surface analytic techniques: Topics by WorldWideScience.org

Sample records for surface analytic techniques

Evaluating empirical/analytical techniques to predict structural integrity of pipe containing surface flaws

International Nuclear Information System (INIS)

Reuter, W.G.; Server, W.L.

1982-01-01

Data from flat-plate specimens containing either triangular-, ellipsoidal- or rectangular-shaped surface flaws were evaluated by several potential analytical techniques. These techniques were modified as needed to predict conditions for initiation of subcritical crack growth, for the defect to penetrate the 6.4 mm (0.25 in.) wall thickness, and for instability (plastic or unstable). The modified analytical techniques developed from the plate specimens were then used to make predictions which are compared with test results obtained from pipe specimens containing triangular-shaped surface flaws
Isotropic and anisotropic surface wave cloaking techniques

International Nuclear Information System (INIS)

McManus, T M; Spada, L La; Hao, Y

2016-01-01

In this paper we compare two different approaches for surface waves cloaking. The first technique is a unique application of Fermat’s principle and requires isotropic material properties, but owing to its derivation is limited in its applicability. The second technique utilises a geometrical optics approximation for dealing with rays bound to a two dimensional surface and requires anisotropic material properties, though it can be used to cloak any smooth surface. We analytically derive the surface wave scattering behaviour for both cloak techniques when applied to a rotationally symmetric surface deformation. Furthermore, we simulate both using a commercially available full-wave electromagnetic solver and demonstrate a good level of agreement with their analytically derived solutions. Our analytical solutions and simulations provide a complete and concise overview of two different surface wave cloaking techniques. (paper)
Isotropic and anisotropic surface wave cloaking techniques

Science.gov (United States)

McManus, T. M.; La Spada, L.; Hao, Y.

2016-04-01

In this paper we compare two different approaches for surface waves cloaking. The first technique is a unique application of Fermat’s principle and requires isotropic material properties, but owing to its derivation is limited in its applicability. The second technique utilises a geometrical optics approximation for dealing with rays bound to a two dimensional surface and requires anisotropic material properties, though it can be used to cloak any smooth surface. We analytically derive the surface wave scattering behaviour for both cloak techniques when applied to a rotationally symmetric surface deformation. Furthermore, we simulate both using a commercially available full-wave electromagnetic solver and demonstrate a good level of agreement with their analytically derived solutions. Our analytical solutions and simulations provide a complete and concise overview of two different surface wave cloaking techniques.
Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface

International Nuclear Information System (INIS)

Ficher, P.; Goutelard, F.; Siitari-Kauppi, M.

2012-01-01

In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient
Degradation of glass artifacts: application of modern surface analytical techniques.

Science.gov (United States)

Melcher, Michael; Wiesinger, Rita; Schreiner, Manfred

2010-06-15

A detailed understanding of the stability of glasses toward liquid or atmospheric attack is of considerable importance for preserving numerous objects of our cultural heritage. Glasses produced in the ancient periods (Egyptian, Greek, or Roman glasses), as well as modern glass, can be classified as soda-lime-silica glasses. In contrast, potash was used as a flux in medieval Northern Europe for the production of window panes for churches and cathedrals. The particular chemical composition of these potash-lime-silica glasses (low in silica and rich in alkali and alkaline earth components), in combination with increased levels of acidifying gases (such as SO(2), CO(2), NO(x), or O(3)) and airborne particulate matter in today's urban or industrial atmospheres, has resulted in severe degradation of important cultural relics, particularly over the last century. Rapid developments in the fields of microelectronics and computer sciences, however, have contributed to the development of a variety of nondestructive, surface analytical techniques for the scientific investigation and material characterization of these unique and valuable objects. These methods include scanning electron microscopy in combination with energy- or wavelength-dispersive spectrometry (SEM/EDX or SEM/WDX), secondary ion mass spectrometry (SIMS), and atomic force microscopy (AFM). In this Account, we address glass analysis and weathering mechanisms, exploring the possibilities (and limitations) of modern analytical techniques. Corrosion by liquid substances is well investigated in the glass literature. In a tremendous number of case studies, the basic reaction between aqueous solutions and the glass surfaces was identified as an ion-exchange reaction between hydrogen-bearing species of the attacking liquid and the alkali and alkaline earth ions in the glass, causing a depletion of the latter in the outermost surface layers. Although mechanistic analogies to liquid corrosion are obvious, atmospheric
Quantitative determination of the intensities of known components in spectra obtained from surface analytical techniques

International Nuclear Information System (INIS)

Nelson, G.C.

1984-01-01

Linear least-squares methods have been used to quantitatively decompose experimental data obtained from surface analytical techniques into its separate components. The mathematical procedure for accomplishing this is described and examples are given of the use of this method with data obtained from Auger electron spectroscopy [both N(E) and derivative], x-ray photoelectron spectroscopy, and low energy ion scattering spectroscopy. The requirements on the quality of the data are discussed
Surface analytical techniques applied to minerals processing

International Nuclear Information System (INIS)

Smart, R.St.C.

1991-01-01

An understanding of the chemical and physical forms of the chemically altered layers on the surfaces of base metal sulphides, particularly in the form of hydroxides, oxyhydroxides and oxides, and the changes that occur in them during minerals processing lies at the core of a complete description of flotation chemistry. This paper reviews the application of a variety of surface-sensitive techniques and methodologies applied to the study of surface layers on single minerals, mixed minerals, synthetic ores and real ores. Evidence from combined XPS/SAM/SEM studies have provided images and analyses of three forms of oxide, oxyhydroxide and hydroxide products on the surfaces of single sulphide minerals, mineral mixtures and complex sulphide ores. 4 refs., 2 tabs., 4 figs
Hyphenated analytical techniques for materials characterisation

International Nuclear Information System (INIS)

Armstrong, Gordon; Kailas, Lekshmi

2017-01-01

This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the
Hyphenated analytical techniques for materials characterisation

Science.gov (United States)

Armstrong, Gordon; Kailas, Lekshmi

2017-09-01

This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the
Surface enhanced raman spectroscopy analytical, biophysical and life science applications

CERN Document Server

Schlücker, Sebastian

2013-01-01

Covering everything from the basic theoretical and practical knowledge to new exciting developments in the field with a focus on analytical and life science applications, this monograph shows how to apply surface-enhanced Raman scattering (SERS) for solving real world problems. From the contents: * Theory and practice of SERS * Analytical applications * SERS combined with other analytical techniques * Biophysical applications * Life science applications including various microscopies Aimed at analytical, surface and medicinal chemists, spectroscopists, biophysicists and materials scientists. Includes a Foreword by the renowned Raman spectroscopist Professor Wolfgang Kiefer, the former Editor-in-Chief of the Journal of Raman Spectroscopy.
Nuclear techniques in analytical chemistry

CERN Document Server

Moses, Alfred J; Gordon, L

1964-01-01

Nuclear Techniques in Analytical Chemistry discusses highly sensitive nuclear techniques that determine the micro- and macro-amounts or trace elements of materials. With the increasingly frequent demand for the chemical determination of trace amounts of elements in materials, the analytical chemist had to search for more sensitive methods of analysis. This book accustoms analytical chemists with nuclear techniques that possess the desired sensitivity and applicability at trace levels. The topics covered include safe handling of radioactivity; measurement of natural radioactivity; and neutron a
Encyclopedia of analytical surfaces

CERN Document Server

Krivoshapko, S N

2015-01-01

This encyclopedia presents an all-embracing collection of analytical surface classes. It provides concise definitions and description for more than 500 surfaces and categorizes them in 38 classes of analytical surfaces. All classes are cross references to the original literature in an excellent bibliography. The encyclopedia is of particular interest to structural and civil engineers and serves as valuable reference for mathematicians.
Analysis and analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Batuecas Rodriguez, T [Department of Chemistry and Isotopes, Junta de Energia Nuclear, Madrid (Spain)

1967-01-01

The technology associated with the use of organic coolants in nuclear reactors depends to a large extent on the determination and control of their physical and chemical properties, and particularly on the viability, speed, sensitivity, precision and accuracy (depending on the intended usage) of the methods employed in detection and analytical determination. This has led to the study and development of numerous techniques, some specially designed for the extreme conditions involved in working with the types of product in question and others adapted from existing techniques. In the specific case of polyphenyl and hydropolyphenyl mixtures, which have been the principal subjects of study to date and offer greatest promise, the analytical problems are broadly as follows: Composition of initial product or virgin coolant composition of macro components and amounts of organic and inorganic impurities; Coolant during and after operation. Determination of gases and organic compounds produced by pyrolysis and radiolysis (degradation and polymerization products); Control of systems for purifying and regenerating the coolant after use. Dissolved pressurization gases; Detection of intermediate products during decomposition; these are generally very unstable (free radicals); Degree of fouling and film formation. Tests to determine potential formation of films; Corrosion of structural elements and canning materials; Health and safety. Toxicity, inflammability and impurities that can be activated. Although some of the above problems are closely interrelated and entail similar techniques, they vary as to degree of difficulty. Another question is the difficulty of distinguishing clearly between techniques for determining physical and physico-chemical properties, on one hand, and analytical techniques on the other. Any classification is therefore somewhat arbitrary (for example, in the case of dosimetry and techniques for determining mean molecular weights or electrical conductivity
Analytical system availability techniques

NARCIS (Netherlands)

Brouwers, J.J.H.; Verbeek, P.H.J.; Thomson, W.R.

1987-01-01

Analytical techniques are presented to assess the probability distributions and related statistical parameters of loss of production from equipment networks subject to random failures and repairs. The techniques are based on a theoretical model for system availability, which was further developed
Analytical characterization using surface-enhanced Raman scattering (SERS) and microfluidic sampling

International Nuclear Information System (INIS)

Wang, Chao; Yu, Chenxu

2015-01-01

With the rapid development of analytical techniques, it has become much easier to detect chemical and biological analytes, even at very low detection limits. In recent years, techniques based on vibrational spectroscopy, such as surface enhanced Raman spectroscopy (SERS), have been developed for non-destructive detection of pathogenic microorganisms. SERS is a highly sensitive analytical tool that can be used to characterize chemical and biological analytes interacting with SERS-active substrates. However, it has always been a challenge to obtain consistent and reproducible SERS spectroscopic results at complicated experimental conditions. Microfluidics, a tool for highly precise manipulation of small volume liquid samples, can be used to overcome the major drawbacks of SERS-based techniques. High reproducibility of SERS measurement could be obtained in continuous flow generated inside microfluidic devices. This article provides a thorough review of the principles, concepts and methods of SERS-microfluidic platforms, and the applications of such platforms in trace analysis of chemical and biological analytes. (topical review)
Surface analytical investigations at Sandia Labs./Albuquerque

International Nuclear Information System (INIS)

Madden, H.H.

1978-01-01

An overview is given of some projects which (1) have used surface analytical techniques in a conventional way to investigate specific surface-related problems; (2) have utilized surface studies to get a more fundamental understanding of the operations of various devices and components, and of the factors that determine such parameters as the lifetime and reliability of such devices; and (3) have been undertaken to better understand just what additional information can be extracted from two of the myriad surface analytical techniques, Auger electron spectroscopy (AES) and electron-stimulated desorption (ESD). The examples in the first two categories are directly related weapons work while the examples discussed in the third category provide more general support to weapons programs. Only work in the first category is tabulated. Two examples of work in the second category are the neutron generator project and the design and production of integrated circuits (IC). Tritide-film targets in neutron generator tubes lose their efficiency for neutron production when they have adsorbed surface contaminants such as oxygen. Ion microprobe analysis has been applied to the study of contaminants on and in these films; and thermal desorption spectroscopy has been used to identify, and to determine the binding energy of gases evolved during outgassing of materials used in tube construction. Long-term outgassing determines the lifetime of the vacuum tubes. AES serves as the common thread in the third category projects. Gas phase, core-valence-valence (CVV) Auger lines have been measured in a systematic attempt, utilizing both theory and experimental results, to determine the factors that influence the shapes of the lines. This work demonstrates the local nature of the information on the energy distribution of valence levels contained in the Auger lineshapes
Advanced analytical techniques

International Nuclear Information System (INIS)

Mrochek, J.E.; Shumate, S.E.; Genung, R.K.; Bahner, C.T.; Lee, N.E.; Dinsmore, S.R.

1976-01-01

The development of several new analytical techniques for use in clinical diagnosis and biomedical research is reported. These include: high-resolution liquid chromatographic systems for the early detection of pathological molecular constituents in physiologic body fluids; gradient elution chromatography for the analysis of protein-bound carbohydrates in blood serum samples, with emphasis on changes in sera from breast cancer patients; electrophoretic separation techniques coupled with staining of specific proteins in cellular isoenzymes for the monitoring of genetic mutations and abnormal molecular constituents in blood samples; and the development of a centrifugal elution chromatographic technique for the assay of specific proteins and immunoglobulins in human blood serum samples
Analytical detection techniques for droplet microfluidics—A review

International Nuclear Information System (INIS)

Zhu, Ying; Fang, Qun

2013-01-01

Graphical abstract: -- Highlights: •This is the first review paper focused on the analytical techniques for droplet-based microfluidics. •We summarized the analytical methods used in droplet-based microfluidic systems. •We discussed the advantage and disadvantage of each method through its application. •We also discuss the future development direction of analytical methods for droplet-based microfluidic systems. -- Abstract: In the last decade, droplet-based microfluidics has undergone rapid progress in the fields of single-cell analysis, digital PCR, protein crystallization and high throughput screening. It has been proved to be a promising platform for performing chemical and biological experiments with ultra-small volumes (picoliter to nanoliter) and ultra-high throughput. The ability to analyze the content in droplet qualitatively and quantitatively is playing an increasing role in the development and application of droplet-based microfluidic systems. In this review, we summarized the analytical detection techniques used in droplet systems and discussed the advantage and disadvantage of each technique through its application. The analytical techniques mentioned in this paper include bright-field microscopy, fluorescence microscopy, laser induced fluorescence, Raman spectroscopy, electrochemistry, capillary electrophoresis, mass spectrometry, nuclear magnetic resonance spectroscopy, absorption detection, chemiluminescence, and sample pretreatment techniques. The importance of analytical detection techniques in enabling new applications is highlighted. We also discuss the future development direction of analytical detection techniques for droplet-based microfluidic systems
Fermi surface mapping: Techniques and visualization

International Nuclear Information System (INIS)

Rotenberg, E.; Denlinger, J.D.; Kevan, S.D.

1997-01-01

Angle-resolved photoemission (ARP) of valence bands is a mature technique that has achieved spectacular success in band-mapping metals, semiconductors, and insulators. The purpose of the present study was the development of experimental and analytical techniques in ARP which take advantage of third generation light sources. Here the authors studied the relatively simple Cu surface in preparation for other metals. Copper and related metals themselves are of current interest, especially due to its role as an interlayer in spin valves and other magnetic heterostructures. A major goal of this study was the development of a systematic technique to quickly (i.e. in a few hours of synchrotron beamtime) measure the FS and separate it into bulk and surface FS's. Often, one needs to avoid bulk features altogether, which one can achieve by carefully mapping their locations in k-space. The authors will also show how they systematically map Fermi surfaces throughout large volumes of k-space, and, by processing the resulting volume data sets, provide intuitive pictures of FS's, both bulk and surface
Analytical models for the rewetting of hot surfaces

International Nuclear Information System (INIS)

Olek, S.

1988-10-01

Some aspects concerning analytical models for the rewetting of hot surface are discussed. These include the problems with applying various forms of boundary conditions, compatibility of boundary conditions with the physics of the rewetting problems, recent analytical models, the use of the separation of variables method versus the Wiener-Hopf technique, and the use of transformations. The report includes an updated list of rewetting models as well as benchmark solutions in tabular form for several models. It should be emphasized that this report is not meant to cover the topic of rewetting models. It merely discusses some points which are less commonly referred to in the literature. 93 refs., 3 figs., 22 tabs

Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

Science.gov (United States)

Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y

2017-01-01

Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.
Semi-analytic techniques for calculating bubble wall profiles

International Nuclear Information System (INIS)

Akula, Sujeet; Balazs, Csaba; White, Graham A.

2016-01-01

We present semi-analytic techniques for finding bubble wall profiles during first order phase transitions with multiple scalar fields. Our method involves reducing the problem to an equation with a single field, finding an approximate analytic solution and perturbing around it. The perturbations can be written in a semi-analytic form. We assert that our technique lacks convergence problems and demonstrate the speed of convergence on an example potential. (orig.)
Low energy ion beam systems for surface analytical and structural studies

International Nuclear Information System (INIS)

Nelson, G.C.

1980-01-01

This paper reviews the use of low energy ion beam systems for surface analytical and structural studies. Areas where analytical methods which utilize ion beams can provide a unique insight into materials problems are discussed. The design criteria of ion beam systems for performing materials studies are described and the systems now being used by a number of laboratories are reviewed. Finally, several specific problems are described where the solution was provided at least in part by information provided by low energy ion analysis techniques
Tablet surface characterisation by various imaging techniques

DEFF Research Database (Denmark)

Seitavuopio, Paulus; Rantanen, Jukka; Yliruusi, Jouko

2003-01-01

The aim of this study was to characterise tablet surfaces using different imaging and roughness analytical techniques including optical microscopy, scanning electron microscopy (SEM), laser profilometry and atomic force microscopy (AFM). The test materials compressed were potassium chloride (KCl......) and sodium chloride (NaCl). It was found that all methods used suggested that the KCl tablets were smoother than the NaCl tablets and higher compression pressure made the tablets smoother. Imaging methods like optical microscopy and SEM can give useful information about the roughness of the sample surface...
Reference materials for micro-analytical nuclear techniques

International Nuclear Information System (INIS)

Valkovic, V.; Zeisler, R.; Bernasconi, G.; Danesi, P.R.

1994-01-01

Direct application of many existing reference materials in micro-analytical procedures such as energy dispersive x-ray fluorescence (EDXRF), particle induced x-ray emission spectroscopy (PIXE) and ion probe techniques for the determination of trace elements is often impossible or difficult because: 1) other constituents present in large amounts interfere with the determination; 2) trace components are not sufficiently homogeneously distributed in the sample. Therefore specific natural-matrix reference materials containing very low levels of trace elements and having high degree of homogeneity are required for many micro-analytical procedures. In this report, selection of the types of environmental and biological materials which are suitable for micro-analytical techniques will be discussed. (author)
Analytical research using synchrotron radiation based techniques

International Nuclear Information System (INIS)

Jha, Shambhu Nath

2015-01-01

There are many Synchrotron Radiation (SR) based techniques such as X-ray Absorption Spectroscopy (XAS), X-ray Fluorescence Analysis (XRF), SR-Fourier-transform Infrared (SRFTIR), Hard X-ray Photoelectron Spectroscopy (HAXPS) etc. which are increasingly being employed worldwide in analytical research. With advent of modern synchrotron sources these analytical techniques have been further revitalized and paved ways for new techniques such as microprobe XRF and XAS, FTIR microscopy, Hard X-ray Photoelectron Spectroscopy (HAXPS) etc. The talk will cover mainly two techniques illustrating its capability in analytical research namely XRF and XAS. XRF spectroscopy: XRF spectroscopy is an analytical technique which involves the detection of emitted characteristic X-rays following excitation of the elements within the sample. While electron, particle (protons or alpha particles), or X-ray beams can be employed as the exciting source for this analysis, the use of X-ray beams from a synchrotron source has been instrumental in the advancement of the technique in the area of microprobe XRF imaging and trace level compositional characterisation of any sample. Synchrotron radiation induced X-ray emission spectroscopy, has become competitive with the earlier microprobe and nanoprobe techniques following the advancements in manipulating and detecting these X-rays. There are two important features that contribute to the superb elemental sensitivities of microprobe SR induced XRF: (i) the absence of the continuum (Bremsstrahlung) background radiation that is a feature of spectra obtained from charged particle beams, and (ii) the increased X-ray flux on the sample associated with the use of tunable third generation synchrotron facilities. Detection sensitivities have been reported in the ppb range, with values of 10 -17 g - 10 -14 g (depending on the particular element and matrix). Keeping in mind its demand, a microprobe XRF beamline has been setup by RRCAT at Indus-2 synchrotron
Characterization of thin films and surfaces by ion-beam analytical techniques

International Nuclear Information System (INIS)

Pelicon, P.; Budnar, M.; Zorko, B.; Razpet, A.

1999-01-01

The optimization of Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) at the tandetron facility of J. Stefan Inst.e is reported. The most recent applications of these techniques for the analysis of thin films and surfaces are presented. The construction of the isotope - resolved Time-Of-Flight ERDA telescope for depth profiling of light elements is reviewed.(author)
Trends in analytical techniques applied to particulate matter characterization: A critical review of fundaments and applications.

Science.gov (United States)

Galvão, Elson Silva; Santos, Jane Meri; Lima, Ana Teresa; Reis, Neyval Costa; Orlando, Marcos Tadeu D'Azeredo; Stuetz, Richard Michael

2018-05-01

Epidemiological studies have shown the association of airborne particulate matter (PM) size and chemical composition with health problems affecting the cardiorespiratory and central nervous systems. PM also act as cloud condensation nuclei (CNN) or ice nuclei (IN), taking part in the clouds formation process, and therefore can impact the climate. There are several works using different analytical techniques in PM chemical and physical characterization to supply information to source apportionment models that help environmental agencies to assess damages accountability. Despite the numerous analytical techniques described in the literature available for PM characterization, laboratories are normally limited to the in-house available techniques, which raises the question if a given technique is suitable for the purpose of a specific experimental work. The aim of this work consists of summarizing the main available technologies for PM characterization, serving as a guide for readers to find the most appropriate technique(s) for their investigation. Elemental analysis techniques like atomic spectrometry based and X-ray based techniques, organic and carbonaceous techniques and surface analysis techniques are discussed, illustrating their main features as well as their advantages and drawbacks. We also discuss the trends in analytical techniques used over the last two decades. The choice among all techniques is a function of a number of parameters such as: the relevant particles physical properties, sampling and measuring time, access to available facilities and the costs associated to equipment acquisition, among other considerations. An analytical guide map is presented as a guideline for choosing the most appropriated technique for a given analytical information required. Copyright © 2018 Elsevier Ltd. All rights reserved.
Nuclear techniques for bulk and surface analysis of materials

International Nuclear Information System (INIS)

D'Agostino, M.D.; Kamykowski, E.A.; Kuehne, F.J.; Padawer, G.M.; Schneid, E.J.; Schulte, R.L.; Stauber, M.C.; Swanson, F.R.

1978-01-01

A review is presented summarizing several nondestructive bulk and surface analysis nuclear techniques developed in the Grumman Research Laboratories. Bulk analysis techniques include 14-MeV-neutron activation analysis and accelerator-based neutron radiography. The surface analysis techniques include resonant and non-resonant nuclear microprobes for the depth profile analysis of light elements (H, He, Li, Be, C, N, O and F) in the surface of materials. Emphasis is placed on the description and discussion of the unique nuclear microprobe analytical capacibilities of immediate importance to a number of current problems facing materials specialists. The resolution and contrast of neutron radiography was illustrated with an operating heat pipe system. The figure shows that the neutron radiograph has a resolution of better than 0.04 cm with sufficient contrast to indicate Freon 21 on the inner capillaries of the heat pipe and pooling of the liquid at the bottom. (T.G.)
Surface analysis and techniques in biology

CERN Document Server

Smentkowski, Vincent S

2014-01-01

This book highlights state-of-the-art surface analytical instrumentation, advanced data analysis tools, and the use of complimentary surface analytical instrumentation to perform a complete analysis of biological systems.
Analytical techniques for thin films treatise on materials science and technology

CERN Document Server

Tu, K N

1988-01-01

Treatise on Materials Science and Technology, Volume 27: Analytical Techniques for Thin Films covers a set of analytical techniques developed for thin films and interfaces, all based on scattering and excitation phenomena and theories. The book discusses photon beam and X-ray techniques; electron beam techniques; and ion beam techniques. Materials scientists, materials engineers, chemical engineers, and physicists will find the book invaluable.
Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

Science.gov (United States)

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-03-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.
Applied predictive analytics principles and techniques for the professional data analyst

CERN Document Server

Abbott, Dean

2014-01-01

Learn the art and science of predictive analytics - techniques that get results Predictive analytics is what translates big data into meaningful, usable business information. Written by a leading expert in the field, this guide examines the science of the underlying algorithms as well as the principles and best practices that govern the art of predictive analytics. It clearly explains the theory behind predictive analytics, teaches the methods, principles, and techniques for conducting predictive analytics projects, and offers tips and tricks that are essential for successful predictive mode
Advanced analytical techniques for boiling water reactor chemistry control

Energy Technology Data Exchange (ETDEWEB)

Alder, H P; Schenker, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-02-01

The analytical techniques applied can be divided into 5 classes: OFF-LINE (discontinuous, central lab), AT-LINE (discontinuous, analysis near loop), ON-LINE (continuous, analysis in bypass). In all cases pressure and temperature of the water sample are reduced. In a strict sense only IN-LINE (continuous, flow disturbance) and NON-INVASIVE (continuous, no flow disturbance) techniques are suitable for direct process control; - the ultimate goal. An overview of the analytical techniques tested in the pilot loop is given. Apart from process and overall water quality control, standard for BWR operation, the main emphasis is on water impurity characterization (crud particles, hot filtration, organic carbon); on stress corrosion crackling control for materials (corrosion potential, oxygen concentration) and on the characterization of the oxide layer on austenites (impedance spectroscopy, IR-reflection). The above mentioned examples of advanced analytical techniques have the potential of in-line or non-invasive application. They are different stages of development and are described in more detail. 28 refs, 1 fig., 5 tabs.
Application of on-line analytical processing technique in accelerator

International Nuclear Information System (INIS)

Xie Dong; Li Weimin; He Duohui; Liu Gongfa; Xuan Ke

2005-01-01

A method of application of the on-line analytical processing technique in accelerator is described, which includes data pre-processing, the process of constructing of data warehouse and on-line analytical processing. (authors)
Nuclear forensics: strategies and analytical techniques

International Nuclear Information System (INIS)

Marin, Rafael C.; Sarkis, Jorge E.S.; Pestana, Rafael C.B.

2013-01-01

The development of nuclear forensics as a field of science arose in response to international demand for methods to investigate the illicit trafficking of nuclear materials. After being seized, unknown nuclear material is collected and analyzed by a set of analytical methods. The fingerprints of these materials can be identified and further used during the investigations. Data interpretation is an extensive process aiming to validate the hypotheses made by the experts, and can help confirm the origin of seized nuclear materials at the end of the process or investigation. This work presents the set of measures and analytical methods that have been inherited by nuclear forensics from several fields of science. The main characteristics of these methods are evaluated and the analytical techniques employed to determine the fingerprint of nuclear materials are described. (author)
Analytical chemistry: Principles and techniques

International Nuclear Information System (INIS)

Hargis, L.G.

1988-01-01

Although this text seems to have been intended for use in a one-semester course in undergraduate analytical chemistry, it includes the range of topics usually encountered in a two-semester introductory course in chemical analysis. The material is arranged logically for use in a two-semester course: the first 12 chapters contain the subjects most often covered in the first term, and the next 10 chapters pertain to the second (instrumental) term. Overall breadth and level of treatment are standards for an undergraduate text of this sort, and the only major omission is that of kinetic methods (which is a common omission in analytical texts). In the first 12 chapters coverage of the basic material is quite good. The emphasis on the underlying principles of the techniques rather than on specifics and design of instrumentation is welcomed. This text may be more useful for the instrumental portion of an analytical chemistry course than for the solution chemistry segment. The instrumental analysis portion is appropriate for an introductory textbook
Studies on Pt–Mo phases using analytical techniques with high resolution

Energy Technology Data Exchange (ETDEWEB)

Topic, M., E-mail: mtopic@tlabs.ac.za [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Khumalo, Z. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); University of Cape Town, Physics Department, Private Bag X3, Rondebosch 7701 (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, CPUT, Belville (South Africa)

2014-01-01

Pt–Mo coated system annealed at 1050 °C for 24 h was investigated using several analytical techniques with high resolution (SEM/EDX, μ-PIXE, RBS and XRD). These techniques provide structural and compositional data throughout the material depth and probing area. The results depend on the applied beam, its energy and size. They contribute to a better understanding of thermal annealing effects on the solid-state phase transformation and morphological changes in Pt–Mo coatings. The results indicate the presence of Pt- and Mo-solid solutions and two Pt–Mo phases (PtMo and Pt{sub 2}Mo{sub 3}), changes in the coating morphology, such as increased surface roughness and formation of “lace morphology”, as well as an increase in coating thickness.
Development of analytical techniques for safeguards environmental samples at JAEA

International Nuclear Information System (INIS)

Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, Chi-Gyu; Yasuda, Kenichiro; Inagawa, Jun; Suzuki, Daisuke; Iguchi, Kazunari; Kokubu, Yoko S.; Miyamoto, Yutaka; Ohzu, Akira

2007-01-01

JAEA has been developing, under the auspices of the Ministry of Education, Culture, Sports, Science and Technology of Japan, analytical techniques for ultra-trace amounts of nuclear materials in environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis, as well as screening, of the environmental swipe samples has been established as ultra-trace analytical methods of uranium and plutonium. In January 2003, JAEA was qualified, including its quality control system, as a member of the JAEA network analytical laboratories for environmental samples. Since 2004, JAEA has conducted the analysis of domestic and the IAEA samples, through which JAEA's analytical capability has been verified and improved. In parallel, advanced techniques have been developed in order to expand the applicability to the samples of various elemental composition and impurities and to improve analytical accuracy and efficiency. This paper summarizes the trace of the technical development in environmental sample analysis at JAEA, and refers to recent trends of research and development in this field. (author)
Activities at Forschungszentrum Juelich in Safeguards Analytical Techniques and Measurements

International Nuclear Information System (INIS)

Duerr, M.; Knott, A.; Middendorp, R.; Niemeyer, I.; Kueppers, S.; Zoriy, M.; Froning, M.; Bosbach, D.

2015-01-01

The application of safeguards by the IAEA involves analytical measurements of samples taken during inspections. The development and advancement of analytical techniques with support from the Member States contributes to strengthened and more efficient verification of compliance with non-proliferation obligations. Since recently, a cooperation agreement has been established between Forschungszentrum Juelich and the IAEA in the field of analytical services. The current working areas of Forschungszentrum Juelich are: (i) Production of synthetic micro-particles as calibration standard and reference material for particle analysis, (ii) qualification of the Forschungszentrum Juelich as a member of the IAEA network of analytical laboratories for safeguards (NWAL), and (iii) analysis of impurities in nuclear material samples. With respect to the synthesis of particles, a dedicated setup for the production of uranium particles is being developed, which addresses the urgent need for material tailored for its use in quality assurance and quality control measures for particle analysis of environmental swipe samples. Furthermore, Forschungszentrum Juelich has been nominated as a candidate laboratory for membership in the NWAL network. To this end, analytical capabilities at Forschungszentrum Juelich have been joined to form an analytical service within a dedicated quality management system. Another activity is the establishment of analytical techniques for impurity analysis of uranium-oxide, mainly focusing on inductively coupled mass spectrometry. This contribution will present the activities at Forschungszentrum Juelich in the area of analytical measurements and techniques for nuclear verification. (author)

Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

Directory of Open Access Journals (Sweden)

Yeonhee Lee

2013-05-01

Full Text Available Time-of-flight secondary ion mass spectrometry (TOF-SIMS and X-ray photoelectron spectroscopy (XPS are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric.
Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

Science.gov (United States)

Lee, Jihye; Kang, Min Hwa; Lee, Kang-Bong; Lee, Yeonhee

2013-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR) measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric. PMID:28809257
Surface science techniques

CERN Document Server

Bracco, Gianangelo

2013-01-01

The book describes the experimental techniques employed to study surfaces and interfaces. The emphasis is on the experimental method. Therefore all chapters start with an introduction of the scientific problem, the theory necessary to understand how the technique works and how to understand the results. Descriptions of real experimental setups, experimental results at different systems are given to show both the strength and the limits of the technique. In a final part the new developments and possible extensions of the techniques are presented. The included techniques provide microscopic as well as macroscopic information. They cover most of the techniques used in surface science.
Analytical Techniques and Pharmacokinetics of Gastrodia elata Blume and Its Constituents.

Science.gov (United States)

Wu, Jinyi; Wu, Bingchu; Tang, Chunlan; Zhao, Jinshun

2017-07-08

Gastrodia elata Blume ( G. elata ), commonly called Tianma in Chinese, is an important and notable traditional Chinese medicine (TCM), which has been used in China as an anticonvulsant, analgesic, sedative, anti-asthma, anti-immune drug since ancient times. The aim of this review is to provide an overview of the abundant efforts of scientists in developing analytical techniques and performing pharmacokinetic studies of G. elata and its constituents, including sample pretreatment methods, analytical techniques, absorption, distribution, metabolism, excretion (ADME) and influence factors to its pharmacokinetics. Based on the reported pharmacokinetic property data of G. elata and its constituents, it is hoped that more studies will focus on the development of rapid and sensitive analytical techniques, discovering new therapeutic uses and understanding the specific in vivo mechanisms of action of G. elata and its constituents from the pharmacokinetic viewpoint in the near future. The present review discusses analytical techniques and pharmacokinetics of G. elata and its constituents reported from 1985 onwards.
Role of thermo-analytical techniques in compositional characterization of nuclear materials

International Nuclear Information System (INIS)

Raje, Naina

2015-01-01

The study of heat effects on different materials has a long history. Extraction of metals from the ores, pottery production, glasses making etc. are the examples, where the performance of products obtained from raw materials depends on the processing temperatures. Concrete, pottery, bricks etc., are severely damaged due to uncontrolled high temperatures. Therefore, the heating of raw materials in controlled manner is of pivotal importance to get products of the desired quality. Thermo-analytical techniques provide the information on the effect of heat under controlled heating conditions. In thermo-analytical techniques, physical properties of materials are measured as a function of temperature. Simultaneous thermo-analytical techniques are beneficial in comparison to any single thermo-analytical technique. Simultaneous techniques refer to the measurement of two or more signals on the same sample at the same time in the same instrument. Nowadays, simultaneous thermo-analytical technique are extensively in use for the analysis of materials. Ammonium diuranate (ADU) and magnesium diuranate (MDU), also known as yellowcake, are intermediate precursors in fuel fabrication process, with stringent specifications along with the need to understand its thermal behavior. In the processing of lowgrade ores, higher levels of impurities are being encountered in the leach solution that affects the properties of ADU/MDU. In order to meet the fuel specifications, quality assurance of these nuclear materials is essential. Current studies describe the application of simultaneous Thermogravimetry (TG) - differential thermal analysis (DTA) - evolved gas analysis (EGA) techniques for the compositional characterization of ADU/MDU with respect to the impurities present in the matrices
Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

OpenAIRE

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-01-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The rev...
Analytical vs. Simulation Solution Techniques for Pulse Problems in Non-linear Stochastic Dynamics

DEFF Research Database (Denmark)

Iwankiewicz, R.; Nielsen, Søren R. K.

Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically-numerical tec......Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically...
Statistical evaluation of recorded knowledge in nuclear and other instrumental analytical techniques

International Nuclear Information System (INIS)

Braun, T.

1987-01-01

The main points addressed in this study are the following: Statistical distribution patterns of published literature on instrumental analytical techniques 1981-1984; structure of scientific literature and heuristics for identifying active specialities and emerging hot spot research areas in instrumental analytical techniques; growth and growth rates of the literature in some of the identified hot research areas; quality and quantity in instrumental analytical research output. (orig.)
Analytic vortex solutions on compact hyperbolic surfaces

International Nuclear Information System (INIS)

Maldonado, Rafael; Manton, Nicholas S

2015-01-01

We construct, for the first time, abelian Higgs vortices on certain compact surfaces of constant negative curvature. Such surfaces are represented by a tessellation of the hyperbolic plane by regular polygons. The Higgs field is given implicitly in terms of Schwarz triangle functions and analytic solutions are available for certain highly symmetric configurations. (paper)
An analytical simulation technique for cone-beam CT and pinhole SPECT

International Nuclear Information System (INIS)

Zhang Xuezhu; Qi Yujin

2011-01-01

This study was aimed at developing an efficient simulation technique with an ordinary PC. The work involved derivation of mathematical operators, analytic phantom generations, and effective analytical projectors developing for cone-beam CT and pinhole SPECT imaging. The computer simulations based on the analytical projectors were developed by ray-tracing method for cone-beam CT and voxel-driven method for pinhole SPECT of degrading blurring. The 3D Shepp-Logan, Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions. The reconstructed phantom images were of good accuracy with the phantoms. The results showed that the analytical simulation technique is an efficient tool for studying cone-beam CT and pinhole SPECT imaging. (authors)
Appendix 1: Analytical Techniques (Online supplementary material ...

Indian Academy of Sciences (India)

HP

Further details of analytical techniques are given in http://www.actlabs.com. Zircon U–Pb dating and trace element analysis. The zircons were separated using standard procedures including crushing (in iron mortar and pestle), sieving (375 to 75 micron), tabling, heavy liquid separation (bromoform and methylene iodide) ...
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
Industrial and environmental applications of nuclear analytical techniques. Report of a workshop

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-01

The IAEA has programme the utilisation of nuclear analytical techniques (NATs), in particular for industrial and environmental applications. A major purpose is to help the developing Member States apply their analytical capabilities optimally for socio-economic progress and development. A large number of institutions in Europe, Africa, Latin America and Asia have established X ray fluorescence (XRF) and gamma ray measurement techniques and facilities for neutron activation analysis (NAA) have been initiated in institutions in these regions. Moreover, there is a growing interest among many institutes in applying more advanced analytical techniques, such as particle induced X ray emission (PIXE) and microanalytical techniques based on X ray emission induced by conventional sources or synchrotron radiation to the analysis of environmental and biological materials and industrial products. In order to define new areas of application of NATs and to extend the range of these techniques, a number of initiatives have recently been taken. It includes a workshop on industrial and environmental applications of nuclear analytical techniques, organized by the IAEA in Vienna, 7-11 September 1998. The main objectives of the workshop were as follows: (1) to review recent applications of NATs in industrial and environmental studies; (2) to identify emerging trends in methodologies and applications of NATs; (3) to demonstrate analytical capabilities of selected NATs. The following topics were reviewed during the workshop: (1) XRF and accelerator based analytical techniques; (2) portable XRF systems and their applications in industry, mineral prospecting and processing, (3) portable gamma ray spectrometers; and (4) NAA and its applications in industry and environmental studies. Micro-XRF and micro-PIXE methods and their applications in the above fields were also discussed, including aspects of synchrotron radiation induced X ray emission.
Industrial and environmental applications of nuclear analytical techniques. Report of a workshop

International Nuclear Information System (INIS)

1999-11-01

The IAEA has programme the utilisation of nuclear analytical techniques (NATs), in particular for industrial and environmental applications. A major purpose is to help the developing Member States apply their analytical capabilities optimally for socio-economic progress and development. A large number of institutions in Europe, Africa, Latin America and Asia have established X ray fluorescence (XRF) and gamma ray measurement techniques and facilities for neutron activation analysis (NAA) have been initiated in institutions in these regions. Moreover, there is a growing interest among many institutes in applying more advanced analytical techniques, such as particle induced X ray emission (PIXE) and microanalytical techniques based on X ray emission induced by conventional sources or synchrotron radiation to the analysis of environmental and biological materials and industrial products. In order to define new areas of application of NATs and to extend the range of these techniques, a number of initiatives have recently been taken. It includes a workshop on industrial and environmental applications of nuclear analytical techniques, organized by the IAEA in Vienna, 7-11 September 1998. The main objectives of the workshop were as follows: (1) to review recent applications of NATs in industrial and environmental studies; (2) to identify emerging trends in methodologies and applications of NATs; (3) to demonstrate analytical capabilities of selected NATs. The following topics were reviewed during the workshop: (1) XRF and accelerator based analytical techniques; (2) portable XRF systems and their applications in industry, mineral prospecting and processing, (3) portable gamma ray spectrometers; and (4) NAA and its applications in industry and environmental studies. Micro-XRF and micro-PIXE methods and their applications in the above fields were also discussed, including aspects of synchrotron radiation induced X ray emission
Real-time analytics techniques to analyze and visualize streaming data

CERN Document Server

Ellis, Byron

2014-01-01

Construct a robust end-to-end solution for analyzing and visualizing streaming data Real-time analytics is the hottest topic in data analytics today. In Real-Time Analytics: Techniques to Analyze and Visualize Streaming Data, expert Byron Ellis teaches data analysts technologies to build an effective real-time analytics platform. This platform can then be used to make sense of the constantly changing data that is beginning to outpace traditional batch-based analysis platforms. The author is among a very few leading experts in the field. He has a prestigious background in research, development,
Surface science techniques

CERN Document Server

Walls, JM

2013-01-01

This volume provides a comprehensive and up to the minute review of the techniques used to determine the nature and composition of surfaces. Originally published as a special issue of the Pergamon journal Vacuum, it comprises a carefully edited collection of chapters written by specialists in each of the techniques and includes coverage of the electron and ion spectroscopies, as well as the atom-imaging methods such as the atom probe field ion microscope and the scanning tunnelling microscope. Surface science is an important area of study since the outermost surface layers play a crucial role
Nuclear analytical techniques in medicine

International Nuclear Information System (INIS)

Cesareo, R.

1988-01-01

This book acquaints one with the fundamental principles and the instrumentation relevant to analytical technique based on atomic and nuclear physics, as well as present and future biomedical applications. Besides providing a theoretical description of the physical phenomena, a large part of the book is devoted to applications in the medical and biological field, particularly in hematology, forensic medicine and environmental science. This volume reviews methods such as the possibility of carrying out rapid multi-element analysis of trace elements on biomedical samples, in vitro and in vivo, by XRF-analysis; the ability of the PIXE-microprobe to analyze in detail and to map trace elements in fragments of biomedical samples or inside the cells; the potentiality of in vivo nuclear activation analysis for diagnostic purposes. Finally, techniques are described such as radiation scattering (elastic and inelastic scattering) and attenuation measurements which will undoubtedly see great development in the immediate future
Nuclear analytical techniques in medicine

Energy Technology Data Exchange (ETDEWEB)

Cesareo, R.

1988-01-01

This book acquaints one with the fundamental principles and the instrumentation relevant to analytical technique based on atomic and nuclear physics, as well as present and future biomedical applications. Besides providing a theoretical description of the physical phenomena, a large part of the book is devoted to applications in the medical and biological field, particularly in hematology, forensic medicine and environmental science. This volume reviews methods such as the possibility of carrying out rapid multi-element analysis of trace elements on biomedical samples, in vitro and in vivo, by XRF-analysis; the ability of the PIXE-microprobe to analyze in detail and to map trace elements in fragments of biomedical samples or inside the cells; the potentiality of in vivo nuclear activation analysis for diagnostic purposes. Finally, techniques are described such as radiation scattering (elastic and inelastic scattering) and attenuation measurements which will undoubtedly see great development in the immediate future.
Analytical fitting model for rough-surface BRDF.

Science.gov (United States)

Renhorn, Ingmar G E; Boreman, Glenn D

2008-08-18

A physics-based model is developed for rough surface BRDF, taking into account angles of incidence and scattering, effective index, surface autocovariance, and correlation length. Shadowing is introduced on surface correlation length and reflectance. Separate terms are included for surface scatter, bulk scatter and retroreflection. Using the FindFit function in Mathematica, the functional form is fitted to BRDF measurements over a wide range of incident angles. The model has fourteen fitting parameters; once these are fixed, the model accurately describes scattering data over two orders of magnitude in BRDF without further adjustment. The resulting analytical model is convenient for numerical computations.
ARPEFS as an analytic technique

International Nuclear Information System (INIS)

Schach von Wittenau, A.E.

1991-04-01

Two modifications to the ARPEFS technique are introduced. These are studied using p(2 x 2)S/Cu(001) as a model system. The first modification is the obtaining of ARPEFS χ(k) curves at temperatures as low as our equipment will permit. While adding to the difficulty of the experiment, this modification is shown to almost double the signal-to-noise ratio of normal emission p(2 x 2)S/Cu(001) χ(k) curves. This is shown by visual comparison of the raw data and by the improved precision of the extracted structural parameters. The second change is the replacement of manual fitting of the Fourier filtered χ(k) curves by the use of the simplex algorithm for parameter determination. Again using p(2 x 2)S/Cu(001) data, this is shown to result in better agreement between experimental χ(k) curves and curves calculated based on model structures. The improved ARPEFS is then applied to p(2 x 2)S/Ni(111) and (√3 x √3) R30 degree S/Ni(111). For p(2 x 2)S/Cu(001) we find a S-Cu bond length of 2.26 Angstrom, with the S adatom 1.31 Angstrom above the fourfold hollow site. The second Cu layer appears to be corrugated. Analysis of the p(2 x 2)S/Ni(111) data indicates that the S adatom adatom adsorbs onto the FCC threefold hollow site 1.53 Angstrom above the Ni surface. The S-Ni bond length is determined to be 2.13 Angstrom, indicating an outwards shift of the first layer Ni atoms. We are unable to assign a unique structure to (√3 x √3)R30 degree S/Ni(111). An analysis of the strengths and weaknesses of ARPEFS as an experimental and analytic technique is presented, along with a summary of problems still to be addressed

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.
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.
Conference on Nuclear and Conventional Analytical Techniques and their Applications

International Nuclear Information System (INIS)

2010-01-01

Full text : A panoply analytic techniques methods has emerged in recent decades due to the challenges of society in quality of products and the increasing demand of chemical analysis services. The industrial progress which came along with an instrumental perfection of devices with analytical use, led to the development of new techniques more and more advanced in this field. These come as well, to answer the disturbing effects of this industrialization and the wishes of a public increasingly conscious and requiring globally. The leaders in this field of analysis and material characterization are more than ever confronted with problems of identification and quantification of different chemical forms of a multitude of products in varied circles; Industrial pollutants, soil, water, air, food, medicines, ceramics, concrete, plants etc. It was from that perspective that the unifying theme ''geomaterials: characterization to applications '' of the conference on nuclear and conventional analytical techniques and their applications (TANCA 2010) was chosen. It contributes to the debate of these subjects and builds relationships between stakeholders in this field, both technically and practically [fr
Development of inspection techniques for quantitatively measuring surface contamination on SRM hardware

Science.gov (United States)

Law, R. D.

1989-01-01

A contaminant is any material or substance which is potentially undesirable or which may adversely affect any part, component, or assembly. Contamination control of SRM hardware surfaces is a serious concern, for both Thiokol and NASA, with particular concern for contaminants which may adversely affect bonding surfaces. The purpose of this study is to develop laboratory analytical techniques which will make it possible to certify the cleanliness of any designated surface, with special focus on particulates (dust, dirt, lint, etc.), oils (hydrocarbons, silicones, plasticizers, etc.), and greases (HD-2, fluorocarbon grease, etc.). The hardware surfaces of concern will include D6AC steel, aluminum alloys, anodized aluminum alloys, glass/phenolic, carbon/phenolic, NBR/asbestos-silica, and EPDM rubber.
Analytical Techniques and the Air Force Logistics Readiness Officer

National Research Council Canada - National Science Library

Main, Bryan D

2008-01-01

.... Over 500 LROs and supervisors provided inputs. Analysis of survey responses found that Forecasting, Graphical Statistics, and Descriptive Statistics are the analytical techniques valued most by both LROs and their supervisors...
Laser-induced plasma spectrometry: truly a surface analytical tool

International Nuclear Information System (INIS)

Vadillo, Jose M.; Laserna, J.

2004-01-01

For a long period, analytical applications of laser induced plasma spectrometry (LIPS) have been mainly restricted to overall and quantitative determination of elemental composition in bulk, solid samples. However, introduction of new compact and reliable solid state lasers and technological development in multidimensional intensified detectors have made possible the seeking of new analytical niches for LIPS where its analytical advantages (direct sampling from any material irrespective of its conductive status without sample preparation and with sensitivity adequate for many elements in different matrices) could be fully exploited. In this sense, the field of surface analysis could take advantage from the cited advantages taking into account in addition, the capability of LIPS for spot analysis, line scan, depth-profiling, area analysis and compositional mapping with a single instrument in air at atmospheric pressure. This review paper outlines the fundamental principles of laser-induced plasma emission relevant to sample surface studies, discusses the experimental parameters governing the spatial (lateral and in-depth) resolution in LIPS analysis and presents the applications concerning surface examination
Nuclear analytical techniques with neutron beams at the Univ. of Texas at Austin

International Nuclear Information System (INIS)

Uenlue, K.; Wehring, B.W.

1996-01-01

Neutron beams produced by nuclear research reactors can be used for analytical chemical analysis by measuring nuclear radiation produced by neutron capture. Prompt gamma activation analysis (PGAA) and neutron depth profiling (NDP) are two such analytical techniques. For the last three decades, these techniques have been applied at a number of research reactors around the world. Within the last 4 yr, we have developed NDP and PGAA facilities at The University of Texas at Austin research reactor, a 1-MW TRIGA Mark II reactor. Brief descriptions of the facilities and summaries of activities for these analytical techniques at the University of Texas at Austin are provided in this paper
SNMS/SIMS. A new surface analytical device in ATOMKI

International Nuclear Information System (INIS)

Berenyi, Z.; Vad, K.; Katona, G.L.; Koever, A.

2004-01-01

Complete text of publication follows. A Secondary Neutral Mass Spectrometer (SNMS) was installed in the institute in 2004. The aim of the investment was to complement the surface analytical methods of the Section of Electron Spectroscopy and Materials Sciences of ATOMKI (eg. preparation, characterization and depth profiling of thin layer and thin multilayer samples) as well as to establish a new surface analytical technique in the institute to be offered for other internal and external users. This equipment is the first SNMS apparatus in Hungary. The device is capable to measure the elemental composition of the surface region (i.e. the topmost 1 μm) of conductor, semiconductor and insulator surfaces with a unique in-depth resolution of some nanometers. As an example figure 1. shows a measured depth profile of a Ru-Co multilayer sample, consisting of 25 bilayers of Co(3nm)-Ru(3nm) sandwiched between two Ru(10nm) layers on the top of a Si substrate. This SNMS method is based on the mass spectrometry of the neutral particles of the analyzed material removed by ion bombardment and ionized in a radio-frequency plasma generated above the sample. In addition to the SNMS method the apparatus is equipped with a Specs IQE 12/38 scanning ion gun and offers the application of elemental mapping of surface layers using Secondary Ion Mass Spectrometry (SIMS) technique with moderate lateral resolution (∼ 120 μm), as well. Application for financial support was submitted to the R and D Programme of the Ministry of Education of Hungary together with the Department of Solid State Physics of the University of Debrecen. Besides the 59.5 MFt supported by the programme a significant contribution of 25.5 MFt from the two applying institutes had to be made. The device was purchased in accordance with the public procurement procedure. Out of the three candidates answering the call for the tender the one submitted by Specs GmbH offering their Specs-INA device was the most appropriate to
Modern techniques of surface science

CERN Document Server

Woodruff, D Phil

2016-01-01

This fully revised, updated and reorganised third edition provides a thorough introduction to the characterisation techniques used in surface science and nanoscience today. Each chapter brings together and compares the different techniques used to address a particular research question, including how to determine the surface composition, surface structure, surface electronic structure, surface microstructure at different length scales (down to sub-molecular), and the molecular character of adsorbates and their adsorption or reaction properties. Readers will easily understand the relative strengths and limitations of the techniques available to them and, ultimately, will be able to select the most suitable techniques for their own particular research purposes. This is an essential resource for researchers and practitioners performing materials analysis, and for senior undergraduate students looking to gain a clear understanding of the underlying principles and applications of the different characterisation tec...
A surface-analytical examination of stringer particles in aluminum-lithium-copper alloys

Science.gov (United States)

Larson, L. A.; Avalos-Borja, M.; Pizzo, P. P.

1984-01-01

A surface analytical examination of powder metallurgy processed Al-Li-Cu alloys was conducted. The oxide stringer particles often found in these alloys are characterized. Particle characterization is important to more fully understand their impact on the stress corrosion and fracture properties of the alloy. The techniques used where SIMS (Secondary Ion Mass Spectroscopy) and SAM (Scanning Auger Microscopy). The results indicate that the oxide stringer particles contain both Al and LI with relatively high Li content and the Li compounds may be associated with the stringer particles, thereby locally depleting the adjacent matrix of Li solute.
An integrated approach using orthogonal analytical techniques to characterize heparan sulfate structure.

Science.gov (United States)

Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Gunay, Nur Sibel; Wang, Jing; Sun, Elaine Y; Pradines, Joël R; Farutin, Victor; Shriver, Zachary; Kaundinya, Ganesh V; Capila, Ishan

2017-02-01

Heparan sulfate (HS), a glycosaminoglycan present on the surface of cells, has been postulated to have important roles in driving both normal and pathological physiologies. The chemical structure and sulfation pattern (domain structure) of HS is believed to determine its biological function, to vary across tissue types, and to be modified in the context of disease. Characterization of HS requires isolation and purification of cell surface HS as a complex mixture. This process may introduce additional chemical modification of the native residues. In this study, we describe an approach towards thorough characterization of bovine kidney heparan sulfate (BKHS) that utilizes a variety of orthogonal analytical techniques (e.g. NMR, IP-RPHPLC, LC-MS). These techniques are applied to characterize this mixture at various levels including composition, fragment level, and overall chain properties. The combination of these techniques in many instances provides orthogonal views into the fine structure of HS, and in other instances provides overlapping / confirmatory information from different perspectives. Specifically, this approach enables quantitative determination of natural and modified saccharide residues in the HS chains, and identifies unusual structures. Analysis of partially digested HS chains allows for a better understanding of the domain structures within this mixture, and yields specific insights into the non-reducing end and reducing end structures of the chains. This approach outlines a useful framework that can be applied to elucidate HS structure and thereby provides means to advance understanding of its biological role and potential involvement in disease progression. In addition, the techniques described here can be applied to characterization of heparin from different sources.
Application of tomographic techniques to two-dimensional surface analysis using the Harwell nuclear microprobe

International Nuclear Information System (INIS)

Huddleston, J.; Hutchinson, I.G.; Pierce, T.B.

1983-01-01

Nuclear methods of surface analysis are discussed briefly, and the circumstances are described in which a two-dimensional analysis of the sample surface is desirable to enable the surface composition to be mapped accurately. Tomographic techniques of data manipulation are outlined. Data acquisition in the present case is performed by moving the sample in a defined sequence of positions, at each of which analytical data are gathered by the proton microprobe. The method and equipment are outlined. Data processing leading to the reconstruction of the image is summarised. (U.K.)
Quality system implementation for nuclear analytical techniques

International Nuclear Information System (INIS)

2004-01-01

techniques. The methodology provided is appropriate for: (a) Analysis of radionuclides as in alpha, beta, and gamma spectrometry for environmental and human-made radioactivity investigations; (b) Analysis of trace, minor and major elements using nuclear and related analytical techniques such as neutron activation analysis, X ray fluorescence, PIXE, etc. This training guidebook can be used by staff of analytical laboratories as a starting kit to better understand the quality assurance and quality control principles as prescribed in the ISO 17025 standard. It follows a logical order related to practical laboratory work rather than the formal clauses as given by the standard. It can be used as a stand alone textbook. However, in some cases, cross-reference is given to the ISO 17025 clauses hence it is recommended to consult the ISO standard for exact wording of specific requirements
Contactless conductivity detection for analytical techniques — Developments from 2014 to 2016

Czech Academy of Sciences Publication Activity Database

Kubáň, Pavel; Hauser, P.C.

2017-01-01

Roč. 38, č. 1 (2017), s. 95-114 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : capacitively coupled contactless conductivity detection * capillary electrophoresis * contactless conductivity detection * analytical techniques * review Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016
A Visual Analytics Technique for Identifying Heat Spots in Transportation Networks

Directory of Open Access Journals (Sweden)

Marian Sorin Nistor

2016-12-01

Full Text Available The decision takers of the public transportation system, as part of urban critical infrastructures, need to increase the system resilience. For doing so, we identified analysis tools for biological networks as an adequate basis for visual analytics in that domain. In the paper at hand we therefore translate such methods for transportation systems and show the benefits by applying them on the Munich subway network. Here, visual analytics is used to identify vulnerable stations from different perspectives. The applied technique is presented step by step. Furthermore, the key challenges in applying this technique on transportation systems are identified. Finally, we propose the implementation of the presented features in a management cockpit to integrate the visual analytics mantra for an adequate decision support on transportation systems.
Pre-concentration technique for reduction in "Analytical instrument requirement and analysis"

Science.gov (United States)

Pal, Sangita; Singha, Mousumi; Meena, Sher Singh

2018-04-01

Availability of analytical instruments for a methodical detection of known and unknown effluents imposes a serious hindrance in qualification and quantification. Several analytical instruments such as Elemental analyzer, ICP-MS, ICP-AES, EDXRF, ion chromatography, Electro-analytical instruments which are not only expensive but also time consuming, required maintenance, damaged essential parts replacement which are of serious concern. Move over for field study and instant detection installation of these instruments are not convenient to each and every place. Therefore, technique such as pre-concentration of metal ions especially for lean stream elaborated and justified. Chelation/sequestration is the key of immobilization technique which is simple, user friendly, most effective, least expensive, time efficient; easy to carry (10g - 20g vial) to experimental field/site has been demonstrated.
Exact analytical modeling of magnetic vector potential in surface inset permanent magnet DC machines considering magnet segmentation

Science.gov (United States)

Jabbari, Ali

2018-01-01

Surface inset permanent magnet DC machine can be used as an alternative in automation systems due to their high efficiency and robustness. Magnet segmentation is a common technique in order to mitigate pulsating torque components in permanent magnet machines. An accurate computation of air-gap magnetic field distribution is necessary in order to calculate machine performance. An exact analytical method for magnetic vector potential calculation in surface inset permanent magnet machines considering magnet segmentation has been proposed in this paper. The analytical method is based on the resolution of Laplace and Poisson equations as well as Maxwell equation in polar coordinate by using sub-domain method. One of the main contributions of the paper is to derive an expression for the magnetic vector potential in the segmented PM region by using hyperbolic functions. The developed method is applied on the performance computation of two prototype surface inset magnet segmented motors with open circuit and on load conditions. The results of these models are validated through FEM method.
Surface-assisted laser desorption ionization mass spectrometry techniques for application in forensics.

Science.gov (United States)

Guinan, Taryn; Kirkbride, Paul; Pigou, Paul E; Ronci, Maurizio; Kobus, Hilton; Voelcker, Nicolas H

2015-01-01

Matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) is an excellent analytical technique for the rapid and sensitive analysis of macromolecules (>700 Da), such as peptides, proteins, nucleic acids, and synthetic polymers. However, the detection of smaller organic molecules with masses below 700 Da using MALDI-MS is challenging due to the appearance of matrix adducts and matrix fragment peaks in the same spectral range. Recently, nanostructured substrates have been developed that facilitate matrix-free laser desorption ionization (LDI), contributing to an emerging analytical paradigm referred to as surface-assisted laser desorption ionization (SALDI) MS. Since SALDI enables the detection of small organic molecules, it is rapidly growing in popularity, including in the field of forensics. At the same time, SALDI also holds significant potential as a high throughput analytical tool in roadside, work place and athlete drug testing. In this review, we discuss recent advances in SALDI techniques such as desorption ionization on porous silicon (DIOS), nano-initiator mass spectrometry (NIMS) and nano assisted laser desorption ionization (NALDI™) and compare their strengths and weaknesses with particular focus on forensic applications. These include the detection of illicit drug molecules and their metabolites in biological matrices and small molecule detection from forensic samples including banknotes and fingerprints. Finally, the review highlights recent advances in mass spectrometry imaging (MSI) using SALDI techniques. © 2014 Wiley Periodicals, Inc.
International conference on isotopic and nuclear analytical techniques for health and environment. Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Decision makers and stakeholders are becoming increasingly dependent on reliable chemical measurements that serve as a basis for decisions related to health, consumer safety, commerce, environment protection and compliance to regulations. Several millions of analytical results are produced annually, thus consuming appreciable amounts of resources. Reliability of these data is of major concern if cost-benefit figures are applied. Nuclear and isotopic analytical techniques (NATs) have been supported by the IAEA as part of their mandate to foster the peaceful use of nuclear energy for many years. Nuclear analytical laboratories have been installed and upgraded through Technical Co-operation assistance in many Member State laboratories. These techniques, including INAA, XRF, PIXE, stable and radioisotopes, spectrometroscopy, etc. have been applied to a wide range of subjects with varying success. Nuclear analytical techniques, featuring some intrinsic quality control aspects, such as multi-nuclide analysis, frequently serve as 'reference methods' to cross-check critical results. As nuclear properties of elements are targeted, matrix problems seem to be negligible to a great extent. The International Conference on Isotopic and Nuclear Analytical Techniques for Health and Environment was held 10-13 June 2003 in Vienna, Austria. The main purpose of this Conference was to bring together scientists, technologists, representatives of industry and regulatory authorities to exchange information and review the status of current developments and applications of isotopic and nuclear analytical techniques, and to discuss future trends and developments. A further objective is to identify potential opportunities for developing countries for applying isotopic and nuclear analytical techniques in health and environmental studies, and to consider the promotion and transfer of such technology. International developments and trends in health care, nutrition, and environmental monitoring
Application of metabonomic analytical techniques in the modernization and toxicology research of traditional Chinese medicine.

Science.gov (United States)

Lao, Yong-Min; Jiang, Jian-Guo; Yan, Lu

2009-08-01

In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM. Among these studies, many metabonomic-based methods have been implemented to facilitate TCM toxicity investigation. At present, the most prevailing methods for TCM toxicity research are mainly single analysis techniques using only one analytical means. These techniques include nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), etc.; with these techniques, some favourable outcomes have been gained in the toxic reaction studies of TCM, such as the action target organs assay, the establishment of action pattern, the elucidation of action mechanism and the exploration of action material foundation. However, every analytical technique has its advantages and drawbacks, no existing analytical technique can be versatile. Multi-analysed techniques can partially overcome the shortcomings of single-analysed techniques. Combination of GC-MS and LC-MS metabolic profiling approaches has unravelled the pathological outcomes of aristolochic acid-induced nephrotoxicity, which can not be achieved by single-analysed techniques. It is believed that with the further development of metabonomic analytical techniques, especially multi-analysed techniques, metabonomics will greatly promote TCM toxicity research and be beneficial to the modernization of TCM in terms of extending the application of modern means in the TCM safety assessment, assisting the formulation of TCM safety norms and establishing the international standards indicators.

Application of advanced nuclear and instrumental analytical techniques for characterisation of environmental materials

International Nuclear Information System (INIS)

Sudersanan, M.; Pawaskar, P.B.; Kayasth, S.R.; Kumar, S.C.

2002-01-01

Full text: Increasing realisation about the toxic effects of metal ions in environmental materials has given an impetus to research on analytical techniques for their characterization. The large number of analytes present at very low levels has necessitated the use of sensitive, selective and element specific techniques for their characterization. The concern about precision and accuracy on such analysis, which have socio-economic bearing, has emphasized the use of Certified Reference Materials and the use of multi-technique approach for the unambiguous characterization of analytes. The recent work carried out at Analytical Chemistry Division, BARC on these aspects is presented in this paper. Increasing use of fossil fuels has led to the generation of large quantities of fly ash which pose problems of safe disposal. The utilization of these materials for land filling is an attractive option but the presence of trace amounts of toxic metals like mercury, arsenic, lead etc may cause environmental problems. In view of the inhomogeneous nature of the material, efficient sample processing is an important factor, in addition to the validation of the results by the use of proper standards. Analysis was carried out on flyash samples received as reference materials and also as samples from commercial sources using a combination of both nuclear techniques like INAA and RNAA as well as other techniques like AAS, ICPAES, cold vapour AAS for mercury and hydride generation technique for arsenic. Similar analysis using nuclear techniques was employed for the characterization of air particulates. Biological materials often serve as sensitive indicator materials for pollution measurements. They are also employed for studies on the uptake of toxic metals like U, Th, Cd, Pb, Hg etc. The presence of large amounts of organic materials in them necessitate an appropriate sample dissolution procedure. In view of the possibility of loss of certain analytes like Cd, Hg, As, by high
Structural level characterization of base oils using advanced analytical techniques

KAUST Repository

Hourani, Nadim; Muller, Hendrik; Adam, Frederick M.; Panda, Saroj K.; Witt, Matthias; Al-Hajji, Adnan A.; Sarathy, Mani

2015-01-01

cyclotron resonance mass spectrometry (FT-ICR MS) equipped with atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) sources. First, the capabilities and limitations of each analytical technique were evaluated
Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.

Science.gov (United States)

Spietelun, Agata; Marcinkowski, Łukasz; de la Guardia, Miguel; Namieśnik, Jacek

2013-12-20

Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including practical applications of these techniques and a critical discussion about their advantages and disadvantages. The proposed solutions fulfill the requirements resulting from the concept of sustainable development, and specifically from the implementation of green chemistry principles in analytical laboratories. Therefore, particular attention was paid to the description of possible uses of novel, selective stationary phases in extraction techniques, inter alia, polymeric ionic liquids, carbon nanotubes, and silica- and carbon-based sorbents. The methodological solutions, together with properly matched sampling devices for collecting analytes from samples with varying matrix composition, enable us to reduce the number of errors during the sample preparation prior to chromatographic analysis as well as to limit the negative impact of this analytical step on the natural environment and the health of laboratory employees. Copyright © 2013 Elsevier B.V. All rights reserved.
Recent analytical applications of magnetic nanoparticles

Directory of Open Access Journals (Sweden)

Mohammad Faraji

2016-07-01

Full Text Available Analytical chemistry has experienced, as well as other areas of science, a big change due to the needs and opportunities provided by analytical nanoscience and nanotechnology. Now, nanotechnology is increasingly proving to be a powerful ally of analytical chemistry to achieve its objectives, and to simplify analytical processes. Moreover, the information needs arising from the growing nanotechnological activity are opening an exciting new field of action for analytical chemists. Magnetic nanoparticles have been used in various fields owing to their unique properties including large specific surface area and simple separation with magnetic fields. For Analytical applications, they have been used mainly for sample preparation techniques (magnetic solid phase extraction with different advanced functional groups (layered double hydroxide, β-cyclodextrin, carbon nanotube, graphen, polymer, octadecylsilane and automation of it, microextraction techniques enantioseparation and chemosensors. This review summarizes the basic principles and achievements of magnetic nanoparticles in sample preparation techniques, enantioseparation and chemosensors. Also, some selected articles recently published (2010-2016 have been reviewed and discussed.
Ion implanters contamination on wafer surface analyzed by ToF-SIMS and SPV analytical techniques

International Nuclear Information System (INIS)

Ricciari, R.; Bertini, M.; Ferlito, E.P.; Pizzo, G.; Anastasi, G.; Mello, D.; Franco, G.

2007-01-01

In ULSI processes, metallic contamination controls are very important issues. For the ion implantation process it is known that several sources of contaminations still need to be controlled: metals from sputtering of the apertures or wafer holders, Na + contaminations from filament impurities and messy maintenance procedure. ToF-SIMS is one of the most promising candidates to perform in-line surface analysis due to its high sensitivity. It is very common to use surface photo-voltage (SPV) techniques to control ion implanter equipments but this kind of analysis is an indirect measure for metallic contamination. The aim of this work is to study the possibility to use ToF-SIMS instead of SPV for in line equipment contamination monitoring. For this reason a comparison between SPV and ToF-SIMS data occurred. Good correlation between the data is shown; moreover ToF-SIMS spectra give detailed information about the other contaminations present on the wafer surface
Analysis of Cultural Heritage by Accelerator Techniques and Analytical Imaging

Science.gov (United States)

Ide-Ektessabi, Ari; Toque, Jay Arre; Murayama, Yusuke

2011-12-01

In this paper we present the result of experimental investigation using two very important accelerator techniques: (1) synchrotron radiation XRF and XAFS; and (2) accelerator mass spectrometry and multispectral analytical imaging for the investigation of cultural heritage. We also want to introduce a complementary approach to the investigation of artworks which is noninvasive and nondestructive that can be applied in situ. Four major projects will be discussed to illustrate the potential applications of these accelerator and analytical imaging techniques: (1) investigation of Mongolian Textile (Genghis Khan and Kublai Khan Period) using XRF, AMS and electron microscopy; (2) XRF studies of pigments collected from Korean Buddhist paintings; (3) creating a database of elemental composition and spectral reflectance of more than 1000 Japanese pigments which have been used for traditional Japanese paintings; and (4) visible light-near infrared spectroscopy and multispectral imaging of degraded malachite and azurite. The XRF measurements of the Japanese and Korean pigments could be used to complement the results of pigment identification by analytical imaging through spectral reflectance reconstruction. On the other hand, analysis of the Mongolian textiles revealed that they were produced between 12th and 13th century. Elemental analysis of the samples showed that they contained traces of gold, copper, iron and titanium. Based on the age and trace elements in the samples, it was concluded that the textiles were produced during the height of power of the Mongol empire, which makes them a valuable cultural heritage. Finally, the analysis of the degraded and discolored malachite and azurite demonstrates how multispectral analytical imaging could be used to complement the results of high energy-based techniques.
Analytical techniques for wine analysis: An African perspective; a review

International Nuclear Information System (INIS)

Villiers, André de; Alberts, Phillipus; Tredoux, Andreas G.J.; Nieuwoudt, Hélène H.

2012-01-01

Highlights: ► Analytical techniques developed for grape and wine analysis in Africa are reviewed. ► The utility of infrared spectroscopic methods is demonstrated. ► An overview of separation of wine constituents by GC, HPLC, CE is presented. ► Novel LC and GC sample preparation methods for LC and GC are presented. ► Emerging methods for grape and wine analysis in Africa are discussed. - Abstract: Analytical chemistry is playing an ever-increasingly important role in the global wine industry. Chemical analysis of wine is essential in ensuring product safety and conformity to regulatory laws governing the international market, as well as understanding the fundamental aspects of grape and wine production to improve manufacturing processes. Within this field, advanced instrumental analysis methods have been exploited more extensively in recent years. Important advances in instrumental analytical techniques have also found application in the wine industry. This review aims to highlight the most important developments in the field of instrumental wine and grape analysis in the African context. The focus of this overview is specifically on the application of advanced instrumental techniques, including spectroscopic and chromatographic methods. Recent developments in wine and grape analysis and their application in the African context are highlighted, and future trends are discussed in terms of their potential contribution to the industry.
Analytical techniques for wine analysis: An African perspective; a review

Energy Technology Data Exchange (ETDEWEB)

Villiers, Andre de, E-mail: ajdevill@sun.ac.za [Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch (South Africa); Alberts, Phillipus [Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch (South Africa); Tredoux, Andreas G.J.; Nieuwoudt, Helene H. [Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch (South Africa)

2012-06-12

Highlights: Black-Right-Pointing-Pointer Analytical techniques developed for grape and wine analysis in Africa are reviewed. Black-Right-Pointing-Pointer The utility of infrared spectroscopic methods is demonstrated. Black-Right-Pointing-Pointer An overview of separation of wine constituents by GC, HPLC, CE is presented. Black-Right-Pointing-Pointer Novel LC and GC sample preparation methods for LC and GC are presented. Black-Right-Pointing-Pointer Emerging methods for grape and wine analysis in Africa are discussed. - Abstract: Analytical chemistry is playing an ever-increasingly important role in the global wine industry. Chemical analysis of wine is essential in ensuring product safety and conformity to regulatory laws governing the international market, as well as understanding the fundamental aspects of grape and wine production to improve manufacturing processes. Within this field, advanced instrumental analysis methods have been exploited more extensively in recent years. Important advances in instrumental analytical techniques have also found application in the wine industry. This review aims to highlight the most important developments in the field of instrumental wine and grape analysis in the African context. The focus of this overview is specifically on the application of advanced instrumental techniques, including spectroscopic and chromatographic methods. Recent developments in wine and grape analysis and their application in the African context are highlighted, and future trends are discussed in terms of their potential contribution to the industry.
Dynamically triangulated surfaces - some analytical results

International Nuclear Information System (INIS)

Kostov, I.K.

1987-01-01

We give a brief review of the analytical results concerning the model of dynamically triangulated surfaces. We will discuss the possible types of critical behaviour (depending on the dimension D of the embedding space) and the exact solutions obtained for D=0 and D=-2. The latter are important as a check of the Monte Carlo simulations applyed to study the model in more physical dimensions. They give also some general insight of its critical properties
A Simplified Analytical Technique for High Frequency Characterization of Resonant Tunneling Diode

Directory of Open Access Journals (Sweden)

DESSOUKI, A. A. S.

2014-11-01

Full Text Available his paper proposes a simplified analytical technique for high frequency characterization of the resonant tunneling diode (RTD. An equivalent circuit of the RTD that consists of a parallel combination of conductance, G (V, f, and capacitance, C (V, f is formulated. The proposed approach uses the measured DC current versus voltage characteristic of the RTD to extract the equivalent circuit elements parameters in the entire bias range. Using the proposed analytical technique, the frequency response - including the high frequency range - of many characteristic aspects of the RTD is investigated. Also, the maximum oscillation frequency of the RTD is calculated. The results obtained have been compared with those concluded and reported in the literature. The reported results in literature were obtained through simulation of the RTD at high frequency using either a computationally complicated quantum simulator or through difficult RF measurements. A similar pattern of results and highly concordant conclusion are obtained. The proposed analytical technique is simple, correct, and appropriate to investigate the behavior of the RTD at high frequency. In addition, the proposed technique can be easily incorporated into SPICE program to simulate circuits containing RTD.
Analytical Solution for Elliptical Cloaks Based on The Frequency Selective Surface

Directory of Open Access Journals (Sweden)

E. Ghasemi Mizuji

2015-01-01

Full Text Available In this paper the elliptical dielectric cylinder which is covered with FSS cloak is considered. Frequency selective surface cloak which Alu named it mantle cloak is one of the recent techniques for cloaking. In this method an appropriate FSS can act as cloaking device for suppressing the scattering of object in the desired frequency. With using this method the dimension of the cloaks is extremely reduced. By this proposed structure, the RCS of elliptical cylinder is reduced about 10-20 dB and designed cloak has an appropriate performance. The analytical solution for the wave in each layer is presented and with using simulation, the electric field and the scattering pattern has been drawn.
2D Analytical Modeling of Magnetic Vector Potential in Surface Mounted and Surface Inset Permanent Magnet Machines

Directory of Open Access Journals (Sweden)

A. Jabbari

2017-12-01

Full Text Available A 2D analytical method for magnetic vector potential calculation in inner rotor surface mounted and surface inset permanent magnet machines considering slotting effects, magnetization orientation and winding layout has been proposed in this paper. The analytical method is based on the resolution of Laplace and Poisson equations as well as Maxwell equation in quasi- Cartesian coordinate by using sub-domain method and hyperbolic functions. The developed method is applied on the performance computation of two prototypes surface mounted permanent magnet motors and two prototypes surface inset permanent magnet motors. A radial and a parallel magnetization orientation is considered for each type of motor. The results of these models are validated through FEM method.
Instrumental analytical techniques in geochemistry: Requirements and applications

International Nuclear Information System (INIS)

Willis, J.P.

1986-01-01

Geochemists must analyse an extremely wide range of terrestrial and planetary materials. The instrumental techniques necessary to cope with this difficult task are considered. The most important analytical techniques in use by the geochemist today are AAS, ICP-OES, INAA, MSID and XRFS, and the electron microscope for in situ mineral analysis. Some applications of these techniques to solving major problems in geochemistry are discussed. The importance of certified reference materials and of high quality geochemical data are emphasized. It is concluded that the general quality of trace element data has improved over the past 25 years, as a direct result of the application of modern instrumental techniques. Surprisingly, the quality of data reported for certain major elements has deteriorated over that time, when compared with data obtainable by classical chemical methods. Predictions are made concerning the instrumentation needs of the next generation of geochemists. (orig.) [de
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 ...
In-depth characterization of prebiotic galactooligosaccharides by a combination of analytical techniques

NARCIS (Netherlands)

Coulier, L.; Timmermans, J.; Richard, B.; Dool, R. van den; Haaksman, I.; Klarenbeek, B.; Slaghek, T.; Dongen, W. van

2009-01-01

A commercial prebiotic galacto-oligosaccharide mixture (Vivinal GOS) was extensively characterized using a combination of analytical techniques. The different techniques were integrated to give complementary information on specific characteristics of the oligosaccharide mixture, ranging from global
Development of analytical techniques in support of waste and effluent characterization

International Nuclear Information System (INIS)

Reed, W.J.

1991-01-01

The Analytical Services Group within Sellafield Technical Department has been established for >40 yr and employs >150 analysts. The group operates >400 analytical methods across a wide range of techniques and has a yearly workload of ∼250,000 determinations. The group operates under a quality system based on statistical process control that has achieved national recognition through the accreditation of its mass spectrometry and radiochemical services to the standard of national testing laboratories. The group offers services ranging from the characterization of highly active wastes to trace elemental and radiochemical measurements in environmental, biological, and effluent streams. The group has vast experience in the management of analytical services to tight time scales and has pioneered developments not only in analytical instrumentation, but also in the adaptation of equipment to radioactive environments and the design of dedicated analytical facilities
Phonon dispersion on Ag (100) surface: A modified analytic embedded atom method study

International Nuclear Information System (INIS)

Zhang Xiao-Jun; Chen Chang-Le

2016-01-01

Within the harmonic approximation, the analytic expression of the dynamical matrix is derived based on the modified analytic embedded atom method (MAEAM) and the dynamics theory of surface lattice. The surface phonon dispersions along three major symmetry directions, and XM-bar are calculated for the clean Ag (100) surface by using our derived formulas. We then discuss the polarization and localization of surface modes at points X-bar and M-bar by plotting the squared polarization vectors as a function of the layer index. The phonon frequencies of the surface modes calculated by MAEAM are compared with the available experimental and other theoretical data. It is found that the present results are generally in agreement with the referenced experimental or theoretical results, with a maximum deviation of 10.4%. The agreement shows that the modified analytic embedded atom method is a reasonable many-body potential model to quickly describe the surface lattice vibration. It also lays a significant foundation for studying the surface lattice vibration in other metals. (paper)
Spectral interference of zirconium on 24 analyte elements using CCD based ICP-AES technique

International Nuclear Information System (INIS)

Adya, V.C.; Sengupta, Arijit; Godbole, S.V.

2014-01-01

In the present studies, the spectral interference of zirconium on different analytical lines of 24 critical analytes using CCD based ICP-AES technique is described. Suitable analytical lines for zirconium were identified along with their detection limits. The sensitivity and the detection limits of analytical channels for different elements in presence of Zr matrix were calculated. Subsequently analytical lines with least interference from Zr and better detection limits were selected for their determinations. (author)
An Example of a Hakomi Technique Adapted for Functional Analytic Psychotherapy

Science.gov (United States)

Collis, Peter

2012-01-01

Functional Analytic Psychotherapy (FAP) is a model of therapy that lends itself to integration with other therapy models. This paper aims to provide an example to assist others in assimilating techniques from other forms of therapy into FAP. A technique from the Hakomi Method is outlined and modified for FAP. As, on the whole, psychotherapy…
Spatial resolution in depth-controlled surface sensitive x-ray techniques

International Nuclear Information System (INIS)

Yun, W.B.; Viccaro, P.J.

1992-01-01

The spatial resolution along the surface normal and the total depth probed are two important parameters in depth-controlled surface sensitive X-ray techniques employing grazing incidence geometry. The two parameters are analyzed in terms of optical properties (refractive indices) of the media involved and parameters of the incident X-ray beam: beam divergence, X-ray energy, and spectral bandwidth. We derive analytical expressions of the required beam divergence and spectral bandwidth of the incident beam as a function of the two parameters. Sample calculations are made for X-ray energies between 0.1 and 100 keV and for solid Be, Cu, and Au, representing material matrices consisting of low, medium, and high atomic number elements. A brief discussion on obtaining the required beam divergence and spectral bandwidth from present X-ray sources and optics is given

Techniques for removing contaminated concrete surfaces

International Nuclear Information System (INIS)

Halter, J.M.; Sullivan, R.G.

1981-01-01

This discussion compares various techniques that have been used to clean concrete surfaces by removing the surface. Three techniques which have been investigated by the Pacific Northwest Laboratory for removing surfaces are also described: the water cannon, the concrete spaller, and high-pressure water jet. The equipment was developed with the assumption that removal of the top 1/8 to 1/4 in. of surface would remove most of the contamination. If the contamination has gone into cracks or deep voids in the surface, the removal processes can be repeated until the surface is acceptable
PHOTOGRAMMETRIC TECHNIQUES FOR ROAD SURFACE ANALYSIS

Directory of Open Access Journals (Sweden)

V. A. Knyaz

2016-06-01

Full Text Available The quality and condition of a road surface is of great importance for convenience and safety of driving. So the investigations of the behaviour of road materials in laboratory conditions and monitoring of existing roads are widely fulfilled for controlling a geometric parameters and detecting defects in the road surface. Photogrammetry as accurate non-contact measuring method provides powerful means for solving different tasks in road surface reconstruction and analysis. The range of dimensions concerned in road surface analysis can have great variation from tenths of millimetre to hundreds meters and more. So a set of techniques is needed to meet all requirements of road parameters estimation. Two photogrammetric techniques for road surface analysis are presented: for accurate measuring of road pavement and for road surface reconstruction based on imagery obtained from unmanned aerial vehicle. The first technique uses photogrammetric system based on structured light for fast and accurate surface 3D reconstruction and it allows analysing the characteristics of road texture and monitoring the pavement behaviour. The second technique provides dense 3D model road suitable for road macro parameters estimation.
International conference on isotopic and nuclear analytical techniques for health and environment. Unedited papers

International Nuclear Information System (INIS)

2004-01-01

The IAEA has been supporting nuclear and isotopic analytical techniques as part of its mandate to foster the peaceful uses of nuclear energy for many years. Nuclear analytical laboratories have been installed and upgraded through technical co-operation assistance in many laboratories of Member States. These techniques, including INAA, CRF, PIXE, stable isotopes and radioisotopes, α, β, γ spectrometry, Moessbauer spectrometry, etc., have been applied to a wide range of subjects with varying success. Nuclear analytical techniques, featuring some intrinsic quality control aspects, such as multi-nuclide analysis, frequently serve as 'reference methods' to crosscheck critical results. As nuclear properties of elements are targeted, matrix problems seem to be negligible. In light of its continued commitment and support, the IAEA organized the International Conference on Isotopic and Nuclear Analytical Techniques for Health and Environment. Out of 220 from 61 countries who applied for participation, 155 official participants and five observers from 47 countries were in attendance, with 67 from 32 developing countries and 21 from international organizations, including the World Health Organization. Eleven plenary sessions were held. Also conducted was a panel discussion on Human Capacity Development Needs in the Areas of Analytical Quality Control Services (AQCS), Radiochemistry and Nutrition. The scientific sessions were divided into several topics, which reflect some of the important activities of the IAEA's Department of Nuclear Sciences and Applications (NA): - Isotopic and nuclear techniques (general); - Metrology and quality assurance in nuclear measurements; - Nuclear analytical techniques for environmental monitoring; - Radioecology; - Environmental monitoring; - Radiological safety of food and water; - Methodological aspects of stable isotope techniques in health and environment; - Applications of isotopic techniques in health and environment; - New
Surface analysis the principal techniques

CERN Document Server

Vickerman, John C

2009-01-01

This completely updated and revised second edition of Surface Analysis: The Principal Techniques, deals with the characterisation and understanding of the outer layers of substrates, how they react, look and function which are all of interest to surface scientists. Within this comprehensive text, experts in each analysis area introduce the theory and practice of the principal techniques that have shown themselves to be effective in both basic research and in applied surface analysis. Examples of analysis are provided to facilitate the understanding of this topic and to show readers how they c
Adhesion, friction, wear, and lubrication research by modern surface science techniques.

Science.gov (United States)

Keller, D. V., Jr.

1972-01-01

The field of surface science has undergone intense revitalization with the introduction of low-energy electron diffraction, Auger electron spectroscopy, ellipsometry, and other surface analytical techniques which have been sophisticated within the last decade. These developments have permitted submono- and monolayer structure analysis as well as chemical identification and quantitative analysis. The application of a number of these techniques to the solution of problems in the fields of friction, lubrication, and wear are examined in detail for the particular case of iron; and in general to illustrate how the accumulation of pure data will contribute toward the establishment of physiochemical concepts which are required to understand the mechanisms that are operational in friction systems. In the case of iron, LEED, Auger and microcontact studies have established that hydrogen and light-saturated organic vapors do not establish interfaces which prevent iron from welding, whereas oxygen and some oxygen and sulfur compounds do reduce welding as well as the coefficient of friction. Interpretation of these data suggests a mechanism of sulfur interaction in lubricating systems.
Nonlinear optical techniques for surface studies

International Nuclear Information System (INIS)

Shen, Y.R.

1981-09-01

Recent effort in developing nonlinear optical techniques for surface studies is reviewed. Emphasis is on monolayer detection of adsorbed molecules on surfaces. It is shown that surface coherent antiStokes Raman scattering (CARS) with picosecond pulses has the sensitivity of detecting submonolayer of molecules. On the other hand, second harmonic or sum-frequency generation is also sensitive enough to detect molecular monolayers. Surface-enhanced nonlinear optical effects on some rough metal surfaces have been observed. This facilitates the detection of molecular monolayers on such surfaces, and makes the study of molecular adsorption at a liquid-metal interface feasible. Advantages and disadvantages of the nonlinear optical techniques for surface studies are discussed
Comparison of analytical techniques for dynamic trace metal speciation in natural freshwaters.

NARCIS (Netherlands)

Sigg, Laura; Black, Frank; Buffle, Jacques; Cao, Jun; Cleven, Rob; Davison, William; Galceran, Josep; Gunkel, Peggy; Kalis, Erwin; Kistler, David; Martin, Michel; Noël, Stéphane; Nur, Yusuf; Odzak, Niksa; Puy, Jaume; Riemsdijk, Willem van; Temminghoff, Erwin; Tercier-Waeber, Mary-Lou; Toepperwien, Stefanie; Town, Raewyn M; Unsworth, Emily R; Warnken, Kent W; Weng, Liping; Xue, Hanbin; Zhang, Hao

2006-01-01

Several techniques for speciation analysis of Cu, Zn, Cd, Pb, and Ni are used in freshwater systems and compared with respect to their performance and to the metal species detected. The analytical techniques comprise the following: (i) diffusion gradients in thin-film gels (DGT); (ii) gel integrated
Nuclear analytical techniques for on-line elemental analysis in industry

International Nuclear Information System (INIS)

1988-06-01

This report is the result of an advisory group meeting held in Espoo, Finland, 1-5 June, 1987. The purpose of the meeting was to assess the present status and development of nuclear analytical techniques used for industrial process control. The report gives an overview of the different nuclear techniques used for process control and the most important applications. A separate abstract was prepared for each of the 7 papers presented at the meeting. Refs, figs and tabs
Surface Coating Technique of Northern Black Polished Ware by the Microscopic Analysis

Directory of Open Access Journals (Sweden)

Dilruba Sharmin

2012-12-01

Full Text Available An organic substance has been identified in the top layer of Northern Black Polished Ware (NBPW excavated from the Wari-Boteshwar and Mahasthangarh sites in Bangladesh. NBPW is the most distinctive ceramic of Early Historic period and the technique of its surface gloss acquired numerous theories. This particular paper is an analytical study of collected NBPW sherds from these two sites including surface observations using binocular and scanning electron microscopes and Thin Section Analysis of potsherds. Thin section analysis identified two different layers of coating on the surface of the NBPW. One layer is a ‘slip’ (ground coat and the other is a ‘top layer or top coat ’. The slip was made from refined clay and the top layer was derived from organic substance. Microscopic analysis confirmed the solid and non-clayey characteristics of the top coat.
Atmospheric pressure surface sampling/ionization techniques for direct coupling of planar separations with mass spectrometry.

Science.gov (United States)

Pasilis, Sofie P; Van Berkel, Gary J

2010-06-18

Planar separations, which include thin layer chromatography and gel electrophoresis, are in widespread use as important and powerful tools for conducting separations of complex mixtures. To increase the utility of planar separations, new methods are needed that allow in situ characterization of the individual components of the separated mixtures. A large number of atmospheric pressure surface sampling and ionization techniques for use with mass spectrometry have emerged in the past several years, and several have been investigated as a means for mass spectrometric read-out of planar separations. In this article, we review the atmospheric pressure surface sampling and ionization techniques that have been used for the read-out of planar separation media. For each technique, we briefly explain the operational basics and discuss the analyte type for which it is appropriate and some specific applications from the literature. Copyright (c) 2010 Elsevier B.V. All rights reserved.
Linear circuit transfer functions an introduction to fast analytical techniques

CERN Document Server

Basso, Christophe P

2016-01-01

Linear Circuit Transfer Functions: An introduction to Fast Analytical Techniques teaches readers how to determine transfer functions of linear passive and active circuits by applying Fast Analytical Circuits Techniques. Building on their existing knowledge of classical loop/nodal analysis, the book improves and expands their skills to unveil transfer functions in a swift and efficient manner. Starting with simple examples, the author explains step-by-step how expressing circuits time constants in different configurations leads to writing transfer functions in a compact and insightful way. By learning how to organize numerators and denominators in the fastest possible way, readers will speed-up analysis and predict the frequency resp nse of simple to complex circuits. In some cases, they will be able to derive the final expression by inspection, without writing a line of algebra. Key features: * Emphasizes analysis through employing time constant-based methods discussed in other text books but not widely us...
Analytical Model of the Nonlinear Dynamics of Cantilever Tip-Sample Surface Interactions for Various Acoustic-Atomic Force Microscopies

Science.gov (United States)

Cantrell, John H., Jr.; Cantrell, Sean A.

2008-01-01

A comprehensive analytical model of the interaction of the cantilever tip of the atomic force microscope (AFM) with the sample surface is developed that accounts for the nonlinearity of the tip-surface interaction force. The interaction is modeled as a nonlinear spring coupled at opposite ends to linear springs representing cantilever and sample surface oscillators. The model leads to a pair of coupled nonlinear differential equations that are solved analytically using a standard iteration procedure. Solutions are obtained for the phase and amplitude signals generated by various acoustic-atomic force microscope (A-AFM) techniques including force modulation microscopy, atomic force acoustic microscopy, ultrasonic force microscopy, heterodyne force microscopy, resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), and the commonly used intermittent contact mode (TappingMode) generally available on AFMs. The solutions are used to obtain a quantitative measure of image contrast resulting from variations in the Young modulus of the sample for the amplitude and phase images generated by the A-AFM techniques. Application of the model to RDF-AFUM and intermittent soft contact phase images of LaRC-cp2 polyimide polymer is discussed. The model predicts variations in the Young modulus of the material of 24 percent from the RDF-AFUM image and 18 percent from the intermittent soft contact image. Both predictions are in good agreement with the literature value of 21 percent obtained from independent, macroscopic measurements of sheet polymer material.
Surface-specific analytical techniques

International Nuclear Information System (INIS)

Riviere, J.C.

1982-01-01

The following methods are discussed: electron excitation (Auger electron spectroscopy; scanning Auger microscopy; electron energy-loss spectroscopy; appearance potential spectroscopy; electron-induced luminescence; electron-stimulated desorption); photon excitation (X-ray photoelectron spectroscopy; X-ray excited Auger electron spectroscopy; synchrotron radiation photoelectron spectroscopy; ultraviolet photoelectron spectroscopy; photoelectron spectromicroscopy; ellipsometry); ion excitation (ion-excited Auger electron spectroscopy; proton-excited Auger electron spectroscopy; ion neutralization spectroscopy; ion beam spectrochemical analysis; glow discharge optical spectroscopy; static secondary ion mass spectrometry; ion scattering spectroscopy; glow discharge mass spectrometry); resolution and sensitivity. (U.K.)
Evaluation of analytical techniques to determine matals in Sodium

International Nuclear Information System (INIS)

Biancifiori, M.A.; Zappa, G.; Amico, A.

1985-01-01

The influence of some instrumental parameters on the analysis of CA, Co, Cr, Cu, Fe, K, Mg, Mn, and Ni in Sodium solutions, by means of Flame Atomic Absorption Spectroscopy (FAAS), is evaluated. The best operating parameters are established and the possibility of application of this analytical technique to the detection of the metallic impurities in Sodium is evaluated, considering the concentration values of nuclear interest
Nuclear analytical techniques in Cuban Sugar Industry

International Nuclear Information System (INIS)

Diaz Riso, O.; Griffith Martinez, J.

1996-01-01

This paper is a review concerning the applications of Nuclear Analytical Techniques in the Cuban sugar industry. The most complete elemental composition of final molasses (34 elements ) and natural zeolites (38) this last one employed as an auxiliary agent in sugar technological processes has been performed by means of Instrumental Neutron Activation Analysis (INAA) and X-Ray Fluorescence Analysis (XRFA). The trace elements sugar cane soil plant relationship and elemental composition of different types of Cuban sugar (rawr, blanco directo and refine) were also studied. As a result, valuable information referred to the possibilities of using these products in animal and human foodstuff so as in other applications are given
Surface Analytical Techniques for Microbiologically Influenced Corrosion. A Review

Science.gov (United States)

1994-01-01

chemical process, oil and gas. and power generation industries and the U.S. pitting of stainle steels is 1h military have acknowledged the occurrence...ony on metal surface. photosynthetic biofilm may influence ennoblement of the open circuit potential of type 316L stainless steel so that it approaches...at depths within an estuarine biofilm on type 304 stainless steel . fur-oxidizing. iron-red ing. sulfate- -producing, and hydr en-producing b
Characterization of pre-hispanic pigments by modern analytical techniques

International Nuclear Information System (INIS)

Ortega A, M.

2003-01-01

In this work, the study of mural painting pigments from two archaeological sites (The Great Temple in Mexico city and Cacaxtla) was performed to know their materials composition, identify their structural characteristics and properties by using modern analytical techniques. Blue, ochre, red and black pigments of Mexica culture (1325-1521 a.C. / late Post Classic period); blue, ochre, red, brown, pink, green and white of Olmeca- Xicalanca culture (700-900 a.C. / Epiclassic period) were studied. Data about materials used, technological evolution, mineralogical background, cultural interchange and origin was obtained. Environmental exposition of these paintings since their discovering has produced changes and damage on their materials. Therefore, stability of some pigments has been notorious, ''Maya Blue'' specially presents extraordinary resistance to diluted and concentrated acids and alkalis including boiling condition, acqua regia, solvents, oxidant and reducing agents, moderate heat and biocorrosi6n; for that reason its study was emphasized. ''Maya Blue'' pigment was synthesized in laboratory using the processes described by historic sources (with indigophera suffruticosa leaves and synthetic indigo) up to obtain a stable pigment including acqua regia action. Clay matrix sorbs nearly 0.4 weight percent of organic dye, which cover 79% of palygorskita surface area. (Author)
Surface analytical characterization of Streptavidin/poly(3-hexylthiophene) bilayers for bio-electronic applications

Science.gov (United States)

Sportelli, M. C.; Picca, R. A.; Manoli, K.; Re, M.; Pesce, E.; Tapfer, L.; Di Franco, C.; Cioffi, N.; Torsi, L.

2017-10-01

The analytical performance of bioelectronic devices is highly influenced by their fabrication methods. In particular, the final architecture of field-effect transistor biosensors combining spin-cast poly(3-hexylthiophene) (P3HT) film and a biomolecule interlayer deposited on a SiO2/Si substrate can lead to the development of highly performing sensing systems, such as for the case of streptavidin (SA) used for biotin sensing. To gain a better understanding of the quality of the interfacial area, critical is the assessment of the morphological features characteristic of the adopted biolayer deposition protocol, namely: the layer-by-layer (LbL) approach and the spin coating technique. The present study relies on a combined surface spectroscopic and morphological characterization. Specifically, X-ray photoelectron spectroscopy operated in the parallel angle-resolved mode allowed the non-destructive investigation of the in-depth chemical composition of the SA film, alone or in the presence of the P3HT overlayer. Spectroscopic data were supported and corroborated by the results obtained with a Scanning Electron and a Helium Ion microscope investigation performed on the SA layer that provided relevant information on the protein structural arrangement or on its surface morphology. Clear differences emerged between the SA layers prepared by the two approaches, with the layer-by-layer deposition resulting in a smoother and better defined bio-electronic interface. Such findings support the superior analytical performance shown by bioelectronic devices based on LbL-deposited protein layers over spin coated ones.
Nuclear analytical techniques and their application to environmental samples

International Nuclear Information System (INIS)

Lieser, K.H.

1986-01-01

A survey is given on nuclear analytical techniques and their application to environmental samples. Measurement of the inherent radioactivity of elements or radionuclides allows determination of natural radioelements (e.g. Ra), man-made radioelements (e.g. Pu) and radionuclides in the environment. Activation analysis, in particular instrumental neutron activation analysis, is a very reliable and sensitive method for determination of a great number of trace elements in environmental samples, because the most abundant main constituents are not activated. Tracer techniques are very useful for studies of the behaviour and of chemical reactions of trace elements and compounds in the environment. Radioactive sources are mainly applied for excitation of characteristic X-rays (X-ray fluorescence analysis). (author)
A Novel Analytic Technique for the Service Station Reliability in a Discrete-Time Repairable Queue

Directory of Open Access Journals (Sweden)

Renbin Liu

2013-01-01

Full Text Available This paper presents a decomposition technique for the service station reliability in a discrete-time repairable GeomX/G/1 queueing system, in which the server takes exhaustive service and multiple adaptive delayed vacation discipline. Using such a novel analytic technique, some important reliability indices and reliability relation equations of the service station are derived. Furthermore, the structures of the service station indices are also found. Finally, special cases and numerical examples validate the derived results and show that our analytic technique is applicable to reliability analysis of some complex discrete-time repairable bulk arrival queueing systems.

Technical meeting on commercial applications of nuclear analytical techniques. Meeting report

International Nuclear Information System (INIS)

2004-01-01

This report summarizes the findings of the Technical Meeting on the Commercial Applications of Nuclear Analytical Techniques held in Vienna on 23-26 November 2004, where an assessment was initiated of the world capacity and market potentials for neutron activation analysis and nuclear spectroscopy, including an estimation of economic revenues. Industry and governmental agencies were identified as stakeholders for these laboratories. Examples are given of potential benefits of these techniques to the stakeholders. The potentials for commercial applications of neutron activation analysis and nuclear spectroscopy (measurement of alpha, beta and gamma ray emitting radionuclides) are addressed. First estimates are given of the worldwide capacity of these laboratories, suggestions and examples are given for potential markets and the typical organizational and technical constraints are discussed. Two case studies of commercial neutron activation analysis laboratories at a small and a medium-size reactor are given in the 'individual contributions' section of this document. An assessment of other nuclear analytical techniques such as X ray Fluorescence Spectrometry, Particle Induced X ray Emission Spectrometry or Ion Beam Analysis Spectrometry has been completed after a comprehensive collection of background information
Technical meeting on commercial applications of nuclear analytical techniques. Meeting report

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

This report summarizes the findings of the Technical Meeting on the Commercial Applications of Nuclear Analytical Techniques held in Vienna on 23-26 November 2004, where an assessment was initiated of the world capacity and market potentials for neutron activation analysis and nuclear spectroscopy, including an estimation of economic revenues. Industry and governmental agencies were identified as stakeholders for these laboratories. Examples are given of potential benefits of these techniques to the stakeholders. The potentials for commercial applications of neutron activation analysis and nuclear spectroscopy (measurement of alpha, beta and gamma ray emitting radionuclides) are addressed. First estimates are given of the worldwide capacity of these laboratories, suggestions and examples are given for potential markets and the typical organizational and technical constraints are discussed. Two case studies of commercial neutron activation analysis laboratories at a small and a medium-size reactor are given in the 'individual contributions' section of this document. An assessment of other nuclear analytical techniques such as X ray Fluorescence Spectrometry, Particle Induced X ray Emission Spectrometry or Ion Beam Analysis Spectrometry has been completed after a comprehensive collection of background information.
Enhanced surface sampler and process for collection and release of analytes

Energy Technology Data Exchange (ETDEWEB)

Addleman, Raymond S; Atkinson, David A; Bays, John T; Chouyyok, Wilaiwan; Cinson, Anthony D; Ewing, Robert G; Gerasimenko, Aleksandr A

2015-02-03

An enhanced swipe sampler and method of making are described. The swipe sampler is made of a fabric containing selected glass, metal oxide, and/or oxide-coated glass or metal fibers. Fibers are modified with silane ligands that are directly attached to the surface of the fibers to functionalize the sampling surface of the fabric. The swipe sampler collects various target analytes including explosives and other threat agents on the surface of the sampler.
A new analytical potential energy surface for the adsorption systemk CO/Cu(100)

NARCIS (Netherlands)

Marquardt, R.; Cuvelier, F.; Olsen, R.A.; Baerends, E.J.; Tremblay, J.C.; Saalfrank, P.

2010-01-01

Electronic structure data and analytical representations of the potential energy surface for the adsorption of carbon monoxide on a crystalline copper Cu(100) substrate are reviewed. It is found that a previously published and widely used analytical hypersurface for this process [J. C. Tully, M.
Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

Science.gov (United States)

Van Eeckhaut, Ann; Mangelings, Debby

2015-09-10

Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples. Copyright © 2015 Elsevier B.V. All rights reserved.
A general analytical equation for phase diagrams of an N-layer ferroelectric thin film with two surface layers

Energy Technology Data Exchange (ETDEWEB)

Lu, Z X; Teng, B H; Rong, Y H; Lu, X H; Yang, X [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)], E-mail: phytbh@163.com

2010-03-15

Within the framework of effective-field theory with correlations, the phase diagrams of an N-layer ferroelectric thin film with two surface layers are studied by the differential operator technique based on the spin-1/2 transverse Ising model. A general analytical equation for the phase diagram of a ferroelectric thin film with arbitrary layer number as well as exchange interactions and transverse fields is derived, and then the effects of exchange interactions and transverse fields on phase diagrams are discussed for an arbitrary layer number N. Meanwhile, the crossover features, from the ferroelectric-dominant phase diagram (FPD) to the paraelectric-dominant phase diagram (PPD), for various parameters of an N-layer ferroelectric thin film with two surface layers are investigated. As a result, an N-independent common intersection point equation is obtained, and the three-dimensional curved surfaces for the crossover values are constructed. In comparison with the usual mean-field approximation, the differential operator technique with correlations reduces to some extent the ferroelectric features of a ferroelectric thin film.
Optimization of analytical techniques to characterize antibiotics in aquatic systems

International Nuclear Information System (INIS)

Al Mokh, S.

2013-01-01

Antibiotics are considered as pollutants when they are present in aquatic ecosystems, ultimate receptacles of anthropogenic substances. These compounds are studied as their persistence in the environment or their effects on natural organisms. Numerous efforts have been made worldwide to assess the environmental quality of different water resources for the survival of aquatic species, but also for human consumption and health risk related. Towards goal, the optimization of analytical techniques for these compounds in aquatic systems remains a necessity. Our objective is to develop extraction and detection methods for 12 molecules of aminoglycosides and colistin in sewage treatment plants and hospitals waters. The lack of analytical methods for analysis of these compounds and the deficiency of studies for their detection in water is the reason for their study. Solid Phase Extraction (SPE) in classic mode (offline) or online followed by Liquid Chromatography analysis coupled with Mass Spectrometry (LC/MS/MS) is the most method commonly used for this type of analysis. The parameters are optimized and validated to ensure the best conditions for the environmental analysis. This technique was applied to real samples of wastewater treatment plants in Bordeaux and Lebanon. (author)
In vivo modulation of foreign body response on polyurethane by surface entrapment technique.

Science.gov (United States)

Khandwekar, Anand P; Patil, Deepak P; Hardikar, Anand A; Shouche, Yogesh S; Doble, Mukesh

2010-11-01

Implanted polymeric materials, such as medical devices, provoke the body to initiate an inflammatory reaction, known as the foreign body response (FBR), which causes several complications. In this study, polyurethane (Tecoflex®, PU) surface modified with the nonionic surfactant Tween80® (PU/T80) and the cell adhesive PLL-RGD peptide (PU/PLL-RGD) by a previously described entrapment technique were implanted in the peritoneal cavity of Wistar rats for 30 days. Implants were retrieved and examined for tissue reactivity and cellular adherence by various microscopic and analytical techniques. Surface-induced inflammatory response was assessed by real-time PCR based quantification of proinflammatory cytokine transcripts, namely, TNF-α and IL-1β, normalized to housekeeping gene GAPDH. Cellular adherence and their distribution profile were assessed by microscopic examination of H&E stained implant sections. It was observed that PU/PLL-RGD followed by the bare PU surface exhibited severe inflammatory and fibrotic response with an average mean thickness of 19 and 12 μm, respectively, in 30 days. In contrast, PU/T80 surface showed only a cellular monolayer of 2-3 μm in thickness, with a mild inflammatory response and no fibrotic encapsulation. The PU/PLL-RGD peptide-modified substrate promoted an enhanced rate of macrophage cell fusion to form foreign body giant cell (FBGCs), whereas FBGCs were rarely observed on Tween80®-modified substrate. The expression levels of proinflammatory cytokines (TNF-α and IL-1β) were upregulated on PU/PLL-RGD surface followed by bare PU, whereas the cytokine expressions were significantly suppressed on PU/T80 surface. Thus, our study highlights modulation of foreign body response on polyurethane surfaces through surface entrapment technique in the form of differential responses observed on PLL-RGD and Tween80® modified surfaces with the former effective in triggering tissue cell adhesion thereby fibrous encapsulation, while the later
Investigations of phosphate coatings of galvanized steel sheets by a surface-analytical multi-method approach

International Nuclear Information System (INIS)

Bubert, H.; Garten, R.; Klockenkaemper, R.; Puderbach, H.

1983-01-01

Corrosion protective coatings on galvanized steel sheets have been studied by a combination of SEM, EDX, AES, ISS and SIMS. Analytical statements concerning such rough, poly-crystalline and contaminated surfaces of technical samples are quite difficult to obtain. The use of a surface-analytical multi-method approach overcomes, the intrinsic limitations of the individual method applied, thus resulting in a consistent picture of those technical surfaces. Such results can be used to examine technical faults and to optimize the technical process. (Author)
Nuclear analytical techniques in Cuban sugar industry

International Nuclear Information System (INIS)

Diaz R, O.; Griffith M, J.

1997-01-01

This paper is a review concerning the application of Nuclear Analytical Techniques in the Cuban sugar industry. The most complete elemental composition of final molasses (34 elements) and natural zeolites (38) this last one employed as an auxiliary agent in sugar technological processe4s has been performed by means of instrumental Neutron Activation Analysis (INAA) and X-Ray Fluorescence Analysis (XRFA). The trace elemental sugar cane soill-plant relationship and elemental composition of different types of Cuban sugar (raw, blanco-directo and refine) were also studied. As a result, valuable information referred to the possibilities of using these products in animal and human foodstuff so as in the other applications are given. (author). 34 refs., 6 figs., 1 tab
Applied research on air pollution using nuclear-related analytical techniques

International Nuclear Information System (INIS)

1994-01-01

A co-ordinated research programme (CRP) on applied research on air pollution using nuclear-related techniques is a global CRP which will run from 1992-1996, and will build upon the experience gained by the Agency from the laboratory support that it has been providing for several years to BAPMoN - the Background Air Pollution Monitoring Network programme organized under the auspices of the World Meterological Organization. The purpose of this CRP is to promote the use of nuclear analytical techniques in air pollution studies, e.g. NAA, XFR, and PIXE for the analysis of toxic and other trace elements in suspended particulate matter (including air filter samples), rainwater and fog-water samples, and in biological indicators of air pollution (e.g. lichens and mosses). The main purposes of the core programme are i) to support the use of nuclear and nuclear-related analytical techniques for practically-oriented research and monitoring studies on air pollution ii) to identify major sources of air pollution affecting each of the participating countries with particular reference to toxic heavy metals, and iii) to obtain comparative data on pollution levels in areas of high pollution (e.g. a city centre or a populated area downwind of a large pollution source) and low pollution (e.g. rural areas). This document reports the discussions held during the first Research Co-ordination Meeting (RCM) for the CRP which took place at the IAEA Headquarters in Vienna. Refs, figs and tabs
One-dimensional model of interacting-step fluctuations on vicinal surfaces: Analytical formulas and kinetic Monte Carlo simulations

Science.gov (United States)

Patrone, Paul N.; Einstein, T. L.; Margetis, Dionisios

2010-12-01

We study analytically and numerically a one-dimensional model of interacting line defects (steps) fluctuating on a vicinal crystal. Our goal is to formulate and validate analytical techniques for approximately solving systems of coupled nonlinear stochastic differential equations (SDEs) governing fluctuations in surface motion. In our analytical approach, the starting point is the Burton-Cabrera-Frank (BCF) model by which step motion is driven by diffusion of adsorbed atoms on terraces and atom attachment-detachment at steps. The step energy accounts for entropic and nearest-neighbor elastic-dipole interactions. By including Gaussian white noise to the equations of motion for terrace widths, we formulate large systems of SDEs under different choices of diffusion coefficients for the noise. We simplify this description via (i) perturbation theory and linearization of the step interactions and, alternatively, (ii) a mean-field (MF) approximation whereby widths of adjacent terraces are replaced by a self-consistent field but nonlinearities in step interactions are retained. We derive simplified formulas for the time-dependent terrace-width distribution (TWD) and its steady-state limit. Our MF analytical predictions for the TWD compare favorably with kinetic Monte Carlo simulations under the addition of a suitably conservative white noise in the BCF equations.
Near-station terrain corrections for gravity data by a surface-integral technique

Science.gov (United States)

Gettings, M.E.

1982-01-01

A new method of computing gravity terrain corrections by use of a digitizer and digital computer can result in substantial savings in the time and manual labor required to perform such corrections by conventional manual ring-chart techniques. The method is typically applied to estimate terrain effects for topography near the station, for example within 3 km of the station, although it has been used successfully to a radius of 15 km to estimate corrections in areas where topographic mapping is poor. Points (about 20) that define topographic maxima, minima, and changes in the slope gradient are picked on the topographic map, within the desired radius of correction about the station. Particular attention must be paid to the area immediately surrounding the station to ensure a good topographic representation. The horizontal and vertical coordinates of these points are entered into the computer, usually by means of a digitizer. The computer then fits a multiquadric surface to the input points to form an analytic representation of the surface. By means of the divergence theorem, the gravity effect of an interior closed solid can be expressed as a surface integral, and the terrain correction is calculated by numerical evaluation of the integral over the surfaces of a cylinder, The vertical sides of which are at the correction radius about the station, the flat bottom surface at the topographic minimum, and the upper surface given by the multiquadric equation. The method has been tested with favorable results against models for which an exact result is available and against manually computed field-station locations in areas of rugged topography. By increasing the number of points defining the topographic surface, any desired degree of accuracy can be obtained. The method is more objective than manual ring-chart techniques because no average compartment elevations need be estimated ?
Nuclear Analytical Techniques for Commercial Applications in China

International Nuclear Information System (INIS)

Chai, Z.; Zhang, Z.; Feng, S.; Yang, J.; Ouyang, H.; Feng, X.; Mao, X.

2013-01-01

Since the establishment of the first Chinese nuclear reactor and accelerator in 1958, the nuclear analytical techniques (NATs) in China have dramatically developed in past half century. Nowadays 10 research nuclear reactors and over 100 small accelerators are available in China. Roughly, about 50 % of the machine time is applied for commercial purpose at the moment. The versatile nuclear analytical methods, mainly NAA, PIXE, XRF, etc., in China have been and are being applied widely and extensively in the following three fields: scientific, training, and commercial. This paper will briefly describe the past experience and present status about NATs for commercial applications. Some practical examples to demonstrate the role of NATs in this aspect will be given as well. Basically, the NATs used for the commercial applications in China can be divided into two types, i.e. off-line and on-line. The former mainly includes instrumental neutron activation analysis (INAA) for compositional determination, particle induced X-ray emission (PIXE) also for compositional analysis, accelerator-based mass-spectrometry (AMS) for analysis of C-14, Be-7, Cl-36 and other long-lived radioactive nuclides, solid state nuclear track detector
Assessing the Value of Structured Analytic Techniques in the U.S. Intelligence Community

Science.gov (United States)

2016-01-01

Analytic Techniques, and Why Do Analysts Use Them? SATs are methods of organizing and stimulating thinking about intelligence problems. These methods... thinking ; and imaginative thinking techniques encourage new perspectives, insights, and alternative scenarios. Among the many SATs in use today, the...more transparent, so that other analysts and customers can bet - ter understand how the judgments were reached. SATs also facilitate group involvement
Application of X-ray fluorescence analytical techniques in phytoremediation and plant biology studies

International Nuclear Information System (INIS)

Necemer, Marijan; Kump, Peter; Scancar, Janez; Jacimovic, Radojko; Simcic, Jurij; Pelicon, Primoz; Budnar, Milos; Jeran, Zvonka; Pongrac, Paula; Regvar, Marjana; Vogel-Mikus, Katarina

2008-01-01

Phytoremediation is an emerging technology that employs the use of higher plants for the clean-up of contaminated environments. Progress in the field is however handicapped by limited knowledge of the biological processes involved in plant metal uptake, translocation, tolerance and plant-microbe-soil interactions; therefore a better understanding of the basic biological mechanisms involved in plant/microbe/soil/contaminant interactions would allow further optimization of phytoremediation technologies. In view of the needs of global environmental protection, it is important that in phytoremediation and plant biology studies the analytical procedures for elemental determination in plant tissues and soil should be fast and cheap, with simple sample preparation, and of adequate accuracy and reproducibility. The aim of this study was therefore to present the main characteristics, sample preparation protocols and applications of X-ray fluorescence-based analytical techniques (energy dispersive X-ray fluorescence spectrometry-EDXRF, total reflection X-ray fluorescence spectrometry-TXRF and micro-proton induced X-ray emission-micro-PIXE). Element concentrations in plant leaves from metal polluted and non-polluted sites, as well as standard reference materials, were analyzed by the mentioned techniques, and additionally by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS). The results were compared and critically evaluated in order to assess the performance and capability of X-ray fluorescence-based techniques in phytoremediation and plant biology studies. It is the EDXRF, which is recommended as suitable to be used in the analyses of a large number of samples, because it is multi-elemental, requires only simple preparation of sample material, and it is analytically comparable to the most frequently used instrumental chemical techniques. The TXRF is compatible to FAAS in sample preparation, but relative to AAS it is fast, sensitive and
A calibration method for fringe reflection technique based on the analytical phase-slope description

Science.gov (United States)

Wu, Yuxiang; Yue, Huimin; Pan, Zhipeng; Liu, Yong

2018-05-01

The fringe reflection technique (FRT) has been one of the most popular methods to measure the shape of specular surface these years. The existing system calibration methods of FRT usually contain two parts, which are camera calibration and geometric calibration. In geometric calibration, the liquid crystal display (LCD) screen position calibration is one of the most difficult steps among all the calibration procedures, and its accuracy is affected by the factors such as the imaging aberration, the plane mirror flatness, and LCD screen pixel size accuracy. In this paper, based on the deduction of FRT analytical phase-slope description, we present a novel calibration method with no requirement to calibrate the position of LCD screen. On the other hand, the system can be arbitrarily arranged, and the imaging system can either be telecentric or non-telecentric. In our experiment of measuring the 5000mm radius sphere mirror, the proposed calibration method achieves 2.5 times smaller measurement error than the geometric calibration method. In the wafer surface measuring experiment, the measurement result with the proposed calibration method is closer to the interferometer result than the geometric calibration method.
Assessment of analytical techniques for characterization of crystalline clopidogrel forms in patent applications

Directory of Open Access Journals (Sweden)

Luiz Marcelo Lira

2014-04-01

Full Text Available The aim of this study was to evaluate two important aspects of patent applications of crystalline forms of drugs: (i the physicochemical characterization of the crystalline forms; and (ii the procedure for preparing crystals of the blockbuster drug clopidogrel. To this end, searches were conducted using online patent databases. The results showed that: (i the majority of patent applications for clopidogrel crystalline forms failed to comply with proposed Brazilian Patent Office guidelines. This was primarily due to insufficient number of analytical techniques evaluating the crystalline phase. In addition, some patent applications lacked assessment of chemical/crystallography purity; (ii use of more than two analytical techniques is important; and (iii the crystallization procedure for clopidogrel bisulfate form II were irreproducible based on the procedure given in the patent application.
Quality assurance and quality control of nuclear analytical techniques

International Nuclear Information System (INIS)

Cincu, Emanuelathor

2001-01-01

Test and analytical laboratories in East and Central European countries need to prove the reliability and credibility of their economic, environmental, medical and legal decisions and their capacity of issuing reliable, verifiable reports. These demands imposed by the European Union aimed at avoiding a possible barrier to trade for the developing countries. In June 1999, in order to help Member States to develop according to EU objectives and the overall situation of the European market, IAEA launched a new co-operation programme designed to help the nuclear analytical laboratories in nuclear institutions and universities of Member States by training in the use of some Nuclear Analytical Techniques (NAT) that include: alpha, beta and gamma-ray spectrometry, radiochemical and neutron activation analysis, total reflection X-ray fluorescence. The Regional IAEA Project, named 'Quality Assurance/Quality Control of Nuclear Analytical Techniques' (NAT) aims at implementing the QA principles via a system of defined consecutive steps leading to a level on which the QA system is self-sustainable for formal accreditation or certification and satisfies the EU technical performance criteria; the requirements are in accordance with the new ISO/IEC 17025 Standard/Dec.1999 'General requirements for the competence of testing and calibration laboratories' - First edition. The Horia Hulubei National Institute for Nuclear Physics and Engineering, IFIN-HH, was admitted for participation in the IAEA Project in June 1999 account taken of its experience in the QA and metrology fields and its performance in the fields of beta and gamma-ray spectrometry, and radiochemical and neutron activation analysis, employed in both basic research and applications for external clients. Two working groups of specialists with the QA and Standardization and Metrology Departments and six analytical groups with the departments of Nuclear Applied Physics, Life Physics and Ionising Radiation Metrology are
Analytical methods for the characterization of surface finishing in bricks

International Nuclear Information System (INIS)

Nardini, I.; Zendri, E.; Biscontin, G.; Brunetin, A.

2006-01-01

The recent restoration works of Santo Stefano Church Facade (XV century) in Venice have shown traces variously saved of different kind of surface finishes. These finishes were found on the brick's surface both in the masonry and in the decorative elements. Different brick's surface and decorative tile samples were investigated using several techniques: optical microscopy, scanning electron-microscopy, thermal analysis, infrared spectroscopy and reflectance Fourier transform infrared microspectroscopy. The evaluation of the reached results was used to understand the decorative techniques and to recognize the material employed

New analytical techniques for cuticle chemical analysis

International Nuclear Information System (INIS)

Schulten, H.R.

1994-01-01

1) The analytical methodology of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and direct pyrolysis-mass spectrometry (Py-MS) using soft ionization techniques by high electric fields (FL) are briefly described. Recent advances of Py-GC/MS and Py-FIMS for the analyses of complex organic matter such as plant materials, humic substances, dissolved organic matter in water (DOM) and soil organic matter (SOM) in agricultural and forest soils are given to illustrate the potential and limitations of the applied methods. 2) Novel applications of Py-GC/MS and Py-MS in combination with conventional analytical data in an integrated, chemometric approach to investigate the dynamics of plant lipids are reported. This includes multivariate statistical investigations on maturation, senescence, humus genesis, and environmental damages in spruce ecosystems. 3) The focal point is the author's integrated investigations on emission-induced changes of selected conifer plant constituents. Pattern recognition of Py-MS data of desiccated spruce needles provides a method for distinguishing needles damaged in different ways and determining the cause. Spruce needles were collected from both controls and trees treated with sulphur dioxide (acid rain), nitrogen dioxide, and ozone under controlled conditions. Py-MS and chemometric data evaluation are employed to characterize and classify leaves and their epicuticular waxes. Preliminary mass spectrometric evaluations of isolated cuticles of different plants such as spruce, ivy, holly, and philodendron, as well as ivy cuticles treated in vivo with air pollutants such as surfactants and pesticides are given. (orig.)
The use of decision analytic techniques in energy policy decisions

International Nuclear Information System (INIS)

Haemaelaeinen, R.P.; Seppaelaeinen, T.O.

1986-08-01

The report reviews decision analytic techniques and their applications to energy policy decision making. Decision analysis consists in techniques for structuring the essential elements of a decision problem and mathematical methods for ranking the alternatives from a set of simple judgments. Because modeling subjective judgments is characteristic of decision analysis, the models can incorporate qualitative factors and values, which escape traditional energy modeling. Decision analysis has been applied to choices among energy supply alternatives, siting energy facilities, selecting nuclear waste repositories, selecting research and development projects, risk analysis and prioritizing alternative energy futures. Many applications are done in universities and research institutions, but during the 70's the use of decision analysis has spread both to the public and the private sector. The settings where decision analysis has been applied range from aiding a single decision maker to clarifying opposing points of view. Decision analytic methods have also been linked with energy models. The most valuable result of decision analysis is the clarification of the problem at hand. Political decisions cannot be made solely on the basis of models, but models can be used to gain insight of the decision situation. Models inevitably simplify reality, so they must be regarded only as aids to judgment. So far there has been only one decision analysis of energy policy issues in Finland with actual political decision makers as participants. The experiences of this project and numerous foreign applications do however suggest that the decision analytic approach is useful in energy policy questions. The report presents a number of Finnish energy policy decisions where decision analysis might prove useful. However, the applicability of the methods depends crucially on the actual circumstances at hand
Surface improvement for inside surface of small diameter pipes by laser cladding technique

International Nuclear Information System (INIS)

Irisawa, Toshio; Morishige, Norio; Umemoto, Tadahiro; Ono, Kazumichi; Hamaoka, Tadashi; Tanaka, Atsushi

1991-01-01

A laser cladding technique has been used for surface improvement in controlling the composition of a metal surface. Recent high power YAG laser development gives an opportunity to use this laser cladding technique for various applications. A YAG laser beam can be transmitted through an optical fiber for a long distance and through narrow spaces. YAG laser cladding was studied for developing alloy steel to prevent stress corrosion cracking in austenitic stainless steel piping. In order to make a cladding layer, mixed metal powder was on the inside surface of the piping using an organic binder. Subsequently the powder beds were melted with a YAG laser beam transmitted through an optical fiber. This paper introduces the Laser cladding technique for surface improvement for the inside surface of a small diameter pipe. (author)
Recent Trends in Microextraction Techniques Employed in Analytical and Bioanalytical Sample Preparation

Directory of Open Access Journals (Sweden)

Abuzar Kabir

2017-12-01

Full Text Available Sample preparation has been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been made in recent years to simplify the overall sample preparation process. Major focusses of these efforts have included miniaturization of the extraction device; minimizing/eliminating toxic and hazardous organic solvent consumption; eliminating sample pre-treatment and post-treatment steps; reducing the sample volume requirement; reducing extraction equilibrium time, maximizing extraction efficiency etc. All these improved attributes are congruent with the Green Analytical Chemistry (GAC principles. Classical sample preparation techniques such as solid phase extraction (SPE and liquid-liquid extraction (LLE are being rapidly replaced with emerging miniaturized and environmentally friendly techniques such as Solid Phase Micro Extraction (SPME, Stir bar Sorptive Extraction (SBSE, Micro Extraction by Packed Sorbent (MEPS, Fabric Phase Sorptive Extraction (FPSE, and Dispersive Liquid-Liquid Micro Extraction (DLLME. In addition to the development of many new generic extraction sorbents in recent years, a large number of molecularly imprinted polymers (MIPs created using different template molecules have also enriched the large cache of microextraction sorbents. Application of nanoparticles as high-performance extraction sorbents has undoubtedly elevated the extraction efficiency and method sensitivity of modern chromatographic analyses to a new level. Combining magnetic nanoparticles with many microextraction sorbents has opened up new possibilities to extract target analytes from sample matrices containing high volumes of matrix interferents. The aim of the current review is to critically audit the progress of microextraction techniques in recent years, which has indisputably transformed the analytical chemistry practices, from biological and therapeutic drug monitoring to the environmental field; from foods to phyto
Directed transport by surface chemical potential gradients for enhancing analyte collection in nanoscale sensors.

Science.gov (United States)

Sitt, Amit; Hess, Henry

2015-05-13

Nanoscale detectors hold great promise for single molecule detection and the analysis of small volumes of dilute samples. However, the probability of an analyte reaching the nanosensor in a dilute solution is extremely low due to the sensor's small size. Here, we examine the use of a chemical potential gradient along a surface to accelerate analyte capture by nanoscale sensors. Utilizing a simple model for transport induced by surface binding energy gradients, we study the effect of the gradient on the efficiency of collecting nanoparticles and single and double stranded DNA. The results indicate that chemical potential gradients along a surface can lead to an acceleration of analyte capture by several orders of magnitude compared to direct collection from the solution. The improvement in collection is limited to a relatively narrow window of gradient slopes, and its extent strongly depends on the size of the gradient patch. Our model allows the optimization of gradient layouts and sheds light on the fundamental characteristics of chemical potential gradient induced transport.
Automated vehicle guidance using discrete reference markers. [road surface steering techniques

Science.gov (United States)

Johnston, A. R.; Assefi, T.; Lai, J. Y.

1979-01-01

Techniques for providing steering control for an automated vehicle using discrete reference markers fixed to the road surface are investigated analytically. Either optical or magnetic approaches can be used for the sensor, which generates a measurement of the lateral offset of the vehicle path at each marker to form the basic data for steering control. Possible mechanizations of sensor and controller are outlined. Techniques for handling certain anomalous conditions, such as a missing marker, or loss of acquisition, and special maneuvers, such as u-turns and switching, are briefly discussed. A general analysis of the vehicle dynamics and the discrete control system is presented using the state variable formulation. Noise in both the sensor measurement and in the steering servo are accounted for. An optimal controller is simulated on a general purpose computer, and the resulting plots of vehicle path are presented. Parameters representing a small multipassenger tram were selected, and the simulation runs show response to an erroneous sensor measurement and acquisition following large initial path errors.
An Accurate Approximate-Analytical Technique for Solving Time-Fractional Partial Differential Equations

Directory of Open Access Journals (Sweden)

M. Bishehniasar

2017-01-01

Full Text Available The demand of many scientific areas for the usage of fractional partial differential equations (FPDEs to explain their real-world systems has been broadly identified. The solutions may portray dynamical behaviors of various particles such as chemicals and cells. The desire of obtaining approximate solutions to treat these equations aims to overcome the mathematical complexity of modeling the relevant phenomena in nature. This research proposes a promising approximate-analytical scheme that is an accurate technique for solving a variety of noninteger partial differential equations (PDEs. The proposed strategy is based on approximating the derivative of fractional-order and reducing the problem to the corresponding partial differential equation (PDE. Afterwards, the approximating PDE is solved by using a separation-variables technique. The method can be simply applied to nonhomogeneous problems and is proficient to diminish the span of computational cost as well as achieving an approximate-analytical solution that is in excellent concurrence with the exact solution of the original problem. In addition and to demonstrate the efficiency of the method, it compares with two finite difference methods including a nonstandard finite difference (NSFD method and standard finite difference (SFD technique, which are popular in the literature for solving engineering problems.
Critical review of analytical techniques for safeguarding the thorium-uranium fuel cycle

International Nuclear Information System (INIS)

Hakkila, E.A.

1978-10-01

Conventional analytical methods applicable to the determination of thorium, uranium, and plutonium in feed, product, and waste streams from reprocessing thorium-based nuclear reactor fuels are reviewed. Separations methods of interest for these analyses are discussed. Recommendations concerning the applicability of various techniques to reprocessing samples are included. 15 tables, 218 references
Nuclear analytical techniques applied to forensic chemistry

International Nuclear Information System (INIS)

Nicolau, Veronica; Montoro, Silvia; Pratta, Nora; Giandomenico, Angel Di

1999-01-01

Gun shot residues produced by firing guns are mainly composed by visible particles. The individual characterization of these particles allows distinguishing those ones containing heavy metals, from gun shot residues, from those having a different origin or history. In this work, the results obtained from the study of gun shot residues particles collected from hands are presented. The aim of the analysis is to establish whether a person has shot a firing gun has been in contact with one after the shot has been produced. As reference samples, particles collected hands of persons affected to different activities were studied to make comparisons. The complete study was based on the application of nuclear analytical techniques such as Scanning Electron Microscopy, Energy Dispersive X Ray Electron Probe Microanalysis and Graphite Furnace Atomic Absorption Spectrometry. The essays allow to be completed within time compatible with the forensic requirements. (author)
Analytical Technique of Selection of Constructive Parameters Pneumatichydraulic Springs

Directory of Open Access Journals (Sweden)

A. A. Tsipilev

2014-01-01

Full Text Available The article "Technique for Analytical Selection of Design Parameters of Pneumatichydraulic Springs concerns the ride smoothness of high-speed vehicles. Author of article Tsipilev A.A. is an assistant at chair "Multi-purpose Tracked Vehicles and Mobile Robots" of BMSTU. The article represents a synthesis of known information on the springing systems and an analysis of relation between spring design data and running gear. It describes standard units of running gear of vehicle in the context of springing systems. Classification of springing systems is considered. Modernization general policy for existing suspensions and prospects for creation of new ones are given. The article considers a design of various pneumatic-hydraulic springs to be set on domestic tracked vehicles. A developed technique allows us to have elastic characteristics of pneumatic-hydraulic springs of various types using these design data and kinematics of the running gear. The article provides recommendations to calculate characteristics of springing systems. The adequacy analysis of the given technique based on the comparison of real and rated characteristics of the existing suspension is conducted. This article can be useful to the experts dealing with springing systems of wheel and tracked vehicles.
Application of nuclear analytical techniques to investigate trace element content in foodstuffs

International Nuclear Information System (INIS)

Gharib, A.

1985-01-01

The study performed as a joint project with the IAEA includes those foodstuffs which are being used widely in Iran. It was investigated their nutritional requirements, interrelations and the role of their trace elements in metabolism. Various analytical techniques was assessed and compared. The methods involved in the study were ASS, PIXE and NAA (instrumental and radiochemical)
Analytical model of radiation-induced precipitation at the surface of dilute binary alloy

Science.gov (United States)

Pechenkin, V. A.; Stepanov, I. A.; Konobeev, Yu. V.

2002-12-01

Growth of precipitate layer at the foil surface of an undersaturated binary alloy under uniform irradiation is treated analytically. Analytical expressions for the layer growth rate, layer thickness limit and final component concentrations in the matrix are derived for coherent and incoherent precipitate-matrix interfaces. It is shown that the high temperature limit of radiation-induced precipitation is the same for both types of interfaces, whereas layer thickness limits are different. A parabolic law of the layer growth predicted for both types of interfaces is in agreement with experimental data on γ '-phase precipitation at the surface of Ni-Si dilute alloys under ion irradiation. Effect of sputtering on the precipitation rate and on the low temperature limit of precipitation under ion irradiation is discussed.
An analytical model for the description of the full-polarimetric sea surface Doppler signature

NARCIS (Netherlands)

Fois, F.; Hoogeboom, P.; Le Chevalier, F.; Stoffelen, A.

2015-01-01

This paper describes an analytical model of the full-polarimetric sea surface scattering and Doppler signature. The model combines the small-slope-approximation theory (at the second order) with a weak nonlinear sea surface representation. Such a model is used to examine the variation of the Doppler
Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV

International Nuclear Information System (INIS)

Caballero S, B.

2013-01-01

To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)
A Novel Analytical Technique for Optimal Allocation of Capacitors in Radial Distribution Systems

Directory of Open Access Journals (Sweden)

Sarfaraz Nawaz

2017-07-01

Full Text Available In this paper, a novel analytical technique is proposed to determine the optimal size and location of shunt capacitor units in radial distribution systems. An objective function is formulated to reduce real power loss, to improve the voltage profile and to increase annual cost savings. A new constant, the Loss Sensitivity Constant (LSC, is proposed here. The value of LSC decides the location and size of candidate buses. The technique is demonstrated on an IEEE-33 bus system at different load levels and the 130-bus distribution system of Jamawa Ramgarh village, Jaipur city. The obtained results are compared with the latest optimization techniques to show the effectiveness and robustness of the proposed technique.
Analytical techniques for the determination of radiochemical purity of radiopharmaceuticals prepared from kits

International Nuclear Information System (INIS)

McLean, J.R.; Rockwell, L.J.; Welsh, W.J.

1977-01-01

The evaluation of efficacy of commercially available kits used for the preparation of radiopharmaceuticals is one aspect of the Radiation Protection Bureau's radiopharmaceutical quality control program. This report describes some of the analytical methodology employed in the program. The techniques may be of interest to hospital radiopharmacy personnel as many of the tests can be performed rapidly and with a minimum of special equipment, thus enabling the confirmation of radiopharmaceutical purity prior to patient administration. Manufacturers of kits may also be interested in learning of the analytical methods used in the assessment of their products. (auth)
Nuclear analytical techniques for nanotoxicology studies

International Nuclear Information System (INIS)

Zhang, Z.Y.; Zhao, Y.L.; Chai, Z.F.

2011-01-01

With the rapid development of nanotechnology and its applications, a wide variety of nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. The potential interactions of nanomaterials with living systems and the environment have attracted increasing attention from the public, as well as from manufacturers of nanomaterial-based products, academic researchers and policymakers. It is important to consider the environmental, health and safety aspects at an early stage of nanomaterial development and application in order to more effectively identify and manage potential human and environmental health impacts from nanomaterial exposure. This will require research in a range of areas, including detection and characterization, environmental fate and transport, ecotoxicology and toxicology. Nuclear analytical techniques (NATs) can play an important role in such studies due to their intrinsic merits such as high sensitivity, good accuracy, high space resolution, ability to distinguish the endogenous or exogenous sources of materials, and ability of in situ and in vivo analysis. In this paper, the applications of NATs in nanotoxicological and nano-ecotoxicological studies are outlined, and some recent results obtained in our laboratory are reported. (orig.)
Microstructural evolution and surface properties of nanostructured Cu-based alloy by ultrasonic nanocrystalline surface modification technique

Energy Technology Data Exchange (ETDEWEB)

Amanov, Auezhan, E-mail: amanov_a@yahoo.com [Department of Mechanical Engineering, Sun Moon University, Asan 336-708 (Korea, Republic of); Cho, In-Sik [R& D Group, Mbrosia Co., Ltd., Asan 336-708 (Korea, Republic of); Pyun, Young-Sik [Department of Mechanical Engineering, Sun Moon University, Asan 336-708 (Korea, Republic of)

2016-12-01

Graphical abstract: - Highlights: • A nanostructured surface was produced by UNSM technique. • Porosities were eliminated from the surface by UNSM technique. • Extremely high hardness obtained at the top surface after UNSM treatment. • Friction and wear behavior was improved by UNSM technique. • Resistance to scratch behavior was improved by UNSM technique. - Abstract: A nanostructured surface layer with a thickness of about 180 μm was successfully produced in Cu-based alloy using an ultrasonic nanocrystalline surface modification (UNSM) technique. Cu-based alloy was sintered onto low carbon steel using a powder metallurgy (P/M) method. Transmission electron microscope (TEM) characterization revealed that the severe plastic deformation introduced by UNSM technique resulted in nano-sized grains in the topmost surface layer and deformation twins. It was also found by atomic force microscope (AFM) observations that the UNSM technique provides a significant reduction in number of interconnected pores. The effectiveness of nanostructured surface layer on the tribological and micro-scratch properties of Cu-based alloy specimens was investigated using a ball-on-disk tribometer and micro-scratch tester, respectively. Results exhibited that the UNSM-treated specimen led to an improvement in tribological and micro-scratch properties compared to that of the sintered specimen, which may be attributed to the presence of nanostructured surface layer having an increase in surface hardness and reduction in surface roughness. The findings from this study are expected to be implemented to the automotive industry, in particular connected rod bearings and bushings in order to increase the efficiency and performance of internal combustion engines (ICEs).
Analytical study on optically measured surface profiles of referential geometry using a finite-difference time-domain method

International Nuclear Information System (INIS)

Fujii, A; Hayashi, S; Fujii, S; Yanagi, K

2014-01-01

This paper deals with the functional performance of optical surface texture measuring instruments on the market. It is well known that their height response curves against certain referential geometry are not always identical to each other. So, a more precise study on the optical instrument's characteristics is greatly needed. Firstly, we developed a new simulation tool using a finite-difference time-domain technique, which enables the prediction of the height response curve against the fundamental surface geometry in the case of the confocal laser scanning microscope. Secondly, by utilizing this new simulation tool, measurement results, including outliers, were compared with the analytical simulation results. The comparison showed the consistency, which indicates that necessary conditions of surface measurement standards for verifying the instrument performance can be established. Consequently, we suggest that the maximum measurable slope angle must be added to evaluation subjects as significant metrological characteristics of measuring instruments, along with the lateral period limit. Finally, we propose a procedure to determine the lateral period limit in an ISO standard. (paper)
Analytical mass formula and nuclear surface properties in the ETF approximation. Part II: asymmetric nuclei

Science.gov (United States)

Aymard, François; Gulminelli, Francesca; Margueron, Jérôme

2016-08-01

We have recently addressed the problem of the determination of the nuclear surface energy for symmetric nuclei in the framework of the extended Thomas-Fermi (ETF) approximation using Skyrme functionals. We presently extend this formalism to the case of asymmetric nuclei and the question of the surface symmetry energy. We propose an approximate expression for the diffuseness and the surface energy. These quantities are analytically related to the parameters of the energy functional. In particular, the influence of the different equation of state parameters can be explicitly quantified. Detailed analyses of the different energy components (local/non-local, isoscalar/isovector, surface/curvature and higher order) are also performed. Our analytical solution of the ETF integral improves previous models and leads to a precision of better than 200 keV per nucleon in the determination of the nuclear binding energy for dripline nuclei.

The pH-dependant attachment of ceria nanoparticles to silica using surface analytical techniques

International Nuclear Information System (INIS)

Dawkins, K.; Rudyk, B.W.; Xu, Z.; Cadien, K.

2015-01-01

Graphical abstract: - Highlights: • A model for interaction between ceria nanoparticles and silica surfaces is proposed. • Proposed model investigated using zeta potential measurements and XPS. • Surface contamination is minimized at higher slurry pH levels. • High-resolution Ce 3d XPS and surface composition measured at different pH levels. • Variations in ceria contamination on silica surfaces via SEM and AES are studied. - Abstract: The adhesion and removal of ceria particles to a silica surface was investigated with the use of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and auger electron spectroscopy (AES) measurements. A model is presented based on electrophoretic mobility measurements of ceria slurry and silica particles at different pH's. XPS results show that at acidic pH values, ceria is present on silica surfaces, but at alkaline pH values, far less ceria is present, or no ceria is present in the extreme case. SEM results corroborated the XPS results showing uniform distribution of ceria particles on silica surface at pH 6 while a clean silica surface is observed at pH 12. However, SEM images show agglomeration of ceria particles occurring at the isoelectric point of ceria at ∼pH 9.6. High resolution Ce 3d XPS analysis indicates that ceria present on the surface is composed ∼31% Ce(III) and ∼69% Ce(IV). AES mapping done at specific points on the silica surface validated both XPS and SEM results. Based on XPS, SEM and AES analyses, it is clear that an alkaline pH is necessary to minimize particulate contamination of silica surface by ceria
An Overview of Analytical Determination of Diltiazem, Cimetidine, Ranitidine, and Famotidine by UV Spectrophotometry and HPLC Technique

Directory of Open Access Journals (Sweden)

Nighat Shafi

2013-01-01

Full Text Available This review article recapitulates the analytical methods for the quantitative determinations of diltiazem and three H2 receptor antagonists (cimetidine, ranitidine, and famotidine by one of the spectroscopic technique (UV spectrophotometery and separation technique such as high-performance liquid chromatography (HPLC. The clinical and pharmaceutical analysis of these drugs requires effective analytical procedures for quality control, pharmaceutical dosage formulations, and biological fluids. An extensive survey of the literature published in various analytical and pharmaceutical chemistry-related journals has been compiled in its review. A synopsis of reported spectrophotometric and high-performance liquid chromatographic methods for individual drug is integrated. This appraisal illustrates that majority of the HPLC methods reviewed are based on the quantitative analysis of drugs in biological fluids, and they are appropriate for therapeutic drug monitoring purpose.
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
Identification of Microorganisms by Modern Analytical Techniques.

Science.gov (United States)

Buszewski, Bogusław; Rogowska, Agnieszka; Pomastowski, Paweł; Złoch, Michał; Railean-Plugaru, Viorica

2017-11-01

Rapid detection and identification of microorganisms is a challenging and important aspect in a wide range of fields, from medical to industrial, affecting human lives. Unfortunately, classical methods of microorganism identification are based on time-consuming and labor-intensive approaches. Screening techniques require the rapid and cheap grouping of bacterial isolates; however, modern bioanalytics demand comprehensive bacterial studies at a molecular level. Modern approaches for the rapid identification of bacteria use molecular techniques, such as 16S ribosomal RNA gene sequencing based on polymerase chain reaction or electromigration, especially capillary zone electrophoresis and capillary isoelectric focusing. However, there are still several challenges with the analysis of microbial complexes using electromigration technology, such as uncontrolled aggregation and/or adhesion to the capillary surface. Thus, an approach using capillary electrophoresis of microbial aggregates with UV and matrix-assisted laser desorption ionization time-of-flight MS detection is presented.
Analytical and Numerical Studies of Sloshing in Tanks

Energy Technology Data Exchange (ETDEWEB)

Solaas, F

1996-12-31

For oil cargo ship tanks and liquid natural gas carriers, the dimensions of the tanks are often such that the highest resonant sloshing periods and the ship motions are in the same period range, which may cause violent resonant sloshing of the liquid. In this doctoral thesis, linear and non-linear analytical potential theory solutions of the sloshing problem are studied for a two-dimensional rectangular tank and a vertical circular cylindrical tank, using perturbation technique for the non-linear case. The tank is forced to oscillate harmonically with small amplitudes of sway with frequency in the vicinity of the lowest natural frequency of the fluid inside the tank. The method is extended to other tank shapes using a combined analytical and numerical method. A boundary element numerical method is used to determine the eigenfunctions and eigenvalues of the problem. These are used in the non-linear analytical free surface conditions, and the velocity potential and free surface elevation for each boundary value problem in the perturbation scheme are determined by the boundary element method. Both the analytical method and the combined analytical and numerical method are restricted to tanks with vertical walls in the free surface. The suitability of a commercial programme, FLOW-3D, to estimate sloshing is studied. It solves the Navier-Stokes equations by the finite difference method. The free surface as function of time is traced using the fractional volume of fluid method. 59 refs., 54 figs., 37 tabs.
Analytical and Numerical Studies of Sloshing in Tanks

Energy Technology Data Exchange (ETDEWEB)

Solaas, F.

1995-12-31

For oil cargo ship tanks and liquid natural gas carriers, the dimensions of the tanks are often such that the highest resonant sloshing periods and the ship motions are in the same period range, which may cause violent resonant sloshing of the liquid. In this doctoral thesis, linear and non-linear analytical potential theory solutions of the sloshing problem are studied for a two-dimensional rectangular tank and a vertical circular cylindrical tank, using perturbation technique for the non-linear case. The tank is forced to oscillate harmonically with small amplitudes of sway with frequency in the vicinity of the lowest natural frequency of the fluid inside the tank. The method is extended to other tank shapes using a combined analytical and numerical method. A boundary element numerical method is used to determine the eigenfunctions and eigenvalues of the problem. These are used in the non-linear analytical free surface conditions, and the velocity potential and free surface elevation for each boundary value problem in the perturbation scheme are determined by the boundary element method. Both the analytical method and the combined analytical and numerical method are restricted to tanks with vertical walls in the free surface. The suitability of a commercial programme, FLOW-3D, to estimate sloshing is studied. It solves the Navier-Stokes equations by the finite difference method. The free surface as function of time is traced using the fractional volume of fluid method. 59 refs., 54 figs., 37 tabs.
MS-Based Analytical Techniques: Advances in Spray-Based Methods and EI-LC-MS Applications

Science.gov (United States)

Medina, Isabel; Cappiello, Achille; Careri, Maria

2018-01-01

Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. This review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.
Surface analytical investigations of the release behaviour of volatile fission products during simulated core meltdown accidents and of the reaction behaviour of iodine with silver surfaces

International Nuclear Information System (INIS)

Moers, H.

1986-07-01

The report presents the results of the analysis of aerosol particles formed in simulated laboratory scale core meltdown experiments. In addition the interaction of silver surfaces with gaseous molecular iodine and with iodide and molecular iodine in aqueous solution was investigated. The composition of the aerosol samples and the progress of the reactions mentioned were determined by use of surface analytical techniques (X-ray photoelectron spectroscopy, Auger electron spectroscopy, secondary ion mass spectroscopy). The major information can be evaluated from X-ray photoelectron spectra which exhibit chemical shifts of the photoelectron lines which allowing a discrimination between different chemical species of the same element. The analyses showed that iodine is present in the aerosol particles mainly as caesium iodide and, to a smaller fraction, as silver iodide. During the adsorption of gaseous molecular iodine at metallic silver surfaces a closed silver iodide overlayer is formed. In aqueous iodide solutions one observes chemisorption of the iodide anions up to a coverage of the metallic silver surface of about half a monolayer. Molecular iodine in aqueous solution is completely converted to silver iodide which covers the substrate irregularly. (orig./HP) [de
Analytical Characterisation of Nanoscale Zero-Valent Iron: A ...

Science.gov (United States)

Zero-valent iron nanoparticles (nZVI) have been widely tested as they are showing significant promise for environmental remediation. However, many recent studies have demonstrated that their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Both the mobility and reactivity of nZVI mainly depends on properties such as particle size, surface chemistry and bulk composition. In order to ensure efficient remediation, it is crucial to accurately assess and understand the implications of these properties before deploying these materials into contaminated environments. Many analytical techniques are now available to determine these parameters and this paper provides a critical review of their usefulness and limitations for nZVI characterisation. These analytical techniques include microscopy and light scattering techniques for the determination of particle size, size distribution and aggregation state, and X-ray techniques for the characterisation of surface chemistry and bulk composition. Example characterisation data derived from commercial nZVI materials is used to further illustrate method strengths and limitations. Finally, some important challenges with respect to the characterisation of nZVI in groundwater samples are discussed. In recent years, manufactured nanoparticles (MNPs) have attracted increasing interest for their potential applications in the treatment of contaminated soil and water. In compar
Fluvial sediment transport: Analytical techniques for measuring sediment load

International Nuclear Information System (INIS)

2005-07-01

Sediment transport data are often used for the evaluation of land surface erosion, reservoir sedimentation, ecological habitat quality and coastal sediment budgets. Sediment transport by rivers is usually considered to occur in two major ways: (1) in the flow as a suspended load and (2) along the bed as a bed load. This publication provides guidance on selected techniques for the measurement of particles moving in both modes in the fluvial environment. The relative importance of the transport mode is variable and depends on the hydraulic and sedimentary conditions. The potential user is directed in the selection of an appropriate technique through the presentation of operating principles, application guidelines and estimated costs. Techniques which require laboratory analysis are grab sample, pump sample, depth sample, point integrated and radioactive tracers. Techniques which will continuously record data are optical backscattering, nuclear transmission, single frequency acoustic and laser diffraction
Analytical mass formula and nuclear surface properties in the ETF approximation. Part I: symmetric nuclei

Science.gov (United States)

Aymard, François; Gulminelli, Francesca; Margueron, Jérôme

2016-08-01

The problem of determination of nuclear surface energy is addressed within the framework of the extended Thomas Fermi (ETF) approximation using Skyrme functionals. We propose an analytical model for the density profiles with variationally determined diffuseness parameters. In this first paper, we consider the case of symmetric nuclei. In this situation, the ETF functional can be exactly integrated, leading to an analytical formula expressing the surface energy as a function of the couplings of the energy functional. The importance of non-local terms is stressed and it is shown that they cannot be deduced simply from the local part of the functional, as it was suggested in previous works.
Waste minimization in analytical chemistry through innovative sample preparation techniques

International Nuclear Information System (INIS)

Smith, L. L.

1998-01-01

water samples. In this SPME technique, a fused-silica fiber coated with a polymeric film is exposed to the sample, extraction is allowed to take place, and then the analytes are thermally desorbed for GC analysis. Unlike liquid-liquid extraction or solid-phase extraction, SPME consumes all of the extracted sample in the analysis, significantly reducing the required sample volume
Study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Pyrovan, H.; Raoffi, N.J.; Taherpoor, H.

1985-01-01

This work is part of project with the IAEA in a coordinated program on 'Trace Elements in Human and Bio-environmental Systems' to evaluate their nutritional requierements, interrelations and the role of trace elements in health, metabolism, etc. Cow's milk is regarded to be one of the most important and most nutritious foodstuffs of mankind. Hence, as a first step, an elemental analysis for milk was carried out: a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of the project was the assessment of various analytical techniques involved. AAS, PIXE and NAA are presented here. The latter was applied both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is, however, some justification to clarify this internal inconsistency. PIXE analysis is very fast and rather routine, but the technique for trace element analysis needs certain adaptations and improvement. (author)
Surface characterization of an energetic material, pentaerythritoltetranitrate (PETN), having a thin coating achieved through a starved addition microencapsulation technique

Energy Technology Data Exchange (ETDEWEB)

Worley, C.M.

1986-05-07

The objective of this research was to: (1) determine the nature of a thin coating on an explosive material which was applied using a starved addition microencapsulation technique, (2) understand the coating/crystal bond, and (3) investigate the wettability/adhesion of plastic/solvent combinations using the coating process. The coating used in this work was a Firestone Plastic Company copolymer (FPC-461) of vinylchloride/trifluorochloroethylene in a 1.5/1.0 weight ratio. The energetic explosive examined was pentaerythritoltetranitrate (PETN). The coating process used was starved addition followed by a solvent evaporation technique. Surface analytical studies, completed for characterization of the coating process, show (1) evidence that the polymer coating is present, but not continuous, over the surface of PETN; (2) the average thickness of the polymer coating is between 16-32 A and greater than 44 A, respectively, for 0.5 and 20 wt % coated PETN; (3) no changes in surface chemistry of the polymer or the explosive material following microencapsulation; and (4) the presence of explosive material on the surface of 0.5 wt % FPC-461 coated explosives. 5 refs., 15 figs., 6 tabs.
Bayesian techniques for surface fuel loading estimation

Science.gov (United States)

Kathy Gray; Robert Keane; Ryan Karpisz; Alyssa Pedersen; Rick Brown; Taylor Russell

2016-01-01

A study by Keane and Gray (2013) compared three sampling techniques for estimating surface fine woody fuels. Known amounts of fine woody fuel were distributed on a parking lot, and researchers estimated the loadings using different sampling techniques. An important result was that precise estimates of biomass required intensive sampling for both the planar intercept...
Critical reflection activation analysis - a new near-surface probe

International Nuclear Information System (INIS)

Gunn, J.M.F.; Trohidou, K.N.

1988-09-01

We propose a new surface analytic technique, Critical Reflection Activation Analysis (CRAA). This technique allows accurate depth profiling of impurities ≤ 100A beneath a surface. The depth profile of the impurity is simply related to the induced activity as a function of the angle of reflection. We argue that the technique is practical and estimate its accuracy. (author)
Quantification of surface contamination: principles and applications

International Nuclear Information System (INIS)

Vo-Dinh, T.

1982-01-01

The applications discussed in this paper underscore the usefulness and versatility of molecular luminescence spectroscopy as an efficient surface detection technique. The technique can be used not only as a qualitative characterization method, but also as a quantitative analytical tool to detect trace contaminants on surfaces. Recent advances in instrumentation and methodology have expanded the applicability of surface luminescence into many new problem areas. Trace organics are emphasized here
An Analytical Model for Prediction of Magnetic Flux Leakage from Surface Defects in Ferromagnetic Tubes

Directory of Open Access Journals (Sweden)

Suresh V.

2016-02-01

Full Text Available In this paper, an analytical model is proposed to predict magnetic flux leakage (MFL signals from the surface defects in ferromagnetic tubes. The analytical expression consists of elliptic integrals of first kind based on the magnetic dipole model. The radial (Bz component of leakage fields is computed from the cylindrical holes in ferromagnetic tubes. The effectiveness of the model has been studied by analyzing MFL signals as a function of the defect parameters and lift-off. The model predicted results are verified with experimental results and a good agreement is observed between the analytical and the experimental results. This analytical expression could be used for quick prediction of MFL signals and also input data for defect reconstructions in inverse MFL problem.
Analytical techniques for the determination of radiochemical purity of radiopharmaceuticals prepared from kits. Pt. III

International Nuclear Information System (INIS)

McLean, J.R.; Rockwell, L.J.; Welsh, W.J.

1982-01-01

The evaluation of efficacy of commercially available kits used for the preparation of radiopharmaceuticals is one aspect of the Radiation Protection Bureau's radiopharmaceutical quality control program. This report describes some of the analytical methodology employed in the program. The techniques may be of interest to hospital radiopharmacy personnel since many of the tests can be performed rapidly and with a minimum of special equipment, thus enabling the confirmation of radiopharmaceutical purity prior to patient administration. Manufacturers of kits may also be interested in learning of the analytical methods used in the assessment of their products
Applications of nuclear analytical techniques to environmental studies

International Nuclear Information System (INIS)

Freitas, M.C.; Marques, A.P.; Reis, M.A.; Pacheco, A.M.G.; Barros, L.I.C.

2001-01-01

A few examples of application of nuclear-analytical techniques to biological monitors - natives and transplants - are given herein. Parmelia sulcata Taylor transplants were set up in a heavily industrialized area of Portugal - the Setubal peninsula, about 50 km south of Lisbon - where indigenous lichens are rare. The whole area was 10x15 km around an oil-fired power station, and a 2.5x2.5 km grid was used. In north-western Portugal, native thalli of the same epiphytes (Parmelia spp., mostly Parmelia sulcata Taylor) and bark from olive trees (Olea europaea) were sampled across an area of 50x50 km, using a 10x10 km grid. This area is densely populated and features a blend of rural, urban-industrial and coastal environments, together with the country's second-largest metro area (Porto). All biomonitors have been analyzed by INAA and PIXE. Results were put through nonparametric tests and factor analysis for trend significance and emission sources, respectively

Development of analytical techniques for water and environmental samples (2)

Energy Technology Data Exchange (ETDEWEB)

Eum, Chul Hun; Jeon, Chi Wan; Jung, Kang Sup; Song, Kyung Sun; Kim, Sang Yeon [Korea Institute of Geology Mining and Materials, Taejon (Korea)

1998-12-01

The purpose of this study is to develop new analytical methods with good detection limit for toxic inorganic and organic compounds. The analyses of CN, organic acids, particulate materials in environmental samples have been done using several methods such as Ion Chromatography, SPE, SPME, GC/MS, GC/FID, SPLITT (split-flow thin cell fractionation) during the second year of this project. Advantage and disadvantage of several distillation method (by KS, JIS, EPA) for CN analysis in wastewater were investigated. As the results, we proposed new distillation apparatus for CN analysis, which was proved to be simpler, faster and to get better recovery than conventional apparatus. And ion chromatograph/pulsed amperometric detector (IC/PAD) system instead of colorimetry for CN detection was setup to solve matrix interference. And SPE(solid phase extraction) and SPME (solid phase micro extraction) as liquid-solid extraction technique were applied to the analysis of phenols in wastewater. Optimum experimental conditions and factors influencing analytical results were determined. From these results, It could be concluded that C{sub 18} cartridge and polystyrene-divinylbenzene disk in SPE method, polyacrylate fiber in SPME were proper solid phase adsorbent for phenol. Optimum conditions to analyze phenol derivatives simultaneously were established. Also, Continuous SPLITT (Split-flow thin cell) Fractionation (CSF) is a new preparative separation technique that is useful for fractionation of particulate and macromolecular materials. CSF is carried out in a thin ribbon-like channel equipped with two splitters at both inlet and outlet of the channel. In this work, we set up a new CSF system, and tested using polystyrene latex standard particles. And then we fractionated particles contained in air and underground water based on their sedimentation coefficients using CSF. (author). 27 refs., 13 tabs., 31 figs.
Evaluation of hydrogen and oxygen impurity levels on silicon surfaces

Energy Technology Data Exchange (ETDEWEB)

Kenny, M.J.; Wielunski, L.S.; Netterfield, R.P.; Martin, P.J.; Leistner, A. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics

1996-12-31

This paper reports on surface analytical techniques used to quantify surface concentrations of impurities such as oxygen and hydrogen. The following analytical techniques were used: Rutherford and Backscattering, elastic recoil detection, time-of-flight SIMS, spectroscopic ellipsometry, x-ray photoelectron spectroscopy. The results have shown a spread in thickness of oxide layer, ranging from unmeasurable to 1.6 nm. The data must be considered as preliminary at this stage, but give some insight into the suitability of the techniques and a general idea of the significance of impurities at the monolayer level. These measurements have been carried out on a small number of silicon surfaces both semiconductor grade <111> crystalline material and silicon which has been used in sphere fabrication. 5 refs., 1 fig.
Evaluation of hydrogen and oxygen impurity levels on silicon surfaces

Energy Technology Data Exchange (ETDEWEB)

Kenny, M J; Wielunski, L S; Netterfield, R P; Martin, P J; Leistner, A [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics

1997-12-31

This paper reports on surface analytical techniques used to quantify surface concentrations of impurities such as oxygen and hydrogen. The following analytical techniques were used: Rutherford and Backscattering, elastic recoil detection, time-of-flight SIMS, spectroscopic ellipsometry, x-ray photoelectron spectroscopy. The results have shown a spread in thickness of oxide layer, ranging from unmeasurable to 1.6 nm. The data must be considered as preliminary at this stage, but give some insight into the suitability of the techniques and a general idea of the significance of impurities at the monolayer level. These measurements have been carried out on a small number of silicon surfaces both semiconductor grade <111> crystalline material and silicon which has been used in sphere fabrication. 5 refs., 1 fig.
Multiple sectioning and perforation techniques for TEM sub-surface studies

International Nuclear Information System (INIS)

Lee, E.H.; Rowcliffe, A.F.

1978-01-01

Techniques for preparing multiple electron transparent regions at several depth levels below the surface of a metal disk specimen are described. These techniques are relatively rapid and find application in many areas involving surface studies. Examples are shown of multiple thin areas produced at intervals of approximately 200 nm below the original surface of a stainless steel bombarded with 4 MeV Ni +2 ions for void swelling studies
Analytical and numerical techniques for predicting the interfacial stresses of wavy carbon nanotube/polymer composites

NARCIS (Netherlands)

Yazdchi, K.; Salehi, M.; Shokrieh, M.M.

2009-01-01

By introducing a new simplified 3D representative volume element for wavy carbon nanotubes, an analytical model is developed to study the stress transfer in single-walled carbon nanotube-reinforced polymer composites. Based on the pull-out modeling technique, the effects of waviness, aspect ratio,
Surface Plasmon Resonance: New Biointerface Designs and High-Throughput Affinity Screening

Science.gov (United States)

Linman, Matthew J.; Cheng, Quan Jason

Surface plasmon resonance (SPR) is a surface optical technique that measures minute changes in refractive index at a metal-coated surface. It has become increasingly popular in the study of biological and chemical analytes because of its label-free measurement feature. In addition, SPR allows for both quantitative and qualitative assessment of binding interactions in real time, making it ideally suited for probing weak interactions that are often difficult to study with other methods. This chapter presents the biosensor development in the last 3 years or so utilizing SPR as the principal analytical technique, along with a concise background of the technique itself. While SPR has demonstrated many advantages, it is a nonselective method and so, building reproducible and functional interfaces is vital to sensing applications. This chapter, therefore, focuses mainly on unique surface chemistries and assay approaches to examine biological interactions with SPR. In addition, SPR imaging for high-throughput screening based on microarrays and novel hyphenated techniques involving the coupling of SPR to other analytical methods is discussed. The chapter concludes with a commentary on the current state of SPR biosensing technology and the general direction of future biosensor research.
Impact of accelerator-based analytical techniques on the knowledge and conservation of cultural heritage

International Nuclear Information System (INIS)

Dran, Jean Claude

2001-01-01

A large set of modern analytical techniques is currently applied to get a better insight on art and archaeological objects as well as to contribute to their conservation and restoration. Because of the precious and sometimes unique character of the works, non-destructive techniques and even those requiring no (or only minute) sampling, are preferred. From this standpoint, ion beam analysis (IBA) constitutes one of the best choices, since it combines quite good analytical performance and non-destructiveness. For over 10 years, an IBA facility has been installed in the Research Laboratory of the Museums of France. Until now it is the only facility of this kind entirely devoted to the study of cultural heritage. A special set-up, namely an external beam line, has been developed which permits the in-air analysis of large or fragile works of art without sampling. This facility is used for both short investigations at the request of museum curators and extensive research works in art history and archaeology. Numerous examples will be given to highlight the impact of this tool on cultural heritage. (author)
Macro elemental analysis of food samples by nuclear analytical technique

Science.gov (United States)

Syahfitri, W. Y. N.; Kurniawati, S.; Adventini, N.; Damastuti, E.; Lestiani, D. D.

2017-06-01

Energy-dispersive X-ray fluorescence (EDXRF) spectrometry is a non-destructive, rapid, multi elemental, accurate, and environment friendly analysis compared with other detection methods. Thus, EDXRF spectrometry is applicable for food inspection. The macro elements calcium and potassium constitute important nutrients required by the human body for optimal physiological functions. Therefore, the determination of Ca and K content in various foods needs to be done. The aim of this work is to demonstrate the applicability of EDXRF for food analysis. The analytical performance of non-destructive EDXRF was compared with other analytical techniques; neutron activation analysis and atomic absorption spectrometry. Comparison of methods performed as cross checking results of the analysis and to overcome the limitations of the three methods. Analysis results showed that Ca found in food using EDXRF and AAS were not significantly different with p-value 0.9687, whereas p-value of K between EDXRF and NAA is 0.6575. The correlation between those results was also examined. The Pearson correlations for Ca and K were 0.9871 and 0.9558, respectively. Method validation using SRM NIST 1548a Typical Diet was also applied. The results showed good agreement between methods; therefore EDXRF method can be used as an alternative method for the determination of Ca and K in food samples.
Directory of Analytical Methods, Department 1820

International Nuclear Information System (INIS)

Whan, R.E.

1986-01-01

The Materials Characterization Department performs chemical, physical, and thermophysical analyses in support of programs throughout the Laboratories. The department has a wide variety of techniques and instruments staffed by experienced personnel available for these analyses, and we strive to maintain near state-of-the-art technology by continued updates. We have prepared this Directory of Analytical Methods in order to acquaint you with our capabilities and to help you identify personnel who can assist with your analytical needs. The descriptions of the various capabilities are requester-oriented and have been limited in length and detail. Emphasis has been placed on applications and limitations with notations of estimated analysis time and alternative or related techniques. A short, simplified discussion of underlying principles is also presented along with references if more detail is desired. The contents of this document have been organized in the order: bulky analysis, microanalysis, surface analysis, optical and thermal property measurements
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.
Application gives the technique the analytic tree in the evaluation the effectiveness programs to radiological protection

International Nuclear Information System (INIS)

Perez Gonzalez, F.; Perez Velazquez, R.S.; Fornet Rodriguez, O.; Mustelier Hechevarria, A.; Miller Clemente, A.

1998-01-01

In the work we develop the IAEA recommendations in the application the analytic tree as instrument for the evaluation the effectiveness the occupational radiological protection programs. Is reflected like it has been assimilated and converted that technique in daily work istruments in the evaluation process the security conditions in the institutions that apply the nuclear techniques with a view to its autorization on the part of the regulatory organ
Development of computational technique for labeling magnetic flux-surfaces

International Nuclear Information System (INIS)

Nunami, Masanori; Kanno, Ryutaro; Satake, Shinsuke; Hayashi, Takaya; Takamaru, Hisanori

2006-03-01

In recent Large Helical Device (LHD) experiments, radial profiles of ion temperature, electric field, etc. are measured in the m/n=1/1 magnetic island produced by island control coils, where m is the poloidal mode number and n the toroidal mode number. When the transport of the plasma in the radial profiles is numerically analyzed, an average over a magnetic flux-surface in the island is a very useful concept to understand the transport. On averaging, a proper labeling of the flux-surfaces is necessary. In general, it is not easy to label the flux-surfaces in the magnetic field with the island, compared with the case of a magnetic field configuration having nested flux-surfaces. In the present paper, we have developed a new computational technique to label the magnetic flux-surfaces. This technique is constructed by using an optimization algorithm, which is known as an optimization method called the simulated annealing method. The flux-surfaces are discerned by using two labels: one is classification of the magnetic field structure, i.e., core, island, ergodic, and outside regions, and the other is a value of the toroidal magnetic flux. We have applied the technique to an LHD configuration with the m/n=1/1 island, and successfully obtained the discrimination of the magnetic field structure. (author)
Self-cleaning Foliar Surfaces Characterization using RIMAPS Technique and Variogram Method

International Nuclear Information System (INIS)

Rosi, Pablo E.

2002-01-01

Along the last ten years many important studies about characterization of self-cleaning foliar surfaces have been done and focused new interest on this kind of surfaces.These studies were possible due to the development of a novel preparation technique for this biological material that let us observe the delicate structures of a foliar surface under scanning electron microscope (S.E.M.).This technique consists of replacing the natural water of the specimen by glycerol. Digital S.E.M. images from both self-cleaning and non-self-cleaning foliar surfaces were obtained and analyzed using RIMAPS technique and Variograms method. Our results revealed the existence of a common and exclusive geometrical pattern that is found in species which present self-cleaning foliar surfaces.This pattern combines at least nine different directions.The results from the Variograms method showed that the stomata play a key role in the determination of foliar surface roughness. In addition, spectra from RIMAPS technique constitute a fingerprint of a foliar surface so they can be used to find evolutionary relationships among species.Further studies will provide more detailed information to fully elucidate the self-cleaning pattern, so it might be possible to reproduce it on an artificial surface and make it self-cleaning
Evaluating the performance of free-formed surface parts using an analytic network process

Science.gov (United States)

Qian, Xueming; Ma, Yanqiao; Liang, Dezhi

2018-03-01

To successfully design parts with a free-formed surface, the critical issue of how to evaluate and select a favourable evaluation strategy before design is raised. The evaluation of free-formed surface parts is a multiple criteria decision-making (MCDM) problem that requires the consideration of a large number of interdependent factors. The analytic network process (ANP) is a relatively new MCDM method that can systematically deal with all kinds of dependences. In this paper, the factors, which come from the life-cycle and influence the design of free-formed surface parts, are proposed. After analysing the interdependence among these factors, a Hybrid ANP (HANP) structure for evaluating the part’s curved surface is constructed. Then, a HANP evaluation of an impeller is presented to illustrate the application of the proposed method.
A pirólise como técnica analítica Pyrolysis as an analytical technique

Directory of Open Access Journals (Sweden)

Flaviano Oliveira Silvério

2008-01-01

Full Text Available In this paper historical aspects of analytical pyrolysis, the equipment used, the fundamentals and the mechanisms of pyrolysis of different polymeric materials are discussed. The latest work on analytical pyrolysis applied to various types of synthetic and natural samples is reviewed. Current applications of this technique that are discussed include identification of microorganisms, analysis of trace compounds by forensic laboratories, investigation of food and agricultural products, study of the chemical composition of wood, authentication and conservation of artworks, and the study of environmental and geochemical samples.
Some recent developments in the surface-analytical application of X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Gries, W.H.

1987-01-01

Standard depth profiles of an analyte deposited into (diffusion or ion implantation) or on (thin-film deposition) a plane surface can be analyzed for profile type and centroid depth or film thickness by means of a standardless method in which the matrix-attenuated signals of the fluorescing analyte measured at two different take-off angles are related to the mathematical distribution moments of the profile. For a binary thin film the element ratio can also be established. Results obtained on phosphorus profiles in silicon and on zinc sulphide optical coatings are referred to. The quantity or concentration level can be determined by use of a reference standard which may contain the analyte in an entirely different distribution. This simplifies the calibration of secondary reference standards. A good lateral resolution in the sub-millimeter range can be achieved with synchrotron radiation. A further improvement of lateral resolution is possible by direct excitation with electron microbeams, though at significantly inferior detection limits. (orig.)
Superhydrophobic analyte concentration utilizing colloid-pillar array SERS substrates.

Science.gov (United States)

Wallace, Ryan A; Charlton, Jennifer J; Kirchner, Teresa B; Lavrik, Nickolay V; Datskos, Panos G; Sepaniak, Michael J

2014-12-02

The ability to detect a few molecules present in a large sample is of great interest for the detection of trace components in both medicinal and environmental samples. Surface enhanced Raman spectroscopy (SERS) is a technique that can be utilized to detect molecules at very low absolute numbers. However, detection at trace concentration levels in real samples requires properly designed delivery and detection systems. The following work involves superhydrophobic surfaces that have as a framework deterministic or stochastic silicon pillar arrays formed by lithographic or metal dewetting protocols, respectively. In order to generate the necessary plasmonic substrate for SERS detection, simple and flow stable Ag colloid was added to the functionalized pillar array system via soaking. Native pillars and pillars with hydrophobic modification are used. The pillars provide a means to concentrate analyte via superhydrophobic droplet evaporation effects. A ≥ 100-fold concentration of analyte was estimated, with a limit of detection of 2.9 × 10(-12) M for mitoxantrone dihydrochloride. Additionally, analytes were delivered to the surface via a multiplex approach in order to demonstrate an ability to control droplet size and placement for scaled-up uses in real world applications. Finally, a concentration process involving transport and sequestration based on surface treatment selective wicking is demonstrated.
Optimization of freeform surfaces using intelligent deformation techniques for LED applications

Science.gov (United States)

Isaac, Annie Shalom; Neumann, Cornelius

2018-04-01

For many years, optical designers have great interests in designing efficient optimization algorithms to bring significant improvement to their initial design. However, the optimization is limited due to a large number of parameters present in the Non-uniform Rationaly b-Spline Surfaces. This limitation was overcome by an indirect technique known as optimization using freeform deformation (FFD). In this approach, the optical surface is placed inside a cubical grid. The vertices of this grid are modified, which deforms the underlying optical surface during the optimization. One of the challenges in this technique is the selection of appropriate vertices of the cubical grid. This is because these vertices share no relationship with the optical performance. When irrelevant vertices are selected, the computational complexity increases. Moreover, the surfaces created by them are not always feasible to manufacture, which is the same problem faced in any optimization technique while creating freeform surfaces. Therefore, this research addresses these two important issues and provides feasible design techniques to solve them. Finally, the proposed techniques are validated using two different illumination examples: street lighting lens and stop lamp for automobiles.
Comparison between energy dispersive X-ray fluorescence and other nuclear analytical techniques in mineral exploration and mining

International Nuclear Information System (INIS)

Clayton, C.G.; Packer, T.W.; Wormald, M.R.

1979-01-01

At the present time there is an increasing awareness of the value and need for in-situ analytical methods throughout the general area of mineral exploration and mining. Of the alternative techniques, the measurement of natural gamma radiation is well established for uranium exploration and it is now being developed for sea-bed and lake-bed surveying. Energy dispersive X-ray fluorescence equipment is becoming more generally accepted, especially for mine control. Neutron techniques, for so long used routinely in oil well logging, are now being developed for a wide range of applications in all aspects of exploration and mining. It is believed that these techniques will result in major applications in the future. The present paper compares the principal characteristics of energy dispersive X-ray fluorescence and neutron techniques in particular, with special emphasis being given to those factors which affect the accuracy of analytical content; such as elemental resolution, matrix effects, material heterogeneity and neutron transport. A generalised comparison between the techniques is difficult to achieve because of the different nature of radiation interactions, but a range of applications is described and these show the complementary nature of the methods and point to the areas for more active development in the future. (author)
Techniques of surface optical breakdown prevention for low-depths femtosecond waveguides writing

International Nuclear Information System (INIS)

Bukharin, M A; Skryabin, N N; Ganin, D V; Khudyakov, D V; Vartapetov, S.K.

2016-01-01

We demonstrated technique of direct femtosecond waveguide writing at record low depth (2-15 μm) under surface of lithium niobate, that play a key role in design of electrooptical modulators with low operating voltage. To prevent optical breakdown of crystal surface we used high numerical aperture objectives for focusing of light and non-thermal regime of inscription in contrast to widespread femtosecond writing technique at depths of tens micrometers or higher. Surface optical breakdown threshold was measured for both x- and z- cut crystals. Inscribed waveguides were examined for intrinsic microstructure. It also reported sharp narrowing of operating pulses energy range with writing depth under the surface of crystal, that should be taken in account when near-surface waveguides design. Novelty of the results consists in reduction of inscription depth under the surface of crystals that broadens applications of direct femtosecond writing technique to full formation of near-surface waveguides and postproduction precise geometry correction of near-surfaces optical integrated circuits produced with proton-exchanged technique. (paper)

Nuclear analytical techniques applied to characterization of atmospheric aerosols in Amazon Region

International Nuclear Information System (INIS)

Gerab, Fabio; Artaxo, Paulo

1996-01-01

This work presents the atmospheric aerosols characterization that exist in different regions of Amazon basin. The biogenic aerosol emission by forest, as well as the atmospheric emissions of particulate materials due to biomass burning, were analyzed. Samples of aerosol particles were collected during three years in two different locations of Amazon region using Stacked Unit Filters. In order to study these samples some analytical nuclear techniques were used. The high concentrations of aerosols as a result of biomass burning process were observed in the period of june-september
Visualization of brain surface structures by weighted summation technique using multislice MR images

International Nuclear Information System (INIS)

Machida, Yoshio; Hatanaka, Masahiko; Hagiwara, Masayuki; Sugimoto, Hiroshi; Yoshida, Tadatoki; Katada, Kazuhiro.

1991-01-01

Surface anatomy scanning (SAS) technique which visualizes brain surface structures has been developed since 1987. In this paper, we propose a modified method called 'multislice SAS', which also generates such surface structure images, and has several advantages compared with conventional SAS technique. The conventional SAS technique uses a very long echo time sequence (e.g. SE(3000, 250)) with a thick slice and a surface coil to enhance CSF on the brain surface. Our modified technique also uses a long echo time sequence. But, added multislice images, each appropriately weighted, are used in stead of a thick slice and a surface coil. Our basic studies have shown that this modified method has the following advantage: Several surface images with slightly different summation directions are obtained, and they are used for stereographic display and cine display. This is very useful for visualizing the spatial relationship of brain surface structures. By choosing appropriate weighting, we can obtain clinically legible surface images. This technique dose not require a surface coil. It means that flexibility of selecting imaging direction is high. We can make a lot of modifications, because the original multislice images of weighted summation are arbitrary. And we also clarify some limitation or disadvantage of this modified method. In conclusion, we think that this technique is one of the practical approaches for surface anatomy imaging. (author)
Analytical Techniques in the Pharmaceutical Sciences

DEFF Research Database (Denmark)

Leurs, Ulrike; Mistarz, Ulrik Hvid; Rand, Kasper Dyrberg

2016-01-01

Mass spectrometry (MS) offers the capability to identify, characterize and quantify a target molecule in a complex sample matrix and has developed into a premier analytical tool in drug development science. Through specific MS-based workflows including customized sample preparation, coupling...
Study of trace elements in milk by nuclear analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

This work is part of a project with the IAEA, in a coordinated programme on ''trace elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of trace elements in health, metabolism etc. Cow's milk is regarded as one of the most important and nutritious foodstuffs consumed by people. Hence, as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is very fast and rather routine, the technique of trace element analysis needs certain adaptations and developments.
Self-consistent Green’s-function technique for surfaces and interfaces

DEFF Research Database (Denmark)

Skriver, Hans Lomholt; Rosengaard, N. M.

1991-01-01

We have implemented an efficient self-consistent Green’s-function technique for calculating ground-state properties of surfaces and interfaces, based on the linear-muffin-tin-orbitals method within the tight-binding representation. In this approach the interlayer interaction is extremely short...... ranged, and only a few layers close to the interface need be treated self-consistently via a Dyson equation. For semi-infinite jellium, the technique gives work functions and surface energies that are in excellent agreement with earlier calculations. For the bcc(110) surface of the alkali metals, we find...
Surface science an introduction

CERN Document Server

Hudson, John

1991-01-01

The whole field of surface science is covered in this work. Starting with a description of the structure and thermodynamics of clean surfaces, the book goes on to discuss kinetic theory of gases and molecular beam formation. This is followed by a largesection on gas-surface interactions, and another major section on energetic particle-surface interactions. The final chapter provides the background to crystal nucleation and growth. The approach adopted is interdisciplinary and slanted towards theexperimental side, with practical analytical techniques being used to illustrate general princi
Use of nuclear and related analytical techniques in environmental research as exemplified by selected air pollution studies

International Nuclear Information System (INIS)

Smodis, B.; Jacimovic, R.; Jeran, Z.; Stropnik, B.; Svetina, M.

2000-01-01

Among nuclear and nuclear related analytical techniques, neutron activation analysis and X-ray fluorescence spectrometry proved to be particularly useful for environmental studies owing to their nondestructive character and multi element capability. This paper emphasizes their importance among other multielement analytical methods by discussing their specific role due to specific physics basis, quite different to other destructive non-nuclear methods, and by summarizing results obtained in several studies related to air pollution research, including analyses of airborne particulate matter, water samples, lichens and mosses. (author)
Quantitative study of Xanthosoma violaceum leaf surfaces using RIMAPS and variogram techniques.

Science.gov (United States)

Favret, Eduardo A; Fuentes, Néstor O; Molina, Ana M

2006-08-01

Two new imaging techniques (rotated image with maximum averaged power spectrum (RIMAPS) and variogram) are presented for the study and description of leaf surfaces. Xanthosoma violaceum was analyzed to illustrate the characteristics of both techniques. Both techniques produce a quantitative description of leaf surface topography. RIMAPS combines digitized images rotation with Fourier transform, and it is used to detect patterns orientation and characteristics of surface topography. Variogram relates the mathematical variance of a surface with the area of the sample window observed. It gives the typical scale lengths of the surface patterns. RIMAPS detects the morphological variations of the surface topography pattern between fresh and dried (herbarium) samples of the leaf. The variogram method finds the characteristic dimensions of the leaf microstructure, i.e., cell length, papillae diameter, etc., showing that there are not significant differences between dry and fresh samples. The results obtained show the robustness of RIMAPS and variogram analyses to detect, distinguish, and characterize leaf surfaces, as well as give scale lengths. Both techniques are tools for the biologist to study variations of the leaf surface when different patterns are present. The use of RIMAPS and variogram opens a wide spectrum of possibilities by providing a systematic, quantitative description of the leaf surface topography.
The study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H.

1983-01-01

This work is part of a project with the IAEA, in a coordinated programme on ''Trace Elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of Trace Elements in health, metabolism etc. Cow's milk being regarded as one of the most important and nutritious foodstuffs consumed by people. Hence as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is a very fast and rather a routine but the technique of trace element analysis needs certain adaptations and developments
Perfect imaging of three object points with only two analytic lens surfaces in two dimensions

Science.gov (United States)

Duerr, Fabian; Benítez, Pablo; Miñano, Juan Carlos; Meuret, Youri; Thienpont, Hugo

2012-06-01

In this work, a new two-dimensional analytic optics design method is presented that enables the coupling of three ray sets with two lens profiles. This method is particularly promising for optical systems designed for wide field of view and with clearly separated optical surfaces. However, this coupling can only be achieved if different ray sets will use different portions of the second lens profile. Based on a very basic example of a single thick lens, the Simultaneous Multiple Surfaces design method in two dimensions (SMS2D) will help to provide a better understanding of the practical implications on the design process by an increased lens thickness and a wider field of view. Fermat's principle is used to deduce a set of functional differential equations fully describing the entire optical system. The transformation of these functional differential equations into an algebraic linear system of equations allows the successive calculation of the Taylor series coefficients up to an arbitrary order. The evaluation of the solution space reveals the wide range of possible lens configurations covered by this analytic design method. Ray tracing analysis for calculated 20th order Taylor polynomials demonstrate excellent performance and the versatility of this new analytical optics design concept.
Fabrication of a wettability-gradient surface on copper by screen-printing techniques

International Nuclear Information System (INIS)

Huang, Ding-Jun; Leu, Tzong-Shyng

2015-01-01

In this study, a screen-printing technique is utilized to fabricate a wettability-gradient surface on a copper substrate. The pattern definitions on the copper surface were freely fabricated to define the regions with different wettabilities, for which the printing definition technique was developed as an alternative to the existing costly photolithography techniques. This fabrication process using screen printing in tandem with chemical modification methods can easily realize an excellent wettability-gradient surface with superhydrophobicity and superhydrophilicity. Surface analyses were performed to characterize conditions in some fabrication steps. A water droplet movement sequence is provided to clearly demonstrate the droplet-driving effectiveness of the fabricated gradient surface. The droplet-driving efficiency offers a promising solution for condensation heat transfer applications in the foreseeable future. (paper)
Hazardous Waste Landfill Siting using GIS Technique and Analytical Hierarchy Process

Directory of Open Access Journals (Sweden)

Ozeair Abessi

2010-07-01

Full Text Available Disposal of large amount of generated hazardous waste in power plants, has always received communities' and authori¬ties attentions. In this paper using site screening method and Analytical Hierarchy Process (AHP a sophisticated approach for siting hazardous waste landfill in large areas is presented. This approach demonstrates how the evaluation criteria such as physical, socio-economical, technical, environmental and their regulatory sub criteria can be introduced into an over layer technique to screen some limited appropriate zones in the area. Then, in order to find the optimal site amongst the primary screened site utilizing a Multiple Criteria Decision Making (MCDM method for hierarchy computations of the process is recommended. Using the introduced method an accurate siting procedure for environmental planning of the landfills in an area would be enabled. In the study this approach was utilized for disposal of hazardous wastes of Shahid Rajaee thermal power plant located in Qazvin province west central part of Iran. As a result of this study 10 suitable zones were screened in the area at first, then using analytical hierarchy process a site near the power plant were chosen as the optimal site for landfilling of the hazardous wastes in Qazvin province.
Twelfth ISAS national symposium on analytical techniques for safety and sufficiency of natural resources/products: technical papers

International Nuclear Information System (INIS)

Padmanabhan, P.K.; Page, A.G.

1997-02-01

This volume contains the proceedings of the ISAS (Indian Society of Analytical Scientists) national symposium. The main thrust of the symposium was on new fuel cycle technologies relevant to thorium utilisation programmes. The technologies for different separation processes, techniques for measurements of various process parameters and highly sensitive analytical methods for the determination of the chemical constituents were among the other topics covered. Quality upgradation, standardisation of methods and validation of measurements which are integral parts of product evaluation were also discussed. Papers relevant to INIS are indexed separately
Does leaf chemistry differentially affect breakdown in tropical vs temperate streams? Importance of standardized analytical techniques to measure leaf chemistry

Science.gov (United States)

Marcelo Ard& #243; n; Catherine M. Pringle; Susan L. Eggert

2009-01-01

Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to measure leaf chemistry. We used standardized analytical techniques to measure chemistry and breakdown rate of leaves from common riparian tree species at 2 sites, 1...
Pedestrian-vehicle crashes and analytical techniques for stratified contingency tables.

Science.gov (United States)

Al-Ghamdi, Ali S

2002-03-01

In 1999 there were 450 fatalities due to road crashes in Riyadh, the capital of Saudi Arabia, of which 130 were pedestrians. Hence, every fourth person killed on the roads is a pedestrian. The aim of this study is to investigate pedestrian-vehicle crashes in this fast-growing city with two objectives in mind: to analyze pedestrian collisions with regard to their causes, characteristics, location of injury on the victim's body, and most common patterns and to determine the potential for use of the odds ratio technique in the analysis of stratified contingency tables. Data from 638 pedestrian-vehicle crashes reported by police, during the period 1997-1999, were used. A systematic sampling technique was followed in which every third record was used. The analysis showed that the pedestrian fatality rate per 10(5) population is 2.8. The rates were relatively high within the childhood (1-9 years) and young adult (10-19 years) groups, and the old-age groups (60 - > 80 years), which indicate that young as well as the elderly people in this city are more likely to be involved in fatal accidents of this type than are those in other age groups. The analysis revealed that 77.1% of pedestrians were probably struck while crossing a roadway either not in a crosswalk or where no crosswalk existed. In addition, the distribution of injuries on the victims' bodies was determined from hospital records. More than one-third of the fatal injuries were located on the head and chest. An attempt was made to conduct an association analysis between crash severity (i.e. injury or fatal) and some of the study variables using chi-square and odds ratio techniques. The categorical nature of the data helped in using these analytical techniques.
Analytical real-time measurement of a three-dimensional weld pool surface

International Nuclear Information System (INIS)

Zhang, WeiJie; Zhang, YuMing; Wang, XueWu

2013-01-01

The ability to observe and measure weld pool surfaces in real-time is the core of the foundation for next generation intelligent welding that can partially imitate skilled welders who observe the weld pool to acquire information on the welding process. This study aims at the real-time measurement of the specular three-dimensional (3D) weld pool surface under a strong arc in gas tungsten arc welding (GTAW). An innovative vision system is utilized in this study to project a dot-matrix laser pattern on the specular weld pool surface. Its reflection from the surface is intercepted at a distance from the arc by a diffuse plane. The intercepted laser dots illuminate this plane producing an image showing the reflection pattern. The deformation of this reflection pattern from the projected pattern (e.g. the dot matrix) is used to derive the 3D shape of the reflection surface, i.e., the weld pool surface. Based on careful analysis, the underlying reconstruction problem is formulated mathematically. An analytic solution is proposed to solve this formulated problem resulting in the weld pool surface being reconstructed on average in 3.04 ms during welding experiments. A vision-based monitoring system is thus established to measure the weld pool surface in GTAW in real-time. In order to verify the effectiveness of the proposed reconstruction algorithm, first numerical simulation is conducted. The proposed algorithm is then tested on a spherical convex mirror with a priori knowledge of its geometry. The detailed analysis of the measurement error validates the accuracy of the proposed algorithm. Results from the real-time experiments verify the robustness of the proposed reconstruction algorithm. (paper)
Application of multivariate techniques to analytical data on Aegean ceramics

International Nuclear Information System (INIS)

Bieber, A.M.; Brooks, D.W.; Harbottle, G.; Sayre, E.V.

1976-01-01

The general problems of data collection and handling for multivariate elemental analyses of ancient pottery are considered including such specific questions as the level of analytical precision required, the number and type of elements to be determined and the need for comprehensive multivariate statistical analysis of the collected data in contrast to element by element statistical analysis. The multivariate statistical procedures of clustering in a multidimensional space and determination of the numerical probabilities of specimens belonging to a group through calculation of the Mahalanobis distances for these specimens in multicomponent space are described together with supporting univariate statistical procedures used at Brookhaven. The application of these techniques to the data on Late Bronze Age Aegean pottery (largely previously analysed at Oxford and Brookhaven with some new specimens considered) have resulted in meaningful subdivisions of previously established groups. (author)
A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhen [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Xia, Changliang [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Yan, Yan, E-mail: yanyan@tju.edu.cn [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Geng, Qiang [Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Shi, Tingna [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China)

2017-08-01

Highlights: • A hybrid analytical model is developed for field calculation of multilayer IPM machines. • The rotor magnetic field is calculated by the magnetic equivalent circuit method. • The field in the stator and air-gap is calculated by subdomain technique. • The magnetic scalar potential on rotor surface is modeled as trapezoidal distribution. - Abstract: Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff’s law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell’s equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.
Radiographic film: surface dose extrapolation techniques

International Nuclear Information System (INIS)

Cheung, T.; Yu, P.K.N.; Butson, M.J.; Cancer Services, Wollongong, NSW; Currie, M.

2004-01-01

Full text: Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate 2 dimensional map of surface dose if required. Results have shown that surface % dose can be estimated within ±3% of parallel plate ionisation chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10cm, 20cmand 30cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. Corresponding parallel plate ionisation chamber measurement are 16%, 27% and 37% respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine
Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

Energy Technology Data Exchange (ETDEWEB)

Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E. [Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

2014-06-15

An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.

Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

Science.gov (United States)

Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E.

2014-06-01

An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.
Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

International Nuclear Information System (INIS)

Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E.

2014-01-01

An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label
An alternative technique for the implementation of an analytical approximation for transients with temperature feedback

Energy Technology Data Exchange (ETDEWEB)

Palma, Daniel A.P. [Instituto Federal do Rio de Janeiro, Nilopolis, RJ (Brazil)], e-mail: dpalmaster@gmail.com; Silva, Adilson C. da; Goncalves, Alessandro C.; Martinez, Aquilino S. [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear], e-mail: asilva@con.ufrj.br, e-mail: agoncalves@con.ufrj.br, e-mail: aquilino@lmp.ufrj.br

2009-07-01

The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting neutron density variation during the operation of a nuclear reactor. Although different approximate solutions for the system of point kinetics equations with temperature feedback may be found in literature, some of them do not present an explicit dependence in time, which makes the computing implementation difficult and, as a result, its applicability in practical cases. The present paper uses the polynomial adjustment technique to overcome this problem in the analytical approximation as proposed by Nahla. In a systematic comparison with other existing approximations it is concluded that the method is adequate, presenting small deviations in relation to the reference values obtained from the reference numerical method. (author)
An alternative technique for the implementation of an analytical approximation for transients with temperature feedback

International Nuclear Information System (INIS)

Palma, Daniel A.P.; Silva, Adilson C. da; Goncalves, Alessandro C.; Martinez, Aquilino S.

2009-01-01

The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting neutron density variation during the operation of a nuclear reactor. Although different approximate solutions for the system of point kinetics equations with temperature feedback may be found in literature, some of them do not present an explicit dependence in time, which makes the computing implementation difficult and, as a result, its applicability in practical cases. The present paper uses the polynomial adjustment technique to overcome this problem in the analytical approximation as proposed by Nahla. In a systematic comparison with other existing approximations it is concluded that the method is adequate, presenting small deviations in relation to the reference values obtained from the reference numerical method. (author)
The role of nuclear analytical techniques in the study of aqueous corrosion of glasses

International Nuclear Information System (INIS)

Trocellier, P.

1984-01-01

Direct observation of resonant nuclear reactions, backscattering spectrometry and X ray microanalysis with a nuclear microprobe were used to determine elementary depth profiles in the near surface region of leached glasses. Some computing programs required to interpretate the analytical information detected were built. Experimental conditions to characterize glass samples without secondary effects were defined; and the influence of some leaching parameters was studied to describe the first stages of aqueous corrosion of borosilicate glasses [fr
Theoretical Study on Synchronous Characterization of Surface and Interfacial Mechanical Properties of Thin-Film/Substrate Systems with Residual Stress Based on Pressure Blister Test Technique

Directory of Open Access Journals (Sweden)

Zhi-xin Yang

2018-01-01

Full Text Available In this study, based on the pressure blister test technique, a theoretical study on the synchronous characterization of surface and interfacial mechanical properties of thin-film/substrate systems with residual stress was presented, where the problem of axisymmetric deformation of a blistering film with initial stress was analytically solved and its closed-form solution was presented. The expressions to determine Poisson’s ratios, Young’s modulus, and residual stress of surface thin films were derived; the work done by the applied external load and the elastic energy stored in the blistering thin film were analyzed in detail and their expressions were derived; and the interfacial adhesion energy released per unit delamination area of thin-film/substrate (i.e., energy release rate was finally presented. The synchronous characterization technique presented here has theoretically made a big step forward, due to the consideration for the residual stress in surface thin films.
Development of a combined surface plasmon resonance/surface acoustic wave device for the characterization of biomolecules

International Nuclear Information System (INIS)

Bender, Florian; Tsortos, Achilleas; Papadakis, George; Gizeli, Electra; Roach, Paul; Newton, Michael I; McHale, Glen

2009-01-01

It is known that acoustic sensor devices, if operated in liquid phase, are sensitive not just to the mass of the analyte but also to various other parameters, such as size, shape, charge and elastic constants of the analyte as well as bound and viscously entrained water. This can be used to extract valuable information about a biomolecule, particularly if the acoustic device is combined with another sensor element which is sensitive to the mass or amount of analyte only. The latter is true in good approximation for various optical sensor techniques. This work reports on the development of a combined surface plasmon resonance/surface acoustic wave sensor system which is designed for the investigation of biomolecules such as proteins or DNA. Results for the deposition of neutravidin and DNA are reported
The earrings of Pancas treasure: Analytical study by X-ray based techniques – A first approach

International Nuclear Information System (INIS)

Tissot, I.; Tissot, M.; Manso, M.; Alves, L.C.; Barreiros, M.A.; Marcelo, T.; Carvalho, M.L.; Corregidor, V.; Guerra, M.F.

2013-01-01

The development of new metallurgical technologies in the Iberian Peninsula during the Iron Age is well represented by the 10 gold earrings from the treasure of Pancas. This work presents a first approach to the analytical study of these earrings and contributes to the construction of a typological evolution of the Iberian earrings. The manufacture techniques and the alloys composition were studied with three complementary X-ray spectroscopy techniques: portable EDXRF, μ-PIXE and SEM–EDS. The results were compared with earrings from the same and previous periods
Proceedings of the national seminar on recent developments in electro analytical techniques: souvenir and abstracts

International Nuclear Information System (INIS)

2012-01-01

In view of deliberations on 'Recent Developments in Electro Analytical Techniques' with special emphasis on batteries, fuel cells, biosensors, chemical sensors modified electrodes, nano electrodes, electrode synthesis and co-ordination compounds, go a long way in creating the necessary awareness and enthusiasm amongst students, young scholars and industrialists to lay their attention on the subject. Papers relevant to INIS are indexed separately
Applied research on air pollution using nuclear-related analytical techniques. Report on the second research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

A co-ordinated research programme (CRP) on applied research on air pollution using nuclear-related techniques is a global CRP which started in 1992, and is scheduled to run until early 1997. The purpose of this CRP is to promote the use of nuclear analytical techniques in air pollution studies, e.g. NAA, XRF, and PIXE for the analysis of toxic and other trace elements in air particulate matter. The main purposes of the core programme are i) to support the use of nuclear and nuclear-related analytical techniques for research and monitoring studies on air pollution, ii) to identify major sources of air pollution affecting each of the participating countries with particular reference to toxic heavy metals, and iii) to obtain comparative data on pollution levels in areas of high pollution (e.g. a city centre or a populated area downwind of a large pollution source) and low pollution (e.g. rural area). This document reports the discussions held during the second Research Co-ordination Meeting (RCM) for the CRP which took place at ANSTO in Menai, Australia. (author)
Applied research on air pollution using nuclear-related analytical techniques. Report on the second research co-ordination meeting

International Nuclear Information System (INIS)

1995-01-01

A co-ordinated research programme (CRP) on applied research on air pollution using nuclear-related techniques is a global CRP which started in 1992, and is scheduled to run until early 1997. The purpose of this CRP is to promote the use of nuclear analytical techniques in air pollution studies, e.g. NAA, XRF, and PIXE for the analysis of toxic and other trace elements in air particulate matter. The main purposes of the core programme are i) to support the use of nuclear and nuclear-related analytical techniques for research and monitoring studies on air pollution, ii) to identify major sources of air pollution affecting each of the participating countries with particular reference to toxic heavy metals, and iii) to obtain comparative data on pollution levels in areas of high pollution (e.g. a city centre or a populated area downwind of a large pollution source) and low pollution (e.g. rural area). This document reports the discussions held during the second Research Co-ordination Meeting (RCM) for the CRP which took place at ANSTO in Menai, Australia. (author)
Biomonitoring of air pollution in Jamaica through trace-element analysis of epiphytic plants using nuclear and related analytical techniques

International Nuclear Information System (INIS)

Vutchkov, Mitko

2001-01-01

The main goal of the Coordinated Research Project (No:9937/R0), entitled 'Biomonitoring of Air Pollution in Jamaica Through Trace-Element Analysis of Epiphytic Plants Using Nuclear and Related Analytical Techniques', is to identify and validate site specific epiphytic plants for biomonitoring the atmospheric pollution in Jamaica using nuclear analytical techniques at the International Centre for Environmental and Nuclear Sciences (ICENS). The specific objectives for the second year of the project were: Development of HOP for sampling epiphytic plants in Jamaica; Sampling design and sample collection; Sample preparation and analysis; Development of an in-house SRM and participation in the NAT-5 inter-laboratory study; Data analysis and interpretation of the results; Development of a work plan of the third year of the project
Surface diffusion studies by optical diffraction techniques

International Nuclear Information System (INIS)

Xiao, X.D.

1992-11-01

The newly developed optical techniques have been combined with either second harmonic (SH) diffraction or linear diffraction off a monolayer adsorbate grating for surface diffusion measurement. Anisotropy of surface diffusion of CO on Ni(l10) was used as a demonstration for the second harmonic dim reaction method. The linear diffraction method, which possesses a much higher sensitivity than the SH diffraction method, was employed to study the effect of adsorbate-adsorbate interaction on CO diffusion on Ni(l10) surface. Results showed that only the short range direct CO-CO orbital overlapping interaction influences CO diffusion but not the long range dipole-dipole and CO-NI-CO interactions. Effects of impurities and defects on surface diffusion were further explored by using linear diffraction method on CO/Ni(110) system. It was found that a few percent S impurity can alter the CO diffusion barrier height to a much higher value through changing the Ni(110) surface. The point defects of Ni(l10) surface seem to speed up CO diffusion significantly. A mechanism with long jumps over multiple lattice distance initiated by CO filled vacancy is proposed to explain the observed defect effect
Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

International Nuclear Information System (INIS)

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan; Ondra, Peter; Válka, Ivo; Ševčík, Juraj; Chrastina, Jan; Maier, Vítězslav

2015-01-01

Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry
Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

Energy Technology Data Exchange (ETDEWEB)

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Ondra, Peter; Válka, Ivo [Department of Forensic Medicine and Medical Law Faculty Hospital, Hněvotínská 3, Olomouc CZ-77146 (Czech Republic); Ševčík, Juraj [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Chrastina, Jan [Institute of Special Education Studies, Faculty of Education, Palacký University, Žižkovo náměsti 5, Olomouc CZ-77146 (Czech Republic); Maier, Vítězslav, E-mail: vitezslav.maier@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic)

2015-05-18

Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry.
Preanalytical and analytical variation of surface-enhanced laser desorption-ionization time-of-flight mass spectrometry of human serum

DEFF Research Database (Denmark)

Albrethsen, Jakob; Bøgebo, Rikke; Olsen, Jesper

2006-01-01

BACKGROUND: Surface-enhanced laser desorption-ionization time-of-flight (SELDI-TOF) mass spectrometry of human serum is a potential diagnostic tool in human diseases. In the present study, the preanalytical and analytical variation of SELDI-TOF mass spectrometry of serum was assessed in healthy...... was 18% (6%-34%, n=4) for 16 peaks, and inter-individual CV was 38% (16%-56%, n=16) for 20 peaks. CONCLUSIONS: The pre-analytical and analytical conditions of SELDI-TOF mass spectrometry of serum have a significant impact on the protein peaks, with the number of peaks low and the assay variation high...
Voltammetric technique, a panacea for analytical examination of environmental samples

International Nuclear Information System (INIS)

Zahir, E.; Mohiuddin, S.; Naqvi, I.I.

2012-01-01

Voltammetric methods for trace metal analysis in environmental samples of marine origin like mangrove, sediments and shrimps are generally recommended. Three different electro-analytical techniques i.e. polarography, anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (ADSV) have been used. Cd/sub 2/+, Pb/sub 2/+, Cu/sub 2/+ and Mn/sub 2/+ were determined through ASV, Cr/sub 6/+ was analyzed by ADSV and Fe/sub 2/+, Zn/sub 2/+, Ni/sub 2/+ and Co/sub 2/+ were determined through polarography. Out of which pairs of Fe/sub 2/+Zn/sub 2/+ and Ni/sub 2/+Co/sub 2/+ were determined in two separate runs while Cd/sub 2/+, Pb/sub 2/+, Cu/sub 2/+ were analyzed in single run of ASV. Sensitivity and speciation capabilities of voltammetric methods have been employed. Analysis conditions were optimized that includes selection of supporting electrolyte, pH, working electrodes, sweep rate etc. Stripping voltammetry was adopted for analysis at ultra trace levels. Statistical parameters for analytical method development like selectivity factor, interference, repeatability (0.0065-0.130 macro g/g), reproducibility (0.08125-1.625 macro g/g), detection limits (0.032-5.06 macro g/g), limits of quantification (0.081-12.652 macro g/g), sensitivities (5.636-2.15 nA mL macro g-1) etc. were also determined. The percentage recoveries were found in between 95-105% using certified reference materials. Real samples of complex marine environment from Karachi coastline were also analyzed. The standard addition method was employed where any matrix effect was evidenced. (author)
Recent Studies on the Speciation and Determination of Mercury in Different Environmental Matrices Using Various Analytical Techniques

Directory of Open Access Journals (Sweden)

Lakshmi Narayana Suvarapu

2017-01-01

Full Text Available This paper reviews the current research on the speciation and determination of mercury by various analytical techniques, including the atomic absorption spectrometry (AAS, voltammetry, inductively coupled plasma optical emission spectrometry (ICP-OES, ICP-mass spectrometry (MS, atomic fluorescence spectrometry (AFS, spectrophotometry, spectrofluorometry, and high performance liquid chromatography (HPLC. Approximately 96 research papers on the speciation and determination of mercury by various analytical instruments published in international journals since 2015 were reviewed. All analytical parameters, including the limits of detection, linearity range, quality assurance and control, applicability, and interfering ions, evaluated in the reviewed articles were tabulated. In this review, we found a lack of information in speciation studies of mercury in recent years. Another important conclusion from this review was that there were few studies regarding the concentration of mercury in the atmosphere.
Proficiency Testing by Interlaboratory Comparison Performed in 2010-2015 for Neutron Activation Analysis and Other Analytical Techniques

International Nuclear Information System (INIS)

2017-12-01

The IAEA supports its Member States to increase the utilization of their research reactors. Small and medium sized reactors are mostly used for neutron activation analysis (NAA). Although the markets for NAA laboratories have been identified, demonstration of valid analytical results and organizational quality of the work process are preconditions for expanding the stakeholder community, particularly in commercial routine application of this powerful technique. The IAEA has implemented a new mechanism for supporting NAA laboratories in demonstrating their analytical performance by participation in proficiency testing schemes by interlaboratory comparison. This activity makes possible the identification of deviations and non-conformities, their causes and the process to implement effective approaches to eliminate them. Over 30 laboratories participated between 2010 and 2015 in consecutive proficiency tests organized by the IAEA in conjunction with the Wageningen Evaluating Programmes for Analytical Laboratories (WEPAL) to assess their analytical performances. This publication reports the findings and includes lessons learned of this activity. An attached CD-ROM contains many individual participating laboratory papers sharing their individual results and experience gained through this participation.
Development and evaluation of analytical techniques for total chlorine in used oils and oil fuels

International Nuclear Information System (INIS)

Gaskill, A. Jr.; Estes, E.D.; Hardison, D.L.; Friedman, P.H.

1990-01-01

A current EPA regulation prohibits the sale for burning in nonindustrial boilers of used oils and oil fuels. This paper discusses how analytical techniques for determining total chlorine were evaluated to provide regulatory agencies and the regulated community with appropriate chlorine test methods. The techniques evaluated included oxygen bomb combustion followed by chemical titration or ion chromatography, instrumental microcoulometry, field test kits, and instrumental furnace/specific ion electrode determinator, a device based on the Beilstein reaction, and x-ray fluorescence spectrometry. These techniques were subjected to interlaboratory testing to estimate their precision, accuracy, and sensitivity. Virgin and used crankcase oils, hydraulic and metalworking oils, oil fuels and oil fuel blends with used oils were tested. The bomb techniques, one of the test kits, microcoulometry and all but one x-ray analyzer were found to be suitable for this application. The chlorine furnace and the Beilstein device were found to be inapplicable at the levels of interest

Analytic geometry

CERN Document Server

Burdette, A C

1971-01-01

Analytic Geometry covers several fundamental aspects of analytic geometry needed for advanced subjects, including calculus.This book is composed of 12 chapters that review the principles, concepts, and analytic proofs of geometric theorems, families of lines, the normal equation of the line, and related matters. Other chapters highlight the application of graphing, foci, directrices, eccentricity, and conic-related topics. The remaining chapters deal with the concept polar and rectangular coordinates, surfaces and curves, and planes.This book will prove useful to undergraduate trigonometric st
Evaluation of available analytical techniques for monitoring the quality of space station potable water

Science.gov (United States)

Geer, Richard D.

1989-01-01

To assure the quality of potable water (PW) on the Space Station (SS) a number of chemical and physical tests must be conducted routinely. After reviewing the requirements for potable water, both direct and indirect analytical methods are evaluated that could make the required tests and improvements compatible with the Space Station operation. A variety of suggestions are made to improve the analytical techniques for SS operation. The most important recommendations are: (1) the silver/silver chloride electrode (SB) method of removing I sub 2/I (-) biocide from the water, since it may interfere with analytical procedures for PW and also its end uses; (2) the orbital reactor (OR) method of carrying out chemistry and electrochemistry in microgravity by using a disk shaped reactor on an orbital table to impart artificial G force to the contents, allowing solution mixing and separation of gases and liquids; and (3) a simple ultra low volume highly sensitive electrochemical/conductivity detector for use with a capillary zone electrophoresis apparatus. It is also recommended, since several different conductivity and resistance measurements are made during the analysis of PW, that the bipolar pulse measuring circuit be used in all these applications for maximum compatibility and redundancy of equipment.
Role of nuclear analytical probe techniques in biological trace element research

International Nuclear Information System (INIS)

Jones, K.W.; Pounds, J.G.

1985-01-01

Many biomedical experiments require the qualitative and quantitative localization of trace elements with high sensitivity and good spatial resolution. The feasibility of measuring the chemical form of the elements, the time course of trace elements metabolism, and of conducting experiments in living biological systems are also important requirements for biological trace element research. Nuclear analytical techniques that employ ion or photon beams have grown in importance in the past decade and have led to several new experimental approaches. Some of the important features of these methods are reviewed here along with their role in trace element research, and examples of their use are given to illustrate potential for new research directions. It is emphasized that the effective application of these methods necessitates a closely integrated multidisciplinary scientific team. 21 refs., 4 figs., 1 tab
Intracavity optogalvanic spectroscopy. An analytical technique for 14C analysis with subattomole sensitivity.

Science.gov (United States)

Murnick, Daniel E; Dogru, Ozgur; Ilkmen, Erhan

2008-07-01

We show a new ultrasensitive laser-based analytical technique, intracavity optogalvanic spectroscopy, allowing extremely high sensitivity for detection of (14)C-labeled carbon dioxide. Capable of replacing large accelerator mass spectrometers, the technique quantifies attomoles of (14)C in submicrogram samples. Based on the specificity of narrow laser resonances coupled with the sensitivity provided by standing waves in an optical cavity and detection via impedance variations, limits of detection near 10(-15) (14)C/(12)C ratios are obtained. Using a 15-W (14)CO2 laser, a linear calibration with samples from 10(-15) to >1.5 x 10(-12) in (14)C/(12)C ratios, as determined by accelerator mass spectrometry, is demonstrated. Possible applications include microdosing studies in drug development, individualized subtherapeutic tests of drug metabolism, carbon dating and real time monitoring of atmospheric radiocarbon. The method can also be applied to detection of other trace entities.
Surface dating of bricks, an application of luminescence techniques

Science.gov (United States)

Galli, Anna; Martini, Marco; Maspero, Francesco; Panzeri, Laura; Sibilia, Emanuela

2014-05-01

Luminescence techniques are a powerful tool to date archaeological ceramic materials and geological sediments. Thermoluminescence (TL) is widely used for bricks dating to reconstruct the chronology of urban complexes and the development of human cultures. However, it can sometimes be inconclusive, since TL assesses the firing period of bricks, which can be reused, even several centuries later. This problem can be circumvented using a dating technique based on a resetting event different from the last heating. OSL (Optically Stimulated Luminescence) exploits the last light exposition of the brick surface, which resets the light-sensitive electron traps until the surface is definitely shielded by mortar and superimposed bricks. This advanced application (surface dating) has been successfully attempted on rocks, marble and stone artifacts, but not yet on bricks. A recent conservation campaign at the Certosa di Pavia gave the opportunity to sample some bricks belonging to a XVII century collapsed wall, still tied to their mortars. This was an advantageous condition to test this technique, comparing the dating results with precise historical data. This attempt gave satisfactory results, allowing to identify bricks surely reused and to fully confirm that the edification of the perimetral wall occurred at the end of XVII century.
A new multi-step technique with differential transform method for analytical solution of some nonlinear variable delay differential equations.

Science.gov (United States)

Benhammouda, Brahim; Vazquez-Leal, Hector

2016-01-01

This work presents an analytical solution of some nonlinear delay differential equations (DDEs) with variable delays. Such DDEs are difficult to treat numerically and cannot be solved by existing general purpose codes. A new method of steps combined with the differential transform method (DTM) is proposed as a powerful tool to solve these DDEs. This method reduces the DDEs to ordinary differential equations that are then solved by the DTM. Furthermore, we show that the solutions can be improved by Laplace-Padé resummation method. Two examples are presented to show the efficiency of the proposed technique. The main advantage of this technique is that it possesses a simple procedure based on a few straight forward steps and can be combined with any analytical method, other than the DTM, like the homotopy perturbation method.
Surface modification technique of structural ceramics: ion implantation-assisted multi-arc ion plating

International Nuclear Information System (INIS)

Peng Zhijian; Miao Hezhuo; Si Wenjie; Qi Longhao; Li Wenzhi

2003-01-01

Through reviewing the advantages and disadvantages of the existed surface modification techniques, a new technique, ion implantation-assisted multi-arc ion plating, was proposed. Using the proposed technique, the surfaces of silicon nitride ceramics were modified by Ti ion implantation, and then three kinds of ternary coatings, (Ti,Al)N, (Ti,Zr)N and (Ti,Cr)N, were deposited on the as-implanted ceramics. The coatings prepared by this technique are of high-hardness and well adhesive to the ceramic substrates. The maximal hardness measured by nanoindentation tests is more than 40 GPa. The maximal critical load by nanoscratch tests is more than 60 mN. The cutting tools prepared by this technique with the presented coatings are of excellent performance in industrial applications. The technique may be promising for the surface modification of structural ceramics. (orig.)
Preparation of uranium targets and application of analytical techniques for its evaluation

International Nuclear Information System (INIS)

Luna Z, D.

1994-01-01

The objective of this work is to establish a method to produce uranium targets. The method selected for this purpose was the molecular plating. The first part of this work is devoted to the proper selection of an analytical technique to evaluate the different steps of the molecular plating method. Neutron Activation Analysis was chosen, because its high sensitivity and can be adapted easily to follow the whole procedure. The second part presents the experimental procedure and the study of the different parameters involved in the molecular plating and the evaluation of its uniformity was made using plastic track detectors. The results obtained are presented and a procedure is suggested to produce uranium targets. (Author)
Uncovering category specificity of genital sexual arousal in women: The critical role of analytic technique.

Science.gov (United States)

Pulverman, Carey S; Hixon, J Gregory; Meston, Cindy M

2015-10-01

Based on analytic techniques that collapse data into a single average value, it has been reported that women lack category specificity and show genital sexual arousal to a large range of sexual stimuli including those that both match and do not match their self-reported sexual interests. These findings may be a methodological artifact of the way in which data are analyzed. This study examined whether using an analytic technique that models data over time would yield different results. Across two studies, heterosexual (N = 19) and lesbian (N = 14) women viewed erotic films featuring heterosexual, lesbian, and gay male couples, respectively, as their physiological sexual arousal was assessed with vaginal photoplethysmography. Data analysis with traditional methods comparing average genital arousal between films failed to detect specificity of genital arousal for either group. When data were analyzed with smoothing regression splines and a within-subjects approach, both heterosexual and lesbian women demonstrated different patterns of genital sexual arousal to the different types of erotic films, suggesting that sophisticated statistical techniques may be necessary to more fully understand women's genital sexual arousal response. Heterosexual women showed category-specific genital sexual arousal. Lesbian women showed higher arousal to the heterosexual film than the other films. However, within subjects, lesbian women showed significantly different arousal responses suggesting that lesbian women's genital arousal discriminates between different categories of stimuli at the individual level. Implications for the future use of vaginal photoplethysmography as a diagnostic tool of sexual preferences in clinical and forensic settings are discussed. © 2015 Society for Psychophysiological Research.
Ultrasensitive detection of phenolic antioxidants by surface enhanced Raman spectroscopy

Science.gov (United States)

Ornelas-Soto, N.; Aguilar-Hernández, I. A.; Afseth, N.; López-Luke, T.; Contreras-Torres, F. F.; Wold, J. P.

2017-08-01

Surface-Enhanced Raman Spectroscopy (SERS) is a powerful surface-sensitive technique to study the vibrational properties of analytes at very low concentrations. In this study, ferulic acid, p-coumaric acid, caffeic acid and sinapic acid were analyzed by SERS using Ag colloids. Analytes were detected up to 2.5x10-9M. For caffeic acid and coumaric acid, this detection limit has been reached for the first time, as well as the SERS analysis of sinapic acid using silver colloids.
Earth Science Data Analytics: Bridging Tools and Techniques with the Co-Analysis of Large, Heterogeneous Datasets

Science.gov (United States)

Kempler, Steve; Mathews, Tiffany

2016-01-01

The continuum of ever-evolving data management systems affords great opportunities to the enhancement of knowledge and facilitation of science research. To take advantage of these opportunities, it is essential to understand and develop methods that enable data relationships to be examined and the information to be manipulated. This presentation describes the efforts of the Earth Science Information Partners (ESIP) Federation Earth Science Data Analytics (ESDA) Cluster to understand, define, and facilitate the implementation of ESDA to advance science research. As a result of the void of Earth science data analytics publication material, the cluster has defined ESDA along with 10 goals to set the framework for a common understanding of tools and techniques that are available and still needed to support ESDA.
Studies of surface loss of materials by TLA technique

International Nuclear Information System (INIS)

Chowdhury, D.P.

2005-01-01

Thin Layer Activation technique is very sensitive and useful for the study of surface wear, corrosion and erosion in various machine or engineering components. It is routinely used in automobiles, power and nuclear and oil industries for on-line monitoring and testing. Its potential in application to bio-engineering material is reported. One of the limitations of the technique is the availability of accelerator
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...
Ion bombardment modification of surfaces

International Nuclear Information System (INIS)

Auciello, O.

1984-01-01

An historical overview of the main advances in the understanding of bombardment-induced surface topography is presented. The implantation and sputtering mechanisms which are relevant to ion bombardment modification of surfaces and consequent structural, electronic and compositional changes are described. Descriptions of plasma and ion-beam sputtering-induced film formation, primary ion-beam deposition, dual beam techniques, cluster of molecule ion-beam deposition, and modification of thin film properties by ion bombardment during deposition are presented. A detailed account is given of the analytical and computational modelling of topography from the viewpoint of first erosion theory. Finally, an account of the possible application and/or importance of textured surfaces in technologies and/or experimental techniques not considered in previous chapters is presented. refs.; figs.; tabs
Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

International Nuclear Information System (INIS)

Parsapour, Amir; Dehkordi, Behzad Mirzaeian; Moallem, Mehdi

2015-01-01

In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated
Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

Energy Technology Data Exchange (ETDEWEB)

Parsapour, Amir, E-mail: amirparsapour@gmail.com [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Dehkordi, Behzad Mirzaeian, E-mail: mirzaeian@eng.ui.ac.ir [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Moallem, Mehdi, E-mail: moallem@cc.iut.ac.ir [Department of Electrical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

2015-03-15

In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated.
In Situ Analytical Characterization of Contaminated Sites Using Nuclear Spectrometry Techniques. Review of Methodologies and Measurements

International Nuclear Information System (INIS)

2017-01-01

Past and current human activities can result in the contamination of sites by radionuclides and heavy metals. The sources of contamination are various. The most important sources for radionuclide release include global fallout from nuclear testing, nuclear and radiological accidents, waste production from nuclear facilities, and activities involving naturally occurring radioactive material (NORM). Contamination of the environment by heavy metals mainly originates from industrial applications and mineralogical background concentration. Contamination of sites by radionuclides and heavy metals can present a risk to people and the environment. Therefore, the estimation of the contamination level and the identification of the source constitute important information for the national authorities with the responsibility to protect people and the environment from adverse health effects. In situ analytical techniques based on nuclear spectrometry are important tools for the characterization of contaminated sites. Much progress has been made in the design and implementation of portable systems for efficient and effective monitoring of radioactivity and heavy metals in the environment directly on-site. Accordingly, the IAEA organized a Technical Meeting to review the current status and trends of various applications of in situ nuclear spectrometry techniques for analytical characterization of contaminated sites and to support Member States in their national environmental monitoring programmes applying portable instrumentation. This publication represents a comprehensive review of the in situ gamma ray spectrometry and field portable X ray fluorescence analysis techniques for the characterization of contaminated sites. It includes papers on the use of these techniques, which provide useful background information for conducting similar studies, in the following Member States: Argentina, Australia, Brazil, Czech Republic, Egypt, France, Greece, Hungary, Italy, Lithuania
Contribution of analytical techniques coupled to the knowledge of the uranium speciation in natural conditions

International Nuclear Information System (INIS)

Petit, J.

2009-06-01

To understand the transport mechanisms and the radionuclides behaviour in the bio-geosphere is necessary to evaluate healthy and environmental risks of nuclear industry. These mechanisms are monitored by radioelements speciation, namely the distribution between their different physico-chemical forms in the environment. From this perspective, this PhD thesis deals with uranium speciation in a natural background. A detailed summary of uranium biogeochemistry has been written, which enables to restrict the PhD issue to uranium complexation with oxalic acid, a hydrophilic organic acid with good binding properties, ubiquitous in soil waters. Analytical conditions have been established by means of speciation diagrams. The speciation diagrams building by means of literature stability constants has allowed to define the analytical conditions of complex formation. The chosen analytical technique is the hyphenation of a separative technique (liquid chromatography LC or capillary electrophoresis CE) with mass spectrometry (ICPMS). The studied complexes presence in the synthetic samples has been confirmed with UV/visible spectrophotometry. LC-ICPMS analyses have proved the lability of the uranyl-organic acid complexes, namely their tendency to dissociate during analysis, which prevents from studying uranium speciation. CE-ICPMS study of labile complexes from a metal-ligand system has been made possible by employing affinity capillary electrophoresis, which enables to determine stability constants and electrophoretic mobilities. This PhD thesis has allowed to compare the different mathematical treatments of binding isotherm and to take into account ionic strength and real ligand concentration. Affinity CE has been applied successfully to lanthanum-oxalate (model system) and uranium-oxalate systems. The obtained results have been applied to a real system (situated in Le Bouchet). This shows the contribution of the developed method to the modelling of uranium speciation. (author)
Analytical techniques for determination and control of silica content in the water in thermal power plants

Directory of Open Access Journals (Sweden)

Ignjatović Nataša R.

2015-01-01

Full Text Available Ultrapure water with minimum contents of impurities is used for the preparation of steam in thermal power plants. More recently it has been found that the corrosion process is also influenced by sodium ions, chloride ions, and all forms of silicon in water. At higher temperatures and under high pressure the less soluble compounds of silicon are extracted, which form deposits on the walls of the boiler, the piping system and the turbine blades. Silicon is found in water in the form of different types (species which are characterized by specific physical and chemical properties. Distinctions can be made between highly reactive species of ionic (silicate anions and molecular forms (silicic acid and relatively inert types (suspended, colloidal, and polymerized silicon. The determination of various forms of silicon in water is a complex analytical task. This paper covers relevant research in the field of silicon specification analysis. Maintaining the unchanged, original composition of silicon species during various stages of analysis (sample collection, storage, and conservation has been given special attention. A large number of methods and procedures have been developed for the analysis of species of silicon, including chromatographic, spectroscopic and electrochemical techniques and combinations thereof. The techniques used for determining both the total amount and individual forms of silicon have been singled out. There is also an overview of the coupled techniques used most frequently in practice by using the methodology which involves preliminary separation of species and then individual specification. The paper offers an overview of analytical properties, advantages and disadvantages of the most representative analytical methods developed specifically for the analysis of silicon species in ultrapure water. The most important studies focusing on the silicon species in water have been highlighted and presented in detail. The determination of
Commissioning of the laboratory of Atucha II NPP. Implementation and optimization of analytical techniques, quality aspects

International Nuclear Information System (INIS)

Schoenbrod, Betina; Quispe, Benjamin; Cattaneo, Alberto; Rodriguez, Ivanna; Chocron, Mauricio; Farias, Silvia

2012-09-01

Atucha II NPP is a Pressurized Vessel Heavy Water Reactor (PVHWR) of 740 MWe designed by SIEMENSKWU. After some years of delay, this NPP is in advanced construction state, being the beginning of commercial operation expected for 2013. Nucleoelectrica Argentina (N.A.S.A.) is the company in charge of the finalization of this project and the future operation of the plant. The Comision Nacional de Energia Atomica (C.N.E.A.) is the R and D nuclear institution in the country that, among many other topics, provides technical support to the stations. The Commissioning Chemistry Division of CNAII is in charge of the commissioning of the demineralization water plant and the organization of the chemical laboratory. The water plant started operating successfully in July 2010 and is providing the plant with nuclear grade purity water. Currently, in the conventional ('cold') laboratory several activities are taking place. On one hand, analytical techniques for the future operation of the plant are being tested and optimized. On the other hand, the laboratory is participating in the cleaning and conservation of the different components of the plant, providing technical support and the necessary analysis. To define the analytical techniques for the normal operation of the plant, the parameters to be measured and their range were established in the Chemistry Manual. The necessary equipment and reagents were bought. In this work, a summary of the analytical techniques that are being implemented and optimized is presented. Common anions (chloride, sulfate, fluoride, bromide and nitrate) are analyzed by ion chromatography. Cations, mainly sodium, are determined by absorption spectrometry. A UV-Vis spectrometer is used to determine silicates, iron, ammonia, DQO, total solids, true color and turbidity. TOC measurements are performed with a TOC analyzer. To optimize the methods, several parameters are evaluated: linearity, detection and quantification limits, precision and

High-Performance, Large Format Surfaces for Surface-Enhanced Raman Spectroscopy: Increasing the Accessibility of an Analytical Platform

Science.gov (United States)

Kanipe, Katherine Nicole

Although surface-enhanced Raman spectroscopy (SERS) is a spectroscopic technique with unusually high sensitivity and molecular specificity, few practical analytical applications have been implemented that take advantage of its power. Based on what is understood about SERS from the experimental and theoretical research of the past forty years, we developed a few well-defined design principles on the basis of which a reliable and reproducibly manufacturable SERS-active substrate could be fabricated that is highly enhancing, highly uniform, stable, and based on a broad range of metals so that various chemical processes could be probed. Finally, we restricted ourselves to using only readily scalable fabrication techniques. The resulting SERS-active device was a metal over silica, two-dimensional nano-grating that was shown to produce enhancements of ˜107 when compared to a smooth surface of the same metal. This SERS substrate also shows unprecedented signal uniformity over square centimeters, and is fabricated using commonly-available foundry-based approaches exclusively. Initially, we explored the properties of a gold-coated substrates in which a first-order grating resonance due to long-range symmetry is augmented by a local resonance due to the individual core-shell grating elements. The SERS properties of such grating systems were systematically studied as a function of various structural parameters such as the grating pitch, the inter-element gap and the thickness of the metal layer. The most enhancing substrates were found to have a grating parameter with a radiative, rather than evanescent, first-order resonance; a sufficiently small gap between nearest neighbor grating elements to produce near-field interactions; and a gold layer whose thickness was larger than the electronic mean-free-path of the conduction electrons, so as to ensure a high conductivity for the metal layer to sustain strong surface plasmons. We applied these same architectural principles to
Atomic and nuclear analytical methods. XRF, Moessbauer, XPS, NAA and ion-beam spectroscopic techniques

International Nuclear Information System (INIS)

Verma, H.R.

2007-01-01

This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Moessbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories. (orig.)
Development and evaluation of analytical techniques for total chlorine in burner fuels

International Nuclear Information System (INIS)

Gaskill, A. Jr.; Estes, E.D.; Hardison, D.L.; Friedman, P.H.

1987-01-01

A current EPA regulation prohibits the sale for burning in non-industrial boilers of used oils and oil fuels contaminated above specified levels with certain metals and total chlorine. When burned as fuel in a small boiler, the contaminants may be emitted to the ambient air at hazardous levels. This regulation establishes a rebuttable presumption that used oil containing more than 1,000 ppm total chlorine has been mixed with halogenated solvents and is a hazardous waste. Rebutting the presumption requires the seller of the oil to prove that this chlorine is not due to halogenated solvents or other hazardous halogenated organics. If the rebuttal is successful, the oil can be sold as fuel up to a level of 4000 ppm total chlorine. Analytical techniques for determination of total chlorine were evaluated or developed to provide regulatory agencies and the regulated community with appropriate chlorine test methods. The techniques evaluated included chemical titrations following oxygen bomb combustion, disposable field test kits, instrumental microcoulometry, and x-ray fluorescence spectrometry. These candidate techniques were subjected to interlaboratory testing to estimate their precision, accuracy, sensitivity, and susceptibility to matrix effects. Information on ease of use and analysis costs was also collected. Based on this pilot study, test methods will be written for the most promising techniques and subjected to a formal collaborative study to generate precision and accuracy data for each method. These methods are to be proposed in the Federal Register as mandatory for compliance with the existing used oil regulation
An analytical and numerical study of the nonlinear reflection at a stress-free surface

Energy Technology Data Exchange (ETDEWEB)

Romer, Anne, E-mail: anne.romer@gmx.net; Kim, Jin-Yeon, E-mail: anne.romer@gmx.net [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Jacobs, Laurence J. [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA and G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

2015-03-31

Implementation of the ultrasonic second harmonic generation has typically been restricted to simple setups such as through-transmission or Rayleigh surface waves. Recent research has evaluated the second harmonic waves generation in P- and SV- waves reflected from a stress-free surface to enable the single-sided interrogation of a specimen. This research considers the second harmonic generation in an aluminum specimen, which is analytically evaluated using an approach based on a perturbation method. Here, the model is chosen to mimic an experimental setup where the longitudinal wave is generated at oblique angle using a wedge transducer. Due to the mode conversion at the interface of the wedge and the specimen, it is necessary to evaluate longitudinal and shear waves, determining all second harmonic waves generated in the bulk and at the stress-free boundary. The theoretically developed model is then implemented in a commercial finite element code, COMSOL, using increasing fundamental wave amplitudes for different values of third order elastic constants. The results of this computational model verify the analytical approach and the proposed measurement setup, taking into account assumptions and approximations of the solution procedure. Furthermore, the computational model is used to draw important conclusions relevant to the experimental setup, including the need to avoid interaction with diffracted waves.
Analytical quality, performance indices and laboratory service

DEFF Research Database (Denmark)

Hilden, Jørgen; Magid, Erik

1999-01-01

analytical error, bias, cost effectiveness, decision-making, laboratory techniques and procedures, mass screening, models, statistical, quality control......analytical error, bias, cost effectiveness, decision-making, laboratory techniques and procedures, mass screening, models, statistical, quality control...
Determination of trace impurities in uranium-transition metal alloy fuels by ICP-MS using extended common analyte internal standardization (ECAIS) technique

International Nuclear Information System (INIS)

Saha, Abhijit; Deb, S.B.; Nagar, B.K.; Saxena, M.K.

2015-01-01

An analytical methodology was developed for the determination of eight trace impurities viz, Al, B, Cd, Co, Cu, Mg, Mn and Ni in three different uranium-transition metal alloy fuels (U-Me; Me = Ti, Zr and Mo) employing inductively coupled plasma mass spectrometry (ICP-MS). The well known common analyte internal standardization (CAIS) chemometric technique was modified and then employed to minimize and account for the matrix effect on analyte intensity. Standard addition of analytes to the pure synthetic U-Me sample solutions and subsequently their ≥ 94% recovery by the ICP-MS measurement validates the proposed methodology. One real sample of each of these alloys was analyzed by the developed analytical methodology and the %RSD observed was in the range of 5-8%. The method detection limits were found to be within 4-10 μg L -1 . (author)
Development of an analytical theory to describe the PNAR and CIPN nondestructive assay techniques

International Nuclear Information System (INIS)

Bolind, Alan Michael

2014-01-01

Highlights: • Neutron albedo is modeled by a discrete and iterative reflection process. • The theory enables the PNAR and CIPN NDA techniques to be compared quantitatively. • Improvements to the data analysis and to the CIPN instrument design are suggested. • A correction to translate real no-reflection PNAR data into ideal data is provided. - Abstract: This paper develops an analytical theory to describe how neutron albedo (reflection) increases the multiplication of neutrons by a used fuel assembly. With this theory, the two nondestructive assay (NDA) techniques of Passive Neutron Albedo Reactivity (PNAR) and Californium-252 Interrogation with Prompt Neutron Detection (CIPN) can be compared directly. Specifically, the theory derives expressions for the PNAR and CIPN metrics in terms of the physical properties of the used fuel assembly, such as the neutron multiplications and fate probabilities. The theory thus clarifies the interpretation of these two NDA techniques and suggests ways to improve both the design of the NDA instruments and the algorithms for analyzing the measurement results
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.
On the analytical flux distribution modeling of an axial-flux surface-mounted permanent magnet motor for control applications

International Nuclear Information System (INIS)

Liu, C.-T.; Lin, S.-C.; Chiang, T.-S.

2004-01-01

By combining the recoil line characteristics of permanent magnet and the equivalent operational magnetic circuits at various rotor positions, a systematic procedure for developing the desired analytical model of an axial-flux surface-mounted permanent magnet motor can be devised. Supported by detailed three-dimensional finite element analysis results and statistical evaluations, accuracies of the developed analytical model can be guaranteed. With such well developed system model, the relative high-precision controls and operations of the motor can then be conveniently realized
Analytical modelling for ultrasonic surface mechanical attrition treatment

Directory of Open Access Journals (Sweden)

Guan-Rong Huang

2015-07-01

Full Text Available The grain refinement, gradient structure, fatigue limit, hardness, and tensile strength of metallic materials can be effectively enhanced by ultrasonic surface mechanical attrition treatment (SMAT, however, never before has SMAT been treated with rigorous analytical modelling such as the connection among the input energy and power and resultant temperature of metallic materials subjected to SMAT. Therefore, a systematic SMAT model is actually needed. In this article, we have calculated the averaged speed, duration time of a cycle, kinetic energy and kinetic energy loss of flying balls in SMAT for structural metallic materials. The connection among the quantities such as the frequency and amplitude of attrition ultrasonic vibration motor, the diameter, mass and density of balls, the sample mass, and the height of chamber have been considered and modelled in details. And we have introduced the one-dimensional heat equation with heat source within uniform-distributed depth in estimating the temperature distribution and heat energy of sample. In this approach, there exists a condition for the frequency of flying balls reaching a steady speed. With these known quantities, we can estimate the strain rate, hardness, and grain size of sample.
Various extraction and analytical techniques for isolation and identification of secondary metabolites from Nigella sativa seeds.

Science.gov (United States)

Liu, X; Abd El-Aty, A M; Shim, J-H

2011-10-01

Nigella sativa L. (black cumin), commonly known as black seed, is a member of the Ranunculaceae family. This seed is used as a natural remedy in many Middle Eastern and Far Eastern countries. Extracts prepared from N. sativa have, for centuries, been used for medical purposes. Thus far, the organic compounds in N. sativa, including alkaloids, steroids, carbohydrates, flavonoids, fatty acids, etc. have been fairly well characterized. Herein, we summarize some new extraction techniques, including microwave assisted extraction (MAE) and supercritical extraction techniques (SFE), in addition to the classical method of hydrodistillation (HD), which have been employed for isolation and various analytical techniques used for the identification of secondary metabolites in black seed. We believe that some compounds contained in N. sativa remain to be identified, and that high-throughput screening could help to identify new compounds. A study addressing environmentally-friendly techniques that have minimal or no environmental effects is currently underway in our laboratory.
Application of the partitive analytical forecasting (PAF) technique to the United States controlled thermonuclear research effort

International Nuclear Information System (INIS)

Nichols, S.P.

1975-01-01

The Partitive Analytical Forecasting (PAF) technique is applied to the overall long-term program plans for the Division of Controlled Thermonuclear Research (DCTR) of the United States Energy Research and Development Administration (ERDA). As part of the PAF technique, the Graphical Evaluation and Review Technique (GERTS) IIIZ computer code is used to perform simulations on a logic network describing the DCTR long-term program plan. Logic networks describing the tokamak, mirror, and theta-pinch developments are simulated individually and then together to form an overall DCTR program network. The results of the simulation of the overall network using various funding schemes and strategies are presented. An economic sensitivity analysis is provided for the tokamak logic networks. An analysis is also performed of the fusion-fission hybrid concept in the context of the present DCTR goals. The results mentioned above as well as the PAF technique itself are evaluated, and recommendations for further research are discussed
A scanning fluid dynamic gauging technique for probing surface layers

International Nuclear Information System (INIS)

Gordon, Patrick W; Chew, Y M John; Wilson, D Ian; Brooker, Anju D M; York, David W

2010-01-01

Fluid dynamic gauging (FDG) is a technique for measuring the thickness of soft solid deposit layers immersed in a liquid environment, in situ and in real time. This paper details the performance of a novel automated, scanning FDG probe (sFDG) which allows the thickness of a sample layer to be monitored at several points during an experiment, with a resolution of ±5 µm. Its application is demonstrated using layers of gelatine, polyvinyl alcohol (PVA) and baked tomato purée deposits. Swelling kinetics, as well as deformation behaviour—based on knowledge of the stresses imposed on the surface by the gauging flow—can be determined at several points, affording improved experimental data. The use of FDG as a surface scanning technique, operating as a fluid mechanical analogue of atomic force microscopy on a millimetre length scale, is also demonstrated. The measurement relies only on the flow behaviour, and is thus suitable for use in opaque fluids, does not contact the surface itself and does not rely on any specific physical properties of the surface, provided it is locally stiff
Application of the thermal plasma technique in the treatment of stone surfaces

International Nuclear Information System (INIS)

Gonzalez A, Z.I.

2000-01-01

The stone materials which form part of the cultural heritage of Mexico, are degraded under the united action of water, atmospheric gases, air pollution, temperature changes and the microorganisms action; provoking on the stone: fissures, crevices, scalings, fragmentations, pulverizations, etc. Therefore, the purpose of this work is to study the possibilities to apply a protective coating on the stone surfaces, previously clean and consolidated, through the thermal plasma technique. The purpose is to analyse the physical and chemical properties of three types of stone materials: quarry, tezontle and chiluca, usually used in constructions of cultural interest such as: historical monuments, churches, sculptures, etc., before and after to be submitted to the action of thermal plasma in order to examine the feasibility in the use of this coating technique in this type of applications. The application of conventional techniques to determine: porosity, density, absorption, low pressure water absorption and crystallization by total immersion of nuclear techniques such as: neutron activation analysis, x-ray diffraction and scanning electron microscopy as well as of instrumental techniques: optical microscopy, mechanical assays of compression, flexure and surface area calculations, allowed to know the chemical and physical properties of the stone material before and after to be treated through the thermal plasma technique, projecting quartz on the stones surface at different distances and current intensity and showing the effect caused by the modifications or surface alterations present by cause of the application of that coating. the obtained results provide a general panorama of the application of this technique as an alternative to the maintenance of the architectural inheritance built in stone. (Author)
Analytical techniques applied to study cultural heritage objects

Energy Technology Data Exchange (ETDEWEB)

Rizzutto, M.A.; Curado, J.F.; Bernardes, S.; Campos, P.H.O.V.; Kajiya, E.A.M.; Silva, T.F.; Rodrigues, C.L.; Moro, M.; Tabacniks, M.; Added, N., E-mail: rizzutto@if.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

2015-07-01

The scientific study of artistic and cultural heritage objects have been routinely performed in Europe and the United States for decades. In Brazil this research area is growing, mainly through the use of physical and chemical characterization methods. Since 2003 the Group of Applied Physics with Particle Accelerators of the Physics Institute of the University of Sao Paulo (GFAA-IF) has been working with various methodologies for material characterization and analysis of cultural objects. Initially using ion beam analysis performed with Particle Induced X-Ray Emission (PIXE), Rutherford Backscattering (RBS) and recently Ion Beam Induced Luminescence (IBIL), for the determination of the elements and chemical compounds in the surface layers. These techniques are widely used in the Laboratory of Materials Analysis with Ion Beams (LAMFI-USP). Recently, the GFAA expanded the studies to other possibilities of analysis enabled by imaging techniques that coupled with elemental and compositional characterization provide a better understanding on the materials and techniques used in the creative process in the manufacture of objects. The imaging analysis, mainly used to examine and document artistic and cultural heritage objects, are performed through images with visible light, infrared reflectography (IR), fluorescence with ultraviolet radiation (UV), tangential light and digital radiography. Expanding more the possibilities of analysis, new capabilities were added using portable equipment such as Energy Dispersive X-Ray Fluorescence (ED-XRF) and Raman Spectroscopy that can be used for analysis 'in situ' at the museums. The results of these analyzes are providing valuable information on the manufacturing process and have provided new information on objects of different University of Sao Paulo museums. Improving the arsenal of cultural heritage analysis it was recently constructed an 3D robotic stage for the precise positioning of samples in the external beam setup
Analytical techniques applied to study cultural heritage objects

International Nuclear Information System (INIS)

Rizzutto, M.A.; Curado, J.F.; Bernardes, S.; Campos, P.H.O.V.; Kajiya, E.A.M.; Silva, T.F.; Rodrigues, C.L.; Moro, M.; Tabacniks, M.; Added, N.

2015-01-01

The scientific study of artistic and cultural heritage objects have been routinely performed in Europe and the United States for decades. In Brazil this research area is growing, mainly through the use of physical and chemical characterization methods. Since 2003 the Group of Applied Physics with Particle Accelerators of the Physics Institute of the University of Sao Paulo (GFAA-IF) has been working with various methodologies for material characterization and analysis of cultural objects. Initially using ion beam analysis performed with Particle Induced X-Ray Emission (PIXE), Rutherford Backscattering (RBS) and recently Ion Beam Induced Luminescence (IBIL), for the determination of the elements and chemical compounds in the surface layers. These techniques are widely used in the Laboratory of Materials Analysis with Ion Beams (LAMFI-USP). Recently, the GFAA expanded the studies to other possibilities of analysis enabled by imaging techniques that coupled with elemental and compositional characterization provide a better understanding on the materials and techniques used in the creative process in the manufacture of objects. The imaging analysis, mainly used to examine and document artistic and cultural heritage objects, are performed through images with visible light, infrared reflectography (IR), fluorescence with ultraviolet radiation (UV), tangential light and digital radiography. Expanding more the possibilities of analysis, new capabilities were added using portable equipment such as Energy Dispersive X-Ray Fluorescence (ED-XRF) and Raman Spectroscopy that can be used for analysis 'in situ' at the museums. The results of these analyzes are providing valuable information on the manufacturing process and have provided new information on objects of different University of Sao Paulo museums. Improving the arsenal of cultural heritage analysis it was recently constructed an 3D robotic stage for the precise positioning of samples in the external beam setup
Production of candidate natural matrix reference materials for micro-analytical techniques

International Nuclear Information System (INIS)

Zeisler, R.; Fajgelj, A.; Zeiller, E.

2002-01-01

Homogeneity is considered to be the most vital prerequisite for a certified reference material (CRM); more stringent requirements exist for the analysis of small subsamples. Many of the natural matrix CRMs are prepared from bulk samples by grinding and milling them to a certain particle size, which is expected to provide a more homogenous material; however recommended sample sizes for biological and environmental reference materials are found to be more than 100 mg. Since the milling of materials is costly and has some drawbacks, natural materials that already occur as small particles such as air particulate matter, certain sediments, and cellular biological materials may form the basis of the required reference materials. The nature of these materials, i.e. naturally occurring particles, may provide ideal model reference material. We describe here the production of the materials and preliminary tests, the evaluation for the micro-analytical techniques
Measurements of x-ray scattering from accelerator vacuum chamber surfaces, and comparison with an analytical model

Directory of Open Access Journals (Sweden)

G. F. Dugan

2015-04-01

Full Text Available This paper compares measurements and calculations of scattering of photons from technical vacuum chamber surfaces typical of accelerators. Synchrotron radiation generated by a charged particle beam in the accelerator is either absorbed, specularly reflected, or scattered by the vacuum chamber surface. This phenomenon has important implications on the operation of the accelerator. Measurements of photon scattering were made at the BESSY-II synchrotron radiation facility using samples of aluminum vacuum chamber from Cornell electron storage ring (CESR. A description of the analytic model used in the calculation is given, which takes into account the reflectivity of the material, the surface features of the sample, the wavelengths and the incident angles of the photons. The surface properties used in these calculations were obtained from measurements made from an atomic force microscope.
Calibration technique for the neutron surface moisture measurement system

International Nuclear Information System (INIS)

Watson, W.T.; Shreve, D.C.

1996-01-01

A technique for calibrating the response of a surface neutron moisture measurement probe to material moisture concentration has been devised. Tests to ensure that the probe will function in the expected in-tank operating environment are also outlined
Near-field Light Scattering Techniques for Measuring Nanoparticle-Surface Interaction Energies and Forces.

Science.gov (United States)

Schein, Perry; Ashcroft, Colby K; O'Dell, Dakota; Adam, Ian S; DiPaolo, Brian; Sabharwal, Manit; Shi, Ce; Hart, Robert; Earhart, Christopher; Erickson, David

2015-08-15

Nanoparticles are quickly becoming commonplace in many commercial and industrial products, ranging from cosmetics to pharmaceuticals to medical diagnostics. Predicting the stability of the engineered nanoparticles within these products a priori remains an important and difficult challenge. Here we describe our techniques for measuring the mechanical interactions between nanoparticles and surfaces using near-field light scattering. Particle-surface interfacial forces are measured by optically "pushing" a particle against a reference surface and observing its motion using scattered near-field light. Unlike atomic force microscopy, this technique is not limited by thermal noise, but instead takes advantage of it. The integrated waveguide and microfluidic architecture allow for high-throughput measurements of about 1000 particles per hour. We characterize the reproducibility of and experimental uncertainty in the measurements made using the NanoTweezer surface instrument. We report surface interaction studies on gold nanoparticles with 50 nm diameters, smaller than previously reported in the literature using similar techniques.

Pressure effects on interfacial surface contacts and performance of organic solar cells

NARCIS (Netherlands)

Agyei-Tuffour, B.; Doumon, Nutifafa Y.; Rwenyagila, E. R.; Asare, J.; Oyewole, O. K.; Shen, Z.; Petoukhoff, C. E.; Zebaze Kana, M. G.; Ocarroll, D. M.; Soboyejo, W. O.

2017-01-01

This paper explores the effects of pressure on the interfacial surface contacts and the performance of organic solar cells. A combination of experimental techniques and analytical/computational models is used to study the evolving surface contacts profiles that occur when compliant, semi-rigid and
Radioactive particles in the environment: sources, particle characterization and analytical techniques

International Nuclear Information System (INIS)

2011-08-01

Over the years, radioactive particles have been released to the environment from nuclear weapons testing and nuclear fuel cycle operations. However, measurements of environmental radioactivity and any associated assessments are often based on the average bulk mass or surface concentration, assuming that radionuclides are homogeneously distributed as simple ionic species. It has generally not been recognised that radioactive particles present in the environment often contain a significant fraction of the bulk sample activity, leading to sample heterogeneity problems and false and/or erratic measurement data. Moreover, the inherent differences in the transport and bioavailability of particle bound radionuclides compared with those existing as molecules or ions have largely been ignored in dose assessments. To date, most studies regarding radionuclide behaviour in the soil-plant system have dealt with soluble forms of radionuclides. When radionuclides are deposited in a less mobile form, or in case of a superposition of different physico-chemical forms, the behaviour of radionuclides becomes much more complicated and extra efforts are required to provide information about environmental status and behaviour of radioactive particles. There are currently no documents or international guides covering this aspect of environmental impact assessments. To fill this gap, between 2001 and 2008 the IAEA performed a Coordinated Research Programme (CRP- G4.10.03) on the 'Radiochemical, Chemical and Physical Characterization of Radioactive Particles in the Environment' with the objective of development, adoption and application of standardized analytical techniques for the comprehensive study of radioactive particles. The CRP was in line with the IAEA project intended to assist the Member States in building capacity for improving environmental assessments and for management of sites contaminated with radioactive particles. This IAEA-TECDOC presents the findings and achievements of
Trace detection of analytes using portable raman systems

Science.gov (United States)

Alam, M. Kathleen; Hotchkiss, Peter J.; Martin, Laura E.; Jones, David Alexander

2015-11-24

Apparatuses and methods for in situ detection of a trace amount of an analyte are disclosed herein. In a general embodiment, the present disclosure provides a surface-enhanced Raman spectroscopy (SERS) insert including a passageway therethrough, where the passageway has a SERS surface positioned therein. The SERS surface is configured to adsorb molecules of an analyte of interest. A concentrated sample is caused to flow over the SERS surface. The SERS insert is then provided to a portable Raman spectroscopy system, where it is analyzed for the analyte of interest.
Ion beam analysis of metal ion implanted surfaces

Energy Technology Data Exchange (ETDEWEB)

Evans, P.J.; Chu, J.W.; Johnson, E.P.; Noorman, J.T. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Sood, D.K. [Royal Melbourne Inst. of Tech., VIC (Australia)

1993-12-31

Ion implantation is an established method for altering the surface properties of many materials. While a variety of analytical techniques are available for the characterisation of implanted surfaces, those based on particle accelerators such as Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) provide some of the most useful and powerful for this purpose. Application of the latter techniques to metal ion implantation research at ANSTO will be described with particular reference to specific examples from recent studies. Where possible, the information obtained from ion beam analysis will be compared with that derived from other techniques such as Energy Dispersive X-ray (EDX) and Auger spectroscopies. 4 refs., 5 figs.
Ion beam analysis of metal ion implanted surfaces

Energy Technology Data Exchange (ETDEWEB)

Evans, P J; Chu, J W; Johnson, E P; Noorman, J T [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Sood, D K [Royal Melbourne Inst. of Tech., VIC (Australia)

1994-12-31

Ion implantation is an established method for altering the surface properties of many materials. While a variety of analytical techniques are available for the characterisation of implanted surfaces, those based on particle accelerators such as Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) provide some of the most useful and powerful for this purpose. Application of the latter techniques to metal ion implantation research at ANSTO will be described with particular reference to specific examples from recent studies. Where possible, the information obtained from ion beam analysis will be compared with that derived from other techniques such as Energy Dispersive X-ray (EDX) and Auger spectroscopies. 4 refs., 5 figs.
Ion beam analysis of metal ion implanted surfaces

International Nuclear Information System (INIS)

Evans, P.J.; Chu, J.W.; Johnson, E.P.; Noorman, J.T.; Sood, D.K.

1993-01-01

Ion implantation is an established method for altering the surface properties of many materials. While a variety of analytical techniques are available for the characterisation of implanted surfaces, those based on particle accelerators such as Rutherford backscattering (RBS) and nuclear reaction analysis (NRA) provide some of the most useful and powerful for this purpose. Application of the latter techniques to metal ion implantation research at ANSTO will be described with particular reference to specific examples from recent studies. Where possible, the information obtained from ion beam analysis will be compared with that derived from other techniques such as Energy Dispersive X-ray (EDX) and Auger spectroscopies. 4 refs., 5 figs
Wipe-rinse technique for quantitating microbial contamination on large surfaces

Science.gov (United States)

Kirschner, L. E.; Puleo, J. R.

1979-01-01

The evaluation of an improved wipe-rinse technique for the bioassay of large areas was undertaken due to inherent inadequacies in the cotton swab-rinse technique to which assay of spacecraft is currently restricted. Four types of contamination control cloths were initially tested. A polyester-bonded cloth (PBC) was selected for further evaluation because of its superior efficiency and handling characteristics. Results from comparative tests with PBC and cotton swabs on simulated spacecraft surfaces indicated a significantly higher recovery efficiency for the PBC than for the cotton (90.4 versus 75.2%). Of the sampling area sites studied, PBC was found to be most effective on surface areas not exceeding 0.74 sq m (8.0 sq ft).
Air particulate pollution studies in Asian countries using nuclear analytical techniques

International Nuclear Information System (INIS)

Hien, P.D.

1998-01-01

Air particulate pollution is regarded as critical in Asian cities. The levels of suspended particulate matter in major Asian cities far exceed the WHO's guideline. Nuclear analytical techniques have been widely used in the studies of air particulate pollution to provide aerosol elemental compositions for the purpose of deriving the structure of emission sources. This paper presents some preliminary observations and findings based on publications in scientific literatures. Data on PM-10 levels and socio-economic indicators are used for searching a relationship between air quality and the level of development across Asia. An inverse linear relationship between PM-10 levels and logarithm of per capita GDP appears to exist, although there are large fluctuations of data caused by the very different climatic and geographical conditions of cities studied. Soil dust is generally a major, or even predominant aerosol source in Asian cities. Other common sources include vehicular emissions, coal and oil combustion, burning of refuse (in open) and biomass (including forest fires). The relevance and the trends of these sources in Asian context are discussed. Multivariate receptor modelling techniques applied in source characterization are illustrated through the cases of Lahore and Hochiminh City. Although having limitations in dealing with mixing and overlapping sources, receptor modelling based on principal component factor analysis has been proven to be uncomplicated and sufficiently reliable for characterising aerosol sources in urban areas. (author)
Prompt nuclear analytical techniques for material research in accelerator driven transmutation technologies: Prospects and quantitative analyses

International Nuclear Information System (INIS)

Vacik, J.; Hnatowicz, V.; Cervena, J.; Perina, V.; Mach, R.

1998-01-01

Accelerator driven transmutation technology (ADTT) is a promising way toward liquidation of spent nuclear fuel, nuclear wastes and weapon grade Pu. The ADTT facility comprises a high current (proton) accelerator supplying a sub-critical reactor assembly with spallation neutrons. The reactor part is supposed to be cooled by molten fluorides or metals which serve, at the same time, as a carrier of nuclear fuel. Assumed high working temperature (400-600 C) and high radiation load in the subcritical reactor and spallation neutron source put forward the problem of optimal choice of ADTT construction materials, especially from the point of their radiation and corrosion resistance when in contact with liquid working media. The use of prompt nuclear analytical techniques in ADTT related material research is considered and examples of preliminary analytical results obtained using neutron depth profiling method are shown for illustration. (orig.)
Analytical method for the identification and assay of 12 phthalates in cosmetic products: application of the ISO 12787 international standard "Cosmetics-Analytical methods-Validation criteria for analytical results using chromatographic techniques".

Science.gov (United States)

Gimeno, Pascal; Maggio, Annie-Françoise; Bousquet, Claudine; Quoirez, Audrey; Civade, Corinne; Bonnet, Pierre-Antoine

2012-08-31

Esters of phthalic acid, more commonly named phthalates, may be present in cosmetic products as ingredients or contaminants. Their presence as contaminant can be due to the manufacturing process, to raw materials used or to the migration of phthalates from packaging when plastic (polyvinyl chloride--PVC) is used. 8 phthalates (DBP, DEHP, BBP, DMEP, DnPP, DiPP, DPP, and DiBP), classified H360 or H361, are forbidden in cosmetics according to the European regulation on cosmetics 1223/2009. A GC/MS method was developed for the assay of 12 phthalates in cosmetics, including the 8 phthalates regulated. Analyses are carried out on a GC/MS system with electron impact ionization mode (EI). The separation of phthalates is obtained on a cross-linked 5%-phenyl/95%-dimethylpolysiloxane capillary column 30 m × 0.25 mm (i.d.) × 0.25 mm film thickness using a temperature gradient. Phthalate quantification is performed by external calibration using an internal standard. Validation elements obtained on standard solutions, highlight a satisfactory system conformity (resolution>1.5), a common quantification limit at 0.25 ng injected, an acceptable linearity between 0.5 μg mL⁻¹ and 5.0 μg mL⁻¹ as well as a precision and an accuracy in agreement with in-house specifications. Cosmetic samples ready for analytical injection are analyzed after a dilution in ethanol whereas more complex cosmetic matrices, like milks and creams, are assayed after a liquid/liquid extraction using ter-butyl methyl ether (TBME). Depending on the type of cosmetics analyzed, the common limits of quantification for the 12 phthalates were set at 0.5 or 2.5 μg g⁻¹. All samples were assayed using the analytical approach described in the ISO 12787 international standard "Cosmetics-Analytical methods-Validation criteria for analytical results using chromatographic techniques". This analytical protocol is particularly adapted when it is not possible to make reconstituted sample matrices. Copyright © 2012
Implementation of an analytical technique for Samarium

International Nuclear Information System (INIS)

Garcia G, N.

2004-01-01

Since the Samarium presents the same chemical properties that the plutonium, it has been used as homologous in studies that allow us to know the behavior that the plutonium presents in solution, with the advantage of working with an inactive and not very dangerous element. At the moment studies of sorption of plutonium or samarium are made on some mineral matrices that present certain surface properties. Due to the low concentrations that are used in the studies of sorption of samarium on those reagent substrates, their detection becomes very difficult for the conventional analysis media. The luminescence is a technique that can detect lower concentrations, smaller at 1 X 10 - 2 M, but when fluorofors are used this limit of detection increases in several orders of magnitude. In this work it has been used the arsenazo-III as fluorofor agent since it reacts in a specific way with the samarium, forming a complex that presents a proportional luminescence to the concentration of the present samarium. The advantage of making the quantification of samarium by luminescence is that it can use the same instrumental equipment to determine the speciation of the samarium sipped in the zircon. (Author)
Workplace and occupational health: The first metal evaluation using nuclear and analytical techniques in the State of Minas Gerais, Brazil

International Nuclear Information System (INIS)

Barros Correia Menezes, M.A. de; Vilhena Schayer Sabino, C. de; Melo Mattos, S.V. de; Santos Filho, S.; Diniz, E.

1998-01-01

Belo Horizonte, the capital of the State of Minas Gerais and its neighbourhood are the second industrial center of Brazil, concentrating many industries in several areas mainly metal refining and transformation. There are no registers about the level of metal concentration in the environmental air in the industry, nor even of the level of workers' contamination. The overall objective of this Project is to make a survey of the exposures to metals related to occupational diseases in galvanizing industry, which is responsible for the majority of occurrences of occupational diseases. The survey will be accomplished using as bio-indicators hair, nails, blood, urine, and individual air filters. These matrixes will indicate the incorporation of metals and the exposure level. The analytical techniques that will be applied are the neutron activation joined to related non nuclear analytical techniques, such as atomic absorption. (author)
Surface Casting Defects Inspection Using Vision System and Neural Network Techniques

Directory of Open Access Journals (Sweden)

Świłło S.J.

2013-12-01

Full Text Available The paper presents a vision based approach and neural network techniques in surface defects inspection and categorization. Depending on part design and processing techniques, castings may develop surface discontinuities such as cracks and pores that greatly influence the material’s properties Since the human visual inspection for the surface is slow and expensive, a computer vision system is an alternative solution for the online inspection. The authors present the developed vision system uses an advanced image processing algorithm based on modified Laplacian of Gaussian edge detection method and advanced lighting system. The defect inspection algorithm consists of several parameters that allow the user to specify the sensitivity level at which he can accept the defects in the casting. In addition to the developed image processing algorithm and vision system apparatus, an advanced learning process has been developed, based on neural network techniques. Finally, as an example three groups of defects were investigated demonstrates automatic selection and categorization of the measured defects, such as blowholes, shrinkage porosity and shrinkage cavity.
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
Simple analytical technique for liquid scintillation counting of environmental carbon-14 using gel suspension method

International Nuclear Information System (INIS)

Okai, Tomio; Wakabayashi, Genichiro; Nagao, Kenjiro; Matoba, Masaru; Ohura, Hirotaka; Momoshima, Noriyuki; Kawamura, Hidehisa

2000-01-01

A simple analytical technique for liquid scintillation counting of environmental 14 C was developed. Commercially available gelling agent, N-lauroyl-L -glutamic -α,γ-dibutylamide, was used for the gel-formation of the samples (gel suspension method) and for the subsequent liquid scintillation counting of 14 C in the form of CaCO 3 . Our procedure for sample preparation is much simpler than that of the conventional methods and requires no special equipment. Self absorption, stability and reproducibility of gel suspension samples were investigated in order to evaluate the characteristics of the gel suspension method for 14 C activity measurement. The self absorption factor is about 70% and slightly decrease as CaCO 3 weight increase. This is considered to be mainly due to the absorption of β-rays and scintillation light by the CaCO 3 sample itself. No change of the counting rate for the gel suspension sample was observed for more than 2 years after the sample preparation. Four samples were used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of 24 C activity within the counting error. No change of the counting rate was observed for the 're-gelated' sample. These results show that the gel suspension method is appropriate for the 14 C activity measurement by the liquid scintillation counting method and useful for a long-term preservation of the sample for repeated measurement. The above analytical technique was applied to actual environmental samples in Fukuoka prefecture, Japan. Results obtained were comparable with those by other researchers and appear to be reasonable. Therefore, the newly developed technique is useful for the routine monitoring of environmental 14 C. (author)
A new multi-domain method based on an analytical control surface for linear and second-order mean drift wave loads on floating bodies

Science.gov (United States)

Liang, Hui; Chen, Xiaobo

2017-10-01

A novel multi-domain method based on an analytical control surface is proposed by combining the use of free-surface Green function and Rankine source function. A cylindrical control surface is introduced to subdivide the fluid domain into external and internal domains. Unlike the traditional domain decomposition strategy or multi-block method, the control surface here is not panelized, on which the velocity potential and normal velocity components are analytically expressed as a series of base functions composed of Laguerre function in vertical coordinate and Fourier series in the circumference. Free-surface Green function is applied in the external domain, and the boundary integral equation is constructed on the control surface in the sense of Galerkin collocation via integrating test functions orthogonal to base functions over the control surface. The external solution gives rise to the so-called Dirichlet-to-Neumann [DN2] and Neumann-to-Dirichlet [ND2] relations on the control surface. Irregular frequencies, which are only dependent on the radius of the control surface, are present in the external solution, and they are removed by extending the boundary integral equation to the interior free surface (circular disc) on which the null normal derivative of potential is imposed, and the dipole distribution is expressed as Fourier-Bessel expansion on the disc. In the internal domain, where the Rankine source function is adopted, new boundary integral equations are formulated. The point collocation is imposed over the body surface and free surface, while the collocation of the Galerkin type is applied on the control surface. The present method is valid in the computation of both linear and second-order mean drift wave loads. Furthermore, the second-order mean drift force based on the middle-field formulation can be calculated analytically by using the coefficients of the Fourier-Laguerre expansion.
Applications of surface analysis in the environmental sciences: dehalogenation of chlorocarbons with zero-valent iron and iron-containing mineral surfaces

Energy Technology Data Exchange (ETDEWEB)

McGuire, Molly M.; Carlson, Daniel L.; Vikesland, Peter J.; Kohn, Tamar; Grenier, Adam C.; Langley, Laura A.; Roberts, A. Lynn; Fairbrother, D. Howard

2003-10-31

Halogenated organic compounds are common pollutants in groundwater. Consequently, there is widespread interest in understanding the reactions of these compounds in the environment and developing remediation strategies. One area of ongoing research involves the reductive dechlorination of organohalides with zero-valent metals or metal sulfide minerals. These processes have been studied almost exclusively from the perspective of the aqueous phase. In this paper we illustrate the utility of surface analysis techniques, including electron spectroscopies, vibrational spectroscopies, and atomic force microscopy in elucidating the roles played by the surface. A dual analysis approach to the study of reductive dechlorination, combining traditional solution phase analysis with surface analytical techniques, also is demonstrated using a liquid cell coupled to an ultrahigh vacuum surface analysis chamber.
Description of measurement techniques for surface contaminations

International Nuclear Information System (INIS)

Bourrez, E.

2001-01-01

The needs of evaluation of the surface contamination are numerous in the processes of production and management of radioactive waste. The market of radiation protection materials proposes a lot of devices answering to the almost all these needs. These device have however their conditions and particular limits for use. To realize correct measurements it is use the device, the technique and the methods adapted to the need, by taking into account the optimization of economical aspect. (N.C.)
Immobilization of Fab' fragments onto substrate surfaces: A survey of methods and applications.

Science.gov (United States)

Crivianu-Gaita, Victor; Thompson, Michael

2015-08-15

Antibody immobilization onto surfaces has widespread applications in many different fields. It is desirable to bind antibodies such that their fragment-antigen-binding (Fab) units are oriented away from the surface in order to maximize analyte binding. The immobilization of only Fab' fragments yields benefits over the more traditional whole antibody immobilization technique. Bound Fab' fragments display higher surface densities, yielding a higher binding capacity for the analyte. The nucleophilic sulfide of the Fab' fragments allows for specific orientations to be achieved. For biosensors, this indicates a higher sensitivity and lower detection limit for a target analyte. The last thirty years have shown tremendous progress in the immobilization of Fab' fragments onto gold, Si-based, polysaccharide-based, plastic-based, magnetic, and inorganic surfaces. This review will show the current scope of Fab' immobilization techniques available and illustrate methods employed to minimize non-specific adsorption of undesirables. Furthermore, a variety of examples will be given to show the versatility of immobilized Fab' fragments in different applications and future directions of the field will be addressed, especially regarding biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.
Analytical and numerical calculation of magnetic field distribution in the slotted air-gap of tangential surface permanent-magnet motors

Directory of Open Access Journals (Sweden)

Boughrara Kamel

2009-01-01

Full Text Available This paper deals with the analytical and numerical analysis of the flux density distribution in the slotted air gap of permanent magnet motors with surface mounted tangentially magnetized permanent magnets. Two methods for magnetostatic field calculations are developed. The first one is an analytical method in which the effect of stator slots is taken into account by modulating the magnetic field distribution by the complex relative air gap permeance. The second one is a numerical method using 2-D finite element analysis with consideration of Dirichlet and anti-periodicity (periodicity boundary conditions and Lagrange Multipliers for simulation of movement. The results obtained by the analytical method are compared to the results of finite-element analysis.

Potentialities of some surface characterization techniques for the development of titanium biomedical alloys

Directory of Open Access Journals (Sweden)

P.S. Vanzillotta

2004-09-01

Full Text Available Bone formation around a metallic implant is a complex process that involves micro- and nanometric interactions. Several surface treatments, including coatings were developed in order to obtain faster osseointegration. To understand the role of these surface treatments on bone formation it is necessary to choose adequate characterization techniques. Among them, we have selected electron microscopy, profilometry, atomic force microscopy (AFM and X-ray photoelectron spectroscopy (XPS to describe them briefly. Examples of the potentialities of these techniques on the characterization of titanium for biomedical applications were also presented and discussed. Unfortunately more than one technique is usually necessary to describe conveniently the topography (scanning electron microsocopy, profilometry and/or AFM and the chemical state (XPS of the external layer of the material surface. The employment of the techniques above described can be useful especially for the development of new materials or products.
FEASIBILITY OF INVESTMENT IN BUSINESS ANALYTICS

Directory of Open Access Journals (Sweden)

Mladen Varga

2007-12-01

Full Text Available Trends in data processing for decision support show that business users need business analytics, i.e. analytical applications which incorporate a variety of business oriented data analysis techniques and task-specific knowledge. The paper discusses the feasibility of investment in two models of implementing business analytics: custom development and packed analytical applications. The consequences of both models are shown on two models of business analytics implementation in Croatia.
Nanotubular surface modification of metallic implants via electrochemical anodization technique.

Science.gov (United States)

Wang, Lu-Ning; Jin, Ming; Zheng, Yudong; Guan, Yueping; Lu, Xin; Luo, Jing-Li

2014-01-01

Due to increased awareness and interest in the biomedical implant field as a result of an aging population, research in the field of implantable devices has grown rapidly in the last few decades. Among the biomedical implants, metallic implant materials have been widely used to replace disordered bony tissues in orthopedic and orthodontic surgeries. The clinical success of implants is closely related to their early osseointegration (ie, the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant), which relies heavily on the surface condition of the implant. Electrochemical techniques for modifying biomedical implants are relatively simple, cost-effective, and appropriate for implants with complex shapes. Recently, metal oxide nanotubular arrays via electrochemical anodization have become an attractive technique to build up on metallic implants to enhance the biocompatibility and bioactivity. This article will thoroughly review the relevance of electrochemical anodization techniques for the modification of metallic implant surfaces in nanoscale, and cover the electrochemical anodization techniques used in the development of the types of nanotubular/nanoporous modification achievable via electrochemical approaches, which hold tremendous potential for bio-implant applications. In vitro and in vivo studies using metallic oxide nanotubes are also presented, revealing the potential of nanotubes in biomedical applications. Finally, an outlook of future growth of research in metallic oxide nanotubular arrays is provided. This article will therefore provide researchers with an in-depth understanding of electrochemical anodization modification and provide guidance regarding the design and tuning of new materials to achieve a desired performance and reliable biocompatibility.
Surface analysis: its uses and abuses in waste form evaluation

International Nuclear Information System (INIS)

McVay, G.L.; Pederson, L.R.

1981-01-01

Surface and near-surface analytical techniques are significant aids in understanding waste form-aqueous solution interactions. They can be beneficially employed to evaluate reaction layers on waste forms, to assess surface treatments prior to and after leaching, and to identify interactions with waste forms. Surface analyses are best used in conjunction with other types of analyses, such as solution analyses, in order to obtain a better overall understanding of reaction processes. In spite of all the benefits to be gained by using surface analyses, misinterpretations can result if care is not taken to properly obtain and analyze the data. In particular, the density variations through a reaction layer must be accounted for in both sputtering and data analysis techniques
Analytical TEM investigations of nanoscale magnetic materials

International Nuclear Information System (INIS)

Meingast, A.

2015-01-01

element identification or, an absolute quantification is possible. Moreover, the parallel acquisition of EDXS and EELS signals allows combining the strength of each respective technique. A careful and precise sample preparation is crucial and knowledge and suitable methods had to be developed. Preparation induced modifications of the investigated material was minimized by identifying changes to the material during thinning to electron transparency. Reducing surface amorphization of TEM specimens and moreover identifying and quantifying surface oxidation was an important factor. Questions regarding the structural architecture of three diverse magnetic materials down to the atomic level have been addressed, and elemental distributions have been determined quantitatively. The first part of the results treats structural and analytical results of crystalline nanocubes. These cubes have dimensions below 30 nm, and represent a class of materials to exploit magnetic exchange coupling on a nanometer scale. Knowledge about the elemental distribution on a nanometer basis within a nanocube is necessary to tailor the magnetic properties. Analytical investigations deal with the determination of the oxidation state of iron oxide reference nanocrystals and the elemental distribution within a multi-component system. Transition metal doped gallium nitride (GaN) falling into the class of dilute magnetic semiconductors was investigated by various high resolution imaging techniques and spectroscopic methods for resolving morphologies and dopant concentrations. The doping of GaN is intended to provide additional magnetic functionalities to the semiconducting material used for future spintronic devices. Quantitative EELS measurements resolved that Mn was incorporated either in a homogeneous way or added to GaN in a pulsed way, leading to a layered doping. Iron was used as another potential dopant for GaN. Hereby specific growth procedures enabled the formation of a layer of iron
Atomic and Nuclear Analytical Methods XRF, Mössbauer, XPS, NAA and Ion-Beam Spectroscopic Techniques

CERN Document Server

Verma, H R

2007-01-01

This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Mössbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories.
Wireless network development for the automatic registration of parameters in laboratories of nuclear analytical techniques

International Nuclear Information System (INIS)

Tincopa, Jean Pierre; Baltuano, Oscar; Bedregal, Patricia

2015-01-01

This paper presents in detail the development of a low-cost wireless network for automatic recording of temperature and relative humidity parameters in the laboratory of nuclear analytical techniques. This prototype has a DHT22 sensor which gives us both parameters with high precision and are automatically read and displayed by a ATmega328P microcontroller. This data is then transmitted through transceivers Xbee Pro S2B forming a mesh network for real time storage using an RTC (Real Time Clock). We present the experimental results obtained in its implementation. (author)
Reliability of surface inspection techniques for pressurized components

International Nuclear Information System (INIS)

Kauppinen, P.; Sillanpaeae, J.

1991-01-01

In the Nordtest NDT-programme (1984 - 1988) the detection of flaws by surface inspection methods has been studied. In the round-robin exercise, 133 test pieces have been inspected by 32 inspectors in Denmark, Finland, Norway and Sweden. From the results, the detectability of defects by magnetic particle and liquid-penetrant testing and the influence of materials and techniques used are evaluated. (author)
Nuclear analytical methods: Past, present and future

International Nuclear Information System (INIS)

Becker, D.A.

1996-01-01

The development of nuclear analytical methods as an analytical tool began in 1936 with the publication of the first paper on neutron activation analysis (NAA). This year, 1996, marks the 60th anniversary of that event. This paper attempts to look back at the nuclear analytical methods of the past, to look around and to see where the technology is right now, and finally, to look ahead to try and see where nuclear methods as an analytical technique (or as a group of analytical techniques) will be going in the future. The general areas which the author focuses on are: neutron activation analysis; prompt gamma neutron activation analysis (PGNAA); photon activation analysis (PAA); charged-particle activation analysis (CPAA)
An analytical solution for the elastic response to surface loads imposed on a layered, transversely isotropic and self-gravitating Earth

OpenAIRE

Pan, E.; Chen, J.Y.; Bevis, M.; Bordoni, Andrea; Barletta, Valentina Roberta; Tabrizi, A. Molavi

2015-01-01

We present an analytical solution for the elastic deformation of an elastic, transversely isotropic, layered and self-gravitating Earth by surface loads. We first introduce the vector spherical harmonics to express the physical quantities in the layered Earth. This reduces the governing equations to a linear system of equations for the expansion coefficients. We then solve for the expansion coefficients analytically under the assumption (i.e. approximation) that in the mantle, the density in ...
New analytical techniques for traffic management on the basis of system studies in logistics

Directory of Open Access Journals (Sweden)

Олександр Павлович Кіркін

2017-07-01

Full Text Available In today's market conditions, it is necessary for enterprises to constantly maintain their competitiveness. This is achieved through raising customer service standards and use of the latest management techniques. In most cases, enterprises adhere to the logistic principles to optimize production. Over time, however, the development of logistics resulted in emergence of its principal subdivisions: transport, storage, etc. Thus, nowadays there are several parallel methodological developments in the field of logistics and making up logistics chains and systems at different stages of the life cycle of the goods. System research in the field of warehouse logistics showed that the majority of its analytical models of management are based on task conflict. Similar tasks of managing traffic flows in transport logistics are solved by methods of SMO, graph theory, linear programming and differential equations of state etc. These methods are not more accurate than the methods of warehouse logistics, have similar important assumptions and simplifications, and require appropriate mathematical training and knowledge in the field of transport, and sometimes lack visible correlation with economic performance. New analytical techniques for the management of transportation systems based on task conflict will reduce the time and resources for optimization and finding solutions. Methods of warehousing logistics can only be used for the continuous transport quantities (intensity, speed, performance, capacity, execution of works, etc.. In the static condition the search for the optimal service intensity can be found in warehouse logistics. In the study of object in dynamics it is better to use transport approach. Some problems such as supplement of warehouse logistics models with elements of the transport task, are still to be decided
Analytical techniques and method validation for the measurement of selected semivolatile and nonvolatile organofluorochemicals in air.

Science.gov (United States)

Reagen, William K; Lindstrom, Kent R; Thompson, Kathy L; Flaherty, John M

2004-09-01

The widespread use of semi- and nonvolatile organofluorochemicals in industrial facilities, concern about their persistence, and relatively recent advancements in liquid chromatography/mass spectrometry (LC/MS) technology have led to the development of new analytical methods to assess potential worker exposure to airborne organofluorochemicals. Techniques were evaluated for the determination of 19 organofluorochemicals and for total fluorine in ambient air samples. Due to the potential biphasic nature of most of these fluorochemicals when airborne, Occupational Safety and Health Administration (OSHA) versatile sampler (OVS) tubes were used to simultaneously trap fluorochemical particulates and vapors from workplace air. Analytical methods were developed for OVS air samples to quantitatively analyze for total fluorine using oxygen bomb combustion/ion selective electrode and for 17 organofluorochemicals using LC/MS and gas chromatography/mass spectrometry (GC/MS). The experimental design for this validation was based on the National Institute of Occupational Safety and Health (NIOSH) Guidelines for Air Sampling and Analytical Method Development and Evaluation, with some revisions of the experimental design. The study design incorporated experiments to determine analytical recovery and stability, sampler capacity, the effect of some environmental parameters on recoveries, storage stability, limits of detection, precision, and accuracy. Fluorochemical mixtures were spiked onto each OVS tube over a range of 0.06-6 microg for each of 12 compounds analyzed by LC/MS and 0.3-30 microg for 5 compounds analyzed by GC/MS. These ranges allowed reliable quantitation at 0.001-0.1 mg/m3 in general for LC/MS analytes and 0.005-0.5 mg/m3 for GC/MS analytes when 60 L of air are sampled. The organofluorochemical exposure guideline (EG) is currently 0.1 mg/m3 for many analytes, with one exception being ammonium perfluorooctanoate (EG is 0.01 mg/m3). Total fluorine results may be used
Workplace and occupational health: The first metal evaluation using nuclear and analytical techniques in the State of Minas Gerais, Brazil

Energy Technology Data Exchange (ETDEWEB)

Barros Correia Menezes, M.A. de; Vilhena Schayer Sabino, C de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Comissao Nacional de Energia Nuclear (CNEN), Sector de Radioquimica, Belo Horizonte, Minas Gerais (Brazil); Melo Mattos, S.V. de [FUNED, Divisao de Bromatologia e Toxicologia, Servico de Quimica Especializada, Belo Horizonte, MG (Brazil); Santos Filho, S [Secretaria Minicipal de Saude de Belo Horizonte, Belo Horizonte, MG (Brazil); Diniz, E [FUNDACENTRO/BH, Belo Horizonte, MG (Brazil)

1999-12-31

Belo Horizonte, the capital of the State of Minas Gerais and its neighbourhood are the second industrial center of Brazil, concentrating many industries in several areas mainly metal refining and transformation. There are no registers about the level of metal concentration in the environmental air in the industry, nor even of the level of workers` contamination. The overall objective of this Project is to make a survey of the exposures to metals related to occupational diseases in galvanizing industry, which is responsible for the majority of occurrences of occupational diseases. The survey will be accomplished using as bio-indicators hair, nails, blood, urine, and individual air filters. These matrixes will indicate the incorporation of metals and the exposure level. The analytical techniques that will be applied are the neutron activation joined to related non nuclear analytical techniques, such as atomic absorption. (author) 7 refs, 2 tabs
Characterization of pre-hispanic pigments by modern analytical techniques; Caracterizacion de pigmentos prehispanicos por tecnicas analiticas modernas

Energy Technology Data Exchange (ETDEWEB)

Ortega A, M

2003-07-01

In this work, the study of mural painting pigments from two archaeological sites (The Great Temple in Mexico city and Cacaxtla) was performed to know their materials composition, identify their structural characteristics and properties by using modern analytical techniques. Blue, ochre, red and black pigments of Mexica culture (1325-1521 a.C. / late Post Classic period); blue, ochre, red, brown, pink, green and white of Olmeca- Xicalanca culture (700-900 a.C. / Epiclassic period) were studied. Data about materials used, technological evolution, mineralogical background, cultural interchange and origin was obtained. Environmental exposition of these paintings since their discovering has produced changes and damage on their materials. Therefore, stability of some pigments has been notorious, ''Maya Blue'' specially presents extraordinary resistance to diluted and concentrated acids and alkalis including boiling condition, acqua regia, solvents, oxidant and reducing agents, moderate heat and biocorrosi6n; for that reason its study was emphasized. ''Maya Blue'' pigment was synthesized in laboratory using the processes described by historic sources (with indigophera suffruticosa leaves and synthetic indigo) up to obtain a stable pigment including acqua regia action. Clay matrix sorbs nearly 0.4 weight percent of organic dye, which cover 79% of palygorskita surface area. (Author)
Characterization of pre-hispanic pigments by modern analytical techniques; Caracterizacion de pigmentos prehispanicos por tecnicas analiticas modernas

Energy Technology Data Exchange (ETDEWEB)

Ortega A, M

2003-07-01

In this work, the study of mural painting pigments from two archaeological sites (The Great Temple in Mexico city and Cacaxtla) was performed to know their materials composition, identify their structural characteristics and properties by using modern analytical techniques. Blue, ochre, red and black pigments of Mexica culture (1325-1521 a.C. / late Post Classic period); blue, ochre, red, brown, pink, green and white of Olmeca- Xicalanca culture (700-900 a.C. / Epiclassic period) were studied. Data about materials used, technological evolution, mineralogical background, cultural interchange and origin was obtained. Environmental exposition of these paintings since their discovering has produced changes and damage on their materials. Therefore, stability of some pigments has been notorious, ''Maya Blue'' specially presents extraordinary resistance to diluted and concentrated acids and alkalis including boiling condition, acqua regia, solvents, oxidant and reducing agents, moderate heat and biocorrosi6n; for that reason its study was emphasized. ''Maya Blue'' pigment was synthesized in laboratory using the processes described by historic sources (with indigophera suffruticosa leaves and synthetic indigo) up to obtain a stable pigment including acqua regia action. Clay matrix sorbs nearly 0.4 weight percent of organic dye, which cover 79% of palygorskita surface area. (Author)
Use of the analytical tree technique to develop a radiological protection program

International Nuclear Information System (INIS)

Domenech N, H.; Jova S, L.

1996-01-01

The results obtained by the Cuban Center for Radiological Protection and Hygiene by using an analytical tree technique to develop its general operational radiation protection program are presented. By the application of this method, some factors such as the organization of the radiation protection services, the provision of administrative requirements, the existing general laboratories requirements, the viability of resources and the current documentation was evaluated. Main components were considered such as: complete normative and regulatory documentation; automatic radiological protection data management; scope of 'on the-job'and radiological protection training for the personnel; previous radiological appraisal for the safety performance of the works and application of dose constrains for the personnel and the public. The detailed development of the program allowed to identify the basic aims to be achieved in its maintenance and improvement. (authors). 3 refs
Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

International Nuclear Information System (INIS)

Alfeld, Matthias; Broekaert, José A.C.

2013-01-01

Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. - Highlights: • All mobile sub-surface and depth-profiling techniques for paintings are reviewed. • The number of techniques available has increased considerably in the last years. • X-ray radiography and infrared reflectography are still the most used techniques. • Scanning macro-XRF and optical coherence tomography begin to establish. • Industrial non destructive testing techniques support the preservation of paintings
Spatial Game Analytics and Visualization

DEFF Research Database (Denmark)

Drachen, Anders; Schubert, Matthias

2013-01-01

, techniques for spatial analysis had their share in these developments. However, the methods for analyzing and visualizing spatial and spatio-temporal patterns in player behavior being used by the game industry are not as diverse as the range of techniques utilized in game research, leaving room...... for a continuing development. This paper presents a review of current work on spatial and spatio-temporal game analytics across industry and research, describing and defining the key terminology, outlining current techniques and their application. We summarize the current problems and challenges in the field......The recently emerged field of game analytics and the development and adaptation of business intelligence techniques to support game design and development has given data-driven techniques a direct role in game development. Given that all digital games contain some sort of spatial operation...
In-situ, real-time, studies of film growth processes using ion scattering and direct recoil spectroscopy techniques.

Energy Technology Data Exchange (ETDEWEB)

Smentkowski, V. S.

1999-04-22

Time-of-flight ion scattering and recoil spectroscopy (TOF-ISARS) enables the characterization of the composition and structure of surfaces with 1-2 monolayer specificity. It will be shown that surface analysis is possible at ambient pressures greater than 3 mTorr using TOF-ISARS techniques; allowing for real-time, in situ studies of film growth processes. TOF-ISARS comprises three analytical techniques: ion scattering spectroscopy (ISS), which detects the backscattered primary ion beam; direct recoil spectroscopy (DRS), which detects the surface species recoiled into the forward scattering direction; and mass spectroscopy of recoiled ions (MSRI), which is 3 variant of DRS capable of isotopic resolution for all surface species--including H and He. The advantages and limitations of each of these techniques will be discussed. The use of the three TOF-ISARS methods for real-time, in situ film growth studies at high ambient pressures will be illustrated. It will be shown that MSRI analysis is possible during sputter deposition. It will be also be demonstrated that the analyzer used for MSRI can also be used for time of flight secondary ion mass spectroscopy (TOF-SIMS) under high vacuum conditions. The use of a single analyzer to perform the complimentary surface analytical techniques of MSRI and SIMS is unique. The dwd functionality of the MSRI analyzer provides surface information not obtained when either MSRI or SIMS is used independently.
Analytical techniques and quality control in biomedical trace element research

DEFF Research Database (Denmark)

Heydorn, K.

1994-01-01

The small number of analytical results in trace element research calls for special methods of quality control. It is shown that when the analytical methods are in statistical control, only small numbers of duplicate or replicate results are needed to ascertain the absence of systematic errors....../kg. Measurement compatibility is obtained by control of traceability to certified reference materials, (C) 1994 Wiley-Liss, Inc....

Deriving Earth Science Data Analytics Requirements

Science.gov (United States)

Kempler, Steven J.

2015-01-01

Data Analytics applications have made successful strides in the business world where co-analyzing extremely large sets of independent variables have proven profitable. Today, most data analytics tools and techniques, sometimes applicable to Earth science, have targeted the business industry. In fact, the literature is nearly absent of discussion about Earth science data analytics. Earth science data analytics (ESDA) is the process of examining large amounts of data from a variety of sources to uncover hidden patterns, unknown correlations, and other useful information. ESDA is most often applied to data preparation, data reduction, and data analysis. Co-analysis of increasing number and volume of Earth science data has become more prevalent ushered by the plethora of Earth science data sources generated by US programs, international programs, field experiments, ground stations, and citizen scientists.Through work associated with the Earth Science Information Partners (ESIP) Federation, ESDA types have been defined in terms of data analytics end goals. Goals of which are very different than those in business, requiring different tools and techniques. A sampling of use cases have been collected and analyzed in terms of data analytics end goal types, volume, specialized processing, and other attributes. The goal of collecting these use cases is to be able to better understand and specify requirements for data analytics tools and techniques yet to be implemented. This presentation will describe the attributes and preliminary findings of ESDA use cases, as well as provide early analysis of data analytics toolstechniques requirements that would support specific ESDA type goals. Representative existing data analytics toolstechniques relevant to ESDA will also be addressed.
[Clinical Application of Analytical and Medical Instruments Mainly Using MS Techniques].

Science.gov (United States)

Tanaka, Koichi

2016-02-01

Analytical instruments for clinical use are commonly required to confirm the compounds and forms related to diseases with the highest possible sensitivity, quantitative performance, and specificity and minimal invasiveness within a short time, easily, and at a low cost. Advancements of technical innovation for Mass Spectrometer (MS) have led to techniques that meet such requirements. Besides confirming known substances, other purposes and advantages of MS that are not fully known to the public are using MS as a tool to discover unknown phenomena and compounds. An example is clarifying the mechanisms of human diseases. The human body has approximately 100 thousand types of protein, and there may be more than several million types of protein and their metabolites. Most of them have yet to be discovered, and their discovery may give birth to new academic fields and lead to the clarification of diseases, development of new medicines, etc. For example, using the MS system developed under "Contribution to drug discovery and diagnosis by next generation of advanced mass spectrometry system," one of the 30 projects of the "Funding Program for World-Leading Innovative R&D on Science and Technology" (FIRST program), and other individual basic technologies, we succeeded in discovering new disease biomarker candidates for Alzheimer's disease, cancer, etc. Further contribution of MS to clinical medicine can be expected through the development and improvement of new techniques, efforts to verify discoveries, and communications with the medical front.
Boehm Titration Revisited (Part II: A Comparison of Boehm Titration with Other Analytical Techniques on the Quantification of Oxygen-Containing Surface Groups for a Variety of Carbon Materials

Directory of Open Access Journals (Sweden)

Jan Schönherr

2018-04-01

Full Text Available The use of the Boehm titration (BT method as an analytical tool for the quantification of oxygen-containing surface groups is systematically investigated for oxidized carbon black, carbon nanotubes and two active carbons with specific surface areas between 60 and 1750 m2 g−1. The accuracy of the BT method is quantitatively compared with results from elemental analysis (EA, temperature programmed desorption (TPD, and X-ray photoelectron spectroscopy (XPS. Overall, the results from TPD are in line with the values obtained by BT. Both show the equal ratio of the oxygen groups to each other. Within the series of carbon samples, all methods provide similar trends for the total oxygen content yet the absolute numbers are deviating significantly. Reasons for these discrepancies are discussed and linked to the specific characteristics of the different methods. As the BT method is a solution based method, it only probes the surface fraction of the carbon that is accessible to the base solution. That means, it probes the relevant fraction for applications where carbon is in contact to aqueous solutions. Overall, the BT method can be conveniently applied to a broad range of carbon materials as long as the samples are sufficiently hydrophilic and of the enough sample amount is provided.
Improving the signal visibility of optical-disk-drive sensors by analyte patterning and frequency-domain analysis

International Nuclear Information System (INIS)

Schaefer, S; Chau, K J

2011-01-01

One limitation of using compact disks (CDs) and optical disk drives for sensing and imaging of analytes placed on a CD is the fluctuations in the voltage signal from the disk drive generated while reading the data on the CD. In this study, we develop a simple, low-cost strategy for sensing and identification using CDs and optical disk drives that spectrally separates contributions to the voltage signal caused by an analyte intentionally placed onto the CD and that caused by the underlying data on the CD. Analytes are printed onto a CD surface with fixed spatial periodicity. As the laser beam in an optical disk drive scans over the section of the CD containing the analyte pattern, the intensity of the laser beam incident onto the photodiode integrated into the disk drive is modulated at a frequency dependent on the spatial periodicity of the analyte pattern and the speed of the optical-disk-drive motor. Fourier transformation of the voltage signal from the optical disk drive yields peaks in the frequency spectrum with amplitudes and locations that enable analyte sensing and identification, respectively. We study the influence of analyte area coverage, pattern periodicity, and CD rotational frequency on the peaks in the frequency spectrum associated with the patterned analyte. We apply this technique to discriminate differently-colored analytes, perform trigger-free detection of multiple analytes distributed on a single CD, and detect at least two different, overlapped analyte patterns on a single CD. The extension of this technique for sensing and identification of colorimetric chemical reagents is discussed
Applied surface analysis of metal materials

International Nuclear Information System (INIS)

Weiss, Z.

1987-01-01

The applications of surface analytical techniques in the solution of technological problems in metalurgy and engineering are reviewed. Some important application areas such as corrosion, grain boundary segregation and metallurgical coatings are presented together with specific requirements for the type of information which is necessary for solving particular problems. The techniques discussed include: electron spectroscopies (Auger Electron Spectroscopy, Electron Spectroscopy for Chemical Analysis), ion spectroscopies (Secondary Ion Mass Spectrometry, Ion Scattering Spectroscopy), Rutherford Back-Scattering, nuclear reaction analysis, optical methods (Glow Discharge Optical Emission Spectrometry), ellipsometry, infrared and Raman spectroscopy, the Moessbauer spectroscopy and methods of consumptive depth profile analysis. Principles and analytical features of these methods are demonstrated and examples of their applications to metallurgy are taken from recent literature. (author). 4 figs., 2 tabs., 112 refs
Surface solitons in waveguide arrays: Analytical solutions.

Science.gov (United States)

Kominis, Yannis; Papadopoulos, Aristeidis; Hizanidis, Kyriakos

2007-08-06

A novel phase-space method is employed for the construction of analytical stationary solitary waves located at the interface between a periodic nonlinear lattice of the Kronig-Penney type and a linear or nonlinear homogeneous medium as well as at the interface between two dissimilar nonlinear lattices. The method provides physical insight and understanding of the shape of the solitary wave profile and results to generic classes of localized solutions having either zero or nonzero semi-infinite backgrounds. For all cases, the method provides conditions involving the values of the propagation constant of the stationary solutions, the linear refractive index and the dimensions of each part in order to assure existence of solutions with specific profile characteristics. The evolution of the analytical solutions under propagation is investigated for cases of realistic configurations and interesting features are presented such as their remarkable robustness which could facilitate their experimental observation.
Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

Energy Technology Data Exchange (ETDEWEB)

Alfeld, Matthias, E-mail: matthias.alfeld@desy.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany); University of Antwerp, Department of Chemistry, Groenenbrogerlaan 171, B-2020 Antwerp (Belgium); Broekaert, José A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany)

2013-10-01

Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. - Highlights: • All mobile sub-surface and depth-profiling techniques for paintings are reviewed. • The number of techniques available has increased considerably in the last years. • X-ray radiography and infrared reflectography are still the most used techniques. • Scanning macro-XRF and optical coherence tomography begin to establish. • Industrial non destructive testing techniques support the preservation of paintings.
Biomimetic polymers in analytical chemistry. Part 1: preparation and applications of MIP (Molecularly Imprinted Polymers) in extraction and separation techniques

International Nuclear Information System (INIS)

Tarley, Cesar Ricardo Teixeira; Sotomayor, Maria del Pilar Taboada; Kubota, Lauro Tatsuo

2005-01-01

MIPs are synthetic polymers that are used as biomimetic materials simulating the mechanism verified in natural entities such as antibodies and enzymes. Although MIPs have been successfully used as an outstanding tool for enhancing the selectivity or different analytical approaches, such as separation science and electrochemical and optical sensors, several parameters must be optimized during their synthesis. Therefore, the state-of-the-art of MIP production as well as the different polymerization methods are discussed. The potential selectivity of MIPs in the extraction and separation techniques focusing mainly on environmental, clinical and pharmaceutical samples as applications for analytical purposes is presented. (author)
Facility and application of nuclear and supplementary analytical techniques at Dalat Nuclear Research Institute

International Nuclear Information System (INIS)

Nguyen Mong Sinh; Ho Manh Dung; Nguyen Thanh Binh

2006-01-01

The main applications of the nuclear and supplementary analytical techniques (N and SATs) in the Dalat Nuclear Research Institute (DNRI) and the facilities for the techniques are presented. The NATs in DNRI include the neutron activation analysis (NAA) with instrumental, radiochemical and prompt gamma methods (INAA, RNAA, PGNAA), the X-ray fluorescence analysis (XRFA) and the low-level counting and spectrometry. The sample irradiation sites for NAA, the automatic and manual pneumatic transfer systems, were installed at channels 7-1 and 13-2 and rotary rack on the Dalat research reactor. An ORTEC automatic sample changer (model ASC2) for γ-ray counting was equipped. A computer software for NAA based on the k 0 -standardization method for calculation of elemental concentration was developed. The low-level counting and spectrometry techniques have been setup. The devices required for sampling, sample preparation and data processing have also been equipped. The applications of N and SATs for determination of elemental composition, particularly important in providing data so-called trace elements, radionuclides and multi-element have been enlarged for objects of geology, archaeology, bio-agriculture, health-nutrition and environment. The implementation a quality system for N and SATs has been planned and initiated. (author)
Surface registration technique for close-range mapping applications

Science.gov (United States)

Habib, Ayman F.; Cheng, Rita W. T.

2006-08-01

Close-range mapping applications such as cultural heritage restoration, virtual reality modeling for the entertainment industry, and anatomical feature recognition for medical activities require 3D data that is usually acquired by high resolution close-range laser scanners. Since these datasets are typically captured from different viewpoints and/or at different times, accurate registration is a crucial procedure for 3D modeling of mapped objects. Several registration techniques are available that work directly with the raw laser points or with extracted features from the point cloud. Some examples include the commonly known Iterative Closest Point (ICP) algorithm and a recently proposed technique based on matching spin-images. This research focuses on developing a surface matching algorithm that is based on the Modified Iterated Hough Transform (MIHT) and ICP to register 3D data. The proposed algorithm works directly with the raw 3D laser points and does not assume point-to-point correspondence between two laser scans. The algorithm can simultaneously establish correspondence between two surfaces and estimates the transformation parameters relating them. Experiment with two partially overlapping laser scans of a small object is performed with the proposed algorithm and shows successful registration. A high quality of fit between the two scans is achieved and improvement is found when compared to the results obtained using the spin-image technique. The results demonstrate the feasibility of the proposed algorithm for registering 3D laser scanning data in close-range mapping applications to help with the generation of complete 3D models.
Sample handling in surface sensitive chemical and biological sensing: a practical review of basic fluidics and analyte transport.

Science.gov (United States)

Orgovan, Norbert; Patko, Daniel; Hos, Csaba; Kurunczi, Sándor; Szabó, Bálint; Ramsden, Jeremy J; Horvath, Robert

2014-09-01

This paper gives an overview of the advantages and associated caveats of the most common sample handling methods in surface-sensitive chemical and biological sensing. We summarize the basic theoretical and practical considerations one faces when designing and assembling the fluidic part of the sensor devices. The influence of analyte size, the use of closed and flow-through cuvettes, the importance of flow rate, tubing length and diameter, bubble traps, pressure-driven pumping, cuvette dead volumes, and sample injection systems are all discussed. Typical application areas of particular arrangements are also highlighted, such as the monitoring of cellular adhesion, biomolecule adsorption-desorption and ligand-receptor affinity binding. Our work is a practical review in the sense that for every sample handling arrangement considered we present our own experimental data and critically review our experience with the given arrangement. In the experimental part we focus on sample handling in optical waveguide lightmode spectroscopy (OWLS) measurements, but the present study is equally applicable for other biosensing technologies in which an analyte in solution is captured at a surface and its presence is monitored. Explicit attention is given to features that are expected to play an increasingly decisive role in determining the reliability of (bio)chemical sensing measurements, such as analyte transport to the sensor surface; the distorting influence of dead volumes in the fluidic system; and the appropriate sample handling of cell suspensions (e.g. their quasi-simultaneous deposition). At the appropriate places, biological aspects closely related to fluidics (e.g. cellular mechanotransduction, competitive adsorption, blood flow in veins) are also discussed, particularly with regard to their models used in biosensing. Copyright © 2014 Elsevier B.V. All rights reserved.
Determination of Rare Earth Elements in Thai Monazite by Inductively Coupled Plasma and Nuclear Analytical techniques

International Nuclear Information System (INIS)

Busamongkol, Arporn; Ratanapra, Dusadee; Sukharn, Sumalee; Laoharojanaphand, Sirinart

2003-10-01

The inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the determination of individual rare-earth elements (REE) was evaluated by comparison with instrumental neutron activation analysis (INAA) and x-ray fluorescence spectrometry (XRF). The accuracy and precision of INAA and ICP-AES were evaluated by using standard reference material IGS-36, a monazite concentrate. For INAA, the results were close to the certified value while ICP-AES were in good agreement except for some low concentration rare earth. The techniques were applied for the analysis of some rare earth elements in two Thai monazite samples preparing as the in-house reference material for the Rare Earth Research and Development Center, Chemistry Division, Office of Atoms for Peace. The analytical results obtained by these techniques were in good agreement with each other
Laser techniques for radioactive decontamination gives metallic surfaces

International Nuclear Information System (INIS)

Escobar Alracon, L.; Molina, G.; Vizuet Gonzalez, J.

1998-01-01

In this work it presented the prototype for system decontamination at diverse component with removable superficial contamination, using the technique gives laser ablation, for the evaporation at the pollutant. It discusses the principle in the fact that system, as well as the different elements that compose it. The are presented the obtained results when irradiating with a laser a surface without radioactive contamination to verify the system operation
A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

Science.gov (United States)

Zhang, Zhen; Xia, Changliang; Yan, Yan; Geng, Qiang; Shi, Tingna

2017-08-01

Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff's law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell's equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.
Automated Predictive Big Data Analytics Using Ontology Based Semantics.

Science.gov (United States)

Nural, Mustafa V; Cotterell, Michael E; Peng, Hao; Xie, Rui; Ma, Ping; Miller, John A

2015-10-01

Predictive analytics in the big data era is taking on an ever increasingly important role. Issues related to choice on modeling technique, estimation procedure (or algorithm) and efficient execution can present significant challenges. For example, selection of appropriate and optimal models for big data analytics often requires careful investigation and considerable expertise which might not always be readily available. In this paper, we propose to use semantic technology to assist data analysts and data scientists in selecting appropriate modeling techniques and building specific models as well as the rationale for the techniques and models selected. To formally describe the modeling techniques, models and results, we developed the Analytics Ontology that supports inferencing for semi-automated model selection. The SCALATION framework, which currently supports over thirty modeling techniques for predictive big data analytics is used as a testbed for evaluating the use of semantic technology.
Inductively coupled plasma-atomic emission spectrometry: analytical assessment of the technique at the beginning of the 90's

International Nuclear Information System (INIS)

Sanz-Medel, A.

1991-01-01

The main application of the inductively coupled plasma (ICP) today is in atomic emission spectroscopy (AES), as an excitation spectrochemical source, although uses of an ICP for fluorescence as just an atomizer, and specially for mass spectrometry, as an ionization source, are rocketing in the last few years. Since its inception, only a quarter of a century ago, ICP-AES has rapidly evolved to one of the preferred routine analytical techniques for convenient determination of many elements with high speed, at low levels and in the most varied samples. Perhaps its comparatively high kinetic temperature (capable of atomizing virtually every compound of any sample), its high excitation and ionization temperatures, and its favourable spatial structure at the core of the ICP success. By now, the ICP-AES can be considered as having achieved maturity in that a huge amount of analytical problems can be tackled with this technique, while no major or fundamental changes have been adopted for several years. Despite this fact, important driving forces are still in operation to further improve the ICP-AES sensitivity, selectivity, precision, sample throughput, etc. Moreover, proposals to extend the scope of the technique to traditionally elusive fields (e.g. non-metals and organic compound analysis) are also appearing in the recent literature. In this paper the 'state of the art', the last developments and the expectations in trying to circumvent the limitations of the ICP-AES (on the light of literature data and personal experience) are reviewed. (author)
Social Data Analytics Using Tensors and Sparse Techniques

Science.gov (United States)

Zhang, Miao

2014-01-01

The development of internet and mobile technologies is driving an earthshaking social media revolution. They bring the internet world a huge amount of social media content, such as images, videos, comments, etc. Those massive media content and complicate social structures require the analytic expertise to transform those flood of information into…
Surface crack testing - state of technique and trends in development

International Nuclear Information System (INIS)

1991-01-01

This Seminar contains 12 lectures on the following subjects: State of technique in magnetic powder testing (K. Goebbels); Recognisability of faults and probability of faults in surface crack testing (W. Morgner); Requirements for picture processing systems for proving and assessing crack indications (M. Stadthaus); Possibilities and limits of automatic crack recognition in magnetic powder testing (V. Deutsch); Development of equipment for eddy current testing (M. Junger); Signal processing - a way of improving the recognisability of faults in eddy current testing (R. Becker); Methods of testing steel products for surface faults and their practical limits of fault recognisability (D. Thiery); Surface crack testing in pipe manufacture (R. Pawelletz); Surface crack testing in powerstation construction (L. v. Bernus); Trends in automation in surface crack testing (G. Maier); Eddy current testing in engine construction (E. Dickhaut); Eddy current testing in aircraft repair (F. Schur). (orig.) [de
Analytical techniques for in-line/on-line monitoring of uranium and plutonium in process solutions : a brief literature survey

International Nuclear Information System (INIS)

Marathe, S.G.; Sood, D.D.

1991-01-01

In-line/on-line monitoring of various parameters such as uranium-plutonium-fission product concentration, acidity, density etc. plays an important role in quickly understanding the efficiency of processes in a reprocessing plant. Efforts in studying and installation of such analytical instruments are going on since more than three decades with adaptation of newer methods and technologies. A review on the developement of in-line analytical instrumentation was carried out in this laboratory about two decades ago. This report presents a very short literature survey of the work in the last two decades. The report includes an outline of principles of the main techniques employed in the in-line/on-line monitoring. (author). 77 refs., 6 tabs
The effect of inclined soil layers on surface vibration from underground railways using a semi-analytical approach

International Nuclear Information System (INIS)

Jones, S; Hunt, H

2009-01-01

Ground vibration due to underground railways is a significant source of disturbance for people living or working near the subways. The numerical models used to predict vibration levels have inherent uncertainty which must be understood to give confidence in the predictions. A semi-analytical approach is developed herein to investigate the effect of soil layering on the surface vibration of a halfspace where both soil properties and layer inclination angles are varied. The study suggests that both material properties and inclination angle of the layers have significant effect (± 10dB) on the surface vibration response.

A Complete Analytical Screening Identifies the Real Pesticide Contamination of Surface Waters

Science.gov (United States)

Moschet, Christoph; Wittmer, Irene; Simovic, Jelena; Junghans, Marion; Singer, Heinz; Stamm, Christian; Leu, Christian; Hollender, Juliane

2014-05-01

A comprehensive assessment of pesticides in surface waters is challenging due to the large number of potential contaminants. In Switzerland for example, roughly 500 active ingredients are registered as either plant protection agent (PPA) or as biocide. In addition, an unlimited number of transformations products (TPs) can enter or be formed in surfaced waters. Most scientific publications or regulatory monitoring authorities have implemented 15-40 pesticides in their analytics. Only a few TPs are normally included. Interpretations of the surface water quality based on these subsets remains error prone. In the presented study, we carried out a nearly complete analytical screening covering 86% of all polar organic pesticides (from agricultural and urban sources) in Switzerland (300 substances) and 134 TPs with limits of quantification in the low ng/L range. The comprehensive pesticide screening was conducted by liquid-chromatography coupled to high-resolution tandem mass spectrometry. Five medium-sized rivers (Strahler stream order 3-4, catchment size 35-105 km2), containing high percentiles of diverse crops, orchards and urban settlements in their catchments, were sampled from March till July 2012. Nine subsequent time-proportional bi-weekly composite samples were taken in order to quantify average concentrations. In total, 104 different active ingredients could be detected in at least one of the five rivers. Thereby, 82 substances were only registered as PPA, 20 were registered as PPA and as biocide and 2 were only registered as biocide. Within the PPAs, herbicides had the most frequent detections and the highest concentrations, followed by fungicides and insecticides. Most concentrations were found between 1 and 50 ng/L; however 31 substances (mainly herbicides) had concentrations above 100 ng/L and 3 herbicides above 1000 ng/L. It has to be noted that the measured concentrations are average concentrations over two weeks in medium sized streams and that maximum
Surface-ionization field mass-spectrometry studies of nonequilibrium surface ionization

International Nuclear Information System (INIS)

Blashenkov, Nikolai M; Lavrent'ev, Gennadii Ya

2007-01-01

The ionization of polyatomic molecules on tungsten and tungsten oxide surfaces is considered for quasiequilibrium or essentially nonequilibrium conditions (in the latter case, the term nonequilibrium surface ionization is used for adsorbate ionization). Heterogeneous reactions are supposed to proceed through monomolecular decay of polyatomic molecules or fragments of multimolecular complexes. The nonequilibrium nature of these reactions is established. The dependences of the current density of disordered ions on the surface temperature, electric field strength, and ionized particle energy distribution are obtained in analytical form. Heterogeneous dissociation energies, the ionization potentials of radicals, and the magnitude of reaction departure from equilibrium are determined from experimental data, as are energy exchange times between reaction products and surfaces, the number of molecules in molecular complexes, and the number of effective degrees of freedom in molecules and complexes. In collecting the data a new technique relying on surface-ionization field mass-spectrometry was applied. (instruments and methods of investigation)
Optical trapping for analytical biotechnology.

Science.gov (United States)

Ashok, Praveen C; Dholakia, Kishan

2012-02-01

We describe the exciting advances of using optical trapping in the field of analytical biotechnology. This technique has opened up opportunities to manipulate biological particles at the single cell or even at subcellular levels which has allowed an insight into the physical and chemical mechanisms of many biological processes. The ability of this technique to manipulate microparticles and measure pico-Newton forces has found several applications such as understanding the dynamics of biological macromolecules, cell-cell interactions and the micro-rheology of both cells and fluids. Furthermore we may probe and analyse the biological world when combining trapping with analytical techniques such as Raman spectroscopy and imaging. Copyright © 2011 Elsevier Ltd. All rights reserved.
Regional technical cooperation model project, IAEA - RER/2/2004 ''quality control and quality assurance for nuclear analytical techniques'

International Nuclear Information System (INIS)

Arikan, P.

2002-01-01

An analytical laboratory should produce high quality analytical data through the use of analytical measurements that is accurate, reliable and adequate for the intended purpose. This objective can be accomplished in a cost-effective manner under a planned and documented quality system of activities. It is well-known that serious deficiencies can occur in laboratory operations when insufficient attention is given to the quality of the work. It requires not only a thorough knowledge of the laboratory's purpose and operation, but also the dedication of the management and operating staff to standards of excellence. Laboratories employing nuclear and nuclear-related analytical techniques are sometimes confronted with performance problems which prevent them from becoming accepted and respected by clients, such as industry, government and regulatory bodies, and from being eligible for contracts. The International Standard ISO 17025 has been produced as the result of extensive experience in the implementation of ISO/IEC Guide 25:1990 and EN 45001:1989, which replaces both of them now. It contains all of the requirements that testing and calibration laboratories must meet if they wish to demonstrate that they operate a quality system that is technically competent, and are able to generate technically valid results. The use of ISO 17025 should facilitate cooperation between laboratories and other bodies to assist in the exchange of information and experience, and in the harmonization of standards and procedures. IAEA model project RER/2/004 entitled 'Quality Assurance/Quality Control in Nuclear Analytical Techniques' was initiated in 1999 as a Regional TC project in East European countries to assist Member State laboratories in the region to install a complete quality system according to the ISO/IEC 17025 standard. 12 laboratories from 11 countries plus the Agency's Laboratories in Seibersdorf have been selected as participants to undergo exercises and training with the
Sensitive molecular diagnostics using surface-enhanced resonance Raman scattering (SERRS)

Science.gov (United States)

Faulds, Karen; Graham, Duncan; McKenzie, Fiona; MacRae, Douglas; Ricketts, Alastair; Dougan, Jennifer

2009-02-01

Surface enhanced resonance Raman scattering (SERRS) is an analytical technique with several advantages over competitive techniques in terms of improved sensitivity and multiplexing. We have made great progress in the development of SERRS as a quantitative analytical method, in particular for the detection of DNA. SERRS is an extremely sensitive and selective technique which when applied to the detection of labelled DNA sequences allows detection limits to be obtained which rival, and in most cases, are better than fluorescence. Here the conditions are explored which will enable the successful detection of DNA using SERRS. The enhancing surface which is used is crucial and in this case suspensions of nanoparticles were used as they allow quantitative behaviour to be achieved and allow analogous systems to current fluorescence based systems to be made. The aggregation conditions required to obtain SERRS of DNA are crucial and herein we describe the use of spermine as an aggregating agent. The nature of the label which is used, be it fluorescent, positively or negatively charged also effects the SERRS response and these conditions are again explored here. We have clearly demonstrated the ability to identify the components of a mixture of 5 analytes in solution by using two different excitation wavelengths and also of a 6-plex using data analysis techniques. These conditions will allow the use of SERRS for the detection of target DNA in a meaningful diagnostic assay.
On numerical-analytic techniques for boundary value problems

Czech Academy of Sciences Publication Activity Database

Rontó, András; Rontó, M.; Shchobak, N.

2012-01-01

Roč. 12, č. 3 (2012), s. 5-10 ISSN 1335-8243 Institutional support: RVO:67985840 Keywords : numerical-analytic method * periodic successive approximations * Lyapunov-Schmidt method Subject RIV: BA - General Mathematics http://www.degruyter.com/view/j/aeei.2012.12.issue-3/v10198-012-0035-1/v10198-012-0035-1.xml?format=INT
Analytical modeling of AlGaN/AlN/GaN heterostructures including effects of distributed surface donor states

Energy Technology Data Exchange (ETDEWEB)

Goyal, Nitin, E-mail: nitin@unik.no [Carinthian Tech Research CTR AG, Europastraße 4/1, Technologiepark Villach, A-9524 Villach/St. Magdalen (Austria); Department of Electronics and Telecommunication, Norwegian University of Science and Technology, Trondheim NO7034 (Norway); Fjeldly, Tor A. [Department of Electronics and Telecommunication, Norwegian University of Science and Technology, Trondheim NO7034 (Norway)

2014-07-14

In this paper, a physics based analytical model is presented for calculation of the two-dimensional electron gas density and the bare surface barrier height of AlGaN/AlN/GaN material stacks. The presented model is based on the concept of distributed surface donor states and the self-consistent solution of Poisson equation at the different material interfaces. The model shows good agreement with the reported experimental data and can be used for the design and characterization of advanced GaN devices for power and radio frequency applications.
Characterizing and modeling protein-surface interactions in lab-on-chip devices

Science.gov (United States)

Katira, Parag

Protein adsorption on surfaces determines the response of other biological species present in the surrounding solution. This phenomenon plays a major role in the design of biomedical and biotechnological devices. While specific protein adsorption is essential for device function, non-specific protein adsorption leads to the loss of device function. For example, non-specific protein adsorption on bioimplants triggers foreign body response, in biosensors it leads to reduced signal to noise ratios, and in hybrid bionanodevices it results in the loss of confinement and directionality of molecular shuttles. Novel surface coatings are being developed to reduce or completely prevent the non-specific adsorption of proteins to surfaces. A novel quantification technique for extremely low protein coverage on surfaces has been developed. This technique utilizes measurement of the landing rate of microtubule filaments on kinesin proteins adsorbed on a surface to determine the kinesin density. Ultra-low limits of detection, dynamic range, ease of detection and availability of a ready-made kinesin-microtubule kit makes this technique highly suitable for detecting protein adsorption below the detection limits of standard techniques. Secondly, a random sequential adsorption model is presented for protein adsorption to PEO-coated surfaces. The derived analytical expressions accurately predict the observed experimental results from various research groups, suggesting that PEO chains act as almost perfect steric barriers to protein adsorption. These expressions can be used to predict the performance of a variety of systems towards resisting protein adsorption and can help in the design of better non-fouling surface coatings. Finally, in biosensing systems, target analytes are captured and concentrated on specifically adsorbed proteins for detection. Non-specific adsorption of proteins results in the loss of signal, and an increase in the background. The use of nanoscale transducers as
Proceedings of the BRNS-AEACI first symposium on current trends in analytical chemistry: book of abstracts

International Nuclear Information System (INIS)

Reddy, A.V.R.

2015-01-01

The symposium was very useful for the scientists on various aspects of current trends in analytical chemistry like separation science, speciation, nuclear analytical techniques, thermo analytical techniques, electro analytical techniques, spectrochemical and microscopic techniques, environmental studies, geochemical studies, chemical metrology, analytical instrumentation. Papers relevant to INIS are indexed separately
Surface chemistry and microscopy of food powders

Science.gov (United States)

Burgain, Jennifer; Petit, Jeremy; Scher, Joël; Rasch, Ron; Bhandari, Bhesh; Gaiani, Claire

2017-12-01

Despite high industrial and scientific interest, a comprehensive review of the surface science of food powders is still lacking. There is a real gap between scientific concerns of the field and accessible reviews on the subject. The global description of the surface of food powders by multi-scale microscopy approaches seems to be essential in order to investigate their complexity and take advantage of their high innovation potential. Links between these techniques and the interest to develop a multi-analytical approach to investigate scientific questions dealing with powder functionality are discussed in the second part of the review. Finally, some techniques used in others fields and showing promising possibilities in the food powder domain will be highlighted.
Determination of alpha-naphthol by an oscillating chemical reaction using the analyte pulse perturbation technique

International Nuclear Information System (INIS)

Yang Wu; Sun Kanjun; Lv Weilian; Bo Lili; He Xiaoyan; Suo Nan; Gao Jinzhang

2005-01-01

An analytical method for the determination of alpha-naphthol (α-NP) is proposed by the sequential perturbation caused by different amounts of alpha-naphthol on the oscillating chemical system involving the Cu(II)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium with the aid of continuous-flow stirred tank reactor (CSTR). The method relies on the linear relationship between the changes in the oscillation amplitude of the chemical system and the concentration of alpha-naphthol. The use of the analyte pulse perturbation technique permits sequential determinations in the same oscillating system owing to the expeditiousness with which the steady state is regained after each perturbation. The calibration curve obeys a linear equation very well when the concentration of alpha-naphthol is over the range 0.034-530 umol/L (r = 0.9991). Influences of temperature, injection points, flow rate and reaction variables on the oscillating system are investigated in detail and the possible mechanism of action of alpha-naphthol to the chemical oscillating system is also discussed. The method has been successfully used for the determination of α-naphthol in carbaryl hydrolysates
A wafer mapping technique for residual stress in surface micromachined films

International Nuclear Information System (INIS)

Schiavone, G; Murray, J; Smith, S; Walton, A J; Desmulliez, M P Y; Mount, A R

2016-01-01

The design of MEMS devices employing movable structures is crucially dependant on the mechanical behaviour of the deposited materials. It is therefore important to be able to fully characterize the micromachined films and predict with confidence the mechanical properties of patterned structures. This paper presents a characterization technique that enables the residual stress in MEMS films to be mapped at the wafer level by using microstructures released by surface micromachining. These dedicated MEMS test structures and the associated measurement techniques are used to extract localized information on the strain and Young’s modulus of the film under investigation. The residual stress is then determined by numerically coupling this data with a finite element analysis of the structure. This paper illustrates the measurement routine and demonstrates it with a case study using electrochemically deposited alloys of nickel and iron, particularly prone to develop high levels of residual stress. The results show that the technique enables wafer mapping of film non-uniformities and identifies wafer-to-wafer differences. A comparison between the results obtained from the mapping technique and conventional wafer bow measurements highlights the benefits of using a procedure tailored to films that are non-uniform, patterned and surface-micromachined, as opposed to simple standard stress extraction methods. The presented technique reveals detailed information that is generally unexplored when using conventional stress extraction methods such as wafer bow measurements. (paper)
Improved Nanomechanical Test Techniques for Surface Engineered Materials

Directory of Open Access Journals (Sweden)

Stephen R. Goodes

2010-06-01

Full Text Available The development and implementation of a wide range of innovative nanomechanical test techniques to solve tribological problems in applications as diverse as biomedical and automotive are described in this review. For improved wear resistance and durability, the importance of understanding the system response rather than the coating-only properties is emphasized. There are many applications involving mechanical contact where the key to understanding the problem is to test at higher load and to combine reliable measurements taken across different length scales using both nano- and micro-indentation and related wear measurement techniques which more closely simulate contact conditions to fully understand the mechanical behaviour and hence deliver improved application performance. Results are presented with the NanoTest platform for applications for biomedical devices and surface engineering of lightweight alloys for the automotive industry. By combining results with different techniques it is possible to postulate predictive design rules – based on the elastic and plastic deformation energies involved in contact - to aid the reliable optimisation of mechanical properties in the various contact situations in the different applications.
SFC-MS/MS as an orthogonal technique for improved screening of polar analytes in anti-doping control.

Science.gov (United States)

Parr, Maria Kristina; Wuest, Bernhard; Naegele, Edgar; Joseph, Jan F; Wenzel, Maxi; Schmidt, Alexander H; Stanic, Mijo; de la Torre, Xavier; Botrè, Francesco

2016-09-01

HPLC is considered the method of choice for the separation of various classes of drugs. However, some analytes are still challenging as HPLC shows limited resolution capabilities for highly polar analytes as they interact insufficiently on conventional reversed-phase (RP) columns. Especially in combination with mass spectrometric detection, limitations apply for alterations of stationary phases. Some highly polar sympathomimetic drugs and their metabolites showed almost no retention on different RP columns. Their retention remains poor even on phenylhexyl phases that show different selectivity due to π-π interactions. Supercritical fluid chromatography (SFC) as an orthogonal separation technique to HPLC may help to overcome these issues. Selected polar drugs and metabolites were analyzed utilizing SFC separation. All compounds showed sharp peaks and good retention even for the very polar analytes, such as sulfoconjugates. Retention times and elution orders in SFC are different to both RP and HILIC separations as a result of the orthogonality. Short cycle times could be realized. As temperature and pressure strongly influence the polarity of supercritical fluids, precise regulation of temperature and backpressure is required for the stability of the retention times. As CO2 is the main constituent of the mobile phase in SFC, solvent consumption and solvent waste are considerably reduced. Graphical Abstract SFC-MS/MS vs. LC-MS/MS.
Complementarities of nuclear-based analytical techniques for the characterization of thin film technological materials

International Nuclear Information System (INIS)

Bamford, Samuel; Kregsamer, Peter; Fazinic, Stjepko; Jaksic, Milko; Wegrzynek, Dariusz; Chinea-Cano, Ernesto; Markowicz, Andrzej

2007-01-01

Two thin film technological materials (A/B) from the aerospace industry have been characterized for their elemental composition, for the purpose of determining their purity and trace element distribution. The results contribute to the assessment of the materials' suitability as part of a spacecraft's thermal hardware. Analysis was done using a combination of PIXE/RBS and energy dispersive X-ray fluorescence (EDXRF) analytical techniques. Samples of the materials were analyzed with PIXE/RBS system using 2 MeV proton beam from a 1 MV Tandetron accelerator and also with separate EDXRF systems employing Am-241 and Mo-secondary target as excitation sources. PIXE/RBS measurements enabled identification of the elemental composition and elucidation of the layer structure of the materials. From the PIXE/RBS results, Am-241-excited EDXRF technique was selected for quantitative determination of indium (In) and tin (Sn) by their K-X-rays, after reasonable absorption corrections. A comparison has been made of the results obtained from EDXRF and PIXE/RBS. Material A has been found to be a thin film with three layers, while material B is a thin film comprised of four layers. Thicknesses and compositions (including trace elements) of all layers have been determined. The limitation of EDXRF in the analysis of inhomogeneously distributed elements was overcome by using PIXE/RBS as an appropriate complimentary technique
Practical guide to surface science and spectroscopy

CERN Document Server

Chung, Yip-Wah

2001-01-01

Practical Guide to Surface Science and Spectroscopy provides a practical introduction to surface science as well as describes the basic analytical techniques that researchers use to understand what occurs at the surfaces of materials and at their interfaces. These techniques include auger electron spectroscopy, photoelectron spectroscopy, inelastic scattering of electrons and ions, low energy electron diffraction, scanning probe microscopy, and interfacial segregation. Understanding the behavior of materials at their surfaces is essential for materials scientists and engineers as they design and fabricate microelectronics and semiconductor devices. The book gives over 100 examples, discussion questions and problems with varying levels of difficulty. Included with this book is a CD-ROM, which not only contains the same information, but also provides many elements of animation and interaction that are not easily emulated on paper. In diverse subject matters ranging from the operation of ion pumps, computer-...
4. Danish symposium in analytical chemistry

International Nuclear Information System (INIS)

1996-01-01

At the 4th Danish Symposium of Analytical Chemistry 11 lectures and 32 posters were presented during two session days on the 20 and 21 August 1996. Various analytical techniques were discussed for foodstuff, pesticide, pharmaceutical, industrial and other analyses. (EG)
Comparison of nuclear analytical methods with competitive methods

International Nuclear Information System (INIS)

1987-10-01

The use of nuclear analytical techniques, especially neutron activation analysis, already have a 50 year old history. Today several sensitive and accurate, non-nuclear trace element analytical techniques are available and new methods are continuously developed. The IAEA is supporting the development of nuclear analytical laboratories in its Member States. In order to be able to advise the developing countries which methods to use in different applications, it is important to know the present status and development trends of nuclear analytical methods, what are their benefits, drawbacks and recommended fields of application, compared with other, non-nuclear techniques. In order to get an answer to these questions the IAEA convened this Advisory Group Meeting. This volume is the outcome of the presentations and discussions of the meeting. A separate abstract was prepared for each of the 21 papers. Refs, figs, tabs
Role of modern analytical techniques in the production of uranium metal

International Nuclear Information System (INIS)

Hareendran, K.N.; Roy, S.B.

2009-01-01

Production of nuclear grade uranium metal conforming to its stringent specification with respect to metallic and non metallic impurities necessitates implementation of a comprehensive quality control regime. Founding members of Uranium Metal Plant realised the importance of this aspect of metal production and a quality control laboratory was set up as part of the production plant. In the initial stages of its existence, the laboratory mainly catered to the process control analysis of the plant process samples and Spectroscopy Division and Analytical Division of BARC provided analysis of trace metallic impurities in the intermediates as well as in the product uranium metal. This laboratory also provided invaluable R and D support for the optimization of the process involving both calciothermy and magnesiothermy. Prior to 1985, analytical procedures used were limited to classical methods of analysis with minimal instrumental procedures. The first major analytical instrument, a Flame AAS was installed in 1985 and a beginning to the trace analysis was made. However during the last 15 years the Quality Control Section has modernized the analytical set up by acquiring appropriate instruments. Presently the facility has implemented a complete quality control and quality assurance program required to cover all aspects of uranium metal production viz analysis of raw materials, process samples, waste disposal samples and also determination of all the specification elements in uranium metal. The current analytical practices followed in QCS are presented here
Actively stabilized optical fiber interferometry technique for online/in-process surface measurement

International Nuclear Information System (INIS)

Wang Kaiwei; Martin, Haydn; Jiang Xiangqian

2008-01-01

In this paper, we report the recent progress in optical-beam scanning fiber interferometry for potential online nanoscale surface measurement based on the previous research. It attempts to generate a robust and miniature measurement device for future development into a multiprobe array measurement system. In this research, both fiber-optic-interferometry and the wavelength-division-multiplexing techniques have been used, so that the optical probe and the optical interferometer are well spaced and fast surface scanning can be carried out, allowing flexibility for online measurement. In addition, this system provides a self-reference signal to stabilize the optical detection with high common-mode noise suppression by adopting an active phase tracking and stabilization technique. Low-frequency noise was significantly reduced compared with unstabilized result. The measurement of a sample surface shows an attained repeatability of 3.3 nm

An Analytical Technique to Determine the Potential for Moisture Accumulation in Deactivated Structures

International Nuclear Information System (INIS)

MINICHAN, RL

2004-01-01

This paper describes an analytical technique developed to predict an order of magnitude volume of moisture accumulation in massive structures after deactivation. This work was done to support deactivation of a Department of Energy nuclear materials processing facility. The structure is a four-story, concrete building with a rectangular footprint that is approximately 250m long by 37m wide by 22m high. Its walls are 1.2m thick. The building will be supplied with unconditioned ventilation air after deactivation. The objective of the work was to provide a cost effective engineering evaluation to determine if the un-conditioned ventilation air would result in condensate accumulating inside the building under study. The analysis described is a simple representation of a complex problem. The modeling method is discussed in sufficient detail to allow its application to the study of similar structures
Multispectral analytical image fusion

International Nuclear Information System (INIS)

Stubbings, T.C.

2000-04-01

With new and advanced analytical imaging methods emerging, the limits of physical analysis capabilities and furthermore of data acquisition quantities are constantly pushed, claiming high demands to the field of scientific data processing and visualisation. Physical analysis methods like Secondary Ion Mass Spectrometry (SIMS) or Auger Electron Spectroscopy (AES) and others are capable of delivering high-resolution multispectral two-dimensional and three-dimensional image data; usually this multispectral data is available in form of n separate image files with each showing one element or other singular aspect of the sample. There is high need for digital image processing methods enabling the analytical scientist, confronted with such amounts of data routinely, to get rapid insight into the composition of the sample examined, to filter the relevant data and to integrate the information of numerous separate multispectral images to get the complete picture. Sophisticated image processing methods like classification and fusion provide possible solution approaches to this challenge. Classification is a treatment by multivariate statistical means in order to extract analytical information. Image fusion on the other hand denotes a process where images obtained from various sensors or at different moments of time are combined together to provide a more complete picture of a scene or object under investigation. Both techniques are important for the task of information extraction and integration and often one technique depends on the other. Therefore overall aim of this thesis is to evaluate the possibilities of both techniques regarding the task of analytical image processing and to find solutions for the integration and condensation of multispectral analytical image data in order to facilitate the interpretation of the enormous amounts of data routinely acquired by modern physical analysis instruments. (author)
Role of analytical chemistry in environmental monitoring

International Nuclear Information System (INIS)

Kayasth, S.; Swain, K.

2004-01-01

Basic aspects of pollution and the role of analytical chemistry in environmental monitoring are highlighted and exemplified, with emphasis on trace elements. Sources and pathways of natural and especially man-made polluting substances as well as physico-chemical characteristics are given. Attention is paid to adequate sampling in various compartments of the environment comprising both lithosphere and biosphere. Trace analysis is dealt with using a variety of analytical techniques, including criteria for choice of suited techniques, as well as aspects of analytical quality assurance and control. Finally, some data on trace elements levels in soil and water samples from India are presented. (author)
Probing droplets on superhydrophobic surfaces by synchrotron radiation scattering techniques

Energy Technology Data Exchange (ETDEWEB)

Accardo, Angelo [Istituto Italiano di Tecnologia, Via Morego 30, Genova 16163 (Italy); Di Fabrizio, Enzo [KAUST (King Abdullah University of Science and Technology), Jeddah (Saudi Arabia); BIONEM Lab at University Magna Graecia, Campus Salvatore Venuta, Viale Europa 88100, Germaneto-Catanzaro (Italy); Limongi, Tania [KAUST (King Abdullah University of Science and Technology), Jeddah (Saudi Arabia); Marinaro, Giovanni [Istituto Italiano di Tecnologia, Via Morego 30, Genova 16163 (Italy); European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France); Riekel, Christian, E-mail: riekel@esrf.fr [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France)

2014-06-10

A comprehensive review about the use of micro- and nanostructured superhydrophobic surfaces as a tool for in situ X-ray scattering investigations of soft matter and biological materials. Droplets on artificially structured superhydrophobic surfaces represent quasi contact-free sample environments which can be probed by X-ray microbeams and nanobeams in the absence of obstructing walls. This review will discuss basic surface wettability concepts and introduce the technology of structuring surfaces. Quasi contact-free droplets are compared with contact-free droplets; processes related to deposition and evaporation on solid surfaces are discussed. Droplet coalescence based on the electrowetting effect allows the probing of short-time mixing and reaction processes. The review will show for several materials of biological interest that structural processes related to conformational changes, nucleation and assembly during droplet evaporation can be spatially and temporally resolved by raster-scan diffraction techniques. Orientational ordering of anisotropic materials deposited during solidification at pinning sites facilitates the interpretation of structural data.
Probing droplets on superhydrophobic surfaces by synchrotron radiation scattering techniques

KAUST Repository

Accardo, Angelo

2014-06-10

Droplets on artificially structured superhydrophobic surfaces represent quasi contact-free sample environments which can be probed by X-ray microbeams and nanobeams in the absence of obstructing walls. This review will discuss basic surface wettability concepts and introduce the technology of structuring surfaces. Quasi contact-free droplets are compared with contact-free droplets; processes related to deposition and evaporation on solid surfaces are discussed. Droplet coalescence based on the electrowetting effect allows the probing of short-time mixing and reaction processes. The review will show for several materials of biological interest that structural processes related to conformational changes, nucleation and assembly during droplet evaporation can be spatially and temporally resolved by raster-scan diffraction techniques. Orientational ordering of anisotropic materials deposited during solidification at pinning sites facilitates the interpretation of structural data. 2014 International Union of Crystallography.
Probing droplets on superhydrophobic surfaces by synchrotron radiation scattering techniques

KAUST Repository

Accardo, Angelo; Di Fabrizio, Enzo M.; Limongi, Tania; Marinaro, Giovanni; Riekel, Christian

2014-01-01

Droplets on artificially structured superhydrophobic surfaces represent quasi contact-free sample environments which can be probed by X-ray microbeams and nanobeams in the absence of obstructing walls. This review will discuss basic surface wettability concepts and introduce the technology of structuring surfaces. Quasi contact-free droplets are compared with contact-free droplets; processes related to deposition and evaporation on solid surfaces are discussed. Droplet coalescence based on the electrowetting effect allows the probing of short-time mixing and reaction processes. The review will show for several materials of biological interest that structural processes related to conformational changes, nucleation and assembly during droplet evaporation can be spatially and temporally resolved by raster-scan diffraction techniques. Orientational ordering of anisotropic materials deposited during solidification at pinning sites facilitates the interpretation of structural data. 2014 International Union of Crystallography.
Quantum confinement and heavy surface states of Dirac fermions in bismuth (111) films: An analytical approach

Science.gov (United States)

Enaldiev, V. V.; Volkov, V. A.

2018-03-01

Recent high-resolution angle-resolved photoemission spectroscopy experiments have given a reason to believe that pure bismuth is a topologically nontrivial semimetal. We derive an analytic theory of surface and size-quantized states of Dirac fermions in Bi(111) films taking into account the new data. The theory relies on a new phenomenological momentum-dependent boundary condition for the effective Dirac equation. The boundary condition is described by two real parameters that are expressed by a linear combination of the Dresselhaus and Rashba interface spin-orbit interaction parameters. In semi-infinite Bi(111), near the M ¯ point the surface states possess anisotropical parabolic dispersion with very heavy effective mass in the Γ ¯-M ¯ direction order of ten free electron masses and light effective mass in the M ¯-K ¯ direction order of one hundredth of free electron mass. In Bi(111) films with equivalent surfaces, the surface states from top and bottom surfaces are not split. In such a symmetric film with arbitrary thickness, the bottom of the lowest quantum confinement subband in the conduction band coincides with the bottom of the bulk conduction band in the M ¯ point.
Data Analysis Techniques for a Lunar Surface Navigation System Testbed

Science.gov (United States)

Chelmins, David; Sands, O. Scott; Swank, Aaron

2011-01-01

NASA is interested in finding new methods of surface navigation to allow astronauts to navigate on the lunar surface. In support of the Vision for Space Exploration, the NASA Glenn Research Center developed the Lunar Extra-Vehicular Activity Crewmember Location Determination System and performed testing at the Desert Research and Technology Studies event in 2009. A significant amount of sensor data was recorded during nine tests performed with six test subjects. This paper provides the procedure, formulas, and techniques for data analysis, as well as commentary on applications.
Effect of Different Cutting Techniques on the Surface Morphology and Composition of Niobium

International Nuclear Information System (INIS)

Cooper, C.A.; Wu, A.; Bauer, P.; Antoine, C.

2009-01-01

The surface morphology and chemical purity of superconducting radio frequency (SRF) niobium cavities are very important for proper accelerator operation. Typically on the order of 120 micrometers of niobium (Nb) is removed from cavities to remove damage done during the forming of Nb sheets and cavities. A study was done to find the effect of cutting or finishing Nb with a band saw, diamond saw, electrical discharge machining (EDM) wire, garnet water jet, sheer, and mill. Surface contamination of the samples was measured before and after buffered chemical polish (BCP) by secondary ion mass spectroscopy (SIMS), energy dispersive spectroscopy (EDS), and by measuring relative resistivity ratios (RRRs). Surface morphology was examined with a digital microscope, a surface profilometer and scanning electron microscope (SEM). It was found that all techniques altered the top 3-5 micrometers of the Nb. It was also found by SIMS that the water jet technique introduced the most hydrogen and oxygen to the Nb in the first 2.5 micrometers of the sample. The EDM wire cutting technique introduced the least amount of hydrogen to the Nb. After 5 micrometers were etched away by BCP on the various samples, no contaminants were found except on the water jet cut samples. Even after 20 micrometers of Nb removal silica could be seen on the surface with EDS. The water jet produced the roughest surface with 50-100 micrometer deep pits made from embedded garnet particles. It was found that the garnet water jet damages the surface to the point where even the typical 120 micrometers of BCP etching may not remove all the defects created
Thin film characterisation by advanced X-ray diffraction techniques

International Nuclear Information System (INIS)

Cappuccio, G.; Terranova, M.L.

1996-09-01

The Fifth School on X-ray diffraction from polycrystalline materials was devoted to thin film characterization by advanced X-ray diffraction techniques. Twenty contributions are contained in this volume; all twenty are recorded in the INIS Database. X-ray diffraction is known to be a powerful analytical tool for characterizing materials and understanding their structural features. The aim of these articles is to illustrate the fundamental contribution of modern diffraction techniques (grazing incidence, surface analysis, standing waves, etc.) to the characterization of thin and ultra-thin films, which have become important in many advanced technologies
Data Analytics in CRM Processes: A Literature Review

Directory of Open Access Journals (Sweden)

Gončarovs Pāvels

2017-12-01

Full Text Available Nowadays, the data scarcity problem has been supplanted by the data deluge problem. Marketers and Customer Relationship Management (CRM specialists have access to rich data on consumer behaviour. The current challenge is effective utilisation of these data in CRM processes and selection of appropriate data analytics techniques. Data analytics techniques help find hidden patterns in data. The present paper explores the characteristics of data analytics as the integrated tool in CRM for sales managers. The paper aims at analysing some of the different analytics methods and tools which can be used for continuous improvement of CRM processes. A systematic literature has been conducted to achieve this goal. The results of the review highlight the most frequently considered CRM processes in the context of data analytics.
Review of analytical techniques to determine the chemical forms of vapours and aerosols released from overheated fuel

International Nuclear Information System (INIS)

Bowsher, B.R.; Nichols, A.L.

1989-12-01

A comprehensive review has been undertaken of appropriate analytical techniques to monitor and measure the chemical effects that occur in large-scale tests designed to study severe reactor accidents. Various methods have been developed to determine the chemical forms of the vapours, aerosols and deposits generated during and after such integral experiments. Other specific techniques have the long-term potential to provide some of the desired data in greater detail, although considerable efforts are still required to apply these techniques to the study of radioactive debris. Such in-situ and post-test methods of analysis have been also assessed in terms of their applicability to the analysis of samples from the Phebus-FP tests. The recommended in-situ methods of analysis are gamma-ray spectroscopy, potentiometry, mass spectrometry, and Raman/UV-visible absorption spectroscopy. Vapour/aerosol and deposition samples should also be obtained at well-defined time intervals during each experiment for subsequent post-test analysis. No single technique can provide all the necessary chemical data from these samples, and the most appropriate method of analysis involves a complementary combination of autoradiography, AES, IR, MRS, SEMS/EDS, SIMS/LMIS, XPS and XRD
Pollution prevention in the analytical laboratory--Microscale and other techniques do add up

International Nuclear Information System (INIS)

Erickson, M.D.; Alvarado, J.S.; Lu, C.-S.; Peterson, D.P.; Silzer, J.

1996-01-01

The principles of pollution prevention in the analytical laboratory have not been addressed sufficiently. Although the amount of reagent used per sample is often only a few milliliters, the aggregate of many routine test each day in thousands of laboratories becomes significant. Current recycling practices are not practical with small streams. Therefore, we have adopted the principles of microscale chemistry, along with other modern analytical approaches, to develop routine analytical methods that significantly curtail waste but still maintain acceptable analytical figures of merit and achieve cost savings through reduced reagent consumption and reduced labor cost
Advanced techniques for analytic liquid wastes management in the Rokkasho reprocessing plant

International Nuclear Information System (INIS)

Madic, C.; Moulin, J.P.; Runge, S.; Schott, R.; Kashiwai, T.; Hayashi, M.

1991-01-01

The JNFS Rokkasho reprocessing plant is a large scale commercial reprocessing plant. Liquid waste treatment relies on concentration by evaporation. The management of liquid wastes is rather sophisticated and implies, beside the organic wastes, sorting out between process and non-process, acidic and salt-bearing, tritiated and low tritiated streams and also according to their level of activity. A particular attention had to be paid to the analytical wastes, as their particularity is to contain not only a significant amount of radioactivity but also some fissile material and exotic chemicals which are useful for analytical purpose but unwanted in the main process mainly because of their corrosive and chelating properties. The analytical wastes are sorted out according to their activity level and fissile material content. On the one hand, a specific process has been developed to recover the bulk of plutonium from the analytical wastes. On the other hand, the foreseeable amount of unwanted chemicals (such as chloride ions) has been drastically reduced by carefully selecting all the analytical methods either by modification of already known methods or in some cases by working out new methods
Evaluation of shot peened surfaces using characterization technique of three-dimensional surface topography

International Nuclear Information System (INIS)

Kurokawa, S; Ariura, Y

2005-01-01

Objective parameters to characterize global topography of three-dimensional surfaces have been derived. The idea of this evaluation is to separate the topography into two global form deviations and residual ones according to the degree of curved surfaces. A shot peened Almen strip is measured by profilometer and concrete parameters of inclination and circular-arc shaped global topography are extracted using the characterization technique. The arc height is calculated using the circular arc-shaped part and compared with a value measured by an Almen gauge. The relation between the coverage and roughness parameters is also investigated. The advantage of this evaluation is that it is possible to determine the arc height and the coverage at the same time from single measured topography. In addition, human error can be excluded from measurement results. This method has the wide application in the field of measurement
A surface flaw sizing study by time-of-flight ultrasonic technique

International Nuclear Information System (INIS)

Lamy, C.A.

1990-07-01

In this work, sizing of inclined slits and surface cracks in ferritic steel using the ultrasonic time-of-flight technique was studied. The surface cracks were vertical and inclined, nut the slits were only inclined. It was surface Rayleigh wave that was converted to shear wave mode in the material. The specimens with surface crack were submitted to a three four point loading fracture mechanics tests, so that the region of the crack tip became under an increasing tensile stress. Thus, the ultrasonic crack sizing could be compared to the material stress intensity factor (K) of the material for different loadings. Results show that the greater the slope and/or lenght of the slits the greater its subsizing. Vertical cracks int he parent metal are reliably and accuratly sized; in the weld the same remark held if one increases the gain of ultrasonic flaw detector to compensate for the weld attenuation phenomenon. Sizing of inclined cracks in the parent metal shows the same trends of the inclined slits, differing only in slopes over 30 sup(0) where the sizing in surface cracks is no longer reliable. A new appraisal procedure here proposed made reliable these results. The techniques employed in this work lead to reliable and accurate results for sizing of different slits and cracks. It should be noted however that good results are only obtained if a tensile stress state exists in the neighbourhood of the c rack tip. (author)
An Analytical Model for Adsorption and Diffusion of Atoms/Ions on Graphene Surface

Directory of Open Access Journals (Sweden)

Yan-Zi Yu

2015-01-01

Full Text Available Theoretical investigations are made on adsorption and diffusion of atoms/ions on graphene surface based on an analytical continuous model. An atom/ion interacts with every carbon atom of graphene through a pairwise potential which can be approximated by the Lennard-Jones (L-J potential. Using the Fourier expansion of the interaction potential, the total interaction energy between the adsorption atom/ion and a monolayer graphene is derived. The energy-distance relationships in the normal and lateral directions for varied atoms/ions, including gold atom (Au, platinum atom (Pt, manganese ion (Mn2+, sodium ion (Na1+, and lithium-ion (Li1+, on monolayer graphene surface are analyzed. The equilibrium position and binding energy of the atoms/ions at three particular adsorption sites (hollow, bridge, and top are calculated, and the adsorption stability is discussed. The results show that H-site is the most stable adsorption site, which is in agreement with the results of other literatures. What is more, the periodic interaction energy and interaction forces of lithium-ion diffusing along specific paths on graphene surface are also obtained and analyzed. The minimum energy barrier for diffusion is calculated. The possible applications of present study include drug delivery system (DDS, atomic scale friction, rechargeable lithium-ion graphene battery, and energy storage in carbon materials.
Two new techniques for the remote evaluation of reactor steel condition - microscopic removal and surface examination

International Nuclear Information System (INIS)

Clayton, R.

Much reactor inspection work involves an assessment of the condition of structural steel. This paper reviews two different techniques which provide information for such an assessment. The first - micro-sample removal (for the measurement of surface oxide thickness and chemical composition) - requires contact with the steel surface, whereas the second - a 'teach and learn' photographic technique (in which a special photogrammatic camera is used to obtain high-quality close-up photographs, to assess surface condition and corrosion growth) can obtain surface information on inaccessible components. (author)
Measurement and image processing evaluation of surface modifications of dental implants G4 pure titanium created by different techniques

Energy Technology Data Exchange (ETDEWEB)

Bulutsuz, A. G., E-mail: asligunaya@gmail.com [Department of Mechanical Engineering, Yildiz Technical University, 34349 Besiktas, İstanbul (Turkey); Demircioglu, P., E-mail: pinar.demircioglu@adu.edu.tr; Bogrekci, I., E-mail: ismail.bogrekci@adu.edu.tr [Adnan Menderes University, Faculty of Engineering, Department of Mechanical Engineering, Aytepe, 09010, Aydin (Turkey); Durakbasa, M. N., E-mail: durakbasa@gmx.at [Department of Interchangeable Manufacturing and Industrial Metrology, Institute for Production Engineering and Laser Technology, Vienna University of Technology, Karlsplatz 13/3113 A-1040 Wien (Austria); Katiboglu, A. B., E-mail: abkatiboglu@hotmail.com [Istanbul University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Istanbul (Turkey)

2015-03-30

Foreign substances and organic tissue interaction placed into the jaw in order to eliminate tooth loss involves a highly complex process. Many biological reactions take place as well as the biomechanical forces that influence this formation. Osseointegration denotes to the direct structural and functional association between the living bone and the load-bearing artificial implant's surface. Taking into consideration of the requirements in the manufacturing processes of the implants, surface characterizations with high precise measurement techniques are investigated and thus long-term success of dental implant is emphasized on the importance of these processes in this study. In this research, the detailed surface characterization was performed to identify the dependence of the manufacturing techniques on the surface properties by using the image processing methods and using the scanning electron microscope (SEM) for morphological properties in 3D and Taylor Hobson stylus profilometer for roughness properties in 2D. Three implant surfaces fabricated by different manufacturing techniques were inspected, and a machined surface was included into the study as a reference specimen. The results indicated that different surface treatments were strongly influenced surface morphology. Thus 2D and 3D precise inspection techniques were highlighted on the importance for surface characterization. Different image analyses techniques such as Dark-light technique were used to verify the surface measurement results. The computational phase was performed using image processing toolbox in Matlab with precise evaluation of the roughness for the implant surfaces. The relationship between the number of black and white pixels and surface roughness is presented. FFT image processing and analyses results explicitly imply that the technique is useful in the determination of surface roughness. The results showed that the number of black pixels in the image increases with increase in
Analytic simulation of the Poincare surface of sections for the diamagnetic Kepler problem

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, H; Harada, A; Okazaki, Y [Kyoto Univ. (Japan). Dept. of Physics

1984-11-11

The Poincare surface-of-section analysis which the authors previously reported on the diamagnetic Kepler problem (classical hydrogen atom in a uniform magnetic field) in a transition region from regular to chaotic motions is simulated by an analytic means, by taking intersections of the energy integral and the approximate integral ..lambda.. of Solovev to obtain sections of the two separate regions of the motion that exist in the limit of a weak magnetic field (B ..-->.. 0). The origin of the unique hyperbolic point and the separatrix around which the onset of chaos takes place are thus identified. The invariant tori arising near the full chaos are shown to be simulated by this method but with modified parameter values in the expression ..lambda...

Analytic simulation of the Poincare surface of sections for the diamagnetic Kepler problem

International Nuclear Information System (INIS)

Hasegawa, H.; Harada, A.; Okazaki, Y.

1984-01-01

The Poincare surface-of-section analysis which the authors previously reported on the diamagnetic Kepler problem (classical hydrogen atom in a uniform magnetic field) in a transition region from regular to chaotic motions is simulated by an analytic means, by taking intersections of the energy integral and the approximate integral Λ of Solovev to obtain sections of the two separate regions of the motion that exist in the limit of a weak magnetic field (B → 0). The origin of the unique hyperbolic point and the separatrix around which the onset of chaos takes place are thus identified. The invariant tori arising near the full chaos are shown to be simulated by this method but with modified parameter values in the expression Λ. (author)
Performance Marketing with Google Analytics Strategies and Techniques for Maximizing Online ROI

CERN Document Server

Tonkin, Sebastian

2010-01-01

An unparalleled author trio shares valuable advice for using Google Analytics to achieve your business goals. Google Analytics is a free tool used by millions of Web site owners across the globe to track how visitors interact with their Web sites, where they arrive from, and which visitors drive the most revenue and sales leads. This book offers clear explanations of practical applications drawn from the real world. The author trio of Google Analytics veterans starts with a broad explanation of performance marketing and gets progressively more specific, closing with step-by-step analysis and a
Quantitative determination of BAF312, a S1P-R modulator, in human urine by LC-MS/MS: prevention and recovery of lost analyte due to container surface adsorption.

Science.gov (United States)

Li, Wenkui; Luo, Suyi; Smith, Harold T; Tse, Francis L S

2010-02-15

Analyte loss due to non-specific binding, especially container surface adsorption, is not uncommon in the quantitative analysis of urine samples. In developing a sensitive LC-MS/MS method for the determination of a drug candidate, BAF312, in human urine, a simple procedure was outlined for identification, confirmation and prevention of analyte non-specific binding to a container surface and to recover the 'non-specific loss' of an analyte, if no transfer has occurred to the original urine samples. Non-specific binding or container surface adsorption can be quickly identified by using freshly spiked urine calibration standards and pre-pooled QC samples during a LC-MS/MS feasibility run. The resulting low recovery of an analyte in urine samples can be prevented through the use of additives, such as the non-ionic surfactant Tween-80, CHAPS and others, to the container prior to urine sample collection. If the urine samples have not been transferred from the bulk container, the 'non-specific binding' of an analyte to the container surface can be reversed by the addition of a specified amount of CHAPS, Tween-80 or bovine serum albumin, followed by appropriate mixing. Among the above agents, Tween-80 is the most cost-effective. beta-cyclodextrin may be suitable in stabilizing the analyte of interest in urine via pre-treating the matrix with the agent. However, post-addition of beta-cyclodextrin to untreated urine samples does not recover the 'lost' analyte due to non-specific binding or container surface adsorption. In the case of BAF312, a dynamic range of 0.0200-20.0 ng/ml in human urine was validated with an overall accuracy and precision for QC sample results ranging from -3.2 to 5.1% (bias) and 3.9 to 10.2% (CV), respectively. Pre- and post-addition of 0.5% (v/v) Tween-80 to the container provided excellent overall analyte recovery and minimal MS signal suppression when a liquid-liquid extraction in combination with an isocratic LC separation was employed. The
Microgenetic Learning Analytics Methods: Workshop Report

Science.gov (United States)

Aghababyan, Ani; Martin, Taylor; Janisiewicz, Philip; Close, Kevin

2016-01-01

Learning analytics is an emerging discipline and, as such, benefits from new tools and methodological approaches. This work reviews and summarizes our workshop on microgenetic data analysis techniques using R, held at the second annual Learning Analytics Summer Institute in Cambridge, Massachusetts, on 30 June 2014. Specifically, this paper…
Evaluation of electrode surface modification techniques for the development of chemical sensors

International Nuclear Information System (INIS)

Galiatsatos, C.

1988-01-01

This thesis covers several aspects of electrode surface modification techniques. The successful application of gamma-radiation to create polymer-coated electrodes, where the polymers can be ion exchangers and consequently of great analytical interest by themselves (such as the polymer poly(diallyl) dimethyl ammonium chloride) or where some other neutral polymers can function as convenient matrices for the introduction of biomolecules and/or other electrochemically interesting species is reported. This is demonstrated by using the neutral polymer poly(vinyl alcohol) (PVAL) as a matrix for immobilization of the enzyme glucose oxidase and the mediator methyl viologen. The effect of γ-radiation on PVAL is discussed, as well as swelling properties of the irradiated polymers and specific characteristics of the created chemical sensors. Results of an experiment where the various kinds of interactions between the ion-exchange polymer Nafion and some positively charged species are explored are reported, and a model system for competition (methyl viologen vs. ruthenium hexaamine) which increases significantly our understanding of the interaction is mentioned. The effect of γ-radiation on Nafion and its ion-exchange compabilities is discussed also. A system of conduction polymers primarily polypyrrole, used as a detector of electroinactive anions due to their doping-undergoing in the film is discussed. Preliminary results on a new method that involves chemical cross-linking of a triisocyane molecule with -OH containing polymers in the presence of enzymes are reported
Sampling practices and analytical techniques used in the monitoring of steam and water in CEGB nuclear boilers

International Nuclear Information System (INIS)

Goodfellow, G.I.

1978-01-01

The steam and water in CEGB Magnox and AGR nuclear boilers are continuously monitored, using both laboratory techniques and on-line instrumentation, in order to maintain the chemical quality within pre-determined limits. The sampling systems in use and some of the difficulties associated with sampling requirements are discussed. The relative merits of chemical instruments installed either locally in various parts of the plant or in centralized instrument rooms are reviewed. The quality of water in nuclear boilers, as with all high-pressure steam-raising plant, is extremely high; consequently very sensitive analytical procedures are required, particularly for monitoring the feed-water of 'once-through boiler' systems. Considerable progress has been made in this field and examples are given of some of the techniques developed for analyses at the 'μ/kg' level together with some of the current problems.(author)
Nuclear analytical methods for platinum group elements

International Nuclear Information System (INIS)

2005-04-01

Platinum group elements (PGE) are of special interest for analytical research due to their economic importance like chemical peculiarities as catalysts, medical applications as anticancer drugs, and possible environmental detrimental impact as exhaust from automobile catalyzers. Natural levels of PGE are so low in concentration that most of the current analytical techniques approach their limit of detection capacity. In addition, Ru, Rh, Pd, Re, Os, Ir, and Pt analyses still constitute a challenge in accuracy and precision of quantification in natural matrices. Nuclear analytical techniques, such as neutron activation analysis, X ray fluorescence, or proton-induced X ray emission (PIXE), which are generally considered as reference methods for many analytical problems, are useful as well. However, due to methodological restrictions, they can, in most cases, only be applied after pre-concentration and under special irradiation conditions. This report was prepared following a coordinated research project and a consultants meeting addressing the subject from different viewpoints. The experts involved suggested to discuss the issue according to the (1) application, hence, the concentration levels encountered, and (2) method applied for analysis. Each of the different fields of application needs special consideration for sample preparation, PGE pre-concentration, and determination. Additionally, each analytical method requires special attention regarding the sensitivity and sample type. Quality assurance/quality control aspects are considered towards the end of the report. It is intended to provide the reader of this publication with state-of-the-art information on the various aspects of PGE analysis and to advise which technique might be most suitable for a particular analytical problem related to platinum group elements. In particular, many case studies described in detail from the authors' laboratory experience might help to decide which way to go. As in many cases
Comparative study of inorganic elements determined in whole blood from Dmd(mdx)/J mice strain by EDXRF and NAA analytical techniques.

Science.gov (United States)

Redígolo, M M; Sato, I M; Metairon, S; Zamboni, C B

2016-04-01

Several diseases can be diagnosed observing the variation of specific elements concentration in body fluids. In this study the concentration of inorganic elements in blood samples of dystrophic (Dmd(mdx)/J) and C57BL/6J (control group) mice strain were determined. The results obtained from Energy Dispersive X-ray Fluorescence (EDXRF) were compared with Neutron Activation Analysis (NAA) technique. Both analytical techniques showed to be appropriate and complementary offering a new contribution for veterinary medicine as well as detailed knowledge of this pathology. Copyright © 2016 Elsevier Ltd. All rights reserved.
Distribution-analytical techniques in the study of AD/HD: Delta plot analyses reveal deficits in response inhibition that are eliminated by methylphenidate treatment

NARCIS (Netherlands)

Ridderinkhof, K.R.; Scheres, A.; Oosterlaan, J.; Sergeant, J.A.

2005-01-01

The authors highlight the utility of distribution-analytical techniques in the study of individual differences and clinical disorders. Cognitive deficits associated with attention-deficit/hyperactivity disorder (AD/HD) were examined by using delta-plot analyses of performance data (reaction time and
A comparative study on surface morphology from the HgI2 semiconductors prepared by different techniques

International Nuclear Information System (INIS)

Martins, Joao F.T.; Ferraz, Caue de M.; Santos, Robinson A. dos; Mesquita, Carlos H. de; Hamada, Margarida M.

2013-01-01

The impurity effect in the surface morphology quality of HgI 2 crystals was evaluated, aiming a future application of these crystals as room temperature radiation semiconductor detector. The crystals were purified and grown by two techniques: (1) physical vapor transport (PVT) and (2) saturated solution from dimethylsulfoxide (DMSO) complexes. Systematic measurements were carried out for determining the stoichiometry, structure orientation, surface morphology and impurity of the crystal. The best quality of surface morphology was found for the crystals purified and grown by the PVT technique. Significant decrease in the impurity concentration was found, purifying the crystal by means of two successive growths by the PVT technique, while a Si contamination in the HgI 2 crystal was observed, during its growth by the DMSO method. Thus, for DMSO technique was not possible to identify the peaks of the other trace elements present as impurities in the PVT crystal, due to the high intensity of the Si peak in the DMSO crystal. It was demonstrated the impurities affect significantly the surface morphology quality from the HgI 2 crystal. Key Words: Semiconductor crystal, Radiation detector, Mercury Iodide crystal, surface morphology. (author)
Surface analysis methods in materials science

CERN Document Server

Sexton, Brett; Smart, Roger

1992-01-01

The idea for this book stemmed from a remark by Philip Jennings of Murdoch University in a discussion session following a regular meeting of the Australian Surface Science group. He observed that a text on surface analysis and applica tions to materials suitable for final year undergraduate and postgraduate science students was not currently available. Furthermore, the members of the Australian Surface Science group had the research experience and range of coverage of sur face analytical techniques and applications to provide a text for this purpose. A of techniques and applications to be included was agreed at that meeting. The list intended readership of the book has been broadened since the early discussions, particularly to encompass industrial users, but there has been no significant alter ation in content. The editors, in consultation with the contributors, have agreed that the book should be prepared for four major groups of readers: - senior undergraduate students in chemistry, physics, metallur...
Mathematical model for biomolecular quantification using large-area surface-enhanced Raman spectroscopy mapping

DEFF Research Database (Denmark)

Palla, Mirkó; Bosco, Filippo; Yang, Jaeyoung

2015-01-01

Surface-enhanced Raman spectroscopy (SERS) based on nanostructured platforms is a promising technique for quantitative and highly sensitive detection of biomolecules in the field of analytical biochemistry. Here, we report a mathematical model to predict experimental SERS signal (or hotspot) inte...
Defects at oxide surfaces

CERN Document Server

Thornton, Geoff

2015-01-01

This book presents the basics and characterization of defects at oxide surfaces. It provides a state-of-the-art review of the field, containing information to the various types of surface defects, describes analytical methods to study defects, their chemical activity and the catalytic reactivity of oxides. Numerical simulations of defective structures complete the picture developed. Defects on planar surfaces form the focus of much of the book, although the investigation of powder samples also form an important part. The experimental study of planar surfaces opens the possibility of applying the large armoury of techniques that have been developed over the last half-century to study surfaces in ultra-high vacuum. This enables the acquisition of atomic level data under well-controlled conditions, providing a stringent test of theoretical methods. The latter can then be more reliably applied to systems such as nanoparticles for which accurate methods of characterization of structure and electronic properties ha...
Surface enhanced Raman scattering

CERN Document Server

Furtak, Thomas

1982-01-01

In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would l...
A novel magnet focusing plate for matrix-assisted laser desorption/ionization analysis of magnetic bead-bound analytes.

Science.gov (United States)

Gode, David; Volmer, Dietrich A

2013-05-15

Magnetic beads are often used for serum profiling of peptide and protein biomarkers. In these assays, the bead-bound analytes are eluted from the beads prior to mass spectrometric analysis. This study describes a novel matrix-assisted laser desorption/ionization (MALDI) technique for direct application and focusing of magnetic beads to MALDI plates by means of dedicated micro-magnets as sample spots. Custom-made MALDI plates with magnetic focusing spots were made using small nickel-coated neodymium micro-magnets integrated into a stainless steel plate in a 16 × 24 (384) pattern. For demonstrating the proof-of-concept, commercial C-18 magnetic beads were used for the extraction of a test compound (reserpine) from aqueous solution. Experiments were conducted to study focusing abilities, the required laser energies, the influence of a matrix compound, dispensing techniques, solvent choice and the amount of magnetic beads. Dispensing the magnetic beads onto the micro-magnet sample spots resulted in immediate and strong binding to the magnetic surface. Light microscope images illustrated the homogeneous distribution of beads across the surfaces of the magnets, when the entire sample volume containing the beads was pipetted onto the surface. Subsequent MALDI analysis of the bead-bound analyte demonstrated excellent and reproducible ionization yields. The surface-assisted laser desorption/ionization (SALDI) properties of the strongly light-absorbing γ-Fe2O3-based beads resulted in similar ionization efficiencies to those obtained from experiments with an additional MALDI matrix compound. This feasibility study successfully demonstrated the magnetic focusing abilities for magnetic bead-bound analytes on a novel MALDI plate containing small micro-magnets as sample spots. One of the key advantages of this integrated approach is that no elution steps from magnetic beads were required during analyses compared with conventional bead experiments. Copyright © 2013 John Wiley
Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

NARCIS (Netherlands)

Taha, T.J.; Thakur, D.B.; van der Meer, Theodorus H.

2012-01-01

In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon
Testing photogrammetry-based techniques for three-dimensional surface documentation in forensic pathology.

Science.gov (United States)

Urbanová, Petra; Hejna, Petr; Jurda, Mikoláš

2015-05-01

Three-dimensional surface technologies particularly close range photogrammetry and optical surface scanning have recently advanced into affordable, flexible and accurate techniques. Forensic postmortem investigation as performed on a daily basis, however, has not yet fully benefited from their potentials. In the present paper, we tested two approaches to 3D external body documentation - digital camera-based photogrammetry combined with commercial Agisoft PhotoScan(®) software and stereophotogrammetry-based Vectra H1(®), a portable handheld surface scanner. In order to conduct the study three human subjects were selected, a living person, a 25-year-old female, and two forensic cases admitted for postmortem examination at the Department of Forensic Medicine, Hradec Králové, Czech Republic (both 63-year-old males), one dead to traumatic, self-inflicted, injuries (suicide by hanging), the other diagnosed with the heart failure. All three cases were photographed in 360° manner with a Nikon 7000 digital camera and simultaneously documented with the handheld scanner. In addition to having recorded the pre-autopsy phase of the forensic cases, both techniques were employed in various stages of autopsy. The sets of collected digital images (approximately 100 per case) were further processed to generate point clouds and 3D meshes. Final 3D models (a pair per individual) were counted for numbers of points and polygons, then assessed visually and compared quantitatively using ICP alignment algorithm and a cloud point comparison technique based on closest point to point distances. Both techniques were proven to be easy to handle and equally laborious. While collecting the images at autopsy took around 20min, the post-processing was much more time-demanding and required up to 10h of computation time. Moreover, for the full-body scanning the post-processing of the handheld scanner required rather time-consuming manual image alignment. In all instances the applied approaches
Forensic collection of trace chemicals from diverse surfaces with strippable coatings.

Science.gov (United States)

Jakubowski, Michael J; Beltis, Kevin J; Drennan, Paul M; Pindzola, Bradford A

2013-11-07

Surface sampling for chemical analysis plays a vital role in environmental monitoring, industrial hygiene, homeland security and forensics. The standard surface sampling tool, a simple cotton gauze pad, is failing to meet the needs of the community as analytical techniques become more sensitive and the variety of analytes increases. In previous work, we demonstrated the efficacy of non-destructive, conformal, spray-on strippable coatings for chemical collection from simple glass surfaces. Here we expand that work by presenting chemical collection at a low spiking level (0.1 g m(-2)) from a diverse array of common surfaces - painted metal, engineering plastics, painted wallboard and concrete - using strippable coatings. The collection efficiency of the strippable coatings is compared to and far exceeds gauze pads. Collection from concrete, a particular challenge for wipes like gauze, averaged 73% over eight chemically diverse compounds for the strippable coatings whereas gauze averaged 10%.
Rotary bending fatigue properties of Inconel 718 alloys by ultrasonic nanocrystal surface modification technique

Directory of Open Access Journals (Sweden)

Jun-Hyong Kim

2015-08-01

Full Text Available This study investigates the influence of ultrasonic nanocrystal surface modification (UNSM technique on fatigue properties of SAE AMS 5662 (solution treatment of Inconel 718 alloys. The fatigue properties of the specimens were investigated using a rotary bending fatigue tester. Results revealed that the UNSM-treated specimens showed longer fatigue life in comparison with those of the untreated specimens. The improvement in fatigue life of the UNSM-treated specimens is attributed mainly to the induced compressive residual stress, increased hardness, reduced roughness and refined grains at the top surface. Fractured surfaces were analysed using a scanning electron microscopy (SEM in order to give insight into the effectiveness of UNSM technique on fracture mechanisms and fatigue life.
Interior beam searchlight semi-analytical benchmark

International Nuclear Information System (INIS)

Ganapol, Barry D.; Kornreich, Drew E.

2008-01-01

Multidimensional semi-analytical benchmarks to provide highly accurate standards to assess routine numerical particle transport algorithms are few and far between. Because of the well-established 1D theory for the analytical solution of the transport equation, it is sometimes possible to 'bootstrap' a 1D solution to generate a more comprehensive solution representation. Here, we consider the searchlight problem (SLP) as a multidimensional benchmark. A variation of the usual SLP is the interior beam SLP (IBSLP) where a beam source lies beneath the surface of a half space and emits directly towards the free surface. We consider the establishment of a new semi-analytical benchmark based on a new FN formulation. This problem is important in radiative transfer experimental analysis to determine cloud absorption and scattering properties. (authors)

Surface-MALDI mass spectrometry in biomaterials research

DEFF Research Database (Denmark)

Griesser, H.J.; Kingshott, P.; McArthur, S.L.

2004-01-01

Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been used for over a decade for the determination of purity and accurate molecular masses of macromolecular analytes, such as proteins, in solution. In the last few years the technique has been adapted to become a new...... surfaces and detecting their molecular ions with high mass resolution and at levels much below monolayer coverage. Thus, Surface-MALDI-MS offers unique means of addressing biomaterial surface analysis needs, such as identification of the proteins and lipids that adsorb from multicomponent biological...... solutions in vitro and in vivo, the study of interactions between biomaterial surfaces and biomolecules, and identification of surface-enriched additives and contaminants. Surface-MALDI-MS is rapid, experimentally convenient, overcomes limitations in mass resolution and sensitivity of established...
Solar Ion Processing of Major Element Surface Compositions of Mature Mare Soils: Insights from Combined XPS and Analytical TEM Observations

Science.gov (United States)

Christoffersen, R.; Dukes, C.; Keller, L. P.; Baragiola, R.

2012-01-01

Solar wind ions are capable of altering the sur-face chemistry of the lunar regolith by a number of mechanisms including preferential sputtering, radiation-enhanced diffusion and sputter erosion of space weathered surfaces containing pre-existing compositional profiles. We have previously reported in-situ ion irradiation experiments supported by X-ray photoelectron spectroscopy (XPS) and analytical TEM that show how solar ions potentially drive Fe and Ti reduction at the monolayer scale as well as the 10-100 nm depth scale in lunar soils [1]. Here we report experimental data on the effect of ion irradiation on the major element surface composition in a mature mare soil.
Surface morphology study of some Cu–Ni reference alloys using laser induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Sheta, S.A. [National Institute of Laser Enhanced Science (NILES), Cairo University, 12613, Giza (Egypt); Di Carlo, G.; Ingo, G.M. [Istituto per lo Studio dei Materiali Nanostrutturati (ISMN-CNR), Area della Ricerca Roma 1 Montelibretti, 00016, Monterotondo Scalo, Rome (Italy); Harith, M.A., E-mail: mharithm@niles.edu.eg [National Institute of Laser Enhanced Science (NILES), Cairo University, 12613, Giza (Egypt)

2016-04-15

In the present work a detailed study of the surface morphology of purposely-prepared Cu–Ni reference alloys has been performed. These alloys have been prepared via tailored casting methods in order to have samples with same chemical composition and different local chemical enrichments of both metals. A micro-LIBS system for surface spatial scanning was set up based on a second harmonic Nd:YAG laser at 532 nm and using a focusing lens of focal length 7 cm to disclose the local chemical composition variation. Surface morphological scanning was performed for some of the binary Cu–Ni reference alloys to differentiate between chemically homogeneous and heterogeneous alloys. LIBS results were compared with the information of the Scanning Electron Microscope coupled with Energy Dispersive X-ray (SEMEDS) investigation carried out to provide surface local large-area chemical analysis via EDS technique. It has been proved that LIBS is a simple, sensitive and direct technique in the determination of homogeneity or heterogeneity of the sample's surface. The LIBS results have been shown to be more sensitive and accurate in the heterogeneity determination than other used conventional analytical techniques. - Highlights: • Surface LIBS scanning was performed for Cu–Ni reference alloy samples. • LIBS system was based on a 2nd harmonic Nd:YAG laser and a focusing lens (f = 7 cm). • LIBS results were compared with SEM imaging and EDS chemical analysis. • Surface homogeneity and heterogeneity have been differentiated successfully. • LIBS is a sensitive analytical tool in surface metallurgical study.
Infrared photothermal imaging spectroscopy for detection of trace explosives on surfaces.

Science.gov (United States)

Kendziora, Christopher A; Furstenberg, Robert; Papantonakis, Michael; Nguyen, Viet; Byers, Jeff; Andrew McGill, R

2015-11-01

We are developing a technique for the standoff detection of trace explosives on relevant substrate surfaces using photothermal infrared (IR) imaging spectroscopy (PT-IRIS). This approach leverages one or more compact IR quantum cascade lasers, which are tuned to strong absorption bands in the analytes and directed to illuminate an area on a surface of interest. An IR focal plane array is used to image the surface and detect increases in thermal emission upon laser illumination. The PT-IRIS signal is processed as a hyperspectral image cube comprised of spatial, spectral, and temporal dimensions as vectors within a detection algorithm. The ability to detect trace analytes at standoff on relevant substrates is critical for security applications but is complicated by the optical and thermal analyte/substrate interactions. This manuscript describes a series of PT-IRIS experimental results and analysis for traces of RDX, TNT, ammonium nitrate, and sucrose on steel, polyethylene, glass, and painted steel panels. We demonstrate detection at surface mass loadings comparable with fingerprint depositions ( 10μg/cm2 to 100μg/cm2) from an area corresponding to a single pixel within the thermal image.
The structural and compositional analysis of single crystal surfaces using low energy ion scattering

International Nuclear Information System (INIS)

Armour, D.G.; Van der Berg, J.A.; Verheij, IL.K.

1979-01-01

The use of ion scattering for surface composition and structure analysis has been reviewed. The extreme surface specificity of this technique has been widely used to obtain quitative information in a straightforward way, but the/aolc/currence of charge exchange processes, thermal lattice vibrations and multiple scattering have precluded quantitative analysis of experimental data. Examples are quoted to illustrate the progress that has been made in understanding these fundamental processes and in applying this knowledge to the development of the analytical capabilities of the technique. (author)
Synchrotron radiation based analytical techniques (XAS and XRF)

International Nuclear Information System (INIS)

Jha, Shambhu Nath

2014-01-01

A brief description of the principles of X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF) techniques is given in this article with emphasis on the advantages of using synchrotron radiation-based instrumentation/beamline. XAS technique is described in more detail to emphasize the strength of the technique as a local structural probe. (author)
Technique of semiautomatic surface reconstruction of the visible Korean human data using commercial software.

Science.gov (United States)

Park, Jin Seo; Shin, Dong Sun; Chung, Min Suk; Hwang, Sung Bae; Chung, Jinoh

2007-11-01

This article describes the technique of semiautomatic surface reconstruction of anatomic structures using widely available commercial software. This technique would enable researchers to promptly and objectively perform surface reconstruction, creating three-dimensional anatomic images without any assistance from computer engineers. To develop the technique, we used data from the Visible Korean Human project, which produced digitalized photographic serial images of an entire cadaver. We selected 114 anatomic structures (skin [1], bones [32], knee joint structures [7], muscles [60], arteries [7], and nerves [7]) from the 976 anatomic images which were generated from the left lower limb of the cadaver. Using Adobe Photoshop, the selected anatomic structures in each serial image were outlined, creating a segmented image. The Photoshop files were then converted into Adobe Illustrator files to prepare isolated segmented images, so that the contours of the structure could be viewed independent of the surrounding anatomy. Using Alias Maya, these isolated segmented images were then stacked to construct a contour image. Gaps between the contour lines were filled with surfaces, and three-dimensional surface reconstruction could be visualized with Rhinoceros. Surface imperfections were then corrected to complete the three-dimensional images in Alias Maya. We believe that the three-dimensional anatomic images created by these methods will have widespread application in both medical education and research. 2007 Wiley-Liss, Inc
Analytic number theory

CERN Document Server

Iwaniec, Henryk

2004-01-01

Analytic Number Theory distinguishes itself by the variety of tools it uses to establish results, many of which belong to the mainstream of arithmetic. One of the main attractions of analytic number theory is the vast diversity of concepts and methods it includes. The main goal of the book is to show the scope of the theory, both in classical and modern directions, and to exhibit its wealth and prospects, its beautiful theorems and powerful techniques. The book is written with graduate students in mind, and the authors tried to balance between clarity, completeness, and generality. The exercis
Molecular Imprinting Techniques Used for the Preparation of Biosensors

Directory of Open Access Journals (Sweden)

Gizem Ertürk

2017-02-01

Full Text Available Molecular imprinting is the technology of creating artificial recognition sites in polymeric matrices which are complementary to the template in their size, shape and spatial arrangement of the functional groups. Molecularly imprinted polymers (MIPs and their incorporation with various transducer platforms are among the most promising approaches for detection of several analytes. There are a variety of molecular imprinting techniques used for the preparation of biomimetic sensors including bulk imprinting, surface imprinting (soft lithography, template immobilization, grafting, emulsion polymerization and epitope imprinting. This chapter presents an overview of all of these techniques with examples from particular publications.
Reliable screening of various foodstuffs with respect to their irradiation status: A comparative study of different analytical techniques

International Nuclear Information System (INIS)

Ahn, Jae-Jun; Akram, Kashif; Kwak, Ji-Young; Jeong, Mi-Seon; Kwon, Joong-Ho

2013-01-01

Cost-effective and time-efficient analytical techniques are required to screen large food lots in accordance to their irradiation status. Gamma-irradiated (0–10 kGy) cinnamon, red pepper, black pepper, and fresh paprika were investigated using photostimulated luminescence (PSL), direct epifluorescent filter technique/the aerobic plate count (DEFT/APC), and electronic-nose (e-nose) analyses. The screening results were also confirmed with thermoluminescence analysis. PSL analysis discriminated between irradiated (positive, >5000 PCs) and non-irradiated (negative, <700 PCs) cinnamon and red peppers. Black pepper had intermediate results (700–5000 PCs), while paprika had low sensitivity (negative results) upon irradiation. The DEFT/APC technique also showed clear screening results through the changes in microbial profiles, where the best results were found in paprika, followed by red pepper and cinnamon. E-nose analysis showed a dose-dependent discrimination in volatile profiles upon irradiation through principal component analysis. These methods can be used considering their potential applications for the screening analysis of irradiated foods. - Highlights: • Detection of irradiated food is important to enforce the applied regulations. • Gamma-irradiated spices were investigated to confirm their irradiation status. • Screening techniques such as PSL, DEFT/APC, and E-nose were tested. • Specificity and potential applications of screening techniques were evaluated. • The screening results were confirmed by promising thermoluminescence technique
An Assessment of the Effectiveness of Computer-based Training for Newly Commissioned Surface Warfare Division Officers

National Research Council Canada - National Science Library

Bowman, William R; Crawford, Alice M; Mehay, Stephen; Stoker, Carol; Paynter, Robert

2008-01-01

...) on-board an officer's ship. The study relied on a variety of analytical techniques, including a literature review of CBT and OJT training, interviews and focus groups with junior and senior surface warfare officers...
Future analytical provision - Relocation of Sellafield Ltd Analytical Services Laboratory

International Nuclear Information System (INIS)

Newell, B.

2015-01-01

Sellafield Ltd Analytical Services provide an essential view on the environmental, safety, process and high hazard risk reduction performances by analysis of samples. It is the largest and most complex analytical services laboratory in Europe, with 150 laboratories (55 operational) and 350 staff (including 180 analysts). Sellafield Ltd Analytical Services Main Laboratory is in need of replacement. This is due to the age of the facility and changes to work streams. This relocation is an opportunity to -) design and commission bespoke MA (Medium-Active) cells, -) modify HA (High-Active) cell design to facilitate an in-cell laboratory, -) develop non-destructive techniques, -) open light building for better worker morale. The option chosen was to move the activities to the NNL Central laboratory (NNLCL) that is based at Sellafield and is the UK's flagship nuclear research and development facility. This poster gives a time schedule
New perspectives in hydrodynamic radial polishing techniques for optical surfaces

Science.gov (United States)

Ruiz, Elfego; Sohn, Erika; Luna, Esteban; Salas, Luis; Cordero, Alberto; González, Jorge; Núñez, Manuel; Salinas, Javier; Cruz-González, Irene; Valdés, Jorge; Cabrera, Victor; Martínez, Benjamín

2004-09-01

In order to overcome classic polishing techniques, a novel hydrodynamic radial polishing tool (HyDRa) is presented; it is useful for the corrective lapping and fine polishing of diverse materials by means of a low-cost abrasive flux and a hydrostatic suspension system that avoids contact of the tool with the working surface. This tool enables the work on flat or curved surfaces of currently up to two and a half meters in diameter. It has the advantage of avoiding fallen edges during the polishing process as well as reducing tool wear out and deformation. The functioning principle is based on the generation of a high-velocity, high-pressure, abrasive emulsion flux with radial geometry. The polishing process is repeatable by means of the control of the tool operational parameters, achieving high degrees of precision and accuracy on optical and semiconductor surfaces, with removal rates of up to 9 mm3/hour and promising excellent surface polishing qualities. An additional advantage of this new tool is the possibility to perform interferometric measurements during the polishing process without the need of dismounting the working surface. A series of advantages of this method, numerical simulations and experimental results are described.
Laboratory insights into the detection of surface biosignatures by remote-sensing techniques

Science.gov (United States)

Poch, O.; Pommerol, A.; Jost, B.; Roditi, I.; Frey, J.; Thomas, N.

2014-03-01

With the progress of direct imaging techniques, it will be possible in the short or long-term future to retrieve more efficiently the information on the physical properties of the light reflected by rocky exoplanets (Traub et al., 2010). The search for visible-infrared absorption bands of peculiar gases (O2, CH4 etc.) in this light could give clues for the presence of life (Kaltenegger and Selsis, 2007). Even more uplifting would be the direct detection of life itself, on the surface of an exoplanet. Considering this latter possibility, what is the potential of optical remote-sensing methods to detect surface biosignatures? Reflected light from the surface of the Earth exhibits a strong surface biosignature in the form of an abrupt change of reflectance between the visible and infrared range of the spectrum (Seager et al., 2005). This spectral feature called "vegetation red-edge" is possibly the consequence of biological evolution selecting the right chemical structures enabling the plants to absorb the visible energy, while preventing them from overheating by reflecting more efficiently the infrared. Such red-edge is also found in primitive photosynthetic bacteria, cyanobacteria, that colonized the surface of the Earth ocean and continents billions of years before multicellular plants (Knacke, 2003). If life ever arose on an Earth-like exoplanet, one could hypothesize that some form of its surface-life evolves into similar photo-active organisms, also exhibiting a red-edge. In this paper, we will present our plan and preliminary results of a laboratory study aiming at precising the potentiality of remote sensing techniques in detecting such surface biosignatures. Using equipment that has been developed in our team for surface photometry studies (Pommerol 2011, Jost 2013, Pommerol 2013), we will investigate the reflectance spectra and bidirectional reflectance function of soils containing bacteria such as cyanobacteria, in various environmental conditions. We will
International Congress on Analytical Chemistry. Abstracts. V. 1

International Nuclear Information System (INIS)

1997-01-01

The collection of materials of the international congress on analytical chemistry taken place in Moscow in June 1997. The main directs of investigations in such regions of analytical chemistry as quantitative and qualitative analysis, microanalysis, sample preparation and preconcentration, analytical reagents, chromatography and related techniques, flow analysis, electroanalytical and kinetic methods sensors are elucidated
Ball assisted device for analytical surface sampling

Science.gov (United States)

ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

2015-11-03

A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.
Big Data Analytics with Datalog Queries on Spark.

Science.gov (United States)

Shkapsky, Alexander; Yang, Mohan; Interlandi, Matteo; Chiu, Hsuan; Condie, Tyson; Zaniolo, Carlo

2016-01-01

There is great interest in exploiting the opportunity provided by cloud computing platforms for large-scale analytics. Among these platforms, Apache Spark is growing in popularity for machine learning and graph analytics. Developing efficient complex analytics in Spark requires deep understanding of both the algorithm at hand and the Spark API or subsystem APIs (e.g., Spark SQL, GraphX). Our BigDatalog system addresses the problem by providing concise declarative specification of complex queries amenable to efficient evaluation. Towards this goal, we propose compilation and optimization techniques that tackle the important problem of efficiently supporting recursion in Spark. We perform an experimental comparison with other state-of-the-art large-scale Datalog systems and verify the efficacy of our techniques and effectiveness of Spark in supporting Datalog-based analytics.
Development of an absolute x-ray fluorescence technique and high accuracy analytical methods for the determination of metals in catalytic materials

International Nuclear Information System (INIS)

LaBrecque, J.J.; Parker, W.C.

1982-09-01

A technique to produce characteristic x-rays by direct beta excitation for x-ray fluorescence analysis is presented. This is carried out by the introduction of 100 uCi of Pm-147 or Ni-63 to a small sample, which is placed directly in the window of a modified Si(Li) semiconductor. Corrected intensities are only given at 300 seconds for synthetic standards oscillating within the range 22 3 was used, to which the radioisotope was directly added. Preliminary results of the determination of eleven different radionuclides by means of an elementary x-ray analysis by using a new analytical technique, are discussed. In this technique the radioisotope and the sample are directly mixed, then this source-sample in the detector window and is protected from contamination with a thin plastic film. Future and possible applications of this technique are presented
Surface Ionization and Soft Landing Techniques in Mass Spectrometry

International Nuclear Information System (INIS)

Futrell, Jean H.; Laskin, Julia

2010-01-01

The advent of soft ionization techniques, notably electrospray and laser desorption ionization methods, has extended mass spectrometric methods to large molecules and molecular complexes. This both greatly expands applications of mass spectrometry and makes the activation and dissociation of complex ions an integral part of large molecule mass spectrometry. A corollary of the much greater number of internal degrees of freedom and high density of states associated with molecular complexity is that internal energies much higher than the dissociation energies for competing fragmentation processes are required for observable fragmentation in time scales sampled by mass spectrometers. This article describes the kinetics of surface-induced dissociation (SID), a particularly efficient activation method for complex ions. Two very important characteristics of SID are very rapid, sub-picosecond activation and precise control of ion internal energy by varying ion collision energy. The nature of the surface plays an important role in SID, determining both efficiency and mechanism of ion activation. Surface composition and morphology strongly influence the relative importance of competing reactions of SID, ion capture (soft-landing), surface reaction and neutralization. The important features of SID and ion soft-landing are described briefly in this review and more fully in the recommended reading list.
Techniques for removing contaminants from optical surfaces

International Nuclear Information System (INIS)

Stowers, I.F.; Patton, H.G.

1978-01-01

Particle removal procedures such as plasma cleaning, ultrasonic agitation of solvents, detergents, solvent wiping, mild abrasives, vapor degreasing, high pressure solvent spraying and others have been evaluated and the results are reported here. Wiping with a lens tissue wetted with an organic solvent and high pressure fluid spraying are the only methods by which particles as small as 5 μm can be effectively removed. All of the other methods tested were found to be at least two orders of magnitude less effective at removing small insoluble particles. An additional and as yet unresolved problem is the development of a reliable method for evaluating particulate surface cleanliness. Without such a reproducible monitoring technique, the large diversity of cleaning methods currently available cannot be quantitatively evaluated

Investigation of Steel Surfaces Treated by a Hybrid Ion Implantation Technique

International Nuclear Information System (INIS)

Reuther, H.; Richter, E.; Prokert, F.; Ueda, M.; Beloto, A. F.; Gomes, G. F.

2004-01-01

Implantation of nitrogen ions into stainless steel in combination with oxidation often results in a decrease or even complete removal of the chromium in the nitrogen containing outermost surface layer. While iron nitrides can be formed easily by this method, due to the absence of chromium, the formation of chromium nitrides is impossible and the beneficial influence of chromium in the steel for corrosion resistance cannot be used. To overcome this problem we use the following hybrid technique. A thin chromium layer is deposited on steel and subsequently implanted with nitrogen ions. Chromium can be implanted by recoil into the steel surface and thus the formation of iron/chromium nitrides should be possible. Both beam line ion implantation and plasma immersion ion implantation are used. Due to the variation of the process parameters, different implantation profiles and different compounds are produced. The produced layers are characterized by Auger electron spectroscopy, conversion electron Moessbauer spectroscopy and X-ray diffraction. The obtained results show that due to the variation of the implantation parameters, the formation of iron/chromium nitrides can be achieved and that plasma immersion ion implantation is the most suitable technique for the enrichment of chromium in the outermost surface layer of the steel when compared to the beam line implantation.
Multi-Intelligence Analytics for Next Generation Analysts (MIAGA)

Science.gov (United States)

Blasch, Erik; Waltz, Ed

2016-05-01

Current analysts are inundated with large volumes of data from which extraction, exploitation, and indexing are required. A future need for next-generation analysts is an appropriate balance between machine analytics from raw data and the ability of the user to interact with information through automation. Many quantitative intelligence tools and techniques have been developed which are examined towards matching analyst opportunities with recent technical trends such as big data, access to information, and visualization. The concepts and techniques summarized are derived from discussions with real analysts, documented trends of technical developments, and methods to engage future analysts with multiintelligence services. For example, qualitative techniques should be matched against physical, cognitive, and contextual quantitative analytics for intelligence reporting. Future trends include enabling knowledge search, collaborative situational sharing, and agile support for empirical decision-making and analytical reasoning.
The analyst's participation in the analytic process.

Science.gov (United States)

Levine, H B

1994-08-01

The analyst's moment-to-moment participation in the analytic process is inevitably and simultaneously determined by at least three sets of considerations. These are: (1) the application of proper analytic technique; (2) the analyst's personally-motivated responses to the patient and/or the analysis; (3) the analyst's use of him or herself to actualise, via fantasy, feeling or action, some aspect of the patient's conflicts, fantasies or internal object relationships. This formulation has relevance to our view of actualisation and enactment in the analytic process and to our understanding of a series of related issues that are fundamental to our theory of technique. These include the dialectical relationships that exist between insight and action, interpretation and suggestion, empathy and countertransference, and abstinence and gratification. In raising these issues, I do not seek to encourage or endorse wild analysis, the attempt to supply patients with 'corrective emotional experiences' or a rationalisation for acting out one's countertransferences. Rather, it is my hope that if we can better appreciate and describe these important dimensions of the analytic encounter, we can be better prepared to recognise, understand and interpret the continual streams of actualisation and enactment that are embedded in the analytic process. A deeper appreciation of the nature of the analyst's participation in the analytic process and the dimensions of the analytic process to which that participation gives rise may offer us a limited, although important, safeguard against analytic impasse.
Bacterial Adhesion and Surface Roughness for Different Clinical Techniques for Acrylic Polymethyl Methacrylate

Directory of Open Access Journals (Sweden)

Lucas Costa de Medeiros Dantas

2016-01-01

Full Text Available This study sought to assess the effect of different surface finishing and polishing protocols on the surface roughness and bacterial adhesion (S. sanguinis to polymethyl methacrylates (PMMA. Fifty specimens were divided into 5 groups (n=10 according to their fabrication method and surface finishing protocol: LP (3 : 1 ratio and laboratory polishing, NF (Nealon technique and finishing, NP (Nealon technique and manual polishing, MF (3 : 1 ratio and manual finishing, and MP (3 : 1 ratio and manual polishing. For each group, five specimens were submitted to bacterial adhesion tests and analyzed by scanning electron microscopy (SEM. Two additional specimens were subjected to surface topography analysis by SEM and the remaining three specimens were subjected to surface roughness measurements. Data were compared by one-way ANOVA. The mean bacterial counts were as follows: NF, 19.6±3.05; MP, 5.36±2.08; NP, 4.96±1.93; MF, 7.36±2.45; and LP, 1.56±0.62 (CFU. The mean surface roughness values were as follows: NF, 3.23±0.15; MP, 0.52±0.05; NP, 0.60±0.08; MF, 2.69±0.12; and LP, 0.07±0.02 (μm. A reduction in the surface roughness was observed to be directly related to a decrease in bacterial adhesion. It was verified that the laboratory processing of PMMA might decrease the surface roughness and consequently the adhesion of S. sanguinis to this material.
Development of statistical and analytical techniques for use in national quality control schemes for steroid hormones

International Nuclear Information System (INIS)

Wilson, D.W.; Gaskell, S.J.; Fahmy, D.R.; Joyce, B.G.; Groom, G.V.; Griffiths, K.; Kemp, K.W.; Nix, A.B.J.; Rowlands, R.J.

1979-01-01

Adopting the rationale that the improvement of intra-laboratory performance of immunometric assays will enable the assessment of national QC schemes to become more meaningful, the group of participating laboratories has developed statistical and analytical techniques for the improvement of accuracy, precision and monitoring of error for the determination of steroid hormones. These developments are now described and their relevance to NQC schemes discussed. Attention has been focussed on some of the factors necessary for improving standards of quality in immunometric assays and their relevance to laboratories participating in NQC schemes as described. These have included the 'accuracy', precision and robustness of assay procedures as well as improved methods for internal quality control. (Auth.)
Investigating biomolecular recognition at the cell surface using atomic force microscopy.

Science.gov (United States)

Wang, Congzhou; Yadavalli, Vamsi K

2014-05-01

Probing the interaction forces that drive biomolecular recognition on cell surfaces is essential for understanding diverse biological processes. Force spectroscopy has been a widely used dynamic analytical technique, allowing measurement of such interactions at the molecular and cellular level. The capabilities of working under near physiological environments, combined with excellent force and lateral resolution make atomic force microscopy (AFM)-based force spectroscopy a powerful approach to measure biomolecular interaction forces not only on non-biological substrates, but also on soft, dynamic cell surfaces. Over the last few years, AFM-based force spectroscopy has provided biophysical insight into how biomolecules on cell surfaces interact with each other and induce relevant biological processes. In this review, we focus on describing the technique of force spectroscopy using the AFM, specifically in the context of probing cell surfaces. We summarize recent progress in understanding the recognition and interactions between macromolecules that may be found at cell surfaces from a force spectroscopy perspective. We further discuss the challenges and future prospects of the application of this versatile technique. Copyright © 2014 Elsevier Ltd. All rights reserved.
Biomonitoring of air pollution in Jamaica through trace-element analysis of epiphytic plants using nuclear and related analytical techniques

International Nuclear Information System (INIS)

Vutchkov, M.; Lalor, G.C.; Preston, J.

1999-01-01

Air quality has been monitored at selected areas in Jamaica using high volume samplers. The results obtained, showed elevated levels of aluminium in bauxitic areas and very high lead concentrations in urban areas, from 5 to 35 times greater than in rural areas. The lower throughput of the conventional air particulate samplers however, restricts the air quality and health assessment on a nation-wide scale. Biomonitoring offers a cost-effective alternative to air-quality assessment if appropriate indicator species are chosen. The epiphytic lower plants such as lichens and mosses have been used as indicators of regional air quality in several European countries and USA. However, there is not enough studies on lichens and mosses in tropical countries, probably due to the lower occurrence of these species, which cover only 8% of the world's land surface. In Jamaica the epiphytic higher plants, represented by the genus Tillandsia are widely distributed, which make them along with the lichens and mosses potential site-specific bioindicators of air quality. The IAEA Co-ordinated Research Project entitled 'Biomonitoring of Air Pollution in Jamaica Through Trace-Element Analysis of Epiphytic Plants Using Nuclear And Related Analytical Techniques' will address these needs of the country. The primary purpose of the present study was to develop specific bioindicators of atmospheric air pollution in Jamaica, which will provide baseline information for health hazards assessment
Wavelength modulated surface enhanced (resonance) Raman scattering for background-free detection.

Science.gov (United States)

Praveen, Bavishna B; Steuwe, Christian; Mazilu, Michael; Dholakia, Kishan; Mahajan, Sumeet

2013-05-21

Spectra in surface-enhanced Raman scattering (SERS) are always accompanied by a continuum emission called the 'background' which complicates analysis and is especially problematic for quantification and automation. Here, we implement a wavelength modulation technique to eliminate the background in SERS and its resonant version, surface-enhanced resonance Raman scattering (SERRS). This is demonstrated on various nanostructured substrates used for SER(R)S. An enhancement in the signal to noise ratio for the Raman bands of the probe molecules is also observed. This technique helps to improve the analytical ability of SERS by alleviating the problem due to the accompanying background and thus making observations substrate independent.
A new sampling technique for surface exposure dating using a portable electric rock cutter

Directory of Open Access Journals (Sweden)

Yusuke Suganuma

2012-07-01

Full Text Available Surface exposure dating using in situ cosmogenic nuclides has contributed to our understanding of Earth-surface processes. The precision of the ages estimated by this method is affected by the sample geometry; therefore, high accuracy measurements of the thickness and shape of the rock sample (thickness and shape is crucial. However, it is sometimes diffi cult to meet these requirements by conventional sampling methods with a hammer and chisel. Here, we propose a new sampling technique using a portable electric rock cutter. This sampling technique is faster, produces more precisely shaped samples, and allows for a more precise age interpretation. A simple theoretical modeldemonstrates that the age error due to defective sample geometry increases as the total sample thickness increases, indicating the importance of precise sampling for surface exposure dating.
Investigation of different types of filters for atmospheric trace elements analysis by three analytical techniques

International Nuclear Information System (INIS)

Ali, A.E.; Bacso, J.

1996-01-01

Different atmospheric aerosol samples were collected on three types of filters. Disks of both loaded and clean areas of each kind of filter were investigated by XRF, PIXE and Scanning Electron Microscope (SEM) methods. The blank concentration values of the elements Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br and Pb in the three types of filters are discussed. It is found that for trace elemental analysis, the Nuclepore membrane filters are the most suitable for sampling. These have much lower blank element concentration values than the glass fibres and ash free filters. It was found also that the PIXE method is a more reliable analytical technique for atmospheric aerosol particles than the other methods. (author). 20 refs., 3 figs., 3 tabs
Prediction of Experimental Surface Heat Flux of Thin Film Gauges using ANFIS

Science.gov (United States)

Sarma, Shrutidhara; Sahoo, Niranjan; Unal, Aynur

2018-05-01

Precise quantification of surface heat fluxes in highly transient environment is of paramount importance from the design point of view of several engineering equipment like thermal protection or cooling systems. Such environments are simulated in experimental facilities by exposing the surface with transient heat loads typically step/impulsive in nature. The surface heating rates are then determined from highly transient temperature history captured by efficient surface temperature sensors. The classical approach is to use thin film gauges (TFGs) in which temperature variations are acquired within milliseconds, thereby allowing calculation of surface heat flux, based on the theory of one-dimensional heat conduction on a semi-infinite body. With recent developments in the soft computing methods, the present study is an attempt for the application of intelligent system technique, called adaptive neuro fuzzy inference system (ANFIS) to recover surface heat fluxes from a given temperature history recorded by TFGs without having the need to solve lengthy analytical equations. Experiments have been carried out by applying known quantity of `impulse heat load' through laser beam on TFGs. The corresponding voltage signals have been acquired and surface heat fluxes are estimated through classical analytical approach. These signals are then used to `train' the ANFIS model, which later predicts output for `test' values. Results from both methods have been compared and these surface heat fluxes are used to predict the non-linear relationship between thermal and electrical properties of the gauges that are exceedingly pertinent to the design of efficient TFGs. Further, surface plots have been created to give an insight about dimensionality effect of the non-linear dependence of thermal/electrical parameters on each other. Later, it is observed that a properly optimized ANFIS model can predict the impulsive heat profiles with significant accuracy. This paper thus shows the
Determination of nanoparticle surface coatings and nanoparticle purity using microscale thermogravimetric analysis.

Science.gov (United States)

Mansfield, Elisabeth; Tyner, Katherine M; Poling, Christopher M; Blacklock, Jenifer L

2014-02-04

The use of nanoparticles in some applications (i.e., nanomedical, nanofiltration, or nanoelectronic) requires small samples with well-known purities and composition. In addition, when nanoparticles are introduced into complex environments (e.g., biological fluids), the particles may become coated with matter, such as proteins or lipid layers. Many of today's analytical techniques are not able to address small-scale samples of nanoparticles to determine purity and the presence of surface coatings. Through the use of an elevated-temperature quartz crystal microbalance (QCM) method we call microscale thermogravimetric analysis, or μ-TGA, the nanoparticle purity, as well as the presence of any surface coatings of nanomaterials, can be measured. Microscale thermogravimetric analysis is used to determine the presence and amount of surface-bound ligand coverage on gold nanoparticles and confirm the presence of a poly(ethylene glycol) coating on SiO2 nanoparticles. Results are compared to traditional analytical techniques to demonstrate reproducibility and validity of μ-TGA for determining the presence of nanoparticle surface coatings. Carbon nanotube samples are also analyzed and compared to conventional TGA. The results demonstrate μ-TGA is a valid method for quantitative determination of the coatings on nanoparticles, and in some cases, can provide purity and compositional data of the nanoparticles themselves.
Self-consistent Green’s-function technique for bulk and surface impurity calculations: Surface core-level shifts by complete screening

DEFF Research Database (Denmark)

Aldén, M.; Abrikosov, I. A.; Johansson, B.

1994-01-01

of the frozen-core and atomic-sphere approximation but, in addition, includes the dipole contribution to the intersphere potential. Within the concept of complete screening, we identify the surface core-level binding-energy shift with the surface segregation energy of a core-ionized atom and use the Green......'s-function impurity technique in a comprehensive study of the surface core-level shifts (SCLS) of the 4d and 5d transition metals. In those cases, where observed data refer to single crystals, we obtain good agreement with experiment, whereas the calculations typically underestimate the measured shift obtained from...
Organic surfaces exposed by self-assembled organothiol monolayers: Preparation, characterization, and application

Science.gov (United States)

Kind, Martin; Wöll, Christof

2009-07-01

Organic surfaces play a major role in materials science. Most surfaces that we touch in our daily lives are made from organic materials, e.g., vegetables, fruit, skin, wood, and textiles made from natural fibers. In the context of biology, organic surfaces play a prominent role too, proteins docking onto cell surfaces are a good example. To better understand the characteristics of organic surfaces, including physico-chemical properties like wettability or chemical reactivities and physical properties like friction and lubrication, a structurally well-defined model system that can be investigated with numerous analytical techniques is desirable. In the last two decades, one particular system, self-assembled monolayers or SAMs, have demonstrated their suitability for this purpose. In particular, organothiols consisting of an organic molecule with an attached SH-group are well suited to fabricating structurally well-defined adlayers of monolayer thickness on gold substrates using a simple preparation procedure. These ultrathin monolayers expose an organic surface with properties that can be tailored by varying the type of organothiol employed. After a short introduction into the preparation of SAMs, this article provides an overview of the possibilities and limitations of organic surfaces exposed by Au-thiolate SAMs. Applications are as diverse as the metallization of organic surfaces, a fundamental problem in materials science, and the fabrication of surfaces that resist the adsorption of proteins. In addition to a number of different case studies, we will also discuss the most powerful analytical techniques needed to characterize these important model systems.
Characterisation of phases in nanostructured, multilayered titanium alloys by analytical and high-resolution electron microscopy.

Science.gov (United States)

Czyrska-Filemonowicz, A; Buffat, P A

2009-01-01

Surface processing of a Ti-6Al-4V alloy led to a complex multilayered microstructure containing several phases of the Ni-Ti-P-Al-O system, which improves the mechanical and tribological surface properties. The microstructure, chemical and phase compositions of the hard layer formed on the surface were investigated by LM, XRD, SEM as well as analytical/high-resolution TEM, STEM, EDS, electron diffraction and FIB. Phase identification based on electron diffraction, HRTEM and EDS microanalysis revealed the presence of several binary and ternary phases in the system Ti-Ni-P, sometimes with partial substitution of Ti by Al. However some phases, mainly nanoparticles, still remain not identified satisfactorily. Electron microscopy techniques used for identification of phases present in surface multilayers and some practical limits to their routine application are reminded here.
Use of analytical electron microscopy and auger electron spectroscopy for evaluating materials

International Nuclear Information System (INIS)

Jones, R.H.; Bruemmer, S.M.; Thomas, M.T.; Baer, D.R.

1982-11-01

Analytical electron microscopy (AEM) can be used to characterize the microstructure and microchemistry of materials over dimensions less than 10 nm while Auger electron spectroscopy (AES) can be used to characterize the chemical composition of surfaces and interfaces to a depth of less than 1 nm. Frequently, the information gained from both instruments can be coupled to give new insight into the behavior of materials. Examples of the use of AEM and AES to characterize segregation, sensitization and radiation damage are presented. A short description of the AEM and AES techniques are given
Laser desorption ionization mass spectrometry: Recent progress in matrix-free and label-assisted techniques.

Science.gov (United States)

Mandal, Arundhoti; Singha, Monisha; Addy, Partha Sarathi; Basak, Amit

2017-10-13

The MALDI-based mass spectrometry, over the last three decades, has become an important analytical tool. It is a gentle ionization technique, usually applicable to detect and characterize analytes with high molecular weights like proteins and other macromolecules. The earlier difficulty of detection of analytes with low molecular weights like small organic molecules and metal ion complexes with this technique arose due to the cluster of peaks in the low molecular weight region generated from the matrix. To detect such molecules and metal ion complexes, a four-prong strategy has been developed. These include use of alternate matrix materials, employment of new surface materials that require no matrix, use of metabolites that directly absorb the laser light, and the laser-absorbing label-assisted LDI-MS (popularly known as LALDI-MS). This review will highlight the developments with all these strategies with a special emphasis on LALDI-MS. © 2017 Wiley Periodicals, Inc.
Experiences with IAEA project: TC Regional Project on Quality Control and Quality Assurance for Nuclear Analytical Techniques (RER/2/004)

International Nuclear Information System (INIS)

Glavic-Cindro, Denis; Korun, Matjaz

2002-01-01

In the TC Regional Project on Quality Control and Quality Assurance for Nuclear Analytical Techniques RER/2/004, 12 laboratories from east and central European countries participated. Within this project 4 workshops, 2 audit inspections and 2 proficiency tests were organized. The aim of this project was to help these laboratories to implement quality assurance system based on the ISO 17025 standard and to help them on the way towards accreditation. (author)
XPS, AES and laser raman spectroscopy: A fingerprint for a materials surface characterisation

International Nuclear Information System (INIS)

Zaidi Embong

2011-01-01

This review briefly describes some of the techniques available for analysing surfaces and illustrates their usefulness with a few examples such as a metal and alloy. In particular, Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and laser Raman spectroscopy are all described as advanced surface analytical techniques. In analysing a surface, AES and XPS would normally be considered first, with AES being applied where high spatial resolution is required and XPS where chemical state information is needed. Laser Raman spectroscopy is useful for determining molecular bonding. A combination of XPS, AES and Laser Raman spectroscopy can give quantitative analysis from the top few atomic layers with a lateral spatial resolution of < 10 nm. (author)
Chemical Sensors Based on IR Spectroscopy and Surface-Modified Waveguides

Science.gov (United States)

Lopez, Gabriel P.; Niemczyk, Thomas

1999-01-01

Sol-gel processing techniques have been used to apply thin porous films to the surfaces of planar infrared (IR) waveguides to produce widely useful chemical sensors. The thin- film coating serves to diminish the concentration of water and increase the concentration of the analyte in the region probed by the evanescent IR wave. These porous films are composed of silica, and therefore, conventional silica surface modification techniques can be used to give the surface a specific functional character. The sol-gel film was surface-modified to make the film highly hydrophobic. These sensors were shown to be capable of detecting non-polar organic analytes, such as benzonitrile, in aqueous solution with detection limits in the ppb range. Further, these porous sol-gel structures allow the analytes to diffuse into and out of the films rapidly, thus reaching equilibrium in less than ten seconds. These sensors are unique because of the fact that their operation is based on the measurement of an IR absorption spectrum. Thus, these sensors are able to identify the analytes as well as measure concentration with high sensitivity. These developments have been documented in previous reports and publications. Recently, we have also targeted detection of the polar organic molecules acetone and isopropanol in aqueous solution. Polar organics are widely used in industrial and chemical processes, hence it is of interest to monitor their presence in effluents or decontamination process flows. Although large improvements in detection limits were expected with non-polar organic molecules in aqueous solutions using very hydrophobic porous sol-gel films on silicon attenuated total reflectance (Si ATR) waveguides, it was not as clear what the detection enhancements might be for polar organic molecules. This report describes the use of modified sol-gel-coated Si ATR sensors for trace detection and quantitation of small polar organic molecules in aqueous solutions. The detection of both acetone

The hydrogen abstraction reaction O(3P) + CH4: A new analytical potential energy surface based on fit to ab initio calculations

International Nuclear Information System (INIS)

González-Lavado, Eloisa; Corchado, Jose C.; Espinosa-Garcia, Joaquin

2014-01-01

Based exclusively on high-level ab initio calculations, a new full-dimensional analytical potential energy surface (PES-2014) for the gas-phase reaction of hydrogen abstraction from methane by an oxygen atom is developed. The ab initio information employed in the fit includes properties (equilibrium geometries, relative energies, and vibrational frequencies) of the reactants, products, saddle point, points on the reaction path, and points on the reaction swath, taking especial caution respecting the location and characterization of the intermediate complexes in the entrance and exit channels. By comparing with the reference results we show that the resulting PES-2014 reproduces reasonably well the whole set of ab initio data used in the fitting, obtained at the CCSD(T) = FULL/aug-cc-pVQZ//CCSD(T) = FC/cc-pVTZ single point level, which represents a severe test of the new surface. As a first application, on this analytical surface we perform an extensive dynamics study using quasi-classical trajectory calculations, comparing the results with recent experimental and theoretical data. The excitation function increases with energy (concave-up) reproducing experimental and theoretical information, although our values are somewhat larger. The OH rotovibrational distribution is cold in agreement with experiment. Finally, our results reproduce experimental backward scattering distribution, associated to a rebound mechanism. These results lend confidence to the accuracy of the new surface, which substantially improves the results obtained with our previous surface (PES-2000) for the same system
Analytic model of the stress waves propagation in thin wall tubes, seeking the location of a harmonic point source in its surface

International Nuclear Information System (INIS)

Boaratti, Mario Francisco Guerra

2006-01-01

Leaks in pressurized tubes generate acoustic waves that propagate through the walls of these tubes, which can be captured by accelerometers or by acoustic emission sensors. The knowledge of how these walls can vibrate, or in another way, how these acoustic waves propagate in this material is fundamental in the detection and localization process of the leak source. In this work an analytic model was implemented, through the motion equations of a cylindrical shell, with the objective to understand the behavior of the tube surface excited by a point source. Since the cylindrical surface has a closed pattern in the circumferential direction, waves that are beginning their trajectory will meet with another that has already completed the turn over the cylindrical shell, in the clockwise direction as well as in the counter clockwise direction, generating constructive and destructive interferences. After enough time of propagation, peaks and valleys in the shell surface are formed, which can be visualized through a graphic representation of the analytic solution created. The theoretical results were proven through measures accomplished in an experimental setup composed of a steel tube finished in sand box, simulating the condition of infinite tube. To determine the location of the point source on the surface, the process of inverse solution was adopted, that is to say, known the signals of the sensor disposed in the tube surface , it is determined through the theoretical model where the source that generated these signals can be. (author)
Surface properties and corrosion behavior of Co-Cr alloy fabricated with selective laser melting technique.

Science.gov (United States)

Xin, Xian-zhen; Chen, Jie; Xiang, Nan; Wei, Bin

2013-01-01

We sought to study the corrosion behavior and surface properties of a commercial cobalt-chromium (Co-Cr) alloy which was fabricated with selective laser melting (SLM) technique. For this purpose, specimens were fabricated using different techniques, such as SLM system and casting methods. Surface hardness testing, microstructure observation, surface analysis using X-ray photoelectron spectroscopy (XPS) and electrochemical corrosion test were carried out to evaluate the corrosion properties and surface properties of the specimens. We found that microstructure of SLM specimens was more homogeneous than that of cast specimens. The mean surface hardness values of SLM and cast specimens were 458.3 and 384.8, respectively; SLM specimens showed higher values than cast ones in hardness. Both specimens exhibited no differences in their electrochemical corrosion properties in the artificial saliva through potentiodynamic curves and EIS, and no significant difference via XPS. Therefore, we concluded that within the scope of this study, SLM-fabricated restorations revealed good surface properties, such as proper hardness, homogeneous microstructure, and also showed sufficient corrosion resistance which could meet the needs of dental clinics.
Controlling the Adhesion of Superhydrophobic Surfaces Using Electrolyte Jet Machining Techniques

Science.gov (United States)

Yang, Xiaolong; Liu, Xin; Lu, Yao; Zhou, Shining; Gao, Mingqian; Song, Jinlong; Xu, Wenji

2016-01-01

Patterns with controllable adhesion on superhydrophobic areas have various biomedical and chemical applications. Electrolyte jet machining technique (EJM), an electrochemical machining method, was firstly exploited in constructing dimples with various profiles on the superhydrophobic Al alloy surface using different processing parameters. Sliding angles of water droplets on those dimples firstly increased and then stabilized at a certain value with the increase of the processing time or the applied voltages of the EJM, indicating that surfaces with different adhesion force could be obtained by regulating the processing parameters. The contact angle hysteresis and the adhesion force that restricts the droplet from sliding off were investigated through experiments. The results show that the adhesion force could be well described using the classical Furmidge equation. On account of this controllable adhesion force, water droplets could either be firmly pinned to the surface, forming various patterns or slide off at designed tilting angles at specified positions on a superhydrophobic surface. Such dimples on superhydrophopbic surfaces can be applied in water harvesting, biochemical analysis and lab-on-chip devices. PMID:27046771
Surface analysis of anodized aluminum clamps from NASA-LDEF satellite

Science.gov (United States)

Grammer, H. L.; Wightman, J. P.; Young, Philip R.

1992-01-01

Surface analysis results of selected anodized aluminum clamps containing black (Z306) and white (A276) paints which received nearly six years of Low Earth Orbit (LEO) exposure on the Long Duration Exposure Facility are reported. Surface analytical techniques, including x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and scanning electron microscopy/energy dispersive analysis by x-ray (SEM/EDAX), showed significant differences in the surface composition of these materials depending upon the position on the LDEF. Differences in the surface composition are attributed to varying amounts of atomic oxygen and vacuum ultraviolet radiation (VUV). Silicon containing compounds were the primary contaminant detected on the materials.
The two-thumb technique using an elevated surface is preferable for teaching infant cardiopulmonary resuscitation.

Science.gov (United States)

Huynh, Trang K; Hemway, Rae Jean; Perlman, Jeffrey M

2012-10-01

To determine whether the two-thumb technique is superior to the two-finger technique for administering chest compressions using the floor surface and the preferred location for performing infant cardiopulmonary resuscitation (CPR) (ie, floor, table, or radiant warmer). Twenty Neonatal Resuscitation Program trained medical personnel performed CPR on a neonatal manikin utilizing the two-thumb vs two-finger technique, a compression to ventilation ratio of 30:2 for 2 minutes in random order on the floor, table, and radiant warmer. Compression depth favored the two-thumb over two-finger technique on the floor (27 ± 8 mm vs 23 ± 7), table (26 ± 7 mm vs 22 ± 7), and radiant warmer (29 ± 4 mm vs 23 ± 4) (all P CPR preferably using an elevated firm surface. Copyright © 2012 Mosby, Inc. All rights reserved.
Tensile bond strength of hydroxyethyl methacrylate dentin bonding agent on dentin surface at various drying techniques

Directory of Open Access Journals (Sweden)

Kun Ismiyatin

2010-06-01

Full Text Available Background: There are several dentin surface drying techniques to provide a perfect resin penetration on dentin. There are two techniques which will be compared in this study. The first technique was by rubbing dentin surface gently using cotton pellet twice, this technique is called blot dry technique. The second technique is by air blowing dentin surface for one second and continued by rubbing dentin surface gently using moist cotton. Purpose: This experiment was aimed to examine the best dentin surface drying techniques after 37% phosphoric acid etching to obtain the optimum tensile bond strength between hydroxyethyl methacrylate (HEMA and dentin surface. Method: Bovine teeth was prepared flat to obtain the dentin surface and than was etched using 37% phosphoric acid for 15 seconds. After etching the dentin was cleaned using 20 cc plain water and dried with blot dry techniques (group I, or dried with air blow for one second (group II, or dried with air blow for one second, and continued with rubbing gently using moist cotton pellet (group III, and without any drying as control group (group IV. After these drying, the dentin surfaces were applied with resin dentin bonding agent and put into plunger facing the composite mould. The antagonist plunger was filled with composite resin. After 24 hours, therefore bond strength was measured using Autograph. Result: Data obtained was analyzed using One-Way ANOVA with 95% confidence level and continued with LSD test on p≤0.05. The result showed that the highest tensile bond strength was on group I, while the lowest on group IV. Group II and IV, III and IV, II and III did not show signigicant difference (p>0.05. Conclusion: Dentin surface drying techniques through gentle rubbing using cotton pellet twice (blot dry technique gave the greatest tensile bond strength.Latar belakang masalah: Tehnik pengeringan permukaan dentin agar resin dapat penetrasi dengan sempurna adalah dengan cara pengusapan secara
Discussion meet on electroanalytical techniques and their applications

International Nuclear Information System (INIS)

Aggarwal, S.K.; Gopinath, N.; Govindan, R.

2008-02-01

Electrochemistry is truly an interdisciplinary science and plays an important role in different branches of science and technology. The present Discussion Meet on ElectroAnalytical Techniques (DM- ELANTE-2008) is focused on the update of various electroanalytical techniques which have brought out a substantial change in electroanalytical chemistry. The aim of this Discussion Meet is to provide a forum to all the electroanalytical scientists to discuss their recent findings and information, learn from the mutual experiences and interests, and to promote cooperation both nationally and internationally. It is proposed to have tutorial lectures as well as invited talks during the Discussion Meet on various electroanalytical techniques including Electrochemical Impedance Spectroscopy (EIS), Spectro-electrochemistry, Scanning Electrochemical Microscopy (SECM), Electrochemical Quartz Crystal Microbalance (EQCM), Surface Plasmon Resonance (SPR) etc. Papers relevant to INIS are indexed separately
Virtual-stereo fringe reflection technique for specular free-form surface testing

Science.gov (United States)

Ma, Suodong; Li, Bo

2016-11-01

Due to their excellent ability to improve the performance of optical systems, free-form optics have attracted extensive interest in many fields, e.g. optical design of astronomical telescopes, laser beam expanders, spectral imagers, etc. However, compared with traditional simple ones, testing for such kind of optics is usually more complex and difficult which has been being a big barrier for the manufacture and the application of these optics. Fortunately, owing to the rapid development of electronic devices and computer vision technology, fringe reflection technique (FRT) with advantages of simple system structure, high measurement accuracy and large dynamic range is becoming a powerful tool for specular free-form surface testing. In order to obtain absolute surface shape distributions of test objects, two or more cameras are often required in the conventional FRT which makes the system structure more complex and the measurement cost much higher. Furthermore, high precision synchronization between each camera is also a troublesome issue. To overcome the aforementioned drawback, a virtual-stereo FRT for specular free-form surface testing is put forward in this paper. It is able to achieve absolute profiles with the help of only one single biprism and a camera meanwhile avoiding the problems of stereo FRT based on binocular or multi-ocular cameras. Preliminary experimental results demonstrate the feasibility of the proposed technique.
Ultrasensitive probing of the protein resistance of PEG surfaces by secondary ion mass spectrometry

DEFF Research Database (Denmark)

Kingshott, P.; McArthur, S.; Thissen, H.

2002-01-01

The highly sensitive surface analytical techniques X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectrometry (ToF-SIMS) were used to test the resistance of poly(ethylene glycol) (PEG) coatings towards adsorption of lysozyme (LYS) and fibronectin (FN). PEG co...
Discourse-Centric Learning Analytics: Mapping the Terrain

Science.gov (United States)

Knight, Simon; Littleton, Karen

2015-01-01

There is an increasing interest in developing learning analytic techniques for the analysis, and support of, high-quality learning discourse. This paper maps the terrain of discourse-centric learning analytics (DCLA), outlining the distinctive contribution of DCLA and outlining a definition for the field moving forwards. It is our claim that DCLA…
Surface enhanced Raman spectroscopy on a flat graphene surface

Science.gov (United States)

Xu, Weigao; Ling, Xi; Xiao, Jiaqi; Dresselhaus, Mildred S.; Kong, Jing; Xu, Hongxing; Liu, Zhongfan; Zhang, Jin

2012-01-01

Surface enhanced Raman spectroscopy (SERS) is an attractive analytical technique, which enables single-molecule sensitive detection and provides its special chemical fingerprints. During the past decades, researchers have made great efforts towards an ideal SERS substrate, mainly including pioneering works on the preparation of uniform metal nanostructure arrays by various nanoassembly and nanotailoring methods, which give better uniformity and reproducibility. Recently, nanoparticles coated with an inert shell were used to make the enhanced Raman signals cleaner. By depositing SERS-active metal nanoislands on an atomically flat graphene layer, here we designed a new kind of SERS substrate referred to as a graphene-mediated SERS (G-SERS) substrate. In the graphene/metal combined structure, the electromagnetic “hot” spots (which is the origin of a huge SERS enhancement) created by the gapped metal nanoislands through the localized surface plasmon resonance effect are supposed to pass through the monolayer graphene, resulting in an atomically flat hot surface for Raman enhancement. Signals from a G-SERS substrate were also demonstrated to have interesting advantages over normal SERS, in terms of cleaner vibrational information free from various metal-molecule interactions and being more stable against photo-induced damage, but with a comparable enhancement factor. Furthermore, we demonstrate the use of a freestanding, transparent and flexible “G-SERS tape” (consisting of a polymer-layer-supported monolayer graphene with sandwiched metal nanoislands) to enable direct, real time and reliable detection of trace amounts of analytes in various systems, which imparts high efficiency and universality of analyses with G-SERS substrates. PMID:22623525
Analytical chemistry

International Nuclear Information System (INIS)

Anon.

1985-01-01

The division for Analytical Chemistry continued to try and develope an accurate method for the separation of trace amounts from mixtures which, contain various other elements. Ion exchange chromatography is of special importance in this regard. New separation techniques were tried on certain trace amounts in South African standard rock materials and special ceramics. Methods were also tested for the separation of carrier-free radioisotopes from irradiated cyclotron discs
Enabling Analytics on Sensitive Medical Data with Secure Multi-Party Computation.

Science.gov (United States)

Veeningen, Meilof; Chatterjea, Supriyo; Horváth, Anna Zsófia; Spindler, Gerald; Boersma, Eric; van der Spek, Peter; van der Galiën, Onno; Gutteling, Job; Kraaij, Wessel; Veugen, Thijs

2018-01-01

While there is a clear need to apply data analytics in the healthcare sector, this is often difficult because it requires combining sensitive data from multiple data sources. In this paper, we show how the cryptographic technique of secure multi-party computation can enable such data analytics by performing analytics without the need to share the underlying data. We discuss the issue of compliance to European privacy legislation; report on three pilots bringing these techniques closer to practice; and discuss the main challenges ahead to make fully privacy-preserving data analytics in the medical sector commonplace.
Direct analyte-probed nanoextraction coupled to nanospray ionization-mass spectrometry of drug residues from latent fingerprints.

Science.gov (United States)

Clemons, Kristina; Wiley, Rachel; Waverka, Kristin; Fox, James; Dziekonski, Eric; Verbeck, Guido F

2013-07-01

Here, we present a method of extracting drug residues from fingerprints via Direct Analyte-Probed Nanoextraction coupled to nanospray ionization-mass spectrometry (DAPNe-NSI-MS). This instrumental technique provides higher selectivity and lower detection limits over current methods, greatly reducing sample preparation, and does not compromise the integrity of latent fingerprints. This coupled to Raman microscopy is an advantageous supplement for location and identification of trace particles. DAPNe uses a nanomanipulator for extraction and differing microscopies for localization of chemicals of interest. A capillary tip with solvent of choice is placed in a nanopositioner. The surface to be analyzed is placed under a microscope, and a particle of interest is located. Using a pressure injector, the solvent is injected onto the surface where it dissolves the analyte, and then extracted back into the capillary tip. The solution is then directly analyzed via NSI-MS. Analyses of caffeine, cocaine, crystal methamphetamine, and ecstasy have been performed successfully. © 2013 American Academy of Forensic Sciences.
Applicability of analytical instrument in trace evidence analysis

International Nuclear Information System (INIS)

Sharma, Mukesh; Jha, Shailendra

2014-01-01

In the present paper, we explain the importance of the analytical instrument used in the field of forensic science for the analysis of the trace evidences collected from the scene of occurrence. The forensic scientist has to rely upon these instrumental analyses of trace amounts of materials like drugs, toxicological specimens, GSR, fibres, glass, paints, soil etc. Through this paper, reviews on these techniques which are extensively used in forensic sciences are reported. Our report summaries on the basis of analytical problem facing for a forensic expert and techniques employed to tackle them like XRD/XRF, inductively coupled plasma (ICP) techniques, Raman spectroscopy and microscopy (optical, GRIM, electron microscopy, TEM). (author)
A novel and inexpensive technique for creating superhydrophobic surfaces using Teflon and sandpaper

Science.gov (United States)

Nilsson, Michael A.; Daniello, Robert J.; Rothstein, Jonathan P.

2010-02-01

Considerable efforts have been spent over the last decade developing hydrophobic surfaces exhibiting very large contact angles with water. Many of these methods require complex and expensive fabrication techniques. We demonstrate that sanding Teflon can produce superhydrophobic surfaces with advancing contact angles of up to 151° and contact angle hysteresis of less than 4°. Furthermore, we show that a wide range of both advancing contact angles and contact angle hysteresis can be achieved by varying the grit size of the sandpaper, allowing for future hysteresis and contact angle studies. Scanning electron microscopy images of the roughened surfaces depict the range and amplitude of length scales imparted on the surface by the sandpaper, which leads to deeper understanding of the state of wetting on the surface.
Comparison of experimental target currents with analytical model results for plasma immersion ion implantation

International Nuclear Information System (INIS)

En, W.G.; Lieberman, M.A.; Cheung, N.W.

1995-01-01

Ion implantation is a standard fabrication technique used in semiconductor manufacturing. Implantation has also been used to modify the surface properties of materials to improve their resistance to wear, corrosion and fatigue. However, conventional ion implanters require complex optics to scan a narrow ion beam across the target to achieve implantation uniformity. An alternative implantation technique, called Plasma Immersion Ion Implantation (PIII), immerses the target into a plasma. The ions are extracted from the plasma directly and accelerated by applying negative high-voltage pulses to the target. An analytical model of the voltage and current characteristics of a remote plasma is presented. The model simulates the ion, electron and secondary electron currents induced before, during and after a high voltage negative pulse is applied to a target immersed in a plasma. The model also includes analytical relations that describe the sheath expansion and collapse due to negative high voltage pulses. The sheath collapse is found to be important for high repetition rate pulses. Good correlation is shown between the model and experiment for a wide variety of voltage pulses and plasma conditions
Surface modification of polyacrylonitrile fiber for immobilization of antibodies and detection of analyte

Energy Technology Data Exchange (ETDEWEB)

Jain, Swati, E-mail: swatijain.iitd@gmail.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India); Chattopadhyay, Sruti, E-mail: srutic@hotmail.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India); Jackeray, Richa, E-mail: richajackeray.iitd@gmail.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India); Singh, Harpal, E-mail: harpal2000@yahoo.com [Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, 110016 (India)

2009-11-10

Pendent nitrile groups of multifilamentous polyacrylonitrile (PAN) fibers were reduced to amino groups using lithium aluminum hydride for different time of reduction and amine content was estimated by performing acid-base titrations. Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) were used for the characterization of the generated amino groups and thermal properties of the reduced fibers, respectively. The surface morphology of the fibers after reduction and immobilization was characterized using Scanning Electron Microscope (SEM). The newly formed amino groups of the fibers were activated by using glutaraldehyde for the covalent linking of Goat anti-Rabbit IgG-HRP (GAR-HRP) antibody enzyme conjugate. Modified PAN fibers were evaluated as a matrix for sandwich ELISA by using Goat anti-Rabbit antibody (GAR-IgG), Rabbit anti-Goat (RAG-IgG) as analyte and enzyme conjugate GAR-HRP. The fibers reduced for 24 h were able to detect the analyte RAG-IgG at a concentration as low as 3.75 ng mL{sup -1} with 12% skimmed milk as blocking reagent for the optimized concentration of primary antibody GAR-IgG 3 {mu}g mL{sup -1} and peroxidase conjugate GAR-HRP dilution of 8000 fold. The sensitivity, specificity and reproducibility of the developed immunoassay was further established with antibodies present in human blood using Rabbit anti-Human (RAH-IgG) antibody and the corresponding HRP enzyme conjugate. As low as 0.1 {mu}L of human blood was sufficient to perform the assay with the modified fibers.
Analytic continuation by duality estimation of the S parameter

International Nuclear Information System (INIS)

Ignjatovic, S. R.; Wijewardhana, L. C. R.; Takeuchi, T.

2000-01-01

We investigate the reliability of the analytic continuation by duality (ACD) technique in estimating the electroweak S parameter for technicolor theories. The ACD technique, which is an application of finite energy sum rules, relates the S parameter for theories with unknown particle spectra to known OPE coefficients. We identify the sources of error inherent in the technique and evaluate them for several toy models to see if they can be controlled. The evaluation of errors is done analytically and all relevant formulas are provided in appendixes including analytical formulas for approximating the function 1/s with a polynomial in s. The use of analytical formulas protects us from introducing additional errors due to numerical integration. We find that it is very difficult to control the errors even when the momentum dependence of the OPE coefficients is known exactly. In realistic cases in which the momentum dependence of the OPE coefficients is only known perturbatively, it is impossible to obtain a reliable estimate. (c) 2000 The American Physical Society

Analytical modeling of split-gate junction-less transistor for a biosensor application

Directory of Open Access Journals (Sweden)

Shradhya Singh

2018-04-01

Full Text Available This paper represents the analytical modeling of split-gate Dielectric Modulated Junction Less Transistor (JLT for label free electrical detection of bio molecules. Some part of the channel region is opened for providing the binding sites for the bio molecules unlike conventional MOSFET which is enclosed with the gate electrode. Due to this open area, the surface potential of this region affected by the charged and neutral bio molecules immobilized to the open region of channel. Surface potential of the channel region obtained by solving two-Dimensional Poisson's equation by potential profile having parabolic nature through channel region using technique called conformal mapping. By deriving the surface potential model, derivation of threshold model can also be done. For the detection of bio molecule, variation in to the threshold voltage due to binding of bio molecule in the gate underlap region is the sensing metric.
A study on environmental pollution monitoring and occupational health in the Capital Iron and Steel Company, Beijing, China, using nuclear and related analytical techniques

International Nuclear Information System (INIS)

Chai Zhifang; Qian Qinfang; Feng Xiangqian; Ding Wenjun; Kuang Minxu; Wang Hongyu; Zhang Yongchen

2000-01-01

Since the First Research Coordination Meeting in Vienna, 20-24 October 1997, on the CRP on Assessment of Levels and Health-effects of Airborne Particulate Matter in Mining, Metal Refining and Metal Working Industries using Nuclear and related Analytical Techniques, our research group has completed the work plan defined by the contract with the Agency, including: (1) collection of airborne particulate, plant and soil samples from sites around the Capital Iron and Steel Company and of human hair, urine, and blood samples from the exposed workers and the control group; (2) validation of the analytical methods (NAA, XRF, SRXRF, JCP-AES etc.) by analyzing appropriate reference materials and by participating in relevant Agency's quality assurance exercises; and (3) analysis of part of the collected samples and preliminary discussion on the available analytical results. Finally, plan for future work was outlined as well. (author)
Analytical study of nonlinear phase shift through stimulated Brillouin scattering in single mode fiber with the pump power recycling technique

International Nuclear Information System (INIS)

Al-Asadi, H A; Mahdi, M A; Bakar, A A A; Adikan, F R Mahamd

2011-01-01

We present a theoretical study of nonlinear phase shift through stimulated Brillouin scattering in single mode optical fiber. Analytical expressions describing the nonlinear phase shift for the pump and Stokes waves in the pump power recycling technique have been derived. The dependence of the nonlinear phase shift on the optical fiber length, the reflectivity of the optical mirror and the frequency detuning coefficient have been analyzed for different input pump power values. We found that with the recycling pump technique, the nonlinear phase shift due to stimulated Brillouin scattering reduced to less than 0.1 rad for 5 km optical fiber length and 0.65 reflectivity of the optical mirror, respectively, at an input pump power equal to 30 mW
Thermodynamics and structure of liquid surfaces investigated directly with surface analytical tools

Energy Technology Data Exchange (ETDEWEB)

Andersson, Gunther [Flinders Univ., Adelaide, SA (Australia). Centre for NanoScale Science and Technology; Morgner, Harald [Leipzig Univ. (Germany). Wilhelm Ostwald Inst. for Physical and Theoretical Chemistry

2017-06-15

Measuring directly the composition, the distribution of constituents as function of the depth and the orientation of molecules at liquid surfaces is essential for determining physicochemical properties of liquid surfaces. While the experimental tools that have been developed for analyzing solid surfaces can in principal be applied to liquid surfaces, it turned out that they had to be adjusted to the particular challenges imposed by liquid samples, e.g. by the unavoidable vapor pressure and by the mobility of the constituting atoms/molecules. In the present work it is shown, how electron spectroscopy and ion scattering spectroscopy have been used for analyzing liquid surfaces. The emphasis of this review is on using the structural information gained for determining the physicochemical properties of liquid surfaces. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
New analytical technique for carbon dioxide absorption solvents

Energy Technology Data Exchange (ETDEWEB)

Pouryousefi, F.; Idem, R.O. [University of Regina, Regina, SK (Canada). Faculty of Engineering

2008-02-15

The densities and refractive indices of two binary systems (water + MEA and water + MDEA) and three ternary systems (water + MEA + CO{sub 2}, water + MDEA + CO{sub 2}, and water + MEA + MDEA) used for carbon dioxide (CO{sub 2}) capture were measured over the range of compositions of the aqueous alkanolamine(s) used for CO{sub 2} absorption at temperatures from 295 to 338 K. Experimental densities were modeled empirically, while the experimental refractive indices were modeled using well-established models from the known values of their pure-component densities and refractive indices. The density and Gladstone-Dale refractive index models were then used to obtain the compositions of unknown samples of the binary and ternary systems by simultaneous solution of the density and refractive index equations. The results from this technique have been compared with HPLC (high-performance liquid chromatography) results, while a third independent technique (acid-base titration) was used to verify the results. The results show that the systems' compositions obtained from the simple and easy-to-use refractive index/density technique were very comparable to the expensive and laborious HPLC/titration techniques, suggesting that the refractive index/density technique can be used to replace existing methods for analysis of fresh or nondegraded, CO{sub 2}-loaded, single and mixed alkanolamine solutions.
Analytical aids in land management planning

Science.gov (United States)

David R. Betters

1978-01-01

Quantitative techniques may be applied to aid in completing various phases of land management planning. Analytical procedures which have been used include a procedure for public involvement, PUBLIC; a matrix information generator, MAGE5; an allocation procedure, linear programming (LP); and an input-output economic analysis (EA). These techniques have proven useful in...
Analytical Chemistry Laboratory: Progress report for FY 1988

International Nuclear Information System (INIS)

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.; Lindahl, P.C.; Erickson, M.D.

1988-12-01

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for fiscal year 1988 (October 1987 through September 1988). The Analytical Chemistry Laboratory is a full-cost recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques
Analytical Chemistry Laboratory progress report for FY 1989

International Nuclear Information System (INIS)

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.; Lindahl, P.C.; Erickson, M.D.

1989-12-01

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1989 (October 1988 through September 1989). The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques
Analytical Chemistry Laboratory: Progress report for FY 1988

Energy Technology Data Exchange (ETDEWEB)

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.; Lindahl, P.C.; Erickson, M.D.

1988-12-01

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for fiscal year 1988 (October 1987 through September 1988). The Analytical Chemistry Laboratory is a full-cost recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques.
VLF surface-impedance modelling techniques for coal exploration

Energy Technology Data Exchange (ETDEWEB)

Wilson, G.; Thiel, D.; O' Keefe, S. [Central Queensland University, Rockhampton, Qld. (Australia). Faculty of Engineering and Physical Systems

2000-10-01

New and efficient computational techniques are required for geophysical investigations of coal. This will allow automated inverse analysis procedures to be used for interpretation of field data. In this paper, a number of methods of modelling electromagnetic surface impedance measurements are reviewed, particularly as applied to typical coal seam geology found in the Bowen Basin. At present, the Impedance method and the finite-difference time-domain (FDTD) method appear to offer viable solutions although both have problems. The Impedance method is currently slightly inaccurate, and the FDTD method has large computational demands. In this paper both methods are described and results are presented for a number of geological targets. 17 refs., 14 figs.
Innovative Technique for High-Accuracy Remote Monitoring of Surface Water

Science.gov (United States)

Gisler, A.; Barton-Grimley, R. A.; Thayer, J. P.; Crowley, G.

2016-12-01

Lidar (light detection and ranging) provides absolute depth and topographic mapping capability compared to other remote sensing methods, which is useful for mapping rapidly changing environments such as riverine systems and agricultural waterways. Effectiveness of current lidar bathymetric systems is limited by the difficulty in unambiguously identifying backscattered lidar signals from the water surface versus the bottom, limiting their depth resolution to 0.3-0.5 m. Additionally these are large, bulky systems that are constrained to expensive aircraft-mounted platforms and use waveform-processing techniques requiring substantial computation time. These restrictions are prohibitive for many potential users. A novel lidar device has been developed that allows for non-contact measurements of water depth down to 1 cm with an accuracy and precision of shallow to deep water allowing for shoreline charting, measuring water volume, mapping bottom topology, and identifying submerged objects. The scalability of the technique opens up the ability for handheld or UAS-mounted lidar bathymetric systems, which provides for potential applications currently unavailable to the community. The high laser pulse repetition rate allows for very fine horizontal resolution while the photon-counting technique permits real-time depth measurement and object detection. The enhanced measurement capability, portability, scalability, and relatively low-cost creates the opportunity to perform frequent high-accuracy monitoring and measuring of aquatic environments which is crucial for monitoring water resources on fast timescales. Results from recent campaigns measuring water depth in flowing creeks and murky ponds will be presented which demonstrate that the method is not limited by rough water surfaces and can map underwater topology through moderately turbid water.
Structural level characterization of base oils using advanced analytical techniques

KAUST Repository

Hourani, Nadim

2015-05-21

Base oils, blended for finished lubricant formulations, are classified by the American Petroleum Institute into five groups, viz., groups I-V. Groups I-III consist of petroleum based hydrocarbons whereas groups IV and V are made of synthetic polymers. In the present study, five base oil samples belonging to groups I and III were extensively characterized using high performance liquid chromatography (HPLC), comprehensive two-dimensional gas chromatography (GC×GC), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) equipped with atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) sources. First, the capabilities and limitations of each analytical technique were evaluated, and then the availed information was combined to reveal compositional details on the base oil samples studied. HPLC showed the overwhelming presence of saturated over aromatic compounds in all five base oils. A similar trend was further corroborated using GC×GC, which yielded semiquantitative information on the compound classes present in the samples and provided further details on the carbon number distributions within these classes. In addition to chromatography methods, FT-ICR MS supplemented the compositional information on the base oil samples by resolving the aromatics compounds into alkyl- and naphtheno-subtituted families. APCI proved more effective for the ionization of the highly saturated base oil components compared to APPI. Furthermore, for the detailed information on hydrocarbon molecules FT-ICR MS revealed the presence of saturated and aromatic sulfur species in all base oil samples. The results presented herein offer a unique perspective into the detailed molecular structure of base oils typically used to formulate lubricants. © 2015 American Chemical Society.
Challenges of Using Learning Analytics Techniques to Support Mobile Learning

Science.gov (United States)

Arrigo, Marco; Fulantelli, Giovanni; Taibi, Davide

2015-01-01

Evaluation of Mobile Learning remains an open research issue, especially as regards the activities that take place outside the classroom. In this context, Learning Analytics can provide answers, and offer the appropriate tools to enhance Mobile Learning experiences. In this poster we introduce a task-interaction framework, using learning analytics…
Effects of different polishing techniques on the surface roughness of dental porcelains

Directory of Open Access Journals (Sweden)

Işil Sarikaya

2010-02-01

Full Text Available OBJECTIVE: The purpose of this study was to evaluate the effects of different polishing techniques on the surface roughness of dental porcelains. MATERIAL AND METHODS: Fifty-five cylindirical specimens (15x2 mm were prepared for each feldspathic (Vita VMK 95, Ceramco III and low-fusing dental porcelain (Matchmaker. Fifty-five specimens of machinable feldspathic porcelain blocks (Vitablocs Mark II, (12x14x18 mm were cut into 2-mm-thick slices (12x14 mm with low speed saw. The prepared specimens were divided into 11 groups (n=5 representing different polishing techniques including control ((C no surface treatment, glaze (G and other 9 groups that were finished and polished with polishing discs (Sof-Lex (Sl, two porcelain polishing kits (NTI (Pk, Dialite II (Di, a diamond polishing paste (Sparkle (Sp, a zirconium silicate based cleaning and polishing prophy paste (Zircate (Zr, an aluminum oxide polishing paste (Prisma Gloss (Pg, and combinations of them. The surface roughness of all groups was measured with a profilometer. The data were analyzed with a 2-way analysis of variance, and the mean values were compared by the Tukey Honestly Significant Difference test (a=0.05. RESULTS: For all porcelain material groups, the lowest Ra values were observed in Group Gl, Group Sl, Group Pk, and Group Di, which were not significantly different from each other (p>0.05.When comparing the 4 different porcelain materials, the machinable feldspathic porcelain block group (Mark II demonstrated statistically significantly less Ra values than the other porcelain materials tested (p<0.05. No significant difference was observed between the VMK 95 and Ceramco III porcelain groups (p=0.919, also these groups demonstrated the highest Ra values. CONCLUSION: Subjected to surface roughness, the surfaces obtained with polishing and/or cleaning-prophy paste materials used alone were rougher compared to the surfaces finished using Sof-lex, Dialite, and NTI polishing kit
Identification and characterization of surface antigens in parasites, using radiolabelling techniques

International Nuclear Information System (INIS)

Ramasamy, R.

1982-04-01

Surface proteins of Schistosoma sp and Leishmania sp were studied using 125-Iodine as tracer. The surface proteins were labelled by the Lactoperoxidase method and the proteins then separated using SDS PAG electrophoresis and autoradiography. The possible immunogens were then separated using immunoprecipitation and Fluorescent Antibody techniques using sera from patients or from artificially immunized rabbits. Four common antigens were identified from the surfaces of male and female adult worms, cercariae and schistosomulae of S.mansoni. These antigens, which had molecular weights of 150,000, 78,000, 45,000, and 22,000 were also isolated from the surfaces of S.haematobium adults. The surface antigens on promastigotes of a Kenyan strain of Leishmania donovani were separated into three protein antigens with molecular weights of 66,000, 59,000 and 43,000 respectively. The 59,000 molecular weight antigen was a glycoprotein and was common to promastigotes of an American and Indian strain of L.donovani and to L.braziliensis mexicana. None of the isolated antigens have been shown to have a protective effect when vaccinated into mice, but the study illustrates the value of radionuclide tracers in the unravelling of the mosaic of antigens which parasites possess
Assessment of levels and 'health-effects' of airborne particulate matter in mining, metal refining and metal working industries using nuclear and related analytical techniques

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-01-15

The International Atomic Energy Agency (IAEA) has been supporting, over the years, several coordinated research programmes (CRPs) on various research topics related to environmental issues impacting human health. A variety of industrial environments such as: galvanisation, iron and steel production, steel construction, coal fired thermal power plants, mining and mineral beneficiation of monazite, zinc smelters, and phosphate fertilizer production plants were included in this CRP. Toxic elements specific for particular industries as potential pollutants were monitored within individual projects. The CRP focussed on the use of nuclear and related analytical techniques for studies of exposure to inorganic constituents and radionuclides from naturally occurring radioactive materials (NORMs), in the workplaces and their impacts on the health of the workers. The objectives were to: develop strategies and techniques for sampling of workplace airborne particulate matter (APM) and of bio-markers (e.g. hair, blood, nails, teeth, urine, breath) of exposed and non-exposed individuals; develop reliable analytical procedures for the analysis of such samples, using nuclear and related analytical techniques; carry out workplace and personal monitoring surveys, and assess workers' exposure to toxic elements on the basis of measurements results. This document provides an overview of the activities performed under the CRP by the participants. The overall achievements are summarized and those aspects that require a further deeper look are also pointed out. The individual country reports include details on the progress made by the respective participants during the CRP period.
Microstructure Characterization and Hardness Evaluation of Alloy 52 Welded Stainless Steel 316 Subjected to Ultrasonic Nanocyrtal Surface Modification Technique

Energy Technology Data Exchange (ETDEWEB)

Kim, H. D.; Amanov, A.; Pyun, Y. S. [Sun Moon Univ., Asan (Korea, Republic of); Kim, Y. S.; Choi, Y. S. [Andong National Univ., Andong (Korea, Republic of)

2015-10-15

In this study, an ultrasonic nanocrystal surface modification (UNSM) technique was applied to dissimilar weld point between STS316L and Alloy 52. This UNSM technique is a patented technology, which can be described as a type of ultrasonic cold-forging technology. It has been demonstrated that the UNSM technique is a simple method to produce a nanocrystalline surface layer at the top surface of metallic materials. Microstructure and hardness of STS316L and Alloy 52 are investigated before and after UNSM treatment. It is expected according to the previous study that the UNSM technique is able to release the residual stress which delays PWSCC. In this study, microstructural characterization and hardness evaluation of STS316L and welded Alloy 52 subjected to UNSM technique were investigated.
Analytical techniques for the study of polyphenol-protein interactions.

Science.gov (United States)

Poklar Ulrih, Nataša

2017-07-03

This mini review focuses on advances in biophysical techniques to study polyphenol interactions with proteins. Polyphenols have many beneficial pharmacological properties, as a result of which they have been the subject of intensive studies. The most conventional techniques described here can be divided into three groups: (i) methods used for screening (in-situ methods); (ii) methods used to gain insight into the mechanisms of polyphenol-protein interactions; and (iii) methods used to study protein aggregation and precipitation. All of these methods used to study polyphenol-protein interactions are based on modifications to the physicochemical properties of the polyphenols or proteins after binding/complex formation in solution. To date, numerous review articles have been published in the field of polyphenols. This review will give a brief insight in computational methods and biosensors and cell-based methods, spectroscopic methods including fluorescence emission, UV-vis adsorption, circular dichroism, Fourier transform infrared and mass spectrometry, nuclear magnetic resonance, X-ray diffraction, and light scattering techniques including small-angle X-ray scattering and small-angle neutron scattering, and calorimetric techniques (isothermal titration calorimetry and differential scanning calorimetry), microscopy, the techniques which have been successfully used for polyphenol-protein interactions. At the end the new methods based on single molecule detection with high potential to study polyphenol-protein interactions will be presented. The advantages and disadvantages of each technique will be discussed as well as the thermodynamic, kinetic or structural parameters, which can be obtained. The other relevant biophysical experimental techniques that have proven to be valuable, such electrochemical methods, hydrodynamic techniques and chromatographic techniques will not be described here.
Side-by-side comparison of analytical techniques; organic acids, total organic carbon, and anions in PWR secondary cycles

International Nuclear Information System (INIS)

Hobart, S.A.; Byers, W.A.; Miller, M.R.; Richards, J.; Silva, H.; Palino, G.F.; Wall, P.S.

1986-01-01

Total Organic Carbon TOC samples should be analyzed no later than one week after they are taken and they should be stored in a refrigerated condition, if at all possible. It can be inferred that for TOC levels in the range of 50 to 120 ppb, state-of-the-art sampling and analysis techniques can produce results varying by 20 to 50 ppb. Any proposed limits for TOC should be reviewed in that light. Agreement between anion results appeared to improve over the course of the project. Both contractors agree that increased attention and care with sampling and analytical techniques probably accounted for this improvement. Utility personnel can therefore conclude that proper employee training, supervision, and motivation for proper sampling and analysis are critical if accurate anion results are to be obtained. Resonable agreement between calculated and measured values of cation conductivity suggest that both contractors had accurately determined all major anionic species
Negations in syllogistic reasoning: evidence for a heuristic-analytic conflict.

Science.gov (United States)

Stupple, Edward J N; Waterhouse, Eleanor F

2009-08-01

An experiment utilizing response time measures was conducted to test dominant processing strategies in syllogistic reasoning with the expanded quantifier set proposed by Roberts (2005). Through adding negations to existing quantifiers it is possible to change problem surface features without altering logical validity. Biases based on surface features such as atmosphere, matching, and the probability heuristics model (PHM; Chater & Oaksford, 1999; Wetherick & Gilhooly, 1995) would not be expected to show variance in response latencies, but participant responses should be highly sensitive to changes in the surface features of the quantifiers. In contrast, according to analytic accounts such as mental models theory and mental logic (e.g., Johnson-Laird & Byrne, 1991; Rips, 1994) participants should exhibit increased response times for negated premises, but not be overly impacted upon by the surface features of the conclusion. Data indicated that the dominant response strategy was based on a matching heuristic, but also provided evidence of a resource-demanding analytic procedure for dealing with double negatives. The authors propose that dual-process theories offer a stronger account of these data whereby participants employ competing heuristic and analytic strategies and fall back on a heuristic response when analytic processing fails.

A technique for the geometric modeling of underground surfaces: Nevada Nuclear Waste Storage Investigations Project

International Nuclear Information System (INIS)

Williams, R.L.

1988-03-01

There is a need within the Nevada Nuclear Waste Storage Investigation (NNWSI) project to develop three-dimensional surface definitions for the subterranean stratigraphies at Yucca Mountain, Nevada. The nature of the data samples available to the project require an interpolation technique that can perform well with sparse and irregularly spaced data. Following an evaluation of the relevant existing methods, a new technique, Multi-Kernel Modulation (MKM), is presented. MKM interpolates sparse and irregularly spaced data by modulating a polynomial trend surface with a linear summation of regular surfaces (kernels). A perspective discussion of MKM, Kriging, and Multiquadric Analysis reveals that MKM has the advantage of simplicity and efficiency when used with sparse samples. An example of the use of MKM to model a complex topography is presented. 24 refs., 6 figs., 2 tabs
A semi-analytical iterative technique for solving chemistry problems

Directory of Open Access Journals (Sweden)

Majeed Ahmed AL-Jawary

2017-07-01

Full Text Available The main aim and contribution of the current paper is to implement a semi-analytical iterative method suggested by Temimi and Ansari in 2011 namely (TAM to solve two chemical problems. An approximate solution obtained by the TAM provides fast convergence. The current chemical problems are the absorption of carbon dioxide into phenyl glycidyl ether and the other system is a chemical kinetics problem. These problems are represented by systems of nonlinear ordinary differential equations that contain boundary conditions and initial conditions. Error analysis of the approximate solutions is studied using the error remainder and the maximal error remainder. Exponential rate for the convergence is observed. For both problems the results of the TAM are compared with other results obtained by previous methods available in the literature. The results demonstrate that the method has many merits such as being derivative-free, and overcoming the difficulty arising in calculating Adomian polynomials to handle the non-linear terms in Adomian Decomposition Method (ADM. It does not require to calculate Lagrange multiplier in Variational Iteration Method (VIM in which the terms of the sequence become complex after several iterations, thus, analytical evaluation of terms becomes very difficult or impossible in VIM. No need to construct a homotopy in Homotopy Perturbation Method (HPM and solve the corresponding algebraic equations. The MATHEMATICA® 9 software was used to evaluate terms in the iterative process.
Proceedings of the 11. ENQA: Brazilian meeting on analytical chemistry. Challenges for analytical chemistry in the 21st century. Book of Abstracts

International Nuclear Information System (INIS)

2001-01-01

The 11th National Meeting on Analytical Chemistry was held from 18 to 21 September, 2001 at the Convention Center of UNICAMP, with the theme Challenges for Analytical Chemistry in the 21st Century. This meeting have discussed on the development of new methods and analytical tools needed to solve new challenges. The papers presented topics related to the different sub-areas of Analytical Chemistry such as Environmental Chemistry; Chemiometry techniques; X-ray Fluorescence Analysis; Spectroscopy; Separation Processes; Electroanalytic Chemistry and others. Were also included lectures on the Past and Future of Analytical Chemistry and on Ethics in Science
Fatigue life extension techniques for weldments via mechanical surface post treatment

International Nuclear Information System (INIS)

Han, Seung Ho; Han, Jeong Woo; Cho, In Ho

2008-01-01

In many welded structures, fatigue failures are often occurred at welded joints in which stress concentrations due to the joint geometry are relatively high. Although employing good detail design practices by upgrading the welded detail class enables to improve the fatigue performance, in many cases, the modification of the detail may not be practicable. As an alternative, fatigue life extension techniques, that reduce the severity of the stress concentration at the weld toe region, remove imperfections, and introduce local compressive welding residual stress, can be applied. These techniques are also used as remedial measures to extend the fatigue life of critical welds that have failed prematurely and have been repaired. This paper introduces peening techniques via a pneumatic hammer peening and ultrasonic impact which make it possible to give the weld not only a favorable shape reducing the local stress concentration, but also a beneficial compressive residual stress into material surface
Approximate analytical relationships for linear optimal aeroelastic flight control laws

Science.gov (United States)

Kassem, Ayman Hamdy

1998-09-01

This dissertation introduces new methods to uncover functional relationships between design parameters of a contemporary control design technique and the resulting closed-loop properties. Three new methods are developed for generating such relationships through analytical expressions: the Direct Eigen-Based Technique, the Order of Magnitude Technique, and the Cost Function Imbedding Technique. Efforts concentrated on the linear-quadratic state-feedback control-design technique applied to an aeroelastic flight control task. For this specific application, simple and accurate analytical expressions for the closed-loop eigenvalues and zeros in terms of basic parameters such as stability and control derivatives, structural vibration damping and natural frequency, and cost function weights are generated. These expressions explicitly indicate how the weights augment the short period and aeroelastic modes, as well as the closed-loop zeros, and by what physical mechanism. The analytical expressions are used to address topics such as damping, nonminimum phase behavior, stability, and performance with robustness considerations, and design modifications. This type of knowledge is invaluable to the flight control designer and would be more difficult to formulate when obtained from numerical-based sensitivity analysis.
Self-assembly of nanosize coordination cages on si(100) surfaces.

Science.gov (United States)

Busi, Marco; Laurenti, Marco; Condorelli, Guglielmo G; Motta, Alessandro; Favazza, Maria; Fragalà, Ignazio L; Montalti, Marco; Prodi, Luca; Dalcanale, Enrico

2007-01-01

Bottom-up fabrication of 3D organic nanostructures on Si(100) surfaces has been achieved by a two-step procedure. Tetradentate cavitand 1 was grafted on the Si surface together with 1-octene (Oct) as a spatial spectator by photochemical hydrosilylation. Ligand exchange between grafted cavitand 1 and self-assembled homocage 2, derived from cavitand 5 bearing a fluorescence marker, led to the formation of coordination cages on Si(100). Formation, quantification, and distribution of the nanoscale molecular containers on a silicon surface was assessed by using three complementary analytical techniques (AFM, XPS, and fluorescence) and validated by control experiments on cavitand-free silicon surfaces. Interestingly, the fluorescence of pyrene at approximately 4 nm above the Si(100) surface can be clearly observed.
Structural Analysis of Composite Laminates using Analytical and Numerical Techniques

Directory of Open Access Journals (Sweden)

Sanghi Divya

2016-01-01

Full Text Available A laminated composite material consists of different layers of matrix and fibres. Its properties can vary a lot with each layer’s or ply’s orientation, material property and the number of layers itself. The present paper focuses on a novel approach of incorporating an analytical method to arrive at a preliminary ply layup order of a composite laminate, which acts as a feeder data for the further detailed analysis done on FEA tools. The equations used in our MATLAB are based on analytical study code and supply results that are remarkably close to the final optimized layup found through extensive FEA analysis with a high probabilistic degree. This reduces significant computing time and saves considerable FEA processing to obtain efficient results quickly. The result output by our method also provides the user with the conditions that predicts the successive failure sequence of the composite plies, a result option which is not even available in popular FEM tools. The predicted results are further verified by testing the laminates in the laboratory and the results are found in good agreement.
Analytical Chemistry Laboratory progress report for FY 1991

Energy Technology Data Exchange (ETDEWEB)

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.; Lindahl, P.C.; Boparai, A.S.

1991-12-01

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1991 (October 1990 through September 1991). This is the eighth annual report for the ACL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques.
Multi-analytical assessment of iron and steel slag characteristics to estimate the removal of metalloids from contaminated water.

Science.gov (United States)

Mercado-Borrayo, B M; Schouwenaars, R; González-Chávez, J L; Ramírez-Zamora, R M

2013-01-01

A multi-analytical approach was used to develop a mathematical regression model to calculate the residual concentration of borate ions in water present at high initial content, as a function of the main physicochemical, mineralogical and electrokinetic characteristics after adsorption on five different types of iron and steel slag. The analytical techniques applied and slag properties obtained in this work were: X-ray Fluorescence for the identification of the main chemical compounds, X-ray Diffraction to determine crystalline phases, physical adsorption of nitrogen for the quantification of textural properties and zeta-potential for electrokinetic measurements of slag particles. Adsorption tests were carried out using the bottle-point technique and a highly concentrated borate solution (700 mg B/L) at pH 10, with a slag dose of 10 g/L. An excellent correlation between the residual concentration of boron and three independent variables (content of magnesium oxide, zeta potential and specific surface area) was established for the five types of slag tested in this work. This shows that the methodology based on a multi-analytical approach is a very strong and useful tool to estimate the performance of iron and steel slag as adsorbent of metalloids.
Analytical model and error analysis of arbitrary phasing technique for bunch length measurement

Science.gov (United States)

Chen, Qushan; Qin, Bin; Chen, Wei; Fan, Kuanjun; Pei, Yuanji

2018-05-01

An analytical model of an RF phasing method using arbitrary phase scanning for bunch length measurement is reported. We set up a statistical model instead of a linear chirp approximation to analyze the energy modulation process. It is found that, assuming a short bunch (σφ / 2 π → 0) and small relative energy spread (σγ /γr → 0), the energy spread (Y =σγ 2) at the exit of the traveling wave linac has a parabolic relationship with the cosine value of the injection phase (X = cosφr|z=0), i.e., Y = AX2 + BX + C. Analogous to quadrupole strength scanning for emittance measurement, this phase scanning method can be used to obtain the bunch length by measuring the energy spread at different injection phases. The injection phases can be randomly chosen, which is significantly different from the commonly used zero-phasing method. Further, the systematic error of the reported method, such as the influence of the space charge effect, is analyzed. This technique will be especially useful at low energies when the beam quality is dramatically degraded and is hard to measure using the zero-phasing method.
uleSIMS characterization of silver reference surfaces

Science.gov (United States)

Palitsin, V. V.; Dowsett, M. G.; Mata, B. Guzmán de la; Oloff, I. W.; Gibbons, R.

2006-07-01

Ultra low energy SIMS (uleSIMS) is a high sensitivity analytical technique that is normally used for ultra shallow profiling at a depth resolution of up to1 nm. This work describes the use of uleSIMS as both a spectroscopic and depth-profiling tool for the characterization of the early stages of corrosion formed on reference surfaces of silver. These samples are being developed to help with the characterization of tarnished surfaces in a cultural heritage context, and uleSIMS enables the tarnishing to be studied from its very earliest stages due to its high sensitivity (ppm-ppb) and surface specificity. We show that, uleSIMS can be used effectively to study the surface chemistry and aid the development of reference surfaces themselves. In particular, handling contaminants, surface dust, and residues from polishing are relatively easy to identify allowing them to be separated from the parts of the mass spectrum specific to the early stages of corrosion.
Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques Using RDX and C-4

Science.gov (United States)

Miller, C. J.; Yoder, T. S.

2010-06-01

Explosive trace detection equipment has been deployed to airports for more than a decade. During this time, the need for standardized procedures and calibrated trace amounts for ensuring that the systems are operating properly and detecting the correct explosive has been apparent but a standard representative of a fingerprint has been elusive. Standards are also necessary to evaluate instrumentation in the laboratories during development and prior to deployment to determine sample throughput, probability of detection, false positive/negative rates, ease of use by operator, mechanical and/or software problems that may be encountered, and other pertinent parameters that would result in the equipment being unusable during field operations. Since many laboratories do not have access to nor are allowed to handle explosives, the equipment is tested using techniques aimed at simulating the actual explosives fingerprint. This laboratory study focused on examining the similarities and differences in three different surface contamination techniques that are used to performance test explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples and to offer scenarios where each contamination technique is applicable. The three techniques used were dry transfer deposition of standard solutions using the Transportation Security Laboratory’s (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards onto substrates, and fingerprinting of actual explosives onto substrates. RDX was deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each substrate type using each contamination technique. The substrate types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that
Analytical solution of the multigroup neutron diffusion kinetic equation in one-dimensional cartesian geometry by the integral transform technique

International Nuclear Information System (INIS)

Ceolin, Celina

2010-01-01

The objective of this work is to obtain an analytical solution of the neutron diffusion kinetic equation in one-dimensional cartesian geometry, to monoenergetic and multigroup problems. These equations are of the type stiff, due to large differences in the orders of magnitude of the time scales of the physical phenomena involved, which make them difficult to solve. The basic idea of the proposed method is applying the spectral expansion in the scalar flux and in the precursor concentration, taking moments and solving the resulting matrix problem by the Laplace transform technique. Bearing in mind that the equation for the precursor concentration is a first order linear differential equation in the time variable, to enable the application of the spectral method we introduce a fictitious diffusion term multiplied by a positive value which tends to zero. This procedure opened the possibility to find an analytical solution to the problem studied. We report numerical simulations and analysis of the results obtained with the precision controlled by the truncation order of the series. (author)
Two-dimensional analytical solution for nodal calculation of nuclear reactors

International Nuclear Information System (INIS)

Silva, Adilson C.; Pessoa, Paulo O.; Silva, Fernando C.; Martinez, Aquilino S.

2017-01-01

Highlights: • A proposal for a coarse mesh nodal method is presented. • The proposal uses the analytical solution of the two-dimensional neutrons diffusion equation. • The solution is performed homogeneous nodes with dimensions of the fuel assembly. • The solution uses four average fluxes on the node surfaces as boundary conditions. • The results show good accuracy and efficiency. - Abstract: In this paper, the two-dimensional (2D) neutron diffusion equation is analytically solved for two energy groups (2G). The spatial domain of reactor core is divided into a set of nodes with uniform nuclear parameters. To determine iteratively the multiplication factor and the neutron flux in the reactor we combine the analytical solution of the neutron diffusion equation with an iterative method known as power method. The analytical solution for different types of regions that compose the reactor is obtained, such as fuel and reflector regions. Four average fluxes in the node surfaces are used as boundary conditions for analytical solution. Discontinuity factors on the node surfaces derived from the homogenization process are applied to maintain averages reaction rates and the net current in the fuel assembly (FA). To validate the results obtained by the analytical solution a relative power density distribution in the FAs is determined from the neutron flux distribution and compared with the reference values. The results show good accuracy and efficiency.
Evaluation of bubbler/diaphragm techniques to measure surface level in the waste storage tanks

International Nuclear Information System (INIS)

Peters, T.J.; Hickman, B.J.; Colson, J.B.

1993-10-01

This report describes the results of tests conducted at the Pacific Northwest Laboratory (PNL) to determine if a bubbler technique can be used to determine the surface level in the waste tanks. Two techniques were evaluated. The first technique is a standard bubbler system in which a tube is placed below the surface of the liquid to be measured and air pressure inside a tube is increased until bubbles begin to become emitted from the tube. The air pressure then is a function of the pressure at the bottom of the tube. The second technique involves a system similar to the standard bubbler technique, but instead of bubbles being released into the material to be gauged, air pressure is increased against a diaphragm until enough pressure is applied to overcome the pressure of the liquid at the given depth, at which time the air then flows in a return loop back to a vent. The advantage of the diaphragm system is that it is a sealed system; thus no air is released into the waste tank materials, and it is not possible for the waste tank materials to get into the air flow. Based on the results of the tests conducted in this program, it appears that the bubbler and diaphragm systems that were tested could not be used for accurate measurements of the level in the waste tanks. Both exhibited deposits of simulated waste tank material at the end of the devices which affected the ability of the gauge to accurately determine changes in the surface level even though the measured value of the level was inaccurate. Further investigations into the cause of this inaccuracy may be warranted. Alternate diaphragm materials may improve the performance of this gauge
Employing socially driven techniques for framing, contextualization, and collaboration in complex analytical threads

Science.gov (United States)

Wollocko, Arthur; Danczyk, Jennifer; Farry, Michael; Jenkins, Michael; Voshell, Martin

2015-05-01

The proliferation of sensor technologies continues to impact Intelligence Analysis (IA) work domains. Historical procurement focus on sensor platform development and acquisition has resulted in increasingly advanced collection systems; however, such systems often demonstrate classic data overload conditions by placing increased burdens on already overtaxed human operators and analysts. Support technologies and improved interfaces have begun to emerge to ease that burden, but these often focus on single modalities or sensor platforms rather than underlying operator and analyst support needs, resulting in systems that do not adequately leverage their natural human attentional competencies, unique skills, and training. One particular reason why emerging support tools often fail is due to the gap between military applications and their functions, and the functions and capabilities afforded by cutting edge technology employed daily by modern knowledge workers who are increasingly "digitally native." With the entry of Generation Y into these workplaces, "net generation" analysts, who are familiar with socially driven platforms that excel at giving users insight into large data sets while keeping cognitive burdens at a minimum, are creating opportunities for enhanced workflows. By using these ubiquitous platforms, net generation analysts have trained skills in discovering new information socially, tracking trends among affinity groups, and disseminating information. However, these functions are currently under-supported by existing tools. In this paper, we describe how socially driven techniques can be contextualized to frame complex analytical threads throughout the IA process. This paper focuses specifically on collaborative support technology development efforts for a team of operators and analysts. Our work focuses on under-supported functions in current working environments, and identifies opportunities to improve a team's ability to discover new information and
A REVIEW ON PREDICTIVE ANALYTICS IN DATA MINING

OpenAIRE

Arumugam.S

2016-01-01

The data mining its main process is to collect, extract and store the valuable information and now-a-days it’s done by many enterprises actively. In advanced analytics, Predictive analytics is the one of the branch which is mainly used to make predictions about future events which are unknown. Predictive analytics which uses various techniques from machine learning, statistics, data mining, modeling, and artificial intelligence for analyzing the current data and to make predictions about futu...
Application of quantum dots as analytical tools in automated chemical analysis: A review

International Nuclear Information System (INIS)

Frigerio, Christian; Ribeiro, David S.M.; Rodrigues, S. Sofia M.; Abreu, Vera L.R.G.; Barbosa, João A.C.; Prior, João A.V.; Marques, Karine L.; Santos, João L.M.

2012-01-01

Highlights: ► Review on quantum dots application in automated chemical analysis. ► Automation by using flow-based techniques. ► Quantum dots in liquid chromatography and capillary electrophoresis. ► Detection by fluorescence and chemiluminescence. ► Electrochemiluminescence and radical generation. - Abstract: Colloidal semiconductor nanocrystals or quantum dots (QDs) are one of the most relevant developments in the fast-growing world of nanotechnology. Initially proposed as luminescent biological labels, they are finding new important fields of application in analytical chemistry, where their photoluminescent properties have been exploited in environmental monitoring, pharmaceutical and clinical analysis and food quality control. Despite the enormous variety of applications that have been developed, the automation of QDs-based analytical methodologies by resorting to automation tools such as continuous flow analysis and related techniques, which would allow to take advantage of particular features of the nanocrystals such as the versatile surface chemistry and ligand binding ability, the aptitude to generate reactive species, the possibility of encapsulation in different materials while retaining native luminescence providing the means for the implementation of renewable chemosensors or even the utilisation of more drastic and even stability impairing reaction conditions, is hitherto very limited. In this review, we provide insights into the analytical potential of quantum dots focusing on prospects of their utilisation in automated flow-based and flow-related approaches and the future outlook of QDs applications in chemical analysis.
Analytic observables in nuclear physics

International Nuclear Information System (INIS)

Borbely, I.

1980-05-01

The analytical dependence of quantum mechanical observables on their variables is discussed by using the assumption that the corresponding probability amplitudes are analytic functions. The properties of the cross section in the energy plane for spinless particles as well as the properties of the most general polarization observables in the cosdelta plane are considered in detail. In particular, the strength of the transfer pole for polarization observables is given. The practical possibilities to extract the different orbital momentum components of nuclei by extrapolation techniques are briefly outlined. (author)
Synthesis of Ag-coated polystyrene colloids by an improved surface seeding and shell growth technique

International Nuclear Information System (INIS)

Tian Chungui; Wang Enbo; Kang Zhenhui; Mao Baodong; Zhang Chao; Lan Yang; Wang Chunlei; Song Yanli

2006-01-01

In this paper, an improved surface seeding and shell growth technique was developed to prepare Ag-polystyrene core shell composite. Polyethyleneimine (PEI) could act as the linker between Ag ions (Ag nanoparticles) and polystyrene (PS) colloids and the reducing agent in the formation of Ag nanoparticles. Due to the multi-functional characteristic of PEI, Ag seeds formed in-situ and were immobilized on the surface of PEI-modified PS colloids and no free Ag clusters coexist with the Ag 'seeding' PS colloids in the system. Then, the additional agents could be added into the resulting dispersions straightly to produce a thick Ag nanoshell. The Ag nanoshell with controllable thickness was formed on the surface of PS by the 'one-pot' surface seeding and shell growth method. The Ag-coverage increased gradually with the increasing of mass ratio of AgNO 3 /PS. The optical properties of the Ag-PS colloids could be tailored by changing the coverage of Ag. - Graphical abstract: An improved surface seeding and shell growth technique was developed to prepare Ag-polystyrene core shell composite. The optical properties of the Ag-PS colloids could be tailored by changing the coverage of Ag. Display Omitted

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