Teaching Multiple Online Sections/Courses: Tactics and Techniques

Science.gov (United States)

Bates, Rodger; LaBrecque, Bryan; Fortner, Emily

2016-01-01

The challenge of teaching online increases as the number of sections or courses increase in a semester. The tactics and techniques which enrich online instruction in the tradition of quality matters can be modified and adapted to the demands of multiple instructional needs during a semester. This paper addresses time management and instructional…

Application of multiplicative array techniques for multibeam sounder systems

Digital Repository Service at National Institute of Oceanography (India)

Chakraborty, B.

modification in terms of additional computation or hardware for improved array gain. The present work is devoted towards the study of a better beamforming method i.e. a multiplicative array technique with some modification proposEd. by Brown and Rowland...

System health monitoring using multiple-model adaptive estimation techniques

Science.gov (United States)

Sifford, Stanley Ryan

Monitoring system health for fault detection and diagnosis by tracking system parameters concurrently with state estimates is approached using a new multiple-model adaptive estimation (MMAE) method. This novel method is called GRid-based Adaptive Parameter Estimation (GRAPE). GRAPE expands existing MMAE methods by using new techniques to sample the parameter space. GRAPE expands on MMAE with the hypothesis that sample models can be applied and resampled without relying on a predefined set of models. GRAPE is initially implemented in a linear framework using Kalman filter models. A more generalized GRAPE formulation is presented using extended Kalman filter (EKF) models to represent nonlinear systems. GRAPE can handle both time invariant and time varying systems as it is designed to track parameter changes. Two techniques are presented to generate parameter samples for the parallel filter models. The first approach is called selected grid-based stratification (SGBS). SGBS divides the parameter space into equally spaced strata. The second approach uses Latin Hypercube Sampling (LHS) to determine the parameter locations and minimize the total number of required models. LHS is particularly useful when the parameter dimensions grow. Adding more parameters does not require the model count to increase for LHS. Each resample is independent of the prior sample set other than the location of the parameter estimate. SGBS and LHS can be used for both the initial sample and subsequent resamples. Furthermore, resamples are not required to use the same technique. Both techniques are demonstrated for both linear and nonlinear frameworks. The GRAPE framework further formalizes the parameter tracking process through a general approach for nonlinear systems. These additional methods allow GRAPE to either narrow the focus to converged values within a parameter range or expand the range in the appropriate direction to track the parameters outside the current parameter range boundary

Direct Position Determination of Multiple Non-Circular Sources with a Moving Coprime Array

Directory of Open Access Journals (Sweden)

Yankui Zhang

2018-05-01

Full Text Available Direct position determination (DPD is currently a hot topic in wireless localization research as it is more accurate than traditional two-step positioning. However, current DPD algorithms are all based on uniform arrays, which have an insufficient degree of freedom and limited estimation accuracy. To improve the DPD accuracy, this paper introduces a coprime array to the position model of multiple non-circular sources with a moving array. To maximize the advantages of this coprime array, we reconstruct the covariance matrix by vectorization, apply a spatial smoothing technique, and converge the subspace data from each measuring position to establish the cost function. Finally, we obtain the position coordinates of the multiple non-circular sources. The complexity of the proposed method is computed and compared with that of other methods, and the Cramer–Rao lower bound of DPD for multiple sources with a moving coprime array, is derived. Theoretical analysis and simulation results show that the proposed algorithm is not only applicable to circular sources, but can also improve the positioning accuracy of non-circular sources. Compared with existing two-step positioning algorithms and DPD algorithms based on uniform linear arrays, the proposed technique offers a significant improvement in positioning accuracy with a slight increase in complexity.

Direct Position Determination of Multiple Non-Circular Sources with a Moving Coprime Array.

Science.gov (United States)

Zhang, Yankui; Ba, Bin; Wang, Daming; Geng, Wei; Xu, Haiyun

2018-05-08

Direct position determination (DPD) is currently a hot topic in wireless localization research as it is more accurate than traditional two-step positioning. However, current DPD algorithms are all based on uniform arrays, which have an insufficient degree of freedom and limited estimation accuracy. To improve the DPD accuracy, this paper introduces a coprime array to the position model of multiple non-circular sources with a moving array. To maximize the advantages of this coprime array, we reconstruct the covariance matrix by vectorization, apply a spatial smoothing technique, and converge the subspace data from each measuring position to establish the cost function. Finally, we obtain the position coordinates of the multiple non-circular sources. The complexity of the proposed method is computed and compared with that of other methods, and the Cramer⁻Rao lower bound of DPD for multiple sources with a moving coprime array, is derived. Theoretical analysis and simulation results show that the proposed algorithm is not only applicable to circular sources, but can also improve the positioning accuracy of non-circular sources. Compared with existing two-step positioning algorithms and DPD algorithms based on uniform linear arrays, the proposed technique offers a significant improvement in positioning accuracy with a slight increase in complexity.

A simplified technique for shakedown limit load determination

International Nuclear Information System (INIS)

Abdalla, Hany F.; Megahed, Mohammad M.; Younan, Maher Y.A.

2007-01-01

In this paper, a simplified technique is presented to determine the shakedown limit load of a structure using the finite element method. The simplified technique determines the shakedown limit load without performing lengthy time consuming full elastic-plastic cyclic loading simulations or conventional iterative elastic techniques. Instead, the shakedown limit load is determined by performing two analyses namely: an elastic analysis and an elastic-plastic analysis. By extracting the results of the two analyses, the shakedown limit load is determined through the calculation of the residual stresses developed within the structure. The simplified technique is applied and verified using two bench mark shakedown problems namely: the two-bar structure subjected to constant axial force and cyclic thermal loading, and the Bree cylinder subjected to constant internal pressure and cyclic high temperature variation across its wall. The results of the simplified technique showed very good correlation with the, analytically determined, Bree diagrams of both structures. In order to gain confidence in the simplified technique, the shakedown limit loads output by the simplified technique are used to perform full elastic-plastic cyclic loading simulations to check for shakedown behavior of both structures

A computer program for determining multiplicities of powder reflexions

International Nuclear Information System (INIS)

Rouse, K.D.; Cooper, M.J.

1977-01-01

A computer program has been written which determines the multiplicity factors for a given set of X-ray or neutron powder diffraction reflexions for crystals of any space group. The value of the multiplicity for each reflexion is determined from a look-up table which is indexed by the symmetry type, determined directly from the space-group number, and the reflexion type, determined from the Miller indices. There are no restrictions on the choice of indices which are used to specify the reflexions. (Auth.)

Simple lock-in detection technique utilizing multiple harmonics for digital PGC demodulators.

Science.gov (United States)

Duan, Fajie; Huang, Tingting; Jiang, Jiajia; Fu, Xiao; Ma, Ling

2017-06-01

A simple lock-in detection technique especially suited for digital phase-generated carrier (PGC) demodulators is proposed in this paper. It mixes the interference signal with rectangular waves whose Fourier expansions contain multiple odd or multiple even harmonics of the carrier to recover the quadrature components needed for interference phase demodulation. In this way, the use of a multiplier is avoided and the efficiency of the algorithm is improved. Noise performance with regard to light intensity variation and circuit noise is analyzed theoretically for both the proposed technique and the traditional lock-in technique, and results show that the former provides a better signal-to-noise ratio than the latter with proper modulation depth and average interference phase. Detailed simulations were conducted and the theoretical analysis was verified. A fiber-optic Michelson interferometer was constructed and the feasibility of the proposed technique is demonstrated.

Determining of the nuclear composition of primary cosmic rays from the experimental distributions of multiple muons in atmospheric showers

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

1993-01-01

Various approaches are discussed for determining the nuclear composition of the primary cosmic radiation from the distributions of multiple muons. Results are presented of calculations of the distributions of multiple muons for A 1 , A 4 , A 14 , A 26 , A 56 nuclei for an infinite plane and for the underground scintillation telescope of the Institute for Nuclear Research of the Academy of Sciences of Russia.The most suitable technique for determination of the primary nuclear composition of cosmic rays from the distribution of multiple muons is shown to be the approximate solution of a set of N equations, in which the respective coefficients of the contributions of various nuclei A i (i=1-N) to the primary composition serve as variables, while the remaining parts of these equations are the distributions of multiple muons obtained experimentally. 7 refs.; 2 tabs

Multiple matings among glossina and the sterile male technique

International Nuclear Information System (INIS)

Pinhao, R.C.

1980-01-01

The fact that multiple matings are a common phenomenon among glossina turns the sterile male technique into a competition not between adult insects but between two types of sperm, and the proportion of females inseminated with the one or the other is given by the binomial (p+q)sup(n), where p is the percentage of normal males, q the percentage of sterile males and n the average number of matings per female. However, multiple matings cannot damage the effectiveness of the technique unless two conditions are present either separately or simultaneously: precocious death of the spermatozoa and reduced inseminating potential among the sterile males. Study of the factors which can alter the inseminating potential is thus important for those who wish to use the sterile male technique. These factors are of three kinds: factors connected with quality, with quantity and with availability. The first are associated with the nature and intensity of the alterations brought about in the spermatozoa by the sterilizing agent, the second with possible variations in the amount of sperm reaching the spermotheca, the third with the behaviour of the sterile males in the nature - that is, the question whether sterilization has a favourable or unfavourable influence on their chances of mating with wild females. The author describes his observations of the quantity of sperm produced by Glossina morsitans submorsitans males from the colony reared at the Institute for Tropical Hygiene and Medicine in Lisbon, compares them with the observations of other authors and discusses their practical significance. Specific research is suggested. Advantages from assessing the behaviour of colonies not by female productivity but by male inseminating potential, and appropriate laboratory techniques

Video Multiple Watermarking Technique Based on Image Interlacing Using DWT

Directory of Open Access Journals (Sweden)

Mohamed M. Ibrahim

2014-01-01

Full Text Available Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

Video multiple watermarking technique based on image interlacing using DWT.

Science.gov (United States)

Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

2014-01-01

Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

Neutron Multiplicity Analysis

Energy Technology Data Exchange (ETDEWEB)

Frame, Katherine Chiyoko [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-06-28

Neutron multiplicity measurements are widely used for nondestructive assay (NDA) of special nuclear material (SNM). When combined with isotopic composition information, neutron multiplicity analysis can be used to estimate the spontaneous fission rate and leakage multiplication of SNM. When combined with isotopic information, the total mass of fissile material can also be determined. This presentation provides an overview of this technique.

Techniques for Performance Improvement of Integer Multiplication in Cryptographic Applications

Directory of Open Access Journals (Sweden)

Robert Brumnik

2014-01-01

Full Text Available The problem of arithmetic operations performance in number fields is actively researched by many scientists, as evidenced by significant publications in this field. In this work, we offer some techniques to increase performance of software implementation of finite field multiplication algorithm, for both 32-bit and 64-bit platforms. The developed technique, called “delayed carry mechanism,” allows to preventing necessity to consider a significant bit carry at each iteration of the sum accumulation loop. This mechanism enables reducing the total number of additions and applies the modern parallelization technologies effectively.

Reactor vital equipment determination techniques

International Nuclear Information System (INIS)

Bott, T.F.; Thomas, W.S.

1983-01-01

The Reactor Vital Equipment Determination Techniques program at the Los Alamos National Laboratory is discussed. The purpose of the program is to provide the Nuclear Regulatory Commission (NRC) with technical support in identifying vital areas at nuclear power plants using a fault-tree technique. A reexamination of some system modeling assumptions is being performed for the Vital Area Analysis Program. A short description of the vital area analysis and supporting research on modeling assumptions is presented. Perceptions of program modifications based on the research are outlined, and the status of high-priority research topics is discussed

Multiple Solutions of Nonlinear Boundary Value Problems of Fractional Order: A New Analytic Iterative Technique

Directory of Open Access Journals (Sweden)

Omar Abu Arqub

2014-01-01

Full Text Available The purpose of this paper is to present a new kind of analytical method, the so-called residual power series, to predict and represent the multiplicity of solutions to nonlinear boundary value problems of fractional order. The present method is capable of calculating all branches of solutions simultaneously, even if these multiple solutions are very close and thus rather difficult to distinguish even by numerical techniques. To verify the computational efficiency of the designed proposed technique, two nonlinear models are performed, one of them arises in mixed convection flows and the other one arises in heat transfer, which both admit multiple solutions. The results reveal that the method is very effective, straightforward, and powerful for formulating these multiple solutions.

Determination of hydrogen content by neutron techniques

International Nuclear Information System (INIS)

Santisteban, J.R.; Granada, J.R.; Mayer, R.E.

1997-01-01

The commonly available techniques for the determination of hydrogen dissolved in solids are usually destructive from the point of view of the sample. A new, nondestructive method for this kind of measurements has been developed at our laboratory, with the requirement of improved sensitivity for massive samples. This scattering method is based on the use of epithermal neutrons, and has been implemented through the design and construction of a spectrometer dedicated to that task. In addition, the traditional transmission method has been employed to determine hydrogen content in metals, using the full sub thermal and thermal neutron energy ranges. A pulsed neutron source based on an electron LINAC is employed, together with time-of-flight techniques. In this work we will present some results illustrative of the sensitivity achieved by these neutron techniques in different systems and for a wide range of hydrogen concentrations. (author) [es

Exact criteria for uniqueness and multiplicity of an nth order chemical reaction via catastrophe theory approach. [Determines boundaries between unique and multiple steady state conditions

Energy Technology Data Exchange (ETDEWEB)

Chang, H C; Calo, J M

1979-01-01

A simple, generalized technique for the exact determination of the boundaries between regions of unique and of multiple solutions to certain nonlinear equations was developed by applying catastrophe theory to the mapping of implicit and explicit functions. Its application to an nth order reaction in continuous stirred tank reactor (CSTR) yields exact, explicit expressions for the boundaries between regions of single and multiple steady states, expressed in terms of the dimensionless heat transfer coefficient and activation energy. An exact implicit expression for the boundaries between regions of uniqueness and multiplicity was also derived for an nth order reaction in a catalyst particle with an intraparticle concentration gradient and uniform temperature and is fully demonstrated for the first-order reaction. In addition, explicit criteria were developed by assuming the limits on d ln g/d ln q, where g is the effectiveness factor and q the Thiele modulus, proposed by van den Bosch and Luss.

[Investigation of RNA viral genome amplification by multiple displacement amplification technique].

Science.gov (United States)

Pang, Zheng; Li, Jian-Dong; Li, Chuan; Liang, Mi-Fang; Li, De-Xin

2013-06-01

In order to facilitate the detection of newly emerging or rare viral infectious diseases, a negative-strand RNA virus-severe fever with thrombocytopenia syndrome bunyavirus, and a positive-strand RNA virus-dengue virus, were used to investigate RNA viral genome unspecific amplification by multiple displacement amplification technique from clinical samples. Series of 10-fold diluted purified viral RNA were utilized as analog samples with different pathogen loads, after a series of reactions were sequentially processed, single-strand cDNA, double-strand cDNA, double-strand cDNA treated with ligation without or with supplemental RNA were generated, then a Phi29 DNA polymerase depended isothermal amplification was employed, and finally the target gene copies were detected by real time PCR assays to evaluate the amplification efficiencies of various methods. The results showed that multiple displacement amplification effects of single-strand or double-strand cDNA templates were limited, while the fold increases of double-strand cDNA templates treated with ligation could be up to 6 X 10(3), even 2 X 10(5) when supplemental RNA existed, and better results were obtained when viral RNA loads were lower. A RNA viral genome amplification system using multiple displacement amplification technique was established in this study and effective amplification of RNA viral genome with low load was achieved, which could provide a tool to synthesize adequate viral genome for multiplex pathogens detection.

Sample size determination in clinical trials with multiple endpoints

CERN Document Server

Sozu, Takashi; Hamasaki, Toshimitsu; Evans, Scott R

2015-01-01

This book integrates recent methodological developments for calculating the sample size and power in trials with more than one endpoint considered as multiple primary or co-primary, offering an important reference work for statisticians working in this area. The determination of sample size and the evaluation of power are fundamental and critical elements in the design of clinical trials. If the sample size is too small, important effects may go unnoticed; if the sample size is too large, it represents a waste of resources and unethically puts more participants at risk than necessary. Recently many clinical trials have been designed with more than one endpoint considered as multiple primary or co-primary, creating a need for new approaches to the design and analysis of these clinical trials. The book focuses on the evaluation of power and sample size determination when comparing the effects of two interventions in superiority clinical trials with multiple endpoints. Methods for sample size calculation in clin...

Implementation of Multiple Access Techniques Applicable for Maritime Satellite Communications

OpenAIRE

Stojce Dimov Ilcev

2013-01-01

In this paper are introduced fundamentals, characteristics, advantages and disadvantages of Multiple Access (MA) employed as transmission techniques in the Maritime Mobile Satellite Communications (MMSC) between ships and Coast Earth Station (CES) via Geostationary Earth Orbit (GEO) or Not-GEO satellite constellations. In fixed satellite communication, as a rule, especially in MMSC many users are active at the same time. The problem of simultaneous communications between many single or multip...

Direct Position Determination of Multiple Radio Signals

Directory of Open Access Journals (Sweden)

Weiss Anthony J

2005-01-01

Full Text Available The most common methods for position determination of radio signal emitters such as communications or radar transmitters are based on measuring a specified parameter such as angle of arrival (AOA or time of arrival (TOA of the signal. The measured parameters are then used to estimate the transmitter's location. Since the measurements are done at each base station independently, without using the constraint that the AOA/TOA estimates at different base stations should correspond to the same transmitter's location, this is a suboptimal location determination technique. Further, if the number of array elements at each base station is , and the signal waveforms are unknown, the number of cochannel simultaneous transmitters that can be localized by AOA is limited to . Also, most AOA algorithms fail when the sources are not well angularly separated. We propose a technique that uses exactly the same data as the common AOA methods but the position determination is direct. The proposed method can handle more than cochannel simultaneous signals. Although there are many stray parameters, only a two-dimensional search is required for a planar geometry. The technique provides a natural solution to the measurements sources association problem that is encountered in AOA-based location systems. In addition to new algorithms, we provide analytical performance analysis, Cramér-Rao bounds and Monte Carlo simulations. We demonstrate that the proposed approach frequently outperforms the traditional AOA methods for unknown as well as known signal waveforms.

A novel fiber-free technique for brain activity imaging in multiple freely behaving mice

Science.gov (United States)

Inagaki, Shigenori; Agetsuma, Masakazu; Nagai, Takeharu

2018-02-01

Brain functions and related psychiatric disorders have been investigated by recording electrophysiological field potential. When recording it, a conventional method requires fiber-based apparatus connected to the brain, which however hampers the simultaneous measurement in multiple animals (e.g. by a tangle of fibers). Here, we propose a fiber-free recording technique in conjunction with a ratiometric bioluminescent voltage indicator. Our method allows investigation of electrophysiological filed potential dynamics in multiple freely behaving animals simultaneously over a long time period. Therefore, this fiber-free technique opens up the way to investigate a new mechanism of brain function that governs social behaviors and animal-to-animal interaction.

Reducing BER of spectral-amplitude coding optical code-division multiple-access systems by single photodiode detection technique

Science.gov (United States)

Al-Khafaji, H. M. R.; Aljunid, S. A.; Amphawan, A.; Fadhil, H. A.; Safar, A. M.

2013-03-01

In this paper, we present a single photodiode detection (SPD) technique for spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems. The proposed technique eliminates both phase-induced intensity noise (PIIN) and multiple-access interference (MAI) in the optical domain. Analytical results show that for 35 simultaneous users transmitting at data rate of 622 Mbps, the bit-error rate (BER) = 1.4x10^-28 for SPD technique is much better compared to 9.3x10^-6 and 9.6x10^-3 for the modified-AND as well as the AND detection techniques, respectively. Moreover, we verified the improved performance afforded by the proposed technique using data transmission simulations.

Application of Soft Computing Techniques and Multiple Regression Models for CBR prediction of Soils

Directory of Open Access Journals (Sweden)

Fatimah Khaleel Ibrahim

2017-08-01

Full Text Available The techniques of soft computing technique such as Artificial Neutral Network (ANN have improved the predicting capability and have actually discovered application in Geotechnical engineering. The aim of this research is to utilize the soft computing technique and Multiple Regression Models (MLR for forecasting the California bearing ratio CBR( of soil from its index properties. The indicator of CBR for soil could be predicted from various soils characterizing parameters with the assist of MLR and ANN methods. The data base that collected from the laboratory by conducting tests on 86 soil samples that gathered from different projects in Basrah districts. Data gained from the experimental result were used in the regression models and soft computing techniques by using artificial neural network. The liquid limit, plastic index , modified compaction test and the CBR test have been determined. In this work, different ANN and MLR models were formulated with the different collection of inputs to be able to recognize their significance in the prediction of CBR. The strengths of the models that were developed been examined in terms of regression coefficient (R2, relative error (RE% and mean square error (MSE values. From the results of this paper, it absolutely was noticed that all the proposed ANN models perform better than that of MLR model. In a specific ANN model with all input parameters reveals better outcomes than other ANN models.

Uranium determination using atomic spectrometric techniques: An overview

International Nuclear Information System (INIS)

Santos, Juracir S.; Teixeira, Leonardo S.G.; Santos, Walter N.L. dos; Lemos, Valfredo A.; Godoy, Jose M.; Ferreira, Sergio L.C.

2010-01-01

This review focuses on the determination of uranium using spectroanalytical techniques that are aimed at total determination such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma optical emission spectrometry (ICP-OES); and inductively coupled plasma mass spectrometry (ICP-MS) that also enables the determination of uranium isotopes. The advantages and shortcomings related to interferences, precision, accuracy, sample type and equipment employed in the analysis are taken into account, as well as the complexity and costs (i.e., acquisition, operation and maintenance) associated with each of the techniques. Strategies to improve their performance that employ separation and/or preconcentration steps are considered, with an emphasis given to solid-phase extraction because of its advantages compared to other preconcentration procedures.

Development of XAFS Into a Structure Determination Technique

Science.gov (United States)

Stern, E. A.

After the detection of diffraction of x-rays by M. Laue in 1912, the technique was soon applied to structure determination by Bragg within a year. On the other hand, although the edge steps in X-Ray absorption were discovered even earlier by Barkla and both the near edge (XANES) and extended X-Ray fine structure (EXAFS) past the edge were detected by 1929, it still took over 40 years to realize the structure information contained in this X-Ray absorption fine structure (XAFS). To understand this delay a brief historical review of the development of the scientific ideas that transformed XAFS into the premiere technique for local structure determination is given. The development includes both advances in theoretical understanding and calculational capabilities, and in experimental facilities, especially synchrotron radiation sources. The present state of the XAFS technique and its capabilities are summarized.

Determination of the QCD color factor ratio CA/CF from the scale dependence of multiplicity in three jet events

CERN Document Server

Gary, J W

2000-01-01

I examine the determination of the QCD color factor ratio CA/CF from the scale evolution of particle multiplicity in e+e- three jet events. I fit an analytic expression for the multiplicity in three jet events to event samples generated with QCD multihadronic event generators. I demonstrate that a one parameter fit of CA/CF yields the expected result CA/CF=2.25 in the limit of asymptotically large energies if energy conservation is included in the calculation. In contrast, a two parameter fit of CA/CF and a constant offset to the gluon jet multiplicity, proposed in a recent study, does not yield CA/CF=2.25 in this limit. I apply the one parameter fit method to recently published data of the DELPHI experiment at LEP and determine the effective value of CA/CF from this technique, at the finite energy of the Z0 boson, to be 1.74+-0.03+-0.10, where the first uncertainty is statistical and the second is systematic.

Optimal assignment of multiple utilities in heat exchange networks

International Nuclear Information System (INIS)

Salama, A.I.A.

2009-01-01

Existing numerical geometry-based techniques, developed by [A.I.A. Salama, Numerical techniques for determining heat energy targets in pinch analysis, Computers and Chemical Engineering 29 (2005) 1861-1866; A.I.A. Salama, Determination of the optimal heat energy targets in heat pinch analysis using a geometry-based approach, Computers and Chemical Engineering 30 (2006) 758-764], have been extended to optimally assign multiple utilities in heat exchange network (HEN). These techniques utilize the horizontal shift between the cold composite curve (CC) and the stationary hot CC to determine the HEN optimal energy targets, grand composite curve (GCC), and the complement grand composite curve (CGCC). The proposed numerical technique developed in this paper is direct and simultaneously determines the optimal heat-energy targets and optimally assigns multiple utilities as compared with an existing technique based on sequential assignment of multiple utilities. The technique starts by arranging in an ascending order the HEN stream and target temperatures, and the resulting set is labelled T. Furthermore, the temperature sets where multiple utilities are introduced are arranged in an ascending order and are labelled T ic and T ih for the cold and hot sides, respectively. The graphical presentation of the results is facilitated by the insertion at each multiple-utility temperature a perturbed temperature equals the insertion temperature minus a small perturbation. Furthermore, using the heat exchanger network (HEN) minimum temperature-differential approach (ΔT min ) and stream heat-capacity flow rates, the presentation is facilitated by using the conventional temperature shift of the HEN CCs. The set of temperature-shifted stream and target temperatures and perturbed temperatures in the overlap range between the CCs is labelled T ol . Using T ol , a simple formula employing enthalpy-flow differences between the hot composite curve CC h and the cold composite curve CC c is

A sectional-splinting technique for impressing multiple implant units by eliminating the use of an open tray

Directory of Open Access Journals (Sweden)

Suryakant C. Deogade

2014-01-01

Full Text Available Since the inception of root form implant dentistry by P-I Branemark in the early 1980′s, so many technical advances have been put forward by several authors. However, the open tray impression technique is still performed for impressing multiple implant fixtures as it was first described in the original Branemark procedure manual. The most critical aspect for a successful implant-supported restoration is the passive and an accurate fit of superstructures to avoid preload and loading stresses. Splinting impression technique in multiple implants has gained popularity. Auto-polymerizing acrylic resin is among the most routinely practiced splinting material for multiple implant units. However, unfortunately, it exhibits shrinkage, which makes an impression quite inaccurate. This case report presents the solution to minimize the shrinkage of resin by utilizing sectional-splinting technique as advocated in the previous implant literature.

Determining the Number of Factors in P-Technique Factor Analysis

Science.gov (United States)

Lo, Lawrence L.; Molenaar, Peter C. M.; Rovine, Michael

2017-01-01

Determining the number of factors is a critical first step in exploratory factor analysis. Although various criteria and methods for determining the number of factors have been evaluated in the usual between-subjects R-technique factor analysis, there is still question of how these methods perform in within-subjects P-technique factor analysis. A…

Analysis of multiple instructional techniques on the understanding and retention of select mechanical topics

Science.gov (United States)

Fetsco, Sara Elizabeth

There are several topics that introductory physics students typically have difficulty understanding. The purpose of this thesis is to investigate if multiple instructional techniques will help students to better understand and retain the material. The three units analyzed in this study are graphing motion, projectile motion, and conservation of momentum. For each unit students were taught using new or altered instructional methods including online laboratory simulations, inquiry labs, and interactive demonstrations. Additionally, traditional instructional methods such as lecture and problem sets were retained. Effectiveness was measured through pre- and post-tests and student opinion surveys. Results suggest that incorporating multiple instructional techniques into teaching will improve student understanding and retention. Students stated that they learned well from all of the instructional methods used except the online simulations.

Preparation of thin actinide metal disks using a multiple disk casting technique

International Nuclear Information System (INIS)

Conner, W.V.

1975-01-01

A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting, This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (Auth.)

Preparation of thin actinide metal disks using a multiple disk casting technique

International Nuclear Information System (INIS)

Conner, W.V.

1976-01-01

A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting. This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (author)

Early cost estimating for road construction projects using multiple regression techniques

Directory of Open Access Journals (Sweden)

Ibrahim Mahamid

2011-12-01

Full Text Available The objective of this study is to develop early cost estimating models for road construction projects using multiple regression techniques, based on 131 sets of data collected in the West Bank in Palestine. As the cost estimates are required at early stages of a project, considerations were given to the fact that the input data for the required regression model could be easily extracted from sketches or scope definition of the project. 11 regression models are developed to estimate the total cost of road construction project in US dollar; 5 of them include bid quantities as input variables and 6 include road length and road width. The coefficient of determination r2 for the developed models is ranging from 0.92 to 0.98 which indicate that the predicted values from a forecast models fit with the real-life data. The values of the mean absolute percentage error (MAPE of the developed regression models are ranging from 13% to 31%, the results compare favorably with past researches which have shown that the estimate accuracy in the early stages of a project is between ±25% and ±50%.

The application of different techniques to determine activated sludge ...

African Journals Online (AJOL)

The application of different techniques to determine activated sludge kinetic parameters in a food industry wastewater. ... method) and a respirometric technique based on oxygen consumption measurements, were used to compare microbial parameters using a wastewater model system of a potato processing plant.

Impact of airway gas exchange on the multiple inert gas elimination technique: theory.

Science.gov (United States)

Anderson, Joseph C; Hlastala, Michael P

2010-03-01

The multiple inert gas elimination technique (MIGET) provides a method for estimating alveolar gas exchange efficiency. Six soluble inert gases are infused into a peripheral vein. Measurements of these gases in breath, arterial blood, and venous blood are interpreted using a mathematical model of alveolar gas exchange (MIGET model) that neglects airway gas exchange. A mathematical model describing airway and alveolar gas exchange predicts that two of these gases, ether and acetone, exchange primarily within the airways. To determine the effect of airway gas exchange on the MIGET, we selected two additional gases, toluene and m-dichlorobenzene, that have the same blood solubility as ether and acetone and minimize airway gas exchange via their low water solubility. The airway-alveolar gas exchange model simulated the exchange of toluene, m-dichlorobenzene, and the six MIGET gases under multiple conditions of alveolar ventilation-to-perfusion, VA/Q, heterogeneity. We increased the importance of airway gas exchange by changing bronchial blood flow, Qbr. From these simulations, we calculated the excretion and retention of the eight inert gases and divided the results into two groups: (1) the standard MIGET gases which included acetone and ether and (2) the modified MIGET gases which included toluene and m-dichlorobenzene. The MIGET mathematical model predicted distributions of ventilation and perfusion for each grouping of gases and multiple perturbations of VA/Q and Qbr. Using the modified MIGET gases, MIGET predicted a smaller dead space fraction, greater mean VA, greater log(SDVA), and more closely matched the imposed VA distribution than that using the standard MIGET gases. Perfusion distributions were relatively unaffected.

Multiple predictor smoothing methods for sensitivity analysis: Description of techniques

International Nuclear Information System (INIS)

Storlie, Curtis B.; Helton, Jon C.

2008-01-01

The use of multiple predictor smoothing methods in sampling-based sensitivity analyses of complex models is investigated. Specifically, sensitivity analysis procedures based on smoothing methods employing the stepwise application of the following nonparametric regression techniques are described: (i) locally weighted regression (LOESS), (ii) additive models, (iii) projection pursuit regression, and (iv) recursive partitioning regression. Then, in the second and concluding part of this presentation, the indicated procedures are illustrated with both simple test problems and results from a performance assessment for a radioactive waste disposal facility (i.e., the Waste Isolation Pilot Plant). As shown by the example illustrations, the use of smoothing procedures based on nonparametric regression techniques can yield more informative sensitivity analysis results than can be obtained with more traditional sensitivity analysis procedures based on linear regression, rank regression or quadratic regression when nonlinear relationships between model inputs and model predictions are present

Super-Resolution Enhancement From Multiple Overlapping Images: A Fractional Area Technique

Science.gov (United States)

Michaels, Joshua A.

With the availability of large quantities of relatively low-resolution data from several decades of space borne imaging, methods of creating an accurate, higher-resolution image from the multiple lower-resolution images (i.e. super-resolution), have been developed almost since such imagery has been around. The fractional-area super-resolution technique developed in this thesis has never before been documented. Satellite orbits, like Landsat, have a quantifiable variation, which means each image is not centered on the exact same spot more than once and the overlapping information from these multiple images may be used for super-resolution enhancement. By splitting a single initial pixel into many smaller, desired pixels, a relationship can be created between them using the ratio of the area within the initial pixel. The ideal goal for this technique is to obtain smaller pixels with exact values and no error, yielding a better potential result than those methods that yield interpolated pixel values with consequential loss of spatial resolution. A Fortran 95 program was developed to perform all calculations associated with the fractional-area super-resolution technique. The fractional areas are calculated using traditional trigonometry and coordinate geometry and Linear Algebra Package (LAPACK; Anderson et al., 1999) is used to solve for the higher-resolution pixel values. In order to demonstrate proof-of-concept, a synthetic dataset was created using the intrinsic Fortran random number generator and Adobe Illustrator CS4 (for geometry). To test the real-life application, digital pictures from a Sony DSC-S600 digital point-and-shoot camera with a tripod were taken of a large US geological map under fluorescent lighting. While the fractional-area super-resolution technique works in perfect synthetic conditions, it did not successfully produce a reasonable or consistent solution in the digital photograph enhancement test. The prohibitive amount of processing time (up to

Initial Clinical Experience in Multiple Myeloma Staging by Means of Whole-Body Resonance Techniques

International Nuclear Information System (INIS)

Gallego, J. I.; Concepcion, L.; Alonso, S.; Sanchez, B.; Manzi, F.

2003-01-01

To develop a magnetic resonance (MR) exploratory technique equivalent to serial bone X-ray, and to compare their precision in the staging of multiple myeloma (MM) patients. Multiple acquisition T1-weights TSE and STIR sequences in the coronal plane were performed. Ten healthy volunteers and 11 multiple myeloma diagnosed patients were included. The visualization of bony structures was particularly noted,with special attention given to those which would normally be included in a serial bone X-ray. In the case of the patients, a comparison was made between diagnostic capacities of the MR sequences. MR highlighters significantly more (p<0.05) bony elements than did the serial bone X-ray. This was greatly due to a sequential displacement of the scanner bed, allowing for field-of-views which were minimally from head to third proximal of the leg. Magnetic resonance detected a significantly higher number (p<0.05) of lesions. It was, in turn, capable of revealing greater lesion extensions, even to the point of implying staging classification changes in 18% of the patients. The utilization of whole-body MR techniques in multiple myeloma patients is feasible and clinically beneficial. MR is both more sensitive and more specific than serial bone X-ray for evaluation of bony lesions in MM. It is currently serving as a valid alternative in a growing numbers of patients. (Author) 10 refs

On functional determinants of matrix differential operators with multiple zero modes

NARCIS (Netherlands)

Falco, G.M.; Fedorenko, Andrey A; Gruzberg, Ilya A

2017-01-01

We generalize the method of computing functional determinants with a single excluded zero eigenvalue developed by McKane and Tarlie to differential operators with multiple zero eigenvalues. We derive general formulas for such functional determinants of $r\\times r$ matrix second order differential

Endoscopic treatment of multilocular walled-off pancreatic necrosis with the multiple transluminal gateway technique.

Science.gov (United States)

Jagielski, Mateusz; Smoczyński, Marian; Adrych, Krystian

2017-06-01

The development of minimally invasive techniques allowed access to the necrotic cavity through transperitoneal, retroperitoneal, transmural and transpapillary routes. The choice of access to walled-off pancreatic necrosis (WOPN) should depend not only on the spread of necrosis, but also on the experience of the clinical center. Herein we describe treatment of a patient with multilocular symptomatic walled-off pancreatic necrosis using minimally invasive techniques. The single transmural access (single transluminal gateway technique - SGT) to the necrotic collection of the patient was ineffective. The second gastrocystostomy was performed using the same minimally invasive technique as an extra way of access to the necrosis (multiple transluminal gateway technique - MTGT). In the described case the performance of the new technique consisting in endoscopic multiplexing transmural access (MTGT) was effective enough and led to complete recovery of the patient.

Determining Plutonium Mass in Spent Fuel with Nondestructive Assay Techniques -- Preliminary Modeling Results Emphasizing Integration among Techniques

International Nuclear Information System (INIS)

Tobin, S.J.; Fensin, M.L.; Ludewigt, B.A.; Menlove, H.O.; Quiter, B.J.; Sandoval, N.P.; Swinhoe, M.T.; Thompson, S.J.

2009-01-01

There are a variety of motivations for quantifying Pu in spent (used) fuel assemblies by means of nondestructive assay (NDA) including the following: strengthen the capabilities of the International Atomic Energy Agencies to safeguards nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at reprocessing facilities and providing quantitative input to burnup credit determination for repositories. For the purpose of determining the Pu mass in spent fuel assemblies, twelve NDA techniques were identified that provide information about the composition of an assembly. A key point motivating the present research path is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the elemental Pu mass of an assembly and (2) detecting the diversion of a significant number of pins. As such, the focus of this work is determining how to best integrate 2 or 3 techniques into a system that can quantify elemental Pu and to assess how well this system can detect material diversion. Furthermore, it is important economically to down-select among the various techniques before advancing to the experimental phase. In order to achieve this dual goal of integration and down-selection, a Monte Carlo library of PWR assemblies was created and is described in another paper at Global 2009 (Fensin et al.). The research presented here emphasizes integration among techniques. An overview of a five year research plan starting in 2009 is given. Preliminary modeling results for the Monte Carlo assembly library are presented for 3 NDA techniques: Delayed Neutrons, Differential Die-Away, and Nuclear Resonance Fluorescence. As part of the focus on integration, the concept of 'Pu isotopic correlation' is discussed and the role of cooling time determination.

Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique.

Science.gov (United States)

Kumar, Alok; Sharma, Dk; Sibi, Maj E; Datta, Barun; Gogoi, Biraj

2014-01-01

The established methods of nerve location were based on either proper motor response on nerve stimulation (NS) or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60), or ultrasound guidance (group US, n = 60) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. The median (range) number of skin punctures were 2 (2-4) in group US and 3 (2-5) in group NS (P =0.27). Insufficient block was observed in three patient (5%) of group US and four patients (6.67%) of group NS (P > =0.35). Patient acceptance was similarly good in the two groups. Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique

Directory of Open Access Journals (Sweden)

Alok Kumar

2014-01-01

Full Text Available Background: The established methods of nerve location were based on either proper motor response on nerve stimulation (NS or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. Methods : A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60, or ultrasound guidance (group US, n = 60 for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. Results: The median (range number of skin punctures were 2 (2-4 in group US and 3 (2-5 in group NS (P =0.27. Insufficient block was observed in three patient (5% of group US and four patients (6.67% of group NS (P > =0.35. Patient acceptance was similarly good in the two groups. Conclusion: Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

A Technique of Fuzzy C-Mean in Multiple Linear Regression Model toward Paddy Yield

Science.gov (United States)

Syazwan Wahab, Nur; Saifullah Rusiman, Mohd; Mohamad, Mahathir; Amira Azmi, Nur; Che Him, Norziha; Ghazali Kamardan, M.; Ali, Maselan

2018-04-01

In this paper, we propose a hybrid model which is a combination of multiple linear regression model and fuzzy c-means method. This research involved a relationship between 20 variates of the top soil that are analyzed prior to planting of paddy yields at standard fertilizer rates. Data used were from the multi-location trials for rice carried out by MARDI at major paddy granary in Peninsular Malaysia during the period from 2009 to 2012. Missing observations were estimated using mean estimation techniques. The data were analyzed using multiple linear regression model and a combination of multiple linear regression model and fuzzy c-means method. Analysis of normality and multicollinearity indicate that the data is normally scattered without multicollinearity among independent variables. Analysis of fuzzy c-means cluster the yield of paddy into two clusters before the multiple linear regression model can be used. The comparison between two method indicate that the hybrid of multiple linear regression model and fuzzy c-means method outperform the multiple linear regression model with lower value of mean square error.

Comparison of static conformal field with multiple noncoplanar arc techniques for stereotactic radiosurgery or stereotactic radiotherapy

International Nuclear Information System (INIS)

Hamilton, Russell J.; Kuchnir, Franca T.; Sweeney, Patrick; Rubin, Steven J.; Dujovny, Manuel; Pelizzari, Charles A.; Chen, George T. Y.

1995-01-01

Purpose: Compare the use of static conformal fields with the use of multiple noncoplanar arcs for stereotactic radiosurgery or stereotactic radiotherapy treatment of intracranial lesions. Evaluate the efficacy of these treatment techniques to deliver dose distributions comparable to those considered acceptable in current radiotherapy practice. Methods and Materials: A previously treated radiosurgery case of a patient presenting with an irregularly shaped intracranial lesion was selected. Using a three-dimensional (3D) treatment-planning system, treatment plans using a single isocenter multiple noncoplanar arc technique and multiple noncoplanar conformal static fields were generated. Isodose distributions and dose volume histograms (DVHs) were computed for each treatment plan. We required that the 80% (of maximum dose) isodose surface enclose the target volume for all treatment plans. The prescription isodose was set equal to the minimum target isodose. The DVHs were analyzed to evaluate and compare the different treatment plans. Results: The dose distribution in the target volume becomes more uniform as the number of conformal fields increases. The volume of normal tissue receiving low doses (> 10% of prescription isodose) increases as the number of static fields increases. The single isocenter multiple arc plan treats the greatest volume of normal tissue to low doses, approximately 1.6 times more volume than that treated by four static fields. The volume of normal tissue receiving high (> 90% of prescription isodose) and intermediate (> 50% of prescription isodose) doses decreases by 29 and 22%, respectively, as the number of static fields is increased from four to eight. Increasing the number of static fields to 12 only further reduces the high and intermediate dose volumes by 10 and 6%, respectively. The volume receiving the prescription dose is more than 3.5 times larger than the target volume for all treatment plans. Conclusions: Use of a multiple noncoplanar

System for prediction and determination of the sub critic multiplication

International Nuclear Information System (INIS)

Martinez, Aquilino S.; Pereira, Valmir; Silva, Fernando C. da

1997-01-01

It is presented a concept of a system which may be used to calculate and anticipate the subcritical multiplication of a PWR nuclear power plant. The system is divided into two different modules. The first module allows the theoretical prediction of the subcritical multiplication factor through the solution of the multigroup diffusion equation. The second module determines this factor based on the data acquired from the neutron detectors of a NPP external nuclear detection system. (author). 3 refs., 3 figs., 2 tabs

Building a new predictor for multiple linear regression technique-based corrective maintenance turnaround time.

Science.gov (United States)

Cruz, Antonio M; Barr, Cameron; Puñales-Pozo, Elsa

2008-01-01

This research's main goals were to build a predictor for a turnaround time (TAT) indicator for estimating its values and use a numerical clustering technique for finding possible causes of undesirable TAT values. The following stages were used: domain understanding, data characterisation and sample reduction and insight characterisation. Building the TAT indicator multiple linear regression predictor and clustering techniques were used for improving corrective maintenance task efficiency in a clinical engineering department (CED). The indicator being studied was turnaround time (TAT). Multiple linear regression was used for building a predictive TAT value model. The variables contributing to such model were clinical engineering department response time (CE(rt), 0.415 positive coefficient), stock service response time (Stock(rt), 0.734 positive coefficient), priority level (0.21 positive coefficient) and service time (0.06 positive coefficient). The regression process showed heavy reliance on Stock(rt), CE(rt) and priority, in that order. Clustering techniques revealed the main causes of high TAT values. This examination has provided a means for analysing current technical service quality and effectiveness. In doing so, it has demonstrated a process for identifying areas and methods of improvement and a model against which to analyse these methods' effectiveness.

Determining Sample Size for Accurate Estimation of the Squared Multiple Correlation Coefficient.

Science.gov (United States)

Algina, James; Olejnik, Stephen

2000-01-01

Discusses determining sample size for estimation of the squared multiple correlation coefficient and presents regression equations that permit determination of the sample size for estimating this parameter for up to 20 predictor variables. (SLD)

Whitelists Based Multiple Filtering Techniques in SCADA Sensor Networks

Directory of Open Access Journals (Sweden)

DongHo Kang

2014-01-01

Full Text Available Internet of Things (IoT consists of several tiny devices connected together to form a collaborative computing environment. Recently IoT technologies begin to merge with supervisory control and data acquisition (SCADA sensor networks to more efficiently gather and analyze real-time data from sensors in industrial environments. But SCADA sensor networks are becoming more and more vulnerable to cyber-attacks due to increased connectivity. To safely adopt IoT technologies in the SCADA environments, it is important to improve the security of SCADA sensor networks. In this paper we propose a multiple filtering technique based on whitelists to detect illegitimate packets. Our proposed system detects the traffic of network and application protocol attacks with a set of whitelists collected from normal traffic.

Blower-door techniques for measuring interzonal leakage

Energy Technology Data Exchange (ETDEWEB)

Hult, Erin L.; Sherman, Max H.; Walker, Iain

2013-01-01

Abstract The standard blower door test methods, such as ASTM E779, describe how to use a single blower door to determine the total leakage of a single-zone structure such as a detached single-family home. There are no standard test methods for measuring interzonal leakage in a two-zone or multi-zone building envelope such as might be encountered in with an attached garage or in a multifamily building. Some practitioners have been using techniques that involve making multiple measurements with a single blower door as well as combined measurements using multiple blower doors. Even for just two zones there are dozens of combinations of one-door and two-door test protocols that could conceivably be used to determine the interzonal air tightness. We examined many of these two-zone configurations using both simulation and measured data to estimate the accuracy and precision of each technique for realistic measurement scenarios. We also considered the impact of taking measurements at a single pressure versus over multiple pressures. We compared the various techniques and evaluated them for specific uses. Some techniques work better in one leakage regime; some are more sensitive to wind and other noise; some are more suited to determining only a subset of the leakage values. This paper makes recommendations on which techniques to use or not use for various cases and provides data that could be used to develop future test methods.

Determination of 226Ra contamination depth in soil using the multiple photopeaks method

International Nuclear Information System (INIS)

Haddad, Kh.; Al-Masri, M.S.; Doubal, A.W.

2014-01-01

Radioactive contamination presents a diverse range of challenges in many industries. Determination of radioactive contamination depth plays a vital role in the assessment of contaminated sites, because it can be used to estimate the activity content. It is determined traditionally by measuring the activity distributions along the depth. This approach gives accurate results, but it is time consuming, lengthy and costly. The multiple photopeaks method was developed in this work for 226 Ra contamination depth determination in a NORM contaminated soil using in-situ gamma spectrometry. The developed method bases on linear correlation between the attenuation ratio of different gamma lines emitted by 214 Bi and the 226 Ra contamination depth. Although this method is approximate, but it is much simpler, faster and cheaper than the traditional one. This method can be applied for any case of multiple gamma emitter contaminant. -- Highlights: • The multiple photopeaks method was developed for 226 Ra contamination depth determination using in-situ gamma spectrometry. • The method bases on linear correlation between the attenuation ratio of 214 Bi gamma lines and 226 Ra contamination depth. • This method is simpler, faster and cheaper than the traditional one, it can be applied for any multiple gamma contaminant

Datafish Multiphase Data Mining Technique to Match Multiple Mutually Inclusive Independent Variables in Large PACS Databases.

Science.gov (United States)

Kelley, Brendan P; Klochko, Chad; Halabi, Safwan; Siegal, Daniel

2016-06-01

Retrospective data mining has tremendous potential in research but is time and labor intensive. Current data mining software contains many advanced search features but is limited in its ability to identify patients who meet multiple complex independent search criteria. Simple keyword and Boolean search techniques are ineffective when more complex searches are required, or when a search for multiple mutually inclusive variables becomes important. This is particularly true when trying to identify patients with a set of specific radiologic findings or proximity in time across multiple different imaging modalities. Another challenge that arises in retrospective data mining is that much variation still exists in how image findings are described in radiology reports. We present an algorithmic approach to solve this problem and describe a specific use case scenario in which we applied our technique to a real-world data set in order to identify patients who matched several independent variables in our institution's picture archiving and communication systems (PACS) database.

Multiple sensitive estimation and optimal sample size allocation in the item sum technique.

Science.gov (United States)

Perri, Pier Francesco; Rueda García, María Del Mar; Cobo Rodríguez, Beatriz

2018-01-01

For surveys of sensitive issues in life sciences, statistical procedures can be used to reduce nonresponse and social desirability response bias. Both of these phenomena provoke nonsampling errors that are difficult to deal with and can seriously flaw the validity of the analyses. The item sum technique (IST) is a very recent indirect questioning method derived from the item count technique that seeks to procure more reliable responses on quantitative items than direct questioning while preserving respondents' anonymity. This article addresses two important questions concerning the IST: (i) its implementation when two or more sensitive variables are investigated and efficient estimates of their unknown population means are required; (ii) the determination of the optimal sample size to achieve minimum variance estimates. These aspects are of great relevance for survey practitioners engaged in sensitive research and, to the best of our knowledge, were not studied so far. In this article, theoretical results for multiple estimation and optimal allocation are obtained under a generic sampling design and then particularized to simple random sampling and stratified sampling designs. Theoretical considerations are integrated with a number of simulation studies based on data from two real surveys and conducted to ascertain the efficiency gain derived from optimal allocation in different situations. One of the surveys concerns cannabis consumption among university students. Our findings highlight some methodological advances that can be obtained in life sciences IST surveys when optimal allocation is achieved. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoelectrode Fabrication of Dye-Sensitized Nanosolar Cells Using Multiple Spray Coating Technique

Directory of Open Access Journals (Sweden)

Chien-Chih Chen

2013-01-01

Full Text Available This paper presents a spray coating technique for fabricating nanoporous film of photoelectrode in dye-sensitized nanosolar cells (DSSCs. Spray coating can quickly fabricate nanoporous film of the photoelectrode with lower cost, which can further help the DSSCs to be commercialized in the future. This paper analyzed photoelectric conversion efficiency of the DSSCs using spray coated photoelectrode in comparison with the photoelectrode made with the doctor blade method. Spray coating can easily control transmittance of the photoelectrode through the multiple spray coating process. This work mainly used a dispersant with help of ultrasonic oscillation to prepare the required nano-TiO2 solution and then sprayed it on the ITO glasses. In this work, a motor-operated conveyor belt was built to transport the ITO glasses automatically for multiple spray coating and drying alternately. Experiments used transmittance of the photoelectrode as a fabrication parameter to analyze photoelectric conversion efficiency of the DSSCs. The influencing factors of the photoelectrode transmittance during fabrication are the spray flow rate, the spray distance, and the moving speed of the conveyor belt. The results show that DSSC with the photoelectrode transmittance of ca. 68.0 ± 1.5% and coated by the spray coating technique has the best photoelectric conversion efficiency in this work.

Development of a multiple immunoaffinity column for simultaneous determination of multiple mycotoxins in feeds using UPLC-MS/MS.

Science.gov (United States)

Hu, Xiaofeng; Hu, Rui; Zhang, Zhaowei; Li, Peiwu; Zhang, Qi; Wang, Min

2016-09-01

A sensitive and specific immunoaffinity column to clean up and isolate multiple mycotoxins was developed along with a rapid one-step sample preparation procedure for ultra-performance liquid chromatography-tandem mass spectrometry analysis. Monoclonal antibodies against aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, zearalenone, ochratoxin A, sterigmatocystin, and T-2 toxin were coupled to microbeads for mycotoxin purification. We optimized a homogenization and extraction procedure as well as column loading and elution conditions to maximize recoveries from complex feed matrices. This method allowed rapid, simple, and simultaneous determination of mycotoxins in feeds with a single chromatographic run. Detection limits for these toxins ranged from 0.006 to 0.12 ng mL(-1), and quantitation limits ranged from 0.06 to 0.75 ng mL(-1). Concentration curves were linear from 0.12 to 40 μg kg(-1) with correlation coefficients of R (2) > 0.99. Intra-assay and inter-assay comparisons indicated excellent repeatability and reproducibility of the multiple immunoaffinity columns. As a proof of principle, 80 feed samples were tested and several contained multiple mycotoxins. This method is sensitive, rapid, and durable enough for multiple mycotoxin determinations that fulfill European Union and Chinese testing criteria.

Nuclear techniques for the determination of protein content in plant material

International Nuclear Information System (INIS)

Niemann, E.G.

1980-01-01

Elemental analysis for nitrogen has gained in importance over the last decade, as protein improvement and protein control in food and feed has come to be recognized as one of the most promising ways of overcoming deficiencies in food production and distribution. The need for fast and reliable screening methods has stimulated the improvement and automation of classic chemical methods for protein and nitrogen determination and, on the other hand, the development and adaptation of physical and nuclear analysis procedures. After about ten years of work this process has come to a stage where a critical evaluation of the existing methods seems necessary and justified. The present review describes and compares nuclear techniques for nitrogen determination in plant material. These include activation analysis techniques, based on various nuclear reactions, initiated by fast and thermal neutrons, energetic photons, protons, deuterons and α-particles. Other nuclear methods have been applied for nitrogen or protein determination, like ESCA, PIXE, NMR, NQR and Moessbauer spectroscopy, some of which possess good potential as screening methods. Depending on the needs, such as sample size, analysis rate and postulated accuracy, different nuclear techniques may be selected today for nitrogen screening. Some of the techniques discussed have additional potential for carbon or oxygen determination, for measuring depth or lateral N distribution, or for the recognition of the type of chemical N binding. Though most if not all techniques need further development for routine application, they are able to compete with chemical techniques in cost, rate and accuracy. (author)

Determination of contraband using fast neutron resonance technique

Energy Technology Data Exchange (ETDEWEB)

Bae, J.; Whang, J. [Kyunghee Univ., Dept. of Nuclear Engineering, Yongin-shi, Kyongki-do (Korea, Republic of)

2004-07-01

'Full-text:' Resonance technique with monoenergetic fast neutron beam is able to map features in bulk samples in a way that is sensitive to their elemental composition. It has a number of potential applications, for example, in mining and in the detection of contraband materials such as illicit drugs and explosives. By moving around the neutron detector experiences neutrons in the form of narrow line beam with different energies as the angle to the neutron source changes. Projection data was obtained using the Monte Carlo code MCNP4C. Therefore the fast neutrons scattered from an unknown object are used to determine the elemental content of the object and hence lead to its identification. Scattered features simulated for various test materials are analyzed using the HEPRO program system (PTB, Braunschweig) to determine the atom weight fractions for H. C. N, O and other elements in the materials. Atom weight fractions determined from scattering features are insensitive to neutron interactions in interfering materials surrounding the object. The simulations demonstrate that the fast neutron resonance technique (FNRT) provides reliable elemental characterization of bulk materials and has the necessary sensitivity to distinguish between drugs, explosives and other materials. (author)

Determination of contraband using fast neutron resonance technique

International Nuclear Information System (INIS)

Bae, J.; Whang, J.

2004-01-01

'Full-text:' Resonance technique with monoenergetic fast neutron beam is able to map features in bulk samples in a way that is sensitive to their elemental composition. It has a number of potential applications, for example, in mining and in the detection of contraband materials such as illicit drugs and explosives. By moving around the neutron detector experiences neutrons in the form of narrow line beam with different energies as the angle to the neutron source changes. Projection data was obtained using the Monte Carlo code MCNP4C. Therefore the fast neutrons scattered from an unknown object are used to determine the elemental content of the object and hence lead to its identification. Scattered features simulated for various test materials are analyzed using the HEPRO program system (PTB, Braunschweig) to determine the atom weight fractions for H. C. N, O and other elements in the materials. Atom weight fractions determined from scattering features are insensitive to neutron interactions in interfering materials surrounding the object. The simulations demonstrate that the fast neutron resonance technique (FNRT) provides reliable elemental characterization of bulk materials and has the necessary sensitivity to distinguish between drugs, explosives and other materials. (author)

Key issues of multiple access technique for LEO satellite communication systems

Institute of Scientific and Technical Information of China (English)

温萍萍; 顾学迈

2004-01-01

The large carrier frequency shift caused by the high-speed movement of satellite (Doppler effects) and the propagation delay on the up-down link are very critical issues in an LEO satellite communication system, which affects both the selection and the implementation of a suitable access method. A Doppler based multiple access technique is used here to control the flow and an MPRMA-HS protocol is proposed for the application in LEO satellite communication systems. The extended simulation trials prove that the proposed scheme seems to be a very promising access method.

3-D thermal weight function method and multiple virtual crack extension technique for thermal shock problems

International Nuclear Information System (INIS)

Lu Yanlin; Zhou Xiao; Qu Jiadi; Dou Yikang; He Yinbiao

2005-01-01

An efficient scheme, 3-D thermal weight function (TWF) method, and a novel numerical technique, multiple virtual crack extension (MVCE) technique, were developed for determination of histories of transient stress intensity factor (SIF) distributions along 3-D crack fronts of a body subjected to thermal shock. The TWF is a universal function, which is dependent only on the crack configuration and body geometry. TWF is independent of time during thermal shock, so the whole history of transient SIF distributions along crack fronts can be directly calculated through integration of the products of TWF and transient temperatures and temperature gradients. The repeated determinations of the distributions of stresses (or displacements) fields for individual time instants are thus avoided in the TWF method. An expression of the basic equation for the 3-D universal weight function method for Mode I in an isotropic elastic body is derived. This equation can also be derived from Bueckner-Rice's 3-D WF formulations in the framework of transformation strain. It can be understood from this equation that the so-called thermal WF is in fact coincident with the mechanical WF except for some constants of elasticity. The details and formulations of the MVCE technique are given for elliptical cracks. The MVCE technique possesses several advantages. The specially selected linearly independent VCE modes can directly be used as shape functions for the interpolation of unknown SIFs. As a result, the coefficient matrix of the final system of equations in the MVCE method is a triple-diagonal matrix and the values of the coefficients on the main diagonal are large. The system of equations has good numerical properties. The number of linearly independent VCE modes that can be introduced in a problem is unlimited. Complex situations in which the SIFs vary dramatically along crack fronts can be numerically well simulated by the MVCE technique. An integrated system of programs for solving the

Retrospective Study on Laser Treatment of Oral Vascular Lesions Using the "Leopard Technique": The Multiple Spot Irradiation Technique with a Single-Pulsed Wave.

Science.gov (United States)

Miyazaki, Hidetaka; Ohshiro, Takafumi; Romeo, Umberto; Noguchi, Tadahide; Maruoka, Yutaka; Gaimari, Gianfranco; Tomov, Georgi; Wada, Yoshitaka; Tanaka, Kae; Ohshiro, Toshio; Asamura, Shinichi

2018-06-01

This study aimed to retrospectively evaluate the efficacy and safety of laser treatment of oral vascular lesions using the multiple spot irradiation technique with a single-pulsed wave. In laser therapy for vascular lesions, heat accumulation induced by excessive irradiation can cause adverse events postoperatively, including ulcer formation, resultant scarring, and severe pain. To prevent heat accumulation and side effects, we have applied a multiple pulsed spot irradiation technique, the so-called "leopard technique" (LT) to oral vascular lesions. This approach was originally proposed for laser treatment of nevi. It can avoid thermal concentration at the same spot and spare the epithelium, which promotes smooth healing. The goal of the study was to evaluate this procedure and treatment outcomes. The subjects were 46 patients with 47 oral vascular lesions treated with the LT using a Nd:YAG laser (1064 nm), including 24 thick lesions treated using a combination of the LT and intralesional photocoagulation. All treatment outcomes were satisfactory without serious complications such as deep ulcer formation, scarring, bleeding, or severe swelling. Laser therapy with the LT is a promising less-invasive treatment for oral vascular lesions.

Recent Developments in the Speciation and Determination of Mercury Using Various Analytical Techniques

Directory of Open Access Journals (Sweden)

Lakshmi Narayana Suvarapu

2015-01-01

Full Text Available This paper reviews the speciation and determination of mercury by various analytical techniques such as atomic absorption spectrometry, voltammetry, inductively coupled plasma techniques, spectrophotometry, spectrofluorometry, high performance liquid chromatography, and gas chromatography. Approximately 126 research papers on the speciation and determination of mercury by various analytical techniques published in international journals since 2013 are reviewed.

Sample size determination for equivalence assessment with multiple endpoints.

Science.gov (United States)

Sun, Anna; Dong, Xiaoyu; Tsong, Yi

2014-01-01

Equivalence assessment between a reference and test treatment is often conducted by two one-sided tests (TOST). The corresponding power function and sample size determination can be derived from a joint distribution of the sample mean and sample variance. When an equivalence trial is designed with multiple endpoints, it often involves several sets of two one-sided tests. A naive approach for sample size determination in this case would select the largest sample size required for each endpoint. However, such a method ignores the correlation among endpoints. With the objective to reject all endpoints and when the endpoints are uncorrelated, the power function is the production of all power functions for individual endpoints. With correlated endpoints, the sample size and power should be adjusted for such a correlation. In this article, we propose the exact power function for the equivalence test with multiple endpoints adjusted for correlation under both crossover and parallel designs. We further discuss the differences in sample size for the naive method without and with correlation adjusted methods and illustrate with an in vivo bioequivalence crossover study with area under the curve (AUC) and maximum concentration (Cmax) as the two endpoints.

Investigation of multiple visualisation techniques and dynamic queries in conjunction with direct sonification to support the browsing of audio resources

OpenAIRE

Brazil, Eoin

2003-01-01

non-peer-reviewed In this thesis, a prototype system for the browsing of audio resources was developed and an initial evaluation of this system was performed. The main contributions of this thesis are dynamic queries and multiple visualisation techniques in conjunction with direct sonification. Dynamic queries are queries that provide immediate feedback while maintaining consistency between the queries themselves and the graphical/auditory display. The multiple visualisation techniques are...

Synthetic Minority Oversampling Technique and Fractal Dimension for Identifying Multiple Sclerosis

Science.gov (United States)

Zhang, Yu-Dong; Zhang, Yin; Phillips, Preetha; Dong, Zhengchao; Wang, Shuihua

Multiple sclerosis (MS) is a severe brain disease. Early detection can provide timely treatment. Fractal dimension can provide statistical index of pattern changes with scale at a given brain image. In this study, our team used susceptibility weighted imaging technique to obtain 676 MS slices and 880 healthy slices. We used synthetic minority oversampling technique to process the unbalanced dataset. Then, we used Canny edge detector to extract distinguishing edges. The Minkowski-Bouligand dimension was a fractal dimension estimation method and used to extract features from edges. Single hidden layer neural network was used as the classifier. Finally, we proposed a three-segment representation biogeography-based optimization to train the classifier. Our method achieved a sensitivity of 97.78±1.29%, a specificity of 97.82±1.60% and an accuracy of 97.80±1.40%. The proposed method is superior to seven state-of-the-art methods in terms of sensitivity and accuracy.

Code division multiple-access techniques in optical fiber networks. II - Systems performance analysis

Science.gov (United States)

Salehi, Jawad A.; Brackett, Charles A.

1989-08-01

A technique based on optical orthogonal codes was presented by Salehi (1989) to establish a fiber-optic code-division multiple-access (FO-CDMA) communications system. The results are used to derive the bit error rate of the proposed FO-CDMA system as a function of data rate, code length, code weight, number of users, and receiver threshold. The performance characteristics for a variety of system parameters are discussed. A means of reducing the effective multiple-access interference signal by placing an optical hard-limiter at the front end of the desired optical correlator is presented. Performance calculations are shown for the FO-CDMA with an ideal optical hard-limiter, and it is shown that using a optical hard-limiter would, in general, improve system performance.

[Application of Multiple Genetic Markers in a Case of Determination of Half Sibling].

Science.gov (United States)

Yang, Xue; Shi, Mei-sen; Yuan, Li; Lu, Di

2016-02-01

A case of half sibling was determined with multiple genetic markers, which could be potentially applied for determination of half sibling relationship from same father. Half sibling relationship was detected by 39 autosomal STR genetic markers, 23 Y-chromosomal STR genetic markers and 12 X -chromosomal STR genetic markers among ZHAO -1, ZHAO -2, ZHAO -3, ZHAO -4, and ZHAO-5. According to autosomal STR, Y-STR and X-STR genotyping results, it was determined that ZHAO-4 (alleged half sibling) was unrelated with ZHAO-1 and ZHAO-2; however, ZHAO-3 (alleged half sibling), ZHAO-5 (alleged half sibling) shared same genetic profile with ZHAO-1, and ZHAO-2 from same father. It is reliable to use multiple genetic markers and family gene reconstruction to determine half sibling relationship from same father, but it is difficult to determination by calculating half sibling index with ITO and discriminant functions.

Single, double or multiple-injection techniques for non-ultrasound guided axillary brachial plexus block in adults undergoing surgery of the lower arm.

Science.gov (United States)

Chin, Ki Jinn; Alakkad, Husni; Cubillos, Javier E

2013-08-08

Regional anaesthesia comprising axillary block of the brachial plexus is a common anaesthetic technique for distal upper limb surgery. This is an update of a review first published in 2006 and updated in 2011. To compare the relative effects (benefits and harms) of three injection techniques (single, double and multiple) of axillary block of the brachial plexus for distal upper extremity surgery. We considered these effects primarily in terms of anaesthetic effectiveness; the complication rate (neurological and vascular); and pain and discomfort caused by performance of the block. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE and reference lists of trials. We contacted trial authors. The date of the last search was March 2013 (updated from March 2011). We included randomized controlled trials that compared double with single-injection techniques, multiple with single-injection techniques, or multiple with double-injection techniques for axillary block in adults undergoing surgery of the distal upper limb. We excluded trials using ultrasound-guided techniques. Independent study selection, risk of bias assessment and data extraction were performed by at least two investigators. We undertook meta-analysis. The 21 included trials involved a total of 2148 participants who received regional anaesthesia for hand, wrist, forearm or elbow surgery. Risk of bias assessment indicated that trial design and conduct were generally adequate; the most common areas of weakness were in blinding and allocation concealment.Eight trials comparing double versus single injections showed a statistically significant decrease in primary anaesthesia failure (risk ratio (RR 0.51), 95% confidence interval (CI) 0.30 to 0.85). Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique.Eight trials comparing multiple with single

Insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations

Energy Technology Data Exchange (ETDEWEB)

Kotsikoris, Ioannis, E-mail: gkotsikoris@gmail.com [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Zygomalas, Apollon, E-mail: azygomalas@upatras.gr [Department of General Surgery, University Hospital of Patras (Greece); Papas, Theofanis, E-mail: pfanis@otenet.gr [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Maras, Dimitris, E-mail: dimmaras@gmail.com [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Pavlidis, Polyvios, E-mail: polpavlidis@yahoo.gr [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Andrikopoulou, Maria, E-mail: madric@gmail.com [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Tsanis, Antonis, E-mail: atsanis@gmail.com [Department of Interventional Radiology, “Erythros Stauros” General Hospital (Greece); Alivizatos, Vasileios, E-mail: valiviz@hol.gr [Department of General Surgery and Artificial Nutrition Unit, “Agios Andreas” General Hospital of Patras (Greece); Bessias, Nikolaos, E-mail: bessias@otenet.gr [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece)

2012-09-15

Introduction: Central venous catheter placement is an effective alternative vascular access for dialysis in patients with chronic renal failure. The purpose of this study was to evaluate the insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations in terms of efficacy of the procedure and early complications. Materials and methods: Between 2008 and 2010, the vascular access team of our hospital placed 409 central venous catheters in patients with chronic renal failure. The procedure was performed using the Seldinger blind technique. In 18 (4.4%) cases it was impossible to advance the guidewire, and so the patients were transported to the angiography suite. Results: Using the angiographic technique, the guidewire was advanced in order to position the central venous catheter. The latter was inserted into the subclavian vein in 12 (66.6%) cases, into the internal jugular vein in 4 (22.2%) and into the femoral vein in 2 (11.1%) cases. There was only one complicated case with severe arrhythmia in 1 (5.5%) patient. Conclusion: Our results suggest that insertion of central venous catheters using angiographic techniques in hemodialysis patients with previous multiple catheterizations is a safe and effective procedure with few complications and high success rates.

Insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations

International Nuclear Information System (INIS)

Kotsikoris, Ioannis; Zygomalas, Apollon; Papas, Theofanis; Maras, Dimitris; Pavlidis, Polyvios; Andrikopoulou, Maria; Tsanis, Antonis; Alivizatos, Vasileios; Bessias, Nikolaos

2012-01-01

Introduction: Central venous catheter placement is an effective alternative vascular access for dialysis in patients with chronic renal failure. The purpose of this study was to evaluate the insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations in terms of efficacy of the procedure and early complications. Materials and methods: Between 2008 and 2010, the vascular access team of our hospital placed 409 central venous catheters in patients with chronic renal failure. The procedure was performed using the Seldinger blind technique. In 18 (4.4%) cases it was impossible to advance the guidewire, and so the patients were transported to the angiography suite. Results: Using the angiographic technique, the guidewire was advanced in order to position the central venous catheter. The latter was inserted into the subclavian vein in 12 (66.6%) cases, into the internal jugular vein in 4 (22.2%) and into the femoral vein in 2 (11.1%) cases. There was only one complicated case with severe arrhythmia in 1 (5.5%) patient. Conclusion: Our results suggest that insertion of central venous catheters using angiographic techniques in hemodialysis patients with previous multiple catheterizations is a safe and effective procedure with few complications and high success rates

Determining flexor-tendon repair techniques via soft computing

Science.gov (United States)

Johnson, M.; Firoozbakhsh, K.; Moniem, M.; Jamshidi, M.

2001-01-01

An SC-based multi-objective decision-making method for determining the optimal flexor-tendon repair technique from experimental and clinical survey data, and with variable circumstances, was presented. Results were compared with those from the Taguchi method. Using the Taguchi method results in the need to perform ad-hoc decisions when the outcomes for individual objectives are contradictory to a particular preference or circumstance, whereas the SC-based multi-objective technique provides a rigorous straightforward computational process in which changing preferences and importance of differing objectives are easily accommodated. Also, adding more objectives is straightforward and easily accomplished. The use of fuzzy-set representations of information categories provides insight into their performance throughout the range of their universe of discourse. The ability of the technique to provide a "best" medical decision given a particular physician, hospital, patient, situation, and other criteria was also demonstrated.

Comparison of techniques for determination of soluble sugars used in feed for ruminant nutrition

Directory of Open Access Journals (Sweden)

Cândida Camila dos Reis

2015-02-01

Full Text Available This study aims to evaluate different techniques for determination of soluble sugars (fraction CA in foods used for ruminant nutrition. Feed analyzed were: sugar-cane, bermuda grass, corn meal and soybean meal. Dry matter (DM, ash, ether extract (EE and crude protein (CP were determined to make possible the calculation of total carbohydrates concentration in the samples. The soluble carbohydrate fraction were determined in 15 repetitions of each sample by two different analytical techniques. One technique based on soluble carbohydrates extraction and its quantification by spectrophotometry after chelation of the sugar with anthrone; and another one that uses phenol as the chelating agent. The experiment were conducted in a completely randomized design and the data submitted to the two-factor factorial analysis of variance (? = 0.05, with the different feeds and the two techniques as factors. There was no statistical difference between techniques, but the effect of the feed and the interaction feed x technique were significant. So, a new analysis of variance was conducted to test the difference between techniques in each feed separately. Only soybean meal did not show statistical difference between the water soluble sugars determined by the two techniques.

Continuous analog of multiplicative algebraic reconstruction technique for computed tomography

Science.gov (United States)

Tateishi, Kiyoko; Yamaguchi, Yusaku; Abou Al-Ola, Omar M.; Kojima, Takeshi; Yoshinaga, Tetsuya

2016-03-01

We propose a hybrid dynamical system as a continuous analog to the block-iterative multiplicative algebraic reconstruction technique (BI-MART), which is a well-known iterative image reconstruction algorithm for computed tomography. The hybrid system is described by a switched nonlinear system with a piecewise smooth vector field or differential equation and, for consistent inverse problems, the convergence of non-negatively constrained solutions to a globally stable equilibrium is guaranteed by the Lyapunov theorem. Namely, we can prove theoretically that a weighted Kullback-Leibler divergence measure can be a common Lyapunov function for the switched system. We show that discretizing the differential equation by using the first-order approximation (Euler's method) based on the geometric multiplicative calculus leads to the same iterative formula of the BI-MART with the scaling parameter as a time-step of numerical discretization. The present paper is the first to reveal that a kind of iterative image reconstruction algorithm is constructed by the discretization of a continuous-time dynamical system for solving tomographic inverse problems. Iterative algorithms with not only the Euler method but also the Runge-Kutta methods of lower-orders applied for discretizing the continuous-time system can be used for image reconstruction. A numerical example showing the characteristics of the discretized iterative methods is presented.

Determination of dynamic fracture toughness using a new experimental technique

Directory of Open Access Journals (Sweden)

Cady Carl M.

2015-01-01

Full Text Available In other studies dynamic fracture toughness has been measured using Charpy impact and modified Hopkinson Bar techniques. In this paper results will be shown for the measurement of fracture toughness using a new test geometry. The crack propagation velocities range from ∼0.15 mm/s to 2.5 m/s. Digital image correlation (DIC will be the technique used to measure both the strain and the crack growth rates. The boundary of the crack is determined using the correlation coefficient generated during image analysis and with interframe timing the crack growth rate and crack opening can be determined. A comparison of static and dynamic loading experiments will be made for brittle polymeric materials. The analysis technique presented by Sammis et al. [1] is a semi-empirical solution, however, additional Linear Elastic Fracture Mechanics analysis of the strain fields generated as part of the DIC analysis allow for the more commonly used method resembling the crack tip opening displacement (CTOD experiment. It should be noted that this technique was developed because limited amounts of material were available and crack growth rates were to fast for a standard CTOD method.

Determination of dynamic fracture toughness using a new experimental technique

Science.gov (United States)

Cady, Carl M.; Liu, Cheng; Lovato, Manuel L.

2015-09-01

In other studies dynamic fracture toughness has been measured using Charpy impact and modified Hopkinson Bar techniques. In this paper results will be shown for the measurement of fracture toughness using a new test geometry. The crack propagation velocities range from ˜0.15 mm/s to 2.5 m/s. Digital image correlation (DIC) will be the technique used to measure both the strain and the crack growth rates. The boundary of the crack is determined using the correlation coefficient generated during image analysis and with interframe timing the crack growth rate and crack opening can be determined. A comparison of static and dynamic loading experiments will be made for brittle polymeric materials. The analysis technique presented by Sammis et al. [1] is a semi-empirical solution, however, additional Linear Elastic Fracture Mechanics analysis of the strain fields generated as part of the DIC analysis allow for the more commonly used method resembling the crack tip opening displacement (CTOD) experiment. It should be noted that this technique was developed because limited amounts of material were available and crack growth rates were to fast for a standard CTOD method.

Self-normalizing multiple-echo technique for measuring the in vivo apparent diffusion coefficient

International Nuclear Information System (INIS)

Perman, W.H.; Gado, M.; Sandstrom, J.C.

1989-01-01

This paper presents work to develop a new technique for quantitating the in vivo apparent diffusion/perfusion coefficient (ADC) by obtaining multiple data points from only two images with the capability to normalize the data from consecutive images, thus minimizing the effect of interimage variation. Two multiple-echo (six-to eight-echo) cardiac-gated images are obtained, one without and one with additional diffusion/perfusion encoding gradients placed about the 180 RF pulses of all but the first echo. Since the first echoes of both images have identical pulse sequence parameters, variations in signal intensity-between the first echoes represent image-to-image variation. The signal intensities of the subsequent echoes with additional diffusion/perfusion encoding gradients are then normalized by using the ratio of the first-echo signal intensities

Impression of multiple implants using photogrammetry: description of technique and case presentation.

Science.gov (United States)

Peñarrocha-Oltra, David; Agustín-Panadero, Rubén; Bagán, Leticia; Giménez, Beatriz; Peñarrocha, María

2014-07-01

To describe a technique for registering the positions of multiple dental implants using a system based on photogrammetry. A case is presented in which a prosthetic treatment was performed using this technique. Three Euroteknika® dental implants were placed to rehabilitate a 55-year-old male patient with right posterior maxillary edentulism. Three months later, the positions of the implants were registered using a photogrammetry-based stereo-camera (PICcamera®). After processing patient and implant data, special abutments (PICabutment®) were screwed onto each implant. The PICcamera® was then used to capture images of the implant positions, automatically taking 150 images in less than 60 seconds. From this information a file was obtained describing the relative positions - angles and distances - of each implant in vector form. Information regarding the soft tissues was obtained from an alginate impression that was cast in plaster and scanned. A Cr-Co structure was obtained using CAD/CAM, and its passive fit was verified in the patient's mouth using the Sheffield test and the screw resistance test. Twelve months after loading, peri-implant tissues were healthy and no marginal bone loss was observed. The clinical application of this new system using photogrammetry to record the position of multiple dental implants facilitated the rehabilitation of a patient with posterior maxillary edentulism by means of a prosthesis with optimal fit. The prosthetic process was accurate, fast, simple to apply and comfortable for the patient.

Multiple Input - Multiple Output (MIMO) SAR

Data.gov (United States)

National Aeronautics and Space Administration — This effort will research and implement advanced Multiple-Input Multiple-Output (MIMO) Synthetic Aperture Radar (SAR) techniques which have the potential to improve...

A Photometric Technique for Determining Fluid Concentration using Consumer-Grade Hardware

Science.gov (United States)

Leslie, F.; Ramachandran, N.

1999-01-01

In support of a separate study to produce an exponential concentration gradient in a magnetic fluid, a noninvasive technique for determining, species concentration from off-the-shelf hardware has been developed. The approach uses a backlighted fluid test cell photographed with a commercial digital camcorder. Because the light extinction coefficient is wavelength dependent, tests were conducted to determine the best filter color to use, although some guidance was also provided using an absorption spectrophotometer. With the appropriate filter in place, the provide attenuation of the light passing, through the test cell was captured by the camcorder. The digital image was analyzed for intensity using, software from Scion Image Corp. downloaded from the Internet. The analysis provides a two-dimensional array of concentration with an average error of 0.0095 ml/ml. This technique is superior to invasive techniques, which require extraction of a sample that disturbs the concentration distribution in the test cell. Refinements of this technique using a true monochromatic laser light Source are also discussed.

Determination of uranium in ground water using different analytical techniques

International Nuclear Information System (INIS)

Sahu, S.K.; Maity, Sukanta; Bhangare, R.C.; Pandit, G.G.; Sharma, D.N.

2014-10-01

The concern over presence of natural radionuclides like uranium in drinking water is growing recently. The contamination of aquifers with radionuclides depends on number of factors. The geology of an area is the most important factor along with anthropogenic activities like mining, coal ash disposal from thermal power plants, use of phosphate fertilizers etc. Whatever may be the source, the presence of uranium in drinking waters is a matter of great concern for public health. Studies show that uranium is a chemo-toxic and nephrotoxic heavy metal. This chemotoxicity affects the kidneys and bones in particular. Seeing the potential health hazards from natural radionuclides in drinking water, many countries worldwide have adopted the guideline activity concentration for drinking water quality recommended by the WHO (2011). For uranium, WHO has set a limit of 30μgL-1 in drinking water. The geological distribution of uranium and its migration in environment is of interest because the element is having environmental and exposure concerns. It is of great interest to use an analytical technique for uranium analysis in water which is highly sensitive especially at trace levels, specific and precise in presence of other naturally occurring major and trace metals and needs small amount of sample. Various analytical methods based on the use of different techniques have been developed in the past for the determination of uranium in the geological samples. The determination of uranium requires high selectivity due to its strong association with other elements. Several trace level wet chemistry analytical techniques have been reported for uranium determination, but most of these involve tedious and pain staking procedures, high detection limits, interferences etc. Each analytical technique has its own merits and demerits. Comparative assessment by different techniques can provide better quality control and assurance. In present study, uranium was analysed in ground water samples

Evaluating Eye Drop Instillation Technique and Its Determinants in Glaucoma Patients

Directory of Open Access Journals (Sweden)

Xinbo Gao

2018-01-01

Full Text Available Aim. To evaluate eye drop instillation technique and to explore its determinants in glaucoma patients. Methods. One hundred and thirteen patients diagnosed with glaucoma and self-administering topical antiglaucoma eye drops for at least 1 month were evaluated. All patients instilled artificial tear solution in one eye as they would do at home. The whole process was evaluated by two study staff. A comprehensive score system associated with eye drop instillation techniques was used to quantify the instillation technique and explore its determinants such as demographic and clinical characteristics. Results. Half of the patients (48.67% finished the administration of eye drop on first attempt.1.7 eye drops were squeezed out on average. 43 patients (37.17% got contact with ocular surface or adnexa. Only 19.7% patients had eye drop instillation techniques being defined as well. 11 patients (9.7% had prior instruction regarding using eye drops, while only 4 patients knew to occlude the tear duct by pressing the dacryocyst area. Older age and worse visual acuity were found to be independent risk factors for worse instillation technique. Conclusions. Eye drop instillation technique in glaucoma patients deserves great attention from eye care practitioners during their lifelong follow-up, especially those aged older and have worse visual acuity.

A new basaltic glass microanalytical reference material for multiple techniques

Science.gov (United States)

Wilson, Steve; Koenig, Alan; Lowers, Heather

2012-01-01

The U.S. Geological Survey (USGS) has been producing reference materials since the 1950s. Over 50 materials have been developed to cover bulk rock, sediment, and soils for the geological community. These materials are used globally in geochemistry, environmental, and analytical laboratories that perform bulk chemistry and/or microanalysis for instrument calibration and quality assurance testing. To answer the growing demand for higher spatial resolution and sensitivity, there is a need to create a new generation of microanalytical reference materials suitable for a variety of techniques, such as scanning electron microscopy/X-ray spectrometry (SEM/EDS), electron probe microanalysis (EPMA), laser ablation inductively coupled mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). As such, the microanalytical reference material (MRM) needs to be stable under the beam, be homogeneous at scales of better than 10–25 micrometers for the major to ultra-trace element level, and contain all of the analytes (elements or isotopes) of interest. Previous development of basaltic glasses intended for LA-ICP-MS has resulted in a synthetic basaltic matrix series of glasses (USGS GS-series) and a natural basalt series of glasses (BCR-1G, BHVO-2G, and NKT-1G). These materials have been useful for the LA-ICP-MS community but were not originally intended for use by the electron or ion beam community. A material developed from start to finish with intended use in multiple microanalytical instruments would be useful for inter-laboratory and inter-instrument platform comparisons. This article summarizes the experiments undertaken to produce a basalt glass reference material suitable for distribution as a multiple-technique round robin material. The goal of the analytical work presented here is to demonstrate that the elemental homogeneity of the new glass is acceptable for its use as a reference material. Because the round robin exercise is still underway, only

222Rn Determination In Drinking Waters - RAD7 And LSC Technique Comparison

International Nuclear Information System (INIS)

Todorovic, N.; Stojkovic, I.; Nikolov, J.; Tenjovic, B.

2015-01-01

A procedure for the determination of 222Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. For radon determination in drinking water from groundwater and surface water sources by LSC, the EPA Method 913.0 was used. A minimum detectable activity of 0.029 Bq L-1 in a 20 mL glass vial (10 mL water sample mixed with 10 mL of liquid scintillation cocktail) has been achieved during 300 minutes of measurement time. The procedure was compared with RAD7 radon detector measurements. Factors that affect the measurement accuracy and precision of RAD7 radon detector are the sampling technique, sample concentration, sample size, counting time, temperature, relative humidity and background effects. The minimal detectable activity (MDA) for RAD7 technique was found to be 0.1 Bq/L. From obtained results of 222Rn measurements in 15 water samples with different 222Rn activities, correlation between the two techniques applied for measurements of 222Rn in water samples (A less than 400 Bq/L) was determined. There is reasonable agreement (within statistical uncertainties) between the various techniques in most cases, while disagreements most likely come from systematic uncertainties associated with sampling procedures. Discrepancy in determined activities between the two techniques becomes more evident with increased 222Rn activities in water. LSC technique gives in general higher activity concentrations for about 30 percent than RAD7 spectrometer. The interpretation of shown results could be that RAD7 is not properly calibrated for higher activities, since USA reference level of 222Rn concentrations in water is only 11.1 Bq/L (US EPA, Proposed Radon in Drinking Water Regulation). (author).

MULTIPLE IMAGING TECHNIQUES DEMONSTRATE THE MANIPULATION OF SURFACES TO REDUCE BACTERIAL CONTAMINATION

Science.gov (United States)

Surface imaging techniques were combined to determine appropriate manipulation of technologically important surfaces for commercial applications. Stainless steel surfaces were engineered to reduce bacterial contamination, biofilm formation, and corrosion during product processing...

Stress wave techniques for determining quality of dimensional lumber from switch ties

Science.gov (United States)

K. C. Schad; D. E. Kretschmann; K. A. McDonald; R. J. Ross; D. W. Green

1995-01-01

Researchers at the Forest Products Laboratory, USDA Forest Service, have been studying nondestructive techniques for evaluating the strength of wood. This report describes the results of a pilot study on using these techniques to determine the quality of large dimensional lumber cut from switch ties. First, pulse echo and dynamic (transverse vibration) techniques were...

ANALYTICAL TECHNIQUES FOR THE DETERMINATION OF MELOXICAM IN PHARMACEUTICAL FORMULATIONS AND BIOLOGICAL SAMPLES

Directory of Open Access Journals (Sweden)

Aisha Noreen

2016-06-01

Full Text Available Meloxicam (MX belongs to the family of oxicams which is the most important group of non steroidal anti-inflammatory drugs (NSAIDs and is widely used for their analgesics and antipyretic activities. It inhibits both COX-I and COX-II enzymes with less gastric and local tissues irritation. A number of analytical techniques have been used for the determination of MX in pharmaceutical as well as in biological fluids. These techniques include titrimetry, spectrometry, chromatography, flow injection spectrometry, fluorescence spectrometry, capillary zone electrophoresis and electrochemical techniques. Many of these techniques have also been used for the simultaneous determination of MX with other compounds. A comprehensive review of these analytical techniques has been done which could be useful for the analytical chemists and quality control pharmacists.

Magnetic resonance techniques for investigation of multiple sclerosis

Science.gov (United States)

MacKay, Alex; Laule, Cornelia; Li, David K. B.; Meyers, Sandra M.; Russell-Schulz, Bretta; Vavasour, Irene M.

2014-11-01

Multiple sclerosis (MS) is a common neurological disease which can cause loss of vision and balance, muscle weakness, impaired speech, fatigue, cognitive dysfunction and even paralysis. The key pathological processes in MS are inflammation, edema, myelin loss, axonal loss and gliosis. Unfortunately, the cause of MS is still not understood and there is currently no cure. Magnetic resonance imaging (MRI) is an important clinical and research tool for MS. 'Conventional' MRI images of MS brain reveal bright lesions, or plaques, which demark regions of severe tissue damage. Conventional MRI has been extremely valuable for the diagnosis and management of people who have MS and also for the assessment of therapies designed to reduce inflammation and promote repair. While conventional MRI is clearly valuable, it lack pathological specificity and, in some cases, sensitivity to non-lesional pathology. Advanced MR techniques have been developed to provide information that is more sensitive and specific than what is available with clinical scanning. Diffusion tensor imaging and magnetization transfer provide a general but non-specific measure of the pathological state of brain tissue. MR spectroscopy provides concentrations of brain metabolites which can be related to specific pathologies. Myelin water imaging was designed to assess brain myelination and has proved useful for measuring myelin loss in MS. To combat MS, it is crucial that the pharmaceutical industry finds therapies which can reverse the neurodegenerative processes which occur in the disease. The challenge for magnetic resonance researchers is to design imaging techniques which can provide detailed pathological information relating to the mechanisms of MS therapies. This paper briefly describes the pathologies of MS and demonstrates how MS-associated pathologies can be followed using both conventional and advanced MR imaging protocols.

Delphi Fuzzy Elicitation Technique in the Determination of Third ...

African Journals Online (AJOL)

The Delphi technique via the expert elicitation method becomes extremely handy particularly in view of limited availability of data in determining failure probabilities of onshore transmission pipelines in the Niger Delta region of Nigeria occasioned by third party activity. Using, ten (10) experts opinion elucidated individually ...

Determination of some trace elements in biological samples using XRF and TXRF techniques

International Nuclear Information System (INIS)

Khuder, A.; Karjou, J.; Sawan, M. K.

2006-07-01

XRF and TXRF techniques were successfully used for the multi-element determination of trace elements in whole blood and human head hair samples. This was achieved by the direct analysis using XRF technique with different collimation units and by the optimized chemical procedures for TXRF analysis. Light element of S and P were preferably determined by XRF with primary x-ray excitation, while, elements of K, Ca, Fe, and Br were determined with a very good accuracy and precision using XRF with Cu- and Mo-secondary targets. The chemical procedure dependent on the preconcentration of trace elements by APDC was superiorly used for the determination of traces of Ni and Pb in the range of 1.0-1.7 μg/dl and 11-23 μg/dl, respectively, in whole blood samples by TXRF technique; determination of other elements as Cu and Zn was also achievable using this approach. Rb in whole blood samples was determined directly after the digestion of samples using PTFE-bomb for TXRF analysis. (author)

Determination of the hexagonal network parameters of the quartz β using neutron multiple diffraction

International Nuclear Information System (INIS)

Campos, L.C.; Parente, C.B.R.; Mazzocchi, V.L.; Helene, O.

2000-01-01

In this work, neutron multiple diffraction is employed for the determination of the parameters a and c of the β-quartz hexagonal cell. This crystalline phase of silica (SiO 2 ) occurs in temperatures between ca. 846 and 1143 K. A β-quartz neutron multiple diffraction pattern has been used in the determinations. This pattern was obtained with a natural quartz single crystal heated to 1003 K. During the indexing of the pattern it was verified that most of the pairs of secondary reflections, which are responsible for the formation of peaks, could be classified as 'good for the determination of a' or 'good for the determination of c'. With this classification, it became possible to employ an iterative method for the determination of both parameters. After 8 cycles of iteration the values found for the parameters were a = 4.9964 +- 0.0018 and c = 5.46268 +- 0.00052 A. (author)

Improvement of Analytical Technique for Determination of Gold in ...

African Journals Online (AJOL)

This article elucidates the improvement of analytical technique for determination of gold in geological matrix. Samples suspected to have gold in them were subjected to neutron flux from the Nigeria Research Reactor (NRR-1), a Miniature Neutron Source Reactor (MNSR). Two geological samples – one sample was ...

Combined interpretation of multiple geophysical techniques: an archaeological case study

Science.gov (United States)

Riedl, S.; Reichmann, S.; Tronicke, J.; Lück, E.

2009-04-01

In order to locate and ascertain the dimensions of an ancient orangery, we explored an area of about 70 m x 60 m in the Rheinsberg Palace Garden (Germany) with multiple geophysical techniques. The Rheinsberg Park, situated about 100 km northwest of Berlin, Germany, was established by the Prussian emperors in the 18th century. Due to redesign of the architecture and the landscaping during the past 300 years, buildings were dismantled and detailed knowledge about some original buildings got lost. We surveyed an area close to a gazebo where, after historical sources, an orangery was planned around the year 1740. However, today it is not clear to what extent this plan has been realized and if remains of this building are still buried in the subsurface. Applied geophysical techniques include magnetic gradiometry, frequency domain electromagnetic (FDEM) and direct current (DC) resistivity mapping as well as ground penetrating radar (GPR). To get an overview of the site, we performed FDEM electrical conductivity mapping using an EM38 instrument and magnetic gradiometry with caesium magnetometers. Both data sets were collected with an in- and crossline data point spacing of ca. 10 cm and 50 cm, respectively. DC resistivity surveying was performed using a pole-pole electrode configuration with an electrode spacing of 1.5 m and a spacing of 1.0 m between individual readings. A 3-D GPR survey was conducted using 200 MHz antennae and in- and crossline spacing of ca. 10 cm and 40 cm, respectively. A standard processing sequence including 3-D migration was applied. A combined interpretation of all collected data sets illustrates that the magnetic gradient and the EM38 conductivity maps is are dominated by anomalies from metallic water pipes from belonging to the irrigation system of the park. The DC resistivity map outlines a rectangular area which might indicate the extension of a former building south of the gazebo. The 3-D GPR data set provides further insights about

Microhardness technique for determination of radiation hardening in austenitic stainless steel using

International Nuclear Information System (INIS)

Hofman, A.

1995-01-01

The use of microhardness technique to determine the radiation hardening has been studied. Microhardness measurements have been conducted on austenitic stainless steel 0H18N10T irradiated up to 2·10 23 nm -2 . It was determined that the increase in microhardness varies directly with the measured increase in the 0,2% offret yield strength and has been found that microhardness technique may be an effective tool to measurements of radiation induced hardening. Based on the results and Cahoon's relation that σ 0,2 (MPa)=3,27HV(0,1) n method for evaluating the yield stress σ 0,2 by microhardness technique is analyzed. 14 refs., 3 figs., 3 tabs

ELISA techniques for the determination of methanogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Bryniok, D; Troesch, W [Fraunhofer-Institut fuer Grenzflaechen- und Bioverfahrenstechnik (IGB), Stuttgart (Germany, F.R.)

1989-12-01

Easy-to-handle enzyme-linked immunosorbent assay (ELISA) techniques have been developed suitable for quantitative species-specific determination of very low numbers of methanogens in complex bacterial populations. The amount and the distribution of different species of methanogens in anaerobic digestors is a reflection of the functional status of the degradation process; this can be recognized with these tests and hence may be used for process control. (orig.).

Crystallographic Orientation Determination of Hexagonal Structure Crystals by Laser Ultrasonic Technique

International Nuclear Information System (INIS)

Li, W; Coulson, J; Marrow, P; Smith, R J; Clark, M; Sharples, S D; Lainé, S J

2016-01-01

Spatially resolved acoustic spectroscopy (SRAS) is a laser ultrasonic technique that shows qualitative contrast between grains of different orientation, illustrating the sensitivity of acoustic waves to the material structure. The technique has been improved significantly on determining the full orientation of multigrain cubic metals, by comparing the measured surface acoustic wave (SAW) velocity to a pre-calculated model. In this paper we demonstrate the ability of this technique to determine the orientation of hexagonal structure crystals, such as magnesium and titanium based alloys. Because of the isotropy of the SAW velocity on the basal plane (0001) of hexagonal crystals, the slowness surface is shown as a circle. As the plane moves from (0001) towards (112-bar0) or towards (101-bar0), the slowness surface gradually turns into an oval. These acoustic properties increase the difficulty in orientation determination. The orientation results of a grade 1 commercially pure titanium by SRAS is presented, with comparison with electron backscattered diffraction (EBSD) results. Due to the nature of SAWs on hexagonal structure crystals, only the results of Euler angles 1 and 2 are discussed. The error between SRAS and EBSD is also investigated. (paper)

MULTIPLE OBJECTS

Directory of Open Access Journals (Sweden)

A. A. Bosov

2015-04-01

Full Text Available Purpose. The development of complicated techniques of production and management processes, information systems, computer science, applied objects of systems theory and others requires improvement of mathematical methods, new approaches for researches of application systems. And the variety and diversity of subject systems makes necessary the development of a model that generalizes the classical sets and their development – sets of sets. Multiple objects unlike sets are constructed by multiple structures and represented by the structure and content. The aim of the work is the analysis of multiple structures, generating multiple objects, the further development of operations on these objects in application systems. Methodology. To achieve the objectives of the researches, the structure of multiple objects represents as constructive trio, consisting of media, signatures and axiomatic. Multiple object is determined by the structure and content, as well as represented by hybrid superposition, composed of sets, multi-sets, ordered sets (lists and heterogeneous sets (sequences, corteges. Findings. In this paper we study the properties and characteristics of the components of hybrid multiple objects of complex systems, proposed assessments of their complexity, shown the rules of internal and external operations on objects of implementation. We introduce the relation of arbitrary order over multiple objects, we define the description of functions and display on objects of multiple structures. Originality.In this paper we consider the development of multiple structures, generating multiple objects.Practical value. The transition from the abstract to the subject of multiple structures requires the transformation of the system and multiple objects. Transformation involves three successive stages: specification (binding to the domain, interpretation (multiple sites and particularization (goals. The proposed describe systems approach based on hybrid sets

Determination of palladium in biological samples applying nuclear analytical techniques

International Nuclear Information System (INIS)

Cavalcante, Cassio Q.; Sato, Ivone M.; Salvador, Vera L. R.; Saiki, Mitiko

2008-01-01

This study presents Pd determinations in bovine tissue samples containing palladium prepared in the laboratory, and CCQM-P63 automotive catalyst materials of the Proficiency Test, using instrumental thermal and epithermal neutron activation analysis and energy dispersive X-ray fluorescence techniques. Solvent extraction and solid phase extraction procedures were also applied to separate Pd from interfering elements before the irradiation in the nuclear reactor. The results obtained by different techniques were compared against each other to examine sensitivity, precision and accuracy. (author)

Automated urinalysis technique determines concentration of creatine and creatinine by colorimetry

Science.gov (United States)

Rho, J. H.

1967-01-01

Continuous urinalysis technique is useful in the study of muscle wastage in primates. Creatinine concentration in urine is determined in an aliquot mixture by a color reaction. Creatine is determined in a second aliquot by converting it to creatinine and measuring the difference in color intensity between the two aliquots.

Technique for determining cesium-137 in milk excluding ashing

International Nuclear Information System (INIS)

Antonova, V.A.; Prokof'ev, O.N.

1984-01-01

For the purpose of simplification of the method of milk sample preparation for the radiochemical analysis for 137 Cs in laboratory sanitary and higienic investigations rapid analysis technique excluding sample ashing is developed. The technique comprises sample mixing with silica gel during an hour, 137 Cs desorption from silica gel into the 1N solution of hydrochloric acid, radiochemical analysis of hydrochloric solution for determining 137 Cs. The comparison of the results obtained by the above method and that with ashing provides perfect agreement. For taking into account the incompleteness of 137 Cs adsorption by silica gel a correction factor is applied in calculation formulae

Multiple and high-throughput droplet reactions via combination of microsampling technique and microfluidic chip

KAUST Repository

Wu, Jinbo

2012-11-20

Microdroplets offer unique compartments for accommodating a large number of chemical and biological reactions in tiny volume with precise control. A major concern in droplet-based microfluidics is the difficulty to address droplets individually and achieve high throughput at the same time. Here, we have combined an improved cartridge sampling technique with a microfluidic chip to perform droplet screenings and aggressive reaction with minimal (nanoliter-scale) reagent consumption. The droplet composition, distance, volume (nanoliter to subnanoliter scale), number, and sequence could be precisely and digitally programmed through the improved sampling technique, while sample evaporation and cross-contamination are effectively eliminated. Our combined device provides a simple model to utilize multiple droplets for various reactions with low reagent consumption and high throughput. © 2012 American Chemical Society.

Determination of the aerosol filters efficiency by means of the tracer techniques

International Nuclear Information System (INIS)

Hirling, J.

1978-01-01

Estimation of the nonradioactive methods of filters efficiency determination and tracer techniques are given. The methods are stated and discriptions of the instrumentation for estimation of the filters efficiency are given, in particular: methodology of production of the radioactive synthetic test-aerosols by means of the disperse and steamcondensation aerosol generators; the radio isotope method of the aerosol filters investigations; the methodology of filtartion efficiency determination. The results are given of the radioisotope investigations of filters; properties of the artificial radioactive test-aerosols; characteristics of filters, determined by the tracer techniques. Curves are given for the filtration efficiency of the viscose filtering nozzles of different density depending on the filters load. (I.T.) [ru

Selecting a Sustainable Disinfection Technique for Wastewater Reuse Projects

Directory of Open Access Journals (Sweden)

Jorge Curiel-Esparza

2014-09-01

Full Text Available This paper presents an application of the Analytical Hierarchy Process (AHP by integrating a Delphi process for selecting the best sustainable disinfection technique for wastewater reuse projects. The proposed methodology provides project managers a tool to evaluate problems with multiple criteria and multiple alternatives which involve non-commeasurable decision criteria, with expert opinions playing a major role in the selection of these treatment technologies. Five disinfection techniques for wastewater reuse have been evaluated for each of the nine criteria weighted according to the opinions of consulted experts. Finally, the VIKOR method has been applied to determine a compromise solution, and to establish the stability of the results. Therefore, the expert system proposed to select the optimal disinfection alternative is a hybrid method combining the AHP with the Delphi method and the VIKOR technique, which is shown to be appropriate in realistic scenarios where multiple stakeholders are involved in the selection of a sustainable disinfection technique for wastewater reuse projects.

Residual stress determination of rail tread using a laser ultrasonic technique

International Nuclear Information System (INIS)

Wang, Jing; Feng, Qibo

2015-01-01

A non-destructive method for measuring the residual stress on rail tread that uses a laser-generated ultrasonic technique is proposed. The residual stress distribution of different parts on both the new rail and used rail were examined. The surface acoustic waves (SAWs) are excited by a scanning line laser and detected by a laser ultrasonic detection system. A digital correlation method was used for calculating the changes in velocity of SAWs, which reflects the stress distribution. A wavelet de-noising technique and a least square fit were used for signal processing to improve the measurement accuracy. The effects of ultrasonic propagation distance and surface roughness on the determination of residual stress were analyzed and simulated. Results from the study demonstrate that the stress distribution results are accordant with the practical situation, and the laser-generated SAWs technique is a promising tool for the determination of residual stress in the railway inspection and other industrial testing fields. (paper)

Proton-activation technique for the determination of antimony

International Nuclear Information System (INIS)

Krivan, V.; Barth, P.

1979-01-01

Photon-activation analysis has been applied to the determination of antimony. Thick-target yields and analytical sensitivities are given for the indicator-radionuclides sup(119m)Te, sup(119g)Te, sup(121m)Te, sup(121g)Te, sup(123m)Te, sup(120m)Sb and sup(122g)Sb for proton energies between 9 and 25 MeV. In irradiations with a 5-μA beam for 5 hr, followed by a specific separation of the indicator-radionuclides, limits of detection at the ppm level can be achieved. Data are given for the most significant interfering reactions. Antimony was determined instrumentally in bismuth of very pure grade and the results are compared with those obtained from two independent techniques. (author)

Comparison of age determination techniques for known-age Cape ...

African Journals Online (AJOL)

Known-age teeth were used to validate age determination techniques for the Cape fur seal (Arctocephalus ... The reliability with which age can be estimated for the Cape fur seal has also been improved. ... The acid solution, with a volume at least 10 times that of ... old female [0 show (he absence of GLGs in the cemenlUnl.

Comparison of dye dilution method to radionuclide techniques for cardiac output determination in dogs

International Nuclear Information System (INIS)

Eng, S.S.; Robayo, J.R.; Porter, W.; Smith, R.E.

1980-01-01

A study was undertaken to identify the most accurate /sup 99m/Tc-labeled radiopharmaceutical and to determine the accuracy of a noninvasive radionuclide technique or cardiac output determinations. Phase I employed sodium pertechnetate, stannous pyrophosphate with sodium pertechnetate, /sup 99m/Tc red blood cells, and /sup 99m/Tc human serum albumin as radionuclide tracers. Cardiac output was determined by the dye dilution method and then by the invasive radionuclide technique. A pairied t test and regression analysis indicated that /sup 99m/Tc human serum albumin was the most accurate radiopharmaceutical for cardiac output determinations, and the results compared favorably to those obtained by the dye dilution method. In Phase II, /sup 99m/Tc human serum albumin was used as the radionuclide tracer for cardiac output determinations with the noninvasive technique. The results compared favorably to those obtained by the dye dilution method

Sulfated oligosaccharide structures, as determined by NMR techniques

International Nuclear Information System (INIS)

Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Cerezo, A.S.

1997-01-01

Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a λ-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author)

Calculation of the flux attenuation and multiple scattering correction factors in time of flight technique for double differential cross section measurements

International Nuclear Information System (INIS)

Martin, G.; Coca, M.; Capote, R.

1996-01-01

Using Monte Carlo method technique , a computer code which simulates the time of flight experiment to measure double differential cross section was developed. The correction factor for flux attenuation and multiple scattering, that make a deformation to the measured spectrum, were calculated. The energy dependence of the correction factor was determined and a comparison with other works is shown. Calculations for Fe 56 at two different scattering angles were made. We also reproduce the experiment performed at the Nuclear Analysis Laboratory for C 12 at 25 celsius degree and the calculated correction factor for the is measured is shown. We found a linear relation between the scatter size and the correction factor for flux attenuation

Gamma spectroscopic studies of the neutron-deficient g-g nucleus 74Kr by means of a neutron multiplicity measurement technique

International Nuclear Information System (INIS)

Roth, J.

1981-01-01

The g-g nucleus 74 Kr was studied by means of the reaction 58 Ni ( 19 F, p2n#betta#) 74 Kr. In order to make gamma spectroscopic studies at neutron deficient nuclei like 74 Kr a neutron multiplicity measurement technique was developed. Beside #betta# single spectra, #betta# excitation functions, #betta#-#betta# coincidences, #betta# angular distributions, and lifetime measurements by means of this technique all measurements in coincidence with up to two neutrons were taken up. From these measurement data an extended term scheme with 17 newly found excited states could be extracted. To all levels spins and parities could be assigned. From the four energetically lowest levels of the yrast cascade the mean lifetimes could be determined. A double backbending in the sequence of the yrast cascade was interpreted as crossing of the g 9/2 bands. The irregularities in the lower part of the yrast band correspond to the shape consistence picture. The results were considered in connection with the systematics of the even krypton isotopes and compared with a two-quasiparticle-plas-rotor model calculation. (HSI)

Multiple regression technique for Pth degree polynominals with and without linear cross products

Science.gov (United States)

Davis, J. W.

1973-01-01

A multiple regression technique was developed by which the nonlinear behavior of specified independent variables can be related to a given dependent variable. The polynomial expression can be of Pth degree and can incorporate N independent variables. Two cases are treated such that mathematical models can be studied both with and without linear cross products. The resulting surface fits can be used to summarize trends for a given phenomenon and provide a mathematical relationship for subsequent analysis. To implement this technique, separate computer programs were developed for the case without linear cross products and for the case incorporating such cross products which evaluate the various constants in the model regression equation. In addition, the significance of the estimated regression equation is considered and the standard deviation, the F statistic, the maximum absolute percent error, and the average of the absolute values of the percent of error evaluated. The computer programs and their manner of utilization are described. Sample problems are included to illustrate the use and capability of the technique which show the output formats and typical plots comparing computer results to each set of input data.

A technique for determining the deuterium/hydrogen contrast map in neutron macromolecular crystallography.

Science.gov (United States)

Chatake, Toshiyuki; Fujiwara, Satoru

2016-01-01

A difference in the neutron scattering length between hydrogen and deuterium leads to a high density contrast in neutron Fourier maps. In this study, a technique for determining the deuterium/hydrogen (D/H) contrast map in neutron macromolecular crystallography is developed and evaluated using ribonuclease A. The contrast map between the D2O-solvent and H2O-solvent crystals is calculated in real space, rather than in reciprocal space as performed in previous neutron D/H contrast crystallography. The present technique can thus utilize all of the amplitudes of the neutron structure factors for both D2O-solvent and H2O-solvent crystals. The neutron D/H contrast maps clearly demonstrate the powerful detectability of H/D exchange in proteins. In fact, alternative protonation states and alternative conformations of hydroxyl groups are observed at medium resolution (1.8 Å). Moreover, water molecules can be categorized into three types according to their tendency towards rotational disorder. These results directly indicate improvement in the neutron crystal structure analysis. This technique is suitable for incorporation into the standard structure-determination process used in neutron protein crystallography; consequently, more precise and efficient determination of the D-atom positions is possible using a combination of this D/H contrast technique and standard neutron structure-determination protocols.

Current status on techniques for determining paleo-temperature using geothermometer

International Nuclear Information System (INIS)

Kanazawa, Sunao; Oikawa, Teruki; Umeda, Koji; Tomiyama, Shingo

2005-01-01

Development of the research technologies for geotectonic events has been carried out to evaluate the long-term stability of geological environment. In terms of the effects of geothermal activity, it is necessary to estimate the geothermal regime and thermal history on any given site. This paper describes the current status on techniques for determining paleo-temperature using geothermometer, and presents a concept of the systematic research techniques. The application of geothermometer, especially thermochronology, has been effective in the studies on the cooling history of geological body and the paleo-geothermal structure at depth. (author)

Use of multiple methods to determine factors affecting quality of care of patients with diabetes.

Science.gov (United States)

Khunti, K

1999-10-01

The process of care of patients with diabetes is complex; however, GPs are playing a greater role in its management. Despite the research evidence, the quality of care of patients with diabetes is variable. In order to improve care, information is required on the obstacles faced by practices in improving care. Qualitative and quantitative methods can be used for formation of hypotheses and the development of survey procedures. However, to date few examples exist in general practice research on the use of multiple methods using both quantitative and qualitative techniques for hypothesis generation. We aimed to determine information on all factors that may be associated with delivery of care to patients with diabetes. Factors for consideration on delivery of diabetes care were generated by multiple qualitative methods including brainstorming with health professionals and patients, a focus group and interviews with key informants which included GPs and practice nurses. Audit data showing variations in care of patients with diabetes were used to stimulate the brainstorming session. A systematic literature search focusing on quality of care of patients with diabetes in primary care was also conducted. Fifty-four potential factors were identified by multiple methods. Twenty (37.0%) were practice-related factors, 14 (25.9%) were patient-related factors and 20 (37.0%) were organizational factors. A combination of brainstorming and the literature review identified 51 (94.4%) factors. Patients did not identify factors in addition to those identified by other methods. The complexity of delivery of care to patients with diabetes is reflected in the large number of potential factors identified in this study. This study shows the feasibility of using multiple methods for hypothesis generation. Each evaluation method provided unique data which could not otherwise be easily obtained. This study highlights a way of combining various traditional methods in an attempt to overcome the

Novel technique for determination of alloy composition with the help of chronopotentiometry

International Nuclear Information System (INIS)

Rizwan, R.; Mehmood, M.

2006-01-01

Single phase gamma (Ni/sub 5/Zn/sub 21/) nanocrystalline zinc-nickel alloy coatings were prepared by electrodeposition in chloride bath. Cyclic voltammetry as well as reverse Chronopotentiometry was performed on platinum substrate. Both of these techniques are well known for determination of phases present in alloy in electrochemistry. A new model is introduced for determining composition of the electrodeposited alloy (Zn-Ni) with the help of Chronopotentiometry. EDX of deposits was also performed. Relative percentages of zinc and nickel determined from Chronopotentiometry were almost same to the results obtained from EDX. So by use of this model, Chronopotentiometry can be used as useful characterization technique for in-situ determination of composition during electrodeposition. X -ray diffraction was performed and it confirms the presence of single phase deposits. Current efficiency of the deposits remain above 90%. Surface compactness of deposits is verified with the help of SEM. (author)

Security of public key encryption technique based on multiple chaotic systems

International Nuclear Information System (INIS)

Wang Kai; Pei Wenjiang; Zou Liuhua; Cheung Yiuming; He Zhenya

2006-01-01

Recently, a new public key encryption technique based on multiple chaotic systems has been proposed [B. Ranjan, Phys. Rev. Lett. 95 (2005) 098702]. This scheme employs m-chaotic systems and a set of linear functions for key exchange over an insecure channel. Security of the proposed algorithm grows as (NP) m , where N, P are the size of the key and the computational complexity of the linear functions respectively. In this Letter, the fundamental weakness of the cryptosystem is pointed out and a successful attack is described. Given the public keys and the initial vector, one can calculate the secret key based on Parseval's theorem. Both theoretical and experimental results show that the attacker can access to the secret key without difficulty. The lack of security discourages the use of such algorithm for practical applications

PHEA-PLA biocompatible nanoparticles by technique of solvent evaporation from multiple emulsions.

Science.gov (United States)

Cavallaro, Gennara; Craparo, Emanuela Fabiola; Sardo, Carla; Lamberti, Gaetano; Barba, Anna Angela; Dalmoro, Annalisa

2015-11-30

Nanocarriers of amphiphilic polymeric materials represent versatile delivery systems for poorly water soluble drugs. In this work the technique of solvent evaporation from multiple emulsions was applied to produce nanovectors based on new amphiphilic copolymer, the α,β-poly(N-2-hydroxyethyl)-DL-aspartamide-polylactic acid (PHEA-PLA), purposely synthesized to be used in the controlled release of active molecules poorly soluble in water. To this aim an amphiphilic derivative of PHEA, a hydrophilic polymer, was synthesized by derivatization of the polymeric backbone with hydrophobic grafts of polylactic acid (PLA). The achieved copolymer was thus used to produce nanoparticles loaded with α tocopherol (vitamin E) adopted as lipophilic model molecule. Applying a protocol based on solvent evaporation from multiple emulsions assisted by ultrasonic energy and optimizing the emulsification process (solvent selection/separation stages), PHEA-PLA nanostructured particles with total α tocopherol entrapment efficiency (100%), were obtained. The drug release is expected to take place in lower times with respect to PLA due to the presence of the hydrophilic PHEA, therefore the produced nanoparticles can be used for semi-long term release drug delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Security and reliability analysis of diversity combining techniques in SIMO mixed RF/FSO with multiple users

KAUST Repository

Abd El-Malek, Ahmed H.; Salhab, Anas M.; Zummo, Salam A.; Alouini, Mohamed-Slim

2016-01-01

In this paper, we investigate the impact of different diversity combining techniques on the security and reliability analysis of a single-input-multiple-output (SIMO) mixed radio frequency (RF)/free space optical (FSO) relay network with opportunistic multiuser scheduling. In this model, the user of the best channel among multiple users communicates with a multiple antennas relay node over an RF link, and then, the relay node employs amplify-and-forward (AF) protocol in retransmitting the user data to the destination over an FSO link. Moreover, the authorized transmission is assumed to be attacked by a single passive RF eavesdropper equipped with multiple antennas. Therefore, the system security reliability trade-off analysis is investigated. Closed-form expressions for the system outage probability and the system intercept probability are derived. Then, the newly derived expressions are simplified to their asymptotic formulas at the high signal-to-noise- ratio (SNR) region. Numerical results are presented to validate the achieved exact and asymptotic results and to illustrate the impact of various system parameters on the system performance. © 2016 IEEE.

Security and reliability analysis of diversity combining techniques in SIMO mixed RF/FSO with multiple users

KAUST Repository

Abd El-Malek, Ahmed H.

2016-07-26

In this paper, we investigate the impact of different diversity combining techniques on the security and reliability analysis of a single-input-multiple-output (SIMO) mixed radio frequency (RF)/free space optical (FSO) relay network with opportunistic multiuser scheduling. In this model, the user of the best channel among multiple users communicates with a multiple antennas relay node over an RF link, and then, the relay node employs amplify-and-forward (AF) protocol in retransmitting the user data to the destination over an FSO link. Moreover, the authorized transmission is assumed to be attacked by a single passive RF eavesdropper equipped with multiple antennas. Therefore, the system security reliability trade-off analysis is investigated. Closed-form expressions for the system outage probability and the system intercept probability are derived. Then, the newly derived expressions are simplified to their asymptotic formulas at the high signal-to-noise- ratio (SNR) region. Numerical results are presented to validate the achieved exact and asymptotic results and to illustrate the impact of various system parameters on the system performance. © 2016 IEEE.

Techniques for rapid determination of effects of synergy between radionuclides and pollutants

International Nuclear Information System (INIS)

Saas, A.; Grauby, A.

1975-01-01

The authors present a number of chromatographic techniques for rapid determination of synergy between radionuclides and various compounds in water. The first technique consists in studying how the chemical equilibrium of iodine varies in the presence of various organic and mineral compounds. The second makes it possible to define the effects of synergy within a given hydrographic basin. A third technique deals with the effects of synergy in ground water in the presence of various types of irrigation water. Finally, to complete this set of techniques, the authors define the mobility potential of a radionuclide in a given aqueous effluent

DETERMINING INDICATORS OF URBAN HOUSEHOLD WATER CONSUMPTION THROUGH MULTIVARIATE STATISTICAL TECHNIQUES

Directory of Open Access Journals (Sweden)

Gledsneli Maria Lima Lins

2010-12-01

Full Text Available Water has a decisive influence on populations’ life quality – specifically in areas like urban supply, drainage, and effluents treatment – due to its sound impact over public health. Water rational use constitutes the greatest challenge faced by water demand management, mainly with regard to urban household water consumption. This makes it important to develop researches to assist water managers and public policy-makers in planning and formulating water demand measures which may allow urban water rational use to be met. This work utilized the multivariate techniques Factor Analysis and Multiple Linear Regression Analysis – in order to determine the participation level of socioeconomic and climatic variables in monthly urban household consumption changes – applying them to two districts of Campina Grande city (State of Paraíba, Brazil. The districts were chosen based on socioeconomic criterion (income level so as to evaluate their water consumer’s behavior. A 9-year monthly data series (from year 2000 up to 2008 was utilized, comprising family income, water tariff, and quantity of household connections (economies – as socioeconomic variables – and average temperature and precipitation, as climatic variables. For both the selected districts of Campina Grande city, the obtained results point out the variables “water tariff” and “family income” as indicators of these district’s household consumption.

Fovea sparing internal limiting membrane peeling using multiple parafoveal curvilinear peels for myopic foveoschisis: technique and outcome.

Science.gov (United States)

Jin, Haiying; Zhang, Qi; Zhao, Peiquan

2016-10-18

To introduce a modified surgical technique, the "parafoveal multiple curvelinear internal limiting membrane (ILM) peeling", to preserve epi-foveal ILM in myopic foveoschisis surgery. Consecutive patients with myopic foveoschisis were enrolled in the present prospective interventional case series. The surgeries were performed using transconjunctival 23-gauge system. The macular area was divided into quadrants. ILM was peeled off in a curvilinear manner centered around the site that was away from the central fovea in each quadrant. Shearing forces were used to control the direction to keep the peeling away from central fovea. ILM at central fovea of about 500 to 1000 μm was preserved by this technique. This technique was performed in 20 eyes of 20 consecutive patients. Epi-foveal ILM was successfully preserved in all cases using the technique. Patients were followed up for more than 12 months. The mean postoperative logMAR visual acuity improved from 1.67 ± 0.65 preoperatively to 1.15 ± 0.49 (P = 0.015; paired t-test). Postoperative OCT examinations showed that full-thickness macular holes (MHs) did not developed in any case. Central fovea thickness decreased from 910 ± 261 μm preoperatively to 125 ± 85 postoperatively (P = 0.001; paired t-test). Fovea sparing ILM peeling using multiple parafoveal curvilinear peels prevents the development of postoperative full-thickness MHs in eyes with myopic foveoschisis.

Sulfated oligosaccharide structures, as determined by NMR techniques

Energy Technology Data Exchange (ETDEWEB)

Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J. [Parana Univ., Curitiba, PR (Brazil). Dept. De Bioquimica; Cerezo, A.S. [Buenos Aires Univ. Nacional (Argentina). Dept. de Quimica Organica

1997-12-31

Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a {lambda}-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author) 4 refs., 8 figs., 1 tabs.

Simultaneous rotational and vibrational CARS generation through a multiple-frequency combination technique

International Nuclear Information System (INIS)

Alden, M.; Bengtsson, P.E.; Edner, H.

1987-01-01

One most promising laser technique for probing combustion processes is coherent anti-Stokes Raman scattering (CARS), which due to its coherent nature and signal strength is applied in several real-world applications. Until today almost all CARS experiments are based on probing the population of molecular vibrational energy levels. However, there are several reasons rotational CARS, i.e. probing of rotational energy levels, may provide a complement to or even a better choice than vibrational CARS. Recently an alternative way to produce rotational CARS spectra is proposed, which is based on a multiple-frequency combination technique. The energy-level diagram for this process is presented. Two dye laser beams at ω/sub r/, and one fix frequency laser beam at ω/sub g/ are employed. ω/sub r,1/ and ω/sub r,2/ are two frequencies of many possible pairs with a frequency difference matching a rotational transition in a molecule. The excitation induced by ω/sub r,1/ and ω/sub r,2/ is then scattered by the narrowband ω/sub g/ beam resulting in a CARS beam ω/sub g/ at ω/sub g/ + ω/sub r,1/ - ω/sub r,2/. An interesting feature with this technique is that it is possible to generate simultaneously a rotational and vibrational CARS spectrum by using a double-folded boxcars phase matching approach. The authors believe that the proposed technique for producing rotational and vibration CARS spectra could be of interest, e.g., when measuring in highly turbulent flows. In this case the rotational CARS spectra could use for temperature measurements in the cooler parts, whereas vibrational CARS are to be preferred when measuring in the hotter parts

A single-gradient junction technique to replace multiple-junction shifts for craniospinal irradiation treatment

International Nuclear Information System (INIS)

Hadley, Austin; Ding, George X.

2014-01-01

Craniospinal irradiation (CSI) requires abutting fields at the cervical spine. Junction shifts are conventionally used to prevent setup error–induced overdosage/underdosage from occurring at the same location. This study compared the dosimetric differences at the cranial-spinal junction between a single-gradient junction technique and conventional multiple-junction shifts and evaluated the effect of setup errors on the dose distributions between both techniques for a treatment course and single fraction. Conventionally, 2 lateral brain fields and a posterior spine field(s) are used for CSI with weekly 1-cm junction shifts. We retrospectively replanned 4 CSI patients using a single-gradient junction between the lateral brain fields and the posterior spine field. The fields were extended to allow a minimum 3-cm field overlap. The dose gradient at the junction was achieved using dose painting and intensity-modulated radiation therapy planning. The effect of positioning setup errors on the dose distributions for both techniques was simulated by applying shifts of ± 3 and 5 mm. The resulting cervical spine doses across the field junction for both techniques were calculated and compared. Dose profiles were obtained for both a single fraction and entire treatment course to include the effects of the conventional weekly junction shifts. Compared with the conventional technique, the gradient-dose technique resulted in higher dose uniformity and conformity to the target volumes, lower organ at risk (OAR) mean and maximum doses, and diminished hot spots from systematic positioning errors over the course of treatment. Single-fraction hot and cold spots were improved for the gradient-dose technique. The single-gradient junction technique provides improved conformity, dose uniformity, diminished hot spots, lower OAR mean and maximum dose, and one plan for the entire treatment course, which reduces the potential human error associated with conventional 4-shifted plans

Liquid scintillation counting techniques for the determination of some alpha emitting actinides: a review

International Nuclear Information System (INIS)

Mirashi, N.N.; Chander, Keshav; Aggarwal, S.K.

2000-12-01

The present report is a review of the work on liquid scintillation counting techniques, for the determination of alpha emitting actinides like uranium, plutonium, americium etc; for the last three decades (1970-1999). It covers the progress that has taken place in conventional liquid scintillation counting employing various solvents, scintillators and extractants. There is gradual development in instrumentation from integral counting of alpha emitters to alpha liquid scintillation spectrometry to resolve and identify different alpha emitters. These advancements have led to Pulse Shape Analysis (PSA) and Photon Electron Rejecting Alpha Liquid Scintillation Spectrometry (PERALS) techniques for the determination of the alpha emitters in the presence of beta and gamma activity. These techniques allow the determination of actinides at very low levels which has increased their applications to almost all the fields of chemistry; be it biomedical, environmental, geological or process chemistry of nuclear fuels. The development of biphasic technique using various extractants to separate different elements and counting in presence of one another has been made possible. Inorganic scintillators have been recently developed which have the advantage of eliminating effects of quenching and presence of beta/gamma emitting actinides. This review will serve as a reference to those who want to carry out work in the field of determination of actinides using liquid scintillation counting techniques. (author)

Multiple-Input Multiple-Output OFDM with Index Modulation

OpenAIRE

Basar, Ertugrul

2015-01-01

Orthogonal frequency division multiplexing with index modulation (OFDM-IM) is a novel multicarrier transmission technique which has been proposed as an alternative to classical OFDM. The main idea of OFDM-IM is the use of the indices of the active subcarriers in an OFDM system as an additional source of information. In this work, we propose multiple-input multiple-output OFDM-IM (MIMO-OFDM-IM) scheme by combining OFDM-IM and MIMO transmission techniques. The low complexity transceiver structu...

Fast sorting measurement technique to determine decontamination priority

International Nuclear Information System (INIS)

Distenfeld, C.H.; Brosey, B.; Igarashi, H.

1986-01-01

The method used to select decontamination priorities for the Three Mile Island Unit 2 (TMI-2) reactor building (RB) is systematic, but costs in personnel exposure and time must be borne. One way of minimizing exposure is to define and treat the one or two surface sources that are important contributors to the collective dose of the recovery personnel. Surface characteristics can then be determined and decontamination techniques developed to match the removal requirements. At TMI-2, a fast sorting technique was developed and used to prioritize surfaces for exposure reduction. A second quick sort can then be used to determine the next generation of surface characterization, decontamination method selection, and performance. The quick-sort method that was developed is based on the Eberline HP 220A probes directional survey system. The angular response of the HP 220A probes approaches 2 pi steradians and allows toward-away type measurements. Sources distributed over 4 pi steradians are hard to define with this system. Angular differentiation was improved to about pi/2 steradians by redesigning the probe shield. The change allows unambiguous six-direction measurements, such as up, down, front, rear, right, and left with practically no angular overlap or exclusion. A simple, light-weight stand was used to establish an angular reference for the rectangular packaged probe. The six surface planes of the rectangle work with the angular reference to establish the six viewing angles

Determination of spent nuclear fuel assembly multiplication with the differential die-away self-interrogation instrument

Energy Technology Data Exchange (ETDEWEB)

Kaplan, Alexis C. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Henzl, Vladimir; Menlove, Howard O.; Swinhoe, Martyn T.; Belian, Anthony P. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Flaska, Marek; Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

2014-09-01

We present a novel method for determining the multiplication of a spent nuclear fuel assembly with a Differential Die-Away Self-Interrogation (DDSI) instrument. The signal, which is primarily created by thermal neutrons, is measured with four {sup 3}He detector banks surrounding a spent fuel assembly. The Rossi-alpha distribution (RAD) at early times reflects coincident events from single fissions as well as fission chains. Because of this fact, the early time domain contains information about both the fissile material and spontaneous fission material in the assembly being measured. A single exponential function fit to the early time domain of the RAD has a die-away time proportional to the spent fuel assembly (SFA) multiplication. This correlation was tested by simulating assay of 44 different SFAs with the DDSI instrument. The SFA multiplication was determined with a variance of 0.7%.

Analysis of classical time-trial performance and technique-specific physiological determinants in elite female cross-country skiers

Directory of Open Access Journals (Sweden)

Øyvind Sandbakk

2016-08-01

Full Text Available The present study investigated the contribution of performance on uphill, flat, and downhill sections to overall performance in an international 10-km classical time-trial in elite female cross-country skiers, as well as the relationships between performance on snow and laboratory-measured physiological variables in the double poling (DP and diagonal (DIA techniques. Ten elite female cross-country skiers were continuously measured by a global positioning system device during an international 10-km cross-country skiing time-trial in the classical technique. One month prior to the race, all skiers performed a 5-min submaximal and 3-min self-paced performance test while roller skiing on a treadmill, both in the DP and DIA techniques. The time spent on uphill (r=0.98 and flat (r=0.91 sections of the race correlated most strongly with the overall 10-km performance (both p<0.05. Approximately 56% of the racing time was spent uphill, and stepwise multiple regression revealed that uphill time explained 95.5% of the variance in overall performance (p<0.001. Distance covered during the 3-min roller-skiing test and body-mass normalized peak oxygen uptake (VO2peak in both techniques showed the strongest correlations with overall time-trial performance (r=0.66-0.78, with DP capacity tending to have greatest impact on the flat and DIA capacity on uphill terrain (all p<0.05. Our present findings reveal that the time spent uphill most strongly determine classical time-trial performance, and that the major portion of the performance differences among elite female cross-country skiers can be explained by variations in technique-specific aerobic power.

Characterising and modelling regolith stratigraphy using multiple geophysical techniques

Science.gov (United States)

Thomas, M.; Cremasco, D.; Fotheringham, T.; Hatch, M. A.; Triantifillis, J.; Wilford, J.

2013-12-01

Regolith is the weathered, typically mineral-rich layer from fresh bedrock to land surface. It encompasses soil (A, E and B horizons) that has undergone pedogenesis. Below is the weathered C horizon that retains at least some of the original rocky fabric and structure. At the base of this is the lower regolith boundary of continuous hard bedrock (the R horizon). Regolith may be absent, e.g. at rocky outcrops, or may be many 10's of metres deep. Comparatively little is known about regolith, and critical questions remain regarding composition and characteristics - especially deeper where the challenge of collecting reliable data increases with depth. In Australia research is underway to characterise and map regolith using consistent methods at scales ranging from local (e.g. hillslope) to continental scales. These efforts are driven by many research needs, including Critical Zone modelling and simulation. Pilot research in South Australia using digitally-based environmental correlation techniques modelled the depth to bedrock to 9 m for an upland area of 128 000 ha. One finding was the inability to reliably model local scale depth variations over horizontal distances of 2 - 3 m and vertical distances of 1 - 2 m. The need to better characterise variations in regolith to strengthen models at these fine scales was discussed. Addressing this need, we describe high intensity, ground-based multi-sensor geophysical profiling of three hillslope transects in different regolith-landscape settings to characterise fine resolution (i.e. a number of frequencies; multiple frequency, multiple coil electromagnetic induction; and high resolution resistivity. These were accompanied by georeferenced, closely spaced deep cores to 9 m - or to core refusal. The intact cores were sub-sampled to standard depths and analysed for regolith properties to compile core datasets consisting of: water content; texture; electrical conductivity; and weathered state. After preprocessing (filtering, geo

White matter tract-specific quantitative analysis in multiple sclerosis: Comparison of optic radiation reconstruction techniques.

Directory of Open Access Journals (Sweden)

Chenyu Wang

Full Text Available The posterior visual pathway is commonly affected by multiple sclerosis (MS pathology that results in measurable clinical and electrophysiological impairment. Due to its highly structured retinotopic mapping, the visual pathway represents an ideal substrate for investigating patho-mechanisms in MS. Therefore, a reliable and robust imaging segmentation method for in-vivo delineation of the optic radiations (OR is needed. However, diffusion-based tractography approaches, which are typically used for OR segmentation are confounded by the presence of focal white matter lesions. Current solutions require complex acquisition paradigms and demand expert image analysis, limiting application in both clinical trials and clinical practice. In the current study, using data acquired in a clinical setting on a 3T scanner, we optimised and compared two approaches for optic radiation (OR reconstruction: individual probabilistic tractography-based and template-based methods. OR segmentation results were applied to subjects with MS and volumetric and diffusivity parameters were compared between OR segmentation techniques. Despite differences in reconstructed OR volumes, both OR lesion volume and OR diffusivity measurements in MS subjects were highly comparable using optimised probabilistic tractography-based, and template-based, methods. The choice of OR reconstruction technique should be determined primarily by the research question and the nature of the available dataset. Template-based approaches are particularly suited to the semi-automated analysis of large image datasets and have utility even in the absence of dMRI acquisitions. Individual tractography methods, while more complex than template based OR reconstruction, permit measurement of diffusivity changes along fibre bundles that are affected by specific MS lesions or other focal pathologies.

An Improved Clutter Suppression Method for Weather Radars Using Multiple Pulse Repetition Time Technique

Directory of Open Access Journals (Sweden)

Yingjie Yu

2017-01-01

Full Text Available This paper describes the implementation of an improved clutter suppression method for the multiple pulse repetition time (PRT technique based on simulated radar data. The suppression method is constructed using maximum likelihood methodology in time domain and is called parametric time domain method (PTDM. The procedure relies on the assumption that precipitation and clutter signal spectra follow a Gaussian functional form. The multiple interleaved pulse repetition frequencies (PRFs that are used in this work are set to four PRFs (952, 833, 667, and 513 Hz. Based on radar simulation, it is shown that the new method can provide accurate retrieval of Doppler velocity even in the case of strong clutter contamination. The obtained velocity is nearly unbiased for all the range of Nyquist velocity interval. Also, the performance of the method is illustrated on simulated radar data for plan position indicator (PPI scan. Compared with staggered 2-PRT transmission schemes with PTDM, the proposed method presents better estimation accuracy under certain clutter situations.

A field comparison of multiple techniques to quantify groundwater - surface-water interactions

Science.gov (United States)

González-Pinzón, Ricardo; Ward, Adam S; Hatch, Christine E; Wlostowski, Adam N; Singha, Kamini; Gooseff, Michael N.; Haggerty, Roy; Harvey, Judson; Cirpka, Olaf A; Brock, James T

2015-01-01

implementing multiple techniques through collaborative research.

Mass determination of U-233 and Pu-239 by gamma spectrometry technique

International Nuclear Information System (INIS)

Moraes, M.A.P.V. de; Pugliesi, R.

1988-09-01

The gamma spectrometry technique has been used for masses determinations of uranium-233 and plutonium-239, granted by AERE-HARWELL. A high purity Ge semicondutor detector was used and the total efficiency curve was obtained for the counting system in the energy range 13 KeV to 135 KeV. The calculated values for the masses compared with that obtained by means of gravimetry technique. (author) [pt

More basic approach to the analysis of multiple specimen R-curves for determination of J/sub c/

International Nuclear Information System (INIS)

Carlson, K.W.; Williams, J.A.

1980-02-01

Multiple specimen J-R curves were developed for groups of 1T compact specimens with different a/W values and depth of side grooving. The purpose of this investigation was to determine J/sub c/ (J at onset of crack extension) for each group. Judicious selection of points on the load versus load-line deflection record at which to unload and heat tint specimens permitted direct observation of approximate onset of crack extension. It was found that the present recommended procedure for determining J/sub c/ from multiple specimen R-curves, which is being considered for standardization, consistently yielded nonconservative J/sub c/ values. A more basic approach to analyzing multiple specimen R-curves is presented, applied, and discussed. This analysis determined J/sub c/ values that closely corresponded to actual observed onset of crack extension

Collectively loading programs in a multiple program multiple data environment

Science.gov (United States)

Aho, Michael E.; Attinella, John E.; Gooding, Thomas M.; Gooding, Thomas M.; Miller, Samuel J.

2016-11-08

Techniques are disclosed for loading programs efficiently in a parallel computing system. In one embodiment, nodes of the parallel computing system receive a load description file which indicates, for each program of a multiple program multiple data (MPMD) job, nodes which are to load the program. The nodes determine, using collective operations, a total number of programs to load and a number of programs to load in parallel. The nodes further generate a class route for each program to be loaded in parallel, where the class route generated for a particular program includes only those nodes on which the program needs to be loaded. For each class route, a node is selected using a collective operation to be a load leader which accesses a file system to load the program associated with a class route and broadcasts the program via the class route to other nodes which require the program.

Determination of biologically active phenols and polyphenols in various objects by chromatographic techniques

International Nuclear Information System (INIS)

Kochetova, M V; Semenistaya, E N; Larionov, Oleg G; Revina, A A

2007-01-01

Chromatographic techniques for determination of biologically active phenols and polyphenols are considered. Various methods for sample preparation and detection are compared. The advantages of high performance liquid chromatography with spectrophotometric detection for determination of antioxidants are demonstrated. Data on determination of biologically active phenols and polyphenols published in the period from 1995 to 2005 are analysed.

Research on Innovating, Applying Multiple Paths Routing Technique Based on Fuzzy Logic and Genetic Algorithm for Routing Messages in Service - Oriented Routing

Directory of Open Access Journals (Sweden)

Nguyen Thanh Long

2015-02-01

Full Text Available MANET (short for Mobile Ad-Hoc Network consists of a set of mobile network nodes, network configuration changes very fast. In content based routing, data is transferred from source node to request nodes is not based on destination addresses. Therefore, it is very flexible and reliable, because source node does not need to know destination nodes. If We can find multiple paths that satisfies bandwidth requirement, split the original message into multiple smaller messages to transmit concurrently on these paths. On destination nodes, combine separated messages into the original message. Hence it can utilize better network resources, causes data transfer rate to be higher, load balancing, failover. Service Oriented Routing is inherited from the model of content based routing (CBR, combined with several advanced techniques such as Multicast, multiple path routing, Genetic algorithm to increase the data rate, and data encryption to ensure information security. Fuzzy logic is a logical field study evaluating the accuracy of the results based on the approximation of the components involved, make decisions based on many factors relative accuracy based on experimental or mathematical proof. This article presents some techniques to support multiple path routing from one network node to a set of nodes with guaranteed quality of service. By using these techniques can decrease the network load, congestion, use network resources efficiently.

Determination of trace elements in plant samples using XRF, PIXE and ICP-OES techniques

International Nuclear Information System (INIS)

Ahmed, Hassan Elzain Hassan

2014-07-01

The purpose of this study is to determine trace element concentration (Ca, Cu, Cr, K,Fe, Mn,Sr, and Za) in some sudanese wild plants namely, Ziziphus Abyssinica and Grewia Tenax. X-ray fluorescence ( X RF), particle-induced x-ray emission ( PIXE) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) techniques were used for element determination. A series of plants standard references materials were used to check the reliability of the different employed techniques as well as to estimate possible factors for correcting the concentration of some elements that deviated significantly from their actual concentration. The results showed that, X RF, PIXE and ICP-OES are equally competitive methods for measuring Ca,K, Fe, Sr and Zn elements. Unlikely to ICP-OES seems to be superior techniques tend to be appropriate methods for Cu determination in plant samples however, for Mn element PIXE and ICP-OES are advisable techniques for measuring this element rather than X RF method. On the other hand, ICP-OES seems to be the superior techniques over PIXE and X RF methods for Cr and Ni determination in plant samples. The effect of geographical location on trace elements concentration in plants has been examined through determination of element in different species of Grewia Tenax than collected from different location. Most of measured elements showed similarity indicating there is no significant impact of locations on the difference of element contents. In addition, two plants with different genetic families namely, Ziziphus Spina Christi and Ziziphus Abyssinica were collected from the same location and screened for their trace element content. It was found that there were no difference between the two plants for Ca, K, Cu, Fe, and Sr element. However, significant variations were observed for Mn and Zn concentrations implying the possibility of using of those two elements for plant taxonomy purposes.(Author)

Technique for Determining Lock Coefficient of Differential "Quif"

Directory of Open Access Journals (Sweden)

A. B. Fominyh

2015-01-01

Full Text Available Increasing the traction qualities of cars on the black ice and snow-covered roads is a relevant task. There are two ways to solve this task, i.e. optimize distribution of the power stream between the driving wheels of the car; introduce a differential (differentials of the increased friction in transmission.Now, an installation of the increased friction differential in transmission is the most widespread measure to increase traction properties of cars. The differential of design "Quif" is one of such differentials. To estimate the efficiency degree of using such a differential is possible either experimentally or theoretically. In case of theoretically determined usefulness of this differential design, as an estimate indicator of the differential installation in transmission a coefficient of lock is accepted.The article considers an algorithm and a technique to calculate a lock coefficient of the differential design "Quif" allowing us to define numeric values of the lock coefficient of such differential at designing stage. It also considers how the lock coefficient depends on the gearing angle and tilt angle of the gear wheel teeth of differential. The given estimating algorithm of designated parameter of differential has more logical and compact structure with regard to the known ones. The lock coefficient values calculated by the offered technique differ from the experimental data by no more than 12%. Taking into account abovementioned, the presented technique for calculating lock coefficient of differential "Quif" is advisable for practical application.

Multiple-Choice Testing Using Immediate Feedback--Assessment Technique (IF AT®) Forms: Second-Chance Guessing vs. Second-Chance Learning?

Science.gov (United States)

Merrel, Jeremy D.; Cirillo, Pier F.; Schwartz, Pauline M.; Webb, Jeffrey A.

2015-01-01

Multiple choice testing is a common but often ineffective method for evaluating learning. A newer approach, however, using Immediate Feedback Assessment Technique (IF AT®, Epstein Educational Enterprise, Inc.) forms, offers several advantages. In particular, a student learns immediately if his or her answer is correct and, in the case of an…

A Technique for Estimating Intensity of Emotional Expressions and Speaking Styles in Speech Based on Multiple-Regression HSMM

Science.gov (United States)

Nose, Takashi; Kobayashi, Takao

In this paper, we propose a technique for estimating the degree or intensity of emotional expressions and speaking styles appearing in speech. The key idea is based on a style control technique for speech synthesis using a multiple regression hidden semi-Markov model (MRHSMM), and the proposed technique can be viewed as the inverse of the style control. In the proposed technique, the acoustic features of spectrum, power, fundamental frequency, and duration are simultaneously modeled using the MRHSMM. We derive an algorithm for estimating explanatory variables of the MRHSMM, each of which represents the degree or intensity of emotional expressions and speaking styles appearing in acoustic features of speech, based on a maximum likelihood criterion. We show experimental results to demonstrate the ability of the proposed technique using two types of speech data, simulated emotional speech and spontaneous speech with different speaking styles. It is found that the estimated values have correlation with human perception.

Nuclear-physical techniques for determination of boron distribution in pure materials

International Nuclear Information System (INIS)

Kadirova, M.; Jumaev, N.; Simakhin, Yu.F.; Idrisov, Kh.; Usmanova, M.M.

2001-01-01

To study deep boron diffusion in the complex silicon structures, consisting of interchange boron doping layers of mono- and polycrystalline silicon, separated by oxide films a technique of sidelong section by using Solid State Nuclear Track Detector (SSNTD) has been elaborated. The boron distribution determination technique is based on the detection of alpha particles from the 10B(n, )7Li reaction with cellulose nitrate film. The etched track registering cellulose nitrate film show the structure image magnified 1/sin fold. Boron concentration defined by density of the etched pits appearing on the film surface. An optical microscope analysis of the sample track-mapping image is realized by examination with closely spaced ( l < x/sin ) and largely spaced ( l x/sin ) movements. All these elaborated techniques can be used to investigate other solid matrix

Application of the Modified Source Multiplication (MSM) technique to subcritical reactivity worth measurements in thermal and fast reactor systems

International Nuclear Information System (INIS)

Blaise, P.; Fougeras, P.; Mellier, F.

2009-01-01

The Amplified Source Multiplication (ASM) method and its improved Modified Source Multiplication (MSM) method have been widely used in the CEA's EOLE and MASURCA critical facilities over the past decades for the determination of reactivity worths by using fission chambers in subcritical configurations. They have been successfully applied to absorber (single or clusters) worth measurement in both thermal and fast spectra, or for (sodium or water) void reactivity worths. The ASM methodology, which is the basic technique to estimate a reactivity worth, uses relatively simple relationships between count rates of efficient miniature fission chambers located in slightly subcritical reference and perturbed configurations. If this method works quite well for small reactivity variation (a few effective delayed neutron fraction), its raw results needs to be corrected to take into account the flux perturbation in the fission chamber. This is performed by applying to the measurement a correction factor called MSM. Its characteristics is to take into account the local space and energy variation of the spectrum in the fission chamber, through standard perturbation theory applied to neutron transport calculation in the perturbed configuration. The proposed paper describes in details both methodologies, with their associated uncertainties. Applications on absorber cluster worth in the MISTRAL-4 full MOX mock-up core and the last core loaded in MASURCA show the importance of the MSM correction on raw data. (authors)

Determining the diet of larvae of western rock lobster (Panulirus cygnus using high-throughput DNA sequencing techniques.

Directory of Open Access Journals (Sweden)

Richard O'Rorke

Full Text Available The Western Australian rock lobster fishery has been both a highly productive and sustainable fishery. However, a recent dramatic and unexplained decline in post-larval recruitment threatens this sustainability. Our lack of knowledge of key processes in lobster larval ecology, such as their position in the food web, limits our ability to determine what underpins this decline. The present study uses a high-throughput amplicon sequencing approach on DNA obtained from the hepatopancreas of larvae to discover significant prey items. Two short regions of the 18S rRNA gene were amplified under the presence of lobster specific PNA to prevent lobster amplification and to improve prey amplification. In the resulting sequences either little prey was recovered, indicating that the larval gut was empty, or there was a high number of reads originating from multiple zooplankton taxa. The most abundant reads included colonial Radiolaria, Thaliacea, Actinopterygii, Hydrozoa and Sagittoidea, which supports the hypothesis that the larvae feed on multiple groups of mostly transparent gelatinous zooplankton. This hypothesis has prevailed as it has been tentatively inferred from the physiology of larvae, captive feeding trials and co-occurrence in situ. However, these prey have not been observed in the larval gut as traditional microscopic techniques cannot discern between transparent and gelatinous prey items in the gut. High-throughput amplicon sequencing of gut DNA has enabled us to classify these otherwise undetectable prey. The dominance of the colonial radiolarians among the gut contents is intriguing in that this group has been historically difficult to quantify in the water column, which may explain why they have not been connected to larval diet previously. Our results indicate that a PCR based technique is a very successful approach to identify the most abundant taxa in the natural diet of lobster larvae.

Evaluation of techniques for determining the density of fine woody debris

Science.gov (United States)

Becky Fasth; Mark E. Harmon; Christopher W. Woodall; Jay. Sexton

2010-01-01

Evaluated various techniques for determining the density (i.e., bulk density) of fine woody debris during forest inventory activities. It was found that only experts in dead wood inventory may be able to identify fine woody debris stages of decay. Suggests various future research directions such as...

Multiple gcd-closed sets and determinants of matrices associated with arithmetic functions

Directory of Open Access Journals (Sweden)

Hong Siao

2016-01-01

Full Text Available Let f be an arithmetic function and S = {x1, …, xn} be a set of n distinct positive integers. By (f(xi, xj (resp. (f[xi, xj] we denote the n × n matrix having f evaluated at the greatest common divisor (xi, xj (resp. the least common multiple [xi, xj] of x, and xj as its (i, j-entry, respectively. The set S is said to be gcd closed if (xi, xj ∈ S for 1 ≤ i, j ≤ n. In this paper, we give formulas for the determinants of the matrices (f(xi, xj and (f[xi, xj] if S consists of multiple coprime gcd-closed sets (i.e., S equals the union of S1, …, Sk with k ≥ 1 being an integer and S1, …, Sk being gcd-closed sets such that (lcm(Si, lcm(Sj = 1 for all 1 ≤ i ≠ j ≤ k. This extends the Bourque-Ligh, Hong’s and the Hong-Loewy formulas obtained in 1993, 2002 and 2011, respectively. It also generalizes the famous Smith’s determinant.

A novel technique to determine concentration-dependent solvent dispersion in Vapex

Energy Technology Data Exchange (ETDEWEB)

Abukhalifeh, H.; Lohi, A.; Upreti, S. R. [Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada)

2009-07-01

Vapex (vapor extraction of heavy oil and bitumen) is a promising recovery technology because it consumes low energy, and is very environmentally-friendly. The dispersion of solvents into heavy oil and bitumen is a crucial transport property governing Vapex. The accurate determination of solvent dispersion in Vapex is essential to effectively predict the amount and time scale of oil recovery as well to optimize the field operations. In this work, a novel technique is developed to experimentally determine the concentration-dependent dispersion coefficient of a solvent in Vapex process. The principles of variational calculus are utilized in conjunction with a mass transfer model of the experimental Vapex process. A computational algorithm is developed to optimally compute solvent dispersion as a function of its concentration in heavy oil. The developed technique is applied to Vapex utilizing propane as a solvent. The results show that dispersion of propane is a unimodal function of its concentration in bitumen. (author)

A Novel Technique to Determine Concentration-Dependent Solvent Dispersion in Vapex

Directory of Open Access Journals (Sweden)

Hadil Abukhalifeh

2009-10-01

Full Text Available Vapex (vapor extraction of heavy oil and bitumen is a promising recovery technology because it consumes low energy, and is very environmentally-friendly. The dispersion of solvents into heavy oil and bitumen is a crucial transport property governing Vapex. The accurate determination of solvent dispersion in Vapex is essential to effectively predict the amount and time scale of oil recovery as well to optimize the field operations. In this work, a novel technique is developed to experimentally determine the concentration-dependent dispersion coefficient of a solvent in Vapex process. The principles of variational calculus are utilized in conjunction with a mass transfer model of the experimental Vapex process. A computational algorithm is developed to optimally compute solvent dispersion as a function of its concentration in heavy oil. The developed technique is applied to Vapex utilizing propane as a solvent. The results show that dispersion of propane is a unimodal function of its concentration in bitumen.

A Monte Carlo simulation technique to determine the optimal portfolio

Directory of Open Access Journals (Sweden)

Hassan Ghodrati

2014-03-01

Full Text Available During the past few years, there have been several studies for portfolio management. One of the primary concerns on any stock market is to detect the risk associated with various assets. One of the recognized methods in order to measure, to forecast, and to manage the existing risk is associated with Value at Risk (VaR, which draws much attention by financial institutions in recent years. VaR is a method for recognizing and evaluating of risk, which uses the standard statistical techniques and the method has been used in other fields, increasingly. The present study has measured the value at risk of 26 companies from chemical industry in Tehran Stock Exchange over the period 2009-2011 using the simulation technique of Monte Carlo with 95% confidence level. The used variability in the present study has been the daily return resulted from the stock daily price change. Moreover, the weight of optimal investment has been determined using a hybrid model called Markowitz and Winker model in each determined stocks. The results showed that the maximum loss would not exceed from 1259432 Rials at 95% confidence level in future day.

Integration of multiple determinants in the neuronal computation of economic values.

Science.gov (United States)

Raghuraman, Anantha P; Padoa-Schioppa, Camillo

2014-08-27

Economic goods may vary on multiple dimensions (determinants). A central conjecture in decision neuroscience is that choices between goods are made by comparing subjective values computed through the integration of all relevant determinants. Previous work identified three groups of neurons in the orbitofrontal cortex (OFC) of monkeys engaged in economic choices: (1) offer value cells, which encode the value of individual offers; (2) chosen value cells, which encode the value of the chosen good; and (3) chosen juice cells, which encode the identity of the chosen good. In principle, these populations could be sufficient to generate a decision. Critically, previous work did not assess whether offer value cells (the putative input to the decision) indeed encode subjective values as opposed to physical properties of the goods, and/or whether offer value cells integrate multiple determinants. To address these issues, we recorded from the OFC while monkeys chose between risky outcomes. Confirming previous observations, three populations of neurons encoded the value of individual offers, the value of the chosen option, and the value-independent choice outcome. The activity of both offer value cells and chosen value cells encoded values defined by the integration of juice quantity and probability. Furthermore, both populations reflected the subjective risk attitude of the animals. We also found additional groups of neurons encoding the risk associated with a particular option, the risky nature of the chosen option, and whether the trial outcome was positive or negative. These results provide substantial support for the conjecture described above and for the involvement of OFC in good-based decisions. Copyright © 2014 the authors 0270-6474/14/3311583-21$15.00/0.

Carbon/Hydrogen ratio determination in hydrocarbons and its mixtures by electron backscattering technique

International Nuclear Information System (INIS)

Padron, I.; Desdin, L.F.; Navarro, A.; Fuentes, M.

1996-01-01

A method carbon/hydrogen ratio (C/H) determination in hydrocarbons and its mixtures was improved using the electron backscattering technique. Besides the hetero atoms (S,O and N) influence in petroleum is studied for being able to determinate the C/H ratio in cuban petroleum with high sulphur contents

Determination of the uranium concentration in apatite by the fission - track registration technique

International Nuclear Information System (INIS)

D'Oliveira Cardoso, D.

1983-01-01

The feasibility of using the fission-track registration technique to determine the uranium content in the phosphate rock beneficiation steps carried on by CompanhiA Arafertil, Araxa, Minas Gerais, Brazil is studied. This determination is of considerable interest to the environmental control of the Arafertil installations as well as of its surroundings or of the areas where these products will be used. The so called wet method was adopted and a 10 μm polycarbonate foil, fabricated by Bayer under the trade name Makrofol KG was used as detector. From the calibration curve obtained, it was possible to determine uranium contents in sample solutions ranging from 21 to 212 μg U/1 with an accuracy of 8 to 14.7%, respectively. The results obtained demonstrated that the technique used is appropriate to the purposes previously aimed at. (Author) [pt

Fast-neutron and gamma-ray transmission technique for the on-line determination of moisture in coal and coke

International Nuclear Information System (INIS)

Sowerby, B.D.; Millen, M.J.; Rafter, P.T.

1988-01-01

A fast neutron and γ-ray transmission technique is being developed for the on-line analysis of moisture. Calculations show that the technique is capable of determining coke moisture to better than 0.2 wt% over a wide range of coke thicknesses. The favoured technique uses a thick Li-glass detector surrounded by a neutron moderator to determine simultaneously the fast neutron and γ-ray intensities. Laboratory measurements on single coke samples showed that moisture can be determined to within 0.2 wt% over the range 3-13 wt% moisture and 300-500 mm thickness. Measurements on a range of coke samples showed that the increase in r.m.s. error due to bound H variations is less than about 0.4 wt% moisture. Applications of the technique, to moisture determination in black and brown coal are also investigated, both by calculation and experiment. Further potential applications of the technique are discussed, including the determination of C in steel. (author)

Whole-Body MRI versus PET in assessment of multiple myeloma disease activity.

LENUS (Irish Health Repository)

Shortt, Conor P

2009-04-01

The purpose of this study was to compare FDG PET; whole-body MRI; and the reference standard, bone marrow aspiration and biopsy, to determine the best imaging technique for assessment of disease activity in multiple myeloma.

Use of the azimuthal resistivity technique for determination of regional azimuth of transmissivity

Science.gov (United States)

Carlson, D.

2010-01-01

Many bedrock units contain joint sets that commonly act as preferred paths for the movement of water, electrical charge, and possible contaminants associated with production or transit of crude oil or refined products. To facilitate the development of remediation programs, a need exists to reliably determine regional-scale properties of these joint sets: azimuth of transmissivity ellipse, dominant set, and trend(s). The surface azimuthal electrical resistivity survey method used for local in situ studies can be a noninvasive, reliable, efficient, and relatively cost-effective method for regional studies. The azimuthal resistivity survey method combines the use of standard resistivity equipment with a Wenner array rotated about a fixed center point, at selected degree intervals, which yields an apparent resistivity ellipse from which joint-set orientation can be determined. Regional application of the azimuthal survey method was tested at 17 sites in an approximately 500 km2 (193 mi2) area around Milwaukee, Wisconsin, with less than 15m (50 ft) overburden above the dolomite. Results of 26 azimuthal surveys were compared and determined to be consistent with the results of two other methods: direct observation of joint-set orientation and transmissivity ellipses from multiple-well-aquifer tests. The average of joint-set trend determined by azimuthal surveys is within 2.5?? of the average of joint-set trend determined by direct observation of major joint sets at 24 sites. The average of maximum of transmissivity trend determined by azimuthal surveys is within 5.7?? of the average of maximum of transmissivity trend determined for 14 multiple-well-aquifer tests. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

Measuring multiple residual-stress components using the contour method and multiple cuts

Energy Technology Data Exchange (ETDEWEB)

Prime, Michael B [Los Alamos National Laboratory; Swenson, Hunter [Los Alamos National Laboratory; Pagliaro, Pierluigi [U. PALERMO; Zuccarello, Bernardo [U. PALERMO

2009-01-01

The conventional contour method determines one component of stress over the cross section of a part. The part is cut into two, the contour of the exposed surface is measured, and Bueckner's superposition principle is analytically applied to calculate stresses. In this paper, the contour method is extended to the measurement of multiple stress components by making multiple cuts with subsequent applications of superposition. The theory and limitations are described. The theory is experimentally tested on a 316L stainless steel disk with residual stresses induced by plastically indenting the central portion of the disk. The stress results are validated against independent measurements using neutron diffraction. The theory has implications beyond just multiple cuts. The contour method measurements and calculations for the first cut reveal how the residual stresses have changed throughout the part. Subsequent measurements of partially relaxed stresses by other techniques, such as laboratory x-rays, hole drilling, or neutron or synchrotron diffraction, can be superimposed back to the original state of the body.

Multiple-level defect species evaluation from average carrier decay

Science.gov (United States)

Debuf, Didier

2003-10-01

An expression for the average decay is determined by solving the the carrier continuity equations, which include terms for multiple defect recombination. This expression is the decay measured by techniques such as the contactless photoconductance decay method, which determines the average or volume integrated decay. Implicit in the above is the requirement for good surface passivation such that only bulk properties are observed. A proposed experimental configuration is given to achieve the intended goal of an assessment of the type of defect in an n-type Czochralski-grown silicon semiconductor with an unusually high relative lifetime. The high lifetime is explained in terms of a ground excited state multiple-level defect system. Also, minority carrier trapping is investigated.

Geomorphological and Geoelectric Techniques for Kwoi's Multiple Tremor Assessment

Science.gov (United States)

Dikedi, P. N.

2017-12-01

This work epicentres on geomorphological and geoelectric techniques for multiple tremor assessment in Kwoi, Nigeria. Earth tremor occurrences have been noted by Akpan and Yakubu (2010) within the last 70 years, in nine regions in Nigeria; on September 11,12,20,22, 23 and 24, 2016, additional earth tremors rocked the village of Kwoi eleven times. Houses cracked and collapsed, a rock split and slid and smoke evolved at N9027''5.909''', E800'44.951'', from an altitude of 798m. By employing the Ohmega Meter and Schlumberger configuration, four VES points are sounded for subsurface structure characterisation. Thereafter, a cylindrical steel ring is hammered into the ground at the first point (VES 1) and earth samples are scooped from this location; this procedure is repeated for other points (VES 2, 3 and 4). Winresist, Geo-earth, and Surfer version 12.0.626 software are employed to generate geo-sections, lithology, resistivity profile, Iso resistivity and Isopach maps, of the region. Outcome of results reveal some lithological formations of lateritic topsoil, fractured basement and fresh basement; additionally, results reveal 206.6m, 90.7m, 73.2m and 99.4m fractured basement thicknesses for four points. Scooped samples are transferred to the specimen stage of a Scanning Electron Microscope (SEM). SEM images show rounded inter-granular boundaries—the granular structures act like micro-wheels making the upper crustal mass susceptible to movement at the slightest vibration. Collapsed buildings are sited around VES1 location; samples from VES 1 are the most well fragmented sample owing to multiple microfractures—this result explains why VES 1 has the thickest fractured basement. Abrupt frictional sliding occurs between networks of fault lines; there is a likelihood that friction is most intense at the rock slide site on N9027'21.516'' and E800'44.9993'', VES 1 at N9027'5.819'' and E8005'3.1120'' and smoke sites—holo-centres are suspected below these locations. The

The development of techniques for determining the residual life time prediction on NPP equipment

International Nuclear Information System (INIS)

Antonov, Alexander V.; Dagaev, Alexander V.; Volnikov, Ivan S.

1999-01-01

The problem of determining the residual life prediction of NPP equipment is presently highly pressing. NPP residual life resources are 30 years, but for particular equipment it is much less. Thus, residual life resource for equipment of control and protection system of NPP unit is 5-10 years. The NPP equipment is expensive and its replacing requires much expense. Hence an urgent problem is to study residual life resources of equipment on the basis of statistic information obtained during operation. Deterministic approach of determining residual life resources for particular equipment is widely known in the literature. Physical and statistical models are also being developed for determining the residual life, e.g. the model (loading-bearing capability). The present work offers the techniques of the residual life determination reasoning from statistic information of functioning objects in the process of operation. To put the techniques into effect it is necessary to have information about the time of operation of a group of objects of the same type, the number of failures; it is desirable to know failure operating time, order of the object replacement and the reason which caused the replacement (failure or planned preventive maintenance). Metrics is based on studying the parameters for the series of failures resulted from real statistic data. Then we can proceed to distribution density of the failure working time. For this purpose the Voltarra's equation of the second order is solved f(t) = ω(t) + ∫ 0 t f(t - τ)ω(τ)dτ. Since statistics of data sampling related to failure is small due to difficulties in solution of Voltaire's equation, the authors offer moderate method of solution for the above equation. After distribution density of the failure working time is determined the calculation of equipment residual life is made by the following formula: T τ (t) 1/P(τ)∫ 0 ∞ P(t)dt. The proposed techniques are realised as the software. In the course of working

Multiple inert gas elimination technique by micropore membrane inlet mass spectrometry--a comparison with reference gas chromatography.

Science.gov (United States)

Kretzschmar, Moritz; Schilling, Thomas; Vogt, Andreas; Rothen, Hans Ulrich; Borges, João Batista; Hachenberg, Thomas; Larsson, Anders; Baumgardner, James E; Hedenstierna, Göran

2013-10-15

The mismatching of alveolar ventilation and perfusion (VA/Q) is the major determinant of impaired gas exchange. The gold standard for measuring VA/Q distributions is based on measurements of the elimination and retention of infused inert gases. Conventional multiple inert gas elimination technique (MIGET) uses gas chromatography (GC) to measure the inert gas partial pressures, which requires tonometry of blood samples with a gas that can then be injected into the chromatograph. The method is laborious and requires meticulous care. A new technique based on micropore membrane inlet mass spectrometry (MMIMS) facilitates the handling of blood and gas samples and provides nearly real-time analysis. In this study we compared MIGET by GC and MMIMS in 10 piglets: 1) 3 with healthy lungs; 2) 4 with oleic acid injury; and 3) 3 with isolated left lower lobe ventilation. The different protocols ensured a large range of normal and abnormal VA/Q distributions. Eight inert gases (SF6, krypton, ethane, cyclopropane, desflurane, enflurane, diethyl ether, and acetone) were infused; six of these gases were measured with MMIMS, and six were measured with GC. We found close agreement of retention and excretion of the gases and the constructed VA/Q distributions between GC and MMIMS, and predicted PaO2 from both methods compared well with measured PaO2. VA/Q by GC produced more widely dispersed modes than MMIMS, explained in part by differences in the algorithms used to calculate VA/Q distributions. In conclusion, MMIMS enables faster measurement of VA/Q, is less demanding than GC, and produces comparable results.

Laboratory model study of newly deposited dredger fills using improved multiple-vacuum preloading technique

Directory of Open Access Journals (Sweden)

Jingjin Liu

2017-10-01

Full Text Available Problems continue to be encountered concerning the traditional vacuum preloading method in field during the treatment of newly deposited dredger fills. In this paper, an improved multiple-vacuum preloading method was developed to consolidate newly dredger fills that are hydraulically placed in seawater for land reclamation in Lingang Industrial Zone of Tianjin City, China. With this multiple-vacuum preloading method, the newly deposited dredger fills could be treated effectively by adopting a novel moisture separator and a rapid improvement technique without sand cushion. A series of model tests was conducted in the laboratory for comparing the results from the multiple-vacuum preloading method and the traditional one. Ten piezometers and settlement plates were installed to measure the variations in excess pore water pressures and moisture content, and vane shear strength was measured at different positions. The testing results indicate that water discharge–time curves obtained by the traditional vacuum preloading method can be divided into three phases: rapid growth phase, slow growth phase, and steady phase. According to the process of fluid flow concentrated along tiny ripples and building of larger channels inside soils during the whole vacuum loading process, the fluctuations of pore water pressure during each loading step are divided into three phases: steady phase, rapid dissipation phase, and slow dissipation phase. An optimal loading pattern which could have a best treatment effect was proposed for calculating the water discharge and pore water pressure of soil using the improved multiple-vacuum preloading method. For the newly deposited dredger fills at Lingang Industrial Zone of Tianjin City, the best loading step was 20 kPa and the loading of 40–50 kPa produced the highest drainage consolidation. The measured moisture content and vane shear strength were discussed in terms of the effect of reinforcement, both of which indicate

Technique for determination of elastic limit of micron band-thick amorphous

International Nuclear Information System (INIS)

Zakharov, E.K.; Pol'dyaeva, G.P.; Tret'yakov, B.N.

1984-01-01

A method is suggested to determine the elastic limit of micron-thick amorphous band under bending. The elastic limit is determined by bending an amorphous band sample around a series of cylindrical mandrels of gradually decreasing radius. Experimental data on measuring the elastic limit of some amorphous iron base alloys according to the suggested technique are presented. The elastic limit of amorphous alloys is shown to lie in the 3140-4110 MPa range depending on chemical composition, which is about 2-2.5 times higher as compared to high-strength crystal alloys

The new technique of using the epigastric arteries in renal transplantation with multiple renal arteries

Directory of Open Access Journals (Sweden)

Mohammad Ali Amirzargar

2013-01-01

Full Text Available The most common anatomic variant seen in the donor kidneys for renal transplantation is multiple renal arteries (MRA, which can cause an increased risk of complications. We describe the long-term outcomes of 16 years of experience in 76 kidney transplantations with MRAs. In a new reconstruction technique, we remove arterial clamps after anastomosing the donor to the recipient′s main renal vessels, which cause backflow from accessory arteries to prevent thrombosis. By this technique, we reduce the ischemic times as well as the operating times. Both in live or cadaver donor kidneys, lower polar arteries were anastomosed to the inferior epigastric artery and upper polar arteries were anastomosed to the superior epigastric arteries. Injection of Papaverine and ablation of sympathic nerves of these arteries dilate and prevent them from post-operative spasm. Follow-up DTPA renal scan in all patients showed good perfusion and function of the transplanted kidney, except two cases of polar arterial thrombosis. Mean creatinine levels during at least two years of follow-up remained acceptable. Patient and graft survival were excellent. No cases of ATN, hypertension, rejection and urologic complications were found. In conclusion, this technique can be safely and successfully utilized for renal transplantation with kidneys having MRAs, and may be associated with a lower complication rate and better graft function compared with the existing techniques.

Comparison of attitude determination approaches using multiple Global Positioning System (GPS antennas

Directory of Open Access Journals (Sweden)

Wang Bing

2013-02-01

Full Text Available GPS-based attitude system is an important research field, since it is a valuable technique for the attitude determination of platforms. There exist two classes approaches for attitude determination using the GPS. The one determines attitude via baseline estimates in two frames, the other one solves for attitude by incorporating the attitude parameters directly into the GPS measurements. However, comparisons between these two classes approaches have been unexplored. First of all, two algorithms are introduced in detail which on behalf of these two kinds of approaches. Then we present numerical simulations demonstrating the performance of our algorithms and provide a comparison evaluating.

Early reoxygenation in tumors after irradiation: Determining factors and consequences for radiotherapy regimens using daily multiple fractions

International Nuclear Information System (INIS)

Crokart, Nathalie; Jordan, Benedicte F.; Baudelet, Christine; Ansiaux, Reginald; Sonveaux, Pierre; Gregoire, Vincent; Beghein, Nelson; Wever, Julie de; Bouzin, Caroline; Feron, Olivier; Gallez, Bernard

2005-01-01

Purpose: To characterize changes in the tumor microenvironment early after irradiation and determine the factors responsible for early reoxygenation. Methods and Materials: Fibrosarcoma type II (FSaII) and hepatocarcinoma transplantable liver tumor tumor oxygenation were determined using electron paramagnetic resonance oximetry and a fiberoptic device. Perfusion was assessed by laser Doppler, dynamic contrast-enhanced MRI, and dye penetration. Oxygen consumption was determined by electron paramagnetic resonance. The interstitial fluid pressure was evaluated by the wick-in-needle technique. Results: An increase in oxygen partial pressure was observed 3-4 h after irradiation. This increase resulted from a decrease in global oxygen consumption and an increase in oxygen delivery. The increase in oxygen delivery was due to radiation-induced acute inflammation (that was partially inhibited by the antiinflammatory agent diclofenac) and to a decrease in interstitial fluid pressure. The endothelial nitric oxide synthase pathway, identified as a contributing factor at 24 h after irradiation, did not play a role in the early stage after irradiation. We also observed that splitting a treatment of 18 Gy into two fractions separated by 4 h (time of maximal reoxygenation) had a greater effect on tumor regrowth delay than when applied as a single dose. Conclusion: Although the cell cycle redistribution effect is important for treatment protocols using multiple daily radiation fractions, the results of this work emphasize that the oxygen effect must be also considered to optimize the treatment strategy

The use of different techniques for determination of pitting corrosion potential of austenitic stainless steel

International Nuclear Information System (INIS)

Eskelinen, P.; Forsen, O.; Onnela, J.; Ylaesaari, S.; Haenninen, H.

1992-01-01

Three different techniques for pitting corrosion potential measurement on austenitic stainless steel (Fe18Cr10Ni) were compared: conventional polarization method, a new Avesta electrochemical corrosion measurement cell and a scratch technique. Special attention was paid to the effects of crevice corrosion during pitting corrosion potential measurement and to their elimination. Development of a rapid test technique for reliable pitting corrosion potential determination was aimed at and resulted from comparison of the different techniques

The determination of acoustic reflection coefficients by using cepstral techniques, II: Extensions of the technique and considerations of accuracy

Science.gov (United States)

Bolton, J. S.; Gold, E.

1986-10-01

In a companion paper the cepstral technique for the measurement of reflection coefficients was described. In particular the concepts of extraction noise and extraction delay were introduced. They are considered further here, and, in addition, a means of extending the cepstral technique to accommodate surfaces having lengthy impulse responses is described. The character of extraction noise, a cepstral component which interferes with reflection measurements, is largely determined by the spectrum of the signal radiated from the source loudspeaker. Here the origin and effects of extraction noise are discussed and it is shown that inverse filtering techniques may be used to reduce extraction noise without making impractical demands of the electrical test signal or the source loudspeaker. The extraction delay, a factor which is introduced when removing the reflector impulse response from the power cepstrum, has previously been estimated by a cross-correlation technique. Here the importance of estimating the extraction delay accurately is emphasized by showing the effect of small spurious delays on the calculation of the normal impedance of a reflecting surface. The effects are shown to accord with theory, and it was found that the real part of the estimated surface normal impedance is very nearly maximized when the spurious delay is eliminated; this has suggested a new way of determining the extraction delay itself. Finally, the basic cepstral technique is suited only to the measurement of surfaces whose impulse responses are shorter than τ, the delay between the arrival of the direct and specularly reflected components at the measurement position. Here it is shown that this restriction can be eliminated, by using a process known as cepstral inversion, when the direct cepstrum has a duration less than τ and cepstral aliasing is insignificant. It is also possible to use this technique to deconvolve a signal from an echo sequence in the time domain, an operation

Determining plutonium mass in spent fuel with non-destructive assay techniques - NGSU research overview and update on 6 NDA techniques

Energy Technology Data Exchange (ETDEWEB)

Tobin, Stephen J [Los Alamos National Laboratory; Conlin, Jeremy L [Los Alamos National Laboratory; Evans, Louise G [Los Alamos National Laboratory; Hu, Jianwei [Los Alamos National Laboratory; Blanc, Pauline C [Los Alamos National Laboratory; Lafleur, Adrienne M [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Schear, Melissa A [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Fensin, Michael L [Los Alamos National Laboratory; Freeman, Corey R [Los Alamos National Laboratory; Koehler, William E [Los Alamos National Laboratory; Mozin, V [Los Alamos National Laboratory; Sandoval, N P [Los Alamos National Laboratory; Lee, T H [KAERI; Cambell, L W [PNNL; Cheatham, J R [ORNL; Gesh, C J [PNNL; Hunt, A [IDAHO STATE UNIV; Ludewigt, B A [LBNL; Smith, L E [PNNL; Sterbentz, J [INL

2010-09-15

This poster is one of two complementary posters. The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel assemblies with non-destructive assay (NDA). This research effort has the goal of quantifying the capability of 14 NDA techniques as well as training a future generation of safeguards practitioners. By November of 2010, we will be 1.5 years into the first phase (2.5 years) of work. This first phase involves primarily Monte Carlo modelling while the second phase (also 2.5 years) will focus on experimental work. The goal of phase one is to quantify the detection capability of the various techniques for the benefit of safeguard technology developers, regulators, and policy makers as well as to determine what integrated techniques merit experimental work, We are considering a wide range of possible technologies since our research horizon is longer term than the focus of most regulator bodies. The capability of all of the NDA techniques will be determined for a library of 64 17 x 17 PWR assemblies [burnups (15, 30, 45, 60 GWd/tU), initial enrichments (2, 3, 4, 5%) and cooling times (1, 5, 20, 80 years)]. The burnup and cooling time were simulated with each fuel pin being comprised of four radial regions. In this paper an overview of the purpose will be given as well as a technical update on the following 6 neutron techniques: {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Passive Neutron Albedo Reactivity, Self-Integration Neutron Resonance Densitometry. The technical update will quantify the anticipated performance of each technique for the 64 assemblies of the spent fuel library.

Determining plutonium mass in spent fuel with non-destructive assay techniques - NGSI research overview and update on 6 NDA techniques

International Nuclear Information System (INIS)

Tobin, Stephen J.; Conlin, Jeremy L.; Evans, Louise G.; Hu, Kianwei; Blanc, P.C.; Lafleur, Am; Menlove, H.O.; Schear, M.A.; Swinhoe, M.T.; Croft, S.; Fensin, M.L.; Freeman, C.R.; Koehler, W.E.; Mozin, V.; Sandoval, N.P.; Lee, T.H.; Cambell, L.W.; Cheatham, J.R.; Gesh, C.J.; Hunt, A.; Ludewigt, B.A.; Smith, L.E.; Sterbentz, J.

2010-01-01

This poster is one of two complementary posters. The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel assemblies with non-destructive assay (NDA). This research effort has the goal of quantifying the capability of 14 NDA techniques as well as training a future generation of safeguards practitioners. By November of 2010, we will be 1.5 years into the first phase (2.5 years) of work. This first phase involves primarily Monte Carlo modelling while the second phase (also 2.5 years) will focus on experimental work. The goal of phase one is to quantify the detection capability of the various techniques for the benefit of safeguard technology developers, regulators, and policy makers as well as to determine what integrated techniques merit experimental work, We are considering a wide range of possible technologies since our research horizon is longer term than the focus of most regulator bodies. The capability of all of the NDA techniques will be determined for a library of 64 17 x 17 PWR assemblies (burnups (15, 30, 45, 60 GWd/tU), initial enrichments (2, 3, 4, 5%) and cooling times (1, 5, 20, 80 years)). The burnup and cooling time were simulated with each fuel pin being comprised of four radial regions. In this paper an overview of the purpose will be given as well as a technical update on the following 6 neutron techniques: 252 Cf Interrogation with Prompt Neutron Detection, Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Passive Neutron Albedo Reactivity, Self-Integration Neutron Resonance Densitometry. The technical update will quantify the anticipated performance of each technique for the 64 assemblies of the spent fuel library.

A Simple Technique for Determining the pH of Whole Cigarette Smoke

Directory of Open Access Journals (Sweden)

Dong J

2014-12-01

Full Text Available A new technique has been developed to determine the pH of whole cigarette smoke. In this technique, whole smoke from ten cigarettes was trapped in 300 mL water containing 1% (w/v sodium chloride and the pH was determined on the resulting aqueous suspension of cigarette smoke. Two impingers with an extra coarse porosity fritted disc were used to dispense the smoke in the aqueous trapping medium. Cigarettes were smoked on a 20-port Borgwaldt RM 20/CS smoking machine using modified FTC (Federal Trade Commission conditions. The puff volume was adjusted to take a 35 mL puff as measured through the cigarette and the collection traps. This new technique accounts for the contributions to smoke pH from both the vapor phase and the particulate phase of smoke. The repeatability of this new technique was determined on eighteen replicates of a commercially available non-menthol, filter cigarette. Each measurement was done on a different day to check for a possible drift in pH with time. The mean pH value for the chosen sample was found to be 4.97 with a standard deviation of 0.07 pH units. The smoke pH values for over 150 commercially available cigarette brands with a variety of “tar” levels were determined. The smoke pH values had a range from 4.6 to 5.5, with an average of 4.79 and a maximum standard deviation of 0.10 pH units. An experimental flue cured cigarette had a smoke pH of around 5.0, while an experimental Burley cigarette had a smoke pH of 5.4. No correlation between smoke pH and “tar” or total particulate matter (TPM and between pH and nicotine levels was found. The purpose of the present study was to develop a practical, relatively simple laboratory method to measure the pH of a water solution of whole smoke, and was not intended to reflect, or have direct relevance for any biochemical or biological phenomena such as inhalability of smoke, flavor perception, nicotine ab-sorption, etc.”

The Achilles Heel of Normal Determinations via Minimum Variance Techniques: Worldline Dependencies

Science.gov (United States)

Ma, Z.; Scudder, J. D.; Omidi, N.

2002-12-01

Time series of data collected across current layers are usually organized by divining coordinate transformations (as from minimum variance) that permits a geometrical interpretation for the data collected. Almost without exception the current layer geometry is inferred by supposing that the current carrying layer is locally planar. Only after this geometry is ``determined'' can the various quantities predicted by theory calculated. The precision of reconnection rated ``measured'' and the quantitative support for or against component reconnection be evaluated. This paper defines worldline traversals across fully resolved Hall two fluid models of reconnecting current sheets (with varying sizes of guide fields) and across a 2-D hybrid solution of a super critical shock layer. Along each worldline various variance techniques are used to infer current sheet normals based on the data observed along this worldline alone. We then contrast these inferred normals with those known from the overview of the fully resolved spatial pictures of the layer. Absolute errors of 20 degrees in the normal are quite commonplace, but errors of 40-90 deg are also implied, especially for worldlines that make more and more oblique angles to the true current sheet normal. These mistaken ``inferences'' are traceable to the degree that the data collected sample 2-D variations within these layers or not. While it is not surprising that these variance techniques give incorrect errors in the presence of layers that possess 2-D variations, it is illuminating that such large errors need not be signalled by the traditional error formulae for the error cones on normals that have been previously used to estimate the errors of normal choices. Frequently the absolute errors that depend on worldline path can be 10 times the random error that formulae would predict based on eigenvalues of the covariance matrix. A given time series cannot be associated in any a priori way with a specific worldline

Comparison of protein fermentation characteristics in rumen fluid determined with the gas production technique and the nylon bag technique

NARCIS (Netherlands)

Cone, J.W.; Rodrigues, M.A.M.; Guedes, C.M.; Blok, M.C.

2009-01-01

In this study, a modified version of the gas production technique was used to determine protein fermentation characteristics in rumen fluid of 19 feedstuffs. Performing the incubations in a N-free environment, and with an excess of rapidly fermentable carbohydrates, made N the limiting factor to

The determination of pesticide residues in local vegetables by means of neutron activation technique

International Nuclear Information System (INIS)

Mongkolphantha, S.; Karasuddhi, P.; Yamkate, P.; Serichareonsatit, N.

1975-01-01

Analytical methods based on neutron activation have been developed for studying pesticides residues of bromine, arsenic and mercury in local vegetables and fruits. The concentration of bromine, arsenic and mercury in samples are enriched prior to neutron irradiations by a technique of dry-ashing and freeze-drying for the determination of arsenic, bromine and mercury respectively. The element bromine is determined instrumentally while arsenic and mercury are determined destructively using a distillation technique. The limit of detection under the conditions used for bromine, arsenic and mercury as obtained are 0.01, 0.001 and 0.0001 microgram respectively. A total of 45 varieties of vegetables and 20 varieties of fruits are analyzed. The results of the investigation and the concentration range in part per million of bromine, arsenic and mercury are also presented

Variable weight Khazani-Syed code using hybrid fixed-dynamic technique for optical code division multiple access system

Science.gov (United States)

Anas, Siti Barirah Ahmad; Seyedzadeh, Saleh; Mokhtar, Makhfudzah; Sahbudin, Ratna Kalos Zakiah

2016-10-01

Future Internet consists of a wide spectrum of applications with different bit rates and quality of service (QoS) requirements. Prioritizing the services is essential to ensure that the delivery of information is at its best. Existing technologies have demonstrated how service differentiation techniques can be implemented in optical networks using data link and network layer operations. However, a physical layer approach can further improve system performance at a prescribed received signal quality by applying control at the bit level. This paper proposes a coding algorithm to support optical domain service differentiation using spectral amplitude coding techniques within an optical code division multiple access (OCDMA) scenario. A particular user or service has a varying weight applied to obtain the desired signal quality. The properties of the new code are compared with other OCDMA codes proposed for service differentiation. In addition, a mathematical model is developed for performance evaluation of the proposed code using two different detection techniques, namely direct decoding and complementary subtraction.

Improving Conductivity Image Quality Using Block Matrix-based Multiple Regularization (BMMR Technique in EIT: A Simulation Study

Directory of Open Access Journals (Sweden)

Tushar Kanti Bera

2011-06-01

Full Text Available A Block Matrix based Multiple Regularization (BMMR technique is proposed for improving conductivity image quality in EIT. The response matrix (JTJ has been partitioned into several sub-block matrices and the highest eigenvalue of each sub-block matrices has been chosen as regularization parameter for the nodes contained by that sub-block. Simulated boundary data are generated for circular domain with circular inhomogeneity and the conductivity images are reconstructed in a Model Based Iterative Image Reconstruction (MoBIIR algorithm. Conductivity images are reconstructed with BMMR technique and the results are compared with the Single-step Tikhonov Regularization (STR and modified Levenberg-Marquardt Regularization (LMR methods. It is observed that the BMMR technique reduces the projection error and solution error and improves the conductivity reconstruction in EIT. Result show that the BMMR method also improves the image contrast and inhomogeneity conductivity profile and hence the reconstructed image quality is enhanced. ;doi:10.5617/jeb.170 J Electr Bioimp, vol. 2, pp. 33-47, 2011

Simple and effective method of determining multiplicity distribution law of neutrons emitted by fissionable material with significant self -multiplication effect

International Nuclear Information System (INIS)

Yanjushkin, V.A.

1991-01-01

At developing new methods of non-destructive determination of plutonium full mass in nuclear materials and products being involved in uranium -plutonium fuel cycle by its intrinsic neutron radiation, it may be useful to know not only separate moments but the multiplicity distribution law itself of neutron leaving this material surface using the following as parameters - firstly, unconditional multiplicity distribution laws of neutrons formed in spontaneous and induced fission acts of the given fissionable material corresponding nuclei and unconditional multiplicity distribution law of neutrons caused by (α,n) reactions at light nuclei of some elements which compose this material chemical structure; -secondly, probability of induced fission of this material nuclei by an incident neutron of any nature formed during the previous fissions or(α,n) reactions. An attempt to develop similar theory has been undertaken. Here the author proposes his approach to this problem. The main advantage of this approach, to our mind, consists in its mathematical simplicity and easy realization at the computer. In principle, the given model guarantees any good accuracy at any real value of induced fission probability without limitations dealing with physico-chemical composition of nuclear material

Nondestructive NMR technique for moisture determination in radioactive materials

International Nuclear Information System (INIS)

Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.

1998-01-01

This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ( 3 H, 3 He, 239 Pu, 241 Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO 2 and UO 2 systems. The total moisture was quantified by means of 1 H NMR detection of H 2 O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96

Reconstruction of elongated bubbles fusing the information from multiple optical probes through a Bayesian inference technique

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Shubhankar; Das, Prasanta Kr., E-mail: pkd@mech.iitkgp.ernet.in [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Roy Chaudhuri, Partha [Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

2016-07-15

In this communication, a novel optical technique has been proposed for the reconstruction of the shape of a Taylor bubble using measurements from multiple arrays of optical sensors. The deviation of an optical beam passing through the bubble depends on the contour of bubble surface. A theoretical model of the deviation of a beam during the traverse of a Taylor bubble through it has been developed. Using this model and the time history of the deviation captured by the sensor array, the bubble shape has been reconstructed. The reconstruction has been performed using an inverse algorithm based on Bayesian inference technique and Markov chain Monte Carlo sampling algorithm. The reconstructed nose shape has been compared with the true shape, extracted through image processing of high speed images. Finally, an error analysis has been performed to pinpoint the sources of the errors.

Determination of trace quantities of uranium in rocks mass spectrometric isotope dilution technique

International Nuclear Information System (INIS)

Kakazu, Mauricio Hiromitu

1980-01-01

A detailed experimental investigation on the thermionic emission of uranium deposited on a single flat type rhenium filament has been carried out. The study was aimed at determining the influence of various forms of deposition on the emission sensitivity and thermal stability of U + , UO + and UO 2 + ions. Based on these investigations, a technique, involving an addition of a small quantity of colloidal suspension of graphite on top of the uranyl nitrate sample deposited, was chosen because of its higher, emission sensitivity for uranium metal ions. The experimental parameters of the technique were optimised and the technique was employed in the determination of trace quantities of uranium in rock samples using mass spectrometric isotope dilution method. For the mass spectrometric isotope dilution analysis National Bureau of Standards uranium isotopic standard NBS-U 970 was employed as a tracer, where as the mass discrimination effect in the uranium isotope analysis was corrected using the uranium isotopic standard NBS-U500. Uranium was determined in each of the seven granite samples from Wyoming, USA and two USGS standard rocks. The precision of the analysis was found to be ±1% . The uranium values obtained on the rock samples were compared with the analyses of other investigators. Influence of the sample splitting on the uranium analysis was discussed in the light of the analytical results obtained.(author)

Probabilistic images (PBIS): A concise image representation technique for multiple parameters

International Nuclear Information System (INIS)

Wu, L.C.; Yeh, S.H.; Chen, Z.; Liu, R.S.

1984-01-01

Based on m parametric images (PIs) derived from a dynamic series (DS), each pixel of DS is regarded as an m-dimensional vector. Given one set of normal samples (pixels) N and another of abnormal samples A, probability density functions (pdfs) of both sets are estimated. Any unknown sample is classified into N or A by calculating the probability of its being in the abnormal set using the Bayes' theorem. Instead of estimating the multivariate pdfs, a distance ratio transformation is introduced to map the m-dimensional sample space to one dimensional Euclidean space. Consequently, the image that localizes the regional abnormalities is characterized by the probability of being abnormal. This leads to the new representation scheme of PBIs. Tc-99m HIDA study for detecting intrahepatic lithiasis (IL) was chosen as an example of constructing PBI from 3 parameters derived from DS and such a PBI was compared with those 3 PIs, namely, retention ratio image (RRI), peak time image (TNMAX) and excretion mean transit time image (EMTT). 32 normal subjects and 20 patients with proved IL were collected and analyzed. The resultant sensitivity and specificity of PBI were 97% and 98% respectively. They were superior to those of any of the 3 PIs: RRI (94/97), TMAX (86/88) and EMTT (94/97). Furthermore, the contrast of PBI was much better than that of any other image. This new image formation technique, based on multiple parameters, shows the functional abnormalities in a structural way. Its good contrast makes the interpretation easy. This technique is powerful compared to the existing parametric image method

Clustering economies based on multiple criteria decision making techniques

Directory of Open Access Journals (Sweden)

Mansour Momeni

2011-10-01

Full Text Available One of the primary concerns on many countries is to determine different important factors affecting economic growth. In this paper, we study some factors such as unemployment rate, inflation ratio, population growth, average annual income, etc to cluster different countries. The proposed model of this paper uses analytical hierarchy process (AHP to prioritize the criteria and then uses a K-mean technique to cluster 59 countries based on the ranked criteria into four groups. The first group includes countries with high standards such as Germany and Japan. In the second cluster, there are some developing countries with relatively good economic growth such as Saudi Arabia and Iran. The third cluster belongs to countries with faster rates of growth compared with the countries located in the second group such as China, India and Mexico. Finally, the fourth cluster includes countries with relatively very low rates of growth such as Jordan, Mali, Niger, etc.

Using the Coefficient of Determination "R"[superscript 2] to Test the Significance of Multiple Linear Regression

Science.gov (United States)

Quinino, Roberto C.; Reis, Edna A.; Bessegato, Lupercio F.

2013-01-01

This article proposes the use of the coefficient of determination as a statistic for hypothesis testing in multiple linear regression based on distributions acquired by beta sampling. (Contains 3 figures.)

The multiple imputation method: a case study involving secondary data analysis.

Science.gov (United States)

Walani, Salimah R; Cleland, Charles M

2015-05-01

To illustrate with the example of a secondary data analysis study the use of the multiple imputation method to replace missing data. Most large public datasets have missing data, which need to be handled by researchers conducting secondary data analysis studies. Multiple imputation is a technique widely used to replace missing values while preserving the sample size and sampling variability of the data. The 2004 National Sample Survey of Registered Nurses. The authors created a model to impute missing values using the chained equation method. They used imputation diagnostics procedures and conducted regression analysis of imputed data to determine the differences between the log hourly wages of internationally educated and US-educated registered nurses. The authors used multiple imputation procedures to replace missing values in a large dataset with 29,059 observations. Five multiple imputed datasets were created. Imputation diagnostics using time series and density plots showed that imputation was successful. The authors also present an example of the use of multiple imputed datasets to conduct regression analysis to answer a substantive research question. Multiple imputation is a powerful technique for imputing missing values in large datasets while preserving the sample size and variance of the data. Even though the chained equation method involves complex statistical computations, recent innovations in software and computation have made it possible for researchers to conduct this technique on large datasets. The authors recommend nurse researchers use multiple imputation methods for handling missing data to improve the statistical power and external validity of their studies.

Single-cell multiple gene expression analysis based on single-molecule-detection microarray assay for multi-DNA determination

Energy Technology Data Exchange (ETDEWEB)

Li, Lu [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang, Xianwei [School of Life Sciences, Shandong University, Jinan 250100 (China); Zhang, Xiaoli [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang, Jinxing [School of Life Sciences, Shandong University, Jinan 250100 (China); Jin, Wenrui, E-mail: jwr@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

2015-01-07

Highlights: • A single-molecule-detection (SMD) microarray for 10 samples is fabricated. • The based-SMD microarray assay (SMA) can determine 8 DNAs for each sample. • The limit of detection of SMA is as low as 1.3 × 10{sup −16} mol L{sup −1}. • The SMA can be applied in single-cell multiple gene expression analysis. - Abstract: We report a novel ultra-sensitive and high-selective single-molecule-detection microarray assay (SMA) for multiple DNA determination. In the SMA, a capture DNA (DNAc) microarray consisting of 10 subarrays with 9 spots for each subarray is fabricated on a silanized glass coverslip as the substrate. On the subarrays, the spot-to-spot spacing is 500 μm and each spot has a diameter of ∼300 μm. The sequence of the DNAcs on the 9 spots of a subarray is different, to determine 8 types of target DNAs (DNAts). Thus, 8 types of DNAts are captured to their complementary DNAcs at 8 spots of a subarray, respectively, and then labeled with quantum dots (QDs) attached to 8 types of detection DNAs (DNAds) with different sequences. The ninth spot is used to detect the blank value. In order to determine the same 8 types of DNAts in 10 samples, the 10 DNAc-modified subarrays on the microarray are identical. Fluorescence single-molecule images of the QD-labeled DNAts on each spot of the subarray are acquired using a home-made single-molecule microarray reader. The amounts of the DNAts are quantified by counting the bright dots from the QDs. For a microarray, 8 types of DNAts in 10 samples can be quantified in parallel. The limit of detection of the SMA for DNA determination is as low as 1.3 × 10{sup −16} mol L{sup −1}. The SMA for multi-DNA determination can also be applied in single-cell multiple gene expression analysis through quantification of complementary DNAs (cDNAs) corresponding to multiple messenger RNAs (mRNAs) in single cells. To do so, total RNA in single cells is extracted and reversely transcribed into their cDNAs. Three

Angle-resolved photoemission extended fine structure: Multiple layers of emitters and multiple initial states

International Nuclear Information System (INIS)

Huff, W.R.A.; Kellar, S.A.; Moler, E.J.; California Univ., Berkeley, CA; Chen, Y.; Wu, H.; Shirley, D.A.; Hussain, Z.

1995-01-01

Recently, angle-resolved photoemission extended fine structure (ARPEFS) has been applied to experimental systems involving multiple layers of emitters and non-s core-level photoemission in an effort to broaden the utility of the technique. Most of the previous systems have been comprised of atomic or molecular overlayers adsorbed onto a single-crystal, metal surface and the photoemission data were taken from an s atomic core-level in the overlayer. For such a system, the acquired ARPEFS data is dominated by the p o final state wave backscattering from the substrate atoms and is well understood. In this study, we investigate ARPEFS as a surface-region structure determination technique when applied to experimental systems comprised of multiple layers of photoemitters and arbitrary initial state core-level photoemission. Understanding the data acquired from multiple layers of photoemitters is useful for studying multilayer interfaces, ''buried'' surfaces, and clean crystals in ultra- high vacuum. The ability to apply ARPEFS to arbitrary initial state core-level photoemission obviously opens up many systems to analysis. Efforts have been ongoing to understand such data in depth. We present clean Cu(111) 3s, 3p, and 3d core-level, normal photoemission data taken on a high resolution soft x-ray beamline 9.3.2 at the Advanced Light Source in Berkeley, California and clean Ni(111) 3p normal photoemission data taken at the National Synchrotron Light Source in Upton, New York, USA

A Compton scattering technique to determine wood density and locating defects in it

International Nuclear Information System (INIS)

Tondon, Akash; Sandhu, B. S.; Singh, Bhajan; Singh, Mohinder

2015-01-01

A Compton scattering technique is presented to determine density and void location in the given wooden samples. The technique uses a well collimated gamma ray beam from 137 Cs along with the NaI(Tl) scintillation detector. First, a linear relationship is established between Compton scattered intensity and known density of chemical compounds, and then density of the wood is determined from this linear relation. In another experiment, the ability of penetration of gamma rays is explored to detect voids in wooden (low Z) sample. The sudden reduction in the Compton scattered intensities agrees well with the position and size of voids in the wooden sample. It is concluded that wood density and the voids of size ∼ 4 mm and more can be detected easily by this method

Sintering equation: determination of its coefficients by experiments - using multiple regression

International Nuclear Information System (INIS)

Windelberg, D.

1999-01-01

Sintering is a method for volume-compression (or volume-contraction) of powdered or grained material applying high temperature (less than the melting point of the material). Maekipirtti tried to find an equation which describes the process of sintering by its main parameters sintering time, sintering temperature and volume contracting. Such equation is called a sintering equation. It also contains some coefficients which characterise the behaviour of the material during the process of sintering. These coefficients have to be determined by experiments. Here we show that some linear regressions will produce wrong coefficients, but multiple regression results in an useful sintering equation. (orig.)

Determination of true coincidence correction factors using Monte-Carlo simulation techniques

Directory of Open Access Journals (Sweden)

Chionis Dionysios A.

2014-01-01

Full Text Available Aim of this work is the numerical calculation of the true coincidence correction factors by means of Monte-Carlo simulation techniques. For this purpose, the Monte Carlo computer code PENELOPE was used and the main program PENMAIN was properly modified in order to include the effect of the true coincidence phenomenon. The modified main program that takes into consideration the true coincidence phenomenon was used for the full energy peak efficiency determination of an XtRa Ge detector with relative efficiency 104% and the results obtained for the 1173 keV and 1332 keV photons of 60Co were found consistent with respective experimental ones. The true coincidence correction factors were calculated as the ratio of the full energy peak efficiencies was determined from the original main program PENMAIN and the modified main program PENMAIN. The developed technique was applied for 57Co, 88Y, and 134Cs and for two source-to-detector geometries. The results obtained were compared with true coincidence correction factors calculated from the "TrueCoinc" program and the relative bias was found to be less than 2%, 4%, and 8% for 57Co, 88Y, and 134Cs, respectively.

2D study of wind forces around multiple cooling towers using ...

African Journals Online (AJOL)

A comprehensive numerical study for the determination of wind pressure coefficients on multiple cooling towers by simulating turbulence using Reynolds Averaged Navier-Stokes Equations (RANS) models of Computational Fluid Dynamics techniques (CFD) such as, Standard k −ε , RNG k −ε , Realizable k −ε and Reynolds ...

Isotopic Determination of Nuclear Materials Using Nuclear Fission Track Registration Technique and Thermal Ionization Mass Spectrometric Technique

International Nuclear Information System (INIS)

Jeon, Young Sin; Pyo, Hyeong Yeol; Park, Yong Joon; Song, Kyu Seok; Kim, Won Ho; Jee, Kwang Yong

2007-05-01

It is very important to develope the technology for the determination of isotopic ratios of hot particles( 234 U, 235 U, 236 U etc.) detected from swipe samples of various nuclear facilities. This technology is highly competitive internationally and has to be established independently as long as our government maintains atomic energy and treats nuclear materials. In this text, sample pretreatment procedure, gamma-ray counting, alpha or fission track techniques, isotopic analysis of U and Pu, background problems and detection limits for mass determination, and their application to the real swipe sample were described with detailed procedure. This technology would contribute to the Korean economy's high growth rate as well as to superiority of government's leading research and development programs if successfully established

Track Detection Technique Using CR-39 for Determining Depleted Uranium in Biological Specimens

International Nuclear Information System (INIS)

Murbat, S.M.

2013-01-01

Track detecting technique using CR-39 track detector has been implemented for determining depleted uranium concentration in biological specimens (tissues, bones, and blood) of patients infected with cancer diseases. Results were compared with specimens of patients infected with conventional diseases (noncancerous). Specimens were collected from middle and south of Iraq have been contaminated with depleted uranium in the Gulf war in 1991. Results show that this technique is efficient for determining depleted uranium concentration in biological specimens. It was found that all studies samples determine for patients infected with cancer diseases contain a high concentration of depleted uranium (more than the international standard) comparing with noncancerous diseases. Moreover, it was found that persons infected with Leukemia show more sensitive to uranium concentrations to induce the diseases (66-202 ppb), while (116- 1910 ppb) concentrations were needed for inducing cancer diseases in organs and tissues. Result confirmed the correlation between cancerous diseases and the munitions made of depleted uranium used in the Gulf war in 1991 leads to contaminate the Iraqi environment and causes a high risk against people in Iraq.

Comparison of multiple support excitation solution techniques for piping systems

International Nuclear Information System (INIS)

Sterkel, H.P.; Leimbach, K.R.

1980-01-01

Design and analysis of nuclear power plant piping systems exposed to a variety of dynamic loads often require multiple support excitation analysis by modal or direct time integration methods. Both methods have recently been implemented in the computer program KWUROHR for static and dynamic analysis of piping systems, following the previous implementation of the multiple support excitation response spectrum method (see papers K 6/15 and K 6/15a of the SMiRT-4 Conference). The results of multiple support excitation response spectrum analyses can be examined by carrying out the equivalent time history analyses which do not distort the time phase relationship between the excitations at different support points. A frequent point of discussion is multiple versus single support excitation. A single support excitation analysis is computationally straightforward and tends to be on the conservative side, as the numerical results show. A multiple support excitation analysis, however, does not incur much more additional computer cost than the expenditure for an initial static solution involving three times the number, L, of excitation levels, i.e. 3L static load cases. The results are more realistic than those from a single support excitation analysis. A number of typical nuclear plant piping systems have been analyzed using single and multiple support excitation algorithms for: (1) the response spectrum method, (2) the modal time history method via the Wilson, Newmark and Goldberg integration operators and (3) the direct time history method via the Wilson integration operator. Characteristic results are presented to compare the computational quality of all three methods. (orig.)

Determination of the uranium concentration in soil solutions by the fission track registration technique

International Nuclear Information System (INIS)

Fernandes, G.P.

1980-02-01

The fission tracks registration technique was used to determine the uranium concentration in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. From the calibration curves obtained, it was possible to determine uranium concentrations in soil solutions, from 90 to 320 μg U/l, with an error between 9.4% and 4.0%, respectively. The method was applied to a few soil samples from Pocos de Caldas, Minas Gerais in Brazil. The uranium concentrations in the sample and residues were also determined by other methods to compare the results obtained; only one sample showed deviation from the results obtained by the fission tracks method. And this discrepancy was explained in a reasonable way. It was shown that the fission tracks technique can be used with sucess for application in soil solutions. (Author) [pt

Neutron-multiplication measurement instrument

Energy Technology Data Exchange (ETDEWEB)

Nixon, K.V.; Dowdy, E.J.; France, S.W.; Millegan, D.R.; Robba, A.A.

1982-01-01

The Advanced Nuclear Technology Group of the Los Alamos National Laboratory is now using intelligent data-acquisition and analysis instrumentation for determining the multiplication of nuclear material. Earlier instrumentation, such as the large NIM-crate systems, depended on house power and required additional computation to determine multiplication or to estimate error. The portable, battery-powered multiplication measurement unit, with advanced computational power, acquires data, calculates multiplication, and completes error analysis automatically. Thus, the multiplication is determined easily and an available error estimate enables the user to judge the significance of results.

Neutron multiplication measurement instrument

International Nuclear Information System (INIS)

Nixon, K.V.; Dowdy, E.J.; France, S.W.; Millegan, D.R.; Robba, A.A.

1983-01-01

The Advanced Nuclear Technology Group of the Los Alamos National Laboratory is now using intelligent data-acquisition and analysis instrumentation for determining the multiplication of nuclear material. Earlier instrumentation, such as the large NIM-crate systems, depended on house power and required additional computation to determine multiplication or to estimate error. The portable, battery-powered multiplication measurement unit, with advanced computational power, acquires data, calculates multiplication, and completes error analysis automatically. Thus, the multiplication is determined easily and an available error estimate enables the user to judge the significance of results

Neutron-multiplication measurement instrument

International Nuclear Information System (INIS)

Nixon, K.V.; Dowdy, E.J.; France, S.W.; Millegan, D.R.; Robba, A.A.

1982-01-01

The Advanced Nuclear Technology Group of the Los Alamos National Laboratory is now using intelligent data-acquisition and analysis instrumentation for determining the multiplication of nuclear material. Earlier instrumentation, such as the large NIM-crate systems, depended on house power and required additional computation to determine multiplication or to estimate error. The portable, battery-powered multiplication measurement unit, with advanced computational power, acquires data, calculates multiplication, and completes error analysis automatically. Thus, the multiplication is determined easily and an available error estimate enables the user to judge the significance of results

Significance of multiple scattering in imaging through turbid media

International Nuclear Information System (INIS)

Zardecki, A.; Gerstl, S.A.W.

1986-01-01

The degradation of image quality in a turbid medium is analyzed within the framework of the small-angle approximation, the diffusion approximation, and a rigorous two-dimensional radiative transfer equation. These three approaches allow us to emphasize different aspects of the imaging problem when multiple scattering effects are important. For a medium with a forward-peaked phase function, the separation of multiple scattering into a series of scatterings of various order provides a fruitful technique. The use of the diffusion approximation and transport theory extends the determination of the modulation transfer function to a turbid medium with an arbitrary degree of anisotropy

Recent Microextraction Techniques for Determination and Chemical Speciation of Selenium

Directory of Open Access Journals (Sweden)

Ibrahim Ahmed S. A.

2017-05-01

Full Text Available Research designed to improve extraction has led to the development of microextraction techniques (ME, which involve simple, low cost, and effective preconcentrationof analytes in various matrices. This review is concerned with the principles and theoretical background of ME, as well as the development of applications for selenium analysis during the period from 2008 to 2016. Among all ME, dispersive liquid-liquid microextraction was found to be most favorable for selenium. On the other hand, atomic absorption spectrometry was the most frequently used instrumentation. Selenium ME have rarely been coupled to spectrophotometry and X-ray spectrophotometry methods, and there is no published application of ME with electrochemical techniques. We strongly support the idea of using a double preconcentration process, which consists of microextraction prior to preconcentration, followed by selenium determination using cathodic stripping voltammetry (ME-CSV. More attention should focus on the development of accurate, precise, and green methods for selenium analysis.

Ant colony optimisation-direct cover: a hybrid ant colony direct cover technique for multi-level synthesis of multiple-valued logic functions

Science.gov (United States)

Abd-El-Barr, Mostafa

2010-12-01

The use of non-binary (multiple-valued) logic in the synthesis of digital systems can lead to savings in chip area. Advances in very large scale integration (VLSI) technology have enabled the successful implementation of multiple-valued logic (MVL) circuits. A number of heuristic algorithms for the synthesis of (near) minimal sum-of products (two-level) realisation of MVL functions have been reported in the literature. The direct cover (DC) technique is one such algorithm. The ant colony optimisation (ACO) algorithm is a meta-heuristic that uses constructive greediness to explore a large solution space in finding (near) optimal solutions. The ACO algorithm mimics the ant's behaviour in the real world in using the shortest path to reach food sources. We have previously introduced an ACO-based heuristic for the synthesis of two-level MVL functions. In this article, we introduce the ACO-DC hybrid technique for the synthesis of multi-level MVL functions. The basic idea is to use an ant to decompose a given MVL function into a number of levels and then synthesise each sub-function using a DC-based technique. The results obtained using the proposed approach are compared to those obtained using existing techniques reported in the literature. A benchmark set consisting of 50,000 randomly generated 2-variable 4-valued functions is used in the comparison. The results obtained using the proposed ACO-DC technique are shown to produce efficient realisation in terms of the average number of gates (as a measure of chip area) needed for the synthesis of a given MVL function.

Resolvent-Techniques for Multiple Exercise Problems

International Nuclear Information System (INIS)

Christensen, Sören; Lempa, Jukka

2015-01-01

We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristics of the problems can be identified more explicitly. We illustrate the main results with explicit examples

Resolvent-Techniques for Multiple Exercise Problems

Energy Technology Data Exchange (ETDEWEB)

Christensen, Sören, E-mail: christensen@math.uni-kiel.de [Christian–Albrechts-University in Kiel, Mathematical Institute (Germany); Lempa, Jukka, E-mail: jukka.lempa@hioa.no [Oslo and Akershus University College, School of business, Faculty of Social Sciences (Norway)

2015-02-15

We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristics of the problems can be identified more explicitly. We illustrate the main results with explicit examples.

Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up.

Science.gov (United States)

Kohlhase, Konstantin David; Korkusuz, Yücel; Gröner, Daniel; Erbelding, Christian; Happel, Christian; Luboldt, Wolfgang; Grünwald, Frank

2016-08-01

Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique ('MOST'). Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST. The nodule volumes were measured prior to ablation and 3 months after the procedure using ultrasound. The population consisted of either solid (>80% solid tissue within the volume of interest), complex, or cystic nodules (nodule volume (ΔV), median 5.3 mL (range 0.13-43.1 mL), corresponding to a relative reduction in mean of 56 ± 17.9%. Median initial volume was 8 mL (range 0.48-62 mL); 3 months after ablation a median volume of 2.3 mL (range 0.3-32 mL) was measured. Nodule growth ≥50% occurred in 70% (14 nodules). At the follow-up no complications such as infections, persisting pain, nerve injuries or immunogen stimulation occurred. Patients with cold nodules (15) remained euthyroid, with hyperfunctioning nodules either euthyroid (2) or latent hypofunctional (1). Conclusion The use of bipolar RFA is an effective, safe and suitable thermoablative technique to treat benign thyroid nodules. Combined with the multiple overlapping shot technique it allows sufficient ablation.

Determination of 210Pb in marine sediment core- A comparison between alpha and gamma techniques

International Nuclear Information System (INIS)

Zal Uyun Wan Mahmood; Yii Mei Wo; Zaharudin Ahmad

2010-01-01

The most commonly used techniques of alpha and gamma spectrometry were performed to measure 210 Pb activity in marine sediment core as a comparison. Alpha analytical technique measured the activity of 210 Pb from its in-grow grand-daughter 210 Po after a chemical separation, assuming radioactive equilibrium between the two radionuclides. Meanwhile, gamma analysis technique allows direct measurement, non-destructive and no preliminary chemical separation. Through the comparison, it is found that both alpha and gamma analysis techniques were slightly difference. Overall, the results from alpha analytical technique were basically higher than those from the gamma analytical techniques. Some logical argument had been discussed to explain this situation. In routine analysis, the analytical technique used should be chosen carefully based on advantages and disadvantages of the each technique and analysis requirements. Therefore, it is recommended to determine exactly the needs and purpose of analysis and to know the sample history before decide the appropriate analytical technique. (author)

Diagnosis of soil-transmitted helminthiasis in an Amazonic community of Peru using multiple diagnostic techniques.

Science.gov (United States)

Machicado, Jorge D; Marcos, Luis A; Tello, Raul; Canales, Marco; Terashima, Angelica; Gotuzzo, Eduardo

2012-06-01

An observational descriptive study was conducted in a Shipibo-Conibo/Ese'Eja community of the rainforest in Peru to compare the Kato-Katz method and the spontaneous sedimentation in tube technique (SSTT) for the diagnosis of intestinal parasites as well as to report the prevalence of soil-transmitted helminth (STH) infections in this area. A total of 73 stool samples were collected and analysed by several parasitological techniques, including Kato-Katz, SSTT, modified Baermann technique (MBT), agar plate culture, Harada-Mori culture and the direct smear examination. Kato-Katz and SSTT had the same rate of detection for Ascaris lumbricoides (5%), Trichuris trichiura (5%), hookworm (14%) and Hymenolepis nana (26%). The detection rate for Strongyloides stercoralis larvae was 16% by SSTT and 0% by Kato-Katz, but 18% by agar plate culture and 16% by MBT. The SSTT also had the advantage of detecting multiple intestinal protozoa such as Blastocystis hominis (40%), Giardia intestinalis (29%) and Entamoeba histolytica/E. dispar (16%). The most common intestinal parasites found in this community were B. hominis, G. intestinalis, H. nana, S. stercoralis and hookworm. In conclusion, the SSTT is not inferior to Kato-Katz for the diagnosis of common STH infections but is largely superior for detecting intestinal protozoa and S. stercoralis larvae. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Autoradiographic techniques to determine noble metal distribution in automotive catalyst substrates

International Nuclear Information System (INIS)

Lange, W.H.

1976-01-01

The distribution of noble metals in the ceramic substrates of automotive catalytic converter systems is important to the functional characteristics of the systems. A radiotracer technique involving microtomy of bead substrate samples and autoradiography using the resultant thin sections was developed to produce detailed images of the metal distributions. The method is particularly valuable to determine the distribution of one metal in the presence of another to aid in the development of more efficient systems

The validation of the Z-Scan technique for the determination of plasma glucose

Science.gov (United States)

Alves, Sarah I.; Silva, Elaine A. O.; Costa, Simone S.; Sonego, Denise R. N.; Hallack, Maira L.; Coppini, Ornela L.; Rowies, Fernanda; Azzalis, Ligia A.; Junqueira, Virginia B. C.; Pereira, Edimar C.; Rocha, Katya C.; Fonseca, Fernando L. A.

2013-11-01

Glucose is the main energy source for the human body. The concentration of blood glucose is regulated by several hormones including both antagonists: insulin and glucagon. The quantification of glucose in the blood is used for diagnosing metabolic disorders of carbohydrates, such as diabetes, idiopathic hypoglycemia and pancreatic diseases. Currently, the methodology used for this determination is the enzymatic colorimetric with spectrophotometric. This study aimed to validate the use of measurements of nonlinear optical properties of plasma glucose via the Z-Scan technique. For this we used samples of calibrator patterns that simulate commercial samples of patients (ELITech ©). Besides calibrators, serum glucose levels within acceptable reference values (normal control serum - Brazilian Society of Clinical Pathology and Laboratory Medicine) and also overestimated (pathological control serum - Brazilian Society of Clinical Pathology and Laboratory Medicine) were used in the methodology proposal. Calibrator dilutions were performed and determined by the Z-Scan technique for the preparation of calibration curve. In conclusion, Z-Scan method can be used to determinate glucose levels in biological samples with enzymatic colorimetric reaction and also to apply the same quality control parameters used in biochemistry clinical.

OSM-Classic : An optical imaging technique for accurately determining strain

Science.gov (United States)

Aldrich, Daniel R.; Ayranci, Cagri; Nobes, David S.

OSM-Classic is a program designed in MATLAB® to provide a method of accurately determining strain in a test sample using an optical imaging technique. Measuring strain for the mechanical characterization of materials is most commonly performed with extensometers, LVDT (linear variable differential transistors), and strain gauges; however, these strain measurement methods suffer from their fragile nature and it is not particularly easy to attach these devices to the material for testing. To alleviate these potential problems, an optical approach that does not require contact with the specimen can be implemented to measure the strain. OSM-Classic is a software that interrogates a series of images to determine elongation in a test sample and hence, strain of the specimen. It was designed to provide a graphical user interface that includes image processing with a dynamic region of interest. Additionally, the stain is calculated directly while providing active feedback during the processing.

Quality Determination of Pipe-Borne Water in Sokoto Metropolis ...

African Journals Online (AJOL)

The quality of the pipe-borne water supplied to Sokoto metropolis was determined in this study. The total bacterial count was carried out using surface plating method of inoculation. The coliforms were enumerated using multiple tube fermentation technique (Most Probable Number Method). Some physicochemical ...

Non-interferometric determination of optical anisotropy in highly-oriented fibres using transport intensity equation technique

Science.gov (United States)

Sokkar, T. Z. N.; El-Farahaty, K. A.; El-Bakary, M. A.; Raslan, M. I.; Omar, E. Z.; Hamza, A. A.

2018-03-01

The optical setup of the transport intensity equation (TIE) technique is developed to be valid for measuring the optical properties of the highly-oriented anisotropic fibres. This development is based on the microstructure models of the highly-oriented anisotropic fibres and the principle of anisotropy. We provide the setup of TIE technique with polarizer which is controlled via stepper motor. This developed technique is used to investigate the refractive indices in the parallel and perpendicular polarization directions of light for the highly-oriented poly (ethylene terephthalate) (PET) fibres and hence its birefringence. The obtained results through the developed TIE technique for PET fibre are compared with that determined experimentally using the Mach-Zehnder interferometer under the same conditions. The comparison shows a good agreement between the obtained results from the developed technique and that obtained from the Mach-Zehnder interferometer technique.

Studies for determining drain solid flow in bed silt, using radioisotope techniques

International Nuclear Information System (INIS)

Sanchez, W.

1976-01-01

A process for measuring solid flow in silt bed using isotopic technique is studied. Comparative studies for initial movement of grinded glass grains and sand grains is done. The development for determining the minimum mass of radioative grains of sand, used for flow evaluation is also studied. Further experiments in the field of reference confirm technological conditions for the method [pt

Combined neutron activation analysis techniques for multiple purposes at Portuguese research reactor

International Nuclear Information System (INIS)

Dung, H.M.; Freitas, M.C.; Beasley, D.; Almeida, S.M.; Dionisio, I; Canha, N.H.; Galinha, C.; Marques, J.G.

2010-01-01

Full text: Developments of the neutron activation analysis (NAA) techniques using Compton suppression system (CSS), fast pneumatic irradiation facility (SIPRA), epithermal neutron and automatic sample changers (ASCs) associated with the traditional NAA for trace element determination in various sample types are described with reference to specific conditions at the 1 MW Portuguese research reactor (RPI). Experiences in application of k o -IAEA software for data processing in order to deduce the results are also discussed. A selected number of sample types which are intended to the application in biological and environmental areas as well as industrial and material samples are demonstrated which provide challenges in the irradiation, measurement and the interpretation of data to which in most cases a combined solution should be made. The role that each NAA technique can play in the combined scheme along with their optimized characteristics has been studied and shown. The combined NAA techniques at RPI established for on-going and potential projects as well as analysis service with respect to the element scope (48), typically Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, CI, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Hf, Hg, I, In, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Th, Ti, U, V, W, Vb, Zn and Zr along with detection limits, accuracies and precision's have been evaluated as a trace analysis method meeting the requirements of the intended applications

Comparative study between the PIXE technique and neutron activation analysis for Zinc determination

International Nuclear Information System (INIS)

Cruvinel, Paulo Estevao; Crestana, Silvio; Artaxo Netto, Paulo Eduardo

1997-01-01

This work presents a comparative study between the PIXE, proton beams and neutron activation analysis (NAA) techniques, for determination of total zinc concentration. Particularly, soil samples from the Pindorama, Instituto Agronomico de Campinas, Sao Paulo State, Brazil, experimental station have been analysed and measuring the zinc contents in μg/g. The results presented good correlation between the mentioned techniques. The PIXE and NAA analyses have been carried out by using the series S, 2.4 MeV proton beams Pelletron accelerator and the IPEN/CNEN-IEA-R1 reactor, both installed at the Sao Paulo - Brazil university

Advanced gamma spectrum processing technique applied to the analysis of scattering spectra for determining material thickness

International Nuclear Information System (INIS)

Hoang Duc Tam; VNUHCM-University of Science, Ho Chi Minh City; Huynh Dinh Chuong; Tran Thien Thanh; Vo Hoang Nguyen; Hoang Thi Kieu Trang; Chau Van Tao

2015-01-01

In this work, an advanced gamma spectrum processing technique is applied to analyze experimental scattering spectra for determining the thickness of C45 heat-resistant steel plates. The single scattering peak of scattering spectra is taken as an advantage to measure the intensity of single scattering photons. Based on these results, the thickness of steel plates is determined with a maximum deviation of real thickness and measured thickness of about 4 %. Monte Carlo simulation using MCNP5 code is also performed to cross check the results, which yields a maximum deviation of 2 %. These results strongly confirm the capability of this technique in analyzing gamma scattering spectra, which is a simple, effective and convenient method for determining material thickness. (author)

Position and mass determination of multiple particles using cantilever based mass sensors

International Nuclear Information System (INIS)

Dohn, Soeren; Schmid, Silvan; Boisen, Anja; Amiot, Fabien

2010-01-01

Resonant microcantilevers are highly sensitive to added masses and have the potential to be used as mass-spectrometers. However, making the detection of individual added masses quantitative requires the position determination for each added mass. We derive expressions relating the position and mass of several added particles to the resonant frequencies of a cantilever, and an identification procedure valid for particles with different masses is proposed. The identification procedure is tested by calculating positions and mass of multiple microparticles with similar mass positioned on individual microcantilevers. Excellent agreement is observed between calculated and measured positions and calculated and theoretical masses.

Determination of the multiplication factor and its bias by the 252Cf-source technique: A method for code benchmarking with subcritical configurations

International Nuclear Information System (INIS)

Perez, R.B.; Valentine, T.E.; Mihalczo, J.T.; Mattingly, J.K.

1997-01-01

A brief discussion of the Cf-252 source driven method for subcritical measurements serves as an introduction to the concept and use of the spectral ratio, Γ. It has also been shown that the Monte Carlo calculation of spectral densities and effective multiplication factors have as a common denominator the transport propagator. This commonality follows from the fact that the Neumann series expansion of the propagator lends itself to the Monte Carlo method. On this basis a linear relationship between the spectral ratio and the effective multiplication factor has been shown. This relationship demonstrates the ability of subcritical measurements of the ratio of spectral densities to validate transport theory methods and cross sections

A simple technique to determine the size distribution of nuclear crater fallback and ejecta

Energy Technology Data Exchange (ETDEWEB)

Anderson, II, Brooks D [U.S. Army Engineer Nuclear Cratering Group, Lawrence Radiation Laboratory, Livermore, CA (United States)

1970-05-15

This report describes the results of an investigation to find an economic method for determining the block size distribution of nuclear crater fallback and ejecta. It is shown that the modal analysis method of determining relative proportions can be applied with the use of a special sampling technique, to provide a size distribution curve for clastic materials similar to one obtainable by sieving and weighing the same materials.

A simple technique to determine the size distribution of nuclear crater fallback and ejecta

International Nuclear Information System (INIS)

Anderson, Brooks D. II

1970-01-01

This report describes the results of an investigation to find an economic method for determining the block size distribution of nuclear crater fallback and ejecta. It is shown that the modal analysis method of determining relative proportions can be applied with the use of a special sampling technique, to provide a size distribution curve for clastic materials similar to one obtainable by sieving and weighing the same materials

Comparative studies of method for determining total mercury in fish. Dithizone and flameless atomic absorption spectrophotometry techniques

International Nuclear Information System (INIS)

Protasowicki, M.; Ociepa, A.; Chodyniecki, A.

1977-01-01

Two methods for determining total mercury in fish were compared: the dithizone and flameless atomic absorption spectrophotometry techniques. The studies involved determination of recovery when 1μg of mercury as solutions of HgCl 2 or CH 3 HgC were added to each sample of herring flesh. Mean recoveries in the dithizone method were found to be 91.4+-7.47% and 90.25+-4.73% for the two solutions respectively, while the recoveries obtained with the flameless atomic absorption spectrophotometry were 95.00+-9.13% and 98.70+-7.14%, respectively. Both techniques were used to determine the mercury content in the same herring flesh sample. The first technique showed the content of 0.050+-0.018μg Hg g -1 while the result obtained with the other one was 0.062+-0.013μg Hg g -1 . The statistical treatment of the results obtained showed no difference between the two techniques, the significance level being α=0.05. Therefore, the results obtained with the dithizone method are comparable with those obtained with the flameless atomic absorption spectrophotometry for mercury contents of the magnitude order of 0.050 ug.g -1 . (author)

Determination of Seric E immuno-globulins. Comparison of two techniques, radioimmunological and immuno enzymatic. Clinical correlations

International Nuclear Information System (INIS)

Lafosse-Marin, Sylvie.

1977-09-01

Because of the very low seric IgE concentrations their research and analysis are difficult and many techniques of a more or less sophisticated kind have been proposed for this reason. Our aim was to compare two total seric IgE determination methods: one recent, the enzymmuno-Plaque-Pasteur (EPP); the other, most commonly used at present, the Radio-Immuno-Sorbent-Test (RIST). For this we measured total seric IgE in a hundred and one children by the EPP technique and compared our results with those supplied from the same samples by a laboratory using the RIST technique; the results were then correlated with clinical evidence. The technique proposed by the Pasteur Institute to determine total seric IgE is based on radial immunodiffusion sensitized by the use of antibodies labelled with glucose oxydase. This simple technique, easy to use, requires no expensive materials but has two disadvantages: it takes rather a long time and can only measure IgE concentrations of 50 UI/ml or more. The RIST technique is based on competitive fixation, onto anti-IgE-coated Sephadex particles of the IgE under analysis and of a fixed dose of radio-labelled IgE. This second technique, though faster, has the major disadvantage of being practicable in few laboratories because of the heavy equipment needed and the radioactivity used. This study has shown on the whole an equivalence (correlation coefficient 0.95) between the results given by the two techniques: EPP and RIST (the comparison was made between the IgE contents and not their logarithm) [fr

Quantitative determination of mineral coal impurities from Brazil through optical emission spectrography technique

International Nuclear Information System (INIS)

Clain, Almir Faria

1982-01-01

The aim of the present research was to develop a spectrographic technique to determine the highest possible number of the chemical elements micro-constituents of Brazilian mineral coals. The experimental technique developed corresponds to the so called total-burning procedure. Coal samples were calcined to ashes at 400°C and then totally burned in graphite electrodes by a DC arc. The spectrographic measurements were made in a Jarrell-Ash emission spectrograph, Ebert mounting type, model Mark IV. An inert atmosphere chamber (for a gaseous mixture 20% 0 2 and 80% air) and a seven step rotating sector were used as main accessories. The analytical curves for the different elements, were obtained using synthetic standards in the concentration range of 10 to 1.000 ppm, and the standards as well as the coal ashes were diluted with spectrographically pure graphite in 1:1 ratio. Seventeen coal samples from different shells and strata of Morungava and Charqueadas mines - Rio Grande do Sul State - were analyzed to test the proposed technique, being possible to determine the following elements: B, Be, Bi, Cd, Co, Cr, Cu, Ga,Pb, Ge, Mn, Mo, Ni, Sn, Sb, V, Y, Zn and Zr. The coefficient of variation was 14% in average for all the elements and the sensitivity was so that the majority of the impurities present in the coals were analyzed. (author)

NEUTRON SPECTRUM MEASUREMENTS USING MULTIPLE THRESHOLD DETECTORS

Energy Technology Data Exchange (ETDEWEB)

Gerken, William W.; Duffey, Dick

1963-11-15

From American Nuclear Society Meeting, New York, Nov. 1963. The use of threshold detectors, which simultaneously undergo reactions with thermal neutrons and two or more fast neutron threshold reactions, was applied to measurements of the neutron spectrum in a reactor. A number of different materials were irradiated to determine the most practical ones for use as multiple threshold detectors. These results, as well as counting techniques and corrections, are presented. Some materials used include aluminum, alloys of Al -Ni, aluminum-- nickel oxides, and magesium orthophosphates. (auth)

Optimum conditions for the determination of ionization potentials, appearance potentials and fine structure in ionization efficiency curves using edd technique

International Nuclear Information System (INIS)

Selim, Ezzat T.; El-Kholy, S.B.; Zahran, Nagwa F.

1978-01-01

The optimum conditions for determining ionization potentials as well as fine structure in electron impact ionization efficiency curves are studied using energy distribution difference technique. Applying these conditions to Ar + , Kr + , CO + 2 and N + from N 2 , very good agreement is obtained when compared with results determined by other techniques including UV spectroscopy. The merits and limitation of the technique are also discussed

Statistical Analysis of Reactor Pressure Vessel Fluence Calculation Benchmark Data Using Multiple Regression Techniques

International Nuclear Information System (INIS)

Carew, John F.; Finch, Stephen J.; Lois, Lambros

2003-01-01

The calculated >1-MeV pressure vessel fluence is used to determine the fracture toughness and integrity of the reactor pressure vessel. It is therefore of the utmost importance to ensure that the fluence prediction is accurate and unbiased. In practice, this assurance is provided by comparing the predictions of the calculational methodology with an extensive set of accurate benchmarks. A benchmarking database is used to provide an estimate of the overall average measurement-to-calculation (M/C) bias in the calculations ( ). This average is used as an ad-hoc multiplicative adjustment to the calculations to correct for the observed calculational bias. However, this average only provides a well-defined and valid adjustment of the fluence if the M/C data are homogeneous; i.e., the data are statistically independent and there is no correlation between subsets of M/C data.Typically, the identification of correlations between the errors in the database M/C values is difficult because the correlation is of the same magnitude as the random errors in the M/C data and varies substantially over the database. In this paper, an evaluation of a reactor dosimetry benchmark database is performed to determine the statistical validity of the adjustment to the calculated pressure vessel fluence. Physical mechanisms that could potentially introduce a correlation between the subsets of M/C ratios are identified and included in a multiple regression analysis of the M/C data. Rigorous statistical criteria are used to evaluate the homogeneity of the M/C data and determine the validity of the adjustment.For the database evaluated, the M/C data are found to be strongly correlated with dosimeter response threshold energy and dosimeter location (e.g., cavity versus in-vessel). It is shown that because of the inhomogeneity in the M/C data, for this database, the benchmark data do not provide a valid basis for adjusting the pressure vessel fluence.The statistical criteria and methods employed in

Coulomb-explosion technique for determining geometrical structures of molecular ions

International Nuclear Information System (INIS)

Gemmell, D.S.

1981-01-01

Traditional experimental techniques (e.g. studies on photon absorption or emission) for determining the sterochemical structures of neutral molecules are extremeley difficult to apply to molecular ions because of problems in obtaining a sufficient spatial density of the ions to be studied. Recent high-resolution measurements on the energy and angle distributions of the fragments produced when fast (MeV) molecular-ion beams from an electrostatic accelerator dissociate (Coulomb explode) in thin foils and in gases, offer promising possibilities for deducing the sterochemical structures of the molecular ions constituting the incident beams. Bond lengths have been determined in this way for several diatomic projectiles (H 2+ , HeH + , CH + , NH + , OH + , N 2+ , O 2+ , etc.) with an accuracy of approx. 0.01 A. H 3+ has been demonstrated (for the first time) to be equilateral triangular and the interproton distance measured. Measurements on single fragments from CO 2+ , N 2 O + , C 3 H 3+ , and CH/sub n/ + have revealed the gross structures of the projectiles. An apparatus has recently been constructed at Argonne to permit precise measurements on fragments in coincidence. The apparatus has been tested on a known structure (OH 2+ ). The O-H bond length was found to be 1.0 +- 0.04 A and the H-O-H bond angle was measured as 110 --- 2 0 . These values are in excellent agreement with those found in optical experiments (0.999 A and 110.5 0 ). This Coulomb explosion technique can be expected to be refined in accuracy and to be extended to a wide range of molecular ions whose structures are inaccessible by other means

Determination of trace uranium in human hair by nuclear track detection technique

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; En, Zinaida; Cho, Seung Yeon; Kang, Sang Hoon; Lee, Jae Ki

2001-01-01

The aim of this study is to describe a usefulness of nuclear analytical technique in assessing and comparing the concentration levels through the analysis of uranium using human hair sample in the field of environment. A fission track detection technique was applied to determine the uranium concentration in human hair. Hair samples were collected from two groups of people - a) workers not dealing with uranium directly, and b) workers possibly contaminated with uranium. The concentration of 235 U for the first group varied from <1 to 39 ng/g and the second group can be estimated up to the level of μg/g. Radiographs of heavy-duty work samples contained high dense 'hot spots' along a single hair. After washing in acetone and distilled water, external contamination was not totally removed. Insoluble uranium compounds were not completely washed out. The (n, f)-radiography technique, having high sensitivity, and capable of getting information on uranium content at each point of a single hair, is an excellent tool for environmental monitoring

A review of analytical techniques for the determination of carbon-14 in environmental samples

International Nuclear Information System (INIS)

Milton, G.M.; Brown, R.M.

1993-11-01

This report contains a brief summary of analytical techniques commonly used for the determination of radiocarbon in a variety of environmental samples. Details of the applicable procedures developed and tested in the Environmental Research Branch at Chalk River Laboratories are appended

Some Problems Connected with Reactivity and its Determination

Energy Technology Data Exchange (ETDEWEB)

Boużyk, J.; Chwaszczewski, S. [Institute of Nuclear Research Reactor Physics Dept., Świerk (Poland)

1969-07-01

The applicability of the reactivity concept for subcritical reactor states determination is discussed. It is based on the general properties of the neutron balance equation in a nuclear reactor. It is shown that the reactor fundamental time constants are very useful parameter for reactor state determination. In the frames of the above mentioned theory the classical methods of reactivity determination las rod-drop, source-jerk and source multiplication) are verified. It was found that the neutron pulse method is especially suitable for sophisticated investigation of the reactor kinetic models. Using this technique the difference between static and dynamic reactor parameters can be measured. The study of the neutron counting statistics was found to be very useful for reactor kinetic parameters measurements. Several new techniques (as flash-start and drop-start methods), for reactor noise analysis by the conditional probability methods are presented. For the current noise analysis the analog computer (operating on-line) for autocorrelation function determination was used. Also, the acquisition system for digitalized current noise data and preliminary results of this technique are given. (author)

An accurate method for determining residual stresses with magnetic non-destructive techniques in welded ferromagnetic steels

International Nuclear Information System (INIS)

Vourna, P

2016-01-01

The scope of the present research work was to investigate the proper selection criteria for developing a suitable methodology for the accurate determination of residual stresses existing in welded parts. Magnetic non-destructive testing took place by the use of two magnetic non-destructive techniques: by the measurement of the magnetic Barkhausen noise and by the evaluation of the magnetic hysteresis loop parameters. The spatial distribution of residual stresses in welded metal parts by both non-destructive magnetic methods and two diffraction methods was determined. The conduction of magnetic measurements required an initial calibration of ferromagnetic steels. Based on the examined volume of the sample, all methods used were divided into two large categories: the first one was related to the determination of surface residual stress, whereas the second one was related to bulk residual stress determination. The first category included the magnetic Barkhausen noise and the X-ray diffraction measurements, while the second one included the magnetic permeability and the neutron diffraction data. The residual stresses determined by the magnetic techniques were in a good agreement with the diffraction ones. (paper)

Sensitivity Analysis of Electromagnetic Induction Technique to Determine Soil Salinity in Large –Scale

Directory of Open Access Journals (Sweden)

Yousef Hasheminejhad

2017-02-01

Full Text Available Introduction: Monitoring and management of saline soils depends on exact and updatable measurements of soil electrical conductivity. Large scale direct measurements are not only expensive but also time consuming. Therefore application of near ground surface sensors could be considered as acceptable time- and cost-saving methods with high accuracy in soil salinity detection. . One of these relatively innovative methods is electromagnetic induction technique. Apparent soil electrical conductivity measurement by electromagnetic induction technique is affected by several key properties of soils including soil moisture and clay content. Materials and Methods: Soil salinity and apparent soil electrical conductivity data of two years of 50000 ha area in Sabzevar- Davarzan plain were used to evaluate the sensitivity of electromagnetic induction to soil moisture and clay content. Locations of the sampling points were determined by the Latin Hypercube Sampling strategy, based on 100 sampling points were selected for the first year and 25 sampling points for the second year. Regarding to difficulties in finding and sampling the points 97 sampling points were found in the area for the first year out of which 82 points were sampled down to 90 cm depth in 30 cm intervals and all of them were measured with electromagnetic induction device at horizontal orientation. The first year data were used for training the model which included 82 points measurement of bulk conductivity and laboratory determination of electrical conductivity of saturated extract, soil texture and moisture content in soil samples. On the other hand, the second year data which were used for testing the model integrated by 25 sampling points and 9 bulk conductivity measurements around each point. Electrical conductivity of saturated extract was just measured as the only parameter in the laboratory for the second year samples. Results and Discussion: Results of the first year showed a

Mouse epileptic seizure detection with multiple EEG features and simple thresholding technique

Science.gov (United States)

Tieng, Quang M.; Anbazhagan, Ashwin; Chen, Min; Reutens, David C.

2017-12-01

Objective. Epilepsy is a common neurological disorder characterized by recurrent, unprovoked seizures. The search for new treatments for seizures and epilepsy relies upon studies in animal models of epilepsy. To capture data on seizures, many applications require prolonged electroencephalography (EEG) with recordings that generate voluminous data. The desire for efficient evaluation of these recordings motivates the development of automated seizure detection algorithms. Approach. A new seizure detection method is proposed, based on multiple features and a simple thresholding technique. The features are derived from chaos theory, information theory and the power spectrum of EEG recordings and optimally exploit both linear and nonlinear characteristics of EEG data. Main result. The proposed method was tested with real EEG data from an experimental mouse model of epilepsy and distinguished seizures from other patterns with high sensitivity and specificity. Significance. The proposed approach introduces two new features: negative logarithm of adaptive correlation integral and power spectral coherence ratio. The combination of these new features with two previously described features, entropy and phase coherence, improved seizure detection accuracy significantly. Negative logarithm of adaptive correlation integral can also be used to compute the duration of automatically detected seizures.

New resin gel for uranium determination by diffusive gradient in thin films technique

Czech Academy of Sciences Publication Activity Database

Gregušová, Michaela; Dočekal, Bohumil

2011-01-01

Roč. 684, 1-2 (2011), s. 142-146 ISSN 0003-2670 R&D Projects: GA ČR GAP503/10/2002 Institutional research plan: CEZ:AV0Z40310501 Keywords : diffusive gradient in thin film technique * 8-hydroxyquinoline resin gel * uranium determination Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.555, year: 2011

In-gel multiple displacement amplification of long DNA fragments diluted to the single molecule level.

Science.gov (United States)

Michikawa, Yuichi; Sugahara, Keisuke; Suga, Tomo; Ohtsuka, Yoshimi; Ishikawa, Kenichi; Ishikawa, Atsuko; Shiomi, Naoko; Shiomi, Tadahiro; Iwakawa, Mayumi; Imai, Takashi

2008-12-15

The isolation and multiple genotyping of long individual DNA fragments are needed to obtain haplotype information for diploid organisms. Limiting dilution of sample DNA followed by multiple displacement amplification is a useful technique but is restricted to short (reaction (PCR)-ready form. The haplotypes of seven SNPs spanning 240 kb of the DNA surrounding the human ATM gene region on chromosome 11 were determined for 10 individuals, demonstrating the feasibility of this new method.

Determination of the dose of traffic in HDR brachytherapy with ALANINE/R PE technique

International Nuclear Information System (INIS)

Guzman Calcina, C. S.; Chen, F.; Almeida, A. de; Baffa, O.

2001-01-01

It determines, experimentally, the dose of traffic in brachytherapy for High Dose Rate (HDR), using for the first-time the Electronic Paramagnetic Resonance (EPR) technique with alanine detectors. The value obtained is the published next to obtained using lithium fluoride thermoluminescent dosimeters [es

Calculation and experimental technique of determination of rolling procedure for cold-rolling tube mills

International Nuclear Information System (INIS)

Igoshin, V.F.; Aleshin, V.A.; Khoroshikh, Yu.G.; Bogatov, A.A.; Mizhiritskij, O.I.

1983-01-01

Calculation and experimental technique of determination of tube cold rolling procedure has been developed. Rolling procedure based on the usage of regression equation epsilon=1.24 psi, where psi is the relative reduction of area, delta-permissible reduction during rolling, has been tested on 08Kh18N10T steel. The effect of tube geometry, tool calibration parameters, lubrication conditions etc. on metal deformability in taking into account experimentally. The use of the technique proposed has allowed to shorten the time of mastering of the production of tubes from different steels

Multiple photon resonances

International Nuclear Information System (INIS)

Elliott, C.J.; Feldman, B.J.

1979-02-01

A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures

Principle of the determination of neutron multiplication coefficients by the Monte Carlo method. Application. Description of a code for ibm 360-75; Principe de la determination des coefficients de multiplication neutronique par methode de Monte-Carlo. Application. Description d'un code pour IBM 360-75

Energy Technology Data Exchange (ETDEWEB)

Moreau, J; Parisot, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The determination of neutron multiplication coefficients by the Monte Carlo method can be carried out in different ways; the are first examined particularly complex geometries; it makes use of multi-group isotropic cross sections. The performances of this code are illustrated by some examples. (author) [French] La determination des coefficients de multiplication neutronique par methode de Monte Carlo peut se faire par differentes voies, elles sont successivement examinees et comparees. On en deduit un code rapide pour des geometries particulierement complexes, il utilise des sections efficaces multigroupes isotropes. Les performances de ce code sont demontrees par quelques exemples. (auteur)

Determination of Nuclear Track Parameters for LR-115 Detector by Using of MATLAB Software Technique

International Nuclear Information System (INIS)

AL-Jomaily, F.M.; AL-joburi, H.A.; Mheemeed, A.K.

2013-01-01

The nuclear track detector parameters, such as nuclear track diameter D(μm), number of track N T and area of track A T were determined by using MATLAB software technique for IR-115 detector irradiated by alpha particle from 241 Am source under 1.5, 2.5 and 3.5 MeV at etching time T B of 90, 120, 150 and 180 min.By using the image analysis of MATLAB software for nuclear track, the full width at half maximum FWHM and relative resolution R% were calculated for each energy of alpha particles.In this study, it was shown that increasing the alpha energy on the IR-115 detector leads to increased etching time T B and the dropping of R% to minimum value, and then reach a stable value before dropping at values 1.5, 2.5 MeV and unstable at 3.5 MeV. Imaging analysis by MATLAB technique which used in this study reflect good and accurate results for nuclear track detector parameters and we recommend using this technique for determination of these parameters

Non-destructive isotopic uranium assay by multiple delayed neutron measurements

International Nuclear Information System (INIS)

Papadopoulos, N.N.; Tsagas, N.F.

1991-01-01

The high accuracy and precision required in nuclear safeguards measurements can be achieved by an improved neutron activation technique based on multiple delayed fission neutron counting under various experimental conditions. For the necessary ultrahigh counting statistics required, cyclic activation of multiple subsamples has been applied. The home-made automated flexible analytical system with neutron flux and spectrum differentiation by irradiation position adjustment and cadmium screening, permits the non-destructive determination of the U235 abundance and the total U element concentration needed in nuclear safeguards sample analysis, with a high throughout and a low operational cost. Careful experimental optimization led to considerable improvement of the results

Determination of wall wear of glassmelting furnaces by a nuclear technique

International Nuclear Information System (INIS)

Harsanyi, Gyoergy; Kodolanyi, Andras; Leitner, Laszlo

1984-01-01

A new in-service inspection technique of glassmelting furnaces is reported. Isotope-labelled refractory tank blocks were prepared, tested experimentally, and built into the furnace. Sup(60)Co isotope tracer was used. The residual wall thickness of the labelled blocks were determined by periodical radiation dose measurements. No environmental or health damage is caused by the specific activity of 3.7 - 4 Bq/g of the labelled furnace blocks, the dose rate in a distance of 1 m from the wall was as low as 0.05 mR/h. (P.J.)

Assessment of Equipment for the Determination of Nutrients in Marine Waters: A Case Study of the Microplate Technique

Science.gov (United States)

Aminot, A.

1996-09-01

An essential prerequisite for quality assurance of the colorimetric determination of nutrients in seawater is the use of suitable photometric equipment. Based on a knowledge of the optical characteristics of a particular system and the absorption coefficient of the analyte, a statistical approach can be used to predict the limit of detection and the limit of quantitation for a given determinand. The microplate technique, widely used for bioassays, is applicable to colorimetric analysis in general, and its use for the determination of nutrients in seawater has been suggested. This paper reports a theoretical assessment of its capabilities in this context and a practical check on its performance, taking the determination of nitrite in seawater as typical. The conclusion is that short optical path length and insufficient repeatability of the absorbance measurement render it unsuitable for the determination of the low concentrations generally encountered in marine work, with the possible exception of nitrate. The perceived advantage of high-speed analysis is a secondary consideration in the overall process of determining nutrients, and the microplate technique's small scale of operation is a definite disadvantage as this increases the risk of exposure to contamination problems, in comparison with conventional techniques.

Nuclear techniques for determining biomass production, evaporation and transpiration, root development and nutritional value

International Nuclear Information System (INIS)

Niemann, E.G.; Kuehn, W.; Kaul, A.K.

1975-01-01

From the Institute of Radiation Botany, Hanover, some nuclear methods are presented which could be of assistance to the plant breeders in selecting for positive plant characters. Several methods have been developed for the continuous determination of biomass by means of gamma-absorption measurements in single plants as well as in experimental field plots. The response of plant growth to environmental conditions such as fertilization, irrigation, and day length, dependent on genetic parameters can easily be followed by these techniques. Primarily for the investigation of water vapour movement in soils and between soil and atmosphere under conditions of temperature inversions, a technique has been worked out using 3 H-labelled water and water vapour. The inclusion of plants in this system will allow the determination of water balance under varying environmental conditions. An autoradiographic method has been applied using 86 Rb as trace element mainly for the measurement of root distribution of trees (apple, coffee). Finally, a sequence of analytical steps are described that have been developed and used in Hanover for the selection for protein amount and quality in crop plants. Though not all of these steps include nuclear methods, the application of tracer techniques in this and other screening sequences is an invaluable help for breeders and analysts. (author)

Determination of mineral matter distribution in a coal seam using O sub 2 chemisorption technique

Energy Technology Data Exchange (ETDEWEB)

Palmer, A.D.; Goulet, J.-C.; Grandsen, J.; Price, J.T.; Furimsky, E. (CANMET, Ottawa, ON (Canada). Energy Research Laboratories)

1990-08-01

A series of samples taken from different depths of the seam of a bituminous coal in Western Canada was used to determine the mineral matter distribution. The measurements were carried out using the O{sub 2} chemisorption based on a thermogravimetric technique. The O{sub 2} chemisorption increased with decreasing mineral matter content. The employed technique was found to be suitable for identifying the portion of coal seam least contaminated with mineral matter. 5 refs., 3 figs., 1 tab.

IMPLANTABLE RESONATORS – A TECHNIQUE FOR REPEATED MEASUREMENT OF OXYGEN AT MULTIPLE DEEP SITES WITH IN VIVO EPR

Science.gov (United States)

Li, Hongbin; Hou, Huagang; Sucheta, Artur; Williams, Benjamin B.; Lariviere, Jean P.; Khan, Nadeem; Lesniewski, Piotr N.; Swartz, Harold M.

2013-01-01

EPR oximetry using implantable resonators allow measurements at much deeper sites than are possible with surface resonators (> 80 mm vs. 10 mm) and have greater sensitivity at any depth. We report here the development of an improvement of the technique that now enables us to obtain the information from multiple sites and at a variety of depths. The measurements from the various sites are resolved using a simple magnetic field gradient. In the rat brain multi-probe implanted resonators measured pO2 at several sites simultaneously for over 6 months to record under normoxic, hypoxic and hyperoxic conditions. This technique also facilitates measurements in moving parts of the animal such as the heart, because the orientation of the paramagnetic material relative to the sensitive small loop is not altered by the motion. The measured response is very fast, enabling measurements in real time of physiological and pathological changes such as experimental cardiac ischemia in the mouse heart. The technique also is quite useful for following changes in tumor pO2, including applications with simultaneous measurements in tumors and adjacent normal tissues. PMID:20204802

Nuclear assay of coal. Volume 4. Moisture determination in coal: survey of electromagnetic techniques. Final report

International Nuclear Information System (INIS)

Bevan, R.; Luckie, P.; Gozani, T.; Brown, D.R.; Bozorgmanesh, H.; Elias, E.

1979-01-01

This survey consists of two basic parts. The first consists of a survey of various non-nuclear moisture determination techniques. Three techniques are identified as promising for eventual on-line application with coal; these are the capacitance, microwave attenuation, and nuclear magnetic resonance (NMR) techniques. The second part is devoted to an in-depth analysis of these three techniques and the current extent to which they have been applied to coal. With a given coal type, accuracies of +- 1% absolute in moisture content are achievable with all three techniques. The accuracy of the two electromagnetic techniques has been demonstrated in the laboratory and on-line in coal burning plants, whereas only small samples have been analyzed with NMR. The current shortcoming of the simple electromagnetic techniques is the sensitivity of calibrations to physical parameters and coal type. NMR is currently limited by small sample sizes and non-rugged design. These findings are summarized and a list of manufacturers of moisture analyzers is given in the Appendix

Tracer techniques for urine volume determination and urine collection and sampling back-up system

Science.gov (United States)

Ramirez, R. V.

1971-01-01

The feasibility, functionality, and overall accuracy of the use of lithium were investigated as a chemical tracer in urine for providing a means of indirect determination of total urine volume by the atomic absorption spectrophotometry method. Experiments were conducted to investigate the parameters of instrumentation, tracer concentration, mixing times, and methods for incorporating the tracer material in the urine collection bag, and to refine and optimize the urine tracer technique to comply with the Skylab scheme and operational parameters of + or - 2% of volume error and + or - 1% accuracy of amount of tracer added to each container. In addition, a back-up method for urine collection and sampling system was developed and evaluated. This back-up method incorporates the tracer technique for volume determination in event of failure of the primary urine collection and preservation system. One chemical preservative was selected and evaluated as a contingency chemical preservative for the storage of urine in event of failure of the urine cooling system.

System for prediction and determination of the sub critic multiplication; Sistema para previsao e determinacao da multiplicacao subcritica

Energy Technology Data Exchange (ETDEWEB)

Martinez, Aquilino S.; Pereira, Valmir; Silva, Fernando C. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

1997-12-01

It is presented a concept of a system which may be used to calculate and anticipate the subcritical multiplication of a PWR nuclear power plant. The system is divided into two different modules. The first module allows the theoretical prediction of the subcritical multiplication factor through the solution of the multigroup diffusion equation. The second module determines this factor based on the data acquired from the neutron detectors of a NPP external nuclear detection system. (author). 3 refs., 3 figs., 2 tabs.

Review of tomography technique for 3-dimensional fission product distribution determination in irradiated fuel

Energy Technology Data Exchange (ETDEWEB)

Pakr, D G; Hong, K P; Joo, Y S; Lee, H K

2006-04-15

Tomography algorithm is reviewed in order to determine radial 2-dimensional fission product distribution of irradiated fuel rod and to reconstruct it's image using computer. Main contents are Radon transformation, Fourier central slice theorem, inverse Fourier transform, accompanied FBP(Filtered Back Projection) and BPB(Back Projection Filtering). In addition, another tomography reconstruction algorithm, namely, ART(Algebraic Reconstruction Technique) is reviewed briefly. According to reviewed results, we devise equipment for determining of 2-dimensional distribution of irradiated nuclear fuel using existing gamma scanning apparatus. On results of review, It is necessary to develop computer program of reconstruction algorithm for determining of object function and image reconstruction.

Review of tomography technique for 3-dimensional fission product distribution determination in irradiated fuel

International Nuclear Information System (INIS)

Pakr, D. G.; Hong, K. P.; Joo, Y. S.; Lee, H. K.

2006-04-01

Tomography algorithm is reviewed in order to determine radial 2-dimensional fission product distribution of irradiated fuel rod and to reconstruct it's image using computer. Main contents are Radon transformation, Fourier central slice theorem, inverse Fourier transform, accompanied FBP(Filtered Back Projection) and BPB(Back Projection Filtering). In addition, another tomography reconstruction algorithm, namely, ART(Algebraic Reconstruction Technique) is reviewed briefly. According to reviewed results, we devise equipment for determining of 2-dimensional distribution of irradiated nuclear fuel using existing gamma scanning apparatus. On results of review, It is necessary to develop computer program of reconstruction algorithm for determining of object function and image reconstruction

Determination of radon and thoron permeability through some plastics by track technique

Energy Technology Data Exchange (ETDEWEB)

Hafez, A.-F.; Somogyi, G.

1986-01-01

Experiments have been performed to study the usefulness of several types of plastic foils as filter to separate radon and thoron. Time-integrated alpha-activity measurements have been carried out by using the so-called ''can-technique'' equipped with both LR-115 and CR-39 track detectors. The track density observed on the detectors, taken as a measure of radon activity concentration, has been determined as a function of the thickness of filter foils. The radon permeability and the thoron separation factors have been determined. It is shown that various plastic foils exhibit considerable differences in radon diffusion coefficient owing to their different chemical structures. Among the plastic foils investigated the polyethylene proved to have the highest gas diffusion coefficient.

Analysis of a production/inventory system with multiple retailers

OpenAIRE

Noblesse, Ann; Boute, Robert; Lambrecht, Marc; Van Houdt, B.

2014-01-01

We study a production/inventory system with one manufacturing plant and multiple retailers. Production lead times at the plant are stochastic and endogenously determined by the orders placed by the different retailers. Assuming stochastic (phase-type distributed) production and setup times, we make use of matrix analytic techniques to develop a queuing model that is capable to compute the distribution of the time orders spend in the production facility, depending on the retailer’s lot s...

Determination Of Natural Boron Concentration In Coffee Leaves, Using de Autobiography by Neutron Capture Technique

International Nuclear Information System (INIS)

Loria, L. G.; Jimenez, R.; Thellier, M.

1999-01-01

Determination of natural boron concentration in coffee leaves, using the autoradiography, by neutron capture technique. The boron absorption coefficient in young coffee leaves was measured using autoradiography by neutron capture. In two experiments carried out in April and November, 1996, it was found that the coefficient varies between 0.9 and 5.3 nmol/h. the concentration of natural boron in coffee leaves in regard to age, symptoms and treatment received was also studied, using the same technique. (Author) [es

Treatment of severe mitral regurgitation caused by lesions in both leaflets using multiple mitral valve plasty techniques in a small dog

Directory of Open Access Journals (Sweden)

Satoko Yokoyama

2017-11-01

Full Text Available Mitral valve plasty (MVP is preferred over mitral valve replacement (MVR for mitral regurgitation in humans because of its favorable effect on quality of life. In small dogs, it is difficult to repair multiple lesions in both leaflets using MVP. Herein, we report a case of severe mitral regurgitation caused by multiple severe lesions in the posterior leaflet (PL in a mixed Chihuahua. Initially, we had planned MVR with an artificial valve. However, MVP combined with artificial chordal reconstruction of both leaflets, semicircular suture annuloplasty, and valvuloplasty using a newly devised direct scallop suture for the PL was attempted in this dog. The dog recovered well and showed no adverse cardiac signs, surviving two major operations. The dog died 4 years and 10 months after the MVP due to non-cardiovascular disease. Our additional technique of using a direct scallop suture seemed useful for PL repair involving multiple scallops in a small dog.

Interference-Assisted Techniques for Transmission and Multiple Access in Optical Communications

Science.gov (United States)

Guan, Xun

communication (VLC) by adopting PNC, with a newly proposed phase-aligning method. PNC could improve the throughput at the bottlenecking relay node in a VLC system, and the proposed phase aligning method can improve the BER performance. The second part of this thesis discusses another interference-assisted technology in communication, that is, non-orthogonal multiple access (NOMA). NOMA multiplexes signals from multiple users in another dimension: power domain, with a non-orthogonal multiplexing in other dimensions such as time, frequency and code. Three schemes are proposed in this part. The first and the second schemes both realize NOMA in VLC, with different multiuser detection (MUD) techniques and a proposed phase pre-distortion method. Although both can decrease the system BER compared to conventional NOMA, the scheme using joint detection (JD) outperforms the one using successive interference cancellation (SIC). The third scheme investigated in this part is a combination of NOMA and a multicarrier precoding (MP) technology based on an orthogonal circulant transform matrix (OCT). This combination can avoid the complicated adaptive bit loading or electronic equalization, making NOMA more attractive in a practical system.

Validation of a residue method to determine pesticide residues in cucumber by using nuclear techniques

International Nuclear Information System (INIS)

Baysoyu, D.; Tiryaki, O.; Secer, E.; Aydin, G.

2009-01-01

In this study, a multi-residue method using ethyl acetate for extraction and gel permeation chromatography for clean-up was validated to determine chlorpyrifos, malathion and dichlorvos in cucumber by gas chromatography. For this purpose, homogenized cucumber samples were fortified with pesticides at 0.02 0.2, 0.8 and 1 mg/kg levels. The efficiency and repeatability of the method in extraction and cleanup steps were performed using 1 4C-carbaryl by radioisotope tracer technique. 1 4C-carbaryl recoveries after the extraction and cleanup steps were between 92.63-111.73 % with a repeatability of 4.85% (CV) and 74.83-102.22 % with a repeatability of 7.19% (CV), respectively. The homogeneity of analytical samples and the stability of pesticides during homogenization were determined using radio tracer technique and chromatographic methods, respectively.

Modified Truncated Multiplicity Analysis to Improve Verification of Uranium Fuel Cycle Materials

International Nuclear Information System (INIS)

LaFleur, A.; Miller, K.; Swinhoe, M.; Belian, A.; Croft, S.

2015-01-01

Accurate verification of 235U enrichment and mass in UF6 storage cylinders and the UO2F2 holdup contained in the process equipment is needed to improve international safeguards and nuclear material accountancy at uranium enrichment plants. Small UF6 cylinders (1.5'' and 5'' diameter) are used to store the full range of enrichments from depleted to highly-enriched UF6. For independent verification of these materials, it is essential that the 235U mass and enrichment measurements do not rely on facility operator declarations. Furthermore, in order to be deployed by IAEA inspectors to detect undeclared activities (e.g., during complementary access), it is also imperative that the measurement technique is quick, portable, and sensitive to a broad range of 235U masses. Truncated multiplicity analysis is a technique that reduces the variance in the measured count rates by only considering moments 1, 2, and 3 of the multiplicity distribution. This is especially important for reducing the uncertainty in the measured doubles and triples rates in environments with a high cosmic ray background relative to the uranium signal strength. However, we believe that the existing truncated multiplicity analysis throws away too much useful data by truncating the distribution after the third moment. This paper describes a modified truncated multiplicity analysis method that determines the optimal moment to truncate the multiplicity distribution based on the measured data. Experimental measurements of small UF6 cylinders and UO2F2 working reference materials were performed at Los Alamos National Laboratory (LANL). The data were analyzed using traditional and modified truncated multiplicity analysis to determine the optimal moment to truncate the multiplicity distribution to minimize the uncertainty in the measured count rates. The results from this analysis directly support nuclear safeguards at enrichment plants and provide a more accurate verification method for UF6

Development of the charcoal adsorption technique for determination of radon content in natural gas

International Nuclear Information System (INIS)

Paewpanchon, P.; Chanyotha, S.

2017-01-01

A technique for the determination of the radon concentration in natural gas using charcoal adsorption has been developed to study the effects of parameters that influence the adsorption efficiency of radon onto activated charcoal. Several sets of experiments were conducted both in the laboratory and in an actual natural gas field for comparison. The results show that the adsorption capability of radon onto activated charcoal varies inversely with temperature, hydrocarbon concentration and the humidity contained within the natural gas. A technique utilizing dry ice as a coolant was found to be the most effective for trapping radon in natural gas samples at the production site. A desiccant can be used to remove moisture from the sampling gas. The technique described here increases the adsorption efficiency of activated charcoal by 10-20% compared to our previous study. (authors)

Mortar and surface dating with Optically Stimulated Luminescence (OSL): Innovative techniques for the age determination of buildings

International Nuclear Information System (INIS)

Panzeri, L.

2013-01-01

In this work the results of a dating study on bricks and mortars using both Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) are shown. The samples came from the outside walls of the Certosa di Pavia, located in northern Italy and independently dated (XVII-XVIII century). TL dating, applied to bricks using the fine grain technique, allowed to determine the time of manufacture of the bricks (XII century), that resulted therefore re-used. To circumvent this problem the application of two innovative dating techniques, OSL surface dating and mortar dating, was attempted. The first was applied to the light-shielded surfaces of bricks and allowed to successfully determine the edification of the wall (XVII century). Mortar dating gave instead severe age overestimation: the results obtained on coarse grain quartz with the SAR technique both on multi-grains aliquots and with single-grain analyses were highly dispersed indicating an incomplete bleaching of the quartz grains. The shine-down curves were in fact characterized by the absence of the so-called fast component, as confirmed by Linear Modulated OSL technique.

Determining neutron multiplication factor in the infinite system by reactivity dependence on one dimension of the reactor core

International Nuclear Information System (INIS)

Pesic, M.

1975-01-01

The objective of this task was to apply Fermi age theory for determining τ and neutron multiplication factor in infinite medium by measuring reactivity coefficient of heavy water in heterogeneous mixed reactor lattice. Basis of experiment is the measurement of stable reactor period. Measurement of heavy water reactivity coefficient by measuring the stable reactor period is described for chosen overcritical heavy water levels. Calculated values of infinite multiplication factor for measured neutron age data are presented and they are compared to expected theoretical values

Construction of an experimental simplified model for determining of flow parameters in chemical reactors, using nuclear techniques

International Nuclear Information System (INIS)

Araujo Paiva, J.A. de.

1981-03-01

The development of a simplified experimental model for investigation of nuclear techniques to determine the solid phase parameters in gas-solid flows is presented. A method for the measurement of the solid phase residence time inside a chemical reactor of the type utilised in the cracking process of catalytic fluids is described. An appropriate radioactive labelling technique of the solid phase and the construction of an eletronic timing circuit were the principal stages in the definition of measurement technique. (Author) [pt

Detection of chemical explosives using multiple photon signatures

International Nuclear Information System (INIS)

Loschke, K.W.; Dunn, W.L.

2008-01-01

Full text: A template-matching procedure to aid in rapid detection of improvised explosive devices (IEDs) is being investigated. Multiple photon-scattered and photon-induced positron annihilation radiation responses are being used as part of a photon-neutron signature-based radiation scanning (SBRS) approach (see companion reference for description of the neutron component), in an attempt to detect chemical explosives at safe standoff distances. Many past and present photon interrogation methods are based on imaging. Imaging techniques seek to determine at high special resolution the internal structure of a target of interest. Our technique simply seeks to determine if an unknown target contains a detectable amount of chemical explosives by comparing multiple responses (signatures) that depend on both density and composition of portions of a target. In the photon component, beams of photons are used to create back-streaming signatures, which are dependent on the density and composition of part of the target being interrogated. These signatures are compared to templates, which are collections of the same signatures if the interrogated volume contained a significant amount of explosives. The signature analysis produces a figure-of-merit and a standard deviation of the figure-of-merit. These two metrics are used to filter safe from dangerous targets. Experiments have been conducted that show that explosive surrogates (fertilizers) can be distinguished from several inert materials using these photon signatures, demonstrating that these signatures can be used effectively to help IEDs

[Difference between perinatal mortality in multiple pregnancies obtained spontaneously versus assisted reproduction].

Science.gov (United States)

del Rayo Rivas-Ortiz, Yazmín; Hernández-Herrera, Ricardo Jorge

2010-06-01

Recently assisted reproduction techniques are more common, which increases multiple pregnancies and adverse perinatal outcomes. Some authors report increased mortality in multiple pregnancies products obtained by techniques of assisted reproduction vs. conceived spontaneously, although other authors found no significant difference. To evaluate mortality rate of multiple pregnancies comparing those obtained by assisted reproduction vs. spontaneous conception. Retrospective, observational and comparative study. We included pregnant women with 3 or more products that went to the Unidad Médica de Alta Especialidad No. 23, IMSS, in Monterrey, NL (Mexico), between 2002-2008. We compared the number of complicated pregnancies and dead products obtained by a technique of assisted reproduction vs. spontaneous. 68 multiple pregnancies were included. On average, spontaneously conceived fetuses had more weeks of gestation and more birth weight than those achieved by assisted reproduction techniques (p = ns). 20.5% (14/68) of multiple pregnancies had one or more fatal events: 10/40 (25%) by assisted reproduction techniques vs. 4/28 (14%) of spontaneous multiple pregnancies (p = 0.22). 21/134 (16%) of the products conceived by assisted reproduction techniques and 6/88 (7%) of spontaneous (p assisted reproduction and 21% of the cases had one or more fatal events (11% more in pregnancies achieved by assisted reproduction techniques). 12% of the products of multiple pregnancies died (9% more in those obtained by a technique of assisted reproduction).

Use of multiple attributes decision-making Technique for Order Preference by Similarity to Ideal Solution (TOPSIS for Ghare-Gheshlagh calcite in determination of optimum geochemical sampling sites

Directory of Open Access Journals (Sweden)

Mansour Rezaei Azizi

2015-04-01

for green, white and pink calcites were varied 0.087, 0.247 and 0.997 respectively. The low amounts of Eu anomaly for green and white calcites attributed to low rock/fluid ratio (Nesbitt et al., 1990 and relatively more pH value (Cheng et al., 2013, however, increasing the Eu anomaly may be due to high rock/fluid ratio and less pH value. Ce anomalies are 0.0241, 0.0113 and 0.0131 in pink, white and green calcites respectively. The most negative Ce anomaly values show that calcite have precipitated under reduction conditions (Nesbitt et al., 1990. Discussion Recently, multiple attributes decision-making techniques help scientist to solve decision-making problems related to various controlling factors (Zhijun et al., 2013. One of these techniques is a Technique for Order Preference by Similarity to Ideal Solution (TOPSIS which is a quantitative weighted method (Momenei 2006. The identified criteria are CaO abundant in solution (C1, Eu anomaly (C2, Ce anomaly (C3, Sr abundant (C4 and volume (C5. The Index-Rock matrix also includes A1, A2 and A3 alternatives; as pink, green and white calcite respectively. The weighted normalized decision matrix can be calculated by multiplying the normalized evaluation matrix with its associated weight to obtain the result. The result show that Eu anomaly, volume, Sr abundant and Ce anomaly in order have higher role to investigate the geochemical study of area. Calculation of the relative closeness to the ideal solution (Cl * for pink, green and white calcites are 0.837, 0.445 and 0.157 respectively. It can be deduced that the most preferable calcite to be sampled for investigating geochemically are pink and green calcites. References Cheng, D.L., Jiang-haob, L., Shou-pengc, Z., Lianga, L., Zhao-bina, Y., Guo-lina, G. and Tinga, L., 2013. Geochemical characteristics of calcite and dolomite in sandstone of Dongying Sinking, Shandong Province, China. Procedia Earth and Planetary Science, 7(4: 504 – 507. Eftekharnezhad, J., 1973

Determination of photophysical parameters of cyanines using different techniques. Application to DODCI (3-3' dietiloxacarbocyanine iodide)

International Nuclear Information System (INIS)

Duchowicz, R.; Scaffardi, L.; Di Paolo, R.E.; Tocho, J.O.

1990-01-01

A number of fluorescence and absorption techniques were developed for the determination of photo-physical parameters of photo-isomerizable cyanines. The application of these techniques, such as saturated fluorescence, double excitation fluorescence and temperature dependent absorption, to the specific case of 3-3' dietiloxadicarbocyanine iodide (DODCI), allowed the particular study of photo-isomer's exited state along with its decay processes. Fluorescence efficiency and the mean life of the photo-isomer as a function of temperature were obtained. The activation energy and the pre-exponential factor for the non-radioactive decay processes were determined. For the first time, the fluorescence spectrum of the transient isomer form was registered free of the emission of the normal species. (Author). 6 refs., 9 figs

Use of decision analysis techniques to determine Hanford cleanup priorities

International Nuclear Information System (INIS)

Fassbender, L.; Gregory, R.; Winterfeldt, D. von; John, R.

1992-01-01

In January 1991, the U.S. Department of Energy (DOE) Richland Field Office, Westinghouse Hanford Company, and the Pacific Northwest Laboratory initiated the Hanford Integrated Planning Process (HIPP) to ensure that technically sound and publicly acceptable decisions are made that support the environmental cleanup mission at Hanford. One of the HIPP's key roles is to develop an understanding of the science and technology (S and T) requirements to support the cleanup mission. This includes conducting an annual systematic assessment of the S and T needs at Hanford to support a comprehensive technology development program and a complementary scientific research program. Basic to success is a planning and assessment methodology that is defensible from a technical perspective and acceptable to the various Hanford stakeholders. Decision analysis techniques were used to help identify and prioritize problems and S and T needs at Hanford. The approach used structured elicitations to bring many Hanford stakeholders into the process. Decision analysis, which is based on the axioms and methods of utility and probability theory, is especially useful in problems characterized by uncertainties and multiple objectives. Decision analysis addresses uncertainties by laying out a logical sequence of decisions, events, and consequences and by quantifying event and consequence probabilities on the basis of expert judgments

Identification of Determinants of Sports Skill Level in Badminton Players Using the Multiple Regression Model

Directory of Open Access Journals (Sweden)

Jaworski Janusz

2016-03-01

Full Text Available Purpose. The aim of the study was to evaluate somatic and functional determinants of sports skill level in badminton players at three consecutive stages of training. Methods. The study examined 96 badminton players aged 11 to 19 years. The scope of the study included somatic characteristics, physical abilities and neurosensory abilities. Thirty nine variables were analysed in each athlete. Coefficients of multiple determination were used to evaluate the effect of structural and functional parameters on sports skill level in badminton players. Results. In the group of younger cadets, quality and effectiveness of playing were mostly determined by the level of physical abilities. In the group of cadets, the most important determinants were physical abilities, followed by somatic characteristics. In this group, coordination abilities were also important. In juniors, the most pronounced was a set of the variables that reflect physical abilities. Conclusions. Models of determination of sports skill level are most noticeable in the group of cadets. In all three groups of badminton players, the dominant effect on the quality of playing is due to a set of the variables that determine physical abilities.

Technique for determining training staff size

International Nuclear Information System (INIS)

Frye, S.R.

1985-01-01

Determining an adequate training staff size is a vital function of a training manager. Today's training requirements and standards have dictated a more stringent work load than ever before. A trainer's role is more than just providing classroom lectures. In most organizations the instructor must develop programs, lesson plans, exercise guides, objectives, test questions, etc. The tasks of a training organization are never ending and the appropriate resources must be determined and allotted to do the total job. A simple method exists for determining an adequate staff. Although not perfect, this method will provide a realistic approach for determining the needed training staff size. This method considers three major factors: instructional man-hours; non-instructional man-hours; and instructor availability. By determining and adding instructional man-hours and non-instructional man-hours a total man-hour distribution can be obtained. By dividing this by instructor availability a staff size can be determined

ACM-based automatic liver segmentation from 3-D CT images by combining multiple atlases and improved mean-shift techniques.

Science.gov (United States)

Ji, Hongwei; He, Jiangping; Yang, Xin; Deklerck, Rudi; Cornelis, Jan

2013-05-01

In this paper, we present an autocontext model(ACM)-based automatic liver segmentation algorithm, which combines ACM, multiatlases, and mean-shift techniques to segment liver from 3-D CT images. Our algorithm is a learning-based method and can be divided into two stages. At the first stage, i.e., the training stage, ACM is performed to learn a sequence of classifiers in each atlas space (based on each atlas and other aligned atlases). With the use of multiple atlases, multiple sequences of ACM-based classifiers are obtained. At the second stage, i.e., the segmentation stage, the test image will be segmented in each atlas space by applying each sequence of ACM-based classifiers. The final segmentation result will be obtained by fusing segmentation results from all atlas spaces via a multiclassifier fusion technique. Specially, in order to speed up segmentation, given a test image, we first use an improved mean-shift algorithm to perform over-segmentation and then implement the region-based image labeling instead of the original inefficient pixel-based image labeling. The proposed method is evaluated on the datasets of MICCAI 2007 liver segmentation challenge. The experimental results show that the average volume overlap error and the average surface distance achieved by our method are 8.3% and 1.5 m, respectively, which are comparable to the results reported in the existing state-of-the-art work on liver segmentation.

Use of modified lip repositioning technique associated with esthetic crown lengthening for treatment of excessive gingival display: A case report of multiple etiologies

Science.gov (United States)

Mantovani, Matheus Bortoluzzi; Souza, Eduardo Clemente; Marson, Fabiano Carlos; Corrêa, Giovani Oliveira; Progiante, Patrícia Saram; Silva, Cléverson Oliveira

2016-01-01

Excessive gingival display during smile can result in compromised esthetics. This study aims to report a case of excessive gingival display with multiple etiologies treated by means of modified lip repositioning technique associated with esthetic crown lengthening. A 23-year-old female patient, with 5-mm gingival display during smile caused by altered passive eruption and hypermobility of the upper lip, underwent the modified lip repositioning technique associated with gingivectomy followed by flap elevation and ostectomy/osteoplasty. Seven months after the second procedure, the patient had her esthetic complaint solved appearing stable in the observation period. The modified lip repositioning technique is an effective procedure employed to reduce gingival display and when associated with esthetic clinical crown lengthening, can appropriately treat cases of gummy smile. PMID:27041845

Increased determinism in brain electrical activity occurs in association with multiple sclerosis.

Science.gov (United States)

Carrubba, Simona; Minagar, Alireza; Chesson, Andrew L; Frilot, Clifton; Marino, Andrew A

2012-04-01

Increased determinism (decreased complexity) of brain electrical activity has been associated with some brain diseases. Our objective was to determine whether a similar association occurred for multiple sclerosis (MS). Ten subjects with a relapsing-remitting course of MS who were in remission were studied; the controls were age- and gender-matched clinically normal subjects. Recurrence plots were calculated using representative electroencephalogram (EEG) epochs (1-7 seconds) from six derivations; the plots were quantified using the nonlinear variables percent recurrence (%R) and percent determinism (%D). The results were averaged over all derivations for each participant, and the means were compared between the groups. As a linear control procedure the groups were also compared using spectral analysis. The mean±SD of %R for the MS subjects was 6·6±1·3%, compared with 5·1±1·3% in the normal group (P = 0·017), indicating that brain activity in the subjects with MS was less complex, as hypothesized. The groups were not distinguishable using %D or spectral analysis. Taken together with our earlier report that %R could be used to discriminate between MS and normal subjects based on the ability to exhibit evoked potentials, the evidence suggests that complexity analysis of the EEG has potential for development as a diagnostic test for MS.

A comparison of multiple regression and neural network techniques for mapping in situ pCO2 data

International Nuclear Information System (INIS)

Lefevre, Nathalie; Watson, Andrew J.; Watson, Adam R.

2005-01-01

Using about 138,000 measurements of surface pCO 2 in the Atlantic subpolar gyre (50-70 deg N, 60-10 deg W) during 1995-1997, we compare two methods of interpolation in space and time: a monthly distribution of surface pCO 2 constructed using multiple linear regressions on position and temperature, and a self-organizing neural network approach. Both methods confirm characteristics of the region found in previous work, i.e. the subpolar gyre is a sink for atmospheric CO 2 throughout the year, and exhibits a strong seasonal variability with the highest undersaturations occurring in spring and summer due to biological activity. As an annual average the surface pCO 2 is higher than estimates based on available syntheses of surface pCO 2 . This supports earlier suggestions that the sink of CO 2 in the Atlantic subpolar gyre has decreased over the last decade instead of increasing as previously assumed. The neural network is able to capture a more complex distribution than can be well represented by linear regressions, but both techniques agree relatively well on the average values of pCO 2 and derived fluxes. However, when both techniques are used with a subset of the data, the neural network predicts the remaining data to a much better accuracy than the regressions, with a residual standard deviation ranging from 3 to 11 μatm. The subpolar gyre is a net sink of CO 2 of 0.13 Gt-C/yr using the multiple linear regressions and 0.15 Gt-C/yr using the neural network, on average between 1995 and 1997. Both calculations were made with the NCEP monthly wind speeds converted to 10 m height and averaged between 1995 and 1997, and using the gas exchange coefficient of Wanninkhof

Radioimmunodiffusion technique for determining diphtheria antitoxin

International Nuclear Information System (INIS)

Maniar, A.C.

1977-01-01

A radioimmunodiffusion technique for detecting low levels of diphtheria antitoxin was developed. Diphtheria toxoid was labelled with 125 I to facilitate detection of lines of precipitation by the use of X-ray film, the lower limit of detection being 0.001 unit per millilitre of diphtheria antitoxin. (author)

The scratch test - Different critical load determination techniques. [adhesive strength of thin hard coatings

Science.gov (United States)

Sekler, J.; Hintermann, H. E.; Steinmann, P. A.

1988-01-01

Different critical load determination techniques such as microscopy, acoustic emission, normal, tangential, and lateral forces used for scratch test evaluation of complex or multilayer coatings are investigated. The applicability of the scratch test to newly developed coating techniques, systems, and applications is discussed. Among the methods based on the use of a physical measurement, acoustic emission detection is the most effective. The dynamics ratio between the signals below and above the critical load for the acoustic emission (much greater than 100) is well above that obtained with the normal, tangential, and lateral forces. The present commercial instruments are limited in load application performance. A scratch tester able to apply accurate loads as low as 0.01 N would probably overcome most of the actual limitations and would be expected to extend the scratch testing technique to different application fields such as optics and microelectronics.

Determination of the protonation enthalpy of humic acid by calorimetric titration technique

International Nuclear Information System (INIS)

Kimuro, Shingo; Kirishima, Akira; Sato, Nobuaki

2015-01-01

Graphical abstract: The thermodynamic quantities of protonation of humic acid were determined by the combination of potentiometric titration and calorimetric titration. It was observed that the protonation enthalpy and Gibbs free energy had been affected by pH of solution. As a result, the thermodynamics of the protonation reaction of humic acid is influenced by the polyelectrolyte effect and the heterogeneity. - Highlights: • We applied calorimetric titration technique to the protonation of humic acid. • The thermodynamic quantities of protonation of humic acid were determined. • The protonation enthalpy of humic acid is affected by the heterogeneity. • Gibbs free energy of the protonation is affected by the polyelectrolyte effect. - Abstract: In this study, the calorimetric titration technique was used to determine the protonation enthalpy of two reference humic acids and polyacrylic acid. First, we obtained the apparent protonation constant of two kinds of humic acid purchased from IHSS (International Humic Substances Society) and polyacrylic acid by potentiometric titration. Second, we obtained the protonation enthalpy of them by calorimetric titration. The protonation enthalpy of humic acid was affected by pH and the ionic strength of bulk solution. From the comparison of ΔH between humic acid and polyacrylic acid, it was concluded that the pH dependence of ΔH is attributed to the heterogeneity of humic acid. And ΔH of phenolic hydroxyl group in humic acid is strongly influenced by the electric double layer of humic acid’s surface. This is considered to be a reason of the ionic strength dependence of ΔH. On the other hand, Gibbs free energy of the protonation of humic acid is affected by the electrostatic attraction with the progress of dissociation of functional groups such as carboxyl group and phenolic hydroxyl group. Consequently, the thermodynamics of the protonation of humic acid is affected by the polyelectrolyte effect and the

Application of the Constrained Admissible Region Multiple Hypothesis Filter to Initial Orbit Determination of a Break-up

Science.gov (United States)

Kelecy, Tom; Shoemaker, Michael; Jah, Moriba

2013-08-01

A break-up in Low Earth Orbit (LEO) is simulated for 10 objects having area-to-mass ratios (AMR's) ranging from 0.1-10.0 m2/kg. The Constrained Admissible Region Multiple Hypothesis Filter (CAR-MHF) is applied to determining and characterizing the orbit and atmospheric drag parameters (CdA/m) simultaneously for each of the 10 objects with no a priori orbit or drag information. The results indicate that CAR-MHF shows promise for accurate, unambiguous and autonomous determination of the orbit and drag states.

The Delphi Technique: Making Sense of Consensus

Directory of Open Access Journals (Sweden)

Chia-Chien Hsu

2007-08-01

Full Text Available The Delphi technique is a widely used and accepted method for gathering data from respondents within their domain of expertise. The technique is designed as a group communication process which aims to achieve a convergence of opinion on a specific real-world issue. The Delphi process has been used in various fields of study such as program planning, needs assessment, policy determination, and resource utilization to develop a full range of alternatives, explore or expose underlying assumptions, as well as correlate judgments on a topic spanning a wide range of disciplines. The Delphi technique is well suited as a method for consensus-building by using a series of questionnaires delivered using multiple iterations to collect data from a panel of selected subjects. Subject selection, time frames for conducting and completing a study, the possibility of low response rates, and unintentionally guiding feedback from the respondent group are areas which should be considered when designing and implementing a Delphi study.

[Determination of acetanilide herbicide residues in tea by gas chromatography-mass spectrometry with two different ionization techniques].

Science.gov (United States)

Shen, Weijian; Xu, Jinzhong; Yang, Wenquan; Shen, Chongyu; Zhao, Zengyun; Ding, Tao; Wu, Bin

2007-09-01

An analytical method of solid phase extraction-gas chromatography-mass spectrometry with two different ionization techniques was established for simultaneous determination of 12 acetanilide herbicide residues in tea-leaves. Herbicides were extracted from tea-leaf samples with ethyl acetate. The extract was cleaned-up on an active carbon SPE column connected to a Florisil SPE column. Analytical screening was determined by the technique of gas chromatography (GC)-mass spectrometry (MS) in the selected ion monitoring (SIM) mode with either electron impact ionization (EI) or negative chemical ionization (NCI). It is reliable and stable that the recoveries of all herbicides were in the range from 50% to 110% at three spiked levels, 10 microg/kg, 20 microg/kg and 40 microg/kg, and the relative standard deviations (RSDs) were no more than 10.9%. The two different ionization techniques are complementary as more ion fragmentation information can be obtained from the EI mode while more molecular ion information from the NCI mode. By comparison of the two techniques, the selectivity of NCI-SIM was much better than that of EI-SIM method. The sensitivities of the both techniques were high, the limit of quantitative (LOQ) for each herbicide was no more than 2.0 microg/kg, and the limit of detection (LOD) with NCI-SIM technique was much lower than that of EI-SIM when analyzing herbicides with several halogen atoms in the molecule.

A self-determination multiple risk intervention trial to improve smokers' health.

Science.gov (United States)

Williams, Geoffrey C; McGregor, Holly; Sharp, Daryl; Kouldes, Ruth W; Lévesque, Chantal S; Ryan, Richard M; Deci, Edward L

2006-12-01

Little is known about how interventions motivate individuals to change multiple health risk behaviors. Self-determination theory (SDT) proposes that patient autonomy is an essential factor for motivating change. An SDT-based intervention to enhance autonomous motivation for tobacco abstinence and improving cholesterol was tested. The Smokers' Health Study is a randomized multiple risk behavior change intervention trial. Smokers were recruited to a tobacco treatment center. A total of 1.006 adult smokers were recruited between 1999 and 2002 from physician offices and by newspaper advertisements. A 6-month clinical intervention (4 contacts) to facilitate internalization of autonomy and perceived competence for tobacco abstinence and reduced percent calories from fat was compared with community care. Clinicians elicited patient perspectives and life strivings, provided absolute coronary artery disease risk estimates,enumerated effective treatment options, supported patient initiatives,minimized clinician control, assessed motivation for change, and developed a plan for change. Twelve-month prolonged tobacco abstinence, and change in percent calories from fat and low-density lipoprotein-cholesterol (LDL-C) from baseline to 18 months. RESULTS- Intention to treat analyses revealed that the intervention significantly increased 12-month prolonged tobacco abstinence (6.2% vs 2.4%; odds ratio [OR]=2.7, P=.01, number needed to treat [NNT] =26), and reduced LDL-C (-8.9 vs -4.1 mg/dL; P=.05). There was no effect on percent calories from fat. An intervention focused on supporting smokers'autonomy was effective in increasing prolonged tobacco abstinence and lowering LDL-C. Clinical interventions for behavior change may be improved by increasing patient autonomy and perceived competence.

Determination of some process parameters in a tyre-cord plant using radiotracer technique

International Nuclear Information System (INIS)

Kirti; Madhavankutti, C.K.; Eapen, A.C.

1979-01-01

In the process industry, it is often necessary to study the process parameters such as the residence time, flow rate, etc., under different operating conditions and equipment. The tracer technique represents in this respect an outstanding and even sometimes singular means of determining some of the above parameters. A method consisting of the introduction of a radioactive tracer at the input of a flow system under study and subsequently determining the distribution of activity with time at the output end is described. The form of the activity time curve depends on the parameters of the installation and the mode of operation. A study conducted at a multi-stage viscose rayon processing plant is described in detail. (auth.)

Machining of AISI D2 Tool Steel with Multiple Hole Electrodes by EDM Process

Science.gov (United States)

Prasad Prathipati, R.; Devuri, Venkateswarlu; Cheepu, Muralimohan; Gudimetla, Kondaiah; Uzwal Kiran, R.

2018-03-01

In recent years, with the increasing of technology the demand for machining processes is increasing for the newly developed materials. The conventional machining processes are not adequate to meet the accuracy of the machining of these materials. The non-conventional machining processes of electrical discharge machining is one of the most efficient machining processes is being widely used to machining of high accuracy products of various industries. The optimum selection of process parameters is very important in machining processes as that of an electrical discharge machining as they determine surface quality and dimensional precision of the obtained parts, even though time consumption rate is higher for machining of large dimension features. In this work, D2 high carbon and chromium tool steel has been machined using electrical discharge machining with the multiple hole electrode technique. The D2 steel has several applications such as forming dies, extrusion dies and thread rolling. But the machining of this tool steel is very hard because of it shard alloyed elements of V, Cr and Mo which enhance its strength and wear properties. However, the machining is possible by using electrical discharge machining process and the present study implemented a new technique to reduce the machining time using a multiple hole copper electrode. In this technique, while machining with multiple holes electrode, fin like projections are obtained, which can be removed easily by chipping. Then the finishing is done by using solid electrode. The machining time is reduced to around 50% while using multiple hole electrode technique for electrical discharge machining.

Study of gamma ray multiplicity spectra for radiative capture of neutrons in 113,115In

International Nuclear Information System (INIS)

Georgiev, G.P.; Fajkov-Stanchik, Kh.; Grigor'ev, Yu.V.; Muradyan, G.V.; Yaneva, N.B.

1997-08-01

Neutron radiative capture measurements were performed for the enriched isotopes 113 In and 115 In on the neutron spectrometer at the Neutron Physics Laboratory of the Joint Institute for Nuclear Research employing the gamma ray multiplicity technique and using a ''Romashka'' multi-sectional 4p detector on the 500 m time base of the IBR-30 booster. The gamma multiplicity spectra of resolved resonances were obtained for the 20-500 eV energy range. The mean gamma ray multiplicity was determined for each resonance. The dependence of the ratio S of the low-energy coincidence multiplicity spectrum to the high-energy coincidence multiplicity spectrum on resonance energy exhibits a non-statistical structure. This structure was found to correlate with the local neutron strength function. (author). 10 refs, 6 figs, 2 tabs

A note on determination of the diffuse-field sensitivity of microphones using the reciprocity technique

DEFF Research Database (Denmark)

Barrera Figueroa, Salvador; Jacobsen, Finn

2008-01-01

angles of incidence but also on the accuracy of the frequency response at normal incidence. By contrast, this paper is concerned with determining the absolute diffuse-field response of a microphone using the reciprocity technique. To examine this possibility, a reciprocity calibration setup is used...

Sex determination of Pohnpei Micronesian kingfishers using morphological and molecular genetic techniques

Science.gov (United States)

Kesler, Dylan C.; Lopes, I.F.; Haig, Susan M.

2006-01-01

Conservation-oriented studies of Micronesian Kingfishers (Todiramphus cinnamominus) have been hindered by a lack of basic natural history information, despite the status of the Guam subspecies (T. c. cinnamominus) as one of the most endangered species in the world. We used tissue samples and morphometric measures from museum specimens and wild-captured Pohnpei Micronesian Kingfishers (T. c. reichenbachii) to develop methods for sex determination. We present a modified molecular protocol and a discriminant function that yields the probability that a particular individual is male or female. Our results revealed that females were significantly larger than males, and the discriminant function correctly predicted sex in 73% (30/41) of the individuals. The sex of 86% (18/21) of individuals was correctly assigned when a moderate reliability threshold was set. Sex determination using molecular genetic techniques was more reliable than methods based on morphology. Our results will facilitate recovery efforts for the critically endangered Guam Micronesian Kingfisher and provide a basis for sex determination in the 11 other endangered congeners in the Pacific Basin.

Determination of NAPL contamination and evolution of remediation by means nuclear techniques

International Nuclear Information System (INIS)

Balcazar, M.; Pena, P.; Lopez, A.; Flores, J. H.; Villegas, D.; Schubert, M.; Knoller, K.

2008-01-01

In this work the application of two nuclear techniques is presented: Natural radioactive tracer and stable isotopics tracer, that allow the localization and delimitation of the contamination in ground and underground water for hydrocarbons denominated NAPL. The work was carry out on the whole and with access permission to facilities and technical information, in a storage center and distribution of fuel of hydrocarbons where occurred a spill for hydrocarbons, approaching actions of remediation that allow to the date to fulfill the normative one applicable. By means of measurement of 222 Rn, in situ, it was possible to be related its ground concentration to the degree of contamination previously determined; the evaluation of 222 Rn in underground water in group with the determination of stable isotope δ 34 S, δ 18 O and δ 13 C as well as the dissolved inorganic coal allowed to locate the contamination source in underground water to 100 m of depth in the aquifer and to determine the existence of a natural bioremediation. (Author)

Application of washed rumen technique for rapid determination of fasting heat production in steers

Science.gov (United States)

Two experiments were conducted to evaluate the use of a washed rumen technique as an alternative approach for determining fasting HP in cattle. In Exp. 1, 8 Holstein steers (322±30 kg) were adapted to a cubed alfalfa-based diet (1.5xNEm) for 10 d. After which steers were placed into individual hea...

Determination of hormonal combination for increased multiplication ...

African Journals Online (AJOL)

ACSS

production; such methods include tissue culture and ... NAA and Vitamins has been reported to increase the ... is a new technique in seed potato production ... Napthalene acetic acid (NAA) were ... to analysis of variance (ANOVA), using.

Experimental determination of nuclear reaction rates (n,γ) by the gamma-rays capture spectrometry technique

International Nuclear Information System (INIS)

Lucatero, M.A.

1976-01-01

The technique of the gamma-rays capture spectrometry was used in the experimental determination of nuclear reaction rates of the type (n,γ). This technique consists in the incidence of a thermal neutrons collimated beam upon a sample, detecting the capture spectrum of gamma rays emitted at a solid fixed angle. In the determination of the efficiency curve intrinsic to the detection electronic system the reactions 199 Hg(n,γ) 200 Hg, 56 Fe(n,γ) 57 Fe and 63 Cu(n,γ) 64 Cu were used with the energy of the gamma rays capture of 5.976, 7.635 and 7.915 Mev respectively, through the irradiation of standard samples of Hg(175.3g), Fe(110.4g) and Cu(108.5g) of cylindrical geometry the two former and parallelepiped the latter. The problem concerning the corrections due to the thermal neutrons flux depression, the gammas auto-attenuation, and the geometric factor due to the cylindrical and parallelepiped geometry are involved in the data process. The experimental determination of the reaction 35 Cl(n,γ) 36 Cl rate was made through the observation of the gamma caputre of 6.111 Mev when a sample of CaCl 2 of cylindrical geometry was irradiated. This rate can be favorably compared with the reaction rate determined theoretically. (author)

Comparison of techniques for the determination of conversion during suspension polymerization reactions

Directory of Open Access Journals (Sweden)

J. C. Santos

2008-06-01

Full Text Available The determination of conversion during suspension polymerization reactions is not an easy task due to the heterogeneity of the reaction medium and the tendency of particles to agglomerate rapidly when stirring is stopped. Usually, bulk polymerization in ampoules is employed to study the kinetics of suspension polymerization reactions. In this work, a comparison of different techniques for the determination of conversion during suspension polymerization reactions is presented. Results showed a good agreement between the conversion obtained by gravimetry during styrene suspension polymerization and on-line conversion monitoring data using fiber-optic based Raman Spectroscopy. Nevertheless, the polymerization rate of styrene bulk polymerization carried out in ampoules was higher than the real reaction rate of styrene suspension polymerization due to slightly higher reaction temperatures. Simulation results using the experimental temperature data in a mathematical model confirmed these results.

Standard Test Method for Determining Thermal Neutron Reaction Rates and Thermal Neutron Fluence Rates by Radioactivation Techniques

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 The purpose of this test method is to define a general procedure for determining an unknown thermal-neutron fluence rate by neutron activation techniques. It is not practicable to describe completely a technique applicable to the large number of experimental situations that require the measurement of a thermal-neutron fluence rate. Therefore, this method is presented so that the user may adapt to his particular situation the fundamental procedures of the following techniques. 1.1.1 Radiometric counting technique using pure cobalt, pure gold, pure indium, cobalt-aluminum, alloy, gold-aluminum alloy, or indium-aluminum alloy. 1.1.2 Standard comparison technique using pure gold, or gold-aluminum alloy, and 1.1.3 Secondary standard comparison techniques using pure indium, indium-aluminum alloy, pure dysprosium, or dysprosium-aluminum alloy. 1.2 The techniques presented are limited to measurements at room temperatures. However, special problems when making thermal-neutron fluence rate measurements in high-...

ATR technique, an appropriate method for determining the degree of conversion in dental giomers

International Nuclear Information System (INIS)

Prejmerean, Cristina; Prodan, Doina; Vlassa, Mihaela; Prejmerean, Vasile; Cuc, Stanca; Moldovan, Marioara; Streza, Mihaela; Buruiana, Tinca; Colceriu, Loredana

2016-01-01

Dental light-curing giomers were developed to combine the favourable properties of diacrylic resin composites (DRCs) and glass-ionomer cements (GICs) in a single material and to eliminate their inherent drawbacks. Giomers are characterized by their aesthetic appearance, high mechanical properties, adhesion to dental tissues as well as fluoride release and recharge abilities. The qualities of the giomers are greatly influenced by the level of conversion of the component resins. Infrared spectroscopy is one of the most largely used techniques for the determination of the degree of conversion in resin-based dental materials. However different results were obtained due to the performances of the used methods. The present work presents the determination of conversion degree in a series of dental copolymers and their corresponding giomers using transmission Fourier transform infrared spectroscopy (FTIR) and an attenuated total reflection technique (ATR) technique, respectively, the main aim being the study of the influence of the materials composition and of the light curing modes upon the achieved conversion in the cured giomers. Beautifil II commercial giomer was used as a control. A halogen lamp and a diode-blue LED lamp were used for the curing of the materials. The results showed that the composition of the resins greatly influenced the conversion. The highest conversions (up to 79%) were obtained in the case of the experimental giomers which contained the experimental Bis-GMA urethane analogue, followed by the Beautifil II giomer (61%) and experimental giomers based on commercial Bis-GMA (up to 50%), respectively. The resins light-cured by using the diode-blue LED lamp presented slightly higher conversions than the resins cured by halogen lamp. The study demonstrates the possibility to evaluate easily and reproducibly the conversion in light-curing composite materials with complex chemical composition and structure, particularly in the case of giomers by using the

Determination of catecholamines and their metabolites by radioisotopic techniques, value in pharmacology and physiopathology

International Nuclear Information System (INIS)

Comoy, E.; Bohuon, C.

1980-01-01

At present the only way to estimate catecholamines and similar compounds at concentrations between 10 and 100 femtomoles is by the use of radioenzymatic techniques. Such methods are all based in practice on the enzymatic transformation of these substrates, in the presence of labelled S-adenosylmethionine, under the action of catechol-O-methyltrans-ferase (COMT) or phenylethanol-amine-N-methyltransferase (PNMT), which means that molecules suitable for such determinations must possess either a catechol group (catecholamines, dihydroxyphenylalanine, dihydroxyphenylacetic acid) or a phenylethanolamine group (noradrenaline, methoxynoradrenaline). At present the largest number of molecules may be estimated by methods based on the principle of O-methylation by COMT. The main processes described in the literature are examined, with special reference to the proposed means of solving problems which arise at various stages of the determination, mention is made of the many difficulties inherent in this kind of manipulation and of the limits to be expected of these tests. The immunological aspect of quantitative research on catecholamines and their derivatives is mentioned, work in this direction at present being based on radioimmunology. As a practical illustration of the many methodological studies mentioned, the application of radioisotopic techniques to in vitro exploration of the catecholamine metabolism is discussed; the contribution of these new techniques is shown particularly in the physiopathological study of certain metabolic disorders observed in man, in the pharmacodynamic study of certain molecules and in experimental studies on the central nervous system [fr

Neutron/gamma dose separation by the multiple-ion-chamber technique

International Nuclear Information System (INIS)

Goetsch, S.J.

1983-01-01

Many mixed n/γ dosimetry systems rely on two dosimeters, one composed of a tissue-equivalent material and the other made from a non-hydrogenous material. The paired chamber technique works well in fields of neutron radiation nearly identical in spectral composition to that in which the dosimeters were calibrated. However, this technique is drastically compromised in phantom due to the degradation of the neutron spectrum. The three-dosimeter technique allows for the fall-off in neutron sensitivity of the two non-hydrogenous dosimeters. Precise and physically meaningful results were obtained with this technique with a D-T source in air and in phantom and with simultaneous D-T neutron and 60 Co gamma ray irradiation in air. The MORSE-CG coupled n/γ three-dimensional Monte Carlo code was employed to calculate neutron and gamma doses in a water phantom. Gamma doses calculated in phantom with this code were generally lower than corresponding ion chamber measurements. This can be explained by the departure of irradiation conditions from ideal narrow-beam geometry. 97 references

Determination of wear metals in engine oil by PIXE and RBS technique

Energy Technology Data Exchange (ETDEWEB)

Alkofahi, M M [Physics Dept., Yarmouk university, Irbid, (Jordan)

1995-10-01

The constituents of fresh and used engine oil were determined by PIXE and RBS techniques using 2 MeV He{sup ++} ion beams. The concentration of generated wear metals in used engine oil was measured as a function of running kilometers. The fresh oil was found to contain the elements: Si, P, S, Cl, K, Ca, and Fe. In addition to theses elements, Pb and Br were found in the used oil. Changes in the concentrations of S, Zn and Br were noticed as the running kilometers increased. 6 figs., 2 tabs.

Primary study on image addition technique in CT measuring used to determine the malalignment of patellofemoral joints

International Nuclear Information System (INIS)

Huan Jian; Gong Jianping; Zhu Jianbing; Dong Qirong; Lu Zhian

2000-01-01

Objective: To evaluate the use of image addition technique in the field of CT measuring on patellofemoral joints. Method: In contractive condition and relaxant condition of quadriceps, 60 knee joints of 30 patients (47 knee joints accompanied with peri-patellar pain) were examined by CT scanning, and the CT image addition and single technique. Results: In contractive and relaxant condition of quadriceps in the normal group, the difference between index measured by image addition technique were not significant and it was found that demonstrated measurement error of image addition was smaller, but there was significant difference between index measured by single technique, and it suggests that its replication was bad. Conclusion: Use of image addition technique can decrease measurement error and play a important role on accurately determining the malalignment of patellofemoral joints

DEVELOPMENT OF THE CHARCOAL ADSORPTION TECHNIQUE FOR DETERMINATION OF RADON CONTENT IN NATURAL GAS.

Science.gov (United States)

Paewpanchon, P; Chanyotha, S

2017-11-01

A technique for the determination of the radon concentration in natural gas using charcoal adsorption has been developed to study the effects of parameters that influence the adsorption efficiency of radon onto activated charcoal. Several sets of experiments were conducted both in the laboratory and in an actual natural gas field for comparison. The results show that the adsorption capability of radon onto activated charcoal varies inversely with temperature, hydrocarbon concentration and the humidity contained within the natural gas. A technique utilizing dry ice as a coolant was found to be the most effective for trapping radon in natural gas samples at the production site. A desiccant can be used to remove moisture from the sampling gas. The technique described here increases the adsorption efficiency of activated charcoal by 10-20% compared to our previous study. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Multiple-Access Quantum-Classical Networks

Science.gov (United States)

Razavi, Mohsen

2011-10-01

A multi-user network that supports both classical and quantum communication is proposed. By relying on optical code-division multiple access techniques, this system offers simultaneous key exchange between multiple pairs of network users. A lower bound on the secure key generation rate will be derived for decoy-state quantum key distribution protocols.

Study on uranium-water multiplicative means of the (RESUCO-Subcritical experimental reactor of uranium with oxygen) subcritical assembly by pulsed neutron technique

International Nuclear Information System (INIS)

Jesus Barbosa, S. de.

1987-01-01

The effective multiplication factor and the nuclear parameters associated with the variation of (RESUCO- Subcritical Experimental Reactor of Uranium with Oxygen) Subcritical Assembly Configuration, using pulsed neutron technique are analysed. BF3 detectors were used to detect the variation of thermal neutrons in the system, positioned parallelly to fuel elements, and a proton recoil detector was used for monitoring the neutron generation. (M.C.K.) [pt

Neutron and gamma-ray transmission technique for the on-line determination of moisture in coal and coke

International Nuclear Information System (INIS)

Sowerby, B.D.; Millen, M.J.; Rafter, P.T.

1985-01-01

A fast neutron and gamma-ray transmission technique is being developed for the on-line analysis of moisture in coal and coke. The technique utilises 252 Cf and 137 Cs sources and 3 He and NaI(Tl) detectors. Laboratory measurements on single coal samples have shown that moisture can be determined to better than 1 wt% over the range 0 to 16 wt% moisture and 5 to 17cm thickness. Reduced errors were obtained for restricted ranges of moisture and thickness. Preliminary measurements on coke of thickness 30 to 50cm have shown that moisture can be determined to within 0.26 wt% over the range 1 to 16 wt% moisture

The determination of multiple resistance, inheritance and cytochrome P450 activity in bifenthrinresistant Tetranychus urticae Koch (Acari: Tetranychidae)

OpenAIRE

AY, Recep; YORULMAZ, Sibel

2010-01-01

In this study, multiple resistance, inheritance and cytochrome P450 enzyme activity were determined in Tetranychus urticae Koch (SAK) population after 20 selections for bifenthrin resistance. Selection study and LC50, 60 levels of SAK population of T. urticae were determined by dry film method. LC50 level of the SAK population selected twenty times with bifenthrin was increased from 984.49 to 11914.40 µl l-1 distiled water. Selected population showing 21.84 fold resistances was named ...

ESTABLISHING A STEREOSCOPIC TECHNIQUE FOR DETERMINING THE KINEMATIC PROPERTIES OF SOLAR WIND TRANSIENTS BASED ON A GENERALIZED SELF-SIMILARLY EXPANDING CIRCULAR GEOMETRY

International Nuclear Information System (INIS)

Davies, J. A.; Perry, C. H.; Harrison, R. A.; Trines, R. M. G. M.; Lugaz, N.; Möstl, C.; Liu, Y. D.; Steed, K.

2013-01-01

The twin-spacecraft STEREO mission has enabled simultaneous white-light imaging of the solar corona and inner heliosphere from multiple vantage points. This has led to the development of numerous stereoscopic techniques to investigate the three-dimensional structure and kinematics of solar wind transients such as coronal mass ejections (CMEs). Two such methods—triangulation and the tangent to a sphere—can be used to determine time profiles of the propagation direction and radial distance (and thereby radial speed) of a solar wind transient as it travels through the inner heliosphere, based on its time-elongation profile viewed by two observers. These techniques are founded on the assumption that the transient can be characterized as a point source (fixed φ, FP, approximation) or a circle attached to Sun-center (harmonic mean, HM, approximation), respectively. These geometries constitute extreme descriptions of solar wind transients, in terms of their cross-sectional extent. Here, we present the stereoscopic expressions necessary to derive propagation direction and radial distance/speed profiles of such transients based on the more generalized self-similar expansion (SSE) geometry, for which the FP and HM geometries form the limiting cases; our implementation of these equations is termed the stereoscopic SSE method. We apply the technique to two Earth-directed CMEs from different phases of the STEREO mission, the well-studied event of 2008 December and a more recent event from 2012 March. The latter CME was fast, with an initial speed exceeding 2000 km s –1 , and highly geoeffective, in stark contrast to the slow and ineffectual 2008 December CME

Cardiac output determined by echocardiography in patients with cirrhosis: comparison with the indicator dilution technique

DEFF Research Database (Denmark)

Andersen, Ulrik B; Møller, Søren; Bendtsen, Flemming

2003-01-01

technique (CO(I)). METHODS: Twelve patients with cirrhosis were studied. CO(d) was measured as the spatial mean velocity of the left ventricular outflow tract, multiplied by the cross-sectional area and the heart rate. CO(I) was determined by the standard indicator dilution technique after injection of 125I...... albumin and 99mTc albumin into the right atrium and subsequent sampling from the femoral artery. RESULTS: The mean CO(d) and CO(I) were similar (7.20 vs 7.15 l/min, NS). A highly significant correlation was present between CO(d) and CO(I) (r = 0.86, P

Analysis of various NDT techniques to determine their feasibility for detecting thin layers of ferrite on Type 316 stainless steel

International Nuclear Information System (INIS)

Dudder, G.B.; Atteridge, D.G.; Davis, T.J.

1978-09-01

The applicability of various NDT techniques for detecting thin layers of ferrite on Type 316 stainless steel cladding was studied. The ability to detect sodium-induced ferrite layers on fuel pins would allow an experimental determination of the fuel pin temperature distribution. The research effort was broken down into three basic sections. Phase one consisted of a theoretical determination of the ferrite detection potential of each of the propsed NDT techniques. The second phase consisted of proof-of-principle experiments on the techniques that passed phase one. The third phase consisted of in-hot cell testing on actual EBR-II fuel pins. Most of the candidate techniques were eliminated in the first phase of analysis. Four potential techniques passed the initial phase of analysis but only three of these passed the second analysis phase. The three techniques that passed the proof-of-principle section of analysis were heat tinting, magnetic force and electromagnetic techniques. The electromagnetic technique was successfully demonstrated on actual fuel pins irradiated in EBR-II in the third phase of analysis while the other two techniques were not carried to the hot cell analysis phase. Results of this technique screening study indicates that an electromagnetic and/or heat tinting ferrite layer NDT technique should be readily adoptable to hot cell inspection requirements. It wasalso concluded that the magnetic force technique, while feasible, would not readily lend itself to hot cell fuel pin inspection

A Review of the State-of-the-Art on Combining Multiple NDT Techniques in Terms of Precise Fault Detection

Directory of Open Access Journals (Sweden)

Ashish Khaira

2017-06-01

Full Text Available The present industrial scenario demands optimum quality, feasible processing time and enhanced machine availability to cope-up with continuously increasing customer expectations. To achieve this target, it is mandatory to ensure the optimum performance and higher availability of machinery. Therefore, the present work begins with, review of the research work of different researchers, which includes the applied combinations from year 2000-2016 proceed with discussion on the parameters being checked before making combination of NDT and finally, covers the maintenance performance parameters for quantifying improvement in performance after combining NDT. The result indicates that very few researches uses combination of NDT’s, in areas like aeronautical, compressors etc., and most of the works done in composites to be tested without using any decision making technique.  The researchers and practitioners can use the outcome of this work as a guideline for combining multiple NDT technique to achieve precise fault prediction and forecasting of upcoming failures.

Genetic variants are major determinants of CSF antibody levels in multiple sclerosis.

Science.gov (United States)

Goris, An; Pauwels, Ine; Gustavsen, Marte W; van Son, Brechtje; Hilven, Kelly; Bos, Steffan D; Celius, Elisabeth Gulowsen; Berg-Hansen, Pål; Aarseth, Jan; Myhr, Kjell-Morten; D'Alfonso, Sandra; Barizzone, Nadia; Leone, Maurizio A; Martinelli Boneschi, Filippo; Sorosina, Melissa; Liberatore, Giuseppe; Kockum, Ingrid; Olsson, Tomas; Hillert, Jan; Alfredsson, Lars; Bedri, Sahl Khalid; Hemmer, Bernhard; Buck, Dorothea; Berthele, Achim; Knier, Benjamin; Biberacher, Viola; van Pesch, Vincent; Sindic, Christian; Bang Oturai, Annette; Søndergaard, Helle Bach; Sellebjerg, Finn; Jensen, Poul Erik H; Comabella, Manuel; Montalban, Xavier; Pérez-Boza, Jennifer; Malhotra, Sunny; Lechner-Scott, Jeannette; Broadley, Simon; Slee, Mark; Taylor, Bruce; Kermode, Allan G; Gourraud, Pierre-Antoine; Sawcer, Stephen J; Andreassen, Bettina Kullle; Dubois, Bénédicte; Harbo, Hanne F

2015-03-01

as female gender, age at onset and severity. This is the largest study population so far investigated for the genetic influence on antibody levels in the cerebrospinal fluid in multiple sclerosis, including 6950 patients. We confirm that genetic factors underlie these antibody levels and identify both the major histocompatibility complex and immunoglobulin heavy chain region as major determinants. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genetic variants are major determinants of CSF antibody levels in multiple sclerosis

Science.gov (United States)

Pauwels, Ine; Gustavsen, Marte W.; van Son, Brechtje; Hilven, Kelly; Bos, Steffan D.; Celius, Elisabeth Gulowsen; Berg-Hansen, Pål; Aarseth, Jan; Myhr, Kjell-Morten; D’Alfonso, Sandra; Barizzone, Nadia; Leone, Maurizio A.; Martinelli Boneschi, Filippo; Sorosina, Melissa; Liberatore, Giuseppe; Kockum, Ingrid; Olsson, Tomas; Hillert, Jan; Alfredsson, Lars; Bedri, Sahl Khalid; Hemmer, Bernhard; Buck, Dorothea; Berthele, Achim; Knier, Benjamin; Biberacher, Viola; van Pesch, Vincent; Sindic, Christian; Bang Oturai, Annette; Søndergaard, Helle Bach; Sellebjerg, Finn; Jensen, Poul Erik H.; Comabella, Manuel; Montalban, Xavier; Pérez-Boza, Jennifer; Malhotra, Sunny; Lechner-Scott, Jeannette; Broadley, Simon; Slee, Mark; Taylor, Bruce; Kermode, Allan G.; Gourraud, Pierre-Antoine; Sawcer, Stephen J.; Andreassen, Bettina Kullle; Dubois, Bénédicte; Harbo, Hanne F.

2015-01-01

as female gender, age at onset and severity. This is the largest study population so far investigated for the genetic influence on antibody levels in the cerebrospinal fluid in multiple sclerosis, including 6950 patients. We confirm that genetic factors underlie these antibody levels and identify both the major histocompatibility complex and immunoglobulin heavy chain region as major determinants. PMID:25616667

Rapid determination of eight bioactive alkaloids in Portulaca oleracea L. by the optimal microwave extraction combined with positive-negative conversion multiple reaction monitor (+/-MRM) technology.

Science.gov (United States)

Liang, Xiao; Tian, Jinlong; Li, Lingzhi; Gao, Jun; Zhang, Qingyi; Gao, Pinyi; Song, Shaojiang

2014-03-01

A rapid and reliable microwave extraction and the triple quadrupole-linear ion trap mass spectrometry method was developed and validated for the determination of eight alkaloids in Portulaca oleracea L. The optimal microwave extraction (MWE) condition was performed at 60 °C for 12 min with ethanol-water (70:30, v/v) as the extracting solvent, and the solvent to solid ratio was 30:1. The alkaloids were first detected simultaneously by electrospray ionization tandem mass spectrometry under positive-negative conversion multiple reaction monitor ((+/-)MRM) technique. With investigating three different columns, samples were separated in only 8 min on a Waters ACQUITY UPLC HSS T3 (50 × 2.1 mm(2), 1.8 μm) column using acetonitrile and formic acid-water solution as a mobile phase with a flow rate at 0.2 mL/min. All calibration curves showed good linearity (r>0.999) within the test ranges. The method developed was validated with acceptable sensitivity, intra- and inter-day precision, reproducibility, and extraction recoveries. It was successfully applied to the determination of eight alkaloids in Portulaca oleracea L. from different sources and different harvest periods. The method also provide a reference for extraction and determination of alkaloids in other complex systems. © 2013 Elsevier B.V. All rights reserved.

DEVELOPMENT OF RAPID TECHNIQUE FOR DETERMINATION OF THE TOTAL MINERALIZATION OF NATURAL WATERS

Directory of Open Access Journals (Sweden)

T. A. Kuchmenko

2015-01-01

Full Text Available A new approach has been proposed for rapid and easy evaluation of a indicator of quality and properties of natural water - soluble salt content (mineralization. The method of quartz crystal microbalance is employed at load of the mass-sensitive resonator electrode (BAW-type with investigated water. The degree of correlation between the various indicators related to the contents of salts and insoluble compounds and the level of mineralization obtained by the standard method (gravimetry has been studied. A procedure for salt weighing by single sensor at unilateral load with small sample of natural water has been developed. The optimal conditions for measurement is established using the design of experiment by model 23 . The possibilities of quartz crystal microbalance for determination of non-volatile compounds in the water are described. The calibration of piezosensor is produced by standard solution NaCl (c = 1.000 g / dm3 at optimal conditions of experiment. The adequacy and accuracy of proposed technique is assessed by the correlation between the results of quartz crystal microbalance and conductometry. The correlation between indicators of mineralization established by quartz crystal microbalance and gravimetry is found. It has been obtained an equation that can be used to calculate the standard indicator of the mineralization by the results of a quartz crystal microbalance using single sensor. The approaches to enhance the analytical capabilities of the developed technique for water with low and high mineralization are proposed. The metrological characteristics of quartz crystal microbalance of insoluble compounds in natural water are estimated. A new technique of determination of the mass concentration of the dry residue in water with a conductivity of 0.2 mS or above has been developed, which can be used for rapid analysis of the water at nonlaboratory conditions and in the laboratory for rapid obtaining the information about a sample.

Determining the stereochemical structures of molecular ions by ''Coulomb-explosion'' techniques with fast (MeV) molecular ion beams

International Nuclear Information System (INIS)

Gemmell, D.S.

1980-01-01

Recent studies on the dissociation of fast (MeV) molecular ion beams in thin foils suggest a novel alternative approach to the determination of molecular ion structures. In this article we review some recent high-resolution studies on the interactions of fast molecular ion beams with solid and gaseous targets and indicate how such studies may be applied to the problem of determining molecular ion structures. The main features of the Coulomb explosion of fast-moving molecular ion projectiles and the manner in which Coulomb-explosion techniques may be applied to the problem (difficult to attack by more conventional means) of determining the stereochemical structures of molecular ions has been described in this paper. Examples have been given of early experiments designed to elicit structure information. The techniques are still in their infancy, and it is to be expected that as both the technology and the analysis are refined, the method will make valuable contributions to the determination of molecular ion structures

An Innovative Technique to Assess Spontaneous Baroreflex Sensitivity with Short Data Segments: Multiple Trigonometric Regressive Spectral Analysis.

Science.gov (United States)

Li, Kai; Rüdiger, Heinz; Haase, Rocco; Ziemssen, Tjalf

2018-01-01

Objective: As the multiple trigonometric regressive spectral (MTRS) analysis is extraordinary in its ability to analyze short local data segments down to 12 s, we wanted to evaluate the impact of the data segment settings by applying the technique of MTRS analysis for baroreflex sensitivity (BRS) estimation using a standardized data pool. Methods: Spectral and baroreflex analyses were performed on the EuroBaVar dataset (42 recordings, including lying and standing positions). For this analysis, the technique of MTRS was used. We used different global and local data segment lengths, and chose the global data segments from different positions. Three global data segments of 1 and 2 min and three local data segments of 12, 20, and 30 s were used in MTRS analysis for BRS. Results: All the BRS-values calculated on the three global data segments were highly correlated, both in the supine and standing positions; the different global data segments provided similar BRS estimations. When using different local data segments, all the BRS-values were also highly correlated. However, in the supine position, using short local data segments of 12 s overestimated BRS compared with those using 20 and 30 s. In the standing position, the BRS estimations using different local data segments were comparable. There was no proportional bias for the comparisons between different BRS estimations. Conclusion: We demonstrate that BRS estimation by the MTRS technique is stable when using different global data segments, and MTRS is extraordinary in its ability to evaluate BRS in even short local data segments (20 and 30 s). Because of the non-stationary character of most biosignals, the MTRS technique would be preferable for BRS analysis especially in conditions when only short stationary data segments are available or when dynamic changes of BRS should be monitored.

Utilization of tritiated water dilution technique in determination of nitrogen partitioning in cashmere goats

International Nuclear Information System (INIS)

Wang Linfeng; Yang Gaiqing; Liu Ping; Zhang Shijun

2010-01-01

In order to investigate nitrogen partitioning in local cashmere goats, six Inner Mogolia White Cashmere goats between 2 to 2.5 years old were used to determine the nitrogen partitioning in cashmere goats. The total retained nitrogen (TN) in body, distribution of body nitrgen and hair nitrogen were measured by general digestive and metabolism method combined with tritiated water dilution technique. Results showed that the combined methods were ideal for determining body nitrgen (BN) and hair nitrogen (fur nitrogen, FN) of Cashmere goats. There were obvious significance between BN and FN in different seasons. In telogen, BN and FN partitioning was 75.7% ± 0.62% and 24.3% ± 0.62%, respectively. Whereas, it changed to 66.6% ± 2.2% and 33.4% ± 2.2% in anagen. BN partitioning decreased when the season changed from telogen to anagen, while FN partitioning increased, which indicated that more nitrogen substance was partitioned to body growth in telogen, and more nitrogen substance was distribute to cashmere growth in anagen. These transformation were related to the changing of photoperiod and some hormones, such as melatonin (MT), prolactin (PRL) and IGF-I. It could be concluded that tritiated water dilution technique can be used to detect body protein content as well as BN, combining general digestive and metabolism experiment, FN partitoning can be determined. BN and FN partitoning varied with the season in cashmere goats because of hormones changing. (authors)

Neutron multiplicity of fission fragments

Energy Technology Data Exchange (ETDEWEB)

Abdelrahman, Y S [Physics department, mu` rah university Al-Karak, (Jordan)

1995-10-01

The total average neutron multiplicity of the fission fragments produced by the spontaneous fission of {sup 248} Cm has been measured. This measurement has been done by using a new experimental technique. This technique mainly depends on {gamma}-{gamma} coincidence using a very high resolution high purity germanium (HPGe) detector. 2 figs.

Optimization of quantitative waste volume determination technique for hanford waste tank closure

International Nuclear Information System (INIS)

Monts, David L.; Jang, Ping-Rey; Long, Zhiling; Okhuysen, Walter P.; Norton, Olin P.; Gresham, Lawrence L.; Su, Yi; Lindner, Jeffrey S.

2011-01-01

The Hanford Site is currently in the process of an extensive effort to empty and close its radioactive single-shell and double-shell waste storage tanks. Before this can be accomplished, it is necessary to know how much residual material is left in a given waste tank and the uncertainty with which that volume is known. The Institute for Clean Energy Technology (ICET) at Mississippi State University is currently developing a quantitative in-tank imaging system based on Fourier Transform Profilometry, FTP. FTP is a non-contact, 3-D shape measurement technique. By projecting a fringe pattern onto a target surface and observing its deformation due to surface irregularities from a different view angle, FTP is capable of determining the height (depth) distribution (and hence volume distribution) of the target surface, thus reproducing the profile of the target accurately under a wide variety of conditions. Hence FTP has the potential to be utilized for quantitative determination of residual wastes within Hanford waste tanks. In this paper, efforts to characterize the accuracy and precision of quantitative volume determination using FTP and the use of these results to optimize the FTP system for deployment within Hanford waste tanks are described. (author)

A heuristic technique to determine corrective control actions for reactive power flows

Energy Technology Data Exchange (ETDEWEB)

Trigo, Angel L.; Martinez, Jose L.; Riquelme, Jesus; Romero, Esther [Department of Electrical Engineering, University of Sevilla (Spain)

2011-01-15

This paper presents a sensitivity-based heuristic tool designed to help the system operator in the reactive power flow control problem. The objective of the proposed technique is to determine control actions to ensure that reactive power flows in transmission-subtransmission boundary transformers remain within specified limits, satisfying the new regulatory constraints imposed in most of deregulated markets. With this new constraint the utilities want to guarantee that the utility is able to satisfy its own reactive power requirements, avoiding reactive power flows through long distances in order to reduce the well known disadvantages that reactive power circulation has in the system. A 5-bus tutorial system is used to present the proposed algorithm. The results of the application of the proposed technique to the IEEE 118 buses system and to a regional subtransmission network of the South of Spain are reported and analyzed. In this last actual case, the aim is to maintain reactive power flows in transmission/distribution transformers between those limits set by the Spanish Regulation. A comparison between the proposed tool and a conventional OPF is discussed. (author)

Determination in soils of soluble uranium fraction in acid medium by fission tracks registration techniques

International Nuclear Information System (INIS)

Fernandes, G.P.

1980-01-01

The fission tracks registration technique was used to determine the concentration of uranium in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. The method was applied to a few samples of soils from Pocos de Caldas, Minas Gerais in Brazil. The concentrations of uranium in the samples and residues were also determined by other methods to compare the results obtained; only one sample showed deviation among the results obtained by the fission tracks method. (author)

Determination of boron in aqueous solutions by solid state nuclear track detectors technique, using a filtered neutron beam

International Nuclear Information System (INIS)

Moraes, M.A.P.V. de; Pugliesi, R.; Khouri, M.T.F.C.

1985-11-01

The solid state nuclear track detectors technique has been used for determination of boron in aqueous solutions, using a filtered neutron beam. The particles tracks from the 10 B(n,α)Li 7 reaction were registered in the CR-39 film, chemically etched in a (30%) KOH solution 70 0 C during 90 minutes. The obtained results showed the usefulness of this technique for boron determination in the ppm range. The inferior detectable limit was 9 ppm. The combined track registration efficiency factor K has been evaluated in the solutions, for the CR-39 detector and its values is K= (4,60 - + 0,06). 10 -4 cm. (Author) [pt

Simultaneous Absorptance and Thermal-Diffusivity Determination of Optical Components with Laser Calorimetry Technique

Science.gov (United States)

Wang, Yanru; Li, Bincheng

2012-11-01

The laser calorimetry (LCA) technique is used to determine simultaneously the absorptances and thermal diffusivities of optical components. An accurate temperature model, in which both the finite thermal conductivity and the finite sample size are taken into account, is employed to fit the experimental temperature data measured with an LCA apparatus for a precise determination of the absorptance and thermal diffusivity via a multiparameter fitting procedure. The uniqueness issue of the multiparameter fitting is discussed in detail. Experimentally, highly reflective (HR) samples prepared with electron-beam evaporation on different substrates (BK7, fused silica, and Ge) are measured with LCA. For the HR-coated sample on a fused silica substrate, the absorptance is determined to be 15.4 ppm, which is close to the value of 17.6 ppm, determined with a simplified temperature model recommended in the international standard ISO11551. The thermal diffusivity is simultaneously determined via multiparameter fitting to be approximately 6.63 × 10-7 m2 · s-1 with a corresponding square variance of 4.8 × 10-4. The fitted thermal diffusivity is in reasonably good agreement with the literature value (7.5 × 10-7 m2 · s -1). Good agreement is also obtained for samples with BK7 and Ge substrates.

The correlated k-distribution technique as applied to the AVHRR channels

Science.gov (United States)

Kratz, David P.

1995-01-01

Correlated k-distributions have been created to account for the molecular absorption found in the spectral ranges of the five Advanced Very High Resolution Radiometer (AVHRR) satellite channels. The production of the k-distributions was based upon an exponential-sum fitting of transmissions (ESFT) technique which was applied to reference line-by-line absorptance calculations. To account for the overlap of spectral features from different molecular species, the present routines made use of the multiplication transmissivity property which allows for considerable flexibility, especially when altering relative mixing ratios of the various molecular species. To determine the accuracy of the correlated k-distribution technique as compared to the line-by-line procedure, atmospheric flux and heating rate calculations were run for a wide variety of atmospheric conditions. For the atmospheric conditions taken into consideration, the correlated k-distribution technique has yielded results within about 0.5% for both the cases where the satellite spectral response functions were applied and where they were not. The correlated k-distribution's principal advantages is that it can be incorporated directly into multiple scattering routines that consider scattering as well as absorption by clouds and aerosol particles.

Determination of phase transitions in a lyotropic liquid crystal by Positron Annihilation technique

International Nuclear Information System (INIS)

Castillo V, V.M.

1994-01-01

Positron annihilation technique was used to determine the phase transitions in a lyotropic liquid crystal, as a function of temperature. Seven different concentrations of the surfactant cetyldimethylethylammonium bromide, were studied. The liquid crystal studied consisted of a binary system, formed by the surfactant and water. Positron annihilation technique has a very high sensitivity toward changes in the microestructure, in condensed matter, this is useful in order to detect the temperatures at which phase transitions occur and the number of these, in a liquid crystalline system. Thus, phase transitions are related with changes occurred in the ortho-positronium parameters: lifetime (τ 3 ) and intensity of formation (I 3 ). Six different kinds of phases were detected in the system studied in a temperature range of 35 to 140 Centigrade degrees, those phases were: hexagonal, hexagonal-lamellae, lamellae, lamellae-cubic, nematic and anisotropic. Using optical microscopic the textures of these phases were assigned. (Author)

Laser tracker error determination using a network measurement

International Nuclear Information System (INIS)

Hughes, Ben; Forbes, Alistair; Lewis, Andrew; Sun, Wenjuan; Veal, Dan; Nasr, Karim

2011-01-01

We report on a fast, easily implemented method to determine all the geometrical alignment errors of a laser tracker, to high precision. The technique requires no specialist equipment and can be performed in less than an hour. The technique is based on the determination of parameters of a geometric model of the laser tracker, using measurements of a set of fixed target locations, from multiple locations of the tracker. After fitting of the model parameters to the observed data, the model can be used to perform error correction of the raw laser tracker data or to derive correction parameters in the format of the tracker manufacturer's internal error map. In addition to determination of the model parameters, the method also determines the uncertainties and correlations associated with the parameters. We have tested the technique on a commercial laser tracker in the following way. We disabled the tracker's internal error compensation, and used a five-position, fifteen-target network to estimate all the geometric errors of the instrument. Using the error map generated from this network test, the tracker was able to pass a full performance validation test, conducted according to a recognized specification standard (ASME B89.4.19-2006). We conclude that the error correction determined from the network test is as effective as the manufacturer's own error correction methodologies

Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques.

Science.gov (United States)

Gauquelin, N; van den Bos, K H W; Béché, A; Krause, F F; Lobato, I; Lazar, S; Rosenauer, A; Van Aert, S; Verbeeck, J

2017-10-01

Nowadays, aberration corrected transmission electron microscopy (TEM) is a popular method to characterise nanomaterials at the atomic scale. Here, atomically resolved images of nanomaterials are acquired, where the contrast depends on the illumination, imaging and detector conditions of the microscope. Visualization of light elements is possible when using low angle annular dark field (LAADF) STEM, annular bright field (ABF) STEM, integrated differential phase contrast (iDPC) STEM, negative spherical aberration imaging (NCSI) and imaging STEM (ISTEM). In this work, images of a NdGaO 3 -La 0.67 Sr 0.33 MnO 3 (NGO-LSMO) interface are quantitatively evaluated by using statistical parameter estimation theory. For imaging light elements, all techniques are providing reliable results, while the techniques based on interference contrast, NCSI and ISTEM, are less robust in terms of accuracy for extracting heavy column locations. In term of precision, sample drift and scan distortions mainly limits the STEM based techniques as compared to NCSI. Post processing techniques can, however, partially compensate for this. In order to provide an outlook to the future, simulated images of NGO, in which the unavoidable presence of Poisson noise is taken into account, are used to determine the ultimate precision. In this future counting noise limited scenario, NCSI and ISTEM imaging will provide more precise values as compared to the other techniques, which can be related to the mechanisms behind the image recording. Copyright © 2017 Elsevier B.V. All rights reserved.

Trace and essential elements determination in baby formulas milk by INAA and k0-INAA techniques

International Nuclear Information System (INIS)

Lylia Hamidatou; Hocine Slamene; Tarik Akhal; Alaa Boulegane

2014-01-01

As a part of the food analysis program executed at Es-Salam research reactor by neutron activation analysis laboratory, the concentration of As, Ba, Br, Ca, Fe, K, La, Rb and Zn in baby formulas milk have been determined by using INAA and k 0 -NAA techniques. It was found that the concentration of all elements obtained by both techniques was relatively identical for the three brands of the 0-6 and 6-12 months of analyzed samples. In addition, the analytical results have been compared with those given by producers. (author)

Determination of Cation Distributions in Mineral Structures by use of the Rietveld Full-Profile Refinement Technique

International Nuclear Information System (INIS)

Nord, A.G.

1986-01-01

Use of the Rietveld full-profile refinement technique with X-ray or neutron powder diffraction data for the determination of divalent-metal cation distributions in three mineral structure types (farringtonite, grafonite, sarcopside) is demonstrated. The accuracy of the conventional cation distribution coefficient Ksub(D) is about 5-10 percent with 24-46 parameters to be refined, and the averaged metal-oxygen distances are reliable and well correlated to the observed cation distribution pattern. In particular the usefulness of the Rietveld technique in combination with Moessbauer spectroscopy is stressed. Some concluding remarks are also given

Non-conventional measurement techniques for the determination of some long-lived radionuclides produced in nuclear fuel

International Nuclear Information System (INIS)

Rosenberg, R.J.

1992-04-01

The results of a literature survey on non-radiometric analytical techniques for the determination of long-lived radionuclides are described. The methods which have been considered are accelerator mass spectrometry, inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry, resonance ionization spectrometry, resonance ionization mass spectrometry and neutron activation analysis. Neutron activation analysis has been commonly used for the determination of 129 I and 237 Np in environmental samples. Inductively coupled mass spectrometry seems likely to become the method of choice for the determination of 99 Tc, 237 Np and Pu-isotopes. The methods are discussed and the chemical separation methods described. (orig.)

Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy

International Nuclear Information System (INIS)

Zarazua O, G.; Carapia M, L.

2000-01-01

This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

[Simultaneous determination of multiple elements in airborne particulate samples by X-ray fluorescence spectrometry].

Science.gov (United States)

Takada, T; Hitosugi, M; Kadowaki, T; Kudo, M

1983-07-01

An energy dispersive X-ray fluorescence spectrometer (EDX) has been applied to determine multielements in the workplace air. The standards for X-ray fluorescence analysis were prepared by the chelate precipitation method on polyvinyl chloride (PVC) membrane filter. And, the specimens were prepared to deposit various metal compounds of different chemical forms by the suspension method on PVC membrane filter, and they were determined with EDX and atomic absorption spectrometer (AAS). The results obtained were as follows. Though there is a difference by each element, an amount less than 3 microgram/cm2 per unit area makes it possible to undergo multielement analysis, that is, is has no influence on fine particle effect (particle size; under 5 microns). Then, effects of the X-ray intensity by different chemical forms are negligible. At the presence the neighboring element and other elements this technique showed greater precision by carrying out on corrective treatment, etc. The coefficient of variation of this technique was in the range of 2.5-6.5% at DDTC-Cu of 0.5-5.0 micrograms/cm2, with the limit of detection for As : 0.002 microgram/cm2, Zn : 0.003 microgram/cm2, Pb : 0.003 microgram/cm2, Cu : 0.004 microgram/cm2, Ni : 0.003 microgram/cm2, Fe : 0.005 microgram/cm2, Mn : 0.008 microgram/cm2, Cr : 0.013 microgram/cm2, respectively. Aerosols collected at the workplace were analyzed with EDX and AAS, and the obtained results showed good agreement with such regression line as y = 1.04 chi + 0.04, the coefficient of correlation being r = 0.995. From these results, this technique was found to be a very excellent method for monitoring of multielements in the workplace air.

Simultaneous determination of Ra-226, Ra-228 and Pb-210 using a successive coprecipitations techniques

International Nuclear Information System (INIS)

Vilhena Schayer Sabino, C. de; Kastner, S.M.S.; Amaral, A.M.

1990-01-01

Several techniques for determination of Ra-226, Ra228 and Pb-210. were developed and used in routine at CDTN in the laboratories of radiochemistry. The matrixes were: water and industrial wastes. Some problems of these techniques were the time spent for analyses and chemical separations, interferents, among others. Now-a-days the method in routine developed here is the one of successive coprecipitations, followed α and β countings of the Ra-226 and Ra-228 daughters. This method is based on coprecipitation, purification of barium radium sulfate with EDTA in acetic solution. Lead is dissolved, radium remains precipitated and suffers a new purification and the time for growing of their daughters is waited to be performed the simultaneous α and β countings for Ra-226 and Ra-228 determination. Pb-210 is analyzed in the floating of the first purification with a carrier of bismuth, and the time for Bi-210 growing is waited. Then it is precipitated as hydroxid, purified as phosphate and the β counting of Bi-210 is done. (author) [pt

Faster Double-Size Bipartite Multiplication out of Montgomery Multipliers

Science.gov (United States)

Yoshino, Masayuki; Okeya, Katsuyuki; Vuillaume, Camille

This paper proposes novel algorithms for computing double-size modular multiplications with few modulus-dependent precomputations. Low-end devices such as smartcards are usually equipped with hardware Montgomery multipliers. However, due to progresses of mathematical attacks, security institutions such as NIST have steadily demanded longer bit-lengths for public-key cryptography, making the multipliers quickly obsolete. In an attempt to extend the lifespan of such multipliers, double-size techniques compute modular multiplications with twice the bit-length of the multipliers. Techniques are known for extending the bit-length of classical Euclidean multipliers, of Montgomery multipliers and the combination thereof, namely bipartite multipliers. However, unlike classical and bipartite multiplications, Montgomery multiplications involve modulus-dependent precomputations, which amount to a large part of an RSA encryption or signature verification. The proposed double-size technique simulates double-size multiplications based on single-size Montgomery multipliers, and yet precomputations are essentially free: in an 2048-bit RSA encryption or signature verification with public exponent e=216+1, the proposal with a 1024-bit Montgomery multiplier is at least 1.5 times faster than previous double-size Montgomery multiplications.

Application of PIXE, NAA and other techniques for the determination of toxic elements in foodstuffs and drinking water in Bangladesh

International Nuclear Information System (INIS)

Tarafdar, S.A.; Khan, A.H.; Hadi, D.A.; Maroof, F.B.A.; Ali, M.

1994-01-01

An investigation was conducted on the status of trace and minor elements in some foodstuffs, meats and also drinking water in Bangladesh, using proton induced X-ray emission (PIXE), radioisotope-induced X-ray fluorescence (XRF), atomic absorption spectrophotometry (AAS) and also ion-selective electrode techniques. The elemental concentrations of K, Ca, Mn, Fe, Ni, Cu, Zn, As, Br, Rb and Sr, were determined in the samples by comparison with X-ray yield curves constructed from IAEA and NBS standard reference materials. Cadmium and zinc in the drinking water of Bangladesh was determined by AAS followed by solvent extraction technique. The total iodine content in different types of vegetables was determined by alkali ashing followed by the ion-selective electrode technique. The results indicate that none of the food regimes and also drinking water investigated here is burdened with heavy metals beyond permissible limits. The significance of the results is discussed in relation to human health an diseases. Three IAEA (2-1, and 2-2 and 2-3) secondary reference standard samples were also analyzed for intercomparison studied using PIXE and ASV techniques. (author). 4 refs, 7 tabs

Influence of the tool construction on determination of iron-grade in parameter P-techniques

International Nuclear Information System (INIS)

Charbucinski, J.

1975-01-01

The results of laboratory tests for utilization of parameter P-technique in gamma-gamma method for the purpose of determination of iron content in an ore have been presented. Measurements were performed in the 4π geometry. The various dependences of the tool response on physical-technical parameters of the tool and the borehole-stratum system have been examined. Optimum construction of the borehole tool has been recommended. (author)

Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

International Nuclear Information System (INIS)

Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H.

2005-12-01

This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here

Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

Energy Technology Data Exchange (ETDEWEB)

Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H

2005-12-15

This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here.

Surge recovery techniques for the Tevatron cold compressors

International Nuclear Information System (INIS)

Martinez, A.; Klebaner, A.L.; Makara, J.N.; Theilacker, J.C.; Fermilab

2006-01-01

The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, made by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/s of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/s and operating speeds between 40 and 95 krpm. Since initial commissioning in 1993, Tevatron transient conditions such as quench recovery have led to multiple-location machine trips as a result of the cold compressors entering the surge regime. Historically, compressors operating at lower inlet pressures and higher speeds have been especially susceptible to these machine trips and it was not uncommon to have multiple compressor trips during large multiple-house quenches. In order to cope with these events and limit accelerator down time, surge recovery techniques have been implemented in an attempt to prevent the compressors from tripping once the machine entered this surge regime. This paper discusses the different methods of surge recovery that have been employed. Data from tests performed at the Cryogenic Test Facility at Fermilab as well as actual Tevatron operational data were utilized. In order to aid in the determination of the surge region, a full mapping study was undertaken to characterize the entire pressure field of the cold compressor. These techniques were then implemented and tested at several locations in the Tevatron with some success

The advantages, and challenges, in using multiple techniques in the estimation of surface water-groundwater fluxes.

Science.gov (United States)

Shanafield, M.; Cook, P. G.

2014-12-01

When estimating surface water-groundwater fluxes, the use of complimentary techniques helps to fill in uncertainties in any individual method, and to potentially gain a better understanding of spatial and temporal variability in a system. It can also be a way of preventing the loss of data during infrequent and unpredictable flow events. For example, much of arid Australia relies on groundwater, which is recharged by streamflow through ephemeral streams during flood events. Three recent surface water/groundwater investigations from arid Australian systems provide good examples of how using multiple field and analysis techniques can help to more fully characterize surface water-groundwater fluxes, but can also result in conflicting values over varying spatial and temporal scales. In the Pilbara region of Western Australia, combining streambed radon measurements, vertical heat transport modeling, and a tracer test helped constrain very low streambed residence times, which are on the order of minutes. Spatial and temporal variability between the methods yielded hyporheic exchange estimates between 10-4 m2 s-1 and 4.2 x 10-2 m2 s-1. In South Australia, three-dimensional heat transport modeling captured heterogeneity within 20 square meters of streambed, identifying areas of sandy soil (flux rates of up to 3 m d-1) and clay (flux rates too slow to be accurately characterized). Streamflow front modeling showed similar flux rates, but averaged over 100 m long stream segments for a 1.6 km reach. Finally, in central Australia, several methods are used to decipher whether any of the flow down a highly ephemeral river contributes to regional groundwater recharge, showing that evaporation and evapotranspiration likely accounts for all of the infiltration into the perched aquifer. Lessons learned from these examples demonstrate the influences of the spatial and temporal variability between techniques on estimated fluxes.

Decoupling Solar Variability and Instrument Trends Using the Multiple Same-Irradiance-Level (MuSIL) Analysis Technique

Science.gov (United States)

Woods, Thomas N.; Eparvier, Francis G.; Harder, Jerald; Snow, Martin

2018-05-01

The solar spectral irradiance (SSI) dataset is a key record for studying and understanding the energetics and radiation balance in Earth's environment. Understanding the long-term variations of the SSI over timescales of the 11-year solar activity cycle and longer is critical for many Sun-Earth research topics. Satellite measurements of the SSI have been made since the 1970s, most of them in the ultraviolet, but recently also in the visible and near-infrared. A limiting factor for the accuracy of previous solar variability results is the uncertainties for the instrument degradation corrections, which need fairly large corrections relative to the amount of solar cycle variability at some wavelengths. The primary objective of this investigation has been to separate out solar cycle variability and any residual uncorrected instrumental trends in the SSI measurements from the Solar Radiation and Climate Experiment (SORCE) mission and the Thermosphere, Mesosphere, Ionosphere, Energetic, and Dynamics (TIMED) mission. A new technique called the Multiple Same-Irradiance-Level (MuSIL) analysis has been developed, which examines an SSI time series at different levels of solar activity to provide long-term trends in an SSI record, and the most common result is a downward trend that most likely stems from uncorrected instrument degradation. This technique has been applied to each wavelength in the SSI records from SORCE (2003 - present) and TIMED (2002 - present) to provide new solar cycle variability results between 27 nm and 1600 nm with a resolution of about 1 nm at most wavelengths. This technique, which was validated with the highly accurate total solar irradiance (TSI) record, has an estimated relative uncertainty of about 5% of the measured solar cycle variability. The MuSIL results are further validated with the comparison of the new solar cycle variability results from different solar cycles.

High Dynamic Velocity Range Particle Image Velocimetry Using Multiple Pulse Separation Imaging

Directory of Open Access Journals (Sweden)

Tadhg S. O’Donovan

2010-12-01

Full Text Available The dynamic velocity range of particle image velocimetry (PIV is determined by the maximum and minimum resolvable particle displacement. Various techniques have extended the dynamic range, however flows with a wide velocity range (e.g., impinging jets still challenge PIV algorithms. A new technique is presented to increase the dynamic velocity range by over an order of magnitude. The multiple pulse separation (MPS technique (i records series of double-frame exposures with different pulse separations, (ii processes the fields using conventional multi-grid algorithms, and (iii yields a composite velocity field with a locally optimized pulse separation. A robust criterion determines the local optimum pulse separation, accounting for correlation strength and measurement uncertainty. Validation experiments are performed in an impinging jet flow, using laser-Doppler velocimetry as reference measurement. The precision of mean flow and turbulence quantities is significantly improved compared to conventional PIV, due to the increase in dynamic range. In a wide range of applications, MPS PIV is a robust approach to increase the dynamic velocity range without restricting the vector evaluation methods.

High dynamic velocity range particle image velocimetry using multiple pulse separation imaging.

Science.gov (United States)

Persoons, Tim; O'Donovan, Tadhg S

2011-01-01

The dynamic velocity range of particle image velocimetry (PIV) is determined by the maximum and minimum resolvable particle displacement. Various techniques have extended the dynamic range, however flows with a wide velocity range (e.g., impinging jets) still challenge PIV algorithms. A new technique is presented to increase the dynamic velocity range by over an order of magnitude. The multiple pulse separation (MPS) technique (i) records series of double-frame exposures with different pulse separations, (ii) processes the fields using conventional multi-grid algorithms, and (iii) yields a composite velocity field with a locally optimized pulse separation. A robust criterion determines the local optimum pulse separation, accounting for correlation strength and measurement uncertainty. Validation experiments are performed in an impinging jet flow, using laser-Doppler velocimetry as reference measurement. The precision of mean flow and turbulence quantities is significantly improved compared to conventional PIV, due to the increase in dynamic range. In a wide range of applications, MPS PIV is a robust approach to increase the dynamic velocity range without restricting the vector evaluation methods.

Endoscopic facelift of the frontal and temporal areas in multiple planes.

Science.gov (United States)

Hu, Xiaogen; Ma, Haihuan; Xue, Zhiqiang; Qi, Huijie; Chen, Bo

2017-02-01

The detachment planes used in endoscopic facelifts play an important role in determining the results of facial rejuvenation. In this study, we introduced the use of multiple detachment planes for endoscopic facelifts of the frontal and temporal areas, and examined its outcome. This study included 47 patients (38 female, 9 male) who requested frontal and temporal facelifts from January 2009 to January 2014. The technique of dissection in multiple planes was used for all 47 patients. In this technique, the frontal dissection was first carried out in the subgaleal plane, before being changed to the subperiosteal plane about 2 cm above the eyebrow line. Temporal dissection was carried out in both the subcutaneous and subgaleal planes. After detachment, frontal and temporal fixations were achieved using nonabsorbable sutures, and the incisions were closed. During follow-up (ranging from 6-24 months after surgery), the patients were shown their pre- and postoperative images, and asked to rate their satisfaction with the procedure. Complications encountered were documented. All 47 patients had complete recovery without any serious complications. The patient satisfaction rate was 93.6%. Minor complications included dimpling at the suture site, asymmetry, overcorrection, transitory paralysis, late oedema, haematoma, infection, scarring and hair loss. These complications resolved spontaneously and were negligible after complete recovery. Dissection in multiple planes is valuable in frontal and temporal endoscopic facelifts. It may be worthwhile to introduce the use of this technique in frontal and temporal facelifts, as it may lead to improved outcomes. Copyright: © Singapore Medical Association

Tehran Survey of Potential Risk Factors for Multiple Births

Directory of Open Access Journals (Sweden)

Reza Omani Samani

2017-09-01

Full Text Available Background The multiple pregnancy incidence is increasing worldwide. This increased incidence is concerning to the health care system. This study aims to determine the frequency of multiple pregnancy and identify factors that affect this frequency in Tehran, Iran. Materials and Methods This cross-sectional study included 5170 mothers in labor between July 6-21, 2015 from 103 hospitals with Obstetrics and Gynecology Wards. The questionnaire used in this study consisted of five parts: demographic characteristics; information related to pregnancy; information related to the infant; information regarding the multiple pregnancy; and information associated with infertility. We recruited 103 trained midwives to collect data related to the questionnaire from eligible participants through an interview and medical records review. Frequencies and odds ratios (OR for the association between multiple pregnancy and the selected characteristics (maternal age, economic status, history of multiple pregnancy in first-degree relatives, and reproductive history were computed by multiple logistic regression. Stata software, version 13 (Stata Corp, College Station, TX, USA was used for all statistical analyses. Results Multiple pregnancy had a prevalence of 1.48% [95% confidence interval (CI: 1.19-1.85]. After controlling for confounding variables, we observed a significant association between frequency of multiple pregnancy and mother’s age (OR=1.04, 95% CI: 1.001-1.09, P=0.044, assisted reproductive technique (ART, OR=6.11, 95% CI: 1.7- 21.97, P=0.006, and history of multiple pregnancy in the mother’s family (OR=5.49, 95% CI: 3.55-9.93, P=0.001. Conclusion The frequency of multiple pregnancy approximated results reported in previous studies in Iran. Based on the results, we observed significantly greater frequency of multiple pregnancy in older women, those with a history of ART, and a history of multiple pregnancy in the mother’s family compared to the other

A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements

Energy Technology Data Exchange (ETDEWEB)

Dewey, Steven Clifford, E-mail: sdewey001@gmail.com [United States Air Force School of Aerospace Medicine, Occupational Environmental Health Division, Health Physics Branch, Radiation Analysis Laboratories, 2350 Gillingham Drive, Brooks City-Base, TX 78235 (United States); Whetstone, Zachary David, E-mail: zacwhets@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States); Kearfott, Kimberlee Jane, E-mail: kearfott@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States)

2011-06-15

When characterizing environmental radioactivity, whether in the soil or within concrete building structures undergoing remediation or decommissioning, it is highly desirable to know the radionuclide depth distribution. This is typically modeled using continuous analytical expressions, whose forms are believed to best represent the true source distributions. In situ gamma ray spectroscopic measurements are combined with these models to fully describe the source. Currently, the choice of analytical expressions is based upon prior experimental core sampling results at similar locations, any known site history, or radionuclide transport models. This paper presents a method, employing multiple in situ measurements at a single site, for determining the analytical form that best represents the true depth distribution present. The measurements can be made using a variety of geometries, each of which has a different sensitivity variation with source spatial distribution. Using non-linear least squares numerical optimization methods, the results can be fit to a collection of analytical models and the parameters of each model determined. The analytical expression that results in the fit with the lowest residual is selected as the most accurate representation. A cursory examination is made of the effects of measurement errors on the method. - Highlights: > A new method for determining radionuclide distribution as a function of depth is presented. > Multiple measurements are used, with enough measurements to determine the unknowns in analytical functions that might describe the distribution. > The measurements must be as independent as possible, which is achieved through special collimation of the detector. > Although the effects of measurements errors may be significant on the results, an improvement over other methods is anticipated.

Approach and landing guidance design for reusable launch vehicle using multiple sliding surfaces technique

Directory of Open Access Journals (Sweden)

Xiangdong LIU

2017-08-01

Full Text Available An autonomous approach and landing (A&L guidance law is presented in this paper for landing an unpowered reusable launch vehicle (RLV at the designated runway touchdown. Considering the full nonlinear point-mass dynamics, a guidance scheme is developed in three-dimensional space. In order to guarantee a successful A&L movement, the multiple sliding surfaces guidance (MSSG technique is applied to derive the closed-loop guidance law, which stems from higher order sliding mode control theory and has advantage in the finite time reaching property. The global stability of the proposed guidance approach is proved by the Lyapunov-based method. The designed guidance law can generate new trajectories on-line without any specific requirement on off-line analysis except for the information on the boundary conditions of the A&L phase and instantaneous states of the RLV. Therefore, the designed guidance law is flexible enough to target different touchdown points on the runway and is capable of dealing with large initial condition errors resulted from the previous flight phase. Finally, simulation results show the effectiveness of the proposed guidance law in different scenarios.

Determination of nitrate pollution sources in the Marano Lagoon (Italy) by using a combined approach of hydrochemical and isotopic techniques

Energy Technology Data Exchange (ETDEWEB)

Saccon, Pierpaolo; Leis, Albrecht [JOANNEUM RESEARCH Forschungsgesellschaft mbH, Institute for Water, Energy and Sustainability, 8010 Graz (Austria); Marca, Alina; Kaiser, Jan; Campisi, Laura [School of Environmental Sciences, University of East Anglia, NR4 7TJ Norwich (United Kingdom); Boettcher, Michael E.; Escher, Peter [Leibniz Institute for Baltic Sea Research (IOW), Geochemistry and Isotope Geochemistry Group, D-18119 Rostock (Germany); Savarino, Joel; Erbland, Joseph [UJF-Grenoble 1/CNRS-INSU, Laboratoire de Glaciologie et Geophysique de l' Environnement (LGGE) UMR 5183 (France); Eisenhauer, Anton [GEOMAR, Helmholtz Zentrum fuer Ozean Forschung Kiel, Wischhofstr. 1-3, 24148 Kiel (Germany)

2013-07-01

Due to increased pollution by nitrate from intensive agricultural and other anthropogenic activities the Marano lagoon (northeast Italy) and part of its catchment area have been investigated, applying a combined approach of hydrochemical and isotopic techniques. Thus, to identify and characterize the potential multiple-sources of nitrate pollution the isotopic compositions of nitrate (δ{sup 15}N, δ{sup 18}O, and Δ{sup 17}O), boron (δ{sup 11}B), water (δ{sup 2}H and δ{sup 18}O), and sulphate (δ{sup 34}S and δ{sup 18}O), as well as the chemical composition of different water types have been determined. In the monitoring program water samples from the lagoon, its tributary rivers, the groundwater upwelling line, groundwater, sewage, and open sea on a quarterly interval from 2009 to 2010 have been collected and analyzed. Coupling isotopic and hydrochemical results indicate that the nitrate load in the lagoon was not only derived from agriculture activities but also from other sources such as urban wastewaters, in situ nitrification, and atmospheric deposition. However, none of the samples showed the isotopic characteristics of synthetic fertilizers. (authors)

Visualizing Matrix Multiplication

Science.gov (United States)

Daugulis, Peteris; Sondore, Anita

2018-01-01

Efficient visualizations of computational algorithms are important tools for students, educators, and researchers. In this article, we point out an innovative visualization technique for matrix multiplication. This method differs from the standard, formal approach by using block matrices to make computations more visual. We find this method a…

[Assisted human reproduction techniques: determination of parentage and users in comparative law].

Science.gov (United States)

Germán Zurriaráin, Roberto

2011-01-01

The paper undertakes the determination of parentage and users of assisted reproduction techniques in comparative law, particularly in three European Union countries: Italy, France and Spain. The idea of artificially conceived child protection, present in the Italian provision, is substituted, partially in French law, and totally in Spanish law, by an exclusively individualistic outlook, configuring a true ″right to maternity″ for married women and for those not living with a male partner (single women, divorced or widowed) or with a female partner (lesbians), and for women inseminated artificially by the semen of the husband before or after their death, and for women already having culminated their fertile life.

Solving Minimal Covering Location Problems with Single and Multiple Node Coverage

Directory of Open Access Journals (Sweden)

Darko DRAKULIĆ

2016-12-01

Full Text Available Location science represents a very attractiveresearch field in combinatorial optimization and it is in expansion in last five decades. The main objective of location problems is determining the best position for facilities in a given set of nodes.Location science includes techniques for modelling problemsand methods for solving them. This paper presents results of solving two types of minimal covering location problems, with single and multiple node coverage, by using CPLEX optimizer and Particle Swarm Optimization method.

Technique for mass-spectrometric determination of moisture content in fuel elements and fuel element claddings

International Nuclear Information System (INIS)

Kurillovich, A.N.; Pimonov, Yu.I.; Biryukov, A.S.

1988-01-01

A technique for mass-spectroimetric determination of moisture content in fuel elements and fuek claddings in the 2x10 -4 -1.5x10 -2 g range is developed. The relative standard deviation is 0.13. A character of moisture extraction from oxide uranium fuels in the 20-700 deg C temperature range is studied. Approximately 80% of moisture is extracted from the fuels at 300 deg C. The moisture content in fuel elements with granular uranium oxide fuels is measured. Dependence of fuel element moisture content on conditions of hot vacuum drying is shown. The technique permits to optimize the fuel element fabrication process to decrease the moisture content in them. 4 refs.; 3 figs.; 2 tabs

Determination of the uranium content in phosphate fertilizers by the fission track registration technique

International Nuclear Information System (INIS)

Rocha, A.C.S. da.

1983-01-01

The application of fission track registration technique (SSNTD) to determine the uranium contents in phosphate fertilizers is dealt with. Samples were prepared by the wet method and the detector used was Makrofol Kg 10μm thick. The determination of uranium in phosphate fertilizer industry is of considerable interest in environmental control. The roots of vegetables tend to absorb and accumulate uranium form soil and so the human body could be contaminated. The phosphate fertilizers were originated from the phosphate-rich apatite deposits located in the high naturally radioactive areas of Araxa and Tapira in the state of Minas Gerais, Brazil. The results obtained ranged from 11.1 to 100ppm of uranium with a total error from 8.2 to 15.7%. The thorium contributions to the total track counting were discounted, though the actual concentrations of thorium in the samples were not determined. (Author) [pt

Determinants of iron accumulation in deep grey matter of multiple sclerosis patients

DEFF Research Database (Denmark)

Ropele, Stefan; Kilsdonk, Iris D; Wattjes, Mike P

2014-01-01

BACKGROUND: Iron accumulation in deep grey matter (GM) structures is a consistent finding in multiple sclerosis (MS) patients. This study focused on the identification of independent determinants of iron accumulation using R2* mapping. SUBJECTS AND METHODS: Ninety-seven MS patients and 81 healthy...... controls were included in this multicentre study. R2* mapping was performed on 3T MRI systems. R2*in deep GM was corrected for age and was related to disease duration, disability, T2 lesion load and brain volume. RESULTS: Compared to controls, R2* was increased in all deep GM regions of MS patients except...... and the red nucleus. In lesions, R2* was inversely correlated with disease duration and higher total lesion load. CONCLUSION: Iron accumulation in deep GM of MS patients is most strongly and independently associated with duration and severity of the disease. Additional associations between cortical GM atrophy...

System identification via sparse multiple kernel-based regularization using sequential convex optimization techniques

DEFF Research Database (Denmark)

Chen, Tianshi; Andersen, Martin Skovgaard; Ljung, Lennart

2014-01-01

Model estimation and structure detection with short data records are two issues that receive increasing interests in System Identification. In this paper, a multiple kernel-based regularization method is proposed to handle those issues. Multiple kernels are conic combinations of fixed kernels...

Evaluation of an innovative radiographic technique - parallel profile radiography - to determine the dimensions of dentogingival unit

Directory of Open Access Journals (Sweden)

Sushama R Galgali

2011-01-01

Full Text Available Background: Maintenance of gingival health is a key factor for longevity of the teeth as well as of restorations. The physiologic dentogingival unit (DGU, which is composed of the epithelial and connective tissue attachments of the gingiva, functions as a barrier against microbial entry into the periodontium. Invasion of this space triggers inflammation and causes periodontal destruction. Despite the clinical relevance of the determination of the length and width of the DGU, there is no standardized technique. The length of the DGU can be either determined by histologic preparations or by transgingival probing. Although width can also be assessed by transgingival probing or with an ultrasound device, they are either invasive or expensive Aims: This study sought to evaluate an innovative radiographic exploration technique - parallel profile radiography - for measuring the dimensions of the DGU on the labial surfaces of anterior teeth. Materials and Methods: Two radiographs were made using the long-cone parallel technique in ten individuals, one in frontal projection, while the second radiograph was a parallel profile radiograph obtained from a lateral position. The length and width of the DGU was measured using computer software. Transgingival probing (trans-sulcular was done for these same patients and length of the DGU was measured. The values obtained by the two methods were compared. Pearson product correlation coefficient was calculated to examine the agreement between the values obtained by PPRx and transgingival probing. Results: The mean biologic width by the parallel profile radiography (PPRx technique was 1.72 mm (range 0.94-2.11 mm, while the mean thickness of the gingiva was 1.38 mm (range 0.92-1.77 mm. The mean biologic width by trans-gingival probing was 1.6 mm (range 0.8-2.2mm. Pearson product correlation coefficient (r for the above values was 0.914; thus, a high degree of agreement exists between the PPRx and TGP techniques

Experimental Determination of Impurity and Interdiffusion Coefficients in Seven Ti and Zr Binary Systems Using Diffusion Multiples

Science.gov (United States)

Chen, Zhangqi; Liu, Zi-Kui; Zhao, Ji-Cheng

2018-05-01

Diffusion coefficients of seven binary systems (Ti-Mo, Ti-Nb, Ti-Ta, Ti-Zr, Zr-Mo, Zr-Nb, and Zr-Ta) at 1200 °C, 1000 °C, and 800 °C were experimentally determined using three Ti-Mo-Nb-Ta-Zr diffusion multiples. Electron probe microanalysis (EPMA) was performed to collect concentration profiles at the binary diffusion regions. Forward simulation analysis (FSA) was then applied to extract both impurity and interdiffusion coefficients in Ti-rich and Zr-rich part of the bcc phase. Excellent agreements between our results and most of the literature data validate the high-throughput approach combining FSA with diffusion multiples to obtain a large amount of systematic diffusion data, which will help establish the diffusion (mobility) databases for the design and development of biomedical and structural Ti alloys.

Scintigraphic determination of gastrointestinal transit times. A comparison with breath hydrogen and radiologic methods

DEFF Research Database (Denmark)

Madsen, J L; Larsen, N E; Hilsted, J

1991-01-01

A scintigraphic method for determination of gastrointestinal transit times was compared with the breath hydrogen test and a multiple-bolus, single-radiograph technique. A close temporal association was found between the caecal appearance of radioactivity and the onset of breath hydrogen excretion...... the breath hydrogen concentration profiles....

Study of Defect Sizing in Carbon Steel Butt Welds using Conventional Ultrasonic Technique and Phased Array Ultrasonic

International Nuclear Information System (INIS)

Amry Amin Abas; Noorhazleena Azaman; Mohd Yusnisyam Mohd Yusoff

2016-01-01

Ultrasonic testing is a proven reliable method which is able to detect and measure the size of defects in butt welds with acceptable tolerance. Recent advancement of technology has introduced a computerized technique which is phased array. Phased array employs focal law that enable focusing and steering of beam at the active aperture axis. This enables one line scanning but covering the whole weld volume as compared to conventional technique which employs aster scan and multiple probes to completely cover the whole weld volume. Phased array also gives multiple data view which assist the interpreter. This paper is about the study of these two techniques and technical analysis of comparison between the two. The conventional technique is performed using GE USM GO with 4 MHz 45 degrees shear wave probe. The phased array technique uses OLYMPUS OMNISCAN MX2 with 5L64 linear array probe with 16 elements aperture and 55 degrees wedge emitting shear wave into the specimen. Sensitivity of both techniques are based on 1.5 mm Side Drilled Hole. The results are compared and analysis such as defect sizing and defect type determination are performed. (author)

An efficient method for generalized linear multiplicative programming problem with multiplicative constraints.

Science.gov (United States)

Zhao, Yingfeng; Liu, Sanyang

2016-01-01

We present a practical branch and bound algorithm for globally solving generalized linear multiplicative programming problem with multiplicative constraints. To solve the problem, a relaxation programming problem which is equivalent to a linear programming is proposed by utilizing a new two-phase relaxation technique. In the algorithm, lower and upper bounds are simultaneously obtained by solving some linear relaxation programming problems. Global convergence has been proved and results of some sample examples and a small random experiment show that the proposed algorithm is feasible and efficient.

Speckle techniques for determining stresses in moving objects

Science.gov (United States)

Murphree, E. A.; Wilson, T. F.; Ranson, W. F.; Swinson, W. F.

1978-01-01

Laser speckle interferometry is a relatively new experimental technique which shows promise of alleviating many difficult problems in experimental mechanics. The method utilizes simple high-resolution photographs of the surface which is illuminated by coherent light. The result is a real-time or permanently stored whole-field record of interference fringes which yields a map of displacements in the object. In this thesis, the time-average theory using the Fourier transform is developed to present the application of this technique to measurement of in-plane displacement induced by the vibration of an object.

Determination of rock depth using artificial intelligence techniques

Institute of Scientific and Technical Information of China (English)

R. Viswanathan; Pijush Samui

2016-01-01

This article adopts three artificial intelligence techniques, Gaussian Process Regression (GPR), Least Square Support Vector Machine (LSSVM) and Extreme Learning Machine (ELM), for prediction of rock depth (d) at any point in Chennai. GPR, ELM and LSSVM have been used as regression techniques. Latitude and longitude are also adopted as inputs of the GPR, ELM and LSSVM models. The performance of the ELM, GPR and LSSVM models has been compared. The developed ELM, GPR and LSSVM models produce spatial variability of rock depth and offer robust models for the prediction of rock depth.

Role of NAA in determination and characterisation of sampling behaviours of multiple elements in CRMs

International Nuclear Information System (INIS)

Tian Weizhi; Ni Bangfa; Wang Pingsheng; Nie Huiling

2002-01-01

Taking the advantage of high precision and accuracy of neutron activation analysis (NAA), sampling constants have been determined for multielements in several international and Chinese reference materials. The suggested technique may be used for finding elements in existing CRMs qualified for quality control (QC) of small size samples (several mg or less), and characterizing sampling behaviors of multielements in new CRMs specifically made for QC of microanalysis. (author)

Aperture Determination in the LHC Based on an Emittance Blowup Technique with Collimator Position Scan

CERN Document Server

Assmann, R W; del Carmen Alabau, M; Giovannozzi, M; Muller, GJ; Redaelli, S; Schmidt, F; Tomas, R; Wenninger, J; Wollmann, D

2011-01-01

A new method to determine the LHC aperture was proposed. The new component is a collimator scan technique that refers the globally measured aperture limit to the shadow of the primary collimator, expressed in sigmas of rms beam size. As a by-product the BLM response to beam loss is quantified. The method is described and LHC measurement results are presented.

An acoustic technique for the determination of liquor level in tanks

International Nuclear Information System (INIS)

Watson, J.; Jones, T.L.

1980-02-01

The design, development and application of a prototype suitable for the measurement of liquor levels in tanks is described. The technique involves directing an acoustic pulse down a constraining tube to the liquor surface and measuring the time of return of the reflected pulse. Using the equipment it is possible to determine the position of a solid surface with a total error of less than 1 mm. The prototype instrument was used to measure the volume of liquors contained in rectangular slab tanks used for accountancy purposes at Dounreay Nuclear Power Development Establishment. The total error obtained in an individual measurement of volume was less than 0.2 litres (95% confidence limits). The instrument may be used as a replacement for a Pneumercator system in existing installations. (author)

Technique for determination of the time constant for relay radioisotope instruments

International Nuclear Information System (INIS)

Gol'din, M.L.; Shestialtynov, V.K.

1981-01-01

A technique for calculating time constant of a gamma relay used in radio isotope automatics is suggested. It is shown that the time constant of a radioisotope relay device (RRD) mainly depends on parameters of the intergrating circuit ratemeter. Considering the ratemeter as a real communication channel with a limited transmission band, the equation for the active front duration at a ratemeter outlet when applying abrupt voltage to its inlet is obtained. From the complex transmission function of a ratemeter the upper boundary cyclic transmission frequency the substitution of which in the equation of the active front durationg ives the RRD time constant is determined. On the example of calculating the ratemeter for the GR-6 gamma relay a satisfactory coincidence of calculational results with the certificate data is shown [ru

ENVIRONMENT INDEPENDENT DIRECTIONAL GESTURE RECOGNITION TECHNIQUE FOR ROBOTS USING MULTIPLE DATA FUSION

Directory of Open Access Journals (Sweden)

Kishore Abishek

2013-10-01

Full Text Available A technique is presented here for directional gesture recognition by robots. The usual technique employed now is using camera vision and image processing. One major disadvantage with that is the environmental constrain. The machine vision system has a lot of lighting constrains. It is therefore only possible to use that technique in a conditioned environment, where the lighting is compatible with camera system used. The technique presented here is designed to work in any environment. It does not employ machine vision. It utilizes a set of sensors fixed on the hands of a human to identify the direction in which the hand is pointing. This technique uses cylindrical coordinate system to precisely find the direction. A programmed computing block in the robot identifies the direction accurately within the given range.

Efficient Time-Domain Ray-Tracing Technique for the Analysis of Ultra-Wideband Indoor Environments including Lossy Materials and Multiple Effects

Directory of Open Access Journals (Sweden)

F. Saez de Adana

2009-01-01

Full Text Available This paper presents an efficient application of the Time-Domain Uniform Theory of Diffraction (TD-UTD for the analysis of Ultra-Wideband (UWB mobile communications for indoor environments. The classical TD-UTD formulation is modified to include the contribution of lossy materials and multiple-ray interactions with the environment. The electromagnetic analysis is combined with a ray-tracing acceleration technique to treat realistic and complex environments. The validity of this method is tested with measurements performed inside the Polytechnic building of the University of Alcala and shows good performance of the model for the analysis of UWB propagation.

Determination of U-235 quantity in fresh fuel elements by neutron coincidence collar technique

International Nuclear Information System (INIS)

Almeida, M.C.M. de; Almeida, S.G. de; Marzo, M.A.S.; Moita, L.P.M.

1990-01-01

The U-235 quantity per lenght of fresh fuel assemblies of the Angra-I first recharge was determined by Neutron Coincidence Collar technique (N.C.C.). This technique is well-founded in fresh fuel assemblies activation by thermal neutrons from AmLi source to generate U-235 fission neutrons. These neutrons are detected by coincidence method in polyethylene structure where 18 He-3 detectors were placed. The coincidence counting results, in active mode (AmLi), showed 0,7% to standard deviation and equal to 1,49% to mass in 1000s of counting. The accuracies of different calibration methods were evaluated and compared. The results showed that the operator declared values are consistent. This evaluation was part of technical-exchange program between Safeguards Laboratory from C.N.E.N. and Los Alamos National Lab., United States. (author)

Multiple variables data sets visualization in ROOT

International Nuclear Information System (INIS)

Couet, O

2008-01-01

The ROOT graphical framework provides support for many different functions including basic graphics, high-level visualization techniques, output on files, 3D viewing etc. They use well-known world standards to render graphics on screen, to produce high-quality output files, and to generate images for Web publishing. Many techniques allow visualization of all the basic ROOT data types, but the graphical framework was still a bit weak in the visualization of multiple variables data sets. This paper presents latest developments done in the ROOT framework to visualize multiple variables (>4) data sets

Determination of molecular parameters by electron collisions and laser techniques

International Nuclear Information System (INIS)

Colon, C.

1989-01-01

In this work a general procedure to study diatomic molecules in intermediate coupling scheme has been developed. This study allows to obtain expressions to calculate molecular line strengths and rotational transition intensities. These results are used in a numerical program to synthetize vibrational and rotational band spectra of any diatomic molecule. With this technique the experimental spectra of the first negative system of N 2 + and the fist positive system of N 2 are reproduced theoretically and it is possible to deduce its electronic transition moments values by comparison. Also the method has been applied to compare the synthetized bands with the experimental spectra of the B O u + -- x 1 Σ g + system of Au 2 and the A 2 Σ--- x 2 π system of OH. From these comparison band intensities and electronic moments can be deduced. The branching ratio method to measure the relative spectral response in the 1100-1560 A o =wavelength range of a vacuum uv monochromator has been used. Relative intensity of rotational lines with origine in a common upper vibrational-rotational level of Warner and Lyman systems of H 2 , have been measured. Also in this work, the deexcitation of the B 3 π + (0 + u ), v'=14 level of I 2 after pulsed laser excitation has been studied. The quenching cross sections by collisions with I 2 , H 2 , CO 2 and CH 4 have been determin-ed. (Author)

Stepped MS(All) Relied Transition (SMART): An approach to rapidly determine optimal multiple reaction monitoring mass spectrometry parameters for small molecules.

Science.gov (United States)

Ye, Hui; Zhu, Lin; Wang, Lin; Liu, Huiying; Zhang, Jun; Wu, Mengqiu; Wang, Guangji; Hao, Haiping

2016-02-11

Multiple reaction monitoring (MRM) is a universal approach for quantitative analysis because of its high specificity and sensitivity. Nevertheless, optimization of MRM parameters remains as a time and labor-intensive task particularly in multiplexed quantitative analysis of small molecules in complex mixtures. In this study, we have developed an approach named Stepped MS(All) Relied Transition (SMART) to predict the optimal MRM parameters of small molecules. SMART requires firstly a rapid and high-throughput analysis of samples using a Stepped MS(All) technique (sMS(All)) on a Q-TOF, which consists of serial MS(All) events acquired from low CE to gradually stepped-up CE values in a cycle. The optimal CE values can then be determined by comparing the extracted ion chromatograms for the ion pairs of interest among serial scans. The SMART-predicted parameters were found to agree well with the parameters optimized on a triple quadrupole from the same vendor using a mixture of standards. The parameters optimized on a triple quadrupole from a different vendor was also employed for comparison, and found to be linearly correlated with the SMART-predicted parameters, suggesting the potential applications of the SMART approach among different instrumental platforms. This approach was further validated by applying to simultaneous quantification of 31 herbal components in the plasma of rats treated with a herbal prescription. Because the sMS(All) acquisition can be accomplished in a single run for multiple components independent of standards, the SMART approach are expected to find its wide application in the multiplexed quantitative analysis of complex mixtures. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of 4 analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs

OpenAIRE

2011-01-01

Abstract Different techniques for the determination of total tin in beverage and canned food by atomic spectrometry were compared. The performance characteristics of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Hydride Generation Inductively Coupled Plasma Atomic Emission Spectrometry (HG-ICP-AES), Electrothermal Atomization Atomic Absorption Spectrometry (ETA-AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) were determined in term of linearity, ...

A heuristic ranking approach on capacity benefit margin determination using Pareto-based evolutionary programming technique.

Science.gov (United States)

Othman, Muhammad Murtadha; Abd Rahman, Nurulazmi; Musirin, Ismail; Fotuhi-Firuzabad, Mahmud; Rajabi-Ghahnavieh, Abbas

2015-01-01

This paper introduces a novel multiobjective approach for capacity benefit margin (CBM) assessment taking into account tie-line reliability of interconnected systems. CBM is the imperative information utilized as a reference by the load-serving entities (LSE) to estimate a certain margin of transfer capability so that a reliable access to generation through interconnected system could be attained. A new Pareto-based evolutionary programming (EP) technique is used to perform a simultaneous determination of CBM for all areas of the interconnected system. The selection of CBM at the Pareto optimal front is proposed to be performed by referring to a heuristic ranking index that takes into account system loss of load expectation (LOLE) in various conditions. Eventually, the power transfer based available transfer capability (ATC) is determined by considering the firm and nonfirm transfers of CBM. A comprehensive set of numerical studies are conducted on the modified IEEE-RTS79 and the performance of the proposed method is numerically investigated in detail. The main advantage of the proposed technique is in terms of flexibility offered to an independent system operator in selecting an appropriate solution of CBM simultaneously for all areas.

A Heuristic Ranking Approach on Capacity Benefit Margin Determination Using Pareto-Based Evolutionary Programming Technique

Directory of Open Access Journals (Sweden)

Muhammad Murtadha Othman

2015-01-01

Full Text Available This paper introduces a novel multiobjective approach for capacity benefit margin (CBM assessment taking into account tie-line reliability of interconnected systems. CBM is the imperative information utilized as a reference by the load-serving entities (LSE to estimate a certain margin of transfer capability so that a reliable access to generation through interconnected system could be attained. A new Pareto-based evolutionary programming (EP technique is used to perform a simultaneous determination of CBM for all areas of the interconnected system. The selection of CBM at the Pareto optimal front is proposed to be performed by referring to a heuristic ranking index that takes into account system loss of load expectation (LOLE in various conditions. Eventually, the power transfer based available transfer capability (ATC is determined by considering the firm and nonfirm transfers of CBM. A comprehensive set of numerical studies are conducted on the modified IEEE-RTS79 and the performance of the proposed method is numerically investigated in detail. The main advantage of the proposed technique is in terms of flexibility offered to an independent system operator in selecting an appropriate solution of CBM simultaneously for all areas.

Markov chain Monte Carlo techniques applied to parton distribution functions determination: Proof of concept

Science.gov (United States)

Gbedo, Yémalin Gabin; Mangin-Brinet, Mariane

2017-07-01

We present a new procedure to determine parton distribution functions (PDFs), based on Markov chain Monte Carlo (MCMC) methods. The aim of this paper is to show that we can replace the standard χ2 minimization by procedures grounded on statistical methods, and on Bayesian inference in particular, thus offering additional insight into the rich field of PDFs determination. After a basic introduction to these techniques, we introduce the algorithm we have chosen to implement—namely Hybrid (or Hamiltonian) Monte Carlo. This algorithm, initially developed for Lattice QCD, turns out to be very interesting when applied to PDFs determination by global analyses; we show that it allows us to circumvent the difficulties due to the high dimensionality of the problem, in particular concerning the acceptance. A first feasibility study is performed and presented, which indicates that Markov chain Monte Carlo can successfully be applied to the extraction of PDFs and of their uncertainties.

Imaging a spinal fracture in a Kohaku Koi (Cyprinus carpio): techniques and case history report

International Nuclear Information System (INIS)

Bakal, R.S.; Love, N.E.; Lewbart, G.A.; Berry, C.R.

1998-01-01

An ornamental pet fish was diagnosed with a spinal fracture and subluxation involving truncal vertebrae 5 and 6 (T5-T6) using conventional radiography, nuclear scintigraphy, and computed tomography. Attempts to evaluate the dynamic nature of the lesion using conventional fluoroscopy in the unanesthetized, moving patient were? unsuccessful, Adaptation of imaging techniques to accommodate a fish patient was not difficult and diagnostic images were obtained. The use of multiple imaging techniques was useful in the diagnosis and determination of the treatment plan of the spinal fracture in this patient

Radiotherapy in the treatment of multiple myeloma.

Science.gov (United States)

Bosch, A; Frias, Z

1988-12-01

Fifty-nine patients with multiple myeloma referred for treatment of painful bony lesions received irradiation to 95 local areas, and 16 of the 59 were irradiated using hemibody techniques. Pain relief was obtained in practically all of the irradiated regions. Most local areas were treated to doses of 3000 cGy in 10 to 15 fractions. Patients with generalized pain due to multiple site involvement were treated with single dose hemibody irradiation, to doses of 600 cGy to the upper hemibody, and of 800 cGy to the lower hemibody. This treatment was well tolerated and side effects minimal. Median survival from diagnosis was 30 months and the survival at 1, 3, and 5 years was 80%, 42%, and 12% respectively. Key articles on radiation therapy of multiple myeloma are reviewed and discussed. Since all patients eventually relapse after chemotherapy, the role of radiotherapy using present techniques should be fully evaluated and considered as an alternative in the primary treatment of multiple myeloma.

Characterisation of ultrasonic structural noise in multiple scattering media using phased arrays

International Nuclear Information System (INIS)

Bedetti, T; Dorval, V; Jenson, F; Derode, A

2013-01-01

The ultrasonic inspection of multiple scattering media gives rise to structural noise which makes it difficult to detect potential damage or crack inside the component. In order to predict the performances of ultrasonic inspection over such complex media, scattering models can be used. Such models rely on specific key parameters describing the multiple scattering process, which can be determined by specific measurements and post-processing techniques. Such experiments were carried out on stainless steel plates using linear phased-arrays. They consist in recording the response matrix constituted by impulse responses between all the elements of the array. By conducting post-processing on this matrix, we measure the elastic mean free path l e and the correlation distance d c of the recorded noise. Additionally, the dynamic behaviour of the coherent backscattering effect was studied in order to measure the diffusion constant D. Plane-wave beamforming has been applied to the response matrix to improve the angular resolution and the signal-to-noise ratio of the backscattered intensity. Details of postprocessing techniques will be shown

Search Strategy of Detector Position For Neutron Source Multiplication Method by Using Detected-Neutron Multiplication Factor

International Nuclear Information System (INIS)

Endo, Tomohiro

2011-01-01

In this paper, an alternative definition of a neutron multiplication factor, detected-neutron multiplication factor kdet, is produced for the neutron source multiplication method..(NSM). By using kdet, a search strategy of appropriate detector position for NSM is also proposed. The NSM is one of the practical subcritical measurement techniques, i.e., the NSM does not require any special equipment other than a stationary external neutron source and an ordinary neutron detector. Additionally, the NSM method is based on steady-state analysis, so that this technique is very suitable for quasi real-time measurement. It is noted that the correction factors play important roles in order to accurately estimate subcriticality from the measured neutron count rates. The present paper aims to clarify how to correct the subcriticality measured by the NSM method, the physical meaning of the correction factors, and how to reduce the impact of correction factors by setting a neutron detector at an appropriate detector position

Two-compartment, two-sample technique for accurate estimation of effective renal plasma flow: Theoretical development and comparison with other methods

International Nuclear Information System (INIS)

Lear, J.L.; Feyerabend, A.; Gregory, C.

1989-01-01

Discordance between effective renal plasma flow (ERPF) measurements from radionuclide techniques that use single versus multiple plasma samples was investigated. In particular, the authors determined whether effects of variations in distribution volume (Vd) of iodine-131 iodohippurate on measurement of ERPF could be ignored, an assumption implicit in the single-sample technique. The influence of Vd on ERPF was found to be significant, a factor indicating an important and previously unappreciated source of error in the single-sample technique. Therefore, a new two-compartment, two-plasma-sample technique was developed on the basis of the observations that while variations in Vd occur from patient to patient, the relationship between intravascular and extravascular components of Vd and the rate of iodohippurate exchange between the components are stable throughout a wide range of physiologic and pathologic conditions. The new technique was applied in a series of 30 studies in 19 patients. Results were compared with those achieved with the reference, single-sample, and slope-intercept techniques. The new two-compartment, two-sample technique yielded estimates of ERPF that more closely agreed with the reference multiple-sample method than either the single-sample or slope-intercept techniques

A New Approach to Adaptive Control of Multiple Scales in Plasma Simulations

Science.gov (United States)

Omelchenko, Yuri

2007-04-01

A new approach to temporal refinement of kinetic (Particle-in-Cell, Vlasov) and fluid (MHD, two-fluid) simulations of plasmas is presented: Discrete-Event Simulation (DES). DES adaptively distributes CPU resources in accordance with local time scales and enables asynchronous integration of inhomogeneous nonlinear systems with multiple time scales on meshes of arbitrary topologies. This removes computational penalties usually incurred in explicit codes due to the global Courant-Friedrich-Levy (CFL) restriction on a time-step size. DES stands apart from multiple time-stepping algorithms in that it requires neither selecting a global synchronization time step nor pre-determining a sequence of time-integration operations for individual parts of the system (local time increments need not bear any integer multiple relations). Instead, elements of a mesh-distributed solution self-adaptively predict and synchronize their temporal trajectories by directly enforcing local causality (accuracy) constraints, which are formulated in terms of incremental changes to the evolving solution. Together with flux-conservative propagation of information, this new paradigm ensures stable and fast asynchronous runs, where idle computation is automatically eliminated. DES is parallelized via a novel Preemptive Event Processing (PEP) technique, which automatically synchronizes elements with similar update rates. In this mode, events with close execution times are projected onto time levels, which are adaptively determined by the program. PEP allows reuse of standard message-passing algorithms on distributed architectures. For optimum accuracy, DES can be combined with adaptive mesh refinement (AMR) techniques for structured and unstructured meshes. Current examples of event-driven models range from electrostatic, hybrid particle-in-cell plasma systems to reactive fluid dynamics simulations. They demonstrate the superior performance of DES in terms of accuracy, speed and robustness.

Multiple equilibria of divertor plasmas

International Nuclear Information System (INIS)

Vu, H.X.; Prinja, A.K.

1993-01-01

A one-dimensional, two-fluid transport model with a temperature-dependent neutral recycling coefficient is shown to give rise to multiple equilibria of divertor plasmas (bifurcation). Numerical techniques for obtaining these multiple equilibria and for examining their stability are presented. Although these numerical techniques have been well known to the scientific community, this is the first time they have been applied to divertor plasma modeling to show the existence of multiple equilibria as well as the stability of these solutions. Numerical and approximate analytical solutions of the present one-dimensional transport model both indicate that there exists three steady-state solutions corresponding to (1) a high-temperature, low-density equilibrium, (2) a low-temperature, high-density equilibrium, and (3) an intermediate-temperature equilibrium. While both the low-temperature and the high-temperature equilibria are stable, with respect to small perturbations in the plasma conditions, the intermediate-temperature equilibrium is physically unstable, i.e., any small perturbation about this equilibrium will cause a transition toward either the high-temperature or low-temperature equilibrium

Robust multiple frequency multiple power localization schemes in the presence of multiple jamming attacks.

Directory of Open Access Journals (Sweden)

Ahmed Abdulqader Hussein

Full Text Available Localization of the wireless sensor network is a vital area acquiring an impressive research concern and called upon to expand more with the rising of its applications. As localization is gaining prominence in wireless sensor network, it is vulnerable to jamming attacks. Jamming attacks disrupt communication opportunity among the sender and receiver and deeply impact the localization process, leading to a huge error of the estimated sensor node position. Therefore, detection and elimination of jamming influence are absolutely indispensable. Range-based techniques especially Received Signal Strength (RSS is facing severe impact of these attacks. This paper proposes algorithms based on Combination Multiple Frequency Multiple Power Localization (C-MFMPL and Step Function Multiple Frequency Multiple Power Localization (SF-MFMPL. The algorithms have been tested in the presence of multiple types of jamming attacks including capture and replay, random and constant jammers over a log normal shadow fading propagation model. In order to overcome the impact of random and constant jammers, the proposed method uses two sets of frequencies shared by the implemented anchor nodes to obtain the averaged RSS readings all over the transmitted frequencies successfully. In addition, three stages of filters have been used to cope with the replayed beacons caused by the capture and replay jammers. In this paper the localization performance of the proposed algorithms for the ideal case which is defined by without the existence of the jamming attack are compared with the case of jamming attacks. The main contribution of this paper is to achieve robust localization performance in the presence of multiple jamming attacks under log normal shadow fading environment with a different simulation conditions and scenarios.

Comparison of neutron activation analysis techniques for the determination of uranium concentrations in geological and environmental materials

International Nuclear Information System (INIS)

Landsberger, S.; Kapsimalis, R.

2013-01-01

We have described the determination of uranium in environmental, geological, and agricultural specimens by three different non-destructive nuclear methods. The effectiveness, as defined as the lower limits of detection in this work, of quantifying trace levels of bulk uranium in geological samples was evaluated for several common NAA techniques. These techniques include short-lived and medium-lived neutron activation analysis using thermal and epithermal neutrons; these results were compared with an assessment of Compton suppressed gamma-ray counting. A careful evaluation of three major (n,γ) reactions with chlorine, manganese and sodium that could impede determining low levels of uranium due to high Compton continuums was done. The evaluation of Compton suppressed passive gamma counting revealed that uranium concentrations below 50 mg kg −1 were not adequate to achieve good counting statistics using the 234m Pa the second daughter product of 238 U. -- Highlights: ► Determination of uranium concentrations in geological, environmental, and agricultural specimens. ► Use of several NAA and passive counting methods. ► Identified several key interferences. ► Use of Compton suppression to minimize effects of interferences

Vapor pressure determination of liquid UO/sub 2/ using a boiling point technique

International Nuclear Information System (INIS)

Bober, M.; Singer, J.

1987-01-01

By analogy with the classic boiling point method, a quasi-stationary millisecond laser-heating technique was applied to measure the saturated vapor pressure curve of liquid UO/sub 2/ in the temperature range of 3500 to 4500 K. The results are represented by log rho (MPa)=5.049 - 23 042/T (K), which gives an average heat of vaporization of 441 kJ/mol and a normal boiling point of 3808 K. In addition, spectral emissivities of liquid UO/sub 2/ were determined as a function of the temperature at the pyrometer wavelengths of 752 and 1064 nm

Update on rehabilitation in multiple sclerosis.

Science.gov (United States)

Donzé, Cécile

2015-04-01

Given that mobility impairment is a hallmark of multiple sclerosis, people with this disease are likely to benefit from rehabilitation therapy throughout the course of their illness. The review provides an update on rehabilitation focused on balance and walking impairment. Classical rehabilitation focusing on muscle rehabilitation, neurotherapeutic facilitation is effective and recommended. Other techniques did not prove their superiority: transcutaneal neurostimulation, repetitive magnetic stimulation, electromagnetic therapy, whole body vibration and robot-assisted gait rehabilitation and need more studies to conclude. Cooling therapy, hydrotherapy, orthoses and textured insoles could represent a complementary service to other techniques in specific conditions. Multidisciplinary rehabilitation program provides positive effects and high satisfaction for patients with multiple sclerosis but needs more evaluation. New technologies using serious game and telerehabilitation seem to be an interesting technique to promote physical activity, self-management and quality of life. Rehabilitation like other therapy needs regular clinical evaluation to adapt the program and propose appropriate techniques. Moreover, the objective of rehabilitation needs to be decided with the patient with realistic expectation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

A comparison between destructive and non-destructive techniques in determining coating thickness

Science.gov (United States)

Haider, F. I.; Suryanto; Ani, M. H.; Mahmood, M. H.

2018-01-01

Measuring coating thickness is an important part in research works related to coating applications. In general, techniques for measuring coating thickness may be divided into destructive and non-destructive methods which are commonly used depending on the applications. The objective of this study is to compare two methods measuring the coating thickness of electroplating copper coating on the austenitic stainless-steel substrate. The electroplating was carried out in a solution containing 200 g/L CuSO4, 100 g/L H2SO4 at room temperature and current of 40mA/cm2 during 20, 40, 60, 80 and 100 mins as coating periods. And the coating thickness was measured by two methods, cross sectional analysis as a destructive technique and weight gain as a non-destructive technique. The results show that at 20 mins coating time interval, the thickness measured by cross sectional method was 16.67 μm and by weight gain method was 17.37 μm, with difference of 0.7 μm and percentage error of 4.11%. This error increased to 5.27% at 100mins time interval, where the values of the thickness measured by cross sectional and weight gain were 86.33 μm and 81.9 μm respectively, and the difference was 4.43 μm. Moreover, though the weight gain method is fast and gives the indication for the termination of a coating process, information regarding the uniformity, porosity and the presence of cracks cannot be obtained. On the other hand, determining the coating thickness using destructive method will damage the sample.

Immunoassay separation technique

International Nuclear Information System (INIS)

1977-01-01

A method for effecting the immunoassay of a multiplicity of samples, each possibly containing an antigen or an antibody to be assayed, is discussed. Each sample is incubated with a solution containing a detectable antigen or antibody to form a multiplicity of mixtures, each mixture containing as components antigen-antibody, non-complexed antigen and non-complexed antibody. At least one of the components of the said mixture is separated by adsorption. There after, quantity of detectable antigen or antibody is detected in one of the non-adsorbed portions of the mixture. An improvement, compared to other techniques, is the continuous and sequential separation of at least one component, which is intended to be separated from each said multiplicity of mixtures

Deformable microparticles with multiple functions for drug delivery and device testing

Science.gov (United States)

Thula, Taili T.

Since the HIV epidemic of the 1990s, researchers have attempted to develop a red blood cell analog. Even though some of these substitutes are now in Phase III of clinical trials, their use is limited by side effects and short half-life in the human body. As a result, there is still a need for an effective erythrocyte analog with minimum immunogenic and side effects, so that it can be used for multiple applications. Finding new approaches to develop more efficient blood substitutes will not only bring valuable advances in the clinical approach, but also in the area of in vitro testing of medical devices. We examined the feasibility of creating a deformable multi-functional, biodegradable, biocompatible particle for applications in drug delivery and device testing. As a preliminary evaluation, we synthesized different types of microcapsules using natural and synthetic polymers, various cross-linking agents, and diverse manufacturing techniques. After fully characterizing of each system, we determined the most promising red blood cell analog in terms of deformability, stability and toxicity. We also examined the encapsulation and release of bovine serum albumin (BSA) within these deformable particles. After removal of cross-linkers, zinc- and copper-alginate microparticles surrounded by multiple polyelectrolyte layers of chitosan oligosaccharide and alginate were deformable and remained stable under physiological pressures applied by the micropipette technique. In addition, multiple coatings decreased toxicity of heavy-metal crosslinked particles. BSA encapsulation and release from chitosan-alginate microspheres were contingent on the crosslinker and number of polyelectrolyte coatings, respectively. Further rheological studies are needed to determine how closely these particles simulate the behavior of erythrocytes. Also, studies on the encapsulation and release of different proteins, including hemoglobin, are needed to establish the desired controlled release of

Film techniques in radiotherapy for treatment verification, determination of patient exit dose, and detection of localization error

International Nuclear Information System (INIS)

Haus, A.G.; Marks, J.E.

1974-01-01

In patient radiation therapy, it is important to know that the diseased area is included in the treatment field and that normal anatomy is properly shielded or excluded. Since 1969, a film technique developed for imaging of the complete patient radiation exposure has been applied for treatment verification and for the detection and evaluation of localization errors that may occur during treatment. The technique basically consists of placing a film under the patient during the entire radiation exposure. This film should have proper sensitivity and contrast in the exit dose exposure range encountered in radiotherapy. In this communication, we describe how various exit doses fit the characteristic curve of the film; examples of films exposed to various exit doses; the technique for using the film to determine the spatial distribution of the absorbed exit dose; and types of errors commonly detected. Results are presented illustrating that, as the frequency of use of this film technique is increased, localization error is reduced significantly

Multiple k Nearest Neighbor Query Processing in Spatial Network Databases

DEFF Research Database (Denmark)

Xuegang, Huang; Jensen, Christian Søndergaard; Saltenis, Simonas

2006-01-01

This paper concerns the efficient processing of multiple k nearest neighbor queries in a road-network setting. The assumed setting covers a range of scenarios such as the one where a large population of mobile service users that are constrained to a road network issue nearest-neighbor queries...... for points of interest that are accessible via the road network. Given multiple k nearest neighbor queries, the paper proposes progressive techniques that selectively cache query results in main memory and subsequently reuse these for query processing. The paper initially proposes techniques for the case...... where an upper bound on k is known a priori and then extends the techniques to the case where this is not so. Based on empirical studies with real-world data, the paper offers insight into the circumstances under which the different proposed techniques can be used with advantage for multiple k nearest...

The use of multiple respiratory inhalers requiring different inhalation techniques has an adverse effect on COPD outcomes

Directory of Open Access Journals (Sweden)

Bosnic-Anticevich S

2016-12-01

Full Text Available Sinthia Bosnic-Anticevich,1 Henry Chrystyn,2 Richard W Costello,3,4 Myrna B Dolovich,5 Monica J Fletcher,6 Federico Lavorini,7 Roberto Rodríguez-Roisin,8 Dermot Ryan,9,10 Simon Wan Yau Ming,2 David B Price2,11 1Woolcock Institute of Medical Research, School of Medical Sciences, University of Sydney and Sydney Local Health District, Sydney, NSW, Australia; 2Observational and Pragmatic Research Institute Pte Ltd, Singapore; 3RCSI Medicine, Royal College of Surgeons, 4RCSI Education & Research Centre, Beaumont Hospital, Beaumont, Dublin, Ireland; 5Department of Medicine, Respirology, McMaster University, ON, Canada; 6Education for Health, Warwick, UK; 7Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; 8Respiratory Institute, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain; 9Optimum Patient Care, Cambridge, 10Centre for Population Health Sciences, University of Edinburgh, Edinburgh, 11Academic Primary Care, University of Aberdeen, Aberdeen, UK Background: Patients with COPD may be prescribed multiple inhalers as part of their treatment regimen, which require different inhalation techniques. Previous literature has shown that the effectiveness of inhaled treatment can be adversely affected by incorrect inhaler technique. Prescribing a range of device types could worsen this problem, leading to poorer outcomes in COPD patients, but the impact is not yet known. Aims: To compare clinical outcomes of COPD patients who use devices requiring similar inhalation technique with those who use devices with mixed techniques. Methods: A matched cohort design was used, with 2 years of data from the Optimum Patient Care Research Database. Matching variables were established from a baseline year of follow-up data, and two cohorts were formed: a “similar-devices cohort” and a “mixed-devices cohort”. COPD-related events were recorded during an outcome year of follow-up. The primary outcome measure was an

Pb, U, Ti, Hf and Zr distributions in zircons determined by proton microprobe and fission track techniques

International Nuclear Information System (INIS)

Clark, G.J.; Gulson, B.L.; Cookson, J.A.

1979-01-01

A proton microprobe has been used to determine Pb, Tl, Hf and Zr distributions across four single zircon crystals separated from a 'rapakivi' granite. The Pb and Zr data are quantitative: Pb and Tl concentrations were below the measurable limits for determinations in situ by most other techniques. The distribution of U in the same crystals was determined by the fission track technique. Limits on precision of U allow only a qualitative correlation of U and Pb, whereas the Tl and Pb correlation is more exactly determined. Zircons with distinct cores and overgrowths exhibited uniform Zr and Hf concentrations across the crystals, whereas the high U rims and 'inclusions' (domains) also had high Tl and Pb contents. Since almost all the Pb in these zircons is derived by radioactive decay of U, the Tl substitution has paralleled that of U. The results indicate that the high U domains are 'hot spots' rather than a separate mineral phase. The strong positive correlation of U and Pb indicates that there is little U daughter product migration relative to U, within the crystal. However, for the zircon population investigated here, the data are equivocal on the question of whether U addition to zircon crystals is associated with new zircon growth or not. In either case, the heterogeneous U and Pb distributions complicate any interpretations of U-Pb isotopic analysis for such zircon populations. (author)

Experiments and Simulations of the Use of Time-Correlated Thermal Neutron Counting to Determine the Multiplication of an Assembly of Highly Enriched Uranium

Energy Technology Data Exchange (ETDEWEB)

David L. Chichester; Mathew T. Kinlaw; Scott M. Watson; Jeffrey M. Kalter; Eric C. Miller; William A. Noonan

2014-11-01

A series of experiments and numerical simulations using thermal-neutron time-correlated measurements has been performed to determine the neutron multiplication, M, of assemblies of highly enriched uranium available at Idaho National Laboratory. The experiments used up to 14.4 kg of highly-enriched uranium, including bare assemblies and assemblies reflected with high-density polyethylene, carbon steel, and tungsten. A small 252Cf source was used to initiate fission chains within the assembly. Both the experiments and the simulations used 6-channel and 8-channel detector systems, each consisting of 3He proportional counters moderated with polyethylene; data was recorded in list mode for analysis. 'True' multiplication values for each assembly were empirically derived using basic neutron production and loss values determined through simulation. A total of one-hundred and sixteen separate measurements were performed using fifty-seven unique measurement scenarios, the multiplication varied from 1.75 to 10.90. This paper presents the results of these comparisons and discusses differences among the various cases.

Determination of 36Cl/Cl ratio in ground water using the accelerator mass spectrometry technique

International Nuclear Information System (INIS)

Sharma, Suman; Deodhar, A.S.; Saravana Kumar, U.; Surendran, P.; Shrivastava, A.; Gupta, A.K.; Nair, J.P.; Yadav, M.L.; Hemalatha, M.; Sparrow, H.; Mahata, K.; Thomas, R.G.; Bhagwat, P.V.; Kailas, S.; Kale, R.M.

2009-01-01

The Accelerator Mass Spectrometry (AMS) programme using the 14 MV Pelletron Accelerator at Mumbai has been initiated with major emphasis on the determination of 36 Cl in water samples, of interest to hydrology and environment. In order to carry out the AMS measurement, a beam chopper to cut down beam intensity by a factor of 20 has been developed and commissioned. A multi-anode gas -si detector has been built to separate 36 Cl from the interfering 36 S. A new TPS system has been procured to operate the machine in the GVM mode. Standard and blank samples from Prime lab, Purdue have been employed in these measurements to standardise the technique for 36 Cl/Cl ratio determination. The detector was calibrated using the stable 35,37 Cl ions. The background 36 Cl in the system has been measured using the blank sample from Purdue and it was estimated that the ratio of 36 Cl/Cl was of the order of 10 -13 in the present setup. Ground water samples collected from South India were converted to AgCl and put in the SNICS ion source for the AMS measurements. These ground water samples, with 14 C content estimated to be in the range of 1 to 4 pMC indicate that the samples may be more than 35,000 years old. Using the AMS technique we have determined the 36 Cl/Cl ratio values for these ground water samples. They are found to range between 2 to 5 x 10 -12 . Additional measurements are planned to determine the age of the water samples and to understand the reasons for the observed high values of 36 Cl in these samples. (author)

Authenticity determination of Ag-Cu Lebanese coins using combined PIXE and RBS techniques

International Nuclear Information System (INIS)

Roumie, M; Nsouli, B; Assafiri, Y

2012-01-01

A set of silver-copper coins were investigated for their stochiometry in order to check any possible counterfeit. The studied coins are 50 Lebanese Piastres and are relatively recent, minted in 1952. They are supposed to have nominal concentration of 60 wt.% Ag and 40 wt.% Cu. In this work, it is shown the utility and capability of combining PIXE (particle induced X-ray emission) and RBS (Rutherford backscattering spectrometry) techniques to determine the elemental content and check the presence, if any, of surface layer. For this aim, 3 MeV proton beam and Al funny filter, used as x-ray absorber, were used to determine the elemental composition, based on the emission and detection of the characteristic x-rays of the corresponding elements. The first PIXE results of the supposed bulky coins showed an excess of silver composition vs. copper. In addition, the experimental protocol was checked by analyzing some other coins of known composition, such as 1-euro and 2-euro coins.

Determination of low concentrations of thorium in granites using X-ray fluorescence technique

International Nuclear Information System (INIS)

Shigematsu, H.M.; Sato, I.M.; Iyer, S.S.

1981-03-01

An analytical method for the accurate determination of low concentrations of thorium in rocks using X-ray fluorescence technique, was developed. A tungsten tube was utilized for the production of X-rays. The samples were prepared in the form of double layer pressed pellets using boric acid as a binding agent. The concentration of thorium was determined by measuring the intensity of the characteristic first order Th L α line. The calibration was carried out with USGS rock standards AGV-1, GSP-1 and G-2. Seven granite rocks samples from Granite Mountains of Wyoming, USA, supplied by Dr. Stuckless. Also were analysed. The results obtained were compared with values obtained in others laboratories using different analytical methods. The analyses show that the thorium is concentrated in accessory minerals and presented a non-uniform distribution, making sampling an important factor in the analysis of thorium. A discussion of the precision and accuracy of the method is presented. (Author) [pt

Inventory verification measurements using neutron multiplicity counting

International Nuclear Information System (INIS)

Ensslin, N.; Foster, L.A.; Harker, W.C.; Krick, M.S.; Langner, D.G.

1998-01-01

This paper describes a series of neutron multiplicity measurements of large plutonium samples at the Los Alamos Plutonium Facility. The measurements were corrected for bias caused by neutron energy spectrum shifts and nonuniform multiplication, and are compared with calorimetry/isotopics. The results show that multiplicity counting can increase measurement throughput and yield good verification results for some inventory categories. The authors provide recommendations on the future application of the technique to inventory verification

Mechanical Properties of Nanostructured Materials Determined Through Molecular Modeling Techniques

Science.gov (United States)

Clancy, Thomas C.; Gates, Thomas S.

2005-01-01

The potential for gains in material properties over conventional materials has motivated an effort to develop novel nanostructured materials for aerospace applications. These novel materials typically consist of a polymer matrix reinforced with particles on the nanometer length scale. In this study, molecular modeling is used to construct fully atomistic models of a carbon nanotube embedded in an epoxy polymer matrix. Functionalization of the nanotube which consists of the introduction of direct chemical bonding between the polymer matrix and the nanotube, hence providing a load transfer mechanism, is systematically varied. The relative effectiveness of functionalization in a nanostructured material may depend on a variety of factors related to the details of the chemical bonding and the polymer structure at the nanotube-polymer interface. The objective of this modeling is to determine what influence the details of functionalization of the carbon nanotube with the polymer matrix has on the resulting mechanical properties. By considering a range of degree of functionalization, the structure-property relationships of these materials is examined and mechanical properties of these models are calculated using standard techniques.

Expected precision of neutron multiplicity measurements of waste drums

International Nuclear Information System (INIS)

Ensslin, N.; Krick, M.S.; Menlove, H.O.

1995-01-01

DOE facilities are beginning to apply passive neutron multiplicity counting techniques to the assay of plutonium scrap and residues. There is also considerable interest in applying this new measurement technique to 208-liter waste drums. The additional information available from multiplicity counting could flag the presence of shielding materials or improve assay accuracy by correcting for matrix effects such as (α,n) induced fission or detector efficiency variations. The potential for multiplicity analysis of waste drums, and the importance of better detector design, can be estimated by calculating the expected assay precision using a Figure of Merit code for assay variance. This paper reports results obtained as a function of waste drum content and detector characteristics. We find that multiplicity analysis of waste drums is feasible if a high-efficiency neutron counter is used. However, results are significantly poorer if the multiplicity analysis must be used to solve for detection efficiency

A new islanding detection technique for multiple mini hydro based on rate of change of reactive power and load connecting strategy

International Nuclear Information System (INIS)

Laghari, J.A.; Mokhlis, H.; Bakar, A.H.A.; Karimi, M.

2013-01-01

Highlights: • The requirement of DG interconnection with existing power system is discussed. • Various islanding detection techniques are discussed with their merits and demerits. • New islanding detection strategy is proposed for multiple mini hydro type DGs. • The proposed strategy is based on dq/dt and load connecting strategy. • The effectiveness of strategy is verified on various other cases. - Abstract: The interconnection of distributed generation (DG) into distribution networks is undergoing a rapid global expansion. It enhances the system’s reliability, while simultaneously reduces pollution problems related to the generation of electrical power. To fully utilize the benefits of DGs, certain technical issues need to be addressed. One of the most important issues in this context is islanding detection. This paper presents a new islanding detection technique that is suitable for multiple mini-hydro type DG units. The proposed strategy is based on the rate of change of reactive power and load connecting strategy to detect islanding within the system. For a large power mismatch, islanding is detected by rate of change of reactive power only. However, for a close power mismatch, the rate of change of reactive power initiates a load connecting strategy, which in turn alters the load on the distribution network. This load variation in the distribution network causes a variation in the rate of change of reactive power, which is utilized to distinguish islanding and other events. The simulation results show that the proposed strategy is effective in detecting islanding occurrence in a distribution network

Radioactive implant induced x-ray emission technique for noninvasive determination of iodine content in thyroid: experimental study

Energy Technology Data Exchange (ETDEWEB)

Amano, R; Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Allied Medical Professions; Tonami, N; Hisada, K [Kanazawa Univ. (Japan). School of Medicine

1984-02-01

A new technique, radioactive implant x-ray emission spectrometry to determine the in vivo iodine content of the human thyroid is proposed. The variations of counting rate and effective excitation efficiencies of I Ksub(..cap alpha..) (28.6 keV) with iodine content, thyroid volume and skin-thyroid distance were studied for the /sup 201/Tl source to examine the properties of excitation and photon attenuation. As a result, the gland depth and volume could be estimated from the peak ratios of 30.7 keV/167.6 keV and 28.6 keV/167.6 keV. Using a 1 MBq /sup 201/Tl implant source, the detectable minimum iodine concentration found was approximately 70 ..mu..g/g for 2000 s measuring time in the phantom experiment. The effectiveness of the RIXE technique is discussed. It was concluded that the /sup 201/Tl RIXE spectrometry might serve to determine the in vivo iodine content of the human thyroid.

Radioactive implant induced x-ray emission technique for noninvasive determination of iodine content in thyroid: experimental study

Energy Technology Data Exchange (ETDEWEB)

Amano, R; Tonami, N; Ando, A; Hiraki, T; Hisada, K

1984-02-01

A new technique, radioactive implant x-ray emission spectrometry to determine the in vivo iodine content of the human thyroid is proposed. The variations of counting rate and effective excitation efficiencies of I K alpha (28.6 keV) with iodine content, thyroid volume and skin-thyroid distance were studied for the /sup 201/Tl source to examine the properties of excitation and photon attenuation. As a result, the gland depth and volume could be estimated from the peak ratios of 30.7 keV/167.6 keV and 28.6 keV/167.6 keV. Using a 1 MBq /sup 201/Tl implant source, the detectable minimum iodine concentration found was approximately 70 micrograms/g for 2000 s measuring time in the phantom experiment. The effectiveness of the RIXE technique is discussed. It was concluded that the /sup 201/Tl RIXE spectrometry might serve to determine the in vivo iodine content of the human thyroid.

One-dimensional multiple-well oscillators: A time-dependent

Indian Academy of Sciences (India)

... quantum mechanical multiple-well oscillators. An imaginary-time evolution technique, coupled with the minimization of energy expectation value to reach a global minimum, subject to orthogonality constraint (for excited states) has been employed. Pseudodegeneracy in symmetric, deep multiple-well potentials, probability ...

Establishment of a Pcr Technique for Determination of Htlv-1 Infection in Paraffin-Embedded Tissues

Directory of Open Access Journals (Sweden)

M Rastin

2007-04-01

Full Text Available Introduction: HTLV-1 , the first known human retrovirus belongs to oncovirus subfamily of retroviruses. The major characteristic of HTLV-1 is its highly restricted geographic prevalence. Northern part of Khorasan is an endemic region of HTLV-1 infection. Epidemiological studies can help in designing preventive programs for HTLV-1 infection. The aim of this study was the establishment of a PCR technique for determination of HTLV-1 infection in paraffin-embedded tissues. Methods: In this experimental laboratory study for establishment of a technique, PCR was initially optimized using Beta-actin primers on various formalin fixed paraffin-embedded tissues from liver, spleen, skin and lymph nodes. The optimized concentration of Mgcl2 was 2mm, primer was 8 pmol. Optimized concentration of DNA was different according to the kind of tissue. HTLV-1 infection was determined by applying tax, pol, env and LTR primers on 50 paraffin-embedded lymph node tissues . The reporoducibility of this technique was shown for skin and lymph node tissues infected with HTLV-1. Resuls: In 50 lymph node tissues, one case with pathologic diagnosis of NHL was positive with all 5 sets of primers (tax, Pol, env and LTR primers and the other case was positive with only two sets of tax primers but was negative with pol, env and LTR primers. The prevalence of infection was 2% among lymph node specimens. (1 of 50 specimens and if the second case is considered, the prevalence would be 4%. Conclusion: Comparison of the results of this study with another study on blood specimens (seroprevalence2.3% was not statistically significant thus confirming the results of one another. (P=0.883

Single injection techniques in determining age-related changes in porcine renal function

International Nuclear Information System (INIS)

Robbins, M.E.C.

1984-01-01

Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined in 32 anaesthetised female Large White pigs, aged 4-24 months, from the plasma disappearance curves of [sup(99m)Tc]DTPA and [ 131 I]hippuran respectively. Clearance was also monitored by external counting over the heart. GFR and ERPF increased markedly with age in pigs up to 12 months old, reaching mean values of 242.06 +- 5.89 and 919.39 +- 79.01 mL/min. In pigs aged 12-24 months ERPF increased slightly but renal function remained essentially unchanged after 1 yr of age. These results for renal function were similar to previous estimates, using continuous infusion techniques inferring that GFR and ERPF could be accurately monitored using single injection procedures. (author)

Applying contemporary statistical techniques

CERN Document Server

Wilcox, Rand R

2003-01-01

Applying Contemporary Statistical Techniques explains why traditional statistical methods are often inadequate or outdated when applied to modern problems. Wilcox demonstrates how new and more powerful techniques address these problems far more effectively, making these modern robust methods understandable, practical, and easily accessible.* Assumes no previous training in statistics * Explains how and why modern statistical methods provide more accurate results than conventional methods* Covers the latest developments on multiple comparisons * Includes recent advanc

Multiple-Vehicle Longitudinal Collision Mitigation by Coordinated Brake Control

Directory of Open Access Journals (Sweden)

Xiao-Yun Lu

2014-01-01

Full Text Available Rear-end collision often leads to serious casualties and traffic congestion. The consequences are even worse for multiple-vehicle collision. Many previous works focused on collision warning and avoidance strategies of two consecutive vehicles based on onboard sensor detection only. This paper proposes a centralized control strategy for multiple vehicles to minimize the impact of multiple-vehicle collision based on vehicle-to-vehicle communication technique. The system is defined as a coupled group of vehicles with wireless communication capability and short following distances. The safety relationship can be represented as lower bound limit on deceleration of the first vehicle and upper bound on maximum deceleration of the last vehicle. The objective is to determine the desired deceleration for each vehicle such that the total impact energy is minimized at each time step. The impact energy is defined as the relative kinetic energy between a consecutive pair of vehicles (approaching only. Model predictive control (MPC framework is used to formulate the problem to be constrained quadratic programming. Simulations show its effectiveness on collision mitigation. The developed algorithm has the potential to be used for progressive market penetration of connected vehicles in practice.

Thermally assisted OSL application for equivalent dose estimation; comparison of multiple equivalent dose values as well as saturation levels determined by luminescence and ESR techniques for a sedimentary sample collected from a fault gouge

Energy Technology Data Exchange (ETDEWEB)

Şahiner, Eren, E-mail: sahiner@ankara.edu.tr; Meriç, Niyazi, E-mail: meric@ankara.edu.tr; Polymeris, George S., E-mail: gspolymeris@ankara.edu.tr

2017-02-01

Highlights: • Multiple equivalent dose estimations were carried out. • Additive ESR and regenerative luminescence were applied. • Preliminary SAR results employing TA-OSL signal were discussed. • Saturation levels of ESR and luminescence were investigated. • IRSL{sub 175} and SAR TA-OSL stand as very promising for large doses. - Abstract: Equivalent dose estimation (D{sub e}) constitutes the most important part of either trap-charge dating techniques or dosimetry applications. In the present work, multiple, independent equivalent dose estimation approaches were adopted, using both luminescence and ESR techniques; two different minerals were studied, namely quartz as well as feldspathic polymineral samples. The work is divided into three independent parts, depending on the type of signal employed. Firstly, different D{sub e} estimation approaches were carried out on both polymineral and contaminated quartz, using single aliquot regenerative dose protocols employing conventional OSL and IRSL signals, acquired at different temperatures. Secondly, ESR equivalent dose estimations using the additive dose procedure both at room temperature and at 90 K were discussed. Lastly, for the first time in the literature, a single aliquot regenerative protocol employing a thermally assisted OSL signal originating from Very Deep Traps was applied for natural minerals. Rejection criteria such as recycling and recovery ratios are also presented. The SAR protocol, whenever applied, provided with compatible D{sub e} estimations with great accuracy, independent on either the type of mineral or the stimulation temperature. Low temperature ESR signals resulting from Al and Ti centers indicate very large D{sub e} values due to bleaching in-ability, associated with large uncertainty values. Additionally, dose saturation of different approaches was investigated. For the signal arising from Very Deep Traps in quartz saturation is extended almost by one order of magnitude. It is

Determination of metals in air samples using X-Ray fluorescence associated the APDC preconcentration technique

Energy Technology Data Exchange (ETDEWEB)

Nardes, Raysa C.; Santos, Ramon S.; Sanches, Francis A.C.R.A.; Gama Filho, Hamilton S.; Oliveira, Davi F.; Anjos, Marcelino J., E-mail: rc.nardes@gmail.com, E-mail: ramonziosp@yahoo.com.br, E-mail: francissanches@gmail.com, E-mail: hamiltongamafilho@hotmail.com, E-mail: davi.oliveira@uerj.br, E-mail: marcelin@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Instituto de Fisica. Departamento de Fisica Aplicada e Termodinamica

2015-07-01

Air pollution has become one of the leading quality degradation factors of life for people in large urban centers. Studies indicate that the suspended particulate matter in the atmosphere is directly associated with risks to public health, in addition, it can cause damage to fauna, flora and public / cultural patrimonies. The inhalable particulate materials can cause the emergence and / or worsening of chronic diseases related to respiratory system and other diseases, such as reduced physical strength. In this study, we propose a new method to measure the concentration of total suspended particulate matter (TSP) in the air using an impinger as an air cleaning apparatus, preconcentration with APDC and Total Reflection X-ray Fluorescence technique (TXRF) to analyze the heavy metals present in the air. The samples were collected from five random points in the city of Rio de Janeiro/Brazil. Analyses of TXRF were performed at the Brazilian Synchrotron Light Laboratory (LNLS). The technique proved viable because it was able to detect five important metallic elements to environmental studies: Cr, Fe, Ni, Cu and Zn. This technique presented substantial efficiency in determining the elementary concentration of air pollutants, in addition to low cost. It can be concluded that the metals analysis technique in air samples using an impinger as sample collection instrument associated with a complexing agent (APDC) was viable because it is a low-cost technique, moreover, it was possible the detection of five important metal elements in environmental studies associated with industrial emissions and urban traffic. (author)

Determination of metals in air samples using X-Ray fluorescence associated the APDC preconcentration technique

International Nuclear Information System (INIS)

Nardes, Raysa C.; Santos, Ramon S.; Sanches, Francis A.C.R.A.; Gama Filho, Hamilton S.; Oliveira, Davi F.; Anjos, Marcelino J.

2015-01-01

Air pollution has become one of the leading quality degradation factors of life for people in large urban centers. Studies indicate that the suspended particulate matter in the atmosphere is directly associated with risks to public health, in addition, it can cause damage to fauna, flora and public / cultural patrimonies. The inhalable particulate materials can cause the emergence and / or worsening of chronic diseases related to respiratory system and other diseases, such as reduced physical strength. In this study, we propose a new method to measure the concentration of total suspended particulate matter (TSP) in the air using an impinger as an air cleaning apparatus, preconcentration with APDC and Total Reflection X-ray Fluorescence technique (TXRF) to analyze the heavy metals present in the air. The samples were collected from five random points in the city of Rio de Janeiro/Brazil. Analyses of TXRF were performed at the Brazilian Synchrotron Light Laboratory (LNLS). The technique proved viable because it was able to detect five important metallic elements to environmental studies: Cr, Fe, Ni, Cu and Zn. This technique presented substantial efficiency in determining the elementary concentration of air pollutants, in addition to low cost. It can be concluded that the metals analysis technique in air samples using an impinger as sample collection instrument associated with a complexing agent (APDC) was viable because it is a low-cost technique, moreover, it was possible the detection of five important metal elements in environmental studies associated with industrial emissions and urban traffic. (author)

Monte Carlo wave packet approach to dissociative multiple ionization in diatomic molecules

DEFF Research Database (Denmark)

Leth, Henriette Astrup; Madsen, Lars Bojer; Mølmer, Klaus

2010-01-01

A detailed description of the Monte Carlo wave packet technique applied to dissociative multiple ionization of diatomic molecules in short intense laser pulses is presented. The Monte Carlo wave packet technique relies on the Born-Oppenheimer separation of electronic and nuclear dynamics...... and provides a consistent theoretical framework for treating simultaneously both ionization and dissociation. By simulating the detection of continuum electrons and collapsing the system onto either the neutral, singly ionized or doubly ionized states in every time step the nuclear dynamics can be solved....... The computational effort is restricted and the model is applicable to any molecular system where electronic Born-Oppenheimer curves, dipole moment functions, and ionization rates as a function of nuclear coordinates can be determined....

Neutron recognition in the LAND detector for large neutron multiplicity

Energy Technology Data Exchange (ETDEWEB)

Pawlowski, P., E-mail: piotr.pawlowski@ifj.edu.pl [Institute of Nuclear Physics, PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Brzychczyk, J. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Leifels, Y.; Trautmann, W. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Adrich, P. [National Centre for Nuclear Research, PL-00681 Warsaw (Poland); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Aumann, T. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Bacri, C.O. [Institut de Physique Nucleaire, IN2P3-CNRS et Universite, F-91406 Orsay (France); Barczyk, T. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Bassini, R. [Istituto di Scienze Fisiche, Universita degli Studi and INFN, I-20133 Milano (Italy); Bianchin, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Boiano, C. [Istituto di Scienze Fisiche, Universita degli Studi and INFN, I-20133 Milano (Italy); Boretzky, K. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Boudard, A. [IRFU/SPhN, CEA/Saclay, F-91191 Gif-sur-Yvette (France); Chbihi, A. [GANIL, CEA et IN2P3-CNRS, F-14076 Caen (France); Cibor, J.; Czech, B. [Institute of Nuclear Physics, PAN, Radzikowskiego 152, 31-342 Krakow (Poland); De Napoli, M. [Dipartimento di Fisica e Astronomia-Universita and INFN-CT and LNS, I-95123 Catania (Italy); and others

2012-12-01

The performance of the LAND neutron detector is studied. Using an event-mixing technique based on one-neutron data obtained in the S107 experiment at the GSI laboratory, we test the efficiency of various analytic tools used to determine the multiplicity and kinematic properties of detected neutrons. A new algorithm developed recently for recognizing neutron showers from spectator decays in the ALADIN experiment S254 is described in detail. Its performance is assessed in comparison with other methods. The properties of the observed neutron events are used to estimate the detection efficiency of LAND in this experiment.

Determination of the uranium concentration in water samples by the technique of fission track recording

International Nuclear Information System (INIS)

Geraldo, L.P.

1979-01-01

The technique of fission track register was developed for the determination of micrograms of uranium. The Makrofol KG, a synthetic plastic made by Bayer, was used as the detector and the wet method was utilized. The detector calibration curve allows the determination of the uranium concentration in a sample within an interval from 8.0 to 0.4μgU/L, the total error ranging from 3.3% to 29.0% respectively. The method was used in the determination of the uranium content in various water samples, obtained from various sources like rivers, sea etc. in the state of Sao Paulo, Brazil. Results were compared with those obtained by other authors using different methods. The average concentration found in sea waters (3.27 +- 9.12μgU/l) by this method is compatible with the international average accepted value of 3.3μgU/l, irrespective of site and depth. The determination of the uranium content by fission track counting has proved to be very convenient. (Author) [pt

Determination of the cell parameters of β-quartz at 1003 K by neutron multiple diffraction

International Nuclear Information System (INIS)

Campos, Luiz Carlos de

2002-01-01

In this work, neutron multiple diffraction (NMD) data was employed for the determination of the parameters a and c of the β-quartz hexagonal cell at 1003 K. An experimental 00.1 β-quartz NMD 'Umweg' pattern has been used for the determinations. During the indexing of the β-quartz pattern it was verified that most of the peaks could be classified as either 'good for the determination of the parameter a' or 'good for the determination of the parameter c'. With such a classification, it became possible to employ an iterative process for the determination of both parameters. To attain this purpose, two methods were developed. The first one, named 'absolute method', used angular azimuthal positions of the peaks, related to the origin of the experimental diagram. The second method, named 'relative method', used azimuthal angular differences between two selected peaks. The values obtained for both parameters, in the two methods employed, were found by applying the angular azimuthal positions, for the first method, and the azimuthal angular differences, for the second method, upon appropriate theoretical indexing diagrams. An iterative process was applied in order to obtain the values of the parameters. In this process, the value obtained for one of the parameters was used in the determination of the other parameter. The process continues until both parameters converge. The iterative process was used in both methods. The relative method proved to be better than the absolute method. The best values of the parameters obtained by the relative method were: a 4.99638 ± 0.00057 angstrom and c = 5.46119 ± 0.00044 angstrom. (author)

Hydrogen clearance: Assessment of technique for measurement of skin-flap blood flow in pigs

International Nuclear Information System (INIS)

Thomson, J.G.; Kerrigan, C.L.

1991-01-01

The hydrogen clearance technique has been used for many years by investigators to determine brain blood flow and has been partially validated in this setting using other methods of blood flow measurement. The method has been modified to allow blood flow measurements in skin, but the accuracy of H2 clearance for measuring skin blood flow has not been determined. Multiple blood flow measurements were performed using H2 clearance and radioactive microspheres on skin flaps and control skin in pigs. On 12 pigs, a total of 117 flap and 42 control skin measurements were available for analysis. There was no significant difference between the two techniques in measuring mean control skin blood flow. In skin flaps, H2 clearance was significantly correlated to microsphere-measured blood flow, but it consistently gave an overestimate. Sources of error may include injury to the tissues by insertion of electrodes, consumption of H2 by the electrodes, or diffusion of H2 from the relatively ischemic flap to its well-vascularized bed. Further studies are necessary to determine the cause of this error and to measure the technique's accuracy in skeletal muscle and other flaps

Dynamics of multiple-goal pursuit.

Science.gov (United States)

Louro, Maria J; Pieters, Rik; Zeelenberg, Marcel

2007-08-01

The authors propose and test a model of multiple-goal pursuit that specifies how individuals allocate effort among multiple goals over time. The model predicts that whether individuals decide to step up effort, coast, abandon the current goal, or switch to pursue another goal is determined jointly by the emotions that flow from prior goal progress and the proximity to future goal attainment, and proximally determined by changes in expectancies about goal attainment. Results from a longitudinal diary study and 2 experiments show that positive and negative goal-related emotions can have diametrically opposing effects on goal-directed behavior, depending on the individual's proximity to goal attainment. The findings resolve contrasting predictions about the influence of positive and negative emotions in volitional behavior, critically amend the goal gradient hypothesis, and provide new insights into the dynamics and determinants of multiple-goal pursuit.

Optimization of constrained multiple-objective reliability problems using evolutionary algorithms

International Nuclear Information System (INIS)

Salazar, Daniel; Rocco, Claudio M.; Galvan, Blas J.

2006-01-01

This paper illustrates the use of multi-objective optimization to solve three types of reliability optimization problems: to find the optimal number of redundant components, find the reliability of components, and determine both their redundancy and reliability. In general, these problems have been formulated as single objective mixed-integer non-linear programming problems with one or several constraints and solved by using mathematical programming techniques or special heuristics. In this work, these problems are reformulated as multiple-objective problems (MOP) and then solved by using a second-generation Multiple-Objective Evolutionary Algorithm (MOEA) that allows handling constraints. The MOEA used in this paper (NSGA-II) demonstrates the ability to identify a set of optimal solutions (Pareto front), which provides the Decision Maker with a complete picture of the optimal solution space. Finally, the advantages of both MOP and MOEA approaches are illustrated by solving four redundancy problems taken from the literature

Optimization of constrained multiple-objective reliability problems using evolutionary algorithms

Energy Technology Data Exchange (ETDEWEB)

Salazar, Daniel [Instituto de Sistemas Inteligentes y Aplicaciones Numericas en Ingenieria (IUSIANI), Division de Computacion Evolutiva y Aplicaciones (CEANI), Universidad de Las Palmas de Gran Canaria, Islas Canarias (Spain) and Facultad de Ingenieria, Universidad Central Venezuela, Caracas (Venezuela)]. E-mail: danielsalazaraponte@gmail.com; Rocco, Claudio M. [Facultad de Ingenieria, Universidad Central Venezuela, Caracas (Venezuela)]. E-mail: crocco@reacciun.ve; Galvan, Blas J. [Instituto de Sistemas Inteligentes y Aplicaciones Numericas en Ingenieria (IUSIANI), Division de Computacion Evolutiva y Aplicaciones (CEANI), Universidad de Las Palmas de Gran Canaria, Islas Canarias (Spain)]. E-mail: bgalvan@step.es

2006-09-15

This paper illustrates the use of multi-objective optimization to solve three types of reliability optimization problems: to find the optimal number of redundant components, find the reliability of components, and determine both their redundancy and reliability. In general, these problems have been formulated as single objective mixed-integer non-linear programming problems with one or several constraints and solved by using mathematical programming techniques or special heuristics. In this work, these problems are reformulated as multiple-objective problems (MOP) and then solved by using a second-generation Multiple-Objective Evolutionary Algorithm (MOEA) that allows handling constraints. The MOEA used in this paper (NSGA-II) demonstrates the ability to identify a set of optimal solutions (Pareto front), which provides the Decision Maker with a complete picture of the optimal solution space. Finally, the advantages of both MOP and MOEA approaches are illustrated by solving four redundancy problems taken from the literature.

EXAFS analysis of uranium speciation in plants using the difference technique

International Nuclear Information System (INIS)

Rossberg, A.; Reich, T.; Guenther, A.; Bernhard, G.

2002-01-01

An EXAFS spectrum is the sum of the signals of scattering contributions from single atoms and multiple scattering (MS) between atoms. The scattering contributions with high intensity are the major and such with low intensity are the minor components in an EXAFS spectrum. A chi-squared fit algorithm is not sensitive enough to the minor components. A difference technique has been developed /1/ to isolate the minor components from the whole EXAFS spectrum to increase the accuracy in determinating of their EXAFS structural parameters. (orig.)

Characterization of forsythoside A metabolites in rats by a combination of UHPLC-LTQ-Orbitrap mass spectrometer with multiple data processing techniques.

Science.gov (United States)

Wang, Fei; Cao, Guang-Shang; Li, Yun; Xu, Lu-Lu; Wang, Zhi-Bin; Liu, Ying; Lu, Jian-Qiu; Zhang, Jia-Yu

2018-05-01

Forsythoside A (FTA), the main active constituent isolated from Fructus Forsythiae, has various biological functions including anti-oxidant, anti-viral and anti-microbial activities. However, while research on FTA has been mainly focused on the treatment of diseases on a material basis, FTA metabolites in vivo have not been comprehensively evaluated. Here, a rapid and sensitive method using a UHPLC-LTQ-Orbitrap mass spectrometer with multiple data processing techniques including high-resolution extracted ion chromatograms, multiple mass defect filters and diagnostic product ions was developed for the screening and identification of FTA metabolites in rats. As the result, a total of 43 metabolites were identified in biological samples including 42 metabolites in urine, 22 metabolites in plasma and 15 metabolites in feces. These results demonstrated that FTA underwent a series of in vivo metabolic reactions including methylation, dimethylation, sulfation, glucuronidation, diglucuronidation, cysteine conjugation and their composite reactions. The research enhanced our understanding of FTA metabolism and built a foundation for further toxicity and safety studies. Copyright © 2017 John Wiley & Sons, Ltd.

A modified discrete algebraic reconstruction technique for multiple grey image reconstruction for limited angle range tomography.

Science.gov (United States)

Liang, Zhiting; Guan, Yong; Liu, Gang; Chen, Xiangyu; Li, Fahu; Guo, Pengfei; Tian, Yangchao

2016-03-01

The `missing wedge', which is due to a restricted rotation range, is a major challenge for quantitative analysis of an object using tomography. With prior knowledge of the grey levels, the discrete algebraic reconstruction technique (DART) is able to reconstruct objects accurately with projections in a limited angle range. However, the quality of the reconstructions declines as the number of grey levels increases. In this paper, a modified DART (MDART) was proposed, in which each independent region of homogeneous material was chosen as a research object, instead of the grey values. The grey values of each discrete region were estimated according to the solution of the linear projection equations. The iterative process of boundary pixels updating and correcting the grey values of each region was executed alternately. Simulation experiments of binary phantoms as well as multiple grey phantoms show that MDART is capable of achieving high-quality reconstructions with projections in a limited angle range. The interesting advancement of MDART is that neither prior knowledge of the grey values nor the number of grey levels is necessary.

Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique

Science.gov (United States)

Ryberg, T.; Haberland, C.H.; Fuis, G.S.; Ellsworth, W.L.; Shelly, D.R.

2010-01-01

Non-volcanic tremor (NVT) has been observed at several subduction zones and at the San Andreas Fault (SAF). Tremor locations are commonly derived by cross-correlating envelope-transformed seismic traces in combination with source-scanning techniques. Recently, they have also been located by using relative relocations with master events, that is low-frequency earthquakes that are part of the tremor; locations are derived by conventional traveltime-based methods. Here we present a method to locate the sources of NVT using an imaging approach for multiple array data. The performance of the method is checked with synthetic tests and the relocation of earthquakes. We also applied the method to tremor occurring near Cholame, California. A set of small-aperture arrays (i.e. an array consisting of arrays) installed around Cholame provided the data set for this study. We observed several tremor episodes and located tremor sources in the vicinity of SAF. During individual tremor episodes, we observed a systematic change of source location, indicating rapid migration of the tremor source along SAF. ?? 2010 The Authors Geophysical Journal International ?? 2010 RAS.

Determination of free acidity in nuclear fuel reprocessing streams by fiber optic aided spectrophotometric technique

International Nuclear Information System (INIS)

Ganesh, S.; Velavendan, P.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

2014-01-01

A fiber optic aided spectrophotometric technique has been developed for the determination of free acidity in nuclear fuel reprocessing streams. The developed method is simple, accurate and applicable to all ranges of nitric acid and heavy metal concentrations relevant to the purex process. The method is based on the formation of yellow colour with an acid-sensitive indicator such as chrome azurol s, the intensity of yellow colour is proportional to the acid concentration. The system obeys Lambert-Beer's law at 455 nm in the range of acidity 1-10 M of nitric acid. The results obtained are reproducible with standard deviation 2% and relative error is less than 3%. The results obtained by the developed technique are in good agreement with those obtained by the standard procedure. This method is adaptable for remote operation and on-line monitoring. (author)

Development of the transverse tensile and fracture toughness test techniques for spent fuel cladding

Energy Technology Data Exchange (ETDEWEB)

Ahn, S. B.; Hong, K. P.; Jung, Y. H.; Seo, H. S.; Oh, W. H.; Yoo, B. O.; Kim, D. S.; Seo, K. S

2001-12-01

To define the cause of cladding damage which can take place during the operation of nuclear power plant and the storage through the degradation aspect of mechanical characteristics, the transverse tensile an fracture toughness test were developed in hot cell at IMEF(Irradiated Material Experiment Facility). The following hot cell techniques were developed. 1. The development of a jig and a specimen for transverse tensile test 2. The acquisition of a manufacturing technique for the transverse tensile specimen at hot cell 3. The acquisition of testing procedures and an analysis technque for the transverse tensile 4. The dimensional determination of an optimized fracture toughness specimen 5. The acquisition of manufacturing technique for the fracture toughness test specimen at the hot cell 6. The acquisition of testing procedures and analysis technique for the fracture toughness test (Multiple specimen method, DCPD method, Load ratio method)

Determination of stability constants of lanthanide nitrate complex formation using a solvent extraction technique

International Nuclear Information System (INIS)

Andersson, S.; Ekberg, C.; Liljenzin, J.O.; Nilsson, M.; Skarnemark, G.; Eberhardt, K.

2006-01-01

For lanthanides and actinides, nitrate complex formation is an important factor with respect to the reprocessing of nuclear fuels and in studies that treat partitioning and transmutation/conditioning. Different techniques, including microcalorimetry, various kinds of spectroscopy, ion-exchange and solvent extraction, can be used to determine stability constants of nitrate complex formation. However, it is uncommon that all lanthanides are studied at the same time, using the same experimental conditions and technique. The strengths of the complexes are different for lanthanides and actinides, a feature that may assist in the separation of the two groups. This paper deals with nitrate complex formation of lanthanides using a solvent extraction technique. Trace amounts of radioactive isotopes of lanthanides were produced at the TRIGA Mainz research reactor and at the Institutt for Energiteknikk in Kjeller, Norway (JEEP II reactor). The extraction of lanthanide ions into an organic phase consisting of 2, 6-bis-(benzoxazolyl)-4-dodecyloxylpyridine, 2-bromodecanoic acid and tert-butyl benzene as a function of nitrate ion concentration in the aqueous phase was studied in order to estimate the stability constants of nitrate complex formation. When the nitrate ion concentration is increased in the aqueous phase, the nitrate complex formation starts to compete with the extraction of metal ions. Thus the stability constants of nitrate complex formation can be estimated by measuring the decrease in extraction and successive fitting of an appropriate model. Extraction curves for La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Dy, Ho and Er were obtained and stability constants for their nitrate complex formation were estimated. Tb, Tm, Yb and Lu were also investigated, but no stability constants could be determined. The distribution ratios for the metal ions at low nitrate ion concentration were obtained at the same time, showing the effect of lanthanide contraction resulting in decreasing

Morphological and clinical aspects of the occurrence of accessory (multiple) renal arteries

Science.gov (United States)

Gulas, Ewelina; Wysiadecki, Grzegorz; Szymański, Jacek; Majos, Agata; Stefańczyk, Ludomir; Topol, Mirosław

2016-01-01

Renal vascularization variants vastly differ between individuals due to the very complex embryogenesis of the kidneys. Moreover, each variant may have implications for clinical and surgical interventions. The number of operating procedures continues to grow, and includes renal transplants, aneurysmorrhaphy and other vascular reconstructions. In any surgical technique, unawareness of the presence of multiple renal arteries may result in a fatal outcome, especially if laparoscopic methods are used. The aim of this review is to comprehensively identify the variation within multiple renal arteries and to highlight the connections between the presence of accessory renal arteries and the coexistence of other variants of vascularization. Another aim is to determine the potential clinical implications of the presence of accessory renal arteries. This study is of particular importance for surgeons, intervention radiologists, nephrologists and vascular surgeons. PMID:29593819

Application to Determination of Scholarship Worthiness Using Simple Multi Attribute Rating Technique and Merkle Hellman Method

Directory of Open Access Journals (Sweden)

Dicky Nofriansyah

2017-10-01

Full Text Available This research was focused on explaining how the concept of simple multi attribute rating technique method in a decision support system based on desktop programming to solve multi-criteria selection problem, especially Scholarship. The Merkle Hellman method is used for securing the results of choices made by the Smart process. The determination of PPA and BBP-PPA scholarship recipients on STMIK Triguna Dharma becomes a problem because it takes a long time in determining the decision. By adopting the SMART method, the application can make decisions quickly and precisely. The expected result of this research is the application can facilitate in overcoming the problems that occur concerning the determination of PPA and BBP-PPA scholarship recipients as well as assisting Student Affairs STMIK Triguna Dharma in making decisions quickly and accurately

Good abundances from bad spectra - I. Techniques

Science.gov (United States)

Jones, J. Bryn; Gilmore, Gerard; Wyse, Rosemary F. G.

1996-01-01

Stellar spectra derived from multiple-object fibre-fed spectroscopic radial-velocity surveys, of the type feasible with, among other examples, AUTOFIB, 2dF, HYDRA, NESSIE, and the Sloan survey, differ significantly from those traditionally used for determination of stellar abundances. The spectra tend to be of moderate resolution (around 1A) and signal-to-noise ratio (around 10-20 per resolution element), and cannot usually have reliable continuum shapes determined over wavelength ranges in excess of a few tens of Angstroms. None the less, with care and a calibration of stellar effective temperature from photometry, independent of the spectroscopy, reliable iron abundances can be derived. We have developed techniques to extract true iron abundances and surface gravities from low-signal-to-noise ratio, intermediate-resolution spectra of G-type stars in the 4000-5000A wavelength region. Spectroscopic indices sensitive to iron abundance and gravity are defined from a set of narrow (few-several A wide) wavelength intervals. The indices are calibrated theoretically using synthetic spectra. Given adequate data and a photometrically determined effective temperature, one can derive estimates of the stellar iron abundance and surface gravity. We have also defined a single abundance indicator for the analysis of very low-signal-to-noise ratio spectra; with the further assumption of a value for the stellar surface gravity, this is able to provide useful iron abundance information from spectra having signal-to-noise ratios as low as 10 (1-A elements). The theoretical basis and calibration using synthetic spectra are described in this paper. The empirical calibration of these techniques by application to observational data is described in a separate paper (Jones, Wyse & Gilmore). The technique provides precise iron abundances, with zero-point correct to ~0.1 dex, and is reliable, with typical uncertainties being <~0.2 dex. A derivation of the in situ thick disc metallicity

Laser-induced breakdown spectroscopy (LIBS) technique for the determination of the chemical composition of complex inorganic materials

Science.gov (United States)

Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Kozioł, Paweł E.; Stepak, Bogusz; Abramski, Krzysztof M.

2014-08-01

Laser-induced breakdown spectroscopy (LIBS) is a fast, fully optical method, that needs little or no sample preparation. In this technique qualitative and quantitative analysis is based on comparison. The determination of composition is generally based on the construction of a calibration curve namely the LIBS signal versus the concentration of the analyte. Typically, to calibrate the system, certified reference materials with known elemental composition are used. Nevertheless, such samples due to differences in the overall composition with respect to the used complex inorganic materials can influence significantly on the accuracy. There are also some intermediate factors which can cause imprecision in measurements, such as optical absorption, surface structure, thermal conductivity etc. This paper presents the calibration procedure performed with especially prepared pellets from the tested materials, which composition was previously defined. We also proposed methods of post-processing which allowed for mitigation of the matrix effects and for a reliable and accurate analysis. This technique was implemented for determination of trace elements in industrial copper concentrates standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for contents of three elements, that is silver, cobalt and vanadium. It has been shown that the described technique can be used to qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates.

The capillary adhesion technique: a versatile method for determining the liquid adhesion force and sample stiffness

Directory of Open Access Journals (Sweden)

Daniel Gandyra

2015-01-01

Full Text Available We report a novel, practical technique for the concerted, simultaneous determination of both the adhesion force of a small structure or structural unit (e.g., an individual filament, hair, micromechanical component or microsensor to a liquid and its elastic properties. The method involves the creation and development of a liquid meniscus upon touching a liquid surface with the structure, and the subsequent disruption of this liquid meniscus upon removal. The evaluation of the meniscus shape immediately before snap-off of the meniscus allows the quantitative determination of the liquid adhesion force. Concurrently, by measuring and evaluating the deformation of the structure under investigation, its elastic properties can be determined. The sensitivity of the method is remarkably high, practically limited by the resolution of the camera capturing the process. Adhesion forces down to 10 µN and spring constants up to 2 N/m were measured. Three exemplary applications of this method are demonstrated: (1 determination of the water adhesion force and the elasticity of individual hairs (trichomes of the floating fern Salvinia molesta. (2 The investigation of human head hairs both with and without functional surface coatings (a topic of high relevance in the field of hair cosmetics was performed. The method also resulted in the measurement of an elastic modulus (Young’s modulus for individual hairs of 3.0 × 105 N/cm2, which is within the typical range known for human hair. (3 Finally, the accuracy and validity of the capillary adhesion technique was proven by examining calibrated atomic force microscopy cantilevers, reproducing the spring constants calibrated using other methods.

An appraisal of neutron activation analysis and other analytical techniques for the determination of arsenic, selenium and tin in environmental samples

International Nuclear Information System (INIS)

Peterson, P.J.; Girling, C.A.; Klumpp, D.W.; Minski, M.J.

1979-01-01

The paper presents an experimental comparison between neutron activation analysis, atomic absorption spectrophotometry and fluorescence spectrophotometry used for the determination of trace amounts of As, Se and Sn and the other two analytical techniques mentioned. Gamma-ray spectrometry has been used to determine 76 As (tsub(1/2)=26.3 h) after 1 day's irradiation at a thermal neutron flux of 1.6x10 12 n.cm -2 .s -1 . High sensitivity was also obtained using an atomic absorption spectrophotometer coupled with covalent hydride generation. Advantages of the latter technique include simplicity of operation, high speed of analysis and negligible background correction. When used in conjuction with selective reduction and a cold-trap this method quantitatively distinguishes between the valence states and some methylated derivatives. Selenium has been analysed by gamma-ray spectrometry using 77 Sesup(m) (tsub(1/2)=17.5 s) after cyclic activation at a thermal neutron flux of 2x10 12 n.cm -2 .s -1 . Atomic absorption spectrophotometry following hydride generation, or fluorescence spectrophotometry of the 2,3 diaminonaphthalene complex constitute additional sensitive analytical methods for the determination of Se. These have the added advantage that valence states can be selectively measured. Low concentrations of Sn have been determined by neutron activation analysis and by spectrophotometric techniques using phenylfluorone as the complexing reagent, but these methods depend on selective extraction of Sn(IV) iodide. Whilst maintaining high sensitivity, these problems were avoided by using the hydride generation technique with an atomic absorption spectrophotometer. Comparative analytical values for Bowen's kale and NBS orchard leaves are presented

Application of the Modified Source Multiplication (MSM) Technique to Subcritical Reactivity Worth Measurements in Thermal and Fast Reactor Systems

International Nuclear Information System (INIS)

Blaise, P.; Fougeras, Ph.; Mellier, F.

2011-01-01

The Amplified Source Multiplication (ASM) method and its improved Modified Source Multiplication (MSM) method have been widely used in the CEA's EOLE and MASURCA critical facilities over the past decades for the determination of reactivity worths by using fission chambers in subcritical configurations. The ASM methodology uses relatively simple relationships between count rates of efficient miniature fission chambers located in slightly subcritical reference and perturbed configurations. While this method works quite well for small reactivity variations, the raw results need to be corrected to take into account the flux perturbation at the fission chamber location. This is performed by applying to the measurement a correction factor called MSM. This paper describes in detail both methodologies, with their associated uncertainties. Applications on absorber cluster worth in the MISTRAL-4 full MOX mock-up core and the last core loaded in MASURCA show the importance of the MSM correction on raw ASM data. (authors)

A REVIEW ON THE ANALYTICAL TECHNIQUES USED FOR THE DETERMINATION OF PARACETAMOL IN PHARMACEUTICAL FORMULATIONS AND BIOLOGICAL FLUIDS

Directory of Open Access Journals (Sweden)

Aisha Noreen

2016-12-01

Full Text Available Paracetamol (PM is an active metabolite of phenacetin and belongs to p-aminophenol derivatives. It is also termed as acetaminophen. PM is one of the non-steroidal anti-inflammatory drugs (NSAIDs which is used as an analgesic and antipyretic agent. It is an OTC drug and is used as a common household analgesic. It is not used as a substitute of aspirin or any other NSAIDs. It is a weak cyclooxygenase (COX 1 and 2 inhibitor but may inhibit COX-3 in the central nervous system. Many analytical techniques have been used for the assay of PM in pharmaceutical preparations and biological fluids. These techniques include spectrometry, chromatography, spectrofluorimetry, chemiluminescence, electrochemical techniques, flow injection spectrometry and chronoamperometry. In many pharmaceutical preparations PM is also used in combination with other drugs and these techniques have also been used for their simultaneous determination. A detailed review of various analytical techniques used for the assay of PM has been carried out which would be of great help to the chemists and pharmacists involved in the analysis and quality control of drugs.

Interleaved Practice with Multiple Representations: Analyses with Knowledge Tracing Based Techniques

Science.gov (United States)

Rau, Martina A.; Pardos, Zachary A.

2012-01-01

The goal of this paper is to use Knowledge Tracing to augment the results obtained from an experiment that investigated the effects of practice schedules using an intelligent tutoring system for fractions. Specifically, this experiment compared different practice schedules of multiple representations of fractions: representations were presented to…

The use of a single technique for the separation and determination of actinides in biological materials

International Nuclear Information System (INIS)

Camera, V.; Giubileo.

1975-01-01

For the radiotoxicological survey of workers exposed to different types of alpha-emitting contaminants, a procedure was developed which permits the estimate of Th, Pa, U, Np, Pu, Am and Cm in biological samples with a single technique. The radionuclides are extracted on a column by tri-n-octylphosphine oxide and separated by elution at different pH values. Afterwards, the quantitative determinations are done by physical methods (alpha counting or spectrometry). In the case of an accident it is possible to use a simplification of the procedure (extraction in a beaker) for checks. A procedure for the rapid determination of actinides in faeces and in nasal secretions is described

Pesticide Residues in Canned Foods, Fruits, and Vegetables: The Application of Supercritical Fluid Extraction and Chromatographic Techniques in the Analysis

OpenAIRE

EL-Saeid, Mohamed H.

2003-01-01

Multiple pesticide residues have been observed in some samples of canned foods, frozen vegetables, and fruit jam, which put the health of the consumers at risk of adverse effects. It is quite apparent that such a state of affairs calls for the need of more accurate, cost-effective, and rapid analytical techniques capable of detecting the minimum concentrations of the multiple pesticide residues. The aims of this paper were first, to determine the effectiveness of the use of Supercritical Flui...

A general technique for confluence of calculational and experimental information with application to power distribution determination

International Nuclear Information System (INIS)

Serov, I.V.; Hoogenboom, J.E.

1994-01-01

Physical quantities can be obtained by utilizing different informational sources. The available information is usually associated with systematic and statistical errors. If the informational sources are utilized simultaneously, then it is possible to obtain posterior estimates of the quantities with better statistical properties than exhibited by any prior estimates. The general technique for confluence of any number possibly dependent informational sources can be developed. Insight into the nature of the informational source allows different types of data associated with the source to be improved. The formulas of the technique are presented and applied to the power distribution determination for research reactor HOR of the Delft University of Technology, employing calculational and experimental data. (authors). 5 refs., 1 tab., 5 figs

Determination of Cu, Cr, and As in preserved wood (Eucalyptus sp.) using x-ray fluorescent spectrometry techniques

International Nuclear Information System (INIS)

Sergio Matias Pereira Junior; Vera Akiko Maihara; Edson Goncalves Moreira; Vera Lucia Ribeiro Salvador; Ivone Mulako Sato

2016-01-01

Energy dispersive (EDXRF) and Portable (PXRF) X-ray fluorescence techniques are proposed for wood treatment control process and wood waste assortment. In this study, different retentions of chromated copper arsenate preservative were applied to Eucalyptus sp. sapwood samples. Cu, Cr and As were determined by XRF techniques in treated sapwood massive blocks and treated sapwood sawdust samples were analyzed by FAAS spectrometry (Flame Atomic Absorption) and INAA (Instrumental Neutron Activation Analysis). Cu, Cr and As mean values, obtained by FAASS and INAA, showed to be statically equal; however, XRF analysis showed considerable deviations, presenting the absorption and the enhancement effects in analytical lines. (author)