoon river as real sample is determined by standard addition method which is 0.141 μg mL-1.The interference of 22 cationic and anionic species have also been evaluated and it was found that most species have no effect on the extraction selectivity. The method was applied to the Karoon river raw water contaminated with industrial and house savages. The results showed high potential of the recommended method for the determination of SDS in water samples. The authors gratefully acknowledge the financial support of this work by Ahwaz Petroleum Faculty

  17. Stability Analysis of Nonuniform Rectangular Beams Using Homotopy Perturbation Method

    Directory of Open Access Journals (Sweden)

    Seval Pinarbasi

    2012-01-01

    Full Text Available The design of slender beams, that is, beams with large laterally unsupported lengths, is commonly controlled by stability limit states. Beam buckling, also called “lateral torsional buckling,” is different from column buckling in that a beam not only displaces laterally but also twists about its axis during buckling. The coupling between twist and lateral displacement makes stability analysis of beams more complex than that of columns. For this reason, most of the analytical studies in the literature on beam stability are concentrated on simple cases: uniform beams with ideal boundary conditions and simple loadings. This paper shows that complex beam stability problems, such as lateral torsional buckling of rectangular beams with variable cross-sections, can successfully be solved using homotopy perturbation method (HPM.

  18. Electron beam directed energy device and methods of using same

    Science.gov (United States)

    Retsky, Michael W.

    2007-10-16

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  19. Analytical And Numerical Methods In Beam Physics

    CERN Document Server

    Andrianov, S

    2004-01-01

    This report is devoted to discussion of numerical and symbolic computing ratio beam physics. We tray to draw attention on basic conceptual and computational problems first of all. It is known that the main problem in modern computational beam physics connected with high performance computing realization. The most of used approaches are not appropriate for computing using multiprocessing systems. Here we give some possible solutions, which based on symbolic presentation of necessary information and modern information technologies.

  20. Determination of trace concentrations in indium in ultrapure materials by the method of stepped laser photoionization from the metastable 5p2P 3/2 state

    International Nuclear Information System (INIS)

    Experiments have been carried out on the photoionization detection of impurity sodium and aluminum atoms by means of stepped photoionization of the atoms in a gaseous medium with laser evaporation of the sample or with an atomic beam with thermal evaporation of the material in a vacuum. Photoionization and detection of impurity atoms in a vacuum permit eliminating the background signal due to the presence of traces of impurities in the gas and quenching collisions and obtaining maximum selectivity. The use of the photoionization method for recording the intensity and elemental composition of atomic beams in molecular epitaxy processes will make it possible to perform more accurately than with other methods a continuous technological monitoring of the conditions of deposition of semiconducting devices. In this paper the authors examine the characteristic features of the photoionization detection of indium atoms in an atomic beam and they present the results of experiments of trace impurities in very pure germanium

  1. Improved parallelization of the modular ray tracing in the method of characteristics code Decart

    International Nuclear Information System (INIS)

    The solution of the Boltzmann transport equation using Method of Characteristics ray tracing can be accurate yet computationally expensive. Ray tracing would be inherently parallelizable with a very fine granularity if the boundary condition associated with each ray were known a priori. In practice, however, ray tracing is serial since the boundary condition for one ray is generally obtained from another ray in the problem. In the work here, an alternative implementation of ray tracing is presented that minimizes serialization and reduces the memory requirements. A new algorithm was implemented in the MOC code DeCART and demonstrated for a BWR assembly model. (authors)

  2. Generalization of the Zgoubi method for ray-tracing to include electric fields

    International Nuclear Information System (INIS)

    The ray-tracing and spin tracking code Zgoubi, originally dedicated to the numerical integration of Lorentz equation in magnetic fields, has been improved in order to allow ray-tracing in electric and electromagnetic fields. This report describes the method, and presents detailed examples of application, including the achromatic quadrupole. (orig.)

  3. Comparison of Methods to Trace Multiple Subskills: Is LR-DBN Best?

    Science.gov (United States)

    Xu, Yanbo; Mostow, Jack

    2012-01-01

    A long-standing challenge for knowledge tracing is how to update estimates of multiple subskills that underlie a single observable step. We characterize approaches to this problem by how they model knowledge tracing, fit its parameters, predict performance, and update subskill estimates. Previous methods allocated blame or credit among subskills…

  4. Modified Wide-angle Beam Propagation Method Using Douglas Operators①

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    A modified wide-angle beam propagation based on the Douglas operators is presented .The truncation error in the modified wide-angle beam propagation is reduced to o(△x)4in the transverse direction nearly without any increase of the computation time,whereas the error in the ordinary wide-angle beam propagation method is typically o(△x)2.With trivial programming changes,the accuracy is higher,especially in wide-angle propagation.

  5. Calculation of narrow beam γ ray mass attenuation coefficients of absorbing medium by Monte Carlo method

    International Nuclear Information System (INIS)

    The mathematics model of particle transportation was built, based on the sample of the impaction trace of the narrow beam γ photon in the medium according to the principle of interaction between γ photon and the material, and a computer procedure was organized to simulate the process of transportation for the γ photon in the medium and record the emission probability of γ photon and its corresponding thickness of medium with LabWindows/CVI, which was used to calculate narrow beam γ ray mass attenuation coefficients of absorbing medium. The results show that it is feasible for Monte Carlo method to calculate narrow beam γ ray mass attenuation coefficients of absorbing medium. (authors)

  6. Synthetic methods for beam to beam power balancing capability of large laser facilities

    International Nuclear Information System (INIS)

    To account for output power balancing capability of large laser facilities, a synthetic method with beam to beam root-mean-square is presented. Firstly, a conversion process for the facilities from original data of beam powers to regular data is given. The regular data contribute to the normal distribution approximately, and then a corresponding simple method of root-mean-square for beam to beam power balancing capability is given.Secondly, based on theory of total control charts and cause-selecting control charts, control charts with root-mean-square are established which show short-term variety of power balancing capability of the facilities. Mean rate of failure occurrence is also defined and used to describe long-term trend of global balancing capabilities of the facilities. Finally, advantages of the intuitive and efficient diagnosis for synthetic methods are illustrated by analysis of experimental data. (authors)

  7. Beam Conditioning for FELs: Consequences and Methods

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, Andrzej; Penn, Gregory; Sessler, Andrew; Wurtele, Jonathan

    2003-10-09

    The consequences of beam conditioning in four example cases (VISA, a Soft X-Ray FEL, LCLS and a ''Greenfield'' FEL) are examined. It is shown that in emittance limited cases, proper conditioning reduces sensitivity to the transverse emittance, and allows stronger focusing in the undulator. Simulations show higher saturation power, with gain lengths reduced up to a factor of two. The beam dynamics in a general conditioning system are studied, with ''matching conditions'' derived for achieving conditioning without growth in effective emittance. Various conditioners are considered, and expressions derived for the amount of conditioning provided in each case when the matching conditions are satisfied. We discuss the prospects for conditioners based on laser and plasma systems.

  8. 60 GHz Indoor Propagation Studies for Wireless Communications Based on a Ray-Tracing Method

    Directory of Open Access Journals (Sweden)

    Lim C-P

    2007-01-01

    Full Text Available This paper demonstrates a ray-tracing method for modeling indoor propagation channels at 60 GHz. A validation of the ray-tracing model with our in-house measurement is also presented. Based on the validated model, the multipath channel parameter such as root mean square (RMS delay spread and the fading statistics at millimeter wave frequencies are easily extracted. As such, the proposed ray-tracing method can provide vital information pertaining to the fading condition in a site-specific indoor environment.

  9. Development of multi-bunch beam energy compensation method

    International Nuclear Information System (INIS)

    A method to compensate for beam loading effects in a multi-bunch beam is under development at Accelerator Test Facility (ATF) in KEK. In this paper we describe the rf high power test for ΔT energy compensation by using the SLED cavities. In this ΔT (early injection and amplitude modulation) energy compensation method, the input waveform into accelerating structure is changed by controlling the rf phase and combining the rf-power from two klystrons with a 3 dB hybrid combiner to compensate multi-bunch beam energy for various beam currents. In this test, an arbitrary waveform was generated by changing the rotating speed of the each klystron phase into the opposite direction and the beam test will be done soon. (author)

  10. Analytical Evaluation of Beam Deformation Problem Using Approximate Methods

    DEFF Research Database (Denmark)

    Barari, Amin; Kimiaeifar, A.; Domairry, G.

    2010-01-01

    , and this process produces noise in the obtained answers. This paper deals with the solution of second order of differential equation governing beam deformation using four analytical approximate methods, namely the Perturbation, Homotopy Perturbation Method (HPM), Homotopy Analysis Method (HAM) and......The beam deformation equation has very wide applications in structural engineering. As a differential equation, it has its own problem concerning existence, uniqueness and methods of solutions. Often, original forms of governing differential equations used in engineering problems are simplified...... Variational Iteration Method (VIM). The comparisons of the results reveal that these methods are very effective, convenient and quite accurate for systems of non-linear differential equation....

  11. Accurate Method for Determining Adhesion of Cantilever Beams

    Energy Technology Data Exchange (ETDEWEB)

    Michalske, T.A.; de Boer, M.P.

    1999-01-08

    Using surface micromachined samples, we demonstrate the accurate measurement of cantilever beam adhesion by using test structures which are adhered over long attachment lengths. We show that this configuration has a deep energy well, such that a fracture equilibrium is easily reached. When compared to the commonly used method of determining the shortest attached beam, the present method is much less sensitive to variations in surface topography or to details of capillary drying.

  12. Patient-specific scatter correction in clinical cone beam computed tomography imaging made possible by the combination of Monte Carlo simulations and a ray tracing algorithm

    International Nuclear Information System (INIS)

    Purpose: Cone beam computed tomography (CBCT) image quality is limited by scattered photons. Monte Carlo (MC) simulations provide the ability of predicting the patient-specific scatter contamination in clinical CBCT imaging. Lengthy simulations prevent MC-based scatter correction from being fully implemented in a clinical setting. This study investigates the combination of using fast MC simulations to predict scatter distributions with a ray tracing algorithm to allow calibration between simulated and clinical CBCT images. Material and methods: An EGSnrc-based user code (egscbct), was used to perform MC simulations of an Elekta XVI CBCT imaging system. A 60keV x-ray source was used, and air kerma scored at the detector plane. Several variance reduction techniques (VRTs) were used to increase the scatter calculation efficiency. Three patient phantoms based on CT scans were simulated, namely a brain, a thorax and a pelvis scan. A ray tracing algorithm was used to calculate the detector signal due to primary photons. A total of 288 projections were simulated, one for each thread on the computer cluster used for the investigation. Results: Scatter distributions for the brain, thorax and pelvis scan were simulated within 2 % statistical uncertainty in two hours per scan. Within the same time, the ray tracing algorithm provided the primary signal for each of the projections. Thus, all the data needed for MC-based scatter correction in clinical CBCT imaging was obtained within two hours per patient, using a full simulation of the clinical CBCT geometry. Conclusions: This study shows that use of MC-based scatter corrections in CBCT imaging has a great potential to improve CBCT image quality. By use of powerful VRTs to predict scatter distributions and a ray tracing algorithm to calculate the primary signal, it is possible to obtain the necessary data for patient specific MC scatter correction within two hours per patient

  13. Travelling Methods: Tracing the Globalization of Qualitative Communication Research

    OpenAIRE

    Bryan C. TAYLOR; Thomas R. LINDLOF

    2013-01-01

    Existing discussion of the relationships between globalization, communication research, and qualitative methods emphasizes two images: the challenges posed by globalization to existing communication theory and research methods, and the impact of post-colonial politics and ethics on qualitative research. We draw in this paper on a third image – qualitative research methods as artifacts of globalization – to explore the globalization of qualitative communication research methods. Following a...

  14. New method of beam bunching in free-ion lasers

    International Nuclear Information System (INIS)

    An effective ion beam bunching method is suggested. This method is based on a selective interaction of line spectrum laser light (e.g. axial mode structure light) with non-fully stripped ion beam cooled in a storage rings, arranging the ion beam in layers in radial direction of an energy-longitudinal coordinate plane and following rotation of the beam at the right angle after switching on the RF cavity or undulator grouper/buncher. Laser cooling of the ion beam can be used at this position after switching off the resonator to decrease the energy spread caused by accelerating field of the resonator. A relativistic multilayer ion mirror will be produced this way. Both monochromatic laser beams and intermediate monochromaticity and bandwidth light sources of spontaneous incoherent radiation can be used for production of hard and high power electromagnetic radiation by reflection from this mirror. The reflectivity of the mirror is rather high because of the cross-section of the backward Rayleigh scattering of photon light by non-fully stripped relativistic ions (∼λ2) is much greater (∼ 10 divided-by 15 orders) then Thompson one (∼ re2). This position is valid even in the case of non-monochromatic laser light (Δω/ω ∼ 10-4). Ion cooling both in longitudinal plane and three-dimensional radiation ion cooling had been proposed based on this observation. The using of these cooling techniques will permit to store high current and low emittance relativistic ion beams in storage rings. The bunched ion beam can be used in ordinary Free-Ion Lasers as well. After bunching the ion beam can be extracted from the storage ring in this case. Storage rings with zero momentum compaction function will permit to keep bunching of the ion beam for a long time

  15. New method of beam bunching in free-ion lasers

    Energy Technology Data Exchange (ETDEWEB)

    Bessonov, E.G. [Lebedev Physics Institute, Moscow (Russian Federation)

    1995-12-31

    An effective ion beam bunching method is suggested. This method is based on a selective interaction of line spectrum laser light (e.g. axial mode structure light) with non-fully stripped ion beam cooled in a storage rings, arranging the ion beam in layers in radial direction of an energy-longitudinal coordinate plane and following rotation of the beam at the right angle after switching on the RF cavity or undulator grouper/buncher. Laser cooling of the ion beam can be used at this position after switching off the resonator to decrease the energy spread caused by accelerating field of the resonator. A relativistic multilayer ion mirror will be produced this way. Both monochromatic laser beams and intermediate monochromaticity and bandwidth light sources of spontaneous incoherent radiation can be used for production of hard and high power electromagnetic radiation by reflection from this mirror. The reflectivity of the mirror is rather high because of the cross-section of the backward Rayleigh scattering of photon light by non-fully stripped relativistic ions ({approximately}{lambda}{sup 2}) is much greater ({approximately} 10{divided_by}15 orders) then Thompson one ({approximately} r{sub e}{sup 2}). This position is valid even in the case of non-monochromatic laser light ({Delta}{omega}/{omega} {approximately} 10{sup -4}). Ion cooling both in longitudinal plane and three-dimensional radiation ion cooling had been proposed based on this observation. The using of these cooling techniques will permit to store high current and low emittance relativistic ion beams in storage rings. The bunched ion beam can be used in ordinary Free-Ion Lasers as well. After bunching the ion beam can be extracted from the storage ring in this case. Storage rings with zero momentum compaction function will permit to keep bunching of the ion beam for a long time.

  16. High Energy Beam Impacts on Beam Intercepting Devices: Advanced Numerical Methods and Experimental Set-Up

    CERN Document Server

    Bertarelli, A; Carra, F; Cerutti, F; Dallocchio, A; Mariani, N; Timmins, M; Peroni, L; Scapin, M

    2011-01-01

    Beam Intercepting Devices are potentially exposed to severe accidental events triggered by direct impacts of energetic particle beams. State-of-the-art numerical methods are required to simulate the behaviour of affected components. A review of the different dynamic response regimes is presented, along with an indication of the most suited tools to treat each of them. The consequences on LHC tungsten collimators of a number of beam abort scenarios were extensively studied, resorting to a novel category of numerical explicit methods, named Hydrocodes. Full shower simulations were performed providing the energy deposition distribution. Structural dynamics and shock wave propagation analyses were carried out with varying beam parameters, identifying important thresholds for collimator operation, ranging from the onset of permanent damage up to catastrophic failure. Since the main limitation of these tools lies in the limited information available on constitutive material models under extreme conditions, a dedica...

  17. High Energy Beam Impacts on Beam Intercepting Devices: Advanced Numerical Methods and Experimental Set-up

    CERN Document Server

    Bertarelli, A; Carra, F; Cerutti, F; Dallocchio, A; Mariani, N; Timmins, M; Peroni, L; Scapin, M

    2011-01-01

    Beam Intercepting Devices are potentially exposed to severe accidental events triggered by direct impacts of energetic particle beams. State-of-the-art numerical methods are required to simulate the behaviour of affected components. A review of the different dynamic response regimes is presented, along with an indication of the most suited tools to treat each of them. The consequences on LHC tungsten collimators of a number of beam abort scenarios were extensively studied, resorting to a novel category of numerical explicit methods, named Hydrocodes. Full shower simulations were performed providing the energy deposition distribution. Structural dynamics and shock wave propagation analyses were carried out with varying beam parameters, identifying important thresholds for collimator operation, ranging from the onset of permanent damage up to catastrophic failure. Since the main limitation of these tools lies in the limited information available on constitutive material models under extreme conditions, a dedica...

  18. An Energy Conservative Ray-Tracing Method With a Time Interpolation of the Force Field

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-02-10

    A new algorithm that constructs a continuous force field interpolated in time is proposed for resolving existing difficulties in numerical methods for ray-tracing. This new method has improved accuracy, but with the same degree of algebraic complexity compared to Kaisers method.

  19. A FINITE-DIFFERENCE, DISCRETE-WAVENUMBER METHOD FOR CALCULATING RADAR TRACES

    Science.gov (United States)

    A hybrid of the finite-difference method and the discrete-wavenumber method is developed to calculate radar traces. The method is based on a three-dimensional model defined in the Cartesian coordinate system; the electromagnetic properties of the model are symmetric with respect ...

  20. Improved multistep method for wide-angle beam propagation

    OpenAIRE

    Yamauchi, Junji; Shibayama, Jun; Sekiguchi, Minoru; Nakano, Hisamatsu

    1996-01-01

    To improve a wide-angle beam propagation method using a finite-difference technique, the generalized Douglas scheme for variable coefficients is applied to a multistep method. A truncation error of O(Δx)4 is achieved in the transverse direction. The effectiveness of the present method is demonstrated in the analysis of a tilted step-index slab waveguide.

  1. Travelling Methods: Tracing the Globalization of Qualitative Communication Research

    Directory of Open Access Journals (Sweden)

    Bryan C. Taylor

    2016-05-01

    Full Text Available Existing discussion of the relationships between globalization, communication research, and qualitative methods emphasizes two images: the challenges posed by globalization to existing communication theory and research methods, and the impact of post-colonial politics and ethics on qualitative research. We draw in this paper on a third image – qualitative research methods as artifacts of globalization – to explore the globalization of qualitative communication research methods. Following a review of literature which tentatively models this process, we discuss two case studies of qualitative research in the disciplinary subfields of intercultural communication and media audience studies. These cases elaborate the forces which influence the articulation of national, disciplinary, and methodological identities which mediate the globalization of qualitative communication research methods.

  2. Travelling Methods: Tracing the Globalization of Qualitative Communication Research

    Directory of Open Access Journals (Sweden)

    Bryan C. TAYLOR

    2013-12-01

    Full Text Available Existing discussion of the relationships between globalization, communication research, and qualitative methods emphasizes two images: the challenges posed by globalization to existing communication theory and research methods, and the impact of post-colonial politics and ethics on qualitative research. We draw in this paper on a third image – qualitative research methods as artifacts of globalization – to explore the globalization of qualitative communication research methods. Following a review of literature which tentatively models this process, we discuss two case studies of qualitative research in the disciplinary subfields of intercultural communication and media audience studies. These cases elaborate the forces which influence the articulation of national, disciplinary, and methodological identities which mediate the globalization of qualitative communication research methods.

  3. Tracing the plasma interactions for pulsed reactive crossed-beam laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Pichler, Markus; Pergolesi, Daniele; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [General Energy Research Department, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

    2015-10-28

    Pulsed reactive crossed-beam laser ablation is an effective technique to govern the chemical activity of plasma species and background molecules during pulsed laser deposition. Instead of using a constant background pressure, a gas pulse with a reactive gas, synchronized with the laser beam, is injected into vacuum or a low background pressure near the ablated area of the target. It intercepts the initially generated plasma plume, thereby enhancing the physicochemical interactions between the gaseous environment and the plasma species. For this study, kinetic energy resolved mass-spectrometry and time-resolved plasma imaging were used to study the physicochemical processes occurring during the reactive crossed beam laser ablation of a partially {sup 18}O substituted La{sub 0.6}Sr{sub 0.4}MnO{sub 3} target using oxygen as gas pulse. The characteristics of the ablated plasma are compared with those observed during pulsed laser deposition in different oxygen background pressures.

  4. Tracing the plasma interactions for pulsed reactive crossed-beam laser ablation

    International Nuclear Information System (INIS)

    Pulsed reactive crossed-beam laser ablation is an effective technique to govern the chemical activity of plasma species and background molecules during pulsed laser deposition. Instead of using a constant background pressure, a gas pulse with a reactive gas, synchronized with the laser beam, is injected into vacuum or a low background pressure near the ablated area of the target. It intercepts the initially generated plasma plume, thereby enhancing the physicochemical interactions between the gaseous environment and the plasma species. For this study, kinetic energy resolved mass-spectrometry and time-resolved plasma imaging were used to study the physicochemical processes occurring during the reactive crossed beam laser ablation of a partially 18O substituted La0.6Sr0.4MnO3 target using oxygen as gas pulse. The characteristics of the ablated plasma are compared with those observed during pulsed laser deposition in different oxygen background pressures

  5. Fast ray tracing method in 3-D structure and its proof of positive definiteness

    Institute of Scientific and Technical Information of China (English)

    GAO Er-gen; Uk HAN; TENG Ji-wen

    2007-01-01

    Based on Fermat's principle. two-point ray tracing method was studied in three-dimensional structure.By means of first order Taylor's incomplete series expansion(i.e.no expansion to the length of the ray), a symmetry block tridiagonal matrix equation set was deduced.Further,the positive definiteness of coefficient matrix was discussed, and the positive definiteness was accurately proved in a mathematical way. It assured that the algorithm was well-posed. Associated with iterative method, the solution to ray tracing call be got through step-by-step linearized iteration of the nonlinear problem. An algorithm of the whole path iterative ray tracing method in three-dimensional velocity structure was obmined.This method shows a clear and simple as well as explicit computation formula, which makes ray tracing computation easily applicable in practice. The correction vector is obtained through finding the solution to the positive definite block tridiagonal equation set, which ensures the method is robust convergence. This study offers a new kind of feasible and efficient ray tracing method for three dimensional seismic migration and tomography. Meanwhile.it also provides the prerequisite guarantee to design a fast algorithm.

  6. Study of transient self-consistent beam dynamics in RF linacs using a particle tracing code

    Science.gov (United States)

    Mytrochenko, V. V.; Opanasenko, A.

    2006-03-01

    The paper describes a simulation technique for study of unsteady self-consistent dynamics of charged particles in RF linacs that consist of cavities and travelling wave sections. The approach proposed is based on unsteady theories of the excitation of cavities and waveguides by a beam of charged particles and RF feeders. The theory of waveguide excitation is extended to the case of spatially inhomogeneous travelling-wave structures. The SUPERFISH code is used to evaluate the characteristics of the axisymmetric travelling-wave sections. The PARMELA code is applied for simulation of particle motion and to obtain data required for solving the equations for excitation of the RF structures by the beam.

  7. Effective beam method for element concentrations

    OpenAIRE

    Tolhurst, Thomas; Barbi, Mauricio; Tokaryk, Tim

    2015-01-01

    There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopi...

  8. Aerosol, Cloud and Trace Gas Observations Derived from Airborne Hyperspectral Radiance and Direct Beam Measurements in Recent Field Campaigns

    Science.gov (United States)

    Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; LeBlanc, S.; Russell, P. B.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.; Johnson, R. R.

    2014-01-01

    The AERONET (AErosol RObotic NETwork) ground-based suite of sunphotometers provides measurements of spectral aerosol optical depth (AOD), precipitable water and spectral sky radiance, which can be inverted to retrieve aerosol microphysical properties that are critical to assessments of aerosol-climate interactions. Because of data quality criteria and sampling constraints, there are significant limitations to the temporal and spatial coverage of AERONET data and their representativeness for global aerosol conditions. The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, jointly developed by NASA Ames and PNNL with NASA Goddard collaboration, combines airborne sun tracking and AERONET-like sky scanning with spectroscopic detection. Being an airborne instrument, 4STAR has the potential to fill gaps in the AERONET data set. Dunagan et al. [2013] present results establishing the performance of the instrument, along with calibration, engineering flight test, and preliminary scientific field data. The 4STAR instrument operated successfully in the SEAC4RS [Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys] experiment in Aug./Sep. 2013 aboard the NASA DC-8 and in the DoE [Department of Energy]-sponsored TCAP [Two Column Aerosol Project, July 2012 & Feb. 2013] experiment aboard the DoE G-1 aircraft (Shinozuka et al., 2013), and acquired a wealth of data in support of mission objectives on all SEAC4RS and TCAP research flights. 4STAR provided direct beam measurements of hyperspectral AOD, columnar trace gas retrievals (H2O, O3, NO2; Segal-Rosenheimer et al., 2014), and the first ever airborne hyperspectral sky radiance scans, which can be inverted to yield the same products as AERONET ground-based observations. In addition, 4STAR measured zenith radiances underneath cloud decks for retrievals of cloud optical depth and effective diameter. In this presentation, we provide an overview of the new

  9. Application of graphical design method to beam transport system

    International Nuclear Information System (INIS)

    A graphical design method in which a partical beam with initial divergence can realize waist to waist transport in both X and Y planed simultaneously by means of quadrupole doublet is presented. Graphical mathod and transport matrix as well as charts can be used so that a quick design can be carried out to save computer time considerably. A concrete example of the beam is given to demonstrate the practical application of the theory mentioned above

  10. Apparatus comprising trace element dosage and method for treating raw water in biofilter

    DEFF Research Database (Denmark)

    2015-01-01

    from the inlet (2) to the outlet (3) or in the reverse direction, - the trace element dosage device (13) is positioned upstream of the porous filter material and microbial biomass and is configured to dose trace element(s) to the water flowing through the filter. A method for treating raw water by......Apparatus for treating raw water in a biofilter The present invention relates to an apparatus in which raw water is treated through microbial activity where microbial activity is controlled by nutrients and other parameters. Some of the nutrients controlling the microbial activity are trace...... elements such as certain metals (Cu, Co, Cr, Mo, Ni, W, Zn or a mixture thereof). The apparatus comprising - a volume provided with an inlet (2) for raw water and an outlet (3) for water having been subjected to microbial activity, a filter and a trace element dosage device (13) are placed in this volume...

  11. Determination of trace elements in ground water by two preconcentration methods using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This is a comparative study between two different methods of preconcentration done to separate the trace elements cadmium, nickel. chromium, manganese, copper, zinc, and lead in drinking (ground) water samples taken from different locations in Gezira State, central Sudan (the map); these methods are (coprecipitation) with aluminium hydroxide and by Ammonium Pyrrolidine Dithiocarbamate (APDC) using Methyl Isobutyl Ketone (MIBK) as an organic solvent; and subsequent analysis by Atomic Absorption Spectrometry (AAS) for both methods. The result of comparison showed the superiority of the (APDC) coprecipitation method over the aluminium hydroxide coprecipitation method in the total percentage recoveries of the studied trace elements in drinking (ground) water samples, such results confirm previous studies. This study also involves direct analysis of these water samples by atomic absorption spectrometry to determine the concentrations of trace elements Cadmium, Nickel, Chromium, Manganese, Copper, Zinc and Lead and compare it to the corresponding guide line values described by the World Health Organization and the maximum concentrations of trace elements in drinking water permitted by the Sudanese Standards and Metrology Organizations (SSMO), where the concentrations of some elements in some samples were found to be different than the described values by both of the organizations. The study includes a trial to throw light on the effect of the proximity of the water samples sources to the Blue Nile river on its trace elements concentrations; no relation was proved to exist in that respect.(Author)

  12. A standardized method for beam design in neutron capture therapy

    International Nuclear Information System (INIS)

    A desirable end point for a given beam design for Neutron Capture Therapy (NCT) should be quantitative description of tumour control probability and normal tissue damage. Achieving this goal will ultimately rely on data from NCT human clinical trials. Traditional descriptions of beam designs have used a variety of assessment methods to quantify proposed or installed beam designs. These methods include measurement and calculation of open-quotes free fieldclose quotes parameters, such as neutron and gamma flux intensities and energy spectra, and figures-of-merit in tissue equivalent phantoms. The authors propose here a standardized method for beam design in NCT. This method would allow all proposed and existing NCT beam facilities to be compared equally. The traditional approach to determining a quantitative description of tumour control probability and normal tissue damage in NCT research may be described by the following path: Beam design → dosimetry → macroscopic effects → microscopic effects. Methods exist that allow neutron and gamma fluxes and energy dependence to be calculated and measured to good accuracy. By using this information and intermediate dosimetric quantities such as kerma factors for neutrons and gammas, macroscopic effect (absorbed dose) in geometries of tissue or tissue-equivalent materials can be calculated. After this stage, for NCT the data begins to become more sparse and in some areas ambiguous. Uncertainties in the Relative Biological Effectiveness (RBE) of some NCT dose components means that beam designs based on assumptions considered valid a few years ago may have to be reassessed. A standard method is therefore useful for comparing different NCT facilities

  13. Batch methods for enriching trace impurities in hydrogen gas for their further analysis

    Science.gov (United States)

    Ahmed, Shabbir; Lee, Sheldon H.D.; Kumar, Romesh; Papdias, Dionissios D.

    2014-07-15

    Provided herein are batch methods and devices for enriching trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentrating impurities using hydrogen transport membranes wherein the time period for concentrating the sample is calculated on the basis of optimized membrane characteristics, comprising its thickness and permeance, with optimization of temperature, and wherein the enrichment of trace impurities is proportional to the pressure ratio P.sub.hi/P.sub.lo and the volume ratio V.sub.1/V.sub.2, with following detection of the impurities using commonly-available detection methods.

  14. Geologichal effectiveness of nuclear trace method in uranium prospecting

    International Nuclear Information System (INIS)

    The results obtained by the track-etch technique in the Uranium prospection, and those obtained using other radiometrical methods, were compared. The Uranium mineralization in the selected test field lye in the 100m depth. A good geological efficacy of the track-etch technique was established

  15. Oil consumption measurements of a production engine using the sulfur-trace method

    Science.gov (United States)

    Benson, Verlyn Royal

    Controlling the oil consumption of diesel engines is important for customer satisfaction. Existing oil consumption measurement methods are adequate; however, improved methods offer the possibility of faster and more comprehensive results. The sulfur-trace method is an example. Major objectives of this investigation were to adopt a sulfur-trace analyzer for oil consumption measurements, to improve the oil consumption measurement process, and to demonstrate application of the sulfur-trace instrument to individual cylinder sampling. To achieve these objectives, four research questions were applied: (1) What procedures and attention to detail are required? (2) how can results be reported to maximize data interpretation? (3) how do the advantages of the sulfur-trace method compare with the drain-and-weigh method? and (4) what is recommended as an optimized test method? Addressing Research Question 1 required careful attention to numerous parts of the sulfur-trace instrument. These parts included: (a) insulating and heating the exhaust sample lines, (b) ensuring continuous and proper operation of the ozone generator, (c) controlling the precise flow rate of the sample, and (d) removing excess water from the sample. Addressing Research Question 2 required a strip chart recorder, a spreadsheet template, and a chart template to organize, record, and report data. The strip chart recorder provided a backup analog record and a means to document daily activity. Raw data were entered into a spreadsheet for subsequent analyses required for chart reporting. Addressing Research Question 3 included a comparison of sulfur-trace vs. drain-and-weigh method durations and capabilities. After optimization, the same oil consumption results were collected in 10 minutes using the sulfur-trace method as compared with the 100 hours required for the drain-and-weigh method. More importantly, the sulfur-trace method may be used to collect oil consumption data from each individual cylinder, which

  16. Devices and methods to detect and quantify trace gases

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Robinson, Alex

    2016-05-03

    Sensing devices based on a surface acoustic wave ("SAW") device coated with an absorbent crystalline or amorphous layer for detecting at least one chemical analyte in a gaseous carrier. Methods for detecting the presence of a chemical analyte in a gaseous carrier using such devices are also disclosed. The sensing devices and methods for their use may be configured for sensing chemical analytes selected from the group consisting of water vapor, carbon dioxide, methanol, ethanol, carbon monoxide, nitric oxide, nitrous oxide, organic amines, organic compounds containing NO.sub.2 groups, halogenated hydrocarbons, acetone, hexane, toluene, isopropanol, alcohols, alkanes, alkenes, benzene, functionalized aromatics, ammonia (NH.sub.3), phosgene (COCl.sub.2), sulfur mustard, nerve agents, sulfur dioxide, tetrahydrofuran (THF) and methyltertbutyl ether (MTBE) and combinations thereof.

  17. Methods for the determination of trace elements, in geological materials

    Energy Technology Data Exchange (ETDEWEB)

    Erzinger, J.; Puchelt, H.

    1982-04-01

    Se, Cd, Tl, Bi, Pb and Zn are analysed by fractional distillation combined with flameless atomic absorption spectrometry, and fluoride with ionselective electrode after separation by pyrohydrolysis method. Least concentrations which can be determined with the described techniques in geological matrices are 3 ppb Se, 5 ppb Cd, 5 ppb Tl, 50 ppb Pb, 5 ppb Bi, 10 ppm F, 10 ppm Zn. Additionally the authors describe their radionuclide energy dispersive X-ray fluorescence system, providing a fast multielement method for determining environmental contaminations (e.g. soils). Detection limits for this technique, which is also applied with geochemical prospecting, needing a minimum of samples preparation are 30 ppm Cu, 30 ppm Zn, 10 ppm As, 20 ppm Pb, 10 ppm Sr, 10 ppm Sn, 10 ppm Sb, 5 ppm Ba, 10 ppm Ce. Parameters of measuring and analytical procedures used in the authors' laboratory are described.

  18. Determination of the size distribution of carbon and trace elements in suspended particulate matter by ion beam analysis

    International Nuclear Information System (INIS)

    The size distribution of carbon and trace elements in suspended particulate matter (SPM) collected by a low pressure impactor has been investigated. Sampling was carried out at Setagaya, a typical residential area located southwest of Tokyo, Japan. The low pressure impactor has a cascade design with 12-stage collection plates, allowing the collection of size-fractionated SPM. It operates at a flow rate of 20 l/min. Elemental composition was determined by ion beam analysis, particle induced X-ray emission (PIXE) and Rutherford backscattering (RBS). PIXE provided data for elements from Al to U while RBS supplied information on elements lighter than Al such as C and O. The analysis is fast, non-destructive and requires no sample preparation. It is very suitable for determination of elements in SPM. In this paper we discuss size distribution and element concentrations in SPM together with their weekly and seasonal variations

  19. Trace element analysis of material scalp hair by external beam proton-induced X-ray emission (PIXE)

    International Nuclear Information System (INIS)

    An external beam proton-induced X-ray emission (PIXE) system has been constructed for trace element analysis of biological and environmental samples. Optimization of sample preparation and experimental PIXE set-up produced a rapid, accurate, sensitive, and reliable PIXE analysis procedure. The analytical procedure was evaluated using scalp hair of pregnant women at 16-19 weeks of gestation. The samples were irradiated with 3.5 MeV protons from the Rutgers Nuclear Physics Department's 8 MV Tandem Fn Van de Graaff accelerator. The concentrations of the elements calcium to cadmium in hair are reported for 50 subjects. The analytical procedure is suitable for non-invasive clinical analysis for evaluation of nutritional states and for environmental exposure to toxic metals. (author)

  20. Method for separating FEL output beams from long wavelength radiation

    Energy Technology Data Exchange (ETDEWEB)

    Neil, George; Shinn, Michelle D.; Gubeli, Joseph

    2016-04-26

    A method for improving the output beam quality of a free electron laser (FEL) by reducing the amount of emission at wavelengths longer than the electron pulse length and reducing the amount of edge radiation. A mirror constructed of thermally conductive material and having an aperture therein is placed at an oblique angle with respect to the beam downstream of the bending magnet but before any sensitive use of the FEL beam. The aperture in the mirror is sized to deflect emission longer than the wavelength of the FEL output while having a minor impact on the FEL output beam. A properly sized aperture will enable the FEL radiation, which is coherent and generally at a much shorter wavelength than the bending radiations, to pass through the aperture mirror. The much higher divergence bending radiations will subsequently strike the aperture mirror and be reflected safely out of the way.

  1. Acoustic emission method for tracing crack propagation in pressure vessels

    International Nuclear Information System (INIS)

    A hemispherical model and a pressure vessel model were used as samples. In the former model, artificial notches were fabricated at the top. In the latter, two types of artificial notches were fabricated at the points of origin of the maximum stress (corners of the inner surface of the nozzles) in four nozzles with different shapes which were mounted on the model proper. The AE method was used to investigate the process of crack initiation and propagation from these artificial notches by means of repeated loading with internal pressure. It was possible to obtain from the results of these tests much useful data concerning the properties of AE and the points of origin of AE (positional tracking) when cracks are initiated and propagated in structures having complex shapes such as these samples. Simultaneously with the measurements by the AE method, Smek gages and crack gages mounted on the nozzle corners were used to investigate the crack initiation and propagation behavior. It was established that there is a close connection between them

  2. Methods of steering and focusing ion and electron beams

    International Nuclear Information System (INIS)

    This patent describes a method for steering or focussing beams such as ion or electron beams with a magnetic field. The method consists of: generating a large electric current in a straight conducting wire; projecting charged particles in proximity with the conducting wire; deflecting the charged particles by generating in proximity with the wire a circular magnetic field; confining each of the charged particles to a path which extends in a direction substantially coplanar with the conducting wire wherein a deflecting force generated by the coaxial magnetic field is exerted on each particle in the plane defined by the conducting wire and the path of the particle

  3. Low temperature Ti-Si-C thin film deposition by ion beam assisted methods

    Science.gov (United States)

    Twardowska, Agnieszka; Rajchel, Boguslaw; Jaworska, Lucyna

    2010-11-01

    Thin, multiphase Ti-Si-C coatings were formed by IBSD or by IBAD methods on AISI 316L steel substrates in room temperature, using single Ti3SiC2 target. In those methods the TiXSiCY coatings were formed from the flux of energetic atoms and ions obtained by ion sputtering of the Ti3SiC2 compound sample. As sputtering beam the beam of Ar+ ions at energy of 15keV was applied. In the IBAD method the dynamically formed coatings were additionally bombarded by beam of Ar+ ions at energy of 15keV. The ion beams parameters were obtained by using Monte Carlo computer simulations. The morphology (SEM, TEM), chemical (EDS/EDX) and phase composition (XRD) examinations of formed coatings were provided as well as confocal Raman microspectroscopy. Analyzed coatings were relatively thin (150nm-1μm), flat and dense. XRD analysis indicated in amorphous TiSi, the traces of Ti5Si3 and other phases from Ti-Si-C system (TiSi, TiSi2,Ti3SiC2). For chemical bonds investigation, the laser beam with length of 532nm was used. Those analyses were performed in the low (LR) or in high (HR) resolution modes in room temperature and in 4000C. In the HR mode the spectral resolution was close to 2 cm-1. In Raman spectra peaks at: 152cm-1, 216cm-1, 278cm-1, 311 cm-1, 608cm-1, 691cm-1 were recorded. Nanoindentation tests were done on coated and uncoated substrates with diamond, Berkovich-type indenter. Vickers hardness HIT and reduced elastic modulus EIT were calculated using Olivier& Pharr method. HIT for coated substrates was in the range 2.7 to 5.3 GPa, EIT was 160 GPa.

  4. Low temperature Ti-Si-C thin film deposition by ion beam assisted methods

    International Nuclear Information System (INIS)

    Thin, multiphase Ti-Si-C coatings were formed by IBSD or by IBAD methods on AISI 316L steel substrates in room temperature, using single Ti3SiC2 target. In those methods the TiXSiCY coatings were formed from the flux of energetic atoms and ions obtained by ion sputtering of the Ti3SiC2 compound sample. As sputtering beam the beam of Ar+ ions at energy of 15keV was applied. In the IBAD method the dynamically formed coatings were additionally bombarded by beam of Ar+ ions at energy of 15keV. The ion beams parameters were obtained by using Monte Carlo computer simulations. The morphology (SEM, TEM), chemical (EDS/EDX) and phase composition (XRD) examinations of formed coatings were provided as well as confocal Raman microspectroscopy. Analyzed coatings were relatively thin (150nm-1μm), flat and dense. XRD analysis indicated in amorphous TiSi, the traces of Ti5Si3 and other phases from Ti-Si-C system (TiSi, TiSi2,Ti3SiC2). For chemical bonds investigation, the laser beam with length of 532nm was used. Those analyses were performed in the low (LR) or in high (HR) resolution modes in room temperature and in 400deg. C. In the HR mode the spectral resolution was close to 2 cm-1. In Raman spectra peaks at: 152cm-1, 216cm-1, 278cm-1, 311 cm-1, 608cm-1, 691cm-1 were recorded. Nanoindentation tests were done on coated and uncoated substrates with diamond, Berkovich-type indenter. Vickers hardness HIT and reduced elastic modulus EIT were calculated using Olivier and Pharr method. HIT for coated substrates was in the range 2.7 to 5.3 GPa, EIT was 160 GPa.

  5. Shallow gas cloud illumination analysis by the focal beam method

    Science.gov (United States)

    Latiff, Abdul Halim Abdul

    2016-02-01

    This research will address the illumination issue of seismic data below a shallow gas cloud, also known as shallow gas accumulation. In general, poor and distorted seismic data underneath gas zones depend on four major factors; namely the velocity of the gas zones, the depth of the target reflector, the location of the source and the receiver during seismic acquisition, and the frequency of the seismic signals. These factors will be scrutinized in detail by using the focal beam method. The focal beam method incorporates the double focusing concept in order to obtain two important attributes for illumination analysis: (i) Resolution function beam, (ii) amplitude versus ray parameter (AVP) imprint, which is obtained by transforming the modelled data into the radon domain. Both illumination attributes are then applied to a gas-affected field in the Malaysia Basin. The results show well-defined illumination beneath the shallow anomalies and provide a better representation of the subsurface.

  6. Mathematic models for a ray tracing method and its applications in wireless optical communications.

    Science.gov (United States)

    Zhang, Minglun; Zhang, Yangan; Yuan, Xueguang; Zhang, Jinnan

    2010-08-16

    This paper presents a new ray tracing method, which contains a whole set of mathematic models, and its validity is verified by simulations. In addition, both theoretical analysis and simulation results show that the computational complexity of the method is much lower than that of previous ones. Therefore, the method can be used to rapidly calculate the impulse response of wireless optical channels for complicated systems. PMID:20721238

  7. A Ray-tracing Method to Analyzing Modulated Planar Fabry-Perot Antennas

    DEFF Research Database (Denmark)

    Hougs, Mikkel Dahl; Kim, Oleksiy S.; Breinbjerg, Olav

    2015-01-01

    A new approach for fast modelling of Fabry-Perot antennas with modulated partially reflective surfaces (PRS) using ray-tracing is proposed. For validation of the method, a configuration is introduced which consists of a cavity with a modulated PRS, fed internally by a magnetic dipole. The PRS...

  8. New Combined Electron-Beam Methods of Wastewater Purification

    International Nuclear Information System (INIS)

    The paper is a brief review of the results obtained with the participation of the authors from the study on combined electron-beam methods for purification of some wastewaters. The data on purification of wastewaters containing dyes or hydrogen peroxide and municipal wastewater in the aerosol flow are considered

  9. Dynamic Response of Inextensible Beams by Improved Energy Balance Method

    DEFF Research Database (Denmark)

    Sfahani, M. G.; Barari, Amin; Omidvar, M.;

    2011-01-01

    An improved He's energy balance method (EBM) for solving non-linear oscillatory differential equation using a new trial function is presented. The problem considered represents the governing equations of the non-linear, large-amplitude free vibrations of a slender cantilever beam with a...

  10. A three-dimensional sound ray tracing method by deploying regular tetrahedrons

    Institute of Scientific and Technical Information of China (English)

    JIANG Wei; LI Taibao

    2005-01-01

    A sound ray tracing algorithm is presented, which helps to rapidly find the sound ray trajectories in three-dimensional (3-D) space. At each step of ray tracing, a small regular tetrahedron is made in front of a ray, so that the sound speed field inside may be approximately regarded as linear. Since a ray trajectory in the linear sound speed field is always on a plane, it may be obtained by the two-dimensional (2-D) sound ray tracing method by deploying triangles.The theoretical derivation is given and a numerical model is discussed. It shows that the algorithm is fast and precise. It is also more concise and reliable than the traditional 3-D algorithms, and may be used to avoid the damage to the precision by the acoustic refraction in the 3-D ultrasound computerized tomography.

  11. Nuclear-based methods for the analysis of trace element pollutants in human hair

    International Nuclear Information System (INIS)

    During the implementation of an IAEA-coordinated international research programme on the use of nuclear methods (i.e. thermal neutron activation analysis, photon activation analysis, heavy particle induced X-ray emission analysis) for detecting trace element pollutants in hair, valuable data have been obtained for various population groups both on normal levels of trace elements and on increased levels caused by pollution. In the article 41 papers are reviewed, together with recommendations on the different procedures and the treatment of raw data. In comparing the data interesting observations were made relating to trace element concentrations. The review was presented at the Second Meeting on Nuclear Analytical Procedures, Dresden (GDR), 19-23 March 1979. (Sz.J.)

  12. Method for extremal control of the beam parameters in charged particle accelerators

    International Nuclear Information System (INIS)

    The method of extremal control of charged particle beam parameters is suggested for the solution of the timization problem ophe IHEP boster operation mode. Motion along the estimation of drift direction with simultaneous adaptation to the value of drift rate is organized in the suggested method of extremal control. It is assumed that trajectory of the drift extremum can be approximated by the piecewise-linear function. Estimation of the drift direction is exercised on the base of fixation of two consequent positions of the extremum in the control space. The identification of the drift-direction are introduced in the algorithm of tracing the extrenum drift. Investigation of the method on the test two-dimensional square surface has shown that the method provides drift tracing within the rate of 0.01 a deg - 2 a deg where a deg - the initial working step of the stochastic approximation method. The average deviation does not exceed 0.7 a deg, and the accuracy of adaptation to the value of drift rate 10-3 K

  13. A rapid and accurate two-point ray tracing method in horizontally layered velocity model

    Institute of Scientific and Technical Information of China (English)

    TIAN Yue; CHEN Xiao-fei

    2005-01-01

    A rapid and accurate method for two-point ray tracing in horizontally layered velocity model is presented in this paper. Numerical experiments show that this method provides stable and rapid convergence with high accuracies, regardless of various 1-D velocity structures, takeoff angles and epicentral distances. This two-point ray tracing method is compared with the pseudobending technique and the method advanced by Kim and Baag (2002). It turns out that the method in this paper is much more efficient and accurate than the pseudobending technique, but is only applicable to 1-D velocity model. Kim(s method is equivalent to ours for cases without large takeoff angles, but it fails to work when the takeoff angle is close to 90o. On the other hand, the method presented in this paper is applicable to cases with any takeoff angles with rapid and accurate convergence. Therefore, this method is a good choice for two-point ray tracing problems in horizontally layered velocity model and is efficient enough to be applied to a wide range of seismic problems.

  14. A method for generating double-ring-shaped vector beams

    Science.gov (United States)

    Huan, Chen; Xiao-Hui, Ling; Zhi-Hong, Chen; Qian-Guang, Li; Hao, Lv; Hua-Qing, Yu; Xu-Nong, Yi

    2016-07-01

    We propose a method for generating double-ring-shaped vector beams. A step phase introduced by a spatial light modulator (SLM) first makes the incident laser beam have a nodal cycle. This phase is dynamic in nature because it depends on the optical length. Then a Pancharatnam–Berry phase (PBP) optical element is used to manipulate the local polarization of the optical field by modulating the geometric phase. The experimental results show that this scheme can effectively create double-ring-shaped vector beams. It provides much greater flexibility to manipulate the phase and polarization by simultaneously modulating the dynamic and the geometric phases. Project supported by the National Natural Science Foundation of China (Grant No. 11547017), the Hubei Engineering University Research Foundation, China (Grant No. z2014001), and the Natural Science Foundation of Hubei Province, China (Grant No. 2014CFB578).

  15. Cardiac rate detection method based on the beam splitter prism

    Science.gov (United States)

    Yang, Lei; Liu, Xiaohua; Liu, Ming; Zhao, Yuejin; Dong, Liquan; Zhao, Ruirui; Jin, Xiaoli; Zhao, Jingsheng

    2013-09-01

    A new cardiac rate measurement method is proposed. Through the beam splitter prism, the common-path optical system of transmitting and receiving signals is achieved. By the focusing effect of the lens, the small amplitude motion artifact is inhibited and the signal-to-noise is improved. The cardiac rate is obtained based on the PhotoPlethysmoGraphy (PPG). We use LED as the light source and use photoelectric diode as the receiving tube. The LED and the photoelectric diode are on the different sides of the beam splitter prism and they form the optical system. The signal processing and display unit is composed by the signal processing circuit, data acquisition device and computer. The light emitted by the modulated LED is collimated by the lens and irradiates the measurement target through the beam splitter prism. The light reflected by the target is focused on the receiving tube through the beam splitter prism and another lens. The signal received by the photoelectric diode is processed by the analog circuit and obtained by the data acquisition device. Through the filtering and Fast Fourier Transform, the cardiac rate is achieved. We get the real time cardiac rate by the moving average method. We experiment with 30 volunteers, containing different genders and different ages. We compare the signals captured by this method to a conventional PPG signal captured concurrently from a finger. The results of the experiments are all relatively agreeable and the biggest deviation value is about 2bmp.

  16. Quantitative evaluation of ultrasonic wave propagation in inhomogeneous anisotropic austenitic welds using 3D ray tracing method. Numerical and experimental validation

    International Nuclear Information System (INIS)

    Austenitic welds and dissimilar welds are extensively used in primary circuit pipes and pressure vessels in nuclear power plants, chemical industries and fossil fuelled power plants because of their high fracture toughness, resistance to corrosion and creep at elevated temperatures. However, cracks may initiate in these weld materials during fabrication process or stress operations in service. Thus, it is very important to evaluate the structural integrity of these materials using highly reliable non-destructive testing (NDT) methods. Ultrasonic non-destructive inspection of austenitic welds and dissimilar weld components is complicated because of anisotropic columnar grain structure leading to beam splitting and beam deflection. Simulation tools play an important role in developing advanced reliable ultrasonic testing (UT) techniques and optimizing experimental parameters for inspection of austenitic welds and dissimilar weld components. The main aim of the thesis is to develop a 3D ray tracing model for quantitative evaluation of ultrasonic wave propagation in an inhomogeneous anisotropic austenitic weld material. Inhomogenity in the anisotropic weld material is represented by discretizing into several homogeneous layers. According to ray tracing model, ultrasonic ray paths are traced during its energy propagation through various discretized layers of the material and at each interface the problem of reflection and transmission is solved. The influence of anisotropy on ultrasonic reflection and transmission behaviour in an anisotropic austenitic weld material are quantitatively analyzed in three dimensions. The ultrasonic beam directivity in columnar grained austenitic steel material is determined three dimensionally using Lamb's reciprocity theorem. The developed ray tracing model evaluates the transducer excited ultrasonic fields accurately by taking into account the directivity of the transducer, divergence of the ray bundle, density of rays and phase

  17. Ray-tracing

    International Nuclear Information System (INIS)

    Ray-tracing procedures applicable to hard X-ray optics are presented. The ray-tracing program was applied to a model beam-line which may be installed in an 8 GeV synchrotron radiation facility. (author)

  18. Tuberculosis case finding: evaluation of a paper slip method to trace contacts.

    Directory of Open Access Journals (Sweden)

    Judith Mwansa-Kambafwile

    Full Text Available SETTING: South Africa has the third highest tuberculosis (TB burden in the world. Intensified case finding, recommended by WHO, is one way to control TB. OBJECTIVE: To evaluate the effectiveness and acceptability of a paper slip method for TB contact tracing. METHOD: TB patients were offered paper slips to give to their contacts, inviting them for TB screening. The number of contacts screened and the proportion diagnosed with TB was calculated. Contacts that returned to the clinic after receiving the slips were interviewed. A focus group discussion (FGD with TB patients was held to determine their acceptability. RESULTS: From 718 paper slips issued, a 26% TB contact tracing rate was found, with a 12% case detection rate. The majority (68% of contacts were screened within 2 weeks of receiving the slip. Age and gender were not significantly associated with time to screening. 16% of the contacts screened did not reside with the TB patients. 98% of the contacts said the method was acceptable. FGD findings show that this method is acceptable and may prevent stigma associated with TB/HIV. CONCLUSION: This simple, inexpensive method yields high contact tracing and case detection rates and potentially would yield additional benefits outside households.

  19. Detection of sub-ppm traces of aqueous heavy-metal ions using micro-electro-mechanical beam resonators

    Science.gov (United States)

    Rahafrooz, Amir; Pourkamali, Siavash

    2009-11-01

    Capacitive silicon micro-mechanical resonators have been utilized in this work as ultra-sensitive mass sensors for the detection of trace amounts of copper ions in water samples. The approach is based on the reduction of aqueous metal ions by the silicon in a resonant structure and consequently deposition of a very thin metal layer on the resonator surface changing its resonant frequency. Measurements demonstrate successful detection of sub-ppm concentrations of copper(II) ions in water. Relatively large frequency shifts (hundreds of ppm) have been measured for resonators exposed to copper concentrations as low as 4 µM (0.26 ppm). An analytical model for the resonant frequency of the resulting complex beams has been derived and used to calculate the thickness of the deposited copper layer based on the measured frequency shifts. The model shows that the measured frequency shifts correspond to only a few atomic layers of copper (as thin as ~7 Å) deposited on the resonator surfaces. This corresponds to a mass sensitivity of more than 4000 Hz µg-1 cm-2 which is much larger than the highest mass sensitivities measured for quartz crystal microbalances.

  20. Material-point Method Analysis of Bending in Elastic Beams

    DEFF Research Database (Denmark)

    Andersen, Søren Mikkel; Andersen, Lars

    The aim of this paper is to test different types of spatial interpolation for the materialpoint method. The interpolations include quadratic elements and cubic splines. A brief introduction to the material-point method is given. Simple liner-elastic problems are tested, including the classical...... cantilevered beam problem. As shown in the paper, the use of negative shape functions is not consistent with the material-point method in its current form, necessitating other types of interpolation such as cubic splines in order to obtain smoother representations of field quantities. It is shown that the...

  1. Material-Point Method Analysis of Bending in Elastic Beams

    DEFF Research Database (Denmark)

    Andersen, Søren Mikkel; Andersen, Lars

    2007-01-01

    The aim of this paper is to test different types of spatial interpolation for the material-point method. The interpolations include quadratic elements and cubic splines. A brief introduction to the material-point method is given. Simple liner-elastic problems are tested, including the classical...... cantilevered beam problem. As shown in the paper, the use of negative shape functions is not consistent with the material-point method in its current form, necessitating other types of interpolation such as cubic splines in order to obtain smoother representations of field quantities. It is shown that the...

  2. Pulse compression method for amplified spontaneous emission smooth beams

    International Nuclear Information System (INIS)

    In order to increase the intensity on target and the coupling efficiency, based on optical gain switching theory the paper presents a method for shortening the amplified spontaneous emission (ASE) smooth pulses. The experiment has been per- formed on EMG-150, a discharge laser in the Department of Experimental Physics, University of Szeged. As a result, the pulse bandwidth is shortened to 7.5 ns from 14.5 ns. and the uniformity of the ASE beams is not affected. (authors)

  3. Methods of Data Processing for Trace Elements Analysis Using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Wang, Rui; Ma, Xiaohong; Yu, Qi; Song, Yang; Zhao, Huafeng; Zhang, Min; Liao, Yanbiao

    2015-11-01

    With the development of Laser Induced Breakdown Spectroscopy (LIBS), increasing numbers of researchers have begun to focus on problems of the application. We are not just satisfied with analyzing what kinds of elements are in the samples but are also eager to accomplish quantitative detection with LIBS. There are several means to improve the limit of detection and stability, which are important to quantitative detection, especially of trace elements, increasing the laser energy and the resolution of spectrometer, using dual pulse setup, vacuuming the ablation environment etc. All of these methods are about to update the hardware system, which is effective but expensive. So we establish the following spectrum data processing methods to improve the trace elements analysis in this paper: spectrum sifting, noise filtering, and peak fitting. There are small algorithms in these three method groups, which we will introduce in detail. Finally, we discuss how these methods affect the results of trace elements detection in an experiment to analyze the lead content in Chinese cabbage. supported by National High-Tech R&D Program (863 Program), China (No. 2013AA102402)

  4. Trace elemental analysis of adenoma and carcinoma thyroid by PIXE method

    Science.gov (United States)

    Reddy, S. Bhuloka; John Charles, M.; Ravi Kumar, M.; Reddy, B. Seetharami; Anjaneyulu, Ch.; Naga Raju, G. J.; Sundareswar, B.; Vijayan, V.

    2002-11-01

    Trace elemental analysis was carried out in the biological samples of normal, adenoma and carcinoma thyroids using particle induced X-ray emission technique (PIXE). A 2 MeV proton beam was employed to excite the samples. The elements Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, I, Hg and Pb were identified and their concentrations were estimated. The concentrations of the elements Ca, Cu, Zn, As, I and Hg are found to be much lower in carcinoma thyroid than those in the normal thyroid while the concentration of the elements K, Ti, V, Cr, Mn, Fe, Co and Sr in carcinoma thyroid are higher than the concentrations in normal thyroid. The lower and higher values of some of the elements in carcinoma thyroid may be attributed to some pathological factors.

  5. Trace elements in human milk. Part of a coordinated programme on comparative methods for the study of trace elements in human nutrition

    International Nuclear Information System (INIS)

    New analytical methods based on radiochemical neutron activation analysis were developed for the determination of Sn, V, I and Se at nanogram levels in biological materials, particularly in milk and other foodstuffs. By the application of these and similar methods, results for trace elements in human and cow's milk were collected from which the normal concentration ranges of up to 12 trace elements were established. Significant data on vanadium levels were also collected allowing assessment of the dietary intake and body pool of this element and a reappraisal of its significance in nutrition. Similar data on a smaller scale were also collected for tin. Results were also obtained for several different trace elements in a range of biological reference materials

  6. Method and apparatus for laser-controlled proton beam radiology

    Science.gov (United States)

    Johnstone, Carol J.

    1998-01-01

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

  7. Phase and group velocity tracing analysis of projected wave packet motion along oblique radar beams – qualitative analysis of QP echoes

    Directory of Open Access Journals (Sweden)

    C. L. Fern

    2007-02-01

    Full Text Available The wave packets of atmospheric gravity waves were numerically generated, with a given characteristic wave period, horizontal wave length and projection mean wind along the horizontal wave vector. Their projection phase and group velocities along the oblique radar beam (vpr and vgr, with different zenith angle θ and azimuth angle φ, were analyzed by the method of phase- and group-velocity tracing. The results were consistent with the theoretical calculations derived by the dispersion relation, reconfirming the accuracy of the method of analysis. The RTI plot of the numerical wave packets were similar to the striation patterns of the QP echoes from the FAI irregularity region. We propose that the striation range rate of the QP echo is equal to the radial phase velocity vpr, and the slope of the energy line across the neighboring striations is equal to the radial group velocity vgr of the wave packet; the horizontal distance between two neighboring striations is equal to the characteristic wave period τ. Then, one can inversely calculate all the properties of the gravity wave responsible for the appearance of the QP echoes. We found that the possibility of some QP echoes being generated by the gravity waves originated from lower altitudes cannot be ruled out.

  8. Analytical calculation of spectral phase of grism pairs by the geometrical ray tracing method

    Science.gov (United States)

    Rahimi, L.; Askari, A. A.; Saghafifar, H.

    2016-07-01

    The most optimum operation of a grism pair is practically approachable when an analytical expression of its spectral phase is in hand. In this paper, we have employed the accurate geometrical ray tracing method to calculate the analytical phase shift of a grism pair, at transmission and reflection configurations. As shown by the results, for a great variety of complicated configurations, the spectral phase of a grism pair is in the same form of that of a prism pair. The only exception is when the light enters into and exits from different facets of a reflection grism. The analytical result has been used to calculate the second-order dispersions of several examples of grism pairs in various possible configurations. All results are in complete agreement with those from ray tracing method. The result of this work can be very helpful in the optimal design and application of grism pairs at various configurations.

  9. Trace elemental analysis of carcinoma kidney and stomach by PIXE method

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, S. Bhuloka E-mail: sbr_r@yahoo.com; John Charles, M.; Naga Raju, G.J.; Vijayan, V.; Seetharami Reddy, B.; Ravi Kumar, M.; Sundareswar, B

    2003-07-01

    Trace elemental analysis was carried out in the biological samples of carcinoma kidney and stomach using particle induced X-ray emission technique. A 2 MeV proton beam was employed to excite the samples. From the present results, the levels of elements K, Ca, Fe, Ni and Se are lower and those of the elements Ti, Co, Zn, As and Cd are higher in the cancer tissue of kidney than those observed in the normal tissue. In the case of stomach, the concentrations of elements Cl, K, Ca, Ti, Mn, Fe, Co, Cu and Zn are lower while concentrations of elements Cr, Ni, As and Br are higher in the cancer tissue of stomach than those observed in the normal tissue. The observed deficiency or excess of certain elements is correlated to carcinogenesis of that organ. The present results of carcinoma stomach support the previous observations that nickel and chromium are carcinogenic agents. The low levels of selenium observed in the carcinoma tissue of kidney and the low levels of manganese observed in the carcinoma tissue of stomach support the view that selenium and manganese inhibit the growth of cancer in kidney and stomach respectively. The observed high levels of zinc in the cancer tissue of kidney suggest that zinc is involved in the tumor growth and development of neoplastic transformation in kidney while the observed low levels of zinc in the carcinoma tissue of stomach suggest that zinc inhibits the growth of cancer in this organ. For correctly assessing the role played by the trace elements in initiating, promoting or inhibiting cancer in various organs, there is a need for acquisition of more data by trace elemental analysis from several investigations of this type undertaken in different regions.

  10. Ray tracing method for the grazing incidence flat-field imaging soft X-ray spectrometer

    International Nuclear Information System (INIS)

    A ray tracing method is introduced for helping adjustment and spectra analysis of the grazing incidence flat-field imaging soft X-ray spectrometer. For a single point source, the spectra images obtained by separate components, the toroidal mirror, and the grazing incidence flat-field concave grating with varied line spaces are given respectively. The calculated spectral images of the single point source by the spectrometer are also given for comparison with measurements with different experimental alignments

  11. Evaluation of Cylinder Volume Estimation Methods for In–Cylinder Pressure Trace Analysis

    OpenAIRE

    Adrian Irimescu

    2012-01-01

    In–cylinder pressure trace analysis is an important investigation tool frequently employed in the study of internal combustion engines. While technical data is usually available for experimental engines, in some cases measurements are performed on automotive engines for which only the most basic geometry features are available. Therefore, several authors aimed to determine the cylinder volume and length of the connecting rod by other methods than direct measurement. This stu...

  12. New method for mass spectrometric trace analysis of metals in biology and medicine

    International Nuclear Information System (INIS)

    A first survey on the basic aspects and applications of a novel method for trace analyses of metals is given. The advantages of this methodology for analyses of trace metals which was developed by our group are: small sample amount, high sensitivity and selectivity, simple sample preparation for the measurement (no ashing) and reliability and precision of the results. The time consumption for one complete quantitative analysis lies below 30 min. The concentration of monoisotopic metals, as for example aluminium, cesium, manganese etc. is determined using a calibration curve. Using stable isotope dilution analysis quantification of metals with at least two stable isotopes further improved the precision of the results. If this technique is utilized, on one hand contamination of the environment by radioactive substances is avoided, on the other even the smallest changes in concentrations of trace metals are detected unambigeously. The accuracy of the resulting quantitative data has been confirmed test measurements with other analytical methods such as atomic absorption spectroscopy and thermal ionization mass spectrometry. Although there is no doubt that the greatest analytical capacity of field desorption mass spectrometry is in the field of high-molecular weight natural products, it has been possible in the last years to modify the method for qualitative and quantitative investigations of more than 60 metals. (orig./EF)

  13. Analysis of reinforced concrete beams by the equivalent section method

    CERN Document Server

    Schulz, Mauro

    2014-01-01

    This research investigates the analysis of reinforced concrete beams subjected to combined axial load, bending moment and shear force. Cross-sections of general shape are divided, along the height, into plane elements. The biaxial behavior is represented according to the smeared rotating crack approach. Using traditionally accepted hypotheses for beams, the shear flow is determined by applying the Jouravski formula to an "equivalent section", which takes into account the nonlinear material behavior. The "Equivalent Section Method", originally proposed by Diaz (1980) and Diaz and Schulz (1981), is improved and simplified. The formulation is implemented applying the bidimensional constitutive model A, proposed by Vecchio and Collins (1993). The tension-stiffening effect is considered as adopted by Polak and Vecchio (1993). Shear slip at crack surfaces, Poisson's ratio and other secondary effects are not considered. Validation is undertaken by comparison with experimental results obtained by other researchers. T...

  14. Beam angle optimization for intensity-modulated radiation therapy using a guided pattern search method

    Science.gov (United States)

    Rocha, Humberto; Dias, Joana M.; Ferreira, Brígida C.; Lopes, Maria C.

    2013-05-01

    Generally, the inverse planning of radiation therapy consists mainly of the fluence optimization. The beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) consists of selecting appropriate radiation incidence directions and may influence the quality of the IMRT plans, both to enhance better organ sparing and to improve tumor coverage. However, in clinical practice, most of the time, beam directions continue to be manually selected by the treatment planner without objective and rigorous criteria. The goal of this paper is to introduce a novel approach that uses beam’s-eye-view dose ray tracing metrics within a pattern search method framework in the optimization of the highly non-convex BAO problem. Pattern search methods are derivative-free optimization methods that require a few function evaluations to progress and converge and have the ability to better avoid local entrapment. The pattern search method framework is composed of a search step and a poll step at each iteration. The poll step performs a local search in a mesh neighborhood and ensures the convergence to a local minimizer or stationary point. The search step provides the flexibility for a global search since it allows searches away from the neighborhood of the current iterate. Beam’s-eye-view dose metrics assign a score to each radiation beam direction and can be used within the pattern search framework furnishing a priori knowledge of the problem so that directions with larger dosimetric scores are tested first. A set of clinical cases of head-and-neck tumors treated at the Portuguese Institute of Oncology of Coimbra is used to discuss the potential of this approach in the optimization of the BAO problem.

  15. Beam angle optimization for intensity-modulated radiation therapy using a guided pattern search method

    International Nuclear Information System (INIS)

    Generally, the inverse planning of radiation therapy consists mainly of the fluence optimization. The beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) consists of selecting appropriate radiation incidence directions and may influence the quality of the IMRT plans, both to enhance better organ sparing and to improve tumor coverage. However, in clinical practice, most of the time, beam directions continue to be manually selected by the treatment planner without objective and rigorous criteria. The goal of this paper is to introduce a novel approach that uses beam’s-eye-view dose ray tracing metrics within a pattern search method framework in the optimization of the highly non-convex BAO problem. Pattern search methods are derivative-free optimization methods that require a few function evaluations to progress and converge and have the ability to better avoid local entrapment. The pattern search method framework is composed of a search step and a poll step at each iteration. The poll step performs a local search in a mesh neighborhood and ensures the convergence to a local minimizer or stationary point. The search step provides the flexibility for a global search since it allows searches away from the neighborhood of the current iterate. Beam’s-eye-view dose metrics assign a score to each radiation beam direction and can be used within the pattern search framework furnishing a priori knowledge of the problem so that directions with larger dosimetric scores are tested first. A set of clinical cases of head-and-neck tumors treated at the Portuguese Institute of Oncology of Coimbra is used to discuss the potential of this approach in the optimization of the BAO problem. (paper)

  16. Chemometric methods for studying the relationships between trace elements in laryngeal cancer and healthy tissues.

    Science.gov (United States)

    Dobrowolski, R; Klatka, J; Brodnjak-Voncina, D; Trojanowska, A; Myśliwiec, D; Ostrowski, J; Remer, M

    2014-06-01

    A quick and reliable method for the evaluation and classification of two types of tissues is presented. Several chemometric methods were applied to evaluate multivariate data of the tissue samples with respect to the content of trace elements. The content of Pb, Al, Zn, Cd, Cu, Ni and Co was determined in samples of healthy and cancerous tissue obtained from 26 patients. Determination was done at milligram/kilogram level with inductively coupled plasma optical emission spectrometry (ICP-OES) and atomic absorption spectroscopy (AAS) techniques. Contents of trace metals in studied tissues are not normally distributed; however, normal distribution was confirmed for log values. There is a statistically significant difference in the content of Zn, Cd, Cu and Al (p<0.01) and Ni and Co (p<0.05) when healthy tissue is compared to cancerous one. Correlation between contents of trace elements for studied tissues was positive; the highest was found between Zn and Cu. A chemometric methodology seems to be a promising tool for classifications of the tissue samples. PMID:24838928

  17. Analysis of trace elements in RSSR and its original juice by PIXE method

    International Nuclear Information System (INIS)

    This work has analyzed trace element contents in the flesh of fruit and its original juice of RSSR growing in Gansu province by PIXE method. The analysis data show that RSSR contains the sufficient trace elements, the most past of which are necessary for the human body, for example, K, Ca, Fe, Ti, Cu, Mn, Rb, Zn and Sr etc. elements have higher contents, among them, the contents of both K and Ca are quite rich, in total amount of the 13 elements; only their content sum account for above 95% the contents of toxic elements of Pb, As are lower than the level of permit dose. So, the drinks made with RSSR are benefit to the human health

  18. The acid cleaning method of labware for trace element analysis in snow and ice samples

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Acid cleaning processes were performed on a class 100 laminar flow clean bench assembled inside a class 1000 clean room.The ultrapure water was produced by Millipore RO (Reverse Osmosis) and Milli-Q water purification systems.The three purity grades of nitric acid used for cleaning include Merck reagent grade HNO3,Fisher "TraceMetal" grade HNO3,and the purest Fisher "Optima" grade HNO3.The various bottles,containers and other labware,which are in contact with the samples,are made of low-density polyethylene (LDPE) and FEP or PFA Teflon materials.The acid cleaning procedures of the bottles and other containers follow a successive four times cleaning through immersion in increasing purity of nitric acid baths at different concentrations during four weeks.The first acid bath is performed at room temperature,but the following three acid baths are heated on ceramic hotplates with a surface temperature of 45℃.In order to verify the efficiency of the acid cleaning method,cleaned bottles underwent a blank determination procedure using ELAN 6100 inductively coupled plasma spectrometry (ICP-MS).Results show that most measured trace elements are not detected and the elements detected are at very low concentrations.The blank values are comparable with that of bottles cleaned at Korea Polar Research Institute (KOPRI).Although the acid cleaning method is developed mainly for reliable measurements of trace elements in snow and ice samples,it can also be used for investigations of trace elements in other environmental samples.

  19. A Fast Radiochemical Method for the Determination of Some Essential Trace Elements in Biology and Medicine

    International Nuclear Information System (INIS)

    A method has been developed for the determination with neutron-activation analysis of the following trace elements in soft biological tissues: Br, Ca, Cl, Cu, K, Mg, Mn, Mo, Na, P, Sr and Zn. The method consists in performing a short-term irradiation of the samples with a high thermal neutron flux, followed by fast chemical separations and gamma-spectrometric measurements. The chemical separations and the measurements of short-lived nuclides from a run are finished within 70 min, after the end of irradiation

  20. Study on method of characteristics based on cell modular ray tracing

    International Nuclear Information System (INIS)

    To address the issue of accurately solving neutron transport problem in complex geometry, method of characteristics (MOC) is studied in this paper, and a quite effective and memory saving cell modular ray tracing (CMRT) method is developed and related angle discretization and boundary condition handling issues are discussed. A CMRT based MOC code-PEACH is developed and tested against C5G7 MOX benchmark problem. Numerical results demonstrate that PEACH can give excellent accuracy for both keff and pin power distribution for neutron transport problem. (authors)

  1. Neutron activation analysis of trace elements in carbonate rocks by using a ko standardization method

    International Nuclear Information System (INIS)

    The quantitative analysis of the trace element was conducted by the ko method using carbonate rock standard sample JLs-1 (limestone) and JDo-1 (Dolomite), and the effectiveness of the activation analysis with the ko method to the carbonate rock sample was confirmed. The accuracy of the quantitative measurement for the analysis results of long-lived nuclides of Al and Ba, middle-lived nuclides of Sm and Ho, and short-lived nuclides of Ce and Yb was evaluated compared with recommended values of Geological Survey of Japan. (H. Katsuta)

  2. An Improved Peak Sidelobe Reduction Method for Subarrayed Beam Scanning

    Directory of Open Access Journals (Sweden)

    Hang Hu

    2015-01-01

    Full Text Available This paper focused on PSL (peak sidelobe level reduction for subarrayed beam scanning in phased array radars. The desired GSP (Gaussian Subarray Patterns are achieved by creating a subarray weighting network. The GSP-based method could reduce PSL of array pattern; compared with the method based on the desired subarray pattern which is defined by ideal space-domain filter, the PSL reduction performance is improved remarkably. Further, based on the concept adopting superelement patterns to approximately express original subarray patterns, the simplified GSP-based method is proposed. So the dimension of each matrix required for creating the weighting network, which was originally the same as the element number, could be reduced to the same as the subarray number. Consequently, we achieve remarkable reduction of the computation burden; simultaneously, the PSL mitigation performance is degraded slightly. Simulation results demonstrate the validity of the introduced methods.

  3. Design method for automotive high-beam LED optics

    Science.gov (United States)

    Byzov, Egor V.; Moiseev, Mikhail A.; Doskolovich, Leonid L.; Kazanskiy, Nikolay L.

    2015-09-01

    New analytical method for the calculation of the LED secondary optics for automotive high-beam lamps is presented. Automotive headlamps should illuminate the road and the curb at the distance of 100-150 meters and create a bright, flat, relatively powerful light beam. To generate intensity distribution of this kind we propose to use TIR optical element (collimator working on the total internal reflection principle) with array of microlenses (optical corrector) on the upper surface. TIR part of the optical element enables reflection of the side rays to the front direction and provides a collimated beam which incidents on the microrelief. Microrelief, in its turn, dissipates the light flux in horizontal direction to meet the requirements of the Regulations 112, 113 and to provide well-illuminated area across the road in the far field. As an example, we computed and simulated the optical element with the diameter of 33 millimeters and the height of 22 millimeters. Simulation data shows that three illuminating modules including Cree XP-G2 LED and lens allow generating an appropriate intensity distribution for the class D of UNECE Regulations.

  4. ACCELERATION RENDERING METHOD ON RAY TRACING WITH ANGLE COMPARISON AND DISTANCE COMPARISON

    Directory of Open Access Journals (Sweden)

    Liliana liliana

    2007-01-01

    Full Text Available In computer graphics applications, to produce realistic images, a method that is often used is ray tracing. Ray tracing does not only model local illumination but also global illumination. Local illumination count ambient, diffuse and specular effects only, but global illumination also count mirroring and transparency. Local illumination count effects from the lamp(s but global illumination count effects from other object(s too. Objects that are usually modeled are primitive objects and mesh objects. The advantage of mesh modeling is various, interesting and real-like shape. Mesh contains many primitive objects like triangle or square (rare. A problem in mesh object modeling is long rendering time. It is because every ray must be checked with a lot of triangle of the mesh. Added by ray from other objects checking, the number of ray that traced will increase. It causes the increasing of rendering time. To solve this problem, in this research, new methods are developed to make the rendering process of mesh object faster. The new methods are angle comparison and distance comparison. These methods are used to reduce the number of ray checking. The rays predicted will not intersect with the mesh, are not checked weather the ray intersects the mesh. With angle comparison, if using small angle to compare, the rendering process will be fast. This method has disadvantage, if the shape of each triangle is big, some triangles will be corrupted. If the angle to compare is bigger, mesh corruption can be avoided but the rendering time will be longer than without comparison. With distance comparison, the rendering time is less than without comparison, and no triangle will be corrupted.

  5. Low temperature Ti-Si-C thin film deposition by ion beam assisted methods

    Energy Technology Data Exchange (ETDEWEB)

    Twardowska, Agnieszka; Rajchel, Boguslaw; Jaworska, Lucyna, E-mail: atwardow@up.krakow.pl

    2010-11-15

    Thin, multiphase Ti-Si-C coatings were formed by IBSD or by IBAD methods on AISI 316L steel substrates in room temperature, using single Ti{sub 3}SiC{sub 2} target. In those methods the Ti{sub X}SiC{sub Y} coatings were formed from the flux of energetic atoms and ions obtained by ion sputtering of the Ti{sub 3}SiC{sub 2} compound sample. As sputtering beam the beam of Ar{sup +} ions at energy of 15keV was applied. In the IBAD method the dynamically formed coatings were additionally bombarded by beam of Ar{sup +} ions at energy of 15keV. The ion beams parameters were obtained by using Monte Carlo computer simulations. The morphology (SEM, TEM), chemical (EDS/EDX) and phase composition (XRD) examinations of formed coatings were provided as well as confocal Raman microspectroscopy. Analyzed coatings were relatively thin (150nm-1{mu}m), flat and dense. XRD analysis indicated in amorphous TiSi, the traces of Ti{sub 5}Si{sub 3} and other phases from Ti-Si-C system (TiSi, TiSi{sub 2},Ti{sub 3}SiC{sub 2}). For chemical bonds investigation, the laser beam with length of 532nm was used. Those analyses were performed in the low (LR) or in high (HR) resolution modes in room temperature and in 400deg. C. In the HR mode the spectral resolution was close to 2 cm{sup -1}. In Raman spectra peaks at: 152cm{sup -1}, 216cm{sup -1}, 278cm{sup -1}, 311 cm{sup -1}, 608cm{sup -1}, 691cm{sup -1} were recorded. Nanoindentation tests were done on coated and uncoated substrates with diamond, Berkovich-type indenter. Vickers hardness H{sub IT} and reduced elastic modulus E{sub IT} were calculated using Olivier and Pharr method. H{sub IT} for coated substrates was in the range 2.7 to 5.3 GPa, E{sub IT} was 160 GPa.

  6. Method and system for treating an interior surface of a workpiece using a charged particle beam

    Science.gov (United States)

    Swenson, David Richard

    2007-05-23

    A method and system of treating an interior surface on an internal cavity of a workpiece using a charged particle beam. A beam deflector surface of a beam deflector is placed within the internal cavity of the workpiece and is used to redirect the charged particle beam toward the interior surface to treat the interior surface.

  7. Lifa Air Secure Box method for chilled beam cleaning

    OpenAIRE

    Leppälä, Vesa-Jukka

    2014-01-01

    The objective of this Bachelor’s Thesis was to introduce a chilled beam cleaning method and to develop an improved version for the prototype introduced in 2011. This thesis was commissioned by Lifa Air Ltd. The company itself is specialized in improving Indoor Air Quality and offers a wide range of products meant for ventilation cleaning. The aim for the development work was to fill the requirements and needs set by the company based on the research done, and to construct a working and improv...

  8. Simulation of intense beam bunching using 3D PIC method

    International Nuclear Information System (INIS)

    Most of the ion sources produce continuous beam of charged particles. In a cyclotron using such an external ion source, only a small fraction of the injected continuous beam is accepted in the central region for further acceleration. By transforming the continuous beam into a suitably bunched beam using a buncher prior to injection, the amount of accepted particles in the central region of cyclotron can be increased. To compress the continuous beam longitudinally one needs to impose a velocity modulation at the buncher gap which results in density modulation as the beam advances. In the case of low beam current the velocity modulation of the beam has very little effect on the transverse envelope of the beam. However, in the case of high intensity beams, the space-charge force introduces much collective behaviour and increase of current in the specified bunch width affects the transverse dynamics

  9. Stability Analysis of Nonuniform Rectangular Beams Using Homotopy Perturbation Method

    OpenAIRE

    Seval Pinarbasi

    2012-01-01

    The design of slender beams, that is, beams with large laterally unsupported lengths, is commonly controlled by stability limit states. Beam buckling, also called “lateral torsional buckling,” is different from column buckling in that a beam not only displaces laterally but also twists about its axis during buckling. The coupling between twist and lateral displacement makes stability analysis of beams more complex than that of columns. For this reason, most of the analytical studies in the li...

  10. Study of the extraction of the traces of Cadmium through the method of subestequiometric isotope dilution

    International Nuclear Information System (INIS)

    In this work, it has been used the method of subestequiometric isotope dilution for the determination of traces of cadmium and it has been compared with other conventional's methods for study its performance. The conditions of the experiment had been studied carefully in order to optimize the parameters such as pH, (8,0 - 10,1) it used the buffer NH3:NH4Cl, the time of agitation (>120 s) and the concentration of the organic reactive (dithizone). Besides, it obtains the respective curve of calibration. In this study, we can watch a line relation in all the range studied (5-40 μg of Cd). This method applied to the analysis of Cadmium in a certified sample of H-8 of the IAEA, it gives us the next value: 195 ± 5,4 ppm (LOD= 1,5 ppm, LOQ= 4,8 ppm), it is enough satisfactory in comparison with the certified middle value of 188,9±19 ppm. It demonstrates the utility of the method in the Cadmium traces analysis if it disposes of the radioisotope of this element and the appropriate detection equipment. (DEM). 34 refs., 15 tabs., 7 figs

  11. Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions

    International Nuclear Information System (INIS)

    The University of Maryland Dynamical Systems and Accelerator Theory Group carries out research in two broad areas: the computation of charged particle beam transport using Lie algebraic methods and advanced methods for the computation of electromagnetic fields and beam-cavity interactions. Important improvements in the state of the art are believed to be possible in both of these areas. In addition, applications of these methods are made to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. The Lie algebraic method of computing and analyzing beam transport handles both linear and nonlinear beam elements. Tests show this method to be superior to the earlier matrix or numerical integration methods. It has wide application to many areas including accelerator physics, intense particle beams, ion microprobes, high resolution electron microscopy, and light optics. With regard to the area of electromagnetic fields and beam cavity interactions, work is carried out on the theory of beam breakup in single pulses. Work is also done on the analysis of the high frequency behavior of longitudinal and transverse coupling impedances, including the examination of methods which may be used to measure these impedances. Finally, work is performed on the electromagnetic analysis of coupled cavities and on the coupling of cavities to waveguides

  12. A hydrogen ion beam method of molecular density measurement inside a 4.2-K beam tube

    International Nuclear Information System (INIS)

    In our first experiments on synchrotron radiation-induced photodesorption in a 4.2-K beam tube, the moleculm density was measured by room temperature ion gauges and RGAs outside the beam tube. The molecular density inside the 4.2-K beam tube was therefore unknown, since the mean molecular speed of photodesorbed molecules had not been measured. To determine the density inside the 4.2-K beam tube we have developed a direct method of measurement utilizing the neutralization of H+ beams, which are proportional to gas density. The hydrogen ion beams (up to 20 keV, ∼1 μA) are extracted from an rf ion source and guided into the cold beam tube by a bending magnet. The H0 and H- produced in the beam tube are magnetically separated from H- and detected with secondary electron multipliers (SEMs). Small superconducting dipole magnets located near the center of the beam tube allow a ∼20-cm segment of the injected ion beam to be offset a few mm from the injection axis; detection of H0 and H- produced along this offset segment provides a localized density measurement. If necessary, detector background due to synchrotron radiation photons can be discriminated against by gating the detector on between the bursts of synchrotron radiation. The experimental setup and initial data will be presented

  13. A hydrogen ion beam method of molecular density measurement inside a 4.2-K beam tube

    Energy Technology Data Exchange (ETDEWEB)

    Alinovsky, N.; Anashin, V.; Beschasny, P. [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)] [and others

    1994-06-01

    In our first experiments on synchrotron radiation-induced photodesorption in a 4.2-K beam tube, the moleculm density was measured by room temperature ion gauges and RGAs outside the beam tube. The molecular density inside the 4.2-K beam tube was therefore unknown, since the mean molecular speed of photodesorbed molecules had not been measured. To determine the density inside the 4.2-K beam tube we have developed a direct method of measurement utilizing the neutralization of H{sup +} beams, which are proportional to gas density. The hydrogen ion beams (up to 20 keV, {approximately}1 {mu}A) are extracted from an rf ion source and guided into the cold beam tube by a bending magnet. The H{sup 0} and H{sup {minus}} produced in the beam tube are magnetically separated from H{sup {minus}} and detected with secondary electron multipliers (SEMs). Small superconducting dipole magnets located near the center of the beam tube allow a {approximately}20-cm segment of the injected ion beam to be offset a few mm from the injection axis; detection of H{sup 0} and H{sup {minus}} produced along this offset segment provides a localized density measurement. If necessary, detector background due to synchrotron radiation photons can be discriminated against by gating the detector on between the bursts of synchrotron radiation. The experimental setup and initial data will be presented.

  14. Nuclear reaction analysis (NRA) for trace element detection

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Noll, K. [Bern Univ. (Switzerland)

    1997-09-01

    Ion beam induced nuclear reactions can be used to analyse trace element concentrations in materials. The method is especially suited for the detection of light contaminants in heavy matrices. (author) 3 figs., 2 refs.

  15. Modified, gallic acid - persulphate method for trace determination of vanadium in water samples

    International Nuclear Information System (INIS)

    The trace determination of vanadium in hydrogeochemical samples has great significance in geochemical exploration of uranium. The international reference method for determination of vanadium in water samples by kinetic spectrophotometric method is based on the catalytic effect of vanadium (V) on the oxidation of gallic acid by persulphate in acidic solution. Though very sensitive (D.L.=1.9 ng/mL), the method demands pin pointedly timed absorbance measurement. This communication recommends the use of ascorbic acid to hold the continuously increasing absorbances of samples, standards and blank. The linear dynamic working range was extended to 400 ng/mL as compared to that of 100 ng/mL reported in literature. Effect of other ions was investigated in detail. This method was applied to the analysis of natural water samples. The determination limit obtained was 0.8 ng/ml with an RSD of ±0.19%. (author)

  16. Trace element concentrations in iron type cosmic spherules determined by the SR-XRF method

    OpenAIRE

    Nozaki,Wataru/Nakamura,Tomoki/Iida,Atsuo/Matsuoka,Kenji/Takaoka,Nobuo

    1999-01-01

    The X-ray fluorescence method using synchrotron radiation (SR-XRF) was applied to determine trace element abundances in iron type (I-type) cosmic spherules collected at deep-sea sediments. Cr, Co, and Ni were detected from almost all spherules and average concentrations are 1336,2991ppm, and 4.0%, respectively. Ga, Ge, and Mn were detected from 20,30,and 20% of spherules and average concentrations are 4,4 and 486ppm, respectively. Spherules containing metallic cores were enriched in Ni and Co...

  17. Sampling and sample preparation methods for the analysis of trace elements in biological material

    International Nuclear Information System (INIS)

    The authors attempt to give a most systamtic possible treatment of the sample taking and sample preparation of biological material (particularly in human medicine) for trace analysis (e.g. neutron activation analysis, atomic absorption spectrometry). Contamination and loss problems are discussed as well as the manifold problems of the different consistency of solid and liquid biological materials, as well as the stabilization of the sample material. The process of dry and wet ashing is particularly dealt with, where new methods are also described. (RB)

  18. Monitoring of ground level air in the framework of trace analysis: methods and results

    International Nuclear Information System (INIS)

    Full text: Trace analysis allows the sensitive detection of radionuclide concentrations in ground level air in the range of μBq/m3. Typical time scales of less than one day up to a few days can be obtained in routine operation. Trace analysis measurements are performed in the framework of the German Integrated Measuring and Information system (IMIS) as well as within the International Monitoring System (IMS) used for the verification of the Comprehensive Nuclear Test Ban Treaty (CTBT). Within the environmental monitoring programmes of IMIS the Federal Office for Radiation Protection (BfS) performs measurements of aerosol bound radionuclides as well as of radioactive noble gases in the atmosphere. Aerosols are collected on filters with high volume air samplers and analysed by γ-spectrometry, α-spectrometry and integral measurements of the β-activity with preceding radiochemical separation. Noble gas samples from 15 sites worldwide are analysed to observe the 85Kr-release from nuclear fuel reprocessing plants and from 7 sites in Germany to monitor the 133Xe emitted from nuclear power plants. As part of the IMS an automatic aerosol sampling and measuring system as well as an automatic noble gas sampling and measuring system will be operated by the BfS at mount Schauinsland near Freiburg. Due to the expertise in noble gas measurements the BfS had been chosen to perform intercomparison experiments in advance with several automatic noble gas sampling and measuring systems to be used within the IMS. The general principles of the methods used for trace analysis and results from the BfS will be presented and discussed. In order to establish quality assurance programmes for trace analysis performed for IMIS a close collaboration between the involved German institutions has been established. First steps for the expansion of the cooperation to other European laboratories have been made. An informal data exchange between trace analysis laboratories in Europe (Ring of Five

  19. Determination of nitrogenase activity of induced cucumber nodules by 15N Trace method

    International Nuclear Information System (INIS)

    The author reports the determination results of nitrogenase activity of induced cucumber root nodules by 15N trace method. The root systems bearing induced nodules of cucumber were exposed to a gas mixture containing 15N2 for 48 h and partial root systems soaked in free-nitrogen culture solution simultaneously. After exposure the 15N content in the modulated root systems of cucumber is 0.431 Atom % 15N by mass spectrometric analysis, whereas in the contrast samples without exposure to 15N is 0.369 Atom % 15N. The statistical t test for the results of 15N trace experiments is: t = 3.15 > t0.01 = 2.819. It has been demonstrated that the nitrogenase activity in cucumber nodules is at a remarkable level of 99.9%. The nitrogenase activity in detached nodules of cucumber was also determined by conventional acetylene reduction method. In both methods clear evidences of nitrogenase activity were obtained for the induced nodules of cucumber

  20. Underwater Environment SDAP Method Using Multi Single-Beam Sonars

    Directory of Open Access Journals (Sweden)

    Zheping Yan

    2013-01-01

    Full Text Available A new autopilot system for unmanned underwater vehicle (UUV using multi-single-beam sonars is proposed for environmental exploration. The proposed autopilot system is known as simultaneous detection and patrolling (SDAP, which addresses two fundamental challenges: autonomous guidance and control. Autonomous guidance, autonomous path planning, and target tracking are based on the desired reference path which is reconstructed from the sonar data collected from the environmental contour with the predefined safety distance. The reference path is first estimated by using a support vector clustering inertia method and then refined by Bézier curves in order to satisfy the inertia property of the UUV. Differential geometry feedback linearization method is used to guide the vehicle entering into the predefined path while finite predictive stable inversion control algorithm is employed for autonomous target approaching. The experimental results from sea trials have demonstrated that the proposed system can provide satisfactory performance implying its great potential for future underwater exploration tasks.

  1. A new method to analyze copolymer based superplasticizer traces in cement leachates.

    Science.gov (United States)

    Guérandel, Cyril; Vernex-Loset, Lionel; Krier, Gabriel; De Lanève, Michel; Guillot, Xavier; Pierre, Christian; Muller, Jean François

    2011-03-15

    Enhancing the flowing properties of fresh concrete is a crucial step for cement based materials users. This is done by adding polymeric admixtures. Such additives have enabled to improve final mechanicals properties and the development of new materials like high performance or self compacting concrete. Like this, the superplasticizers are used in almost cement based materials, in particular for concrete structures that can have a potential interaction with drinking water. It is then essential to have suitable detection techniques to assess whether these organic compounds are dissolved in water after a leaching process or not. The main constituent of the last generation superplasticizer is a PolyCarboxylate-Ester copolymer (PCE), in addition this organic admixture contains polyethylene oxide (free PEO) which constitutes a synthesis residue. Numerous analytical methods are available to characterize superplasticizer content. Although these techniques work well, they do not bring suitable detection threshold to analyze superplasticizer traces in solution with high mineral content such as leachates of hardened cement based materials formulated with superplasticizers. Moreover those techniques do not enable to distinguish free PEO from PCE in the superplasticizer. Here we discuss two highly sensitive analytical methods based on mass spectrometry suitable to perform a rapid detection of superplasticizer compounds traces in CEM I cement paste leachates: MALDI-TOF mass spectrometry, is used to determine the free PEO content in the leachate. However, industrial copolymers (such as PCE) are characterized by high molecular weight and polymolecular index. These two parameters lead to limitation concerning analysis of copolymers by MALDI-TOFMS. In this study, we demonstrate how pyrolysis and a Thermally assisted Hydrolysis/Methylation coupled with a triple-quadrupole mass spectrometer, provides good results for the detection of PCE copolymer traces in CEM I cement paste

  2. A review of methods for assessment of trace element bioavailability in humans

    International Nuclear Information System (INIS)

    Deficiency of micronutrients is widespread among the low socio-economic strata of population. Different intervention strategies are used to eradicate these deficiencies. The most important step in the confirmation of the efficacy/success of an intervention is bioavailability. There are a number of methods for determining the bioavailability, involving both nuclear and non-nuclear techniques. Traditionally, bioavailability of different micronutrients was determined using the chemical balance method, that is, amount excreted subtracted from the amount ingested. Nowadays, methodologies have been developed for measuring the bioavailability of different trace elements incorporating the use of isotopes. The isotopic techniques are very accurate and highly specific. This paper summarizes the various methodologies available with special emphasis on nuclear methods. (author)

  3. Deflation as a Method of Variance Reduction for Estimating the Trace of a Matrix Inverse

    CERN Document Server

    Gambhir, Arjun Singh; Orginos, Kostas

    2016-01-01

    Many fields require computing the trace of the inverse of a large, sparse matrix. The typical method used for such computations is the Hutchinson method which is a Monte Carlo (MC) averaging over matrix quadratures. To improve its convergence, several variance reductions techniques have been proposed. In this paper, we study the effects of deflating the near null singular value space. We make two main contributions. First, we analyze the variance of the Hutchinson method as a function of the deflated singular values and vectors. Although this provides good intuition in general, by assuming additionally that the singular vectors are random unitary matrices, we arrive at concise formulas for the deflated variance that include only the variance and mean of the singular values. We make the remarkable observation that deflation may increase variance for Hermitian matrices but not for non-Hermitian ones. This is a rare, if not unique, property where non-Hermitian matrices outperform Hermitian ones. The theory can b...

  4. A new method for beam stacking in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C.M.; /Fermilab

    2008-06-01

    Recently, I developed a new beam stacking scheme for synchrotron storage rings called 'longitudinal phase-space coating' (LPSC). This scheme has been convincingly validated by multi-particle beam dynamics simulations and has been demonstrated with beam experiments at the Fermilab Recycler. Here, I present the results from both simulations and experiments. The beam stacking scheme presented here is the first of its kind.

  5. Robotics Methods for Beam Line Instrument Simulation and Control

    International Nuclear Information System (INIS)

    The majority of sample positioning systems in use at neutron and synchrotron beam line facilities around the world, may be accurately described as serial robot manipulators, i.e. they comprise a series of rotating or translating links connected together in a chain, with the tool or sample that is to be manipulated attached to one end. This characterization suggests that the methods of serial robot kinematic modeling might be usefully applied to the task of simulating and controlling beam line positioning systems. We describe how this approach is being developed within the planning, simulation and control software, SScanSS. The advantages of using the robotics approach are shown to include the ability to: (1) model any number of disparate positioning systems from within one software (and hence one user interface), with a minimum of instrument specific code, (2) accurately and speedily position and orientate samples of arbitrary complexity, and (3) provide options for automatically optimizing other important experimental parameters, such as the measurement count time. The possible extension of this technique to include parallel robotic systems, such as Stewart Platforms, is also discussed

  6. A method of beam control for NFZ-10 industrial irradiation linac

    International Nuclear Information System (INIS)

    Traditionally negative feedback coming from output beam is used to stabilize output beam by regulating filament voltage of bombarding diode electron gun. The authors analysed the shortcomings of the method in detail and put forward a new method of regulating bombarding high voltage in NFZ-10 industrial irradiation linac. Output beam with high stability and high accuracy was obtained

  7. Beam based gain calibration method for beam position monitor at J-PARC MR

    International Nuclear Information System (INIS)

    Stability of the closed orbit is one of very important points for stable operations to keep a small beam loss in MR. The relative gains of the output data may drift due to unpredictable imbalance among output signals from the pickup electrodes, because the output signals must travel through separate paths, such as cables, connectors, attenuators, switches, and then are measured by detectors. In KEKB, we found noticeable errors larger than 0.1mm in the almost all BPM readings. In KEKB, A non-linear chi-square method has received practical application to calibrate these errors come from the imbalance among 4 output voltage of a BPM. However, we were not able to apply a same method as KEKB to analyze a gain of BPMs in J-PARC. W noticed linear relations among 4 outputs voltage and analyzed the imbalance by the total least-squares method. This paper introduce the new method to estimate the related gains from four output data of a BPM head. (author)

  8. Very accurate (definitive) methods by radiochemical NAA and their significance for quality assurance in trace analysis

    International Nuclear Information System (INIS)

    The idea of very accurate (definitive) methods by RNAA for the determination of individual trace elements in selected matrices is presented. The approach is based on combination of neutron activation with selective and truly quantitative post-irradiation isolation of an indicator radionuclide by column chromatography followed by high resolution γ-ray spectrometric measurement. The method should be, in principle, a single element method to optimize all conditions with respect to determination of this particular element. Radiochemical separation scheme should assure separation of the analyte from practically all accompanying radionuclides to provide interference-free γ-ray spectrometric measurement and achieving best detection limits. The method should have some intrinsic mechanisms incorporated into the procedure preventing any possibility of making gross errors. Several criteria were formulated which must be simultaneously fulfilled in order to acknowledge the analytical result as obtained by definitive method. Such methods are not intended for routine measurements but rather for verifying the accuracy of other methods of analysis and certification of the candidate reference materials. The usefulness of such methods is illustrated on the example of Cd and references are given to similar methods elaborated for the determination of several other elements (Co, Cu, Mo, Ni and U) in biological materials. (author)

  9. Method and apparatus for efficient photodetachment and purification of negative ion beams

    Science.gov (United States)

    Beene, James R.; Liu, Yuan; Havener, Charles C.

    2008-02-26

    Methods and apparatus are described for efficient photodetachment and purification of negative ion beams. A method of purifying an ion beam includes: inputting the ion beam into a gas-filled multipole ion guide, the ion beam including a plurality of ions; increasing a laser-ion interaction time by collisional cooling the plurality of ions using the gas-filled multipole ion guide, the plurality of ions including at least one contaminant; and suppressing the at least one contaminant by selectively removing the at least one contaminant from the ion beam by electron photodetaching at least a portion of the at least one contaminant using a laser beam.

  10. Spin tracking simulations in AGS based on ray-tracing methods - bare lattice, no snakes

    International Nuclear Information System (INIS)

    This Note reports on the first simulations of and spin dynamics in the AGS using the ray-tracing code Zgoubi. It includes lattice analysis, comparisons with MAD, DA tracking, numerical calculation of depolarizing resonance strengths and comparisons with analytical models, etc. It also includes details on the setting-up of Zgoubi input data files and on the various numerical methods of concern in and available from Zgoubi. Simulations of crossing and neighboring of spin resonances in AGS ring, bare lattice, without snake, have been performed, in order to assess the capabilities of Zgoubi in that matter, and are reported here. This yields a rather long document. The two main reasons for that are, on the one hand the desire of an extended investigation of the energy span, and on the other hand a thorough comparison of Zgoubi results with analytical models as the 'thin lens' approximation, the weak resonance approximation, and the static case. Section 2 details the working hypothesis : AGS lattice data, formulae used for deriving various resonance related quantities from the ray-tracing based 'numerical experiments', etc. Section 3 gives inventories of the intrinsic and imperfection resonances together with, in a number of cases, the strengths derived from the ray-tracing. Section 4 gives the details of the numerical simulations of resonance crossing, including behavior of various quantities (closed orbit, synchrotron motion, etc.) aimed at controlling that the conditions of particle and spin motions are correct. In a similar manner Section 5 gives the details of the numerical simulations of spin motion in the static case: fixed energy in the neighboring of the resonance. In Section 6, weak resonances are explored, Zgoubi results are compared with the Fresnel integrals model. Section 7 shows the computation of the (rvec n) vector in the AGS lattice and tuning considered. Many details on the numerical conditions as data files etc. are given in the Appendix Section

  11. Dynamic Calculation Method of Beam System Under Low Velocity Impact

    Institute of Scientific and Technical Information of China (English)

    LI Wen-pei; WANG De-rong; SONG Chun-ming; WANG Ming-yang

    2008-01-01

    The beating beams and the supporting beams under low velocity impact may be in four different strain stages of deformation depending on the impact intensity and beam structure strength. Based on the different judging conditions of deformation stages, the corresponding calculation models are proposed, the calculation formulae for the determination of the impact force and the beam's lateral displacement are obtained. Calculation shows that the beam's total deflection is small when the flexibility of the supporting component is high and the effect of diminishing deflection disappears almost when the stiffness of the supporting component is high.

  12. Supporting soil remediation at Fernald by electron beam methods

    International Nuclear Information System (INIS)

    Electron beam techniques have been used to characterize uranium-contaminated soils at the Fernald Site, Ohio. The major uranium phases have been identified by analytical electron microscopy (AEM) as uranyl phosphate (autunite), uranium oxide (uraninite), and uranium phosphite [U(PO3)4]. Luminescence and X-ray absorption spectroscopy incorrectly identified uranium oxide hydrate (schoepite) as the major phase in Fernald soils. The solubilities of schoepite and autunite are very different, so a solubility-dependent remediation method selected for schoepite will not be effective for removing autunite. AEM is the only technique capable of precisely identifying unknown submicron phases. The uranium phosphite has been found predominantly at the incinerator site at Fernald. This phase has not been removed successfully by any of the chemical remediation technologies. We suggest that an alternative physical extraction procedure be applied to remove this phase

  13. Mathematical and Numerical Methods for Non-linear Beam Dynamics

    CERN Document Server

    Herr, W

    2014-01-01

    Non-linear effects in accelerator physics are important for both successful operation of accelerators and during the design stage. Since both of these aspects are closely related, they will be treated together in this overview. Some of the most important aspects are well described by methods established in other areas of physics and mathematics. The treatment will be focused on the problems in accelerators used for particle physics experiments. Although the main emphasis will be on accelerator physics issues, some of the aspects of more general interest will be discussed. In particular, we demonstrate that in recent years a framework has been built to handle the complex problems in a consistent form, technically superior and conceptually simpler than the traditional techniques. The need to understand the stability of particle beams has substantially contributed to the development of new techniques and is an important source of examples which can be verified experimentally. Unfortunately, the documentation of ...

  14. Stability Analysis of Nonlinear Feedback Control Methods for Beam Halo-chaos

    Institute of Scientific and Technical Information of China (English)

    WANGZhong-sheng; FANGJin-qing; CHENGuan-rong

    2003-01-01

    Control of beam halo-chaos has been a more challenge subject in recent years, in which nonlinear feedback method for beam halo-chaos has been developed for control of beam halo-chaos in high-current proton linear accelerators. However, stability analysis of nonlinear feedback control methods for beam halo-chaos has still been an open and important topic in this field. In this letter.

  15. Uniform irradiation system using beam scanning method for cyclotron

    International Nuclear Information System (INIS)

    JAERI AVF-cyclotron is equipped with an ion beam scanner for large area irradiation. The two-dimensional fluence distribution of ion beam obtained using cellulose triacetate film dosimeter was not uniform. This is resulted from the distortion of excitation current for electromagnet of the scanner. So, the beam scanning condition, i.e., the relation between the ion species, the beam profile and the scanning width, was extremely limited to make a good uniformity. We have developed a beam scanning simulator to get fluence distributions by calculation and then compared the simulated distributions with the measured ones. It was revealed that the both of them are in good agreement and the beam scanning condition to get good uniformity was led by using this simulator. On the basis of these results, the power supply of scanner was improved. A good uniformity of beam distribution was available. (author)

  16. Evaluation of Cylinder Volume Estimation Methods for In–Cylinder Pressure Trace Analysis

    Directory of Open Access Journals (Sweden)

    Adrian Irimescu

    2012-09-01

    Full Text Available In–cylinder pressure trace analysis is an important investigation tool frequently employed in the study of internal combustion engines. While technical data is usually available for experimental engines, in some cases measurements are performed on automotive engines for which only the most basic geometry features are available. Therefore, several authors aimed to determine the cylinder volume and length of the connecting rod by other methods than direct measurement. This study performs an evaluation of two such methods. The most appropriate way was found to be the estimation of connecting rod length based on general engine category as opposed to the use of an equation that predicts cylinder volume with good accuracy around top dead centre for most geometries.

  17. Evaluation of welding residual stresses in austenitic stainless steel using diffraction spot trace method

    International Nuclear Information System (INIS)

    A diffraction spot trace method (DSTM) was developed to measure internal stresses of materials with coarse grains. The DSTM was applied to light metals, such as aluminum alloy and magnesium alloy. In this study, validity of the DSTM was examined using high energy synchrotron X-rays of 70 keV. The specimen was a welded plate of austenitic stainless steel (SUS316L). The thickness of the specimen was 9 mm. The improved rotating slit-system was used, and PILATUS was used as an area detector. It was difficult to detect the high energy X-rays due to the reduction of counting efficiency of the PILATUS. However, the residual stress map of the welding specimen was obtained spending long exposure time. The residual stresses of the welding specimen were simulated by a finite element method (FEM). The outline of the residual stress measured by the DSTM coincided with that by the FEM. (author)

  18. Evaluation of welding residual stresses in austenitic stainless steel using diffraction spot trace method

    International Nuclear Information System (INIS)

    A diffraction spot trace method (DSTM) was developed to measure internal stresses of materials with coarse grains. The DSTM was applied to light metals, such as aluminum alloy and magnesium alloy. In this study, validity of the DSTM was examined using high energy synchrotron X-rays of 70 keV. The specimen was a welded plate of austenitic stainless steel (SUS316L). The thickness of the specimen was 9 mm. The improved rotating slit-system was used, and PILATUS was used as an area detector. It was difficult to detect the high energy X-rays due to the reduction of counting efficiency of the PILATUS. However, the residual stress map of the welding specimen was obtained by long exposure time. The residual stresses of the welding specimen were simulated by a finite element method (FEM). The outline of the residual stress measured by the DSTM coincided with that by the FEM. (author)

  19. The method innovation in nuclear equipment quality witness tracing and management

    International Nuclear Information System (INIS)

    The total construction cost of a nuclear power plant, equipment procurement cost accounts for about 47%-53%. Whether the quality of equipment can meet the technical requirements plays a significant role in the operation and maintenance of a nuclear power plant. Only if we adopt effective management can the equipment quality be ensured. As the most important method of quality control, the effective attendance and track of quality witness points has a crucial effect on contract smooth implementation as well. The essay mainly illustrates the method of quality witness point tracing and management and how to incorporate serious minded ideas and all take part in ways into quality management, hoping to offer some enlightenment on the innovation of nuclear power equipment quality management. (author)

  20. Electrochemical preconcentration and hydride generation methods for trace determination of selenium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The use of atomic absorption spectrometry in combination with two different preconcentration/separation techniques for the determination of trace concentrations of selenium is described. Electrochemical preconcentration onto a platinum electrode with a subsequent atomization of selenium is discussed briefly. Several parameters are considered such as the presence of depolarizers, and the temperature of the electrolyzed solutions. Special attention is payed to the efficiency of the atomization step, and a method to improve this is proposed. Applications of the technique to real samples are also reported. Secondly, the separation of the selenium as the volatile selenium hydride from the sample solution is considered. Several papers in this thesis deal with commonly occurring interferants as nickel and copper and with ways of minimizing or avoiding the interferring effects, whereas other papers relate to more theoretical aspects of the hydride generation process. New methods for the determination of selenium in technical samples with high contents of nickel and copper are also presented

  1. Heat-Flux Analysis of Solar Furnace Using the Monte Carlo Ray-Tracing Method

    International Nuclear Information System (INIS)

    An understanding of the concentrated solar flux is critical for the analysis and design of solar-energy-utilization systems. The current work focuses on the development of an algorithm that uses the Monte Carlo ray-tracing method with excellent flexibility and expandability; this method considers both solar limb darkening and the surface slope error of reflectors, thereby analyzing the solar flux. A comparison of the modeling results with measurements at the solar furnace in Korea Institute of Energy Research (KIER) show good agreement within a measurement uncertainty of 10%. The model evaluates the concentration performance of the KIER solar furnace with a tracking accuracy of 2 mrad and a maximum attainable concentration ratio of 4400 sun. Flux variations according to measurement position and flux distributions depending on acceptance angles provide detailed information for the design of chemical reactors or secondary concentrators

  2. Introducing GAMER: A fast and accurate method for ray-tracing galaxies using procedural noise

    Energy Technology Data Exchange (ETDEWEB)

    Groeneboom, N. E.; Dahle, H., E-mail: nicolaag@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)

    2014-03-10

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  3. Introducing GAMER: A fast and accurate method for ray-tracing galaxies using procedural noise

    International Nuclear Information System (INIS)

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  4. Determination of trace elements in epiphytic lichens from Bandar Baru Bangi, Selangor using INAA method

    International Nuclear Information System (INIS)

    Full-text: Lichens have been used as effective bio monitors of atmospheric pollutants as they can take up nutrients and pollutants directly from the atmosphere. In this study, trace element contents in epiphytic lichens were determined using INAA method. Samples were collected from 7 sampling locations around Bandar Baru Bangi, Selangor. The elements detected were As (1.73 ± 0.85 mg/ kg), Ce (3.65 ± 1.91 mg/ kg), Co (0.29 ± 0.12 mg/ kg), Cr (5.92 ± 3.54 mg/kg), Cs (0.92 ± 0.25 mg/ kg), Eu (0.03 ± 0.02 mg/ kg), Fe (1280 ± 760 mg/ kg), Hf (0.37 ± 0.18 mg/ kg), La (1.52 ± 0.89 mg/kg), Rb (27.7 ± 4.8 mg/ kg), Sc (0.33 ± 0.19 mg/ kg), Sm (0.28 ± 0.16 mg/ kg), Th (1.21 ± 0.62 mg/ kg) and Zn (116 ± 27 mg/ kg). Comparisons were then made between the elemental concentrations obtained and the baseline data from literature. Results showed that most of the elements were within the concentration range of the baseline data. Enrichment factors (EF) of the trace element in lichens showed that most of the elements were within the range of the baseline data except for As which was found to be slightly enriched (EF: 13.2 - 28.5). Regression analysis indicated significant correlation (p<0.05) with Sc for most of the elements which signifies crustal input except for Cs and Rb. The poor correlations of Cs and Rb with Sc may be due to the mobility of these elements. In summary, trace element data obtained using INAA were very useful and demonstrated that lichens were suitable bio monitors for identifying potential trace element pollutants in ambient air around the sampling area. (author)

  5. Methods for beam data acquisition offered by a mini-phantom

    International Nuclear Information System (INIS)

    Mini-phantoms are an important tool for measurement of basic head scatter parameters in high-energy photon beams, and recently they have also been used for beam quality specification. Therefore the feasibility and reliability of basic beam parameter acquisition using only a mini-phantom is checked in 6, 18 and 25 MV photon beams. These parameters include head scatter correction factors, phantom scatter correction factors, total scatter correction factors, wedge factors, off-axis ratios, as well as beam attenuation coefficients and beam hardening coefficients. In order to specify beam quality variations and beam quality modifications by a wedge, two different methods are compared: the first method uses a constant source to chamber distance of 1 m, the second method refers to narrow beam geometry. μ values derived with two different beam quality specification methods show a systematic deviation. However, relative variations of the attenuation coefficient within the beam and the associated beam quality modifications observed with the two methods show good agreement in open and wedged beams. Phantom scatter correction factors are calculated from measured head scatter correction factors and total scatter correction factors as well as from attenuation coefficients. Measured and calculated phantom scatter correction factors agree within 1% with the values given in literature. For 18 and 25 MV photon beam, wedge factors measured in water or in the mini-phantom agree within 0.5%, but maximum deviations of ∼1.5% are observed at 6 MV for the largest field sizes. It is demonstrated that the determination of several beam data related to full scatter conditions does not necessarily require the availability of a full scatter phantom. The mini-phantom is a reliable but very cheap and simple tool. It offers versatile possibilities to measure, check and verify basic beam parameters in high-energy photon beams. (author)

  6. A sensitive fluorimetric method for determination of trace amounts of nitrite based on luminescence energy transfer

    International Nuclear Information System (INIS)

    An efficient luminescence energy transfer (LET) system based on terbium(III)-sodium hexametaphosphate (Tb/SHMP) chelates as donor and 4-((4-(2-aminoethylamino)naphthalen-1-yl)diazenyl)benzenesulfonic acid dihydrochloride (ANDBS) as acceptor was developed for sensitive determination of trace nitrite. Stable and strong fluorescence Tb/SHMP chelates were prepared in aqueous solution. Based on Griess Reaction, ANDBS was generated by the quantitative reaction of nitrite, sulfanilamide and N-(1-naphtyl)-ethylenediamine dihydrochloride (N1NED). The degree of the overlap was effective for LET between the emission spectrum of Tb/SHMP chelates and the absorption spectrum of ANDBS. Based on the luminescence intensity quenching of Tb/SHMP chelates in proportion to the trace amounts of nitrite, a new assay for the selective and sensitive determination of nitrite was developed. Under the optimum conditions, the linear calibration graph was obtained with a linear range of 0.00040-0.20 μg mL-1 (R=0.99657). The detection limit of NO2- was 0.00010 μg mL-1 (R=0.99657). The method was applied successfully to the determination of nitrite for synthetic samples.

  7. The method of polarized traces for the 2D Helmholtz equation

    Science.gov (United States)

    Zepeda-Núñez, Leonardo; Demanet, Laurent

    2016-03-01

    We present a solver for the 2D high-frequency Helmholtz equation in heterogeneous acoustic media, with online parallel complexity that scales optimally as O (N/L), where N is the number of volume unknowns, and L is the number of processors, as long as L grows at most like a small fractional power of N. The solver decomposes the domain into layers, and uses transmission conditions in boundary integral form to explicitly define "polarized traces", i.e., up- and down-going waves sampled at interfaces. Local direct solvers are used in each layer to precompute traces of local Green's functions in an embarrassingly parallel way (the offline part), and incomplete Green's formulas are used to propagate interface data in a sweeping fashion, as a preconditioner inside a GMRES loop (the online part). Adaptive low-rank partitioning of the integral kernels is used to speed up their application to interface data. The method uses second-order finite differences. The complexity scalings are empirical but motivated by an analysis of ranks of off-diagonal blocks of oscillatory integrals. They continue to hold in the context of standard geophysical community models such as BP and Marmousi 2, where convergence occurs in 5 to 10 GMRES iterations. While the parallelism in this paper stems from decomposing the domain, we do not explore the alternative of parallelizing the systems solves with distributed linear algebra routines.

  8. A sensitive fluorimetric method for determination of trace amounts of nitrite based on luminescence energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Wang Lun, E-mail: wanglun@mail.ahnu.edu.c [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Chen Jingguo; Chen Hongqi; Zhou Cailing; Ling Bo; Fu Jie [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China)

    2011-01-15

    An efficient luminescence energy transfer (LET) system based on terbium(III)-sodium hexametaphosphate (Tb/SHMP) chelates as donor and 4-((4-(2-aminoethylamino)naphthalen-1-yl)diazenyl)benzenesulfonic acid dihydrochloride (ANDBS) as acceptor was developed for sensitive determination of trace nitrite. Stable and strong fluorescence Tb/SHMP chelates were prepared in aqueous solution. Based on Griess Reaction, ANDBS was generated by the quantitative reaction of nitrite, sulfanilamide and N-(1-naphtyl)-ethylenediamine dihydrochloride (N1NED). The degree of the overlap was effective for LET between the emission spectrum of Tb/SHMP chelates and the absorption spectrum of ANDBS. Based on the luminescence intensity quenching of Tb/SHMP chelates in proportion to the trace amounts of nitrite, a new assay for the selective and sensitive determination of nitrite was developed. Under the optimum conditions, the linear calibration graph was obtained with a linear range of 0.00040-0.20 {mu}g mL{sup -1} (R=0.99657). The detection limit of NO{sub 2}{sup -} was 0.00010 {mu}g mL{sup -1} (R=0.99657). The method was applied successfully to the determination of nitrite for synthetic samples.

  9. Fast beam cut-off method in RF-knockout extraction for spot-scanning

    CERN Document Server

    Furukawa, T

    2002-01-01

    An irradiation method with magnetic scanning has been developed in order to provide accurate irradiation even for an irregular target shape. The scanning method has strongly required a lower ripple of the beam spill and a faster response to beam-on/off in slow extraction from a synchrotron ring. At HIMAC, RF-knockout extraction has utilized a bunched beam to reduce the beam-spill ripple. Therefore, particles near the resonance can be spilled out from the separatrices by synchrotron oscillation as well as by a transverse RF field. From this point of view, a fast beam cut-off method has been proposed and verified by both simulations and experiments. The maximum delay from the beam cut-off signal to beam-off has been improved to around 60 mu s from 700 mu s by a usual method. Unwanted dose has been considerably reduced by around a factor of 10 compared with that by the usual method.

  10. Arrayed waveguide grating using the finite difference beam propagation method

    Science.gov (United States)

    Toledo, M. C. F.; Alayo, M. I.

    2013-03-01

    The purpose of this work is to analyze by simulation the coupling effects occurring in Arrayed Waveguide Grating (AWG) using the finite difference beam propagation method (FD-BPM). Conventional FD-BPM techniques do not immediately lend themselves to the analysis of large structures such as AWG. Cooper et al.1 introduced a description of the coupling between the interface of arrayed waveguides and star couplers using the numerically-assisted coupled-mode theory. However, when the arrayed waveguides are spatially close, such that, there is strong coupling between them, and coupled-mode theory is not adequate. On the other hand, Payne2 developed an exact eigenvalue equation for the super modes of a straight arrayed waveguide which involve a computational overhead. In this work, an integration of both methods is accomplished in order to describe the behavior of the propagation of light in guided curves. This new method is expected to reduce the necessary effort for simulation while also enabling the simulation of large and curved arrayed waveguides using a fully vectorial finite difference technique.

  11. Experimental device for measurement of dielectronic recombination cross section of C3+: method of confluent beam method

    International Nuclear Information System (INIS)

    Description of an instrumental device allowing dielectronic recombination cross section measurement is presented. Recombination of C3+ for high quantum number is studied. This device, using the confluent beam method, entailed the development of an electron gun producing weakly divergent beam. A detector of highly excited ion allowing a quick and accurate measurement of ion beam energy is described in detail. Beam-residual gas interaction mechanisms are studied and instrumental incertitudes are calculated

  12. On alternative methods for measuring the radius and propagation ratio of axially symmetric laser beams

    International Nuclear Information System (INIS)

    Based on the developed efficient numerical methods for calculating the propagation of light beams, the alternative methods for measuring the beam radius and propagation ratio proposed in the international standard ISO 11146 are analysed. The specific calculations of the alternative beam propagation ratios Mi2 performed for a number of test beams with a complicated spatial structure showed that the correlation coefficients ci used in the international standard do not establish the universal one-to-one relation between the alternative propagation ratios Mi2 and invariant propagation ratios Mσ2 found by the method of moments. (laser beams)

  13. Gaussian Beams Tracing and Predicting Model Based on Space Quad-tree Division%基于空间四叉树分区的高斯波束跟踪预测模型

    Institute of Scientific and Technical Information of China (English)

    任佳敏; 徐大专; 朱秋明; 唐亚平; 周生奎

    2013-01-01

    As to using radio wave propagation prediction in urban areas, the process of intersection detection for the tracing of Gaussian beams is too complicated, this paper proposes a space division method based on quad-tree to equally distribute the obstacles of the scene into a series of sub-space and accurately locate the grids where the axis of the beams cross through. Simulation result shows that the accelerated Gaussian beam tracing method is roughly equal than and as accurate as ray racing, but prediction efficiency can be increased several times, which is quite useful for the design and optimization of wireless network.%在城市环境中运用三维高斯波束跟踪进行电波传播预测时,障碍物碰撞的波束跟踪过程较为复杂。为此,提出一种基于空间四叉树的加速算法,将仿真场景进行层次分区,保证建筑物在各个分区中得到均匀分配,通过准确定位射线经过的分区,减少相交测试的数目。仿真结果表明,该算法的预测精度与传统射线跟踪法基本相当,但预测效率可提高数十倍,可用于辅助无线网络的规划、设计和优化。

  14. Method and apparatus for reducing coherence of high-power laser beams

    Science.gov (United States)

    Moncur, Norman K.; Mayer, Frederick J.

    1978-01-01

    Method and apparatus for reducing the coherence and for smoothing the power density profile of a collimated high-power laser beam in which the beam is focused at a point on the surface of a target fabricated of material having a low atomic number. The initial portion of the focused beam heats the material to form a hot reflective plasma at the material surface. The remaining, major portion of the focused beam is reflected by the plasma and recollected to form a collimated beam having reduced beam coherence.

  15. New Wideband Beam-forming Method Used in Underwater Communication System%New Wideband Beam-forming Method Used in Underwater Communication System

    Institute of Scientific and Technical Information of China (English)

    苏为; 黄晓燕; 程恩; 袁飞; 孙海信

    2011-01-01

    A novel wideband beam-forming structure with constant beam width based on complex coefficients (FIR) digital filters used in underwater acoustic communication is proposed. First, the received signals are compensated with integer sampling period by using delay line. Then their complex envelopes are calculated by using frequency shift method. Finally, the envelopes are weighted by using complex coefficients FIR digital filters whose coefficients are optimized. Simulation re- sults show that, in the communication band, the maximum difference between the designed beam and desired beam is less than 0.3 dB when the ratio of communication band to carrier frequency is 0. 85.

  16. Influence of Sample Pretreatment Methods on the Determination of Trace Oxygen in Iron and Steel

    Science.gov (United States)

    Yasuhara, H.; Shimura, M.; Yoshioka, K.

    1997-04-01

    Removing the oxide film from the sample surface is an important process in analyzing trace oxygen in iron and steel. The depth profiles of oxygen on the surface after electropolishing in CH3COOH - HClO4, CrO3 - H3PO4, and HCl, and chemical polishing by HF- H2O2 are investigated. The thickness of the oxide layer after electropolishing is estimated to be about 3 nm, which is approximately equivalent to 1 mass ppm oxygen. This indicates that the currently available surface polishing methods are inadequate for the analysis of mass ppm or sub-ppm oxygen levels. A surface without an oxide layer is obtained by Ar ion sputtering in a vacuum, but the oxide layer reappears within 1 min when the sample comes into contact with air.

  17. Ethylene and ammonia traces measurements from the patients' breath with renal failure via LPAS method

    Science.gov (United States)

    Popa, C.; Dutu, D. C. A.; Cernat, R.; Matei, C.; Bratu, A. M.; Banita, S.; Dumitras, D. C.

    2011-11-01

    The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurements of breath biomarkers has opened up new promises for monitoring and diagnostics in recent years, especially because breath test is a non-invasive method, safe, rapid and acceptable to patients. Our study involved assessment of breath ethylene and breath ammonia levels in patients with renal failure receiving haemodialysis (HD) treatment. Breath samples from healthy subjects and from patients with renal failure were collected using chemically inert aluminized bags and were subsequently analyzed using the LPAS technique. We have found out that the composition of exhaled breath in patients with renal failure contains not only ethylene, but also ammonia and gives valuable information for determining efficacy and endpoint of HD. Analysis of ethylene and ammonia traces from the human breath may provide insight into severity of oxidative stress and metabolic disturbances and may ensure optimal therapy and prevention of pathology at patients on continuous HD.

  18. Stein's method and the multivariate CLT for traces of powers on the classical compact groups

    CERN Document Server

    Döbler, Christian

    2010-01-01

    Let $M_n$ be a random element of the unitary, special orthogonal, or unitary symplectic groups, distributed according to Haar measure. By a classical result of Diaconis and Shahshahani, for large matrix size $n$, the vector $ (\\on{Tr}(M_n), \\on{Tr}(M_n^2),..., \\on{Tr}(M_n^d))$ tends to a vector of independent, (real or complex) Gaussian random variables. Recently, Jason Fulman has demonstrated that for a single power $j$ (which may grow with $n$), a speed of convergence result may be obtained via Stein's method of exchangeable pairs. In this note, we extend Fulman's result to the multivariate central limit theorem for the full vector of traces of powers.

  19. Analytic Method Based on Identification of Ellipse Parameters for Scanner Calibration in Cone-Beam Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Noo, F.; Clackdoyle, R.; Mennessier, C.; White, Timothy Andrew; Roney, Timothy Joseph

    2000-11-01

    This paper is about calibration of cone-beam (CB) scanners for both x-ray computed tomography and single-photon emission computed tomography. Scanner calibration refers here to the estimation of a set of parameters which fully describe the geometry of data acquisition. Such parameters are needed for the tomographic reconstruction step. The discussion is limited to the usual case where the cone vertex and planar detector move along a circular path relative to the object. It is also assumed that the detector does not have spatial distortions. We propose a new method which requires a small set of measurements of a simple calibration object consisting of two spherical objects, that can be considered as `point' objects. This object traces two ellipses on the detector and from the parametric description of these ellipses, the calibration geometry can be determined analytically using explicit formulae. The method is robust and easy to implement. However, it is not fully general as it is assumed that the detector is parallel to the rotation axis of the scanner. Implementation details are given for an experimental x-ray CB scanner.

  20. Analytic method based on identification of ellipse parameters for scanner calibration in cone-beam tomography

    International Nuclear Information System (INIS)

    This paper is about calibration of cone-beam (CB) scanners for both x-ray computed tomography and single-photon emission computed tomography. Scanner calibration refers here to the estimation of a set of parameters which fully describe the geometry of data acquisition. Such parameters are needed for the tomographic reconstruction step. The discussion is limited to the usual case where the cone vertex and planar detector move along a circular path relative to the object. It is also assumed that the detector does not have spatial distortions. We propose a new method which requires a small set of measurements of a simple calibration object consisting of two spherical objects, that can be considered as 'point' objects. This object traces two ellipses on the detector and from the parametric description of these ellipses, the calibration geometry can be determined analytically using explicit formulae. The method is robust and easy to implement. However, it is not fully general as it is assumed that the detector is parallel to the rotation axis of the scanner. Implementation details are given for an experimental x-ray CB scanner. (author)

  1. Analytic method based on identification of ellipse parameters for scanner calibration in cone-beam tomography

    Energy Technology Data Exchange (ETDEWEB)

    Noo, Frederic [Institut d' Electricite Montefiore, Universite de Liege (Belgium); Department of Radiology, University of Utah (United States). E-mail: noo at montefiore.ulg.ac.be; Clackdoyle, Rolf [Department of Radiology, University of Utah (United States); Mennessier, Catherine [Universite J. Fourier, Grenoble (France); White, Timothy A.; Roney, Timothy J. [Idaho National Engineering and Environmental Laboratory (United States)

    2000-11-01

    This paper is about calibration of cone-beam (CB) scanners for both x-ray computed tomography and single-photon emission computed tomography. Scanner calibration refers here to the estimation of a set of parameters which fully describe the geometry of data acquisition. Such parameters are needed for the tomographic reconstruction step. The discussion is limited to the usual case where the cone vertex and planar detector move along a circular path relative to the object. It is also assumed that the detector does not have spatial distortions. We propose a new method which requires a small set of measurements of a simple calibration object consisting of two spherical objects, that can be considered as 'point' objects. This object traces two ellipses on the detector and from the parametric description of these ellipses, the calibration geometry can be determined analytically using explicit formulae. The method is robust and easy to implement. However, it is not fully general as it is assumed that the detector is parallel to the rotation axis of the scanner. Implementation details are given for an experimental x-ray CB scanner. (author)

  2. Analytic method based on identification of ellipse parameters for scanner calibration in cone-beam tomography.

    Science.gov (United States)

    Noo, F; Clackdoyle, R; Mennessier, C; White, T A; Roney, T J

    2000-11-01

    This paper is about calibration of cone-beam (CB) scanners for both x-ray computed tomography and single-photon emission computed tomography. Scanner calibration refers here to the estimation of a set of parameters which fully describe the geometry of data acquisition. Such parameters are needed for the tomographic reconstruction step. The discussion is limited to the usual case where the cone vertex and planar detector move along a circular path relative to the object. It is also assumed that the detector does not have spatial distortions. We propose a new method which requires a small set of measurements of a simple calibration object consisting of two spherical objects, that can be considered as 'point' objects. This object traces two ellipses on the detector and from the parametric description of these ellipses, the calibration geometry can be determined analytically using explicit formulae. The method is robust and easy to implement. However, it is not fully general as it is assumed that the detector is parallel to the rotation axis of the scanner. Implementation details are given for an experimental x-ray CB scanner. PMID:11098919

  3. Study of biomaterials by ion-beam based methods

    International Nuclear Information System (INIS)

    primary beam and is activated following the nuclear reaction A(a,b)B. Some generated radioactive heavy ions B acquire sufficient kinetic energy to recoil out of the target and be implanted in the material. The nuclear reaction 56 Fe(p,n)56Co has been chosen to apply the UTLA (Ultra Thin Layer Activation) method because of its high cross section. Moreover, the half-life T= 77.1 days and the 846 keV gamma ray of the 56 Co radioelement is well suited for this study. The radioactive ions are implanted into the near surface (a few hundred nanometers). Wear/corrosion rate of the component by using tribological testers is observed via the variation of its activity caused by the loss of material. The layout of the experimental setup is presented as well as the angular distribution of the implanted recoil ions. In case of direct method the nuclear reaction occurs on the material surface. In order to obtain supplementary data concerning radiation influence on polyethylene samples doses up to 100 kGy were used. The advantages of this technique is the possibility to extend its applicability to any kind of solid material: plastics, ceramics, semiconductors , and metals. (authors)

  4. The beam steering in beamlines and rings using the methods of sequential filtering

    International Nuclear Information System (INIS)

    The method of sequential filtering was used in the field of accelerator monitoring and control. The application of this method in wide field of accelerator identification and control is presented. The identification theory and sequential filtering survey, algorithms based on the methods of sequential filtering for the beam-kick errors and beam-focus errors estimation, for the trajectory and closed orbit correction in the beam-lines and rings are overviewed. (R.P.) 5 refs.; 3 figs

  5. Performance of a novel multiple-signal luminescence sediment tracing method

    Science.gov (United States)

    Reimann, Tony

    2014-05-01

    Optically Stimulated Luminescence (OSL) is commonly used for dating sediments. Luminescence signals build up due to exposure of mineral grains to natural ionizing radiation, and are reset when these grains are exposed to (sun)light during sediment transport and deposition. Generally, luminescence signals can be read in two ways, potentially providing information on the burial history (dating) or the transport history (sediment tracing) of mineral grains. In this study we use a novel luminescence measurement procedure (Reimann et al., submitted) that simultaneously monitors six different luminescence signals from the same sub-sample (aliquot) to infer the transport history of sand grains. Daylight exposure experiments reveal that each of these six signals resets (bleaches) at a different rate, thus allowing to trace the bleaching history of the sediment in six different observation windows. To test the feasibility of luminescence sediment tracing in shallow-marine coastal settings we took eight sediment samples from the pilot mega-nourishment Zandmotor in Kijkduin (South-Holland). This site provides relatively controlled conditions as the morphological evolution of this nourishment is densely monitored (Stive et al., 2013). After sampling the original nourishment source we took samples along the seaward facing contour of the spit that was formed from August 2011 (start of nourishment) to June 2012 (sampling). It is presumed that these samples originate from the source and were transported and deposited within the first year after construction. The measured luminescence of a sediment sample was interpolated onto the daylight bleaching curve of each signal to assign the Equivalent Exposure Time (EET) to a sample. The EET is a quantitative measure of the full daylight equivalent a sample was exposed to during sediment transport, i.e. the higher the EET the longer the sample has been transported or the more efficient it has been exposed to day-light during sediment

  6. Suppression of beam halo-chaos using nonlinear feedback discrete control method

    CERN Document Server

    Fang Jin Qing; Chen Guan Rong; Luo Xiao Shu; Weng Jia Qiang

    2002-01-01

    Based on nonlinear feedback control method, wavelet-based feedback controller as a especial nonlinear feedback function is designed for controlling beam halo-chaos in high-current accelerators of driven clean nuclear power system. PIC simulations show that suppression of beam halo-chaos are realized effectively after discrete control of wavelet-based feed-back is applied to five kinds of the initial proton beam distributions, respectively. The beam halo strength factor is quickly reduced to zero, and other statistical physical quantities of beam halo-chaos are more than doubly reduced. These performed PIC simulation results demonstrate that the developed methods are very effective for control of beam halo-chaos. Potential application of the beam halo-chaos control methods is discussed finally

  7. Simultaneous determination of electron beam profile and material response using self-consistent iterative method

    Science.gov (United States)

    Kandel, Yudhishthir; Denbeaux, Gregory

    2016-08-01

    We develop a novel iterative method to accurately measure electron beam shape (current density distribution) and monotonic material response as a function of position. A common method is to scan an electron beam across a knife edge along many angles to give an approximate measure of the beam profile, however such scans are not easy to obtain in all systems. The present work uses only an electron beam and multiple exposed regions of a thin film of photoresist to measure the complete beam profile for any beam shape, where the material response is characterized externally. This simplifies the setup of new experimental tools. We solve for self-consistent photoresist thickness loss response to dose and the electron beam profile simultaneously by optimizing a novel functional iteratively. We also show the successful implementation of the method in a real world data set corrupted by noise and other experimental variabilities.

  8. Official Methods for the Determination of Minerals and Trace Elements in Infant Formula and Milk Products: A Review.

    Science.gov (United States)

    Poitevin, Eric

    2016-01-01

    The minerals and trace elements that account for about 4% of total human body mass serve as materials and regulators in numerous biological activities in body structure building. Infant formula and milk products are important sources of endogenic and added minerals and trace elements and hence, must comply with regulatory as well as nutritional and safety requirements. In addition, reliable analytical data are necessary to support product content and innovation, health claims, or declaration and specific safety issues. Adequate analytical platforms and methods must be implemented to demonstrate both the compliance and safety assessment of all declared and regulated minerals and trace elements, especially trace-element contaminant surveillance. The first part of this paper presents general information on the mineral composition of infant formula and milk products and their regulatory status. In the second part, a survey describes the main techniques and related current official methods determining minerals and trace elements in infant formula and milk products applied for by various international organizations (AOAC INTERNATIONAL, the International Organization for Standardization, the International Dairy Federation, and the European Committe for Standardization). The third part summarizes method officialization activities by Stakeholder Panels on Infant Formula and Adult Nutritionals and Stakeholder Panel on Strategic Food Analytical Methods. The final part covers a general discussion focusing on analytical gaps and future trends in inorganic analysis that have been applied for in infant formula and milk-based products. PMID:26821839

  9. Radioactive ion beam production by the ISOL method for SPIRAL

    International Nuclear Information System (INIS)

    This work is directly related to the SPIRAL project (Systeme de Production d'Ions Radioactifs Acceleres en Lignes) of which the start up will begin in September 2001 at GANIL (Grand Accelerateur National d'Ions Lourds) in Caen. This thesis primarily concerns the development of radioactive ion production systems (target/ion source) by the thorough study of each production stage of the ISOL (Isotopic Separation On Line) method: target and/or projectile fragmentation production, diffusion out of target material, effusion into the ion source and finally the ionization of the radioactive atoms. A bibliographical research and thermal simulations allowed us to optimize materials and the shape of the production and diffusion targets. A first target was optimized and made reliable for the radioactive noble gases production (argon, neon...). A second target dedicated to the radioactive helium production was entirely designed and realised (from the specifications to the 'off line' and 'on line' tests). Finally, a third target source system was defined for singly-charged radioactive alkaline production. The intensities of secondary beams planned for SPIRAL are presented here. A detailed study of the diffusion effusion efficiency for these various targets showed that the use of a fine microstructure carbon (grain size of 1 μm) improved the diffusion and showed the importance of thickness of the lamella for the short lived isotope effusion. (author)

  10. A novel method for trapping and analyzing 15N in NO for tracing NO sources

    Science.gov (United States)

    Kang, Ronghua; Mulder, Jan; Dörsch, Peter

    2016-04-01

    15N isotope tracing is an effective and direct approach to investigate the biological and chemical sources of nitric oxide (NO) in soil. However, NO is highly reactive and rapidly converted to nitrogen dioxide (NO2) in the presence of ozone. Various chemical conversions of NO to the more stable solutes nitrite (NO2-) and nitrate (NO3-) have been proposed, which allow analysing the 15N abundance without major fractionation. However, NO emissions from soils are usually small, posing major challenges to conversion efficiency and background contamination. Here we present a novel method in which NO is oxidized to NO2- by chromium trioxide (CrO3) prior to conversion to NO2- and NO3- in an alkaline hydrogen peroxide (H2O2) solution. Immediately following trapping, manganese dioxide (MnO2) and 5M HCl are added to remove excess H2O2, and to adjust the pH to around 6.0-7.0, respectively. The resulting solution can be stored until analysis and is none-toxic, allowing to use a modified denitrifier method (Zhu et al., submitted), where NO2- and NO3- are reduced quantitatively to nitrous oxide (N2O). Optimum NO conversion rates of > 90% even at extremely low initial NO concentration were obtained with 4% H2O2, 0.5 M NaOH, and 0.5 L min-1 gas flow rate. In a laboratory test, using NO gas with different 15N signals produced from unlabelled and labelled NO2-, we found an overall precision of 0.4‰ for unlabelled and 49.7‰ for NO enriched with 1.0 atom% 15N, respectively. This indicates that this method can be used for both natural abundance studies of NO, as well as in labelling studies tracing NO sources. Zhu J, Yu L, Bakken LR, Mørkved PT, Mulder J, Dörsch P. Controlled induction of denitrification in Pseudomonas aureofaciens: a modified denitrifier method for 15N and 18O analysis in NO3- from natural water samples by IRMS. Submitted.

  11. Determination of trace uranyl ions in aquatic medium by a useful and simple method

    International Nuclear Information System (INIS)

    Determination of trace uranyl ions was performed by using mixed micellar system and spectrophotometric determination. The method is based on cloud point extraction of uranyl ions after formation of an ion-association complex in the presence of Celestine Blue and sodium dodecyl sulfate. Then, the formed complex was extracted to non-ionic surfactant phase of Triton X-114 at pH 8.0. The optimal extraction and reaction conditions (e.g. concentrations and types of surfactants, concentration of complex forming agent, incubation conditions) were studied and analytical characteristics of the method (e.g. limit of detection, linear range, pre-concentration factor) were obtained by experimental studies. Linearity was obeyed in the range of 50-1,500 ng mL-1 for uranium(VI) ion and the detection limit of is 14.20 ng mL-1. The interference effects of common ions were also tested and validation studies were performed by using recovery test. The method was applied to the determination of uranium(VI) in several real samples. (author)

  12. Heavy ion beams in extended materials - Computational methods and experiment

    Science.gov (United States)

    Wilson, J. W.; Schimmerling, W.; Wong, M.; Townsend, L. W.

    1987-01-01

    The transport of heavy ion beams in extended materials is a problem of interest in accelerator and space shielding, radiation therapy, and astrophysical and radiobiological studies. The beam particles change their energy and direction of motion through atomic/molecular collisions and undergo occasional radical transformation in nuclear collision. In health physics applications, a heavy ion beam of initially well defined radiation quality is transformed into a complex mixture of diverse quality components after passing through a modest amount of material. This transformation of radiation quality must be understood to adequately explain the biological response of tissue to heavy ion radiation. A theoretical/experimental program to define an ion beam and its products in extended matter is described.

  13. Electrostatic dispersion lenses and ion beam dispersion methods

    Science.gov (United States)

    Dahl, David A [Idaho Falls, ID; Appelhans, Anthony D [Idaho Falls, ID

    2010-12-28

    An EDL includes a case surface and at least one electrode surface. The EDL is configured to receive through the EDL a plurality of ion beams, to generate an electrostatic field between the one electrode surface and either the case surface or another electrode surface, and to increase the separation between the beams using the field. Other than an optional mid-plane intended to contain trajectories of the beams, the electrode surface or surfaces do not exhibit a plane of symmetry through which any beam received through the EDL must pass. In addition or in the alternative, the one electrode surface and either the case surface or the other electrode surface have geometries configured to shape the field to exhibit a less abrupt entrance and/or exit field transition in comparison to another electrostatic field shaped by two nested, one-quarter section, right cylindrical electrode surfaces with a constant gap width.

  14. ANALYSIS OF REINFORCED CONCRETE BEAMS BY THE EQUIVALENT SECTION METHOD

    OpenAIRE

    Schulz, Mauro; Santisi D'Avila, Maria Paola

    2011-01-01

    This research investigates the analysis of reinforced concrete beams subjected to combined axial load, bending moment and shear force. Cross-sections of general shape are divided, along the height, into plane elements. The biaxial behavior is represented according to the smeared rotating crack approach. Using traditionally accepted hypotheses for beams, the shear flow is determined by applying the Jouravski formula to an "equivalent section", which takes into account the nonlinear material be...

  15. CRIS: A new method in isomeric beam production

    Directory of Open Access Journals (Sweden)

    Lynch K.M.

    2013-12-01

    Full Text Available The Collinear Resonance Ionization Spectroscopy (CRIS experiment at ISOLDE, CERN, uses laser radiation to stepwise excite and ionize an atomic beam for the purpose of ultra-sensitive detection of rare isotopes, and hyperfine-structure measurements. The technique also offers the ability to purify an ion beam that is heavily contaminated with radioactive isobars, including the ground state of an isotope from its isomer, allowing decay spectroscopy on nuclear isomeric states to be performed. The isomeric ion beam is selected by resonantly exciting one of its hyperfine structure levels, and subsequently ionizing it. This selectively ionized beam is deflected to a decay spectroscopy station (DSS. This consists of a rotating wheel implantation system for alpha- and beta-decay spectroscopy, and up to three germanium detectors around the implantation site for gamma-ray detection. Resonance ionization spectroscopy and the new technique of laser assisted nuclear decay spectroscopy have recently been performed at the CRIS beam line on the neutron-deficient francium isotopes. Here an overview of the two techniques will be presented, alongside a description of the CRIS beam line and DSS.

  16. CRIS: A new method in isomeric beam production

    International Nuclear Information System (INIS)

    The Collinear Resonance Ionization Spectroscopy (CRIS) experiment at ISOLDE, CERN, uses laser radiation to stepwise excite and ionize an atomic beam for the purpose of ultra-sensitive detection of rare isotopes, and hyperfine-structure measurements. The technique also offers the ability to purify an ion beam that is heavily contaminated with radioactive isobars, including the ground state of an isotope from its isomer, allowing decay spectroscopy on nuclear isomeric states to be performed. The isomeric ion beam is selected by resonantly exciting one of its hyperfine structure levels, and subsequently ionizing it. This selectively ionized beam is deflected to a decay spectroscopy station (DSS). This consists of a rotating wheel implantation system for alpha- and beta-decay spectroscopy, and up to three germanium detectors around the implantation site for gamma-ray detection. Resonance ionization spectroscopy and the new technique of laser assisted nuclear decay spectroscopy have recently been performed at the CRIS beam line on the neutron-deficient francium isotopes. Here an overview of the two techniques will be presented, alongside a description of the CRIS beam line and DSS. (authors)

  17. Preparation of Permalloy nanostructures using focused ion beam methods

    International Nuclear Information System (INIS)

    Focused ion beam (FIB) milling is a powerful and versatile tool for the maskless fabrication of structures and devices at micro- and nanometer scales. The approach is based on the milling and deposition capabilities of a focused ion beam, where the latter is achieved by ion-beam-assisted decomposition of a metalorganic gas precursor of the specific material that has to be deposited. The combination of FIB and scanning electron microscopy in the same unit (so-called dual-beam unit) further expands the capabilities of the approach by the possibility of performing electron-beam-assisted deposition and inspection. Permalloy nanowires with electrical contacts patterned by FIB-Pt deposition were prepared in the dual-beam unit. Various types of notches to pin magnetic domain walls were additionally fabricated by means of FIB. The fabrication parameters for a structural modification of the Permalloy structures without too strongly affecting the material properties were determined previously. Magnetic force microscopy was employed for an observation of the resulting magnetic domain structures.

  18. Application of Isotope and Dye Tracing Methods in Hydrology (Case Study: Havassan Dam Construction)

    International Nuclear Information System (INIS)

    Iran, with its annual average precipitation rate of 260 mm, is considered among the arid and semiarid regions of the world. So, water scarcity as a primitive problem has hindered development in agricultural, economic, social and industrial fields. Constructing dams across the rivers is one of the most accepted methods to control and exploit surface waters. Reservoirs formed by constructing dams change fluvial morphology from a river course to a lake. This causes changes in groundwater flow behaviour at the dam site, i.e. a kind of conversion takes place from the role of the aquifers as a recharge source for the rivers before dam construction, into the role of the river-reservoir as the recharge source for the aquifer. As a result, water leakage might occur in the reservoir. Isotope and dye tracing methods could be used to investigate questions such as the present condition of the river, the process of surface water leakage into aquifers, the specification of water leakage locations, the relationships between different water resources, age, class, type, velocity and direction of groundwater flows, the status of permeability of formations of the reservoir, karst development, etc. The paper presents the study on application of environmental isotopes and dye tracers to investigate interaction between surface water and groundwater and possible threats of water leakage from the reservoir at the Havassan Dam site. (author)

  19. Real-time simulation of ultrasound refraction phenomena using ray-trace based wavefront construction method.

    Science.gov (United States)

    Szostek, Kamil; Piórkowski, Adam

    2016-10-01

    Ultrasound (US) imaging is one of the most popular techniques used in clinical diagnosis, mainly due to lack of adverse effects on patients and the simplicity of US equipment. However, the characteristics of the medium cause US imaging to imprecisely reconstruct examined tissues. The artifacts are the results of wave phenomena, i.e. diffraction or refraction, and should be recognized during examination to avoid misinterpretation of an US image. Currently, US training is based on teaching materials and simulators and ultrasound simulation has become an active research area in medical computer science. Many US simulators are limited by the complexity of the wave phenomena, leading to intensive sophisticated computation that makes it difficult for systems to operate in real time. To achieve the required frame rate, the vast majority of simulators reduce the problem of wave diffraction and refraction. The following paper proposes a solution for an ultrasound simulator based on methods known in geophysics. To improve simulation quality, a wavefront construction method was adapted which takes into account the refraction phenomena. This technique uses ray tracing and velocity averaging to construct wavefronts in the simulation. Instead of a geological medium, real CT scans are applied. This approach can produce more realistic projections of pathological findings and is also capable of providing real-time simulation. PMID:27586490

  20. A Wigner-based ray-tracing method for imaging simulations

    Science.gov (United States)

    Mout, B. M.; Wick, M.; Bociort, F.; Urbach, H. P.

    2015-09-01

    The Wigner Distribution Function (WDF) forms an alternative representation of the optical field. It can be a valuable tool for understanding and classifying optical systems. Furthermore, it possesses properties that make it suitable for optical simulations: both the intensity and the angular spectrum can be easily obtained from the WDF and the WDF remains constant along the paths of paraxial geometrical rays. In this study we use these properties by implementing a numerical Wigner-Based Ray-Tracing method (WBRT) to simulate diffraction effects at apertures in free-space and in imaging systems. Both paraxial and non-paraxial systems are considered and the results are compared with numerical implementations of the Rayleigh-Sommerfeld and Fresnel diffraction integrals to investigate the limits of the applicability of this approach. The results of the different methods are in good agreement when simulating free-space diffraction or calculating point spread functions (PSFs) for aberration-free imaging systems, even at numerical apertures exceeding the paraxial regime. For imaging systems with aberrations, the PSFs of WBRT diverge from the results using diffraction integrals. For larger aberrations WBRT predicts negative intensities, suggesting that this model is unable to deal with aberrations.

  1. Ion microscopy, a method for imaging the distribution of trace elements in the lung

    International Nuclear Information System (INIS)

    Analytical ion microscopy, a method of surface microanalysis, is applied to the detection of trace elements in the lung. With this method it is possible to obtain images of the distribution of any element in lung tissue sections with a resolution of 0.5 μm and with very high sensitivity (of an order of magnitude 3 or 4 times greater than with x-ray microanalysis). Under these conditions it is possible to study at the microscopic level the penetration into the lung cells of mineral materials administered in physiological amounts. The images are formed by ion microscopy of atoms sputtered as charged particles from the specimen, and these atoms are selected by mass spectrometry. This technique has been applied to the detection of aerosols (diam. < 1 μm) of rare earths (thulium or cerium chloride), inhaled in very small amounts (20-50 μg), in cells from the lung of a rat. Images of the distribution of these elements were obtained in a few seconds or minutes, when x-ray microanalysis gave either a weak signal or none at all. Their behaviour in the lung could be easily studied several weeks after the end of the inhalation. (author)

  2. Ray tracing: Experience at SRC

    International Nuclear Information System (INIS)

    SHADOW [B. Lai and F. Cerrina, Nucl. Instrum. Methods A 246, 337 (1986)] is the primary ray-tracing program used at SRC. Ray tracing provides a tremendous amount of information regarding beamline layout, mirror sizes, resolution, alignment tolerances, and beam size at various locations. It also provides a way to check the beamline design for errors. Two recent designs have been ray traced extensively: an undulator-based, 4-meter, normal-incidence monochromator (NIM) [R. Reininger, M.C. Severson, R.W.C. Hansen, W.R. Winter, M.A. Green, and W.S. Trzeciak, Rev. Sci. Instrum. 66, 2194 (1995)] and an undulator-based, plane-grating monochromator (PGM) [R. Reininger, S.L. Crossley, M.A. Lagergren, M.C. Severson, and R.W.C. Hansen, Nucl. Instrum. Methods A 347, 304 (1994)]. copyright 1996 American Institute of Physics

  3. LHCb: A novel method for an absolute luminosity measurement at LHCb using beam-gas imaging

    CERN Multimedia

    Barschel, C

    2013-01-01

    A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used van der Meer scan method (VDM). This poster presents the principles of the Beam Gas Imaging method used to measure the beam overlap integral. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch.

  4. Analytical examination of a spiral beam scanning method for uniform irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Mitsuhiro; Okumura, Susumu; Arakawa, Kazuo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    A new circular beam scanning method for uniform irradiation of high-energy, intense ion beams over a large area has been developed. A sweeping speed and a trajectory density in a radial direction are kept constant to obtain uniform fluence distribution. A radial position of a beam spot on a target and an angular frequency of the circular motion are expressed by an irrational function of time. The beam is swept continuously, and a beam trajectory becomes spiral. More than 90 % uniformity of the fluence distribution can been achieved over a large area. (author)

  5. Investigation of the transverse beam dynamics in the thermal wave model with a functional method

    OpenAIRE

    Jang, Ji-Ho; Cho, Yong-sub; Kwon, Hyeok-jung

    2006-01-01

    We investigated the transverse beam dynamics in a thermal wave model by using a functional method. It can describe the beam optical elements separately with a kernel for a component. The method can be applied to general quadrupole magnets beyond a thin lens approximation as well as drift spaces. We found that the model can successfully describe the PARMILA simulation result through an FODO lattice structure for the Gaussian input beam without space charge effects.

  6. Free Vibration Analysis of Laminated Composite Beams Using Differential Quadrature Method

    Institute of Scientific and Technical Information of China (English)

    冯丽娟; 钟宏志; 郝照平; 吴德隆

    2002-01-01

    A higher-order theory for laminated composite beams is used to study the free vibration of laminated composite beams, and the differential quadrature method is employed to obtain the numerical solution of the governing differential equations. Free vibration analysis of beams with rectangular cross-section for various combinations of end conditions is studied. The results show that the differential quadrature method is reliable and accurate compared with other available results.

  7. A Crack Identification Method For Beam Type Structures Subject To Moving Vehicle Using Particle Swarm Optimization

    OpenAIRE

    GÖKDAĞ, Hakan

    2013-01-01

    In this work a crack identification method for beam type structures under moving vehicle is proposed. The basic of the method is to formulate damage detection as an inverse problem, and solve for damage locations and extents. To this end, an objective function is defined based on the difference of damaged beam dynamic response and the response calculated by the mathematical model of the beam. The optimization problem is solved through a popular evolutionary algorithm, i.e. the particle swarm ...

  8. Method for traveling-wave deceleration of buffer-gas beams of CH

    OpenAIRE

    Fabrikant, M. I.; Li, Tian; Fitch, N J; N. Farrow; Weinstein, Jonathan D.; Lewandowski, H. J.

    2013-01-01

    Cryogenic buffer-gas beams are a promising method for producing bright sources of cold molecular radicals for cold collision and chemical reaction experiments. In order to use these beams in studies of reactions with controlled collision energies, or in trapping experiments, one needs a method of controlling the forward velocity of the beam. A Stark decelerator can be an effective tool for controlling the mean speed of molecules produced by supersonic jets, but efficient deceleration of buffe...

  9. On the absorbed dose determination method in high energy electrons beams

    International Nuclear Information System (INIS)

    The absorbed dose determination method in water for electron beams with energies in the range from 1 MeV to 50 MeV is presented herein. The dosimetry equipment for measurements is composed of an UNIDOS.PTW electrometer and different ionization chambers calibrated in air kerma in a Co60 beam. Starting from the code of practice for high energy electron beams, this paper describes the method adopted by the secondary standard dosimetry laboratory (SSDL) in NILPRP - Bucharest

  10. Localization of brain functions by dipole tracing method using individually measured tissue conductivities

    International Nuclear Information System (INIS)

    The dipole tracing method (DT) has permitted calculations of source locations using a Scalp-Skull-Brain (SSB) real-shaped three-shell model of the head because bone conductivity is lower than the skin and the brain. The SSB/DT method utilizes standard conductivities of the three layers: scalp, skull, and brain. These conductivities are not calculated for each individual. We have previously used a realistic three-shell head model using realistic individually calculated conductivities of the scalp and skull layers with the SSB/DT method for current location mapping. The individual conductivities of the scalp and the skull were calculated from electrical stimulation through surface electrodes. Individual conductivities were used to calculate the source locations of SEP based upon surface EEG recordings using the SSB/DT method. A current square-wave pulse (0.1 mA and 10 msec duration) was applied through a pair of EEG electrodes; four different pairs were usually selected. The voltage change during the stimulation was recorded with the remaining surface electrodes and the conductivities of the skin and skull were calculated from the recorded signals. In nine healthy men, the mean skin conductivity was 0.61441±0.30128 [S/m], while the skull conductivity mean 0.00576±0.00397 [S/m]. Simulation for dipole current movement indicated lower bone conductivity in the inner location and high bone conductivity in the outer location. The conductivity ratios of bone and skin were 0.0125 in standard model and 0.00956 (mean) in realistic individually calculated conductivities. We compared the locations of the SEP estimated with the standard conductivity and realistic individually calculated conductivities; the dipole location was not significantly different. (author)

  11. Localization of the sentinel lymph node in breast cancer: prospective comparison of vital staining and radioactive tracing methods.

    Science.gov (United States)

    Marrazzo, Antonio; Taormina, Pietra; Noto, Antonio; Cardinale, Giovanni; Casà, Luigi; Mercadante, Sebastiano; Lo Gerfo, Domenico; David, Massimo

    2004-01-01

    The aim of the study was to evaluate possible differences in accuracy between the radioactive tracing and vital staining method in the search for sentinel nodes in patients with breast cancer. From January 1999 to December 2000, 102 patients with T1 N0 breast carcinoma were recruited into the study for localization of sentinel nodes with vital blue dye staining and radioactive tracing and were then submitted to lumpectomy and axillary dissection. For the two methods, we estimated the percentage of sentinel nodes localized, the false-negative rate, the predictive negative and positive value and the accuracy. The vital blue dye staining method permitted localization of the sentinel node in 73% of patients with a false-negative rate of 8%, a predictive negative value of 92% and 92% accuracy. The radioactive tracing method permitted localization of the sentinel node in 97% cases with a false-negative rate of 0%, a predictive negative value of 100% and 100% accuracy (P<0.0005). The method that offers the better results is radioactive tracing. Currently, many authors use both techniques, since, in common practice, staining helps to identify the sentinel node with the probe. PMID:15553432

  12. Methods for tracing the origin of white marbles used in antiquity

    Science.gov (United States)

    Prochaska, Walter; Grillo, Silvana Maria

    2013-04-01

    The topic of this paper is to given an overview of the methods to pinpoint the origin of white marbles and to discuss the progress made in this field during the last years. To pinpoint the place of origin of the marble to an area or even to a special quarry may be of appreciable importance in investigating ancient trading routes and trade relations. A material-specific classification can be conducive to understand if the workshops of an area used marbles of acceptable quality from a local quarry or quarrying areas or if they used imported marbles in or without combination with local ones. Furthermore during restoration activities the knowledge of the origin of the marbles used in architecture may be of importance for supplying more or less original types of marbles. It may also be of interest for evaluating the authenticity of artifact information on the provenance of the used material. The first attempt to discriminate between different marbles used petrographic methods followed by instrumental chemical analyses, especially the analysis of trace elements. In the last decades multi-element neutron activation analysis (NAA) of various trace elements was attempted to pinpoint the origins of marbles. A few decades ago stable isotope analysis seemed to be the solution of this problem and became the standard methods for investigation the origin of white marbles. However, with the rapidly increasing number of historical marble quarrying sites and with the increasing number of analyzed samples in general, the compositional fields in the isotope diagram became larger and many classical marbles show large ranges of overlap. Therefore special attention is drawn to a new method to characterize the chemical properties of microinclusiones of the marbles additional to the conventionally used methods to ascribe their origin to a special quarry or at least to a defined geological formation of a given area. Several case studies will be presented: Different types of marbles were

  13. Determination of elemental concentrations at trace levels in alumina by charged particle activation analysis using proton beam from VEC accelerator

    International Nuclear Information System (INIS)

    The elemental impurities have been determined in high purity alumina material used in nuclear reactors at ppb (μg kg-1) to ppm (mg kg-1) levels by CPAA using proton beam from VEC machine. Proton beam has the advantage of high cross section for (p, n) reaction to produce suitable nuclide for activation analysis by instrumental approach. The cross sections of higher reaction channels like (p, 2n), (p, pn) are found to be less than 1 mb below 13 MeV proton by theoretical calculation using ALICE 91 computer code. Therefore, 13 MeV proton beam was used to irradiate the alumina samples along with standards, Lake (IAEA-SL-1) and Marine (PACS-2) sediments, both in pellet and powder forms. The irradiation was carried out with 50 nA to 1μA beam current for 10 min to 10 h depending on types of samples and standards. The beam current was measured by Faraday cup and also checked by putting Ti monitoring foil before the target. Ni is determined by (p, pn) reaction using 18 MeV proton as there is no suitable product from (p, n) reaction. The counting measurements of irradiated samples were performed with a high resolution γ-spectrometer using HPGe detector (relative efficiency - 40%, resolution - 2.0 keV at 1332 keV) coupled to a PC based 8 k MCA. The validation of the CPAA results has been carried out by INAA with the same alumina samples, carried out in Dhruva reactor with neutron flux 1014 cm2 s-1 using standards IAEA-SL-1 and PACS-2

  14. Comparison of methods of producing very highly stripped uranium beams

    International Nuclear Information System (INIS)

    A comparison is made between the production of high intensity beams of helium-like uranium ions, U90+, by conventional and exotic ion sources, and by the foil stripping of highly accelerated ions output from the Bevalac. The parameter requirements are specified and compared to the parameters achievable by present day ion source technology. The EBIS (Electron Beam Ion Source) comes closest to satisfying the necessary parameters, and this possibility is considered in some detail. We conclude that existing and near-future ion source technology does not provide a means of production of high intensity U90+ beams. Foil stripping of lower charge state species that have been accelerated through the Bevalac provides a convenient approach

  15. An interpretation and guide to single-pass beam shaping methods using SLMs and DMDs

    Science.gov (United States)

    Stilgoe, Alexander B.; Kashchuk, Anatolii V.; Preece, Daryl; Rubinsztein-Dunlop, Halina

    2016-06-01

    Exquisite manipulations of light can be performed with devices such as spatial light modulators (SLMs) and digital micromirror devices (DMDs). These devices can be used to simulate transverse paraxial beam wavefunction eigenstates such as the Hermite–Laguerre–Gaussian mode families. We investigate several beam shaping methods in terms of the wavefunctions of scattered light. Our analysis of the efficiency, behaviour and limitations of beam shaping methods is applied to both theory and experiment. The deviation from the ideal output from a valid beam shaping method is shown to be due to experimental factors which are not necessarily being accounted for. Incident beam mode shape, aberration, and the amplitude/phase transfer functions of the DMD and SLM impact the distribution of scattered light and hence the effectiveness and efficiency of a beam shaping method. Correcting for these particular details of the optical system accounts for all differences in efficiency and mode fidelity between experiment and theory. We explicitly show the impact of experimental parameter variations so that these problems may be diagnosed and corrected in an experimental beam shaping apparatus. We show that several beam shaping methods can be used for the production of beam modes in a single pass and the choice is based on the particular experimental conditions.

  16. Quality parameters and pattern recognition methods as a tool in tracing regional origin of multifloral honey

    Directory of Open Access Journals (Sweden)

    Lazarević Kristina B.

    2013-01-01

    Full Text Available The characterization of multifloral honey regarding the mineral composition, sugar content and basic physicochemical properties has been done. The total of 164 honey samples was collected from six regions of Serbia during 2009 harvesting season. Univariate data analysis (descriptive statistics and analysis of variance, geographic information system and pattern recognition methods (principal component analysis and cluster analysis have been performed in order to identify geographical origin of honey. The content of Mg, K, and Cu, electrical conductivity, and optical rotation were established as useful indicators in tracing regional differences between honey samples. Samples originated from Zlatibor region were clearly distinguished from those from the rest of Serbia showing higher K and Mg content, as well as higher values of optical rotation, electrical conductivity, and free acidity. The influence of the soil composition, and climate conditions, as well as the presence of particular flora on the honey composition is stressed out. The modeling of geographic origin of honey has been attempted by the means of linear discriminant analysis. [Projekat Ministarstva nauke Republike Srbije, br. 172017 and 451-03-2372-IP i FP7 RegPot project FCUB ERA GA No. 256716

  17. Comparison of methods for the measurement of trace metals in power plant waste streams

    International Nuclear Information System (INIS)

    Over the last eight years, the Electric Power Research Institute has sponsored a project (RP 1851-1) to compile data on aqueous discharges from steam electric power plants and to validate the monitoring methods used for measuring trace metals. The validation work has consisted of a series of interlaboratory round robin validation programs using samples of known concentration prepared from typical utility matrices. Matrices that have been used for these tests include: river water, ash pond overflow, seawater, seawater with metal cleaning wastes, and treated chemical metal cleaning wastes. Techniques and metals studied include: Graphite Furnace Atomic Absorption Spectroscopy (As, Cd, Cr, Cu, Ni, Pb, Se), Cold Vapor AAS (Hg), Flame AAS (Fe, Zn) , and Inductively Coupled Plasma (ICP) for 14 elements (Al , Ba, Be, B, Cd, Cr, Cu, Fe, Pb, Mn, Mo, Ni, V, Zn). Results were evaluated using a statistical program developed under RP 1851-1. The resulting single operator and overall precision were used to compute limits of detection and quantitation for each of the elements in each matrix. These limits of detection were compared to published EPA detection limits and interpretations of the differences were made. The influence of matrix effects was also examined

  18. Analysis of trace elements responsible for antioxidant protection by SRXFA method

    International Nuclear Information System (INIS)

    The possibilities of using the energy dispersion synchrotron radiation X-ray fluorescence analysis (SRXFA) for control of blood plasma and liver trace element (TE) content in rats with hyperproduction of oxygen radicals and hair TE content in women with mammary hyperplasia and cancer are demonstrated. Our data show that activity of antioxidant enzymes superoxide dismutase (SOD) and catalase in the blood and liver depends on the amount of TE incorporated into the structure of the active center of these enzymes, which are responsible for antioxidant protection. A decrease of activity of these enzymes is accompanied by an increase of production of free OH radicals in the tissues. Clinical data demonstrated that scalp hair of patients with oncological mammary pathology was characterized by a significant decrease of concentrations of selenium (Se) and zinc (Zn) and by an increase of chromium (Cr). The Se deficit was more pronounced in patients with cancer than in those with mammary hyperplasia (p<0.05). The SRXFA method permits one to carry out a controllable correction of TE imbalance in many diseases whose development is caused by oxygen radical injury

  19. Amino Acid Sequence and Structural Comparison of BACE1 and BACE2 Using Evolutionary Trace Method

    Directory of Open Access Journals (Sweden)

    Hoda Mirsafian

    2014-01-01

    Full Text Available Beta-amyloid precursor protein cleavage enzyme 1 (BACE1 and beta-amyloid precursor protein cleavage enzyme 2 (BACE2, members of aspartyl protease family, are close homologues and have high similarity in their protein crystal structures. However, their enzymatic properties differ leading to disparate clinical consequences. In order to identify the residues that are responsible for such differences, we used evolutionary trace (ET method to compare the amino acid conservation patterns of BACE1 and BACE2 in several mammalian species. We found that, in BACE1 and BACE2 structures, most of the ligand binding sites are conserved which indicate their enzymatic property of aspartyl protease family members. The other conserved residues are more or less randomly localized in other parts of the structures. Four group-specific residues were identified at the ligand binding site of BACE1 and BACE2. We postulated that these residues would be essential for selectivity of BACE1 and BACE2 biological functions and could be sites of interest for the design of selective inhibitors targeting either BACE1 or BACE2.

  20. Ray tracing method using genetic algorithms; Tracado de raios atraves de algoritmos geneticos

    Energy Technology Data Exchange (ETDEWEB)

    Cunha Filho, Carlos Alves da; Castro Thedy, Fernanda Amorim de [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    A new ray tracing method is proposed, using genetic algorithms and based upon Fermat`s principle. For each source-receiver pair we no longer have a single ray, but a family of rays, each one with a different probability. Within the framework of this probabilistic formulation genetic algorithms are used to obtain the extremes of the problem, which is represented by those rays whose travel times follow Fermat`s principle to a certain degree. Algorithms simulating real geological situations were implemented for cases where velocity may be constant or vary in two space coordinates along a layer. The effects of all the parameters manipulated by genetic algorithms are tested in two different objective functions: travel time and the sum of the squares of its derivatives related to parameters that characterize the model. Low values of mutation and update probability, moderate values of crossover probability and initial temperature (used as a control parameter during selection process), acting in a population of about 100 rays in 100 generations, seems to be ideal to guarantee optimum convergence of the algorithms. Further developments of this formulations may help to fill in the gap between ray theoretical and wave theoretical descriptions of wave propagation. (author). 11 refs., 4 figs

  1. Development of new measurement and analytical method to trace 41K for long-term

    International Nuclear Information System (INIS)

    To establish a control technique of fertilizer application for resource-saving and environmental conservation, non-radiative 41K tracer method in the field has been developed. In this paper, potassium silicate fertilizer, one of slow-release fertilizer, was synthesized and marked by 41K. Potassium silicate fertilizer with natural abundance of 41K/39K was prepared by mixing 76.2 g fly ash, 23.4 g potassium carbonate and 7.2 g magnesium hydroxide and colicinating the mixture for 47 min at 850degC. The product was satisfied the conditions of potasium silicate fertilizer. Then, the potassium silicate fertilizer marked with 41K was synthesized by calicinating the mixture 1.85 KCl (6.77% 41K and 93.23% 39K) and 11.45 g 41KCl under the above conditions. 41K excess% of product fertilizer was about -2.00%, which is possible to trace 41K of crop plant of soil culture pot test during the growing process. (S.Y.)

  2. Ray tracing method with Fresnel's transmission to calculate polarized radiation power distribution focused by a terahertz Silicon lens antenna

    Science.gov (United States)

    Apriono, Catur; Rahardjo, Eko Tjipto; Hiromoto, Norihisa

    2015-03-01

    We study a method for simulating a power-flow density distribution of terahertz-wave focused by a hemispherical Silicon lens antenna. A regular ray-tracing method is not enough to evaluate a correct radiation power-flow because it does not take into account transmittances dependent on angles of incidence at different positions on the spherical boundary of the Si-lens. In this study, we propose a ray-tracing method including Fresnel's transmission coefficients on the surface of a Si-lens for incoming polarized rays. The power-flow-density distribution calculated by the proposed method has a good agreement except for interference and diffraction with the result obtained by an electromagnetic wave simulator. Our method is so simple and reliable that it is useful for designing and evaluating THz optical systems using dielectric lens antennas.

  3. The principle and applications of an iso-energetic intensity modulation method for therapeutic electron beams

    International Nuclear Information System (INIS)

    Purpose/Objective: Many clinical situations indicate that an electron beam with a modified dose profile, i.e., tilted, concave or other shape is useful for the treatment with a curved, oblique or other non-flat skin surface. The well known difficulty in electron beam dose profile modification is the energy degradation while using absorbers with different thickness, such as wedge shape filter, similar to photon wedges. In this presentation, we describe the principle and applications of an iso-energetic electron beam intensity modulation method, a general technique which can be used to modified the intensity of a static electron field with virtually no alteration of the original beam energy. Materials and Methods: Due to the Coulomb multiple-scattering effect in air medium, Gaussian spread in air of the electron beam broadens with increasing distance from the source. Two narrow parallel electron beams with limited separation will join together as one composite distribution at certain distance from the source. Based on this physical principle, the intensity distribution of a broad electron beam can be modulated into different shapes by dividing the broad beam into a plurality of narrow slit electron beams with different spatial separation. With an adequate distance, these narrow electron beams merge to form a profile with desired shape and smoothness. Since an intensity modulated electron beam results from the plurality of narrow electron beams which have the same energy characteristics, the modulated beam will have the same energy as the original open beam. The applications of this new technique include the constructions of iso-energetic electron beam 'wedge' filters, concave filters (for dome shape skin surface such as skull), flattening filters for total skin treatment at an extended SSD, linac internal electron beam scattering/flattening filter, and other general electron beam compensating filters for irregular skin surface. Results: Several iso-energetic electron

  4. Radiogram enhancement and linearization using the beam hardening correction method

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Jakůbek, J.

    2009-01-01

    Roč. 607, - (2009), s. 212-214. ISSN 0168-9002. [International Workshop on Radiation Imaging Detectors. Helsinky, 29.06.2008-03.07.2008] Institutional research plan: CEZ:AV0Z20710524 Keywords : beam hardening correction * flat-field correction * digital radiography Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.317, year: 2009

  5. Dual-beam, second-derivative tunable diode-laser infrared spectroscopy applied to trace-gas measurement

    International Nuclear Information System (INIS)

    A dual beam diode laser spectrometer has been constructed using off-axis reflective optics. The spectrometer can be amplitude modulated for direct absorption measurements or frequency modulated to obtain derivative spectra. The spectrometer has high throughput, is easy to operate and align, provides good dual beam compensation, and has no evidence of the interference effects that have been observed in diode laser spectrometers using refractive optics. Unpurged, using second derivative techniques, the instrument has measured 108 parts-per-million CO (10 cm absorption cell, atmospheric pressure-broadened) with good signal/noise. With the replacement of marginal instrumental components, the signal/noise should be substantially increased. This instrument was developed to monitor the evolution of decomposition gases in sealed containers of small volume at atmospheric pressure

  6. A new method for RF power generation for two-beam linear colliders

    International Nuclear Information System (INIS)

    In this paper we discuss a new approach to two-beam acceleration. The energy for RF production is initially stored in a long-pulse electron beam which is efficiently accelerated to about 1.2 GeV by a fully loaded, conventional, low frequency (∼1 GHz) linac. The beam pulse length is twice the length of the high-gradient linac. Segments of this long pulse beam are compressed using combiner rings to create a sequence of higher peak power drive beams with gaps in between. This train of drive beams is distributed from the end of the linac against the main beam direction down a common transport line so that each drive beam can power a section of the main linac. After a 180-degree turn, each high-current, low-energy drive beam is decelerated in low-impedance decelerator structures, and the resulting power is used to accelerate the low-current, high-energy beam in the main linac. The method discussed here seems relatively inexpensive, is very flexible and can be used to accelerate beams for linear colliders over the entire frequency and energy range

  7. Noninterceptive method to measure longitudinal Twiss parameters of a beam in a hadron linear accelerator using beam position monitors

    Science.gov (United States)

    Shishlo, A.; Aleksandrov, A.

    2013-06-01

    A new method of measuring of the rms longitudinal Twiss parameters of a beam in linear accelerators is presented. It is based on using sum signals from beam position monitors sensitive to the longitudinal charge distribution in the bunch. The applicability of the method is demonstrated on the superconducting section of the Oak Ridge Spallation Neutron Source linear accelerator. The results are compared to a direct measurement of the bunch longitudinal profiles using an interceptive bunch shape monitor in the linac warm section of the same accelerator. Limitations of the method are discussed. The method is fast and simple, and can be used to obtain the initial parameters for the longitudinal matching in linear accelerators where interceptive diagnostics are not desirable.

  8. Novel ray tracing method for stray light suppression from ocean remote sensing measurements.

    Science.gov (United States)

    Oh, Eunsong; Hong, Jinsuk; Kim, Sug-Whan; Park, Young-Je; Cho, Seong-Ick

    2016-05-16

    We developed a new integrated ray tracing (IRT) technique to analyze the stray light effect in remotely sensed images. Images acquired with the Geostationary Ocean Color Imager show a radiance level discrepancy at the slot boundary, which is suspected to be a stray light effect. To determine its cause, we developed and adjusted a novel in-orbit stray light analysis method, which consists of three simulated phases (source, target, and instrument). Each phase simulation was performed in a way that used ray information generated from the Sun and reaching the instrument detector plane efficiently. This simulation scheme enabled the construction of the real environment from the remote sensing data, with a focus on realistic phenomena. In the results, even in a cloud-free environment, a background stray light pattern was identified at the bottom of each slot. Variations in the stray light effect and its pattern according to bright target movement were simulated, with a maximum stray light ratio of 8.5841% in band 2 images. To verify the proposed method and simulation results, we compared the results with the real acquired remotely sensed image. In addition, after correcting for abnormal phenomena in specific cases, we confirmed that the stray light ratio decreased from 2.38% to 1.02% in a band 6 case, and from 1.09% to 0.35% in a band 8 case. IRT-based stray light analysis enabled clear determination of the stray light path and candidates in in-orbit circumstances, and the correction process aided recovery of the radiometric discrepancy. PMID:27409848

  9. Matrix method and program design of intense beam transport in quadrupole magnet

    International Nuclear Information System (INIS)

    It is very difficult to calculate the nonlinear transport of a intense beam,because the particle trajectories depend on the electric potentials excited by the particle beams, and the electric potentials of the beams depend on the particle trajectories and the particle distributions in the phase spaces. So, it is necessary to solve the problem by iterations to get self-consistent solutions. We use transport matrix method to analyze the transportation in quadrupole magnet of non-intense pulsed beam and intense pulsed beam respectively, and write a computer code for the pulsed beam transporting in quadrupole magnet. The self-consistent solution can obtained by using iteration calculation method. During the calculation, the result can be shown by the prompt graph. (authors)

  10. A new method of rapid power measurement for MW-scale high-current particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yongjian, E-mail: yjxu@ipp.ac.cn; Hu, Chundong; Xie, Yuanlai; Liu, Zhimin; Xie, Yahong; Liu, Sheng; Liang, Lizheng; Jiang, Caichao; Sheng, Peng; Yu, Ling

    2015-09-21

    MW-scale high current particle beams are widely applied for plasma heating in the magnetic confinement fusion devices, in which beam power is an important indicator for efficient heating. Generally, power measurement of MW-scale high current particle beam adopts water flow calorimetry (WFC). Limited by the principles of WFC, the beam power given by WFC is an averaged value. In this article a new method of beam power for MW-scale high-current particle beams is introduced: (1) the temperature data of thermocouples embedded in the beam stopping elements were obtained using high data acquire system, (2) the surface heat flux of the beam stopping elements are calculated using heat transfer, (3) the relationships between positions and heat flux were acquired using numerical simulation, (4) the real-time power deposited on the beam stopping elements can be calculated using surface integral. The principle of measurement was described in detail and applied to the EAST neutral beam injector for demonstration. The result is compared with that measured by WFC. Comparison of the results shows good accuracy and applicability of this measuring method.

  11. A new method of rapid power measurement for MW-scale high-current particle beams

    Science.gov (United States)

    Xu, Yongjian; Hu, Chundong; Xie, Yuanlai; Liu, Zhimin; Xie, Yahong; Liu, Sheng; Liang, Lizheng; Jiang, Caichao; Sheng, Peng; Yu, Ling

    2015-09-01

    MW-scale high current particle beams are widely applied for plasma heating in the magnetic confinement fusion devices, in which beam power is an important indicator for efficient heating. Generally, power measurement of MW-scale high current particle beam adopts water flow calorimetry (WFC). Limited by the principles of WFC, the beam power given by WFC is an averaged value. In this article a new method of beam power for MW-scale high-current particle beams is introduced: (1) the temperature data of thermocouples embedded in the beam stopping elements were obtained using high data acquire system, (2) the surface heat flux of the beam stopping elements are calculated using heat transfer, (3) the relationships between positions and heat flux were acquired using numerical simulation, (4) the real-time power deposited on the beam stopping elements can be calculated using surface integral. The principle of measurement was described in detail and applied to the EAST neutral beam injector for demonstration. The result is compared with that measured by WFC. Comparison of the results shows good accuracy and applicability of this measuring method.

  12. Modeling Transcient Trace Data

    OpenAIRE

    Mathur, Anup; Abrams, Marc

    1996-01-01

    This paper introduces a novel technique to construct an empirical workload model fitting time-varying (transient) trace data. The trace can be a categorical or numerical time-series. We model the trace as a Piecewise Independent stochastic process. To estimate the parameters for our model we first build a Rate Evolution Graph from the trace data. Piecewise linear regression is then used to construct a joint time-dependent probablity mass function for the trace data. Two methods are propo...

  13. A calculation method of cracking moment for the high strength concrete beams under pure torsion

    Indian Academy of Sciences (India)

    Metin Husem; Ertekin Oztekin; Selim Pul

    2011-02-01

    In this study, a method is given to calculate cracking moments of high strength reinforced concrete beams under the effect of pure torsion. To determine the method, both elastic and plastic theories were used. In this method, dimensions of beam cross-section were considered besides stirrup and longitudinal reinforcements. Two plain high strength concrete (without reinforcement) and eight high strength reinforced concrete beams which have two different cross-sections (150 × 250 mm and 150 × 300 mm) were produced to examine the validity of the proposed method. The predictions of the proposed approach for the calculation of the cracking moment of beams under pure torsion were compared with the experimental and the analytical results of previous studies. From these comparisons it is concluded that the predictions of the proposed equations for the cracking moment of plain and reinforced high strength concrete beams under pure torsion are closer to the experimental data compared to the analytical results of previous theories.

  14. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  15. Closed vessel microwave assisted extraction - An innovative method for determination of trace metals in plant materials

    Science.gov (United States)

    Oeztan, S.; Duering, R.-A.

    2012-04-01

    Determination of metal concentrations in plant samples is important for better understanding of effects of toxic metals that are biologically magnified through the food chain and compose a great danger to all living beings. In recent years the use of microwave assisted extraction for plant samples has shown tremendous research interest which will probably substitute conventional procedures in the future. Generally conventional procedures have disadvantages including consuming of time and solvents. The objective of this study is to investigate and compare a new closed vessel microwave extraction (MAE) method with the combination of EDTA (MAE-EDTA) for the determination of metal contents (Cd, Mn, Pb, Zn) in plant samples (Lolio-Cynosuretum) by ICP-OES. Validation of the method was done by comparison of the results with another MAE procedure (MAE-H) which is applied with the mixture of 69% nitric acid (HNO3) and 30% hydrogen peroxide (H2O2). Moreover, conventional plant extraction (CE) method, for which the dissolution of plant samples were handled in HNO3 after dry ashing at 420° C, was used as a reference method. Approximately 0.5 g of sample was digested in 5 ml HNO3, 3 ml H2O2, and 5 ml deionized H2O for MAE-H and in 8 ml EDTA solution for MAE-EDTA. Certified plant reference materials (CRMs) were used for comparison of recovery rates from different extraction protocols. Thereby, the applicability of both MAE-H and MAE-EDTA procedures could be demonstrated. For 58 plant samples MAE-H showed the same extraction yields as CE in the determination of trace metal contents of the investigated elements in plant samples. MAE-EDTA gave similar values when compared to MAE-H and highly linear relationships were found for determination of Cd, Mn, Pb and Zn amounts. The recoveries for the CRMs were within the range 89.6-115%. Finally, strategic characteristics of MAE-EDTA for determination metal contents (Cd, Mn, Pb, Zn) in plant samples are: (i) applicability to a large set

  16. A pilot test of methods for determination of trace metals bound to colloids in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Kersti (Geosigma AB (Sweden))

    2011-01-15

    Two methods have been tested for the determination of trace metals associated with colloid species in surface waters, using test water from Eckarfjaerden (PFM000070) in Forsmark; 1) fractionation (ultra filtration) using special membrane filters with cut-offs of 1 kD and 5 kD and 2) filtration using a system of standard membrane filters with varying pore sizes connected in series. Both methods were somewhat modified compared to previous methods for colloid determination in groundwater within the site investigations at Forsmark and Laxemar (PLU). The results show that, in general, the largest amounts of metals associated with a colloid phase were recovered in the fraction between 1kD and 5 kD which indicates that the metal ions are associated with low molecular weight organic acids. Similar amounts were recovered on the filters in the filtration experiment. A minor part of the colloidal phase metals was recovered in the fraction larger than 5 kD i.e. metal ions associated with larger organic acids or colloidal size clay minerals. The metals present preferably as colloids in the fractionation experiment were: iron, thorium, cerium, uranium, neodymium, titanium, zirconium and yttrium. The filtering experiment showed larger parts of titanium and aluminum in the colloid phase than the fractionation experiment while the iron and cerium portions were equal and the uranium, yttrium and neodymium portions were lower. The results from the fractionation test showed that the dissolved parts were large for barium, manganese, strontium and rubidium. In the filtration test, uranium, yttrium and rubidium, were also present mainly as dissolved ions. The detection limit for filter analysis of thorium was high, and the part of thorium present as colloids was determined to <50%. Issues and methodological problems: - Severe contamination caused interpretation difficulties for several metal ions, especially chromium, nickel and zinc. - Both methods are time consuming and difficult to

  17. Determination of trace contaminants of Cu, Pb, Cd and Zn in fluorides of alkaline metals by inversion voltammetry method

    International Nuclear Information System (INIS)

    The method of determination of n·10-5-n·10-6% trace contaminants of copper, lead, cadmium and zink by means of inversion voltammetry method in fluorides of calcium and lithium is elaborated. Researches are conducted with application of mercury-graphite electrodes on polarographic analyzer and oscillograph polarography. The influence of conditions of electrochemical concentration on characteristics of anode peaks of copper, lead, cadmium and zinc is studied.

  18. Ion Micro Beam, promising methods for interdisciplinary research

    Science.gov (United States)

    Cutroneo, M.; Havranek, V.; Torrisi, L.; Svecova, B.

    2016-05-01

    An increasing attractiveness of top-down nanotechnology using nuclear microprobe techniques have been gathered to the micro and nano patterning process for polymers. This paper presents the research activity on innovative promising techniques able to produce three- dimensional (3D) micro-structures in polymeric resists as well as to obtain images of fabricated nanostructures at Tandetron Laboratory (LT) of the Nuclear Physics Institute in Rez (Czech Republic). The Proton Beam Writing (PBW) technique was used to irradiate PMMA resist with energy of MeVs protons. The fabricated patterns were developed in chemical bath using different etching rates. An overview of micro-scale structures have been fabricated selecting the beam, the energy, the fluence and the exposition time. The produced structures were investigated by different analysis techniques among which Scanning Transmission Ion Microscopy (STIM). The characterizations of the fabricated microtunnels are presented and discussed.

  19. Creation of biomaterials using the dual beam IBAD methods

    International Nuclear Information System (INIS)

    The Dual Beam Ion Assisted Deposition technique (IBAD) application for creation of the hard, biocompatible coating layers has been presented and discussed. As substrate the stainless steel, Ti, special titanium alloys, the Al2O3 or other solid materials can be used. Presently, the biocompatible coating layers such as DLC (Diamond Like Coating), β-SiC, TiC, hydroxyapatite and thin coating layer based on Ca, P, O, H have been prepared and investigated

  20. Apparatus and methods for continuous beam fourier transform mass spectrometry

    Science.gov (United States)

    McLuckey, Scott A.; Goeringer, Douglas E.

    2002-01-01

    A continuous beam Fourier transform mass spectrometer in which a sample of ions to be analyzed is trapped in a trapping field, and the ions in the range of the mass-to-charge ratios to be analyzed are excited at their characteristic frequencies of motion by a continuous excitation signal. The excited ions in resonant motions generate real or image currents continuously which can be detected and processed to provide a mass spectrum.

  1. Beam-cooling methods in the NICA project

    Science.gov (United States)

    Kostromin, S. A.; Meshkov, I. N.; Sidorin, A. O.; Smirnov, A. V.; Trubnikov, G. V.; Shurkhno, N.

    2012-07-01

    The Nuclotron-based Ion Collider Facility (NICA) is a new accelerator complex under construction at the Joint Institute for Nuclear Research (JINR) for experiments with colliding beams of heavy ions up to gold at energies as high as 4.5 × 4.5 GeV/u aimed at studying hot and dense strongly interacting nuclear matter and searching for possible indications of the mixed phase state and critical points of phase transitions. This facility comprises an ion source of the electron-string type, a 3-MeV/u linear accelerator, a 600-MeV/u superconducting booster synchrotron (Booster), a Nuclotron (upgraded superconducting synchrotron with a maximum energy of 4.5 GeV/u for ions with the charge-to-mass ratio Z/ A = 1/3), and a collider consisting of two vertically separated superconducting rings with an average luminosity of 1027 cm-2 s-1 in an energy range over 3.0 GeV/u. Beam cooling is supposed to be used in two NICA elements, the Booster, and the collider rings. The Booster is intended for the storage of 197Au31+ ions to an intensity of about 4 × 109 particles; their acceleration to the energy 600 MeV/u, which is sufficient for the complete stripping of nuclei (an increase in the injection energy and the charge state of ions makes the requirements for vacuum conditions in the Nuclotron less stringent); and the formation of the necessary beam emittance using the electron cooling system. Two independent beam-cooling systems, a stochastic one and an electron one, are supposed to be used in the collider. The parameters of the cooling systems, the optimum mode of operation for the collider, and the arrangement and design of the elements of the systems are discussed.

  2. Pseudo-beam method for compressive buckling characteristics analysis of space inflatable load-carrying structures

    Institute of Scientific and Technical Information of China (English)

    Changguo Wang; Huifeng Tan; Xingwen Du

    2009-01-01

    This paper extends Le van's work to the case of nonlinear problem and the complicated configuration. The wrinkling stress distribution and the pressure effects are also included in our analysis. Pseudo-beam method is presented based on the inflatable beam theory to model the inflatable structures as a set of inflatable beam elements with a pre-stressed state. In this method, the discretized nonlinear equations are given based upon the virtual work principle with a 3-node Timoshenko's beam model. Finite element simulation is performed by using a 3-node BEAM189 element incorporating ANSYS nonlinear program. The pressure effect is equivalent included in our method by modifying beam element cross-section parameters related to pressure. A benchmark example, the bending case of an inflatable cantilever beam, is performed to verify the accuracy of our pro-posed method. The comparisons reveal that the numerical results obtained with our method are close to open published analytical and membrane finite element results. The method is then used to evaluate the whole buckling and the load-carrying characteristics of an inflatable support frame subjected to a compression force. The wrinkling stress and region characteristics are also shown in the end. This method gives better convergence characteristics, and requires much less computation time. It is very effective to deal with the whole load-carrying ability analytical problems for large scale inflatable structures with complex configuration.

  3. Method of temperature rising velocity and threshold control of electron beam brazing

    Institute of Scientific and Technical Information of China (English)

    Xuedong Wang; Shun Yao

    2005-01-01

    In order to accommodate electron beam to the brazing of the joints with various curve shapes and the brazing of thermo sensitive materials, the method of electron beam scanning and brazing temperature control was developed, in which electron beam was controlled to scan according to predefined scanning track, and the actual temperature rising velocity of the brazed seam was limited in an allowed scope by detecting the brazed seam temperature, calculating the temperature rising velocity and adjusting the beam current during the brazing process; in addition, through the setting of the highest allowed temperature, the actual temperature of the brazed seam could be controlled not exceeding the threshold set value, and these two methods could be employed alone or jointly. It is shown that high precision temperature control in electron beam brazing could be realized and the productivity be increased by the proposed method.

  4. Sensitive neutron activation method for determination of trace impurities in Cr metal

    International Nuclear Information System (INIS)

    Many chromium metal samples from a considerable number of suppliers were analyzed for 13-15 trace element impurities by neutron activation analysis. By use of suitable γ-ray absorber between sample and detector the overwhelming intensity of lower energy γ radiation (320 keV) produced from the matrix was reduced to a satisfactory level. In this work the (n,γ) products from the trace elements of interest have characteristic γ rays with energies above 680 keV, and the sensitivity levels were in the range of 1-100 ppb. The tabulated results show wide variations in the pattern of impurities but the powdered samples generally had considerably higher levels of iron and trace elements

  5. The application of Monte Carlo method to electron and photon beams transport

    International Nuclear Information System (INIS)

    The application of a Monte Carlo method to study a transport in matter of electron and photon beams is presented, especially for electrons with energies up to 18 MeV. The SHOWME Monte Carlo code, a modified version of GEANT3 code, was used on the CONVEX C3210 computer at Swierk. It was assumed that an electron beam is mono directional and monoenergetic. Arbitrary user-defined, complex geometries made of any element or material can be used in calculation. All principal phenomena occurring when electron beam penetrates the matter are taken into account. The use of calculation for a therapeutic electron beam collimation is presented. (author). 20 refs, 29 figs

  6. Modeling the spatial shape of nondiffracting beams: Experimental generation of Frozen Waves via holographic method

    Science.gov (United States)

    Vieira, Tárcio A.; Zamboni-Rached, Michel; Gesualdi, Marcos R. R.

    2014-03-01

    In this paper we experimentally implement the spatial shape modeling of nondiffracting optical beams via computer generated holograms reconstructed optically by spatial light modulators. The results reported here are an experimental confirmation of the so-called Frozen Wave method, developed a few years ago. Optical beams of this type have potential applications in optical tweezers, medicine, atom guiding, remote sensing, etc.

  7. A simple method for boosting the beam quality of commercial DPL

    Institute of Scientific and Technical Information of China (English)

    张光寅; 焦志勇; 颜彩繁; 丁欣; 张潮波; 张晓华; 顾学文; 宋峰

    2003-01-01

    A simple method for boosting the beam quality of a commercial laser diode pumped laser (DPL) is put forward.By keeping one of the mirrors unchanged and the moving the other mirror a proper distance away from the laser rod,high beam quality laser output is realized.

  8. Stability Analysis of Some Nonlinear Feedback Control Methods for Beam Halo-Chaos Suppression

    Institute of Scientific and Technical Information of China (English)

    FANG Jin-Qing; WANG Zhong-Sheng; CHEN Guan-Rong

    2004-01-01

    Control of beam halo-chaos has been a very challenging subject for research in recent years, in which some nonlinear feedback methods have been developed for suppression of beam halo-chaos in high-current proton linear accelerators. However, stability analysis of such successful nonlinear feedback control methods has not yet been rigorously carried out, which remains an important open topic in the field. In this letter, we present a rigorous mathematical analysis of several nonlinear feedback control methods that are applied to control beam halo-chaos with great success on simulations.

  9. Stability Analysis of Some Nonlinear Feedback Control Methods for Beam Halo-ChaosSuppression

    Institute of Scientific and Technical Information of China (English)

    FANGJin-Qing; WANGZhong-Sheng; CHENGuan-Rong

    2004-01-01

    Control of beam halo-chaos has been a very challenging subject for research in recent years, in which some nonlinear feedback methods have been developed for suppression of beam halo-chaos in high-current proton linear accelerators. However, stability analysis of such successful nonlinear feedback control methods has not yet been rigorously carried out, which remains an important open topic in the field. In this letter, we present a rigorous mathematical analysis of several nonlinear feedback control methods that are applied to control beam halo-chaos with great success on simulations.

  10. A simple method for generating unidirectional surface plasmon polariton beams with arbitrary profiles.

    Science.gov (United States)

    You, Oubo; Bai, Benfeng; Wu, Xiaoyu; Zhu, Zhendong; Wang, Qixia

    2015-12-01

    The efficient steering of surface plasmon polariton (SPP) fields is a vital issue in various plasmonic applications, such as plasmonic circuitry. We present a straightforward and efficient method for generating unidirectionally propagating SPP beams with arbitrary amplitude and phase profiles by manipulating Δ-shaped nanoantennas. As an example, a second-order Hermite-Gauss SPP beam is generated with this method. The near-field distribution of the generated SPP beam is experimentally characterized to validate the effectiveness of the method. PMID:26625032

  11. Polarized atomic hydrogen beam

    Energy Technology Data Exchange (ETDEWEB)

    Chan, N.; Crowe, D.M.; Lubell, M.S.; Tang, F.C.; Vasilakis, A.; Mulligan, F.J.; Slevin, J.

    1988-12-01

    We describe the design and operating characteristics of a simple polarized atomic hydrogen beam particularly suitable for applications to crossed beams experiments. In addition to experimental measurements, we present the results of detailed computer models, using Monte-Carlo ray tracing techniques, optical analogs, and phase-space methods, that not only provide us with a confirmation of our measurement, but also allow us to characterize the density, polarization, and atomic fraction of the beam at all points along its path. As a subsidiary result, we also present measurements of the relative and absolute efficiencies of the V/G Supavac mass analyzer for masses 1 and 2.

  12. A new method for improving beam quality of LINAC

    International Nuclear Information System (INIS)

    The principle of the self-adaptive feed-forward (SAFF) control to improve the beam quality of linac is introduced. the analytical procedure for calculating the control signals, the structure of a practical control system, and applications of SAFF in klystron, RF gun, and linac are presented, especially the application in the thermionic gun whose response is non-linear, time-variant and of large time-delay. The described control system is operational and some primary experimental results have been obtained, including the control of amplitude and phase fluctuations of the klystron output, the microwave field in the gun cavity and linac

  13. Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions

    International Nuclear Information System (INIS)

    The University of Maryland Dynamical Systems and Accelerator Theory Group has been carrying out long-term research work in the general area of Dynamical Systems with a particular emphasis on applications to Accelerator Physics. This work is broadly divided into two tasks: Charged Particle Beam Transport and the Computation of Electromagnetic Fields and Beam-Cavity Interactions. Each of these tasks is described briefly. Work is devoted both to the development of new methods and the application of these methods to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. In addition to its research effort, the Dynamical Systems and Accelerator Theory Group is actively engaged in the education of students and postdoctoral research associates

  14. A new method study biodegradation kinetics of anorganic trace pollutants by activated sludge

    NARCIS (Netherlands)

    Temmink, H.; Klapwijk, A.

    2003-01-01

    A reliable prediction of the behaviour of organic trace compounds in activated sludge plants requires an accurate input of the biodegradation kinetics. Often these kinetics are extrapolated from the results of standardised biodegradation tests. However, these tests generally are not designed to yiel

  15. Fast Contour-Tracing Algorithm Based on a Pixel-Following Method for Image Sensors.

    Science.gov (United States)

    Seo, Jonghoon; Chae, Seungho; Shim, Jinwook; Kim, Dongchul; Cheong, Cheolho; Han, Tack-Don

    2016-01-01

    Contour pixels distinguish objects from the background. Tracing and extracting contour pixels are widely used for smart/wearable image sensor devices, because these are simple and useful for detecting objects. In this paper, we present a novel contour-tracing algorithm for fast and accurate contour following. The proposed algorithm classifies the type of contour pixel, based on its local pattern. Then, it traces the next contour using the previous pixel's type. Therefore, it can classify the type of contour pixels as a straight line, inner corner, outer corner and inner-outer corner, and it can extract pixels of a specific contour type. Moreover, it can trace contour pixels rapidly because it can determine the local minimal path using the contour case. In addition, the proposed algorithm is capable of the compressing data of contour pixels using the representative points and inner-outer corner points, and it can accurately restore the contour image from the data. To compare the performance of the proposed algorithm to that of conventional techniques, we measure their processing time and accuracy. In the experimental results, the proposed algorithm shows better performance compared to the others. Furthermore, it can provide the compressed data of contour pixels and restore them accurately, including the inner-outer corner, which cannot be restored using conventional algorithms. PMID:27005632

  16. Fast Contour-Tracing Algorithm Based on a Pixel-Following Method for Image Sensors

    Directory of Open Access Journals (Sweden)

    Jonghoon Seo

    2016-03-01

    Full Text Available Contour pixels distinguish objects from the background. Tracing and extracting contour pixels are widely used for smart/wearable image sensor devices, because these are simple and useful for detecting objects. In this paper, we present a novel contour-tracing algorithm for fast and accurate contour following. The proposed algorithm classifies the type of contour pixel, based on its local pattern. Then, it traces the next contour using the previous pixel’s type. Therefore, it can classify the type of contour pixels as a straight line, inner corner, outer corner and inner-outer corner, and it can extract pixels of a specific contour type. Moreover, it can trace contour pixels rapidly because it can determine the local minimal path using the contour case. In addition, the proposed algorithm is capable of the compressing data of contour pixels using the representative points and inner-outer corner points, and it can accurately restore the contour image from the data. To compare the performance of the proposed algorithm to that of conventional techniques, we measure their processing time and accuracy. In the experimental results, the proposed algorithm shows better performance compared to the others. Furthermore, it can provide the compressed data of contour pixels and restore them accurately, including the inner-outer corner, which cannot be restored using conventional algorithms.

  17. Micrometeoroid Impacts on the Hubble Sace Telescope Wide Field and Planetary Camera 2: Ion Beam Analysis of Subtle Impactor Traces

    Science.gov (United States)

    Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V. V.; Colaux, J. L.; Kearsley, A. T.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; Griffin, T.; Gerlach, L.; Wozniakiewicz, P. J.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2014-01-01

    Recognition of origin for particles responsible for impact damage on spacecraft such as the Hubble Space Telescope (HST) relies upon postflight analysis of returned materials. A unique opportunity arose in 2009 with collection of the Wide Field and Planetary Camera 2 (WFPC2) from HST by shuttle mission STS-125. A preliminary optical survey confirmed that there were hundreds of impact features on the radiator surface. Following extensive discussion between NASA, ESA, NHM and IBC, a collaborative research program was initiated, employing scanning electron microscopy (SEM) and ion beam analysis (IBA) to determine the nature of the impacting grains. Even though some WFPC2 impact features are large, and easily seen without the use of a microscope, impactor remnants may be hard to find.

  18. USEPA METHOD STUDY 38 - SW-846 METHOD 3010, ACID DIGESTION OF AQUEOUS SAMPLES AND EXTRACTS FOR TRACE METALS BY FLAME ATOMIC ABSORPTION SPECTROSCOPY

    Science.gov (United States)

    An interlaboratory collaborative study was conducted on SW-846 Method 3010, "Acid Digestion of Aqueous Samples and Extracts for Total Metals for Analysis by Flame Atomic Absorption Spectroscopy", to determine the mean recovery and precision for analyses of 21 trace metals in surf...

  19. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores.

    Science.gov (United States)

    Baccolo, Giovanni; Clemenza, Massimiliano; Delmonte, Barbara; Maffezzoli, Niccolò; Nastasi, Massimiliano; Previtali, Ezio; Prata, Michele; Salvini, Andrea; Maggi, Valter

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10(-13)-10(-6) g, improving previous results of 1-3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. PMID:27154827

  20. Effects of landforms on the erosion rate in a small watershed by the 137Cs tracing method

    International Nuclear Information System (INIS)

    It's very important to analyze and evaluate quantitatively the effects of landforms on soil erosion for the prevention and treatment of soil loss in a small watershed. The objective of this study was to evaluate the effects of landform factors on erosion rate by the 137Cs tracing method in a small watershed in the Purple Hilly Area of China. The erosion rates under different slope lengths, slope gradients and slope aspects were estimated in Xiangshuitan watershed in the Purple Hilly Area in Sichuan Basin by the 137Cs tracing method. The results showed that the erosion rate decreased exponentially with downslope distance, and it increased with increasing slope gradient during the scope of 5 deg. - 16 deg. The slope aspect had great impact on the erosion rate, and the hillside on the sunny slope had larger erosion rate than that on the shady slope, particularly for the farmland.

  1. A solid-phase extraction method using Transcarpathian clinoptilolite for preconcentration of trace amounts of terbium in water samples

    OpenAIRE

    Vasylechko, Volodymyr O.; Gryshchouk, Galyna V.; Zakordonskiy, Victor P.; Vyviurska, Olga; Pashuk, Andriy V.

    2015-01-01

    Background In spite of the fact that terbium is one of the rarest elements in the Earth’s crust, it is frequently used for the production of high technological materials. At the result, an effective combination of sample preparation procedure and detection method for terbium ions in different matrices is highly required. The solid-phase extraction procedure with natural Transcarpathian clinoptilolite thermally activated at 350 °C was used to preconcentrate trace amounts of terbium ions in aqu...

  2. Accurate finite difference beam propagation method for complex integrated optical structures

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Povlsen, Jørn Hedegaard; Bjarklev, Anders Overgaard

    1993-01-01

    A simple and effective finite-difference beam propagation method in a z-varying nonuniform mesh is developed. The accuracy and computation time for this method are compared with a standard finite-difference method for both the 3-D and 2-D versions......A simple and effective finite-difference beam propagation method in a z-varying nonuniform mesh is developed. The accuracy and computation time for this method are compared with a standard finite-difference method for both the 3-D and 2-D versions...

  3. Preliminary investigation of trace element in Pterygium using Synchrotron radiation micro-beam X-ray fluorescence analysis (-XRF)

    International Nuclear Information System (INIS)

    We have assessed the relative content and distribution of Iron and Zinc elements using microbeam synchrotron radiation X-ray fluorescence technique. One such technique is X-ray fluorescence (XRF), which has been used previously to map trace elements distribution in Physical samples. In this article a compromise is suggested in issue Pterygium samples. In this study, a prospective randomized clinical trial was conducted. Serial frozen sections of pterygium tissues and conjunctival tissues of 40 μm thickness were collected from 8 patients 10 eyes undergoing pterygium excision combine with limbal stem cell transplantation. A synchrotron-based XRF microprobe was used to map the distribution of Fe and Zn in whole frozen pterygium sections. The frozen sections were tested by synchrotron radiation X-ray fluorescence technique. These experiments were performed at BL15U in Shanghai, China. Then, the results have palyed that Iron and Zinc were present in both pterygium tissues and normal conjunctiva tissues (relevance ratio 100%). The contents of Iron and Zinc in normal conjunctiva tissues were significantly lower than in pterygium tissues (P < 0.05). The microelements were mostly clusteredin the pterygium tissues, while sparsely distributed in the normal conjunctiva tissue. Finally, we found that XRF imaging will be useful for mapping elemental distribution in Pterygium tissues. 40 μm frozen section on 6 μm mylar film is good for the test on BL15U. The contents of Iron and Zinc in pterygium tissue were significantly higher than in the control tissues. The results seem to be valuable in that Iron and Zinc may play a role in the development process of Pterygium

  4. Three-beam interferogram analysis method for surface flatness testing of glass plates and wedges

    Science.gov (United States)

    Sunderland, Zofia; Patorski, Krzysztof

    2015-09-01

    When testing transparent plates with high quality flat surfaces and a small angle between them the three-beam interference phenomenon is observed. Since the reference beam and the object beams reflected from both the front and back surface of a sample are detected, the recorded intensity distribution may be regarded as a sum of three fringe patterns. Images of that type cannot be succesfully analyzed with standard interferogram analysis methods. They contain, however, useful information on the tested plate surface flatness and its optical thickness variations. Several methods were elaborated to decode the plate parameters. Our technique represents a competitive solution which allows for retrieval of phase components of the three-beam interferogram. It requires recording two images: a three-beam interferogram and the two-beam one with the reference beam blocked. Mutually subtracting these images leads to the intensity distribution which, under some assumptions, provides access to the two component fringe sets which encode surfaces flatness. At various stages of processing we take advantage of nonlinear operations as well as single-frame interferogram analysis methods. Two-dimensional continuous wavelet transform (2D CWT) is used to separate a particular fringe family from the overall interferogram intensity distribution as well as to estimate the phase distribution from a pattern. We distinguish two processing paths depending on the relative density of fringe sets which is connected with geometry of a sample and optical setup. The proposed method is tested on simulated data.

  5. Dynamic modeling and analysis of the PZT-bonded composite Timoshenko beams: Spectral element method

    Science.gov (United States)

    Lee, Usik; Kim, Daehwan; Park, Ilwook

    2013-03-01

    The health of thin laminated composite beams is often monitored using the ultrasonic guided waves excited by wafer-type piezoelectric transducers (PZTs). Thus, for the smart composite beams which consist of a laminated composite base beam and PZT layers, it is very important to develop a very reliable mathematical model and to use a very accurate computational method to predict accurate dynamic characteristics at very high ultrasonic frequency. In this paper, the axial-bending-shear-lateral contraction coupled differential equations of motion are derived first by the Hamilton's principle with Lagrange multipliers. The smart composite beam is represented by a Timoshenko beam model by adopting the first-order shear deformation theory (FSDT) for the laminated composite base beam. The axial deformation of smart composite beam is improved by taking into account the effects of lateral contraction by adopting the concept of Mindlin-Herrmann rod theory. The spectral element model is then formulated by the variation approach from coupled differential equations of motion transformed into the frequency domain via the discrete Fourier transform. The high accuracy of the present spectral element model is verified by comparing with other solution methods: the finite element model developed in this paper and the commercial FEA package ANSYS. Finally the dynamics and wave characteristics of some example smart composite beams are investigated through the numerical studies.

  6. A finite element beam propagation method for simulation of liquid crystal devices

    OpenAIRE

    Vanbrabant, P. J. M.; Beeckman, J.; Neyts, K.; James, R.; Fernandez, F. A.

    2009-01-01

    An efficient full-vectorial finite element beam propagation method is presented that uses higher order vector elements to calculate the wide angle propagation of an optical field through inhomogeneous, anisotropic optical materials such as liquid crystals. The full dielectric permittivity tensor is considered in solving Maxwell's equations. The wide applicability of the method is illustrated with different examples: the propagation of a laser beam in a uniaxial medium, the tunability of a dir...

  7. The development of an analytical technique for the determination of traces of mercury by substoichiometric isotope dilution method

    International Nuclear Information System (INIS)

    A procedure has been developed for the quantitative determination of traces of mercury in biological samples. The radiochemical separation method used involves the combustion of samples in an oxygen flask, followed by a substoichiometric isotope dilution method utilizing a solvent extraction technique. The method was primarily tested using radiotracer experiments and then by analyzing two already certified NBS Standard Reference Materials, Orchard Leaves and Bovine Liver, and a Bowen's Standard Kale Sample. The limit of detection is 0.005 ppm. The technique developed is comparatively simple, inexpensive, fast and suitable for routine work. (author)

  8. Simultaneous determination of 20 trace elements in geologic samples by the isotope dilution method combined with spark source mass spectrography

    International Nuclear Information System (INIS)

    A technique is described to simultaneously determine 20 or more trace elements in geologic samples applying the isotope dilution method combined with spark source mass spectrography. The advantages of this technique are: (a) the measurements are independent from calibration standards and (b) the analyses of sundry samples with similar chemical compositions are simplified by using isotopically spiked graphite. Concentrations determined by this method are in good agreement with those obtained by other analytical methods. The average of all relative standard deviations is better than 10%. 2 figures, 5 tables

  9. Development of an Origin Trace Method based on Bayesian Inference and Artificial Neural Network for Missing or Stolen Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bin, Yim Ho; Min, Lee Seung; Min, Kim Kyung; Jeong, Hong Yoon; Kim, Jae Kwang [Nuclear Security Div., Daejeon (Korea, Republic of)

    2014-05-15

    Thus, 'to put nuclear materials under control' is an important issue for prosperity mankind. Unfortunately, numbers of illicit trafficking of nuclear materials have been increased for decades. Consequently, security of nuclear materials is recently spotlighted. After the 2{sup nd} Nuclear Security Summit in Seoul in 2012, the president of Korea had showed his devotion to nuclear security. One of the main responses for nuclear security related interest of Korea was to develop a national nuclear forensic support system. International Atomic Energy Agency (IAEA) published the document of Nuclear Security Series No.2 'Nuclear Forensics Support' in 2006 to encourage international cooperation of all IAEA member states for tracking nuclear attributions. There are two main questions related to nuclear forensics to answer in the document. The first question is 'what type of material is it?', and the second one is 'where did the material come from?' Korea Nuclear Forensic Library (K-NFL) and mathematical methods to trace origins of missing or stolen nuclear materials (MSNMs) are being developed by Korea Institute of Nuclear Non-proliferation and Control (KINAC) to answer those questions. Although the K-NFL has been designed to perform many functions, K-NFL is being developed to effectively trace the origin of MSNMs and tested to validate suitability of trace methods. New fuels and spent fuels need each trace method because of the different nature of data acquisition. An inductive logic was found to be appropriate for new fuels, which had values as well as a bistable property. On the other hand, machine learning was suitable for spent fuels, which were unable to measure, and thus needed simulation.

  10. Development of an Origin Trace Method based on Bayesian Inference and Artificial Neural Network for Missing or Stolen Nuclear Materials

    International Nuclear Information System (INIS)

    Thus, 'to put nuclear materials under control' is an important issue for prosperity mankind. Unfortunately, numbers of illicit trafficking of nuclear materials have been increased for decades. Consequently, security of nuclear materials is recently spotlighted. After the 2nd Nuclear Security Summit in Seoul in 2012, the president of Korea had showed his devotion to nuclear security. One of the main responses for nuclear security related interest of Korea was to develop a national nuclear forensic support system. International Atomic Energy Agency (IAEA) published the document of Nuclear Security Series No.2 'Nuclear Forensics Support' in 2006 to encourage international cooperation of all IAEA member states for tracking nuclear attributions. There are two main questions related to nuclear forensics to answer in the document. The first question is 'what type of material is it?', and the second one is 'where did the material come from?' Korea Nuclear Forensic Library (K-NFL) and mathematical methods to trace origins of missing or stolen nuclear materials (MSNMs) are being developed by Korea Institute of Nuclear Non-proliferation and Control (KINAC) to answer those questions. Although the K-NFL has been designed to perform many functions, K-NFL is being developed to effectively trace the origin of MSNMs and tested to validate suitability of trace methods. New fuels and spent fuels need each trace method because of the different nature of data acquisition. An inductive logic was found to be appropriate for new fuels, which had values as well as a bistable property. On the other hand, machine learning was suitable for spent fuels, which were unable to measure, and thus needed simulation

  11. Material-Point Method Analysis of Bending in Elastic Beams

    DEFF Research Database (Denmark)

    Andersen, Søren Mikkel; Andersen, Lars

    2007-01-01

    The aim of this paper is to rest different kinds of spatial interpolation for the material-point method.......The aim of this paper is to rest different kinds of spatial interpolation for the material-point method....

  12. Contribution to the study of radioactive ion beam production by the ISOL method

    International Nuclear Information System (INIS)

    This thesis is related to the R and D program for the production of radioactive ion beams by the ISOL method at GANIL in Caen. This work concerns several different techniques based on the ISOL method. The first one is the production of radioactive ion beams with a SPIRAL target-source system (target + ECR source). The production rates of radioactive neon beams were determined on the SIRa test bench and previsions for SPIRAL were established. The feasibility of the production of radioactive condensable element beams with such target-source system, using a transport under a volatile molecular form between the target and the source, was experimentally proven by the production of radioactive oxygen beams via the CO molecule. The second technique is the production of radioactive alkaline beams with the target-source system MONOLITHE (target + hot cavity source). The production efficiencies of lithium and sodium radioactive beams were determined. A new methodology, the 'global method', has been developed as part of this thesis, for deducing diffusion, effusion and ionisation properties of these two elements with this ensemble. It is shown that the evolution of diffusion properties between different alkali elements is similar to noble gases. The third one is the IGISOL technique (target + ion guide). The MI-GI-CHEMIN code was created for simulating the movement of ions in an ion guide filled with helium and a given concentration of impurities, including electric and magnetic fields. A first IGISOL prototype is in realisation at GANIL. (author)

  13. Two-dimensional differential calibration method for a neutron dosemeter using a thermal neutron beam.

    Science.gov (United States)

    Matsumoto, Tetsuro; Harano, Hideki; Masuda, Akihiko; Nishiyama, Jun; Matsue, Hideaki; Uritani, Akira; Nunomiya, Tomoya

    2013-08-01

    A new thermal neutron calibration method to experimentally determine the energy response function of a neutron detector using a pulse parallel beam and the time-of-flight (TOF) technique is developed. The calibration method was experimentally demonstrated for a (3)He proportional counter and an electric personal dosemeter using a pulsed thermal neutron beam from the research reactor JRR-3M. The responses of the detectors were successfully obtained as a function of neutron energy. However, detailed information on the detector structure is required to obtain the spatial response distribution for the detector. The authors further propose an improved calibration method obtaining the spatial response distribution using a pulsed narrow beam, the TOF technique and a beam scanning technique. PMID:23509397

  14. Fabrication of a polymer with three-dimensional structure by the ion beam graft polymerization method

    International Nuclear Information System (INIS)

    The graft polymerization method is one of the most effective techniques to produce a new polymer with unique function. To produce the polymer, we conducted experiments on radiation graft polymerization using ion beams of several hundred keV energy. A high density polyethylene (PE) film was irradiated with H+ beams, then, graft polymerization with monomer solution such as acrylic acid or acrylonitrile was conducted. Radicals generated by the interaction between the beam ions and the PE molecules become the starting point of the graft polymerization. Since the range in PE depends on ion energy, the density distribution of the graft chain can be controlled by the ion energy. Using a mask which restricts the ion beam incidence, PE sheets containing graft chains only in the unmasked area were obtained. Multiple ion beam graft polymerization can produce a polymer which has some functional bases at specified position. We have demonstrated the production of a polymer film with a three-dimensional structure.

  15. System and method for deflecting and focusing a broad ion beam

    International Nuclear Information System (INIS)

    A method and system for deflecting a broad ion plasma beam which includes an ion source for forming an ion plasma, an extraction means for extracting a broad ion plasma beam from the ion plasma, and deflection means including a non-grounded surface located in the path of the ion plasam beam and at an angle to the path for deflecting the ion plasma beam to a target material. A grounded, screen grid is located in front of the deflecting means in the path of the ion plasma. The screen grid has openings which permit passage of the ions in the ion plasma, but block passage of the electrons. The plasma beam is deflected by the deflection means and the grounded, screen grid onto the target material for sputter cleaning, deposition and ion milling applications

  16. Nonlocal beam models for buckling of nanobeams using state-space method regarding different boundary conditions

    International Nuclear Information System (INIS)

    Buckling analysis of nanobeams is investigated using nonlocal continuum beam models of the different classical beam theories namely as Euler-Bernoulli beam theory (EBT), Timoshenko beam theory (TBT), and Levinson beam theory (LBT). To this end, Eringen's equations of nonlocal elasticity are incorporated into the classical beam theories for buckling of nanobeams with rectangular cross-section. In contrast to the classical theories, the nonlocal elastic beam models developed here have the capability to predict critical buckling loads that allowing for the inclusion of size effects. The values of critical buckling loads corresponding to four commonly used boundary conditions are obtained using state-space method. The results are presented for different geometric parameters, boundary conditions, and values of nonlocal parameter to show the effects of each of them in detail. Then the results are fitted with those of molecular dynamics simulations through a nonlinear least square fitting procedure to find the appropriate values of nonlocal parameter for the buckling analysis of nanobeams relevant to each type of nonlocal beam model and boundary conditions analysis

  17. Two methods of beam position signal processing for closed orbit measurement

    International Nuclear Information System (INIS)

    This paper describes two methods of processing lineraly detected signals of the beam position from pickup electrodes. The first method is based on the tracking self-balanced analog-digital bridge and the second one is based on the tracking ADC with varying reference. The operating features of the units realizing these methods are presented

  18. Major, minor and trace elements in four kinds of cement powder using INAA and k0-standardization methods

    International Nuclear Information System (INIS)

    In this work, we aim to get the concentration of major, minor and trace elements in four kinds of cements powder using INAA and k0-NAA methods. All samples were irradiated at Es-Salam research reactor with a thermal neutron flux of 3.76 1013 n/cm2 s. In this study, the concentration values of 32 elements were determined using both techniques. The comparison was carried out by the mean of ratios between experimental results obtained by k0-NAA and INAA of four cement samples. Certified reference materials NIST1646a and GSD12, respectively, were used to check reliability of the methods. (author)

  19. Uncertainty determination for activity measurements by means of the TDCR method and the CIEMAT/NIST efficiency tracing technique

    International Nuclear Information System (INIS)

    Liquid scintillation counting is a very powerful technique for the activity determination of a number of radionuclides. In radionuclide metrology, the TDCR method and the CIEMAT/NIST efficiency tracing technique are widely used in many laboratories. Both methods require rather complex calculation techniques to derive the counting efficiency of the nuclide under study. This article explores the various sources of uncertainty that should be considered when applying these two techniques, and focuses on possible ways to evaluate them. Concrete examples are provided within the paper. (authors)

  20. Homotopy perturbation method for free vibration analysis of beams on elastic foundation

    International Nuclear Information System (INIS)

    In this study, the homotopy perturbation method (HPM) is applied for free vibration analysis of beam on elastic foundation. This numerical method is applied on a previously available case study. Analytical solutions and frequency factors are evaluated for different ratios of axial load N acting on the beam to Euler buckling load, Nr. The application of HPM for the particular problem in this study gives results which are in excellent agreement with both analytical solutions and the variational iteration method (VIM) solutions for the case considered in this study and the differential transform method (DTM) results available in the literature.

  1. Trace element analysis of wild rodent tissues using the PIXE method

    International Nuclear Information System (INIS)

    Five species of rodents have been collected in an area near Lake Powell Utah. Common names of the five species are: Long-tailed Mouse, Small Pocket Mouse, Deer Mouse, Antelope Ground Squirrel and Kangaroo Rat. Liver, lung, kidney and hair tissues from each animal were analyzed for trace element content by proton particle-induced x-ray emission (proton PIXE) analysis. Mean concentrations for the following elements were established for the tissues of each animal type: K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb and Pb. Analyses of variance were performed on the set of elements common to all tissues. Some significant differences in element concentrations were found between animal species and between tissue types. These differences lead to the following orders based on element concentration: Long-tailed Mouse greater than or equal to Antelope Ground Squirrel greater than or equal to Kangaroo Rat greater than or equal to Small Pocket Mouse and liver greater than or equal to kidney greater than or equal to lung greater than or equal to hair. Linear regression analyses were also performed on mean elemental concentrations in tissues. These analyses lead to several conclusions. First, the pattern of trace element concentrations in each of the four tissues is the same in all five species. Second, the pattern of trace element concentrations is the same in all four tissues of one species with the exception of Ti and Fe in hair. Third, the variation of an element in the hair cannot predict the variation of that same element in the other three tissues. Only K, Ca, Ti, Mn, Fe, Cu, and Zn were included in the third study

  2. Monitoring ground-level air for trace analysis: methods and results

    International Nuclear Information System (INIS)

    Trace analysis enables the sensitive detection of radionuclide concentrations in ground-level air in the range of microbecquerel per cubic meter (μBq m-3). Typical sampling intervals of less than one day up to a few days can be used in routine operation. Trace analysis measurements are performed in the framework of the German Integrated Measuring and Information system (IMIS) and the International Monitoring System (IMS) used for verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Within the environmental monitoring programmes of the German IMIS the Federal Office for Radiation Protection (BfS) performs measurements of aerosol-bound radionuclides and of radioactive noble gases in the atmosphere. Aerosols are collected on filters with high-volume air samplers and analysed by γ-spectrometry, α-spectrometry, and integral measurements of β-activity, with preceding radiochemical separation. Noble gas samples from 15 sites world-wide are analysed to observe the 85Kr-release from nuclear fuel reprocessing plants and from seven sites in Germany to monitor the 133Xe emitted from nuclear power plants. As part of the International Monitoring System (IMS) of the CTBT an automatic aerosol sampling and measuring system and an automatic noble gas sampling and measuring system will be operated by the BfS at Mount Schauinsland near Freiburg. Because of its expertise in noble gas measurements the BfS had been chosen to perform an intercomparison experiment in the BfS laboratory in Freiburg with several automatic noble gas sampling and measurement systems before their installation at IMS sites. To establish quality-assurance programmes for trace analysis performed for the German IMIS close collaboration between the involved German institutions has been established. First steps have been taken to expand cooperation to other European laboratories. Informal data exchange already occurs between trace-analysis laboratories in Europe (Ring of Five) and helps in cases of

  3. Measurements of reactive trace gases in the marine boundary layer using novel DOAS methods

    OpenAIRE

    Lampel, Johannes

    2014-01-01

    Reactive Halogen Species (RHS) can have a large impact on tropospheric chemistry. Already small concentrations in the marine boundary layer (MBL) can have a significant impact on the global budget of ozone and other trace-gases. Shipborne measurements of BrO and IO were conducted in the MBL from 70°S to 90°N to obtain a global picture of their distribution over several years. A focus were upwelling regions, which can provide large amounts of precursor substances for RHS in the MBL, of which s...

  4. Development of a choronocoulometric method for determining traces of uranium using the catalytic nitrate reduction

    International Nuclear Information System (INIS)

    With the aim of improving the sensitivity of the electroanalytical determination of uranium at trace levels. The uranium catalyzed reduction of nitrate on mercury electrode and the technique of chronocoulometry were used. Several experimental parameters were investigated (electrolyte composition, potential program, integration time, blank correction, temperature, previous separation) and adequate conditions were selected for the analytical determination. Under these conditions it was possible to exceed the best reported sensitivity for the catalytic determination, extending the detection limit to 3.10-10M. Exploratory study of the combination of this procedure with pre-concentration of uranium ions on the electrode revealed a detection limit ten limes lower. (author)

  5. Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods

    International Nuclear Information System (INIS)

    Evaporation plays an important role in many technical applications including beam-based additive manufacturing processes, such as selective electron beam or selective laser melting (SEBM/SLM). In this paper, we describe an evaporation model which we employ within the framework of a two-dimensional free surface lattice Boltzmann method. With this method, we solve the hydrodynamics as well as thermodynamics of the molten material taking into account the mass and energy losses due to evaporation and the recoil pressure acting on the melt pool. Validation of the numerical model is performed by measuring maximum melt depths and evaporative losses in samples of pure titanium and Ti–6Al–4V molten by an electron beam. Finally, the model is applied to create processing maps for an SEBM process. The results predict that the penetration depth of the electron beam, which is a function of the acceleration voltage, has a significant influence on evaporation effects. (paper)

  6. New Spectral Method for Halo Particle Definition in Intense Mis-matched Beams

    International Nuclear Information System (INIS)

    An advanced spectral analysis of a mis-matched charged particle beam propagating through a periodic focusing transport lattice is utilized in particle-in-cell (PIC) simulations. It is found that the betatron frequency distribution function of a mismatched space-charge-dominated beam has a bump-on-tail structure attributed to the beam halo particles. Based on this observation, a new spectral method for halo particle definition is proposed that provides the opportunity to carry out a quantitative analysis of halo particle production by a beam mismatch. In addition, it is shown that the spectral analysis of the mismatch relaxation process provides important insights into the emittance growth attributed to the halo formation and the core relaxation processes. Finally, the spectral method is applied to the problem of space-charge transport limits.

  7. ANALYSIS OF COMPOSITE LAMINATE BEAMS USING COUPLING CROSS-SECTION FINITE ELEMENT METHOD

    Institute of Scientific and Technical Information of China (English)

    JIANG Wen-guang; John L. Henshall

    2006-01-01

    Beams and plates manufactured from laminates of composite materials have distinct advantages in a significant number of applications. However, the anisotropy arising from these materials adds a significant degree of complexity, and thus time, to the stress and deformation analyses of such components, even using numerical approaches such as finite elements. The analysis of composite laminate beams subjected to uniform extension, bending, and/or twisting loads was performed by a novel implementation of the usual finite element method. Due to the symmetric features of the deformations,only a thin slice of the beam to be analysed needs to be modelled. Conventional threedimensional ,solid finite elements were used for the structural discretization. The accurate deformation relationships were formulated and implemented through the coupling of nodal translational degrees of freedom in the numerical analysis. A sample solution for a rectangular composite laminate beam is presented to show the validity and accuracy of the proposed method.

  8. Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods

    Science.gov (United States)

    Klassen, Alexander; Scharowsky, Thorsten; Körner, Carolin

    2014-07-01

    Evaporation plays an important role in many technical applications including beam-based additive manufacturing processes, such as selective electron beam or selective laser melting (SEBM/SLM). In this paper, we describe an evaporation model which we employ within the framework of a two-dimensional free surface lattice Boltzmann method. With this method, we solve the hydrodynamics as well as thermodynamics of the molten material taking into account the mass and energy losses due to evaporation and the recoil pressure acting on the melt pool. Validation of the numerical model is performed by measuring maximum melt depths and evaporative losses in samples of pure titanium and Ti-6Al-4V molten by an electron beam. Finally, the model is applied to create processing maps for an SEBM process. The results predict that the penetration depth of the electron beam, which is a function of the acceleration voltage, has a significant influence on evaporation effects.

  9. Oblique Du-Fort Frankel Beam Propagation Method

    Directory of Open Access Journals (Sweden)

    Ken Chan

    2011-01-01

    Full Text Available The oblique BPM based on the Du-Fort Frankel method is presented. The paper demonstrates the accuracy and the computational improvements of the scheme compared to the oblique BPM based on Crank-Nicholson (CN scheme.

  10. Beyond the transect: An alternative microchemical imaging method for fine scale analysis of trace elements in fish otoliths during early life

    Energy Technology Data Exchange (ETDEWEB)

    McGowan, Nicole [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); CCFS ARC Centre of Excellence, Department of Earth and Planetary Sciences, Macquarie University, Sydney (Australia); Fowler, Ashley M.; Parkinson, Kerryn [Fish Ecology Laboratory, School of the Environment, University of Technology, Sydney, New South Wales (Australia); Bishop, David P. [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); Ganio, Katherine [Florey Department of Neuroscience and Mental Health, University of Melbourne, Victoria (Australia); Doble, Philip A. [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); Booth, David J. [Fish Ecology Laboratory, School of the Environment, University of Technology, Sydney, New South Wales (Australia); Hare, Dominic J., E-mail: dominic.hare@uts.edu.au [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); Florey Department of Neuroscience and Mental Health, University of Melbourne, Victoria (Australia)

    2014-10-01

    Microchemical analysis of otolith (calcified ‘ear stones’ used for balance and orientation) of fishes is an important tool for studying their environmental history and management. However, the spatial resolution achieved is often too coarse to examine short-term events occurring in early life. Current methods rely on single points or transects across the otolith surface, which may provide a limited view of elemental distributions, a matter that has not previously been investigated. Imaging by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) permits microchemical analyses of short-term events in early life with high (< 10 μm) resolution, two-dimensional (2D) visualization of elemental distributions. To demonstrate the potential of this method, we mapped the concentrations of Sr and Ba, two key trace elements, in a small number of juvenile otoliths of neon damselfish (Pomacentrus coelestis) using an 8 μm beam diameter (laser fluence of 13.8 ± 3.5 J cm{sup −2}). Quantification was performed using the established method by Longerich et al. (1996), which is applied to 2D imaging of a biological matrix here for the first time. Accuracy of > 97% was achieved using a multi-point non matrix-matched calibration of National Institute of Standards and Technology (NIST) 610 and 612 (trace elements in glass) using Longerich's calculation method against the matrix-matched standard FEBS-1 (powdered red snapper [Lutjanus campechanus] otolith). The spatial resolution achieved in the otolith corresponded to a time period of 2 ± 1 days during the larval phase, and 4 ± 1 days during the post-settlement juvenile phase. This method has the potential to improve interpretations of early life-history events at scales corresponding to specific events. While the images showed gradients in Sr and Ba across the larval settlement zone more clearly than single transects, the method proved sample homogeneity throughout the structure; demonstrating that 2D

  11. Beyond the transect: An alternative microchemical imaging method for fine scale analysis of trace elements in fish otoliths during early life

    International Nuclear Information System (INIS)

    Microchemical analysis of otolith (calcified ‘ear stones’ used for balance and orientation) of fishes is an important tool for studying their environmental history and management. However, the spatial resolution achieved is often too coarse to examine short-term events occurring in early life. Current methods rely on single points or transects across the otolith surface, which may provide a limited view of elemental distributions, a matter that has not previously been investigated. Imaging by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) permits microchemical analyses of short-term events in early life with high (< 10 μm) resolution, two-dimensional (2D) visualization of elemental distributions. To demonstrate the potential of this method, we mapped the concentrations of Sr and Ba, two key trace elements, in a small number of juvenile otoliths of neon damselfish (Pomacentrus coelestis) using an 8 μm beam diameter (laser fluence of 13.8 ± 3.5 J cm−2). Quantification was performed using the established method by Longerich et al. (1996), which is applied to 2D imaging of a biological matrix here for the first time. Accuracy of > 97% was achieved using a multi-point non matrix-matched calibration of National Institute of Standards and Technology (NIST) 610 and 612 (trace elements in glass) using Longerich's calculation method against the matrix-matched standard FEBS-1 (powdered red snapper [Lutjanus campechanus] otolith). The spatial resolution achieved in the otolith corresponded to a time period of 2 ± 1 days during the larval phase, and 4 ± 1 days during the post-settlement juvenile phase. This method has the potential to improve interpretations of early life-history events at scales corresponding to specific events. While the images showed gradients in Sr and Ba across the larval settlement zone more clearly than single transects, the method proved sample homogeneity throughout the structure; demonstrating that 2D scanning

  12. Intense Electron Beams Formation and Analysis Methods in Static Electromagnetic Fields (Review

    Directory of Open Access Journals (Sweden)

    G.S. Vorobyov

    2011-01-01

    Full Text Available In this review basic principles of electron beams formation in static electric and magnetic fields are reported. Traditional and new perspective designs of electron-optical systems and magnetic systems are also considered. Questions of charged-particle beam focusing and transport on the level of modern technologies are being analyzed and their theoretic and experimental parameter research methods are examined as well.

  13. The principles of a new method of determining ion beam profile density distribution

    International Nuclear Information System (INIS)

    The theoretical basis of a technique to determine the spatial density flux distribution in non-uniform ion beams is described. The technique relies on the mapping of the flux distribution into fluence collected distributions when the flux is translated at variable prescribed velocity relative to a series of ion collectors. The method determines the spatial moments of the flux distribution and does not require collector dimensions to be small with respect to the ion beam profile dimensions. (author)

  14. A polarized atomic hydrogen beam

    OpenAIRE

    Chan, N; Crowe, D.M.; Lubell, M. S.; Tang, F.C.; Vasilakis, A.; Mulligan, F. J.; Slevin, J.

    1988-01-01

    We describe the design and operating characteristics of a simple polarized atomic hydrogen beam particularly suitable for applications to crossed beams experiments. In addition to experimental measurements, we present the results of detailed computer models, using Monte-Carlo ray tracing techniques, optical analogs, and phase-space methods, that not only provide us with a confirmation of our measurement, but also allow us to characterize the density, polarization, and atomic fraction of the b...

  15. High-energy polarized-beam energy-dispersive X-ray fluorescence analysis combined with activated thin layers for cadmium determination at trace levels in complex environmental liquid samples.

    Science.gov (United States)

    Marguí, Eva; Fontàs, Clàudia; Van Meel, Katleen; Van Grieken, René; Queralt, Ignasi; Hidalgo, Manuela

    2008-04-01

    In this paper, we describe a new method for trace level Cd determination in complex environmental liquid samples. Thin layers activated with the extractant Aliquat 336 were prepared either by direct impregnation of commercial polymeric supports or by physical inclusion in a cellulose triacetate matrix, and both were effectively used to collect Cd present at low concentration in different aqueous matrixes. Quantitation of Cd contained in the thin layers was performed by high-energy polarized-beam energy-dispersive X-ray fluorescence. The effects of various experimental parameters such as layer composition, equilibration time, and instrumental conditions have been investigated. The analysis of different impregnated layers contacted with solutions ranging from 5 to 8000 microg L-1 Cd showed a linear response between the Cd concentration in the aqueous solutions and the metal present in the thin layer, with a detection limit of 0.7 microg L-1. The accuracy of the proposed method was confirmed by analyzing spiked seawater samples and a synthetic water sample containing, besides Cd, high amounts of other metal pollutants such as Ni, Cu, and Pb. The attained results were comparable to those obtained by anodic stripping voltammetry or inductively coupled plasma spectrometry. PMID:18327919

  16. Generalized ray tracing method for the calculation of the peripheral refraction induced by an ophthalmic lens

    Science.gov (United States)

    Rojo, Pilar; Royo, Santiago; Caum, Jesus; Ramírez, Jorge; Madariaga, Ines

    2015-02-01

    Peripheral refraction, the refractive error present outside the main direction of gaze, has lately attracted interest due to its alleged relationship with the progression of myopia. The ray tracing procedures involved in its calculation need to follow an approach different from those used in conventional ophthalmic lens design, where refractive errors are compensated only in the main direction of gaze. We present a methodology for the evaluation of the peripheral refractive error in ophthalmic lenses, adapting the conventional generalized ray tracing approach to the requirements of the evaluation of peripheral refraction. The nodal point of the eye and a retinal conjugate surface will be used to evaluate the three-dimensional distribution of refractive error around the fovea. The proposed approach enables us to calculate the three-dimensional peripheral refraction induced by any ophthalmic lens at any direction of gaze and to personalize the lens design to the requirements of the user. The complete evaluation process for a given user prescribed with a -5.76D ophthalmic lens for foveal vision is detailed, and comparative results obtained when the geometry of the lens is modified and when the central refractive error is over- or undercorrected. The methodology is also applied for an emmetropic eye to show its application for refractive errors other than myopia.

  17. Study on correlation of trace elements in human hair and internal organs by nuclear methods

    International Nuclear Information System (INIS)

    Autopsy samples from 24 human males, aged 35-60 years were collected from Shanghai, People's Republic of China, to study possible relationships between the trace element content in hair and internal tissues. Samples of hair, kidney-cortex and lung were collected and analyzed. A radiochemical neutron activation analysis (RNAA) procedure was developed based on a simple group extraction scheme using zinc-diethyl dithiocarbamate and methyl-isobutyl ketone-iodide. The trace elements As, Cd, Hg, Cu and Zn were measured following this procedure. In addition, the elements Se, Na, Mg, Cl, Br, S, Cr, Co, and Rb were determined using instrumental neutron activation analysis (INAA). The reliability of the analytical procedures were checked analyzing several biological reference materials, such as IAEA-H-8 Horse Kidney, NBS-SRM-1573 Tomato Leaves and NIES-5 Human Hair. The results showed a larger concentration variability for As, Cd and Hg than for Cu, Se and Zn. Some significant positive correlations were found for some elements among different tissues. (author). 15 refs, 22 figs, 4 tabs

  18. Shadow effects in simulated ultrasound images derived from computed tomography images using a focused beam tracing model

    DEFF Research Database (Denmark)

    Pham, An Hoai; Lundgren, Bo; Stage, Bjarne;

    2012-01-01

    Simulation of ultrasound images based on computed tomography (CT) data has previously been performed with different approaches. Shadow effects are normally pronounced in ultrasound images, so they should be included in the simulation. In this study, a method to capture the shadow effects has been......Focus ultrasound scanner (BK Medical, Herlev, Denmark) equipped with a dedicated research interface giving access to beamformed radio frequency data. CT images were obtained with an Aquilion ONE Toshiba CT scanner (Toshiba Medical Systems Corp., Tochigi, Japan). CT data were mapped from Hounsfield units to...

  19. A novel in situ method for sampling urban soil dust: Particle size distribution, trace metal concentrations, and stable lead isotopes

    International Nuclear Information System (INIS)

    In this study, a novel in situ sampling method was utilized to investigate the concentrations of trace metals and Pb isotope compositions among different particle size fractions in soil dust, bulk surface soil, and corresponding road dust samples collected within an urban environment. The aim of the current study was to evaluate the feasibility of using soil dust samples to determine trace metal contamination and potential risks in urban areas in comparison with related bulk surface soil and road dust. The results of total metal loadings and Pb isotope ratios revealed that soil dust is more sensitive than bulk surface soil to anthropogenic contamination in urban areas. The new in situ method is effective at collecting different particle size fractions of soil dust from the surface of urban soils, and that soil dust is a critical indicator of anthropogenic contamination and potential human exposure in urban settings. -- Highlights: ► A novel in situ sampling method for soil dust was proposed. ► Different particle size fractions of soil dust and bulk soil were studied. ► Soil dust is critical for understanding anthropogenic pollution in urban areas. ► Soil dust can be useful to estimate potential human exposure. -- Soil dust collected by a novel in situ sampling method can provide critical information about contamination and potential human exposure in urban environments

  20. A surrogate-based metaheuristic global search method for beam angle selection in radiation treatment planning

    International Nuclear Information System (INIS)

    An important element of radiation treatment planning for cancer therapy is the selection of beam angles (out of all possible coplanar and non-coplanar angles in relation to the patient) in order to maximize the delivery of radiation to the tumor site and minimize radiation damage to nearby organs-at-risk. This category of combinatorial optimization problem is particularly difficult because direct evaluation of the quality of treatment corresponding to any proposed selection of beams requires the solution of a large-scale dose optimization problem involving many thousands of variables that represent doses delivered to volume elements (voxels) in the patient. However, if the quality of angle sets can be accurately estimated without expensive computation, a large number of angle sets can be considered, increasing the likelihood of identifying a very high quality set. Using a computationally efficient surrogate beam set evaluation procedure based on single-beam data extracted from plans employing equally-spaced beams (eplans), we have developed a global search metaheuristic process based on the nested partitions framework for this combinatorial optimization problem. The surrogate scoring mechanism allows us to assess thousands of beam set samples within a clinically acceptable time frame. Tests on difficult clinical cases demonstrate that the beam sets obtained via our method are of superior quality. (paper)

  1. Adaptive synthesis method for broadband array with frequency invariant beam pattern

    Institute of Scientific and Technical Information of China (English)

    ZHUWeijie; SUNJincai; ZENGXiangyang

    2003-01-01

    Based on adaptive technique, a design method for broadband array with frequency invariant beam pattern is presented. For a given beam pattern, the all design process can be completed automatically by computer without deriving expression of weight vector. The design process is divided into three steps: (1) Evaluate the weight vector in reference frequency by numerical method. (2) Obtain the weight vectors in other frequency by adaptive technique.(3) For the design target of frequency response given by weight vector at different frequency point, design FIR filter. The proposed method can be applied to arbitrary array and have no restriction on element patterns.

  2. A method for evaluating aberration in the crossover image in mask irradiation optics of electron beam

    Science.gov (United States)

    Sohda, Yasunari; Ohta, Hiroya; Saitou, Norio

    2002-02-01

    A method for evaluating aberration in the crossover image in a cell projection lithography system has been developed. In an electron-beam lithography system of projection-type such as a cell projection lithography system, the aberration in the crossover image causes the electron beam to pass off-axis in the electron optics. Optical simulation has quantitatively shown that the aberration in the crossover image causes an electron-beam blur and a positioning error on a writing sample. The evaluating method consists of four square apertures and a mark-detection function in a cell projection system. By measuring each position of the images of the four square apertures on the writing sample at difference focuses, the aberration can be calculated. The field curvature and the astigmatism in a cell projection system were evaluated by using this method. The field curvature agrees with the simulation. In addition, the measurement of the effect of beam alignment is also demonstrated. It is thus concluded that the method can effectively evaluate the aberration in the crossover image. This method is also useful for other projection-type lithographies of charged particles—like ion and electron beams.

  3. Interlaminar Stresses by Refined Beam Theories and the Sinc Method Based on Interpolation of Highest Derivative

    Science.gov (United States)

    Slemp, Wesley C. H.; Kapania, Rakesh K.; Tessler, Alexander

    2010-01-01

    Computation of interlaminar stresses from the higher-order shear and normal deformable beam theory and the refined zigzag theory was performed using the Sinc method based on Interpolation of Highest Derivative. The Sinc method based on Interpolation of Highest Derivative was proposed as an efficient method for determining through-the-thickness variations of interlaminar stresses from one- and two-dimensional analysis by integration of the equilibrium equations of three-dimensional elasticity. However, the use of traditional equivalent single layer theories often results in inaccuracies near the boundaries and when the lamina have extremely large differences in material properties. Interlaminar stresses in symmetric cross-ply laminated beams were obtained by solving the higher-order shear and normal deformable beam theory and the refined zigzag theory with the Sinc method based on Interpolation of Highest Derivative. Interlaminar stresses and bending stresses from the present approach were compared with a detailed finite element solution obtained by ABAQUS/Standard. The results illustrate the ease with which the Sinc method based on Interpolation of Highest Derivative can be used to obtain the through-the-thickness distributions of interlaminar stresses from the beam theories. Moreover, the results indicate that the refined zigzag theory is a substantial improvement over the Timoshenko beam theory due to the piecewise continuous displacement field which more accurately represents interlaminar discontinuities in the strain field. The higher-order shear and normal deformable beam theory more accurately captures the interlaminar stresses at the ends of the beam because it allows transverse normal strain. However, the continuous nature of the displacement field requires a large number of monomial terms before the interlaminar stresses are computed as accurately as the refined zigzag theory.

  4. Development of methods for beam angle optimization for IMRT using an accelerated exhaustive search strategy

    International Nuclear Information System (INIS)

    Purpose: The purpose of this article is to explore the use of the accelerated exhaustive search strategy for developing and validating methods for optimizing beam orientations for intensity-modulated radiation therapy (IMRT). Combining beam-angle optimization (BAO) with intensity distribution optimization is expected to improve the quality of IMRT treatment plans. However, BAO is one of the most difficult problems to solve adequately because of the huge hyperspace of possible beam configurations (e.g., selecting 7 of 36 uniformly spaced coplanar beams would require the intercomparison of 8,347,680 IMRT plans). Methods and materials: An 'influence vector' (IV) approximation technique for high-speed estimation of IMRT dose distributions was used in combination with a fast gradient search algorithm (Newton's method) for IMRT optimization. In the IV approximation, it is assumed that the change in intensity of a ray (or bixel) proportionately changes dose along the ray. Evidence is presented that the IV approximation is valid for BAO. The scatter contribution at points away from the ray is accounted for fully in IMRT optimization after the optimum beam orientation has been determined. IVs for all candidate beam angles are generated before the start of optimization. For all subsets of beams selected from a given pool of beams (e.g., 5 of 24 uniformly spaced beams), the distribution of planning scores for the best and the worst plans, optimum angle distributions, dose distributions, and dose-volume histograms (DVH) were analyzed for one prostate and two lung cancer cases. The results of the exhaustive search technique were used to develop a 'multiresolution' search strategy. In this approach, a smaller number of beams (e.g., three) is first used to explore the hyperspace of solutions to determine the most preferred and the least preferred directions. The results of such exploration are then used as a starting point for determining an optimum configuration comprising a

  5. Levels of trace elements of few Indian spices by energy dispersive x-ray fluorescence (EDXRF) method

    International Nuclear Information System (INIS)

    Concentrations of K, Ca, Mn, Fe, Cu, Zn, Rb and Sr were determined in Indian spices namely, pepper, clove, cardamom, cinnamon and cumin by radioisotope excited energy dispersive x-ray fluorescence method. The levels of K and Ca were highest in cinnamon and cumin and that of Mn was highest in clove and cinnamon. Rubidium and strontium were found in all spices except cinnamon. Chromium and titanium were found only in pepper. The level of toxicity and the significance of the above trace elements in the human diet are discussed. (author)

  6. Contents of arsenic, mercury and other trace elements in Napoleon's hair determined by INAA using the k0-method

    International Nuclear Information System (INIS)

    Two samples of Napoleon's hair were received for determination of arsenic, mercury and other trace elements by INAA. Before sample irradiation, the hairs were washed following the IAEA washing procedure. Two standard reference materials of GBW09101 (human hair) and NIST/SRM1572 (citrus leaves) were analyzed along with Napoleon's hair for quality control. Standardization was conducted by applying the k0-method implemented in the program MULTINAA. The contents of arsenic and mercury as well as three additional elements chromium, antimony and zinc in Napoleon's hair are reported. Compared to the present normal levels, all of the determined elements in Napoleon's hair, except the mercury, are found to be irregular. (author)

  7. Mass spectrometric methods for studying nutrient mineral and trace element absorption and metabolism in humans using stable isotopes: a review

    International Nuclear Information System (INIS)

    Mass spectrometric methods for determining stable isotopes of nutrient minerals and trace elements in human metabolic studies are described and discussed. The advantages and disadvantages of the techniques of electron ionization, fast atom bombardment, thermal ionization, and inductively coupled plasma and gas chromatography mass spectrometry are evaluated with reference to their accuracy, precision, sensitivity, and convenience, and the demands of human nutrition research. Examples of specific applications are described and the significance of current developments in mass spectrometry are discussed with reference to present and probable future research needs. (Author)

  8. Effect of plant cultivation methods on content of major and trace elements in foodstuffs and retention in rats

    DEFF Research Database (Denmark)

    Kristensen, Mette; Østergaard, Lars F.; Halekoh, Ulrich;

    2008-01-01

    major and trace element contents of dried foodstuffs (carrots, kale, peas, potatoes and apples) grown in two consecutive years, as well as mineral retention determined in 36 rats (second generation in a multi-generation study) fed diets based on these foodstuffs from one year. RESULTS: Overall, there...... was no evident trend towards differences in element content of foodstuffs or diets due to the use of different cultivation systems, and differences between harvest years exceeded those seen between cultivation methods. Also, no significant differences in the retention of elements in rats fed diets...

  9. Estimating the erosion and deposition rates in a small watershed by the 137Cs tracing method

    International Nuclear Information System (INIS)

    Understanding the erosion and deposition rates in a small watershed is important for designing soil and water conservation measures. The objective of this study is to estimate the net soil loss and gain at points with various land use types and landform positions in a small watershed in the Sichuan Hilly Basin of China by the 137Cs tracing technique. Among various land use types, the order of erosion rate was bare rock > sloping cultivated land > forest land. The paddy field and Caotu (a kind of cultivated land located at the foot of hills) were depositional areas. The erosion rate under different landform was in this order: hillside > saddle > hilltop. The footslope and the valley were depositional areas. The 137Cs technique was shown to provide an effective means of documenting the spatial distribution of soil erosion and deposition within the small watershed

  10. A method for selective separation and preconcentration of boron in nuclear grade graphite at trace levels

    International Nuclear Information System (INIS)

    Determination of trace amounts of boron in nuclear grade graphite was carried out using ICP-OES after selective preconcentration of boron on the boron specific anion exchange resin Amberlite IRA 743. Borate ion was quantitatively separated from aqueous solution by the anion exchange resin. Analytical parameters for pre-concentration of boron as borate ion from the matrix and its quantitative elution were optimized. The preconcentration achieved by the use of anion exchanger has improved the detection limit of boron using ICP-OES from 10 mgkg-1 to 0.1 mgkg-1. The recovery of boron in graphite matrix was in the range 95-99 %. This methodology has been applied to determine boron in graphite samples. (author)

  11. Concept Modelling of Vehicle Joints and Beam-Like Structures through Dynamic FE-Based Methods

    Directory of Open Access Journals (Sweden)

    G. De Gaetano

    2014-01-01

    Full Text Available This paper presents dynamic methodologies able to obtain concept models of automotive beams and joints, which compare favourably with the existing literature methods, in terms of accuracy, easiness of implementation, and computational loads. For the concept beams, the proposed method is based on a dynamic finite element (FE approach, which estimates the stiffness characteristics of equivalent 1D beam elements using the natural frequencies, computed by a modal analysis of the detailed 3D FE model of the structure. Concept beams are then connected to each other by a concept joint, which is obtained through a dynamic reduction technique that makes use of its vibration normal modes. The joint reduction is improved through the application of a new interface beam-to-joint element, able to interpolate accurately the nodal displacements of the outer contour of the section, to obtain displacements and rotations of the central connection node. The proposed approach is validated through an application case that is typical in vehicle body engineering: the analysis of a structure formed by three spot-welded thin-walled beams, connected by a joint.

  12. Method of Light Beam Orbital Angular Momentum Evaluation by Means of Space-Angle Intensity Moments

    Directory of Open Access Journals (Sweden)

    A.Ya. Bekshaev

    2002-12-01

    Full Text Available Value of the orbital angular momentum (OAM of an optical beam can be determined through the structure of matrix of its space-angle intensity moments. Considering the properties of these moments and their transformations, a conclusion has been made that any light beam with the OAM experiences a characteristic transverse shift during its interaction with a plane refracting boundary or a diffraction grating. On this base, a method for the immediate measurement of the beam OAM is proposed. The simple experimental arrangement for such a measurement includes a self-collimating diffraction grating, a position-sensitive quadrant photodetector and a device for the beam rotation around its longitudinal axis.

  13. Freeze dried samples of volcanic gases - a new method for the determination of trace elements by NAA

    International Nuclear Information System (INIS)

    A new routine technique for the determination of trace elements in volcanic gases by NAA is presented. For time and money saving reasons this method is applicable to samples, collected by the conventional method. This technique uses evacuated glass bottles, partly filled with NaOH solution to absorb acidic gas components and CO2, which is the main constituent of the incondensable gas fraction at ambient conditions. The application of NAA to samples collected by this method shows two main sources of difficulties: drying of NaOH without loosing volatile elements of interest (in particular Hg and Se) and the high activities of 24Na after neutron irradiation. The first can be avoided by liquid irradiation, thereby limiting the irradiation time, the second excludes the determination of short and medium lived nuclides because of the high γ-background due to 24Na. A new freeze drying technique enables the application of long irradiation times and therefore the use of long-lived activation products for analysis. The samples of volcanic gases were collected at the fumarole fields of La Fossa volcano on the island Vulcano. Southern Italy. This technique allows very sensitive determinations of trace elements in volcanic gases and adds highly valuable information to the understanding and modeling of volcanic gas sources. (orig.)

  14. Damage identification in beam type structures based on statistical moment using a two step method

    Science.gov (United States)

    Wang, Dansheng; Xiang, Wei; Zhu, Hongping

    2014-02-01

    This paper defines a novel damage index-strain statistical moment, and formulates the fourth strain statistical moment (FSSM) of beam-type structures under white noise excitation. Based on this newly defined strain statistical moment index and the least square optimization algorithm, a two-step damage identification method is proposed. This two-step method is operated like this: first use the difference curves of FSSMs before and after damage to locate damage elements; then for those identified damage elements, employ the model updating method based on the least square algorithm to assess their damage severity. Numerical studies on a simply supported beam and a two-span continuous beam are performed and the study results show that the newly defined index is effective to locate damages, even when the noise intensity is as high as 15 percent. Integrating with the least square-based model updating technique, the damage severities of beam-type structures can also be determined quantitatively. In this way, the proposed two-step method is verified and found to be capable of identifying damage positions and severities of beam-type structures and insensitive to measurement noise.

  15. Analysis of transverse shear strains in pre-twisted thick beams using variational asymptotic method

    Energy Technology Data Exchange (ETDEWEB)

    Ameen, Maqsood M.; Harursampath, Dineshkumar, E-mail: m.ameen@tue.nl, E-mail: dinesh@aero.iisc.ernet.in [Department of Aerospace Engineering, Indian Institute of Science, Bangalore-560012 (India)

    2015-03-10

    The cross-sectional stiffness matrix is derived for a pre-twisted, moderately thick beam made of transversely isotropic materials and having rectangular cross sections. An asymptotically-exact methodology is used to model the anisotropic beam from 3-D elasticity, without any further assumptions. The beam is allowed to have large displacements and rotations, but small strain is assumed. The strain energy is computed making use of the beam constitutive law and kinematical relations derived with the inclusion of geometrical nonlinearities and an initial twist. The energy functional is minimized making use of the Variational Asymptotic Method (VAM), thereby reducing the cross section to a point on the beam reference line with appropriate properties, forming a 1-D constitutive law. VAM is a mathematical technique employed in the current problem to rigorously split the 3-D analysis of beams into two: a 2-D analysis over the beam cross-sectional domain, which provides a compact semi-analytical form of the properties of the cross sections, and a nonlinear 1-D analysis of the beam ref-erence curve. In this method, as applied herein, the cross-sectional analysis is performed asymptotically by taking advantage of a material small parameter and two geometric small parameters. 3-D strain components are derived using kinematics and arranged in orders of the small parameters. Closed-form expressions are derived for the 3-D non-linear warping and stress fields. Warping functions are obtained by the minimization of strain energy subject to certain set of constraints that render the 1-D strain measures well-defined. The zeroth-order 3-D warping field thus yielded is then used to integrate the 3-D strain energy density over the cross section, resulting in the 1-D strain energy density, which in turn helps identify the corresponding cross-sectional stiffness matrix. The model is capable of predicting interlaminar and transverse shear stresses accurately up to first order.

  16. Analysis of transverse shear strains in pre-twisted thick beams using variational asymptotic method

    International Nuclear Information System (INIS)

    The cross-sectional stiffness matrix is derived for a pre-twisted, moderately thick beam made of transversely isotropic materials and having rectangular cross sections. An asymptotically-exact methodology is used to model the anisotropic beam from 3-D elasticity, without any further assumptions. The beam is allowed to have large displacements and rotations, but small strain is assumed. The strain energy is computed making use of the beam constitutive law and kinematical relations derived with the inclusion of geometrical nonlinearities and an initial twist. The energy functional is minimized making use of the Variational Asymptotic Method (VAM), thereby reducing the cross section to a point on the beam reference line with appropriate properties, forming a 1-D constitutive law. VAM is a mathematical technique employed in the current problem to rigorously split the 3-D analysis of beams into two: a 2-D analysis over the beam cross-sectional domain, which provides a compact semi-analytical form of the properties of the cross sections, and a nonlinear 1-D analysis of the beam ref-erence curve. In this method, as applied herein, the cross-sectional analysis is performed asymptotically by taking advantage of a material small parameter and two geometric small parameters. 3-D strain components are derived using kinematics and arranged in orders of the small parameters. Closed-form expressions are derived for the 3-D non-linear warping and stress fields. Warping functions are obtained by the minimization of strain energy subject to certain set of constraints that render the 1-D strain measures well-defined. The zeroth-order 3-D warping field thus yielded is then used to integrate the 3-D strain energy density over the cross section, resulting in the 1-D strain energy density, which in turn helps identify the corresponding cross-sectional stiffness matrix. The model is capable of predicting interlaminar and transverse shear stresses accurately up to first order

  17. A novel method involving Matlab coding to determine the distribution of a collimated ionizing radiation beam

    Science.gov (United States)

    Ioan, M.-R.

    2016-08-01

    In ionizing radiation related experiments, precisely knowing of the involved parameters it is a very important task. Some of these experiments are involving the use of electromagnetic ionizing radiation such are gamma rays and X rays, others make use of energetic charged or not charged small dimensions particles such are protons, electrons, neutrons and even, in other cases, larger accelerated particles such are helium or deuterium nuclei are used. In all these cases the beam used to hit an exposed target must be previously collimated and precisely characterized. In this paper, a novel method to determine the distribution of the collimated beam involving Matlab coding is proposed. The method was implemented by using of some Pyrex glass test samples placed in the beam where its distribution and dimension must be determined, followed by taking high quality pictures of them and then by digital processing the resulted images. By this method, information regarding the doses absorbed in the exposed samples volume are obtained too.

  18. Simplified vibration analysis method of shells of revolution using beam model

    International Nuclear Information System (INIS)

    A simplified vibration analysis method for the shells of revolution using the beam model is now under consideration. In the beam model, the relations between the shear forces and horizontal deformations are used for the calculations of the shear area and the relations between the overturning moments and rotation angles are for those of the inertia moment. The calculations of the vibration characteristics of the cylindrical shell, spherical shell and the cylindrical shell with the spherical cap were conducted to verify the accuracy of the beam model. The natural frequencies and the vibration modes of the proposed method are in good agreement with that of the FEM analysis using the axisymmetrical shell model. The proposed method is easily applicable to the vibration analysis of actual shell structures. (author)

  19. Application of different methods of neutron activation analysis to the determination of trace elements in rock samples

    International Nuclear Information System (INIS)

    In this report three different methods of neutron activation analysis applied to the determination of up to 20 trace elements in Egyptian rock samples and the results obtained are discussed. In Part I a physical approach is described for instrumental multielement activation analysis with whole neutron spectrum (without Cd-cover) using the monostandard (single comparator) method. 15 Samples representing different Egyptian granite rocks were analyzed. As many as 21 trace elements beside Fe, K and Na were determined. The accuracy of the method for nondestructive multielement analysis agrees within 3% with the relative method using multielement standards. In Part II a method is described for epithermal neutron activation analysis of 20 elements in granite rock samples using only one standard. Gold has been used as a single comparator due to its relatively high resonance integral value (Io = 400) and in addition, it is preferable on Co in order to obtain a large epithermal activation in a short irradiation. The method of calculation is simple and rapid and can be done using small calculator. In Part III experiments are described in which a neutron capture gamma-ray spectroscopy facility assembled at the Institute of Radiochemistry, KfK (for analytical purposes) using Cf252 neutron source of strength ∝ 6x107 n/sec, has been used to check its applicability and sensitivity for quantitative analyses of ores. The analysis of Sm, Gd and Mn in phosphate and monazite rock samples has been carried out. The results from this study show a variation of about 25% from the values determined by RNAA method. The reasons for this discrepancy are discussed and suggestions are made to optimize the conditions of measurement and irradiation. (orig./RB)

  20. Determination of lead element trace in some Syrian cigarettes and Its mixtures using voltammetric method on HMDE

    International Nuclear Information System (INIS)

    This study aims for estimating of trace for these elements in various brands of Syrian Cigarettes and its mixtures, by using voltammetric method (HMDE) hanging mercury drop elec trod. This method is first used to determined Syrian Cigarettes brand and its mixtures, during this study it was found that we can use it easily with low commission, high sensitivity and accurate results comparing with others studies. We prepare the samples by using reference methods. The samples were collected during two times in one year from the same kinds of samples. We noticed that the high concentrations was (3.795μg/g) in Gitanes samples, and the low concentrations in shame samples was (0.37 μg/g). This study refers that there is different concentrations of lead element in this samples.(author)

  1. System and method for sonic wave measurements using an acoustic beam source

    Science.gov (United States)

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2015-08-11

    A method and system for investigating structure near a borehole are described herein. The method includes generating an acoustic beam by an acoustic source; directing at one or more azimuthal angles the acoustic beam towards a selected location in a vicinity of a borehole; receiving at one or more receivers an acoustic signal, the acoustic signal originating from a reflection or a refraction of the acoustic wave by a material at the selected location; and analyzing the received acoustic signal to characterize features of the material around the borehole.

  2. A Simple and Accurate Method for Calculating the Gaussian Beam Expansion Coefficients

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; YANG Jun

    2010-01-01

    @@ The calculation of the diffraction field radiated from the ultrasonic transducer can be simplified by using the Gaussian beam expansion technique.The key problem of this technique is how to determine the coefficients of Gaussian functions.We present a simple and accurate optimization method to calculate the Gaussian beam expansion Coefficients.Half of the coefficients are obtained by solving linear equations.The other half are derived from the Fourier series expansion.Wave field simulation results demonstrate the validity of the new method.

  3. A new quantitative method for gunshot residue analysis by ion beam analysis.

    OpenAIRE

    Christopher, ME; Warmenhoeven, JW; Romolo, FS; Donghi, M; Webb, RP; Jeynes, C.; Ward, NI; Kirkby, KJ; Bailey, MJ

    2013-01-01

    Imaging and analyzing gunshot residue (GSR) particles using the scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDS) is a standard technique that can provide important forensic evidence, but the discrimination power of this technique is limited due to low sensitivity to trace elements and difficulties in obtaining quantitative results from small particles. A new, faster method using a scanning proton microbeam and Particle Induced X-ray Emission (μ-PIXE...

  4. SU-E-I-01: A Fast, Analytical Pencil Beam Based Method for First Order X-Ray Scatter Estimation of Kilovoltage Cone Beam X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J; Bourland, J [Wake Forest University, Winston-salem, NC (United States)

    2014-06-01

    Purpose: To analytically estimate first-order x-ray scatter for kV cone beam x-ray imaging with high computational efficiency. Methods: In calculating first-order scatter using the Klein-Nishina formula, we found that by integrating the point-to-point scatter along an interaction line, a “pencil-beam” scatter kernel (BSK) can be approximated to a quartic expression when the imaging field is small. This BSK model for monoenergetic, 100keV x-rays has been verified on homogeneous cube and cylinder water phantoms by comparing with the exact implementation of KN formula. For heterogeneous medium, the water-equivalent length of a BSK was acquired with an improved Siddon's ray-tracing algorithm, which was also used in calculating pre- and post- scattering attenuation. To include the electron binding effect for scattering of low-kV photons, the mean corresponding scattering angle is determined from the effective point of scattered photons of a BSK. The behavior of polyenergetic x-rays was also investigated for 120kV x-rays incident to a sandwiched infinite heterogeneous slab phantom, with the electron binding effect incorporated. Exact computation and Monte Carlo simulations were performed for comparisons, using the EGSnrc code package. Results: By reducing the 3D volumetric target (o(n{sup 3})) to 2D pencil-beams (o(n{sup 2})), the computation expense can be generally lowered by n times, which our experience verifies. The scatter distribution on a flat detector shows high agreement between the analytic BSK model and exact calculations. The pixel-to-pixel differences are within (-2%, 2%) for the homogeneous cube and cylinder phantoms and within (0, 6%) for the heterogeneous slab phantom. However, the Monte Carlo simulation shows increased deviation of the BSK model toward detector periphery. Conclusion: The proposed BSK model, accommodating polyenergetic x-rays and electron binding effect at low kV, shows great potential in efficiently estimating the first

  5. Generalized Propagation Channel Model for 2GHz Low Elevation Links Using a Ray-tracing Method

    Directory of Open Access Journals (Sweden)

    J. Zeleny

    2015-12-01

    Full Text Available Unmanned Aerial Vehicles (UAV will increasingly be used for responding to emergencies or for law enforcement in civil surveillance applications. Transferring the enormous amounts of information from UAV-mounted cameras or sensors will require large bandwidths, unlike the information required for remotely controlling a UAV, thus necessitating higher frequency bands typically in the vicinity of 2 or 5 GHz. Novel hardware developments will need to rely on a versatile propagation channel model for the envisaged scenarios ranging from deep shadow urban areas to open fields. This paper studies more complex intermediate scenarios, which fall between the aforementioned ones, and which are more difficult to model. A semi-deterministic model, first developed for open, flat areas, has been generalized to accommodate any possible operational scenario and was tested in built-up areas. The model involves a stochastic part and a determinist which is a ray-tracing based part used to compute the long term mean (LTM of the signal's coherent component.

  6. Method for maximizing the brightness of the bunches in a particle injector by converting a highly space-charged beam to a relativistic and emittance-dominated beam

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Fay

    2016-08-02

    A method for maximizing the brightness of the bunches in a particle injector by converting a highly space-charged beam to a relativistic and emittance-dominated beam. The method includes 1) determining the bunch charge and the initial kinetic energy of the highly space-charge dominated input beam; 2) applying the bunch charge and initial kinetic energy properties of the highly space-charge dominated input beam to determine the number of accelerator cavities required to accelerate the bunches to relativistic speed; 3) providing the required number of accelerator cavities; and 4) setting the gradient of the radio frequency (RF) cavities; and 5) operating the phase of the accelerator cavities between -90 and zero degrees of the sinusoid of phase to simultaneously accelerate and bunch the charged particles to maximize brightness, and until the beam is relativistic and emittance-dominated.

  7. Application of Energy Finite Element Method in Active Vibration Control of Piezoelectric Intelligent Beam

    Directory of Open Access Journals (Sweden)

    Jinhua Xie

    2012-01-01

    Full Text Available Based on the transmission and equilibrium relationship of vibration energy in beam-like structures, the Galerkin weighted residual method was applied to equation discretization. An equivalent transformation of feedback element was suggested to develop the Energy Finite Element model of a composite piezoelectric cantilever beam driven by harmonic excitation on lateral direction, with both systems with and without time delay being studied and the power input estimation of harmonic excitation was discussed for the resolution of Energy Finite Element function. Then the energy density solutions of the piezoelectric coupling beam through Energy Finite Element Method (EFEM and classical wave theory were compared to verify the EFEM model, which presented a good accordance. Further investigation was undertaken about the influence of control parameters including the feedback gain and arrangement of piezoelectric patches on characteristics of system energy density distribution.

  8. Mixed-DT neutral-beam injection: An alternative heating method for tokamaks

    International Nuclear Information System (INIS)

    In this paper, the authors propose an alternative method for the heating, and perhaps also refueling, of tokamak fusion devices. The alternative method replaces the deuterium neutral-beam injectors (NBIs) such as those now used, for example, on the Tokamak Fusion Test Reactor (TFTR) device. Instead they make use of a mixed (deuterium-tritium) NBI (MNBI) and thereby vastly reduce the cost and complexity of the fuel-recovery cycle. Another like consequence is the reduction of the total amount of tritium in the on-site inventory. The authors suspect that the alternative plant design would have a positive effect on safety, although they have not done an accident analysis based on the mixed-beam injectors. They have, however, studied the requirements of the new fuel cycle and have looked at the question of optimizing some of the parameters associated with a mixed-beam injector. 3 refs

  9. Modeling liquid-crystal devices with the three-dimensional full-vector beam propagation method

    Science.gov (United States)

    Wang, Qian; Farrell, Gerald; Semenova, Yuliya

    2006-08-01

    Simulation of light propagation within nematic liquid-crystal (LC) devices is considered, of which the director is aligned normal to the z axis. A three-dimensional full-vector finite-difference beam propagation method for an anisotropic medium is presented and an alternating direction implicit scheme is adopted. Simulations of light propagation in a bulk polarization converter, a waveguide with a LC covering layer, and an integrated polarization splitter and optical switch are presented. Comparison with an existing simulation method is carried out for beam behavior within the bulk polarization converter. The effect of strong surface anchoring of a LC cell on the beam behaviors within the integrated switch is also demonstrated.

  10. Development of the multielemental determination method for bioactive trace metals in open ocean seawater and its application to international intercalibration

    International Nuclear Information System (INIS)

    Bioactive trace metals are essential or highly toxic elements for organisms. The most important bioactive trace elements in the ocean environment are Al, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb, whose concentrations in seawater are generally less than tens of nmol kg-1. In previous methods, there were problems, such as contamination, interferences by major constituents and a non-quantitative recovery of the target metals, especially Al and Mn. We developed a novel method for analyzing the 9 elements based on solid-phase extraction-inductively coupled plasma mass spectrometry (ICP-MS). In this method, a column packed with chelating absorbent, which had ethylenediaminetriacetic and iminodiacetic acid groups, was used in a closed concentration system. The proposed method was able to concentrate all of the 9 elements simultaneously and quantitatively, and to remove the major constituents in seawater. The procedural blanks for Mn, Co, Ni, Cu and Cd were less than the detection limits for ICP-MS (3 times the standard deviations of 1 mol L-1 HNO3), and those for Al, Fe, Zn and Pb were 0.14, 0.03, 0.07 and 0.003 nmol kg-1, respectively. The overall detection limits for Al, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb were 0.24, 0.01, 0.04, 0.002, 0.01, 0.01, 0.06, 0.01 and 0.001 nmol kg-1, respectively. In this paper, we review the development of this method and its application to international intercalibration using open-ocean seawater. (author)

  11. A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique

    OpenAIRE

    Kuo Men; Jian-Rong Dai; Ming-Hui Li; Xin-Yuan Chen; Ke Zhang; Yuan Tian; Peng Huang; Ying-Jie Xu

    2015-01-01

    Purpose. To develop a dual energy imaging method to improve the accuracy of electron density measurement with a cone-beam CT (CBCT) device. Materials and Methods. The imaging system is the XVI CBCT system on Elekta Synergy linac. Projection data were acquired with the high and low energy X-ray, respectively, to set up a basis material decomposition model. Virtual phantom simulation and phantoms experiments were carried out for quantitative evaluation of the method. Phantoms were also scanned ...

  12. A generalized reverse projection method for fan beam geometry under partially coherent illumination

    Science.gov (United States)

    Wu, Z.; Wang, Z. L.; Gao, K.; Zhang, K.; Ge, X.; Wang, D. J.; Wang, S. H.; Chen, J.; Pan, Z. Y.; Zhu, P. P.; Wu, Z. Y.

    2014-02-01

    In this paper, a generalized reverse projection (RP) method for grating-based fan beam phase contrast imaging is presented. Compared to the original RP method, rays rather than projection images are taken into account during the information extraction process. We also discuss the influence of partial coherence on the extracted information. Theoretical derivations and numerical simulations are performed to confirm the validity of the method.

  13. Treatment of liquid separated from sludge by the method using electron beam and ozone in combination

    International Nuclear Information System (INIS)

    Since the liquid separated from sludge in the dehydration or concentration process of sewer sludge contains considerable amount of organic compositions that are hard to be decomposed by microorganisms, it has become difficult to be treated by conventional activated sludge process. In the case of discharging the separated liquid into closed water areas, the higher quality treatment is required. The method of using electron beam irradiation and ozone oxidation in combination for cleaning the liquid separated from sludge was examined, therefore, the results are reported. The water quality of the sample from the sludge treatment plant in A City is shown. The method of bio-pretreatment, the treatment method by using electron beam and ozone in combination, and the method of analyzing the water quality are described. The effect of the treatment by activated sludge process, as the effect of the treatment by the combined use of electron beam and ozone, the change of COD and TOC, the change of chromaticity, the change of gel chromatogram, and the reaction mechanism are reported. In this paper, only the basic concept on the model plant for applying the method of the combined use of electron beam and ozone to the treatment of the liquid separated from sludge is discussed. (K.I.)

  14. Riccati discrete time transfer matrix method for elastic beam undergoing large overall motion

    International Nuclear Information System (INIS)

    An efficient method for dynamics simulation for elastic beam with large overall spatial motion and nonlinear deformation, namely, the Riccati discrete time transfer matrix method (Riccati-DT-TMM), is proposed in this investigation. With finite segments, continuous deformation field of a beam can be decomposed into many rigid bodies connected by rotational springs. Discrete time transfer matrices of rigid bodies and rotational springs are used to analyze the dynamic characteristic of the beam, and the Riccati transform is used to improve the numerical stability of discrete time transfer matrix method of multibody system dynamics. A predictor-corrector method is used to improve the numerical accuracy of the Riccati-DT-TMM. Using the Riccati-DT-TMM in dynamics analysis, the global dynamics equations of the system are not needed and the computation time required increases linearly with the system's number of degrees of freedom. Three numerical examples are given to validate the method for the dynamic simulation of a geometric nonlinear beam undergoing large overall motion

  15. Iterative method for determination of the laser beam profile and τV-T

    Directory of Open Access Journals (Sweden)

    Rabasović Mihailo D.

    2008-01-01

    Full Text Available Measuring the vibrational-to-translational relaxation time τV-T in gases is one of the first applications of the photoacoustic effect. The spatial profile of the laser beam is crucial in these measurements because the multiphoton excitation is investigated. The multiphoton absorption is a non-linear process. Because of this, the top hat profile is preferable. It allows one to deal with nonlinearity in a simple manner. In order to reveal the real laser beam profile, we have slightly changed the theoretical profiles in such a manner that the best matching is obtained between theoretical and experimental photoacoustic signals. Still, there was a question: Is it possible to deduce the laser beam profile directly from the photoacoustic signal, thus avoiding manual changing of the laser beam profile? According to this paper, it is possible. The appropriate method has been found in another photoacoustics application: photoacoustic tomography. Thus, the method for the simultaneous determination of the spatial profile of the laser beam and vibrational-to-translational relaxation time is presented in this paper. It employs pulsed photoacoustics and an algorithm developed for photoacoustic tomography.

  16. Study on optical radiation of a relativistic electron beam for giving reasons for the impulse-dosimetry absolute method

    International Nuclear Information System (INIS)

    Spectral and amplitude-time characteristics of optical emission of a relativistic electron beam in air is stidied by the photoelectron method. Application of the optical method for absolute measurements of characteristics of the dose field of an impulse relativistic electron beam is considered. The distribution of the energy absorbed along the 1 MeV electron beam axis is experimentally investigated. The absolute method of impulse dosimetry of heightened accuracy is substantiated on the basis of the results obtained

  17. The use of trace element data to complement stable isotope methods in the characterization of grape musts

    International Nuclear Information System (INIS)

    Objective physico-chemical methods for the characterization of agricultural produce are important ways of providing impartial information on the composition and origin of food products. Of those techniques successful in this area, stable isotope analyses and especially Site Specific Natural Isotope Fractionation studied by nuclear magnetic resonance (SNIF-NMR) are among the most noteworthy. The use of this technique allows the determination of geographical origin of a variety of finished and raw materials in the food industry. The current capabilities of this technique in the wine industry allow the general area of production to be determined. Trace element concentrations have been analyzed for five regions of France (1989 vintage) in order to improve the accuracy of the SNIF-NMR method. When used in conjunction with stable isotope ratios, the elements Zn, Ca, Sr, and Mg increase the overall classification from 78% (with isotope data only) to 89%. (author)

  18. Curved ray tracing method for one-dimensional radiative transfer in the linear-anisotropic scattering medium with graded index

    International Nuclear Information System (INIS)

    The curved ray tracing method (CRT) is extended to radiative transfer in the linear-anisotropic scattering medium with graded index from non-scattering medium. In this paper, the CRT is presented to solve one-dimensional radiative transfer in the linear-anisotropic scattering gray medium with a linear refractive index and two black boundaries. The predicted temperature distributions and radiative heat flux at radiative equilibrium are determined by the proposed method, and numerical results are compared with the data in references. The results show that the CRT has a good accuracy for radiative transfer in the linear-anisotropic scattering medium with graded index and the dimensionless emissive power and dimensionless radiative heat flux depend on the dimensionless refractive index gradient. It can also be seen that the dimensionless refractive index gradient has important effects on the temperature discontinuity at the boundaries.

  19. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg2+ ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg+ into Hg2+ ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 μg l-1 (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l-1. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment

  20. The equivalence problem for the Euler-Bernoulli beam equation via Cartan's method

    International Nuclear Information System (INIS)

    We completely solve the local point equivalence problem for the Euler-Bernoulli beam equation using Cartan's method of equivalence. We obtain five equivalence classes. For each equivalence class, we establish the necessary and sufficient conditions for similarity, and derive a basis of differential invariants as well as operators of invariant differentiation

  1. A steering magnet optimized by random search method for high current beam transport line

    International Nuclear Information System (INIS)

    We present an improved design of the steering magnet which produces almost uniform magnetic field in the region through which beam passes. Optimization of the parameters of the steering magnet is done by random search method. It is shown that use of a suitable shim reduces the field deviation by a great extent. (author)

  2. Highly Accurate Beam Torsion Solutions Using the p-Version Finite Element Method

    Science.gov (United States)

    Smith, James P.

    1996-01-01

    A new treatment of the classical beam torsion boundary value problem is applied. Using the p-version finite element method with shape functions based on Legendre polynomials, torsion solutions for generic cross-sections comprised of isotropic materials are developed. Element shape functions for quadrilateral and triangular elements are discussed, and numerical examples are provided.

  3. Development for ultra-trace analysis method of U and Pu in safeguards environmental samples at the clean facility

    International Nuclear Information System (INIS)

    Based on the strengthen safeguard program of the IAEA to detect undeclared nuclear activities and nuclear materials, the method of precise and accurate isotope ratio determination for uranium and plutonium in the environmental samples (cotton swipes) has been developed at JAERI. The samples should be treated in clean environment in order to secure the analytical reliability by eliminating external contamination from the samples containing trace amount of uranium and plutonium. Since the measurement by ICP-MS is favorable to bulk analysis from view points of analytical capacity and operation simplicity, we have studied sample preparation procedures for the trace amount of uranium and plutonium to be applied to ICP-MS. Up to the present, interfering factors involved during analytical processes and the ICP-MS measurement of uranium and plutonium were examined. As a result, uranium isotope measurement more than 100 pg became possible at JAERI clean facility by diminishing uranium blank introduced in the entire sample treatment procedure. And also, the estimation of plutonium recovery yield and uranium decontamination factor suggested the possibility in plutonium isotope measurement more than 100 fg. (author)

  4. A Fast Stripping Continuous Cyclic Voltammetry Method for Determination of Ultra Trace Amounts of Nalidixic Acid

    OpenAIRE

    Norouzi, Parviz; Ganjali, Mohammad Reza; Bagher LARIJANI; Karamdoust, Sanaz

    2008-01-01

    In recent years, modern electroanalytical techniques, especially cyclic voltammetry, are becoming increasingly important in the determination of pharmaceutical products. This study presents a novel method for the determination of nalidixic acid (NA) in flow-injection systems, called fast stripping continuous cyclic voltammetry. This technique is simple, precise, accurate and time saving compared to similar methods. Initially, the effects of several method parameters on sensitiv...

  5. Four methods for determining the composition of trace radioactive surface contamination of low-radioactivity metal

    OpenAIRE

    O'Keeffe, H. M.; Burritt, T. H.; Cleveland, B. T.; Doucas, G.; Gagnon, N.; Jelley, N. A.; C. Kraus; Lawson, I.T.; Majerus, S.; McGee, S. R.; Myers, A. W.; Poon, A. W. P.; Rielage, K.; Robertson, R. G. H.; Rosten, R. C.

    2011-01-01

    Four methods for determining the composition of low-level uranium- and thorium-chain surface contamination are presented. One method is the observation of Cherenkov light production in water. In two additional methods a position-sensitive proportional counter surrounding the surface is used to make both a measurement of the energy spectrum of alpha particle emissions and also coincidence measurements to derive the thorium-chain content based on the presence of short-lived isotopes in that dec...

  6. A polarized atomic hydrogen beam

    International Nuclear Information System (INIS)

    We describe the design and operating characteristics of a simple polarized atomic hydrogen beam particularly suitable for applications to crossed beams experiments. In addition to experimental measurements, we present the results of detailed computer models, using Monte-Carlo ray tracing techniques, optical analogs, and phase-space methods, that not only provide us with a confirmation of our measurement, but also allow us to characterize the density, polarization, and atomic fraction of the beam at all points along its path. As a subsidiary result, we also present measurements of the relative and absolute efficiencies of the V/G Supavac mass analyzer for masses 1 and 2. (orig.)

  7. Damping of rotating beams with particle dampers: Discrete element method analysis

    Science.gov (United States)

    Els, D. N. J.

    2013-06-01

    The performance of particle dampers (PDs) under centrifugal loads was investigated. A test bench consisting of a rotating cantilever beam with a particle damper at the tip was developed (D. N. J. Els, AIAA Journal 49, 2228-2238 (2011)). Equal mass containers with different depths, filled with a range of uniform-sized steel ball bearings, were used as particle dampers. The experiments were duplicated numerically with a discrete element method (DEM) model, calibrated against the experimental data. The DEM model of the rotating beam with a PD at the tip captured the performance of the PD very well over a wide range of tests with different configurations and rotation velocities.

  8. Fractal Two-Level Finite Element Method For Free Vibration of Cracked Beams

    Directory of Open Access Journals (Sweden)

    A.Y.T. Leung

    1998-01-01

    Full Text Available The fractal two-level finite element method is extended to the free vibration behavior of cracked beams for various end boundary conditions. A cracked beam is separated into its singular and regular regions. Within the singular region, infinite number of finite elements are virturally generated by fractal geometry to model the singular behavior of the crack tip. The corresponding numerous degrees of freedom are reduced to a small set of generalized displacements by fractal transformation technique. The solution time and computer storage can be remarkably reduced without sacrifying accuracy. The resonant frequencies and mode shapes computed compared well with the results from a commercial program.

  9. Future carbon beams at SPIRAL1 facility: Which method is the most efficient?

    International Nuclear Information System (INIS)

    Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P. Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO2), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well

  10. A Novel Analytical Method for Trace Ammonium in Freshwater and Seawater Using 4-Methoxyphthalaldehyde as Fluorescent Reagent

    Directory of Open Access Journals (Sweden)

    Ying Liang

    2015-01-01

    Full Text Available A novel fluorescent reagent for determination of ammonium, 4-methoxyphthalaldehyde (MOPA, was successfully synthesized in this study. Under alkaline conditions, MOPA could reacted with ammonium rapidly at room temperature, producing fluorescent substance which had maximum excitation at 370 nm and emission wavelength at 454 nm. Based on this, a novel fluorescence analysis method was established for the determination of trace ammonium in natural water. Experimental parameters including reagent concentration, pH, reaction equilibrium time, and metal ions masking agent were optimized. The results showed that the optimized MOPA concentration was 0.12 g/L, pH was in the range of 11.2–12.0, and sulfite concentration was 0.051 g/L, respectively. Metal ions masking agent had no obvious effect on the fluorescence signal. With the reaction time of 15 minutes, linear range of this method was between 0.025 and 0.300 μmol/L, and the method detecting limit was 0.0058 μmol/L. The matrix recovery of the proposed method was in the range of 93.6–108.1%. Compared with the OPA method, this method was much more sensitive and rapid without the interference of background peak and would be more suitable for developing a portable fluorescence detection system.

  11. Method of beam steering with FWM in ICF. Compensation and generation of a PC beam for a foam target

    International Nuclear Information System (INIS)

    In beam steering with a phase conjugate (PC) mirror in inertial fusion energy (ICF), the path of the PC beam has to be compensated since the target moves several hundred micrometers during beam propagation. In this paper we show that compensation can be achieved by adjusting the angle between two pump beams in four-wave mixing (FWM) used as a PC mirror. The compensation angle depends on the target position along the optical axis, focal point of the final optics, and angle adjusted with FWM. For the parameter values of GEKKO XII and an accuracy of laser irradiation of ±10 µm, the compensation angle is 4.5 mrad and the margin of error for target injection is ±0.3 mm. We also show that a PC beam can be generated from the beam scattered by a foam target rotating at ∼ 43 m/s is confirmed. (author)

  12. The FLUKA code for application of Monte Carlo methods to promote high precision ion beam therapy

    CERN Document Server

    Parodi, K; Cerutti, F; Ferrari, A; Mairani, A; Paganetti, H; Sommerer, F

    2010-01-01

    Monte Carlo (MC) methods are increasingly being utilized to support several aspects of commissioning and clinical operation of ion beam therapy facilities. In this contribution two emerging areas of MC applications are outlined. The value of MC modeling to promote accurate treatment planning is addressed via examples of application of the FLUKA code to proton and carbon ion therapy at the Heidelberg Ion Beam Therapy Center in Heidelberg, Germany, and at the Proton Therapy Center of Massachusetts General Hospital (MGH) Boston, USA. These include generation of basic data for input into the treatment planning system (TPS) and validation of the TPS analytical pencil-beam dose computations. Moreover, we review the implementation of PET/CT (Positron-Emission-Tomography / Computed- Tomography) imaging for in-vivo verification of proton therapy at MGH. Here, MC is used to calculate irradiation-induced positron-emitter production in tissue for comparison with the +-activity measurement in order to infer indirect infor...

  13. Single-slice rebinning method for helical cone-beam CT.

    Science.gov (United States)

    Noo, F; Defrise, M; Clackdoyle, R

    1999-02-01

    In this paper, we present reconstruction results from helical cone-beam CT data, obtained using a simple and fast algorithm, which we call the CB-SSRB algorithm. This algorithm combines the single-slice rebinning method of PET imaging with the weighting schemes of spiral CT algorithms. The reconstruction is approximate but can be performed using 2D multislice fan-beam filtered backprojection. The quality of the results is surprisingly good, and far exceeds what one might expect, even when the pitch of the helix is large. In particular, with this algorithm comparable quality is obtained using helical cone-beam data with a normalized pitch of 10 to that obtained using standard spiral CT reconstruction with a normalized pitch of 2. PMID:10070801

  14. Single-slice rebinning method for helical cone-beam CT

    International Nuclear Information System (INIS)

    In this paper, we present reconstruction results from helical cone-beam CT data, obtained using a simple and fast algorithm, which we call the CB-SSRB algorithm. This algorithm combines the single-slice rebinning method of PET imaging with the weighting schemes of spiral CT algorithms. The reconstruction is approximate but can be performed using 2D multislice fan-beam filtered backprojection. The quality of the results is surprisingly good, and far exceeds what one might expect, even when the pitch of the helix is large. In particular, with this algorithm comparable quality is obtained using helical cone-beam data with a normalized pitch of 10 to that obtained using standard spiral CT reconstruction with a normalized pitch of 2. (author)

  15. High precision beam momentum determination in a synchrotron using a spin resonance method

    CERN Document Server

    Goslawski, P; Gebel, R; Hartmann, M; Kacharava, A; Lehrach, A; Lorentz, B; Maier, R; Mielke, M; Papenbrock, M; Prasuhn, D; Stassen, R; Stein, H J; Stockhorst, H; Ströher, H; Wilkin, C

    2009-01-01

    In order to measure the mass of the eta meson with high accuracy using the d+p -> 3He+eta reaction, the momentum of the circulating deuteron beam in the Cooler Synchrotron COSY of the Forschungszentrum Juelich has to be determined with unprecedented precision. This has been achieved by studying the spin dynamics of the polarized deuteron beam. By depolarizing the beam through the use of an artificially induced spin resonance, it was possible to evaluate its momentum p with a precision of dp/p < 10-4 for a momentum of roughly 3 GeV/c. Different possible sources of error in the application of the spin resonance method are discussed in detail and its possible use during a standard experiment is considered.

  16. Study on advanced cancer treatment method using quantum beam fusion technology

    International Nuclear Information System (INIS)

    This study on advanced cancer treatment method using quantum beam fusion technology aims at the realization of the fusion therapy device between boron neutron capture therapy device and THz wave hyperthermia device. To achieve this purpose, it is necessary to develop an intra-body transmission technology of THz beams. From the transmission experiment of 0.2 THz wave using sapphire microfiber, it has been found that the transmission of THz microbeam into the intra-body cancer affected part is possible. As the technologies to commercially realize the intra-body transmission of THz beams, this paper describes the coupler for transmission, flexible corrugated horn, and the micro-fabrication techniques of microfibers. In addition, the authors conducted the development of an optical fiber type rotary encoder for the long-distance transmission of THz waves, and confirmed that the effects of vibration did not exist through the evaluation of vibration durability. (A.O.)

  17. Measurement and evaluation methods for beam characterization of commercial excimer lasers

    Science.gov (United States)

    Albrecht, Hans Stephen; Rebhan, Ulrich; Mann, Klaus R.; Ohlenbusch, J.

    1996-11-01

    This paper describes the specific requirements for measurement of excimer laser beam profiles for standardized characterization 'of commercial excimer lasers. A corresponding measurement system is presented which allows a simultaneous characterization of energy density distribution in the near field as well as in the focal plane of a lens (far field). Specially adapted UV-cameras make possible sings pulse diagnostic. Beam widths are calculated from the digitized camera data by different methods corresponding to the proposals of ISO 11146 (second moment, moving knife edge, and moving slit) and the results are compared. In particular, the influence of background signals as well as the typical shape of energy density distribution in the near field to the determined beam widths are analyzed.

  18. A Numerical Method of the Euler-Bernoulli Beam with Optimal Local Kelvin-Voigt Damping

    Directory of Open Access Journals (Sweden)

    Xin Yu

    2014-01-01

    Full Text Available This paper deals with the numerical approximation problem of the optimal control problem governed by the Euler-Bernoulli beam equation with local Kelvin-Voigt damping, which is a nonlinear coefficient control problem with control constraints. The goal of this problem is to design a control input numerically, which is the damping and distributes locally on a subinterval of the region occupied by the beam, such that the total energy of the beam and the control on a given time period is minimal. We firstly use the finite element method (FEM to obtain a finite-dimensional model based on the original PDE system. Then, using the control parameterization method, we approximate the finite-dimensional problem by a standard optimal parameter selection problem, which is a suboptimal problem and can be solved numerically by nonlinear mathematical programming algorithm. At last, some simulation studies will be presented by the proposed numerical approximation method in this paper, where the damping controls act on different locations of the Euler-Bernoulli beam.

  19. Comparison of various spectrophotometric methods for oil traces determination in WWER type reactor primary circuit

    International Nuclear Information System (INIS)

    Three methods are compared of detecting crude oil substances in the coolant of the primary circuit of nuclear power plants: spectrophotometry in the IR, UV and visible (VIS) regions of the spectrum. A detailed analysis is made of the preconcentration of oil by extraction into n-hexane organic solvent for the UV and VIS methods and into CCl4 for the IR method. From the practical point of view (sample volume, cuvette volume and extract processing losses) the most suitable was the extraction ratio 1:67 for the IR method and 1:100 for the UV method. It was also experimentally verified that extraction proceeds with higher yield at pH≤4, i.e., when the effect of admixtures of boric acid, ammonia and potassium hydroxide is negligible. Statistical processing of results of the analyses with a view to the specificities of the methods showed that spectrophotometry in the IR region is the best method for determining the presence of crude oil products in the primary circuit. The VIS spectroscopy was found unsuitable. (author)

  20. Beam propagation method using a [(p- 1)/ p] Padé approximant of the propagator.

    Science.gov (United States)

    Lu, Ya Yan; Ho, Pui Lin

    2002-05-01

    A new beam propagation method (BPM) is developed based on a direct approximation to the propagator by its [(p-1)/p] Padé approximant. The approximant is simple to construct and has the desired damping effect for the evanescent modes. The method is applied to a tapered waveguide for TM-polarized waves, based on the energy-conserving improvement of the one-way Helmholtz equation. Numerical results are compared with those obtained with other variants of the BPM. PMID:18007898

  1. Implicit Yee-Mesh-Based Finite-Difference Full-Vectorial Beam-Propagation Method

    OpenAIRE

    Yamauchi, Junji; Mugita, Takanori; Nakano, Hisamatsu

    2005-01-01

    A novel Yee-mesh-based finite-difference fullvectorialbeam-propagation method is proposed with the aid of animplicit scheme. The efficient algorithm is developed by splittingthe propagation axis into two steps. The eigenmode analysisof a rib waveguide is performed using the imaginary-distanceprocedure. The results show that the present method offers reductionin computational time and memory, while maintainingthe same accuracy as the conventional explicit Yee-mesh-basedimaginary-distance beam-...

  2. Determination of trace element content in some plants with application of a set of radioactivation methods

    International Nuclear Information System (INIS)

    Using neutron-activation (NAA), proton-activation (PAA) and deuteron-activation (DAA) analyses distribution of 17 chemical elements (Na, K, Rb, Ca, Sr, Sn, Sb, Sc, La, Zn, Cu, Co, Fe, Mn, Ti, Au, Br) in 5 types of medicinal plants (Plantago Major L, Salvia officinalis L, Artemisia absinthium L, Alhagi Persarum, Eremurus) is investigated. The results obtained by different methods including activation and emission spectral analyses are compared. It is shown that the developed techniques permit quantitative determination of the given elements with the relative standard error ∼ 0.2, therewith for Ca, Sr, Ti determination PAA and DAA methods and for other elements - NAA method should be used

  3. SERS-based sensing technique for trace melamine detection - A new method exploring.

    Science.gov (United States)

    Zhuang, Hongjun; Zhu, Wenfeng; Yao, Zhiyi; Li, Min; Zhao, Yuliang

    2016-06-01

    We present a SERS-based method for the detection of melamine utilizing multi-hydrogen bonding induced charge-transfer (CT) effects. In this system, silver-2-nitro-5-mercaptobenzoic acids (Ag-TNBs) were chosen as the promising probe for melamine sensing. This method relies on the multi-hydrogen-bonding between TNB and melamine which leads to significant Raman frequency shifts in Raman spectra. When being exposure to other potential interfering substances in milk, this system exhibits high selectivity towards melamine. The limit of detection (LOD) of this method is as low as 10(-12)M, which is far below the safety of FDA and USA. The proposed method can be further applied to monitoring the amount of melamine in both caw milk and milk powder. PMID:27130107

  4. Development methods for tracing phosphorus concentration during the process of recovery from Syrian commercial phosphoric acid

    International Nuclear Information System (INIS)

    In this work the methods (gravimetric and spectrophotometric) which have been used in french and Algerian phosphate laboratories for determining the phosphorus concentration in phosphate rocks, were investigated. Some changes were done on producer to be applicable for determining phosphorus in phosphoric acid. Although the effect of uranium extraction on phosphorus concentration in Syrian commercial phosphoric acid was studied, the best analytical stoichiometric of phosphovanadomolybdate complex was studied by spectrophotometric method. (authors)

  5. Four methods for determining the composition of trace radioactive surface contamination of low-radioactivity metal

    International Nuclear Information System (INIS)

    Four methods for determining the composition of low-level uranium- and thorium-chain surface contamination are presented. One method is the observation of Cherenkov light production in water. In two additional methods a position-sensitive proportional counter surrounding the surface is used to make both a measurement of the energy spectrum of alpha particle emissions and also coincidence measurements to derive the thorium-chain content based on the presence of short-lived isotopes in that decay chain. The fourth method is a radiochemical technique in which the surface is eluted with a weak acid, the eluate is concentrated, added to liquid scintillator and assayed by recording beta-alpha coincidences. These methods were used to characterize two ‘hotspots’ on the outer surface of one of the 3He proportional counters in the Neutral Current Detection array of the Sudbury Neutrino Observatory experiment. The methods have similar sensitivities, of order tens of ng, to both thorium- and uranium-chain contamination.

  6. Four methods for determining the composition of trace radioactive surface contamination of low-radioactivity metal

    CERN Document Server

    O'Keeffe, H M; Cleveland, B T; Doucas, G; Gagnon, N; Jelley, N A; Kraus, C; Lawson, I T; Majerus, S; McGee, S R; Myers, A W; Poon, A W P; Rielage, K; Robertson, R G H; Rosten, R C; Stonehill, L C; VanDevender, B A; Van Wechel, T D

    2011-01-01

    Four methods for determining the composition of low-level uranium- and thorium-chain surface contamination are presented. One method is the observation of Cherenkov light production in water. In two additional methods a position-sensitive proportional counter surrounding the surface is used to make both a measurement of the energy spectrum of alpha particle emissions and also coincidence measurements to derive the thorium-chain content based on the presence of short-lived isotopes in that decay chain. The fourth method is a radiochemical technique in which the surface is eluted with a weak acid, the eluate is concentrated, added to liquid scintillator and assayed by recording beta-alpha coincidences. These methods were used to characterize two `hotspots' on the outer surface of one of the He-3 proportional counters in the Neutral Current Detection array of the Sudbury Neutrino Observatory experiment. The methods have similar sensitivities, of order tens of ng, to both thorium- and uranium-chain contamination.

  7. Method for measuring the speed distribution of blown sand using laser beam

    International Nuclear Information System (INIS)

    A new method for measuring the speed distribution of blown sand grains using He-Ne laser beam has been developed. This method enables us to measure the rate of sand movement as well as the number of blown sand at the some region in the wind tunnel and field. The apparatus is composed of a He-Ne laser (l mW)., a photodetection system with a slit (width: 0.3-3.0 mm), a five channel pulse width analyzer and a multi-purpose counter. When a sand grain passes across the laser beam, a shadow is thrown upon the light sensitive area of photodetector. The change in photocurrent after amplification and pulse shaping, is fed to the pulse width analyzer. The pulse width has information on both the speed and size of blown sand. Using nearly uniform size of sand grains, the speed distribution of blown sand can be measured. This method has many merits for studying the physical phenomena of blown sand in the field. First, the laser beam does not disturb the stream line of wind, but this condition is not satisfied in the case of using the sand trap. Second, in case of use of sand trap, the base of this must be buried in the sand surface and this handling affect the physical properties of sand surface. Third, this method is strong differential method in time and space, whereas the sand trap is .strong in integral method and easy handling

  8. Method for tracing simulated CO2 leak in terrestrial environment with a 13CO2 tracer

    Science.gov (United States)

    Moni, Christophe; Rasse, Daniel

    2013-04-01

    Facilities for the geological storage of carbon dioxide (CO2) as part of carbon capture and storage (CCS) schemes will be designed to prevent any leakage from the defined 'storage complex'. However, developing regulations and guidance throughout the world (e.g. the EC Directive and the USEPA Vulnerability Evaluation Framework) recognize the importance of assessing the potential for environmental impacts from CO2 storage. RISCS, a European (FP7) project, aims to improve understanding of those impacts that could plausibly occur in the hypothetical case that unexpected leakage occurs. As part of the RISCS project the potential impacts that an unexpected CO2 leaks might have on a cropland ecosystems was investigated. A CO2 exposure field experiment based on CO2 injection at 85 cm depth under an oats culture was designed. To facilitate the characterization of the simulated leaking zone the gas used for injection was produced from natural gas and had a δ13C of -46‰. The aim of the present communication is to depict how the injected gas was traced within the soil-vegetation-atmosphere continuum using 13CO2 continuous cavity ring-down spectrometry (CRDS). Four subsurface experimental injection plots (6m x 3m) were set up. In order to test the effects of different intensity of leakage, the field experiment was designed as to create a longitudinal CO2 gradient for each plot. For this purpose gas supply pipes were inserted at one extremity of each plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under the clayey plough layer of Norwegian moraine soils. Soil CO2 concentration and isotopic signature were punctually recorded: 1) in the soil at 20 cm depth at 6 positions distributed on the central transect, 2) at the surface following a (50x50 cm) grid sampling pattern, and 3) in the canopy atmosphere at 10, 20, 30 cm along three longitudinal transects (seven sampling point per transect). Soil CO2 fluxes and isotopic signature were finally

  9. Standardization of radionuclides 45Ca, 137Cs, 204Tl by tracing method using 4πβ-γ coincidence system

    International Nuclear Information System (INIS)

    The procedure followed for the standardization of 45Ca, 137Cs and 204Tl is described. The activity measurements was carried out in a 4πβ-γ coincidence system by the tracing method. The radionuclides chosen as the P-y emitting tracer nuclide were 60Co for the 45Ca and 134Cs for 137Cs and 204TL because their end-point beta-ray energy are close to the respective beta emitters. The radioactive sources were prepared using two different techniques: one was the drops technique and the other was the solution technique. In the drop technique the sources were prepared by dropping directly on the subtract both solutions (tracer and beta pure). In the other technique a solution of tracer plus beta pure was mixed previously before making the radioactive sources. The activities of the radionuclides obtained with these technique were compared and the values are in agreement within the experimental uncertainties. (author)

  10. Basis of the retrospective reconstruction method for parameters determining internal irradiation along the trace following a nuclear explosion

    International Nuclear Information System (INIS)

    This paper describes the method for receiving all of the radiation data that is required for a realistic estimation of probable internal doses, committed both as a result of inhalation of radioactive substances during the period of formation of a nuclear trace and as a result of consuming local agricultural food products. The quantitative characterization of radioactivity transfer along links of biological chains, by which radio-nuclides transfer from the environment into the human organism, is based on relations predetermining the local gamma-exposure rate. On one hand, such an approach makes the problem of getting the appropriate data easier. On the other hand, the approach improves the data reliability, as it is based on reliable experimental data. (orig./GL)

  11. A general ray-tracing algorithm for the solution of the neutron transport equation by the collision probability method

    International Nuclear Information System (INIS)

    The development and analysis of methods for generating first-flight collision probabilities in two-dimensional geometries consistent with Light Water Moderated (LWR) fuel assemblies are examined. A new ray-tracing algorithm is discussed. A number of numerical results are given demonstrating the feasibility of this algorithm and the effects of the moderator (and fuel) sectorizations on the resulting flux distributions. The collision probabilties have been introduced and their subsequent utilization in the flux calculation procedures illustrated. A brief description of the Coxy-1 and Coxy-2 programs (which were developed in the Reactor Theory Division of the Atomic Energy Agency of South Africa Ltd) has also been added. 41 figs., 9 tabs., 18 refs

  12. Trace gas retrieval for limb DOAS under changing atmospheric conditions: The X-gas scaling method vs optimal estimation

    Science.gov (United States)

    Hueneke, Tilman; Grossmann, Katja; Knecht, Matthias; Raecke, Rasmus; Stutz, Jochen; Werner, Bodo; Pfeilsticker, Klaus

    2016-04-01

    Changing atmospheric conditions during DOAS measurements from fast moving aircraft platforms pose a challenge for trace gas retrievals. Traditional inversion techniques to retrieve trace gas concentrations from limb scattered UV/vis spectroscopy, like optimal estimation, require a-priori information on Mie extinction (e.g., aerosol concentration and cloud cover) and albedo, which determine the atmospheric radiative transfer. In contrast to satellite applications, cloud filters can not be applied because they would strongly reduce the usable amount of expensively gathered measurement data. In contrast to ground-based MAX-DOAS applications, an aerosol retrieval based on O4 is not able to constrain the radiative transfer in air-borne applications due to the rapidly decreasing amount of O4 with altitude. Furthermore, the assumption of a constant cloud cover is not valid for fast moving aircrafts, thus requiring 2D or even 3D treatment of the radiative transfer. Therefore, traditional techniques are not applicable for most of the data gathered by fast moving aircraft platforms. In order to circumvent these limitations, we have been developing the so-called X-gas scaling method. By utilising a proxy gas X (e.g. O3, O4, …), whose concentration is either a priori known or simultaneously in-situ measured as well as remotely measured, an effective absorption length for the target gas is inferred. In this presentation, we discuss the strengths and weaknesses of the novel approach along with some sample cases. A particular strength of the X-gas scaling method is its insensitivity towards the aerosol abundance and cloud cover as well as wavelength dependent effects, whereas its sensitivity towards the profiles of both gases requires a priori information on their shapes.

  13. Development and application of a shipboard method for spectrophotometric determination of trace dissolved manganese in estuarine and coastal waters

    Science.gov (United States)

    Feng, Sichao; Huang, Yongming; Yuan, Dongxing; Zhu, Yong; Zhou, Tingjin

    2015-01-01

    A shipboard method for the determination of trace dissolved manganese in estuarine and coastal waters was developed using a technique of reverse flow injection analysis, which adopted a 1-m liquid waveguide capillary cell and spectrophotometric detection of manganese derivation with 1-(2-pyridylazo)-2-naphthol (PAN). The design of dual-sample-carrier speeded up the sample throughput and eliminated the Schlieren effect. The salinity of estuarine and coastal waters caused a huge increase in the blank absorption value at the maximum absorption wavelength; therefore, a less sensitive detection wavelength was selected to achieve a low blank value while the method sensitivity was not significantly decreased. Method parameters were optimized. The salinity effect from estuarine and coastal waters was carefully investigated, and interference from iron was evaluated. The proposed method had high sensitivity with a detection limit of 3.0 nmol L-1 and a wide linear range of 10-1500 nmol L-1 for dissolved manganese in seawater (S=35). The analytical results of five water samples with different salinities obtained using the proposed method showed good agreement with those using a reference ICP-MS method. The sample throughput of the proposed method was 120 h-1, which was capable of obtaining high spatial and temporal resolution data in shipboard analysis. The proposed method had the advantages of convenient application in estuarine and coastal waters with different salinities, low detection limit, as well as high sample throughput. The proposed method was successfully applied to a 24 h on-line analysis and a shipboard underway analysis of dissolved manganese in the Jiulongjiang Estuary.

  14. Collaborative study of an anion exchange method for the determination of trace plutonium in water

    International Nuclear Information System (INIS)

    A single-laboratory evaluation and an interlaboratory collaborative study were made of a method for determining plutonium in water. The method was written for the analysis of one-liter samples and involves coprecipitation, acid dissolution, anion exchange, electrodeposition, and alpha pulse height analysis. After the single-laboratory evaluation of the selected method, four samples were prepared for the collaborative study: two river-water samples, a substitute ocean water sample, and sample containing sediment. These samples contained plutonium-239 and plutonium-238 at concentrations ranging from 0.42 to 28.9 dis/min/liter. In the collaborative study standard deviations of plutonium concentrations ranged from 5 to 13%. In three cases, standard deviations agreed with those expected from counting statistics. It is believed that hydrolysis occurred in the river water samples resulting in errors greater than those expected from counting statistics

  15. Beam-Based Error Identification and Correction Methods for Particle Accelerators

    CERN Document Server

    AUTHOR|(SzGeCERN)692826; Tomas, Rogelio; Nilsson, Thomas

    2014-06-10

    Modern particle accelerators have tight tolerances on the acceptable deviation from their desired machine parameters. The control of the parameters is of crucial importance for safe machine operation and performance. This thesis focuses on beam-based methods and algorithms to identify and correct errors in particle accelerators. The optics measurements and corrections of the Large Hadron Collider (LHC), which resulted in an unprecedented low β-beat for a hadron collider is described. The transverse coupling is another parameter which is of importance to control. Improvement in the reconstruction of the coupling from turn-by-turn data has resulted in a significant decrease of the measurement uncertainty. An automatic coupling correction method, which is based on the injected beam oscillations, has been successfully used in normal operation of the LHC. Furthermore, a new method to measure and correct chromatic coupling that was applied to the LHC, is described. It resulted in a decrease of the chromatic coupli...

  16. Coordinate transformation based cryo-correlative methods for electron tomography and focused ion beam milling

    International Nuclear Information System (INIS)

    Correlative microscopy allows imaging of the same feature over multiple length scales, combining light microscopy with high resolution information provided by electron microscopy. We demonstrate two procedures for coordinate transformation based correlative microscopy of vitrified biological samples applicable to different imaging modes. The first procedure aims at navigating cryo-electron tomography to cellular regions identified by fluorescent labels. The second procedure, allowing navigation of focused ion beam milling to fluorescently labeled molecules, is based on the introduction of an intermediate scanning electron microscopy imaging step to overcome the large difference between cryo-light microscopy and focused ion beam imaging modes. These methods make it possible to image fluorescently labeled macromolecular complexes in their natural environments by cryo-electron tomography, while minimizing exposure to the electron beam during the search for features of interest. - Highlights: • Correlative light microscopy and focused ion beam milling of vitrified samples. • Coordinate transformation based cryo-correlative method. • Improved correlative light microscopy and cryo-electron tomography

  17. Coordinate transformation based cryo-correlative methods for electron tomography and focused ion beam milling

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Yoshiyuki; Schrod, Nikolas; Schaffer, Miroslava; Feng, Li Rebekah; Baumeister, Wolfgang; Lucic, Vladan, E-mail: vladan@biochem.mpg.de

    2014-08-01

    Correlative microscopy allows imaging of the same feature over multiple length scales, combining light microscopy with high resolution information provided by electron microscopy. We demonstrate two procedures for coordinate transformation based correlative microscopy of vitrified biological samples applicable to different imaging modes. The first procedure aims at navigating cryo-electron tomography to cellular regions identified by fluorescent labels. The second procedure, allowing navigation of focused ion beam milling to fluorescently labeled molecules, is based on the introduction of an intermediate scanning electron microscopy imaging step to overcome the large difference between cryo-light microscopy and focused ion beam imaging modes. These methods make it possible to image fluorescently labeled macromolecular complexes in their natural environments by cryo-electron tomography, while minimizing exposure to the electron beam during the search for features of interest. - Highlights: • Correlative light microscopy and focused ion beam milling of vitrified samples. • Coordinate transformation based cryo-correlative method. • Improved correlative light microscopy and cryo-electron tomography.

  18. Trace element analysis of red beet and its cell cultures by x-ray fluorescence method

    International Nuclear Information System (INIS)

    Cell cultures from red beet root and beet sprout were analysed by isotope excited energy-dispersive X-ray fluorescence method. The excitation source was 125I. High zinc ion concentrations were found in cell cultures together with high histidine content. (author)

  19. Determination of trace elements in standard reference materials by the ko-standardization method

    International Nuclear Information System (INIS)

    The ko-standardization method is suitable for routine multielement determinations by reactor neutron activation analysis (NAA). Investigation of NIST standard reference materials SRM 1571 Orchard Leaves, SRM 1572 Citrus leaves, and SRM 1573 Tomato Leaves showed the systematic error of 12 certified elements determined to be less than 8%. Thirty-four elements were determined in NIST proposed SRM 1515 Apple Leaves

  20. Control of metallic trace elements in the concentrated copper by neutron activation method

    International Nuclear Information System (INIS)

    In order to value the activation analysis technique in the copper concentrates analysis, six copper concentrates were quantitatively analysed, whereas others were impossible to determine in consequence of the great radioactivities of the copper or their presence below the detection limit of the method. Among the detected elements Co, U and In are at concentrations which allow their economical recovery. (AF)

  1. Trace Level Determination of Mesityl Oxide and Diacetone Alcohol in Atazanavir Sulfate Drug Substance by a Gas Chromatography Method

    Science.gov (United States)

    Raju, K. V. S. N.; Pavan Kumar, K. S. R.; Siva Krishna, N.; Madhava Reddy, P.; Sreenivas, N.; Kumar Sharma, Hemant; Himabindu, G.; Annapurna, N.

    2016-01-01

    A capillary gas chromatography method with a short run time, using a flame ionization detector, has been developed for the quantitative determination of trace level analysis of mesityl oxide and diacetone alcohol in the atazanavir sulfate drug substance. The chromatographic method was achieved on a fused silica capillary column coated with 5% diphenyl and 95% dimethyl polysiloxane stationary phase (Rtx-5, 30 m x 0.53 mm x 5.0 µm). The run time was 20 min employing programmed temperature with a split mode (1:5) and was validated for specificity, sensitivity, precision, linearity, and accuracy. The detection and quantitation limits obtained for mesityl oxide and diacetone alcohol were 5 µg/g and 10 µg/g, respectively, for both of the analytes. The method was found to be linear in the range between 10 µg/g and 150 µg/g with a correlation coefficient greater than 0.999, and the average recoveries obtained in atazanavir sulfate were between 102.0% and 103.7%, respectively, for mesityl oxide and diacetone alcohol. The developed method was found to be robust and rugged. The detailed experimental results are discussed in this research paper.

  2. Trace Level Determination of Mesityl Oxide and Diacetone Alcohol in Atazanavir Sulfate Drug Substance by a Gas Chromatography Method.

    Science.gov (United States)

    Raju, K V S N; Pavan Kumar, K S R; Siva Krishna, N; Madhava Reddy, P; Sreenivas, N; Kumar Sharma, Hemant; Himabindu, G; Annapurna, N

    2016-01-01

    A capillary gas chromatography method with a short run time, using a flame ionization detector, has been developed for the quantitative determination of trace level analysis of mesityl oxide and diacetone alcohol in the atazanavir sulfate drug substance. The chromatographic method was achieved on a fused silica capillary column coated with 5% diphenyl and 95% dimethyl polysiloxane stationary phase (Rtx-5, 30 m x 0.53 mm x 5.0 µm). The run time was 20 min employing programmed temperature with a split mode (1:5) and was validated for specificity, sensitivity, precision, linearity, and accuracy. The detection and quantitation limits obtained for mesityl oxide and diacetone alcohol were 5 µg/g and 10 µg/g, respectively, for both of the analytes. The method was found to be linear in the range between 10 µg/g and 150 µg/g with a correlation coefficient greater than 0.999, and the average recoveries obtained in atazanavir sulfate were between 102.0% and 103.7%, respectively, for mesityl oxide and diacetone alcohol. The developed method was found to be robust and rugged. The detailed experimental results are discussed in this research paper. PMID:27222607

  3. New density estimation methods for charged particle beams with applications to microbunching instability

    Science.gov (United States)

    Terzić, Balša; Bassi, Gabriele

    2011-07-01

    In this paper we discuss representations of charge particle densities in particle-in-cell simulations, analyze the sources and profiles of the intrinsic numerical noise, and present efficient methods for their removal. We devise two alternative estimation methods for charged particle distribution which represent significant improvement over the Monte Carlo cosine expansion used in the 2D code of Bassi et al. [G. Bassi, J. A. Ellison, K. Heinemann, and R. Warnock, Phys. Rev. ST Accel. Beams 12, 080704 (2009); PRABFM1098-440210.1103/PhysRevSTAB.12.080704G. Bassi and B. Terzić, in Proceedings of the 23rd Particle Accelerator Conference, Vancouver, Canada, 2009 (IEEE, Piscataway, NJ, 2009), TH5PFP043], designed to simulate coherent synchrotron radiation (CSR) in charged particle beams. The improvement is achieved by employing an alternative beam density estimation to the Monte Carlo cosine expansion. The representation is first binned onto a finite grid, after which two grid-based methods are employed to approximate particle distributions: (i) truncated fast cosine transform; and (ii) thresholded wavelet transform (TWT). We demonstrate that these alternative methods represent a staggering upgrade over the original Monte Carlo cosine expansion in terms of efficiency, while the TWT approximation also provides an appreciable improvement in accuracy. The improvement in accuracy comes from a judicious removal of the numerical noise enabled by the wavelet formulation. The TWT method is then integrated into the CSR code [G. Bassi, J. A. Ellison, K. Heinemann, and R. Warnock, Phys. Rev. ST Accel. Beams 12, 080704 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.080704], and benchmarked against the original version. We show that the new density estimation method provides a superior performance in terms of efficiency and spatial resolution, thus enabling high-fidelity simulations of CSR effects, including microbunching instability.

  4. New density estimation methods for charged particle beams with applications to microbunching instability

    International Nuclear Information System (INIS)

    In this paper we discuss representations of charge particle densities in particle-in-cell simulations, analyze the sources and profiles of the intrinsic numerical noise, and present efficient methods for their removal. We devise two alternative estimation methods for charged particle distribution which represent significant improvement over the Monte Carlo cosine expansion used in the 2D code of Bassi et al. (G. Bassi, J.A. Ellison, K. Heinemann and R. Warnock Phys. Rev. ST Accel. Beams 12 080704 (2009)G. Bassi and B. Terzic, in Proceedings of the 23rd Particle Accelerator Conference, Vancouver, Canada, 2009 (IEEE, Piscataway, NJ, 2009), TH5PFP043), designed to simulate coherent synchrotron radiation (CSR) in charged particle beams. The improvement is achieved by employing an alternative beam density estimation to the Monte Carlo cosine expansion. The representation is first binned onto a finite grid, after which two grid-based methods are employed to approximate particle distributions: (i) truncated fast cosine transform; and (ii) thresholded wavelet transform (TWT). We demonstrate that these alternative methods represent a staggering upgrade over the original Monte Carlo cosine expansion in terms of efficiency, while the TWT approximation also provides an appreciable improvement in accuracy. The improvement in accuracy comes from a judicious removal of the numerical noise enabled by the wavelet formulation. The TWT method is then integrated into the CSR code (G. Bassi, J.A. Ellison, K. Heinemann and R. Warnock Phys. Rev. ST Accel. Beams 12 080704 (2009)), and benchmarked against the original version. We show that the new density estimation method provides a superior performance in terms of efficiency and spatial resolution, thus enabling high-fidelity simulations of CSR effects, including microbunching instability.

  5. Effectiveness of noncoplanar IMRT planning using a parallelized multiresolution beam angle optimization method for paranasal sinus carcinoma

    International Nuclear Information System (INIS)

    Purpose: To determine the effectiveness of noncoplanar beam configurations and the benefit of plans using fewer but optimally placed beams designed by a parallelized multiple-resolution beam angle optimization (PMBAO) approach. Methods and Materials: The PMBAO approach uses a combination of coplanar and noncoplanar beam configurations for intensity-modulated radiation therapy (IMRT) treatment planning of paranasal sinus cancers. A smaller number of beams (e.g. 3) are first used to explore the solution space to determine the best and worst beam directions. The results of this exploration are then used as a starting point for determining an optimum beam orientation configuration with more beams (e.g. 5). This process is parallelized using a message passing interface, which greatly reduces the overall computation time for routine clinical practice. To test this approach, treatment for 10 patients with paranasal sinus cancer was planned using a total of 5 beams from a pool of 46 possible beam angles. The PMBAO treatment plans were also compared with IMRT plans designed using 9 equally spaced coplanar beams, which is the standard approach in our clinic. Plans with these two different beam configurations were compared with respect to dose conformity, dose heterogeneity, dose-volume histograms, and doses to organs at risk (i.e., eyes, optic nerve, optic chiasm, and brain). Results: The noncoplanar beam configuration was superior in most paranasal sinus carcinoma cases. The target dose homogeneity was better using a PMBAO 5-beam configuration. However, the dose conformity using PMBAO was not improved and was case dependent. Compared with the 9-beam configuration, the PMBAO configuration significantly reduced the mean dose to the eyes and optic nerves and the maximum dose to the contralateral optical path (e.g. the contralateral eye and optic nerve). The maximum dose to the ipsilateral eye and optic nerve was also lower using the PMBAO configuration than using the 9-beam

  6. Phthalates in surface water - a method for routine trace level analysis

    International Nuclear Information System (INIS)

    A routine method for the determination of phthalates in water is presented. It is suitable for all kinds of water like surface water, waste water, landfill leachate, rain water and ground water. Unfiltered water samples including all suspended particulate matter are extracted by solid-phase extraction in an all-glass apparatus using RPC-18. The extracts are measured by GC/MSD in the SIM mode. Due to an easy but efficient decontamination technique, method blanks could be decreased below 0.02 μg/l for all phthalates. The detection limits are 0.01 to 0.02 μg/l, the determination limits are 0.02 to 0.05 μg/l. Recovery for all phthalates is about 98% (± 5%). Phthalates were measured in about 400 samples of water of the river Rhine and its main affluents in Northrhine-Westfalia. (orig.)

  7. A method for real-time profiling of organic trace gases in the planetary boundary layer

    Directory of Open Access Journals (Sweden)

    R. Schnitzhofer

    2009-07-01

    Full Text Available A method for real time profiling of volatile organic compounds (VOCs was developed combining the advantages of a tethered balloon as a research platform and of proton transfer reaction mass spectrometry (PTR-MS as an analytical technique for fast and highly sensitive VOC measurements. A 200 m Teflon tube was used to draw sampling air from a tethered aerodynamic balloon to the PTR-MS instrument. Potential positive and negative VOC artifacts of the inlet line were characterized in the laboratory and in the field and were found to be insignificant for most compounds. The method was successfully deployed during a winter field campaign to determine the small scale spatial and temporal pattern of air pollutants under winter inversion conditions.

  8. Visualization of potential acupuncture points in rat and nude mouse and DiI tracing method

    OpenAIRE

    Byung-Cheon Lee; Ki-Hoon Uhm; Kyoung-Hee Bae; Dae-In Kang; Kwang-Sup Soh

    2009-01-01

    Objectives: To find the potential acupuncture points by using Trypan blue staining on the skin of rat and Nude mouse. Methods: 0.4% Trypan blue was applied to the skin of rat or Nude mouse previously treated by surfactant. Washing by warm saline was followed after enough application of trypan blue and surfactant. Frequency of Trypan blue application should be varied to the experimental animals' condition for visualizing significant spots. Results: Blue spots appeared roughly in symmetry...

  9. Development of activation analytical methods for the determination of trace amounts in natural wastes

    International Nuclear Information System (INIS)

    Large volumina of sample material are activated in a reactor by neutrons. Based on the resulting #betta#-spectra a method has been developed, which allows to separate 17 elements with a sufficiently low detection limit necessary to judge the quality of drinking water. Selective separation techniques have been worked out to analyse the toxic elements Sb, Cd, Hg, Se and U with high sensitivity for special applications in the field of environmental research. (DG)

  10. Tracing and quantifying groundwater inflow into lakes using a simple method for radon-222 analysis

    Directory of Open Access Journals (Sweden)

    T. Kluge

    2007-09-01

    Full Text Available Due to its high activities in groundwater, the radionuclide 222Rn is a sensitive natural tracer to detect and quantify groundwater inflow into lakes, provided the comparatively low activities in the lakes can be measured accurately. Here we present a simple method for radon measurements in the low-level range down to 3 Bq m−3, appropriate for groundwater-influenced lakes, together with a concept to derive inflow rates from the radon budget in lakes. The analytical method is based on a commercially available radon detector and combines the advantages of established procedures with regard to efficient sampling and sensitive analysis. Large volume (12 l water samples are taken in the field and analyzed in the laboratory by equilibration with a closed air loop and alpha spectrometry of radon in the gas phase. After successful laboratory tests, the method has been applied to a small dredging lake without surface in- or outflow in order to estimate the groundwater contribution to the hydrological budget. The inflow rate calculated from a 222Rn balance for the lake is around 530 m³ per day, which is comparable to the results of previous studies. In addition to the inflow rate, the vertical and horizontal radon distribution in the lake provides information on the spatial distribution of groundwater inflow to the lake. The simple measurement and sampling technique encourages further use of radon to examine groundwater-lake water interaction.

  11. Direct liquid deposition calibration method for trace cyclotrimethylenetrinitramine using thermal desorption instrumentation.

    Science.gov (United States)

    Field, Christopher R; Lubrano, Adam L; Rogers, Duane A; Giordano, Braden C; Collins, Greg E

    2013-03-22

    A simple method for establishing calibration curves with sorbent-filled thermal desorption tubes has been demonstrated for nitroaromatic and nitramine vapor samples using a thermal desorption system with a cooled inlet system (TDS-CIS), which was coupled to a gas chromatograph (GC) with an electron capture detector (ECD). The method relies upon the direct liquid deposition of standard solutions onto the glass frit at the head of sorbent-filled thermal desorption tubes. Linear calibration results and ideal system conditions for the TDS-CIS-GC-ECD were established for mixtures containing both cyclotrimethylenetrinitramine, a.k.a. RDX, and 2,4,6-trinitrotoluene (TNT). Because of the chemical characteristics of RDX, a higher TDS-CIS flow rate relative to the optimized approach for TNT was required for efficient RDX desorption. Simultaneous quantitation of TNT and RDX using the direct liquid deposition method with optimized instrumentation parameters for RDX were compared to results from a standard split/splitless GC inlet and a CIS. PMID:23415141

  12. Tracing and quantifying groundwater inflow into lakes using a simple method for radon-222 analysis

    Science.gov (United States)

    Kluge, T.; Ilmberger, J.; von Rohden, C.; Aeschbach-Hertig, W.

    2007-09-01

    Due to its high activities in groundwater, the radionuclide 222Rn is a sensitive natural tracer to detect and quantify groundwater inflow into lakes, provided the comparatively low activities in the lakes can be measured accurately. Here we present a simple method for radon measurements in the low-level range down to 3 Bq m-3, appropriate for groundwater-influenced lakes, together with a concept to derive inflow rates from the radon budget in lakes. The analytical method is based on a commercially available radon detector and combines the advantages of established procedures with regard to efficient sampling and sensitive analysis. Large volume (12 l) water samples are taken in the field and analyzed in the laboratory by equilibration with a closed air loop and alpha spectrometry of radon in the gas phase. After successful laboratory tests, the method has been applied to a small dredging lake without surface in- or outflow in order to estimate the groundwater contribution to the hydrological budget. The inflow rate calculated from a 222Rn balance for the lake is around 530 m³ per day, which is comparable to the results of previous studies. In addition to the inflow rate, the vertical and horizontal radon distribution in the lake provides information on the spatial distribution of groundwater inflow to the lake. The simple measurement and sampling technique encourages further use of radon to examine groundwater-lake water interaction.

  13. Direct online HPLC-CV-AFS method for traces of methylmercury without derivatisation: a matrix-independent method for urine, sediment and biological tissue samples.

    Science.gov (United States)

    Brombach, Christoph-Cornelius; Gajdosechova, Zuzana; Chen, Bin; Brownlow, Andrew; Corns, Warren T; Feldmann, Jörg; Krupp, Eva M

    2015-01-01

    Mercury (Hg) is a global pollutant which occurs in different species, with methylmercury (MeHg) being the critical compound due to its neurotoxicity and bioaccumulation through the food chain. Methods for trace speciation of MeHg are therefore needed for a vast range of sample matrices, such as biological tissues, fluids, soils or sediments. We have previously developed an ultra-trace speciation method for methylmercury in water, based on a preconcentration HPLC cold vapour atomic fluorescence spectrometry (HPLC-CV-AFS) method. The focus of this work is mercury speciation in a variety of sample matrices to assess the versatility of the method. Certified reference materials were used where possible, and samples were spiked where reference materials were not available, e.g. human urine. Solid samples were submitted for commonly used digestion or extraction processes to obtain a liquid sample for injection into the analytical system. For MeHg in sediment samples, an extraction procedure was adapted to accommodate MeHg separation from high amounts of Hg(2+) to avoid an overload of the column. The recovery for MeHg determination was found to be in the range of 88-104% in fish reference materials (DOLT-2, DOLT-4, DORM-3), lobster (TORT-2), seaweed (IAEA-140/TM), sediments (ERM(®)-CC580) and spiked urine and has been proven to be robust, reliable, virtually matrix-independent and relatively cost-effective. Applications in the ultra-trace concentration range are possible using the preconcentration up to 200 mL, while for higher MeHg-containing samples, lower volumes can be applied. A comparison was carried out between species-specific isotope dilution gas chromatography inductively coupled plasma mass spectrometry (SSID-GC-ICP-MS) as the gold standard and HPLC-CV-AFS for biological tissues (liver, kidney and muscle of pilot whales), showing a slope of 1.008 and R (2) = 0.97, which indicates that the HPLC-CV-AFS method achieves well-correlated results for MeHg in

  14. Selective Beam Shielding Method of Gamma-Knife Unit Using Various Plugging Patterns

    International Nuclear Information System (INIS)

    The B-type gamma knife unit was installed at Kyung-Hee University Hospital in March 1992. The selective beam plugging method can be used to reduce the low percentage isodose profiles of normal sensitive organ and to codify the isodose cuties of treatment volume for better shaping of the target volume. For representing the changes of the law percentage isodose profiles, the variations of dose distribution for several cases were discussed in this paper. The film dosimetry was performed for the evaluation of calculated isodose profiles predicted by KULA dose planning system. The results were verified by RFA-3 automatic densitometry. The clinical application of selective beam shielding method was performed in 17 patients in 100 patients who have undergone gamma knife radiosurgery for a year. The calculated and the measured isodose profiles for the high percentage regions were well consistent with each other. When the target of pituitary tumor is macro-size, the selective beam shielding method is the most applicable method. When the target size, however, is small, the correct selection of the proper helmet size is very important. All patients were exposed almost about 3-12 Gy for brain stem, and 3-11.2 Gy for optic apparatus. It is recommended that the same or other plugging patterns with multiple isocenters should be used for protection of the radiosensitive normal structures with precise treatment of CNS lesions

  15. Research of On-line Analytical Method of Trace Oxygen and Water in Argon

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Metal sodium has an active chemical quality. When it is used as a coolant in a fast neutron reactor, it must be protected by a cover gas argon for safety operation of the reactor. But oxygen and water in argon can produce chemical reaction with sodium. Then sodium hydroxide, sodium oxide and hydrogen can be produced. This will be harmful to the safety operation of reactor. The purpose of controlling a level of impurity in the cover gas is for controlling a level of impurity in sodium. The research is to find an on-line determining method and a sampling system to monitor

  16. The determination of trace impurities in uranium by nuclear analytical methods

    International Nuclear Information System (INIS)

    Nuclear-grade uranium dioxides is utilized in nuclear fuel production and it must satisfy stringent requirements as to purity. Many of these impurities are suitable for determination by neutron activation analysis. This technique has extremely good sensitivity for most of the impurity elements that are of interest in high-purity uranium dioxide. This study formed part of a project to determine the impurity elements in high-purity uranium dioxide that was intended as a reference standard for spark-source mass spectrography. A radiochemical neutron-activation method was developed for the determination of chromium, iron, cobalt and nickel in the uranium sample

  17. Generalized ray tracing method for the calculation of the peripheral refraction induced by an ophthalmic lens

    OpenAIRE

    Rojo Badenas, Pilar

    2015-01-01

    This thesis proposes a method to evaluate and quantify in a precise way the peripheral refraction induced by an ophthalmic lens. The motivation for this work stems from the progression of myopia and its possible causes; two of them are particularly key for this PhD: (a) Peripheral refraction of the eye may have an important role in the progression of myopia and (b) ophthalmic lenses are the compensating element more used in children and teenagers. These two elements fully justify the need for...

  18. Numerical test of the method for revealing traces of deterministic chaos in the accreting black holes

    OpenAIRE

    Suková, Petra; Janiuk, Agnieszka

    2016-01-01

    The high energy radiation emitted by black hole X-ray binaries originates in an accretion disk, hence the variability of the lightcurves mirrors the dynamics of the disc. We study the time evolution of the emitted flux in order to find evidences, that low dimensional non-linear equations govern the accretion flow. Here we test the capabilities of our novel method to find chaotic behaviour on the two numerical time series describing the motion of a test particle around a black hole surrounded ...

  19. Numerical test of the method for revealing traces of deterministic chaos in the accreting black holes

    CERN Document Server

    Suková, Petra

    2016-01-01

    The high energy radiation emitted by black hole X-ray binaries originates in an accretion disk, hence the variability of the lightcurves mirrors the dynamics of the disc. We study the time evolution of the emitted flux in order to find evidences, that low dimensional non-linear equations govern the accretion flow. Here we test the capabilities of our novel method to find chaotic behaviour on the two numerical time series describing the motion of a test particle around a black hole surrounded by a thin massive disc, one being regular and the other one chaotic.

  20. [Two steps elution method FI on-line adsorption and preconcentration coupled with FAAS for the determination of trace zinc].

    Science.gov (United States)

    Wang, Zhong-yuan; Zhang, Hong-kang; Fang, Hong-da; Su, Yao-dong; Mittal, Gauri S

    2011-12-01

    A flow injection two steps elution method on-line sorption and preconcentration system coupled to flame atomic absorption spectrometry (FAAS) was developed for the determination of trace Zn in water samples. The conventional elution procedure was divided into two steps: elution procedure and detection procedure. During the elution procedure, the eluent was pumped into KR by the suction of the peristaltic pump and through PTFE tube instead of peristaltic pump tube. By the new method, the dispersion of the analyte was decreased notably, and high absorbance peak value was achieved. Because the eluent was not through the peristaltic pump tube, the peristaltic pump tube was protected from being eroded. Emptying procedure was added in order to insure the veracity and repeatability of the experiment of every time. With 60 s (sample throughput of 37 x h(-1)) of sampling at a flow rate of 6.0 mL x min(-1), an enhancement factor (EF) of 28 (higher than 9 achieved by conventional elution method) and a detection limit (3sigma) of 0.35 x L(-1) were obtained. The precision (RSD, n=11) was 2.1% at the 20 microg x L(-1) level. When 0.1% phi triethannolamine was used as masking reagent, the recovery rate was from 98.7% to 99.6%. PMID:22295800

  1. Solid-phase extraction of trace Au(Ⅲ) with SDG and determination by the catalytic spectrophotometric method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The new catalytic kinetic spectrophotometric method for Au(Ⅲ) determination was developed and validated.It was based on the catalytic effect of gold on the oxidation of sudan red Ⅲ by ammonium peroxodisulfate ((NH4)2S2O8) with nitrilo triaeetic acid as an activator in microemulsion and H2SO4 medium.Under optimum conditions,there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au(Ⅲ) at 520 nm.The relative standard deviation was 3.0% with a correlation coefficient of 0.9986.The detection limit achieved was 9.75×10-5 μg/mL.A new method using a column packed with sulfhydryl dextrose gel (SDG) as a solid-phase extraetant has been developed for the preeoncentration and separation of Au(Ⅲ) ions.The method has been applied to the determination of trace gold with satisfactory results.

  2. The development of TXRF method and its application on the study of trace elements in water at SSRF

    Science.gov (United States)

    Wang, L. L.; Yu, H. S.; Li, L. N.; Wei, X. J.; Huang, Y. Y.

    2016-05-01

    The objective of this study is the development of Total Reflection X-ray Fluorescence (TXRF) method at Shanghai Synchrotron Radiation Facility (SSRF). In this paper, the SR-TXRF setup and the related experimental methods and results for the determination of trace elements in water were described. Compared with the conventional lab TXRF, the detection limits obtained in our experiment are very lower due to the advantages of synchrotron radiation, which varied from 1.11 pg (Cr) to 0.28 pg (Zn). The average deviation of the specimen replicates is below 5%, and the deviations of measured element concentrations for Cr, Mn, Co, Ni and Cu by SR-TXRF are within 10% compared with the values by ICP-MS, so our TXRF results are agreed with those obtained by ICP-MS for the detected metals. Based on the results, the SR-TXRF setup and method have been feasible for the quantitative analysis of multi-elements in water at SSRF and that will play an important role in the research area for the environmental liquid samples analysis.

  3. Novel method for the production of spin-aligned RI beams in projectile fragmentation reaction with the dispersion matching technique

    International Nuclear Information System (INIS)

    A novel method to produce spin-aligned rare-isotope (RI) beam has been developed, that is the two-step projectile fragmentation method with a technique of dispersion matching. The present method was verified in an experiment at the RIKEN RIBF, where an RI beam of 32Al with spin alignment of 8(1) % was successfully produced from a primary beam of 48Ca, with 33Al as an intermediate nucleus. Figure of merit of the present method was found to be improved by a factor larger than 50 compared with a conventional method employing single-step projectile fragmentation.

  4. Novel method for the production of spin-aligned RI beams in projectile fragmentation reaction with the dispersion matching technique

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Y., E-mail: yuichikawa@phys.titech.ac.jp [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H. [RIKEN Nishina Center (Japan); Ishii, Y. [Tokyo Institute of Technology, Department of Physics (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Yoshimi, A. [Okayama University, Research Core for Extreme Quantum World (Japan); Kameda, D.; Watanabe, H.; Aoi, N. [RIKEN Nishina Center (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Balabanski, D. L. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Chevrier, R.; Daugas, J. M. [CEA, DAM, DIF (France); Fukuda, N. [RIKEN Nishina Center (Japan); Georgiev, G. [CSNSM, IN2P3-CNRS, Universite Paris-sud (France); Hayashi, H.; Iijima, H. [Tokyo Institute of Technology, Department of Physics (Japan); Inabe, N. [RIKEN Nishina Center (Japan); Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Ishihara, M.; Kubo, T. [RIKEN Nishina Center (Japan); and others

    2013-05-15

    A novel method to produce spin-aligned rare-isotope (RI) beam has been developed, that is the two-step projectile fragmentation method with a technique of dispersion matching. The present method was verified in an experiment at the RIKEN RIBF, where an RI beam of {sup 32}Al with spin alignment of 8(1) % was successfully produced from a primary beam of {sup 48}Ca, with {sup 33}Al as an intermediate nucleus. Figure of merit of the present method was found to be improved by a factor larger than 50 compared with a conventional method employing single-step projectile fragmentation.

  5. A new method for designing dual foil electron beam forming systems. II. Feasibility of practical implementation of the method

    Science.gov (United States)

    Adrich, Przemysław

    2016-05-01

    In Part I of this work a new method for designing dual foil electron beam forming systems was introduced. In this method, an optimal configuration of the dual foil system is found by means of a systematic, automatized scan of system performance in function of its parameters. At each point of the scan, Monte Carlo method is used to calculate the off-axis dose profile in water taking into account detailed and complete geometry of the system. The new method, while being computationally intensive, minimizes the involvement of the designer. In this Part II paper, feasibility of practical implementation of the new method is demonstrated. For this, a prototype software tools were developed and applied to solve a real life design problem. It is demonstrated that system optimization can be completed within few hours time using rather moderate computing resources. It is also demonstrated that, perhaps for the first time, the designer can gain deep insight into system behavior, such that the construction can be simultaneously optimized in respect to a number of functional characteristics besides the flatness of the off-axis dose profile. In the presented example, the system is optimized in respect to both, flatness of the off-axis dose profile and the beam transmission. A number of practical issues related to application of the new method as well as its possible extensions are discussed.

  6. A Numerical Method for Cavity Identification in Beams on an Elastic Foundation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An analytical solution for the natural frequencies of a beam containing a cavity on an elastic foundation is presented. Based on the analytical solution, a numerical method for identifying cavities in the foundation is developed. The position and size of the cavities are identified by minimizing an objective function, which is formulated according to the difference between the computed and measured natural frequencies of the system. The conjugate gradient algorithm is adopted for minimizing the objective function. Some numerical examples are presented to demonstrate the applicability of the presented cavity determination method. The results show that the presented method can be used to identify the cavity position and size conveniently and efficiently.

  7. Development and validation of a laser-induced breakdown spectroscopic method for ultra-trace determination of Cu, Mn, Cd and Pb metals in aqueous droplets after drying.

    Science.gov (United States)

    Aras, Nadir; Yalçın, Şerife

    2016-03-01

    The present study reports a fast and accurate methodology for laser-induced breakdown spectroscopic, LIBS, analysis of aqueous samples for environmental monitoring purposes. This methodology has two important attributes: one is the use of a 300nm oxide coated silicon wafer substrate (Si+SiO2) for the first time for manual injection of 0.5 microliter aqueous metal solutions, and two is the use of high energy laser pulses focused outside the minimum focus position of a plano convex lens at which relatively large laser beam spot covers the entire droplet area for plasma formation. Optimization of instrumental LIBS parameters like detector delay time, gate width and laser energy has been performed to maximize atomic emission signal of target analytes; Cu, Mn, Cd and Pb. Under the optimal conditions, calibration curves were constructed and enhancements in the LIBS emission signal were obtained compared to the results of similar studies given in the literature. The analytical capability of the LIBS technique in liquid analysis has been improved. Absolute detection limits of 1.3pg Cu, 3.3pg Mn, 79pg Cd and 48pg Pb in 0.5 microliter volume of droplets were obtained from single shot analysis of five sequential droplets. The applicability of the proposed methodology to real water samples was tested on the Certified Reference Material, Trace Metals in Drinking Water, CRM-TMDW and on ICP multi-element standard samples. The accuracy of the method was found at a level of minimum 92% with relative standard deviations of at most 20%. Results suggest that 300nm oxide coated silicon wafer has an excellent potential to be used as a substrate for direct analysis of contaminants in water supplies by LIBS and further research, development and engineering will increase the performance and applicability of the methodology. PMID:26717813

  8. Preparation of PbSe nanoparticles by electron beam irradiation method

    Indian Academy of Sciences (India)

    Zhen Li; Chao Wu; Yanyan Liu; Tiebing Liu; Zheng Jiao; Minghong Wu

    2008-11-01

    A novel method has been developed by electron beam irradiation to prepare PbSe nanoparticles. 2 MeV 10mA GJ-2-II electronic accelerator was used as radiation source. Nanocrystalline PbSe was prepared rapidly at room temperature under atmospheric pressure without any kind of toxic reagents. The structure and morphology of prepared PbSe nanoparticles were analysed by X-ray diffraction, transmission electron microscope and atomic force microscope. The results indicated that the obtained materials were cubic nanocrystalline PbSe with an average grain size of 30 nm. The optical properties of prepared PbSe nanocrystalline were characterized by using photoluminescence spectroscopy. The possible mechanism of the PbSe grain growth by electron beam irradiation method is proposed.

  9. Generation of Shaped beam Radiation patterns from a Line source using Iterative sampling method

    Directory of Open Access Journals (Sweden)

    G.R.L.V.N.Srinivasa Raju

    2013-08-01

    Full Text Available For the generation of cosecant and trapezoidal radiation patterns an iterative sampling method is introduced by Stutzman. In this paper, an original radiation pattern which is some approximation to the desired radiation pattern is generated by a standard synthesis method and a series of correction patterns are applied to it by addinga correction pattern. This process is continued until the desired performance is achieved. In the present work, ramp, sector, cosecant, trapezoidal and stair stepped radiation patterns are generated using iterative procedure. The current distribution is found after corrections are applied. Studies are made with good number of examples, which showed that patterns with low side lobe level or low main beam ripple or sharp cut off from the main beam can be obtained. An iterative procedure is simple and converges rapidly.

  10. In situ baking method for degassing of a kicker magnet in accelerator beam line

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Junichiro, E-mail: kamiya.junichiro@jaea.go.jp; Ogiwara, Norio; Yanagibashi, Toru; Kinsho, Michikazu [Japan Atomic Energy Agency, J-PARC Center, Ooaza Shirakata 2-4, Tokai, Naka, Ibaraki 319-1195 (Japan); Yasuda, Yuichi [SAKAGUCHI E.H VOC CORP., Sakura Dai-san Kogyodanchi 1-8-6, Osaku, Sakura, Chiba 285-0802 (Japan)

    2016-03-15

    In this study, the authors propose a new in situ degassing method by which only kicker magnets in the accelerator beam line are baked out without raising the temperature of the vacuum chamber to prevent unwanted thermal expansion of the chamber. By simply installing the heater and thermal radiation shield plates between the kicker magnet and the chamber wall, most of the heat flux from the heater directs toward the kicker magnet. The result of the verification test showed that each part of the kicker magnet was heated to above the target temperature with a small rise in the vacuum chamber temperature. A graphite heater was selected in this application to bake-out the kicker magnet in the beam line to ensure reliability and easy maintainability of the heater. The vacuum characteristics of graphite were suitable for heater operation in the beam line. A preliminary heat-up test conducted in the accelerator beam line also showed that each part of the kicker magnet was successfully heated and that thermal expansion of the chamber was negligibly small.

  11. Establishment of the method for profile evaluation in matter using the therapeutic carbon pencil beam

    International Nuclear Information System (INIS)

    The scanning irradiation of the pencil beam is superior in comparison to the conventional extended-field irradiation in dose concentration. The carbon pencil beam spreads its profile in matter. The factors that cause the profile change are the nuclear fragmentation reactions and the multiple Coulomb scatterings. The fragmentation reaction is a type of nuclear reactions, where the high-energy incident particles interact with target nuclei and fragment the incident particles themselves or the target nucleus. In order to improve the accuracy of the treatment planning for the carbon beam, it is necessary to evaluate quantitatively the effect of the nuclear fragmentation reactions. The objective of this study is to establish the evaluation method for the carbon pencil beam profile in matter by selectively acquiring the nuclear fragmentation reactions and the multiple Coulomb scattering. This experiment was proposed to carry out in three years. Events with the nuclear fragmentation reactions and the multiple Coulomb scatterings were separately identified by a dedicated detector devised by our group. Profiles of these events were successfully measured. (author)

  12. Deflection of a monochromatic THz beam by acousto-optic methods

    International Nuclear Information System (INIS)

    The possibility of controlled deflection of an electromagnetic THz beam of a free-electron laser by acousto-optic (AO) methods has been demonstrated for the first time. The material of the AO deflector was chosen to be single-crystal germanium, which has a fairly large refractive index (n = 4.0) and a relatively low absorption coefficient for electromagnetic waves. The absorption coefficient α in germanium is 0.75 ± 0.02 cm-1 at a wavelength λ = 140 μm. The diffracted beam intensity is shown to be maximum at an effective AO interaction length l = 1/α. A diffraction efficiency of 0.05% at a travelling acoustic wave power of 1.0 W is experimentally obtained. It is established that a change in the ultrasonic frequency from 25 to 39 MHz leads to variation in the external Bragg angle in the range from 19.5° to 27.5°. At a fixed Bragg angle θB = 22.4° the frequency band of diffraction is 4.2 ± 0.1 MHz and the angular range of laser beam scanning reaches 2.5° ± 0.5°. The results obtained indicate that AO interaction can be used for controlled deflection of electromagnetic THz beams. (terahertz radiation)

  13. A design method for two-layer beams consisting of normal and fibered high strength concrete

    International Nuclear Information System (INIS)

    Two-layer fibered concrete beams can be analyzed using conventional methods for composite elements. The compressed zone of such beam section is made of high strength concrete (HSC), and the tensile one of normal strength concrete (NSC). The problems related to such type of beams are revealed and studied. An appropriate depth of each layer is prescribed. Compatibility conditions between HSC and NSC layers are found. It is based on the shear deformations equality on the layers border in a section with maximal depth of the compression zone. For the first time a rigorous definition of HSC is given using a comparative analysis of deformability and strength characteristics of different concrete classes. According to this definition, HSC has no download branch in the stress-strain diagram, the stress-strain function has minimum exponent, the ductility parameter is minimal and the concrete tensile strength remains constant with an increase in concrete compression strength. The application fields of two-layer concrete beams based on different static schemes and load conditions make known. It is known that the main disadvantage of HSCs is their low ductility. In order to overcome this problem, fibers are added to the HSC layer. Influence of different fiber volume ratios on structural ductility is discussed. An upper limit of the required fibers volume ratio is found based on compatibility equation of transverse tensile concrete deformations and deformations of fibers

  14. Electron beam irradiation as a method to modify the wheat starch characteristics

    International Nuclear Information System (INIS)

    Full text: Starch is a renewable bioresource with wide range of potential applications. At present time, considerable efforts are made worldwide with respect to research and mainly to development of processes for treating and modifying of different starches in order to extend their industrial applicability. Our previous work proved the potential of the electron beam irradiation to modify the functional properties of maize starch. The aim of this work is to investigate the possibility to use the electron beam irradiation to change some characteristics of wheat starch. The physicochemical and structural characteristics of the irradiated wheat starch are analyzed in comparison to the native wheat starch ones. The electron beam irradiation lead to the reduction of the paste pH, clarity and apparent viscosity as the absorbed dose increase, while the thermal stability is not affected. Also, changes at the structure level in the irradiated starch can be observed. Electron beam irradiation may be an alternative method to modify some of the wheat starch properties

  15. Deflection of a monochromatic THz beam by acousto-optic methods

    Energy Technology Data Exchange (ETDEWEB)

    Voloshinov, V B; Nikitin, P A [Department of Physics, M.V. Lomonosov Moscow State University (Russian Federation); Gerasimov, V V; Choporova, Yu Yu [G.I. Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation); Knyazev, B A [Novosibirsk National Research State University, Novosibirsk (Russian Federation)

    2013-12-31

    The possibility of controlled deflection of an electromagnetic THz beam of a free-electron laser by acousto-optic (AO) methods has been demonstrated for the first time. The material of the AO deflector was chosen to be single-crystal germanium, which has a fairly large refractive index (n = 4.0) and a relatively low absorption coefficient for electromagnetic waves. The absorption coefficient α in germanium is 0.75 ± 0.02 cm{sup -1} at a wavelength λ = 140 μm. The diffracted beam intensity is shown to be maximum at an effective AO interaction length l = 1/α. A diffraction efficiency of 0.05% at a travelling acoustic wave power of 1.0 W is experimentally obtained. It is established that a change in the ultrasonic frequency from 25 to 39 MHz leads to variation in the external Bragg angle in the range from 19.5° to 27.5°. At a fixed Bragg angle θ{sub B} = 22.4° the frequency band of diffraction is 4.2 ± 0.1 MHz and the angular range of laser beam scanning reaches 2.5° ± 0.5°. The results obtained indicate that AO interaction can be used for controlled deflection of electromagnetic THz beams. (terahertz radiation)

  16. PReBeaM FOR PLANCK: A POLARIZED REGULARIZED BEAM DECONVOLUTION MAP-MAKING METHOD

    International Nuclear Information System (INIS)

    We describe a maximum-likelihood regularized beam deconvolution map-making algorithm for data from high-resolution, polarization-sensitive instruments, such as the Planck data set. The resulting algorithm, which we call PReBeaM, is pixel-free and solves for the map directly in spherical harmonic space, avoiding pixelization artifacts. While Fourier methods like ours are expected to work best when applied to smooth, large-scale asymmetric beam systematics (such as far-side lobe effects), we show that our m-truncated spherical harmonic representation of the beam results in negligible reconstruction error-even for m as small as 4 for a polarized elliptically asymmetric beam. We describe a hybrid OpenMP/MPI parallelization scheme which allows us to store and manipulate the time-ordered data from satellite instruments with a typical full-sky scanning strategy. Finally, we apply our technique to noisy data and show that it succeeds in removing visible power spectrum artifacts without generating excess noise on small scales.

  17. Research of photon beam dose deposition kernel based on Monte Carlo method

    International Nuclear Information System (INIS)

    Using Monte Carlo program BEAMnrc to simulate Siemens accelerator 6 MV photon beam, using BEAMdp program to analyse the energy spectrum distribution and mean energy from phase space data of different field sizes, then building beam source, energy spectrum and mono-energy source, to use DOSXYZnrc program to calculate the dose deposition kernels at dmax in standard water phantom with different beam sources and make comparison with different dose deposition kernels. The results show that the dose difference using energy spectrum source is small, the maximum percentage dose discrepancy is 1.47%, but it is large using mono-energy source, which is 6.28%. The maximum dose difference for the kernels derived from energy spectrum source and mono-energy source of the same field is larger than 9%, up to 13.2%. Thus, dose deposition has dependence on photon energy, it can lead to larger errors only using mono-energy source because of the beam spectrum distribution of accelerator. A good method to calculate dose more accurately is to use deposition kernel of energy spectrum source. (authors)

  18. An inverse finite element method for beam shape sensing: theoretical framework and experimental validation

    International Nuclear Information System (INIS)

    Shape sensing, i.e., reconstruction of the displacement field of a structure from surface-measured strains, has relevant implications for the monitoring, control and actuation of smart structures. The inverse finite element method (iFEM) is a shape-sensing methodology shown to be fast, accurate and robust. This paper aims to demonstrate that the recently presented iFEM for beam and frame structures is reliable when experimentally measured strains are used as input data. The theoretical framework of the methodology is first reviewed. Timoshenko beam theory is adopted, including stretching, bending, transverse shear and torsion deformation modes. The variational statement and its discretization with C0-continuous inverse elements are briefly recalled. The three-dimensional displacement field of the beam structure is reconstructed under the condition that least-squares compatibility is guaranteed between the measured strains and those interpolated within the inverse elements. The experimental setup is then described. A thin-walled cantilevered beam is subjected to different static and dynamic loads. Measured surface strains are used as input data for shape sensing at first with a single inverse element. For the same test cases, convergence is also investigated using an increasing number of inverse elements. The iFEM-recovered deflections and twist rotations are then compared with those measured experimentally. The accuracy, convergence and robustness of the iFEM with respect to unavoidable measurement errors, due to strain sensor locations, measurement systems and geometry imperfections, are demonstrated for both static and dynamic loadings. (paper)

  19. Impact resonance method for damage detection in RC beams strengthened with composites

    Science.gov (United States)

    Gheorghiu, Catalin; Rhazi, Jamal E.; Labossiere, Pierre

    2005-05-01

    There are numerous successful applications of fibre-reinforced composites for strengthening the civil engineering infrastructure. Most of these repairs are being continuously or intermittently monitored for assessing their effectiveness and safety. The impact resonance method (IRM), a non-destructive technique, utilized in civil engineering exclusively for determining the dynamic concrete properties, could be a valuable and viable damage detection tool for structural elements. The IRM gives useful information about the dynamic characteristics of rectangular and circular concrete members such as beams and columns. In this experimental program, a 1.2-m-long reinforced concrete beam strengthened with a carbon fibre-reinforced polymer (CFRP) plate has been employed. The CFRP-strengthened beam has been loaded in fatigue for two million cycles at 3 Hz. The load amplitude was from 15 to 35% of the anticipated yielding load of the beam. Throughout fatigue testing the cycling was stopped for IRM measurements to be taken. The obtained data provided information about changes in modal properties such as natural frequencies of vibration. These results have shown the successful use of the IRM for detecting fatigue damage in concrete members strengthened with composites.

  20. VIBRATION ANALYSIS ON A COMPOSITE BEAM TO IDENTIFY DAMAGE AND DAMAGE SEVERITY USING FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    E.V.V.Ramanamurthy

    2011-07-01

    Full Text Available The objective of this paper is to develop a damage detection method in a composite cantilever beam with an edge crack has been studied using finite element method. A number of analytical, numerical andexperimental techniques are available for the study of damage identification in beams. Studies were carried out for three different types of analysis on a composite cantilever beam with an edge crack as damage. The material used in this analysis is glass-epoxy composite material. The finite element formulation was carried out in the analysis section of the package, known as ANSYS. The types of vibration analysis studied on a composite beam are Modal, Harmonic andTransient analysis. The crack is modeled such that the cantilever beam is replaced with two intact beams with the crack as additional boundary condition. Damage algorithms are used to identify and locate the damage. Damage index method is also used to find the severity of the damage. The results obtained from modal analysis were compared with the transient analysis results.The vibration-based damage detection methods are based on the fact that changes of physical properties (stiffness, mass and damping due to damage will manifest themselves as changes in the structural modal parameters (natural frequencies, mode shapes and modal damping. The task is then to monitor the selected indicators derived from modal parameters to distinguish between undamaged and damaged states. However, the quantitative changes of global modal parameters are not sufficiently sensitive to a local damage. The proposed approach, on the other hand, interprets the dynamic changes caused by damage in a different way. Although the basis for vibration-based damage detection appears intuitive, the implementation in real structures may encounter many significant challenges. The most fundamental issue is the fact that damage typically is a local phenomenon and may not dramatically influence the global dynamic response of a

  1. Complexity Theory of Beam Halo-Chaos and Its Control Methods With Prospective Applications

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This article offers an overview and comprehensive survey of the complexity theory of beamhalo-chaos and its control methods with prospective applications. In recent years, there has been growinginterest in proton beams of high power linear accelerator due to its attractive features in possiblebreakthrough applications, such as production of nuclear materials (e.g., tritium, transforming 232Th to233U), transmutation of radioactive wastes, productions of radioactive isotopes for medical use, heavy ion

  2. A method for the dimensioning of a cantileva-beam submitted to aleatory effects

    International Nuclear Information System (INIS)

    The laboratory study of behavior of materials, related to fatigue, is generally done by applying constant amplitude sine wave excitation. The data can be used for the stochastic approach of the problem. One of the methods is called RCA, which incorporates the Linear Rule or Miner's Cumulative Damage Rule. A summary of the theory and a computer program for the calculations are here presented. A cantilever beam is studied as a numerical example and the results are discussed. (Author)

  3. Modeling Liquid-Crystal Devices with the Three-Dimensional Full-Vector Beam Propagation Method

    OpenAIRE

    Wang, Qian; Farrell, Gerald; Semenova, Yuliya

    2006-01-01

    Simulation of light propagation within nematic liquid-crystal (LC) devices is considered, of which the director is aligned normal to the z axis. A three-dimensional full-vector finite-difference beam propagation method for an anisotropic medium is presented and an alternating direction implicit scheme is adopted. Simulations of light propagation in a bulk polarization converter, a waveguide with a LC covering layer, and an integrated polarization splitter and optical switch are presented. Com...

  4. Robust methods for automatic image-to-world registration in cone-beam CT interventional guidance

    OpenAIRE

    Dang, H; Otake, Y.; Schafer, S.; Stayman, J. W.; Kleinszig, G.; Siewerdsen, J. H.

    2012-01-01

    Purpose: Real-time surgical navigation relies on accurate image-to-world registration to align the coordinate systems of the image and patient. Conventional manual registration can present a workflow bottleneck and is prone to manual error and intraoperator variability. This work reports alternative means of automatic image-to-world registration, each method involving an automatic registration marker (ARM) used in conjunction with C-arm cone-beam CT (CBCT). The first involves a Known-Model re...

  5. Determination of trace elements in human hair, kidney and liver by the method of proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The content of trace elements in normal human hair, liver and kidney is determined by the method of proton induced X-ray emission (PIXE) analysis. Sampling, specimen preparation and experimental procedures are described in detail. The accuracy of the system has been checked up with the determination of standard reference materials. The preliminary results on correlations between trace elements in human tissues are discussed. Application of the method described in the paper gives evidence in favour of the PIXE as a good tool for investigation of biological medicine

  6. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ashkenani, Hamid [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Dadfarnia, Shayessteh [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of)], E-mail: sdadfarnia@yazduni.ac.ir; Shabani, Ali Mohammad Haji; Jaffari, Abbas Ali [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Behjat, Abbas [Department of physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2009-01-15

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg{sup 2+} ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg{sup +} into Hg{sup 2+} ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 {mu}g l{sup -1} (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l{sup -1}. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment.

  7. A modified time-of-flight method for precise determination of high speed ratios in molecular beams

    International Nuclear Information System (INIS)

    Time-of-flight (TOF) is a standard experimental technique for determining, among others, the speed ratio S (velocity spread) of a molecular beam. The speed ratio is a measure for the monochromaticity of the beam and an accurate determination of S is crucial for various applications, for example, for characterising chromatic aberrations in focussing experiments related to helium microscopy or for precise measurements of surface phonons and surface structures in molecular beam scattering experiments. For both of these applications, it is desirable to have as high a speed ratio as possible. Molecular beam TOF measurements are typically performed by chopping the beam using a rotating chopper with one or more slit openings. The TOF spectra are evaluated using a standard deconvolution method. However, for higher speed ratios, this method is very sensitive to errors related to the determination of the slit width and the beam diameter. The exact sensitivity depends on the beam diameter, the number of slits, the chopper radius, and the chopper rotation frequency. We present a modified method suitable for the evaluation of TOF measurements of high speed ratio beams. The modified method is based on a systematic variation of the chopper convolution parameters so that a set of independent measurements that can be fitted with an appropriate function are obtained. We show that with this modified method, it is possible to reduce the error by typically one order of magnitude compared to the standard method

  8. A modified time-of-flight method for precise determination of high speed ratios in molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Salvador Palau, A.; Eder, S. D., E-mail: sabrina.eder@uib.no; Kaltenbacher, T.; Samelin, B.; Holst, B. [Department of Physics and Technology, University of Bergen, Allégaten 55, 5007 Bergen (Norway); Bracco, G. [Department of Physics and Technology, University of Bergen, Allégaten 55, 5007 Bergen (Norway); CNR-IMEM, Department of Physics, University of Genova, V. Dodecaneso 33, 16146 Genova (Italy)

    2016-02-15

    Time-of-flight (TOF) is a standard experimental technique for determining, among others, the speed ratio S (velocity spread) of a molecular beam. The speed ratio is a measure for the monochromaticity of the beam and an accurate determination of S is crucial for various applications, for example, for characterising chromatic aberrations in focussing experiments related to helium microscopy or for precise measurements of surface phonons and surface structures in molecular beam scattering experiments. For both of these applications, it is desirable to have as high a speed ratio as possible. Molecular beam TOF measurements are typically performed by chopping the beam using a rotating chopper with one or more slit openings. The TOF spectra are evaluated using a standard deconvolution method. However, for higher speed ratios, this method is very sensitive to errors related to the determination of the slit width and the beam diameter. The exact sensitivity depends on the beam diameter, the number of slits, the chopper radius, and the chopper rotation frequency. We present a modified method suitable for the evaluation of TOF measurements of high speed ratio beams. The modified method is based on a systematic variation of the chopper convolution parameters so that a set of independent measurements that can be fitted with an appropriate function are obtained. We show that with this modified method, it is possible to reduce the error by typically one order of magnitude compared to the standard method.

  9. Ultra-trace quantification method for chlordecone in human fluids and tissues.

    Science.gov (United States)

    Bichon, Emmanuelle; Guiffard, Ingrid; Vénisseau, Anaïs; Marchand, Philippe; Antignac, Jean-Philippe; Le Bizec, Bruno

    2015-08-21

    Chlordecone is an organochlorine pesticide (OCP) considered as a Persistent Organic Pollutant (POP) as it persists in the environment, bio-accumulates through the food web, causes adverse effects to human health and the environment and transports across international boundaries far from its sources. The atypical physico-chemical properties of chlordecone make its inclusion in classical analytical approaches non applicable. The aim of our work was to include chlordecone in a multi organochlorine residue method preventing any degradation during the analytical process and thus allowing quantification at ppt (ngkg(-1) or ngL(-1)) levels for a wide range of OCPs in breast milk, human serum and adipose tissue. After GC-HRMS vs. MS/MS and EI vs. APCI comparisons, the major improvement in terms of sensitivity was found in decreasing the length and film thickness of the gas chromatography column. Thanks to a linear correlation between relative response and quantity of chlordecone injected, LC-(ESI-)-MS/MS was finally preferred. An acetonitrile based gradient optimized on a C30 coreshell HPLC column has led to reaching limits of quantification as low as 8ngL(-1), 25pgmL(-1) and 0.2ngg(-1) fat for breast milk, serum and adipose tissue, respectively, allowing multiresidue OCP quantification at concentration levels compatible with biomonitoring purposes and pre-requisites. PMID:26184709

  10. Proceedings of Tracer 3. International Conference on Tracers and Tracing Methods

    International Nuclear Information System (INIS)

    Tracer 3 conference is a continuation of former Tracer 1 (1998) and Tracer 2 (2001) conferences organized by CNRS - Nancy France. The objective of this 3rd conference is presentation of different aspects of tracer method applications and development of tracer methodology.The new field of activity presented at the Conference was application of stable isotopes as natural tracers for investigations of environmental processes. The conference gave the possibility for scientific information exchange between specialists from different fields of activity such as chemical engineering, chemistry, bioengineering, environmental engineering, hydrology, civil engineering, metallurgy, etc. The presentations were divided into groups covering the principal items of Conference. Section A. Fundamental development - RTD and tracer methodology, - RTD methodology and Computational Fluid Dynamics (CFD), - New tracers and detectors. Section B. Industrial applications - Environment, - Geology, hydrogeology and oil field applications, - Civil engineering, mineral engineering and metallurgy applications, - Food engineering and bioengineering, - Material engineering, - Chemical engineering. During the Conference INIS promotion materials were exposed by INIS liaison officer for Poland

  11. Frequency Modulated Spectroscopy (FMS) - A Novel Method for Standoff Trace Gas Detection

    Science.gov (United States)

    Fessenden, J. E.; Clegg, S. M.; Nowak-Lovato, K.; Martinez, R.; Dobeck, L. M.; Spangler, L.

    2015-12-01

    Geologic storage of carbon rich gases captured from the emissions of fossil fuel combustion is a promising option to mitigate against greenhouse warming scenarios. Monitoring surface gas seepage is a strategy to create a successful geologic storage facility. At Los Alamos National Laboratory, new laser systems have been engineered which can measure concentration and isotope ratios of CO2, CH4, and H2S in real time and up to 1 km distances. These systems can work in closed and open path (LIght Detection And Ranging or LIDAR) settings where we use Frequency Modulated Spectroscopy (FMS) to measure the harmonics of the primary absorption peak for CO2, CH4, and H2S absorptions. This provides between 100-1000 times sensitivity to allow for small concentrations or low abundance isotopes to be observed at distance. We tested these systems at various locations around Los Alamos National Laboratory and at the ZERT Controlled Release site in Bozeman Montana. Results show pollution signatures, ecologically productive fluxes, and carbon storage signatures depending upon location monitored. We will present these results and share unique features of this novel system. Remote detection of concentration and isotope profiles of greenhouse and toxic gases can provide a new method for stand-off detection and mapping of gas in the environment. For geologic storage scenarios, this will allow for larger areas to be interrogated for subsurface CO2 leak detection and can accelerate the Monitoring Verification and Accounting (MVA) mission goals for the Carbon Sequestration and Storage (CCS) communities.

  12. Trace elements determination in silicon and ferrosilicon reference materials by instrumental neutron activation analysis method

    International Nuclear Information System (INIS)

    The use of certified reference materials, CRM, is of uppermost importance in the rastreability realization of the measurement process. At times, CRM use is restricted by the non existence of a suitable CRM with similarity to the sample in respect to matrix composition or with element levels in different orders of magnitude. IPT Chemical Division launched a project to prepare a metallic silicon CRM, due to the requirements of the industries in this field. To characterize this new CRM, IPEN Nuclear Reactor Center is able to perform instrumental neutron activation analysis, INAA, a very suitable method for silicon matrix samples because they produce basically the short lived radionuclide 31 Si under thermal neutrons flux, which after radioactive decay, does not interfere in the determination of other elements. In this paper, it is presented the determination of As, Br, Co, Cr, K, Eu, Fe, La, Mn, Na Nb, Sb, Sm, Sc, Th, Tb, U, V, W and Yb in silicon CRM NBS SRM 57; ferrosilicon CRM IPT 56; IPT 70; NBS SRM 58a; NBS SRM 59a and silicon RM under preparation IPT 132. From the results, the accuracy and the precision of the process were assessed. (author)

  13. SU-E-J-126: An Online Replanning Method for FFF Beams Without Couch Shift

    Energy Technology Data Exchange (ETDEWEB)

    Ahunbay, E; Ates, O; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2015-06-15

    Purpose: In a situation that couch shift for patient positioning is not preferred or prohibited (e.g., MR-Linac), segment aperture morphing (SAM) can address target dislocation and deformation. For IMRT/VMAT with flattening filter free (FFF) beams, however, SAM method would lead to an adverse translational dose effect due to the beam unflattening. Here we propose a new 2-step process to address both the translational effect of FFF beams and the target deformation. Methods: The replanning method consists of an offline and an online steps. The offline step is to create a series of pre-shifted plans (PSP) obtained by a so called “warm start” optimization (starting optimization from the original plan, rather from scratch) at a series of isocenter shifts with fixed distance (e.g. 2 cm, at x,y,z = 2,0,0 ; 2,2,0 ; 0,2,0; …;− 2,0,0). The PSPs all have the same number of segments with very similar shapes, since the warm-start optimization only adjusts the MLC positions instead of regenerating them. In the online step, a new plan is obtained by linearly interpolating the MLC positions and the monitor units of the closest PSPs for the shift determined from the image of the day. This two-step process is completely automated, and instantaneously fast (no optimization or dose calculation needed). The previously-developed SAM algorithm is then applied for daily deformation. We tested the method on sample prostate and pancreas cases. Results: The two-step interpolation method can account for the adverse dose effects from FFF beams, while SAM corrects for the target deformation. The whole process takes the same time as the previously reported SAM process (5–10 min). Conclusion: The new two-step method plus SAM can address both the translation effects of FFF beams and target deformation, and can be executed in full automation requiring no additional time from the SAM process. This research was supported by Elekta inc. (Crawley, UK)

  14. SU-E-J-126: An Online Replanning Method for FFF Beams Without Couch Shift

    International Nuclear Information System (INIS)

    Purpose: In a situation that couch shift for patient positioning is not preferred or prohibited (e.g., MR-Linac), segment aperture morphing (SAM) can address target dislocation and deformation. For IMRT/VMAT with flattening filter free (FFF) beams, however, SAM method would lead to an adverse translational dose effect due to the beam unflattening. Here we propose a new 2-step process to address both the translational effect of FFF beams and the target deformation. Methods: The replanning method consists of an offline and an online steps. The offline step is to create a series of pre-shifted plans (PSP) obtained by a so called “warm start” optimization (starting optimization from the original plan, rather from scratch) at a series of isocenter shifts with fixed distance (e.g. 2 cm, at x,y,z = 2,0,0 ; 2,2,0 ; 0,2,0; …;− 2,0,0). The PSPs all have the same number of segments with very similar shapes, since the warm-start optimization only adjusts the MLC positions instead of regenerating them. In the online step, a new plan is obtained by linearly interpolating the MLC positions and the monitor units of the closest PSPs for the shift determined from the image of the day. This two-step process is completely automated, and instantaneously fast (no optimization or dose calculation needed). The previously-developed SAM algorithm is then applied for daily deformation. We tested the method on sample prostate and pancreas cases. Results: The two-step interpolation method can account for the adverse dose effects from FFF beams, while SAM corrects for the target deformation. The whole process takes the same time as the previously reported SAM process (5–10 min). Conclusion: The new two-step method plus SAM can address both the translation effects of FFF beams and target deformation, and can be executed in full automation requiring no additional time from the SAM process. This research was supported by Elekta inc. (Crawley, UK)

  15. Development of a method for detecting trace metals in aqueous solutions based on the coordination chemistry of hexahydrotriazines.

    Science.gov (United States)

    Wojtecki, Rudy J; Yuen, Alexander Y; Zimmerman, Thomas G; Jones, Gavin O; Horn, Hans W; Boday, Dylan J; Hedrick, James L; García, Jeannette M

    2015-08-01

    The detection of trace amounts (indicators and a low cost fluorimeter-based detection system. This method takes advantage of the inherent properties of HTs to coordinate strongly with metal ions in solution, a fundamental property that was studied using a combination of analytical tools (UV-Vis titrations, (1)H-NMR titrations and computational modeling). Based on these fundamental studies that show significant changes in the HT UV signature when a metal ion is present, HT compounds were used to prepare indicator strips that resulted in significant fluorescence changes when a metal was present. A portable and economical approach was adopted to test the concept of utilizing HTs to detect heavy metals using a fluorimeter system that consisted of a low-pressure mercury lamp, a photo-detector, a monolithic photodiode and an amplifier, which produces a voltage proportional to the magnitude of the visible fluorescence emission. Readings of the prepared HT test strips were evaluated by exposure to two different heavy metals at the safe threshold concentration described by the U.S. Environmental Protection Agency (EPA) for Cr(3+) and Ag(2+) (100 μg L(-1) and 6.25, respectively). This method of detection could be used to the presence of either metal at these threshold concentrations. PMID:26035633

  16. A new and simple calibration-independent method for measuring the beam energy of a cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Katherine, E-mail: kgagnon1@ualberta.c [Cross Cancer Institute, Edmonton PET Centre, University of Alberta, Edmonton, AB, T6G 1Z2 (Canada); Jensen, Mikael; Thisgaard, Helge [Hevesy Laboratory, Risoe-DTU, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Publicover, Julia; Lapi, Suzanne [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); McQuarrie, Steve A. [Cross Cancer Institute, Edmonton PET Centre, University of Alberta, Edmonton, AB, T6G 1Z2 (Canada); Ruth, Thomas J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)

    2011-01-15

    This work recommends a new and simple-to-perform method for measuring the beam energy of an accelerator. The proposed method requires the irradiation of two monitor foils interspaced by an energy degrader. The primary advantage of the proposed method, which makes this method unique from previous energy evaluation strategies that employ the use of monitor foils, is that this method is independent of the detector efficiency calibration. This method was evaluated by performing proton activation of {sup nat}Cu foils using both a cyclotron and a tandem Van de Graaff accelerator. The monitor foil activities were read using a dose calibrator set to an arbitrary calibration setting. Excellent agreement was noted between the nominal and measured proton energies.

  17. A new and simple calibration-independent method for measuring the beam energy of a cyclotron.

    Science.gov (United States)

    Gagnon, Katherine; Jensen, Mikael; Thisgaard, Helge; Publicover, Julia; Lapi, Suzanne; McQuarrie, Steve A; Ruth, Thomas J

    2011-01-01

    This work recommends a new and simple-to-perform method for measuring the beam energy of an accelerator. The proposed method requires the irradiation of two monitor foils interspaced by an energy degrader. The primary advantage of the proposed method, which makes this method unique from previous energy evaluation strategies that employ the use of monitor foils, is that this method is independent of the detector efficiency calibration. This method was evaluated by performing proton activation of (nat)Cu foils using both a cyclotron and a tandem Van de Graaff accelerator. The monitor foil activities were read using a dose calibrator set to an arbitrary calibration setting. Excellent agreement was noted between the nominal and measured proton energies. PMID:20926304

  18. Impact of beam smoothing method on direct drive target performance for the NIF

    International Nuclear Information System (INIS)

    The impact of smoothing method on the performance of a direct drive target is modeled and examined in terms of its l-mode spectrum. In particular, two classes of smoothing methods are compared, smoothing by spectral dispersion (SSD) and the induced spatial incoherence (ISI) method. It is found that SSD using sinusoidal phase modulation (FM) results in poor smoothing at low l-modes and therefore inferior target performance at both peak velocity and ignition. Modeling of the hydrodynamic nonlinearity shows that saturation tends to reduce the difference between target performance for the smoothing methods considered. However, using SSD with more generalized phase modulation results in a smoothed spatial spectrum, and therefore target performance, which is identical to that obtained with the ISI or similar method where random phase plates are present in both methods and identical beam divergence is assumed

  19. A new source number estimation method based on the beam eigenvalue

    Institute of Scientific and Technical Information of China (English)

    JIANG Lei; CAI Ping; YANG Juan; WANG Yi-ling; XU Dan

    2007-01-01

    Most source number estimation methods based on the eigenvalues are decomposed by covariance matrix in MUSIC algorithm. To develop the source number estimation method which has lower signal to noise ratio and is suitable to both correlated and uncorrelated impinging signals, a new source number estimation method called beam eigenvalue method (BEM) is proposed in this paper.Through analyzing the space power spectrum and the correlation of the line array, the covariance matrix is constructed in a new way, which is decided by the line array shape when the signal frequency is given.Both of the theory analysis and the simulation results show that the BEM method can estimate the source number for correlated signals and can be more effective at lower signal to noise ratios than the normal source number estimation methods.

  20. Determination of trace uranium by resonance fluorescence method coupled with photo-catalytic technology and dual cloud point extraction.

    Science.gov (United States)

    Li, Jiekang; Li, Guirong; Han, Qian

    2016-12-01

    In this paper, two kinds of salophens (Sal) with different solubilities, Sal1 and Sal2, have been respectively synthesized, and they all can combine with uranyl to form stable complexes: [UO2(2+)-Sal1] and [UO2(2+)-Sal2]. Among them, [UO2(2+)-Sal1] was used as ligand to extract uranium in complex samples by dual cloud point extraction (dCPE), and [UO2(2+)-Sal2] was used as catalyst for the determination of uranium by photocatalytic resonance fluorescence (RF) method. The photocatalytic characteristic of [UO2(2+)-Sal2] on the oxidized pyronine Y (PRY) by potassium bromate which leads to the decrease of RF intensity of PRY were studied. The reduced value of RF intensity of reaction system (ΔF) is in proportional to the concentration of uranium (c), and a novel photo-catalytic RF method was developed for the determination of trace uranium (VI) after dCPE. The combination of photo-catalytic RF techniques and dCPE procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimal conditions, the linear calibration curves range for 0.067 to 6.57ngmL(-1), the linear regression equation was ΔF=438.0 c (ngmL(-1))+175.6 with the correlation coefficient r=0.9981. The limit of detection was 0.066ngmL(-1). The proposed method was successfully applied for the separation and determination of uranium in real samples with the recoveries of 95.0-103.5%. The mechanisms of the indicator reaction and dCPE are discussed. PMID:27380304

  1. New Density Estimation Methods for Charged Particle Beams With Applications to Microbunching Instability

    International Nuclear Information System (INIS)

    In this paper we discuss representations of charge particle densities in particle-in-cell (PIC) simulations, analyze the sources and profiles of the intrinsic numerical noise, and present efficient methods for their removal. We devise two alternative estimation methods for charged particle distribution which represent significant improvement over the Monte Carlo cosine expansion used in the 2d code of Bassi, designed to simulate coherent synchrotron radiation (CSR) in charged particle beams. The improvement is achieved by employing an alternative beam density estimation to the Monte Carlo cosine expansion. The representation is first binned onto a finite grid, after which two grid-based methods are employed to approximate particle distributions: (i) truncated fast cosine transform (TFCT); and (ii) thresholded wavelet transform (TWT). We demonstrate that these alternative methods represent a staggering upgrade over the original Monte Carlo cosine expansion in terms of efficiency, while the TWT approximation also provides an appreciable improvement in accuracy. The improvement in accuracy comes from a judicious removal of the numerical noise enabled by the wavelet formulation. The TWT method is then integrated into Bassi's CSR code, and benchmarked against the original version. We show that the new density estimation method provides a superior performance in terms of efficiency and spatial resolution, thus enabling high-fidelity simulations of CSR effects, including microbunching instability.

  2. New Density Estimation Methods for Charged Particle Beams With Applications to Microbunching Instability

    Energy Technology Data Exchange (ETDEWEB)

    Balsa Terzic, Gabriele Bassi

    2011-07-01

    In this paper we discuss representations of charge particle densities in particle-in-cell (PIC) simulations, analyze the sources and profiles of the intrinsic numerical noise, and present efficient methods for their removal. We devise two alternative estimation methods for charged particle distribution which represent significant improvement over the Monte Carlo cosine expansion used in the 2d code of Bassi, designed to simulate coherent synchrotron radiation (CSR) in charged particle beams. The improvement is achieved by employing an alternative beam density estimation to the Monte Carlo cosine expansion. The representation is first binned onto a finite grid, after which two grid-based methods are employed to approximate particle distributions: (i) truncated fast cosine transform (TFCT); and (ii) thresholded wavelet transform (TWT). We demonstrate that these alternative methods represent a staggering upgrade over the original Monte Carlo cosine expansion in terms of efficiency, while the TWT approximation also provides an appreciable improvement in accuracy. The improvement in accuracy comes from a judicious removal of the numerical noise enabled by the wavelet formulation. The TWT method is then integrated into Bassi's CSR code, and benchmarked against the original version. We show that the new density estimation method provides a superior performance in terms of efficiency and spatial resolution, thus enabling high-fidelity simulations of CSR effects, including microbunching instability.

  3. Application of digital image correlation method for analysing crack variation of reinforced concrete beams

    Indian Academy of Sciences (India)

    Ming-Hsiang Shih; Wen-Pei Sung

    2013-08-01

    The Digital Image Correlation (DIC) method is a fast-growing emerging technology that provides a low-cost method for measuring the strain of an object. In this study, the feasibility of using this method to observe cracks developed in reinforced concrete beams will be explored so that a practical application can be proposed. The DIC method has been applied for analysing the field of surface displacement and strain; it is not applicable for measuring non-continuous field of displacement. However, if a singular point (i.e., crack points) can be considered as the area of concentrated strain by imitating the treatment of micro-cracks using the finite element method, the region of concentrated strain field based on analyses of digital images can be applied for determining the locations of cracks. Laboratory results show that cracks developed in reinforced cement beams can be observed with a good precision using the von Mises strain field, and that smaller grids lead to clearer crack images. In addition to identifying visible cracks, the DIC image analysis will enable researchers to identify minute cracks that are not visible to naked eyes. Additionally, the DIC method has more accuracy and precision than visual observation for analysing crack loadings so that earlier warnings can be realized before cracks develop in the specimen.

  4. Analysis of trace elements in opal using PIXE

    Science.gov (United States)

    Hinrichs, Ruth; Bertol, A. P. L.; Vasconcellos, M. A. Z.

    2015-11-01

    Particle induced X-ray emission (PIXE) analysis is particularly important for the analysis of trace elements of precious samples, being one of the few methods to determine elements with ppm concentration that does not affect sample integrity. A PIXE methodology for trace element analysis in opal was developed. To avoid detector count saturation due to the high number of Si-Kα X-rays generated in the sample, several filters were employed to optimize the reduction of the Si-Kα signal, while maintaining acceptable intensities of the other relevant X-ray lines. Two proton beam energies were tested, to establish the signal to noise ratio in different X-ray energies. Spectra were fitted with the software GUPIX, using a matrix composition determined with electron beam excited energy dispersive X-ray spectrometry. Above the energy of the silicon X-ray, several trace elements were quantified.

  5. On Approximate Analytical Solutions of Nonlinear Vibrations of Inextensible Beams using Parameter-Expansion Method

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Lund, Erik; Thomsen, Ole Thybo; Barari, Amin

    2010-01-01

    In this work, an analytical method, which is referred to as Parameter-expansion Method is used to obtain the exact solution for the problem of nonlinear vibrations of an inextensible beam. It is shown that one term in the series expansion is sufficient to obtain a highly accurate solution, which is...... valid for the whole domain of the problem. A comparison of the obtained the numerical solution demonstrates that PEM is effective and convenient for solving such problems. After validation of the obtained results, the system response and stability are also discussed....

  6. Characterization of X-ray beams by attenuation method for personnel dosemeters calibration

    International Nuclear Information System (INIS)

    It has been used the attenuation method to characterize the X rays beams used for calibration of personal dosemeters at Calibration and Dosimetry Laboratory of Peruvian Institute of Nuclear Energy (IPEN). Voltages applied to the X ray tube and the additional filters have been made according to publication ANSI No.13. Half value layer, the homogeneity coefficient and mean energy were determined from attenuation data. Average relative differences of 3, 40 and 4 % respectively were found with respect to values published in ANSI No.13. Also spectral distributions and their resolutions were determined. Relative differences of 16 and 9% respectively were found in comparison with values calculated by the Montecarlo's Method. (author)

  7. Trace test

    OpenAIRE

    Leykin, Anton; Sottile, Frank

    2016-01-01

    We give a brief derivation of the trace test to verify completeness of a partial witness set of an irreducible variety in affine or projective space. We then consider the trace test for subvarieties of products of projective spaces working with multihomogeneous witness sets. We show how a dimension reduction based on Bertini's Theorem leads to a practical trace test in this case involving a curve in a small-dimensional affine space.

  8. TURTLE with MAD input (Trace Unlimited Rays Through Lumped Elements) -- A computer program for simulating charged particle beam transport systems and DECAY TURTLE including decay calculations

    International Nuclear Information System (INIS)

    TURTLE is a computer program useful for determining many characteristics of a particle beam once an initial design has been achieved, Charged particle beams are usually designed by adjusting various beam line parameters to obtain desired values of certain elements of a transfer or beam matrix. Such beam line parameters may describe certain magnetic fields and their gradients, lengths and shapes of magnets, spacings between magnetic elements, or the initial beam accepted into the system. For such purposes one typically employs a matrix multiplication and fitting program such as TRANSPORT. TURTLE is designed to be used after TRANSPORT. For convenience of the user, the input formats of the two programs have been made compatible. The use of TURTLE should be restricted to beams with small phase space. The lumped element approximation, described below, precludes the inclusion of the effect of conventional local geometric aberrations (due to large phase space) or fourth and higher order. A reading of the discussion below will indicate clearly the exact uses and limitations of the approach taken in TURTLE

  9. Calculational methods for estimating skin dose from electrons in Co-60 gamma-ray beams

    International Nuclear Information System (INIS)

    Several methods have been employed to calculate the relative contribution to skin dose due to scattered electrons in Co-60 γ-ray beams. Either the Klein--Nishina differential scattering probability is employed to determine the number and initial energy of electrons scattered into the direction of a detector, or a Gaussian approximation is used to specify the surface distribution of initial pencil electron beams created by parallel or diverging photon fields. Results of these calculations are compared with experimental data. In addition, that fraction of relative surface dose resulting from photon interactions in air alone is estimated and compared with data extrapolated from measurements at large source--surface distance (SSD). The contribution to surface dose from electrons generated in air is 50% or more of the total skin dose for SSDs greater than 80 cm

  10. Beam injection and accumulation method in storage rings for heavy ion fusion

    International Nuclear Information System (INIS)

    A combination of multiturn injection and rf stacking is proposed as an efficient beam injection method in storage rings for heavy ion fusion. Five turn injection in each transverse phase space and four rf stackings give a total of 100 stacking turns. This represents a compromise between the tolerable emittances and momentum spread in the ring. Space charge limitations and coherent beam instabilities are investigated. The most severe limit is found to be the transverse coherent instability, but this can be controlled by the use of sextupole and octupole magnetic fields. Assuming a charge exchange cross section of 1 x 10-15 cm2, the e-folding life time is estimated at 180 ms, while the stacking time is 40 ms

  11. A precise method for analyzing Bessel-like beams generated by broadband waves

    Science.gov (United States)

    Cheng, Zhiming; Wu, Fengtie; Fan, Dandan; Fang, Xiang

    2013-11-01

    The current study proposes spectrum analysis, which is a novel analytical method proposed for the first time, for analyzing Bessel-like beams generated by broadband wave. The main idea is to decompose the consecutive spectrum into an incoherent superposition of a series of different wavelengths. Integrating spheres play a significant role in spectrum analysis and a series of wavelengths matched with relative intensity can be read according to the spectrum measured by an integral ball. Moreover, the Sellmeier dispersion equation, which indicates that the refractive index can be matched with wavelength, is also employed. Combining with the Fresnel diffraction integral formula, the distribution of fields behind an axicon is obtained. Two broadband sources, including a light-emitting diode (LED) with a narrow band and a halogen lamp with a broad band, are used to generate a Bessel-like beam. The experimental results fit well with the theoretical analysis.

  12. Formation of Hard Surfacing Layers of WC-Co with Electron Beam Cladding Method

    Science.gov (United States)

    Abe, Nobuyuki; Morimoto, Junji

    Hard surfacing layers of WC-Co/Ni-base self-fluxing alloy were successfully formed on a steel substrate using an electron beam cladding method. The WC particles were densely and homogenously dispersed within the Ni-base self-fluxing alloy without porosity. The effect of the electron beam conditions on layer formation was investigated, and the cladding layer properties were examined by hardness tests, abrasive wear tests and immersion corrosion tests. It was found that the cladding layers showed higher hardness and abrasion resistance with increasing WC-Co mixing ratio, however, corrosion resistance decreased with WC-Co mixing ratio. A coating layer having high abrasive and corrosion resistance simultaneously was achieved by multiple cladding of high WC-Co mixing ratio layers after low WC-Co mixing ratio layers.

  13. Effect of Scanning Beam Profile to Fabricate Fused Fiber Tapers by CO_2 Laser Irradiation Method

    Institute of Scientific and Technical Information of China (English)

    Bayle; Fabien; Luo; Aiping; Marin; Emmanuel; Meunier; Jean-Pierre

    2003-01-01

    Beam uniformity is a crucial building block of CO2 experiments aimed at fusing and stretching optical fibers in a lossless manner. When the irradiation beam is expanded through a galvanometer mirror, ways to achieve beam uniformity are investigated.

  14. Effect of Scanning Beam Profile to Fabricate Fused Fiber Tapers by CO2 Laser Irradiation Method

    Institute of Scientific and Technical Information of China (English)

    Bayle Fabien; Luo Aiping; Marin Emmanuel; Meunier Jean-Pierre

    2003-01-01

    Beam uniformity is a crucial building block of CO2 experiments aimed at fusing and stretching optical fibers in a lossless manner. When the irradiation beam is expanded through a galvanometer mirror, ways to achieve beam uniformity are investigated.

  15. Optimisation of the ion optical range adaptation method for tracking of moving tumours with scanned ion beams

    International Nuclear Information System (INIS)

    Currently an ion optical solution for beam tracking of moving targets with scanned ion beams is being investigated at GSI for the treatment of moving tumours, such as lung cancer. Beam tracking compensates target motion by adapting the lateral beam position as well as the beam range according to the motion parameters. Tracking of the lateral position is achieved via scanning magnets. For range adaptation the proposed ion optical solution uses an energy degrader with variable thickness inserted into the therapy beam line downstream of the synchrotron. By deflecting the particle beam via dipole magnets to different positions on the degrader, the range of the Bragg peak can be adjusted in real-time. Hence density changes due to organ motion can be compensated for each target spot during beam scanning. In order to reach a beam quality suitable for therapy with this method, systematic studies on the ion optical parameters have to be carried out. Different degrader designs (ramp or discrete step shaped), different materials (e.g. PMMA, graphite), as well as optimised degrader positions have been examined. The results of simulated beam profiles are presented.

  16. Focused-ion-beam-fabricated Au nanorods coupled with Ag nanoparticles used as surface-enhanced Raman scattering-active substrate for analyzing trace melamine constituents in solution

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Well-ordered Au-nanorod array with a controlled tip ring diameter (AuNRsd) is made by focused ion beam. •AuNRsd coupled with Ag nanoparticles (Ag NPs/AuNRsd) is competent to sense target molecules in a solution. •Ag NPs/AuNRsd SERS active substrate can detect a single molecule of crystal violet. •Ag NPs/AuNRsd as a SERS-active substrate can distinguish melamine contaminants at low concentrations (e.g., 10−12 M). -- Abstract: A well-ordered Au-nanorod array with a controlled tip ring diameter (AuNRsd) was fabricated using the focused ion beam method. AuNRsd was then coupled with Ag nanoparticles (Ag NPs) to bridge the gaps among Au nanorods. The effect of surface-enhanced Raman scattering (SERS) on AuNRsd and Ag NPs/AuNRsd was particularly verified using crystal violet (CV) as the molecular probe. Raman intensity obtained from a characteristic peak of CV on AuNRsd was estimated by an enhancement factor of ≈107 in magnitude, which increased ≈1012 in magnitude for that on Ag NPs/AuNRsd. A highly SERS-active Ag NPs/AuNRsd was furthermore applied for the detection of melamine (MEL) at very low concentrations. Raman-active peaks of MEL (10−3 to 10−12 M) in water or milk solution upon AuNRsd or Ag NPs/AuNRsd were well distinguished. The peaks at 680 and 702 cm−1 for MEL molecules were found suitable to be used as the index for sensing low-concentration MEL in a varied solution, while that at 1051 cm−1 was practical to interpret MEL molecules in water or milk solution bonded with Au (i.e., AuNRsd) or Ag (i.e., Ag NPs/AuNRsd) surface. At the interface of Ag NPs/AuNRsd and MEL molecules in milk solution, a laser-induced electromagnetic field or hotspot effect was produced and competent to sense low-concentration MEL molecules interacting with Ag and Au surfaces. Accordingly, Ag NPs/AuNRsd is very promising to be used as a fast and sensitive tool for screening MEL in complex matrices such as adulteration in e.g., food

  17. An optimization-based method for geometrical calibration in cone-beam CT without dedicated phantoms

    Science.gov (United States)

    Panetta, D.; Belcari, N.; DelGuerra, A.; Moehrs, S.

    2008-07-01

    In this paper we present a new method for the determination of geometrical misalignments in cone-beam CT scanners, from the analysis of the projection data of a generic object. No a priori knowledge of the object shape and positioning is required. We show that a cost function, which depends on the misalignment parameters, can be defined using the projection data and that such a cost function has a local minimum in correspondence to the actual parameters of the system. Hence, the calibration of the scanner can be carried out by minimizing the cost function using standard optimization techniques. The method is developed for a particular class of 3D object functions, for which the redundancy of the fan beam sinogram in the transaxial midplane can be extended to cone-beam projection data, even at wide cone angles. The method has an approximated validity for objects which do not belong to that class; in that case, a suitable subset of the projection data can be selected in order to compute the cost function. We show by numerical simulations that our method is capable to determine with high accuracy the most critical misalignment parameters of the scanner, i.e., the transversal shift and the skew of the detector. Additionally, the detector slant can be determined. Other parameters such as the detector tilt, the longitudinal shift and the error in the source-detector distance cannot be determined with our method, as the proposed cost function has a very weak dependence on them. However, due to the negligible influence of these latter parameters in the reconstructed image quality, they can be kept fixed at estimated values in both calibration and reconstruction processes without compromising the final result. A trade-off between computational cost and calibration accuracy must be considered when choosing the data subset used for the computation of the cost function. Results on real data of a mouse femur as obtained with a small animal micro-CT are shown as well, proving

  18. Tracing coffee tabletop traces.

    Science.gov (United States)

    Leiterer, Jork; Emmerling, Franziska; Panne, Ulrich; Christen, Wolfgang; Rademann, Klaus

    2008-08-01

    Crystallization processes under different conditions are of fundamental interest in chemistry, pharmacy, and medicine. Therefore, we have studied the formation of micro- and nanosized crystals using water-caffeine (1,3,7-trimethyl-1 H-purine-2,6(3 H,7 H)-dione) solutions under ambient conditions as a relevant model system. When droplets of an aqueous caffeine solution evaporate and eventually dry on surfaces (glass, polystyrene, and polyester), stable "coffee tabletop" rings with a perimeter of typically 3 mm are formed after 20 to 50 min. Using a micro focus X-ray beam available at the BESSY muSpot-beamline, the fine structure of different caffeine needles can be distinguished. Unexpectedly, both crystal modifications (alpha- and beta-caffeine) are present, but locally separated in these rings. Furthermore, AFM studies reveal the presence of even smaller particles on a nanometer length scale. To eliminate influences of surface irregularities from the crystallization process, acoustic levitation of liquid samples was employed. Such levitated droplets are trapped in a stable position and only surrounded by air. The solvent in an ultrasonically levitated drop evaporates completely, and the resulting crystallization of caffeine was followed in situ by synchrotron X-ray diffraction. In this case, the diffraction pattern is in accordance with pure alpha-caffeine and does not indicate the formation of the room temperature polymorph beta-caffeine. Hence, our investigations open new vistas that may lead to a controlled formation of cocrystals and novel polymorphs of micro- and nanocrystalline materials, which are of relevance for fundamental studies as well as for pharmaceutical and medical applications. PMID:18582001

  19. CONTENT AND UPTAKE OF SELECTED TRACE ELEMENTS BY WEEDS IN POTATO TO CULTIVATION UNDER DIFFERENT CONDITIONS OF SOIL TILLAGE AND WEED CONTROL METHODS

    OpenAIRE

    Krystyna Zarzecka; Marek Gugała; Alicja Baranowska

    2014-01-01

    The study utilized data from a field experiment carried out at the Experimental Station in Zawady owned by the University of Natural Sciences and Humanities in Siedlce in the years 2005–2007. The experimental factors included two soil tillage systems and seven weed control methods in potato. Iron, copper and zinc in weeds were determined with the AAS method. The trace element content in weed dry matter before row closure of potato depended significantly on soil tillage methods (excluding Cu),...

  20. Estimated total emissions of trace gases from the Canberra Wildfires of 2003: a new method using satellite measurements of aerosol optical depth & the MOZART chemical transport model

    OpenAIRE

    Paton-Walsh, C.; L. K. Emmons; S. R. Wilson

    2010-01-01

    In this paper we describe a new method for estimating trace gas emissions from large vegetation fires using satellite measurements of aerosol optical depth (AOD) at 550 nm, combined with an atmospheric chemical transport model. The method uses a threshold value to screen out normal levels of AOD that may be caused by raised dust, sea salt aerosols or diffuse smoke transported from distant fires. Using this method we infer an estimated total emission of 15±5 Tg of carbon monoxide, 0...