Determination of elemental composition of coffee using UV-pulsed laser induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Gondal, M. A., E-mail: magondal@kfupm.edu.sa; Baig, Umair; Dastageer, M. A.; Sarwar, Mohsin [Laser Research Group, Physics Department, King Fahd University of Petroleum and Minerals, P.O Box 5047, Dhahran 31261 (Saudi Arabia)

2016-06-10

A detection system based on laser induced breakdown spectroscopy (LIBS) was built using 266 nm wavelength pulsed laser from the fourth harmonic of Nd:YAG laser, 500 mm spectrograph and gated ICCD camera with built-in delay generator. The LIBS system was used to study the elemental composition in coffee available in the local market of Saudi Arabia for the detection of elements in coffee samples. The LIBS spectrum of coffee sample revealed the presence magnesium, calcium, aluminum, copper, sodium, barium, bromine, cobalt, chromium, cerium manganese and molybdenum. Atomic transition line of sodium is used to study the parametric dependence of LIBS signal. The study of the dependence of LIBS signal on the laser pulse energy is proven to be linear and the dependence of LIBS signal on the time delay between the excitation and data acquisition showed a typical increase, a peak value and a decrease with the optimum excitation – acquisition delay at 400 ns.

Linear pulse motor type control element drive mechanism for the integral reactor

International Nuclear Information System (INIS)

Yu, J. Y.; Choi, S.; Kim, J. H.; Huh, H.; Park, K. B.

2007-01-01

The integral reactor SMART currently under development at Korea Atomic Energy Research Institute is designed with soluble boron free operation and use of nuclear heating for reactor startup. These design features require the Control Element Drive Mechanism (CEDM) for SMART to have fine-step movement capability as well as high reliability for the fine reactivity control. In this paper, design characteristics of a new concept CEDM driven by the Linear Pulse Motor (LPM) which meets the design requirements of the integral reactor SMART are introduced. The primary dimensions of the linear pulse motor are determined by the electro-magnetic analysis and the results are also presented. In parallel with the electro-magnetic analysis, the conceptual design of the CEDM is visualized and checked for interferences among parts by assembling three dimensional (3D) models on the computer. Prototype of LPM with double air-gaps for the CEDM sub-assemblies to lift 100 kg is designed, analysed, manufactured and tested to confirm the validity of the CEDM design concept. A converter and a test facility are manufactured to verify the dynamic performance of the LPM. The mover of the LPM is welded with ferromagnetic material and non-ferromagnetic material to get the magnetic flux path between inner stator and outer stator. The thrust forces of LPM predicted by analytic model have shown good agreement with experimental results from the prototype LPM. It is found that the LPM type CEDM has high force density and simple drive mechanism to reduce volume and satisfy the reactor operating circumstances with high pressure and temperature

Compression and radiation of high-power short rf pulses. II. A novel antenna array design with combined compressor/radiator elements

KAUST Repository

Sirenko, Kostyantyn

2011-01-01

The paper discusses the radiation of compressed high power short RF pulses using two different types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a compressor and a radiator. The studies on the monopole antenna demonstrate the possibility of a high power short RF pulse\\'s efficient radiation even using simple antennas. The studies on the novel array design demonstrate that a reduced size array with lower pulse distortion and power decay can be constructed by assembling the array from elements each of which integrates a compressor and a radiator. This design idea can be used with any type of antenna array; in this work it is applied to a phased array.

Quantitative pulsed eddy current analysis

International Nuclear Information System (INIS)

Morris, R.A.

1975-01-01

The potential of pulsed eddy current testing for furnishing more information than conventional single-frequency eddy current methods has been known for some time. However, a fundamental problem has been analyzing the pulse shape with sufficient precision to produce accurate quantitative results. Accordingly, the primary goal of this investigation was to: demonstrate ways of digitizing the short pulses encountered in PEC testing, and to develop empirical analysis techniques that would predict some of the parameters (e.g., depth) of simple types of defect. This report describes a digitizing technique using a computer and either a conventional nuclear ADC or a fast transient analyzer; the computer software used to collect and analyze pulses; and some of the results obtained. (U.S.)

Development of linear pulse motor type control element drive mechanism for smart

International Nuclear Information System (INIS)

Je-Yong, Yu; Jong-in, Kim; Ji-ho, Kim; Hyung, Huh; Moon-Hee, Chang

2001-01-01

The system-integrated modular advanced reactor (SMART) currently under development at the Korea Atomic Energy Research Institute is being designed with soluble boron free operation and the use of nuclear heating for reactor start-up. These design features require a Control Element Drive Mechanism(CEDM) for SMART to have fine-step movement capability as well as high reliability for fine reactivity control. In this paper, the design characteristics of a new concept CEDM driven by a Linear Pulse Motor (LPM) which meets the design requirements of the integral reactor SMART are introduced. The primary dimensions of the linear pulse motor are determined by electro-magnetic analysis and the results are also presented. In parallel with the electro-magnetic analysis, the conceptual design of the CEDM is visualized and checked for interferences among parts by assembling three dimensional (3D) models on computer. A prototype of the LPM with double air-gaps for the CEDM sub-assemblies to lift 100 kg is designed, analysed, manufactured and tested to confirm the validity of the CEDM design concept. A converter and test facility are manufactured to verify the dynamic performance of the LPM. The mover of the LPM is welded with ferromagnetic material and non-ferromagnetic material to get the magnetic flux path between the inner stator and outer stator. The thrust forces of LPM predicted by the analytic model have shown good agreement with experimental results from the prototype LPM. It is found that the LPM type CEDM has high force density and a simple drive mechanism to reduce volume and satisfy reactor operating circumstances with high pressure and temperature. (authors)

Coupling analysis of the target temperature and thermal stress due to pulsed ion beam

International Nuclear Information System (INIS)

Yan Jie; Liu Meng; Lin Jufang; An Li; Long Xinggui

2013-01-01

Background: Target temperature has an important effect on the target life for the sealed neutron generator without cooling system. Purpose: To carry out the thermal-mechanical coupling analysis of the film-substrate target bombarded by the pulsed ion beam. Methods: The indirect coupling Finite Element Method (FEM) with a 2-dimensional time-space Gaussian axisymmetric power density as heat source was used to simulate the target temperature and thermal stress fields. Results: The effects of the target temperature and thermal stress fields under difference pulse widths and beam sizes were analyzed in terms of the FEM results. Conclusions: Combining with the temperature requirement and the thermal stress inducing film thermal mechanical destruction effect of the sealed neutron generator film-substrate targets, an optimized pulsed ion beam work status was proposed. (authors)

The influence of pulse duration on the stress levels in ablation of ceramics: A finite element study

International Nuclear Information System (INIS)

Verde, A. Vila; Ramos, Marta M.D.

2006-01-01

We present a finite element model to investigate the dynamic thermal and mechanical response of ceramic materials to pulsed infrared radiation. The model was applied to the specific problem of determining the influence of the pulse duration on the stress levels reached in human dental enamel irradiated by a CO 2 laser at 10.6 μm with pulse durations between 0.1 and 100 μs and sub-ablative fluence. Our results indicate that short pulses with durations much larger than the characteristic acoustic relaxation time of the material can still cause high stress transients at the irradiated site, and indicate that pulse durations of the order of 10 μs may be more adequate both for enamel surface modification and for ablation than pulse durations up to 1 μs. The model presented here can easily be modified to investigate the dynamic response of ceramic materials to mid-infrared radiation and help determine optimal pulse durations for specific procedures

Transient behaviour study program of research reactors fuel elements at the Hydra Pulse Reactor

International Nuclear Information System (INIS)

Khvostionov, V.E.; Egorenkov, P.M.; Malankin, P.V.

2004-01-01

Program on behavior study of research reactor Fuel Elements (FE) under transient regimes initiated by excessive reactivity insertion is being presented. Program would be realized at HYDRA pulse reactor at Russian Research Center 'Kurchatov Institute' (RRC 'K1'). HYDRA uses aqueous solution of uranyl sulfate (UO 2 SO 4 ) as a fuel. Up to 30 MJ of energy can be released inside the core during the single pulse, effective power pulse width varying from 2 to 10 ms. Reactor facility allows to investigate behaviour of FE consisting of different types of fuel composition, being developed according to Russian RERTR. First part of program is aimed at transient behaviour studying of FE MR, IRT-3M, WWR-M5 types containing meats based on dioxide uranium in aluminum matrix. Mentioned FEs use 90% and 36% enriched uranium. (author)

Highly sensitive analysis of boron and lithium in aqueous solution using dual-pulse laser-induced breakdown spectroscopy.

Science.gov (United States)

Lee, Dong-Hyoung; Han, Sol-Chan; Kim, Tae-Hyeong; Yun, Jong-Il

2011-12-15

We have applied a dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) to sensitively detect concentrations of boron and lithium in aqueous solution. Sequential laser pulses from two separate Q-switched Nd:YAG lasers at 532 nm wavelength have been employed to generate laser-induced plasma on a water jet. For achieving sensitive elemental detection, the optimal timing between two laser pulses was investigated. The optimum time delay between two laser pulses for the B atomic emission lines was found to be less than 3 μs and approximately 10 μs for the Li atomic emission line. Under these optimized conditions, the detection limit was attained in the range of 0.8 ppm for boron and 0.8 ppb for lithium. In particular, the sensitivity for detecting boron by excitation of laminar liquid jet was found to be excellent by nearly 2 orders of magnitude compared with 80 ppm reported in the literature. These sensitivities of laser-induced breakdown spectroscopy are very practical for the online elemental analysis of boric acid and lithium hydroxide serving as neutron absorber and pH controller in the primary coolant water of pressurized water reactors, respectively.

Multi-Pulse Excitation for Underwater Analysis of Copper-Based Alloys Using a Novel Remote Laser-Induced Breakdown Spectroscopy (LIBS) System.

Science.gov (United States)

Guirado, Salvador; Fortes, Francisco J; Laserna, J Javier

2016-04-01

In this work, the use of multi-pulse excitation has been evaluated as an effective solution to mitigate the preferential ablation of the most volatile elements, namely Sn, Pb, and Zn, observed during laser-induced breakdown spectroscopy (LIBS) analysis of copper-based alloys. The novel remote LIBS prototype used in this experiments featured both single-pulse (SP-LIBS) and multi-pulse excitation (MP-LIBS). The remote instrument is capable of performing chemical analysis of submersed materials up to a depth of 50 m. Laser-induced breakdown spectroscopy analysis was performed at air pressure settings simulating the conditions during a real subsea analysis. A set of five certified bronze standards with variable concentration of Cu, As, Sn, Pb, and Zn were used. In SP-LIBS, signal emission is strongly sensitive to ambient pressure. In this case, fractionation effect was observed. Multi-pulse excitation circumvents the effect of pressure over the quantitative analysis, thus avoiding the fractionation phenomena observed in single pulse LIBS. The use of copper as internal standard minimizes matrix effects and discrepancies due to variation in ablated mass. © The Author(s) 2016.

Multi-parametric study of temperature and thermal damage of tumor exposed to high-frequency nanosecond-pulsed electric fields based on finite element simulation.

Science.gov (United States)

Mi, Yan; Rui, Shaoqin; Li, Chengxiang; Yao, Chenguo; Xu, Jin; Bian, Changhao; Tang, Xuefeng

2017-07-01

High-frequency nanosecond-pulsed electric fields were recently introduced for tumor or abnormal tissue ablation to solve some problems of conventional electroporation. However, it is necessary to study the thermal effects of high-field-intensity nanosecond pulses inside tissues. The multi-parametric analysis performed here is based on a finite element model of liver tissue with a tumor that has been punctured by a pair of needle electrodes. The pulse voltage used in this study ranges from 1 to 4 kV, the pulse width ranges from 50 to 500 ns, and the repetition frequency is between 100 kHz and 1 MHz. The total pulse length is 100 μs, and the pulse burst repetition frequency is 1 Hz. Blood flow and metabolic heat generation have also been considered. Results indicate that the maximum instantaneous temperature at 100 µs can reach 49 °C, with a maximum instantaneous temperature at 1 s of 40 °C, and will not cause thermal damage during single pulse bursts. By parameter fitting, we can obtain maximum instantaneous temperature at 100 µs and 1 s for any parameter values. However, higher temperatures will be achieved and may cause thermal damage when multiple pulse bursts are applied. These results provide theoretical basis of pulse parameter selection for future experimental researches.

Using laser-induced breakdown spectroscopy on vacuum alloys-production process for elements concentration analysis

Science.gov (United States)

Zhao, Tianzhuo; Fan, Zhongwei; Lian, Fuqiang; Liu, Yang; Lin, Weiran; Mo, Zeqiang; Nie, Shuzhen; Wang, Pu; Xiao, Hong; Li, Xin; Zhong, Qixiu; Zhang, Hongbo

2017-11-01

Laser-induced breakdown spectroscopy (LIBS) utilizing an echelle spectrograph-ICCD system is employed for on-line analysis of elements concentration in a vacuum induction melting workshop. Active temperature stabilization of echelle spectrometer is implemented specially for industrial environment applications. The measurement precision is further improved by monitoring laser parameters, such as pulse energy, spatial and temporal profiles, in real time, and post-selecting laser pulses with specific pulse energies. Experimental results show that major components of nickel-based alloys are stable, and can be well detected. By using internal standard method, calibration curves for chromium and aluminum are obtained for quantitative determination, with determination coefficient (relative standard deviation) to be 0.9559 (< 2.2%) and 0.9723 (< 2.8%), respectively.

Fault analysis and strategy of high pulsed power supply for high power laser

International Nuclear Information System (INIS)

Liu Kefu; Qin Shihong; Li Jin; Pan Yuan; Yao Zonggan; Zheng Wanguo; Guo Liangfu; Zhou Peizhang; Li Yizheng; Chen Dehuai

2001-01-01

according to the requirements of driving flash-lamp, a high pulsed power supply (PPS) based on capacitors as energy storage elements is designed. The author analyzes in detail the faults of high pulsed power supply for high power laser. Such as capacitor internal short-circuit, main bus breakdown to ground, flashlamp sudden short or break. The fault current and voltage waveforms were given by circuit simulations. Based on the analysis and computation, the protection strategy with the fast fuse and ZnO was put forward, which can reduce the damage of PPS to the lower extent and provide the personnel safe and collateral property from the all threats. The preliminary experiments demonstrated that the design of the PPS can satisfy the project requirements

Analysis and prediction of radioelement dispersion in the marine environment by the pulse response method

International Nuclear Information System (INIS)

Boust, D.; Fraizier, A.; Hairie, A.; Baron, Y.

1995-01-01

This work presents analysis and prediction of the dispersion of radioelements in the marine environment based on the pulse response theory. The analysis is made on three data sets over the period 1984-1988: the amounts of gamma-emitting radioelements contained in controlled releases from the nuclear reprocessing plant of La Hague (=signal emission point), and gamma-emitting radionuclide concentrations in sea water at two stations (signal reception points), situated at 8 and 35 km distance from the release point. Using this data base, the pulse response is determined for each station and for each element. This allows us to estimate the mean delay and the amplitude of the reception signal (i.e. the concentrations of radioelements) and its sensitivity to wind forcing. We then demonstrate that the convolution of the pulse response and released radionuclide time-series is capable of yielding a fairly good prediction of the concentrations at each station. Some particularities of the behaviour of 137 Cs, 106 Ru and 60 Co are evidenced by comparison with that of 125 Sb, assumed to be a conservative element in sea water: adsorption of 106 Ru and 60 Co on to particles, additional sources of 137 Cs. The mean delays calculated for 125 Sb at each station are close to each other (28-30 days) despite their different distances from the release point, and are explained by the specific hydrodynamics of the studied area. (Authors). 16 refs., 9 figs

[Rapid multi-elemental analysis on four precious Tibetan medicines based on LIBS technique].

Science.gov (United States)

Liu, Xiao-na; Shi, Xin-yuan; Jia, Shuai-yun; Zhao, Na; Wu, Zhi-sheng; Qiao, Yan-jiang

2015-06-01

The laser-induced breakdown spectroscopy (LIBS) was applied to perform a qualitative elementary analysis on four precious Tibetan medicines, i. e. Renqing Mangjue, Renqing Changjue, 25-herb coral pills and 25-herb pearl pills. The specific spectra of the four Tibetan medicines were established. In the experiment, Nd: YAG and 1 064 nm-baseband pulse laser were adopted to collect the spectra. A laser beam focused on the surface of the samples to generate plasma. Its spectral signal was detected by using spectrograph. Based on the National Institute of Standard and Technology (NIST) database, LIBS spectral lines were indentified. The four Tibetan medicines mainly included Ca, Na, K, Mg and other elements and C-N molecular band. Specifically, Fe was detected in Renqing Changjue and 25-herb pearl pills; heavy mental elements Hg and Cu were shown in Renqing Mangjue and Renqing Changjue; Ag was found in Renqing Changjue. The results demonstrated that LIBS is a reliable and rapid multi-element analysis on the four Tibetan medicines. With Real-time, rapid and nondestructive advantages, LIBS has a wide application prospect in the element analysis on ethnic medicines.

A study of Venus surface elemental composition from 14 MeV neutron induced gamma ray spectroscopy: Activation analysis

International Nuclear Information System (INIS)

Jun, I.; Kim, W.; Smith, M.; Mitrofanov, I.; Litvak, M.

2011-01-01

The surface elemental composition of Venus can be determined using an artificially pulsed 14 MeV neutron generator (PNG) combined with a gamma ray spectrometer (GRS). The 14 MeV neutrons will interact with the surface materials and generate gamma rays, characteristic of specific elements, whose energy spectrum will be measured by GRS. These characteristic gamma rays are produced mainly through 3 different neutron interaction mechanisms: capture, inelastic, and activation reactions. Each reaction type has a different neutron energy dependency and different time scale for gamma ray production and transport. Certain elements are more easily identified through one reaction type over the others. Thus, careful analysis of the gamma ray spectra during and after the neutron pulse provides a comprehensive understanding of the surface elemental composition. In this paper, we use a well-tested neutron/gamma transport code, called Monte Carlo N-Particles (MCNP), to investigate the measurement capability of a PNG-GRS detection system through the neutron activation reactions. An activation analysis was performed for a representative soil composition of Venus with a notional operational scenario of PNG and GRS. The analysis shows that the proposed instrument concept can identify most of the modeled surface elements at Venus with sufficient accuracy through the activation mode. Specifically, U, Th, K, Si can be measured to within 1%, Fe within 2%, Al within 10%, Ca within 5%, Mg with 15%, Mn with 20%, and Cl within 6%. Although modeled in the analysis, it is shown that the activation mode alone cannot distinguish the S and Ti peaks.

Effect of the measured power distribution in a FLIP fuel element on the safety analysis report of the NSCR

International Nuclear Information System (INIS)

Feltz, D.E.; Randall, J.D.

1976-01-01

The experimentally determined power distribution of a FLIP Fuel Element resulted in a different power peaking factor than that used in the safety analysis for a pulsed Mixed TRIGA Core. The results of this difference are discussed. (author)

Exploring new frontiers in the pulsed power laboratory: Recent progress

Directory of Open Access Journals (Sweden)

S. Adamenko

2015-01-01

Full Text Available One of the most fundamental processes in the Universe, nucleosynthesis of elements drives energy production in stars as well as the creation of all atoms heavier than hydrogen. To harness this process and open new ways for energy production, we must recreate some of the extreme conditions in which it occurs. We present results of experiments using a pulsed power facility to induce collective nuclear interactions producing stable nuclei of virtually every element in the periodic table. A high-power electron beam pulse striking a small metallic target is used to create the extreme dynamic environment. Material analysis studies detect an anomalously high presence of new chemical elements in the remnants of the exploded target supporting theoretical conjectures of the experiment. These results provide strong motivation to continue our research looking for additional proofs that heavy element nucleosynthesis is possible in pulsed power laboratory.

Selenium and Trace Element Distribution in Astragalus Plants: Developing a Differential Pulse Polarographic Method for Their Determination

OpenAIRE

SOMER, Güler; ÇALIŞKAN, A. Cengiz

2007-01-01

Astragalus plants have a wide range of applications in pharmaceuticals (gum tragacanth), as thickening agents in foods, and may have applications in controlling cancer cells. They are used as feed for animals and they are indicator plants for selenium. Because of their use in health-related areas it is very important to determine their selenium and trace element content with high accuracy. A new differential pulse polarographic method was established for trace element determination (...

The Dynamic Response of an Euler-Bernoulli Beam on an Elastic Foundation by Finite Element Analysis using the Exact Stiffness Matrix

International Nuclear Information System (INIS)

Kim, Jeong Soo; Kim, Moon Kyum

2012-01-01

In this study, finite element analysis of beam on elastic foundation, which received great attention of researchers due to its wide applications in engineering, is performed for estimating dynamic responses of shallow foundation using exact stiffness matrix. First, element stiffness matrix based on the closed solution of beam on elastic foundation is derived. Then, we performed static finite element analysis included exact stiffness matrix numerically, comparing results from the analysis with some exact analysis solutions well known for verification. Finally, dynamic finite element analysis is performed for a shallow foundation structure under rectangular pulse loading using trapezoidal method. The dynamic analysis results exist in the reasonable range comparing solution of single degree of freedom problem under a similar condition. The results show that finite element analysis using exact stiffness matrix is evaluated as a good tool of estimating the dynamic response of structures on elastic foundation.

Modelling optimization involving different types of elements in finite element analysis

International Nuclear Information System (INIS)

Wai, C M; Rivai, Ahmad; Bapokutty, Omar

2013-01-01

Finite elements are used to express the mechanical behaviour of a structure in finite element analysis. Therefore, the selection of the elements determines the quality of the analysis. The aim of this paper is to compare and contrast 1D element, 2D element, and 3D element used in finite element analysis. A simple case study was carried out on a standard W460x74 I-beam. The I-beam was modelled and analyzed statically with 1D elements, 2D elements and 3D elements. The results for the three separate finite element models were compared in terms of stresses, deformation and displacement of the I-beam. All three finite element models yield satisfactory results with acceptable errors. The advantages and limitations of these elements are discussed. 1D elements offer simplicity although lacking in their ability to model complicated geometry. 2D elements and 3D elements provide more detail yet sophisticated results which require more time and computer memory in the modelling process. It is also found that the choice of element in finite element analysis is influence by a few factors such as the geometry of the structure, desired analysis results, and the capability of the computer

Electronic system for recording proportional counter rare pulses with the pulse shape analysis

International Nuclear Information System (INIS)

Barabanov, I.R.; Gavrin, V.N.; Zakharov, Yu.I.; Tikhonov, A.A.

1984-01-01

The anutomated system for recording proportional counter rare pulses is described. The proportional counters are aimed at identification of 37 Ar and H7 1 Gr decays in chemical radiation detectors of solar neutrino. Pulse shape recording by means of a storage oscilloscope and a TV display is performed in the system considered besides two-parametric selection of events (measurement of pulse amplitude in a slow channel and the amplitude of pulse differentiated with time constant of about 10 ns in a parallel fast channel). Pulse discrimination by a front rise rate provides background decrease in the 55 Fe range (5.9 keV) by 6 times; the visual analysis of pulse shapes recorded allows to decrease the background additionally by 25-30%. The background counting rate in the 55 Fe range being equal to 1 pulse per 1.5 days, is obtained when using the installation described above, as well as the passive Pb shield 5 cm thick, and the active shield based on the anticoincidence NaI(Tl) detector with the cathode 5.6 mm in-diameter made of Fe fabircated by zone melting. The installation described allows to reach the background level of 0.6 pulse/day (the total coefficient of background attenuation is 400). Further background decrease is supposed to be provided by installation allocation in the low-noise underground laboratory of the Baksan Neutrino Observatory

A Quantitative Analysis of Pulsed Signals Emitted by Wild Bottlenose Dolphins.

Directory of Open Access Journals (Sweden)

Ana Rita Luís

Full Text Available Common bottlenose dolphins (Tursiops truncatus, produce a wide variety of vocal emissions for communication and echolocation, of which the pulsed repertoire has been the most difficult to categorize. Packets of high repetition, broadband pulses are still largely reported under a general designation of burst-pulses, and traditional attempts to classify these emissions rely mainly in their aural characteristics and in graphical aspects of spectrograms. Here, we present a quantitative analysis of pulsed signals emitted by wild bottlenose dolphins, in the Sado estuary, Portugal (2011-2014, and test the reliability of a traditional classification approach. Acoustic parameters (minimum frequency, maximum frequency, peak frequency, duration, repetition rate and inter-click-interval were extracted from 930 pulsed signals, previously categorized using a traditional approach. Discriminant function analysis revealed a high reliability of the traditional classification approach (93.5% of pulsed signals were consistently assigned to their aurally based categories. According to the discriminant function analysis (Wilk's Λ = 0.11, F3, 2.41 = 282.75, P < 0.001, repetition rate is the feature that best enables the discrimination of different pulsed signals (structure coefficient = 0.98. Classification using hierarchical cluster analysis led to a similar categorization pattern: two main signal types with distinct magnitudes of repetition rate were clustered into five groups. The pulsed signals, here described, present significant differences in their time-frequency features, especially repetition rate (P < 0.001, inter-click-interval (P < 0.001 and duration (P < 0.001. We document the occurrence of a distinct signal type-short burst-pulses, and highlight the existence of a diverse repertoire of pulsed vocalizations emitted in graded sequences. The use of quantitative analysis of pulsed signals is essential to improve classifications and to better assess the

Fs–ns double-pulse Laser Induced Breakdown Spectroscopy of copper-based-alloys: Generation and elemental analysis of nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Guarnaccio, A.; Parisi, G.P.; Mollica, D. [CNR-ISM, U.O.S. Tito Scalo, Zona Industriale, 85050 Tito Scalo, PZ (Italy); De Bonis, A. [CNR-ISM, U.O.S. Tito Scalo, Zona Industriale, 85050 Tito Scalo, PZ (Italy); Dipartimento di Scienze, Università degli Studi della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Teghil, R. [Dipartimento di Scienze, Università degli Studi della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Santagata, A. [CNR-ISM, U.O.S. Tito Scalo, Zona Industriale, 85050 Tito Scalo, PZ (Italy)

2014-11-01

Evolution of nanoparticles ejected during ultra-short (250 fs) laser ablation of certified copper alloys and relative calibration plots of a fs–ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration is presented. All work was performed in air at atmospheric pressure using certified copper-based-alloy samples irradiated by a fs laser beam and followed by a delayed perpendicular ns laser pulse. In order to evaluate possible compositional changes of the fs induced nanoparticles, it was necessary to consider, for all samples used, comparable features of the detected species. With this purpose the induced nanoparticles black-body-like emission evolution and their relative temperature decay have been studied. These data were exploited for defining the distance between the target surface and the successive ns laser beam to be used. The consequent calibration plots of minor constituents (i.e. Sn, Pb and Zn) of the certified copper-based-alloy samples have been reported by taking into account self-absorption effects. The resulting linear regression coefficients suggest that the method used, for monitoring and ruling the fs laser induced nanoparticles, could provide a valuable approach for establishing the occurrence of potential compositional changes of the detected species. All experimental data reveal that the fs laser induced nanoparticles can be used for providing a coherent composition of the starting target. In the meantime, the fs–ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration here used can be considered as an efficient technique for compositional determination of the nanoparticles ejected during ultra-short laser ablation processes. - Highlights: • Laser induced NP continuum black-body-like emission was used for T determination. • Invariable composition of generated NPs was assumed in the range of 20 μs. • Fs-ns DP-LIBS was employed for the compositional characterization of NPs. • NPs obtained by fs

Thermal analysis of an indirectly heat pulsed non-volatile phase change material microwave switch

International Nuclear Information System (INIS)

Young, Robert M.; El-Hinnawy, Nabil; Borodulin, Pavel; Wagner, Brian P.; King, Matthew R.; Jones, Evan B.; Howell, Robert S.; Lee, Michael J.

2014-01-01

We show the finite element simulation of the melt/quench process in a phase change material (GeTe, germanium telluride) used for a radio frequency switch. The device is thermally activated by an independent NiCrSi (nickel chrome silicon) thin film heating element beneath a dielectric separating it electrically from the phase change layer. A comparison is made between the predicted and experimental minimum power to amorphize (MPA) for various thermal pulse powers and pulse time lengths. By including both the specific heat and latent heat of fusion for GeTe, we find that the MPA and the minimum power to crystallize follow the form of a hyperbola on the power time effect plot. We also find that the simulated time at which the entire center GeTe layer achieves melting accurately matches the MPA curve for pulse durations ranging from 75–1500 ns and pulse powers from 1.6–4 W

Thermal analysis of an indirectly heat pulsed non-volatile phase change material microwave switch

Energy Technology Data Exchange (ETDEWEB)

Young, Robert M., E-mail: rm.young@ngc.com; El-Hinnawy, Nabil; Borodulin, Pavel; Wagner, Brian P.; King, Matthew R.; Jones, Evan B.; Howell, Robert S.; Lee, Michael J. [Northrop Grumman Corp., Electronic Systems, P.O. Box 1521, Baltimore, Maryland 21203 (United States)

2014-08-07

We show the finite element simulation of the melt/quench process in a phase change material (GeTe, germanium telluride) used for a radio frequency switch. The device is thermally activated by an independent NiCrSi (nickel chrome silicon) thin film heating element beneath a dielectric separating it electrically from the phase change layer. A comparison is made between the predicted and experimental minimum power to amorphize (MPA) for various thermal pulse powers and pulse time lengths. By including both the specific heat and latent heat of fusion for GeTe, we find that the MPA and the minimum power to crystallize follow the form of a hyperbola on the power time effect plot. We also find that the simulated time at which the entire center GeTe layer achieves melting accurately matches the MPA curve for pulse durations ranging from 75–1500 ns and pulse powers from 1.6–4 W.

Ultrasonic Nebulizer Assisted LIBS: a Promising Metal Elements Detection Method for Aqueous Sample Analysis

International Nuclear Information System (INIS)

Zhong Shilei; Zheng Ronger; Lu Yuan; Cheng Kai; Xiu Junshan

2015-01-01

A newly developed approach for trace metal elements detection for aqueous samples analysis is presented in this paper. The idea of this approach is to improve ablation efficiency by transforming the liquid sample into a dense cloud of droplets using an ultrasonic nebulizer. The resulting droplets are then subjected to analysis by laser induced breakdown spectroscopy (LIBS). A purpose-built ultrasonic nebulizer assisted LIBS (UN-LIBS) system has been applied to the analysis of aqueous samples at trace levels of concentration. Experimental investigations of solution samples were carried out with various dissolved trace metal elements (Mn, Zn, Cu, Pb, Fe, Mg and Na) using this approach. The characteristics of UN-LIBS signal of the elements were investigated regarding the lifetime and S/B ratio and the calibration curves for trace metal elements analyses. The obtained LODs are comparable or much better than the LODS of the reported signal enhancement approaches when the laser pulse energy was as low as 30 mJ. The good linearity of calibration curves and the low LODs shows the potential ability of this method for metal elements analysis application. The density of the electrons was calculated by measuring the Stark width of the line of H α . The possible mechanism of the LIBS signal enhancement of this approach was briefly discussed. (paper)

Response Analysis on Electrical Pulses under Severe Nuclear Accident Temperature Conditions Using an Abnormal Signal Simulation Analysis Module

Directory of Open Access Journals (Sweden)

Kil-Mo Koo

2012-01-01

Full Text Available Unlike design basis accidents, some inherent uncertainties of the reliability of instrumentations are expected while subjected to harsh environments (e.g., high temperature and pressure, high humidity, and high radioactivity occurring in severe nuclear accident conditions. Even under such conditions, an electrical signal should be within its expected range so that some mitigating actions can be taken based on the signal in the control room. For example, an industrial process control standard requires that the normal signal level for pressure, flow, and resistance temperature detector sensors be in the range of 4~20 mA for most instruments. Whereas, in the case that an abnormal signal is expected from an instrument, such a signal should be refined through a signal validation process so that the refined signal could be available in the control room. For some abnormal signals expected under severe accident conditions, to date, diagnostics and response analysis have been evaluated with an equivalent circuit model of real instruments, which is regarded as the best method. The main objective of this paper is to introduce a program designed to implement a diagnostic and response analysis for equivalent circuit modeling. The program links signal analysis tool code to abnormal signal simulation engine code not only as a one body order system, but also as a part of functions of a PC-based ASSA (abnormal signal simulation analysis module developed to obtain a varying range of the R-C circuit elements in high temperature conditions. As a result, a special function for abnormal pulse signal patterns can be obtained through the program, which in turn makes it possible to analyze the abnormal output pulse signals through a response characteristic of a 4~20 mA circuit model and a range of the elements changing with temperature under an accident condition.

PULSTRI-1 computer program for mixed core pulse calculation

International Nuclear Information System (INIS)

Ravnik, M.; Mele, I.; Dimic, V.

1990-01-01

PUISTRI-1 is a computer code designed for calculations of the pulse parameters of TRIGA Mark II reactor with mixed core. The code is provided with data for four types of fuel elements: standard 8.5 and 12 w/o, LEU and FLIP. The pulse parameters, such as maximum power, prompt pulse energy and average fuel temperatures are calculated in adiabatic point kinetics, approximation, modified by taking into account temperature dependence of fuel temperature reactivity coefficient and thermal capacity factor averaged over all elements in the core. Maximal fuel temperature at power peaking location is calculated from total released energy using total power peaking factor and heat capacity of the element at the location of the power peaking. Results of the code were compared to data found in references (mainly General Atomics safety analysis reports) showing good agreement for all main pulse parameters. The most important parameters, average and maximal fuel temperature, are found to be systematically slightly overpredicted (20 C and 50 C, respectively). Other parameters (energy, peak power, width) agree within ± 10 % to the reference values. The code is written in FORTRAN for IBM PC computer. The input is user friendly. running time of IBM PC AT is a few seconds. It is designed for practical applications in pulse experiments as an analytical tool for predicting pulse parameters. (orig.)

Fast neutron activating detectors for pulsed flow measurements

International Nuclear Information System (INIS)

Dyatlov, V.D.; Kunaev, G.T.; Popytaev, A.N.; Cheremukhov, B.V.

1979-01-01

The requirements to the activation detectors of the pulsed flows of the fast neutrons are considered; the criteria of optimum measurement time, geometrical moderator sizes and radioactive detector element properties have been obtained. On their analysis parameter selection has been carried out. The neutron detector to register the short pulses has been designed and calibrated. The ways of further increase of sensitivity and efficiency of such detectors are discussed

Application of dynamic response analysis to JET heat pulse data

International Nuclear Information System (INIS)

Griguoli, A.; Sips, A.C.C.

1993-09-01

The plasma dynamic response can be used to study transport processes in a tokamak plasma. A method has been developed for the application of dynamic response analysis to study perturbations away from the plasma equilibrium. In this report perturbations on the electron temperature following a sawtooth collapse in the center of the plasma are considered. The method has been used to find mathematical description of a series of heat pulses at the Joint European Torus project (JET). From the plasma dynamic response, the time constants which characterise the heat pulse are obtained. These time constants are compared to the transport coefficients found in previous analysis of the JET heat pulse data. Various methods are discussed for applying dynamic response analysis to JET heat pulse data. (author)

Pulse shape analysis using CsI(Tl) Crystals

International Nuclear Information System (INIS)

Silva, J.; Fiori, E.; Loher, B.; Savran, D.; Wirth, R.; Vencelj, M.

2013-06-01

The decay time of CsI(Tl) scintillating material consists of more than a single exponential component. The ratio between the intensity of these components varies as a function of the ionizing power of the absorbed particles, such as γ -rays or protons, and the temperature. This property can therefore be used for particle discrimination and for temperature monitoring, using pulse shape analysis. An unsupervised method that uses fuzzy clustering algorithms for particle identification based on pulse shape analysis is presented. The method is applied to discriminate between photon and proton-induced signals in CsI(Tl) scintillator detectors. The first results of a method that uses pulse shape analysis for correcting the temperature-dependent gain effect of the detector are also presented. The method aims at conserving a good energy resolution in a temperature varying environment without the need to measure the temperature of the detector externally (authors)

Elemental and mineralogical imaging of a weathered limestone rock by double-pulse micro-Laser-Induced Breakdown Spectroscopy

Science.gov (United States)

Senesi, Giorgio S.; Campanella, Beatrice; Grifoni, Emanuela; Legnaioli, Stefano; Lorenzetti, Giulia; Pagnotta, Stefano; Poggialini, Francesco; Palleschi, Vincenzo; De Pascale, Olga

2018-05-01

The present work aims to evaluate the alteration conditions of historical limestone rocks exposed to urban environment using the Laser-Induced Breakdown Spectroscopy (LIBS) technique. The approach proposed is based on the microscale three dimensional (3D) compositional imaging of the sample through double-pulse micro-Laser-Induced Breakdown Spectroscopy (DP-μLIBS) in conjunction with optical microscopy. DP-μLIBS allows to perform a quick and detailed in-depth analysis of the composition of the weathered artifact by creating a 'virtual thin section' (VTS) of the sample which can estimate the extent of the alteration processes occurred at the limestone surface. The DP-μLIBS analysis of these thin sections showed a reduction with depth of the elements (mainly Fe, Si and Na) originating from atmospheric dust, particulate deposition and the surrounding environment (due to the proximity of the sea), whereas, the LIBS signal of Ca increased in intensity from the black crust to the limestone underneath.

Development of pulse neutron coal analyzer

International Nuclear Information System (INIS)

Jing Shiwie; Gu Deshan; Qiao Shuang; Liu Yuren; Liu Linmao; Jing Shiwei

2005-01-01

This article introduced the development of pulsed neutron coal analyzer by pulse fast-thermal neutron analysis technology in the Radiation Technology Institute of Northeast Normal University. The 14 MeV pulse neutron generator and bismuth germanate detector and 4096 multichannel analyzer were applied in this system. The multiple linear regression method employed to process data solved the interferential problem of multiple elements. The prototype (model MZ-MKFY) had been applied in Changshan and Jilin power plant for about a year. The results of measuring the main parameters of coal such as low caloric power, whole total water, ash content, volatile content, and sulfur content, with precision acceptable to the coal industry, are presented

Determination of trace elements in Turkish tea leaves by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Demiralp, R.

1986-01-01

The human body continuously assimilates a variety of inorganic elements from food and the environment. Some of these elements are closely related to human health and disorder. Tea is one of the most popular stimulating beverages which is consumed by low and high income family groups in many countries. Instrumental neutron activation analysis is one of the preferred methods because information on a large number of elements can be obtained simultaneously. Five packets each of the seven commonly used brands of tea were obtained from the market. In order to determine the transfer of trace elements into the drinkable portion about 2-3g. of the tea leaves were boiled in hot water for 2 min. After filtration the used tea leaves were dried at 65 deg. C in an oven and a portion, about 200mg was used for analysis. Samples and standards were irradiated 10 min. and 2 hrs. at pneumatic system and central thimble in the TRIGA MARK-II research reactor. After irradiation, the activities of samples and standards were measured with a aoaxial Ge detector coupled to a spectroscopic amplifier. A Canbera 90 model multi- channel analyzer with an 8K memory was used for pulse height analysis. The system has a resolution of 2.0 KeV. for the 1332.5 KeV gamma ray of 60 Co. The activity of the sample and standard was compared and the element contst of the sample was calculated. (author)

A feasibility study on age-related factors of wrist pulse using principal component analysis.

Science.gov (United States)

Jang-Han Bae; Young Ju Jeon; Sanghun Lee; Jaeuk U Kim

2016-08-01

Various analysis methods for examining wrist pulse characteristics are needed for accurate pulse diagnosis. In this feasibility study, principal component analysis (PCA) was performed to observe age-related factors of wrist pulse from various analysis parameters. Forty subjects in the age group of 20s and 40s were participated, and their wrist pulse signal and respiration signal were acquired with the pulse tonometric device. After pre-processing of the signals, twenty analysis parameters which have been regarded as values reflecting pulse characteristics were calculated and PCA was performed. As a results, we could reduce complex parameters to lower dimension and age-related factors of wrist pulse were observed by combining-new analysis parameter derived from PCA. These results demonstrate that PCA can be useful tool for analyzing wrist pulse signal.

Numerical Analysis of Through Transmission Pulsed Eddy Current Testing and Effects of Pulse Width Variation

International Nuclear Information System (INIS)

Shin, Young Kil; Choi, Dong Myung

2007-01-01

By using numerical analysis methods, through transmission type pulsed eddy current (PEC) testing is modeled and PEC signal responses due to varying material conductivity, permeability, thickness, lift-off and pulse width are investigated. Results show that the peak amplitude of PEC signal gets reduced and the time to reach the peak amplitude is increased as the material conductivity, permeability, and specimen thickness increase. Also, they indicate that the pulse width needs to be shorter when evaluating the material conductivity and the plate thickness using the peak amplitude, and when the pulse width is long, the peak time is found to be more useful. Other results related to lift-off variation are reported as well

HPGe detectors timing using pulse shape analysis techniques

International Nuclear Information System (INIS)

Crespi, F.C.L.; Vandone, V.; Brambilla, S.; Camera, F.; Million, B.; Riboldi, S.; Wieland, O.

2010-01-01

In this work the Pulse Shape Analysis has been used to improve the time resolution of High Purity Germanium (HPGe) detectors. A set of time aligned signals was acquired in a coincidence measurement using a coaxial HPGe and a cerium-doped lanthanum chloride (LaCl 3 :Ce) scintillation detector. The analysis using a Constant Fraction Discriminator (CFD) time output versus the HPGe signal shape shows that time resolution ranges from 2 to 12 ns depending on the slope in the initial part of the signal. An optimization procedure of the CFD parameters gives the same final time resolution (8 ns) as the one achieved after a correction of the CFD output based on the current pulse maximum position. Finally, an algorithm based on Pulse Shape Analysis was applied to the experimental data and a time resolution between 3 and 4 ns was obtained, corresponding to a 50% improvement as compared with that given by standard CFDs.

Pulsed neutron generator system for astrobiological and geochemical exploration of planetary bodies

International Nuclear Information System (INIS)

Akkurt, Hatice; Groves, Joel L.; Trombka, Jacob; Starr, Richard; Evans, Larry; Floyd, Samuel; Hoover, Richard; Lim, Lucy; McClanahan, Timothy; James, Ralph; McCoy, Timothy; Schweitzer, Jeffrey

2005-01-01

A pulsed neutron/gamma-ray detection system for use on rovers to survey the elemental concentrations of Martian and Lunar surface and subsurface materials is evaluated. A robotic survey system combining a pulsed neutron generator (PNG) and detectors (gamma ray and neutron) can measure the major constituents to a depth of about 30 cm. Scanning mode measurements can give the major elemental concentrations while the rover is moving; analyzing mode measurements can give a detailed elemental analysis of the adjacent material when the rover is stationary. A detailed map of the subsurface elemental concentrations will provide invaluable information relevant to some of the most fundamental astrobiological questions including the presence of water, biogenic activity, life habitability and deposition processes

Tunable pulse-shaping with gated graphene nanoribbons

DEFF Research Database (Denmark)

Prokopeva, Ludmila; Emani, Naresh K.; Boltasseva, Alexandra

2014-01-01

We propose a pulse-shaper made of gated graphene nanoribbons. Simulations demonstrate tunable control over the shapes of transmitted and reflected pulses using the gating bias. Initial fabrication and characterization of graphene elements is also discussed.......We propose a pulse-shaper made of gated graphene nanoribbons. Simulations demonstrate tunable control over the shapes of transmitted and reflected pulses using the gating bias. Initial fabrication and characterization of graphene elements is also discussed....

Determination of pseudo multi-pulse production rate in GM counters by correlation analysis between signal pulses

International Nuclear Information System (INIS)

Hashimoto, Kengo; Ueda, Taizou

1996-01-01

A technique, based on the correlation analysis of signal pulses in time sequence, is proposed to determine the production rate of the pseudo multi-pulse in Geiger-Mueller (GM) counter. With a multi-channel scaler initiated by a signal pulse, subsequent pulses are recorded in sequence. The production of the multi-pulse increases the counting probability immediately after the initiation. By examining the deviation of the measured probability from the ideal counting probability, the production rate and the average lag time to produce the multi-pulse can be determined. By the use of the present technique, the production rate and the average lag time were obtained for the various GM tubes. These results indicate that the consumption of the quench gas results in a significant increase in the production rate but little variation in the lag time, and that the lag time strongly depends on the tube diameter. (author)

Cardiac output by pulse contour analysis does not match the increase measured by rebreathing during human spaceflight.

Science.gov (United States)

Hughson, Richard L; Peterson, Sean D; Yee, Nicholas J; Greaves, Danielle K

2017-11-01

Pulse contour analysis of the noninvasive finger arterial pressure waveform provides a convenient means to estimate cardiac output (Q̇). The method has been compared with standard methods under a range of conditions but never before during spaceflight. We compared pulse contour analysis with the Modelflow algorithm to estimates of Q̇ obtained by rebreathing during preflight baseline testing and during the final month of long-duration spaceflight in nine healthy male astronauts. By Modelflow analysis, stroke volume was greater in supine baseline than seated baseline or inflight. Heart rate was reduced in supine baseline so that there were no differences in Q̇ by Modelflow estimate between the supine (7.02 ± 1.31 l/min, means ± SD), seated (6.60 ± 1.95 l/min), or inflight (5.91 ± 1.15 l/min) conditions. In contrast, rebreathing estimates of Q̇ increased from seated baseline (4.76 ± 0.67 l/min) to inflight (7.00 ± 1.39 l/min, significant interaction effect of method and spaceflight, P < 0.001). Pulse contour analysis utilizes a three-element Windkessel model that incorporates parameters dependent on aortic pressure-area relationships that are assumed to represent the entire circulation. We propose that a large increase in vascular compliance in the splanchnic circulation invalidates the model under conditions of spaceflight. Future spaceflight research measuring cardiac function needs to consider this important limitation for assessing absolute values of Q̇ and stroke volume. NEW & NOTEWORTHY Noninvasive assessment of cardiac function during human spaceflight is an important tool to monitor astronaut health. This study demonstrated that pulse contour analysis of finger arterial blood pressure to estimate cardiac output failed to track the 46% increase measured by a rebreathing method. These results strongly suggest that alternative methods not dependent on pulse contour analysis are required to track cardiac function in spaceflight

Pulse-shaping mechanism in colliding-pulse mode-locked laser diodes

DEFF Research Database (Denmark)

Bischoff, Svend; Sørensen, Mads Peter; Mørk, J.

1995-01-01

The large signal dynamics of passively colliding pulse mode-locked laser diodes is studied. We derive a model which explains modelocking via the interplay of gain and loss dynamics; no bandwidth limiting element is necessary for pulse formation. It is found necessary to have both fast and slow...... absorber dynamics to achieve mode-locking. Significant chirp is predicted for pulses emitted from long lasers, in agreement with experiment. The pulse width shows a strong dependence on both cavity and saturable absorber length. (C) 1995 American Institute of Physics....

Trace element characterization of Indian vegetarian diet and its constituents by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Singh, V.K.N.; Garg, A.N.; Burte, P.P.

1995-01-01

Nutritive trace elements have been determined in a typical vegetarian diet and its various components. A hospital diet, pulses and vegetables have been characterised for 18 elements. Daily intake of elements have been compared with the International diet standards. (author). 5 refs., 1 tab

Non-destructive characterization using pulsed fast-thermal neutrons

International Nuclear Information System (INIS)

Womble, P.C.

1995-01-01

Explosives, illicit drugs, and other contraband materials contain various chemical elements in quantities and ratios that differentiate them from each other and from innocuous substances. Furthermore, the major chemical elements in coal can provide information about various parameters of importance to the coal industry. In both examples, the non-destructive identification of chemical elements can be performed using pulsed fast-thermal neutrons that, through nuclear reactions, excite the nuclei of the various elements. This technique is being currently developed for the dismantling of nuclear weapons classified as trainers, and for the on-line coal bulk analysis. (orig.)

Pulsed rf operation analysis

International Nuclear Information System (INIS)

Puglisi, M.; Cornacchia, M.

1981-01-01

The need for a very low final amplifier output impedance, always associated with class A operation, requires a very large power waste in the final tube. The recently suggested pulsed rf operation, while saving a large amount of power, increases the inherent final amplifier non linearity. A method is presented for avoiding the large signal non linear analysis and it is shown how each component of the beam induced voltage depends upon all the beam harmonics via some coupling coefficients which are evaluated

Comparative performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs

Directory of Open Access Journals (Sweden)

Sudip Bhattrai

2013-09-01

Full Text Available Combined-cycle pulse detonation engines are promising contenders for hypersonic propulsion systems. In the present study, design and propulsive performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs is presented. Analysis is done with respect to Mach number at two consecutive modes of operation: (1 Combined-cycle PDTE using a pulse detonation afterburner mode (PDA-mode and (2 combined-cycle PDTE in pulse detonation ramjet engine mode (PDRE-mode. The performance of combined-cycle PDTEs is compared with baseline afterburning turbofan and ramjet engines. The comparison of afterburning modes is done for Mach numbers from 0 to 3 at 15.24 km altitude conditions, while that of pulse detonation ramjet engine (PDRE is done for Mach 1.5 to Mach 6 at 18.3 km altitude conditions. The analysis shows that the propulsive performance of a turbine engine can be greatly improved by replacing the conventional afterburner with a pulse detonation afterburner (PDA. The PDRE also outperforms its ramjet counterpart at all flight conditions considered herein. The gains obtained are outstanding for both the combined-cycle PDTE modes compared to baseline turbofan and ramjet engines.

Transient thermal analysis of semiconductor diode lasers under pulsed operation

Science.gov (United States)

Veerabathran, G. K.; Sprengel, S.; Karl, S.; Andrejew, A.; Schmeiduch, H.; Amann, M.-C.

2017-02-01

Self-heating in semiconductor lasers is often assumed negligible during pulsed operation, provided the pulses are `short'. However, there is no consensus on the upper limit of pulse width for a given device to avoid-self heating. In this paper, we present an experimental and theoretical analysis of the effect of pulse width on laser characteristics. First, a measurement method is introduced to study thermal transients of edge-emitting lasers during pulsed operation. This method can also be applied to lasers that do not operate in continuous-wave mode. Secondly, an analytical thermal model is presented which is used to fit the experimental data to extract important parameters for thermal analysis. Although commercial numerical tools are available for such transient analyses, this model is more suitable for parameter extraction due to its analytical nature. Thirdly, to validate this approach, it was used to study a GaSb-based inter-band laser and an InP-based quantum cascade laser (QCL). The maximum pulse-width for less than 5% error in the measured threshold currents was determined to be 200 and 25 ns for the GaSb-based laser and QCL, respectively.

Compression and radiation of high-power short rf pulses. II. A novel antenna array design with combined compressor/radiator elements

KAUST Repository

Sirenko, Kostyantyn; Pazynin, Vadim L.; Sirenko, Yu K.; Bagci, Hakan

2011-01-01

The paper discusses the radiation of compressed high power short RF pulses using two different types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a compressor and a

Evaluation of a pulsed phase-locked loop system for noninvasive tracking of bone deformation under loading with finite element and strain analysis

International Nuclear Information System (INIS)

Serra-Hsu, Frederick; Cheng, Jiqi; Qin, Yi-Xian; Lynch, Ted

2011-01-01

Ultrasound has been widely used to nondestructively evaluate various materials, including biological tissues. Quantitative ultrasound has been used to assess bone quality and fracture risk. A pulsed phase-locked loop (PPLL) method has been proven for very sensitive tracking of ultrasound time-of-flight (TOF) changes. The objective of this work was to determine if the PPLL TOF tracking is sensitive to bone deformation changes during loading. The ability to noninvasively detect bone deformations has many implications, including assessment of bone strength and more accurate osteoporosis diagnostics and fracture risk prediction using a measure of bone mechanical quality. Fresh sheep femur cortical bone shell samples were instrumented with three 3-element rosette strain gauges and then tested under mechanical compression with eight loading levels using an MTS machine. Samples were divided into two groups based on internal marrow cavity content: with original marrow, or replaced with water. During compressive loading ultrasound waves were measured through acoustic transmission across the mid-diaphysis of bone. Finite element analysis (FEA) was used to describe ultrasound propagation path length changes under loading based on µCT-determined bone geometry. The results indicated that PPLL output correlates well to measured axial strain, with R 2 values of 0.70 ± 0.27 and 0.62 ± 0.29 for the marrow and water groups, respectively. The PPLL output correlates better with the ultrasound path length changes extracted from FEA. For the two validated FEA tests, correlation was improved to R 2 = 0.993 and R 2 = 0.879 through cortical path, from 0.815 and 0.794 via marrow path, respectively. This study shows that PPLL readings are sensitive to displacement changes during external bone loading, which may have potential to noninvasively assess bone strain and tissue mechanical properties

Validation of Noninvasive MOEMS-Assisted Measurement System Based on CCD Sensor for Radial Pulse Analysis

Directory of Open Access Journals (Sweden)

Rolanas Dauksevicius

2013-04-01

Full Text Available Examination of wrist radial pulse is a noninvasive diagnostic method, which occupies a very important position in Traditional Chinese Medicine. It is based on manual palpation and therefore relies largely on the practitioner’s subjective technical skills and judgment. Consequently, it lacks reliability and consistency, which limits practical applications in clinical medicine. Thus, quantifiable characterization of the wrist pulse diagnosis method is a prerequisite for its further development and widespread use. This paper reports application of a noninvasive CCD sensor-based hybrid measurement system for radial pulse signal analysis. First, artery wall deformations caused by the blood flow are calibrated with a laser triangulation displacement sensor, following by the measurement of the deformations with projection moiré method. Different input pressures and fluids of various viscosities are used in the assembled artificial blood flow system in order to test the performance of laser triangulation technique with detection sensitivity enhancement through microfabricated retroreflective optical element placed on a synthetic vascular graft. Subsequently, the applicability of double-exposure whole-field projection moiré technique for registration of blood flow pulses is considered: a computational model and representative example are provided, followed by in vitro experiment performed on a vascular graft with artificial skin atop, which validates the suitability of the technique for characterization of skin surface deformations caused by the radial pulsation.

Fabrication of Elemental Copper by Intense Pulsed Light Processing of a Copper Nitrate Hydroxide Ink.

Science.gov (United States)

Draper, Gabriel L; Dharmadasa, Ruvini; Staats, Meghan E; Lavery, Brandon W; Druffel, Thad

2015-08-05

Printed electronics and renewable energy technologies have shown a growing demand for scalable copper and copper precursor inks. An alternative copper precursor ink of copper nitrate hydroxide, Cu2(OH)3NO3, was aqueously synthesized under ambient conditions with copper nitrate and potassium hydroxide reagents. Films were deposited by screen-printing and subsequently processed with intense pulsed light. The Cu2(OH)3NO3 quickly transformed in less than 100 s using 40 (2 ms, 12.8 J cm(-2)) pulses into CuO. At higher energy densities, the sintering improved the bulk film quality. The direct formation of Cu from the Cu2(OH)3NO3 requires a reducing agent; therefore, fructose and glucose were added to the inks. Rather than oxidizing, the thermal decomposition of the sugars led to a reducing environment and direct conversion of the films into elemental copper. The chemical and physical transformations were studied with XRD, SEM, FTIR and UV-vis.

System for increasing laser pulse rate

International Nuclear Information System (INIS)

1980-01-01

A technique of static elements is disclosed for combining a plurality of laser beams having time sequenced, pulsed radiation to achieve an augmented pulse rate. The technique may also be applied in a system for combining both time sequenced pulses and frequency distinct pulses for use in a system for isotope enrichment. (author)

HARMONIC ANALYSIS OF SVPWM INVERTER USING MULTIPLE-PULSES METHOD

Directory of Open Access Journals (Sweden)

Mehmet YUMURTACI

2009-01-01

Full Text Available Space Vector Modulation (SVM technique is a popular and an important PWM technique for three phases voltage source inverter in the control of Induction Motor. In this study harmonic analysis of Space Vector PWM (SVPWM is investigated using multiple-pulses method. Multiple-Pulses method calculates the Fourier coefficients of individual positive and negative pulses of the output PWM waveform and adds them together using the principle of superposition to calculate the Fourier coefficients of the all PWM output signal. Harmonic magnitudes can be calculated directly by this method without linearization, using look-up tables or Bessel functions. In this study, the results obtained in the application of SVPWM for values of variable parameters are compared with the results obtained with the multiple-pulses method.

Soft error rate analysis methodology of multi-Pulse-single-event transients

International Nuclear Information System (INIS)

Zhou Bin; Huo Mingxue; Xiao Liyi

2012-01-01

As transistor feature size scales down, soft errors in combinational logic because of high-energy particle radiation is gaining more and more concerns. In this paper, a combinational logic soft error analysis methodology considering multi-pulse-single-event transients (MPSETs) and re-convergence with multi transient pulses is proposed. In the proposed approach, the voltage pulse produced at the standard cell output is approximated by a triangle waveform, and characterized by three parameters: pulse width, the transition time of the first edge, and the transition time of the second edge. As for the pulse with the amplitude being smaller than the supply voltage, the edge extension technique is proposed. Moreover, an efficient electrical masking model comprehensively considering transition time, delay, width and amplitude is proposed, and an approach using the transition times of two edges and pulse width to compute the amplitude of pulse is proposed. Finally, our proposed firstly-independently-propagating-secondly-mutually-interacting (FIP-SMI) is used to deal with more practical re-convergence gate with multi transient pulses. As for MPSETs, a random generation model of MPSETs is exploratively proposed. Compared to the estimates obtained using circuit level simulations by HSpice, our proposed soft error rate analysis algorithm has 10% errors in SER estimation with speed up of 300 when the single-pulse-single-event transient (SPSET) is considered. We have also demonstrated the runtime and SER decrease with the increment of P0 using designs from the ISCAS-85 benchmarks. (authors)

Research on digital multi-channel pulse height analysis techniques

International Nuclear Information System (INIS)

Xiao Wuyun; Wei Yixiang; Ai Xianyun; Ao Qi

2005-01-01

Multi-channel pulse height analysis techniques are developing in the direction of digitalization. Based on digital signal processing techniques, digital multi-channel analyzers are characterized by powerful pulse processing ability, high throughput, improved stability and flexibility. This paper analyzes key techniques of digital nuclear pulse processing. With MATLAB software, main algorithms are simulated, such as trapezoidal shaping, digital baseline estimation, digital pole-zero/zero-pole compensation, poles and zeros identification. The preliminary general scheme of digital MCA is discussed, as well as some other important techniques about its engineering design. All these lay the foundation of developing homemade digital nuclear spectrometers. (authors)

Optical selection of trace elements for discriminant analysis

International Nuclear Information System (INIS)

Rasmussen, S.E.; Erasmus, C.S.; Watterson, J.I.W.; Sellschop, J.P.F.

This report describes different methods of element selection; a combination of stepwise multivariate analysis of variance for primary element selection, and principle component analysis regression for the element interrelationship analysis. These offer a satisfactory solution to the problem of element selection

Reliability model analysis and primary experimental evaluation of laser triggered pulse trigger

International Nuclear Information System (INIS)

Chen Debiao; Yang Xinglin; Li Yuan; Li Jin

2012-01-01

High performance pulse trigger can enhance performance and stability of the PPS. It is necessary to evaluate the reliability of the LTGS pulse trigger, so we establish the reliability analysis model of this pulse trigger based on CARMES software, the reliability evaluation is accord with the statistical results. (authors)

Analysis of pulse-shape discrimination techniques for BC501A using GHz digital signal processing

International Nuclear Information System (INIS)

Rooney, B.D.; Dinwiddie, D.R.; Nelson, M.A.; Rawool-Sullivan, Mohini W.

2001-01-01

A comparison study of pulse-shape analysis techniques was conducted for a BC501A scintillator using digital signal processing (DSP). In this study, output signals from a preamplifier were input directly into a 1 GHz analog-to-digital converter. The digitized data obtained with this method was post-processed for both pulse-height and pulse-shape information. Several different analysis techniques were evaluated for neutron and gamma-ray pulse-shape discrimination. It was surprising that one of the simplest and fastest techniques resulted in some of the best pulse-shape discrimination results. This technique, referred to here as the Integral Ratio technique, was able to effectively process several thousand detector pulses per second. This paper presents the results and findings of this study for various pulse-shape analysis techniques with digitized detector signals.

Resonance-enhanced laser-induced plasma spectroscopy for sensitive elemental analysis: Elucidation of enhancement mechanisms

International Nuclear Information System (INIS)

Lui, S.L.; Cheung, N.H.

2002-01-01

When performing laser-induced plasma spectroscopy for elemental analysis, the analyte signal-to-noise ratio increased from four to over fifty if the plume was reheated by a dye laser pulse tuned to resonant absorption. Time-resolved studies showed that the enhancement was not due to resonance photoionization. Rather, efficient and controlled rekindling of a larger plume volume was the key mechanism. The signal-to-noise ratio further increased to over a hundred if the atmosphere was replaced by a low-pressure heavy inert gas. The ambient gas helped confine and thermally insulate the expanding vapor

Application of different methodologies in the preparation of organic matrices for determination of trace elements by differential pulse anodic stripping voltammetry

International Nuclear Information System (INIS)

Sisti, Cristina

2001-01-01

The determination of trace elements in food samples is of great importance for the human health, considering the factors of essentiality and toxicity. On the other hand, the chemical analysis is largely affected for the steps of sample preparation; laboratory contamination of the sample and the reagents or still volatilization and losses of the elements. If these parameters are not controlled the achieved precision and accuracy could be low. In this work, the content of zinc, cadmium, lead and copper was determined in adults diet samples collected by duplicate portion technique and bovine liver, applying the differential pulse anodic stripping voltametry - (DP-ASV) technique. In the digestion of the matrices in acid medium, conventional methodologies were used, conductive heating in open recipients and equipment with microwaves source in open and closed vessels. The best procedure was the sample digestion by microwaves, in closed vessels and the other treatments made in controlled atmosphere with hood laminar-airflow class 100. The established methodology was validated with the use of a certified sample as reference (NIST - bovine liver 1577b). (author)

A Dual Super-Element Domain Decomposition Approach for Parallel Nonlinear Finite Element Analysis

Science.gov (United States)

Jokhio, G. A.; Izzuddin, B. A.

2015-05-01

This article presents a new domain decomposition method for nonlinear finite element analysis introducing the concept of dual partition super-elements. The method extends ideas from the displacement frame method and is ideally suited for parallel nonlinear static/dynamic analysis of structural systems. In the new method, domain decomposition is realized by replacing one or more subdomains in a "parent system," each with a placeholder super-element, where the subdomains are processed separately as "child partitions," each wrapped by a dual super-element along the partition boundary. The analysis of the overall system, including the satisfaction of equilibrium and compatibility at all partition boundaries, is realized through direct communication between all pairs of placeholder and dual super-elements. The proposed method has particular advantages for matrix solution methods based on the frontal scheme, and can be readily implemented for existing finite element analysis programs to achieve parallelization on distributed memory systems with minimal intervention, thus overcoming memory bottlenecks typically faced in the analysis of large-scale problems. Several examples are presented in this article which demonstrate the computational benefits of the proposed parallel domain decomposition approach and its applicability to the nonlinear structural analysis of realistic structural systems.

Tests of experimental fuel elements by the method of nuclear-thermal pulse loadings in 'HYDRA' reactor

International Nuclear Information System (INIS)

Nastoyashchaya, O.V.; Lebedev, Yu. M.; Chechurov, A.M.; Khvostionov, Ye

1997-01-01

The results of tests of experimental fuel elements with uranium dioxide fuel composition embedded in Al and Zr matrix with the enrichment from 90% to 36% in respect to U-235 performed at the pulse 'HYDRA' reactor are presented in this paper. Testing is performed in the frame-work of extensive research program studying the behavior of fuel elements (FE) of research and mini nuclear power systems in case of practically immediate energy release in the fuel taking place during the RIA-type accidents. Duration of the neutron pulse when testing in 'HYDRA' reactor is from 7 to 20 ms. The methods of diagnostics of the state of FE prior to and after testing in the reactor are developed and verified. Mathematical model describing temperature fields inside the FE in the process of testing. and accounting for non-uniformity of fuel composition has been developed in order to summarize experimental results. Experimental data on the limiting values of the energy density leading to deformation and degradation of FE depending on the type of fuel composition have been obtained and the mechanisms for the development of these processes have been determined. The nature of physical-chemical processes taking place in the fuel composition and fuel cladding depending on material composition under different levels of energy deposition is demonstrated. The data on hydrogen generation and radioactive product release out of fuel after failure of FE are presented. (author)

Effect of a Roughness Element on the Receptivity of a Hypersonic Boundary Layer over a Blunt Cone Due to Pulse Entropy Disturbance with a Single Frequency

Directory of Open Access Journals (Sweden)

Zhenqing Wang

2018-05-01

Full Text Available A high-order finite difference method was used to simulate the hypersonic flow field over a blunt cone with different height roughness elements. The unsteady flow field induced by pulse disturbances was analyzed and compared with that under continuous disturbances. The temporal and spatial evolution characteristics of disturbances in the boundary layer were investigated and the propagation of different disturbance modes in the boundary layer was researched through the fast Fourier transform (FFT method. The effect of the roughness element on the receptivity characteristic of the hypersonic boundary layer under pulse entropy disturbances was explored. The results showed that the different mode disturbances near roughness in the boundary layer were enlarged in the upstream half of the roughness element and suppressed in the downstream half. However, the effect of roughness weakened gradually as the disturbance frequency increased in the boundary layer. A phenomenon of mode competition in the downstream region of the roughness element exited. As the disturbances propagated downstream, the fundamental mode gradually became the dominant mode. A certain promotion effect on the mode competition was induced by the roughness element and the effect was enhanced with the increase in the roughness element height.

A new coding concept for fast ultrasound imaging using pulse trains

DEFF Research Database (Denmark)

Misaridis, T.; Jensen, Jørgen Arendt

2002-01-01

Frame rate in ultrasound imaging can he increased by simultaneous transmission of multiple beams using coded waveforms. However, the achievable degree of orthogonality among coded waveforms is limited in ultrasound, and the image quality degrades unacceptably due to interbeam interference....... In this paper, an alternative combined time-space coding approach is undertaken. In the new method all transducer elements are excited with short pulses and the high time-bandwidth (TB) product waveforms are generated acoustically. Each element transmits a short pulse spherical wave with a constant transmit...... delay from element to element, long enough to assure no pulse overlapping for all depths in the image. Frequency shift keying is used for "per element" coding. The received signals from a point scatterer are staggered pulse trains which are beamformed for all beam directions and further processed...

A Comparative Analysis of the Universal Elements of Music and the Fetal Environment

Science.gov (United States)

Teie, David

2016-01-01

Although the idea that pulse in music may be related to human pulse is ancient and has recently been promoted by researchers (Parncutt, 2006; Snowdon and Teie, 2010), there has been no ordered delineation of the characteristics of music that are based on the sounds of the womb. I describe features of music that are based on sounds that are present in the womb: tempo of pulse (pulse is understood as the regular, underlying beat that defines the meter), amplitude contour of pulse, meter, musical notes, melodic frequency range, continuity, syllabic contour, melodic rhythm, melodic accents, phrase length, and phrase contour. There are a number of features of prenatal development that allow for the formation of long-term memories of the sounds of the womb in the areas of the brain that are responsible for emotions. Taken together, these features and the similarities between the sounds of the womb and the elemental building blocks of music allow for a postulation that the fetal acoustic environment may provide the bases for the fundamental musical elements that are found in the music of all cultures. This hypothesis is supported by a one-to-one matching of the universal features of music with the sounds of the womb: (1) all of the regularly heard sounds that are present in the fetal environment are represented in the music of every culture, and (2) all of the features of music that are present in the music of all cultures can be traced to the fetal environment. PMID:27555828

Repeated pulsed x-ray emission equipment

International Nuclear Information System (INIS)

Terauchi, Hikaru; Iida, Satoshi

1982-01-01

X-ray diffraction technique has been applied to determine the spatial positions of atoms which compose a material, and it is needless to say that the technique is a fundamental means regardless of the fields of research. However, the application of X-ray diffraction to the research on physical properties has been so far limited to know the spatial positions of atoms or molecules under thermal equilibrium condition. The addition of time element to the conventional technique, that is, the analysis of material structure including the time-varying processes under non-equilibrium conditions, is considered to approach the elucidation of the essence of materials. The authors call this dynamic structural analysis. The authors have planned to analyze X-ray diffraction intensity which has the resolution of about 10 -8 s in the real time which is conjugate with energy. However, present pulsed X-ray sources are not suitable for diffraction experiment because the pulse width is too long or X-ray wavelength is too short. Accordingly, the authors have made for trial a pulsed X-ray source for diffraction experiment. Its specifications are: diode voltage (X-ray tube voltage) from 200 to 300 kV, diode current from 2 to 5 kA, pulse width of about 30ns, maximum repetition frequency 10 pps, and X-ray focus size of 2 mm diameter. One of the features of this source is the repeated generation of pulsed X-ray. This is the first trial in the world, and is indispensable to the dynamic structural analysis described above. The quality of the emitted X-ray is also written. (Wakatsuki, Y.)

Properties of gamma-ray burst time profiles using pulse decomposition analysis

Energy Technology Data Exchange (ETDEWEB)

Lee, A.

2000-02-08

The time profiles of many gamma-ray bursts consist of distinct pulses, which offers the possibility of characterizing the temporal structure of these bursts using a relatively small set of pulse shape parameters. This pulse decomposition analysis has previously been performed on a small sample of bright long bursts using binned data from BATSE, which comes in several data types, and on a sample of short bursts using the BATSE Time-Tagged Event (TTE) data type. The authors have developed an interactive pulse-fitting program using the phenomenological pulse model of Norris, et. al. and a maximum-likelihood fitting routine. They have used this program to analyze the Time-to-Spill (TTS) data for all bursts observed by BATSE up through trigger number 2000, in all energy channels for which TTS data is available. They present statistical information on the attributes of pulses comprising these bursts, including relations between pulse characteristics through the course of a burst. They carry out simulations to determine the biases that their procedures may introduce. They find that pulses tend to have shorter rise times than decay times, and tend to be narrower and peak earlier at higher energies. They also find that pulse brightness, pulse width, and pulse hardness ratios do not evolve monotonically within bursts, but that the ratios of pulse rise times to decay times tends to decrease with time within bursts.

Pulse-width discriminators

International Nuclear Information System (INIS)

Budyashov, Yu.G.; Grebenyuk, V.M.; Zinov, V.G.

1978-01-01

A pulse duration discriminator is described which is intended for processing signals from multilayer scintillators. The basic elements of the scintillator are: an input gate, a current generator, an integrating capacitor, a Schmidt trigger and an anticoincidence circuit. The basic circuit of the discriminator and its time diagrams explaining its operating are given. The discriminator is based on microcircuits. Pulse duration discrimination threshold changes continuously from 20 to 100 ns, while its amplitude threshold changes within 20 to 100 mV. The temperature instability of discrimination thresholds (both in pulse width and in amplitude) is better than 0.1 per cent/deg C

Copper vapour laser with an efficient semiconductor pump generator having comparable pump pulse and output pulse durations

Energy Technology Data Exchange (ETDEWEB)

Yurkin, A A [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2016-03-31

We report the results of experimental studies of a copper vapour laser with a semiconductor pump generator capable of forming virtually optimal pump pulses with a current rise steepness of about 40 A ns{sup -1} in a KULON LT-1.5CU active element. To maintain the operating temperature of the active element's channel, an additional heating pulsed oscillator is used. High efficiency of the pump generator is demonstrated. (lasers)

Why do probabilistic finite element analysis ?

CERN Document Server

Thacker, Ben H

2008-01-01

The intention of this book is to provide an introduction to performing probabilistic finite element analysis. As a short guideline, the objective is to inform the reader of the use, benefits and issues associated with performing probabilistic finite element analysis without excessive theory or mathematical detail.

Femtosecond pulse shaping using plasmonic snowflake nanoantennas

Energy Technology Data Exchange (ETDEWEB)

Tok, Ruestue Umut; Sendur, Kuersat [Sabanci University, Orhanli-Tuzla, 34956, Istanbul (Turkey)

2011-09-15

We have theoretically demonstrated femtosecond pulse manipulation at the nanoscale using the plasmonic snowflake antenna's ability to localize light over a broad spectrum. To analyze the interaction of the incident femtosecond pulse with the plasmonic nanoantenna, we first decompose the diffraction limited incident femtosecond pulse into its spectral components. The interaction of each spectral component with the nanoantenna is analyzed using finite element technique. The time domain response of the plasmonic antenna is obtained using inverse Fourier transformation. It is shown that the rich spectral characteristics of the plasmonic snowflake nanoantenna allow manipulation of the femtosecond pulses over a wide spectrum. Light localization around the gap region of the nanoantenna is shown for femtosecond pulses. As the alignment of incident light polarization is varied, different antenna elements oscillate, which in turn creates a different spectrum and a distinct femtosecond response.

Solid-state pulse modulator for a 1.7-MW X-band magnetron

International Nuclear Information System (INIS)

Choi, Jaegu; Shin, Yongmoon; Choi, Youngwook; Kim, Kwanho

2014-01-01

Medical linear accelerators (LINAC) for cancer treatment require pulse modulators to generate high-power pulses with a fast rise time, flat top and short duration to drive high-power magnetrons. Solid-state pulse modulators (SSPM) for medical LINACs that use high power semiconductor switches with high repetition rates, high stability and long lifetimes have been introduced to replace conventional linear-type pulse generators that use gaseous discharge switches. In this paper, the performance of a developed SSPM, which mainly consists of a capacitor charger, an insulated-gate bipolar transistor (IGBT) - capacitor stack and a pulse transformer, is evaluated with a dummy load and an X-band magnetron load. A theoretical analysis of the pulse transformer, which is a critical element of the SSPM, is carried out. The output pulse has a fast rise time and low droop, such that the modulator can drive the X-band magnetron.

Nondestructive analysis of the natural uranium mass through the measurement of delayed neutrons using the technique of pulsed neutron source

International Nuclear Information System (INIS)

Coelho, Paulo Rogerio Pinto

1979-01-01

This work presents results of non destructive mass analysis of natural uranium by the pulsed source technique. Fissioning is produced by irradiating the test sample with pulses of 14 MeV neutrons and the uranium mass is calculated on a relative scale from the measured emission of delayed neutrons. Individual measurements were normalised against the integral counts of a scintillation detector measuring the 14 MeV neutron intensity. Delayed neutrons were measured using a specially constructed slab detector operated in anti synchronism with the fast pulsed source. The 14 MeV neutrons were produced via the T(d,n) 4 He reaction using a 400 kV Van de Graaff accelerated operated at 200 kV in the pulsed source mode. Three types of sample were analysed, namely: discs of metallic uranium, pellets of sintered uranium oxide and plates of uranium aluminium alloy sandwiched between aluminium. These plates simulated those of Material Testing Reactor fuel elements. Results of measurements were reproducible to within an overall error in the range 1.6 to 3.9%; the specific error depending on the shape, size and mass of the sample. (author)

Phytochemical screening, proximate and elemental analysis of ...

African Journals Online (AJOL)

Citrus sinensis was screened for its phytochemical composition and was evaluated for the proximate and elemental analysis. The phytochemical analysis indicated the presence of reducing sugar, saponins, cardiac glycosides, tannins and flavonoids. The elemental analysis indicated the presence of the following mineral ...

Elemental analysis with external-beam PIXE

Science.gov (United States)

Lin, E. K.; Wang, C. W.; Teng, P. K.; Huang, Y. M.; Chen, C. Y.

1992-05-01

A beamline system and experimental setup has been established for elemental analysis using PIXE with an external beam. Experiments for the study of the elemental composition of ancient Chinese potsherds (the Min and Ching ages) were performed. Continuum X-ray spectra from the samples bombarded by 3 MeV protons have been measured with a Si(Li) detector. From the analysis of PIXE data, the concentration of the main elements (Al, Si, K, and Ca) and of more than ten trace elements in the matrices and glazed surfaces were determined. Results for two different potsherds are presented, and those obtained from the glaze colorants are compared with the results of measurements on a Ching blue-and-white porcelain vase.

Chemical analysis of rare earth elements

International Nuclear Information System (INIS)

Tsukahara, Ryoichi; Sakoh, Takefumi; Nagai, Iwao

1994-01-01

Recently attention has been paid to ICP-AES or ICP-MS, and the reports on the analysis of rare earth elements by utilizing these methods continue to increase. These reports have become to take about 30% of the reports on rare earth analysis, and this is because these methods are highly sensitive to rare earth elements, and also these methods have spread widely. In ICP-AES and ICP-MS, mostly solution samples are measured, therefore, solids must be made into solution. At the time of quantitatively determining the rare earth elements of low concentration, separation and concentration are necessary. Referring to the literatures reported partially in 1990 and from 1991 to 1993, the progress of ICP-AES and ICP-MS is reported. Rare earth oxides and the alloys containing rare earth elements are easily decomposed with acids, but the decomposition of rocks is difficult, and its method is discussed. The separation of the rare earth elements from others in geochemical samples, cation exchange process is frequently utilized. Also solvent extraction process has been studied. For the separation of rare earth elements mutually, chromatography is used. The spectral interference in spectral analysis was studied. The comparison of these methods with other methods is reported. (K.I)

Finite element analysis of piezoelectric materials

International Nuclear Information System (INIS)

Lowrie, F.; Stewart, M.; Cain, M.; Gee, M.

1999-01-01

This guide is intended to help people wanting to do finite element analysis of piezoelectric materials by answering some of the questions that are peculiar to piezoelectric materials. The document is not intended as a complete beginners guide for finite element analysis in general as this is better dealt with by the individual software producers. The guide is based around the commercial package ANSYS as this is a popular package amongst piezoelectric material users, however much of the information will still be useful to users of other finite element codes. (author)

Dynamical analysis of a PWR internals using super-elements in an integrated 3-D model model. Part 1: model description and static tests

International Nuclear Information System (INIS)

Jesus Miranda, C.A. de.

1992-01-01

An integrated 3-D model of a research PWR reactor core support internals structures was developed for its dynamic analyses. The static tests for the validation of the model are presented. There are about 90 super-elements with, approximately, 85000 degrees of freedom (DoF), 8200 masters DoF, 12000 elements with about 8400 thin shell elements. A DEC VAX computer 11/785 model and the ANSYS program were used. If impacts occurs the spectral seismic analysis will be changed to a non-linear one with direct integration of the displacement pulse derived from the seismic accelerogram. This last will be obtained from the seismic acceleration response spectra. (author)

Pulse shape analysis for γ-ray tracking. Part I: Pulse shape simulation with JASS

International Nuclear Information System (INIS)

Schlarb, M.; Gernhaeuser, R.; Klupp, S.; Kruecken, R.

2011-01-01

Next-generation γ -ray spectrometers based on highly segmented HPGe detectors are using the recent technique of γ -ray tracking to significantly improve on efficiency and Doppler correction capabilities. A precise reconstruction of the individual interaction locations within the active material is possible through the use of pulse shape analysis (PSA) which, in turn, demands an accurate knowledge of the detector response. We developed JASS, a Java-based simulation software package to generate pulse shapes for the AGATA detectors from physics constraints and basic material parameters. For verifying the simulation experimental data from a coincidence scan with known interaction locations was used. The achieved position resolution, in the order of a few millimeters, is within the requirements of the γ -ray tracking array. (orig.)

Finite element analysis theory and application with ANSYS

CERN Document Server

Moaveni, Saeed

2015-01-01

For courses in Finite Element Analysis, offered in departments of Mechanical or Civil and Environmental Engineering. While many good textbooks cover the theory of finite element modeling, Finite Element Analysis: Theory and Application with ANSYS is the only text available that incorporates ANSYS as an integral part of its content. Moaveni presents the theory of finite element analysis, explores its application as a design/modeling tool, and explains in detail how to use ANSYS intelligently and effectively. Teaching and Learning Experience This program will provide a better teaching and learning experience-for you and your students. It will help: *Present the Theory of Finite Element Analysis: The presentation of theoretical aspects of finite element analysis is carefully designed not to overwhelm students. *Explain How to Use ANSYS Effectively: ANSYS is incorporated as an integral part of the content throughout the book. *Explore How to Use FEA as a Design/Modeling Tool: Open-ended design problems help stude...

Chemical and physical analysis on hard tissues after irradiation with short pulse Nd:YAG laser

International Nuclear Information System (INIS)

Pereira, Andrea Antunes

2003-01-01

This work reports on a study that was designed to investigate chemical, physical and morphological alterations in the dental enamel surface. The influence of application of laser in enamel surface by microscopic technical, X-ray fluorescence for chemical analysis, physical property as well as hardness and thermal analysis with Nd:YAG laser is also pointed out. A prototype of Nd:YAG (Q-switched) laser developed at the Center of Lasers and Applications - Institute of Energetic and Nuclear Research, aiming applications in the Medical Sciences that typical wavelength of 1.064 nm was used. The modifications in human dental enamel chemical composition for major and trace elements are here outlined. The accuracy of procedures was performed by analysis of natural hydroxyapatite as standard reference material. The identification and quantification of the chemical elements presented in the dental tissue samples were performed trough EDS, XRF and INAA. We determined the rate Calcium/Phosphorus (Ca/P) for different techniques. We performed an analysis in different regions of the surface and for different areas allowing a description of the chemical change in the total area of the specimen and the assessment of the compositional homogeneity of the each specimen. A comparison between XRF and INAA is presented. Based on morphological analysis of the irradiated surfaces with short pulse Nd:YAG laser we determined the area surrounded by the irradiation for the parameters for this thesis, and this technique allowed us to visualize the regions of fusion and re-solidification. The energy densities ranged from 10 J/cm 2 to 40 J/cm 2 , with pulse width of 6, 10 e 200 ns, and repetition rates of 5 and 7 Hz. In this thesis, FTIR-spectroscopy is used to analyze powder of mineralized tissue as well as enamel, dentine, root and cementum for human and bovine teeth after irradiation with short-pulse Nd:YAG laser. Characteristic spectra were obtained for the proteins components and mineral

New neutron imaging using pulsed sources. Characteristics of a pulsed neutron source and principle of pulsed neutron imaging

International Nuclear Information System (INIS)

Kiyanagi, Yoshiaki

2012-01-01

Neutron beam is one of important tools to obtain the transmission image of an object. Until now, steady state neutron sources such as reactors are mainly used for this imaging purpose. Recently, it has been demonstrated that pulsed neutron imaging based on accelerator neutron sources can provide a real-space distribution of physical information of materials such as crystallographic structure, element, temperature, hydrogen bound state, magnetic field and so on, by analyzing wavelength dependent transmission spectrum, which information cannot be observed or difficult to obtain with a traditional imaging method using steady state neutrons. Here, characteristics of the pulsed neutron source and principle of the pulsed neutron imaging are explained as a basic concept of the new method. (author)

Instrumental trace element analysis of California market milk

International Nuclear Information System (INIS)

Ragaini, R.C.; Langhorst, A.L.; Ralston, H.R.; Heft, R.

1975-01-01

Trace element analysis for 15 elements (Zn, Na, Br, Rb, Sr, Mg, Al, Ca, Cl, I, K, Fe, Co, Se, Cs) was carried out on 32 samples of California market milk and 6 samples of Colorado milk in a pilot study of toxic and nutrient trace elements in the soil-forage-cow-milk food chain. The techniques of instrumental neutron activation analysis and x-ray fluorescence analysis are described. Sample collection, preparation, analysis, and data reduction procedures are discussed. The mean values and variations of trace element concentrations in milk are compared to data from other studies. (U.S.)

Finite elements for analysis and design

CERN Document Server

Akin, J E; Davenport, J H

1994-01-01

The finite element method (FEM) is an analysis tool for problem-solving used throughout applied mathematics, engineering, and scientific computing. Finite Elements for Analysis and Design provides a thoroughlyrevised and up-to-date account of this important tool and its numerous applications, with added emphasis on basic theory. Numerous worked examples are included to illustrate the material.Key Features* Akin clearly explains the FEM, a numerical analysis tool for problem-solving throughout applied mathematics, engineering and scientific computing* Basic theory has bee

Cryosurgery with Pulsed Electric Fields

Science.gov (United States)

Daniels, Charlotte S.; Rubinsky, Boris

2011-01-01

This study explores the hypothesis that combining the minimally invasive surgical techniques of cryosurgery and pulsed electric fields will eliminate some of the major disadvantages of these techniques while retaining their advantages. Cryosurgery, tissue ablation by freezing, is a well-established minimally invasive surgical technique. One disadvantage of cryosurgery concerns the mechanism of cell death; cells at high subzero temperature on the outer rim of the frozen lesion can survive. Pulsed electric fields (PEF) are another minimally invasive surgical technique in which high strength and very rapid electric pulses are delivered across cells to permeabilize the cell membrane for applications such as gene delivery, electrochemotherapy and irreversible electroporation. The very short time scale of the electric pulses is disadvantageous because it does not facilitate real time control over the procedure. We hypothesize that applying the electric pulses during the cryosurgical procedure in such a way that the electric field vector is parallel to the heat flux vector will have the effect of confining the electric fields to the frozen/cold region of tissue, thereby ablating the cells that survive freezing while facilitating controlled use of the PEF in the cold confined region. A finite element analysis of the electric field and heat conduction equations during simultaneous tissue treatment with cryosurgery and PEF (cryosurgery/PEF) was used to study the effect of tissue freezing on electric fields. The study yielded motivating results. Because of decreased electrical conductivity in the frozen/cooled tissue, it experienced temperature induced magnified electric fields in comparison to PEF delivered to the unfrozen tissue control. This suggests that freezing/cooling confines and magnifies the electric fields to those regions; a targeting capability unattainable in traditional PEF. This analysis shows how temperature induced magnified and focused PEFs could be used to

Cryosurgery with pulsed electric fields.

Directory of Open Access Journals (Sweden)

Charlotte S Daniels

Full Text Available This study explores the hypothesis that combining the minimally invasive surgical techniques of cryosurgery and pulsed electric fields will eliminate some of the major disadvantages of these techniques while retaining their advantages. Cryosurgery, tissue ablation by freezing, is a well-established minimally invasive surgical technique. One disadvantage of cryosurgery concerns the mechanism of cell death; cells at high subzero temperature on the outer rim of the frozen lesion can survive. Pulsed electric fields (PEF are another minimally invasive surgical technique in which high strength and very rapid electric pulses are delivered across cells to permeabilize the cell membrane for applications such as gene delivery, electrochemotherapy and irreversible electroporation. The very short time scale of the electric pulses is disadvantageous because it does not facilitate real time control over the procedure. We hypothesize that applying the electric pulses during the cryosurgical procedure in such a way that the electric field vector is parallel to the heat flux vector will have the effect of confining the electric fields to the frozen/cold region of tissue, thereby ablating the cells that survive freezing while facilitating controlled use of the PEF in the cold confined region. A finite element analysis of the electric field and heat conduction equations during simultaneous tissue treatment with cryosurgery and PEF (cryosurgery/PEF was used to study the effect of tissue freezing on electric fields. The study yielded motivating results. Because of decreased electrical conductivity in the frozen/cooled tissue, it experienced temperature induced magnified electric fields in comparison to PEF delivered to the unfrozen tissue control. This suggests that freezing/cooling confines and magnifies the electric fields to those regions; a targeting capability unattainable in traditional PEF. This analysis shows how temperature induced magnified and focused

The concept of biologically motivated time-pulse information processing for design and construction of multifunctional devices of neural logic

Science.gov (United States)

Krasilenko, Vladimir G.; Nikolsky, Alexander I.; Lazarev, Alexander A.; Sholohov, V. I.

2004-04-01

On the basis of the analysis of advanced approaches and optoelectronic systems for realization of various logics: two-valued, multi-valued, neural, continuous and others the biologically motivated time-pulse conception for building of multifunctional reconfigurable universal elements with programmable tuning for neurobiologic is grounded. The concept consists in usage of preliminary conversion of multi-level or continuous optic 2D signals into durations of time intervals (the conversion to a temporal area) and further use of time-pulse two-level digital signals that allows to ensure fast tuning to a required function of two-valued, multi-valued and other logics. It is shown that optoelectronic pulse-phase and pulse-width modulators (PPM and PWM) are the base elements for that. Time-pulse coding universal elements for matrix two-valued and multi-valued logics and structural-functional design of universal time-pulse coding elements for neural (continuous) logic are considered in the article. PPMs realized on 1.5μm technology CMOS transistors are considered. The PPMs have parameters: the input photocurrent range is 10nA...10μA the conversion period is 10μs...1ms the conversion relative error is 0.1...1%; the conversion law is ramp; the supply voltage is 3V and the power consumption is 83μW. The small power consumption of such PPMs enables successfully their integration in 2Darray with size of 128x128 elements and more and productivity equals 1...10 Giga continuous logic operations per sec.

Application of the pulsed neutron technique on the reactors ALIZE - AQUILON (1963); Application de la methode des neutrons pulses sur les piles ALIZE et AQUILON (1963)

Energy Technology Data Exchange (ETDEWEB)

Jacquemart, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Different methods of measuring the ratio effective delayed fraction / prompt neutron lifetime, {alpha}{sub c}, are described. According to the classic pulsed neutron technique the negative reactivity due to a localized absorber is given by {rho} / {beta}{sub eff} = {alpha} / {alpha}{sub c} -1 Experiments are reported which show that in this case {alpha}{sub c} can not be considered constant for large reactivities. The absorber element distorts the flux in the system, increasing the importance of the reflector. An application of the pulsed neutron method to the measurement of critical distributed boron concentrations of various absorber elements is described. Less time is required than for the usual super-critical techniques, and the experimental analysis is simplified. It is interesting to note that the results are not influenced by the spectral sensitivity of the control element. A modified pulsed neutron method has been tried out. This procedure was used to determine by measurements at sub-critical the critical water level of uranium-heavy water lattices with a high precision. (author) [French] Differents modes operatoires pour definir la valeur du rapport pourcentage effectif de neutrons retardes / temps de vie, {alpha}{sub c}, sont exposes. La methode classique par neutrons pulses definit l'anti-reactivite d'un element absorbant a partir de la relation: {rho} / {beta}{sub eff} {alpha} / {alpha}{sub c} -1 Les manipulations effectuees montrent qu'on ne peut considerer dans ce cas {alpha}{sub c} constant pour de tres grandes anti-reactivites. L'absorbant introduit dans la pile deforme le flux et augmente l'importance du reflecteur. Une application de la methode des neutrons pulses pour mesurer le titre critique en mg de B/l de divers absorbants est signalee. Les operations sont effectuees en regime sous-critique avec un certain gain de temps et une grande facilite de depouillement. Il est interessant de noter que les resultats ne sont pas affectes par la

Application of the pulsed neutron technique on the reactors ALIZE - AQUILON (1963); Application de la methode des neutrons pulses sur les piles ALIZE et AQUILON (1963)

Energy Technology Data Exchange (ETDEWEB)

Jacquemart, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Different methods of measuring the ratio effective delayed fraction / prompt neutron lifetime, {alpha}{sub c}, are described. According to the classic pulsed neutron technique the negative reactivity due to a localized absorber is given by {rho} / {beta}{sub eff} = {alpha} / {alpha}{sub c} -1 Experiments are reported which show that in this case {alpha}{sub c} can not be considered constant for large reactivities. The absorber element distorts the flux in the system, increasing the importance of the reflector. An application of the pulsed neutron method to the measurement of critical distributed boron concentrations of various absorber elements is described. Less time is required than for the usual super-critical techniques, and the experimental analysis is simplified. It is interesting to note that the results are not influenced by the spectral sensitivity of the control element. A modified pulsed neutron method has been tried out. This procedure was used to determine by measurements at sub-critical the critical water level of uranium-heavy water lattices with a high precision. (author) [French] Differents modes operatoires pour definir la valeur du rapport pourcentage effectif de neutrons retardes / temps de vie, {alpha}{sub c}, sont exposes. La methode classique par neutrons pulses definit l'anti-reactivite d'un element absorbant a partir de la relation: {rho} / {beta}{sub eff} {alpha} / {alpha}{sub c} -1 Les manipulations effectuees montrent qu'on ne peut considerer dans ce cas {alpha}{sub c} constant pour de tres grandes anti-reactivites. L'absorbant introduit dans la pile deforme le flux et augmente l'importance du reflecteur. Une application de la methode des neutrons pulses pour mesurer le titre critique en mg de B/l de divers absorbants est signalee. Les operations sont effectuees en regime sous-critique avec un certain gain de temps et une grande facilite de depouillement. Il est interessant de noter que les resultats ne sont pas

The Real-time Frequency Spectrum Analysis of Neutron Pulse Signal Series

International Nuclear Information System (INIS)

Tang Yuelin; Ren Yong; Wei Biao; Feng Peng; Mi Deling; Pan Yingjun; Li Jiansheng; Ye Cenming

2009-01-01

The frequency spectrum analysis of neutron pulse signal is a very important method in nuclear stochastic signal processing Focused on the special '0' and '1' of neutron pulse signal series, this paper proposes new rotation-table and realizes a real-time frequency spectrum algorithm under 1G Hz sample rate based on PC with add, address and SSE. The numerical experimental results show that under the count rate of 3X10 6 s -1 , this algorithm is superior to FFTW in time-consumption and can meet the real-time requirement of frequency spectrum analysis. (authors)

Finite Element Analysis of Pipe T-Joint

OpenAIRE

P.M.Gedkar; Dr. D.V. Bhope

2012-01-01

This paper reports stress analysis of two pressurized cylindrical intersection using finite element method. The different combinations of dimensions of run pipe and the branch pipe are used to investigate thestresses in pipe at the intersection. In this study the stress analysis is accomplished by finite element package ANSYS.

Determination of transport and reaction swarm coefficients from the analysis of complex transient pulses from the pulsed Townsend experiment

International Nuclear Information System (INIS)

Bekstein, A; De Urquijo, J; Rodríguez-Luna, J C; Juárez, A M; Ducasse, O

2012-01-01

We present in this paper the interpretation and analysis of transient pulses from a pulsed Townsend experiment by solving the continuity equations of the charged carriers (electrons and ions) involved in the avalanche. The set of second order partial differential equations is solved by SIMAV, a simulator designed specifically for the pulsed Townsend avalanche. Complex situations involving processes such as electron detachment, ion-molecule reactions, Penning ionization and secondary electron emission from ion impact at the cathode, virtually impossible to solve analytically, are discussed here to illustrate the capability of the simulator to help explain the various reaction processes involved in the avalanche, and also to derive some of the transport and reaction coefficients.

Double-pulse laser-induced breakdown spectroscopy analysis of scales from petroleum pipelines

International Nuclear Information System (INIS)

o – CEP 24210-346 – Niterói, Rio de Janeiro (Brazil))" data-affiliation=" (Physics Department of University Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no – CEP 24210-346 – Niterói, Rio de Janeiro (Brazil))" >Cavalcanti, G.H.; Rocha, A.A.; Damasceno, R.N.; Legnaioli, S.; Lorenzetti, G.; Pardini, L.; Palleschi, V.

2013-01-01

Pipeline scales from the Campos Bay Petroleum Field near Rio de Janeiro, Brazil have been analyzed by both Raman spectroscopy and by laser-induced breakdown spectroscopy (LIBS) using a double-pulse, calibration-free approach. Elements that are characteristic of petroleum (e.g. C, H, N, O, Mg, Na, Fe and V) were detected, in addition to the Ca, Al, and Si which form the matrix of the scale. The LIBS results were compared with the results of micro-Raman spectroscopy, which confirmed the nature of the incrustations inferred by the LIBS analysis. Results of this preliminary study suggest that diffusion of pipe material into the pipeline intake column plays an important role in the growth of scale. Thanks to the simplicity and relative low cost of equipment and to the fact that no special chemical pre-treatment of the samples is needed, LIBS can offer very fast acquisition of data and the possibility of in situ measurements. LIBS could thus represent an alternative or complementary method for the chemical characterization of the scales by comparison to conventional analytical techniques, such as X-ray diffraction or X-ray fluorescence. - Highlights: • Samples of scales from petroleum pipelines were analyzed using double pulse LIBS. • LIBS is proposed as an alternative method to conventional analytical techniques. • The scale growth is influenced by the product of corrosion in the column of production. • The diffusion of pipe material into the inlay is important for the growth of scale

Finite element analysis of inclined nozzle-plate junctions

International Nuclear Information System (INIS)

Dixit, K.B.; Seth, V.K.; Krishnan, A.; Ramamurthy, T.S.; Dattaguru, B.; Rao, A.K.

1979-01-01

Estimation of stress concentration at nozzle to plate or shell junctions is a significant problem in the stress analysis of nuclear reactors. The topic is a subject matter of extensive investigations and earlier considerable success has been reported on analysis for the cases when the nozzle is perpendicular to the plate or is radial to the shell. Analytical methods for the estimation of stress concentrations for the practical situations when the intersecting nozzle is inclined to the plate or is non-radial to the shell is rather scanty. Specific complications arise in dealing with the junction region when the nozzle with circular cross-section meets the non-circular cut-out on the plate or shell. In this paper a finite element analysis is developed for inclined nozzles and results are presented for nozzle-plate junctions. A method of analysis is developed with a view to achieving simultaneously accuracy of results and simplicity in the choice of elements and their connectivity. The circular nozzle is treated by axisymmetric conical shell elements. The nozzle portion in the region around the junction and the flat plate is dealt with by triangular flat shell elements. Special transition elements are developed for joining the flat shell elements with the axisymmetric elements under non-axisymmetric loading. A substructure method of analysis is adopted which achieves considerable economy in handling the structure and also conveniently combines the different types of elements in the structure. (orig.)

Pulsed Direct Current Electrospray: Enabling Systematic Analysis of Small Volume Sample by Boosting Sample Economy.

Science.gov (United States)

Wei, Zhenwei; Xiong, Xingchuang; Guo, Chengan; Si, Xingyu; Zhao, Yaoyao; He, Muyi; Yang, Chengdui; Xu, Wei; Tang, Fei; Fang, Xiang; Zhang, Sichun; Zhang, Xinrong

2015-11-17

We had developed pulsed direct current electrospray ionization mass spectrometry (pulsed-dc-ESI-MS) for systematically profiling and determining components in small volume sample. Pulsed-dc-ESI utilized constant high voltage to induce the generation of single polarity pulsed electrospray remotely. This method had significantly boosted the sample economy, so as to obtain several minutes MS signal duration from merely picoliter volume sample. The elongated MS signal duration enable us to collect abundant MS(2) information on interested components in a small volume sample for systematical analysis. This method had been successfully applied for single cell metabolomics analysis. We had obtained 2-D profile of metabolites (including exact mass and MS(2) data) from single plant and mammalian cell, concerning 1034 components and 656 components for Allium cepa and HeLa cells, respectively. Further identification had found 162 compounds and 28 different modification groups of 141 saccharides in a single Allium cepa cell, indicating pulsed-dc-ESI a powerful tool for small volume sample systematical analysis.

Stress analysis and optimization of Nd:YAG pulsed laser processing of notches for fracture splitting of a C70S6 connecting rod

International Nuclear Information System (INIS)

Kou, Shuqing; Gao, Yan; Zhao, Yong; Lin, Baojun

2017-01-01

The pulsed laser pre-processing of a notch as the fracture initiation source for the splitting process is the key mechanism of an advanced fracture splitting technology for C70S6 connecting rods. This study investigated the stress field of Nd:YAG pulsed laser grooving, which affects the rapid fracture initiation at the notch root and the controlled crack extension in the critical fracture splitting quality, to improve manufacturing quality. Thermal elastic-plastic incremental theory was applied to build the finite element analysis model of the stress field of pulsed laser grooving for fracture splitting based on the Rotary-Gauss body heat source. The corresponding numerical simulation of the stress field was conducted. The changes and distributions of the stress during pulsed laser grooving were examined, the influence rule of the primary technological parameters on the residual stress was analyzed, and the analysis results were validated by the corresponding cutting experiment. Results showed that the residual stress distribution was concentrated in the Heat-affected zone (HAZ) near the fracture splitting notch, which would cause micro-cracks in the HAZ. The stress state of the notch root in the fracture initiation direction was tensile stress, which was beneficial to the fracture initiation and the crack rapid extension in the subsequent fracture splitting process. However, the uneven distribution of the stress could lead to fracture splitting defects, and thus the residual stress should be lowered to a reasonable range. Decreasing the laser pulse power, increasing the processing speed, and lowering the pulse width can lower the residual stress. Along with the actual production, the reasonable main technological parameters were obtained.

Stress analysis and optimization of Nd:YAG pulsed laser processing of notches for fracture splitting of a C70S6 connecting rod

Energy Technology Data Exchange (ETDEWEB)

Kou, Shuqing; Gao, Yan; Zhao, Yong; Lin, Baojun [Jilin University, Changchun (China)

2017-05-15

The pulsed laser pre-processing of a notch as the fracture initiation source for the splitting process is the key mechanism of an advanced fracture splitting technology for C70S6 connecting rods. This study investigated the stress field of Nd:YAG pulsed laser grooving, which affects the rapid fracture initiation at the notch root and the controlled crack extension in the critical fracture splitting quality, to improve manufacturing quality. Thermal elastic-plastic incremental theory was applied to build the finite element analysis model of the stress field of pulsed laser grooving for fracture splitting based on the Rotary-Gauss body heat source. The corresponding numerical simulation of the stress field was conducted. The changes and distributions of the stress during pulsed laser grooving were examined, the influence rule of the primary technological parameters on the residual stress was analyzed, and the analysis results were validated by the corresponding cutting experiment. Results showed that the residual stress distribution was concentrated in the Heat-affected zone (HAZ) near the fracture splitting notch, which would cause micro-cracks in the HAZ. The stress state of the notch root in the fracture initiation direction was tensile stress, which was beneficial to the fracture initiation and the crack rapid extension in the subsequent fracture splitting process. However, the uneven distribution of the stress could lead to fracture splitting defects, and thus the residual stress should be lowered to a reasonable range. Decreasing the laser pulse power, increasing the processing speed, and lowering the pulse width can lower the residual stress. Along with the actual production, the reasonable main technological parameters were obtained.

Electrical and optical analysis of fast transient discharges in a pulsed corona pilot unit

NARCIS (Netherlands)

Blom, P.P.M.; Smulders, H.W.M.; Heesch, van E.J.M.; Laan, van der P.C.T.

1997-01-01

We give a detailed analysis of intense pulsed corona dis charges. CCD movies and current, voltage and energy in put measurements are the basis of the description. The discharges are generated in a 1.5 kW pilot unit, which cre ates pulsed corona discharges energized by 100 kV pulses of 200 us width,

50-fs pulse generation directly from a colliding-pulse mode-locked Ti:sapphire laser using an antiresonant ring mirror

Science.gov (United States)

Naganuma, Kazunori; Mogi, Kazuo

1991-05-01

50-fs pulses were directly generated from a colliding-pulse mode-locked Ti:sapphire laser. To achieve the colliding-pulse mode locking, a miniature antiresonant ring containing an organic saturable dye jet was employed as the end mirror for the linear cavity laser. Based on measured dispersion of intracavity elements, a prism pair was implemented to control the cavity dispersion. The generated pulses have no linear chirp but do exhibit parabolic instantaneous frequency owing to third-order dispersion introduced by the prism pair.

Laser beam welding of titanium nitride coated titanium using pulse-shaping

Directory of Open Access Journals (Sweden)

Milton Sergio Fernandes de Lima

2005-09-01

Full Text Available A new welding method which allows the assembly of two titanium nitride coated titanium parts is proposed. The welding procedure utilizes the possibility for pulse-shaping in order to change the energy distribution profile during the laser pulse. The pulse-shaping is composed of three elements: a a short high power pulse for partial ablation at the surface; b a long pulse for thermal penetration; and c a quenching slope for enhanced weldability. The combination of these three elements produces crack-free welds. The weld microstructure is changed in comparison to normal welding, i.e. with a rectangular pulse, as the nitrogen and the microhardness are more homogenously distributed in the weld under pulse-shaping conditions. This laser pulse dissolves the TiN layer and allows nitrogen to diffuse into the melt pool, also contributing to an enhanced weldability by providing suitable thermal conditions.

Determination of reactivity of multiplying systems filled with spherical HTGR-fuel elements using kinetic methods with regard to the pulsed-neutron method

International Nuclear Information System (INIS)

Drueke, V.

1978-06-01

At three critical or subcritical facilities - two of them filled with spherical HTGR-fuel elements - the reactivity is determined using kinetic methods. Besides the inverskinetic method the applicability of the pulsed-neutron method is investigated. The experimental results using the pulsed-neutron method are compared partly with the inverskinetic method and partly with diffusion-calculations. It is shown, that in the HTGR the space dependence of the reactivity in radial direction is not remarkable in spite of the 'kinetic distortion'; on the contrary in axial direction - the direction of the external neutron source - space dependent reactivity worths are measured. The results of the pulsed-neutron methods of Sjoestrand and Simmons-King are rather good applicable in all configurations. For the method of Sjoestrand it is necessary to select the detector positions, whereas for Simmons-King the calculated life-time determines the results. Therefore it is proposed to compare calculated and measured decay constants of the prompt neutron field in future. (orig.) [de

Trace elements in Turkish tea leaves determined by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Demiralp, R.

1985-01-01

The concentrations of the elements As, Sb, Zn, Co, which are closely related to human health and disorder, was determined by means of INAA in seven of the most commonly used brands of tea. Samples and standards were irradiated 10 min and 2 hrs at pneumatic system and central thimble in the TRIGA MARK-11 research reactor. After irradiation the activities were measured with a coaxial Ge detector coupled to a spectroscopic amplifier. A Cambera 90 model multichannel analyser with an 8K memory was used for pulse hight analysis. The system has a resolution of 2,0 KeV for 1332,5 KeV gamma ray of 60 Co with peak to Compton ratio of 43:1 and efficiency of 18 relative to the 3'' x 3'' NaI(Tl) crystal. Results of the study were presented

Pulsed rf excited spectrometer having improved pulse width control

International Nuclear Information System (INIS)

1977-01-01

RF excitation for a spectrometer is obtained by pulse width modulating an RF carrier to produce the desired broadband RF exciting spectrum. The RF excitation includes a train of composite RF pulses, each composite pulse having a primary pulse portion of a first RF phase and a second pulse portion of a second RF phase opposite that of the first. In this manner, the finite rise and fall times of the primary pulse portion are compensated for by the corresponding rise and fall times of the secondary pulse portion. The primary pulse portion is lengthened by an amount equal to the secondary pulse portion so that the secondary pulse portion cancels the added primary pulse portion. In a spectrometer, the compensating second pulse component removes certain undesired side bands of the RF excitation caused by the finite rise and fall times of the applied RF pulses. The compensating second pulse component removes certain undesired side bands associated with each of the resonant lines of the excited resonance spectrum of the sample under analysis, particularly for wide band RF excitation

High-voltage nanosecond pulse shaper

International Nuclear Information System (INIS)

Kapishnikov, N.K.; Muratov, V.M.; Shatanov, A.A.

1987-01-01

A high-voltage pulse shaper with an output of up to 250 kV, a base duration of ∼ 10 nsec, and a repetition frequency of 50 pulses/sec is described. The described high-voltage nanosecond pulse shaper is designed for one-orbit extraction of an electron beam from a betatron. A diagram of the pulse shaper, which employs a single-stage generator is shown. The shaping element is a low-inductance capacitor bank of series-parallel KVI-3 (2200 pF at 10 kV) or K15-10 (4700 pF at 31.5 kV) disk ceramic capacitors. Four capacitors are connected in parallel and up to 25 are connected in series

Component Analysis of Long-Lag, Wide-Pulse Gamma-Ray Burst ...

Indian Academy of Sciences (India)

Principal Component Analysis of Long-Lag, Wide-Pulse Gamma-Ray. Burst Data. Zhao-Yang Peng. ∗. & Wen-Shuai Liu. Department of Physics, Yunnan Normal University, Kunming 650500, China. ∗ e-mail: pzy@ynao.ac.cn. Abstract. We have carried out a Principal Component Analysis (PCA) of the temporal and spectral ...

Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media

Science.gov (United States)

2016-03-04

AFRL-AFOSR-VA-TR-2016-0112 Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media Natalie Cartwright RESEARCH FOUNDATION OF STATE... Electromagnetic Pulse Propagation through Causal Media 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0013 5c.  PROGRAM ELEMENT NUMBER 61102F 6...SUPPLEMENTARY NOTES 14. ABSTRACT When an electromagnetic pulse travels through a dispersive material each frequency of the transmitted pulse changes in both

Stress-strain state analysis and optimization of rod system under periodic pulse load

Directory of Open Access Journals (Sweden)

Grebenyuk Grigory

2018-01-01

Full Text Available The paper considers the problem of analysis and optimization of rod systems subjected to combined static and periodic pulse load. As a result of the study the analysis method was developed based on traditional approach to solving homogeneous matrix equations of state and a special algorithm for developing a particular solution. The influence of pulse parameters variations on stress-strain state of a rod system was analyzed. Algorithms for rod systems optimization were developed basing on strength recalculation and statement and solution of optimization problem as a problem of nonlinear mathematical programming. Recommendations are developed for efficient organization of process for optimization of rod systems under static and periodic pulse load.

Ring-element analysis of layered orthotropic bodies

DEFF Research Database (Denmark)

Jørgensen, O.

1993-01-01

For the analysis of arbitrarily laminated circular bodies, a displacement-based ring-element is presented. The analysis is performed in a cylindrical coordinate system. The method of analysis requires the boundary conditions as well as the external forces to be pi-periodic. The element formulation...... accounts for a desired degree of approximation of the displacement field in the direction of the circumference. This is done by a truncated Fourier expansion of the angular dependence of the displacements in terms of trigonometric functions. Thus the Fourier expansion coefficients are the unknowns...... to that of solutions obtained by traditional 3D elements. A scheme for analytical integration of the angular dependence of the stiffness matrix is given....

Electrical machine analysis using finite elements

CERN Document Server

Bianchi, Nicola

2005-01-01

OUTLINE OF ELECTROMAGNETIC FIELDSVector AnalysisElectromagnetic FieldsFundamental Equations SummaryReferencesBASIC PRINCIPLES OF FINITE ELEMENT METHODSIntroductionField Problems with Boundary ConditionsClassical Method for the Field Problem SolutionThe Classical Residual Method (Galerkin's Method)The Classical Variational Method (Rayleigh-Ritz's Method)The Finite Element MethodReferencesAPPLICATIONS OF THE FINITE ELEMENT METHOD TO TWO-DIMENSIONAL FIELDSIntroductionLinear Interpolation of the Function fApplication of the Variational MethodSimple Descriptions of Electromagnetic FieldsAppendix: I

Dual-Pulse Pulse Position Modulation (DPPM) for Deep-Space Optical Communications: Performance and Practicality Analysis

Science.gov (United States)

Li, Jing; Hylton, Alan; Budinger, James; Nappier, Jennifer; Downey, Joseph; Raible, Daniel

2012-01-01

Due to its simplicity and robustness against wavefront distortion, pulse position modulation (PPM) with photon counting detector has been seriously considered for long-haul optical wireless systems. This paper evaluates the dual-pulse case and compares it with the conventional single-pulse case. Analytical expressions for symbol error rate and bit error rate are first derived and numerically evaluated, for the strong, negative-exponential turbulent atmosphere; and bandwidth efficiency and throughput are subsequently assessed. It is shown that, under a set of practical constraints including pulse width and pulse repetition frequency (PRF), dual-pulse PPM enables a better channel utilization and hence a higher throughput than it single-pulse counterpart. This result is new and different from the previous idealistic studies that showed multi-pulse PPM provided no essential information-theoretic gains than single-pulse PPM.

Elemental hair analysis: A review of procedures and applications

International Nuclear Information System (INIS)

Pozebon, D.; Scheffler, G.L.; Dressler, V.L.

2017-01-01

Although exogenous contamination and unreliable reference values have limited the utility of scalp hair as a biomarker of chemical elements exposure, its use in toxicological, clinical, environmental and forensic investigations is growing and becoming more extensive. Therefore, hair elemental analysis is reviewed in the current manuscript which spans articles published in the last 10 years. It starts with a general discussion of history, morphology and possible techniques for elemental analysis, where inductively coupled plasma-mass spectrometry (ICP-MS) is clearly highlighted since this technique is leading quantitative ultra-trace elemental analysis. Emphasis over sampling, quality assurance, washing procedures and sample decomposition is given with detailed protocols compiled in tables as well as the utility of hair to identify human gender, age, diseases, healthy conditions, nutrition status and contamination sites. Isotope ratio information, chemical speciation analysis and analyte preconcentration are also considered for hair. Finally, the potential of laser ablation ICP-MS (LA-ICP-MS) to provide spatial resolution and time-track the monitoring of elements in hair strands instead of conventional bulk analysis is spotlighted as a real future trend in the field. - Highlights: • Elemental analysis of hair is critically reviewed, with focus on ICP-MS employment. • Standards protocols of hair washing and sample decomposition are compiled. • The usefulness of elemental and/or isotopic analysis of hair is demonstrated. • The potential of LA-ICP-MS for elemental time tracking in hair is highlighted.

Finite element analysis of tibial fractures

DEFF Research Database (Denmark)

Wong, Christian Nai En; Mikkelsen, Mikkel Peter W; Hansen, Leif Berner

2010-01-01

Project. The data consisted of 21,219 3D elements with a cortical shell and a trabecular core. Three types of load of torsion, a direct lateral load and axial compression were applied. RESULTS: The finite element linear static analysis resulted in relevant fracture localizations and indicated relevant...

METHODOLOGICAL ELEMENTS OF SITUATIONAL ANALYSIS

Directory of Open Access Journals (Sweden)

Tetyana KOVALCHUK

2016-07-01

Full Text Available The article deals with the investigation of theoretical and methodological principles of situational analysis. The necessity of situational analysis is proved in modern conditions. The notion “situational analysis” is determined. We have concluded that situational analysis is a continuous system study which purpose is to identify dangerous situation signs, to evaluate comprehensively such signs influenced by a system of objective and subjective factors, to search for motivated targeted actions used to eliminate adverse effects of the exposure of the system to the situation now and in the future and to develop the managerial actions needed to bring the system back to norm. It is developed a methodological approach to the situational analysis, its goal is substantiated, proved the expediency of diagnostic, evaluative and searching functions in the process of situational analysis. The basic methodological elements of the situational analysis are grounded. The substantiation of the principal methodological elements of system analysis will enable the analyst to develop adaptive methods able to take into account the peculiar features of a unique object which is a situation that has emerged in a complex system, to diagnose such situation and subject it to system and in-depth analysis, to identify risks opportunities, to make timely management decisions as required by a particular period.

Statistical analysis of random pulse trains

International Nuclear Information System (INIS)

Da Costa, G.

1977-02-01

Some experimental and theoretical results concerning the statistical properties of optical beams formed by a finite number of independent pulses are presented. The considered waves (corresponding to each pulse) present important spatial variations of the illumination distribution in a cross-section of the beam, due to the time-varying random refractive index distribution in the active medium. Some examples of this kind of emission are: (a) Free-running ruby laser emission; (b) Mode-locked pulse trains; (c) Randomly excited nonlinear media

Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

Science.gov (United States)

Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

2013-10-01

The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

Neutron-activation analysis of trace elements in thyroids

International Nuclear Information System (INIS)

Boulyga, S.F.; Petri, H.; Kanash, N.V.; Malenchenko, A.F.

1999-01-01

Neutron activation analysis was used for routine measurement of trace elements in thyroids of inhabitants of Belarus as well as in thyroids of people operated for thyroid cancer. The method chosen allowed the analysis of 28 elements, among them essential and toxic ones, with a good accuracy. The results obtained showed significant differences in the elemental composition of thyroid from the different regions. The changes of elemental composition of thyroids of inhabitants of the Gomel region, where goiter is endemic, seem to be identical to those in the tumor tissue. (author)

Modelling NDE pulse-echo inspection of misorientated planar rough defects using an elastic finite element method

Energy Technology Data Exchange (ETDEWEB)

Pettit, J. R.; Lowe, M. J. S. [UK Research Centre for NDE, Imperial College London, Exhibition Road, London, SW7 2AZ (United Kingdom); Walker, A. E. [Rolls-Royce Nuclear, PO BOX 2000, Derby, DE21 7XX (United Kingdom)

2015-03-31

Pulse-echo ultrasonic NDE examination of large pressure vessel forgings is a design and construction code requirement in the power generation industry. Such inspections aim to size and characterise potential defects that may have formed during the forging process. Typically these defects have a range of orientations and surface roughnesses which can greatly affect ultrasonic wave scattering behaviour. Ultrasonic modelling techniques can provide insight into defect response and therefore aid in characterisation. However, analytical approaches to solving these scattering problems can become inaccurate, especially when applied to increasingly complex defect geometries. To overcome these limitations a elastic Finite Element (FE) method has been developed to simulate pulse-echo inspections of embedded planar defects. The FE model comprises a significantly reduced spatial domain allowing for a Monte-Carlo based approach to consider multiple realisations of defect orientation and surface roughness. The results confirm that defects aligned perpendicular to the path of beam propagation attenuate ultrasonic signals according to the level of surface roughness. However, for defects orientated away from this plane, surface roughness can increase the magnitude of the scattered component propagating back along the path of the incident beam. This study therefore highlights instances where defect roughness increases the magnitude of ultrasonic scattered signals, as opposed to attenuation which is more often assumed.

VIRTUAL EXPERIMENTAL ANALYSIS ON CLEANING ELEMENT OF SUGARCANE HARVESTER

Institute of Scientific and Technical Information of China (English)

Ma Fanglan; Li Shangping; He Yulin; Meng Yanmei; Chen Weixu

2005-01-01

The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester.Based on the principle of orthogonal experiment design, the virtual-orthogonal-experimental analysis for the cleaning element is carried out on the finite element analysis (FEA) software-ANSYS after analyzing the nonlinear structural behavior in the working procedure. The results are analyzed with the overall balancing method, and then the optimal combination is got, which is made up of different levels of different factors. Also the optimal combination of design parameters of the cleaning element received from the virtual experimental analysis is conducted an experiment to confirm that the virtual analysis model and results are right, and the effect of factors on the function of the cleaning element is obtained by more analysis and further optimizing.

Analysis of concrete beams using applied element method

Science.gov (United States)

Lincy Christy, D.; Madhavan Pillai, T. M.; Nagarajan, Praveen

2018-03-01

The Applied Element Method (AEM) is a displacement based method of structural analysis. Some of its features are similar to that of Finite Element Method (FEM). In AEM, the structure is analysed by dividing it into several elements similar to FEM. But, in AEM, elements are connected by springs instead of nodes as in the case of FEM. In this paper, background to AEM is discussed and necessary equations are derived. For illustrating the application of AEM, it has been used to analyse plain concrete beam of fixed support condition. The analysis is limited to the analysis of 2-dimensional structures. It was found that the number of springs has no much influence on the results. AEM could predict deflection and reactions with reasonable degree of accuracy.

Radial artery pulse waveform analysis based on curve fitting using discrete Fourier series.

Science.gov (United States)

Jiang, Zhixing; Zhang, David; Lu, Guangming

2018-04-19

Radial artery pulse diagnosis has been playing an important role in traditional Chinese medicine (TCM). For its non-invasion and convenience, the pulse diagnosis has great significance in diseases analysis of modern medicine. The practitioners sense the pulse waveforms in patients' wrist to make diagnoses based on their non-objective personal experience. With the researches of pulse acquisition platforms and computerized analysis methods, the objective study on pulse diagnosis can help the TCM to keep up with the development of modern medicine. In this paper, we propose a new method to extract feature from pulse waveform based on discrete Fourier series (DFS). It regards the waveform as one kind of signal that consists of a series of sub-components represented by sine and cosine (SC) signals with different frequencies and amplitudes. After the pulse signals are collected and preprocessed, we fit the average waveform for each sample using discrete Fourier series by least squares. The feature vector is comprised by the coefficients of discrete Fourier series function. Compared with the fitting method using Gaussian mixture function, the fitting errors of proposed method are smaller, which indicate that our method can represent the original signal better. The classification performance of proposed feature is superior to the other features extracted from waveform, liking auto-regression model and Gaussian mixture model. The coefficients of optimized DFS function, who is used to fit the arterial pressure waveforms, can obtain better performance in modeling the waveforms and holds more potential information for distinguishing different psychological states. Copyright © 2018 Elsevier B.V. All rights reserved.

On-line analysis of bulk materials using pulsed neutron interrogation

International Nuclear Information System (INIS)

Lebrun, P.; Tourneur, P. Le; Poumarede, B.; Bach, P.; Moeller, H.

1999-01-01

On the basis of our joint experience in neutronics for SODERN and in cement plant engineering for KRUPP POLYSIUS, we have developed a new on-line bulk materials analyser for the cement industry. This equipment includes a pulsed neutron generator GENIE 16, some gamma ray and neutron detectors, specially designed electronics with high counting rate, software delivering the mean elemental composition of raw material, and adequate shielding. This material is transported through the equipment on a conveyor belt, the size of which is adapted to the requirements. This paper briefly describes the equipment and some results, as obtained in dynamic test from a demonstrator installed in Germany

On-line analysis of bulk materials using pulsed neutron interrogation

Science.gov (United States)

Lebrun, P.; Tourneur, P. Le; Poumarede, B.; Möller, H.; Bach, P.

1999-06-01

On the basis of our joint experience in neutronics for SODERN and in cement plant engineering for KRUPP POLYSIUS, we have developed a new on-line bulk materials analyser for the cement industry. This equipment includes a pulsed neutron generator GENIE 16, some gamma ray and neutron detectors, specially designed electronics with high counting rate, software delivering the mean elemental composition of raw material, and adequate shielding. This material is transported through the equipment on a conveyor belt, the size of which is adapted to the requirements. This paper briefly describes the equipment and some results, as obtained in dynamic test from a demonstrator installed in Germany.

Reactor kinetics - pulse and steady state

Energy Technology Data Exchange (ETDEWEB)

Estes, B F; Morris, F M [Sandia Laboratories (United States)

1974-07-01

An analytical model has been developed which couples the nuclear and thermal characteristics of the Annular Core Pulse Reactor (ACPR) into a solution which describes both the neutron kinetics of the reactor and the temperature behavior of a fuel-moderator element. The model describes both pulse and steady state operations. This paper describes the important aspects of the reactor, the fuel- moderator elements, the neutron kinetic equations of the reactor, and the time-temperature behavior of a fuel-moderator element that is being subjected to the maximum power density in the core. The parameters which are utilized in the equations are divided into two classes, those that can be measured directly and those that are assumed to be known (each is described briefly). Some of the solutions which demonstrate the versatility of the analytical model are described. (author)

Thermodynamic analysis of a pulse tube engine

International Nuclear Information System (INIS)

Moldenhauer, Stefan; Thess, André; Holtmann, Christoph; Fernández-Aballí, Carlos

2013-01-01

Highlights: ► Numerical model of the pulse tube engine process. ► Proof that the heat transfer in the pulse tube is out of phase with the gas velocity. ► Proof that a free piston operation is possible. ► Clarifying the thermodynamic working principle of the pulse tube engine. ► Studying the influence of design parameters on the engine performance. - Abstract: The pulse tube engine is an innovative simple heat engine based on the pulse tube process used in cryogenic cooling applications. The working principle involves the conversion of applied heat energy into mechanical power, thereby enabling it to be used for electrical power generation. Furthermore, this device offers an opportunity for its wide use in energy harvesting and waste heat recovery. A numerical model has been developed to study the thermodynamic cycle and thereby help to design an experimental engine. Using the object-oriented modeling language Modelica, the engine was divided into components on which the conservation equations for mass, momentum and energy were applied. These components were linked via exchanged mass and enthalpy. The resulting differential equations for the thermodynamic properties were integrated numerically. The model was validated using the measured performance of a pulse tube engine. The transient behavior of the pulse tube engine’s underlying thermodynamic properties could be evaluated and studied under different operating conditions. The model was used to explore the pulse tube engine process and investigate the influence of design parameters.

Passive mode locking of a femtosecond Ti:sapphire laser with pulsed synchronous pumping by a finite train of picosecond pulses

International Nuclear Information System (INIS)

Borisevich, N A; Buganov, O V; Tikhomirov, S A; Tolstorozhev, G B; Shkred, G L

1999-01-01

An analysis is made, with the aid of the self-consistent nonlinear ABCD matrix method, of the specific features of the mechanism of passive mode locking of a femtosecond Ti:sapphire laser under conditions of pulsed synchronous pumping. The conditions of stable laser operation are studied. It is proposed to use an additional aperture as an element of negative feedback for the stabilisation of passive mode locking. Practical recommendations concerning the optimisation of a femtosecond laser are given. (control of laser radiation parameters)

Noise Pulses in Large Area Optical Modules

International Nuclear Information System (INIS)

Aiello, Sebastiano; Leonora, Emanuele; Giordano, Valentina

2013-06-01

A great number of large area photomultipliers are widely used in neutrino and astro-particle detector to measure Cherenkov light in medium like water or ice. The key element of these detectors are the so-called 'optical module', which consist in photodetectors closed in a transparent pressure-resistant container to protect it and ensure good light transmission. The noise pulses present on the anode of each photomultiplier affect strongly the performance of the detector. A large study was conducted on noise pulses of large area photomultipliers, considering time and charge distributions of dark pulses, prepulses, delayed pulses, and after pulses. The contribution to noise pulses due to the presence of the external glass spheres was also studied, even comparing two vessels of different brands. (authors)

Analysis of picosecond pulsed laser melted graphite

International Nuclear Information System (INIS)

Steinbeck, J.; Braunstein, G.; Speck, J.; Dresselhaus, M.S.; Huang, C.Y.; Malvezzi, A.M.; Bloembergen, N.

1986-01-01

A Raman microprobe and high resolution TEM have been used to analyze the resolidified region of liquid carbon generated by picosecond pulse laser radiation. From the relative intensities of the zone center Raman-allowed mode for graphite at 1582 cm -1 and the disorder-induced mode at 1360 cm -1 , the average graphite crystallite size in the resolidified region is determined as a function of position. By comparison with Rutherford backscattering spectra and Raman spectra from nonosecond pulsed laser melting experiments, the disorder depth for picosecond pulsed laser melted graphite is determined as a function of irradiating energy density. Comparisons of TEM micrographs for nanosecond and picosecond pulsed laser melting experiments show that the structure of the laser disordered regions in graphite are similar and exhibit similar behavior with increasing laser pulse fluence

Single cell elemental analysis using nuclear microscopy

International Nuclear Information System (INIS)

Ren, M.Q.; Thong, P.S.P.; Kara, U.; Watt, F.

1999-01-01

The use of Particle Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM) to provide quantitative elemental analysis of single cells is an area which has high potential, particularly when the trace elements such as Ca, Fe, Zn and Cu can be monitored. We describe the methodology of sample preparation for two cell types, the procedures of cell imaging using STIM, and the quantitative elemental analysis of single cells using RBS and PIXE. Recent work on single cells at the Nuclear Microscopy Research Centre,National University of Singapore has centred around two research areas: (a) Apoptosis (programmed cell death), which has been recently implicated in a wide range of pathological conditions such as cancer, Parkinson's disease etc, and (b) Malaria (infection of red blood cells by the malaria parasite). Firstly we present results on the elemental analysis of human Chang liver cells (ATTCC CCL 13) where vanadium ions were used to trigger apoptosis, and demonstrate that nuclear microscopy has the capability of monitoring vanadium loading within individual cells. Secondly we present the results of elemental changes taking place in individual mouse red blood cells which have been infected with the malaria parasite and treated with the anti-malaria drug Qinghaosu (QHS)

Predicting blood transfusion using automated analysis of pulse oximetry signals and laboratory values.

Science.gov (United States)

Shackelford, Stacy; Yang, Shiming; Hu, Peter; Miller, Catriona; Anazodo, Amechi; Galvagno, Samuel; Wang, Yulei; Hartsky, Lauren; Fang, Raymond; Mackenzie, Colin

2015-10-01

Identification of hemorrhaging trauma patients and prediction of blood transfusion needs in near real time will expedite care of the critically injured. We hypothesized that automated analysis of pulse oximetry signals in combination with laboratory values and vital signs obtained at the time of triage would predict the need for blood transfusion with accuracy greater than that of triage vital signs or pulse oximetry analysis alone. Continuous pulse oximetry signals were recorded for directly admitted trauma patients with abnormal prehospital shock index (heart rate [HR] / systolic blood pressure) of 0.62 or greater. Predictions of blood transfusion within 24 hours were compared using Delong's method for area under the receiver operating characteristic (AUROC) curves to determine the optimal combination of triage vital signs (prehospital HR + systolic blood pressure), pulse oximetry features (40 waveform features, O2 saturation, HR), and laboratory values (hematocrit, electrolytes, bicarbonate, prothrombin time, international normalization ratio, lactate) in multivariate logistic regression models. We enrolled 1,191 patients; 339 were excluded because of incomplete data; 40 received blood within 3 hours; and 14 received massive transfusion. Triage vital signs predicted need for transfusion within 3 hours (AUROC, 0.59) and massive transfusion (AUROC, 0.70). Pulse oximetry for 15 minutes predicted transfusion more accurately than triage vital signs for both time frames (3-hour AUROC, 0.74; p = 0.004) (massive transfusion AUROC, 0.88; p transfusion prediction (3-hour AUROC, 0.84; p transfusion AUROC, 0.91; p blood transfusion during trauma resuscitation more accurately than triage vital signs or pulse oximetry analysis alone. Results suggest automated calculations from a noninvasive vital sign monitor interfaced with a point-of-care laboratory device may support clinical decisions by recognizing patients with hemorrhage sufficient to need transfusion. Epidemiologic

Pulsed glow discharge mass spectrometry for molecular depth profiling of polymers

International Nuclear Information System (INIS)

Lobo, L.; Pereiro, R.; Sanz-Medel, A.; Bordel, N.; Pisonero, J.; Licciardello, A.; Tuccitto, N.; Tempez, A.; Chapon, P.

2009-01-01

Full text: Nowadays thin films of polymeric materials involve a wide range of industrial applications, so techniques capable of providing in-depth profile information are required. Most of the techniques available for this purpose are based on the use of energetic particle beams which interact with polymers producing undesirable physicochemical modifications. Radiofrequency pulsed glow discharge (rf-pulsed-GD) coupled to time-of-flight mass spectrometry (TOFMS) could afford the possibility of acquiring both elemental and molecular information creating minimal damage to surfaces and thereby obtaining depth profiles. This work will evaluate rf-GDs coupled to an orthogonal TOFMS for direct analysis of polymers. (author)

Analysis of light elements by PIGE

International Nuclear Information System (INIS)

Kim, Y. S.; Choi, H. W.; Kim, D. K.; Woo, H. J.; Kim, N. B.; Park, K. S.

2000-01-01

The PIGE (Proton Induced Gamma ray Emission) method was applied for the measurement of light elements Li - K. A test measurement has been performed for geological, biological, environmental and material samples by using a standard sample for each element. The measurement was performed for the two proton energies of 2.4 and 3.4 MeV, and 3.4MeV was found to yield better result for multielemental analysis. The result shows a fair agreement within 15% for all elements with standard values. The detection limits of Li, B, F and Na are less than 100 ppm, while those of the other elements are from a few hundred ppm to a few percents. (author)

PERCEPTION LEVEL EVALUATION OF RADIO ELECTRONIC MEANS TO A PULSE OF ELECTROMAGNETIC RADIATION

Directory of Open Access Journals (Sweden)

2016-01-01

Full Text Available The method for evaluating the perception level of electronic means to pulsed electromagnetic radiation is consid- ered in this article. The electromagnetic wave penetration mechanism towards the elements of electronic systems and the impact on them are determined by the intensity of the radiation field on the elements of electronic systems. The impact of electromagnetic radiation pulses to the electronic systems refers to physical and analytical parameters of the relationship between exposure to pulses of electromagnetic radiation and the sample parameters of electronic systems. A physical and mathematical model of evaluating the perception level of electronic means to pulsed electromagnetic radiation is given. The developed model was based on the physics of electronics means failure which represents the description of electro- magnetic, electric and thermal processes that lead to the degradation of the original structure of the apparatus elements. The conditions that lead to the total equation electronic systems functional destruction when exposed to electromagnetic radia- tion pulses are described. The internal characteristics of the component elements that respond to the damaging effects are considered. The ratio for the power failure is determined. A thermal breakdown temperature versus pulse duration of expo- sure at various power levels is obtained. The way of evaluation the reliability of electronic systems when exposed to pulses of electromagnetic radiation as a destructive factor is obtained.

Transient pulse analysis of ionized electronics exposed to γ-radiation generated from a relativistic electron beam

Science.gov (United States)

Min, Sun-Hong; Kwon, Ohjoon; Sattorov, Matlabjon; Baek, In-Keun; Kim, Seontae; Hong, Dongpyo; Jeong, Jin-Young; Jang, Jungmin; Bera, Anirban; Barik, Ranjan Kumar; Bhattacharya, Ranajoy; Cho, Ilsung; Kim, Byungsu; Park, Chawon; Jung, Wongyun; Park, Seunghyuk; Park, Gun-Sik

2018-02-01

When a semiconductor element is irradiated with radiation in the form of a transient pulse emitted from a nuclear explosion, a large amount of charge is generated in a short time in the device. A photocurrent amplified in a certain direction by these types of charges cause the device to break down and malfunction or in extreme cases causes them to burn out. In this study, a pulse-type γ-ray generator based on a relativistic electron beam accelerator (γ=2.2, β=0.89) which functions by means of tungsten impingement was constructed and tested in an effort to investigate the process and effects of the photocurrent formed by electron hole pairs (EHP) generated in a pMOSFET device when a transient radiation pulse is incident in the device. The pulse-type γ-ray irradiating device used here to generate the electron beam current in a short time was devised to allow an increase in the irradiation dose. A precise signal processing circuit was constructed to measure the photocurrent of the small signal generated by the pMOSFET due to the electron beam accelerator pulse signal from the large noise stemming from the electromagnetic field around the relativistic electron beam accelerator. The pulse-type γ-ray generator was installed to meet the requirements of relativistic electron beam accelerators, and beam irradiation was conducted after a beam commissioning step.

A Meta-Analysis about the Screening Role of Pulse Oximetry for Congenital Heart Disease

Directory of Open Access Journals (Sweden)

Caiju Du

2017-01-01

Full Text Available Objective. The opinions about the application of pulse oximetry in diagnosis of congenital heart disease (CHD were debatable. We performed this meta-analysis to confirm the diagnostic role of pulse oximetry screening for CHD. Methods. Relevant articles were searched in the databases of Pubmed, Embase, Google Scholar, and Chinese National Knowledge Infrastructure (CNKI up to April 2017. Data was processed in the MetaDiSc 1.4 software. Pooled sensitivity and specificity with 95% confidence interval (95% CI were calculated to explain the diagnostic role of pulse oximetry screening for CHD. I2⩾50% or p<0.05 indicated significant heterogeneity. Area under curve (AUC of summary receiver operating characteristics (SROC was calculated to assess its diagnostic accuracy. The robustness of overall results was evaluated by sensitivity analysis. Publication bias was evaluated by Deek’s funnel plot. Results. 22 eligible articles were selected. Pooled sensitivity and specificity were 0.69 (0.67–0.72 and 0.99 (0.99-0.99, respectively. The corresponding AUC was 0.9407, suggesting high diagnostic accuracy of pulse oximetry screening for CHD. Sensitivity analysis demonstrated that the pooled results were robust. Deek’s funnel plot seemed to be symmetrical. Conclusions. Pulse oximetry screening could be used to diagnose CHD. It shows high diagnosis specificity and accuracy.

Finite Element Analysis of Circular Plate using SolidWorks

International Nuclear Information System (INIS)

Kang, Yeo Jin; Jhung, Myung Jo

2011-01-01

Circular plates are used extensively in mechanical engineering for nuclear reactor internal components. The examples in the reactor vessel internals are upper guide structure support plate, fuel alignment plate, lower support plate etc. To verify the structural integrity of these plates, the finite element analyses are performed, which require the development of the finite element model. Sometimes it is very costly and time consuming to make the model especially for the beginners who start their engineering job for the structural analysis, necessitating a simple method to develop the finite element model for the pursuing structural analysis. Therefore in this study, the input decks are generated for the finite element analysis of a circular plate as shown in Fig. 1, which can be used for the structural analysis such as modal analysis, response spectrum analysis, stress analysis, etc using the commercial program Solid Works. The example problems are solved and the results are included for analysts to perform easily the finite element analysis of the mechanical plate components due to various loadings. The various results presented in this study would be helpful not only for the benchmark calculations and results comparisons but also as a part of the knowledge management for the future generation of young designers, scientists and computer analysts

X-ray fluorescent elemental analysis. Ch. 16

International Nuclear Information System (INIS)

Baryshev, V.; Kulipanov, G.; Skrinsky, A.

1991-01-01

X-ray fluorescence analysis (XFA) is used worldwide to define a quantitative content of the elements as well as to visualize the distribution of elements in different regions (element mapping). Utilization of synchrotron radiation (SR) to excite X-ray fluorescence enables the XFA method to be qualitatively improved. This chapter reviews the experimental work in especially the last decade (author). 71 refs.; 24 figs.; 3 tabs

Electromagnetic Pulse Coupling Analysis of Electronic Equipment

OpenAIRE

Hong Lei; Qingying LI

2017-01-01

High-intensity nuclear explosion caused by high-altitude nuclear electromagnetic pulse through the antenna, metal cables, holes and other channels, coupled with very high energy into the electronic device, and cause serious threats. In this paper, the mechanism, waveform, coupling path and damage effect of nuclear electromagnetic pulse is analyzed, and the coupling mechanism of nuclear electromagnetic pulse is studied.

A seismic analysis of the driving system for the pulsed reactor

International Nuclear Information System (INIS)

Hu Yongtao; Fu Shixiang; Zeng Jianhua; Hong Jingfeng

1991-01-01

The driving system of the pulsed reactor contains control rods, pulsing o rod and sample rack. They are slender, and their drive function is required more strictly. First, a complete model which contains all driving system and reactor bridge is used. Then the substructure models are adopted. The results of calculation are compared with the experimental results. It shows that the analysis results are reliable and the substructure method is simple, available and utility. The seismic safety is evaluated by the results from response spectra method

Analysis of trace elements in opal using PIXE

Energy Technology Data Exchange (ETDEWEB)

Hinrichs, Ruth, E-mail: ruth.hinrichs@ufrgs.br [Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Programa de Pós-graduação em Física, UFRGS, Porto Alegre, RS (Brazil); Bertol, A.P.L. [Programa de Pós-graduação em Física, UFRGS, Porto Alegre, RS (Brazil); Vasconcellos, M.A.Z. [Programa de Pós-graduação em Física, UFRGS, Porto Alegre, RS (Brazil); Instituto de Física, UFRGS, Porto Alegre, RS (Brazil)

2015-11-15

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.

Recent Pulse Sequences for Heteronuclear Long-Range Correlation and More

DEFF Research Database (Denmark)

Sørensen, Ole W.

This talk will give an overview of the key elements and principles of experiments listed on http://www.crc.dk/nmr/, from where also pulse programs in Bruker and Varian format can be downloaded.......This talk will give an overview of the key elements and principles of experiments listed on http://www.crc.dk/nmr/, from where also pulse programs in Bruker and Varian format can be downloaded....

Sandia Pulsed Reactor Facility (SPRF) calculator-assisted pulse analysis and display system

International Nuclear Information System (INIS)

Estes, B.F.; Berry, D.T.

1980-02-01

Two solid-metal fast burst type reactors (SPR II and SPR III) are operated at the Sandia Pulsed Reactor Facility. Since startup of the reactors, oscilloscope traces have been used to record (by camera) the pulse (power) shape while log N systems have measured initial reactor period. Virtually no other pulse information is available. A decision was made to build a system that could collect the basic input data available from the reactor - fission chambers, photodiodes, and thermocouples - condition the signals and output the various parameters such as power, energy, temperature, period and lifetime on hard copy that would provide a record for operations personnel as well as the experimenter. Because the reactors operate in short time frames - pulse operation - it is convenient to utilize the classical Nordheim-Fuchs approximation of the diffusion equation to describe reactor behavior. This report describes the work performed to date in developing the calculator system and analytical models for computing the desired parameters

Trace and ultratrace level elemental and speciation analysis

International Nuclear Information System (INIS)

Arunachalam, J.

2012-01-01

Accurate determination of elements present at parts per million and billion levels in various matrices is a growing requirement in different fields. In environmental sciences various trace elements need to be analyzed so as establish the dispersal models of pollutants or the adequacy of effluent treatment prior to discharge into water bodies. The issues of bioaccumulation and magnification are important in aquatic systems. In nutrition and biochemistry one has to establish the bio-availability of essential and toxic elemental species as toxic elements prevent assimilation of essential elements. Fission and fusion technologies use a variety of structural materials requiring many trace elements to be present at levels strictly below the specified levels. Ultra-pure bulk semiconductor materials are required for fabrication devices. In metallurgy and materials sciences too, various trace elements are known to influence the properties. In the emerging fields like nanotechnology, it is necessary to understand the passage and accumulation of nano-particles inside the cells, through trace analysis. Many analytical techniques exist which can provide the concentration information in the bulk materials with good accuracy. They include ICP-AES, FAAS, and ICP-MS, which are solution based techniques. Direct solid state analytical techniques are Glow Discharge Mass Spectrometry (GDMS) and XRF. Accelerator based ion-beam analysis techniques can provide information on concentration and depth profiles of different elements in layered structures. Hyphenated techniques such as HPLC/lC-ICPMS, are helpful in identifying various chemical oxidation states in which a given element might be present in a matrix, which is termed as speciation analysis. This presentation will include the existing analytical competencies and the laboratory requirements for trace and ultra trace element elemental and speciation analyses and their applications. (author)

Trace element analysis of common salt using neutron activation analysis

International Nuclear Information System (INIS)

Usman, K.

1993-01-01

Instrumental Fast Neutron Activation Analysis (IFNAA) technique has been used in the qualitative and quantitative determination of the impurity elements in common salt. Samples of the different types of common salt processed in Nigeria and some of those imported into the country were used. The type A711 KAMAN neutron generator and a high-purity Germanium (HpGe) gamma spectrometer available at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria has been used. The ORTEC ADCAM 100 Emulation Software (Maestro) was used in the qualitative measurement of the detected elements. The G.R.G Activation Analysis System by G. R. Gilmore, 1987, was used in the quantitative determination of the elements detected by relative method. Aluminium and arsenic were detected and measured

Storage and pre-neutron-activation-analysis treatment for trace-element analysis in urine

International Nuclear Information System (INIS)

Blotcky, A.J.; Rack, E.P.

1985-01-01

The problems regarding storage and pre-neutron-activation-analysis treatment for the elements aluminum, calcium, vanadium, selenium, copper, iodine, zinc, manganese, and magnesium in a urine matrix are reviewed. The type of collection and storage procedure and pre-neutron activation analysis treatment of urine depend on the specific trace element; that is, its inherent physical and chemical properties. Specifically polyethylene in teflon containers are the most suitable for general determinations. Whether any preservative is added would depend upon the stability of the trace element and its tendency for surface adsorption. Preferably, preservatives should contain no radioactivatable elements for maximum efficacy. Freeze drying or packing urine shipments under dry ice needs to be explored on an individual basis. Each pre- or post-neutron activation analysis treatment is specific and optimized for the trace element analyzed

ANSYS mechanical APDL for finite element analysis

CERN Document Server

Thompson, Mary Kathryn

2017-01-01

ANSYS Mechanical APDL for Finite Element Analysis provides a hands-on introduction to engineering analysis using one of the most powerful commercial general purposes finite element programs on the market. Students will find a practical and integrated approach that combines finite element theory with best practices for developing, verifying, validating and interpreting the results of finite element models, while engineering professionals will appreciate the deep insight presented on the program's structure and behavior. Additional topics covered include an introduction to commands, input files, batch processing, and other advanced features in ANSYS. The book is written in a lecture/lab style, and each topic is supported by examples, exercises and suggestions for additional readings in the program documentation. Exercises gradually increase in difficulty and complexity, helping readers quickly gain confidence to independently use the program. This provides a solid foundation on which to build, preparing readers...

Multi-element analysis of unidentified fallen objects from Tatale in ...

African Journals Online (AJOL)

A multi-element analysis has been carried out on two fallen objects, # 01 and # 02, using instrumental neutron activation analysis technique. A total of 17 elements were identified in object # 01 while 21 elements were found in object # 02. The two major elements in object # 01 were Fe and Mg, which together constitute ...

Dynamic pulse buckling of cylindrical shells under axial impact: A comparison of 2D and 3D finite element calculations with experimental data

International Nuclear Information System (INIS)

Hoffman, E.L.; Ammerman, D.J.

1995-04-01

A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several 2D and 3D finite element simulations of the event. The purpose of the work is to investigate the performance of various analysis codes and element types on a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. Four axial impact tests were performed on 4 in-diameter, 8 in-long, 304 L stainless steel cylinders with a 3/16 in wall thickness. The cylinders were struck by a 597 lb mass with an impact velocity ranging from 42.2 to 45.1 ft/sec. During the impact event, a buckle formed at each end of the cylinder, and one of the two buckles became unstable and collapsed. The instability occurred at the top of the cylinder in three tests and at the bottom in one test. Numerical simulations of the test were performed using the following codes and element types: PRONTO2D with axisymmetric four-node quadrilaterals; PRONTO3D with both four-node shells and eight-node hexahedrons; and ABAQUS/Explicit with axisymmetric two-node shells and four-node quadrilaterals, and 3D four-node shells and eight-node hexahedrons. All of the calculations are compared to the tests with respect to deformed shape and impact load history. As in the tests, the location of the instability is not consistent in all of the calculations. However, the calculations show good agreement with impact load measurements with the exception of an initial load spike which is proven to be the dynamic response of the load cell to the impact. Finally, the PRONIT02D calculation is compared to the tests with respect to strain and acceleration histories. Accelerometer data exhibited good qualitative agreement with the calculations. The strain comparisons show that measurements are very sensitive to gage placement

Use of a prototype pulse oximeter for time series analysis of heart rate variability

Science.gov (United States)

González, Erika; López, Jehú; Hautefeuille, Mathieu; Velázquez, Víctor; Del Moral, Jésica

2015-05-01

This work presents the development of a low cost pulse oximeter prototype consisting of pulsed red and infrared commercial LEDs and a broad spectral photodetector used to register time series of heart rate and oxygen saturation of blood. This platform, besides providing these values, like any other pulse oximeter, processes the signals to compute a power spectrum analysis of the patient heart rate variability in real time and, additionally, the device allows access to all raw and analyzed data if databases construction is required or another kind of further analysis is desired. Since the prototype is capable of acquiring data for long periods of time, it is suitable for collecting data in real life activities, enabling the development of future wearable applications.

Multi-element analysis of small biological samples

International Nuclear Information System (INIS)

Rokita, E.; Cafmeyer, J.; Maenhaut, W.

1983-01-01

A method combining PIXE and INAA was developed to determine the elemental composition of small biological samples. The method needs virtually no sample preparation and less than 1 mg is sufficient for the analysis. The method was used for determining up to 18 elements in leaves taken from Cracow Herbaceous. The factors which influence the elemental composition of leaves and the possible use of leaves as an environmental pollution indicator are discussed

Finite element application to global reactor analysis

International Nuclear Information System (INIS)

Schmidt, F.A.R.

1981-01-01

The Finite Element Method is described as a Coarse Mesh Method with general basis and trial functions. Various consequences concerning programming and application of Finite Element Methods in reactor physics are drawn. One of the conclusions is that the Finite Element Method is a valuable tool in solving global reactor analysis problems. However, problems which can be described by rectangular boxes still can be solved with special coarse mesh programs more efficiently. (orig.) [de

A CAREM type fuel element dynamic analysis

International Nuclear Information System (INIS)

Magoia, J.E.

1990-01-01

A first analysis on the dynamic behaviour of a fuel element designed for the CAREM nuclear reactor (Central Argentina de Elementos Modulares) was performed. The model used to represent this dynamic behaviour was satisfactorily evaluated. Using primary estimations for some of its numerical parameters, a first approximation to its natural vibrational modes was obtained. Results obtained from fuel elements frequently used in nuclear power plants of the PWR (Pressurized Water Reactors) type, are compared with values resulting from similar analysis. (Author) [es

Time-Frequency (Wigner Analysis of Linear and Nonlinear Pulse Propagation in Optical Fibers

Directory of Open Access Journals (Sweden)

José Azaña

2005-06-01

Full Text Available Time-frequency analysis, and, in particular, Wigner analysis, is applied to the study of picosecond pulse propagation through optical fibers in both the linear and nonlinear regimes. The effects of first- and second-order group velocity dispersion (GVD and self-phase modulation (SPM are first analyzed separately. The phenomena resulting from the interplay between GVD and SPM in fibers (e.g., soliton formation or optical wave breaking are also investigated in detail. Wigner analysis is demonstrated to be an extremely powerful tool for investigating pulse propagation dynamics in nonlinear dispersive systems (e.g., optical fibers, providing a clearer and deeper insight into the physical phenomena that determine the behavior of these systems.

Trace element analysis of nail polishes

International Nuclear Information System (INIS)

Misra, G.; Mittal, V.K.; Sahota, H.S.

1999-01-01

Instrumental neutron activation analysis (INAA) technique was used to measure the concentrations of various trace elements in nail polishes of popular Indian and foreign brands. The aim of the present experiment was to see whether trace elements could distinguish nail polishes of different Indian and foreign brands from forensic point of view. It was found that cesium can act as a marker to differentiate foreign and Indian brands. (author)

Time-lens based optical packet pulse compression and retiming

DEFF Research Database (Denmark)

Laguardia Areal, Janaina; Hu, Hao; Palushani, Evarist

2010-01-01

recovery, resulting in a potentially very efficient solution. The scheme uses a time-lens, implemented through a sinusoidally driven optical phase modulation, combined with a linear dispersion element. As time-lenses are also used for pulse compression, we design the circuit also to perform pulse...

Using the ion microprobe mass analyser for trace element analysis

International Nuclear Information System (INIS)

Schilling, J.H.

1978-01-01

Most techniques for the analysis of trace elements are capable of determining the concentrations in a bulk sample or solution, but without reflecting their distribution. In a bulk analysis therefore elements which occur in high concentration in a few precipitates would still be considered trace elements even though their local concentration greatly exceed the normally accepted trace elements concentration limit. Anomalous distribution is also shown by an oxide layer, a few hundred Angstrom thick, on an aluminium sample. A low oxide concentration would be reported if it were included in the bulk analysis, which contradicts the high surface concentration. The importance of a knowledge of the trace element distribution is therefore demonstrated. Distributional trace element analysis can be carried out using the ion microprobe mass analyser (IMMA). Since the analytical technique used in this instrument, namely secondary ion mass spectrometry (SIMS), is not universally appreciated, the instrument and its features will be described briefly followed by a discussion of quantitative analysis and the related subjects of detection limit and sample consumption. Finally, a few examples of the use of the instrument are given

Prepulse suppression using a self-induced, ultrashort pulse plasma mirror

International Nuclear Information System (INIS)

Gold, D.M.; Nathel, H.; Bolton, P.R.; White, W.E.; Van Woerkom, L.D.

1991-01-01

The plasma mirror is a self-induced, plasm-based optical element which can be inserted into existing experiments to reduce repulse energy without significant degradation of ultrashort pulse laser light. The authors have characteristics of the reflected pulse. The initial measurements indicate that the incident pulse reflects specularly from a high density, highly reflective plasma. The reflected pulse has a smoothed spatial profile and reduced pulsewidth. This paper outlines future work to characterize both the plasm mirror technique of repulse suppression and its reflected pulse

Molecular Analysis of Mycobacterium avium Isolates by Using Pulsed-Field Gel Electrophoresis and PCR

Science.gov (United States)

Pestel-Caron, Martine; Graff, Gabriel; Berthelot, Gilles; Pons, Jean-Louis; Lemeland, Jean-François

1999-01-01

Genetic relationships among 46 isolates of Mycobacterium avium recovered from 37 patients in a 2,500-bed hospital from 1993 to 1998 were assessed by pulsed-field gel electrophoresis (PFGE) and PCR amplification of genomic sequences located between the repetitive elements IS1245 and IS1311. Each technique enabled the identification of 27 to 32 different patterns among the 46 isolates, confirming that the genetic heterogeneity of M. avium strains is high in a given community. Furthermore, this retrospective analysis of sporadic isolates allowed us (i) to suggest the existence of two remanent strains in our region, (ii) to raise the question of the possibility of nosocomial acquisition of M. avium strains, and (iii) to document laboratory contamination. The methods applied in the present study were found to be useful for the typing of M. avium isolates. In general, both methods yielded similar results for both related and unrelated isolates. However, the isolates in five of the six PCR clusters were distributed among two to three PFGE patterns, suggesting that this PCR-based method may have limitations for the analysis of strains with low insertion sequence copy numbers or for resolution of extended epidemiologic relationships. PMID:10405383

Finite element analysis of an inflatable torus considering air mass structural element

Science.gov (United States)

Gajbhiye, S. C.; Upadhyay, S. H.; Harsha, S. P.

2014-01-01

Inflatable structures, also known as gossamer structures, are at high boom in the current space technology due to their low mass and compact size comparing to the traditional spacecraft designing. Internal pressure becomes the major source of strength and rigidity, essentially stiffen the structure. However, inflatable space based membrane structure are at high risk to the vibration disturbance due to their low structural stiffness and material damping. Hence, the vibration modes of the structure should be known to a high degree of accuracy in order to provide better control authority. In the past, most of the studies conducted on the vibration analysis of gossamer structures used inaccurate or approximate theories in modeling the internal pressure. The toroidal shaped structure is one of the important key element in space application, helps to support the reflector in space application. This paper discusses the finite-element analysis of an inflated torus. The eigen-frequencies are obtained via three-dimensional small-strain elasticity theory, based on extremum energy principle. The two finite-element model (model-1 and model-2) have cases have been generated using a commercial finite-element package. The structure model-1 with shell element and model-2 with the combination of the mass of enclosed fluid (air) added to the shell elements have been taken for the study. The model-1 is computed with present analytical approach to understand the convergence rate and the accuracy. The convergence study is made available for the symmetric modes and anti-symmetric modes about the centroidal-axis plane, meeting the eigen-frequencies of an inflatable torus with the circular cross section. The structural model-2 is introduced with air mass element and analyzed its eigen-frequency with different aspect ratio and mode shape response using in-plane and out-plane loading condition are studied.

Elemental analysis techniques using proton microbeam

International Nuclear Information System (INIS)

Sakai, Takuro; Oikawa, Masakazu; Sato, Takahiro

2005-01-01

Proton microbeam is a powerful tool for two-dimensional elemental analysis. The analysis is based on Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE) techniques. The paper outlines the principles and instruments, and describes the dental application has been done in JAERI Takasaki. (author)

Derivation and analysis of the Feynman-alpha formula for deterministically pulsed sources

International Nuclear Information System (INIS)

Wright, J.; Pazsit, I.

2004-03-01

The purpose or this report is to give a detailed description of the calculation of the Feynman-alpha formula with deterministically pulsed sources. In contrast to previous calculations, Laplace transform and complex function methods are used to arrive at a compact solution in form of a Fourier series-like expansion. The advantage of this method is that it is capable to treat various pulse shapes. In particular, in addition to square- and Dirac delta pulses, a more realistic Gauss-shaped pulse is also considered here. The final solution of the modified variance-to-mean, that is the Feynman Y(t) function, can be quantitatively evaluated fast and with little computational effort. The analytical solutions obtained are then analysed quantitatively. The behaviour of the number or neutrons in the system is investigated in detail, together with the transient that follows the switching on of the source. An analysis of the behaviour of the Feynman Y(t) function was made with respect to the pulse width and repetition frequency. Lastly, the possibility of using me formulae for the extraction of the parameter alpha from a simulated measurement is also investigated

Structural analysis of reactor fuel elements

International Nuclear Information System (INIS)

Weeks, R.W.

1977-01-01

An overview of fuel-element modeling is presented that traces the development of codes for the prediction of light-water-reactor and fast-breeder-reactor fuel-element performance. It is concluded that although the mathematical analysis is now far advanced, the development and incorporation of mechanistic constitutive equations has not kept pace. The resultant reliance on empirical correlations severely limits the physical insight that can be gained from code extrapolations. Current efforts include modeling of alternate fuel systems, analysis of local fuel-cladding interactions, and development of a predictive capability for off-normal behavior. Future work should help remedy the current constitutive deficiencies and should include the development of deterministic failure criteria for use in design

Elements of real analysis

CERN Document Server

Sprecher, David A

2010-01-01

This classic text in introductory analysis delineates and explores the intermediate steps between the basics of calculus and the ultimate stage of mathematics: abstraction and generalization.Since many abstractions and generalizations originate with the real line, the author has made it the unifying theme of the text, constructing the real number system from the point of view of a Cauchy sequence (a step which Dr. Sprecher feels is essential to learn what the real number system is).The material covered in Elements of Real Analysis should be accessible to those who have completed a course in

Qualitative and quantitative spectro-chemical analysis of dates using UV-pulsed laser induced breakdown spectroscopy and inductively coupled plasma mass spectrometry.

Science.gov (United States)

Mehder, A O; Habibullah, Y B; Gondal, M A; Baig, Umair

2016-08-01

Laser Induced Breakdown Spectroscopy (LIBS) is demonstrated for the spectral analysis of nutritional and toxic elements present in several varieties of date fruit samples available in the Saudi Arabia market. The method analyzes the optical emission of a test sample when subjected to pulsed laser ablation. In this demonstration, our primary focus is on calcium (Ca) and magnesium (Mg), as nutritional elements, and on chromium (Cr), as a toxic element. The local thermodynamic equilibrium (LTE) condition was confirmed prior to the elemental characterization of date samples to ensure accuracy of the LIBS analysis. This was achieved by measuring parameters associated with the plasma, such as the electron temperature and the electron number density. These plasma parameters aid interpretation of processes such as ionization, dissociation, and excitation occurring in the plasma plume formed by ablating the date palm sample. The minimum detection limit was established from calibration curves that involved plotting the LIBS signal intensity as a function of standard date samples with known concentrations. The concentration of Ca and Mg detected in different varieties of date samples was between 187 and 515 and 35-196mgL(-1) respectively, while Cr concentration measured between 1.72 and 7.76mgL(-1). In order to optimize our LIBS system, we have studied how the LIBS signal intensity depends on the incident laser energy and the delay time. In order to validate our LIBS analysis results, standard techniques such as inductively coupled plasma mass spectrometry (ICP-MS) were also applied on an identical (duplicate) date samples as those used for the LIBS analysis. The LIBS results exhibit remarkable agreement with those obtained from the ICP-MS analysis. In addition, the finger print wavelengths of other elements present in date samples were also identified and are reported here, which has not been previously reported, to the best of our knowledge. Copyright © 2016 Elsevier B

Analysis and design of lumped element Marchand baluns

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Krozer, Viktor

2008-01-01

In this paper a novel design procedure for lumped element Marchand baluns is proposed. An analysis is performed on the balun structure in order to determine the conditions for ideal balun performance in terms of the lumped element values. The analysis is verified by two broadband designs centered...... around 22.75 GHz and differing only in terms of their impedance transformation ratio. EM simulation results on our proposed lumped element Marchand balun structure predicts an insertion loss of 4 dB and return loss of 40 dB at the design frequency of 22.75 GHz. The amplitude and phase imbalance...

Complex pulsing schemes for high frame rate imaging

DEFF Research Database (Denmark)

Misaridis, Thanassis; Fink, Mathias; Jensen, Jørgen Arendt

2002-01-01

up to a pulse train. The acoustically generated high time-bandwidth (TB) product waveforms can be compressed by using a filter bank of matched filters one for every beam direction. Matched filtering compresses the pulse train to a single pulse at the scatterer position plus a number of spike axial...... with linear frequency modulation along the transducer elements, that cover the 70% fractional bandwidth of the 7 MHz transducer. The resulted images (after beamforming and matched filtering) show an axial resolution at the same order as in conventional pulse excitation and axial sidelobes down to -45 d...

Frequency-Domain Maximum-Likelihood Estimation of High-Voltage Pulse Transformer Model Parameters

CERN Document Server

Aguglia, D; Martins, C.D.A.

2014-01-01

This paper presents an offline frequency-domain nonlinear and stochastic identification method for equivalent model parameter estimation of high-voltage pulse transformers. Such kinds of transformers are widely used in the pulsed-power domain, and the difficulty in deriving pulsed-power converter optimal control strategies is directly linked to the accuracy of the equivalent circuit parameters. These components require models which take into account electric fields energies represented by stray capacitance in the equivalent circuit. These capacitive elements must be accurately identified, since they greatly influence the general converter performances. A nonlinear frequency-based identification method, based on maximum-likelihood estimation, is presented, and a sensitivity analysis of the best experimental test to be considered is carried out. The procedure takes into account magnetic saturation and skin effects occurring in the windings during the frequency tests. The presented method is validated by experim...

A method of precise profile analysis of diffuse scattering for the KENS pulsed neutrons

International Nuclear Information System (INIS)

Todate, Y.; Fukumura, T.; Fukazawa, H.

2001-01-01

An outline of our profile analysis method, which is now of practical use for the asymmetric KENS pulsed thermal neutrons, are presented. The analysis of the diffuse scattering from a single crystal of D 2 O is shown as an example. The pulse shape function is based on the Ikeda-Carpenter function adjusted for the KENS neutron pulses. The convoluted intensity is calculated by a Monte-Carlo method and the precision of the calculation is controlled. Fitting parameters in the model cross section can be determined by the built-in nonlinear least square fitting procedure. Because this method is the natural extension of the procedure conventionally used for the triple-axis data, it is easy to apply with generality and versatility. Most importantly, furthermore, this method has capability of precise correction of the time shift of the observed peak position which is inevitably caused in the case of highly asymmetric pulses and broad scattering function. It will be pointed out that the accurate determination of true time-of-flight is important especially in the single crystal inelastic experiments. (author)

Usability of a new multiple high-speed pulse time data registration, processing and real-time display system for pulse time interval analysis

International Nuclear Information System (INIS)

Yawata, Takashi; Sakaue, Hisanobu; Hashimoto, Tetsuo; Itou, Shigeki

2006-01-01

A new high-speed multiple pulse time data registration, processing and real-time display system for time interval analysis (TIA) was developed for counting either β-α or α-α correlated decay-events. The TIA method has been so far limited to selective extraction of successive α-α decay events within the milli-second time scale owing to the use of original electronic hardware. In the present pulse-processing system, three different high-speed α/β(γ) pulses could be fed quickly to original 32 bit PCI board (ZN-HTS2) within 1 μs. This original PCI board is consisting of a timing-control IC (HTS-A) and 28 bit counting IC (HTS-B). All channel and pulse time data were stored to FIFO RAM, followed to transfer into temporary CPU RAM (32 MB) by DMA. Both data registration (into main RAM (200 MB)) and calculation of pulse time intervals together with real-time TIA-distribution display simultaneously processed using two sophisticate softwares. The present system has proven to succeed for the real-time display of TIA distribution spectrum even when 1.6x10 5 cps pulses from pulse generator were given to the system. By using this new system combined with liquid scintillation counting (LSC) apparatus, both a natural micro-second order β-α correlated decay-events and a milli-second order α-α correlated decay-event could be selectively extracted from the mixture of natural radionuclides. (author)

Quasi-real-time photon pulse duration measurement by analysis of FEL radiation spectra

Energy Technology Data Exchange (ETDEWEB)

Engel, Robin, E-mail: robin.engel@uni-oldenburg.de [Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Institut für Physik, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg (Germany); Institut für Laser und Optik, Hochschule Emden/Leer, University of Applied Sciences, Constantiaplatz 4, D-26723 Emden (Germany); Düsterer, Stefan; Brenner, Günter [Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Teubner, Ulrich [Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Institut für Physik, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg (Germany); Institut für Laser und Optik, Hochschule Emden/Leer, University of Applied Sciences, Constantiaplatz 4, D-26723 Emden (Germany)

2016-01-01

Considering the second-order spectral correlation function of SASE-FEL radiation allows a real-time observation of the photon pulse duration during spectra acquisition. For photon diagnostics at free-electron lasers (FELs), the determination of the photon pulse duration is an important challenge and a complex task. This is especially true for SASE FELs with strongly fluctuating pulse parameters. However, most techniques require an extensive experimental setup, data acquisition and evaluation time, limiting the usability in all-day operation. In contrast, the presented work uses an existing approach based on the analysis of statistical properties of measured SASE FEL spectra and implements it as a software tool, integrated in FLASH’s data acquisition system. This allows the calculation of the average pulse durations from a set of measured spectral distributions with only seconds of delay, whenever high-resolution spectra are recorded.

Artificial neural network based pulse-shape analysis for cryogenic detectors operated in CRESST-II

Energy Technology Data Exchange (ETDEWEB)

Zoeller, Andreas [Physik-Department and Excellence Cluster Universe, Technische Universitaet Muenchen, D-85747 Garching (Germany); Collaboration: CRESST-Collaboration

2016-07-01

In this talk we report on results of a pulse-shape analysis of cryogenic detectors based on artificial neural networks. To train the neural network a large amount of pulses with known properties are necessary. Therefore, a data-driven simulation used to generate these sets will be explained. The presented analysis shows an excellent discrimination performance even down to the energy threshold. The method is applied to several detectors, among them is the module with the lowest threshold (307eV) operated in CRESST-II phase 2. The performed blind analysis of this module confirms the substantially enhanced sensitivity for light dark matter published in 2015.

Prediction and phylogenetic analysis of mammalian short interspersed elements (SINEs).

Science.gov (United States)

Rogozin, I B; Mayorov, V I; Lavrentieva, M V; Milanesi, L; Adkison, L R

2000-09-01

The presence of repetitive elements can create serious problems for sequence analysis, especially in the case of homology searches in nucleotide sequence databases. Repetitive elements should be treated carefully by using special programs and databases. In this paper, various aspects of SINE (short interspersed repetitive element) identification, analysis and evolution are discussed.

Determination of base-line levels of trace amounts in pulses and spices using neutron activation technique

International Nuclear Information System (INIS)

Zaidi, J.H.; Arif, M.; Fatima, I.; Qureshi, I.H.

1993-01-01

It has been established that essential trace elements are vitally important for biochemical systems, whereas toxic elements if present in relatively higher amounts adversely affect these systems. Trace elements reach the human body mainly through foodstuffs. The different articles contain varying amount of toxic and essential elements. It is therefore necessary to asses the adequacy and safety of the diet by determining the base-line levels of these elements. In continuation of our previous work, some varieties of pulses and spices were analyzed using neutron activation technique. Among the four varieties of pulses lentil (lens esculenta) was found to contain higher amounts of essential elements and lower amounts of toxic elements. The daily intake of essential and toxic elements through pulses was estimated and compared with the suggested values. The estimated intake of essential elements is adequate and that of toxic elements is well below the tolerance limit. In spices cumin and caraway seeds were found to contain relatively higher amounts of essential as well as toxic elements. The studies showed that food spices were additional source of trace element intake. (author)

Toenail elemental analysis of Korean young adults by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Lee, O.

2016-01-01

The element contents in toenail clippings of healthy Korean young adults were measured using an instrumental neutron activation analysis. The average contents of elements such as Na, K, Cl, Ca, Fe, Se, and Zn are 449, 474, 1024, 1677, 66, 0.7 and 94 mg/kg in men, whereas those contents in women respectively 332, 476, 836, 1097, 66, 0.8 and 104 mg/kg. The correlation analysis of toenail elements with chronic disease risks showed positive associations between Na and serum HDL-cholesterol, blood pressure, and negative associations between Se and Hs-CRP, between Zn and hemoglobin level. (author)

Finite element analysis of FRP-strengthened RC beams

Directory of Open Access Journals (Sweden)

Teeraphot Supaviriyakit

2004-05-01

Full Text Available This paper presents a non-linear finite element analysis of reinforced concrete beam strengthened with externally bonded FRP plates. The finite element modeling of FRP-strengthened beams is demonstrated. Concrete and reinforcing bars are modeled together as 8-node isoparametric 2D RC element. The FRP plate is modeled as 8-node isoparametric 2D elastic element. The glue is modeled as perfect compatibility by directly connecting the nodes of FRP with those of concrete since there is no failure at the glue layer. The key to the analysis is the correct material models of concrete, steel and FRP. Cracks and steel bars are modeled as smeared over the entire element. Stress-strain properties of cracked concrete consist of tensile stress model normal to crack, compressive stress model parallel to crack and shear stress model tangential to crack. Stressstrain property of reinforcement is assumed to be elastic-hardening to account for the bond between concrete and steel bars. FRP is modeled as elastic-brittle material. From the analysis, it is found that FEM can predict the load-displacement relation, ultimate load and failure mode of the beam correctly. It can also capture the cracking process for both shear-flexural peeling and end peeling modes similar to the experiment.

A General Finite Element Scheme for Limit State Analysis and Optimization

DEFF Research Database (Denmark)

Damkilde, Lars

1999-01-01

Limit State analysis which is based on a perfect material behaviour is used in many different applications primarily within Structural Engineering and Geotechnics. The calculation methods have not reached the same level of automation such as Finite Element Analysis for elastic structures....... The computer based systems are more ad hoc based and are typically not well-integrated with pre- and postprocessors well-known from commercial Finite Element codes.A finite element based formulation of limit state analysis is presented which allows an easy integration with standard Finite Element codes...... for elastic analysis. In this way the user is able to perform a limit state analysis on the same model used for elastic analysis only adding data for the yield surface.The method is based on the lower-bound theorem and uses stress-based elements with a linearized yield surface. The mathematical problem...

Slice-selective RF pulses for in vivo B1+ inhomogeneity mitigation at 7 tesla using parallel RF excitation with a 16-element coil.

Science.gov (United States)

Setsompop, Kawin; Alagappan, Vijayanand; Gagoski, Borjan; Witzel, Thomas; Polimeni, Jonathan; Potthast, Andreas; Hebrank, Franz; Fontius, Ulrich; Schmitt, Franz; Wald, Lawrence L; Adalsteinsson, Elfar

2008-12-01

Slice-selective RF waveforms that mitigate severe B1+ inhomogeneity at 7 Tesla using parallel excitation were designed and validated in a water phantom and human studies on six subjects using a 16-element degenerate stripline array coil driven with a butler matrix to utilize the eight most favorable birdcage modes. The parallel RF waveform design applied magnitude least-squares (MLS) criteria with an optimized k-space excitation trajectory to significantly improve profile uniformity compared to conventional least-squares (LS) designs. Parallel excitation RF pulses designed to excite a uniform in-plane flip angle (FA) with slice selection in the z-direction were demonstrated and compared with conventional sinc-pulse excitation and RF shimming. In all cases, the parallel RF excitation significantly mitigated the effects of inhomogeneous B1+ on the excitation FA. The optimized parallel RF pulses for human B1+ mitigation were only 67% longer than a conventional sinc-based excitation, but significantly outperformed RF shimming. For example the standard deviations (SDs) of the in-plane FA (averaged over six human studies) were 16.7% for conventional sinc excitation, 13.3% for RF shimming, and 7.6% for parallel excitation. This work demonstrates that excitations with parallel RF systems can provide slice selection with spatially uniform FAs at high field strengths with only a small pulse-duration penalty. (c) 2008 Wiley-Liss, Inc.

Double-pulse laser-induced breakdown spectroscopy analysis of scales from petroleum pipelines

Science.gov (United States)

Cavalcanti, G. H.; Rocha, A. A.; Damasceno, R. N.; Legnaioli, S.; Lorenzetti, G.; Pardini, L.; Palleschi, V.

2013-09-01

Pipeline scales from the Campos Bay Petroleum Field near Rio de Janeiro, Brazil have been analyzed by both Raman spectroscopy and by laser-induced breakdown spectroscopy (LIBS) using a double-pulse, calibration-free approach. Elements that are characteristic of petroleum (e.g. C, H, N, O, Mg, Na, Fe and V) were detected, in addition to the Ca, Al, and Si which form the matrix of the scale. The LIBS results were compared with the results of micro-Raman spectroscopy, which confirmed the nature of the incrustations inferred by the LIBS analysis. Results of this preliminary study suggest that diffusion of pipe material into the pipeline intake column plays an important role in the growth of scale. Thanks to the simplicity and relative low cost of equipment and to the fact that no special chemical pre-treatment of the samples is needed, LIBS can offer very fast acquisition of data and the possibility of in situ measurements. LIBS could thus represent an alternative or complementary method for the chemical characterization of the scales by comparison to conventional analytical techniques, such as X-ray diffraction or X-ray fluorescence.

Organization of pulse-height analysis programs for high event rates

Energy Technology Data Exchange (ETDEWEB)

Cohn, C E [Argonne National Lab., Ill. (USA)

1976-09-01

The ability of a pulse-height analysis program to handle high event rates can be enhanced by organizing it so as to minimize the time spent in interrupt housekeeping. Specifically, the routine that services the data-ready interrupt from the ADC should test whether another event is ready before performing the interrupt return.

Elemental analysis: Reduction to SI units; Rueckfuehrung in der Elementanalytik

Energy Technology Data Exchange (ETDEWEB)

Rienitz, O.; Jaehrling, R.; Schiel, D. [PTB-Arbeitsgruppe ' ' Anorganische Analytik' ' , Braunschweig (Germany); Matschat, R.; Kipphardt, H. [Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Gernand, W.; Oeter, D. [MercK KGaA (Germany)

2005-12-15

In a joint project, PTB, BAM and Merck KGaA worked on a metrological reduction system for all elements relevant to analysis. The BAM certified primary pure substances with a relative error of U{sub rel} {<=} 0.01% for the mass of the main element. This was achieved by measuring the mass components of all potential impurities, i.e. practically all elements of the periodic system except the main element. These pure substances are the national reference standards of elemental analysis. From them, PTB produces primary elementa solutions and transfer solutions which are passed on as reference standards. The industrial partner constructed the DKD calibration laboratory, which certifies commercial secondary calibration solutions on the basis of the reference standard solutions produced by PTB. With this final product, measurements in elemental analysis can be reduced to the SI units system as a routine procedure. (orig.)

Comparative Study on Interface Elements, Thin-Layer Elements, and Contact Analysis Methods in the Analysis of High Concrete-Faced Rockfill Dams

Directory of Open Access Journals (Sweden)

Xiao-xiang Qian

2013-01-01

Full Text Available This paper presents a study on the numerical performance of three contact simulation methods, namely, the interface element, thin-layer element, and contact analysis methods, through the analysis of the contact behavior between the concrete face slab and the dam body of a high concrete-faced rockfill dam named Tianshengqiao-I in China. To investigate the accuracy and limitations of each method, the simulation results are compared in terms of the dam deformation, contact stress along the interface, stresses in the concrete face slab, and separation of the concrete face slab from the cushion layer. In particular, the predicted dam deformation and slab separation are compared with the in-situ observation data to classify these methods according to their agreement with the in-situ observations. It is revealed that the interface element and thin-layer element methods have their limitations in predicting contact stress, slab separation, and stresses in the concrete face slab if a large slip occurs. The contact analysis method seems to be the best choice whether the separation is finite or not.

P-wave pulse analysis to retrieve source and propagation effects in the case of Vrancea earthquakes

International Nuclear Information System (INIS)

Popescu, E.; Popa, M.; Placinta, A.; Grecu, B.; Radulian, M.

2004-01-01

Seismic source parameters and attenuation structure properties are obtained from the first P-wave pulse analysis and empirical Green's function deconvolution. The P pulse characteristics are combined effects of source and path properties. To reproduce the real source and structure parameters it is crucial to apply a method able to distinguish between the different factors affecting the observed seismograms. For example the empirical Green's function deconvolution method (Hartzell, 1978) allows the retrieval of the apparent source time function or source spectrum corrected for path, site and instrumental effects. The apparent source duration is given by the width of the deconvoluted source pulse and is directly related to the source dimension. Once the source time function established, next we can extract the parameters related to path effects. The difference between the pulse recorded at a given station and the source pulse obtained by deconvolution is a measure of the attenuation along the path from focus to the station. On the other hand, the pulse width variations with azimuth depend critically on the fault plane orientation and source directivity. In favourable circumstances (high signal/noise ratio, high resolution and station coverage), the method of analysis proposed in this paper allows the constraint of the rupture plane among the two nodal planes characterizing the fault plane solution, even for small events. P-wave pulse analysis was applied for 25 Vrancea earthquakes recorded between 1999 and 2003 by the Romanian local network to determine source parameters and attenuation properties. Our results outline high-stress drop seismic energy release with relatively simple rupture process for the considered events and strong lateral variation of attenuation of seismic waves across Carpathians Arc. (authors)

Alphavirus replicon approach to promoterless analysis of IRES elements.

Science.gov (United States)

Kamrud, K I; Custer, M; Dudek, J M; Owens, G; Alterson, K D; Lee, J S; Groebner, J L; Smith, J F

2007-04-10

Here we describe a system for promoterless analysis of putative internal ribosome entry site (IRES) elements using an alphavirus (family Togaviridae) replicon vector. The system uses the alphavirus subgenomic promoter to produce transcripts that, when modified to contain a spacer region upstream of an IRES element, allow analysis of cap-independent translation of genes of interest (GOI). If the IRES element is removed, translation of the subgenomic transcript can be reduced >95% compared to the same transcript containing a functional IRES element. Alphavirus replicons, used in this manner, offer an alternative to standard dicistronic DNA vectors or in vitro translation systems currently used to analyze putative IRES elements. In addition, protein expression levels varied depending on the spacer element located upstream of each IRES. The ability to modulate the level of expression from alphavirus vectors should extend the utility of these vectors in vaccine development.

Simultaneous hit finding and timing method for pulse shape analysis of drift chamber signals

Energy Technology Data Exchange (ETDEWEB)

Schaile, D; Schaile, O; Schwarz, J

1986-01-01

An algorithm for the analysis of the digitized signal waveform of drift chamber pulses is described which yields a good multihit resolution and an accurate drift time determination with little processing time. The method has been tested and evaluated with measured pulse shapes from the full size prototype of the OPAL central detector which were digitized by 100 MHz FADCs. (orig.).

Simultaneous hit finding and timing method for pulse shape analysis of drift chamber signals

Energy Technology Data Exchange (ETDEWEB)

Schaile, D; Schaile, O; Schwarz, J

1986-01-01

An algorithm for the analysis of the digitized signal waveform of drift chamber pulses is described which yields a good multihit resolution and an accurate drift time determination with little processing time. The method has been tested and evaluated with measured pulse shapes from the full size prototype of the OPAL central detector which were digitized by 100 MHz FADCs.

Correct use of Membrane Elements in Structural Analysis

Directory of Open Access Journals (Sweden)

Rothman Timothy

2016-01-01

Full Text Available Structural analysis of consumer electronic devices such as phones and tablets involves Finite Element Analysis (FEA. Dynamic loading conditions such as device dropping and bending dictate accurate FEA models to reduce design risk in many areas. The solid elements typically used in structural analysis do not have integration points on the surface. The outer surface is of most interest because that is where the cracks start. Analysts employ a post processing trick through using membranes to bring accurate stress/strain results to the surface. This paper explains numerical issues with implementation of membranes and recommends a methodology for accurate structural analysis.

Fast pulse amplifier

International Nuclear Information System (INIS)

Lepetit, J.; Poussier, E.

1984-01-01

This amplifier comprises an inverter transformer, the primary circuit of which receives a pulse and the secondary circuit of which is connected to several amplifying elements in parallel. The inverter transformer is made of coaxial cable segments winded around a magnetic torus; the cable cores connected in series constitute the primary circuit and the braiding of cables, connected in parallel, are the secondary circuit. The transformer comprises, besides, delay lines in series with each braiding of the secondary circuit, these ones are such that pulses issued from each braiding arrive together to the secondary circuit connectors. This invention applies, noticeably in the case of a high voltage amplifier, to the control of deflection blocks of particles used in medicine or in particle accelerators [fr

Elemental analysis of cotton by laser-induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Schenk, Emily R.; Almirall, Jose R.

2010-05-01

Laser-induced breakdown spectroscopy (LIBS) has been applied to the elemental characterization of unprocessed cotton. This research is important in forensic and fraud detection applications to establish an elemental fingerprint of U.S. cotton by region, which can be used to determine the source of the cotton. To the best of our knowledge, this is the first report of a LIBS method for the elemental analysis of cotton. The experimental setup consists of a Nd:YAG laser that operates at the fundamental wavelength as the LIBS excitation source and an echelle spectrometer equipped with an intensified CCD camera. The relative concentrations of elements Al, Ba, Ca, Cr, Cu, Fe, Mg, and Sr from both nutrients and environmental contributions were determined by LIBS. Principal component analysis was used to visualize the differences between cotton samples based on the elemental composition by region in the U.S. Linear discriminant analysis of the LIBS data resulted in the correct classification of >97% of the cotton samples by U.S. region and >81% correct classification by state of origin.

Elemental analysis of bottom ash from municipal incinerator by neutron activation analysis

International Nuclear Information System (INIS)

Kim, S. H.; Jang, S. H.; Moon, J. H.; Jung, Y. S.; Kim, Y. J.

2003-01-01

Elemental analysis of bottom ash generated from municipal solid waste incinerator was performed by neutron activation analysis. For this study, ash samples monthly collected from incinerator in D city were sieved with 5 mm mesh size, dried, pulverized by agate mortar and finally re-sieved with 200μ mesh size. Prepared samples were irradiated by neutrons using NAA No.1 irradiation hole in Korea Atomic Energy Research Institute. Activated samples were measured by gamma-ray spectrometer according to the relevant nuclear properties of target nuclides and the concentration of 33 elements were determined from the collected ash samples. Quality control was conducted by comparative analysis with two NIST standard reference materials simultaneously. Mean values and standard deviations of hazardous elements such as As, Cr, Cu, Fe, Mn, Sb and Zn among the determined elements were 3.8±6.9mg/kg, 620±0.12 %, 4.76±0.37 %, 0.26±0.10 %, 115±29 mg/kg and 0.71±0.19 %, respectively

Pulse polarography - special application; Polarographie a impulsions - applications particulieres

Energy Technology Data Exchange (ETDEWEB)

Chapron, Y [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

The calculation of the current on a plane electrode in particular conditions is presented briefly, the first part of the report then consists of a theoretical and methodological presentation of pulse polarography. The calculation of the current in pulse polarography is given for different modes of measurement and for redox systems of variable reversibility. Various extensions are proposed with a view to extending the field of application of the method. The second part presents two particular applications. One application is to analytical chemistry: organometallic complexes applied to the pulse polarographic analysis; the other application is to electrochemical kinetics using integral pulse polarography. This research has enabled us to determine, in the first case, elements present in minute traces, and in the second case the kinetic parameters of an electrochemical reaction which is too fast to be analyzed by conventional polarography. (author) [French] Apres un rappel sur le calcul du courant sur electrode plane dans des conditions precises, la premiere partie du memoire est consacree a l'expose theorique et methodologique de la polarographie a impulsions. Le calcul du courant en polarographie a impulsions est donne pour divers modes de mesures et pour des systemes redox de reversibilites variees. Diverses extensions sont proposees de facon a elargir le domaine d'application de la methode. La deuxieme partie introduit deux applications particulieres. Une application a la chimie analytique: les complexes organometalliques appliques a l'analyse pulsopolarographique et une application a la cinetique electrochimique par polarographie a impulsions integrale. Ces recherches nous ont permis de determiner dans le premier cas, des elements a l'etat de traces infimes, dans le deuxieme cas, les parametres cinetiques d'une reaction electrochimique trop rapide pour etre analysee par polarographie classique. (auteur)

Investigating Pulsed Discharge Polarity Employing Solid-State Pulsed Power Electronics

DEFF Research Database (Denmark)

Davari, Pooya; Zare, Firuz; Blaabjerg, Frede

2015-01-01

condition plays an important role in maintaining the desired performance. Investigating the system parameters contributed to the generated pulses is an effective way in improving the system performance further ahead. One of these parameters is discharge polarity which has received less attention....... In this paper, effects of applied voltage polarity on plasma discharge have been investigated in different mediums at atmospheric pressure. The experiments have been conducted based on high voltage DC power supply and high voltage pulse generator for point-to-point and point-to-plane geometries. Furthermore......, the influence of electric field distribution is analyzed using Finite Element simulations for the employed geometries and mediums. The experimental and simulation results have verified the important role of the applied voltage polarity, employed geometry and medium of the system on plasma generation....

Chemical analysis of useful trace elements in sea water

International Nuclear Information System (INIS)

Katoh, Shunsaku; Fujii, Ayako; Miyai, Yoshitaka; Sakane, Kohji; Ogata, Noboru.

1983-01-01

The methods for the analysis of useful trace elements in sea water which have been tried so far are reviewed, and these methods are described briefly from the standpoint of studying the collection of resources. Ag and Au can be determined by concentrating sea water by ion-exchange method, solvent extraction method and electrodeposition method, then the elements are measured quantitatively by activation analysis and atomic absorption spectrochemical analysis. Sr, B and Li, which exist in relatively high concentration in sea water, are determined easily by atomic absorption spectrochemical analysis and absorption spectrometry. U, Mo and V are measured suitably by concentrating the elements by coprecipitation or solvent extraction method, and measuring by fluorescence analysis and arsenazo-3 method for U and through graphite-atomic absorption analysis for Mo and V. It has been revealed that the concentration of Ag and Au in sea water is extremely low, accordingly the recovery study is not conducted recently. On the other hand, the adsorption method using hydrated titanium oxide and amidoxim adsorbents for U, Mo and V, the adsorption method using aluminum adsorbent for Li, and the adsorption method using magnesium oxide and zirconium hydroxide and the solvent extraction method for B are hopeful to recover these elements. (Yoshitake, I.)

Neutron-gamma discrimination by pulse analysis with superheated drop detector

International Nuclear Information System (INIS)

Das, Mala; Seth, S.; Saha, S.; Bhattacharya, S.; Bhattacharjee, P.

2010-01-01

Superheated drop detector (SDD) consisting of drops of superheated liquid of halocarbon is irradiated to neutrons and gamma-rays from 252 Cf fission neutron source and 137 Cs gamma source, respectively, separately. Analysis of pulse height of signals at the neutron and gamma-ray sensitive temperature provides significant information on the identification of neutron and gamma-ray induced events.

Nonlinear Finite Element Analysis of Shells with Large Aspect Ratio

Science.gov (United States)

Chang, T. Y.; Sawamiphakdi, K.

1984-01-01

A higher order degenerated shell element with nine nodes was selected for large deformation and post-buckling analysis of thick or thin shells. Elastic-plastic material properties are also included. The post-buckling analysis algorithm is given. Using a square plate, it was demonstrated that the none-node element does not have shear locking effect even if its aspect ratio was increased to the order 10 to the 8th power. Two sample problems are given to illustrate the analysis capability of the shell element.

Perspectives for online analysis of raw material by pulsed neutron irradiation

Science.gov (United States)

Bach, Pierre; Le Tourneur, P.; Poumarede, B.

1997-02-01

On-line analysis by pulsed neutron irradiation is an example of an advanced technology application of nuclear techniques, concerning real problems in the cement, mineral and coal industries. The most significant of these nuclear techniques is their capability of continuous measurement without contact and without sampling, which can lead to improved control of processes and resultant large financial savings. Compared to Californium neutron sources, the use of electrical pulsed neutron generators allows to obtain a higher signal/noise ratio for a more sensitive measurement, and allows to overcome a number of safety problems concerning transportation, installation and maintenance. An experiment related to a possible new on-line raw material analyzer is described, using a pulsed neutron generator. The key factors contributing to an accurate measurement are related to a suitable generator, to a high count rate gamma ray spectroscopy electronics, and to computational tools. Calculation and results for the optimization of the neutron irradiation time diagram are reported. One of the operational characteristics of such an equipment is related to neutron flux available: it is possible to adjust it to the requested accuracy, i.e. for a high accuracy during a few hours/day and for a lower accuracy the rest of the time. This feature allows to operate the neutron tube during a longer time, and then to reduce the cost of analysis.

Finite element analysis of structures through unified formulation

CERN Document Server

Carrera, Erasmo; Petrolo, Marco; Zappino, Enrico

2014-01-01

The finite element method (FEM) is a computational tool widely used to design and analyse  complex structures. Currently, there are a number of different approaches to analysis using the FEM that vary according to the type of structure being analysed: beams and plates may use 1D or 2D approaches, shells and solids 2D or 3D approaches, and methods that work for one structure are typically not optimized to work for another. Finite Element Analysis of Structures Through Unified Formulation deals with the FEM used for the analysis of the mechanics of structures in the case of linear elasticity. The novelty of this book is that the finite elements (FEs) are formulated on the basis of a class of theories of structures known as the Carrera Unified Formulation (CUF). It formulates 1D, 2D and 3D FEs on the basis of the same ''fundamental nucleus'' that comes from geometrical relations and Hooke''s law, and presents both 1D and 2D refined FEs that only have displacement variables as in 3D elements. It also covers 1D...

Multi-element analysis for environmental characterization and its future trends

International Nuclear Information System (INIS)

Sansoni, B.

1987-04-01

Before starting to characterize the environment by its elemental composition, it may be useful to ask about the objective of these efforts. This includes questions about the scope of environmental protection, the definition of the environment and the limitations of its characterization by elemental composition alone. In the second part of this lecture, examples are given of the elemental composition of well analysed samples from the atmosphere, hydrosphere, lithosphere and biosphere. The third part introduces the principle of multi-element analysis and the fourth part gives examples. Finally, future aspects of modern chemical analysis are outlined with respect to the multi-element principle. (orig.)

Development of a pulse magnet of a superconducting storage ring and degradation of the pulse magnetic field by the vacuum chamber

International Nuclear Information System (INIS)

Tsukishima, Chihiro; Nakata, Shuhei

1993-01-01

A pulse magnet and its modulator are developed for a superconducting storage ring commissioning at Mitsubishi Electric Corp. The magnet is a window flame type one and uses a ceramic chamber with thin metallic coating for the vacuum shielding. The modulator generates a pulse current of 5.5 kA and the magnetic field is up to 1,300 G. The rise time of the field should be less than 300 ns in order to obtain enough injection efficiency to the storage ring. The shielding effects of the pulse magnetic field by the vacuum chamber are estimated using a three dimensional transient analysis program. The program solves the magnetic charge on the yoke surface of the magnet using the boundary element method and the eddy currents on the vacuum chamber using the network circuits method. The degradation of the magnetic field is measured by the search coil for different coating thickness to check the calculations results, and the results show good agreement with the calculation results. The calculation and the measurement results show the thickness should be less than 10 nm when the pulse width of the field is 600 ns. The dependence of the ununiformity of the coating thickness on the shielding effects is also estimated and the requirements for the uniformity are not so strict when the thickness is less than 10 nm. (author)

PIXE - a new method for elemental analysis

International Nuclear Information System (INIS)

Johansson, S.A.E.

1983-01-01

With elemental analysis we mean the determination of which chemical elements are present in a sample and of their concentration. This is an old and important problem in chemistry. The earliest methods were purely chemical and many such methods are still used. However, various methods based on physical principles have gradually become more and more important. One such method is neutron activation. When the sample is bombarded with neutrons it becomes radioactive and the various radioactive isotopes produced can be identified by the radiation they emit. From the measured intensity of the radiation one can calculate how much of a certain element that is present in the sample. Another possibility is to study the light emitted when the sample is excited in various ways. A spectroscopic investigation of the light can identify the chemical elements and allows also a determination of their concentration in the sample. In the same way, if a sample can be brought to emit X-rays, this radiation is also characteristic for the elements present and can be used to determine the elemental concentration. One such X-ray method which has been developed recently is PIXE. The name is an acronym for Particle Induced X-ray Emission and indicates the principle of the method. Particles in this context means heavy, charged particles such as protons and a-particles of rather high energy. Hence, in PIXE-analysis the sample is irradiated in the beam of an accelerator and the emitted X-rays are studied. (author)

Electromagnetic or other directed energy pulse launcher

Science.gov (United States)

Ziolkowski, Richard W.

1990-01-01

The physical realization of new solutions of wave propagation equations, such as Maxwell's equations and the scaler wave equation, produces localized pulses of wave energy such as electromagnetic or acoustic energy which propagate over long distances without divergence. The pulses are produced by driving each element of an array of radiating sources with a particular drive function so that the resultant localized packet of energy closely approximates the exact solutions and behaves the same.

VCSELs in short-pulse operation for time-of-flight applications

Science.gov (United States)

Moench, Holger; Gronenborn, Stephan; Gu, Xi; Gudde, Ralph; Herper, Markus; Kolb, Johanna; Miller, Michael; Smeets, Michael; Weigl, Alexander

2018-02-01

VCSEL arrays are the ideal light source for 3D imaging applications. The narrow emission spectrum and the ability for short pulses make them superior to LEDs. Combined with fast photodiodes or special camera chips spatial information can be obtained which is needed in diverse applications like camera autofocus, indoor navigation, 3D-object recognition, augmented reality or autonomously driving vehicles. Pulse operation at the ns scale and at low duty cycle can work with significantly higher current than traditionally used for VCSELs in continuous wave operation. With reduced thermal limitations at low average heat dissipation very high currents become feasible and tens of Watts output power have been realized with small VCSEL chips. The optical emission pattern of VCSELs can be tailored to the desired field of view using beam shaping elements. Such optical elements also enable laser safe class 1 products. A detailed analysis of the complete system and the operation mode is required to calculate the maximum permitted power for a safe system. The good VCSEL properties like robustness, stability over temperature and the potential for integrated solutions open a huge potential for VCSELs in new mass applications in the consumer and automotive markets.

Pulse shaper for scintillation detectors with NaI(Tl) or CsI(Tl) crystals

International Nuclear Information System (INIS)

Novisov, B.S.; Maksimenko, A.S.; Baryshev, A.V.; Zhukov, A.V.

1978-01-01

The basic circuit of a signal shaper for scintillation detectors with NaI(Tl) and CsI(Tl) crystals is described. To increase amplitude resolution, it is suggested to integrate not the whole charge at the photomultiplier output, but a part of the charge during the initial 100 ns of the current pulse; the remaining part of the current signal is compensated directly at the photomultiplier anode by means of an electric circuit. The principal elements of the spectrometric signal shaper include an input transistor amplifier, a compensation circuit, a key element, a shaper amplifier of time pulses, a shaper of signal duration for controlling the key element, and an output spectrometric amplifier. This device, being used, one can shape pulses at durations of 100 ns and more. The shaper restoration time does not exceed 50 ns. When the shaper operates with NaI(Tl) crystals and at counting rate of 10 6 pulse/s, the amplitude resolution with and without the compensation circuit is 17% and 21% respectively

Data processing for the multichannel pulse height analysis system ND-50/50, (1)

International Nuclear Information System (INIS)

Katagiri, Masaki

1977-03-01

The multichannel pulse height analysis system ND-50/50 manufactured by Nuclear Data Inc. consists of a 4096 channel pulse height analyzer and a small computer PDP-8/L (Digital Equipment Corporation). A conversational interpretive language, MACAL (Multichannel Analyzer CALculator) has been developed to analyze gamma-ray spectra in ND-50/50. It is a modification of the FOCAL (FOrmula CALculator) language of Digital Equipment Corporation. MACAL consists of imperative English commands and mathematical expressions, and has standard mathematical functions and functions for controlling the multichannel pulse height analyzer and I/O devices (high-speed reader, high-speed punch, and digital plotter). With MACAL, the following five programs were prepared : 1) program for controlling the multichannel pulse height analyzer and data handling, 2) program for automatically analyzing gamma-ray spectra obtained by germanium detectors, 3) program for automatically measuring characteristics of germanium detectors, 4) program for calculating the center energy of gamma-ray peaks, and 5) program for plotting the pulse height distribution and diagraming the results obtained with the programs. By combining the programs according to experimental purposes, the system can be highly effective. (auth.)

A refined element-based Lagrangian shell element for geometrically nonlinear analysis of shell structures

Directory of Open Access Journals (Sweden)

Woo-Young Jung

2015-04-01

Full Text Available For the solution of geometrically nonlinear analysis of plates and shells, the formulation of a nonlinear nine-node refined first-order shear deformable element-based Lagrangian shell element is presented. Natural co-ordinate-based higher order transverse shear strains are used in present shell element. Using the assumed natural strain method with proper interpolation functions, the present shell element generates neither membrane nor shear locking behavior even when full integration is used in the formulation. Furthermore, a refined first-order shear deformation theory for thin and thick shells, which results in parabolic through-thickness distribution of the transverse shear strains from the formulation based on the third-order shear deformation theory, is proposed. This formulation eliminates the need for shear correction factors in the first-order theory. To avoid difficulties resulting from large increments of the rotations, a scheme of attached reference system is used for the expression of rotations of shell normal. Numerical examples demonstrate that the present element behaves reasonably satisfactorily either for the linear or for geometrically nonlinear analysis of thin and thick plates and shells with large displacement but small strain. Especially, the nonlinear results of slit annular plates with various loads provided the benchmark to test the accuracy of related numerical solutions.

Analysis of trace elements in serum from human eating irradiated food

International Nuclear Information System (INIS)

Huang Zongzhi; Zhou Hongdi; Chen Shijie; Gao Sumei

1987-01-01

A method of trace element analysis by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AEC) in serum from human eating food preserved by irradiation is described. Trace element analysis in human serum is one of the research projects concerning the wholesomeness. 78 serum samples of the human eating food preserved by irradiation were collected. After ashing and solving ICP-AES analysis of serum is performed for detecting 12 trace elements in specimen solution. The detection limitations are in the range of 10 -2 - 10 -3 ppm for differemt elements. The recoveries of elements are over 73%. Concentrations of 12 trace elements in 78 human serum has been calculated with F and t tests at PDP 11/70 computer and it was concluded that there is no significant difference between testing group and control group

A computer program for structural analysis of fuel elements

International Nuclear Information System (INIS)

Hayashi, I.M.V.; Perrotta, J.A.

1988-01-01

It's presented the code ELCOM for the matrix analysis of tubular structures coupled by rigid spacers, typical of PWR's fuel elements. The code ELCOM makes a static structural analysis, where the displacements and internal forces are obtained for each structure at the joints with the spacers, and also, the natural frequencies and vibrational modes of an equivalent integrated structure are obtained. The ELCOM result is compared to a PWR fuel element structural analysis obtained in published paper. (author) [pt

[Principal component analysis and cluster analysis of inorganic elements in sea cucumber Apostichopus japonicus].

Science.gov (United States)

Liu, Xiao-Fang; Xue, Chang-Hu; Wang, Yu-Ming; Li, Zhao-Jie; Xue, Yong; Xu, Jie

2011-11-01

The present study is to investigate the feasibility of multi-elements analysis in determination of the geographical origin of sea cucumber Apostichopus japonicus, and to make choice of the effective tracers in sea cucumber Apostichopus japonicus geographical origin assessment. The content of the elements such as Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Hg and Pb in sea cucumber Apostichopus japonicus samples from seven places of geographical origin were determined by means of ICP-MS. The results were used for the development of elements database. Cluster analysis(CA) and principal component analysis (PCA) were applied to differentiate the sea cucumber Apostichopus japonicus geographical origin. Three principal components which accounted for over 89% of the total variance were extracted from the standardized data. The results of Q-type cluster analysis showed that the 26 samples could be clustered reasonably into five groups, the classification results were significantly associated with the marine distribution of the sea cucumber Apostichopus japonicus samples. The CA and PCA were the effective methods for elements analysis of sea cucumber Apostichopus japonicus samples. The content of the mineral elements in sea cucumber Apostichopus japonicus samples was good chemical descriptors for differentiating their geographical origins.

Chirp analysis of high-order harmonics from atoms driven by intense femtosecond laser pulses

International Nuclear Information System (INIS)

Kim, Hyung Taek; Kim, I Jong; Hong, Kyung-Han; Lee, Dong Gun; Kim, Jung-Hoon; Nam, Chang Hee

2004-01-01

The spectral structure of harmonics was experimentally controlled by changing the chirp of femtosecond laser pulses, and the dependence of harmonic chirp on atomic species was analysed using harmonics from neon and helium. Experimental results and theoretical analysis based on the Wigner distribution function showed that the spectral structure varied sensitively to laser chirp and the harmonic chirp was determined by the competition between dynamically induced negative chirp and self-phase modulation induced positive chirp. The generation of sharp and bright harmonics was achieved with appropriately chirped laser pulses under given experimental conditions, especially negatively chirped pulses in the case of laser intensity above the saturation intensity for optical-field ionization

Pulse pileup effects of plasma electron temperature measurements by soft x-ray energy analysis

International Nuclear Information System (INIS)

Dyer, G.R.; Neilson, G.H.; Kelley, G.G.

1978-10-01

The electron temperature of hot plasmas is conveniently derived from bremsstrahlung spectra obtained by pulse-height analysis using a lithium-compensated silicon detector. Time-resolved temperature measurements require high counting rates, with ultimate rate limited by pulse pileup. To evaluate this limit, spectral distortion due to pileup and consequent effects on temperature determination are investigated. Expressions for distorted spectra are derived as functions of Maxwellian temperature and pileup fraction for both square and triangular pulse shapes. A comparison of temperatures obtained from distorted spectra with actual values indicates that measurements with less than 10% error can be made in the absence of line radiation, even from spectra containing 40% pileup

Ultrashort pulse energy distribution for propulsion in space

Science.gov (United States)

Bergstue, Grant Jared

This thesis effort focuses on the development of a novel, space-based ultrashort pulse transmission system for spacecraft. The goals of this research include: (1) ultrashort pulse transmission strategies for maximizing safety and efficiency; (2) optical transmission system requirements; (3) general system requirements including control techniques for stabilization; (4) optical system requirements for achieving effective ablative propulsion at the receiving spacecraft; and (5) ultrashort pulse transmission capabilities required for future missions in space. A key element of the research is the multiplexing device required for aligning the ultrashort pulses from multiple laser sources along a common optical axis for transmission. This strategy enables access to the higher average and peak powers required for useful missions in space.

Integral finite element analysis of turntable bearing with flexible rings

Science.gov (United States)

Deng, Biao; Liu, Yunfei; Guo, Yuan; Tang, Shengjin; Su, Wenbin; Lei, Zhufeng; Wang, Pengcheng

2018-03-01

This paper suggests a method to calculate the internal load distribution and contact stress of the thrust angular contact ball turntable bearing by FEA. The influence of the stiffness of the bearing structure and the plastic deformation of contact area on the internal load distribution and contact stress of the bearing is considered. In this method, the load-deformation relationship of the rolling elements is determined by the finite element contact analysis of a single rolling element and the raceway. Based on this, the nonlinear contact between the rolling elements and the inner and outer ring raceways is same as a nonlinear compression spring and bearing integral finite element analysis model including support structure was established. The effects of structural deformation and plastic deformation on the built-in stress distribution of slewing bearing are investigated on basis of comparing the consequences of load distribution, inner and outer ring stress, contact stress and other finite element analysis results with the traditional bearing theory, which has guiding function for improving the design of slewing bearing.

Analysis of rod drop and pulsed source measurements of reactivity in the Winfrith SGHWR

International Nuclear Information System (INIS)

Brittain, I.

1970-05-01

Reactivity measurements by the rod-drop and pulsed source methods in the Winfrith SGHWR are seriously affected by spatial harmonics. A method of calculation is described which enables the spatial harmonics to be calculated in non-uniform cores in two or three dimensions, and thus allows a much more rigorous analysis of the experimental results than the usual point model. The method is used to analyse all the rod-drop measurements made during commissioning of the Winfrith SGHWR, and to comment on the results of pulsed source measurements. The reactivity worths of banks of ten and twelve shut-down tubes deduced from rod-drop and pulsed source experiments are in satisfactory agreement with each other and also with AIMAZ calculated values. The ability to calculate higher spatial harmonics in nonuniform cores is thought to be new, and may have a wider application to reactor kinetics through the method of Modal Analysis. (author)

Studies of Effect Analysis of Electromagnetic Pulses (EMP) in Operating Nuclear Power Plants (NPP)

Energy Technology Data Exchange (ETDEWEB)

Ye, Song Hae; Ryu, Ho Sun; Kim, Min Yi; Lee, Eui Jong [KHNP, Daejeon (Korea, Republic of)

2016-05-15

The effect analysis of electromagnetic pulses (EMPs) has been studied for the past year by the Central Research Institute of Korea Hydro Nuclear Power Co. (KHNP) in order to better establish safety measures in operating nuclear power plants. What is an electromagnetic pulse (EMP)? As a general term for high-power electromagnetic radiation, it refers to strong electromagnetic pulses that destroy only electronic equipment devices in a short period without loss of life. The effect analysis of EMPs in operating NPPs and their corresponding safety measures in terms of selecting target devices against EMP impact have been examined in this paper. In general, domestic nuclear power plants do apply the design of fail-safe concepts. For example, if key instruments of a system fail because of EMPs, the control rods of a nuclear reactor are dropped automatically in order to maintain safe conditions of the NPP. Reactor cooling presents no problem because the diesel generator will adopt the analog starting circuit least affected by the electromagnetic waves.

Analysis of Brick Masonry Wall using Applied Element Method

Science.gov (United States)

Lincy Christy, D.; Madhavan Pillai, T. M.; Nagarajan, Praveen

2018-03-01

The Applied Element Method (AEM) is a versatile tool for structural analysis. Analysis is done by discretising the structure as in the case of Finite Element Method (FEM). In AEM, elements are connected by a set of normal and shear springs instead of nodes. AEM is extensively used for the analysis of brittle materials. Brick masonry wall can be effectively analyzed in the frame of AEM. The composite nature of masonry wall can be easily modelled using springs. The brick springs and mortar springs are assumed to be connected in series. The brick masonry wall is analyzed and failure load is determined for different loading cases. The results were used to find the best aspect ratio of brick to strengthen brick masonry wall.

Elements of abstract harmonic analysis

CERN Document Server

Bachman, George

2013-01-01

Elements of Abstract Harmonic Analysis provides an introduction to the fundamental concepts and basic theorems of abstract harmonic analysis. In order to give a reasonably complete and self-contained introduction to the subject, most of the proofs have been presented in great detail thereby making the development understandable to a very wide audience. Exercises have been supplied at the end of each chapter. Some of these are meant to extend the theory slightly while others should serve to test the reader's understanding of the material presented. The first chapter and part of the second give

Study of laser pulses propagation through an ultrashort pulse amplifying systems for the development of an Offner temporal stretcher

International Nuclear Information System (INIS)

Cordeiro, Thiago da Silva

2009-01-01

The study of laser pulses propagation through an ultrashort pulses amplifying system containing dispersive and spectral modifying media was performed. The study emphasis was the development of an ultrashort pulse stretcher to replace the one inside a hybrid Ti:Sapphire/Cr:LiSAF CPA system operating at the Center for Lasers and Applications at IPEN/CNEN-SP. A spherical aberration free Offner stretcher was theoretically studied, aiming to obtain a stretching ratio larger than the one available in our system. The influence of the phase components in the amplified pulse final duration was also studied, and the bandwidth limiting elements of the system in operation were mapped, with the purpose of determining the conditions under which a new stretcher should be implemented. Based on the actual measurements, computing routines were implemented in order to determine the consequences of an ultrashort pulse travelling through a bandwidth limiting component. (author)

Complex finite element sensitivity method for creep analysis

International Nuclear Information System (INIS)

Gomez-Farias, Armando; Montoya, Arturo; Millwater, Harry

2015-01-01

The complex finite element method (ZFEM) has been extended to perform sensitivity analysis for mechanical and structural systems undergoing creep deformation. ZFEM uses a complex finite element formulation to provide shape, material, and loading derivatives of the system response, providing an insight into the essential factors which control the behavior of the system as a function of time. A complex variable-based quadrilateral user element (UEL) subroutine implementing the power law creep constitutive formulation was incorporated within the Abaqus commercial finite element software. The results of the complex finite element computations were verified by comparing them to the reference solution for the steady-state creep problem of a thick-walled cylinder in the power law creep range. A practical application of the ZFEM implementation to creep deformation analysis is the calculation of the skeletal point of a notched bar test from a single ZFEM run. In contrast, the standard finite element procedure requires multiple runs. The value of the skeletal point is that it identifies the location where the stress state is accurate, regardless of the certainty of the creep material properties. - Highlights: • A novel finite element sensitivity method (ZFEM) for creep was introduced. • ZFEM has the capability to calculate accurate partial derivatives. • ZFEM can be used for identification of the skeletal point of creep structures. • ZFEM can be easily implemented in a commercial software, e.g. Abaqus. • ZFEM results were shown to be in excellent agreement with analytical solutions

A proposal for a determination method of element division on an analytical model for finite element elastic waves propagation analysis

International Nuclear Information System (INIS)

Ishida, Hitoshi; Meshii, Toshiyuki

2010-01-01

This study proposes an element size selection method named the 'Impact-Meshing (IM) method' for a finite element waves propagation analysis model, which is characterized by (1) determination of element division of the model with strain energy in the whole model, (2) static analysis (dynamic analysis in a single time step) with boundary conditions which gives a maximum change of displacement in the time increment and inertial (impact) force caused by the displacement change. In this paper, an example of application of the IM method to 3D ultrasonic wave propagation problem in an elastic solid is described. These examples showed an analysis result with a model determined by the IM method was convergence and calculation time for determination of element subdivision was reduced to about 1/6 by the IM Method which did not need determination of element subdivision by a dynamic transient analysis with 100 time steps. (author)

Pulse-shaping strategies in short-pulse fiber amplifiers

Energy Technology Data Exchange (ETDEWEB)

Schimpf, Damian Nikolaus

2010-02-09

Ultrashort pulse lasers are an important tool in scientific and industrial applications. However, many applications are demanding higher average powers from these ultrashort pulse sources. This can be achieved by combining direct diode pumping with novel gain media designs. In particular, ultrashort pulse fiber lasers are now delivering average powers in the kW range. However, the design of fiber lasers, producing pulses with high peak-powers, is challenging due to the impact of nonlinear effects. To significantly reduce these detrimental effects in ultrashort pulse fiber amplifers, the combination of chirped pulse amplification (CPA) and large mode area fibers is employed. Using these methods, the pulse energy of fiber lasers has been steadily increasing for the past few years. Recently, a fiber-based CPA-system has been demonstrated which produces pulse energies of around 1 mJ. However, both the stretching and the enlargement of the mode area are limited, and therefore, the impact of nonlinearity is still noticed in systems employing such devices. The aim of this thesis is the analysis of CPA-systems operated beyond the conventional nonlinear limit, which corresponds to accumulated nonlinear phase-shifts around 1 rad. This includes a detailed discussion of the influence of the nonlinear effect self-phase modulation on the output pulse of CPA-systems. An analytical model is presented. Emphasis is placed on the design of novel concepts to control the impact of self-phase modulation. Pulse-shaping is regarded as a powerful tool to accomplish this goal. Novel methods to control the impact of SPM are experimentally demonstrated. The design of these concepts is based on the theoretical findings. Both amplitude- and phase-shaping are studied. Model-based phase-shaping is implemented in a state-of-the-art fiber CPA-system. The influence of the polarization state is also highlighted. Additionally, existing techniques and recent advances are put into context. (orig.)

Pulse-shaping strategies in short-pulse fiber amplifiers

International Nuclear Information System (INIS)

Schimpf, Damian Nikolaus

2010-01-01

Ultrashort pulse lasers are an important tool in scientific and industrial applications. However, many applications are demanding higher average powers from these ultrashort pulse sources. This can be achieved by combining direct diode pumping with novel gain media designs. In particular, ultrashort pulse fiber lasers are now delivering average powers in the kW range. However, the design of fiber lasers, producing pulses with high peak-powers, is challenging due to the impact of nonlinear effects. To significantly reduce these detrimental effects in ultrashort pulse fiber amplifers, the combination of chirped pulse amplification (CPA) and large mode area fibers is employed. Using these methods, the pulse energy of fiber lasers has been steadily increasing for the past few years. Recently, a fiber-based CPA-system has been demonstrated which produces pulse energies of around 1 mJ. However, both the stretching and the enlargement of the mode area are limited, and therefore, the impact of nonlinearity is still noticed in systems employing such devices. The aim of this thesis is the analysis of CPA-systems operated beyond the conventional nonlinear limit, which corresponds to accumulated nonlinear phase-shifts around 1 rad. This includes a detailed discussion of the influence of the nonlinear effect self-phase modulation on the output pulse of CPA-systems. An analytical model is presented. Emphasis is placed on the design of novel concepts to control the impact of self-phase modulation. Pulse-shaping is regarded as a powerful tool to accomplish this goal. Novel methods to control the impact of SPM are experimentally demonstrated. The design of these concepts is based on the theoretical findings. Both amplitude- and phase-shaping are studied. Model-based phase-shaping is implemented in a state-of-the-art fiber CPA-system. The influence of the polarization state is also highlighted. Additionally, existing techniques and recent advances are put into context. (orig.)

High accuracy 3D electromagnetic finite element analysis

International Nuclear Information System (INIS)

Nelson, Eric M.

1997-01-01

A high accuracy 3D electromagnetic finite element field solver employing quadratic hexahedral elements and quadratic mixed-order one-form basis functions will be described. The solver is based on an object-oriented C++ class library. Test cases demonstrate that frequency errors less than 10 ppm can be achieved using modest workstations, and that the solutions have no contamination from spurious modes. The role of differential geometry and geometrical physics in finite element analysis will also be discussed

High accuracy 3D electromagnetic finite element analysis

International Nuclear Information System (INIS)

Nelson, E.M.

1996-01-01

A high accuracy 3D electromagnetic finite element field solver employing quadratic hexahedral elements and quadratic mixed-order one-form basis functions will be described. The solver is based on an object-oriented C++ class library. Test cases demonstrate that frequency errors less than 10 ppm can be achieved using modest workstations, and that the solutions have no contamination from spurious modes. The role of differential geometry and geometrical physics in finite element analysis will also be discussed

Spectrum library concept and pulse shape analysis in liquid scintillation counting

Energy Technology Data Exchange (ETDEWEB)

Kaihola, L [Wallac Oy, Turku (Finland)

1997-03-01

Wallac introduced in 1990 a new absolute liquid scintillation counting (LSC) method, Digital Overlay Technique (DOT) to correct for quench. This method allows quantization of multilabel samples by referring to library spectra which are generated against chemical and color quench indices at the factory. The libraries can further be expanded to any beta emitter by user with a method called fine tuning, which can be carried out even with a single sample. Spectrum libraries are created over the whole spectrum range of the radionuclide and allow automatic identification of a single label beta emitting radionuclide, called Easy Count method. Another improvement in LSC is commercial introduction of Pulse Shape Analysis (PSA) in 1986 by Wallac. This method recognizes alpha particle decay by pulse shape and leads to excellent sensitivity in alpha counting because most of the background signal in LSC comprises of short or beta like pulses. PSA detects alpha events in the presence of high excess of beta activity over alphas, up to a ratio 100000 to 1. (orig.)

Finite element simulation of moisture movement and solute transport in a large caisson

International Nuclear Information System (INIS)

Huyakorn, P.S.; Jones, B.G.; Parker, J.C.; Wadsworth, T.D.; White, H.O. Jr.

1987-01-01

The results of the solute transport experiments performed on compacted, crushed Bandelier Tuff in caisson B of the experimental cluster described by DePoorter (1981) are simulated. Both one- and three-dimensional simulations of solute transport have been performed using two selected finite element codes. Results of bromide and iodide tracer experiments conducted during near-steady flow conditions have been analyzed for pulse additions made on December 6, 1984, and followed over a period of up to 60 days. In addition, a pulse addition of nonconservative strontium tracer on September 28, 1984, during questionably steady flow conditions has been analyzed over a period of 240 days. One-dimensional finite element flow and transport simulations were carried out assuming the porous medium to be homogeneous and the injection source uniformly distributed. To evaluate effects of the nonuniform source distribution and also to investigate effects of inhomogeneous porous medium properties, three dimensional finite element analyses of transport were carried out. Implications of the three-dimensional effects for the design and analysis of future tracer studies are discussed

Neutron activation analysis of trace elements in IAEA reference materials

International Nuclear Information System (INIS)

Cheema, M.N.; Hasany, S.M.; Hanif, I.; Chaudhry, M.S.; Qureshi, I.H.

1978-09-01

Analytical Chemistry Group of Nuclear Chemistry Division at PINSTECH has been participating in IAEA Intercomparison programme of analytical quality control since 1972. So far fifteen samples of a variety of materials received from the Agency have been analyzed for different minor and trace elements. Mostly destructive and non-destructive neutron activation analysis techniques have been used for elemental analysis. In this report the description of the samples and the experimental procedures employed have been mentioned. The results of elemental analysis have been reported and compared with IAEA values which are based on the average computed from the results of different participating laboratories. (authors)

Application of trace element analysis to determine trace element concentrations in the field of medicine

International Nuclear Information System (INIS)

Kasperek, K.; Feinendegen, L.E.

1976-01-01

Applied trace elements research in medicine requires a sensitive and efficient technique of trace elements analysis such as, e.g., neutron activation analysis. Essential trace elements act as stabilisators (iron in haem), structural elements (silicium in fibrous tissue), in hormones (iodine in thyroid hormone), in vitamins (cobalt in vitamin B 12), and in enzymes. Most of the essential trace elements act as coenzymes or in coenzymes or directly as metabolic catalysators. For example, selenium deficiency in PKU and maple syrup patients receiving dietary treatment can be detected by determining the selenium content of the serum, while low selenium values in the whole blood indicate liver cirrhosis. Acrodermatitis enteropathica can be diagnosed by determinig zinc in the serum, and pancreatic insufficiency by determining zinc in the pancreatic juice. Zinc also plays a part in disturbances of growth, in the healing of wounds, and in the insulin metabolism. Cobalt is important in some types of anaemia and in myocardiopathies. Trace elements are also necessary in the treatment of diseases, e.g. iron cobalt in some types of anaemia, and zinc in the delayed healing of wounds in the postoperative phase and in acrodermatitis enteropathica. Chromium is now being tested for the treatment of diabetes mellitus, and fluorides may be of interest in the treatment of osteoporosis. Finally, trace elements are important in the aetiology of acute poisoning, in nutrition, and in environmental protection. (orig./AK) [de

Microstructural evolution of a cold work tool steel after pulsed laser remelting

Directory of Open Access Journals (Sweden)

L. Kosec

2012-01-01

Full Text Available The aim of this study is the investigation of micro-structural behaviour of a Mat. No. 1.2379 (EN-X160CrMoV121; AISI D2 cold work tool steel after remelting with a precise pulsed Nd:YAG laser. The investigated steel is one of the most hard to weld tool steels, due to large amount of alloying elements. The analysis was done on single spots remelted with specific laser pulse shape and parameters, assuring crack-less solidification. Re-solidifi ed areas were investigated with microscopy, hardness measurements, X-ray spectroscopy and diffraction method. Laser treatment causes rapid solidifi cation leading into a formation of a fine dendritic microstructures containing high amount of retained austenite causing a significant decrease of hardness.

Dynamic relaxation method in analysis of reinforced concrete bent elements

Directory of Open Access Journals (Sweden)

Anna Szcześniak

2015-12-01

Full Text Available The paper presents a method for the analysis of nonlinear behaviour of reinforced concrete bent elements subjected to short-term static load. The considerations in the range of modelling of deformation processes of reinforced concrete element were carried out. The method of structure effort analysis was developed using the finite difference method. The Dynamic Relaxation Method, which — after introduction of critical damping — allows for description of the static behaviour of a structural element, was used to solve the system of nonlinear equilibrium equations. In order to increase the method effectiveness in the range of the post-critical analysis, the Arc Length Parameter on the equilibrium path was introduced into the computational procedure.[b]Keywords[/b]: reinforced concrete elements, physical nonlinearity, geometrical nonlinearity, dynamic relaxation method, arc-length method

Precise generator of stability amplitude pulses

International Nuclear Information System (INIS)

Zhuk, N.A.; Zdesenko, Yu.G.; Kuts, V.N.

1989-01-01

A generator of stability amplitude pulses, designed for stabilization of a low-noise semiconducting spectrometer, used in investigations of 76 Ge2β-decay, is described. The generator contains a permanent-voltage source, a storage element and a switch based on a Hg relay. A thermostatic source provides a relative voltage instability less than ±5x10 -6 per 80h (standard deviation). The Hg relay is placed into a separate thermostat. The relative instability of output generator pulse amplitude does not exceed ±1.5x10 -5 per 24h

Isogeometric finite element analysis of poroelasticity

NARCIS (Netherlands)

Irzal, F.; Remmers, J.J.C.; Verhoosel, C.V.; Borst, de R.

2013-01-01

We present an alternative numerical approach for predicting the behaviour of a deformable fluid-saturated porous medium. The conventional finite element technology is replaced by isogeometric analysis that uses non-uniform rational B-splines. The ability of these functions to provide higher-order

Feasibility analysis for attosecond X-ray pulses at FERMI@ELETTRA free electron laser

Energy Technology Data Exchange (ETDEWEB)

Zholents, Alexander

2004-09-01

We present preliminary analysis for the feasibility of the attosecond x-ray pulses at a proposed FERMI@ELETTRA free electron laser (FEL) [1]. In part 1 we restrict ourselves to minimal modifications to the proposed FEL and consider a scheme for attosecond x-ray production which can be qualified as a small add-on to a primary facility. We demonstrate that at 5-nm wavelength our scheme is capable for production of pulses with an approximate duration of 100 attoseconds at approximately 2 MW peak power and with an absolute temporal synchronization to a pump laser pulse. In part 2 we propose to use an FEL amplifier seeded by a VUV signal and to follow it by the scheme for attosecond x-ray production described in part 1.

Effect of Large Negative Phase of Blast Loading on Structural Response of RC Elements

Directory of Open Access Journals (Sweden)

Syed Zubair Iman

2016-01-01

Full Text Available Structural response of reinforced concrete (RC elements for analysis and design are often obtained using the positive phase of the blast pressure curve disregarding the negative phase assuming insignificant contribution from the negative phase of the loading. Although, some insight on the effect of negative phase of blast pressure based on elastic single-degree-of-freedom (SDOF analysis was presented before, the influence of negative phase on different types of resistance functions of SDOF models and on realistic finite element analysis has not been explored. In this study, the effects of inclusion of pulse negative phase on structural response of RC elements from SDOF analysis and from more detailed finite element analysis have been investigated. Investigation of SDOF part has been conducted using MATLAB code that utilizes non-linear resistance functions of SDOF model. Detailed numerical investigation using finite element code DIANA was conducted on the significance of the negative phase on structural response. In the FE model, different support stiffness was used to explore the effect of support stiffness on the structural response due to blast negative phase. Results from SDOF and FE analyses present specific situations where the effect of large negative phase was found to be significant on the structural response of RC elements.

Biomonitoring of air pollution through trace element analysis

International Nuclear Information System (INIS)

Bamford, S.A.; Osae, E.K.; Aboh, I.J.; Serfor-Armah, Y.; Nyarko, B.; Odamtten, G.T.

1999-01-01

Studies are being carried out to determine the potential and reliability in the use of local lichen species for biomonitoring air pollution in Ghana. The location of most of the gold mines in forest areas of the country presents the gold mining industry as a suitable setting for such investigations. The nuclear-related techniques being used in the multielement analysis of lichen samples and air filter samples are instrumental neutron activation analysis (Miniature Neutron Source Reactor) and energy dispersive x-ray fluorescence analysis (tube-excitation). Validation of the quantitative methods of the INAA through analysis of standard and certified reference materials of orchard leaves NBS SRM 1571 and BCR-CRM No. 279 gave very good results for most elements analyzed. Elemental analysis of identified lichen samples will be done beating in mind microclimatic factors, specie type and nature of soil. (author)

Biomonitoring of air pollution through trace element analysis

International Nuclear Information System (INIS)

Bamford, S.A.; Osae, E.K.; Aboh, I. J.; Serfor-Armah, Y.; Nyarko, B.; Ofosu, F.; Odamtten, G.T.

1999-04-01

Studies are being carried out to determine the potential and reliability in the use of local lichen species for biomonitoring air pollution in Ghana. The location of most of the gold mines in forest areas of the country presents the gold mining industry as a suitable setting for such investigations. The nuclear-related techniques being used in the multielement analysis of lichen samples and air filter samples are instrumental neutron activation analysis (Miniature Neutron Source Reactor) and energy dispersive x-ray fluorescence analysis (tube-excitation). Validation of the quantitative methods of the INAA through analysis of standard certified reference materials of orchard leaves NBS SRM 1571 and BCR-CRM No. 279 gave very good results for most elements analyzed. Elemental analysis of identified lichen samples will be done bearing in mind microclimatic factors, specie type and nature of soil. (author)

Elemental analysis of granite by instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF)

International Nuclear Information System (INIS)

El-Taher, A.

2012-01-01

The instrumental neutron activation analysis technique (INAA) was used for qualitative and quantitative analysis of granite samples collected from four locations in the Aswan area in South Egypt. The samples were prepared together with their standards and simultaneously irradiated in a neutron flux of 7×10 11 n/cm 2 s in the TRIGA Mainz research reactor. Gamma-ray spectra from an hyper-pure germanium detector were analyzed. The present study provides the basic data of elemental concentrations of granite rocks. The following elements have been determined Na, Mg, K, Fe, Mn, Sc, Cr, Ti, Co, Zn, Ga, Rb, Zr, Nb, Sn, Ba, Cs, La, Ce, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U. The X-ray fluorescence (XRF) was used for comparison and to detect elements, which can be detected only by XRF such as F, S, Cl, Co, Cu, Mo, Ni, Pb, Se and V. The data presented here are our contribution to understanding the elemental composition of the granite rocks. Because there are no existing databases for the elemental analysis of granite, our results are a start to establishing a database for the Egyptian granite. It is hoped that the data presented here will be useful to those dealing with geochemistry, granite chemistry and related fields. - Highlights: ► Instrumental neutron activation analysis technique (INAA) was used for qualitative and quantitative analysis of granite. ► The samples were prepared together with their standards and simultaneously irradiated in a neutron flux of 7×10 11 n/cm 2 s in the TRIGA Mainz research reactor. ► Following elements have been determined Na, Mg, K, Fe, Mn, Sc, Cr, Ti, Co, Zn, Ga, Rb, Zr, Nb, Sn, Ba, Cs, La, Ce, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U.

Utilization of the intense pulsed neutron source (IPNS) at Argonne National Laboratory for neutron activation analysis

International Nuclear Information System (INIS)

Heinrich, R.R.; Greenwood, L.R.; Popek, R.J.; Schulke, A.W. Jr.

1983-01-01

The Intense Pulsed Neutron Source (IPNS) neutron scattering facility (NSF) has been investigated for its applicability to neutron activation analysis. A polyethylene insert has been added to the vertical hole VT3 which enhances the thermal neutron flux by a factor of two. The neutron spectral distribution at this position has been measured by the multiple-foil technique which utilized 28 activation reactions and the STAYSL computer code. The validity of this spectral measurement was tested by two irradiations of National Bureau of Standards SRM-1571 (orchard leaves), SRM-1575 (pine needles), and SRM-1645 (river sediment). The average thermal neutron flux for these irradiations normalized to 10 μamp proton beam is 4.0 x 10 11 n/cm 2 -s. Concentrations of nine trace elements in each of these SRMs have been determined by gamma-ray spectrometry. Agreement of measured values to certified values is demonstrated to be within experiment error

Pulsed power

International Nuclear Information System (INIS)

Anon.

1977-01-01

The key element of our pulsed power program is concentration of power in time and space by suppression of breakdown in dielectrics and in vacuum. Magnetically insulated vacuum transmission lines and magnetic suppression of insulator flashover have continued as the main reserch directions. Vacuum insulated line studies at Physics International have been expanded and a test bed at Sandia, called MITE (Magnetically Insulated Transmission Experiment), is under development. The choice for the baseline EBFA design will depend on the outcome of these studies and should be made in July 1977. The slow and intermediate speed pulsed power approaches to EBFA will be based on Proto I and Proto II results and several of the projected EBFA subsystems are presently being tested in Proto II. A further stage of power concentration, within the vacuum diode itself, would considerably ease the burden on dielectrics; methods of power multiplication involving magnetically imploded plasmas are being considered and tests have begun using the Ripple III apparatus

Finite element analysis of plastic recycling machine designed for ...

African Journals Online (AJOL)

... design was evaluated using finite element analysis (FEA) tool in Solid Works Computer ... Also, a minimum factor of safety value of 5.3 was obtained for shredder shaft ... Machine; Design; Recycling; Sustainability; Finite Element; Simulation ...

Evaluation of arterial propagation velocity based on the automated analysis of the Pulse Wave Shape

International Nuclear Information System (INIS)

Clara, F M; Scandurra, A G; Meschino, G J; Passoni, L I

2011-01-01

This paper proposes the automatic estimation of the arterial propagation velocity from the pulse wave raw records measured in the region of the radial artery. A fully automatic process is proposed to select and analyze typical pulse cycles from the raw data. An adaptive neuro-fuzzy inference system, together with a heuristic search is used to find a functional approximation of the pulse wave. The estimation of the propagation velocity is carried out via the analysis of the functional approximation obtained with the fuzzy model. The analysis of the pulse wave records with the proposed methodology showed small differences compared with the method used so far, based on a strong interaction with the user. To evaluate the proposed methodology, we estimated the propagation velocity in a population of healthy men from a wide range of ages. It has been found in these studies that propagation velocity increases linearly with age and it presents a considerable dispersion of values in healthy individuals. We conclude that this process could be used to evaluate indirectly the propagation velocity of the aorta, which is related to physiological age in healthy individuals and with the expectation of life in cardiovascular patients.

A Study on the Effect of Cohesive Laws on Finite Element Analysis of Crack Propagation Using Cohesive Elements

Energy Technology Data Exchange (ETDEWEB)

Seo, Hyeongseok; Baek, Hyungchan; Kim, Hyungyu [Seoul Nat' l Univ. of Sci. and Tech., Seoul (Korea, Republic of)

2014-04-15

In this paper, the effect of cohesive laws on the finite element analysis of crack propagation using cohesive elements is investigated through three-point bending and double cantilever beam problems. The cohesive elements are implemented into ABAQUS/Standard user subroutines(UEL), and the shape of cohesive law is varied by changing parameters in polynomial functions of cohesive traction-separation relations. In particular, crack propagation behaviors are studied by comparing load-displacement curves of the analysis models which have different shapes of cohesive laws with the same values of fracture energy and cohesive strength. Furthermore, the influence of the element size on crack propagation is discussed in this study.

High accuracy 3D electromagnetic finite element analysis

International Nuclear Information System (INIS)

Nelson, E.M.

1997-01-01

A high accuracy 3D electromagnetic finite element field solver employing quadratic hexahedral elements and quadratic mixed-order one-form basis functions will be described. The solver is based on an object-oriented C++ class library. Test cases demonstrate that frequency errors less than 10 ppm can be achieved using modest workstations, and that the solutions have no contamination from spurious modes. The role of differential geometry and geometrical physics in finite element analysis will also be discussed. copyright 1997 American Institute of Physics

The System of Nanosecond 280-KeV He+ Pulsed Beam

International Nuclear Information System (INIS)

Junphong, P.; Ano, V.; Lekprasert, B.; Suwannakachorn, D.; Thongnopparat, N.; Vilaithong, T.; Chiang Mai U.; Wiedemann, H.; SLAC/SLAC, SSRL

2006-01-01

At Fast Neutron Research Facility, the 150 kV-pulses neutron generator is being upgraded to a 280-kV-pulsed-He beam for time-of-flight Rutherford backscattering spectrometry. It involves replacing the existing beam line elements by a multicusp ion source, a 400-kV accelerating tube, 45-double focusing dipole magnet and quadrupole lens. The multicusp ion source is a compact filament-driven of 2.6 cm in diameter and 8 cm in length. The current extracted is 20.4 μ A with 13 kV of extraction voltage and 8.8 kV of Einzel lens voltage. The beam emittance has found to vary between 6-12 mm mrad. The beam transport system has to be redesigned based on the new elements. The important part of a good pulsed beam depends on the pulsing system. The two main parts are the chopper and buncher. An optimized geometry for the 280 keV pulsed helium ion beam will be presented and discussed. The PARMELA code has been used to optimize the space charge effect, resulting in pulse width of less than 2 ns at a target. The calculated distance from a buncher to the target is 4.6 m. Effects of energy spread and phase angle between chopper and buncher have been included in the optimization of the bunch length

A Fiber-Optic System Generating Pulses of High Spectral Density

Science.gov (United States)

Abramov, A. S.; Zolotovskii, I. O.; Korobko, D. A.; Fotiadi, A. A.

2018-03-01

A cascade fiber-optic system that generates pulses of high spectral density by using the effect of nonlinear spectral compression is proposed. It is demonstrated that the shape of the pulse envelope substantially influences the degree of compression of its spectrum. In so doing, maximum compression is achieved for parabolic pulses. The cascade system includes an optical fiber exhibiting normal dispersion that decreases along the fiber length, thereby ensuring that the pulse envelope evolves toward a parabolic shape, along with diffraction gratings and a fiber spectral compressor. Based on computer simulation, we determined parameters of cascade elements leading to maximum spectral density of radiation originating from a subpicosecond laser pulse of medium energy.

Einstein-Podolsky-Rosen paradox and quantum steering in pulsed optomechanics

Science.gov (United States)

He, Q. Y.; Reid, M. D.

2013-11-01

We describe how to generate an Einstein-Podolsky-Rosen (EPR) paradox between a mesoscopic mechanical oscillator and an optical pulse. We find two types of paradox, defined by whether it is the oscillator or the pulse that shows the effect Schrödinger called “steering”. Only the oscillator paradox addresses the question of mesoscopic local reality for a massive system. In that case, EPR's “elements of reality” are defined for the oscillator, and it is these elements of reality that are falsified (if quantum mechanics is complete). For this sort of paradox, we show that a thermal barrier exists, meaning that a threshold level of pulse-oscillator interaction is required for a given thermal occupation n0 of the oscillator. We find there is no equivalent thermal barrier for the entanglement of the pulse with the oscillator or for the EPR paradox that addresses the local reality of the optical system. Finally, we examine the possibility of an EPR paradox between two entangled oscillators. Our work highlights the asymmetrical effect of thermal noise on quantum nonlocality.

Performance analysis of pulse analog control schemes for LLC resonant DC/DC converters suitable in portable applications

Directory of Open Access Journals (Sweden)

P. Kowstubha

2016-12-01

Full Text Available Performance Analysis of Pulse Analog Control Schemes, predominantly Pulse-Width Modulation (PWM and Pulse-Position Modulation (PPM for LLC resonant DC/DC converter suitable in portable applications is addressed in this paper. The analysis is done for closed loop performance, frequency domain performance, primary and secondary side conduction losses and soft commutation using PSIM 6.0 software and observed that PPM scheme provides better performance at high input voltage with a good selectivity of frequency over a wide range of line and load variations. The performance of LLC resonant DC/DC converter is demonstrated using PPM scheme for a design specifications of 12 V, 5 A output.

Application of trace element analysis to determine trace element concentrations in the field of medicine. [Neutrons

Energy Technology Data Exchange (ETDEWEB)

Kasperek, K; Feinendegen, L E

1976-01-01

Applied trace elements research in medicine requires a sensitive and efficient technique of trace elements analysis, such as neutron activation analysis. Essential trace elements act as stabilizators (iron in haem), structural elements (silicon in fibrous tissue), in hormones (iodine in thyroid hormone), in vitamins (cobalt in vitamin B 12), and in enzymes. Most of the essential trace elements act as coenzymes or in coenzymes or directly as metabolic catalyzers. For example, selenium deficiency in PKU and maple syrup patients receiving dietary treatment can be detected by determining the selenium content of the serum, while low selenium values in the whole blood indicate liver cirrhosis. Acrodermatitis enteropathica can be diagnosed by determinig zinc in the serum, and pancreatic insufficiency by determining zinc in the pancreatic juice. Zinc also plays a part in disturbances of growth, in the healing of wounds, and in the insulin metabolism. Cobalt is important in some types of anaemia and in myocardiopathies. Trace elements are also necessary in the treatment of diseases, e.g. iron cobalt in some types of anaemia, and zinc in the delayed healing of wounds in the postoperative phase and in acrodermatitis enteropathica. Chromium is now being tested for the treatment of diabetes mellitus, and fluorides may be of interest in the treatment of osteoporosis. Finally, trace elements are important in the aetiology of acute poisoning, in nutrition, and in environmental protection.

Application of activation analysis for determination of some elements in cassiterite samples

International Nuclear Information System (INIS)

Armelin, Maria Jose Aguirre

1978-01-01

This work consists in the development of an analytical method using activation by thermal neutrons for the determination of some minor elements and traces present in cassiterite (tin ore). This method was then applied to determine these elements in samples of cassiterite from different regions of Brazil. An analysis was made of the mineralogy characteristic of cassiterite as well as of the minerals most commonly associated with it. Four main types of interference were found to occur in the analysis by activation of trace elements in samples of cassiterite. The method involves the analysis without chemical separation for the determination of some elements and the analysis with chemical separation for the determination of other elements. The steps involved in both types of analysis are described. In the analysis with chemical separation the matrix element (tin) is separated by distillation in an H 2 SO 4 -HBr medium, after fusion of the ore with Na 2 O 2 . Arsine and antimony are determined in the distilled, whereas some lanthanide elements and uranium are determined in the distillation residue by separating them as a group by precipitation with lanthanum fluoride. A discussion on the precision, accuracy and sensibility of the method is also included. (author)

Multi-element analysis of emeralds and associated rocks by k0 neutron activation analysis

International Nuclear Information System (INIS)

Acharya, R.N.; Mondal, R.K.; Burte, P.P.; Nair, A.G.C.; Reddy, N.B.Y.; Reddy, L.K.; Reddy, A.V.R.; Manohar, S.B.

2000-01-01

Multi-element analysis was carried out in natural emeralds, their associated rocks and one sample of beryl obtained from Rajasthan, India. The concentrations of 21 elements were assayed by Instrumental Neutron Activation Analysis using the k 0 method (k 0 INAA method) and high-resolution gamma ray spectrometry. The data reveal the segregation of some elements from associated (trapped and host) rocks to the mineral beryl forming the gemstones. A reference rock standard of the US Geological Survey (USGS BCR-1) was also analysed as a control of the method

Orthodontic treatment: Introducing finite element analysis

NARCIS (Netherlands)

Driel, W.D. van; Leeuwen, E.J. van

1998-01-01

The aim of orthodontic treatment is the displacement of teeth by means ofspecial appliances, like braces and brackets. Through these appliances the orthodontist can apply a set of forces to the teeth which wilt result in its displacement through the jawbone. Finite Element analysis of this process

A study on the nonlinear finite element analysis of reinforced concrete structures: shell finite element formulation

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Jin; Seo, Jeong Moon

2000-08-01

The main goal of this research is to establish a methodology of finite element analysis of containment building predicting not only global behaviour but also local failure mode. In this report, we summerize some existing numerical analysis techniques to be improved for containment building. In other words, a complete description of the standard degenerated shell finite element formulation is provided for nonlinear stress analysis of nuclear containment structure. A shell finite element is derived using the degenerated solid concept which does not rely on a specific shell theory. Reissner-Mindlin assumptions are adopted to consider the transverse shear deformation effect. In order to minimize the sensitivity of the constitutive equation to structural types, microscopic material model is adopted. The four solution algorithms based on the standard Newton-Raphson method are discussed. Finally, two numerical examples are carried out to test the performance of the adopted shell medel.

A study on the nonlinear finite element analysis of reinforced concrete structures: shell finite element formulation

International Nuclear Information System (INIS)

Lee, Sang Jin; Seo, Jeong Moon

2000-08-01

The main goal of this research is to establish a methodology of finite element analysis of containment building predicting not only global behaviour but also local failure mode. In this report, we summerize some existing numerical analysis techniques to be improved for containment building. In other words, a complete description of the standard degenerated shell finite element formulation is provided for nonlinear stress analysis of nuclear containment structure. A shell finite element is derived using the degenerated solid concept which does not rely on a specific shell theory. Reissner-Mindlin assumptions are adopted to consider the transverse shear deformation effect. In order to minimize the sensitivity of the constitutive equation to structural types, microscopic material model is adopted. The four solution algorithms based on the standard Newton-Raphson method are discussed. Finally, two numerical examples are carried out to test the performance of the adopted shell medel

Numerical analysis on acoustic impulse response for watermelon

International Nuclear Information System (INIS)

Kim, Yong Sul; Yang, Dong Hoon; Choi, Young Jae; Bae, Tas Joo; So, Chul Ho; Lee, Yun Ho

2002-01-01

In this study, we conducted both analysis on impact pulse signal and acoustic impulse response method using numerical analysistic finite element method. Considering its velocity, density, Young's Modulus, and Poisson's Ratio, we extracted featured parameters and compared both results of analysis on impact pulse signal and numerical analysis on acoustic impulse response then we found the feature of generated acoustic sound signal by way of numerical analysis varying featured parameters and consequently intended to extract feature indices influenced on its internal maturity through analysis of acoustic impulse response. As we analyzed impact pulse signal and extracted featured parameters concerned with evaluation of its ripeness, we found the plausibility of progress on nondestructive evaluation of ripeness and adoption of numerical analysis on acoustic impulse response.

TRACE ANALYSIS BY LASER-EXCITED ATOMIC FLUORESCENCE WITH ATOMIZATION IN A PULSED PLASMA

OpenAIRE

Lunyov , O.; Oshemkov , S.; Petrov , A.

1991-01-01

The possibilities of plasma atomization for laser fluorescence trace analysis are discussed. Pulsed hot hollow cathode discharge was used for analysis of solutions and powdered samples. The high voltage spark and laser-induced breakdown (laser spark) were used as atomizers of metal-containing atmospheric aerosols. Detection limits were improved by means of temporal background selection.

Introduction to nonlinear finite element analysis

CERN Document Server

Kim, Nam-Ho

2015-01-01

This book introduces the key concepts of nonlinear finite element analysis procedures. The book explains the fundamental theories of the field and provides instructions on how to apply the concepts to solving practical engineering problems. Instead of covering many nonlinear problems, the book focuses on three representative problems: nonlinear elasticity, elastoplasticity, and contact problems. The book is written independent of any particular software, but tutorials and examples using four commercial programs are included as appendices: ANSYS, NASTRAN, ABAQUS, and MATLAB. In particular, the MATLAB program includes all source codes so that students can develop their own material models, or different algorithms. This book also: ·         Presents clear explanations of nonlinear finite element analysis for elasticity, elastoplasticity, and contact problems ·         Includes many informative examples of nonlinear analyses so that students can clearly understand the nonlinear theory ·    ...

Monte Carlo simulations to advance characterisation of landmines by pulsed fast/thermal neutron analysis

NARCIS (Netherlands)

Maucec, M.; Rigollet, C.

The performance of a detection system based on the pulsed fast/thermal neutron analysis technique was assessed using Monte Carlo simulations. The aim was to develop and implement simulation methods, to support and advance the data analysis techniques of the characteristic gamma-ray spectra,

Three dimensional finite element linear analysis of reinforced concrete structures

International Nuclear Information System (INIS)

Inbasakaran, M.; Pandarinathan, V.G.; Krishnamoorthy, C.S.

1979-01-01

A twenty noded isoparametric reinforced concrete solid element for the three dimensional linear elastic stress analysis of reinforced concrete structures is presented. The reinforcement is directly included as an integral part of the element thus facilitating discretization of the structure independent of the orientation of reinforcement. Concrete stiffness is evaluated by taking 3 x 3 x 3 Gauss integration rule and steel stiffness is evaluated numerically by considering three Gaussian points along the length of reinforcement. The numerical integration for steel stiffness necessiates the conversion of global coordiantes of the Gaussian points to nondimensional local coordinates and this is done by Newton Raphson iterative method. Subroutines for the above formulation have been developed and added to SAP and STAP routines for solving the examples. The validity of the reinforced concrete element is verified by comparison of results from finite element analysis and analytical results. It is concluded that this finite element model provides a valuable analytical tool for the three dimensional elastic stress analysis of concrete structures like beams curved in plan and nuclear containment vessels. (orig.)

Statistical Energy Analysis (SEA) and Energy Finite Element Analysis (EFEA) Predictions for a Floor-Equipped Composite Cylinder

Science.gov (United States)

Grosveld, Ferdinand W.; Schiller, Noah H.; Cabell, Randolph H.

2011-01-01

Comet Enflow is a commercially available, high frequency vibroacoustic analysis software founded on Energy Finite Element Analysis (EFEA) and Energy Boundary Element Analysis (EBEA). Energy Finite Element Analysis (EFEA) was validated on a floor-equipped composite cylinder by comparing EFEA vibroacoustic response predictions with Statistical Energy Analysis (SEA) and experimental results. Statistical Energy Analysis (SEA) predictions were made using the commercial software program VA One 2009 from ESI Group. The frequency region of interest for this study covers the one-third octave bands with center frequencies from 100 Hz to 4000 Hz.

Pulsed hydrogen fluoride laser oscillator-amplifier experiments

International Nuclear Information System (INIS)

Schott, G.L.

1975-01-01

Pulsed HF chemical laser oscillator energies were scaled from millijoules to several kilojoules over the period 1970-1974, reaching approximately 10 J with SF 6 and transverse discharges, and using electron-beam initiation and elemental F 2 above 1000J. This demonstrated scalability to large energy with acceptable electrical efficiency is only one prerequisite for application of this gas laser in fusion; equally important matters are achievement of focusable, approximately 1 ns pulses, couplable to light-element targets, all from an affordable system. Exploratory MOPA experiments are reported which address control of HF laser beam focusability and pulse duration, using SF 6 -based experimental oscillator--amplifier sequences and Pockels' cell switching. Simultaneous multiline lasing with 2.6 less than or equal to lambda less than or equal to 3.1 μm and high specific gain and energy density are particularly important factors encountered with HF, where amplifier pumping and lasing occur in a substantially cw temporal relationship, even in less than 100 ns bursts. Time-resolved SF 6 --HI oscillator spectra contain 27 simultaneous lines from six vibrational bands. An apertured, SF 6 -hydrocarbon pin-discharge oscillator generates approximately 10 mJ of TEM 00 radiation, which is amplified to approximately 1 J in approximately 150 ns by a TEA amplifier and p []opagated tens of meters. A three-stage system coupling these elements through an approximately 1 ns electrooptic gate to a greater than 10 J, e-beam energized amplifier is under development. (auth)

Identification of metal elements by time-resolved LIBS technique in sediments lake the “Cisne”

Science.gov (United States)

Pacheco, P.; Arregui, E.; Álvarez, J.; Rangel, N.; Sarmiento, R.

2017-01-01

Laser induced breakdown spectroscopy (LIBS), is a kind of spectral method of atomic emission that uses pulses of radiation high energy laser as excitation source. One of the advantages of technical LIBS lies in the possibility of analyse the substances in any State of aggregation, already is solid, liquid or gaseous, even in colloids as aerosols, gels and others. Another advantage over other conventional techniques is the simultaneous analysis of elements present in a sample of multielement. This work is made in the use of this technique for the identification of metal pollutants in the Swan Lake sediment samples, collected by drilling cores. Plasmas were generated by focusing the radiation of Nd: YAG laser with an energy per pulse 13mJ and 4ns duration, wavelength of 532nm. The spectra of radiation from the plasmas of sediment were recorded with an Echelle spectrograph type coupled to an ICCD camera. The delay times were between 0.5μs and 7μs, while the gate width was of 2μs. To ensure the homogeneity of the plasmas, the sediment sample was placed in a positioning system of linear and rotary adjustment of smooth step synchronized with the trigger of the laser pulse. The registration of the spectra of the sediment to different times of delay, allowed to identify the lines prominent of the different elements present in the sample. The analysis of the Spectra allowed the identification of some elements in the sample as if, Ca, Na, Mg, and Al through the measurement of wavelengths of the prominent peaks.

Identification of metal elements by time-resolved LIBS technique in sediments lake the “Cisne”

International Nuclear Information System (INIS)

Pacheco, P; Arregui, E; Álvarez, J; Rangel, N; Sarmiento, R

2017-01-01

Laser induced breakdown spectroscopy (LIBS), is a kind of spectral method of atomic emission that uses pulses of radiation high energy laser as excitation source. One of the advantages of technical LIBS lies in the possibility of analyse the substances in any State of aggregation, already is solid, liquid or gaseous, even in colloids as aerosols, gels and others. Another advantage over other conventional techniques is the simultaneous analysis of elements present in a sample of multielement. This work is made in the use of this technique for the identification of metal pollutants in the Swan Lake sediment samples, collected by drilling cores. Plasmas were generated by focusing the radiation of Nd: YAG laser with an energy per pulse 13mJ and 4ns duration, wavelength of 532nm. The spectra of radiation from the plasmas of sediment were recorded with an Echelle spectrograph type coupled to an ICCD camera. The delay times were between 0.5μs and 7μs, while the gate width was of 2μs. To ensure the homogeneity of the plasmas, the sediment sample was placed in a positioning system of linear and rotary adjustment of smooth step synchronized with the trigger of the laser pulse. The registration of the spectra of the sediment to different times of delay, allowed to identify the lines prominent of the different elements present in the sample. The analysis of the Spectra allowed the identification of some elements in the sample as if, Ca, Na, Mg, and Al through the measurement of wavelengths of the prominent peaks. (paper)

Pulse radiolysis experiments: synthesis and analysis of composite spectra

Energy Technology Data Exchange (ETDEWEB)

Schuler, R H; Buzzard, G K [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry

1976-01-01

Methods are outlined for compiling optical spectra obtained in pulse radiolysis experiments in a form suitable for detailed synthesis and analysis of composite spectra. The experimental data are processed with a programmable calculator having a cassette recorder for the storage of the output data files and a peripheral plotter. The spectra are first smoothed by fitting them parabolically segment by segment. The overall spectrum is then assembled in digital form by interpolating the fitted data on a 1 nm grid and the results are stored on cassette files for further processing. Composite spectra can be readily calculated and plotted from the data on these files or known components can be subtracted from observed spectra to examine underlying contributions. The use of the fairly simple data processing methods described here permits an interactive mode of operation by the investigator which can maximize insight into details of the various contributions to an observed spectrum. Several examples of the use of these methods in conjunction with data obtained with a computer controlled pulse radiolysis data acquisition system are given.

Optimization of the integration time of pulse shape analysis for dual-layer GSO detector with different amount of Ce

International Nuclear Information System (INIS)

Yamamoto, Seiichi

2008-01-01

For a multi-layer depth-of-interaction (DOI) detector using different decay times, pulse shape analysis based on two different integration times is often used to distinguish scintillators in DOI direction. This method measures a partial integration and a full integration, and calculates the ratio of these two to obtain the pulse shape distribution. The full integration time is usually set to integrate full width of the scintillation pulse. However, the optimum partial integration time is not obvious for obtaining the best separation of the pulse shape distribution. To make it clear, a theoretical analysis and experiments were conducted for pulse shape analysis by changing the partial integration time using a scintillation detector of GSOs with different amount of Ce. A scintillation detector with 1-in. round photomultiplier tube (PMT) optically coupled GSO of 1.5 mol% (decay time: 35 ns) and that of 0.5 mol% (decay time: 60 ns) was used for the experiments. The signal from PMT was digitally integrated with partial (50-150 ns) and full (160 ns) integration times and ratio of these two was calculated to obtain the pulse shape distribution. In the theoretical analysis, partial integration time of 50 ns showed largest distance between two peaks of the pulse shape distribution. In the experiments, it showed maximum at 70-80 ns of partial integration time. The peak to valley ratio showed the maximum at 120-130 ns. Because the separation of two peaks is determined by the peak to valley ratio, we conclude the optimum partial integration time for these combinations of GSOs is around 120-130 ns, relatively longer than the expected value

Regression analysis and transfer function in estimating the parameters of central pulse waves from brachial pulse wave.

Science.gov (United States)

Chai Rui; Li Si-Man; Xu Li-Sheng; Yao Yang; Hao Li-Ling

2017-07-01

This study mainly analyzed the parameters such as ascending branch slope (A_slope), dicrotic notch height (Hn), diastolic area (Ad) and systolic area (As) diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP), subendocardial viability ratio (SEVR), waveform parameter (k), stroke volume (SV), cardiac output (CO) and peripheral resistance (RS) of central pulse wave invasively and non-invasively measured. These parameters extracted from the central pulse wave invasively measured were compared with the parameters measured from the brachial pulse waves by a regression model and a transfer function model. The accuracy of the parameters which were estimated by the regression model and the transfer function model was compared too. Our findings showed that in addition to the k value, the above parameters of the central pulse wave and the brachial pulse wave invasively measured had positive correlation. Both the regression model parameters including A_slope, DBP, SEVR and the transfer function model parameters had good consistency with the parameters invasively measured, and they had the same effect of consistency. The regression equations of the three parameters were expressed by Y'=a+bx. The SBP, PP, SV, CO of central pulse wave could be calculated through the regression model, but their accuracies were worse than that of transfer function model.

Finite element analysis of degraded concrete structures - Workshop proceedings

International Nuclear Information System (INIS)

1999-09-01

This workshop is related to the finite element analysis of degraded concrete structures. It is composed of three sessions. The first session (which title is: the use of finite element analysis in safety assessments) comprises six papers which titles are: Historical Development of Concrete Finite Element Modeling for Safety Evaluation of Accident-Challenged and Aging Concrete Structures; Experience with Finite Element Methods for Safety Assessments in Switzerland; Stress State Analysis of the Ignalina NPP Confinement System; Prestressed Containment: Behaviour when Concrete Cracking is Modelled; Application of FEA for Design and Support of NPP Containment in Russia; Verification Problems of Nuclear Installations Safety Software of Strength Analysis (NISS SA). The second session (title: concrete containment structures under accident loads) comprises seven papers which titles are: Two Application Examples of Concrete Containment Structures under Accident Load Conditions Using Finite Element Analysis; What Kind of Prediction for Leak rates for Nuclear Power Plant Containments in Accidental Conditions; Influence of Different Hypotheses Used in Numerical Models for Concrete At Elevated Temperatures on the Predicted Behaviour of NPP Core Catchers Under Severe Accident Conditions; Observations on the Constitutive Modeling of Concrete Under Multi-Axial States at Elevated Temperatures; Analyses of a Reinforced Concrete Containment with Liner Corrosion Damage; Program of Containment Concrete Control During Operation for the Temelin Nuclear Power Plant; Static Limit Load of a Deteriorated Hyperbolic Cooling Tower. The third session (concrete structures under extreme environmental load) comprised five papers which titles are: Shear Transfer Mechanism of RC Plates After Cracking; Seismic Back Calculation of an Auxiliary Building of the Nuclear Power Plant Muehleberg, Switzerland; Seismic Behaviour of Slightly Reinforced Shear Wall Structures; FE Analysis of Degraded Concrete

Completely non-destructive elemental analysis of bulky samples by PGA

International Nuclear Information System (INIS)

Oura, Y.; Nakahara, H.; Sueki, K.; Sato, W.; Tomizawa, T.

1998-01-01

A new non-destructive method is proposed for the elemental analysis of bulk samples. It is essentially a combination of PGA and NAA by a single neutron irradiation, and allows determinations of elemental contents of both major and minor constituents relative to that of some reference element. Major elements and some trace elements such as B, Sm, and Gd are mostly determined by the measurement of prompt gamma rays emitted when a bulky sample in its original form, namely, without any reduction of the sample size, is placed in the beam of neutrons guided from a nuclear reactor. Minor elements are then determined by the off-line measurements of gamma rays emitted from the radioactive nuclides produced within the sample by neutron capture reactions. As the radioactivity remaining in the sample becomes negligibly small after a few weeks cooling, the proposed method will be most usefully applied for the elemental analysis of bulky precious samples such as archaeological samples, and arts and crafts. In this presentation, applicability of the method will be demonstrated for porcelain and bronze samples. (author)

Finite element analysis of car hood for impact test by using ...

African Journals Online (AJOL)

Finite element analysis of car hood for impact test by using solidworks software ... high safety and at the same time can be built according to market demands. ... Keywords: finite element analysis; impact test; Solidworks; automation, car hood.

Pulsed neutron generator

International Nuclear Information System (INIS)

Bespalov, D.F.; Bykovskii, Yu.A.; Vergun, I.I.; Kozlovskii, K.I.; Kozyrev, Yu.P.; Leonov, R.K.; Simagin, B.I.; Tsybin, A.S.; Shikanov, A.Ie.

1986-03-01

The paper describes a new device for generating pulsed neutron fields, utilized in nuclear geophysics for carrying out pulsed neutron logging and activation analysis under field conditions. The invention employs a sealed-off neutron tube with a laser ion source which increases neutron yield to the level of 10 neutrons per second or higher. 2 refs., 1 fig

Prolonged methylprednisolone therapy after the pulse treatment for patients with moderate-to-severe paraquat poisoning: A retrospective analysis.

Science.gov (United States)

Gao, Jie; Feng, ShunYi; Wang, Jian; Yang, SiYuan; Li, Yong

2017-06-01

This retrospective study aims to evaluate the effect of prolonged methylprednisolone (MP) therapy on the mortality of patients with moderate-to-severe paraquat (PQ) poisoning after the pulse treatment.We performed a retrospective analysis of patients with acute moderate-to-severe PQ poisoning that were admitted to the emergency department from May 2012 to August 2016. Out of 138 patients, 60 were treated with pulse treatment (15 mg kg day MP for 3 days) and 78 were treated with prolonged MP therapy after pulse treatment (15 mg kg day MP for 3 days; afterward, the dosage was reduced in half every 2 days, and the MP therapy was terminated until 0.47 mg kg day). Kaplan-Meier method was used to compare the mortality between the 2 groups. Cox proportional hazard models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI).The mortality of the prolonged MP therapy after pulse treatment group was lower than that of the pulse group (47.4% vs 63.3%; log-rank tests, P  =  .003). According to the multivariate Cox analysis, the prolonged MP therapy after pulse treatment was significantly associated with a lower mortality risk (HR: 0.31, 95% CI: 0.19-0.52, P treatment caused more incidences of leucopenia than the pulse treatment alone (25.6% vs 11.7%, P  =  .04).The prolonged MP therapy after pulse treatment can reduce the mortality of moderate-to-severe PQ poisoning patients.

Probing Trace-elements in Bitumen by Neutron Activation Analysis

NARCIS (Netherlands)

Nahar, S.N.; Schmets, A.J.M.; Scarpas, Athanasios

Trace elements and their concentrations play an important role in both chemical and physical properties of bitumen. Instrumental Neutron Activation Analysis (INAA) has been applied to determine the concentration of trace elements in bitumen. This method requires irradiation of the material with

Non destructive multi elemental analysis using prompt gamma neutron activation analysis techniques: Preliminary results for concrete sample

Energy Technology Data Exchange (ETDEWEB)

Dahing, Lahasen Normanshah [School of Applied Physics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia and Malaysian Nuclear Agency (Nuklear Malaysia), Bangi 43000, Kajang (Malaysia); Yahya, Redzuan [School of Applied Physics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Yahya, Roslan; Hassan, Hearie [Malaysian Nuclear Agency (Nuklear Malaysia), Bangi 43000, Kajang (Malaysia)

2014-09-03

In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10×10×10 cm{sup 3} and 15×15×15 cm{sup 3} were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with NAA and XRF techniques as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed.

Interpretation of heat and density pulse measurements in JET in terms of coupled transport

International Nuclear Information System (INIS)

Haas, J.C.M. de; O'Rourke, J.; Sips, A.C.C.; Lopes Cardozo, N.J.

1990-01-01

The perturbations of electron density and temperature profiles in a tokamak following a sawtooth collapse are considered. An analytic model for the interpretation of such perturbations is presented. It is shown that the perturbation can be decomposed into two contributions, which are eigenmodes of the linearised coupled diffusion equations for particle and energy. The approximations made in the analytical treatment are checked using computer simulations. Measurements of heat and density pulses in Joint European Torus are used to illustrate the power of the new approach. It is shown that using the coupled equations, an improved description of the heat and density pulses is obtained. The analysis yields the four diffusion coefficients in the linearised transport matrix. The non-zero off-diagonal elements explain certain salient features of the measurements, notably a marked decrease of the local density which occurs during the maximum of the temperature pulse. (author)

Theoretical and Experimental Investigations of Coincidences in Poisson Distributed Pulse Trains and Spectral Distortion Caused by Pulse Pileup.

Science.gov (United States)

Bristow, Quentin

1990-01-01

Part one of this two-part study is concerned with the multiple coincidences in pulse trains from X-ray and gamma radiation detectors which are the cause of pulse pileup. A sequence of pulses with inter-arrival times less than tau, the resolving time of the pulse-height analysis system used to acquire spectra, is called a multiple pulse string. Such strings can be classified on the basis of the number of pulses they contain, or the number of resolving times they cover. The occurrence rates of such strings are derived from theoretical considerations. Logic circuits were devised to make experimental measurements of multiple pulse string occurrence rates in the output from a NaI(Tl) scintillation detector over a wide range of count rates. Markov process theory was used to predict state transition rates in the logic circuits, enabling the experimental data to be checked rigorously for conformity with those predicted for a Poisson distribution. No fundamental discrepancies were observed. Part two of the study is concerned with a theoretical analysis of pulse pileup and the development of a discrete correction algorithm, based on the use of a function to simulate the coincidence spectrum produced by partial sums of pulses. Monte Carlo simulations, incorporating criteria for pulse pileup inherent in the operation of modern ADC's, were used to generate pileup spectra due to coincidences between two pulses, (1st order pileup) and three pulses (2nd order pileup), for different semi-Gaussian pulse shapes. Coincidences between pulses in a single channel produced a basic probability density function spectrum which can be regarded as an impulse response for a particular pulse shape. The use of a flat spectrum (identical count rates in all channels) in the simulations, and in a parallel theoretical analysis, showed the 1st order pileup distorted the spectrum to a linear ramp with a pileup tail. The correction algorithm was successfully applied to correct entire spectra for 1st and

Particle identification in a wide dynamic range based on pulse-shape analysis with solid-state detectors

International Nuclear Information System (INIS)

Pausch, G.; Hilscher, D.; Ortlepp, H.G.

1994-04-01

Heavy ions detected in a planar silicon detector were identified by exploiting a recently proposed combination of the pulse-shape and the time-of-flight techniques. We were able to resolve charge numbers up to Z = 16 within a wide dynamic range of ∼ 1:5, and to identify even isotopes for the elements up to Magnesium. The simple scheme of signal processing is based on conventional electronics and cheap enough to be exploited in large multidetector arrays. (orig.)

Effective laser-induced breakdown spectroscopy (LIBS) detection using double pulse at optimum configuration.

Science.gov (United States)

Choi, Soo Jin; Yoh, Jack J

2011-08-01

A short laser pulse is irradiated on a sample to create a highly energetic plasma that emits light of a specific peak wavelength according to the material. By identifying different peaks for the analyzed samples, their chemical composition can be rapidly determined. The characteristics of the laser-induced breakdown spectroscopy (LIBS) plasma are strongly dependent on the ambient conditions. Research aimed at enhancing LIBS intensity is of great benefit in advancing LIBS for the exploration of harsh environments. By using double-pulse LIBS, the signal intensity of Al and Ca lines was enhanced by five times compared to the single-pulse signal. Also, the angles of the target and detector are adjusted to simulate samples of arbitrary shape. We verified that there exists an optimal angle at which specific elements of a test sample may be detected with stronger signal intensity. We provide several optimum configurations for the LIBS system for maximizing the signal intensity for the analysis of a nonstandard aluminum sample.

PIXE methodology of rare earth element analysis and its applications

International Nuclear Information System (INIS)

Ma Xinpei

1992-01-01

The Proton Induced X-ray Emission (PIXE) methodology of rare earth element (REEs) analysis is discussed, including the significance of REE analysis, the principle of PIXE applied to REE, selection of characteristic X-ray for Lanthanide series elements, deconvolution of highly over lapped PIXE spectrum and minimum detection limit (MDL) of REEs. Some practical applications are presented. And the specialities of PIXE analysis to the high pure REE chemicals are discussed. (author)

Analysis of elements present in beers and brewing waters by neutron activation analysis

International Nuclear Information System (INIS)

Krausova, Ivana; Kucera, Jan; Dostalek, Pavel; Potesil, Vaclav

2011-01-01

Neutron activation analysis (NAA) was used for determination of Si, Na, K, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Rb, Cs, and La in Czech beers and brewing waters. The Si concentration in beer determined by the reaction 29 Si(n,p) 29 Al with fast neutrons confirmed that beer is an important Si source in human diet. Determination of other trace elements by NAA with the whole spectrum of reactor neutrons aimed at the feasibility of identification of Gambrinus beers brewed in various breweries. The elements Ca and V appeared to be the best candidates for this purpose. The concentrations of elements determined by NAA were also compared with the recommended daily element intake for humans. The accuracy of the method was proved by analysis of reference materials, specifically NIST SRM 2704 Buffalo River Sediment, NIST SRM 1633b Coal Fly Ash, and NIST SRM 1515 Apple Leaves. (author)

Cost analysis of commercial pasteurization of orange juice by pulsed electric fields

Science.gov (United States)

The cost of pulsed electric field (PEF) pasteurization of orange juice was estimated. The cost analysis was based on processing conditions that met the US FDA (5 log reduction) requirement for fruit juice pasteurization and that achieved a 2 month microbial shelf-life. PEF-treated samples processed ...

Program for the analysis of pulse height spectra and the background from a proportional detector

International Nuclear Information System (INIS)

Flores-Llamas, H.; Yee-Madeira, H.; Contreras-Puente, G.; Zamorano-Ulloa, R.

1991-01-01

A PC-Fortran program is presented for fitting of lineshapes and the analysis of pulse height spectra obtainable with proportional detectors. The common fitting and analysis of pulse height spectra by means of mixed Gaussian lineshapes is readily improved by using Voigt lineshapes. In addition, the background can be evaluated during the fitting process without the need of extra measurements. As an application of the program, a pulse height transmission spectrum accumulated with a static 57 Co source and detected with an argon-metane proportional detector, was least squares fitted to an elaborated complex trial lineshape function containing two Voigt lines plus a straight line. The fitting straight line parameters a and b characterize quantitatively the background. The very good PC-fitting obtained shows that the fitting of experimental spectra with the more realistic Voigt lineshapes is no longer a formidable task and that it is possible to evaluate and subtract the background inherent to the experiment during the fitting process. (orig.)

Introduction to finite element analysis using MATLAB and Abaqus

CERN Document Server

Khennane, Amar

2013-01-01

There are some books that target the theory of the finite element, while others focus on the programming side of things. Introduction to Finite Element Analysis Using MATLAB(R) and Abaqus accomplishes both. This book teaches the first principles of the finite element method. It presents the theory of the finite element method while maintaining a balance between its mathematical formulation, programming implementation, and application using commercial software. The computer implementation is carried out using MATLAB, while the practical applications are carried out in both MATLAB and Abaqus. MA

Analysis of pulsed injection for microgravity receiver tank chilldown

Science.gov (United States)

Honkonen, Scott C.; Pietrzyk, Joe R.; Schuster, John R.

The dominant heat transfer mechanism during the hold phase of a tank chilldown cycle in a low-gravity environment is due to fluid motion persistence following the charge. As compared to the single-charge per vent cycle case, pulsed injection maintains fluid motion and the associated high wall heat transfer coefficients during the hold phase. As a result, the pulsed injection procedure appears to be an attractive method for reducing the time and liquid mass required to chill a tank. However, for the representative conditions considered, no significant benefit can be realized by using pulsed injection as compared to the single-charge case. A numerical model of the charge/hold/vent process was used to evaluate the pulsed injection procedure for tank chilldown in microgravity. Pulsed injection results in higher average wall heat transfer coefficients during the hold, as compared to the single-charge case. However, these high levels were not coincident with the maximum wall-to-fluid temperature differences, as in the single-charge case. For representative conditions investigated, the charge/hold/vent process is very efficient. A slightly shorter chilldown time was realized by increasing the number of pulses.

Structural weights analysis of advanced aerospace vehicles using finite element analysis

Science.gov (United States)

Bush, Lance B.; Lentz, Christopher A.; Rehder, John J.; Naftel, J. Chris; Cerro, Jeffrey A.

1989-01-01

A conceptual/preliminary level structural design system has been developed for structural integrity analysis and weight estimation of advanced space transportation vehicles. The system includes a three-dimensional interactive geometry modeler, a finite element pre- and post-processor, a finite element analyzer, and a structural sizing program. Inputs to the system include the geometry, surface temperature, material constants, construction methods, and aerodynamic and inertial loads. The results are a sized vehicle structure capable of withstanding the static loads incurred during assembly, transportation, operations, and missions, and a corresponding structural weight. An analysis of the Space Shuttle external tank is included in this paper as a validation and benchmark case of the system.

Capture analysis of element content of a substance with other neutron methods

International Nuclear Information System (INIS)

Kurbanov, B.I.

2004-01-01

Full text: Neutron analysis method of determining element composition have found wide range of applications in industry thanks to different types of interaction of neutron with substances /1/. With the aim of widening the range of problems to be solved, on the basis of the device /2/ for determining the element content of substance, possibilities of combining the method based on the use of neutron capture gamma-ray spectrometry with other neutron methods, in particular neutron activation analysis and neutron absorption analysis were studied. In this radionuclide source ( 252 Cf) with the yield of 1,5 x 10 7 neutron/sec is used. By means of using neutron capture gamma radiation spectrometry the possibilities of determining some elements (H, B, N, S etc. ), which are not determined by very widely used method, activation analysis. These elements can be determined by both the semiconductor and scintillation detectors with parameters fitting the manufacturing requirements. And for a number of elements ( B, Cl, Cd, Sm, Gd) very high limits of determination ( up to 10- 5 %) are possible using semiconductor Ge (Li) -detectors with high resolution. Possibility of determination of some 'well' activated elements ( K, Al, Fe, Mn, Ti, Sc etc.) in samples of ore and products of their processing using the neutron-activation analysis. For 1 hour of irradiation on the experimental device quite accurate analytical peak, of these elements are obtained, allowing to determine them qualitatively. However, with decreasing neutron yield of radionuclide source it becomes more difficult to achieve the necessary parameters both in neutron capture and activation analysis. Experimental works on determination of some elements with large cross-sections of capture ( B, Cd, Sm ) by absorption of neutrons in the investigated substance, i.e. using the neutron absorption analysis method with absence of other large capture cross section elements in the samples being studied

Scanning Electron Microscope-Cathodoluminescence Analysis of Rare-Earth Elements in Magnets.

Science.gov (United States)

Imashuku, Susumu; Wagatsuma, Kazuaki; Kawai, Jun

2016-02-01

Scanning electron microscope-cathodoluminescence (SEM-CL) analysis was performed for neodymium-iron-boron (NdFeB) and samarium-cobalt (Sm-Co) magnets to analyze the rare-earth elements present in the magnets. We examined the advantages of SEM-CL analysis over conventional analytical methods such as SEM-energy-dispersive X-ray (EDX) spectroscopy and SEM-wavelength-dispersive X-ray (WDX) spectroscopy for elemental analysis of rare-earth elements in NdFeB magnets. Luminescence spectra of chloride compounds of elements in the magnets were measured by the SEM-CL method. Chloride compounds were obtained by the dropwise addition of hydrochloric acid on the magnets followed by drying in vacuum. Neodymium, praseodymium, terbium, and dysprosium were separately detected in the NdFeB magnets, and samarium was detected in the Sm-Co magnet by the SEM-CL method. In contrast, it was difficult to distinguish terbium and dysprosium in the NdFeB magnet with a dysprosium concentration of 1.05 wt% by conventional SEM-EDX analysis. Terbium with a concentration of 0.02 wt% in an NdFeB magnet was detected by SEM-CL analysis, but not by conventional SEM-WDX analysis. SEM-CL analysis is advantageous over conventional SEM-EDX and SEM-WDX analyses for detecting trace rare-earth elements in NdFeB magnets, particularly dysprosium and terbium.

Probabilistic finite elements for transient analysis in nonlinear continua

Science.gov (United States)

Liu, W. K.; Belytschko, T.; Mani, A.

1985-01-01

The probabilistic finite element method (PFEM), which is a combination of finite element methods and second-moment analysis, is formulated for linear and nonlinear continua with inhomogeneous random fields. Analogous to the discretization of the displacement field in finite element methods, the random field is also discretized. The formulation is simplified by transforming the correlated variables to a set of uncorrelated variables through an eigenvalue orthogonalization. Furthermore, it is shown that a reduced set of the uncorrelated variables is sufficient for the second-moment analysis. Based on the linear formulation of the PFEM, the method is then extended to transient analysis in nonlinear continua. The accuracy and efficiency of the method is demonstrated by application to a one-dimensional, elastic/plastic wave propagation problem. The moments calculated compare favorably with those obtained by Monte Carlo simulation. Also, the procedure is amenable to implementation in deterministic FEM based computer programs.

Investigation of the Behavior of Steel Shear Walls Using Finite Elements Analysis

Directory of Open Access Journals (Sweden)

K. Abubakri

2016-10-01

Full Text Available Currently, steel shear walls are considered by engineers as an economic method against lateral loads imposed by wind and earthquake in tall structures. Accordingly, there is a growing need to develop accurate methods alongside approximation methods to estimate the behavior of these structural elements. The finite element technique is one of the strongest numerical methods in analysis of solid mechanics problems. Finite element analysis however requires high technical knowledge of the behavioral models of materials. Therefore, it is less used by designers for certain structural elements such as steel shear walls. This study examines the failure mechanism of steel shear walls using finite elements analysis and validates this modeling by comparing the results with experimental studies.

Elemental analysis of biological materials. Current problems and techniques with special reference to trace elements

International Nuclear Information System (INIS)

1980-01-01

Selected techniques were reviewed for the assay of trace and minor elements in biological materials. Other relevant information is also presented on the need for such analyses, sampling, sample preparation and analytical quality control. In order to evaluate and compare the applicability of the various analytical techniques on a meaningful and objective basis, the materials chosen for consideration were intended to be typical of a wide range of biological matrics of different elemental compositions, namely Bowen's kale, representing a plant material, and NBS bovine liver, IAEA animal muscle, and blood serum, representing animal tissues. The subject is reviewed under the following headings: on the need for trace element analyses in the life sciences (4 papers); sampling and sample preparation for trace element analysis (2 papers); analytical techniques for trace and minor elements in biological materials (7 papers); analytical quality control (2 papers)

Upgrade of the Annular Core Pulse Reactor

Energy Technology Data Exchange (ETDEWEB)

Reuscher, J A [Sandia Laboratories, Albuquerque, NM (United States)

1976-07-01

The Annular Core Pulse Reactor (ACPR) is a TRIGA type reactor which has been in operation at Sandia Laboratories since 1967. The reactor is utilized in a wide variety of experimental programs which include radiation effects, neutron radiography, activation analysis, and fast reactor safety. During the past two years, the ACPR has become an important experimental facility for the United States Fast Reactor Safety Research Program and questions of interest to the safety of the LMFBR are being addressed. In order to enhance the capabilities of the ACPR for reactor safety experiments, a project to improve the performance of the reactor was initiated. It is anticipated that the pulse fluence can be increased by a factor of 2.0 to 2.5 by utilizing a two-region core concept with high heat capacity fuel elements around the central irradiation cavity. In addition, the steady-state power of the reactor will be increased by about a factor of two. Preliminary studies have identified several potential approaches to the ACPR performance improvement. The most promising approach appears to be the two-region core concept. The inner region, surrounding the irradiation cavity, would consist of a high-heat capacity fuel capable of absorbing the fission energy associated with a large nuclear pulse. The number of fissions occurring near the cavity would be greatly increased which, in turn, would significantly increase the fluence in the cavity. The outer region would consist of a U-ZrH fuel to provide an overall negative temperature coefficient for the two region core. Two candidate high heat capacity fuels [(BeO-UO{sub 2} and UC-ZrC) - graphite] are under consideration. Since this reactor upgrade represents a modification to an existing facility, it can be achieved in a relatively short time. It is anticipated that most of the existing reactor structure can be used for the upgrade. The present core occupies about one-half of the location in the grid plate. The high-heat capacity fuel

Elemental analysis of soil and hair sample by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Chung, Yong Sam; Quraishi, Shamshad Begum; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Yeoil; Kang, Sang Hoon; Lim, Jong Myoung; Cho, Hyun Je; Kim, Young Jin

2004-03-01

Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used

Elemental analysis of soil and hair sample by instrumental neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Chung, Yong Sam; Quraishi, Shamshad Begum; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Yeoil; Kang, Sang Hoon; Lim, Jong Myoung; Cho, Hyun Je; Kim, Young Jin

2004-03-01

Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used.

Pile-up and defective pulse rejection by pulse shape discrimination in surface barrier detectors

International Nuclear Information System (INIS)

Sjoeland, K.A.; Kristiansson, P.

1994-01-01

A technique to reject pile-up pulses and defective tail pulses from surface barrier detectors by the use of pulse shape discrimination is demonstrated. The electronic implementation of the pulse shape discrimination is based upon the zero crossing technique and for data reduction multiparameter techniques are used. The characteristic τ value for pile-up rejection is shown to be less than 56 ns. Its effect on detection limits from tail reduction in Particle Elastic Scattering Analysis (PESA) and pile-up peak suppression is discussed. ((orig.))

Optimization methods of pulse-to-pulse alignment using femtosecond pulse laser based on temporal coherence function for practical distance measurement

Science.gov (United States)

Liu, Yang; Yang, Linghui; Guo, Yin; Lin, Jiarui; Cui, Pengfei; Zhu, Jigui

2018-02-01

An interferometer technique based on temporal coherence function of femtosecond pulses is demonstrated for practical distance measurement. Here, the pulse-to-pulse alignment is analyzed for large delay distance measurement. Firstly, a temporal coherence function model between two femtosecond pulses is developed in the time domain for the dispersive unbalanced Michelson interferometer. Then, according to this model, the fringes analysis and the envelope extraction process are discussed. Meanwhile, optimization methods of pulse-to-pulse alignment for practical long distance measurement are presented. The order of the curve fitting and the selection of points for envelope extraction are analyzed. Furthermore, an averaging method based on the symmetry of the coherence function is demonstrated. Finally, the performance of the proposed methods is evaluated in the absolute distance measurement of 20 μ m with path length difference of 9 m. The improvement of standard deviation in experimental results shows that these approaches have the potential for practical distance measurement.

Giant pulses of pulsar radio emission

OpenAIRE

Kuzmin, A. D.

2007-01-01

Review report of giant pulses of pulsar radio emission, based on our detections of four new pulsars with giant pulses, and the comparative analysis of the previously known pulsars with giant pulses, including the Crab pulsar and millisecond pulsar PSR B1937+21.

Sleep disordered breathing analysis in a general population using standard pulse oximeter signals.

Science.gov (United States)

Barak-Shinar, Deganit; Amos, Yariv; Bogan, Richard K

2013-09-01

Obstructive sleep apnea reported as the apnea-hypopnea index (AHI) is usually measured in sleep laboratories using a high number of electrodes connected to the patient's body. In this study, we examined the use of a standard pulse oximeter system with an automated analysis based on the photoplethysmograph (PPG) signal for the diagnosis of sleep disordered breathing. Using a standard and simple device with high accuracy might provide a convenient diagnostic or screening solution for patient evaluation at home or in other out of center testing environments. The study included 140 consecutive patients that were referred routinely to a sleep laboratory [SleepMed Inc.] for the diagnosis of sleep disordered breathing. Each patient underwent an overnight polysomnography (PSG) study according to AASM guidelines in an AASM-accredited sleep laboratory. The automatic analysis is based on photoplethysmographic and saturation signals only. Those two signals were recorded for the entire night as part of the full overnight PSG sleep study. The AHI calculated from the PPG analysis is compared to the AHI calculated from the manual scoring gold standard full PSG. The AHI and total respiratory events measured by the pulse oximeter analysis correlated very well with the corresponding results obtained by the gold standard full PSG. The sensitivity and specificity of AHI = or > 5 and 15 levels measured by the analysis are both above 90 %. The sensitivity and positive predictive value for the detection of respiratory event are both above 84 %. The tested system in this study yielded an acceptable result of sleep disordered breathing compared to the gold standard PSG in patients with moderate to severe sleep apnea. Accordingly and given the convenience and simplicity of the standard pulse oximeter device, the new system can be considered suitable for home and ambulatory diagnosis or screening of sleep disordered breathing patients.

Downhole Elemental Analysis with LIBS

Science.gov (United States)

Moreschini, Paolo; Zacny, Kris; Rickman, Doug

2011-01-01

In this paper we discuss a novel instrument, currently under development at Honeybee Robotics with SBIR funding from NASA. The device is designed to characterize elemental composition as a function of depth in non-terrestrial geological formations. The instrument consists of a miniaturized laser-induced breakdown spectrometer (LIBS) analyzer integrated in a 2" diameter drill string. While the drill provides subsurface access, the LIBS analyzer provides information on the elemental composition of the borehole wall. This instrument has a variety of space applications ranging from exploration of the Moon for which it was originally designed, to Mars, as well as a variety of terrestrial applications. Subsurface analysis is usually performed by sample acquisition through a drill or excavator, followed by sample preparation and subsequent sample presentation to an instrument or suite of instruments. An alternative approach consisting in bringing a miniaturized version of the instrument to the sample has many advantages over the traditional methodology, as it allows faster response, reduced probability of cross-contamination and a simplification in the sampling mechanisms. LIBS functions by focusing a high energy laser on a material inducing a plasma consisting of a small fraction of the material under analysis. Optical emission from the plasma, analyzed by a spectrometer, can be used to determine elemental composition. A triangulation sensor located in the sensor head determines the distance of the sensor from the borehole wall. An actuator modifies the position of the sensor accordingly, in order to compensate for changes due to the profile of the borehole walls. This is necessary because LIBS measurements are negatively affected by changes in the relative position of the focus of the laser with respect to the position of the sample (commonly referred to as the "lens to sample distance"). Profiling the borehole is done by adjusting the position of the sensor with a

Structure analysis of liquids and disordered materials using pulsed neutron diffraction and total scattering

International Nuclear Information System (INIS)

Suzuya, Kentaro

2011-01-01

Neutron diffraction·total scattering at pulsed neutron source is a powerful method to analyze the complex structure of disordered materials: liquids, glasses, amorphous materials and disordered crystals. The basic idea of the structure of disordered materials, the fundamental diffraction theory for disordered materials, and structure analysis of disordered materials using pulsed neutron diffraction·total scattering technique (TOF method) are described in detail. In addition, the precise information of the world highest class J-PARC MLF spallation neutron source and typical J-PARC neutron total scattering instrument NOVA are also given. Recent structural modelling methods of disordered materials such like reverse Monte Carlo (RMC) simulation method is briefly described using an example of the analysis of a typical disordered material silica glass. (author)

Single-mode pulsed dye laser pumped by using a diode-pumped Nd:YAG laser with a long pulse width

International Nuclear Information System (INIS)

Yi, Jong Hoon; Kim, Jin Tae; Moon, Hee Jong; Rho, Si Pyo; Han, Jae Min; Rhee, Yong Joo; Lee, Jong Min

1999-01-01

The lasing characteristics of a single-mode dye laser pumped by using a diode-pumped solid-state laser (DPSSL) with a high repetition rate is described. A 45-mm-long Nd:YAG rod was pumped by three CW diode arrays and it was acousto-optically Q-switched. A KTP crystal was used for intracavity frequency doubling. The pulse width of the laser ranged from 90 ns to 200 ns, depending on the diode current and the Q-switching frequency. The single-mode dye laser had a grazing incidence configuration. The pulse width of the dye laser was reduced to about 1/8 of the pumping laser pulse width. The effects of the DPSSL Q-switching frequency, the driving current, and the cavity loss on the dye laser pulse width were investigated by using a simple plane-parallel cavity. From the measured pulse width of the dye laser as a function of the reflectivity of the dye laser output coupler, we found that the cavity loss due to the frequency selection elements and the output coupler should be less than 70 % in order to avoid a drastically reduced pulse width

Static Analysis of Steel Fiber Concrete Beam With Heterosis Finite Elements

Directory of Open Access Journals (Sweden)

James H. Haido

2014-08-01

Full Text Available Steel fiber is considered as the most commonly used constructional fibers in concrete structures. The formulation of new nonlinearities to predict the static performance of steel fiber concrete composite structures is considered essential. Present study is devoted to investigate the efficiency of utilizing heterosis finite elements analysis in static analysis of steel fibrous beams. New and simple material nonlinearities are proposed and used in the formulation of these elements. A computer program coded in FORTRAN was developed to perform current finite element static analysis with considering four cases of elements stiffness matrix determination. The results are compared with the experimental data available in literature in terms of central deflections, strains, and failure form, good agreement was found. Suitable outcomes have been observed in present static analysis with using of tangential stiffness matrix and stiffness matrix in second iteration of the load increment.

Application of pulse spectro- zonal luminescent method for the rapid method of material analysis

International Nuclear Information System (INIS)

Lisitsin, V.M.; Oleshko, V.I.; Yakovlev, A.N.

2004-01-01

Full text: The scope of luminescent methods of the analysis covers enough a big around of substances as the luminescence can be excited in overwhelming majority of nonmetals. Analytical opportunities of luminescent methods can be essentially expanded by use of pulse excitation and registration of spectra of a luminescence with the time resolved methods. The most perspective method is to use pulses of high-current electron beams with the nanosecond duration for excitation from the following reasons: excitation is carried out ionizing, deeply enough by a penetrating radiation; the pulse of radiation has high capacity, up to 10 8 W, but energy no more than 1 J; the pulse of radiation has the nanosecond duration. Electrons with energy in 300-400 keV will penetrate on depth into some tenth shares of mm, i.e. they create volumetric excitation of a sample. Therefore the luminescence raised by an electronic beam has the information about volumetric properties of substance. High density of excitation allow to find out and study the centers (defects) having a small yield of a luminescence, to analyze the weakly luminescent objects. Occurrence of the new effects is possible useful to analyze of materials. There is an opportunity of reception of the information from change of spectral structure of a luminescence during the time after the ending of a pulse of excitation and kinetic characteristics of attenuation of luminescence. The matter is the energy of radiation is absorbed mainly by a matrix, then electronic excitations one is transferred the centers of a luminescence (defects) of a lattice. Therefore during the time after creation electronic excitations the spectrum of a luminescence can repeatedly change, transferring the information on the centers (defects) which are the most effective radiators at present time. Hence, the study of change of spectra of radiation during the time allows providing an additional way of discrimination of the information on the centers of a

Full 3D modelling of pulse propagation enables efficient nonlinear frequency conversion with low energy laser pulses in a single-element tripler

Science.gov (United States)

Kardaś, Tomasz M.; Nejbauer, Michał; Wnuk, Paweł; Resan, Bojan; Radzewicz, Czesław; Wasylczyk, Piotr

2017-02-01

Although new optical materials continue to open up access to more and more wavelength bands where femtosecond laser pulses can be generated, light frequency conversion techniques are still indispensable in filling the gaps on the ultrafast spectral scale. With high repetition rate, low pulse energy laser sources (oscillators) tight focusing is necessary for a robust wave mixing and the efficiency of broadband nonlinear conversion is limited by diffraction as well as spatial and temporal walk-off. Here we demonstrate a miniature third harmonic generator (tripler) with conversion efficiency exceeding 30%, producing 246 fs UV pulses via cascaded second order processes within a single laser beam focus. Designing this highly efficient and ultra compact frequency converter was made possible by full 3-dimentional modelling of propagation of tightly focused, broadband light fields in nonlinear and birefringent media.

Double pulse laser induced breakdown spectroscopy: A potential tool for the analysis of contaminants and macro/micronutrients in organic mineral fertilizers.

Science.gov (United States)

Nicolodelli, Gustavo; Senesi, Giorgio Saverio; de Oliveira Perazzoli, Ivan Luiz; Marangoni, Bruno Spolon; De Melo Benites, Vinícius; Milori, Débora Marcondes Bastos Pereira

2016-09-15

Organic fertilizers are obtained from waste of plant or animal origin. One of the advantages of organic fertilizers is that, from the composting, it recycles waste-organic of urban and agriculture origin, whose disposal would cause environmental impacts. Fast and accurate analysis of both major and minor/trace elements contained in organic mineral and inorganic fertilizers of new generation have promoted the application of modern analytical techniques. In particular, laser induced breakdown spectroscopy (LIBS) is showing to be a very promising, quick and practical technique to detect and measure contaminants and nutrients in fertilizers. Although, this technique presents some limitations, such as a low sensitivity, if compared to other spectroscopic techniques, the use of double pulse (DP) LIBS is an alternative to the conventional LIBS in single pulse (SP). The macronutrients (Ca, Mg, K, P), micronutrients (Cu, Fe, Na, Mn, Zn) and contaminant (Cr) in fertilizer using LIBS in SP and DP configurations were evaluated. A comparative study for both configurations was performed using optimized key parameters for improving LIBS performance. The limit of detection (LOD) values obtained by DP LIBS increased up to seven times as compared to SP LIBS. In general, the marked improvement obtained when using DP system in the simultaneous LIBS quantitative determination for fertilizers analysis could be ascribed to the larger ablated mass of the sample. The results presented in this study show the promising potential of the DP LIBS technique for a qualitative analysis in fertilizers, without requiring sample preparation with chemical reagents. Copyright © 2016 Elsevier B.V. All rights reserved.

Analysis and fabrication of tungsten CERMET materials for ultra-high temperature reactor applications via pulsed electric current sintering

Science.gov (United States)

Webb, Jonathan A.

The optimized development path for the fabrication of ultra-high temperature W-UO2 CERMET fuel elements were explored within this dissertation. A robust literature search was conducted, which concluded that a W-UO 2 fuel element must contain a fine tungsten microstructure and spherical UO2 kernels throughout the entire consolidation process. Combined Monte Carlo and Computational Fluid Dynamics (CFD) analysis were used to determine the effects of rhenium and gadolinia additions on the performance of W-UO 2 fuel elements at refractory temperatures and in dry and water submerged environments. The computational analysis also led to the design of quasi-optimized fuel elements that can meet thermal-hydraulic and neutronic requirements A rigorous set of experiments were conducted to determine if Pulsed Electric Current Sintering (PECS) can fabricate tungsten and W-Ce02 specimens to the required geometries, densities and microstructures required for high temperature fuel elements as well as determine the mechanisms involved within the PECS consolidation process. The CeO2 acts as a surrogate for UO 2 fuel kernels in these experiments. The experiments seemed to confirm that PECS consolidation takes place via diffusional mass transfer methods; however, the densification process is rapidly accelerated due to the effects of current densities within the consolidating specimen. Fortunately the grain growth proceeds at a traditional rate and the PECS process can yield near fully dense W and W-Ce02 specimens with a finer microstructure than other sintering techniques. PECS consolidation techniques were also shown to be capable of producing W-UO2 segments at near-prototypic geometries; however, great care must be taken to coat the fuel particles with tungsten prior to sintering. Also, great care must be taken to ensure that the particles remain spherical in geometry under the influence of a uniaxial stress as applied during PECS, which involves mixing different fuel kernel sizes in

Temperature field analysis of single layer TiO2 film components induced by long-pulse and short-pulse lasers

International Nuclear Information System (INIS)

Wang Bin; Zhang Hongchao; Qin Yuan; Wang Xi; Ni Xiaowu; Shen Zhonghua; Lu Jian

2011-01-01

To study the differences between the damaging of thin film components induced by long-pulse and short-pulse lasers, a model of single layer TiO 2 film components with platinum high-absorptance inclusions was established. The temperature rises of TiO 2 films with inclusions of different sizes and different depths induced by a 1 ms long-pulse and a 10 ns short-pulse lasers were analyzed based on temperature field theory. The results show that there is a radius range of inclusions that corresponds to high temperature rises. Short-pulse lasers are more sensitive to high-absorptance inclusions and long-pulse lasers are more easily damage the substrate. The first-damage decision method is drawn from calculations.

A finger-free wrist-worn pulse oximeter for the monitoring of chronic obstructive pulmonary disease

Science.gov (United States)

Chu, Chang-Sheng; Chuang, Shuang-Chao; Lee, Yeh Wen; Fan, Chih-Hsun; Chung, Lung Pin; Li, Yu-Tang; Chen, Jyh-Chern

2016-03-01

Herein, a finger-free wrist-worn pulse oximeter is presented. This device allows patients to measure blood oxygen level and pulse rate without hindering their normal finger movement. This wrist-worn pulse oximeter is built with a reflectance oximetry sensor, which consists of light emitting diodes and photodiode light detectors located side by side. This reflectance oximetry sensor is covered with an optical element with micro structured surface. This micro structured optical element is designed to modulate photon propagation beneath the skin tissue so that the photoplethysmogram signals of reflected lights or backscattered lights detected by the photodetector are therefore enhanced.

Investigation of faulted tunnel models by combined photoelasticity and finite element analysis

International Nuclear Information System (INIS)

Ladkany, S.G.; Huang, Yuping

1994-01-01

Models of square and circular tunnels with short faults cutting through their surfaces are investigated by photoelasticity. These models, when duplicated by finite element analysis can predict the stress states of square or circular faulted tunnels adequately. Finite element analysis, using gap elements, may be used to investigate full size faulted tunnel system

Recoupling and decoupling of nuclear spin interactions at high MAS frequencies: numerical design of CNnν symmetry-based RF pulse schemes

International Nuclear Information System (INIS)

Herbst, Christian; Herbst, Jirada; Kirschstein, Anika; Leppert, Joerg; Ohlenschlaeger, Oliver; Goerlach, Matthias; Ramachandran, Ramadurai

2009-01-01

The CN n ν class of RF pulse schemes, commonly employed for recoupling and decoupling of nuclear spin interactions in magic angle spinning solid state NMR studies of biological systems, involves the application of a basic 'C' element corresponding to an RF cycle with unity propagator. In this study, the design of CN n ν symmetry-based RF pulse sequences for achieving 13 C- 13 C double-quantum dipolar recoupling and through bond scalar coupling mediated 13 C- 13 C chemical shift correlation has been examined at high MAS frequencies employing broadband, constant-amplitude, phase-modulated basic 'C' elements. The basic elements were implemented as a sandwich of a small number of short pulses of equal duration with each pulse characterised by an RF phase value. The phase-modulation profile of the 'C' element was optimised numerically so as to generate efficient RF pulse sequences. The performances of the sequences were evaluated via numerical simulations and experimental measurements and are presented here

Energy balance and efficiency of power stations with a pulsed Tokamak reactor

International Nuclear Information System (INIS)

Davenport, P.A.; Mitchell, J.T.D.; Darvas, J.; Foerster, S.; Sack, B.

1976-06-01

The energy balance of a fusion power station based on the TOKAMAK concept is examined with the aid of a model comprising three distinct elements: the reactor, the energy converter and the reactor operation equipment. The efficiency of each element is expressed in terms of the various energy flows and the product of these efficiencies gives the net station efficiency. The analysis takes account of pulsed operation and has general applicability. Numerical values for the net station efficiency are derived from detailed estimates of the energy flows for a TOKAMAK reactor and its auxiliary equipment operating with advanced energy converters. The derivation of these estimates is given in eleven appendices. The calculated station efficiencies span ranges similar to those quoted for the current generation of fission reactors, though lower than those predicted for HTGR and LMFBR stations. Credible parameter domains for pulsed TOKAMAK operation are firmly delineated and factors inimical to improved performance are indicated. It is concluded that the net thermal efficiency of a TOKAMAK reactor power station based on present designs and using advanced thermal converters will be approximately 0.3 and is unlikely to exceed 0.33. (orig.) [de

In-vivo elemental analysis at Birmingham 1968-1981

International Nuclear Information System (INIS)

Chettle, D.R.; Scott, M.C.

1986-01-01

Techniques have been developed to measure a number of elements in-vivo. Some have been measured by producing a radioactive isotope in the body by neutron bombardment and subsequently counting γ-rays given off during its decay. Measurements of calcium and sodium have been those most frequently used; copper, iron and phosphorus have also been measured in this way. Gamma-rays emitted 10 -18 s-10 -12 s following neutron capture have also been used for elemental analysis. This method, which involved detectors being in position by the subject during the neutron irradiation, has been widely applied to measurements of both nitrogen and cadmium. Preliminary studies of nuclear resonance scattering have suggested that this could be used for in-vivo elemental analysis, provided technical difficulties in source preparation could be overcome. Recently the use of X-ray fluorescence has been investigated for in-vivo analyses of lead in bone; the extension of this technique to measure mercury in the kidney is under consideration. (author)

Nonlinear nonstationary analysis with the finite element method

International Nuclear Information System (INIS)

Vaz, L.E.

1981-01-01

In this paper, after some introductory remarks on numerical methods for the integration of initial value problems, the applicability of the finite element method for transient diffusion analysis as well as dynamic and inelastic analysis is discussed, and some examples are presented. (RW) [de

Numerical analysis on acoustic impulse response for watermelon

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Sul; Yang, Dong Hoon; Choi, Young Jae; Bae, Tas Joo; So, Chul Ho [Dongshin University, Naju (Korea, Republic of); Lee, Yun Ho [Korea Inspection and Engineering CO.,LTD., Seoul (Korea, Republic of)

2002-11-15

In this study, we conducted both analysis on impact pulse signal and acoustic impulse response method using numerical analysistic finite element method. Considering its velocity, density, Young's Modulus, and Poisson's Ratio, we extracted featured parameters and compared both results of analysis on impact pulse signal and numerical analysis on acoustic impulse response then we found the feature of generated acoustic sound signal by way of numerical analysis varying featured parameters and consequently intended to extract feature indices influenced on its internal maturity through analysis of acoustic impulse response. As we analyzed impact pulse signal and extracted featured parameters concerned with evaluation of its ripeness, we found the plausibility of progress on nondestructive evaluation of ripeness and adoption of numerical analysis on acoustic impulse response.

Determination of mutually interfering elements in activation analysis

International Nuclear Information System (INIS)

Figueiredo, A.M.G.

1979-01-01

The determination of the elements present in the groups scandium-zinc, mercury-selenium and arsenic-antimony-bromine represents a classical problem in thermal neutron activation analysis because the gamma-ray peaks of the radioisotopes produced from these elements by activation appear very close in the spectrum. A study is made of the possibility of simultaneous instrumental determination of these elements by means of the spectrum stripping technique, using a 400-channel analyser coupled to a Nal(Tl) detector and a 4096-channel analyser coupled to a Ge(Li) detector. Artificial mixtures of the interfering elements in varying proportions are prepared, so as to reproduce possible real samples, where the elements may be present at several concentrations. Radiochemical separation techniques for the cited elements are studied with the use of tracers. For the separation of scadium and zinc, the technique of extraction chromatography is applied. The separation of mercury and selenium is accomplished by means of ion exchange. The technique of coprecipitation is used to separate bromine from arsenic and antimony followed by ion exchange to isolate these two elements from each other. The precision and the accuracy of the results are discussed. (Author) [pt

Proposal for element size and time increment selection guideline by 3-D finite element method for elastic waves propagation analysis

International Nuclear Information System (INIS)

Ishida, Hitoshi; Meshii, Toshiyuki

2008-01-01

This paper proposes a guideline for selection of element size and time increment by 3-D finite element method, which is applied to elastic wave propagation analysis for a long distance of a large structure. An element size and a time increment are determined by quantitative evaluation of strain, which must be 0 on the analysis model with a uniform motion, caused by spatial and time discretization. (author)

Direct spectral analysis of tea samples using 266 nm UV pulsed laser-induced breakdown spectroscopy and cross validation of LIBS results with ICP-MS.

Science.gov (United States)

Gondal, M A; Habibullah, Y B; Baig, Umair; Oloore, L E

2016-05-15

Tea is one of the most common and popular beverages spanning vast array of cultures all over the world. The main nutritional benefits of drinking tea are its anti-oxidant properties, presumed protection against certain cancers, inhibition of inflammation and possible protective effects against diabetes. Laser induced breakdown spectrometer (LIBS) was assembled as a powerful tool for qualitative and quantitative analysis of various brands of tea samples using 266 nm pulsed UV laser. LIBS spectra for six brands of tea samples in the wavelength range of 200-900 nm was recorded and all elements present in our tea samples were identified. The major toxic elements detected in several brands of tea samples were bromine, chromium and minerals like iron, calcium, potassium and silicon. The spectral assignment was conducted prior to the determination of concentration of each element. For quantitative analysis, calibration curves were drawn for each element using standard samples prepared in known concentration in the tea matrix. The plasma parameters (electron temperature and electron density) were also determined prior to the tea samples spectroscopic analysis. The concentration of iron, chromium, potassium, bromine, copper, silicon and calcium detected in all tea samples was between 378-656, 96-124, 1421-6785, 99-1476, 17-36, 2-11 and 92-130 mg L(-1) respectively. The limits of detection estimated for Fe, Cr, K, Br, Cu, Si, Ca in tea samples were 22, 12, 14, 11, 6, 1 and 12 mg L(-1) respectively. To further confirm the accuracy of our LIBS results, we determined the concentration of each element present in tea samples by using standard analytical technique like ICP-MS. The concentrations detected with our LIBS system are in excellent agreement with ICP-MS results. The system assembled for spectral analysis in this work could be highly applicable for testing the quality and purity of food and also pharmaceuticals products. Copyright © 2016 Elsevier B.V. All rights reserved.

Volkov transform generalized projection algorithm for attosecond pulse characterization

International Nuclear Information System (INIS)

Keathley, P D; Bhardwaj, S; Moses, J; Laurent, G; Kärtner, F X

2016-01-01

An algorithm for characterizing attosecond extreme ultraviolet pulses that is not bandwidth-limited, requires no interpolation of the experimental data, and makes no approximations beyond the strong-field approximation is introduced. This approach fully incorporates the dipole transition matrix element into the retrieval process. Unlike attosecond retrieval methods such as phase retrieval by omega oscillation filtering (PROOF), or improved PROOF, it simultaneously retrieves both the attosecond and infrared (IR) pulses, without placing fundamental restrictions on the IR pulse duration, intensity or bandwidth. The new algorithm is validated both numerically and experimentally, and is also found to have practical advantages. These include an increased robustness to noise, and relaxed requirements for the size of the experimental dataset and the intensity of the streaking pulse. (paper)

Temperature field analysis of single layer TiO2 film components induced by long-pulse and short-pulse lasers.

Science.gov (United States)

Wang, Bin; Zhang, Hongchao; Qin, Yuan; Wang, Xi; Ni, Xiaowu; Shen, Zhonghua; Lu, Jian

2011-07-10

To study the differences between the damaging of thin film components induced by long-pulse and short-pulse lasers, a model of single layer TiO(2) film components with platinum high-absorptance inclusions was established. The temperature rises of TiO(2) films with inclusions of different sizes and different depths induced by a 1 ms long-pulse and a 10 ns short-pulse lasers were analyzed based on temperature field theory. The results show that there is a radius range of inclusions that corresponds to high temperature rises. Short-pulse lasers are more sensitive to high-absorptance inclusions and long-pulse lasers are more easily damage the substrate. The first-damage decision method is drawn from calculations. © 2011 Optical Society of America

Propulsive efficiency of a biomorphic pulsed-jet underwater vehicle

International Nuclear Information System (INIS)

Moslemi, Ali A; Krueger, Paul S

2010-01-01

The effect of the velocity program and duty cycle (St L ) on the propulsive efficiency of pulsed-jet propulsion was studied experimentally on a self-propelled, pulsed-jet underwater vehicle, dubbed Robosquid due to the similarity of essential elements of its propulsion system with squid jet propulsion. Robosquid was tested for jet slug length-to-diameter ratios (L/D) in the range 2-6 and St L in the range 0.2-0.6 with jet velocity programs commanded to be triangular or trapezoidal. Digital particle image velocimetry was used for measuring the impulse and energy of jet pulses to calculate the pulsed-jet propulsive efficiency and compare it with an equivalent steady jet system. Robosquid's Reynolds number (Re) based on average vehicle velocity and vehicle diameter ranged between 1300 and 2700 for the conditions tested. The results indicated better propulsive efficiency of the trapezoidal velocity program (up to 20% higher) compared to the triangular velocity program. Also, an increase in the ratio of the pulsed-jet propulsive efficiency to the equivalent steady jet propulsive efficiency (η P /η P,ss ) was observed as St L increased and L/D decreased. For cases of short L/D and high St L , η P /η P,ss was found to be as high as 1.2, indicating better performance of pulsed jets. This result demonstrates a case where propulsion using essential elements of a biological locomotion system can outperform the traditional mechanical system equivalent in terms of efficiency. It was also found that changes in St L had a proportionately larger effect on propulsive efficiency compared to changes in L/D. A simple model is presented to explain the results in terms of the contribution of over-pressure at the nozzle exit plane associated with the formation of vortex rings with each jet pulse.

Fast XRF analysis of mineral elements in dental composites

International Nuclear Information System (INIS)

Preoteasa, E. A.; Constantinescu, B.; Preoteasa, E.

2001-01-01

Dental composites, made of particles of glass, ceramics or quartz embedded in an organic polymer matrix, extensively replaced silver amalgam in tooth fillings and enabled new applications for restorative dentistry. Long-term alteration of dental fillings together with market pressure motivates the development of composites at a high rate, largely by progress of materials forming their mineral phase. Therefore, dental composites constantly bring at the interface with enamel and dentine new elements foreign to the organism, whose biological action has not been studied. Atomic and nuclear methods for surface multielemental analysis have been used in dental research but not for composites. X-ray fluorescence (XRF) is suited for the fast microanalytical screening of the elements and of their changes at the biomaterial's surface. The potential of radioisotope-excited XRF for the analysis of dental composites has been examined. Flat disk-shaped samples of composites have been prepared and polymerized chemically or by irradiation with intense 420-500 nm light. The measurements were performed with a spectrometric chain containing a 30 mCi source of 241 Am, a Si(Li) detector, and a multichannel analyzer. The spectra were built up for 2000-6000 sec. The characteristic X lines were integrated and normalized to source lines. The following Z ≥ 20 elements were detected in the studied composites: Ba only in Charisma (Kulzer) and Pekafill (Bayer); Zr, Ba, Yb in Tetric Ceram, and Ca, Ba, Yb together with traces of possibly Ti and Fe in Ariston (both from Vivadent); Zr, Hf in Valux Plus (3M Dental); and Sr, Ba together with some trace element, seemingly Cu, in F2000 Compomer (3M Dental) and with other trace elements like Ca, Fe in Surefil (Dentsply). Among older materials, Concise (3M Dental) contained only light (Z 3 that releases F for protection of enamel and dentine. Yb, Zr, Ba, Hf improve the radiological opacity of the materials. Some elements may accompany others as

Medical and health-related trace element analysis by TXRF

International Nuclear Information System (INIS)

Greaves, E.D.

2000-01-01

The advantages offered with TXRF analysis by direct irradiation with monochromatic X-rays of tissue homogenates and body fluids make the technique appropriate for a number of medical and health related applications. The ability to detect low levels of toxic heavy elements is being used as an aid in accidental poisoning diagnosis and treatment, in treatment-induced toxicity control and as an accessory in medical and health research. Thus lead-in-whole-blood analysis is used in confirmation of diagnosis of victims of poisoning, or monitoring the evolution and efficiency of the clinical treatment. Measurement and control of plasma platinum levels of cancer patients undergoing chemotherapy with Pt-containing drugs includes: establishment of the drug level-tumor remission response, measurement of Pt plasma level curves and establishment of optimum dosage to minimize the nephrotoxicity of platinum, and bioequivalence comparisons of different commercially available platinum containing anticancer drugs. Analysis as an aid in clinical research applications includes: trace element determination of amniotic fluid in fetus malformation studies; analysis of brain specimens and cerebrospinal fluid in diagnosis of central nervous system disorders; the influence of trace elements in cataract genesis and the influence of heavy elements in semen quality in human reproduction studies. Human body samples require the use of monochromatized beams of x-rays in order to derive the special advantage of its use: i) The reduction in the spectrum background allowing direct irradiation of organic matter specimens. Hence human tissue and body fluids are prepared by simple procedures involving dilution, homogenization and standard addition avoiding the need for specimen digestion. This results in faster, cheaper methods that decrease sample contamination problems. ii) The presence of a large Compton scattered signal in the spectrum and its use as an internal standard reference allows further

Finite element stress analysis of brick-mortar masonry under ...

African Journals Online (AJOL)

Stress analysis of a brick-mortar couplet as a substitute for brick wall structure has been performed by finite element method, and algorithm for determining the element stiffness matrix for a plane stress problem using the displacement approach was developed. The nodal displacements were derived for the stress in each ...

Multi-element analysis of emeralds and associated rocks by k{sub 0} neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Acharya, R.N.; Mondal, R.K.; Burte, P.P.; Nair, A.G.C.; Reddy, N.B.Y.; Reddy, L.K.; Reddy, A.V.R.; Manohar, S.B

2000-12-15

Multi-element analysis was carried out in natural emeralds, their associated rocks and one sample of beryl obtained from Rajasthan, India. The concentrations of 21 elements were assayed by Instrumental Neutron Activation Analysis using the k{sub 0} method (k{sub 0} INAA method) and high-resolution gamma ray spectrometry. The data reveal the segregation of some elements from associated (trapped and host) rocks to the mineral beryl forming the gemstones. A reference rock standard of the US Geological Survey (USGS BCR-1) was also analysed as a control of the method.

Investigation of Shear Stud Performance in Flat Plate Using Finite Element Analysis

Directory of Open Access Journals (Sweden)

T.S. Viswanathan

2014-09-01

Full Text Available Three types of shear stud arrangement, respectively featuring an orthogonal, a radial and a critical perimeter pattern, were evaluated numerically. A numerical investigation was conducted using the finite element software ABAQUS to evaluate their ability to resist punching shear in a flat plate. The finite element analysis here is an application of the nonlinear analysis of reinforced concrete structures using three-dimensional solid finite elements. The nonlinear characteristics of concrete were achieved by employing the concrete damaged plasticity model in the finite element program. Transverse shear stress was evaluated using finite element analysis in terms of shear stress distribution for flat plate with and without shear stud reinforcement. The model predicted that shear studs placed along the critical perimeter are more effective compared to orthogonal and radial patterns.

Proton induced X-Ray fluorescence study as a tool trace element analysis

International Nuclear Information System (INIS)

El-Kady, Ahmed A.

1978-01-01

Usefulness and limitations of trace elemental analysis by high energy charged particles and photon induced X-ray have been discussed. Comparison with the well established neutron activation analysis technique is also given. Back-ground radiation due to bremsstrahlung from secondary electrons and due to charged particle bremsstrahlung have been reviewed for different projectiles. The sensitivity of elemental analysis by proton induced X-ray fluorescence have been examined by measuring the characteristic X-ray emission cross section for K and L transitions of many elements and for different proton energies and compared with theroretical values. The discussion given in this report show that with suitable proton generator and a high resolution X-ray detector, proton X-ray fluorescence technique is capable of analyzing many elements simultaneously at the part per million level and offers a rapid and reliable method for trace element analysis. Data on water, blood and tissue samples given in this report are few examples of many possible applications

Trace elements in Australian opals using neutron activation analysis

International Nuclear Information System (INIS)

McOrist, G.D.; Fardy, J.J.

1994-01-01

Neutron activation analysis was used to determine the concentration of trace elements in 42 samples of black, grey and white opals taken from a number of recognised Australian field. The results were evaluated to determine if a relationship exited between trace element content and opal colour. (author) 12 refs.; 12 figs.; 3 tabs

Elemental analysis of hair using PIXE-tomography and INAA

International Nuclear Information System (INIS)

Beasley, D.; Gomez-Morilla, I.; Spyrou, N.

2008-01-01

3D quantitative elemental maps of a section of a strand of hair were produced using a combination of PIXE-Tomography and simultaneous On/Off Axis STIM-Tomography at the University of Surrey Ion Beam Centre. The distributions of S, K, Cl, Ca, Fe and Zn were determined using the PIXE-T reconstruction package DISRA. The results were compared with conventional bulk PIXE analysis of tomographic data as determined using Dan32. The overall concentrations determined by PIXE were compared with elemental concentrations held in the University of Surrey Hair Database. All the entries currently in the database were produced using INAA. The merits and possible contributions of tomographic PIXE analysis to analysis of hair are discussed. The conclusions drawn from the PIXE-Tomography analysis can be used to argue for more stringent procedures for hair analysis at the University of Surrey. (author)

Processing and Probability Analysis of Pulsed Terahertz NDE of Corrosion under Shuttle Tile Data

Science.gov (United States)

Anastasi, Robert F.; Madaras, Eric I.; Seebo, Jeffrey P.; Ely, Thomas M.

2009-01-01

This paper examines data processing and probability analysis of pulsed terahertz NDE scans of corrosion defects under a Shuttle tile. Pulsed terahertz data collected from an aluminum plate with fabricated corrosion defects and covered with a Shuttle tile is presented. The corrosion defects imaged were fabricated by electrochemically etching areas of various diameter and depth in the plate. In this work, the aluminum plate echo signal is located in the terahertz time-of-flight data and a threshold is applied to produce a binary image of sample features. Feature location and area are examined and identified as corrosion through comparison with the known defect layout. The results are tabulated with hit, miss, or false call information for a probability of detection analysis that is used to identify an optimal processing threshold.

Fast differential pulse discriminator-counter

International Nuclear Information System (INIS)

Shelevoj, K.D.

1985-01-01

The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

Improvement in the electronic quality of pulsed laser deposited CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2} thin films via post-deposition elemental sulfur annealing process

Energy Technology Data Exchange (ETDEWEB)

Beres, M., E-mail: matthewcberes@gmail.com [University of California, Department of Mechanical Engineering, 6141 Etcheverry Hall, Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 (United States); Yu, K.M., E-mail: kinmanyu@cityu.edu.hk [Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 (United States); City University of Hong Kong, Department of Physics and Materials Science, 83 Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Syzdek, J., E-mail: jego.mejl@gmail.com [Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 (United States); Bio-Logic USA, 9050 Executive Park Dr NW, Knoxville, TN 37923 (United States); Mao, S.S., E-mail: ssmao@me.berkeley.edu [University of California, Department of Mechanical Engineering, 6141 Etcheverry Hall, Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 (United States)

2016-06-01

We synthesized CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2} thin films on soda lime glass substrates using pulsed laser deposition and post-annealing under different conditions. Increasing substrate temperature during deposition and vacuum annealing after deposition both increased grain size but had negligible effect on the electronic properties of the films. As-deposited films demonstrated P-type conductivities with high carrier concentrations and low Hall mobilities, but annealing in elemental sulfur environment significantly improved the electronic properties of the films. We found that the incorporation of even small quantities of sulfur into the films reduced carrier concentrations by over three orders of magnitude and increased Hall mobilities by an order of magnitude. This resulted in films with resistivity ~ 5 Ω·cm suitable for photovoltaic applications. - Highlights: • CIGSe thin films were deposited by pulsed laser deposition. • Laser deposition parameters and annealing parameters were investigated. • As-deposited films demonstrated high hole concentrations and low Hall mobilities. • Elemental sulfur annealing significantly enhanced the electronic quality of films.

Thermal-hydraulic investigations of fuel elements

International Nuclear Information System (INIS)

Rehme, K.; Weinberg, D.

1983-01-01

Extensive fluid-dynamic examining of flow distribution and turbulent flow distribution was done to control and safeguard calculation methods allowing the determination of three-dimensional flow distribution in fuel elements. Results show that the flow distribution greatly depends on the frequency of pulse exchange between subchannels in narrow rod grids. The comparison of these measured values to VELASCO's results shows that the calculation methods need to be considerably improved. The subchannel analysis proved to be very suitable to calculate mean flow temperatures conforming with the subchannel analysis principle. However, this does not include statements on wall temperatures occurring in the structures. Mean wall temperatures can be determined by empirical interrelationships for Nusseltnumbers. On the other hand, the calculation of detailed wall temperature distributions is not possible with the subchannel analysis unless it can be further improved due to more detailed measurement results. (orig.) [de

Elemental content of Vietnamese rice. Part 2. Multivariate data analysis.

Science.gov (United States)

Kokot, S; Phuong, T D

1999-04-01

Rice samples were obtained from the Red River region and some other parts of Vietnam as well as from Yanco, Australia. These samples were analysed for 14 elements (P, K, Mg, Ca, Mn, Zn, Fe, Cu, Al, Na, Ni, As, Mo and Cd) by ICP-AES, ICP-MS and FAAS as described in Part 1. This data matrix was then submitted to multivariate data analysis by principal component analysis to investigate the influences of environmental and crop cultivation variables on the elemental content of rice. Results revealed that geographical location, grain variety, seasons and soil conditions are the most likely significant factors causing changes in the elemental content between the rice samples. To assess rice quality according to its elemental content and physio-biological properties, a multicriteria decision making method (PROMETHEE) was applied. With the Vietnamese rice, the sticky rice appeared to contain somewhat higher levels of nutritionally significant elements such as P, K and Mg than the non-sticky rice. Also, rice samples grown during the wet season have better levels of nutritionally significant mineral elements than those of the dry season, but in general, the wet season seemed to provide better overall elemental and physio-biological rice quality.

Advanced chemical analysis service for elements, radionuclides and phases

International Nuclear Information System (INIS)

Sansoni, B.

1986-01-01

A review is given on the structure, organisation and performance of the chemical analysis service of the Central Department for Chemical Analysis at the Kernforschungsanlage Juelich GmbH. The research and development programs together with the infrastructure of the Centre afford to analyse almost all stable elements of the periodical table in almost any material. The corresponding chemical analysis service has been organized according to a new modular system of analytical steps. According to this, the most complicated and, therefore, most general case of an analytical scheme for element and radionuclide analysis in any type of material can be differentiated into about 14 different steps, the modules. They are more or less independent of the special problem. The laboratory is designed and organized according to these steps. (orig./PW) [de

Background reduction and noise discrimination in the proportional counting of tritium using pulse-shape analysis

Energy Technology Data Exchange (ETDEWEB)

Hochel, R C; Hayes, D W [Du Pont de Nemours (E.I.) and Co., Aiken, S.C. (USA). Savannah River Lab.

1975-12-01

A pulse-shape analysis (PSA) unit of commercial design has been incorporated into a proportional counting system to determine the effectiveness of pulse-shape discrimination in increasing the sensitivity of tritium counting. It was found that a quantitative determination of tritium could be obtained directly from the PSA time spectrum eliminating the need for beta-ray energy selection used in the pulse-shape discrimination (PSD) technique. The performance of the proportional counting system was tested using the PSA unit and anticoincidence shielding, both singly and combined, under several types of background. A background reduction factor of 169 was obtained from the combined PSA-anticoincidence system with only a 2% loss in tritium counting efficiency. The PSA method was also found to offer significant reductions in noise background.

Infinite elements for soil-structure interaction analysis in multi-layered halfspaces

International Nuclear Information System (INIS)

Yun, Chung Bang; Kim, Jae Min; Yang, Shin Chu

1994-01-01

This paper presents the theoretical aspects of a computer code (KIESSI) for soil-structure interaction analysis in a multi-layered halfspace using infinite elements. The shape functions of the infinite elements are derived from approximate expressions of the analytical solutions. Three different infinite elements are developed. They are the horizontal, the vertical and the comer infinite elements (HIE, VIE and CIE). Numerical example analyses are presented for demonstrating the effectiveness of the proposed infinite elements

Element analysis of Japanese traditional papers by PIXE method

International Nuclear Information System (INIS)

Suzuki, Tatsuya; Yasuda, Keisuke; Tani, Teruhiro

2000-01-01

The Japanese papers, 'washi', are made from the bast fibers of the plants. Since washi have the informations of the raw material plants, there is potentiality of the identification of the production place by the element analysis of the washi. Three kinds of washi made of kozo, which have different habitats, were prepared. The elements in their washi were measured by the PIXE. It was confirmed that the amount of elements included in the washi depend on the habitats of their raw material plants. (author)

The use of synchrotron radiation for trace element analysis and element mapping by scanning X-ray fluorescence

International Nuclear Information System (INIS)

Davies, S.T.

1983-01-01

Synchrotron Radiation excited X-Ray Fluorescence is a potentially powerful tool for the routine quantitative chemical analysis of materials, with minimum detection limits typically of the order of a tenth of a ppm, and with the added advantages of simultaneous multi-element detection capability, spatial resolution on a micron scale, large signal to noise ratios and short analysis times. This paper presents a brief review of the use of Synchrotron Radiation in Trace Element Analysis and discusses the requirements for a microprobe for chemical analysis utilising SR. Data obtained at the Synchrotron Radiation Source, Daresbury Laboratory include XRF spectra of standard reference materials and an application of the technique to the study of ion implanted layers in semiconductors is outlined. (author)

PIXE analysis of trace and other mineral elements in phytopharmaceutical drugs

International Nuclear Information System (INIS)

Preoteasa, E. A.; Harangus, Livia; Iordan, Andreea; Gugiu, M.

2002-01-01

Despite of ongoing progress in the biochemistry of phytopharmaceutical drugs, their mineral micro- and trace elements have not been studied in detail. These elements may have therapeutic or toxic activity which should be assessed by sensitive investigations. The latter can be done by multielemental analysis with nuclear and atomic methods. We previously found 28 elements in some Romanian plant drugs by nuclear activation analysis. The availability of this method is, however, limited by the access to a nuclear reactor. Particle-induced X-ray emission (PIXE) is an alternative method with high performances in biomedicine and requiring no sample preparation for drugs' studies. We applied PIXE in the qualitative analysis of three plant drugs - Liv52, Mentat, and Geriforte - used as invigorators, protectors and prophylactics in oxidative stress diseases. Measurements with 3 MeV protons at the 8.5 MV NIPNE-HH (Horia Hulubei National Institute for Physics and Nuclear Engineering) tandem accelerator, using a hyper-pure Ge detector and no additional absorber foil, evidenced unusually complex elemental compositions of drugs. Up to 31 elements with Z > 15 were found: P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Br, Rb, Sr, Y, Zr, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Hg, and As and/or Pb, from major to trace levels. The three drugs' qualitative composition were found to be rather similar. Relative concentrations were well evaluated with X-ray yields calculated for another kind of light element thick target. Drug's toxic elements - As and/or Pb, Hg, and possibly Ga - were all at trace levels, but their accumulation might be harmful. Some essential elements like K, Ca, Cr, Fe, Cu, Zn, Br, Rb, Sr can be biologically useful. X-ray yields improvement and other ways for PIXE quantitative analysis of the phytotherapeutic drugs are outlined. (authors)

Semianalytic Design Sensitivity Analysis of Nonlinear Structures With a Commercial Finite Element Package

International Nuclear Information System (INIS)

Lee, Tae Hee; Yoo, Jung Hun; Choi, Hyeong Cheol

2002-01-01

A finite element package is often used as a daily design tool for engineering designers in order to analyze and improve the design. The finite element analysis can provide the responses of a system for given design variables. Although finite element analysis can quite well provide the structural behaviors for given design variables, it cannot provide enough information to improve the design such as design sensitivity coefficients. Design sensitivity analysis is an essential step to predict the change in responses due to a change in design variables and to optimize a system with the aid of the gradient-based optimization techniques. To develop a numerical method of design sensitivity analysis, analytical derivatives that are based on analytical differentiation of the continuous or discrete finite element equations are effective but analytical derivatives are difficult because of the lack of internal information of the commercial finite element package such as shape functions. Therefore, design sensitivity analysis outside of the finite element package is necessary for practical application in an industrial setting. In this paper, the semi-analytic method for design sensitivity analysis is used for the development of the design sensitivity module outside of a commercial finite element package of ANSYS. The direct differentiation method is employed to compute the design derivatives of the response and the pseudo-load for design sensitivity analysis is effectively evaluated by using the design variation of the related internal nodal forces. Especially, we suggest an effective method for stress and nonlinear design sensitivity analyses that is independent of the commercial finite element package is also discussed. Numerical examples are illustrated to show the accuracy and efficiency of the developed method and to provide insights for implementation of the suggested method into other commercial finite element packages

Analysis of the effects of Eye-Tracker performance on the pulse positioning errors during refractive surgery☆

Science.gov (United States)

Arba-Mosquera, Samuel; Aslanides, Ioannis M.

2012-01-01

Purpose To analyze the effects of Eye-Tracker performance on the pulse positioning errors during refractive surgery. Methods A comprehensive model, which directly considers eye movements, including saccades, vestibular, optokinetic, vergence, and miniature, as well as, eye-tracker acquisition rate, eye-tracker latency time, scanner positioning time, laser firing rate, and laser trigger delay have been developed. Results Eye-tracker acquisition rates below 100 Hz correspond to pulse positioning errors above 1.5 mm. Eye-tracker latency times to about 15 ms correspond to pulse positioning errors of up to 3.5 mm. Scanner positioning times to about 9 ms correspond to pulse positioning errors of up to 2 mm. Laser firing rates faster than eye-tracker acquisition rates basically duplicate pulse-positioning errors. Laser trigger delays to about 300 μs have minor to no impact on pulse-positioning errors. Conclusions The proposed model can be used for comparison of laser systems used for ablation processes. Due to the pseudo-random nature of eye movements, positioning errors of single pulses are much larger than observed decentrations in the clinical settings. There is no single parameter that ‘alone’ minimizes the positioning error. It is the optimal combination of the several parameters that minimizes the error. The results of this analysis are important to understand the limitations of correcting very irregular ablation patterns.

Toeless pulse shaping with a single delay-line network

International Nuclear Information System (INIS)

Tauhata, L.; Binns, D.C.

1976-04-01

New unipolar delay-line clippers producing negligible cancellation remnant have been developed. Near perfect clipping is achieved using a combination of several types of coaxial cable tranformers working as a phase inverter, a new pulse adder, or an impedance transformer. Only passive elements are used in the bridge network. The construction is simple and the performance is extremely stable and wide in dynamic range and frequency band width. Completely symmetrical bipolar pulses are also easily obtained using this technique

Probabilistic finite elements for fracture and fatigue analysis

Science.gov (United States)

Liu, W. K.; Belytschko, T.; Lawrence, M.; Besterfield, G. H.

1989-01-01

The fusion of the probabilistic finite element method (PFEM) and reliability analysis for probabilistic fracture mechanics (PFM) is presented. A comprehensive method for determining the probability of fatigue failure for curved crack growth was developed. The criterion for failure or performance function is stated as: the fatigue life of a component must exceed the service life of the component; otherwise failure will occur. An enriched element that has the near-crack-tip singular strain field embedded in the element is used to formulate the equilibrium equation and solve for the stress intensity factors at the crack-tip. Performance and accuracy of the method is demonstrated on a classical mode 1 fatigue problem.

Design and application of pulse information acquisition and analysis ...

African Journals Online (AJOL)

... two-dimensional information acquisition, multiplex signals combination and deep data mining. Conclusions: The newly developed system could translate the pulse signals into digital, visual and measurable motion information of vessel. Keywords: Visualized pulse information; Radial artery; B mode ultrasound; Traditional ...

Analysis of noise in energy-dispersive spectrometers using time-domain methods

CERN Document Server

Goulding, F S

2002-01-01

This paper presents an integrated time domain approach to the optimization of the signal-to-noise ratio in all spectrometer systems that contain a detector that converts incoming quanta of radiation into electrical pulse signals that are amplified and shaped by an electronic pulse shaper. It allows analysis of normal passive pulse shapers as well as time-variant systems where switching of shaping elements occurs in synchronism with the signal. It also deals comfortably with microcalorimeters (sometimes referred to as bolometers), where noise-determining elements, such as the temperature-sensing element's resistance and temperature, change with time in the presence of a signal. As part of the purely time-domain approach, a new method of calculating the Johnson noise in resistors using only the statistics of electron motion is presented. The result is a time-domain analog of the Nyquist formula.

Opacity and atomic analysis of double pulse laser ablated Li plasma

Science.gov (United States)

Sivakumaran, V.; Joshi, H. C.; Kumar, Ajai

2014-09-01

Opacity effects for neutral and ionic emission lines of lithium have been investigated by Atomic Data Analysis Structure (ADAS). Line ratios and opacity corrected photon emissivity coefficients are calculated over a wide range of electron temperatures and densities. The experimentally measured temporal evolution of the line profiles of the over dense Li plasma formed in the double pulse laser ablation experiment have been explained using the ADAS analysis and the plasma parameters of the plasma plume under consideration have been estimated. These results could be projected as a diagnostic tool to estimate plasma parameters of an over dense lithium plasma.

Preliminary Nuclear Analysis for the HANARO Fuel Element with Burnable Absorber

Energy Technology Data Exchange (ETDEWEB)

Seo, Chul Gyo; Kim, So Young; In, Won Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

Burnable absorber is used for reducing reactivity swing and power peaking in high performance research reactors. Development of the HANARO fuel element with burnable absorber was started in the U-Mo fuel development program at HANARO, but detailed full core analysis was not performed because the current HANARO fuel management system is uncertain to analysis the HANARO core with burnable absorber. A sophisticated reactor physics system is required to analysis the core. The McCARD code was selected and the detailed McCARD core models, in which the basic HANARO core model was developed by one of the McCARD developers, are used in this study. The development of nuclear fuel requires a long time and correct developing direction especially by the nuclear analysis. This paper presents a preliminary nuclear analysis to promote the fuel development. Based on the developed fuel, the further nuclear analysis will improve reactor performance and safety. Basic nuclear analysis for the HANARO and the AHR were performed for getting the proper fuel elements with burnable absorber. Addition of 0.3 - 0.4% Cd to the fuel meat is promising for the current HANARO fuel element. Small addition of burnable absorber may not change any fuel characteristics of the HANARO fuel element, but various basic tests and irradiation tests at the HANARO core are required.

Intercomparison and determination of trace elements in urban dust by neutron activation analysis

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Park, Kwang Won; Kang, Sang Hun

2000-01-01

Trace elements in air samples artificially loaded on filters with urban dust and the bulk material of urban dust as an environmental sample were determined non-destructively using instrumental neutron activation analysis. Standard reference material (Urban Dust, SRM 1648) of the National Institute of Standard and Technology was used for the analytical quality control. The relative error for 37 elements was less than 15% and the standard deviation was less than 10%. 29 elements in the urban dust and 21 elements in the loaded filter sample were determined respectively. To evaluate the proficiency and reliability of the measurement, data intercomparison was performed and 39 analytical laboratories participated in the analysis using different analytical methods; neutron activation analysis, particle induced X-ray emission analysis, X-ray fluorescence analysis and atomic absorption spectrometry. Z-scores were calculated using the standard deviation of the laboratory's mean as target standard deviation, and a good result was obtained that the values fall between-1 and +1 except some elements. (author)

Finite element elastic-plastic analysis of LMFBR components

International Nuclear Information System (INIS)

Levy, A.; Pifko, A.; Armen, H. Jr.

1978-01-01

The present effort involves the development of computationally efficient finite element methods for accurately predicting the isothermal elastic-plastic three-dimensional response of thick and thin shell structures subjected to mechanical and thermal loads. This work will be used as the basis for further development of analytical tools to be used to verify the structural integrity of liquid metal fast breeder reactor (LMFBR) components. The methods presented here have been implemented into the three-dimensional solid element module (HEX) of the Grumman PLANS finite element program. These methods include the use of optimal stress points as well as a variable number of stress points within an element. This allows monitoring the stress history at many points within an element and hence provides an accurate representation of the elastic-plastic boundary using a minimum number of degrees of freedom. Also included is an improved thermal stress analysis capability in which the temperature variation and corresponding thermal strain variation are represented by the same functional form as the displacement variation. Various problems are used to demonstrate these improved capabilities. (Auth.)

Applications of X-ray emission to elemental analysis of foods

International Nuclear Information System (INIS)

Flocchini, R.G.; Lagunas-Solar, M.C.; Perley, B.P.

1996-01-01

Trace element analysis via X-Ray Fluorescence (XRF) and Proton-Induced X-Ray Emission (PIXE) techniques were applied to several samples of fresh and processed foods. Thin samples of fresh fruits and vegetables, processed dry foods, and spices were included in these analyses. The results indicate that XRF and/or PIXE analysis is applicable to these types of samples but require special and simple modifications in sample preparation techniques, and the inclusion of new matrix type corrections for data analysis. However, the non-destructive nature, reproducibility, efficiency and high sensitivity that characterize these multi-element analytical procedures can provide new potential methods for detecting trace elements in foods and in many agricultural commodities. Toxic metals such as Hg, Pb, and As were detected in some foods. In addition, other essential or neutral trace elements such as Na, K, Mg, Ca, Cu, Cr, V, Zn, Mo, Fe, Mn, Ni, Se, Cl, S, and P were also detected. These and other elements can be analyzed rapidly and with high sensitivity for applications in process control and for certification of food quality. Developing these techniques and procedures specifically for food and for various agricultural products may provide new analytical options and help mitigate the expected impact of forthcoming regulations intended to establish limits and tolerance levels for micro toxicants and other essential nutrients in foods and agricultural products. (author)

Analysis of ultrasonic beam profile due to change of elements' number for phased array transducer (part 2)

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun

1998-01-01

The phased array offers many advantages and improvements over conventional single-element transducers such as the straight-beam and angle-beam. The advantages of array sensors for large structures are two folds; firstly, array transducers provide a method of rapid beam steering and sequential addressing of a large area of interest without requiring mechanical or manual scanning which is particularly important in real-time application. Secondly, array transducer provide a method of dynamic focusing, in which the focal length of the ultrasonic beam varies as the pulse propagates through the material. There are some parameters such as number, size, center to center space of elements to design phased array transducer. In previous study. the characteristics of beam steering and dynamic focusing had been simulated for ultrasonic SH-wave with varying the number of phased array transducer's element. In this study, the characteristic of beam steering for phased array transducer has been simulated for ultrasonic SH-wave on the basis of Huygen's principle with varying center to center space of elements. Ultrasonic beam directivity and focusing due to change of time delay of each element were discussed with varying center to center space of elements.

Dye laser spectrometer for the analysis of pulsed vacuum arcs

International Nuclear Information System (INIS)

Hargis, P.J. Jr.; Robertson, M.M.

1975-01-01

A pulsed dye laser spectrometer which is used to obtain detailed single shot spectroscopic measurements of the plasma in a pulsed vacuum arc was developed. The capabilities of this spectrometer are indicated by the detection of laser induced fluorescence signals from 10 6 neutral Ti atoms in the plasma of a pulsed vacuum arc with a Ti anode. (U.S.)

Shape analysis of pulsed second sound in He II

International Nuclear Information System (INIS)

Worthington, T.; Yan, J.; Trefny, J.U.

1976-01-01

Second sound in He II has been observed using a heat pulse method. At temperatures where well-developed second sound is observed, the entire pulse shape can be understood if heat sources and geometrical effects are properly taken into account. 4 figures

Trace elements in coloured opals using neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

McOrist, G D; Smallwood, A [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1997-12-31

Neutron activation analysis (NAA) is a technique particularly suited to analysing opals since it is non-destructive and the silica matrix of opals is not prone to significant activation. It was used to determine the concentration of trace elements in 50 samples of orange, yellow, green, blue and pink opals as well as 18 samples of colourless opals taken from a number of recognised fields in Australia, Peru, Mexico and USA. The results were then evaluated to determine if a relationship existed between trace element content and opal colour. The mean concentration of most of the elements found in orange, yellow and colourless opals were similar with few exceptions. This indicated that, for these samples, colour is not related to the trace elements present. However, the trace element profile of the green, pink and blue opals was found to be significantly different with each colour having a much higher concentration of certain trace elements when compared with all other opals analysed. 7 refs.

Trace elements in coloured opals using neutron activation analysis

International Nuclear Information System (INIS)

McOrist, G.D.; Smallwood, A.

1996-01-01

Neutron activation analysis (NAA) is a technique particularly suited to analysing opals since it is non-destructive and the silica matrix of opals is not prone to significant activation. It was used to determine the concentration of trace elements in 50 samples of orange, yellow, green, blue and pink opals as well as 18 samples of colourless opals taken from a number of recognised fields in Australia, Peru, Mexico and USA. The results were then evaluated to determine if a relationship existed between trace element content and opal colour. The mean concentration of most of the elements found in orange, yellow and colourless opals were similar with few exceptions. This indicated that, for these samples, colour is not related to the trace elements present. However, the trace element profile of the green, pink and blue opals was found to be significantly different with each colour having a much higher concentration of certain trace elements when compared with all other opals analysed. 7 refs

Trace elements in coloured opals using neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

McOrist, G.D.; Smallwood, A. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1996-12-31

Neutron activation analysis (NAA) is a technique particularly suited to analysing opals since it is non-destructive and the silica matrix of opals is not prone to significant activation. It was used to determine the concentration of trace elements in 50 samples of orange, yellow, green, blue and pink opals as well as 18 samples of colourless opals taken from a number of recognised fields in Australia, Peru, Mexico and USA. The results were then evaluated to determine if a relationship existed between trace element content and opal colour. The mean concentration of most of the elements found in orange, yellow and colourless opals were similar with few exceptions. This indicated that, for these samples, colour is not related to the trace elements present. However, the trace element profile of the green, pink and blue opals was found to be significantly different with each colour having a much higher concentration of certain trace elements when compared with all other opals analysed. 7 refs.

Theoretical and experimental investigation of the nonlinear structural dynamics of Fast Breeder Reactor fuel elements

International Nuclear Information System (INIS)

Liebe, R.

1978-04-01

This study describes theoretical and experimental investigations of the dynamic deformation behavior of single and clustered fuel elements under local fault conditions in a Fast Breeder Reactor core. In particular an energetic molten-fuel-coolant-interaction (FCI) is assumed in one subassembly with corresponding pressure pulses, which may rupture the wrapper and load the adjacent fuel elements impulsively. Associated coherent structural deformation may exceed tolerable and damage the control rods. To attack the outlined coupled fluid-structure-interaction problem it is assumed, that the loading at the structures is known in space and time, and that there is no feedback from the deformation response. Then current FCI-knowledge and experience from underwater core model explosion tests is utilized to estimate upper limits of relevant pulse characteristics. As a first step the static carrying capacity of the rigid-plastic hexagonal wrapper tube is calculated using the methods of limit analysis. Then for a general dynamic simulation of the complete elastoplastic subassembly response the concept of a discrete nonlinear hinge is introduced. A corresponding physical lumped parameter hinge model is presented, and general equations of motion are derived using D'Alembert's principle. Application to the static and dynamic analysis of a single complete fuel element includes the semiempirical modelling of the fuel-pin bundle by a homogeneous compressible medium. Most important conclusions are concerning the capability of the theoretical models, the failure modes and threshold load levels of single as well as clustered SNR-300 fuel elements and the safety relevant finding, that only limited deformations are found in the first row around the incident element. This shows in agreement with explosion test results that the structured and closely spaced fuel elements constitute an effective, inherent barrier against extreme dynamic loadings. (orig.) [de

Single-mode pulsed dye laser pumped by using a diode-pumped Nd:YAG laser with a long pulse width

CERN Document Server

Yi, J H; Moon, H J; Rho, S P; Han, J M; Rhee, Y J; Lee, J M

1999-01-01

The lasing characteristics of a single-mode dye laser pumped by using a diode-pumped solid-state laser (DPSSL) with a high repetition rate is described. A 45-mm-long Nd:YAG rod was pumped by three CW diode arrays and it was acousto-optically Q-switched. A KTP crystal was used for intracavity frequency doubling. The pulse width of the laser ranged from 90 ns to 200 ns, depending on the diode current and the Q-switching frequency. The single-mode dye laser had a grazing incidence configuration. The pulse width of the dye laser was reduced to about 1/8 of the pumping laser pulse width. The effects of the DPSSL Q-switching frequency, the driving current, and the cavity loss on the dye laser pulse width were investigated by using a simple plane-parallel cavity. From the measured pulse width of the dye laser as a function of the reflectivity of the dye laser output coupler, we found that the cavity loss due to the frequency selection elements and the output coupler should be less than 70 % in order to avoid a drast...

Experience with pulsed tig-welding at UKAEA Springfields

International Nuclear Information System (INIS)

Taylor, A.F.

1973-01-01

Welding investigations at Springfields are primarily concerned with development of jointing procedures for nuclear fuel elements, where high standards of integrity are required. Equipment and work which developed from a pulsed TIG-welding technique, set up in 1963 for welding of 0.4 mm thick tubing are described. A computer based control system, which is illustrated, can provide direct digital control of continuous or pulsed TIG or plasma welding. The work has been mainly concerned with stainless and low alloy steel between 0.4 and 4 mm thick. Some applications are mentioned. Tentative conclusions are drawn and it is felt that because of development at Springfields in continuous TIG-welding there is no advantage in using pulsed TIG on materials thinner than about 2 mm. (U.K.)

Elemental Study in Soybean and Products by Neutron Activation Analysis

International Nuclear Information System (INIS)

Vorapot, Permnamtip; Arporn Busamongkol; Sirinart, Laoharojanaphand

2009-07-01

Full text: Elements were analyzed in soybean and products by Instrumental Neutron Activation Analysis (INAA), Pseudo-Cyclic Instrumental Neutron Activation Analysis (PCINAA) and Epithermal Instrumental Neutron Activation Analysis (EINAA). Elements detected in sample were include Al, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn Na, Se and Zn. The result showed that the nutritional contents changed after food processing. From experiments (n = 2), it was found that after food processing, the concentration of Cl and Na in soy bean curd increased from 0.0045 and 0.0011% to found 0.91 and 0.39 %, respectively. Other elements did not differ from soybean. Limits of detection for Al, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn Na, Se and Zn were 0.05, 0.2, 50, 6, 10, 15, 0.05, 30, 40, 5, 5, 0.05 and 1 mg.kg - 1, respectively

PIXE analysis of trace elements in cetacean teeth

International Nuclear Information System (INIS)

Mitani, Yoko; Arai, Nobuaki; Sakamoto, Wataru; Yoshida, Koji

1997-01-01

PIXE was adopted for analysis of trace elements in teeth of two species of cetaceans, sperm whale (Physeter microcephalus) and pantropical spotted dolphin (Stenella attenuata). The analyses were performed along with the growth layer of the teeth, which is formed annually, suitable for age determination. Mn, Fe, Cu, Zu and Sr were detected in the teeth of sperm whale and pantropical spotted dolphin. Among these trace elements, gradual increase was observed for Zn/Ca ratio in the sperm whale's teeth. (author)

Background reduction and noise discrimination in the proportional counting of tritium using pulse-shape analysis

International Nuclear Information System (INIS)

Hochel, R.C.; Hayes, D.W.

1975-01-01

A pulse-shape analysis (PSA) unit of commercial design has been incorporated into a proportional counting system to determine the effectiveness of pulse-shape discrimination in increasing the sensitivity of tritium counting. It was found that a quantitative determination of tritium could be obtained directly from the PSA time spectrum eliminating the need for beta-ray energy selection used in the pulse-shape discrimination (PSD) technique. The performance of the proportional counting system was tested using the PSA unit and anticoincidence shielding, both singly and combined, under several types of background. A background reduction factor of 169 was obtained from the combined PSA-anticoincidence system with only a 2% loss in tritium counting efficiency. The PSA method was also found to offer significant reductions in noise background. (Auth.)

Adaptive finite-element ballooning analysis of bipolar ionized fields

International Nuclear Information System (INIS)

Al-Hamouz, Z.M.

1995-01-01

This paper presents an adaptive finite-element iterative method for the analysis of the ionized field around high-voltage bipolar direct-current (HVDC) transmission line conductors without resort to Deutsch's assumption. A new iterative finite-element ballooning technique is proposed to solve Poisson's equation wherein the commonly used artificial boundary around the transmission line conductors is simulated at infinity. Unlike all attempts reported in the literature for the solution of ionized field, the constancy of the conductors' surface field at the corona onset value is directly implemented in the finite-element formulation. In order to investigate the effectiveness of the proposed method, a laboratory model was built. It has been found that the calculated V-I characteristics and the ground-plane current density agreed well with those measured experimentally. The simplicity in computer programming in addition to the low number of iterations required to achieve convergence characterize this method of analysis

Analysis and mitigation of systematic errors in spectral shearing interferometry of pulses approaching the single-cycle limit [Invited

International Nuclear Information System (INIS)

Birge, Jonathan R.; Kaertner, Franz X.

2008-01-01

We derive an analytical approximation for the measured pulse width error in spectral shearing methods, such as spectral phase interferometry for direct electric-field reconstruction (SPIDER), caused by an anomalous delay between the two sheared pulse components. This analysis suggests that, as pulses approach the single-cycle limit, the resulting requirements on the calibration and stability of this delay become significant, requiring precision orders of magnitude higher than the scale of a wavelength. This is demonstrated by numerical simulations of SPIDER pulse reconstruction using actual data from a sub-two-cycle laser. We briefly propose methods to minimize the effects of this sensitivity in SPIDER and review variants of spectral shearing that attempt to avoid this difficulty

Rapid quantitative analysis of elemental composition and depth profile of Cu(In,Ga)Se{sub 2} thin solar cell film using laser-induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

In, Jung-Hwan; Kim, Chan-Kyu; Lee, Seok-Hee; Choi, Jang-Hee; Jeong, Sungho, E-mail: shjeong@gist.ac.kr

2015-03-31

Laser-induced breakdown spectroscopy (LIBS) is reported as a method for rapid quantitative analysis of elemental composition and depth profile of Cu(In,Ga)Se{sub 2} (CIGS) thin film. A calibration model considering compositional grading over depth was developed and verified with test samples. The results from eight test samples showed that the average concentration of Cu, In, Ga and Se could be predicted with a root mean square error of below 1% and a relative standard deviation of also below 1%. The depth profile of each constituent element of CIGS predicted by LIBS was close to those by Auger electron spectroscopy and secondary ion mass spectrometry. The average ablation depth per pulse during depth profiling was about 100 nm. - Highlights: • LIBS was adopted for quantitative analysis of CIGS thin film. • A calibration model considering compositional grading over depth was developed. • Concentration prediction of CIGS thin film was accurate and precise. • Quantitative depth profiling by LIBS was compared with those by AES and SIMS.

Qualitative PIXE analysis of mineral elements in some phytopharmaceutic drugs

International Nuclear Information System (INIS)

Preoteasa, E.A.; Harangus, Livia; Gugiu, M; Iordan, Andreea; Ciortea, C.

2002-01-01

A large number of phytopharmaceutic drugs are being developed, due to positive effects in various diseases and to high tolerance by the organism. While their medicinally active compounds have been identified, little attention has been paid to their mineral micro- and trace elements. The mineral elements in the drug may have therapeutic or toxic effects which should be properly assessed. Nuclear and atomic methods allow sensitive multielement detection and we previously performed nuclear activation analysis of some Romanian drugs made by plants. Despite this method's high sensitivity, its use is limited by the availability of a nuclear reactor. Particle-induced X-ray emission (PIXE) provides an alternative, and here we examined its potential for the analysis of mineral elements in three commercial phytopharmaceutical preparations, namely, Liv52, Mentat, and Geriforte. The PIXE measurements were performed with 3 MeV protons at the 8.5 MV NIPNE-HH tandem accelerator, using a hyper pure Ge detector, normally oriented and connected to a multichannel analyzer and to a computer; the drug pills were fixed at 45 angle with respect to the beam. In all drugs PIXE detected mineral elements with Z > 16 down to trace levels. Major elements included K, Ca, Fe, Cu, and Zn, and minor/trace amounts of S, Cl, Ti, Cr, Mn, Ni, Ga, Br, Rb, Sr, Hg, and As/Pb were detected. Some differences were seen between the three drugs. Although at trace levels Ga, As, Hg and Pb are not toxic, one should consider that their accumulation might be harmful and caution seems recommendable on long-term cure. Most of the other elements are known to exert a positive biological role, and both in major and trace levels they may contribute to the therapeutic action. Thus PIXE analysis of mineral elements in phytopharmaceutic drugs, even qualitative, is useful for evaluating the benefits and risks in the therapy. (authors)

Finite element analysis of tubular joints in offshore structures ...

African Journals Online (AJOL)

... representing a 2-D model of the joint between the brace and the chord walls. This was subsequently followed but finite element analysis of six tubular joints. A global analysis was initially undertaken, then the submodel analysis carried in the areas of stress concentration. Journal of Civil Engineering, JKUAT (2001) Vol 6, ...

About a fuel for burnup reactor of periodical pulsed nuclear pumped laser

International Nuclear Information System (INIS)

Volkov, A.I.; Lukin, A.V.; Magda, L.E.; Magda, E.P.; Pogrebov, I.S.; Putnikov, I.S.; Khmelnitsky, D.V.; Scherbakov, A.P.

1998-01-01

A physical scheme of burnup reactor for a Periodic Pulsed Nuclear Pumped Laser was supposed. Calculations of its neutron physical parameters were made. The general layout and construction of basic elements of the reactor are discussed. The requirements for the fuel and fuel elements are established. (author)

Investigation of the Behavior of Steel Shear Walls Using Finite Elements Analysis

OpenAIRE

Abubakri, K.; Veladi, H.

2016-01-01

Currently, steel shear walls are considered by engineers as an economic method against lateral loads imposed by wind and earthquake in tall structures. Accordingly, there is a growing need to develop accurate methods alongside approximation methods to estimate the behavior of these structural elements. The finite element technique is one of the strongest numerical methods in analysis of solid mechanics problems. Finite element analysis however requires high technical knowledge of the behavior...

Elemental analysis of Oum er Rbia Moroccan river-water using TXRF

International Nuclear Information System (INIS)

Zahry, F.; Bounakhla, M.; El Hamdaoui, A.; Labraimi, M.

2000-01-01

The x-ray fluorescence analysis of water and suspended particulate matter (SPM) from Oum er Rbia Moroccan river for the content of 17 elements has been performed utilizing the energy dispersive x-ray fluorescence spectrometer and total reflection excitation. SPM samples were dissolved in nitric acid. For all samples direct measurements are feasible by spiking a few ml of the sample with Ga as internal standard element, and drying an aliquot of 20 μl on a quartz glass carrier. The detection limits of 10 to 20 ppb are sufficient for most of the elements to be determined. Results were assessed for accuracy by the analysis of the 15474 ICP multi-elemental standard I. Some results were also compared with AAS and ICP-AES. The results for most of the elements obtained by TXRF were accurate to about 2-15 %. The objectives of the analysis were to determine the geo-chemical areas on this river, to explain the mechanism of sediment transport and to assess the pollution of the river by human activities. 36 samples had been collected along the river between its source in Middle Atlas and the Atlantic ocean at Azemour city. (author)

Liquid phase microextraction for the analysis of trace elements and their speciation

International Nuclear Information System (INIS)

Hu, Bin; He, Man; Chen, Beibei; Xia, Linbo

2013-01-01

Trace/ultra-trace elements and their speciation analysis in complex matrices usually require sample preparation procedures to achieve sample clean-up and analyte preconcentration. Sample preparation is often the bottleneck in trace elements and their speciation analysis which has a direct impact on accuracy, precision and limits of detection and is often the rate-determining step of the analytical process. Recent trends in sample preparation include miniaturization, automation, high-throughput performance and reduction in solvent/sample consumption and operation time. Liquid-phase microextraction (LPME) technique as a novel and promising alternative in sample preparation can meet these requirements and has become a very efficient sample preparation technique. This review updates the state of art of LPME for trace elements and their speciation analysis and discusses its promising prospects. The major thrust of the article highlights the applications of LPME including single-drop microextraction (SDME), hollow fiber-liquid phase microextraction (HF-LPME), dispersive liquid liquid microextraction (DLLME) and solidified floating organic drop microextraction (SFODME) to the fields of elemental and their speciation analysis by atomic spectrometry-based methods, especially inductively coupled plasma mass spectrometry. General and specific concepts, different extraction formats and characteristics of LPME are described and compared, along with examples of recent innovations and applications presented to demonstrate its potential for trace elements and their speciation analysis in biological and environmental fields. Moreover, the application potential and an outlook on the combination of LPME and atomic spectrometry-based techniques for inorganic analysis are commentated. - Highlights: • The state of art of LPME for trace elements and their speciation analysis is updated. • Different extraction formats of LPME are described. • The application potential and future

Trace Element Analysis of Selenium

International Nuclear Information System (INIS)

Soliman, M.S.A.

2010-01-01

The present thesis divided into four chapters as follows:Chapter (1):This chapter contains an introduction on different oxidation states of organic and inorganic species for selenium in environmental and biological samples, the process for separation of selenium from these samples and the importance of selenium as a component for these samples. Also gives notes about the techniques which are used in the elemental analysis for selenium species and the detection limits for selenium in these techniques, selenium species in human body and the importance of these species in protecting the body from the different types of cancer and the sources of selenium in environmental samples (soil and water) and distribution levels of selenium in these samples.Chapter (2):This chapter is divided into two parts :The first part deals with the sample collection process for environmental samples (underground water, soil) and the wet digestion ( microwave digestion ) process of soil samples. It also contains the theory of work of the closed microwave digestion system.The second part contains detailed information concerning the theoretical considerations of the used analytical techniques. These techniques include Hydride generation - Atomic Absorption Spectrometer (HG-AAS), Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and Neutron Activation Analysis (NAA).Chapter (3): This chapter includes the methods of sampling, sample preparation, and sample digesition. The measures of quality assurance are disscused in this chapter. It describes in details the closed microwave digestion technique and the analytical methods used in this study which are present in Central Laboratory for Elemental and Isotopic Analysis (CLEIA) and the Egypt Second Research Reactor (ETRR-2). The described techniques are Atomic Absorption Spectrometer (AAS 6 vario, Analytical Jena GmbH, Germany), JMS-PLASMAX2 Mass Spectrometer (ICP-MS) and the Egypt Second Research Reactor (NAA).

Seismic analysis of the APR1400 nuclear reactor system using a verified beam element model

Energy Technology Data Exchange (ETDEWEB)

Park, Jong-beom [Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Park, No-Cheol, E-mail: pnch@yonsei.ac.kr [Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Lee, Sang-Jeong; Park, Young-Pil [Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Choi, Youngin [Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon 34142 (Korea, Republic of)

2017-03-15

Highlights: • A simplified beam element model is constructed based on the real dynamic characteristics of the APR1400. • Time history analysis is performed to calculate the seismic responses of the structures. • Large deformations can be observed at the in-phase mode of reactor vessel and core support barrel. - Abstract: Structural integrity is the first priority in the design of nuclear reactor internal structures. In particular, nuclear reactor internals should be designed to endure external forces, such as those due to earthquakes. Many researchers have performed finite element analyses to meet these design requirements. Generally, a seismic analysis model should reflect the dynamic characteristics of the target system. However, seismic analysis based on the finite element method requires long computation times as well as huge storage space. In this research, a beam element model was developed and confirmed based on the real dynamic characteristics of an advanced pressurized water nuclear reactor 1400 (APR1400) system. That verification process enhances the accuracy of the finite element analysis using the beam elements, remarkably. Also, the beam element model reduces seismic analysis costs. Therefore, the beam element model was used to perform the seismic analysis. Then, the safety of the APR1400 was assessed based on a seismic analysis of the time history responses of its structures. Thus, efficient, accurate seismic analysis was demonstrated using the proposed beam element model.

Seismic analysis of the APR1400 nuclear reactor system using a verified beam element model

International Nuclear Information System (INIS)

Park, Jong-beom; Park, No-Cheol; Lee, Sang-Jeong; Park, Young-Pil; Choi, Youngin

2017-01-01

Highlights: • A simplified beam element model is constructed based on the real dynamic characteristics of the APR1400. • Time history analysis is performed to calculate the seismic responses of the structures. • Large deformations can be observed at the in-phase mode of reactor vessel and core support barrel. - Abstract: Structural integrity is the first priority in the design of nuclear reactor internal structures. In particular, nuclear reactor internals should be designed to endure external forces, such as those due to earthquakes. Many researchers have performed finite element analyses to meet these design requirements. Generally, a seismic analysis model should reflect the dynamic characteristics of the target system. However, seismic analysis based on the finite element method requires long computation times as well as huge storage space. In this research, a beam element model was developed and confirmed based on the real dynamic characteristics of an advanced pressurized water nuclear reactor 1400 (APR1400) system. That verification process enhances the accuracy of the finite element analysis using the beam elements, remarkably. Also, the beam element model reduces seismic analysis costs. Therefore, the beam element model was used to perform the seismic analysis. Then, the safety of the APR1400 was assessed based on a seismic analysis of the time history responses of its structures. Thus, efficient, accurate seismic analysis was demonstrated using the proposed beam element model.

Stochastic analysis of a pulse-type prey-predator model

Science.gov (United States)

Wu, Y.; Zhu, W. Q.

2008-04-01

A stochastic Lotka-Volterra model, a so-called pulse-type model, for the interaction between two species and their random natural environment is investigated. The effect of a random environment is modeled as random pulse trains in the birth rate of the prey and the death rate of the predator. The generalized cell mapping method is applied to calculate the probability distributions of the species populations at a state of statistical quasistationarity. The time evolution of the population densities is studied, and the probability of the near extinction time, from an initial state to a critical state, is obtained. The effects on the ecosystem behaviors of the prey self-competition term and of the pulse mean arrival rate are also discussed. Our results indicate that the proposed pulse-type model shows obviously distinguishable characteristics from a Gaussian-type model, and may confer a significant advantage for modeling the prey-predator system under discrete environmental fluctuations.

Daily dietary intake of trace elements of radiological and nutritional importance by the adult Indian population

International Nuclear Information System (INIS)

Dang, H.S.; Jaiswal, D.D.; Nair, S.

2001-01-01

The concentrations of eleven elements: Ca, Co, Cr, Cs, Fe, I, K, Se, Sr, Th and Zn were determined in total diet samples and also in individual food materials which constitute the typical Indian diet. Instrumental neutron activation analysis (INAA) and radiochemical neutron activation analysis (RNAA) were employed for the analysis. Whereas the elements Fe, Co, Cr, Se and Zn are important from the view point of their role in nutrition, the elements Cs, K, Sr and Th are of importance in radiation protection, and Ca and I have dual importance: both in nutrition as well as in radiation protection. Based on the analysis of twenty total diet samples, prepared as per the data on the dietary intake pattern of four provinces of India and the data on intake pattern of an average adult Indian, the geometric mean (GM) intake of various elements was estimated to be 0.33 g (0.2-0.67) for Ca, 16.5 μg (8.3-31.1) for Co, 52.3μg (35.1-131) for Cr, 4.7μg (2.79-11.8) for Cs, 94.6μg (60.6-201) for I, 1.90 g (1.25-3.54) for K, 1.13 mg (0.78-2.97) for Sr, 0.76μg (0.45-1.66) for Th, 15.9 mg (10.2-34.3) for Fe, 56.3μg (27.6-105.3) for Se and 8.6 mg (5.1-16.7) for Zn. Some of the important individual food materials, such as cereals, pulses, milk, vegetables etc., were also analysed for these elements to observe the contributions of the individual food materials to their daily dietary intake. The results of the analysis showed that in the case of Cs, K, Sr, Th, Fe, Zn and Co, almost 50% of the daily dietary intake of the above stated elements is contributed by cereals and pulses. In the case of Ca however, significant amount is amount is contributed by milk and in case of I, iodised salt could make significant contribution. The data collected so far, for Se and Cr, was not sufficient to draw any definite conclusion. (author)

Finite element analysis of rotating beams physics based interpolation

CERN Document Server

Ganguli, Ranjan

2017-01-01

This book addresses the solution of rotating beam free-vibration problems using the finite element method. It provides an introduction to the governing equation of a rotating beam, before outlining the solution procedures using Rayleigh-Ritz, Galerkin and finite element methods. The possibility of improving the convergence of finite element methods through a judicious selection of interpolation functions, which are closer to the problem physics, is also addressed. The book offers a valuable guide for students and researchers working on rotating beam problems – important engineering structures used in helicopter rotors, wind turbines, gas turbines, steam turbines and propellers – and their applications. It can also be used as a textbook for specialized graduate and professional courses on advanced applications of finite element analysis.

Neutron activation analysis for bulk and trace elements in urine

International Nuclear Information System (INIS)

Cornelis, R.; Speecke, A.; Hoste, J.

1975-01-01

Problems in sampling urine for trace element analysis by neutron activation are systematically examined. Collection, storage, sample preparation and contamination hazards during irradiation are studied in detail. Three different sizes of urine samples are prepared for analysis, depending on the concentration and nuclear properties of the elements, and suitable multielement doped urine standards are used. As, Br, Ca, Cl, Co, Cr, Cs, Cu, Hg, I, K, Mg, Mn, Na, Rb, Se and Zn are determined. The extreme care given to sample collection, use of ''ultra-clean'' vials, and work in a dust-free room allows consistent values to be obtained over long periods of time. A literature review of the amounts of forty elements present in urine per day is also given

Pulse Detecting Genetic Circuit – A New Design Approach

Science.gov (United States)

Inniss, Mara; Iba, Hitoshi; Way, Jeffrey C.

2016-01-01

A robust cellular counter could enable synthetic biologists to design complex circuits with diverse behaviors. The existing synthetic-biological counters, responsive to the beginning of the pulse, are sensitive to the pulse duration. Here we present a pulse detecting circuit that responds only at the falling edge of a pulse–analogous to negative edge triggered electric circuits. As biological events do not follow precise timing, use of such a pulse detector would enable the design of robust asynchronous counters which can count the completion of events. This transcription-based pulse detecting circuit depends on the interaction of two co-expressed lambdoid phage-derived proteins: the first is unstable and inhibits the regulatory activity of the second, stable protein. At the end of the pulse the unstable inhibitor protein disappears from the cell and the second protein triggers the recording of the event completion. Using stochastic simulation we showed that the proposed design can detect the completion of the pulse irrespective to the pulse duration. In our simulation we also showed that fusing the pulse detector with a phage lambda memory element we can construct a counter which can be extended to count larger numbers. The proposed design principle is a new control mechanism for synthetic biology which can be integrated in different circuits for identifying the completion of an event. PMID:27907045

Trace elements in coloured opals using neutron activation analysis

International Nuclear Information System (INIS)

McOrist, G.D.; Smallwood, A.

1995-01-01

Neutron activation analysis was used to determine the concentration of trace elements in 50 samples of orange, yellow, honey, green, blue and pink opals as well as 18 samples of colourless opals taken from a number of recognised fields in Australia, Peru, Mexico and USA. The results were evaluated to determine the relationship between trace elements content and opal colour. (author). 10 refs., 10 figs., 3 tabs

Profile correction to electron temperature and enhancement factor in soft-x-ray pulse-height-analysis measurements in tokamaks

International Nuclear Information System (INIS)

Sesnic, S.; Diesso, M.; Hill, K.; Holland, A.; Pohl, F.

1988-01-01

Because soft-x-ray pulse-height-analysis spectra contain chordal information, the electron temperature and the radiation intensity (enhancement factor) measurements do not represent the local values. The correction factors for the electron temperature and the enhancement factor as a function of the temperature and density profile parameters and the energy are obtained. The spectrum distortion due to pulse pileup effects is also evaluated. A set of curves is given from which the distortion of the spectrum can be obtained if the electron temperature, the Be filter thickness, and the electronic parameters of the acquisition system are known. PG 1810,1812 ID 131801CON N X-ray diagnostics TT Profile correction to electron temperature and enhancement factor in soft-x-ray pulse-height-analysis measurements in tokamaks AU S. Sesnic, M. Diesso, K. Hill, and A. Holland LO Princeton University, Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 AU F. Pohl LO Max-Planck Institut fuer Plasmaphysik, 8046-Garching, Federal Republic of Germany SD (Presented on 16 March 1988) AB Because soft-x-ray pulse-height-analysis spectra contain chordal information, the electron temperature and the radiation intensity (enhancement factor) measurements do not represent the local values. The correction factors for the electron temperature and the enhancement factor as a function of the temperature and density profile parameters and the energy are obtained. The spectrum distortion due to pulse pileup effects is also evaluated. A set of curves is given from which the distortion of the spectrum can be obtained if the electron tempe

Uncertainties in elemental quantitative analysis by PIXE

International Nuclear Information System (INIS)

Montenegro, E.C.; Baptista, G.B.; Paschoa, A.S.; Barros Leite, C.V.

1979-01-01

The effects of the degree of non-uniformity of the particle beam, matrix composition and matrix thickness in a quantitative elemental analysis by particle induced X-ray emission (PIXE) are discussed and a criterion to evaluate the resulting degree of uncertainty in the mass determination by this method is established. (Auth.)

Acoustic emission linear pulse holography

International Nuclear Information System (INIS)

Collins, H.D.; Busse, L.J.; Lemon, D.K.

1983-01-01

This paper describes the emission linear pulse holography which produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. A thirty two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The concept behind the AE linear pulse holography is illustrated, and a block diagram of a data acquisition system to implement the concept is given. Array element spacing, synthetic frequency criteria, and lateral depth resolution are specified. A reference timing transducer positioned between the array and the inspection zone and which inititates the time-of-flight measurements is described. The results graphically illustrate the technique using a one-dimensional FFT computer algorithm (ie. linear backward wave) for an AE image reconstruction

Validation of multi-element isotope dilution ICPMS for the analysis of basalts

Energy Technology Data Exchange (ETDEWEB)

Willbold, M.; Jochum, K.P.; Raczek, I.; Amini, M.A.; Stoll, B.; Hofmann, A.W. [Max-Planck-Institut fuer Chemie, Mainz (Germany)

2003-09-01

In this study we have validated a newly developed multi-element isotope dilution (ID) ICPMS method for the simultaneous analysis of up to 12 trace elements in geological samples. By evaluating the analytical uncertainty of individual components using certified reference materials we have quantified the overall analytical uncertainty of the multi-element ID ICPMS method at 1-2%. Individual components include sampling/weighing, purity of reagents, purity of spike solutions, calibration of spikes, determination of isotopic ratios, instrumental sources of error, correction of mass discrimination effect, values of constants, and operator bias. We have used the ID-determined trace elements for internal standardization to improve indirectly the analysis of 14 other (mainly mono-isotopic trace elements) by external calibration. The overall analytical uncertainty for those data is about 2-3%. In addition, we have analyzed USGS and MPI-DING geological reference materials (BHVO-1, BHVO-2, KL2-G, ML3B-G) to quantify the overall bias of the measurement procedure. Trace element analysis of geological reference materials yielded results that agree mostly within about 2-3% relative to the reference values. Since these results match the conclusions obtained by the investigation of the overall analytical uncertainty, we take this as a measure for the validity of multi-element ID ICPMS. (orig.)

Analysis of trace elements in human hair by PIXE

International Nuclear Information System (INIS)

Baptista, G.B.; Montenegro, E.C.; Paschoa, A.S.; Barros Leite, C.V. de.

1980-10-01

The PIXE method was applied to the analysis of trace elements in scalp hair using two methods for target preparation. In the first method eigth hair strands each with nearly cylindrical geommetry and approximately the same diameter were selected and placed on an aluminum frame. In the second method a given mass of hair was dissolved with nitric acid and a known amount of strontium was added to the solution and dripped on a membrane filter using a micropipet. The results for the concentrations of trace elements in hair obtained by the two methods are compared and several aspects of the analysis is discussed. (Author) [pt

Developments in Dynamic Analysis for quantitative PIXE true elemental imaging

International Nuclear Information System (INIS)

Ryan, C.G.

2001-01-01

Dynamic Analysis (DA) is a method for projecting quantitative major and trace element images from PIXE event data-streams (off-line or on-line) obtained using the Nuclear Microprobe. The method separates full elemental spectral signatures to produce images that strongly reject artifacts due to overlapping elements, detector effects (such as escape peaks and tailing) and background. The images are also quantitative, stored in ppm-charge units, enabling images to be directly interrogated for the concentrations of all elements in areas of the images. Recent advances in the method include the correction for changing X-ray yields due to varying sample compositions across the image area and the construction of statistical variance images. The resulting accuracy of major element concentrations extracted directly from these images is better than 3% relative as determined from comparisons with electron microprobe point analysis. These results are complemented by error estimates derived from the variance images together with detection limits. This paper provides an update of research on these issues, introduces new software designed to make DA more accessible, and illustrates the application of the method to selected geological problems.

Trace element determination study in human hair by neutron activation analysis

International Nuclear Information System (INIS)

Frazao, Selma Violato

2008-01-01

Human hair analysis studies have been subject of continuous interest due to the fact that they can be used as an important tool to evaluate trace element levels in the human body. These determinations have been carried out to use hair for environmental and occupational monitoring, to identify intoxication or poisoning by toxic metals, to assess nutritional status, to diagnose and to prevent diseases and in forensic sciences. Although hair analysis presents several advantages over other human tissue or fluid analyses, such as organ tissue, blood, urine and saliva, there are some controversies regarding the use of hair analysis data. These controversies arise from the fact that it is difficult to establish reliable reference values for trace elements in hair. The purpose of this study was to evaluate the factors that affect element concentrations in hair samples from a population considered healthy and residing in the Sao Paulo metropolitan area. The collected human head hair was cut in small pieces, washed, dried and analyzed by neutron activation analysis (NAA). Aliquots of hair samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor for 16 h under a thermal neutron flux of about 5x10 12 n cm -2 s -1 for As, Br, Ca, Co, Cr, Cs, Cu, Fe, K, La, Na, Sb, Sc, Se and Zn determinations. The induced gamma activities of the standards and samples were measured using a gamma ray spectrometer coupled to an hiperpure Ge detector. For quality control of the results, IAEA- 85 Human Hair and INCT-TL-1 Tea Leaves certified reference materials (CRMs) were analyzed. Results obtained in these CRMs presented for most of elements, good agreement with the values of the certificates (relative errors less than 10%) and good precision (variation coefficients less than 13.6%). Results of replicate hair sample analysis showed good reproducibility indicating homogeneity of the prepared sample. Results obtained in the analyses of dyed and non-dyed hair

Elemental analysis of two Egyptian iron ores and produced industrial iron samples by neutron activation analysis

International Nuclear Information System (INIS)

Sroor, A.; Abdel-Basset, N.; Abdel-Haleem, A.S.; Hassan, A.M.

2001-01-01

Elemental analysis of two iron ores and initial industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were performed by the instrumental neutron activation analysis technique. Five samples of each type were irradiated for 48 h in a thermal neutron flux of 4x10 12 n/cm 2 s in the first Egyptian research reactor ET-RR-1. Also, the Pneumatic Irradiation Rabbit System (PIRS), attached to the reactor ET-RR-1 in Inshass, was used to measure short-life elements. The γ-ray spectra were obtained with a hyper pure germanium detection system. The concentration percentage values of major, minor and trace elements are presented. Implications of the elemental concentration values obtained are presented

Upstand Finite Element Analysis of Slab Bridges

OpenAIRE

O'Brien, Eugene J.; Keogh, D.L.

1998-01-01

For slab bridge decks with wide transverse edge cantilevers, the plane grillage analogy is shown to be an inaccurate method of linear elastic analysis due to variations in the vertical position of the neutral axis. The upstand grillage analogy is also shown to give inaccurate results, this time due to inappropriate modelling of in-plane distortions. An alternative method, known as upstand finite element analysis, is proposed which is sufficiently simple to be used on an everyday basis in the ...

Elemental analysis of combustion products by neutron activation

International Nuclear Information System (INIS)

Heft, R.E.; Koszykowski, R.F.

1980-01-01

This paper gives a brief description of the neutron activation analysis method, which is being used to determine the elemental profile of combustion products from coal-fired power plants, oil shale retorting, and underground coal gasification

The fingerprint element analysis on provenance of ancient chinese Jun porcelain

International Nuclear Information System (INIS)

Gao Zhengyao; Chen Songhua; Wang Jie; Huang Zhongxiang; Jia Xiuqin; Han Song

1997-01-01

Forty-three samples of ancient Jun porcelains and so on were chosen. Neutron activation analysis (NAA) was used to measure the 36 trace elements in every sample. Seven elements were chosen as the 'fingerprint elements'. The provenance of the glazes and bodies of ancient Chinese Jun porcelain were investigated by the fingerprint element analysis method. The result shows that although the ancient Chinese Jun porcelain samples have been leapt over six hundred years, and glaze colors are utterly different and are from many different kilns, there are long term, stable and same mainly raw material source. The near provenance relation between ancient Jun porcelain and ancient Ru porcelain is preliminarily analyzed. A few modern Jun porcelains approximate from ancient Jun porcelains, the majority become estranged from ancient Jun porcelain

A finite-element for the analysis of shell intersections

International Nuclear Information System (INIS)

Koves, W.J.; Nair, S.

1994-01-01

The analysis of discontinuity stresses at shell intersections is a problem of great importance in several major industries. Some of the major areas of interest are pressure-containing equipment, such as reactors and piping, in the nuclear and fossil power industry; pressure vessels and heat exchangers in the petrochemical industry; bracing in offshore oil platforms; and aerospace structures. A specialized shell-intersection finite element, which is compatible with adjoining shell elements, has been developed that has the capability of physically representing the complex three-dimensional geometry and stress state at shell intersections. The element geometry is a contoured shape that matches a wide variety of practical nozzle configurations used in ASME Code pressure vessel construction, and allows computational rigor. A closed-form theory of elasticity solution was used to compute the stress state and strain energy in the element. The concept of an energy-equivalent nodal displacement and force vector set was then developed to allow complete compatibility with adjoining shell elements and retain the analytical rigor within the element. This methodology provides a powerful and robust computation scheme that maintains the computational efficiency of shell element solutions. The shell-intersection element was then applied to the cylinder-sphere and cylinder-cylinder intersection problems

Elemental fractionation in 785 nm picosecond and femtosecond laser ablation inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Shaheen, M.E.; Gagnon, J.E.; Fryer, B.J.

2015-01-01

Elemental fractionation and ICP-MS signal response were investigated for two different pulse width laser beams originating from the same laser system. Femtosecond and picosecond laser beams at pulse widths of 130 fs and 110 ps, respectively, and wavelength of 785 nm were used to ablate NIST 610 synthetic glass and SRM 1107 Naval Brass B at the same spot for 800 to 1000 laser pulses at different repetition rates (5 to 50 Hz). Elemental fractionation was found to depend on repetition rate and showed a trend with femtosecond laser ablation that is opposite to that observed in picosecond laser ablation for most measured isotopes. ICP-MS signal intensity was higher in femtosecond than picosecond LA-ICP-MS in both NIST 610 and naval brass when ablation was conducted under the same fluence and repetition rate. The differences in signal intensity were partly related to differences in particle size distribution between particles generated by femtosecond and picosecond laser pulses and the consequent differences in transport and ionization efficiencies. The main reason for the higher signal intensity resulting from femtosecond laser pulses was related to the larger crater sizes compared to those created during picosecond laser ablation. Elemental ratios measured using 66 Zn/ 63 Cu, 208 Pb/ 238 U, 232 Th/ 238 U, 66 Zn/ 232 Th and 66 Zn/ 208 Pb were found to change with the number of laser pulses with data points being more scattered in picosecond than femtosecond laser pulses. Reproducibility of replicate measurements of signal intensities, fractionation and elemental ratios was better for fs-LA-ICP-MS (RSD ~ 3 to 6%) than ps-LA-ICP-MS (RSD ~ 7 to 11%). - Highlights: • Fractionation and ICP-MS signal response were investigated for two different pulse widths using NIST 610 and Naval Brass. • Dependence of fractionation indices on repetition rate and pulse width. • Higher ablation rate was observed in picosecond compared to femtosecond laser ablation of NIST 610 and Brass

Numerical Analysis of Ultrasonic Beam Profile Due to the Change of the Number of Piezoelectric Elements for Phased Array Transducer

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun

1999-01-01

A phased array is a multi-element piezoelectric device whose elements are individually excited by electric pulses at programmed delay time. One of the advantages of using phased array in nondestructive evaluation (NDE) application over conventional ultrasonic transducers is their great maneuverability of ultrasonic beam. There are some parameters such as the number and the size of the piezoelectric elements and the inter-element spacing of the elements to design phased array transducer. In this study, the characteristic of ultrasonic beam for phased array transducer due to the variation of the number of elements has been simulated for ultrasonic SH-wave on the basis of Huygen's principle. Ultrasonic beam directivity and focusing due to the change of time delay of each element were discussed due to the change of the number of piezoelectric elements. It was found that ultrasonic beam was much more spreaded and hence its sound pressure was decreased as steering angle of ultrasonic beam was increased. In addition, the ability of ultrasonic bean focusing decreased gradually with the increase of focal length at the same piezoelectric elements. However, the ability of beam focusing was improved as the number of consisting elements was increased

Controlled generation of a single Trichel pulse and a series of single Trichel pulses in air

Science.gov (United States)

Mizeraczyk, Jerzy; Berendt, Artur; Akishev, Yuri

2018-04-01

In this paper, a simple method for the controlled generation of a single Trichel pulse or a series of single Trichel pulses of a regulated repetition frequency in air is proposed. The concept of triggering a single Trichel pulse or a series of such pulses is based on the precise controlling the voltage inception of the negative corona, which can be accomplished through the use of a ramp voltage pulse or a series of such pulses with properly chosen ramp voltage pulse parameters (rise and fall times, and ramp voltage pulse repetition frequency). The proposal has been tested in experiments using a needle-to-plate electrode arrangement in air, and reproducible Trichel pulses (single or in a series) were obtained by triggering them with an appropriately designed voltage waveform. The proposed method and results obtained have been qualitatively analysed. The analysis provides guidance for designing the voltage ramp pulse in respect of the generation of a single Trichel pulse or a series of single Trichel pulses. The controlled generation of a single Trichel pulse or a series of such pulses would be a helpful research tool for the refined studies of the fundamental processes in a negative corona discharge in a single- (air is an example) and multi-phase gaseous fluids. The controlled generation of a single Trichel pulse or a series of Trichel pulses can also be attractive for those corona treatments which need manipulation of the electric charge and heat portions delivered by the Trichel pulses to the object.

Fluorescence decay data analysis correcting for detector pulse pile-up at very high count rates

Science.gov (United States)

Patting, Matthias; Reisch, Paja; Sackrow, Marcus; Dowler, Rhys; Koenig, Marcelle; Wahl, Michael

2018-03-01

Using time-correlated single photon counting for the purpose of fluorescence lifetime measurements is usually limited in speed due to pile-up. With modern instrumentation, this limitation can be lifted significantly, but some artifacts due to frequent merging of closely spaced detector pulses (detector pulse pile-up) remain an issue to be addressed. We propose a data analysis method correcting for this type of artifact and the resulting systematic errors. It physically models the photon losses due to detector pulse pile-up and incorporates the loss in the decay fit model employed to obtain fluorescence lifetimes and relative amplitudes of the decay components. Comparison of results with and without this correction shows a significant reduction of systematic errors at count rates approaching the excitation rate. This allows quantitatively accurate fluorescence lifetime imaging at very high frame rates.

Analysis of pipe mitred bends using beam models - by finite element method

International Nuclear Information System (INIS)

Salles, A.C.S.L. de.

1984-01-01

The formulation of a recently proposed displacement based straight pipe element for the analysis of pipe mitred bends is summarized in this work. The element kinematics includes axial, bending, torsional and ovalisation displacements, all varying cubically along the axis of the element. Interaction effects between angle adjoined straight pipe section are modeled including the appropriate additional strain terms in the stiffness matrix formulation and by using a penalty procedure to enforce continuity of pipe skin flexural rotations at the common helical edge. The element model capabilities are ilustrated in some sample analysis and the results are compared with other available experimental, analytical or more complex numerical models. (Author) [pt