Determination of structural geometric parameters of industrial ceramic foams by gamma rays transmission and X-rays microtomography

International Nuclear Information System (INIS)

Rocha, Wilson Roberto Dejato da

2005-01-01

In this work, the gamma rays transmission and X-rays microtomography techniques are used for the evaluation of the porosity and the pore size distribution of SiC ceramic foams. It was also accomplished the three-dimensional images after the determination of samples geometric parameters. The geometric parameters were obtained by two-dimensional images analyses, generated by a Microfocus system, with a CCD camera, an images intensifier, a X-rays tube and an automatic system for rotation of the sample. The spatial resolution of the images was about 32 μm. In the gamma rays transmission methodology, a Nal(Tl) scintillation detector, an 241 Am (59.53 keV, 100 mCi) radioactive source and an automatic X-Z micrometric table was used. The analyzed samples had pores density of 30, 45, 60, 80 and 100 ppi (pores per inch). The gamma rays transmission technique was accurate to supply the porosity of the samples, which ranged about 90% and was in agreement with the values supplied by manufacturer of the foams. The 30 and 45 ppi samples analyzed by X-rays microtomography showed porosity results that agree with the average porosity supplied by the manufacturer. In other hand, the 60, 80 and 100 ppi samples systematically showed average porosity about 4%, lower than the average of the manufacturer. The pore size distributions found through the software IMAGO show the presence of smaller pores than those nominated by the manufacturer. The 30 ppi samples had voids inside the solid material of the ceramic foams structure. Gaussian truncated method, used in the three-dimensional reconstruction, was not able to take into the account the voids inside the solid matrix. (author)

Microstructural characterization of porous materials by X-ray microtomography and gamma ray transmission techniques

International Nuclear Information System (INIS)

Moreira, Anderson Camargo

2006-01-01

This work presents the application of the X-ray microtomography and gamma ray transmission techniques for the microstructure characterization of different kinds of materials. Total porosity, pore size distribution and the two point correlation functions were measured. The two point correlation function, which allows the reconstruction of 3D models, was carried out for two samples. Seven ceramic tablets of Alumina (Al 2 O 3 ), seven tablets of Boron Carbide (B 4 C), three samples of sedimentary rocks and one sample of Titanium foam were analyzed. The experimental set up for the Gamma Ray Transmission technique consisted of: a 2'' x 2'' crystal NaI(Tl) detector, an 241 Am radioactive source (59,53 keV, 100 mCi), an automatic micrometric table for the sample XZ movement and standard gamma spectrometry electronics. Two microtomography systems were used: a Fein Focus system, constituted by an X-ray tube, operated at 160 kV and 0.3 to 1.1 mA, a CCD camera and the movement sample system, and a Skyscan system, model 1072, with a X-ray tube operated at 100 kV and 100μA, and a CCD camera. The ceramic tablets, analyzed by the gamma ray transmission technique presented results for most of the porosities data with smaller confidence intervals and inside the intervals supplied by the tablets manufacturer. The Titanium porous sample was analyzed by the two techniques, its microtomography images achieved a resolution of 17μm, obtained employing the Fein Focus system. For both techniques, this sample showed high porosity, which allows its application for this purpose. The sandstones samples were analyzed by the Skyscan system, achieving resolutions of 19μm, 11μm and 3.8μm for each sample, respectively. The resolutions of 11μm and 3.8μm were the ones that generated better 2D sections for the respective samples and, consequently, more reliable porosities. The 3.8μm resolution was the one that best quantified the pore size distribution data, showing information not shown by

Characteristics of Transmission-type Microfocus X-ray Tube based-on Carbon Nanotube Field Emitter

International Nuclear Information System (INIS)

Heo, Sung Hwan; Ihsan, Aamir; Cho, Sung Oh

2007-01-01

A high resolution microfocus x-ray source is widely applied to noninvasive detection for industrial demands, material science and engineering, and to diagnostic study of microbiology and micro-tomography. Carbon nanotube (CNT) is regarded as an excellent electron emitter, which outperforms conventional electron sources in point of brightness. It has been suggested that CNT is used as an electron source of a high resolution x-ray tube according to their low threshold field with atomically sharp geometry, chemically robust structure, and electric conductivity. Several researchers have reported miniaturized x-ray tube based on diode structure and micro x-ray radiography and computed tomography systems using triode types with precise emission control and electrostatic focusing. Especially, a microfocus x-ray source of 30 μm resolution has been demonstrated recently using an elliptical CNT cathode and asymmetrical Eingel lens. However, to increase the spatial resolution of x-ray source, a smaller CNT emitter is desired. Electron focusing optics must be corrected to reduce aberrations. A thin wire tip end can provide a micro-area of CNT substrate, and a magnetic lens and transmission x-ray target are proper to reduce the lens aberration and a focal length. Until now, CNT based microfocus x-ray source with less than 10 um resolution has not been shown. Here we report a microfocus x-ray source with 4.7 μm x-ray focal spot consisted of a conical CNT tip, a single solenoid lens, and a transmission type x-ray target. A magnified x-ray image larger than 230 times was resolved with advantage of microfocused focal spot and transmission x-ray target

Analytical device for X-ray tomography by transmission

International Nuclear Information System (INIS)

Allemand, Robert.

1975-01-01

The invention concerns an analytical system for X ray tomography by transmission. The principle of these appliances is based on measuring the absorption of an X ray beam in terms of the density of the tissue being examined. In the apparatus marketed by E.M.I. (Electric and Musical Industries Ltd) of Great Britain, one hundred absorption determinations are performed during a scan lasting around one second; with this apparatus the number of scans is 180. In order to extend this examination to organs other than the brain, it is necessary to use shorter examination times. To do so, the detection cells employed are ionization chambers and they are associated with instrumentation for determining the charge collected in each chamber over a given time under the effect of the X rays which have passed through the organ being examined [fr

Compact scanning transmission x-ray microscope at the photon factory

International Nuclear Information System (INIS)

Takeichi, Yasuo; Inami, Nobuhito; Ono, Kanta; Suga, Hiroki; Takahashi, Yoshio

2016-01-01

We report the design and performance of a compact scanning transmission X-ray microscope developed at the Photon Factory. Piezo-driven linear stages are used as coarse stages of the microscope to realize excellent compactness, mobility, and vibrational and thermal stability. An X-ray beam with an intensity of ∼10 7 photons/s was focused to a diameter of ∼40 nm at the sample. At the soft X-ray undulator beamline used with the microscope, a wide range of photon energies (250–1600 eV) is available. The microscope has been used to research energy materials and in environmental sciences

Research on temperature measurement by X-ray transmission intensity

International Nuclear Information System (INIS)

Chen, Shuyue; Cheng, Rong

2013-01-01

The relationship between temperature and X-ray transmission intensity was researched and analyzed by inspecting material density change, which is caused by thermal expansion. A digital radiographic system was employed to obtain the images. On this basis, we deduced the temperature formula based on the average gray level of the captured images. The measured temperatures were obtained from the experiments and the errors were analyzed. We concluded that when X-rays pass through an object, the X-ray strength and the gray level of the image under high temperatures are greater than those under lower temperatures and the image gray level error has great impact on the accuracy of the measured temperature. The presented approach allowed the non-contact temperature measurement of material

Effect of particle size, filler loadings and x-ray tube voltage on the transmitted x-ray transmission in tungsten oxide—epoxy composites

International Nuclear Information System (INIS)

Noor Azman, N.Z.; Siddiqui, S.A.; Hart, R.; Low, I.M.

2013-01-01

The effect of particle size, filler loadings and x-ray tube voltage on the x-ray transmission in WO 3 -epoxy composites has been investigated using the mammography unit and a general radiography unit. Results indicate that nano-sized WO 3 has a better ability to attenuate the x-ray beam generated by lower tube voltages (25–35 kV) when compared to micro-sized WO 3 of the same filler loading. However, the effect of particle size on x-ray transmission was negligible at the higher x-ray tube voltages (40–120 kV). - Highlights: ► Investigated the effect of particle size of WO 3 on the x-ray attenuation ability. ► Nano-sized WO 3 has a better ability to attenuate lower x-ray energies (22–49 kV p ). ► Particle size has negligible effect at the higher x-ray energy range (40–120 kV p ).

Design and construction of the gamma ray transmission tomographer g-TAC-02

International Nuclear Information System (INIS)

Pavon Hernandez, Noriel; Ravelo Sanchez, Alberto; Idel, Pedro; Macias Perez, Rafael; Garcia Trapaga, Cesar; Campos Montenegro, Augusto

2000-01-01

An equipment for gamma ray transmission tomographer was designed and constructed in the Higher Institute of Nuclear Sciences and Technology. It was the g-TAC-01, based on a nuclear instrumentation, a mechanic instrumentation, and the control of the system from a personal computer. This first version permitted to obtain the know how of the technology of construction of equipment for tomography. The present work describes the second version of the gamma ray transmission tomographer: the g-TAC-02, with very important upgrading in the control session. Now the control system is a microcontroller based, electronic control system, designed to work in multiples forms: manual, automatic and with the computer

3D elemental sensitive imaging using transmission X-ray microscopy.

Science.gov (United States)

Liu, Yijin; Meirer, Florian; Wang, Junyue; Requena, Guillermo; Williams, Phillip; Nelson, Johanna; Mehta, Apurva; Andrews, Joy C; Pianetta, Piero

2012-09-01

Determination of the heterogeneous distribution of metals in alloy/battery/catalyst and biological materials is critical to fully characterize and/or evaluate the functionality of the materials. Using synchrotron-based transmission x-ray microscopy (TXM), it is now feasible to perform nanoscale-resolution imaging over a wide X-ray energy range covering the absorption edges of many elements; combining elemental sensitive imaging with determination of sample morphology. We present an efficient and reliable methodology to perform 3D elemental sensitive imaging with excellent sample penetration (tens of microns) using hard X-ray TXM. A sample of an Al-Si piston alloy is used to demonstrate the capability of the proposed method.

Applications of Hard X-ray Full-Field Transmission X-ray Microscopy at SSRL

International Nuclear Information System (INIS)

Liu, Y.; Andrews, J. C.; Mehta, A.; Pianetta, P.; Meirer, F.; Gil, S. Carrasco; Sciau, P.; Mester, Z.

2011-01-01

State-of-the-art hard x-ray full-field transmission x-ray microscopy (TXM) at beamline 6-2C of Stanford Synchrotron Radiation Lightsource has been applied to various research fields including biological, environmental, and material studies. With the capability of imaging a 32-micron field-of-view at 30-nm resolution using both absorption mode and Zernike phase contrast, the 3D morphology of yeast cells grown in gold-rich media was investigated. Quantitative evaluation of the absorption coefficient was performed for mercury nanoparticles in alfalfa roots exposed to mercury. Combining XANES and TXM, we also performed XANES-imaging on an ancient pottery sample from the Roman pottery workshop at LaGraufesenque (Aveyron).

Applications of Hard X-ray Full-Field Transmission X-ray Microscopy at SSRL

Science.gov (United States)

Liu, Y.; Andrews, J. C.; Meirer, F.; Mehta, A.; Gil, S. Carrasco; Sciau, P.; Mester, Z.; Pianetta, P.

2011-09-01

State-of-the-art hard x-ray full-field transmission x-ray microscopy (TXM) at beamline 6-2C of Stanford Synchrotron Radiation Lightsource has been applied to various research fields including biological, environmental, and material studies. With the capability of imaging a 32-micron field-of-view at 30-nm resolution using both absorption mode and Zernike phase contrast, the 3D morphology of yeast cells grown in gold-rich media was investigated. Quantitative evaluation of the absorption coefficient was performed for mercury nanoparticles in alfalfa roots exposed to mercury. Combining XANES and TXM, we also performed XANES-imaging on an ancient pottery sample from the Roman pottery workshop at LaGraufesenque (Aveyron).

Porosity determination of alumina and boron carbide ceramic samples by gamma ray transmission

International Nuclear Information System (INIS)

Moreira, Anderson Camargo; Appoloni, Carlos Roberto

2009-01-01

The aim of this work is to apply the Gamma Ray Transmission (GRT), a non destructive technique, for structural characterization of ceramic samples. With this technique, the porosity of Alumina (Al 2 O 3 ) and Boron Carbide (B 4 C) ceramic samples, in tablet format, was determined. The equipment employed is constituted by a 241 Am gamma ray source (59.6 keV and 100mCi), a 2''x2'' diameter NaI (Tl) scintillation detector coupled to a standard gamma ray transmission electronic and a micrometric and automated table for sample movement. The porosity profile of the samples shows a homogeneous porosity distribution, within the spatial resolution of the employed transmission system. The mean porosity determined for Al 2 O 3 and B 4 C were 17.8±1.3% and 3.87±0.43%, respectively. A statistical treatment of these results was performed and showed that the mean porosity values determinate by the GRT are the same as those supplied by the manufacturer. (author)

Evaluation of the water equivalence of solid phantoms using gamma ray transmission measurements

International Nuclear Information System (INIS)

Hill, R.F.; Brown, S.; Baldock, C.

2008-01-01

Gamma ray transmission measurements have been used to evaluate the water equivalence of solid phantoms. Technetium-99m was used in narrow beam geometry and the transmission of photons measured, using a gamma camera, through varying thickness of the solid phantom material and water. Measured transmission values were compared with Monte Carlo calculated transmission data using the EGSnrc Monte Carlo code to score fluence in a geometry similar to that of the measurements. The results indicate that the RMI457 Solid Water, CMNC Plastic Water and PTW RW3 solid phantoms had similar transmission values as compared to water to within ±1.5%. However, Perspex had a greater deviation in the transmission values up to ±4%. The agreement between the measured and EGSnrc calculated transmission values agreed to within ±1% over the range of phantom thickness studied. The linear attenuation coefficients at the gamma ray energy of 140.5 keV were determined from the measured and EGSnrc calculated transmission data and compared with predicted values derived from data provided by the National Institute of Standards and Technology (NIST) using the XCOM program. The coefficients derived from the measured data were up to 6% lower than those predicted by the XCOM program, while the coefficients determined from the Monte Carlo calculations were between measured and XCOM values. The results indicate that a similar process can be followed to determine the water equivalency of other solid phantoms and at other photon energies

Saturation and porosity measurements of different soil samples by gamma ray transmission

International Nuclear Information System (INIS)

Akbal, S.; Filiz Baytas, A.

2000-01-01

Gamma-ray transmission methods have been used accurately for the study of the properties of soil samples. In this study, the soil samples were collected from various regions of Turkey and a Nal (TI) detector measured the attenuation of strongly collimated monoenergetic gamma beam (from Cs-137) through soil samples. The water saturation and porosity were therefore calculated from the transmission measurements for each soil sample. (authors)

Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research

Energy Technology Data Exchange (ETDEWEB)

Moffet, Ryan C.; Tivanski, Alexei V.; Gilles, Mary K.

2011-01-20

Scanning transmission x-ray microscopy (STXM) combines x-ray microscopy and near edge x-ray absorption fine structure spectroscopy (NEXAFS). This combination provides spatially resolved bonding and oxidation state information. While there are reviews relevant to STXM/NEXAFS applications in other environmental fields (and magnetic materials) this chapter focuses on atmospheric aerosols. It provides an introduction to this technique in a manner approachable to non-experts. It begins with relevant background information on synchrotron radiation sources and a description of NEXAFS spectroscopy. The bulk of the chapter provides a survey of STXM/NEXAFS aerosol studies and is organized according to the type of aerosol investigated. The purpose is to illustrate the current range and recent growth of scientific investigations employing STXM-NEXAFS to probe atmospheric aerosol morphology, surface coatings, mixing states, and atmospheric processing.

Scatter and transmission doses from several pediatric X-ray examinations in a nursery

International Nuclear Information System (INIS)

Burrage, John W.; Rampant, Peter L.; Beeson, Brendan P.

2003-01-01

While several studies have investigated the dose from scattered radiation from X-ray procedures in a pediatric nursery, they examined scatter from chest procedures only, or the types of examination were not specified. The aim of this study was to collect scatter and transmission data from several types of X-ray examinations. Using a ''newborn'' anthropomorphic phantom and an ion chamber, a series of scatter and transmission dose measurements were performed using typical exposure factors for chest, chest and abdomen, skull, skeletal long bone and spine procedures. The phantom was inside a crib for all exposures. The maximum scatter dose measured at 1 m from the field center was about 0.05 μGy per exposure for lateral skulls. Transmission doses for lateral exams were around 0.1 μGy per exposure at 1 m from the isocenter. The study demonstrated that scatter dose to other patients in a neonatal unit is not significant, assuming the distance between adjacent cribs is in the order of 1 m. Transmission doses are also low provided the beam is fully intercepted by the cassette. For an average workload the dose received by imaging technologists would be small. (orig.)

Longitudinal detection of ferromagnetic resonance using x-ray transmission measurements

International Nuclear Information System (INIS)

Boero, G.; Rusponi, S.; Kavich, J.; Rizzini, A. Lodi; Piamonteze, C.; Nolting, F.; Tieg, C.; Thiele, J.-U.; Gambardella, P.

2009-01-01

We describe a setup for the x-ray detection of ferromagnetic resonance in the longitudinal geometry using element-specific transmission measurements. Thin magnetic film samples are placed in a static magnetic field collinear with the propagation direction of a polarized soft x-ray beam and driven to ferromagnetic resonance by a continuous wave microwave magnetic field perpendicular to it. The transmitted photon flux is measured both as a function of the x-ray photon energy and as a function of the applied static magnetic field. We report experiments performed on a 15 nm film of doped Permalloy (Ni 73 Fe 18 Gd 7 Co 2 ) at the L 3 /L 2 -edges of Fe, Co, and Ni. The achieved ferromagnetic resonance sensitivity is about 0.1 monolayers/√(Hz). The obtained results are interpreted in the framework of a conductivity tensor based formalism. The factors limiting the sensitivity as well as different approaches for the x-ray detection of ferromagnetic resonance are discussed.

Measurement of the porosity of amorphous materials by gamma ray transmission methodology

International Nuclear Information System (INIS)

Pottker, Walmir Eno; Appoloni, Carlos Roberto

2000-01-01

In this work it is presented the measurement of the total porosity of TRe soil, Sandstone Berea rocks and porous ceramics samples. For the determination of the total porosity, the Arquimedes method (conventional) and the gamma ray transmission methodology were employed. The porosity measurement using the gamma methodology has a significant advantage respect to the conventional method due to the fast and non-destructive determination, and also for supplying results with a greater characterization in small scales, in relation to the heterogeneity of the porosity. The conventional methodology presents good results only for homogeneous samples. The experimental set up for the gamma ray transmission technique consisted of a 241 Am source (59,53 keV ), a NaI(Tl) scintillation detector, collimators, a XYZ micrometric table and standard gamma spectrometry electronics connected to a multichannel analyser. (author)

Gamma ray transmission for hydraulic conductivity measurement of undisturbed soil columns

Directory of Open Access Journals (Sweden)

Anderson Camargo Moreira

2007-03-01

Full Text Available This work had the objective to determine the Hydraulic Conductivity K(theta function for different depth levels z, of columns of undisturbed soil, using the gamma ray transmission technique applied to the Sisson method. The results indicated a growing behavior for K(theta and a homogeneous soil density, both in relation to the increase of the depth. The methodology of gamma ray transmission showed satisfactory results on the determination of the hydraulic conductivity in columns of undisturbed soil, besides being very reliable and a nondestructive method.O estudo da condutividade hidráulica para solos não saturados é essencial quando aplicado às situações relacionadas à irrigação, drenagem e transporte de nutrientes no solo, é uma importante propriedade para desenvolvimentos de culturas agrícolas. Este trabalho tem o objetivo de determinar a função Condutividade Hidráulica K(teta, em diferentes níveis z de profundidade, em colunas de solo indeformado, utilizando a transmissão de raios gama aplicada ao método de Sisson. Os resultados indicam um comportamento crescente para K(teta e uma densidade de solo homogênea, ambos em relação ao aumento da profundidade. A metodologia de transmissão de raios gama mostrou resultados bastante satisfatórios na determinação da condutividade hidráulica em colunas de solo indeformado, além de ser muito confiável e não destrutivo.

Bragg transmission phase plates for the production of circularly polarized x-rays

International Nuclear Information System (INIS)

Lang, J.C.; Srajer, G.

1994-01-01

A thin-crystal Si (400) Bragg transmission x-ray phase plate has been constructed for the production of 5 to 12 keV circularly polarized x-rays. Using multiple beam diffraction from a GaAs crystal, a direct measurement of the degree of circular polarization as a function of off-Bragg position was made. These measurements indicated nearly complete circular polarization (|P c | ≥ 0.95) and full helicity reversal on opposite sides of the rocking curve

Using angular dispersion and anomalous transmission to shape ultramonochromatic x rays

Energy Technology Data Exchange (ETDEWEB)

Shvyd' ko, Yuri; Stoupin, Stanislav; Shu, Deming; Khachatryan, Ruben [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2011-11-15

Optical spectrometers, instruments that work with highly monochromatic light, are commonly rated by the spectral bandwidth, which defines the ability to resolve closely spaced spectral components. Another equally important feature is the spectral contrast, the ability to detect faint objects among these components. Here we demonstrate that a combined effect of angular dispersion (AD) and anomalous transmission (AT) of x rays in Bragg reflection from asymmetrically cut crystals can shape spectral distributions of x rays to profiles with high contrast and small bandwidths. The AD and AT x-ray optics is implemented as a five-reflection, three-crystal arrangement featuring a combination of the above-mentioned attributes so desirable for x-ray monochromators and analyzers: a spectral contrast of {approx_equal} 500, a bandwidth of {approx_equal} 0.46 meV, and a remarkably large angular acceptance of {approx_equal} 107 {mu}rad with 9.1 keV x rays. The new optics can become a foundation for the next-generation inelastic x-ray scattering spectrometers for studies of atomic dynamics.

Sexualidade na terceira idade: medidas de prevenção para doenças sexualmente transmissíveis e AIDS Sexualidad en la tercera edad: medidas de prevención de enfermedades de transmisión sexual y SIDA Sexuality in the elderly: prevention methods for sexually transmissible illnesses and AIDS

Directory of Open Access Journals (Sweden)

Manoela Busato Mottin Maschio

2011-09-01

Full Text Available O objetivo deste estudo foi identificar as medidas de prevenção que os idosos estão utilizando para à prevenção das Doenças Sexualmente Transmissíveis e Síndrome da Imunodeficiência Adquirida. A pesquisa foi de caráter prospectivo, quantitativo e descritivo com uma amostragem intencional, realizada com 98 idosos. Foi aplicado um questionário com perguntas abertas e fechadas, relacionadas à vida sexual dos idosos frequentadores de uma instituição que desenvolve programas para a melhoria da qualidade de vida dos idosos no município de Curitiba, Paraná. Dos entrevistados 43%, relatam fazer uso de alguma medida de prevenção. A realização de programas de prevenção voltados para o atendimento de pessoas com 50 anos ou mais, deve estar atenta às questões de sexualidade no envelhecimento. Os idosos devem ser vistos como indivíduos que possuem desejos, necessidades sexuais e que fazem projetos para o futuro.El objetivo de este estudio es identificar medidas que los ancianos están utilizando para la prevención de enfermedades de transmisión sexual y el Enfermedades de Transmisión Sexual Síndrome de Inmunodeficiencia Adquirida. La encuesta fue de carácter prospectivo y cuantitativo con una muestra intencional, realizado con 98 personas de edad avanzada. Se aplicó un cuestionario con preguntas abiertas y cerradas, relacionadas con la vida sexual de los visitantes mayores de una institución que desarrolla programas para la mejora de la calidad de vida de las personas mayores en la ciudad de Curitiba, Paraná, Brasil. De los 43% de los encuestados informaron que usan de alguna medida de prevención. La ejecución de los programas de prevención se centró en la atención de personas mayores de 50 años o más, deben de estar atentos a las cuestiones de la sexualidad en el envejecimiento. Los ancianos deben ser vistos como individuos que tienen necesidades sexuales y deseos, que hacen proyectos para el futuro.This study aimed

3D imaging of a rice pollen grain using transmission X-ray microscopy.

Science.gov (United States)

Wang, Shengxiang; Wang, Dajiang; Wu, Qiao; Gao, Kun; Wang, Zhili; Wu, Ziyu

2015-07-01

For the first time, the three-dimensional (3D) ultrastructure of an intact rice pollen cell has been obtained using a full-field transmission hard X-ray microscope operated in Zernike phase contrast mode. After reconstruction and segmentation from a series of projection images, complete 3D structural information of a 35 µm rice pollen grain is presented at a resolution of ∼100 nm. The reconstruction allows a clear differentiation of various subcellular structures within the rice pollen grain, including aperture, lipid body, mitochondrion, nucleus and vacuole. Furthermore, quantitative information was obtained about the distribution of cytoplasmic organelles and the volume percentage of each kind of organelle. These results demonstrate that transmission X-ray microscopy can be quite powerful for non-destructive investigation of 3D structures of whole eukaryotic cells.

Scanning transmission x-ray microscope for materials science spectromicroscopy at the ALS

Energy Technology Data Exchange (ETDEWEB)

Warwick, T.; Seal, S.; Shin, H. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The brightness of the Advanced Light Source will be exploited by several new instruments for materials science spectromicroscopy over the next year or so. The first of these to become operational is a scanning transmission x-ray microscope with which near edge x-ray absorption spectra (NEXAFS) can be measured on spatial features of sub-micron size. Here the authors describe the instrument as it is presently implemented, its capabilities, some studies made to date and the developments to come. The Scanning Transmission X-ray Microscope makes use of a zone plate lens to produce a small x-ray spot with which to perform absorption spectroscopy through thin samples. The x-ray beam from ALS undulator beamline 7.0 emerges into the microscope vessel through a silicon nitride vacuum window 160nm thick and 300{mu}m square. The vessel is filled with helium at atmospheric pressure. The zone plate lens is illuminated 1mm downstream from the vacuum window and forms an image in first order of a pinhole which is 3m upstream in the beamline. An order sorting aperture passes the first order converging light and blocks the unfocused zero order. The sample is at the focus a few mm downstream of the zone plate and mounted from a scanning piezo stage which rasters in x and y so that an image is formed, pixel by pixel, by an intensity detector behind the sample. Absorption spectra are measured point-by-point as the photon energy is scanned by rotating the diffraction grating in the monochromator and changing the undulator gap.

Pixelated transmission-mode diamond X-ray detector.

Science.gov (United States)

Zhou, Tianyi; Ding, Wenxiang; Gaowei, Mengjia; De Geronimo, Gianluigi; Bohon, Jen; Smedley, John; Muller, Erik

2015-11-01

Fabrication and testing of a prototype transmission-mode pixelated diamond X-ray detector (pitch size 60-100 µm), designed to simultaneously measure the flux, position and morphology of an X-ray beam in real time, are described. The pixel density is achieved by lithographically patterning vertical stripes on the front and horizontal stripes on the back of an electronic-grade chemical vapor deposition single-crystal diamond. The bias is rotated through the back horizontal stripes and the current is read out on the front vertical stripes at a rate of ∼ 1 kHz, which leads to an image sampling rate of ∼ 30 Hz. This novel signal readout scheme was tested at beamline X28C at the National Synchrotron Light Source (white beam, 5-15 keV) and at beamline G3 at the Cornell High Energy Synchrotron Source (monochromatic beam, 11.3 keV) with incident beam flux ranges from 1.8 × 10(-2) to 90 W mm(-2). Test results show that the novel detector provides precise beam position (positional noise within 1%) and morphology information (error within 2%), with an additional software-controlled single channel mode providing accurate flux measurement (fluctuation within 1%).

VladBot. Robot para posicionamiento de medida

OpenAIRE

Plata Rueda, Ángel

2013-01-01

VladBot es un robot autónomo diseñado para posicionar en interiores un micrófono de medida. Este prototipo puede valorar la idea de automatizar medidas acústicas en interiores mediante un robot autónomo. Posee dos ruedas motrices y una rueda loca. Ésta rueda loca aporta maniobrabilidad al robot. Un soporte extensible hecho de aluminio sostiene el micrófono de medida. VladBot ha sido diseñado con tecnologías de bajo coste y bajo una plataforma abierta, Arduino. Arduino es una plataforma el...

Confocal soft X-ray scanning transmission microscopy: setup, alignment procedure and limitations

International Nuclear Information System (INIS)

Späth, Andreas; Raabe, Jörg; Fink, Rainer H.

2015-01-01

A conventional STXM setup has been upgraded with a second micro zone plate and aligned to confocal geometry. Two confocal geometries (in-line and off-axis) have been evaluated and a discussion on prospects and limitations is presented. Zone-plate-based scanning transmission soft X-ray microspectroscopy (STXM) is a well established technique for high-contrast imaging of sufficiently transparent specimens (e.g. ultrathin biological tissues, polymer materials, archaeometric specimens or magnetic thin films) with spatial resolutions in the regime of 20 nm and high spectroscopic or chemical sensitivity. However, due to the relatively large depth of focus of zone plates, the resolution of STXM along the optical axis so far stays unambiguously behind for thicker X-ray transparent specimens. This challenge can be addressed by the implementation of a second zone plate in the detection pathway of the beam, resulting in a confocal arrangement. Within this paper a first proof-of-principle study for a confocal STXM (cSTXM) and an elaborate alignment procedure in transmission and fluorescence geometry are presented. Based on first confocal soft X-ray micrographs of well known specimens, the advantage and limitation of cSTXM as well as further development potentials for future applications are discussed

Confocal soft X-ray scanning transmission microscopy: setup, alignment procedure and limitations

Energy Technology Data Exchange (ETDEWEB)

Späth, Andreas [Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058 Erlangen (Germany); Raabe, Jörg [Paul Scherrer Institut, 5232 Villigen (Switzerland); Fink, Rainer H., E-mail: rainer.fink@fau.de [Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058 Erlangen (Germany); Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058 Erlangen (Germany)

2015-01-01

A conventional STXM setup has been upgraded with a second micro zone plate and aligned to confocal geometry. Two confocal geometries (in-line and off-axis) have been evaluated and a discussion on prospects and limitations is presented. Zone-plate-based scanning transmission soft X-ray microspectroscopy (STXM) is a well established technique for high-contrast imaging of sufficiently transparent specimens (e.g. ultrathin biological tissues, polymer materials, archaeometric specimens or magnetic thin films) with spatial resolutions in the regime of 20 nm and high spectroscopic or chemical sensitivity. However, due to the relatively large depth of focus of zone plates, the resolution of STXM along the optical axis so far stays unambiguously behind for thicker X-ray transparent specimens. This challenge can be addressed by the implementation of a second zone plate in the detection pathway of the beam, resulting in a confocal arrangement. Within this paper a first proof-of-principle study for a confocal STXM (cSTXM) and an elaborate alignment procedure in transmission and fluorescence geometry are presented. Based on first confocal soft X-ray micrographs of well known specimens, the advantage and limitation of cSTXM as well as further development potentials for future applications are discussed.

Hard-x-ray phase-imaging microscopy using the self-imaging phenomenon of a transmission grating

International Nuclear Information System (INIS)

Yashiro, Wataru; Harasse, Sebastien; Momose, Atsushi; Takeuchi, Akihisa; Suzuki, Yoshio

2010-01-01

We report on a hard-x-ray imaging microscope consisting of a lens, a sample, and a transmission grating. After the theoretical framework of self-imaging phenomenon by the grating in the system is presented, equations for the electric field on the image plane are derived for ideal and real lenses and an equation for the intensity on the image plane for partially coherent illumination is derived. The equations are simple and similar to those applying to a projection microscope consisting of a transmission grating except that there is no defocusing effect, regardless of whether the grating is in front of or behind the lens. This means that x-ray phase-imaging microscopy can be done without the defocusing effect. It is also shown that, by resolving the self-image on the image plane, high-sensitive x-ray phase-imaging microscopy can be attained without degradation in the spatial resolution due to diffraction by the grating. Experimental results obtained using partially coherent illumination from a synchrotron x-ray source confirm that hard-x-ray phase-imaging microscopy can be quantitatively performed with high sensitivity and without the spatial resolution degradation.

Development of a scanning transmission x-ray microscope for the beamline P04 at PETRA III DESY

International Nuclear Information System (INIS)

Andrianov, Konstantin; Ewald, Johannes; Nisius, Thomas; Wilhein, Thomas; Lühl, Lars; Malzer, Wolfgang; Kanngießer, Birgit

2016-01-01

We present a scanning transmission x-ray microscope (STXM) built on top of our existing modular platform for high resolution imaging experiments. This platform consists of up to three separate vacuum chambers and custom designed piezo stages. These piezo stages are able to move precisely in x-, y- and z-direction, this makes it possible to adjust the components for different imaging modes. During recent experiments the endstation was operated mainly as a transmission x-ray microscope (TXM) [1, 2

Time-resolved X-ray transmission microscopy on magnetic microstructures; Zeitaufloesende Roentgentransmissionsmikroskopie an magnetischen Mikrostrukturen

Energy Technology Data Exchange (ETDEWEB)

Puzic, Aleksandar

2007-10-23

Three excitation schemes were designed for stroboscopic imaging of magnetization dynamics with time-resolved magnetic transmission X-ray microscopy (TR-MTXM). These techniques were implemented into two types of X-ray microscopes, namely the imaging transmission X-ray microscope (ITXM) and the scanning transmission X-ray microscope (STXM), both installed at the electron storage ring of the Advanced Light Source in Berkeley, USA. Circular diffraction gratings (Fresnel zone plates) used in both microscopes as focusing and imaging elements presently allow for lateral resolution down to 30 nm. Magnetic imaging is performed by using the X-ray magnetic circular dichroism (XMCD) as element specific contrast mechanism. The developed methods have been successfully applied to the experimental investigation of magnetization dynamics in ferromagnetic microstructures. A temporal resolution well below 100 ps was achieved. A conventional pump-probe technique was implemented first. The dynamic response of the magnetization excited by a broadband pulsed magnetic field was imaged spatially resolved using focused X-ray flashes. As a complementary method, the spatially resolved ferromagnetic resonance (SR-FMR) technique was developed for experimental study of magnetization dynamics in the frequency domain. As a third excitation mode, the burst excitation was implemented. The performance and efficiency of the developed methods have been demonstrated by imaging the local magnetization dynamics in laterally patterned ferromagnetic thin-film elements and three-layer stacks. The existence of multiple eigenmodes in the excitation spectra of ferromagnetic microstructures has been verified by using the pump-probe technique. Magnetostatic spin waves were selectively excited and detected with a time resolution of 50 ps using the SR-FMR technique. Thorough analysis of 20 in most cases independently prepared samples has verified that vortices which exhibit a low-amplitude switching of their core

Soft X-ray scanning transmission X-ray microscopy (STXM) of actinide particles.

Science.gov (United States)

Nilsson, Hans J; Tyliszczak, Tolek; Wilson, Richard E; Werme, Lars; Shuh, David K

2005-09-01

A descriptive account is given of our most recent research on the actinide dioxides with the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 soft X-ray scanning transmission X-ray microscope (STXM) at the Lawrence Berkeley National Laboratory (LBNL). The ALS-MES STXM permits near-edge X-ray absorption fine structure (NEXAFS) and imaging with 30-nm spatial resolution. The first STXM spectromicroscopy NEXAFS spectra at the actinide 4d5/2 edges of the imaged transuranic particles, NpO2 and PuO2, have been obtained. Radiation damage induced by the STXM was observed in the investigation of a mixed oxidation state particle (Np(V,VI)) and was minimized during collection of the actual spectra at the 4d5/2 edge of the Np(V,VI) solid. A plutonium elemental map was obtained from an irregular PuO2 particle with the dimensions of 650 x 650 nm. The Pu 4d5/2 NEXAFS spectra were collected at several different locations from the PuO2 particle and were identical. A representative oxygen K-edge spectrum from UO2 was collected and resembles the oxygen K-edge from the bulk material. The unique and current performance of the ALS-MES STXM at extremely low energies (ca. 100 eV) that may permit the successful measurement of the actinide 5d edge is documented. Finally, the potential of STXM as a tool for actinide investigations is briefly discussed.

Integrated image presentation of transmission and fluorescent X-ray CT using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Zeniya, T.; Takeda, T. E-mail: ttakeda@md.tsukuba.ac.jp; Yu, Q.; Hasegawa, Y.; Hyodo, K.; Yuasa, T.; Hiranaka, Y.; Itai, Y.; Akatsuka, T

2001-07-21

We have developed a computed tomography (CT) system with synchrotron radiation (SR) to detect fluorescent X-rays and transmitted X-rays simultaneously. Both SR transmission X-ray CT (SR-TXCT) and SR fluorescent X-ray CT (SR-FXCT) can describe cross-sectional images with high spatial and contrast resolutions as compared to conventional CT. TXCT gives morphological information and FXCT gives functional information of organs. So, superposed display system for SR-FXCT and SR-TXCT images has been developed for clinical diagnosis with higher reliability. Preliminary experiment with brain phantom was carried out and the superposition of both images was performed. The superposed SR-CT image gave us both functional and morphological information easily with high reliability, thus demonstrating the usefulness of this system.

Integrated image presentation of transmission and fluorescent X-ray CT using synchrotron radiation

Science.gov (United States)

Zeniya, T.; Takeda, T.; Yu, Q.; Hasegawa, Y.; Hyodo, K.; Yuasa, T.; Hiranaka, Y.; Itai, Y.; Akatsuka, T.

2001-07-01

We have developed a computed tomography (CT) system with synchrotron radiation (SR) to detect fluorescent X-rays and transmitted X-rays simultaneously. Both SR transmission X-ray CT (SR-TXCT) and SR fluorescent X-ray CT (SR-FXCT) can describe cross-sectional images with high spatial and contrast resolutions as compared to conventional CT. TXCT gives morphological information and FXCT gives functional information of organs. So, superposed display system for SR-FXCT and SR-TXCT images has been developed for clinical diagnosis with higher reliability. Preliminary experiment with brain phantom was carried out and the superposition of both images was performed. The superposed SR-CT image gave us both functional and morphological information easily with high reliability, thus demonstrating the usefulness of this system.

Transmission X-ray scattering as a probe for complex liquid-surface structures

Energy Technology Data Exchange (ETDEWEB)

Fukuto, Masafumi; Yang, Lin; Nykypanchuk, Dmytro; Kuzmenko, Ivan

2016-01-28

The need for functional materials calls for increasing complexity in self-assembly systems. As a result, the ability to probe both local structure and heterogeneities, such as phase-coexistence and domain morphologies, has become increasingly important to controlling self-assembly processes, including those at liquid surfaces. The traditional X-ray scattering methods for liquid surfaces, such as specular reflectivity and grazing-incidence diffraction, are not well suited to spatially resolving lateral heterogeneities due to large illuminated footprint. A possible alternative approach is to use scanning transmission X-ray scattering to simultaneously probe local intermolecular structures and heterogeneous domain morphologies on liquid surfaces. To test the feasibility of this approach, transmission small- and wide-angle X-ray scattering (TSAXS/TWAXS) studies of Langmuir films formed on water meniscus against a vertically immersed hydrophilic Si substrate were recently carried out. First-order diffraction rings were observed in TSAXS patterns from a monolayer of hexagonally packed gold nanoparticles and in TWAXS patterns from a monolayer of fluorinated fatty acids, both as a Langmuir monolayer on water meniscus and as a Langmuir–Blodgett monolayer on the substrate. The patterns taken at multiple spots have been analyzed to extract the shape of the meniscus surface and the ordered-monolayer coverage as a function of spot position. These results, together with continual improvement in the brightness and spot size of X-ray beams available at synchrotron facilities, support the possibility of using scanning-probe TSAXS/TWAXS to characterize heterogeneous structures at liquid surfaces.

Characterizing automotive fuel cell materials by soft x-ray scanning transmission x-ray microscopy

International Nuclear Information System (INIS)

Hitchcock, A. P.; Lee, V.; Wu, J.; Cooper, G.; West, M. M.; Berejnov, V.; Soboleva, T.; Susac, D.; Stumper, J.

2016-01-01

Proton-Exchange Membrane Fuel Cell (PEM-FC) based engines are being developed rapidly for near-term implementation in hydrogen fueled, mass production, personal automobiles. Research is focused on understanding and controlling various degradation processes (carbon corrosion, Pt migration, cold start), and reducing cost by reducing or eliminating Pt catalyst. We are using soft X-ray scanning transmission X-ray microscopy (STXM) at the S 2p, C 1s, O 1s and F 1s edges to study a variety of issues related to optimization of PEM-FC materials for automotive applications. A method to efficiently and accurately measure perfluorosulfonic acid distributions was developed and is being used to better understand how different loadings and preparation methods affect the ionomer distribution in the cathode. Progress towards an environmental cell capable of controlling the temperature and humidity of a PEM-FC sample in the STXM is described. Methods for studying the 3D chemical structure of PEM-FC are outlined

Characterizing automotive fuel cell materials by soft x-ray scanning transmission x-ray microscopy

Energy Technology Data Exchange (ETDEWEB)

Hitchcock, A. P., E-mail: aph@mcmaster.ca; Lee, V.; Wu, J.; Cooper, G. [Chemistry & Chemical Biology, McMaster University, Hamilton, ON, L8S 4M1 (Canada); West, M. M.; Berejnov, V. [Faculty of Health Sciences Electron Microscopy, McMaster University, Hamilton, ON L8N 3Z5 (Canada); Soboleva, T.; Susac, D.; Stumper, J. [Automotive Fuel Cell Cooperation Corp., Burnaby BC V5J 5J8 (Canada)

2016-01-28

Proton-Exchange Membrane Fuel Cell (PEM-FC) based engines are being developed rapidly for near-term implementation in hydrogen fueled, mass production, personal automobiles. Research is focused on understanding and controlling various degradation processes (carbon corrosion, Pt migration, cold start), and reducing cost by reducing or eliminating Pt catalyst. We are using soft X-ray scanning transmission X-ray microscopy (STXM) at the S 2p, C 1s, O 1s and F 1s edges to study a variety of issues related to optimization of PEM-FC materials for automotive applications. A method to efficiently and accurately measure perfluorosulfonic acid distributions was developed and is being used to better understand how different loadings and preparation methods affect the ionomer distribution in the cathode. Progress towards an environmental cell capable of controlling the temperature and humidity of a PEM-FC sample in the STXM is described. Methods for studying the 3D chemical structure of PEM-FC are outlined.

Precise rotational alignment of x-ray transmission diffraction gratings

International Nuclear Information System (INIS)

Hill, S.L.

1988-01-01

Gold transmission diffraction gratings used for x-ray spectroscopy must sometimes be rotationally aligned to the axis of a diagnostic instrument to within sub-milliradian accuracy. We have fabricated transmission diffraction gratings with high line-densities (grating period of 200 and 300 nm) using uv holographic and x-ray lithography. Since the submicron features of the gratings are not optically visible, precision alignment is time consuming and difficult to verify in situ. We have developed a technique to write an optically visible alignment pattern onto these gratings using a scanning electron microscope (SEM). At high magnification (15000 X) several submicron lines of the grating are observable in the SEM, making it possible to write an alignment pattern parallel to the grating lines in an electron-beam-sensitive coating that overlays the grating. We create an alignment pattern by following a 1-cm-long grating line using the SEM's joystick-controlled translation stage. By following the same grating line we are assured the traveled direction of the SEM electron beam is parallel to the grating to better than 10 μradian. The electron-beam-exposed line-width can be large (5 to 15 μm wide) depending on the SEM magnification, and is therefore optically visible. The exposed pattern is eventually made a permanent feature of the grating by ion beam etching or gold electroplating. The pattern can be used to accurately align the grating to the axis of a diagnostic instrument. More importantly, the alignment of the grating can be quickly verified in situ

Patient size and x-ray transmission in body CT.

Science.gov (United States)

Ogden, Kent; Huda, Walter; Scalzetti, Ernest M; Roskopf, Marsha L

2004-04-01

Physical characteristics were obtained for 196 patients undergoing chest and abdomen computed tomography (CT) examinations. Computed tomography sections for these patients having no evident pathology were analyzed to determine patient dimensions (AP and lateral), together with the average attenuation coefficient. Patient weights ranged from approximately 3 kg to about 120 kg. For chest CT, the mean Hounsfield unit (HU) fell from about -120 HU for newborns to about -300 HU for adults. For abdominal CT, the mean HU for children and normal-sized adults was about 20 HU, but decreased to below -50 HU for adults weighing more than 100 kg. The effective photon energy and percent energy fluence transmitted through a given patient size and composition was calculated for representative x-ray spectra at 80, 100, 120, and 140 kV tube potentials. A 70-kg adult scanned at 120 kVp transmits 2.6% of the energy fluence for chest and 0.7% for abdomen CT examinations. Reducing the patient size to 10 kg increases transmission by an order of magnitude. For 70 kg patients, effective energies in body CT range from approximately 50 keV at 80 kVp to approximately 67 keV at 140 kVp; increasing patient size from 10 to 120 kg resulted in an increase in effective photon energy of approximately 4 keV. The x-ray transmission data and effective photon energy data can be used to determine CT image noise and image contrast, respectively, and information on patient size and composition can be used to determine patient doses.

Visualization of magnetic dipolar interaction based on scanning transmission X-ray microscopy

International Nuclear Information System (INIS)

Ohtori, Hiroyuki; Iwano, Kaoru; Takeichi, Yasuo; Ono, Kanta; Mitsumata, Chiharu; Yano, Masao; Kato, Akira; Miyamoto, Noritaka; Shoji, Tetsuya; Manabe, Akira

2014-01-01

Using scanning transmission X-ray microscopy (STXM), in this report we visualized the magnetic dipolar interactions in nanocrystalline Nd-Fe-B magnets and imaged their magnetization distributions at various applied fields. We calculated the magnetic dipolar interaction by analyzing the interaction between the magnetization at each point and those at the other points on the STXM image.

3-d chemical imaging using angle-scan nanotomography in a soft X-ray scanning transmission X-ray microscope

Energy Technology Data Exchange (ETDEWEB)

Hitchcock, A.P.; Johansson, G.A. [McMaster, BIMR, Hamilton (Canada); Mitchell, G.E. [Dow Chemical, Analytical Science, Midland, MI (United States); Keefe, M.H. [Dow Chemical, Dow Latex, Midland, MI (United States); Tyliszcak, T. [LBNL, Advanced Light Source, Berkeley, CA (United States)

2008-08-15

Three-dimensional chemical mapping using angle scan nanotomography in a soft X-ray scanning transmission X-ray microscope (STXM) has been used to investigate the spatial distributions of a low density polyacrylate polyelectrolyte ionomer inside submicron sized polystyrene microspheres. Acquisition of tomograms at multiple photon energies provides true, quantifiable 3-d chemical sensitivity. Both pre-O 1s and C 1s results are shown. The study reveals aspects of the 3-d distribution of the polyelectrolyte that were inferred indirectly or had not been known prior to this study. The potential and challenges for extension of the technique to studies of other polymeric and to biological systems is discussed. (orig.)

Quantifying vertical stress transmission and compaction-induced soil structure using sensor mat and X-ray computed tomography

DEFF Research Database (Denmark)

Naveed, Muhammad; Schjønning, Per; Keller, Thomas

2016-01-01

tillage. In this study, partially confined uniaxial compression tests were carried out on intact topsoil columns placed on subsoil columns. Two methods were employed for estimation of stress transmission in soil: (i) soil deformation patterns were quantified using X-ray CT and converted to stress......Accurate estimation of stress transmission in soil and quantification of compaction-induced soil pore structure is important for efficient soil use and management. Continuum mechanics have so far mostly been applied for agricultural soils, even if topsoil structure is aggregated due to regular...... distributions, and (ii) a tactile sensor mat was employed for measuring stresses at the interface of the topsoil and subsoil columns. The resulting soil pore structure under applied stresses was quantified using X-ray CT and by air-permeability measurements. In topsoil discrete stress transmission patterns were...

Transmission x-ray microscopy at Diamond-Manchester I13 Imaging Branchline

Energy Technology Data Exchange (ETDEWEB)

Vila-Comamala, Joan, E-mail: joan.vila.comamala@gmail.com; Wagner, Ulrich; Bodey, Andrew J.; Garcia-Fernandez, Miryam; Rau, Christoph [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom); Bosgra, Jeroen; David, Christian [Paul Scherrer Institut, 5232 PSI-Villigen (Switzerland); Eastwood, David S. [Manchester X-ray Imaging Facility, School of Materials, University of Manchester, Manchester M13 9PL, UK and Research Complex at Harwell, Harwell Campus, Didcot OX11 0FA (United Kingdom)

2016-01-28

Full-field Transmission X-ray Microscopy (TXM) has been shown to be a powerful method for obtaining quantitative internal structural and chemical information from materials at the nanoscale. The installation of a Full-field TXM station will extend the current microtomographic capabilities of the Diamond-Manchester I13 Imaging Branchline at Diamond Light Source (UK) into the sub-100 nm spatial resolution range using photon energies from 8 to 14 keV. The dedicated Full-field TXM station will be built in-house with contributions of Diamond Light Source support divisions and via collaboration with the X-ray Optics Group of Paul Scherrer Institut (Switzerland) which will develop state-of-the-art diffractive X-ray optical elements. Preliminary results of the I13 Full-field TXM station are shown. The Full-field TXM will become an important Diamond Light Source direct imaging asset for material science, energy science and biology at the nanoscale.

Transmission x-ray microscopy at Diamond-Manchester I13 Imaging Branchline

International Nuclear Information System (INIS)

Vila-Comamala, Joan; Wagner, Ulrich; Bodey, Andrew J.; Garcia-Fernandez, Miryam; Rau, Christoph; Bosgra, Jeroen; David, Christian; Eastwood, David S.

2016-01-01

Full-field Transmission X-ray Microscopy (TXM) has been shown to be a powerful method for obtaining quantitative internal structural and chemical information from materials at the nanoscale. The installation of a Full-field TXM station will extend the current microtomographic capabilities of the Diamond-Manchester I13 Imaging Branchline at Diamond Light Source (UK) into the sub-100 nm spatial resolution range using photon energies from 8 to 14 keV. The dedicated Full-field TXM station will be built in-house with contributions of Diamond Light Source support divisions and via collaboration with the X-ray Optics Group of Paul Scherrer Institut (Switzerland) which will develop state-of-the-art diffractive X-ray optical elements. Preliminary results of the I13 Full-field TXM station are shown. The Full-field TXM will become an important Diamond Light Source direct imaging asset for material science, energy science and biology at the nanoscale

Transmission x-ray microscopy at Diamond-Manchester I13 Imaging Branchline

Science.gov (United States)

Vila-Comamala, Joan; Bosgra, Jeroen; Eastwood, David S.; Wagner, Ulrich; Bodey, Andrew J.; Garcia-Fernandez, Miryam; David, Christian; Rau, Christoph

2016-01-01

Full-field Transmission X-ray Microscopy (TXM) has been shown to be a powerful method for obtaining quantitative internal structural and chemical information from materials at the nanoscale. The installation of a Full-field TXM station will extend the current microtomographic capabilities of the Diamond-Manchester I13 Imaging Branchline at Diamond Light Source (UK) into the sub-100 nm spatial resolution range using photon energies from 8 to 14 keV. The dedicated Full-field TXM station will be built in-house with contributions of Diamond Light Source support divisions and via collaboration with the X-ray Optics Group of Paul Scherrer Institut (Switzerland) which will develop state-of-the-art diffractive X-ray optical elements. Preliminary results of the I13 Full-field TXM station are shown. The Full-field TXM will become an important Diamond Light Source direct imaging asset for material science, energy science and biology at the nanoscale.

Simbol-X Mirror Module Thermal Shields: I-Design and X-Ray Transmission

Science.gov (United States)

Collura, A.; Barbera, M.; Varisco, S.; Basso, S.; Pareschi, G.; Tagliaferri, G.; Ayers, T.

2009-05-01

The Simbol-X mission is designed to fly in formation flight configuration. As a consequence, the telescope has both ends open to space, and thermal shielding at telescope entrance and exit is required to maintain temperature uniformity throughout the mirrors. Both mesh and meshless solutions are presently under study for the shields. We discuss the design and the X-ray transmission.

Simbol-X Mirror Module Thermal Shields: I - Design and X-Ray Transmission

International Nuclear Information System (INIS)

Collura, A.; Varisco, S.; Barbera, M.; Basso, S.; Pareschi, G.; Tagliaferri, G.; Ayers, T.

2009-01-01

The Simbol-X mission is designed to fly in formation flight configuration. As a consequence, the telescope has both ends open to space, and thermal shielding at telescope entrance and exit is required to maintain temperature uniformity throughout the mirrors. Both mesh and meshless solutions are presently under study for the shields. We discuss the design and the X-ray transmission.

Data transmission from the DRON-2 X-ray diffractometers to a computer

International Nuclear Information System (INIS)

Abramov, V.G.; Monov, N.A.; Sazonov, V.F.; Chernomorskaya, E.A.

1991-01-01

The circuit of data transmission from DRON-2 X-ray diffractometer to a measurement-computation complex based on UVK SM-3 computer and CAMAC crate is described. The data is transmitted along two-wire TRP 1x2 telephone line of 'current loop type'. Pulses from intensity channel outlet are transmitted as unipolar mark pulses of ∼1 μs duration. The channels are separated by amplitudes

An angle-dependent estimation of CT x-ray spectrum from rotational transmission measurements

International Nuclear Information System (INIS)

Lin, Yuan; Samei, Ehsan; Ramirez-Giraldo, Juan Carlos; Gauthier, Daniel J.; Stierstorfer, Karl

2014-01-01

Purpose: Computed tomography (CT) performance as well as dose and image quality is directly affected by the x-ray spectrum. However, the current assessment approaches of the CT x-ray spectrum require costly measurement equipment and complicated operational procedures, and are often limited to the spectrum corresponding to the center of rotation. In order to address these limitations, the authors propose an angle-dependent estimation technique, where the incident spectra across a wide range of angular trajectories can be estimated accurately with only a single phantom and a single axial scan in the absence of the knowledge of the bowtie filter. Methods: The proposed technique uses a uniform cylindrical phantom, made of ultra-high-molecular-weight polyethylene and positioned in an off-centered geometry. The projection data acquired with an axial scan have a twofold purpose. First, they serve as a reflection of the transmission measurements across different angular trajectories. Second, they are used to reconstruct the cross sectional image of the phantom, which is then utilized to compute the intersection length of each transmission measurement. With each CT detector element recording a range of transmission measurements for a single angular trajectory, the spectrum is estimated for that trajectory. A data conditioning procedure is used to combine information from hundreds of collected transmission measurements to accelerate the estimation speed, to reduce noise, and to improve estimation stability. The proposed spectral estimation technique was validated experimentally using a clinical scanner (Somatom Definition Flash, Siemens Healthcare, Germany) with spectra provided by the manufacturer serving as the comparison standard. Results obtained with the proposed technique were compared against those obtained from a second conventional transmission measurement technique with two materials (i.e., Cu and Al). After validation, the proposed technique was applied to measure

Broadband transmission masks, gratings and filters for extreme ultraviolet and soft X-ray lithography

International Nuclear Information System (INIS)

Brose, S.; Danylyuk, S.; Juschkin, L.; Dittberner, C.; Bergmann, K.; Moers, J.; Panaitov, G.; Trellenkamp, St.; Loosen, P.; Grützmacher, D.

2012-01-01

Lithography and patterning on a nanometre scale with extreme ultraviolet (EUV) and soft X-ray radiation allow creation of high resolution, high density patterns independent of a substrate type. To realize the full potential of this method, especially for EUV proximity printing and interference lithography, a reliable technology for manufacturing of the transmission masks and gratings should be available. In this paper we present a development of broadband amplitude transmission masks and gratings for extreme ultraviolet and soft X-ray lithography based on free-standing niobium membranes. In comparison with a standard silicon nitride based technology the transmission masks demonstrate high contrast not only for in-band EUV (13.5 nm) radiation but also for wavelengths below Si L-absorption edge (12.4 nm). The masks and filters with free standing areas up to 1000 × 1000 μm 2 and 100 nm to 300 nm membrane thicknesses are shown. Electron beam structuring of an absorber layer with dense line and dot patterns with sub-50 nm structures is demonstrated. Diffractive and filtering properties of obtained structures are examined with EUV radiation from a gas discharge plasma source. - Highlights: ► Broadband transmission masks for EUV proximity and interference lithography. ► Technology for free standing niobium membranes with areas up to 1 mm 2 . ► High density patterns with periods of 100 nm and structure sizes below 40 nm. ► Measured diffraction efficiency at 11 nm is in agreement with the theory. ► Produced masks can be effectively used with wavelengths between 6 nm and 17 nm.

Kaolinite flocculation induced by smectite addition - a transmission X-ray microscopic study.

Science.gov (United States)

Zbik, Marek S; Song, Yen-Fang; Frost, Ray L

2010-09-01

The influence of smectite addition on kaolinite suspensions in water was investigated by transmission X-ray microscopy (TXM) and Scanning Electron Microscopy (SEM). Sedimentation test screening was also conducted. Micrographs were processed by the STatistic IMage Analysing (STIMAN) program and structural parameters were calculated. From the results of the sedimentation tests important influences of small smectite additions to about 3wt.% on kaolinite suspension flocculation has been found. In order to determine the reason for this smectite impact on kaolinite suspension, macroscopic behaviour micro-structural examination using Transmission X-ray Microscope (TXM) and SEM has been undertaken. TXM & SEM micrographs of freeze-dried kaolinite-smectite suspensions with up to 20% smectite showed a high degree of orientation of the fabric made of highly oriented particles and greatest density when 3wt.% of smectite was added to the 10wt.% dense kaolinite suspension. In contrast, suspensions containing pure kaolinite do not show such platelet mutual orientation but homogenous network of randomly oriented kaolinite platelets. This suggests that in kaolinite-smectite suspensions, smectite forms highly oriented basic framework into which kaolinite platelets may bond in face to face preferential contacts strengthening structure and allowing them to show plastic behaviour which is cause of platelets orientation. Copyright 2010 Elsevier Inc. All rights reserved.

Final Report on Small Particle Speciation for Forensics Analysis by Soft X-ray Scanning Transmission X-ray Microscopy

Energy Technology Data Exchange (ETDEWEB)

Pacold, J. I. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Altman, A. B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Donald, S B [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dai, Z. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Davisson, M. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Holliday, K S [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knight, K. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kristo, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Minasian, S. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nelson, A J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tyliszczak, T [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Booth, C. H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shuh, D. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-09-30

Materials of interest for nuclear forensic science are often highly heterogeneous, containing complex mixtures of actinide compounds in a wide variety of matrices. Scanning transmission X-ray microscopy (STXM) is ideally suited to study such materials, as it can be used to chemically image specimens by acquiring X-ray absorption near-edge spectroscopy (XANES) data with 25 nm spatial resolution. In particular, STXM in the soft X-ray synchrotron radiation regime (approximately 120 – 2000 eV) can collect spectroscopic information from the actinides and light elements in a single experiment. Thus, STXM combines the chemical sensitivity of X-ray absorption spectroscopy with high spatial resolution in a single non-destructive characterization method. This report describes the application of STXM to a broad range of nuclear materials. Where possible, the spectroscopic images obtained by STXM are compared with information derived from other analytical methods, and used to make inferences about the process history of each material. STXM measurements can yield information including the morphology of a sample, “elemental maps” showing the spatial distribution of major chemical constituents, and XANES spectra from localized regions of a sample, which may show spatial variations in chemical composition.

Characterization of the Carancas-Puno meteorite by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Moessbauer spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ceron Loayza, Maria L., E-mail: malucelo@hotmail.com; Bravo Cabrejos, Jorge A. [Universidad Nacional Mayor de San Marcos, Laboratorio de Analisis de Suelos, Facultad de Ciencias Fisicas (Peru)

2011-11-15

We report the results of the study of a meteorite that impacted an inhabited zone on 15 September 2007 in the neighborhood of the town of Carancas, Puno Region, about 1,300 km south of Lima. The analysis carried out by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Moessbauer spectroscopy (at room temperature and at 4.2 K), reveal the presence in the meteorite sample of magnetic sites assigned to taenite (Fe,Ni) and troilite (Fe,S) phases, and of two paramagnetic doublets assigned to Fe{sup 2 + }, one associated with olivine and the other to pyroxene. In accord with these results, this meteorite is classified as a type IV chondrite meteorite.

Soft x-ray transmission measurements on thin films used for XMM CCD-filters

Science.gov (United States)

Stephan, K.-H.; Reppin, C.; Maier, H. J.; Frischke, D.; Fuchs, D.; Müller, P.

1997-02-01

We have been developing optical filters for ESA's X-ray astronomy project XMM (X-ray Multi Mirror Mission). Specific CCDs will be used as detectors in the focal plane on board the observatory (1). Since these detectors are sensitive from the X-ray to the near infrared spectral range, X-ray observations require optical filters, which combine a high transparency for photon energies in the soft X-ray region and a high opacity for ultraviolet and visible radiation as well. With respect to the mission goal in orbit three types of flight model filters are designed having different spectral transmittance functions. We report on one of these types, a so-called "thick" filter, which has been realized within the EQM (Electrical Qualification Model)-phase of the project. The filter features a cut-off in the extreme ultraviolet spectral range and suppresses radiation below ˜10 eV photon energy by more than 8 orders of magnitude. It has an effective aperture of 73 mm without any support structure. A 0.35 μm thick polypropylene carrier foil is coated with metallic films of Al and Sn. We describe transmission measurements in the soft X-ray photon energy range to determine the thickness of the individual layers and present the optical performance data of the filter.

Sistema ultra-sonico para medida volumetrica

OpenAIRE

Isaias Ferreira da Silva

1999-01-01

Resumo: Um método inovador para a medida do volume de um líquido dentro de um recipiente fechado é proposto. A motivação deste trabalho é a aplicação do método para a medida do volume de combustível dentro de um tanque de automóvel. Este método se baseia no fenômeno de reverberação sonora que relaciona o tempo de decaimento da intensidade do som dentro de um ambiente com o seu volume. Este tempo, conhecido como tempo de reverberação, está associado ao volume vazio dentro do recipiente, ao mat...

Design parameters of transmission curved crystal spectrometer for hard X-ray diagnoses

International Nuclear Information System (INIS)

Qian Feng; Cao Leifeng; Zhou Weimin; Zhao Zongqing; Gu Yuqiu; Yan Yonghong; Wei Lai; Xiao Shali

2013-01-01

The high resolving measurement of hard X-ray spectra generated in laser-produced plasma is usually performed using a cylindrically curved crystal spectrometer. In this paper, theoretical analysis and numerical simulation are performed to investigate the dependence of the energy range and resolving power on various design parameters, including crystal bending radius, source to crystal standoff distance, source size, location of the detector, etc. The investigation provides a means to design and develop cylindrically transmission curved crystal spectrometer which is used in hard X-ray diagnostics. The results show that crystal bending radius has a great influence on energy range of spectra and resolving power, and the separation between the spectral lines increases with the distance behind the focal circle faster than the line width, resulting in increased resolving power with distance. (authors)

Instrumentation for in situ flow electrochemical Scanning Transmission X-ray Microscopy (STXM)

Science.gov (United States)

Prabu, Vinod; Obst, Martin; Hosseinkhannazer, Hooman; Reynolds, Matthew; Rosendahl, Scott; Wang, Jian; Hitchcock, Adam P.

2018-06-01

We report the design and performance of a 3-electrode device for real time in situ scanning transmission X-ray microscopy studies of electrochemical processes under both static (sealed, non-flow) conditions and with a continuous flow of electrolytes. The device was made using a combination of silicon microfabrication and 3D printing technologies. The performance is illustrated by results of a study of copper deposition and stripping at a gold working electrode. X-ray absorption spectromicroscopy at the Cu 2p edge was used to follow the evolution as a function of potential and time of the spatial distributions of Cu(0) and Cu(i) species electro-deposited from an aqueous solution of copper sulphate. The results are interpreted in terms of competing mechanisms for the reduction of Cu(ii).

Diffuse x-ray scattering and transmission electron microscopy study of defects in antimony-implanted silicon

Science.gov (United States)

Takamura, Y.; Marshall, A. F.; Mehta, A.; Arthur, J.; Griffin, P. B.; Plummer, J. D.; Patel, J. R.

2004-04-01

Ion implantation followed by laser annealing has been used to create supersaturated and electrically active concentrations of antimony in silicon. Upon subsequent thermal annealing, however, these metastable dopants deactivate towards the equilibrium solubility limit. In this work, the formation of inactive antimony structures has been studied with grazing incidence diffuse x-ray scattering, and transmission electron microscopy, and the results are correlated to previous high-resolution x-ray diffraction data. We find that at a concentration of 6.0×1020 cm-3, small, incoherent clusters of radius 3-4 Å form during annealing at 900 °C. At a higher concentration of 2.2×1021 cm-3, deactivation at 600 °C occurs through the formation of small, antimony aggregates and antimony precipitates. The size of these precipitates from diffuse x-ray scattering is roughly 15 Å in radius for anneal times from 15 to 180 seconds. This value is consistent with the features observed in high-resolution and mass contrast transmission electron microscopy images. The coherent nature of the aggregates and precipitates causes the expansion of the surrounding silicon matrix as the deactivation progresses. In addition, the sensitivity of the diffuse x-ray scattering technique has allowed us to detect the presence of small clusters of radius ˜2 Å in unprocessed Czochralski silicon wafers. These defects are not observed in floating zone silicon wafers, and are tentatively attributed to thermal donors.

Measurement of structured purple soil porosity by using gamma ray transmission technique

International Nuclear Information System (INIS)

Costa, Elizabeth Cristina S. da; Rocha, Wilson Roberto Dejato da; Oliveira, Ricardo M. de; Silva, Luzeli Moreira da; Moreira, Anderson Camargo; Portezan, Otaio Portezan; Appoloni, Carlos Roberto; Coimbra, Melayne Martins

2002-01-01

The soil structure defines the particle arrangement which in turn largely determines the pore size distribution. In this work, we present the measurements of total, macro and microporosity for TRe soil with clayey texture. Soil samples were collected from a trench located at University of Londrina. The deformed and undeformed soil samples were collected from soil surface down to the depth of 0,50 m in 0,10 m intervals and separated into six aggregate size classes: 0.053; 0.125; 0.30; 0.71; 2 e 4 mm. We also prepared samples mixing different size classes, like as: (4+0.125), (2+0.125), (4+2+0.71), (4+2+0.30) e (4+0.30+0.125)mm. Measurements of particle density and aggregate bulk density using conventional method were performed to all depths. The linear soil attenuation coefficients and aggregate soil attenuation coefficients were measured with gamma-ray transmission system using an 241 Am (59,53 keV and 100 mCi) radiation source, a (2 x 2) in NaI scintillation detector, cylindric collimators (2 mm diameter to the source and 5 mm diameter to the detector) and gamma spectrometry standard electronics, connected to a multichannel. The obtained results for total, macro and microporosity are in a good agreement with the ones using the convention method, showing the applicability of the gamma-ray transmission method. (author)

Single x-ray transmission system for bone mineral density determination

International Nuclear Information System (INIS)

Jimenez-Mendoza, Daniel; Vargas-Vazquez, Damian; Espinosa-Arbelaez, Diego G.; Giraldo-Betancur, Astrid L.; Hernandez-Urbiola, Margarita I.; Rodriguez-Garcia, Mario E.

2011-01-01

Bones are the support of the body. They are composed of many inorganic compounds and other organic materials that all together can be used to determine the mineral density of the bones. The bone mineral density is a measure index that is widely used as an indicator of the health of the bone. A typical manner to evaluate the quality of the bone is a densitometry study; a dual x-ray absorptiometry system based study that has been widely used to assess the mineral density of some animals' bones. However, despite the success stories of utilizing these systems in many different applications, it is a very expensive method that requires frequent calibration processes to work properly. Moreover, its usage in small species applications (e.g., rodents) has not been quite demonstrated yet. Following this argument, it is suggested that there is a need for an instrument that would perform such a task in a more reliable and economical manner. Therefore, in this paper we explore the possibility to develop a new, affordable, and reliable single x-ray absorptiometry system. The method consists of utilizing a single x-ray source, an x-ray image sensor, and a computer platform that all together, as a whole, will allow us to calculate the mineral density of the bone. Utilizing an x-ray transmission theory modified through a version of the Lambert-Beer law equation, a law that expresses the relationship among the energy absorbed, the thickness, and the absorption coefficient of the sample at the x-rays wavelength to calculate the mineral density of the bone can be advantageous. Having determined the parameter equation that defines the ratio of the pixels in radiographies and the bone mineral density [measured in mass per unit of area (g/cm 2 )], we demonstrated the utility of our novel methodology by calculating the mineral density of Wistar rats' femur bones.

Transmission of broad W/Rh and W/Al (target/filter) x-ray beams operated at 25-49 kVp through common shielding materials.

Science.gov (United States)

Li, Xinhua; Zhang, Da; Liu, Bob

2012-07-01

To provide transmission data for broad 25-39 kVp (kilovolt peak) W/Rh and 25-49 kVp W/Al (target/filter, W-tungsten, Rh-rhodium, and Al-aluminum) x-ray beams through common shielding materials, such as lead, concrete, gypsum wallboard, wood, steel, and plate glass. The unfiltered W-target x-ray spectra measured on a Selenia Dimensions system (Hologic Inc., Bedford, MA) set at 20-49 kVp were, respectively, filtered using 50-μm Rh and 700-μm Al, and were subsequently used for Monte Carlo calculations. The transmission of broad x-ray beams through shielding materials was simulated using Geant4 low energy electromagnetic physics package with photon- and electron-processes above 250 eV, including photoelectric effect, Compton scattering, and Rayleigh scattering. The calculated transmission data were fitted using Archer equation with a robust fitting algorithm. The transmission of broad x-ray beams through the above-mentioned shielding materials was calculated down to about 10(-5) for 25-39 kVp W/Rh and 25-49 kVp W/Al. The fitted results of α, β, and γ in Archer equation were provided. The α values of kVp ≥ 40 were approximately consistent with those of NCRP Report No. 147. These data provide inputs for the shielding designs of x-ray imaging facilities with W-anode x-ray beams, such as from Selenia Dimensions.

Estudio de medidas y proyectos de movilidad ambiental en el entorno europeo

OpenAIRE

Moya González, Luis

2011-01-01

Índice Introducción Tablas resumen de medidas ambientales sobre movilidad Medidas específicas para ciudades históricas Mejora del transporte públicoGestión de automóvilesVehículos compartidosInnovación en vehículos y carburantesTransporte de mercancíasBicicletasPeatonesGestión: demanda, incentivos, etcOtras medidasMedidas coordinadas y planes integrales Experiencias europeasLa situación en EspañaProgramas y proyectos subvencionados Programas de la Unión EuropeaProyectos internacionales no vin...

MEDIDA SOCIOEDUCATIVA DE INTERNAÇÃO: ESTRATÉGIA PUNITIVA OU PROTETIVA?

Directory of Open Access Journals (Sweden)

Andrea Cristina Coelho Scisleski

2015-12-01

Full Text Available ResumoEste artigo problematiza como os jovens em conflito com a lei são administrados nas medidas socioeducativas de internação e busca a discussão das diferenças entre as formas de atender aqueles que recebem medidas de proteção e aqueles que recebem medidas socioeducativas. No que concerne à gestão, encontra-se uma separação na administração das medidas de proteção e das medidas socioeducativas em meio aberto, geridas pela Assistência Social, e as medidas socioeducativas de internação, geridas pela Segurança Pública. A pesquisa se desenvolveu pelo método cartográfico, que abrangeu entrevistas realizadas com profissionais do sistema socioeducativo, visitas às unidades de internação, leitura de processos jurídicos e oitivas de audiências na Vara da Infância e da Juventude. Conclui-se que a proteção integral preconizada pelo ECA não atinge todos, como é o caso dos adolescentes em conflito com a lei que estão internados, tendo seus direitos violados em prol da manutenção da segurança da população.

Multispecies Biofilms Transform Selenium Oxyanions into Elemental Selenium Particles: Studies Using Combined Synchrotron X-ray Fluorescence Imaging and Scanning Transmission X-ray Microscopy

Energy Technology Data Exchange (ETDEWEB)

Yang, Soo In; George, Graham N.; Lawrence, John R.; Kaminskyj, Susan G. W.; Dynes, James J.; Lai, Barry; Pickering, Ingrid J.

2016-10-04

Selenium (Se) is an element of growing environmental concern, because low aqueous concentrations can lead to biomagnification through the aquatic food web. Biofilms, naturally occurring microbial consortia, play numerous important roles in the environment, especially in biogeochemical cycling of toxic elements in aquatic systems. The complexity of naturally forming multispecies biofilms presents challenges for characterization because conventional microscopic techniques require chemical and physical modifications of the sample. Here, multispecies biofilms biotransforming selenium oxyanions were characterized using X-ray fluorescence imaging (XFI) and scanning transmission X-ray microscopy (STXM). These complementary synchrotron techniques required minimal sample preparation and were applied correlatively to the same biofilm areas. Sub-micrometer XFI showed distributions of Se and endogenous metals, while Se K-edge X-ray absorption spectroscopy indicated the presence of elemental Se (Se0). Nanoscale carbon K-edge STXM revealed the distributions of microbial cells, extracellular polymeric substances (EPS), and lipids using the protein, saccharide, and lipid signatures, respectively, together with highly localized Se0 using the Se LIII edge. Transmission electron microscopy showed the electron-dense particle diameter to be 50–700 nm, suggesting Se0 nanoparticles. The intimate association of Se0 particles with protein and polysaccharide biofilm components has implications for the bioavailability of selenium in the environment.

Nanoscale characterization of local structures and defects in photonic crystals using synchrotron-based transmission soft X-ray microscopy

Science.gov (United States)

Nho, Hyun Woo; Kalegowda, Yogesh; Shin, Hyun-Joon; Yoon, Tae Hyun

2016-01-01

For the structural characterization of the polystyrene (PS)-based photonic crystals (PCs), fast and direct imaging capabilities of full field transmission X-ray microscopy (TXM) were demonstrated at soft X-ray energy. PS-based PCs were prepared on an O2-plasma treated Si3N4 window and their local structures and defects were investigated using this label-free TXM technique with an image acquisition speed of ~10 sec/frame and marginal radiation damage. Micro-domains of face-centered cubic (FCC (111)) and hexagonal close-packed (HCP (0001)) structures were dominantly found in PS-based PCs, while point and line defects, FCC (100), and 12-fold symmetry structures were also identified as minor components. Additionally, in situ observation capability for hydrated samples and 3D tomographic reconstruction of TXM images were also demonstrated. This soft X-ray full field TXM technique with faster image acquisition speed, in situ observation, and 3D tomography capability can be complementally used with the other X-ray microscopic techniques (i.e., scanning transmission X-ray microscopy, STXM) as well as conventional characterization methods (e.g., electron microscopic and optical/fluorescence microscopic techniques) for clearer structure identification of self-assembled PCs and better understanding of the relationship between their structures and resultant optical properties. PMID:27087141

Simultaneous transmission of neutrons and gamma rays (NEUGAT) to measure fat in meat

International Nuclear Information System (INIS)

Bartle, C.M.

1991-01-01

A new method has been established for the measurement of fat in boneless meat based on the simultaneous transmission through the mixture of neutrons and γ-rays (NEUGAT Technique). The method is insensitive to the manner in which the fat is distributed in the meat, and to the thickness of the mixture. The method has been applied in a meat packing plant to fat measurement in boxes of boneless meat for export. (author)

Determination of tungsten target parameters for transmission X-ray tube: A simulation study using Geant4

Energy Technology Data Exchange (ETDEWEB)

Nasseri, Mohammad M. [School of Plasma Physics and Nuclear Fusion, Institute of Nuclear Science and Technology (AEOI), Tehran (Iran, Islamic Republic of)

2016-06-15

Transmission X-ray tubes based on carbon nanotube have attracted significant attention recently. In most of these tubes, tungsten is used as the target material. In this article, the well-known simulator Geant4 was used to obtain some of the tungsten target parameters. The optimal thickness for maximum production of usable X-rays when the target is exposed to electron beams of different energies was obtained. The linear variation of optimal thickness of the target for different electron energies was also obtained. The data obtained in this study can be used to design X-ray tubes. A beryllium window was considered for the X-ray tube. The X-ray energy spectra at the moment of production and after passing through the target and window for different electron energies in the 30-110 keV range were also obtained. The results obtained show that with a specific thickness, the target material itself can act as filter, which enables generation of X-rays with a limited energy.

Studies of soft x-ray transmission through grid supported CH layers

Science.gov (United States)

Davis, J. S.; Keiter, P. A.; Klein, S. R.; Frank, Y.; Drake, R. P.; Shvarts, D.

2017-10-01

Recent experiments have shown that it may be possible to use laser-heated high-Z foils to drive new radiation transport (RadTran) experiments in gas fill tubes. These tubes must be pressurized above 1atm and the x-ray source needs to be physically separated from the gas. To achieve this, a grid-supported CH seal is implemented. The grid reduces the total surface area of the gas-seal interaction region lowering the thickness requirements for the CH layer. However, as mesh spacing is reduced, hole closure from wire ablation may reduce the x-ray flux. To optimize the seal design, experiments were performed measuring x-ray transmission through CH layers supported by meshes composed of copper, gold, or stainless steel and using hexagonal or square mesh geometries. The x-ray source was formed by heating a 0.5 μm thick planar gold foil with a 4 ns laser pulse at an intensity of 2 ×1014 W / cm 2. Emission data was collected using an x-ray framing camera and a Dante photodiode array. Experiments show that the CH layers can reach effective temperatures of nearly 100 eV but mesh design significantly affects performance, with a nearly 20 eV difference between the best and worst performing seal targets. This talk will discuss our findings and their impact on future RadTran experiments. This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HED Laboratory Plasmas, Grant Number DE-NA0001840, the National LUFP, Grant Number DE-NA0000850, and through NNSA/OICF under Cooperatvie Agreement No. DE-FC52-08NA2830.

Microstructural characterization of industrial foams by gamma ray transmission and X-ray microtomography; Caracterizacao microestrutural de espumas industriais por transmissao de raios gama e microtomografia de raios X

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Luiz Eduardo

2004-07-01

This work presents the total porosity measurements of the aluminum and silicon carbide (SiC) foams samples. For porosity determination the gamma ray transmission and X-ray microtomography with conic beam techniques were used. These methods have more advantage than conventional ones, because they are non destructive and provide more details of the analyzed material porous structure. The aluminum foam samples with 10, 20, 30, 40 and 45 ppi (pores per inch) and SiC ceramic foam samples with 20, 30, 45, 60, 75, 80 and 90 ppi were analysed by gamma transmission. The SiC 60, 75 and 90 ppi samples were also analyzed by X-ray microtomography. For the gamma ray transmission measurements it was used an {sup 241} Am source (59.53 keV), a NaI(Tl) scintillation detector, collimators, a XYZ micrometric table and standard gamma spectrometry electronics connected to a multichannel analyzer, at the LFNA/UEL. For the X-ray microtomographic measurements, the Fein Focus X-ray system of the Nuclear Instrumentation Laboratory of the COPPE, located at the Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, was used. This equipment provide us images with micrometric resolution (53.48 {mu}m) using a conic X-ray beam and bidimensional detection. The microtomographic images were pre-processed and analyzed by the Imago software, developed at Porous Media and Materials Thermophysical Properties Laboratory (LMPT) of the Mechanical Engineering Department, located at Universidade Federal de Santa Catarina, Florianopolis, SC. Employing the The Imago software it was calculated the total porosity, pore size distribution and autocorrelation function C(u) of the binarized microtomographic images of the each sample. The microtomographic 3-D image of each sample was compared with 3-D image reconstructed by the Gaussian truncated method. This method generates a periodic 3-D porous structure by using of the autocorrelation function of one 2-D cross sectional image of the sample. (author)

Nanoscale examination of microdamage in sheep cortical bone using synchrotron radiation transmission x-ray microscopy.

Directory of Open Access Journals (Sweden)

Garry R Brock

Full Text Available Microdamage occurs in bone through repeated and excessive loading. Accumulation of microdamage weakens bone, leading to a loss of strength, stiffness and energy dissipation in the tissue. Imaging techniques used to examine microdamage have typically been limited to the microscale. In the current study microdamage was examined at the nanoscale using transmission x-ray microscopy with an x-ray negative stain, lead-uranyl acetate. Microdamage was generated in notched and unnotched beams of sheep cortical bone (2×2×20 mm, with monotonic and fatigue loading. Bulk sections were removed from beams and stained with lead-uranyl acetate to identify microdamage. Samples were sectioned to 50 microns and imaged using transmission x-ray microscopy producing projection images of microdamage with nanoscale resolution. Staining indicated microdamage occurred in both the tensile and compressive regions. A comparison between monotonic and fatigue loading indicated a statistically significant greater amount of stain present in fatigue loaded sections. Microdamage occurred in three forms: staining to existing bone structures, cross hatch damage and a single crack extending from the notch tip. Comparison to microcomputed tomography demonstrated differences in damage morphology and total damage between the microscale and nanoscale. This method has future applications for understanding the underlying mechanisms for microdamage formation as well as three-dimensional nanoscale examination of microdamage.

Monitoring the mass of UF6 gas and uranium deposits in aluminium pipes using X-ray fluorescence and X-ray transmission gauges

International Nuclear Information System (INIS)

Packer, T.W.; Smith, S.M.

1984-12-01

In order to determine the enrichment of UF 6 gas in centrifuge plant pipework it is necessary to measure the mass of the gas (pressure) and the mass per unit area of any uranium deposited on the pipe. This paper shows that it is possible to determine the pressure of the UF 6 gas in pipes 120 mm in diameter using an energy-dispersive X-ray fluorescence spectrometer. Results are also given of transmission measurements made using a low power X-ray generator operated at two different applied voltages. A method of using the two measurements to determine the mass per unit area of deposited uranium is described. (author)

Non-invasive analysis of industrial products using the simultaneous transmission of neutrons and gamma rays (Neugat) method

International Nuclear Information System (INIS)

Bartle, C.M.

1998-01-01

This research programme is designed to develop industrial measurement systems utilising simultaneous transmission of neutrons and gamma rays (Neugat method). Descriptions of these systems have been given in reports and magazine articles, and industrial site trials have been undertaken. (author)

Structural characterization of titanium porous foams by gamma rays transmission and X ray microtomography

International Nuclear Information System (INIS)

Moreira, Anderson C.; Appoloni, Carlos R.

2007-01-01

The advance in porous media studies and the consequent progresses of their applications in medicine, petroleum industry, metallurgy and others, rises the prominence of the area among scientists. This fact increases the research on different characterization techniques of porous materials. In this work three Titanium foams were analyzed by gamma rays transmission (GRT), and one of these was also analyzed by X-ray microtomography (μ-CT). The GRT experimental set consisted by a 2'' x 2''. NaI(Tl) detector, a 241-Am radioactive source (59,53 keV, 100 mCi) and a standard gamma spectrometry electronic chain. In the μ-CT technique it was used a SKYSCAN 1172 scanner consisting of an X-ray tube (20-100 kV and 0-250 μA), a CCD detector and a proper mechanic system for sample and detector movement. The system may reach ∼0.8 μm image resolution. Images of 815 slices of the sample were generated and analyzed by the IMAGO software. It permitted the determination of geometrical parameters like pore size distribution, total porosity and autocorrelation function. The analysis of data, obtained by both techniques, showed that porous media are homogeneous in the reached resolutions (1 mm to GRT and 5 μm to μ-CT). The average total porosities determined by GRT for each sample were φ 1 =53,47±0,36%, φ 2 =55,95±0,23% and φ 3 =56,80±0,56%, and the determined by μ-CT was φ 1 =53,47±0,36%. The porosity data of the Ti-1 sample shows good agreement from both techniques. The pore size distribution, from μ-CT technique of the Ti-1 sample, showed that 57% of porous phase have porous with radius in 20 to 80 μm range. (author)

Monitoring catalyst flow rate in a FCC cold pilot unity by gamma ray transmission measurements

International Nuclear Information System (INIS)

Brito, Marcio F.P.; Netto, Wilson F.S.; Miranda, Marcia V.F.E.S.; Junior, Isacc A.S.; Dantas, Carlos C.; Melo, Silvio B.; Lima, Emerson A.O.

2013-01-01

A model for monitoring catalyst mass flow in riser of Fluid Catalytic Cracking - FCC, pilot unity as a function of air flow and solid injection is proposed. The fluidized FCC- catalyst bed system is investigated in an experimental setup the Cold Pilot Unity - CPU by means of gamma ray transmission measurements. Riser in CPU simulates the reactor in FCC process. By automation control air flow is instrumentally measured in riser and the solid injection is manually controlled by valve adjusting. Keeping a constant solid injection, catalyst level at the return column was measured by gamma transmission for several air flow values in riser. The operational condition reached a steady state regime before given to setup a new air flow value. A calibration of catalyst level as a function of air flow in riser is calculated, therefore, a model for solid feed rate is derived. Recent published work evaluates solid concentration in riser of the CPU by means of gamma ray transmission, and a correlation with air velocity is obtained. In this work, the model for solid feed rate was further investigated by carrying out experiments to measure catalyst concentration at the same air flow values. These experiments lead to a model for monitoring catalyst flow in riser as function of solid feed rate and air flow. Simulation with random numbers produced with Matlab software allows to define validation criteria for the model parameters. (author)

A weighted least-squares lump correction algorithm for transmission-corrected gamma-ray nondestructive assay

International Nuclear Information System (INIS)

Prettyman, T.H.; Sprinkle, J.K. Jr.; Sheppard, G.A.

1993-01-01

With transmission-corrected gamma-ray nondestructive assay instruments such as the Segmented Gamma Scanner (SGS) and the Tomographic Gamma Scanner (TGS) that is currently under development at Los Alamos National Laboratory, the amount of gamma-ray emitting material can be underestimated for samples in which the emitting material consists of particles or lumps of highly attenuating material. This problem is encountered in the assay of uranium and plutonium-bearing samples. To correct for this source of bias, we have developed a least-squares algorithm that uses transmission-corrected assay results for several emitted energies and a weighting function to account for statistical uncertainties in the assay results. The variation of effective lump size in the fitted model is parameterized; this allows the correction to be performed for a wide range of lump-size distributions. It may be possible to use the reduced chi-squared value obtained in the fit to identify samples in which assay assumptions have been violated. We found that the algorithm significantly reduced bias in simulated assays and improved SGS assay results for plutonium-bearing samples. Further testing will be conducted with the TGS, which is expected to be less susceptible than the SGS to systematic source of bias

Development of wave length-dispersive soft x-ray emission spectrometers for transmission electron microscopes - an introduction of valence electron spectroscopy for transmission electron microscopy

International Nuclear Information System (INIS)

Terauchi, Masami; Koike, Masato; Fukushima, Kurio; Kimura, Atsushi

2010-01-01

Two types of wavelength-dispersive soft X-ray spectrometers, a high-dispersion type and a conventional one, for transmission electron microscopes were constructed. Those spectrometers were used to study the electronic states of valence electrons (bonding electrons). Both spectrometers extended the acceptable energy regions to higher than 2000 eV. The best energy resolution of 0.08 eV was obtained for an Al L-emission spectrum by using the high-dispersion type spectrometer. By using the spectrometer, C K-emission of carbon allotropes, Cu L-emission of Cu 1-x Zn x alloys and Pt M-emission spectra were presented. The FWHM value of 12 eV was obtained for the Pt Mα-emission peak. The performance of the conventional one was also presented for ZnS and a section specimen of a multilayer device. W-M and Si-K emissions were clearly resolved. Soft X-ray emission spectroscopy based on transmission electron microscopy (TEM) has an advantage for obtaining spectra from a single crystalline specimen with a defined crystal setting. As an example of anisotropic soft X-ray emission, C K-emission spectra of single crystalline graphite with different crystal settings were presented. From the spectra, density of states of π- and σ-bondings were separately derived. These results demonstrated a method to analyse the electronic states of valence electrons of materials in the nanometre scale based on TEM. (author)

Una medida de inflación subyacente exclusion-based para el Perú

OpenAIRE

Hauer, Erik Sebastián

2015-01-01

Hay poco consenso en la literatura sobre el diseño y evaluación de medidas de inflación subyacente. Estudios previos han mostrado que las medidas más técnicas de influencia limitada tienen mejor rendimiento empírico. Sin embargo, es deseado que las medidas de inflación subyacente sean lo más transparentes y replicables posibles, lo cual usualmente resulta en medidas más simples “exclusion-based”. A este respecto, se utiliza una nueva metodología de extracción de señal a la inflación para enco...

Comparison of x-ray computed tomography, through-transmission ultrasound, and low-kV x-ray imaging for characterizing green-state ceramics

International Nuclear Information System (INIS)

Roberts, R.A.; Ellingson, W.A.; Vannier, M.W.

1985-06-01

Green-state MgAl 2 O 4 compact disk specimens have been studied by x-ray computed tomography (CT), through-transmission pulsed ultrasound, and low-kV x-ray imaging to compare the abilities of these nondestructive evaluation (NDE) methods to detect flaws and density variations. X-ray computed tomographic images were obtained from a 125-kV (peak) imaging system with a 512 x 512 matrix and a pixel size of 100 μm. A 3- to 10- MHz focused-beam ultrasonic transducer was used, together with special immersion techniques, to obtain topographical maps of acoustic attenuation and phase velocity; a 30 x 30 matrix was used in the ultrasonic scans. A 35-kV x-ray system with high-resolution type RR film was used to obtain conventional radiographs. Large-scale nonuniform density gradients were detected with CT and ultrasonics in supposedly uniform ceramic disks. In addition, inclusions in the green-state samples were detected by all three methods, with each method providing certain advantages. The influence of grain structure and other ceramic powder characteristics will be examined in the future. 5 refs., 9 figs

Image statistics and nonlinear artifacts in composed transmission x-ray tomography

International Nuclear Information System (INIS)

Duerinckx, A.J.G.

1979-01-01

Knowledge of the image quality and image statistics in Computed Tomography (CT) images obtained with transmission x-ray CT scanners can increase the amount of clinically useful information that can be retrieved. Artifacts caused by nonlinear shadows are strongly object-dependent and are visible over larger areas of the image. No simple technique exists for their complete elimination. One source of artifacts in the first order statistics is the nonlinearities in the measured shadow or projection data used to reconstruct the image. One of the leading causes is the polychromaticity of the x-ray beam used in transmission CT scanners. Ways to improve the resulting image quality and techniques to extract additional information using dual energy scanning are discussed. A unique formalism consisting of a vector representation of the material dependence of the photon-tissue interactions is generalized to allow an in depth analysis. Poly-correction algorithms are compared using this analytic approach. Both quantum and detector electronic noise decrease the quality or information content of first order statistics. Preliminary results are presented using an heuristic adaptive nonlinear noise filter system for projection data. This filter system can be improved and/or modified to remove artifacts in both first and second order image statistics. Artifacts in the second order image statistics arise from the contribution of quantum noise. This can be described with a nonlinear detection equivalent model, similar to the model used to study artifacts in first order statistics. When analyzing these artifacts in second order statistics, one can divide them into linear artifacts, which do not present any problem of interpretation, and nonlinear artifacts, referred to as noise artifacts. A study of noise artifacts is presented together with a discussion of their relative importance in diagnostic radiology

Improvement of air transport data and wall transmission/reflection data in the SKYSHINE code. 2. Calculation of gamma-ray wall transmission and reflection data

Energy Technology Data Exchange (ETDEWEB)

Hayashida, Yoshihisa [Toshiba Corp., Kawasaki, Kanagawa (Japan); Ishikawa, Satoshi; Harima, Yoshiko [CRC Research Institute Inc., Tokyo (Japan); Hayashi, Katsumi; Tayama, Ryuichi [Hitachi Engineering Co. Ltd., Ibaraki (Japan); Hirayama, Hideo [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nemoto, Makoto [Visible Information Center, Tokai, Ibaraki (Japan); Sato, Osamu [Mitsubishi Research Inst., Inc., Tokyo (Japan)

2000-03-01

Transmission and reflection data of concrete and steel for 6.2 MeV gamma-ray in the SKYSHINE code have been generated using up-to-date data and method with a view to improving an accuracy of results. The transmission and reflection data depend on energy and angle. The invariant embedding method, which has merits of producing no negative angular flux and of taking small computer time, is suitable and adopted to the present purpose. Transmission data were calculated for concrete of 12 {approx} 160 cm thick and steel of 4 {approx} 39 cm thick based on the PHOTX library. Reflection data were calculated for semi-infinite slabs of concrete and steel. Consequently, smooth and consistent differential data over whole angle and energy were obtained compared with the original data calculated by discrete ordinates Sn code and Monte Carlo code. In order to use these data in the SKYSHINE code, further verification is needed using various calculation method or experimental data. (author)

desarrollo y validación de un instrumento de medida

Directory of Open Access Journals (Sweden)

Arménio Rego

2005-01-01

Full Text Available El artículo describe cómo un instrumento de medida de la Inteligencia Emocional fue construido y validado. Cuatro etapas fueron seguidas: 1 Fueron escritos 96 ítems con base en la literatura y en trabajo propio de los autores; 2 Fue elaborado un cuestionario y aplicado a una muestra de 339 individuos; 3 Se procedió a un análisis factorial de las componentes principales; 4 Se relacionaron los factores emergentes con una medida de satisfacción con la vida. Los resultados sugirieron una solución factorial de seis componentes. Las consistencias internas de las escalas son invariablemente superiores a 0.70. Las seis dimensiones explican el 29% de la varianza de la medida de satisfacción con la vida

Comparison of contrast-to-noise ratios of transmission and dark-field signal in grating-based X-ray imaging for healthy murine lung tissue

International Nuclear Information System (INIS)

Schwab, Felix; Schleede, Simone; Hahn, Dieter

2013-01-01

Purpose: An experimental comparison of the contrast-to-noise ratio (CNR) between transmission and dark-field signals in grating-based X-ray imaging for ex-vivo murine lung tissue. Materials and Methods: Lungs from three healthy mice were imaged ex vivo using a laser-driven compact synchrotron X-ray source. Background noise of transmission and dark-field signal was quantified by measuring the standard deviation in a region of interest (ROI) placed in a homogeneous area outside the specimen. Image contrast was quantified by measuring the signal range in rectangular ROIs placed in central and peripheral lung parenchyma. The relative contrast gain (RCG) of dark-field over transmission images was calculated as CNRDF / CNRT. Results: In all images, there was a trend for contrast-to-noise ratios of dark-field images (CNRDF) to be higher than for transmission images (CNRT) for all ROIs (median 61 vs. 38, p = 0.10), but the difference was statistically significant only for peripheral ROIs (61 vs. 32, p = 0.03). Median RCG was >1 for all ROIs (1.84). RCG values were significantly smaller for central ROIs than for peripheral ROIs (1.34 vs. 2.43, p = 0.03). Conclusion: The contrast-to-noise ratio of dark-field images compares more favorably to the contrast-to-noise ratio of transmission images for peripheral lung regions as compared to central regions. For any specific specimen, a calculation of the RCG allows comparing which X-ray modality (dark-field or transmission imaging) produces better contrast-to-noise characteristics in a well-defined ROI. (orig.)

Automated correction on X-rays calibration using transmission chamber and LabVIEWTM

International Nuclear Information System (INIS)

Betti, Flavio; Potiens, Maria da Penha Albuquerque

2009-01-01

Uncertainties during prolonged exposure times on X-rays calibration procedures at the Instruments Calibration facilities at IPEN may suffer from efficiency (and therefore intensity) variations on the industrial X-Ray generator used. Using a transmission chamber as an online reference chamber during the whole irradiation process is proposed in order to compensate for such error source. Also temperature (and pressure) fluctuations may arise from the performance limited calibration room air conditioning system. As an open ionization chamber, that monitor chamber does require calculation of a correction factor due to the temperature and pressure effects on air density. Sending and processing data from all related instruments (electrometer, thermometer and barometer) can be more easily achieved by interfacing them to a host computer running an especially developed algorithm using LabVIEW TM environment which will not only apply the proper correction factors during runtime, but also determine the exact length of time to reach a desired condition, which can be: time period, charge collected, or air kerma, based on the previous calibration of the whole system using a reference chamber traceable to primary standard dosimetry laboratories. When performing such calibration, two temperature sensors (secondary standard thermistors) are simultaneously used, one for the transmission chamber, and other for the reference chamber. As the substitution method is used during actual customer's calibration, the readings from the second thermistor can also be used when desired for further corrections. Use of LabVIEW TM programming language allowed for a shorter development time, and it is also extremely convenient to make things easier when improvements and modifications are called for. (author)

Three-dimensional visualization of material flow during friction stir welding by two pairs of X-ray transmission systems

International Nuclear Information System (INIS)

Morisada, Y.; Fujii, H.; Kawahito, Y.; Nakata, K.; Tanaka, M.

2011-01-01

Material flow during friction stir welding is crucial to obtaining sound joints. However, this phenomenon is still not fully understood despite many investigations and numerous models. In this study, the material flow is three-dimensionally visualized by X-ray radiography using a tiny spherical tungsten tracer. The movement of the tracer during the friction stir welding is observed by two pairs of X-ray transmission real-time imaging systems. The three-dimensional material flow is obtained by following the locus of the tracer.

Preparation of biological samples for transmission X-ray microanalysis: a review of alternative procedures to the use of sectioned material

International Nuclear Information System (INIS)

Sigee, D.C.

1988-01-01

Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular. The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case of cell homogenates and biological fluids, the technique has been used mainly with microdroplets of animal material. The use of X-ray microanalysis with purified biochemicals is considered in relation to both particulate and non-particulate samples. In the latter category, the application of this technique for analysis of thin films of metalloprotein is particularly emphasised. It is concluded that wider use could be made of the range of preparative techniques available - both within a particular investigation, and in diverse fields of study. Transmission X-ray microanalysis has implications for environmental, physiological and molecular biology as well as cell biology

A full-field transmission x-ray microscope for time-resolved imaging of magnetic nanostructures

Energy Technology Data Exchange (ETDEWEB)

Ewald, J.; Nisius, T.; Abbati, G.; Baumbach, S.; Overbuschmann, J.; Wilhein, T. [Institute for X-Optics (IXO), Hochschule Koblenz, Joseph-Rovan-Allee 2, 53424 Remagen (Germany); Wessels, P.; Wieland, M.; Drescher, M. [The Hamburg Centre for Ultrafast Imaging (CUI), University of Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Institut für Experimentalphysik, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Vogel, A. [Institut für Angewandte Physik, University of Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); Viefhaus, J. [Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg (Germany); Meier, G. [The Hamburg Centre for Ultrafast Imaging (CUI), University of Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany)

2016-01-28

Sub-nanosecond magnetization dynamics of small permalloy (Ni{sub 80}Fe{sub 20}) elements has been investigated with a new full-field transmission microscope at the soft X-ray beamline P04 of the high brilliance synchrotron radiation source PETRA III. The soft X-ray microscope generates a flat-top illumination field of 20 μm diameter using a grating condenser. A tilted nanostructured magnetic sample can be excited by a picosecond electric current pulse via a coplanar waveguide. The transmitted light of the sample plane is directly imaged by a micro zone plate with < 65 nm resolution onto a 2D gateable X-ray detector to select one particular bunch in the storage ring that probes the time evolution of the dynamic information successively via XMCD spectromicroscopy in a pump-probe scheme. In the experiments it was possible to generate a homogeneously magnetized state in patterned magnetic layers by a strong magnetic Oersted field pulse of 200 ps duration and directly observe the recovery to the initial flux-closure vortex patterns.

X-ray and visible light transmission as two-dimensional, full-field moisture-sensing techniques: A preliminary comparison

International Nuclear Information System (INIS)

Tidwell, V.C.; Glass, R.J.

1992-01-01

Two independent high-resolution moisture-sensing techniques, x-ray absorption and light transmission, have been developed for use in two-dimensional, thin-slab experimental systems. The techniques yield full-field measurement capabilities with exceptional resolution of moisture content in time and space. These techniques represent powerful tools for the experimentalist to investigate processes governing unsaturated flow and transport through fractured and nonfractured porous media. Evaluation of these techniques has been accomplished by direct comparison of data obtained by means of the x-ray and light techniques as well as comparison with data collected by gravimetric and gamma-ray densitometry techniques. Results show excellent agreement between data collected by the four moisture-content measurement techniques. This program was established to support the Yucca Mountain Site Characterization Project

Delayed Fission Product Gamma-Ray Transmission Through Low Enriched UO₂ Fuel Pin Lattices in Air

Energy Technology Data Exchange (ETDEWEB)

Trumbull, TH [Rensselaer Polytechnic Inst., Troy, NY (United States)

2004-10-18

The transmission of delayed fission-product gamma rays through various arrangements of low-enriched UO2 fuel pin lattices in an air medium was studied. Experimental measurements, point-kernel and Monte Carlo photon transport calculations were performed to demonstrate the shielding effect of ordered lattices of fuel pins on the resulting gamma-ray dose to a detector outside the lattice. The variation of the gamma-ray dose on the outside of the lattice as a function of radial position, the so-called “channeling” effect, was analyzed. Techniques for performing experimental measurements and data reduction at Rensselaer Polytechnic Institute’s Reactor Critical Facility (RCF) were derived. An experimental apparatus was constructed to hold the arrangements of fuel pins for the measurements. A gamma-ray spectroscopy system consisting of a sodium-iodide scintillation detector was used to collect data. Measurements were made with and without a collimator installed. A point-kernel transport code was developed to map the radial dependence of the gamma-ray flux. Input files for the Monte Carlo code, MCNP, were also developed to accurately model the experimental measurements. The results of the calculations were compared to the experimental measurements. In order to determine the delayed fission-product gamma-ray source for the calculations, a technique was developed using a previously written code, DELBG and the reactor state-point data obtained during the experimental measurements. Calculations were performed demonstrating the effects of material homogenization on the gamma-ray transmission through the fuel pin lattice.Homogeneous and heterogeneous calculations were performed for all RCF fuel pin lattices as well as for a typical commercial pressurized water reactor fuel bundle. The results of the study demonstrated the effectiveness of the experimental measurements to isolate the channeling effect of delayed fission-product gamma-rays through lattices of RCF fuel pins

Pair distribution functions of amorphous organic thin films from synchrotron X-ray scattering in transmission mode

Directory of Open Access Journals (Sweden)

Chenyang Shi

2017-09-01

Full Text Available Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements. This ability to measure the total scattering of amorphous organic thin films in transmission will enable accurate in situ structural studies for a wide range of materials.

Simulation of transmitted X-rays in a polycapillary X-ray lens

Energy Technology Data Exchange (ETDEWEB)

Peng, Shiqi [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Liu, Zhiguo, E-mail: liuzhiguo512@126.com [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi; Wang, Kai; Yi, Longtao; Yang, Kui; Chen, Man; Wang, Jinbang [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

2015-09-21

The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results.

Medidas antidumping: instrumento del neoproteccionismo

OpenAIRE

Fernando Gutiérrez Solsona

1994-01-01

El objetivo fundamental de este trabajo se puede expresar fácilmente: demostrar que las medidas antidumping, que hoy en día son tan utilizadas por la Unión Europea (U.E.) y por los Estados Unidos (EE. UU.), tienen exclusivamente un fin proteccionista. Proteccionismo entendido en el sentido económico, esto es proteger a los sectores nacionales frente a la competencia extranjera, porque los primeros son menos eficientes que los segundos.

Mecanismos alternativos de transmissão do Trypanosoma cruzi no Brasil e sugestões para sua prevenção

Directory of Open Access Journals (Sweden)

João Carlos Pinto Dias

2011-06-01

Full Text Available INTRODUÇÃO: Com o avanço no controle da transmissão vetorial e por transfusão sanguínea da doença de Chagas, as formas alternativas de transmissão ganharam relevância. Este artigo de opinião discute a importância de cada uma dessas modalidades e as medidas para sua prevenção. MÉTODOS: Foi realizada uma revisão bibliográfica sobre os mecanismos de transmissão do Trypanosoma cruzi através de modalidades alternativas, vigentes no Brasil, e as possibilidades de sua prevenção. Foram consultadas as bases de dados PubMed e BVS. RESULTADOS: Foram identificadas 25 publicações que discutiam as modalidades alternativas de transmissão da doença de Chagas. CONCLUSÕES: A transmissão oral, pela ingestão de alimentos contaminados, tem sido o modo de transmissão predominante no Brasil nos últimos anos. Os demais modos alternativos de transmissão são de ocorrência menos frequente. É importante conhecer essas ocorrências, sobretudo agora que a veiculação vetorial do parasita está controlada. Conforme os conhecimentos atuais foram apresentadas medidas preventivas, de acordo com cada uma das situações consideradas.

Fabrication update on critical-angle transmission gratings for soft x-ray grating spectrometers

Science.gov (United States)

Heilmann, Ralf K.; Bruccoleri, Alex; Mukherjee, Pran; Yam, Jonathan; Schattenburg, Mark L.

2011-09-01

Diffraction grating-based, wavelength dispersive high-resolution soft x-ray spectroscopy of celestial sources promises to reveal crucial data for the study of the Warm-Hot Intergalactic Medium, the Interstellar Medium, warm absorption and outflows in Active Galactic Nuclei, coronal emission from stars, and other areas of interest to the astrophysics community. Our recently developed critical-angle transmission (CAT) gratings combine the advantages of the Chandra high and medium energy transmission gratings (low mass, high tolerance of misalignments and figure errors, polarization insensitivity) with those of blazed reflection gratings (high broad band diffraction efficiency, high resolution through use of higher diffraction orders) such as the ones on XMM-Newton. Extensive instrument and system configuration studies have shown that a CAT grating-based spectrometer is an outstanding instrument capable of delivering resolving power on the order of 5,000 and high effective area, even with a telescope point-spread function on the order of many arc-seconds. We have fabricated freestanding, ultra-high aspect-ratio CAT grating bars from silicon-on-insulator wafers using both wet and dry etch processes. The 200 nm-period grating bars are supported by an integrated Level 1 support mesh, and a coarser external Level 2 support mesh. The resulting grating membrane is mounted to a frame, resulting in a grating facet. Many such facets comprise a grating array that provides light-weight coverage of large-area telescope apertures. Here we present fabrication results on the integration of CAT gratings and the different high-throughput support mesh levels and on membrane-frame bonding. We also summarize recent x-ray data analysis of 3 and 6 micron deep wet-etched CAT grating prototypes.

An environmental sample chamber for reliable scanning transmission x-ray microscopy measurements under water vapor

Energy Technology Data Exchange (ETDEWEB)

Kelly, Stephen T.; Nigge, Pascal; Prakash, Shruti; Gilles, Mary K. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Laskin, Alexander; Wang, Bingbing [William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Tyliszczak, Tolek [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leone, Stephen R. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry and Department of Physics, University of California, Berkeley, California 94720 (United States)

2013-07-15

We have designed, fabricated, and tested a compact gas-phase reactor for performing in situ soft x-ray scanning transmission x-ray microscopy (STXM) measurements. The reactor mounts directly to the existing sample holder used in the majority of STXM instruments around the world and installs with minimal instrument reconfiguration. The reactor accommodates many gas atmospheres, but was designed specifically to address the needs of measurements under water vapor. An on-board sensor measures the relative humidity and temperature inside the reactor, minimizing uncertainties associated with measuring these quantities outside the instrument. The reactor reduces x-ray absorption from the process gas by over 85% compared to analogous experiments with the entire STXM instrument filled with process gas. Reduced absorption by the process gas allows data collection at full instrumental resolution, minimizes radiation dose to the sample, and results in much more stable imaging conditions. The reactor is in use at the STXM instruments at beamlines 11.0.2 and 5.3.2.2 at the Advanced Light Source.

Radiation transmission of heavyweight and normal-weight concretes containing colemanite for 6 MV and 18 MV X-rays using linear accelerator

International Nuclear Information System (INIS)

Demir, F.; Budak, G.; Sahin, R.; Karabulut, A.; Oltulu, M.; Serifoglu, K.; Un, A.

2010-01-01

Accurate measurements have been made to determine radiation transmission of concretes produced with barite, colemanite and normal aggregate by using beam transmission method for 6 and 18 MV X-rays with a linear accelerator (LINAC). Linear attenuation coefficients of thirteen heavy- and four normal-weight concretes were calculated. It was determined that linear attenuation coefficient (μ, cm -1 ) decreased with colemanite concentration and increased with barite concentration in both types of the concretes.

Image and diagnosis quality of X-ray image transmission via cell phone camera: a project study evaluating quality and reliability.

Directory of Open Access Journals (Sweden)

Hans Goost

Full Text Available INTRODUCTION: Developments in telemedicine have not produced any relevant benefits for orthopedics and trauma surgery to date. For the present project study, several parameters were examined during assessment of x-ray images, which had been photographed and transmitted via cell phone. MATERIALS AND METHODS: A total of 100 x-ray images of various body regions were photographed with a Nokia cell phone and transmitted via email or MMS. Next, the transmitted photographs were reviewed on a laptop computer by five medical specialists and assessed regarding quality and diagnosis. RESULTS: Due to their poor quality, the transmitted MMS images could not be evaluated and this path of transmission was therefore excluded. Mean size of transmitted x-ray email images was 394 kB (range: 265-590 kB, SD ± 59, average transmission time was 3.29 min ± 8 (CI 95%: 1.7-4.9. Applying a score from 1-10 (very poor - excellent, mean image quality was 5.8. In 83.2 ± 4% (mean value ± SD of cases (median 82; 80-89%, there was agreement between final diagnosis and assessment by the five medical experts who had received the images. However, there was a markedly low concurrence ratio in the thoracic area and in pediatric injuries. DISCUSSION: While the rate of accurate diagnosis and indication for surgery was high with a concurrence ratio of 83%, considerable differences existed between the assessed regions, with lowest values for thoracic images. Teleradiology is a cost-effective, rapid method which can be applied wherever wireless cell phone reception is available. In our opinion, this method is in principle suitable for clinical use, enabling the physician on duty to agree on appropriate measures with colleagues located elsewhere via x-ray image transmission on a cell phone.

Neutron activation analysis for sulphur in coal samples and moisture content by gamma-ray transmission

International Nuclear Information System (INIS)

Selvi, S.

1993-01-01

A neutron activation analysis method is described for the determination of sulphur in coal samples by analysing the beta spectrum emitted from 32 P and 33 P following the reactions 32 S(n, p) 32 P and 33 S(n, p) 33 P using 252 Cf as a source of neutrons. The transmission of the combined gamma-rays emitted from three 137 Cs and three 241 Am sources is used to measure the water content of the coal samples. (author)

Medidas automatizadas de psicrômetro de termopar aspirado versus não aspirado

Directory of Open Access Journals (Sweden)

Antonio Ribeiro da Cunha

2014-06-01

Full Text Available O termopar ou par termoelétrico é utilizado na obtenção da temperatura do ar com ótima precisão, sensibilidade e com grande vantagem sobre o termômetro de mercúrio ou álcool, pois geram sinais elétricos que podem ser armazenados em sistemas automatizados. No entanto, quando se trata da obtenção da umidade relativa a partir de termopar, o processo se torna mais cauteloso devido a outros fatores envolvidos. Neste estudo, avaliaram-se dois conjuntos psicrômetros de termopar, aspirado e não aspirado, em relação a um conjunto Vaisala, no período de 17 a 31/01/2008 (15 dias. A partir de medidas de temperaturas de bulbos seco e úmido foram obtidas medidas da umidade relativa, e com isso, foi possível compará-las com as medidas obtidas pelo conjunto Vaisala. Os dois tipos de psicrômetros apresentaram precisão e exatidão nas medidas de temperatura do ar, e apenas precisão nas medidas de umidade relativa do ar, sendo que o psicrômetro aspirado foi o mais preciso. Apesar do psicrômetro não aspirado ter apresentado menor precisão nas medidas, ele é mais robusto porque independe do micro-ventilador de 12 VDC, o que faz dele um sensor com menos riscos de medidas inadequadas. Ambos os psicrômetros, aspirado e não aspirado, não medem com exatidão a umidade relativa do ar no período noturno.

Resonancia magnética cardiaca: medidas lineales y volumétricas en adultos sanos

OpenAIRE

Heredia Sánchez, Fabian Mauricio; Cabezas, Andrés Mauricio

2015-01-01

Introducción: La gran mayoría de las medidas de normalidad utilizadas para la interpretación de resonancia cardiaca son extrapoladas de las medidas de ecocardiografía. Los limitados registros de medidas de normalidad se encuentran ajustados en poblaciones extranjeras, no hay registros en latinoamericanos. Objetivo: Determinar las dimensiones cardiacas utilizando resonancia magnética en una población de personas sin antecedente médicos con repercusión cardiaca para lograr una muestra de val...

Medidas de la felicidad nacional bruta

NARCIS (Netherlands)

R. Veenhoven (Ruut)

2009-01-01

textabstractResumen. La felicidad está abriéndose hueco en la agenda política, lo cual reclama medir el éxito alcanzado por los distintos países en crear felicidad para un gran número de personas, de un modo análogo a las medidas del éxito en la creación de riqueza, como el PNB. La felicidad se

Small angle X-ray scattering and transmission electron microscopy study of the Lactobacillus brevis S-layer protein

Energy Technology Data Exchange (ETDEWEB)

Jaeaeskelaeinen, Pentti [Department of Biomedical Engineering and Computational Science, PO Box 2200, FI-02015 Aalto University School of Science and Technology (Finland); Engelhardt, Peter [Haartman Institute, Department of Pathology, PO Box 21, FIN-00014 University of Helsinki (Finland); Hynoenen, Ulla; Palva, Airi [Department of Basic Veterinary Sciences, Division of Microbiology, FIN-00014 University of Helsinki (Finland); Torkkeli, Mika; Serimaa, Ritva, E-mail: ritva.serimaa@helsinki.f [Department of Physics, POB 64, 00014 University of Helsinki (Finland)

2010-10-01

The structure of self-assembly domain containing recombinant truncation mutants of Lactobacillus brevis surface layer protein SlpA in aqueous solution was studied using small-angle X-ray scattering and transmission electron microscopy. The proteins were found out to interact with each other forming stable globular oligomers of about 10 monomers. The maximum diameter of the oligomers varied between 75 A and 435 A.

Measurement of the vertical infiltration parameters and water redistribution in LRd and LEa soils by gamma-ray transmission technique

International Nuclear Information System (INIS)

Souza, A.D.B. de; Saito, H.; Appoloni, C.R.; Coimbra, M.M.; Parreira, P.S.

1991-01-01

The properties of soil water diffusivity and soil hydraulic conductivity of two horizons (0-20 cm and 20-40 cm) from Latossolo Roxo distrofico (LRd) and Latossolo Vermelho escuro (LEa) soil samples, have been measured in laboratory through the vertical infiltration and redistribution of water in soil columns. The moisture profile as a function of time for each position in the soil column were obtained with the gamma-ray transmission technique, using a sup(241)Am gamma-ray source, a Na (I) T1 scintillation detector and gamma spectrometry standard electronic. (author)

Determination of the hydraulic conductivity in column of undeformed soil by gamma rays transmission

International Nuclear Information System (INIS)

Moreira, Anderson C.; Cavalcante, Fabio H.M.; Portezan Filho, Otavio; Coimbra, Melayne M.; Appoloni, Carlos Roberto

2000-01-01

The water infiltration process in undeformed soil column and the measurement of redistribution process by gamma rays transmission in different depth allow the determination of Hydraulic Conductivity K(Θ) function, using the Sisson et al. (1980) method. A LRd (dystrophic dark red soil) soil column with 60 cm of height, 10 cm of width and 5 cm of thickness, was analyzed in laboratory, reproducing the field conditions concerning to the water infiltration and redistribution in the soil. The soil moisture content data was obtained with a radioactivity source 241 Am (100 mCi; 59,6 keV), NaI (Tl) 2x2 detector, coupled to an gamma rays spectrometric electronic chain and a measurement table that allowed the vertical displacement of the soil column. The results indicate a growing behavior for K(Θ) in relation to the depth. The collimators had 2 mm and 5 mm diameter for radioactivity source and detector respectively. (author)

Determination of structural geometric parameters of industrial ceramic foams by gamma rays transmission and X-rays microtomography; Determinacao de parametros geometricos estruturais de espumas ceramicas industriais por transmissao de raios gama e microtomografia de raios X

Energy Technology Data Exchange (ETDEWEB)

Rocha, Wilson Roberto Dejato da

2005-07-01

In this work, the gamma rays transmission and X-rays microtomography techniques are used for the evaluation of the porosity and the pore size distribution of SiC ceramic foams. It was also accomplished the three-dimensional images after the determination of samples geometric parameters. The geometric parameters were obtained by two-dimensional images analyses, generated by a Microfocus system, with a CCD camera, an images intensifier, a X-rays tube and an automatic system for rotation of the sample. The spatial resolution of the images was about 32 {mu}m. In the gamma rays transmission methodology, a Nal(Tl) scintillation detector, an {sup 241}Am (59.53 keV, 100 mCi) radioactive source and an automatic X-Z micrometric table was used. The analyzed samples had pores density of 30, 45, 60, 80 and 100 ppi (pores per inch). The gamma rays transmission technique was accurate to supply the porosity of the samples, which ranged about 90% and was in agreement with the values supplied by manufacturer of the foams. The 30 and 45 ppi samples analyzed by X-rays microtomography showed porosity results that agree with the average porosity supplied by the manufacturer. In other hand, the 60, 80 and 100 ppi samples systematically showed average porosity about 4%, lower than the average of the manufacturer. The pore size distributions found through the software IMAGO show the presence of smaller pores than those nominated by the manufacturer. The 30 ppi samples had voids inside the solid material of the ceramic foams structure. Gaussian truncated method, used in the three-dimensional reconstruction, was not able to take into the account the voids inside the solid matrix. (author)

Fabrication and characterization of free-standing, high-line-density transmission gratings for the vacuum UV to soft X-ray range

NARCIS (Netherlands)

Goh, S.J.; Bastiaens, Hubertus M.J.; Vratzov, B.; Huang, Qiushi; Bijkerk, Frederik; Boller, Klaus J.

2015-01-01

We present state-of-the-art high resolution transmission gratings, applicable for spectroscopy in the vacuum ultraviolet (VUV) and the soft X-ray (SRX) wavelength range, fabricated with a novel process using ultraviolet based nano imprint lithography (UV-NIL). Free-standing, high-line-density

Medida de espessura de filmes finos com interferometro de haidinger

OpenAIRE

Elisabeth Andreoli de Oliveira

1987-01-01

Resumo: Apresentamos um método não destrutivo para medida de espessura de filmes finos transparentes depositados em substratos transparentes, usando um interferômetro de Haidinger. A partir das frações de interferência, medidas para vários comprimentos de onda, e do índice de refração para um único comprimento de onda, determinamos a espessura do filme e sua dispersão cromática, através de um procedimento analítico-numérico Abstract: We introduce a non-destructive method for the thickness ...

An on-line identification device for coal and gangue based on dual-energy γ-ray transmission and microcontroller

International Nuclear Information System (INIS)

Chen Guojie; Zhu Xing

2004-01-01

The operating principle, hardware design, software design and stabled-spectrum method of on-line identification device for coal and gangue based on dual-energy γ-ray transmission and microcontroller are introduced. The integrated linear amplifier and integrated single channel pulse height analyzer are analyzed. The on-line identification device has advantages of small size, low cost as well stabilization. (authors)

Medidas tipográficas: un recuento

Directory of Open Access Journals (Sweden)

Oriol Moret Viñals

2015-07-01

Full Text Available Breve repaso al desarrollo de la concepción métrica en la tipografía en plomo, alternativa y complemento de la visión habitual en lo que conocemos como “tipometría”. Se parte de una noción amplia de medida: el factor cuantitativo se dilata con la articulación de relaciones proporcionales e integra la dimensión cualitativa de los sistemas métricos tradicionales. La tipografía se considera bajo presupuestos similares: como sistema articulado de piezas materiales cuyas magnitudes contienen usos y valores específicos, más allá de su simple expresión numérica. Con tales premisas, se revisan fuentes documentales significativas del “período de la imprenta manual”. Su examen, vinculado a los usos y costumbres de oficio, desvela la distinta aproximación métrica, que puede resumirse en tres fases evolutivas: hermética, intensiva, expansiva –como recogen las referencias de los cuerpos tipográficos: adjetivas, sustantivas, numéricas. Se proporciona así un marco para apreciar el cambio de sentido en las medidas tipográficas hasta nuestros días.

Human exposition to non ionizing electromagnetic radiations. Legislation and base stations measurements Exposición humana a las radiaciones electromagnéticas no ionizantes. Legislación y medidas de estaciones base

Directory of Open Access Journals (Sweden)

Antonio García Pino

2004-12-01

Full Text Available This work deals about measurement procedures of non-ionizing radiations and their recorded levels in practice. The analyzed radiation sources cover the most common broadcasting media such as AM and FM transmissions and the GSM mobile telephony base stations. These sources currently radiate locations with high density of population. Spanish radiation level regulations are briefly described and some possible improvements are pointed out. The measurement results are discussed.Este trabajo trata sobre los procedimientos de medida de las radiaciones no ionizantes y sus niveles registrados en medidas reales. Las fuentes de radiación analizadas cubren los medios de radiodifusión más corrientes, tales como las transmisiones AM y FM y también las estaciones base de telefonía móvil GSM. Estas fuentes habitualmente radian sobre áreas con alta densidad de población. Se describe brevemente el marco legal que regula los niveles de radiación en España y se señalan algunas posibles mejoras. Se valorarán los resultados encontrados en las medidas.

Adolescente em conflito com a lei e medidas socioeducativas: limites e (impossibilidades

Directory of Open Access Journals (Sweden)

Francischini, Rosângela

2005-01-01

Full Text Available Reinserção social, readaptação, ajustamento social, integração à família e sociedade. Várias são as expressões empregadas para referir-se ao efeito desejado do trabalho com o jovem em conflito com a lei, em cumprimento de medidas socioeducativas, particularmente em privação de liberdade. Parte do aparato legal do Estado, a partir da promulgação do Estatuto da Criança e do Adolescente, significaram, essas medidas, uma chamada à responsabilização do jovens, em face da transgressão cometida. No entanto, avalia-se, o que dá a essas medidas o caráter socioeducativo, fazendo com que o trabalho desenvolvido nas instituições diferencie-se do cumprimento de pena? Estrutura física, formação de recursos humanos, ações educativas e trabalho transdiciplinar são alguns dos aspectos implicados nesta questão. Neste contexto de discussão insere-se o presente artigo, que tem por objetivo discutir o caráter socioeducativo das medidas de privação de liberdade e as possibilidades de reinserção social do jovem em conflito com a lei

Hacia una definición de la medida

OpenAIRE

Parot, Jean Jacques

2012-01-01

Hacia una definición de la medida A. Primera situación Un granjero va al mercado para vender a) Una gallina (20 pesos) b) Un bulto de naranjas (45 pesos) c) Un pate (38 pesos) d) Una docena de huevos (12 pesos)

El trabajo en Smith: valor o medida del valor?

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Adolfo Rodríguez Herrera

2016-12-01

Este artículo revisa los conceptos desarrollados por Smith para formular su teoría del valor (valor, precio real y valor de  cambio. Nuestra interpretación de sus textos sobre el valor no coincide con la que tradicionalmente se ha hecho. De acuerdo con nuestra interpretación, no sería correcta la crítica de Ricardo y Marx a la posición de Smith sobre el papel del trabajo como medida de valor. Para estos autores, Smith no es consistente al proponer que el valor de una mercancía es definido o medido como la cantidad de trabajo necesaria para producirla y simultáneamente como la cantidad de trabajo que puede ser comprada por esta mercancía. Tratamos de demostrar que para Smith el trabajo tiene un doble papel –como fuente y como medida del valor–, y que a ello se debe la confusión generada por su uso de algunos términos: Smith propone el trabajo como una medida de valor porque lo concibe como una fuente de valor. Con esta interpretación queda claro, paradójicamente, que la teoría del valor trabajo de Smith corresponde sustancialmente con la que más tarde desarrollarán Ricardo y Marx.

LAS MEDIDAS PREVENTIVAS AMBIENTALES, UNA APROXIMACIÓN DESDE EL DERECHO ADMINISTRATIVO.

Directory of Open Access Journals (Sweden)

Iván Andrés Páez Páez

2013-05-01

Full Text Available Las medidas preventivas previstas en el régimen sancionatorio ambiental sonuna especie de las medidas cautelares consagradas en el ordenamiento jurídicocolombiano, aunque con algunas particularidades propias de su ámbito deaplicación, que es el derecho ambiental. El artículo realiza una aproximaciónrespecto al contenido, alcance, antecedentes y justificación de las medidaspreventivas ambientales desde la óptica del derecho administrativo y comomanifestación de una de las funciones del ejecutivo, cual es el mantenimientodel orden público.

Transmission X-ray microscopy (TXM) reveals the nanostructure of a smectite gel.

Science.gov (United States)

Zbik, Marek S; Martens, Wayde N; Frost, Ray L; Song, Yen-Fang; Chen, Yi-Ming; Chen, Jian-Hua

2008-08-19

The unusual behavior of smectites, the ability to change volume when wetted (swelling) or dried (shrinking), makes soil rich in smectites very unstable and dangerous for the building industry because of the movement of building foundations and poor slope stability. These macroscopic properties are dominated by the structural arrangement of the smectites' finest fraction. Here, we show in three dimensions how the swelling phenomenon in smectite, caused by a combination of hydratation and electrostatic forces, may expand the dry smectite volume not 10-fold, as previously thought, but to more than 1000-fold. A new technique, transmission X-ray microscopy, makes it possible to investigate the internal structure and 3-D tomographic reconstruction of clay aggregates. This reveals, for the first time, the smectite gel arrangement in the voluminous cellular tactoid structure within a natural aqueous environment.

Violência Juvenil e Medidas Socioeducativas: Revisão de Literatura

Directory of Open Access Journals (Sweden)

Jacqueline de Oliveira Moreira

2017-10-01

Full Text Available RESUMO Neste artigo, partindo do objetivo de compreender a relação entre violência juvenil e a resposta do Estado através das medidas socioeducativas, buscamos explicitar o pano de fundo das pesquisas científicas atuais. Realizamos uma meta-análise dos artigos publicados sobre adolescência e medidas socioeducativas, no campo da psicologia, entre os anos de 2000 e 2012. Concluímos que essa produção nacional pode ser reunida em três grandes categorias: (a prático-experiencial, que apresenta relatos analíticos da prática na aplicação das medidas socioeducativas, privilegiando a experiência concreta; (b político-institucional, que discute criticamente a dimensão política da lógica socioeducativa, detendo-se na análise estrutural de sua legislação e de suas instituições; (c sociocultural, que analisa os determinantes sociais e psíquicos do fenômeno da violência juvenil.

A Monte Carlo study of the energy spectra and transmission characteristics of scattered radiation from x-ray computed tomography.

Science.gov (United States)

Platten, David John

2014-06-01

Existing data used to calculate the barrier transmission of scattered radiation from computed tomography (CT) are based on primary beam CT energy spectra. This study uses the EGSnrc Monte Carlo system and Epp user code to determine the energy spectra of CT scatter from four different primary CT beams passing through an ICRP 110 male reference phantom. Each scatter spectrum was used as a broad-beam x-ray source in transmission simulations through seventeen thicknesses of lead (0.00-3.50 mm). A fit of transmission data to lead thickness was performed to obtain α, β and γ parameters for each spectrum. The mean energy of the scatter spectra were up to 12.3 keV lower than that of the primary spectrum. For 120 kVp scatter beams the transmission through lead was at least 50% less than predicted by existing data for thicknesses of 1.5 mm and greater; at least 30% less transmission was seen for 140 kVp scatter beams. This work has shown that the mean energy and half-value layer of CT scatter spectra are lower than those of the corresponding primary beam. The transmission of CT scatter radiation through lead is lower than that calculated with currently available data. Using the data from this work will result in less lead shielding being required for CT scanner installations.

Medidas cautelares innominadas en la protección de los derechos de autor y conexos en Colombia

Directory of Open Access Journals (Sweden)

Nixon Jefrey Gil Aguirre

2016-12-01

Full Text Available Actualmente, el ejercicio de funciones jurisdiccionales atribuidas a las autoridades administrativas ha generado interpretaciones judiciales confusas, en la aplicación de medidas cautelares innominadas para la protección de derechos de autor y conexos en Colombia; así lo evidencia el análisis realizado a las medidas cautelares descritas en la Ley 1493 del año 2011, que otorgó competencias de inspección, vigilancia y control sobre las sociedades de gestión colectiva de derechos de autor y conexos; en este sentido se requiere describir las funciones jurisdiccionales de la Dirección Nacional de Derecho de Autor respecto a las medidas cautelares y su importancia en la protección de los derechos de autor y conexos, al igual que analizar las medidas cautelares innominadas desde su origen, las características y lo propuesto por la Corte Constitucional en materia de funciones jurisdiccionales de la Dirección Nacional de Derecho de Autor y respecto de la procedencia de las medidas cautelares innominadas como competencia de esta entidad. Se concluye que las medidas cautelares nominadas no son suficientes, y que se hace necesario acudir a las medidas cautelares innominadas, como herramienta jurídica del funcionario administrativo, sin que ello implique arbitrariedad y prejuzgamiento en el proceso.

Bone histomorphometric quantification by X-ray phase contrast and transmission 3D SR microcomputed tomography

International Nuclear Information System (INIS)

Nogueira, L.P.; Pinheiro, C.J.G.; Braz, D.; Oliveira, L.F.; Barroso, R.C.

2008-01-01

Full text: Conventional histomorphometry is an important method for quantitative evaluation of bone microstructure. X-ray computed tomography is a noninvasive technique, which can be used to evaluate histomorphometric indices. In this technique, the output 3D images are used to quantify the whole sample, differently from the conventional one, in which the quantification is performed in 2D slices and extrapolated for 3D case. Looking for better resolutions and visualization of soft tissues, X-ray phase contrast imaging technique was developed. The objective of this work was to perform histomorphometric quantification of human cancellous bone using 3D synchrotron X ray computed microtomography, using two distinct techniques: transmission and phase contrast, in order to compare the results and evaluate the viability of applying the same methodology of quantification for both technique. All experiments were performed at the ELETTRA Synchrotron Light Laboratory in Trieste (Italy). MicroCT data sets were collected using the CT set-up on the SYRMEP (Synchrotron Radiation for Medical Physics) beamline. Results showed that there is a better correlation between histomorphometric parameters of both techniques when morphological filters had been used. However, using these filters, some important information given by phase contrast are lost and they shall be explored by new techniques of quantification

Microstructural characterization of porous materials by X-ray microtomography and gamma ray transmission techniques; Caracterizacao da microestrutura de materiais porosos por microtomografia de raios X e transmissao de raios gama

Energy Technology Data Exchange (ETDEWEB)

Moreira, Anderson Camargo

2006-07-01

This work presents the application of the X-ray microtomography and gamma ray transmission techniques for the microstructure characterization of different kinds of materials. Total porosity, pore size distribution and the two point correlation functions were measured. The two point correlation function, which allows the reconstruction of 3D models, was carried out for two samples. Seven ceramic tablets of Alumina (Al{sub 2}O{sub 3}), seven tablets of Boron Carbide (B{sub 4}C), three samples of sedimentary rocks and one sample of Titanium foam were analyzed. The experimental set up for the Gamma Ray Transmission technique consisted of: a 2'' x 2'' crystal NaI(Tl) detector, an {sup 241} Am radioactive source (59,53 keV, 100 mCi), an automatic micrometric table for the sample XZ movement and standard gamma spectrometry electronics. Two microtomography systems were used: a Fein Focus system, constituted by an X-ray tube, operated at 160 kV and 0.3 to 1.1 mA, a CCD camera and the movement sample system, and a Skyscan system, model 1072, with a X-ray tube operated at 100 kV and 100{mu}A, and a CCD camera. The ceramic tablets, analyzed by the gamma ray transmission technique presented results for most of the porosities data with smaller confidence intervals and inside the intervals supplied by the tablets manufacturer. The Titanium porous sample was analyzed by the two techniques, its microtomography images achieved a resolution of 17{mu}m, obtained employing the Fein Focus system. For both techniques, this sample showed high porosity, which allows its application for this purpose. The sandstones samples were analyzed by the Skyscan system, achieving resolutions of 19{mu}m, 11{mu}m and 3.8{mu}m for each sample, respectively. The resolutions of 11{mu}m and 3.8{mu}m were the ones that generated better 2D sections for the respective samples and, consequently, more reliable porosities. The 3.8{mu}m resolution was the one that best quantified the pore size

Una medida de eficiencia de mercado. Un enfoque de teoría de la información

Directory of Open Access Journals (Sweden)

Reyna Susana García Ruiz

2014-01-01

Full Text Available En este trabajo, con base en el concepto de entropía de Shan-non, se propone una medida de eficiencia de mercado que uti-liza la función de densidad empírica de los rendimientos comoalfabeto para calcular la entropía del sistema y proveer con ellouna medida de eficiencia de mercado. Se demuestra que bajociertas condiciones de ergodicidad y de estacionariedad la en-tropía muestral converge a la entropía del estado dominante,lo que valida el uso de la entropía muestral como medida deeficiencia del sistema. Asimismo, se demuestra que la medidapropuesta es consistente con algunos de los axiomas de Artz-neret al.(1999 acerca de una medida coherente de riesgo. Porúltimo, con fines ilustrativos, se llevan a cabo varias aplicacio-nes de la medida de eficiencia propuesta a distintos mercadosde capitales: DJIA, S&P500, FTSE100 e IPC.

Ato infracional e medida socioeducativa: representações de adolescentes em L.A.

Directory of Open Access Journals (Sweden)

Bianca Izoton Coelho

2013-01-01

Full Text Available A pesquisa analisou as representações sociais de ato infracional e medida socioeducativa em adolescentes em conflito com a lei. Utilizou-se, como aporte teórico e metodológico, a Teoria das Representações Sociais. Participaram da pesquisa quarenta e seis adolescentes que cumpriam, há mais de três meses, a medida de Liberdade Assistida. Os dados foram coletados, por meio de entrevistas, com um roteiro semiestruturado e consistiram na técnica das evocações livres por meio dos termos ato infracional e medida socioeducativa. Utilizou-se o software EVOC para análise das evocações emitidas. Os resultados apontaram como caracterização socioeconômica dos adolescentes: renda familiar baixa, baixo nível de escolaridade, local de residência precário, etnias afro-descendentes predominantes e distanciamento da religião. As representações sociais de ato infracional relacionaram-se aos tipos de atos infracionais e às suas causas e consequências. As representações sociais de medida socioeducativa relacionaram-se a ações positivas em que, além da aprendizagem, houve a possibilidade de mudança.

Bulk sample self-attenuation correction by transmission measurement

International Nuclear Information System (INIS)

Parker, J.L.; Reilly, T.D.

1976-01-01

Various methods used in either finding or avoiding the attenuation correction in the passive γ-ray assay of bulk samples are reviewed. Detailed consideration is given to the transmission method, which involves experimental determination of the sample linear attenuation coefficient by measuring the transmission through the sample of a beam of gamma rays from an external source. The method was applied to box- and cylindrically-shaped samples

Nodo sensor para la medida ambiental de CO2, temperatura y humedad

OpenAIRE

Jara Burgos, Marcos

2007-01-01

En este documento se describe el diseño y la implementación de un nodo sen-sor para la medida ambiental del nivel de CO2, la temperatura y la humedad relativa. El sistema se basa en un interfaz directo sensor a microcontrolador para las medidas de temperatura y humedad relativa, mientras que para el sensor de CO2 se basa en una conversión analógica digital. El sistema utiliza un sensor resistivo para medir la temperatura, un sensor capacitivo para medir la humedad relativa y un sensor...

Medidas preventivas, correctoras y compensatorias del impacto ecológico de carreteras

OpenAIRE

Aizpurúa Giráldez, Nerea

2011-01-01

Las medidas preventivas, correctoras y compensatorias empleadas en los proyectos de carretera son uno de los elementos clave para conseguir la integración ambiental de estas infraestructuras. De ellas dependerá que los posibles impactos ambientales generados durante su construcción y explotación no supongan un detrimento inadmisible de la calidad ambiental. La tipología de medidas que se vienen aplicando desde hace más de veinte años en durante el proceso de Evaluación de Impacto Ambiental (E...

Medidas de administración pesquera.

OpenAIRE

2014-01-01

En el Titulo II de la Ley General de Pesca y Acuicultura "De la Administración de las Pesquerías", específicamente en facultades de conservación de los recursos hidrobiológicos, se establece lo siguiente: En cada área de pesca, independiente del régimen de acceso a que se encuentre sometida, el Ministerio, mediante decreto supremo fundado, podrá establecer una o más prohibiciones o medidas de administración de recursos hidrobiológicos. Esta presentación que proporciona información refere...

Medidas de pobreza: un enfoque alternativo

OpenAIRE

Lazzari, Luisa L; Fernández, María José

2006-01-01

Una medida creíble de pobreza e indigencia puede ser un poderoso instrumento para concentrar la atención del policymaker en las condiciones de vida de los pobres. Las opciones elegidas para fijarlas tienen gran importancia para las decisiones políticas a tomar. El método indirecto o enfoque del ingreso parte de la valorización de una Canasta Básica Alimentaria (CBA) que determina la cantidad de calorías mínimas necesarias para satisfacer las necesidades biológicas básicas de...

In situ observation of Cu-Ni alloy nanoparticle formation by X-ray diffraction, X-ray absorption spectroscopy, and transmission electron microscopy: Influence of Cu/Ni ratio

DEFF Research Database (Denmark)

Wu, Qiongxiao; Duchstein, Linus Daniel Leonhard; Chiarello, Gian Luca

2014-01-01

Silica-supported, bimetallic Cu-Ni nanomaterials were prepared with different ratios of Cu to Ni by incipient wetness impregnation without a specific calcination step before reduction. Different in situ characterization techniques, in particular transmission electron microscopy (TEM), X-ray...... diffraction (XRD), and X-ray absorption spectroscopy (XAS), were applied to follow the reduction and alloying process of Cu-Ni nanoparticles on silica. In situ reduction of Cu-Ni samples with structural characterization by combined synchrotron XRD and XAS reveals a strong interaction between Cu and Ni species......, which results in improved reducibility of the Ni species compared with monometallic Ni. At high Ni concentrations silica-supported Cu-Ni alloys form a homogeneous solid solution of Cu and Ni, whereas at lower Ni contents Cu and Ni are partly segregated and form metallic Cu and Cu-Ni alloy phases. Under...

Medida de la evapotranspiración real en coberturas vegetales semiáridas (Cuenca de Mula, Murcia), según las varicaciones de humedad del suelo medidas mediante el procedimiento (TDR)

OpenAIRE

Belmonte Serrato, Francisco; Romero Díaz, María Asunción

2006-01-01

En este trabajo se presenta un método de medida directa de la Evapotranspiración Real (ETR) bajo distintas coberturas vegetales, basado en las diferencias de humedad en el suelo medidas mediante el procedimiento TDR, en un intervalo temporal de 15 días y su comparación con los valores calculados mediante el método de Thornthwaite, que usa la temperatura media como parámetro fundamental. Los resultados demuestran la validez del método utilizado, habiendo obtenido valores de E...

Medidas directas e indirectas de las funciones ejecutivas en niños con trastorno de espectro autista

Directory of Open Access Journals (Sweden)

María Fernanda Pérez Pichardo

2018-01-01

Full Text Available INTRODUCCIÓN: los niños con trastorno del espectro autista (TEA tienen dificultades en las funciones ejecutivas (FE pero se han sugerido discrepancias entre las medidas directas e indirectas.   OBJETIVO: conocer si existen diferencias en las funciones ejecutivas mediante medidas directas e indirectas entre niños con y sin TEA.   MÉTODO: se incluyeron 14 varones entre primero y tercero de primaria, 50% con diagnóstico de TEA y 50% con desarrollo neurotípico, seleccionados por emparejamiento en edad y grado escolar. El promedio de edad de la muestra fue de 7.43 (DE 0.98 años. Se aplicaron las pruebas de Evaluación neuropsicológica de funciones ejecutivas en niños (ENFEN y el Inventario de clasificación comportamental de las funciones ejecutivas (BRIEF.   RESULTADOS: se encontraron diferencias significativas en las medidas de las FE indirectas, pero no en las directas, entre los grupos (p < 0.05. Así mismo, las correlaciones entre las medidas directas e indirectas fueron mayores en el grupo con TEA.   CONCLUSIONES: los niños con TEA son evaluados con más dificultades en las medidas indirectas de las funciones ejecutivas, pero obtienen puntuaciones similares a los niños con desarrollo neurotípico cuando son evaluados en condiciones estructuradas empleando medidas directas.

Medidas de experiencia e cienciometria para avaliar impacto da producao cientifica

Directory of Open Access Journals (Sweden)

Marco Akerman

2013-08-01

Full Text Available Propõe-se a “experienciometria” como medida da experiência acadêmica de pesquisadores de modo a complementar a medida consagrada da cienciometria nas avaliações de competências em pesquisa. O artigo baseia-se em parte na produção cientifica do autor, utilizada sob uma perspectiva qualitativa para explorar possibilidades de análise de impactos. Ensaia-se uma síntese com possíveis implicações dessa análise, indicando algumas possibilidades para se avaliar impacto de pesquisas e artigos que não se restrinjam exclusivamente à contagem de números de citações dos autores para o cálculo do fator de impacto.

As medidas aplicadas aos acordos SPS e TBT sobre as exportações brasileiras de fumo

Directory of Open Access Journals (Sweden)

Carlos Otávio de Freitas

2015-11-01

Full Text Available O presente estudo tem como objetivo analisar os efeitos das medidas não tarifárias, especificamente as medidas sanitárias e fitossanitárias - SPS e medidas técnicas - TBT, sobre as exportações brasileiras de fumo e se tais efeitos permaneceram nos períodos subsequentes à emissão das notificações. Para tal, foi estimado um modelo gravitacional utilizando uma amostra de 89 países importadores do fumo do Brasil entre o período de 1997 a 2011. O método utilizado na estimação das equações foi o modelo Poisson-Pseudo Maximum Likehood-PPML. Os resultados obtidos mostram que as medidas ou SPS afetaram negativamente o fluxo internacional do comércio de fumo. Além disso, verificou-se que esses efeitos perduraram nos períodos posteriores à emissão da notificação, sendo que as empresas exportadores podem demorar até dois anos para se ajustarem às exigências requeridas. Dentre os objetivos das notificações SPS, a maior parte está relacionada a medidas para proteção da saúde humana e proteção da planta, o que pode explicar a maior dificuldade de adequação, pois são exigências que demandam grandes investimentos. Já as medidas TBT não foram estatisticamente significativas, confirmando o caráter não restritivo dessas notificações sobre o comércio internacional de fumo. Apesar da maior parte das notificações ao fumo estarem associadas a medidas técnicas, os resultados indicaram que elas não configuraram como barreiras ao comércio de fumo. Isso pode sugerir que as exigências a elas referidas, que, em sua grande maioria, foi referente à rotulagem e/ou embalagem, foram atendidas pelo Brasil sem maiores dificuldades. Dessa forma, torna-se importante a inclusão de questões referentes à regulamentação dessas medidas nas discussões e processos de tomada de decisão das empresas exportadoras de fumo. Em termos de ações governamentais, seria interessante a criação ou aperfeiçoamento de políticas no sentido

Design and performance of a compact scanning transmission X-ray microscope at the Photon Factory

Energy Technology Data Exchange (ETDEWEB)

Takeichi, Y., E-mail: yasuo.takeichi@kek.jp; Mase, K.; Ono, K. [Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba 305-0801 (Japan); Department of Materials Structure Science, SOKENDAI (The Graduate University for Advanced Studies), 1-1 Oho, Tsukuba 305-0801 (Japan); Inami, N. [Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba 305-0801 (Japan); Suga, H. [Department of Earth and Planetary Systems Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Miyamoto, C. [Department of Earth and Planetary Systems Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-0033 (Japan); Ueno, T. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Takahashi, Y. [Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba 305-0801 (Japan); Department of Earth and Planetary Systems Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Department of Earth and Planetary Systems Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-0033 (Japan)

2016-01-15

We present a new compact instrument designed for scanning transmission X-ray microscopy. It has piezo-driven linear stages, making it small and light. Optical components from the virtual source point to the detector are located on a single optical table, resulting in a portable instrument that can be operated at a general-purpose spectroscopy beamline without requiring any major reconstruction. Careful consideration has been given to solving the vibration problem common to high-resolution microscopy, so as not to affect the spatial resolution determined by the Fresnel zone plate. Results on bacteriogenic iron oxides, single particle aerosols, and rare-earth permanent magnets are presented as examples of its performance under diverse applications.

Ilustração de incertezas em medidas utilizando experimentos de queda livre

OpenAIRE

Coluci,Vitor R.; Paulino,Guilherme; Souza,Diego C. de; Vasconcelos,Elba P.R.

2013-01-01

O conhecimento da incerteza de uma medida é crucial para obter conclusões a partir de resultados experimentais. Erros aleatórios, comuns em experimentos, produzem uma distribuição dos valores medidos que segue o formato gaussiano. Neste trabalho desenvolvemos uma montagem baseada no fenômeno de queda livre para auxiliar na ilustração do conceito de incerteza em medidas. Os tempos de queda de um objeto foram obtidos automaticamente pela placa Arduino e exibidos na forma de um histograma na tel...

A laboratory 8 keV transmission full-field x-ray microscope with a polycapillary as condenser for bright and dark field imaging

Energy Technology Data Exchange (ETDEWEB)

Baumbach, S., E-mail: baumbach@rheinahrcampus.de; Wilhein, T. [Institute for X-Optics, University of Applied Sciences Koblenz, RheinAhrCampus Remagen, Joseph-Rovan-Allee 2, D-53424 Remagen (Germany); Kanngießer, B.; Malzer, W. [Institute for Optics and Atomic Physics, Technical University of Berlin, Hardenbergstrasse 36, D-10623 Berlin (Germany); Stiel, H. [Max-Born-Institute, Max-Born-Strasse 2A, D-12489 Berlin (Germany)

2015-08-15

This article introduces a laboratory setup of a transmission full-field x-ray microscope at 8 keV photon energy. The microscope operates in bright and dark field imaging mode with a maximum field of view of 50 μm. Since the illumination geometry determines whether the sample is illuminated homogeneously and moreover, if different imaging methods can be applied, the condenser optic is one of the most significant parts. With a new type of x-ray condenser, a polycapillary optic, we realized bright field imaging and for the first time dark field imaging at 8 keV photon energy in a laboratory setup. A detector limited spatial resolution of 210 nm is measured on x-ray images of Siemens star test patterns.

CRL X-ray tube

International Nuclear Information System (INIS)

Kolchevsky, N.N.; Petrov, P.V.

2015-01-01

A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed. (authors)

Fusão INS/GNSS com auxílio de medidas de baseline e ângulo GNSS

OpenAIRE

Priscylla Angélica da Silva Oliveira

2014-01-01

Este trabalho investiga sistemas de navegação INS/GNSS auxiliado por medidas de baseline e ângulo GNSS. Os dados gerados para as simulações foram os dados IMU, dados GNSS e informações de baseline e ângulo GNSS. Estas informações, determinadas a partir de um sistema multiantenas para o posicionamento simples e relativo e no método direto, respectivamente, foram utilizadas como medidas auxiliares para a fusão INS/GNSS. Foi estudada a influência dessas medidas auxiliares nas estimativas de atit...

La medida de la inteligencia emocional en el ámbito psicoeducativo

Directory of Open Access Journals (Sweden)

Iratxe Antonio-Agirre

2017-01-01

Full Text Available La diversidad individual que alberga la escuela representa un reto ineludible. Para promover el desarrollo integral del alumnado resulta necesario favorecer competencias para la vida, como la inteligencia emocional, que les ayuden a lograr un mejor ajuste sociopersonal y escolar. Sin embargo, la diversidad conceptual en torno a la inteligencia emocional ha contribuido a la proliferación de medidas y ha dificultado la integración de la investigación. En todo caso, atendiendo a las propiedades psicométricas y a las dimensiones que miden, este trabajo recoge los principales instrumentos de medida de la inteligencia emocional que posibilitan una evaluación más rigurosa y exhaustiva del constructo en niños, niñas y adolescentes.

Consecuencias de las medidas no arancelarias impuestas a Colombia por Ecuador y Argentina

OpenAIRE

Perez Giraldo, Johanna Sembelly; Vargas, William

2016-01-01

Con la apertura económica y comercial ha aumentado la negociación de acuerdos comerciales por medio de los cuales los países han logrado tener acceso preferencial libre de aranceles aduaneros. Esta dinámica ha incrementado el uso de medidas no arancelaria como instrumentos para controlar y restringir el acceso a los mercados de los países. Por lo expuesto, esta investigación presenta y analiza las medidas no arancelarias que fueron aplicadas a Colombia por Ecuador y Argentina desde el año 201...

Composition measurement in substitutionally disordered materials by atomic resolution energy dispersive X-ray spectroscopy in scanning transmission electron microscopy.

Science.gov (United States)

Chen, Z; Taplin, D J; Weyland, M; Allen, L J; Findlay, S D

2017-05-01

The increasing use of energy dispersive X-ray spectroscopy in atomic resolution scanning transmission electron microscopy invites the question of whether its success in precision composition determination at lower magnifications can be replicated in the atomic resolution regime. In this paper, we explore, through simulation, the prospects for composition measurement via the model system of Al x Ga 1-x As, discussing the approximations used in the modelling, the variability in the signal due to changes in configuration at constant composition, and the ability to distinguish between different compositions. Results are presented in such a way that the number of X-ray counts, and thus the expected variation due to counting statistics, can be gauged for a range of operating conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Normatização de medidas acústicas da voz normal

Directory of Open Access Journals (Sweden)

Araújo Simone Adad

2002-01-01

Full Text Available Introdução: A análise acústica da voz com o avanço da tecnologia digital surge como um exame complementar promissor para aumentar a precisão diagnóstica em laringologia. Objetivo: Normatização das medidas acústicas de freqüência fundamental, perturbação e ruído na voz normal de brasileiros dos sexos masculino e feminino. Forma de estudo: Clínico prospectivo. Material e Método: Pesquisa no período de março a agosto de 1997, no Ambulatório de Otorrinolaringologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, com 80 voluntários da cidade de Ribeirão Preto e região, sendo 40 do sexo masculino e 40 do feminino, selecionados por meio de triagem, foram realizadas gravações digitais dos fonemas /a/, /e/ e /i/, originando uma amostra de 240 sinais acústicos submetidos ao Programa de Análise Acústica da Voz, desenvolvido na Escola de Engenharia de São Carlos da Universidade de São Paulo com obtenção das medidas acústicas. Resultados: Foram obtidos valores médios em relação a sexo e fonemas das medidas de: Freqüência fundamental, Jitter (Directional Perturbation Factor, Perturbation Variation Index, Jitter Ratio, Jitter Factor, Period Perturbation Quotient, Shimmer (Directional Perturbation Factor, Amplitude Variation Index, Amplitude Perturbation Quotient, Spectral Noise Level, Harmonic-to-noise ratio, Harmonic-to-noise ratio cepstrum, Normalized Noise Energy e Breathiness ratio. Conclusão: A normatização das medidas acústicas é necessária para conhecer melhor a voz normal. Os valores obtidos são compatíveis em sua grande maioria com à literatura existente.

Monitoreo neurointensivo en pediatría (III: Tratamiento. Medidas generales

Directory of Open Access Journals (Sweden)

Eduardo M. Pleguezuelo Rodríguez

2001-06-01

Full Text Available Se informa que con el neuromonitoreo y el manejo intensivo del traumatismo craneoencefálico grave, se han identificado un grupo de fenómenos fisiopatológicos diferentes, los cuales requieren de medidas disímiles y específicas para cada paciente, lo que hace más racional el tratamiento de ellos. De la misma manera esto ha propiciado que cambien radicalmente las concepciones acerca de antiguos patrones terapéuticos establecidos durante muchos años; ejemplo de esto es el cambio en la reposición hídrica de ellos, los cuales antes se mantenían sobre una vertiente seca y hoy se preconiza la euvolemia estricta, la sustitución de la hiperventilación de rutina por la ventilación optimizada, cambios en la política del uso de agentes osmóticos, la terapia barbitúrica y la craneotomía descompresiva en casos de hipertensión intracraneal refractaria a medidas terapéuticas convencionales. En este trabajo se hace una revisión actualizada de las principales medidas terapéuticas utilizadas en estos pacientes, acorde con lo que plantean los lineamientos para el tratamiento del traumatismo craneal grave de la Asociación Americana de Cirujanos Neurológicos y los del consorcio europeo para la lesión cerebral. Las medidas terapéuticas utilizadas en estos pacientes se dividen en 2 fases. En este tercer trabajo de actualización se aborda el manejo de la primera fase que corresponde a la estabilización urgente inicial antes de establecer la medición de la presión intracraneal (PIC, así como las medidas generales de la segunda fase una vez iniciado el monitoreo de la PIC. Principios terapéuticos que desde hace algunos años se vienen utilizando en el Hospital provincial General y el Hospital Pediátrico Provincial Docente de Camagüey para el manejo del trauma craneal grave, los cuales se basan en medidas iniciales en la recepción, acorde con lo que plantean los principios del soporte vital avanzado en trauma para la reanimaci

MEDIDAS DE DESEMPENHO E ONTOLOGIAS: UM ESTUDO BIBLIOMÉTRICO PARA IDENTIFICAÇÃO DO USO DE ONTOLOGIAS PARA O SUPORTE DOS PROCESSOS DE MEDIDAS DE DESEMPENHO

Directory of Open Access Journals (Sweden)

Vanderlei Freitas Junior

2015-09-01

Full Text Available O presente trabalho se propõe analisar as publicações internacionais acerca do emprego das ontologias no contexto de medidas de desempenho. Para isso, foi realizada uma pesquisa bibliométrica em três bases de dados internacionais: Web of Science, Scopus e IEEE. Essa pesquisa foi desenvolvida em duas grandes etapas: (i busca sistemática da literatura, e (ii análise e síntese das informações bibliométricas. Foram localizados 115 trabalhos, escritos por 362 autores vinculados a 84 instituições de 101 países diferentes e estão publicados em 38 periódicos. Os autores identificaram ainda 981 palavras-chave diferentes em seus estudos. Os estudos, de maneira geral, evidenciam a possibilidade de utilização das ontologias como ferramenta semântica em diversas etapas e momentos do processo de medidas de desempenho, especialmente no que tange à representação do conhecimento e elu-cidação dos indicadores chaves, permitindo a interoperabilidade destes indicadores. A partir da identificação destes estudos o presente trabalho contribui para a compreensão das possibilidades de aplicação das ontologias para o suporte aos pro-cessos de medida de desempenho, realizando o mapeamento das publicações inter-nacionais desta temática e evidenciando a possibilidade de representação do conhecimento envolvido nesta tarefa.

Scanning transmission X-ray microscopy as a speciation tool for natural organic molecules

Energy Technology Data Exchange (ETDEWEB)

Rothe, J.; Plaschke, M.; Denecke, M.A. [Inst. fuer Nukleare Entsorgung, Forschungszentrum Karlsruhe, Karlsruhe (Germany)

2004-07-01

A molecular-scale understanding of the basic processes affecting stability and transport behavior of actinide cations, complexes or hydroxide ('eigencolloid') species is prerequisite to performance assessment of nuclear waste disposal in geological formations. Depending on their functional group chemistry and macromolecular structure, naturally occurring organic molecules (NOM) possess a high tendency towards actinide complexation reactions. However, the compositional and structural heterogeneity of NOM and mixed aggregates with inorganic phases makes speciation by spectromicroscopy techniques highly desirable. The applicability of Scanning Transmission X-ray Microscopy (STXM) as a speciation tool for the characterization of NOM is demonstrated for a multifunctional natural organic acid (chlorogenic acid), Eu(III)-loaded humic acid (HA) aggregates and Eu(III)-oxo/hydroxide/HA hetero-aggregates. It is shown that in situ probing of HA functional group chemistry down to a spatial resolution < 100 nm (i.e., less than femto-liter sampled volumes) is feasible, at the same time revealing morphological details on NOM aggregates and NOM/mineral associations. (orig.)

Transmission X-ray Diffraction (XRD) Patterns Relevant to the MSL Chemin Amorphous Component: Sulfates And Silicates

Science.gov (United States)

Morris, R. V.; Rampe, E. B.; Graff, T. G.; Archer, P. D., Jr.; Le, L.; Ming, D. W.; Sutter, B.

2015-01-01

The Mars Science Laboratory (MSL) CheMin instrument on the Curiosity rover is a transmission X-ray diffractometer (Co-Kalpha radiation source and a approx.5deg to approx.52deg 2theta range) where the analyzed powder samples are constrained to have discrete particle diameters XRD amorphous component. Estimates of amorphous component abundance, based on the XRD data itself and on mass-balance calculations using APXS data crystalline component chemistry derived from XRD data, martian meteorites, and/or stoichiometry [e.g., 6-9], range from approx.20 wt.% to approx.50 wt.% of bulk sample. The APXSbased calculations show that the amorphous component is rich in volatile elements (esp. SO3) and is not simply primary basaltic glass, which was used as a surrogate to model the broad band in the RN CheMin pattern. For RN, the entire volatile inventory (except minor anhydrite) is assigned to the amorphous component because no volatile-bearing crystalline phases were reported within detection limits [2]. For JK and CB, Fesaponite, basanite, and akaganeite are volatile-bearing crystalline components. Here we report transmission XRD patterns for sulfate and silicate phases relevant to interpretation of MSL-CheMin XRD amorphous components.

X-ray interferometric Fourier holography

International Nuclear Information System (INIS)

Balyan, M.K.

2016-01-01

The X-ray interferometric Fourier holography is proposed and theoretically investigated. Fourier The X-ray interferometric Young fringes and object image reconstruction are investigated. It is shown that the interference pattern of two slits formed on the exit surface of the crystal-analyzer (the third plate of the interferometer) is the X-ray interferometric Young fringes. An expression for X-ray interferometric Young fringes period is obtained. The subsequent reconstruction of the slit image as an object is performed by means of Fourier transform of the intensity distribution on the hologram. Three methods of reconstruction of the amplitude transmission complex function of the object are presented: analytical - approximate method, method of iteration and step by step method. As an example the X-ray Fourier interferometric hologram recording and the complex amplitude transmission function reconstruction for a beryllium circular wire are considered

Self-consistent method for quantifying indium content from X-ray spectra of thick compound semiconductor specimens in a transmission electron microscope.

Science.gov (United States)

Walther, T; Wang, X

2016-05-01

Based on Monte Carlo simulations of X-ray generation by fast electrons we calculate curves of effective sensitivity factors for analytical transmission electron microscopy based energy-dispersive X-ray spectroscopy including absorption and fluorescence effects, as a function of Ga K/L ratio for different indium and gallium containing compound semiconductors. For the case of InGaN alloy thin films we show that experimental spectra can thus be quantified without the need to measure specimen thickness or density, yielding self-consistent values for quantification with Ga K and Ga L lines. The effect of uncertainties in the detector efficiency are also shown to be reduced. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Abuso de las medidas y medidas abusivas. Crítica al pensamiento bibliométrico hegemónico

OpenAIRE

GÒMEZ-MORALES, YURI JACK

2018-01-01

RESUMEN En este ensayo reflexivo se hace una crítica a la economía política de la medición de la ciencia, la cual se ejemplifica mediante el análisis del factor de impacto como medida de la calidad científica; se explican los mecanismos sociales y culturales que operan en la construcción de estas formas de pensar y actuar hegemónicas; y se advierte sobre las graves consecuencias de este proyecto global para la desinstitucionalización de la ciencia local, y el surgimiento de una ciencia nacion...

3D nanoscale imaging of the yeast, Schizosaccharomyces pombe, by full-field transmission x-ray microscopy at 5.4 keV

Science.gov (United States)

Chen, Jie; Yang, Yunhao; Zhang, Xiaobo; Andrews, Joy C.; Pianetta, Piero; Guan, Yong; Liu, Gang; Xiong, Ying; Wu, Ziyu; Tian, Yangchao

2010-01-01

Three-dimensional (3D) nanoscale structures of the fission yeast, Schizosaccharomyces pombe, can be obtained by full-field transmission hard x-ray microscopy with 30 nm resolution using synchrotron radiation sources. Sample preparation is relatively simple and the samples are portable across various imaging environments, allowing for high throughput sample screening. The yeast cells were fixed and double stained with Reynold’s lead citrate and uranyl acetate. We performed both absorption contrast and Zernike phase contrast imaging on these cells in order to test this method. The membranes, nucleus and subcellular organelles of the cells were clearly visualized using absorption contrast mode. The x-ray images of the cells could be used to study the spatial distributions of the organelles in the cells. These results show unique structural information, demonstrating that hard x-ray microscopy is a complementary method for imaging and analyzing biological samples. PMID:20349228

3D nanoscale imaging of the yeast, Schizosaccharomyces pombe, by full-field transmission X-ray microscopy at 5.4 keV.

Science.gov (United States)

Chen, Jie; Yang, Yunhao; Zhang, Xiaobo; Andrews, Joy C; Pianetta, Piero; Guan, Yong; Liu, Gang; Xiong, Ying; Wu, Ziyu; Tian, Yangchao

2010-07-01

Three-dimensional (3D) nanoscale structures of the fission yeast, Schizosaccharomyces pombe, can be obtained by full-field transmission hard X-ray microscopy with 30 nm resolution using synchrotron radiation sources. Sample preparation is relatively simple and the samples are portable across various imaging environments, allowing for high-throughput sample screening. The yeast cells were fixed and double-stained with Reynold's lead citrate and uranyl acetate. We performed both absorption contrast and Zernike phase contrast imaging on these cells in order to test this method. The membranes, nucleus, and subcellular organelles of the cells were clearly visualized using absorption contrast mode. The X-ray images of the cells could be used to study the spatial distributions of the organelles in the cells. These results show unique structural information, demonstrating that hard X-ray microscopy is a complementary method for imaging and analyzing biological samples.

X-ray beam generator

International Nuclear Information System (INIS)

Koller, T.J.; Randmer, J.A.

1977-01-01

A method of minimizing the preferential angular absorption of the divergent beam from an X-ray generator is described. The generator consists of an X-ray shielded housing with an X-ray transmissive window symmetrically placed in radial alignment with a focal spot area on a sloped target surface of an X-ray tube in the housing. The X-ray tube may be of the stationary anode type or of the rotating anode type. (U.K.)

Characterization of a quadrant diamond transmission X-ray detector including a precise determination of the mean electron-hole pair creation energy.

Science.gov (United States)

Keister, Jeffrey W; Cibik, Levent; Schreiber, Swenja; Krumrey, Michael

2018-03-01

Precise monitoring of the incoming photon flux is crucial for many experiments using synchrotron radiation. For photon energies above a few keV, thin semiconductor photodiodes can be operated in transmission for this purpose. Diamond is a particularly attractive material as a result of its low absorption. The responsivity of a state-of-the art diamond quadrant transmission detector has been determined, with relative uncertainties below 1% by direct calibration against an electrical substitution radiometer. From these data and the measured transmittance, the thickness of the involved layers as well as the mean electron-hole pair creation energy were determined, the latter with an unprecedented relative uncertainty of 1%. The linearity and X-ray scattering properties of the device are also described.

Advancement of Solidification Processing Technology Through Real Time X-Ray Transmission Microscopy: Sample Preparation

Science.gov (United States)

Stefanescu, D. M.; Curreri, P. A.

1996-01-01

Two types of samples were prepared for the real time X-ray transmission microscopy (XTM) characterization. In the first series directional solidification experiments were carried out to evaluate the critical velocity of engulfment of zirconia particles in the Al and Al-Ni eutectic matrix under ground (l-g) conditions. The particle distribution in the samples was recorded on video before and after the samples were directionally solidified. In the second series samples of the above two type of composites were prepared for directional solidification runs to be carried out on the Advanced Gradient Heating Facility (AGHF) aboard the space shuttle during the LMS mission in June 1996. X-ray microscopy proved to be an invaluable tool for characterizing the particle distribution in the metal matrix samples. This kind of analysis helped in determining accurately the critical velocity of engulfment of ceramic particles by the melt interface in the opaque metal matrix composites. The quality of the cast samples with respect to porosity and instrumented thermocouple sheath breakage or shift could be easily viewed and thus helped in selecting samples for the space shuttle experiments. Summarizing the merits of this technique it can be stated that this technique enabled the use of cast metal matrix composite samples since the particle location was known prior to the experiment.

Medidas relativas al acoso escolar y ciberacoso en la normativa autonómica española. Un estudio comparativo

Directory of Open Access Journals (Sweden)

Fuensanta Cerezo Ramírez

2017-01-01

Full Text Available Sendos informes del Defensor del Pueblo Español alertaron de la necesidad de adoptar medidas para controlar el acoso entre escolares y mejorar la convivencia en las aulas. Sus recomendaciones fueron recogidas por las Comunidades Autónomas (CC.AA. y plasma das en normativas propias. El presente artículo reflexiona sobre las medidas adoptadas, como normas de convivencia, por las administraciones públicas, para los centros educativos sostenidos con fondos públicos. Se plantea un estudio comparativo sobre la no rmativa relacionada con los fenómenos de acoso escolar o bullying y ciberacoso o cyberbullying en ocho CC.AA. seleccionadas al azar. El objetivo principal es conocer cómo se ha abordado esta problemática, así como comparar los protocolos de actuación propu estos y el carácter de las medidas recogidas para su intervención en cada CC.AA. Los resultados indican que la mayoría de las políticas hacen referencia expresa al bullying y una de cada cuatro menciona el cyberbullying, también se detectó que la mitad de los protocolos proponen medidas de actuación ante violencia escolar. En cuanto al carácter de las medidas adoptadas, el análisis demuestra que éstas se dirigen, casi exclusivamente, al alumnado agresor y que, en la mayoría de los casos, son de índole corre ctiva/disciplinaria. Se destaca que en las normativas apenas se hace referencia a medidas de carácter educativo, dejando sin respuesta la propuesta del Defensor del Pueblo que hacía hincapié en las medidas educativas.

Soil compaction: Evaluation of stress transmission and resulting soil structure

DEFF Research Database (Denmark)

Naveed, Muhammad; Schjønning, Per; Keller, Thomas

strength. As soon as the applied load is lower than the aggregate strength, the mode of stress transmission is discrete as stresses were mainly transmitted through chain of aggregates. With increasing applied load soil aggregates start deforming that transformed heterogeneous soil into homogenous......, as a result stress transmission mode was shifted from discrete towards more like a continuum. Continuum-like stress transmission mode was better simulated with Boussinesq (1885) model based on theory of elasticity compared to discrete. The soil-pore structure was greatly affected by increasing applied...... and compaction-resulted soil structure at the same time. Stress transmission was quantified using both X-ray CT and Tactilus sensor mat, and soil-pore structure was quantified using X-ray CT. Our results imply that stress transmission through soil highly depends on the magnitude of applied load and aggregate...

Dose and induction to cancer risk evaluation associated to use of X ray body scanners by transmission at airports

International Nuclear Information System (INIS)

Correa, Samanda Cristine Arruda; Aquino, Josilto Oliveira de; Souza, Edmilson Monteiro de; Silva, Ademir Xavier da

2011-01-01

This paper uses the Monte Carlo MCNPX and the phantoms in male voxel and female voxel to evaluate the absorbed doses effective doses and the induction risk and the mortality due to cancer associated to exposures of individual submitted to X ray body scanners by transmission at various projections. The values of effective dose were calculated according to the recommended by the new ICRP 103 and the values of induction risks and mortality due to cancer were estimated through the document BEIR VII. (author)

Binary pseudo-random patterned structures for modulation transfer function calibration and resolution characterization of a full-field transmission soft x-ray microscope

Energy Technology Data Exchange (ETDEWEB)

Yashchuk, V. V., E-mail: VVYashchuk@lbl.gov; Chan, E. R.; Lacey, I. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fischer, P. J. [Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of California Santa Cruz, Santa Cruz, California 94056 (United States); Conley, R. [Advance Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States); McKinney, W. R. [Diablo Valley College, 321 Golf Club Road, Pleasant Hill, California 94523 (United States); Artemiev, N. A. [KLA-Tencor Corp., 1 Technology Drive, Milpitas, California 95035 (United States); Bouet, N. [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States); Cabrini, S. [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Calafiore, G.; Peroz, C.; Babin, S. [aBeam Technologies, Inc., Hayward, California 94541 (United States)

2015-12-15

We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope’s MTF, tests with the BPRML sample can be used to fine tune the instrument’s focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters.

Binary pseudo-random patterned structures for modulation transfer function calibration and resolution characterization of a full-field transmission soft x-ray microscope

International Nuclear Information System (INIS)

Yashchuk, V. V.; Chan, E. R.; Lacey, I.; Fischer, P. J.; Conley, R.; McKinney, W. R.; Artemiev, N. A.; Bouet, N.; Cabrini, S.; Calafiore, G.; Peroz, C.; Babin, S.

2015-01-01

We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope’s MTF, tests with the BPRML sample can be used to fine tune the instrument’s focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters

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

International Nuclear Information System (INIS)

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

1988-01-01

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

Monte Carlo simulation of x-ray buildup factors of lead and its applications in shielding of diagnostic x-ray facilities

International Nuclear Information System (INIS)

Kharrati, Hedi; Agrebi, Amel; Karaoui, Mohamed-Karim

2007-01-01

X-ray buildup factors of lead in broad beam geometry for energies from 15 to 150 keV are determined using the general purpose Monte Carlo N-particle radiation transport computer code (MCNP4C). The obtained buildup factors data are fitted to a modified three parameter Archer et al. model for ease in calculating the broad beam transmission with computer at any tube potentials/filters combinations in diagnostic energies range. An example for their use to compute the broad beam transmission at 70, 100, 120, and 140 kVp is given. The calculated broad beam transmission is compared to data derived from literature, presenting good agreement. Therefore, the combination of the buildup factors data as determined and a mathematical model to generate x-ray spectra provide a computationally based solution to broad beam transmission for lead barriers in shielding x-ray facilities

Consciência metatextual: evidências de validade para instrumento de medida Consciencia metatextual: evidencias de validez para instrumento de medida Metatextual awareness: evidence of validity for measuring instrument

Directory of Open Access Journals (Sweden)

Acácia Aparecida Angeli dos Santos

2012-08-01

Full Text Available O objetivo estabelecido nesta pesquisa descritivo-correlacional foi a averiguação da consciência metatextual por meio de um questionário especialmente elaborado para este fim, analisando sua validade pela relação com medidas de compreensão de leitura e o critério de diferenciação do nível escolar. Participaram 315 alunos do 3º ao 5º ano do ensino fundamental, de escolas públicas, cujas idades variaram de 8 a 13 anos, sendo 169 meninos. Os escores obtidos com a medida de avaliação da consciência metatextual (QACM foram convergentes com a pontuação em compreensão de leitura e o instrumento mostrou-se sensível para captar o progresso das crianças em identificar os gêneros textuais com o avanço da escolaridade. Dessa forma, o estudo forneceu evidências de validade tanto no que se refere à convergência de construtos, identificada com base nas medidas relacionadas, como de critério, distinguindo os alunos pelo seu nível de escolaridade.El objetivo establecido en esta investigación descriptivo-correlacional fue averiguar la consciencia metatextual a través de un cuestionario especialmente diseñado para este fin, analizando su validez por la relación con medidas de comprensión de lectura y el criterio de diferenciación por nivel escolar. Participaron 315 alumnos del 3º al 5º año de la enseñanza básica, de escuelas públicas, cuyas edades variaron de 8 a 13 años, siendo 169 niños. Los puntajes obtenidos con la medida de evaluación de la consciencia metatextual (QACM fueron convergentes con los de la comprensión de lectura y el instrumento se mostró sensible para captar el desarrollo de los niños en identificar los géneros textuales con el avance de la escolaridad. De esa forma, el estudio forneció evidencias de validez por la convergencia de constructos, identificada con base en las medidas relacionadas, como de criterio, distinguiendo los alumnos por su nivel de escolaridad.The stated goal of this

Camiones y dumpers: medidas de seguridad. (Tercera parte

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Chinchilla, M.

1963-04-01

Full Text Available Safety measures to be adopted in connection with any type of work should be those that are specifically adequate for the kind of risks involved, for it is just as wrong to adopt measures that are too ellaborate as not to take any at all. Two kinds of safety measures can be considered: those applying to the personnel, and those that protect the equipment. The efficiency and trouble free completion of the work will depend on the nature of the safety measures that are taken. Accidents are easy to avoid in general if the right safety precautions are taken. Such accidents involve both moral and financial damage, and a consequent loss of efficiency.Las medidas de seguridad que deberán adoptarse en cualquier trabajo serán las precisas, puesto que puede ser tan perjudicial señalar demasiadas como no señalar ninguna. Pueden considerarse dos tipos de medidas de seguridad: las concernientes a la seguridad del personal y las referentes a la maquinaria empleada. De la determinación de unas y otras, así como de su exacta observancia, dependerá que el trabajo se realice de forma eficaz y sin contratiempos, fácilmente evitables, por otra parte, que acarrearían consecuencias de tipo moral y económico, con el consiguiente descenso del rendimiento obtenido.

Ultrasound beam transmission using a discretely orthogonal Gaussian aperture basis

Science.gov (United States)

Roberts, R. A.

2018-04-01

Work is reported on development of a computational model for ultrasound beam transmission at an arbitrary geometry transmission interface for generally anisotropic materials. The work addresses problems encountered when the fundamental assumptions of ray theory do not hold, thereby introducing errors into ray-theory-based transmission models. Specifically, problems occur when the asymptotic integral analysis underlying ray theory encounters multiple stationary phase points in close proximity, due to focusing caused by concavity on either the entry surface or a material slowness surface. The approach presented here projects integrands over both the transducer aperture and the entry surface beam footprint onto a Gaussian-derived basis set, thereby distributing the integral over a summation of second-order phase integrals which are amenable to single stationary phase point analysis. Significantly, convergence is assured provided a sufficiently fine distribution of basis functions is used.

Licenciamento ambiental: acompanhamento de implantação de linhas de transmissão no Estado de São Paulo

OpenAIRE

Tania Regina Sano Sugawara

2016-01-01

O licenciamento ambiental de linhas de transmissão no Estado de São Paulo é conduzido pela Companhia Ambiental do Estado de São Paulo (CETESB), com uso dos princípios da Avaliação de Impacto Ambiental (AIA). Na fase de planejamento dos projetos de Linhas de Transmissão (LTs), isto é, etapa de obtenção da Licença Ambiental Prévia, são estimados os impactos ambientais da implantação e operação do empreendimento, bem como as medidas mitigadoras ou minimizadoras destes impactos. Nas fases de inst...

Medidas Explícitas e Implícitas de las Actitudes Hacia las Mujeres

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Manuel Cárdenas

2009-01-01

Full Text Available El presente estudio tiene como objeto utilizar el IAT (Implicit Association Test para medir actitudes hacia las mujeres, de modo de comparar dichas evaluaciones de carácter automático con las obtenidas por medio de una medida explícita. Además, los participantes respondieron a un inventario de roles sexuales de modo de ver si los sujetos manejaban el estereotipo dominante asociado a lo femenino y sus efectos sobre el prejuicio. La muestra quedó conformada por 80 estudiantes universitarios. No se detectaron diferencias significativas entre hombres y mujeres en los estereotipos asociados a la mujer, ni en la evaluación que se hace de estas (medida explícita. En la medida de IAT las diferencias entre sexos aparecen, indicando que los hombres muestran una actitud implícita más negativa hacia las mujeres. De este modo se confirma que la aparente disminución del prejuicio que puede constatarse en los cuestionarios podría encubrir el hecho de que las actitudes negativas se mantienen a nivel implícito.

Trabajos en espacios confinados. Riesgos y medidas preventivas

OpenAIRE

Fernández, Sergio

2012-01-01

La ejecución de trabajos en espacios confinados resulta una necesidad en diversos sectores como por ejemplo en la industria química, redes de alcantarillado, construcción de barcos, en pozos,… con el fin desarrollar diversas tareas como limpiezas, inspecciones interiores, trabajos de pintura, reparaciones varias,… lo que implica la implantación de medidas especiales y rigurosas a planificar y llevar a cabo. Los riesgos que presentan la ejecución de estos trabajos en espacios confinados ...

Analysis of gypsum ore conversion with aid of gamma-ray transmission and CCRD

International Nuclear Information System (INIS)

Vasconcelos, W.E.; Dantas, C.C.; Lira, C.A.B.O.; Narain, R.; Santos, V.A.

2009-01-01

Nowadays, except for very few kettles imported, the monitoring of the conversion of the produced plaster at the Pole Plaster of Araripe is not done with aid of on-line techniques. It shows a simulation of operational conditions with an online meter of chemically combined water in plaster, by means of Central Composite Rotatable Designs (CCRD) and nuclear technique of gamma-ray transmission. In the family of central composite rotatable designs, the CCRD is more efficient than the others, regarding uniformity of variances of the points at the same distance from the center of the design. It is a simulation of operational conditions with an online meter of chemically combined water in plaster, by means of nuclear technique of gamma radiation transmission. Such determination can be achieved by the effect caused by the variation of the mass attenuation coefficient of the dehydrated partially material. An Americium-241 gamma source (60 keV) was simulated in the implementation of the Beer-Lambert equation. The nuclear data required for simulation were obtained from XMuDat software, available from site of the International Atomic Energy Agency. A program in Matlab programming language has demonstrated the possibility of monitoring at all stages of the dehydration process with measures of the specific mass of the sample having an estimated error of the order of 1%. To verify the operating conditions suitable for the process, experiments were simulated using a CCRD. The independent variables were the thickness sample and chemically combined water in plaster. Optimal conditions of the process were determined (STATISTICA software, Release 7.0), which allowed the derivation of a model represented by response surface of the gypsum conversion. (author)

Abdominoplastia y pexia de pubis: estandarización de medidas

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O. Ballestas-Campo

2014-06-01

Full Text Available La abdominoplastia es el procedimiento de elección para corregir la flacidez abdominal, la lipodistrofia supra e infraumbilical y la diástasis de los rectos abdominales. Los nuevos métodos añaden liposucción para definir el contorno corporal. Presentamos una estandarización de medidas para lograr una cicatriz abdominal baja y pexia pubiana en casos de lipodistrofias tipo III y IV de Matarasso. Realizamos un estudio observacional, descriptivo y retrospectivo, evaluando las historias clínicas y las fotografías sobre 420 mujeres, con edades entre 18 y 63 años, intervenidas entre 2004 y 2011. Basamos la técnica quirúrgica en los siguientes principios: referencias anatómicas; medidas estandarizadas con la paciente de pie sobre zapatos de tacón alto para el trazado de una incisión suprapúbica baja, siguiendo diseño de los autores; pexia de pubis y región inguinal; cicatriz suprapúbica baja cubierta por un biquini estándar. El 70,95 % de los casos (298 pacientes correspondieron a abdomen grado IV de lipodistrofia, el 28,57 % (120 pacientes al grado III y el 0,47 % (2 pacientes al grado II según Matarasso. Las complicaciones más frecuentes fueron: seroma, (4,04 % , alteraciones cicatríciales (7,37 % , necrosis parcial y epidermolisis (2,38 % y estenosis umbilical (1,19 % . Como conclusión creemos que la estandarización de medidas para el diseño de la cicatriz en la abdominoplastia permite obtener resultados estéticos predecibles y funcionales buenos: cicatriz baja cubierta por un biquini o ropa interior estándar, cicatriz umbilical ovalada, pexia de pubis y excelente definición del contorno abdominal y corporal, con baja tasa de complicaciones.

Transmission and fluorescence X-ray absorption spectroscopy cell/flow reactor for powder samples under vacuum or in reactive atmospheres

KAUST Repository

Hoffman, A. S.; Debefve, L. M.; Bendjeriou-Sedjerari, Anissa; Ould-Chikh, Samy; Bare, Simon R.; Basset, Jean-Marie; Gates, B. C.

2016-01-01

X-ray absorption spectroscopy is an element-specific technique for probing the local atomic-scale environment around an absorber atom. It is widely used to investigate the structures of liquids and solids, being especially valuable for characterization of solid-supported catalysts. Reported cell designs are limited in capabilities—to fluorescence or transmission and to static or flowing atmospheres, or to vacuum. Our goal was to design a robust and widely applicable cell for catalyst characterizations under all these conditions—to allow tracking of changes during genesis and during operation, both under vacuum and in reactive atmospheres. Herein, we report the design of such a cell and a demonstration of its operation both with a sample under dynamic vacuum and in the presence of gases flowing at temperatures up to 300 °C, showing data obtained with both fluorescence and transmission detection. The cell allows more flexibility in catalyst characterization than any reported.

Transmission and fluorescence X-ray absorption spectroscopy cell/flow reactor for powder samples under vacuum or in reactive atmospheres

KAUST Repository

Hoffman, A. S.

2016-07-26

X-ray absorption spectroscopy is an element-specific technique for probing the local atomic-scale environment around an absorber atom. It is widely used to investigate the structures of liquids and solids, being especially valuable for characterization of solid-supported catalysts. Reported cell designs are limited in capabilities—to fluorescence or transmission and to static or flowing atmospheres, or to vacuum. Our goal was to design a robust and widely applicable cell for catalyst characterizations under all these conditions—to allow tracking of changes during genesis and during operation, both under vacuum and in reactive atmospheres. Herein, we report the design of such a cell and a demonstration of its operation both with a sample under dynamic vacuum and in the presence of gases flowing at temperatures up to 300 °C, showing data obtained with both fluorescence and transmission detection. The cell allows more flexibility in catalyst characterization than any reported.

Gamma ray detecting device using dislocation-free crystal

International Nuclear Information System (INIS)

Vali, V.; Chang, D.B.

1991-01-01

This patent describes a γ-ray detector. It comprises: a dislocation-free single crystal having an input surface and a transmission surface at opposite ends thereof; an active shield surrounding the crystal and functioning as an anticoincidence counter; and γ-ray detector means disposed adjacent the transmission surface of the crystal for receiving and detecting γ-rays of a predetermined wavelength incident on the input surface of the crystal at a specific Bragg angle and transmitted through the crystal

Analytical electron microscope based on scanning transmission electron microscope with wavelength dispersive x-ray spectroscopy to realize highly sensitive elemental imaging especially for light elements

International Nuclear Information System (INIS)

Koguchi, Masanari; Tsuneta, Ruriko; Anan, Yoshihiro; Nakamae, Koji

2017-01-01

An analytical electron microscope based on the scanning transmission electron microscope with wavelength dispersive x-ray spectroscopy (STEM-WDX) to realize highly sensitive elemental imaging especially for light elements has been developed. In this study, a large-solid-angle multi-capillary x-rays lens with a focal length of 5 mm, long-time data acquisition (e.g. longer than 26 h), and a drift-free system made it possible to visualize boron-dopant images in a Si substrate at a detection limit of 0.2 atomic percent. (paper)

Medidas dinámicas de predictibilidad en el índice s&p 500 y sus determinantes

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Javier Humberto Ospina Holguín

2015-04-01

Full Text Available El objeto de este estudio es medir la predictibilidad del índice accionario estadounidense S&P 500 y establecer posibles determinantes de esta predictibilidad. La predictibilidad se ha estudiado ampliamente, pero en pocos casos mediante medidas dinámicas y per se, como se hace aquí. Para establecer la predictibilidad se utilizan la medida eta del campo de las redes neuronales, el valor p del test de la razón de varianzas del campo de la econometría financiera y el análisis de fluctuación sin tendencia del campo de la econofísica. Se construye un algoritmo de inversión basado en las medidas dinámicas de predictibilidad que es mejor que la estrategia de comprar y mantenerse en el periodo estudiado. Para la medida más promisoria, se establece una relación empírica entre la predictibilidad y varios factores económicos y financieros. El panorama que arroja este estudio es el de un mercado que no es estáticamente predecible, sino cuya predictibilidad evoluciona dinámicamente en el tiempo, lo cual es compatible con la hipótesis del mercado adaptativo.

Diagnosing and mapping pulmonary emphysema on X-ray projection images: incremental value of grating-based X-ray dark-field imaging.

Science.gov (United States)

Meinel, Felix G; Schwab, Felix; Schleede, Simone; Bech, Martin; Herzen, Julia; Achterhold, Klaus; Auweter, Sigrid; Bamberg, Fabian; Yildirim, Ali Ö; Bohla, Alexander; Eickelberg, Oliver; Loewen, Rod; Gifford, Martin; Ruth, Ronald; Reiser, Maximilian F; Pfeiffer, Franz; Nikolaou, Konstantin

2013-01-01

To assess whether grating-based X-ray dark-field imaging can increase the sensitivity of X-ray projection images in the diagnosis of pulmonary emphysema and allow for a more accurate assessment of emphysema distribution. Lungs from three mice with pulmonary emphysema and three healthy mice were imaged ex vivo using a laser-driven compact synchrotron X-ray source. Median signal intensities of transmission (T), dark-field (V) and a combined parameter (normalized scatter) were compared between emphysema and control group. To determine the diagnostic value of each parameter in differentiating between healthy and emphysematous lung tissue, a receiver-operating-characteristic (ROC) curve analysis was performed both on a per-pixel and a per-individual basis. Parametric maps of emphysema distribution were generated using transmission, dark-field and normalized scatter signal and correlated with histopathology. Transmission values relative to water were higher for emphysematous lungs than for control lungs (1.11 vs. 1.06, pemphysema provides color-coded parametric maps, which show the best correlation with histopathology. In a murine model, the complementary information provided by X-ray transmission and dark-field images adds incremental diagnostic value in detecting pulmonary emphysema and visualizing its regional distribution as compared to conventional X-ray projections.

Equipo adiabático para medida del coeficiente de absorción específico de un material sometido a un campo magnético alterno y método para realizar dicha medida

OpenAIRE

Mediano, Arturo; Natividad, Eva; Palacio, Fernando; Castro, Miguel

2007-01-01

Equipo adiabático para medida del coeficiente de absorción específico de un material sometido a un campo magnético alterno y método para realizar dicha medida. En esta patente se describe un equipo que permite medir de forma adiabática el incremento de temperatura experimentado por aquellos materiales que presentan mecanismos activos de disipación de calor al someterlos a un campo magnético alterno. Conocida esta magnitud y el tiempo de aplicación del campo y, conocien...

Quantitative analysis by energy dispersive X-ray fluorescence by the transmission method applied to geological samples Análise quantitativa por fluorescência de raios X com dispersão por energia pelo método da transmissão aplicada à amostras geológicas

Directory of Open Access Journals (Sweden)

S.M. Simabuco

1994-08-01

Full Text Available Three certified samples of different matrices (Soil-5, SL-1/IAEA and SARM-4/SABS were quantitatively analysed by energy dispersive X-ray fluorescence with radioisotopic excitation. The observed errors were about 10-20% for the majority of the elements and less than 10% for Fe and Zn in the Soil-5, Mn in SL-1, and Ti, Fe and Zn in SARM-4 samples. Annular radioactive sources of Fe-55 and Cd-109 were utilized for the excitation of elements while a Si(Li semiconductor detector coupled to a multichannel emulation card inserted in a microcomputer was used for the detection of the characteristic X-rays. The fundamental parameters method was used for the determination of elemental sensitivities and the irradiator or transmission method for the correction of the absorption effect of characteristic X-rays of elements on the range of atomic number 22 to 42 (Ti to Mo and excitation with Cd-109. For elements in the range of atomic number 13 to 23 (Al to V the irradiator method cannot be applied since samples are not transparent for the incident and emergent X-rays. In order to perform the absorption correction for this range of atomic number excited with Fe-55 source, another method was developed based on the experimental value of the absorption coefficients, associated with absorption edges of the elements.Foi realizada a análise quantitativa de três amostras certificadas de diferentes matrizes (Soil-5/IAEA, SL-1/IAEA e SARM-4/SABS através da fluorescência de raios X por dispersão de energia e excitação radioisotópica. Os erros observados foram em torno de 10 a 20% para a maioria dos elementos e inferiores a 10% para Fe e Zn na amostra Soil-5, Mn na amostra SL-1 e Ti, Fe e Zn na amostra SARM-4. Para a excitação dos elementos presentes foram empregadas as fontes radioativas anelares de Fe-55 e Cd-109, enquanto que na detecção dos raios X característicos utilizou-se um detector de Si(Li, acoplado a uma placa analisadora de pulsos multicanal

Application of an expectation maximization method to the reconstruction of X-ray-tube spectra from transmission data

International Nuclear Information System (INIS)

Endrizzi, M.; Delogu, P.; Oliva, P.

2014-01-01

An expectation maximization method is applied to the reconstruction of X-ray tube spectra from transmission measurements in the energy range 7–40 keV. A semiconductor single-photon counting detector, ionization chambers and a scintillator-based detector are used for the experimental measurement of the transmission. The number of iterations required to reach an approximate solution is estimated on the basis of the measurement error, according to the discrepancy principle. The effectiveness of the stopping rule is studied on simulated data and validated with experiments. The quality of the reconstruction depends on the information available on the source itself and the possibility to add this knowledge to the solution process is investigated. The method can produce good approximations provided that the amount of noise in the data can be estimated. - Highlights: • An expectation maximization method was used together with the discrepancy principle. • The discrepancy principle is a suitable criterion for stopping the iteration. • The method can be applied to a variety of detectors/experimental conditions. • The minimum information required is the amount of noise that affects the data. • Improved results are achieved by inserting more information when available

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Aplicaciones de los modelos multinivel al análisis de medidas repetidas en estudios longitudinales

OpenAIRE

María Victoria Zunzunegui; María Jesús García de Yébenes; Mathieu Forster; María Dolores Aguilar Conesa; Angel Rodríguez Laso; Ángel Otero

2004-01-01

Este trabajo es una introducción al análisis de medidas repetidas en estudios longitudinales. Se utiliza un marco analítico con dos etapas, ajustando modelos jerárquicos lineales con dos niveles. El primer nivel corresponde a la ocasión (tiempo) de medida y el segundo al individuo. Estos modelos estadísticos proceden de las ciencias sociales, en las que se han utilizado durante más de 25 años para analizar datos en organizaciones con múltiples niveles. Su aplicación permi...

Electroadsorption-assisted direct determination of trace arsenic without interference using transmission X-ray fluorescence spectroscopy.

Science.gov (United States)

Jiang, Tian-Jia; Guo, Zheng; Liu, Jin-Huai; Huang, Xing-Jiu

2015-08-18

An analytical technique based on electroadsorption and transmission X-ray fluorescence (XRF) for the quantitative determination of arsenic in aqueous solution with ppb-level limits of detection (LOD) is proposed. The approach uses electroadsorption to enhance the sensitivity and LOD of the arsenic XRF response. Amine-functionalized carbonaceous microspheres (NH2-CMSs) are found to be the ideal materials for both the quantitative adsorption of arsenic and XRF analysis due to the basic amine sites on the surface and their noninterference in the XRF spectrum. In electroadsorptive X-ray fluorescence (EA-XRF), arsenic is preconcentrated by a conventional three-electrode system with a positive electricity field around the adsorbents. Then, the quantification of arsenic on the adsorbents is achieved using XRF. The electroadsorption preconcentration can realize the fast transfer of arsenic from the solution to the adsorbents and improve the LOD of conventional XRF compared with directly determining arsenic solution by XRF alone. The sensitivity of 0.09 cnt ppb(-1) is obtained without the interferences from coexisted metal ions in the determination of arsenic, and the LOD is found to be 7 ppb, which is lower than the arsenic guideline value of 10 ppb given by the World Health Organization (WHO). These results demonstrated that XRF coupled with electroadsorption was able to determine trace arsenic in real water sample.

Medida del coeficiente d33 de piezocomposites por interferometría láser

Directory of Open Access Journals (Sweden)

Montero de Espinosa, F.

2002-02-01

Full Text Available The measurement of piezoelectric coefficient d33 is made using devices like the Berlincourt Meter ®, based on a force generator internally calibrated by a reference piezoelectric element which measures the charge ratio Culomb/Newton. For estructures such as piezoelectric composites, formed by materials of very different elastic properties, the measurements made by the described system present a great dispersión which depends on both the size of the pressing head and the aplied arm pressure. This work presents a set of systematic measurements of d33 for several piezocomposite geometries by means of optical interferometry. These measurements are compared with those obtained with the Berlincourt. It is observed that both techniques render closer results as the net step is reduced.La medida del coeficiente piezoeléctrico d33 se realiza utilizando equipos como el Berlincourt Meter ®, basados en un generador de fuerza calibrado internamente por un elemento piezoeléctrico de referencia que mide la relación de carga, Culombio/ Newton. Estos sistemas están absolutamente contrastados, tomando los grupos de investigación sus medidas como estándar. En el caso de estructuras tales como los composites piezoeléctricos, en los que la estructura está formada por materiales de muy distinta elasticidad, bien por este hecho, bien por la misma estructura, las medidas con el sistema descrito presentan una gran dispersión dependiendo del tamaño de la cabeza presionante y la presión del brazo. Dado que en el modelado de resonadores piezocomposite para su uso en aplicaciones con acoplamiento en aire es necesario conocer dicho parámetro sin incertidumbre, se presentan en el trabajo una serie de medidas sistemáticas de dicho coeficiente para varias geometrías de piezocomposites utilizando interferometría óptica. Se relaciona así mismo estas medidas con el resultado obtenido con el equipo estándar antes referido observando como cuanto más pequeño es

Optimization of planar metallic nonrefracting transmission-grating profiles for M/sup th/-order intensity maximization in the soft x-ray range

International Nuclear Information System (INIS)

Tatchyn, R.; Csonka, P.L.; Lindau, I.

1982-01-01

In this paper, we derive the thickness profiles of metallic transmission-grating bars which maximize either the power throughput into the m/sup th/ diffracted order or the ratio of the m/sup th/-order diffracted power to the total output power (in the soft x-ray range). The derivation is performed for both general and symmetric bar shapes and for the two physically important cases of continuous gratings and gratings with integral bars. The solutions derived are shown to be valid for cases where the optical constants are generalized to be functions of position in a direction perpendicular to the grating bars. Examples of some optimum profiles for gold in the soft x-ray range are computed on the basis of the presented analysis and tabulated for convenient reference. 18 references

Miniature x-ray point source for alignment and calibration of x-ray optics

International Nuclear Information System (INIS)

Price, R.H.; Boyle, M.J.; Glaros, S.S.

1977-01-01

A miniature x-ray point source of high brightness similar to that of Rovinsky, et al. is described. One version of the x-ray source is used to align the x-ray optics on the Argus and Shiva laser systems. A second version is used to determine the spatial and spectral transmission functions of the x-ray optics. The spatial and spectral characteristics of the x-ray emission from the x-ray point source are described. The physical constraints including size, intensity and thermal limitations, and useful lifetime are discussed. The alignment and calibration techniques for various x-ray optics and detector combinations are described

Transmission versus reflectance spectroscopy for quantitation

Science.gov (United States)

Gardner, Craig M.

2018-01-01

The objective of this work was to compare the accuracy of analyte concentration estimation when using transmission versus diffuse reflectance spectroscopy of a scattering medium. Monte Carlo ray tracing of light through the medium was used in conjunction with pure component absorption spectra and Beer-Lambert absorption along each ray's pathlength to generate matched sets of pseudoabsorbance spectra, containing water and six analytes present in skin. PLS regression models revealed an improvement in accuracy when using transmission compared to reflectance for a range of medium thicknesses and instrument noise levels. An analytical expression revealed the source of the accuracy degradation with reflectance was due both to the reduced collection efficiency for a fixed instrument etendue and to the broad pathlength distribution that detected light travels in the medium before exiting from the incident side.

Transmission of electric dipole radiation through an interface

Energy Technology Data Exchange (ETDEWEB)

Arnoldus, Henk F., E-mail: hfa1@msstate.edu [Department of Physics and Astronomy, Mississippi State University, P.O. Drawer 5167, Mississippi State, MS 39762-5167 (United States); Berg, Matthew J., E-mail: matt.berg@msstate.edu [Department of Physics and Astronomy, Mississippi State University, P.O. Drawer 5167, Mississippi State, MS 39762-5167 (United States); Li, Xin, E-mail: Xin.Li@millersville.edu [Department of Physics, P.O. Box 1002, Millersville University, Millersville, PA 17551 (United States)

2014-02-07

We consider the transmission of electric dipole radiation through an interface between two dielectrics, for the case of a vertical dipole. Energy flows along the field lines of the Poynting vector, and in the optical near field these field lines are curves (as opposed to optical rays). When the radiation passes through the interface into a thicker medium, the field lines bend to the normal (as rays do), but the transmission angle is not related to the angle of incidence. The redirection of the radiation at the interface is determined by the angle dependence of the transmission coefficient. This near-field redistribution is responsible for the far-field angular power pattern. When the transmission medium is thinner than the embedding medium of the dipole, some energy flows back and forth through the interface in an oscillating fashion. In each area where field lines dip below the interface, an optical vortex appears just above the interface. The centers of these vortices are concentric singular circles around the dipole axis.

Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales.

Science.gov (United States)

Burke, Kerry B; Stapleton, Andrew J; Vaughan, Ben; Zhou, Xiaojing; Kilcoyne, A L David; Belcher, Warwick J; Dastoor, Paul C

2011-07-01

Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N'-(4-butylphenyl)-bis-N, N'-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

Science.gov (United States)

Burke, Kerry B.; Stapleton, Andrew J.; Vaughan, Ben; Zhou, Xiaojing; Kilcoyne, A. L. David; Belcher, Warwick J.; Dastoor, Paul C.

2011-07-01

Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N'-(4-butylphenyl)-bis-N, N'-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

International Nuclear Information System (INIS)

Burke, Kerry B; Stapleton, Andrew J; Vaughan, Ben; Zhou Xiaojing; Belcher, Warwick J; Dastoor, Paul C; Kilcoyne, A L David

2011-01-01

Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N ' -(4-butylphenyl)-bis-N, N ' -phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

Absolutely calibrated, time-resolved measurements of soft x rays using transmission grating spectrometers at the Nike Laser Facility

International Nuclear Information System (INIS)

Weaver, J.L.; Feldman, U.; Seely, J.F.; Holland, G.; Serlin, V.; Klapisch, M.; Columbant, D.; Mostovych, A.

2001-01-01

Accurate simulation of pellet implosions for direct drive inertial confinement fusion requires benchmarking the codes with experimental data. The Naval Research Laboratory (NRL) has begun to measure the absolute intensity of radiation from laser irradiated targets to provide critical information for the radiatively preheated pellet designs developed by the Nike laser group. Two main diagnostics for this effort are two spectrometers incorporating three detection systems. While both spectrometers use 2500 lines/mm transmission gratings, one instrument is coupled to a soft x-ray streak camera and the other is coupled to both an absolutely calibrated Si photodiode array and a charge coupled device (CCD) camera. Absolute calibration of spectrometer components has been undertaken at the National Synchrotron Light Source at Brookhaven National Laboratories. Currently, the system has been used to measure the spatially integrated soft x-ray flux as a function of target material, laser power, and laser spot size. A comparison between measured and calculated flux for Au and CH targets shows reasonable agreement to one-dimensional modeling for two laser power densities

Arrangement for X-ray shield

International Nuclear Information System (INIS)

1980-01-01

X-ray screen unit consisting of a light transmissive carrier onto which scintillation material is deposited, which is able to generate light under the influence of incident X-ray irradiation, characterised in that the X-ray screen comprises a number of sectors, wherein the surface with respect to the incident X-radiation is maintained at an acute angle. (G.C.)

Laboratory-size three-dimensional x-ray microscope with Wolter type I mirror optics and an electron-impact water window x-ray source

Energy Technology Data Exchange (ETDEWEB)

Ohsuka, Shinji, E-mail: ohsuka@crl.hpk.co.jp [Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, 434-8601 (Japan); The Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsu-cho, Nishi-ku, Hamamatsu-City, 431-1202 (Japan); Ohba, Akira; Onoda, Shinobu; Nakamoto, Katsuhiro [Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, 434-8601 (Japan); Nakano, Tomoyasu [Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, 434-8601 (Japan); Ray-Focus Co. Ltd., 6009 Shinpara, Hamakita-ku, Hamamatsu-City, 434-0003 (Japan); Miyoshi, Motosuke; Soda, Keita; Hamakubo, Takao [Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

2014-09-15

We constructed a laboratory-size three-dimensional water window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques, and observed bio-medical samples to evaluate its applicability to life science research fields. It consists of a condenser and an objective grazing incidence Wolter type I mirror, an electron-impact type oxygen Kα x-ray source, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit of around 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-μm scale three-dimensional fine structures were resolved.

Laboratory-size three-dimensional x-ray microscope with Wolter type I mirror optics and an electron-impact water window x-ray source.

Science.gov (United States)

Ohsuka, Shinji; Ohba, Akira; Onoda, Shinobu; Nakamoto, Katsuhiro; Nakano, Tomoyasu; Miyoshi, Motosuke; Soda, Keita; Hamakubo, Takao

2014-09-01

We constructed a laboratory-size three-dimensional water window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques, and observed bio-medical samples to evaluate its applicability to life science research fields. It consists of a condenser and an objective grazing incidence Wolter type I mirror, an electron-impact type oxygen Kα x-ray source, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit of around 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-μm scale three-dimensional fine structures were resolved.

Medida da visão em candelas: description of a psychophysical technique to quantify luminous intensity

Directory of Open Access Journals (Sweden)

Airton Leite Kronbauer

2011-04-01

Full Text Available OBJETIVO: Desenvolver um método e um dispositivo para quantificar a visão em candela (cd. Os estudos de medida da visão são importantes para todas as ciências visuais. MÉTODOS: É um estudo teórico e experimental. Foram descritos os detalhes do método psicofísico e da calibração do dispositivo. Foram realizados testes preliminares em voluntários. RESULTADOS: É um teste psicofísico simples e com resultado expresso em unidades do sistema internacional de medidas. Com a descrição técnica será possível reproduzir o experimento em outros centros de pesquisa. CONCLUSÃO: Os resultados aferidos em intensidade luminosa (cd são uma opção para estudo visual. Esses resultados possibilitarão extrapolar medidas para modelos matemáticos e para simular efeitos individuais com dados aberrométricos.

Transmission X-ray Microscopy—A New Tool in Clay Mineral Floccules Characterization

Directory of Open Access Journals (Sweden)

Ray L. Frost

2012-10-01

Full Text Available Effective flocculation and dewatering of mineral processing streams containing clays are microstructure dependent in clay-water systems. Initial clay flocculation is crucial in the design and for the development of a new methodology of gas exploitation. Microstructural engineering of clay aggregates using covalent cations and Keggin macromolecules have been monitored using the new state of the art Transmission X-ray Microscope (TXM with 60 nm tomography resolution installed in a Taiwanese synchrotron. The 3-D reconstructions from TXM images show complex aggregation structures in montmorillonite aqueous suspensions after treatment with Na+, Ca2+ and Al13 Keggin macromolecules. Na-montmorillonite displays elongated, parallel, well-orientated and closed-void cellular networks, 0.5–3 µm in diameter. After treatment by covalent cations, the coagulated structure displays much smaller, randomly orientated and openly connected cells, 300–600 nm in diameter. The average distances measured between montmorillonite sheets was around 450 nm, which is less than half of the cell dimension measured in Na-montmorillonite. The most dramatic structural changes were observed after treatment by Al13 Keggin; aggregates then became arranged in compacted domains of a 300 nm average diameter composed of thick face-to-face oriented sheets, which forms porous aggregates with larger intra-aggregate open and connected voids.

Quantified abundance of magnetofossils at the Paleocene-Eocene boundary from synchrotron-based transmission X-ray microscopy.

Science.gov (United States)

Wang, Huapei; Wang, Jun; Chen-Wiegart, Yu-Chen Karen; Kent, Dennis V

2015-10-13

The Paleocene-Eocene boundary (∼55.8 million years ago) is marked by an abrupt negative carbon isotope excursion (CIE) that coincides with an oxygen isotope decrease interpreted as the Paleocene-Eocene thermal maximum. Biogenic magnetite (Fe3O4) in the form of giant (micron-sized) spearhead-like and spindle-like magnetofossils, as well as nano-sized magnetotactic bacteria magnetosome chains, have been reported in clay-rich sediments in the New Jersey Atlantic Coastal Plain and were thought to account for the distinctive single-domain magnetic properties of these sediments. Uncalibrated strong field magnet extraction techniques have been typically used to provide material for scanning and transmission electron microscopic imaging of these magnetic particles, whose concentration in the natural sediment is thus difficult to quantify. In this study, we use a recently developed ultrahigh-resolution, synchrotron-based, full-field transmission X-ray microscope to study the iron-rich minerals within the clay sediment in their bulk state. We are able to estimate the total magnetization concentration of the giant biogenic magnetofossils to be only ∼10% of whole sediment. Along with previous rock magnetic studies on the CIE clay, we suggest that most of the magnetite in the clay occurs as isolated, near-equidimensional nanoparticles, a suggestion that points to a nonbiogenic origin, such as comet impact plume condensates in what may be very rapidly deposited CIE clays.

Guiding hard x rays with glass polycapillary fiber

International Nuclear Information System (INIS)

Xiao, Q.F.; Ponomarev, I.Y.; Kolomitsev, A.I.; Gibson, D.M.; Dilmanian, F.A.; Nachaliel, E.

1993-01-01

X rays can be guided through a polycapillary fiber by multiple total reflections from the smooth channel walls of the fiber. Using monochromatic Synchrotron Radiation at energies of 22 and 44 keV, we measured the efficiency of transmission of x rays through polycapillary fibers with channel diameters of about 13 μm. Efficiencies of 57.3% and 54.5% for 22 keV and 44 keV x rays, respectively, were obtained with a 120-mm-long straight polycapillary fiber aligned with the incident beam. These values are close to the open fraction of the fiber, which is about 60%. In addition, transmission efficiency was measured as a function of the tilt angle between the incident beam and the axis of the fiber. We also measured the transmission efficiency as a function of the deflection angle for a 114-mm-long curved polycapillary fiber. The measurements are compared with a ray-tracing simulation

CONTROL EJECUTIVO Y FLUIDEZ VERBAL EN POBLACIÓN INFANTIL: MEDIDAS CUANTITATIVAS, CUALITATIVAS Y TEMPORALES

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JULIÁN MARINO

2011-01-01

Full Text Available Para evaluar la evocación de palabras asociadas bajo una consigna de prueba de fluidez verbal (PFV se tienen en cuenta la cantidad de palabras producidas, las asociaciones categoriales y fonológicas entre ellas y el tiempo en que son evocadas. A continuación se presenta un estudio que se realizó aplicando PFV semánticas y fonológicas en una población infantil (8 - 12 años de la ciu dad de Granada (España, que tuvo por objetivos: (1 revisar las tradicionales medidas en PFV, (2 actualizar los índices temporales de medición y (3 presentar combinaciones de éstas con el fin de establecer con mayor precisión la participación del control ejecutivo en PFV. Se encontraron resultados significativos entre los que se destaca que la combinación entre la medida temporal de evocación de palabras conjuntas y la cualitativa de palabras en relación cluster podría aislar con mayor fiabilidad el compromiso de funciones ejecutivas como el control inhibitorio y la flexibilidad cognitiva. Esto se determinó empleando medidas de regresión, ingre sando como variables independientes funciones ejecutivas y como variables dependientes cada una de las medidas de Fluidez Verbal. Para la mencionada combinación de palabras conjuntas - palabras en relación cluster (PFV fonológica letra P se halló un R2 de .41 (p = .000 ingresando como variables predictoras el Trail Making B y la parte Color - Palabra de la versión Trenerry del paradigma Stroop (Lezak, 1995. Se describen también otras posibilidades de medición temporales - cualitativas y su posible utilidad clínica y de investigación.

Confiabilidade da medida de espessuras musculares pela ultrassonografia Reliability of muscle thickness measurements using ultrasound

Directory of Open Access Journals (Sweden)

Paulo Sergio Chagas Gomes

2010-02-01

Full Text Available OBJETIVO: Determinar a confiabilidade das medidas de espessuras dos músculos flexores e extensores do cotovelo e joelho pela ultrassonografia (US, quantificando o erro típico associado a essas medidas (ETM. MÉTODOS: A confiabilidade (duas medidas interdias foi determinada em 15 voluntários aparentemente saudáveis (oito mulheres, 33,9 ± 11,4 anos, 76 ± 21kg, 170 ± 10cm. As imagens da musculatura flexora (FC e extensora do cotovelo (EC e flexora (FJ e extensora do joelho (EJ foram obtidas pela US bidimensional no modo B, utilizando transdutor de 7,5MHz. As espessuras do tecido muscular compreendidas entre as interfaces com o osso e com o tecido adiposo foram medidas em sítios anatômicos identificados e registrados para ser repetidos na segunda medida. RESULTADOS: A ANOVA não identificou diferenças significativas entre as medidas repetidas. Os coeficientes de correlação intraclasse foram FC = 0,970, EC = 0,971, FJ = 0,555 e EJ = 0,929 (P PURPOSE: To determine the reliability of muscle thickness measurements of elbow and knee flexors and extensors using ultrasound, and to quantify the typical error associated to the measurements (TEM. METHODS: The test-retest reliability was determined in 15 apparently healthy volunteers (8 women, 34 ± 11 years, 76 ± 21 kg, 170 ± 10 cm. The images of elbow flexors (EF and extensors (EE and knee flexors (KF and extensors (KE were obtained using a two dimensional mode B ultrasound instrument with a 7.5 MHz transducer. Muscle thickness between the adipose tissue and bone interfaces were measured at anatomical landmarks previously identified and recorded to assure the exact site for the retest. RESULTS: ANOVA did not identify any significant differences between the repeated measurements. Intraclass correlation coefficients (ICC of each pair of measure were EF = 0.970, EE = 0.971, KF = 0.555 e KE = 0.929 (P < 0.05 for all. The coefficients of variation were 3.9 %, 6.1 %, 6.6 % e 4.6 %, and TEM 1.3 mm, 1

Neutron Transmission through Sapphire Crystals

DEFF Research Database (Denmark)

of simulations, in order to reproduce the transmission of cold neutrons through sapphire crystals. Those simulations were part of the effort of validating and improving the newly developed interface between the Monte-Carlo neutron transport code MCNP and the Monte Carlo ray-tracing code McStas....

USO DE MEDIDAS AUTO-REFERIDAS PARA AVALIAÇÃO DO ESTADO NUTRICIONAL DE ADOLESCENTES

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ROZANE APARECIDA TOSO BLEIL

2009-12-01

Full Text Available

Comparar os valores referidos e aferidos de peso e estatura em estudantes adolescentes de um município da região oeste paranaense. Participaram do estudo 125 adolescentes com idade entre 10 e 18 anos. Os estudantes relataram aos pesquisadores dados referentes ao peso e estatura e, após o registro das informações, os jovens foram pesados e medidos. Foram coletadas informações sobre a percepção corporal para verifi car como o adolescente percebe seu peso em relação a sua estatura e as respostas foram agrupadas em três categorias. O teste t-student pareado foi utilizado para identifi car possíveis diferenças nas medidas referidas e aferidas de peso, estatura e do Índice de Massa Corporal - IMC. Para avaliar a concordância entre as medidas aferidas e referidas, calculou-se o coefi ciente de correlação intraclasse de Pearson (CCI, de acordo com a faixa etária e o gênero de cada indivíduo. O teste t-student foi adotado para verifi car possíveis diferenças entre os resultados obtidos, de acordo com o gênero dos alunos. Adotouse o nível de signifi cância de 5%. Os resultados obtidos mostraram que as meninas mais jovens apresentaram melhor percepção corporal quando comparadas às alunas com maior idade. Não foram identifi cadas diferenças signifi cativas entre as medidas referidas e aferidas do grupo estudado, em relação ao gênero e à faixa etária. Porém, nota-se que osadolescentes tendem a subestimar suas medidas corporais, sendo a estatura, a que apresentou menor concordância entreos valores informados e aferidos. As medidas referidas devem ser utilizadas com cuidado na avaliação nutriciona lde adolescentes. Sugere-se a implementação de outros estu dospara confi rmar a validade do uso de tais medidas e ainda avaliar outros fatores que possam interferir nos resulta dos.

A method for describing the doses delivered by transmission x-ray computed tomography

International Nuclear Information System (INIS)

Shope, T.B.; Gagne, R.M.; Johnson, G.C.

1981-01-01

A method for describing the absorbed dose delivered by x-ray transmission computed tomography (CT) is proposed which provides a means to characterize the dose resulting from CT procedures consisting of a series of adjacent scans. The dose descriptor chosen is the average dose at several locations in the imaged volume of the central scan of the series. It is shown that this average dose, as defined, for locations in the central scan of the series can be obtained from the integral of the dose profile perpendicular to the scan plane at these same locations for a single scan. This method for estimating the average dose from a CT procedure has been evaluated as a function of the number of scans in the multiple scan procedure and location in the dosimetry phantom using single scan dose profiles obtained from five different types of CT systems. For the higher dose regions in the phantoms, the multiple scan dose descriptor derived from the single scan dose profiles overestimates the multiple scan average dose by no more than 10%, provided the procedure consists of at least eight scans

Refração atmosferica nas medidas Doppler

OpenAIRE

Oliveira, Leonardo Castro de

1990-01-01

Orientador: Jose Bittencourt de Andrade Dissertação (mestrado) - Universidade Federal do Parana. Setor de Tecnologia Resumo: Esta dissertação tem por objetivo realizar investigações referentes à refração atmosférica nas medidas Doppler. São considerados quatro modelos para correção troposférica, e o modelo de duas frequências para a correção da refração ionosférica . São também testados de diferentes fontes de dados meteorológicos. Todos os testes são feitos utilizando-se o programa GEO...

A Medida socioeducativa de internação

OpenAIRE

Meggiato, Jaqueline da Rosa

2011-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico, Programa de Pós-Graduação em Serviço Social, Florianópolis, 2011 O presente trabalho teve como preocupação central, investigar as diferentes correntes teóricas sobre o Direito da Criança e do Adolescente caracterizando-se, assim, como pesquisa de caráter teórico. A partir dessa investigação buscou-se entender os fundamentos que influenciam os magistrados em suas decisões pela medida socioeducativa de i...

Altura do joelho como medida alternativa confiável na avaliação nutricional de idosos

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Vera Elizabeth CLOSS

2015-10-01

Full Text Available Objetivo:Avaliar o uso da altura do joelho como medida alternativa confiável na avaliação nutricional de idosos atendidos em um ambulatório de geriatria.Métodos:Estudo transversal com idosos atendidos em ambulatório de geriatria de um hospital universitário, entre novembro de 2009 e novembro de 2010. Variáveis investigadas: gênero, idade, peso, estatura, altura do joelho, estatura estimada através das equações de Chumlea, índice de massa corporal para as medidas de estatura aferida e estimada e classificado segundo Lipschitz, e dados sociodemográficos. Na análise descritiva dos dados foram usadas medidas de tendência central, dispersão e proporção; a homogeneidade entre as medidas foi verificada através do coeficiente de correlação intraclasse e do gráfico de Bland e Altman e a concordância entre a avaliação nutricional baseada no índice de massa corporal calculado a partir da estatura aferida e a avaliação nutricional baseada no índice de massa corporal calculado a partir da estatura estimada foi avaliada através do coeficiente Kappa ponderado com pesos quadráticos.Resultados:Foram avaliados 186 idosos com média de idade de 74,3±7,1 anos. A média do índice de massa corporal aferido e estimado foi 28,96±5,86 kg/m2e 27,95±5,47 kg/m2, respectivamente, e a prevalência de sobrepeso foi de 59,7% para o índice de massa corporal aferido e 53,2% para o estimado. Foi observada uma boa concordância (Kappa=0,79; p<0,001 entre as duas avaliações.Conclusão:Os resultados mostraram ser possível utilizar a altura do joelho na estimativa da estatura para cálculo do índice de massa corporal em idosos atendidos em ambulatório, alternativa útil para aqueles que apresentam limitações na aferição das medidas, sendo esta uma medida alternativa importante na avaliação nutricional de idosos.

Evaluation of X-ray shielding performance of protective aprons

International Nuclear Information System (INIS)

Kumagai, Michitomo; Shintani, Mitsuo; Kuranishi, Makoto

1999-01-01

Lead equivalent, which offers protection against x-rays, is rated with a 100 kV tube voltage in Japanese Industrial Standard (JIS) Z 4501-1988, Testing method of lead equivalent for x-ray protective devices.'' However, the actual tube voltage in general diagnostic examinations (normal to special radiography; including computed tomography, CT) is 50 to 150 kV. Therefore, we measured whether the performance of current lead aprons (three products) and protective aprons using composite materials (two products) changes at 60 to 141 kV of tube voltage. Furthermore, we evaluated x-ray shielding performance by measuring the transmission ratio of scattered x-rays. The lead equivalent of two currently used lead aprons was almost the same at all voltages. However, in one currently used lead apron and both protective aprons made of composite materials, lead equivalent decreased rapidly when tube voltage exceeded 100 kV. The transmission ratio of scattered x-rays increased with increasing tube voltage in all of the protective aprons examined. Further, in all aprons examined, the transmission ratio of scattered x-rays declined with widening of the scatter angle. As mentioned above, the x-ray shielding performance of some x-ray protective aprons suddenly decreased at tube voltages over 100 kV. Thus the performance of x-ray protective aprons should be published, and JIS Z 4501 needs to be revised. (author)

Evaluation of X-ray shielding performance of protective aprons

Energy Technology Data Exchange (ETDEWEB)

Kumagai, Michitomo; Shintani, Mitsuo; Kuranishi, Makoto [Toyama Medical and Pharmaceutical Univ. (Japan). Hospital

1999-04-01

Lead equivalent, which offers protection against x-rays, is rated with a 100 kV tube voltage in Japanese Industrial Standard (JIS) Z 4501-1988, Testing method of lead equivalent for x-ray protective devices.`` However, the actual tube voltage in general diagnostic examinations (normal to special radiography; including computed tomography, CT) is 50 to 150 kV. Therefore, we measured whether the performance of current lead aprons (three products) and protective aprons using composite materials (two products) changes at 60 to 141 kV of tube voltage. Furthermore, we evaluated x-ray shielding performance by measuring the transmission ratio of scattered x-rays. The lead equivalent of two currently used lead aprons was almost the same at all voltages. However, in one currently used lead apron and both protective aprons made of composite materials, lead equivalent decreased rapidly when tube voltage exceeded 100 kV. The transmission ratio of scattered x-rays increased with increasing tube voltage in all of the protective aprons examined. Further, in all aprons examined, the transmission ratio of scattered x-rays declined with widening of the scatter angle. As mentioned above, the x-ray shielding performance of some x-ray protective aprons suddenly decreased at tube voltages over 100 kV. Thus the performance of x-ray protective aprons should be published, and JIS Z 4501 needs to be revised. (author)

Development of x-ray laminography under an x-ray microscopic condition

International Nuclear Information System (INIS)

Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto

2011-01-01

An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.

Medidas de bioseguridad adoptadas en el manejo con materiales biológicos en Laboratorios Liorad

Directory of Open Access Journals (Sweden)

Nancy Burguet Lago

2013-03-01

Full Text Available Introducción: el trabajo con microorganismos puede conllevar a riesgos tanto para el personal que trabaja con los mismos como para el medio ambiente. La existencia de laboratorios de seguridad biológica y la implementación de medidas en la manipulación de los agentes biológicos minimizan el riesgo. Objetivo: evaluar las medidas de bioseguridad adoptadas en el manejo con materiales biológicos en Laboratorios Liorad. Métodos: empleo de una lista de chequeo y análisis de los resultados a través de una Matriz DAFO para valorar si el diseño de la instalación cumple con la bioseguridad. Además establecer un sistema documental para la manipulación de microorganismos y la confección de un plan de capacitación para el personal que trabaja en el laboratorio de control microbiológico. Resultados: la lista de chequeo permitió identificar como principal debilidad el no disponer de un doble pasillo para el traslado del material limpio y sucio. Como fortalezas, cumplir con las prácticas y procesamientos adecuados y el contar con equipos de seguridad biológica. El sistema documental incorporó a los procedimientos establecidos para la manipulación, un acápite referido a la «Peligrosidad y Medidas de Seguridad». El programa de capacitación desarrollado permitió proveer conocimientos específicos referidos a esta temática. Conclusión: las medidas adoptadas en el laboratorio permiten plantear que de manera general se cumplen los requisitos establecidos en materia de Bioseguridad para el trabajo con microorganismos.

Characterization by Raman scattering, x-ray diffraction, and transmission electron microscopy of (AlAs)m(InAs)m short period superlattices grown by migration enhanced epitaxy

DEFF Research Database (Denmark)

Bradshaw, J.; Song, X.J.; Shealy, J.R.

1992-01-01

We report growth of (InAs)1(AlAs)1 and (InAs)2(AlAs)2 strained layer superlattices by migration enhanced epitaxy. The samples were grown on InP (001) substrates and characterized by Raman spectroscopy, x-ray diffraction, and transmission electron microscopy. Satellite peaks in the x-ray data...... confirm the intended periodicity and indicate the presence of some disorder in the monolayer sample. The energies of the zone folded and quantum confined optic phonons are in reasonable agreement with calculations based on one-dimensional elastic continuum and linear chain models. Journal of Applied...

Aplicação de medidas cefalométricas em 3D-TC: Application of cephalometric measurements in 3D-TC

Directory of Open Access Journals (Sweden)

Patrícia de Medeiros Loureiro Lopes

2007-01-01

Full Text Available OBJETIVO: o objetivo desta pesquisa foi avaliar a precisão e acurácia (validade de medidas cefalométricas lineares em imagens reconstruídas em terceira dimensão (3D, pela técnica de volume, a partir da tomografia computadorizada (TC multislice. METODOLOGIA: o material da pesquisa consistiu de 10 (dez crânios secos, previamente selecionados, sem distinção de etnia ou gênero, os quais foram submetidos à TC multislice 16 cortes com 0,5mm de espessura por 0,3mm de intervalo de reconstrução. Posteriormente, os dados obtidos foram enviados para uma estação de trabalho independente, contendo o programa Vitrea®. Os pontos cefalométricos (n=13 foram localizados e as respectivas medidas ósseas lineares (n=15 foram realizadas por 2 examinadores, previamente treinados, medindo cada um duas vezes, independentemente, em 3D. As medidas físicas foram obtidas por um terceiro examinador, utilizando um paquímetro digital. A análise dos dados foi realizada mediante um estudo comparativo entre as medidas inter e intra-examinadores, em 3D-TC, e entre estas e as medidas físicas obtidas diretamente nos crânios, utilizando ANOVA (análise de variância. RESULTADOS: não foram encontradas diferenças estatisticamente significantes entre os valores das medidas inter e intra-examinadores, nem entre as medidas físicas e em 3D, com p>0,6 para todas as medidas. O erro percentual foi de 2,05% para as medidas interexaminadores e de 2,11% para as medidas intra-examinadores. A média do erro percentual entre as medidas físicas e em 3D variou de 0,96% a 1,47%. CONCLUSÃO: todas as medidas cefalométricas lineares foram consideradas precisas e acuradas utilizando a técnica de volume em 3D por meio da TC multislice.AIM: To test the precision and accuracy of conventional linear cephalometric measurements in 3D reconstructed images using a multislice CT. METHODS: The study population consisted of 10 dry skulls, previously selected, without distinction of

X-ray detector array

International Nuclear Information System (INIS)

Houston, J.M.

1980-01-01

The object of the invention (an ionization chamber X-ray detector array for use with high speed computerised tomographic imaging apparatus) is to reduce the time required to produce a tomographic image. The detector array described determines the distribution of X-ray intensities in one or more flat, coplanar X-ray beams. It comprises three flat anode sheets parallel to the X-ray beam, a plurality of rod-like cathodes between the anodes, a detector gas between the electrodes and a means for applying a potential between the electrodes. Each of the X-ray sources is collimated to give a narrow, planar section of X-ray photons. Sets of X-ray sources in the array are pulsed simultaneously to obtain X-ray transmission data for tomographic image reconstruction. (U.K.)

X-ray data booklet. Revision

Energy Technology Data Exchange (ETDEWEB)

Vaughan, D. (ed.)

1986-04-01

A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

Energy Technology Data Exchange (ETDEWEB)

Burke, Kerry B; Stapleton, Andrew J; Vaughan, Ben; Zhou Xiaojing; Belcher, Warwick J; Dastoor, Paul C [Centre for Organic Electronics, University of Newcastle, Callaghan, NSW 2308 (Australia); Kilcoyne, A L David, E-mail: Paul.Dastoor@newcastle.edu.au [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2011-07-01

Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N{sup '}-(4-butylphenyl)-bis-N, N{sup '}-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

X-ray dense cellular inclusions in the cells of the green alga Chlamydomonas reinhardtii as seen by soft-x-ray microscopy

International Nuclear Information System (INIS)

Stead, A.D.; Ford, T.W.; Page, A.M.; Brown, J.T.; Meyer-Ilse, W.

1997-01-01

Soft x-rays, having a greater ability to penetrate biological material than electrons, have the potential for producing images of intact, living cells. In addition, by using the so-called open-quotes water windowclose quotes area of the soft x-ray spectrum, a degree of natural contrast is introduced into the image due to differential absorption of the wavelengths by compounds with a high carbon content compared to those with a greater oxygen content. The variation in carbon concentration throughout a cell therefore generates an image which is dependent upon the carbon density within the specimen. Using soft x-ray contact microscopy the authors have previously examined the green alga Chlamydomonas reinhardtii, and the most prominent feature of the cells are the numerous x-ray absorbing spheres, But they were not seen by conventional transmission electron microscopy. Similar structures have also been reported by the Goettingen group using their cryo transmission x-ray microscope at BESSY. Despite the fact that these spheres appear to occupy up to 20% or more of the cell volume when seen by x-ray microscopy, they are not visible by transmission electron microscopy. Given the difficulties and criticisms associated with soft x-ray contact microscopy, the present study was aimed at confirming the existence of these cellular inclusions and learning more of their possible chemical composition

X-ray dense cellular inclusions in the cells of the green alga Chlamydomonas reinhardtii as seen by soft-x-ray microscopy

Energy Technology Data Exchange (ETDEWEB)

Stead, A.D.; Ford, T.W.; Page, A.M. [Univ. of London (United Kingdom); Brown, J.T.; Meyer-Ilse, W. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

1997-04-01

Soft x-rays, having a greater ability to penetrate biological material than electrons, have the potential for producing images of intact, living cells. In addition, by using the so-called {open_quotes}water window{close_quotes} area of the soft x-ray spectrum, a degree of natural contrast is introduced into the image due to differential absorption of the wavelengths by compounds with a high carbon content compared to those with a greater oxygen content. The variation in carbon concentration throughout a cell therefore generates an image which is dependent upon the carbon density within the specimen. Using soft x-ray contact microscopy the authors have previously examined the green alga Chlamydomonas reinhardtii, and the most prominent feature of the cells are the numerous x-ray absorbing spheres, But they were not seen by conventional transmission electron microscopy. Similar structures have also been reported by the Goettingen group using their cryo transmission x-ray microscope at BESSY. Despite the fact that these spheres appear to occupy up to 20% or more of the cell volume when seen by x-ray microscopy, they are not visible by transmission electron microscopy. Given the difficulties and criticisms associated with soft x-ray contact microscopy, the present study was aimed at confirming the existence of these cellular inclusions and learning more of their possible chemical composition.

In-plant measurements of gamma-ray transmissions for precise K-edge and passive assay of plutonium concentration and isotopic abundance in product solutions at the Tokai Reprocessing Plant

International Nuclear Information System (INIS)

Asakura, Y.; Kondo, I.; Masui, J.; Shoji, K.; Russo, P.A.; Hsue, S.T.; Sprinkle, J.K. Jr.; Johnson, S.S.

1982-01-01

A field test has been carried out for more than 2 years for determination of plutonium concentration by K-edge absorption densitometry and for determination of plutonium isotopic abundance by transmission-corrected passive gamma-ray spectrometry. This system was designed and built at Los Alamos National Laboratory and installed at the Tokai reprocessing plant of the Power Reactor and Nuclear Fuel Development Corporation as a part of the Tokai Advanced Safeguards Technology Exercise (TASTEX). For K-edge measurement of plutonium concentration, the transmissions at two discrete gamma-ray energies are measured using the 121.1- and 122.1-keV gamma rays from 75 Se and 57 Co. Intensities of the plutonium passive gamma rays in the energy regions between 38 and 51 keV and between 129 and 153 keV are used for determination of the isotopic abundances. More than 200 product solution samples have been measured in a timely fashion during these 2 years. The relative precisions and accuracies of the plutonium concentration measurement are shown to be within 0.6% (1 sigma) in these applications, and those for plutonium isotopic abundances are within 3% for 238 Pu, 0.4% for 239 Pu, 1.2% for 240 Pu, 1.3% for 241 Pu, and 7% for 242 Pu. The time required is 10 min for the concentration assay, 10 min for the isotopics assay, and about 15 min for handling procedures in the laboratory

Optimización de la medida de conductividad en membranas poliméricas para pilas de combustible

OpenAIRE

Espeso González, Iván

2016-01-01

El objetivo de este Trabajo de Fin de Grado se centra en la medida de conductividad iónica de membranas poliméricas de intercambio iónico en diferentes celdas de conductividad para poder optimizar este tipo de medidas y evaluar las ventajas e inconvenientes que presenta cada una de las celdas de conductividad utilizadas para poder ser utilizadas con otro tipo de membranas poliméricas utilizadas también como electrolitos sólidos en pilas de combustible. Se han utilizado co...

Scanning transmission X-ray microscopy probe for in situ mechanism study of graphene-oxide-based resistive random access memory.

Science.gov (United States)

Nho, Hyun Woo; Kim, Jong Yun; Wang, Jian; Shin, Hyun-Joon; Choi, Sung-Yool; Yoon, Tae Hyun

2014-01-01

Here, an in situ probe for scanning transmission X-ray microscopy (STXM) has been developed and applied to the study of the bipolar resistive switching (BRS) mechanism in an Al/graphene oxide (GO)/Al resistive random access memory (RRAM) device. To perform in situ STXM studies at the C K- and O K-edges, both the RRAM junctions and the I0 junction were fabricated on a single Si3N4 membrane to obtain local XANES spectra at these absorption edges with more delicate I0 normalization. Using this probe combined with the synchrotron-based STXM technique, it was possible to observe unique chemical changes involved in the BRS process of the Al/GO/Al RRAM device. Reversible oxidation and reduction of GO induced by the externally applied bias voltages were observed at the O K-edge XANES feature located at 538.2 eV, which strongly supported the oxygen ion drift model that was recently proposed from ex situ transmission electron microscope studies.

Dois pesos e duas medidas: uma proposta para discutir a natureza do sistema de unidades de medida na sala de aula

Directory of Open Access Journals (Sweden)

Lidiany C. de O. Godoi

2009-01-01

Full Text Available http://dx.doi.org/10.5007/2175-7941.2008v25n3p523 Sugerimos neste artigo um plano de ensino que, envolvendo um trabalho interdisciplinar, discuta a natureza do Sistema de Unidades de Medida. Por meio de dinâmicas de grupos, leitura e interpretação de textos históricos, poemas e ilustrações e também através de outras fontes, acreditamos ser possível mostrar que o sistema de unidades de medida adotado atualmente (SI não é um dado natural, mas o resultado de um processo histórico de negociação de significados e, portanto, contingente das relações sociais. A partir da perspectiva dos Estudos Sociais da Ciência (ou Nova História e Sociologia do Conhecimento, apresentamos algumas discussões que envolveram a adoção do Sistema Decimal na França, bem como as dificuldades de sua posterior implementação no Brasil, expressa pela Revolta do Quebra-Quilos. Esperamos que as dinâmicas sugeridas neste trabalho possibilitem aos estudantes reconhecerem a si mesmos como participantes do processo de construção do conhecimento científico através da observação diária das mudanças que conferem novas feições a ele e também da tentativa de tornar mais significativo um tópico do currículo que, muitas vezes, é considerado desinteressante, enfadonho ou simples memorização de grandezas e de suas conversões.

Exposición humana a las radiaciones electromagnéticas no ionizantes. Legislación y medidas de estaciones base

Directory of Open Access Journals (Sweden)

Alonso Alonso Alonso

2004-12-01

Full Text Available Este trabajo trata sobre los procedimientos de medida de las radiaciones no ionizantes y sus niveles registrados en medidas reales. Las fuentes de radiación analizadas cubren los medios de radiodifusión más corrientes, tales como las transmisiones AM y FM y también las estaciones base de telefonía móvil GSM. Estas fuentes habitualmente radian sobre áreas con alta densidad de población. Se describe brevemente el marco legal que regula los niveles de radiación en España y se señalan algunas posibles mejoras. Se valorarán los resultados encontrados en las medidas.

Medidas Sanitarias y Fitosanitarias, ¿Barreras al Comercio?: el Caso Peruano en el Asia-Pacífico

Directory of Open Access Journals (Sweden)

Marcelo Alonso Valverde Arevalo

2016-01-01

Full Text Available Los aranceles han dejado de representar la principal barrera al comercio exterior, debido a la reducción constante de éstos en el ámbito multilateral o bilateral. Contrariamente, las medidas no arancelarias han ido en aumento, siendo la principal preocupación para las exportaciones mundiales. En este escenario, se presentan las medidas sanitarias y fitosanitarias, las cuales sirven para proteger la salud de las personas, animales y plantas en contra de riesgos asociados con enfermedades, pestes u otros; sin embargo, por la naturaleza de las mismas pueden distorsionar el comercio hasta ser utilizadas con fines proteccionistas en favor de las industrias nacionales de los países importadores. El presente artículo cuestiona si es que a pesar de contar con una serie de acuerdos comerciales internacionales, los cuales han disminuido progresivamente los aranceles, el Perú ha logrado un acceso real al mercado del Asia-Pacífico con productos agropecuarios y pesqueros. En ese sentido, se presentan casos históricos y pendientes en materia de acceso a mercados por medidas de carácter sanitario o fitosanitario, tal como el acceso de paltas a Japón. Asimismo, se analizan las disposiciones de los acuerdos comerciales en materia de medidas sanitarias y fitosanitarias y se presentan las potenciales oportunidades que se establecen en estos acuerdos, a fin de agilizar el acceso a mercados internacionales, y que no se han aprovechado.

X-ray microscopy in Aarhus

International Nuclear Information System (INIS)

Uggerhoej, Erik; Abraham-Peskir, Joanna V.

2000-01-01

The Aarhus imaging soft X-ray microscope is now a busy multi-user facility. The optical set-up will be described and project highlights discussed. a) Metal-induced structural changes in whole cells in solution. The effects of aluminum, copper, nickel and zinc on protozoa investigated by using a combination of light microscopy, confocal scanning laser microscopy and X-ray microscopy. b) Botanical studies by X-ray microscopy used to compliment electron microscopy studies. c) Sludge morphology and iron precipitation in Danish freshwater plants by combining X-ray, scanning electron and transmission electron microscopy

Diferencia en la medida centrada y descentrada del espesor y volumen retiniano con Tomografía de Coherencia Óptica (OCT 3D)

OpenAIRE

Carrero Peñaranda, Rocio

2013-01-01

Se realizaron diferentes medidas centradas y descentradas del espesor y volumen retiniano con OCT para determinar si un ligero descentramiento en la medida puede ocasionar una medida errónea del espesor macular y, en consecuencia, una mala decisión por parte del oftalmólogo a la hora de decidir un tratamiento en pacientes con edema macular. Máster en Física de los sistemas de diagnóstico, tratamiento y protección en Ciencias de la Salud

Abnormal increase of cosmic ray on August 7th, 1972

International Nuclear Information System (INIS)

Kodama, Masahiro; Murakami, Kazuaki; Wada, Masami

1974-01-01

The abnormal increase of cosmic ray on Aug. 7th particularly the dependence of its starting time on local time was studied. Cosmic ray increased twice before and after the greatest Forbush decrease in history on August 4th and 7th, 1972. This study is a trial to estimate the anisotropic flow of solar cosmic ray from the time difference time at different places. Further, the past instance of 23 ground-level events were statistically restudied, and the relationship between the time of generation of solar cosmic ray and the time of transmission to the earth was investigated. A list is given regarding the solar cosmic ray of more than 10 9 eV which occurred since the observation had started. The list shows definite three groups. Attention is paid to the transmission time of F type which is considered to have the most simplest transmission mechanism. The dispersion of the transmission time is large regarding flare-starting time and peak wave intensity time, but is small regarding solar wave-starting time, but the dependence on the longitude is systematic. After all, cosmic ray is accelerated after 10 minutes since solar electric wave has started, and arrives at the earth most early in the case of a flare occurred at the root of garden force line toward the earth. In conclusion, the method of studying the difference of the starting time of abnormal increase according to local time may be an effective means for examining in the characteristics of anisotropic flow of solar cosmic ray. (Iwakiri, K.)

Medida de la dureza de sólidos mediante nanoindentación

Directory of Open Access Journals (Sweden)

Alkorta, J.

2005-10-01

Full Text Available Hardness is not readily measurable by means of instrumented indentation since the value of the contact area depends on the pile-up or sink-in occurring near the contact surface of the sample. The most widespread method to estimate it by means of the loading/unloading curve of indentation, Oliver and Pharr’s method, deviates, in the extreme cases, up to a 25% from the real values since it only takes into account the elastic deflection. In this work, a new correction based on Oliver and Pharr’s method is proposed that agrees with the numerical calculations. Plastic hardening behaviour of the sample must be known to accurately estimate the contact area.

La medida de la dureza mediante indentación con registro de carga y desplazamiento no es evidente, dada la incertidumbre sobre el tamaño de huella debido al levantamiento (pile-up o hundimiento (sink-in plásticos de la superficie de la muestra alrededor del indentador. El método más utilizado para la medida de la dureza mediante la curva de carga/descarga de indentación, el de Oliver y Pharr, sólo tiene en cuenta hundimiento elástico, por lo que el error en la medida de la dureza y el módulo de Young puede llegar hasta un 25% en los casos más extremos. En el presente trabajo se discute una posible corrección al método de Oliver y Pharr para una obtención más ajustada del área de contacto de la huella. Esta corrección requiere de un conocimiento a priori o a posteriori del comportamiento plástico del material.

VIOLENCIA DE GÉNERO EN LAS UNIVERSIDADES: INVESTIGACIONES Y MEDIDAS PARA PREVENIRLA

Directory of Open Access Journals (Sweden)

Rosa Larena

2010-12-01

Full Text Available Normal 0 21 false false false ES ZH-TW X-NONE MicrosoftInternetExplorer4 En este artículo recogemos los resultados de la investigación “Violencia de género en las universidades españolas”, la primera investigación que analiza la violencia de género en el contexto universitario en España. Las investigaciones sobre esta clase de violencia en el ámbito internacional muestran, por un lado, que es una realidad existente en la universidad, de la misma forma que lo es en otros ámbitos sociales. Por otro lado, el análisis de las actuaciones implementadas por universidades de prestigio muestra la existencia de diferentes medidas para prevenirla y superarla. Estas evidencias, contrastadas con las percepciones de diferentes colectivos de la comunidad universitaria sobre la aplicabilidad de estas medidas en las universidades españolas, son el punto de partida para iniciar el desarrollo de medidas que erradiquen la violencia de género en nuestras universidades. In this article we present the findings from the research “Gender violence in Spanish universities”, the first study that analyses gender violence in the university context in Spain. Studies on gender violence at the international level show, on the one hand, that gender violence is a reality that exists in universities, in the same way that it exists in other social contexts. On the other hand, the analysis of the actions implemented in prestigious universities shows the existence of measures to prevent and overcome it. Contrasting these evidences with the perceptions of different university collectives about the applicability of these measures in Spanish universities is the starting point to develop measures to eradicate gender violence in our universities.

Intensities of incident and transmitted ultraviolet-a rays through gafchromic films

Directory of Open Access Journals (Sweden)

Toshizo Katsuda

2017-01-01

Full Text Available Gafchromic films have been applied to X-ray dosimetry in diagnostic radiology. To correct nonuniformity errors in Gafchromic films, X-rays in the double-exposure technique can be replaced with ultraviolet (UV-A rays. Intensities of the incident and transmitted UV-A rays were measured. However, it is unclear whether the chemical color change of Gafchromic films affects the UV-A transmission intensity. Gafchromic EBT3 films were suitable to be used in this study because non-UV protection layers are present on both sides of the film. The film is placed between UV-A ray light-emitting diodes and a probe of a UV meter. Gafchromic EBT3 films were irradiated by UV-A rays for up to 60 min. Data for analysis were obtained in the subsequent 60 min. Images from before and after UV-A irradiation were subtracted. When using 375 nm UV-A, the mean ± standard deviation (SD of the pixel values in the subtracted image was remarkably high (11,194.15 ± 586.63. However, the UV-A transmissivity remained constant throughout the 60 min irradiation period. The mean ± SD UV-A transmission intensity was 184.48 ± 0.50 μm/cm2. Our findings demonstrate that color density changes in Gafchromic EBT3 films do not affect their UV-A transmission. Therefore, Gafchromic films were irradiated by UV-A rays as a preexposure.

Medidas de protección del menor en los casos de violencia de género

Directory of Open Access Journals (Sweden)

Francisca Ramón Fernández

2013-04-01

Full Text Available En el presente trabajo nos proponemos realizar un análisis de los distintos preceptos que contemplan las medidas de protección del menor en los casos de violencia de género, tanto en la legislación internacional, estatal y autonómica. El menor como sujeto, directo o indirecto, de la violencia sobre la mujer es protegido a través de una serie de medidas y reconocimiento de derechos, que es más amplio en una legislación que en otra de las estudiadas. Sería conveniente una uniformidad sobre esa protección al menor, ya que en la mayoría de las veces sufre esa violencia en el entorno familiar. La reflexión del análisis de los preceptos nos indica que es el interés superior del menor el que tiene que prevalecer en todas las situaciones, y que, en muchas ocasiones, la legislación no dota de suficientes medidas de protección al menor que se encuentra en una situación de violencia doméstica.

Chemical and structural composition study through transmission and reflection electron microscopy and X-ray microanalysis of damaged duramater cardiac valves

International Nuclear Information System (INIS)

Verginelli, G.; Didio, L.J.A.; Puig, L.B.; Allen, D.J.; Highinson, G.H.; Zerbini, E.J.

1982-01-01

Ten malfunctioning durameter aortic prosthesis, excised surgically after 44 to 54 months of implantation were studied through transmission and reflection electron microscopy and X-ray microanalysis. Duramater extracted at necropsy but not used for valve prosthesis and duramater aortic prosthesis not implanted in patients were used as controls. It was concluded that homologous duramater valves present subcellular changes following implantation, with degenerating and proliferating areas which could correspond either to normal adaptation or consequence of degeneration - rebuilding which begins with implantation; it is also emphazised the need for ultramicroscopic studies in evaluating biological tissues and establishing its applicability in cardiac surgery. (M.A.C.) [pt

Application of low power X-ray tubes in geology

International Nuclear Information System (INIS)

Massalski, J.M.; Zaraska, W.

1981-01-01

Low power X-ray tubes with transmission anodes for X-ray fluorescence analysis with energy dispersion were elaborated. Paper contains experimental results of application of X-ray tubes in the apparatus for nondestructive measurements of the concentration of some elements in borehole cores. (author)

Overview of high intensity x-ray and gamma-ray sources

International Nuclear Information System (INIS)

Prestwich, K.R.; Lee, J.R.; Ramirez, J.J.; Sanford, T.W.L.; Agee, F.J.; Frazier, G.B.; Miller, A.R.

1987-01-01

The requirements for intense x-ray and gamma-ray sources to simulate the radiation effects from nuclear weapons has led to the development of several types of terawatt-pulsed power systems. One example of a major gamma-ray source is Aurora, a 10-MV, 1.6-MA, 120-ns four-module, electron-beam generator. Recent requirements to improve the dose rate has led to the Aurora upgrade program and to the development of the 20-MV, 800-kA, 40-ns Hermes-III electron-beam accelerator. The Aurora program includes improvements to the pulsed power system and research on techniques to improve the pulse shape of the electron beam. Hermes III will feature twenty 1-MV, 800-kA induction accelerator cavities supplying energy to a magnetically insulated transmission line adder. Hermes III will become operational in 1988. Intense x-ray sources consist of pulsed power systems that operate with 1-MV to 2-MV output voltages and up to 25-TW output powers. These high powers are achieved with either low impedance electron-beam generators or multimodular pulsed power systems. The low-impedance generators have high voltage Marx generators that store the energy and then sequentially transfer this energy to pulse-forming transmission lines with lower and lower impedance until the high currents are reached. In the multimode machines, each module produces 0.7-TW to 4-TW output pulses, and all of the modules are connected together to supply energy to a single diode

Medidas procesales especiales y proteccíon de los derechos humanos Informe general

NARCIS (Netherlands)

Vervaele, J.A.E.

2009-01-01

El objetivo del informe general es realizar un análisis comparativo de los informes nacionales para evidenciar los procesos de transformación de los sistemas nacionales de justicia penal, en particular del proceso penal, en el que se han introducido medidas procesales especiales para hacer frente al

Medida de la temperatura con conexión directa sensor-microcontrolador para estación marítima

OpenAIRE

SISCAR ESCRIVÀ, XAVIER RAMÓN

2013-01-01

En el presente trabajo se ha diseñado e implementado un sistema de medida de la temperatura para una estación marina, usando una interfaz de conexión directa sensor-microcontrolador. El sistema se basa en un sensor resistivo para medir la temperatura, un microcontrolador para procesar los datos y una memoria donde se almacenan. La interfaz de conexión directa sensormicrocontrolador permite realizar medidas de manera más rápida y con menor consumo respecto al uso de convertidore...

X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation - Modelling, experiment, and Monte-Carlo simulation

International Nuclear Information System (INIS)

Hodoroaba, V.-D.; Radtke, M.; Vincze, L.; Rackwitz, V.; Reuter, D.

2010-01-01

X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses.

Fast and robust ray casting algorithms for virtual X-ray imaging

International Nuclear Information System (INIS)

Freud, N.; Duvauchelle, P.; Letang, J.M.; Babot, D.

2006-01-01

Deterministic calculations based on ray casting techniques are known as a powerful alternative to the Monte Carlo approach to simulate X- or γ-ray imaging modalities (e.g. digital radiography and computed tomography), whenever computation time is a critical issue. One of the key components, from the viewpoint of computing resource expense, is the algorithm which determines the path length travelled by each ray through complex 3D objects. This issue has given rise to intensive research in the field of 3D rendering (in the visible light domain) during the last decades. The present work proposes algorithmic solutions adapted from state-of-the-art computer graphics to carry out ray casting in X-ray imaging configurations. This work provides an algorithmic basis to simulate direct transmission of X-rays, as well as scattering and secondary emission of radiation. Emphasis is laid on the speed and robustness issues. Computation times are given in a typical case of radiography simulation

Fast and robust ray casting algorithms for virtual X-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Freud, N. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France)]. E-mail: Nicolas.Freud@insa-lyon.fr; Duvauchelle, P. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France); Letang, J.M. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France); Babot, D. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France)

2006-07-15

Deterministic calculations based on ray casting techniques are known as a powerful alternative to the Monte Carlo approach to simulate X- or {gamma}-ray imaging modalities (e.g. digital radiography and computed tomography), whenever computation time is a critical issue. One of the key components, from the viewpoint of computing resource expense, is the algorithm which determines the path length travelled by each ray through complex 3D objects. This issue has given rise to intensive research in the field of 3D rendering (in the visible light domain) during the last decades. The present work proposes algorithmic solutions adapted from state-of-the-art computer graphics to carry out ray casting in X-ray imaging configurations. This work provides an algorithmic basis to simulate direct transmission of X-rays, as well as scattering and secondary emission of radiation. Emphasis is laid on the speed and robustness issues. Computation times are given in a typical case of radiography simulation.

Hydraulic conductivity of indeformed soil columns determination by gamma ray transmission

International Nuclear Information System (INIS)

Moreira, Anderson Camargo; Moraes Cavalcante, Fabio Henrique de; Rocha, Marcos Correa da; Filho, Otavio Portezan; Quinones, Fernando Rodolfo Espinosa; Appoloni, Carlos Roberto

2000-01-01

The spatial variation of the soil structure influences the water movement through its porous geometry, which could cause problems in the development of agricultural cultures and also accelerate processes of soil erosion. The gamma ray transmission method has established efficiency for the non-destructive measurement of moisture temporal and space evolution, and consequently in the determination of the hydraulic conductivity of the soil, K(θ). Columns of undisturbed soil (approximately 0.11 x 0.06 x 0.60 m) were removed from a trench in the Campus of Londrina State University. The used soil was classified like distrophic dark red soil (LRd). The indeformed soil columns were wrapped up with paraffin and gauze and were fixed on the table of measurement. The water vertical infiltration in the soil was accomplished by maintaining a water layer of approximately 0.01 m over an area of soil of 75 x 10 -4 m 2 . Layers of filter papers and foam controlled the flow of water in the soil surface. After the conclusion of the infiltration, began the process of redistribution of the water in the soil column, with the objective to determine the function K(θ) in relation to the depth in the column. The moisture profiles θ(z,t) are obtained using a radioactive source of 241 Am (3.7 x 10 9 Bq; 0.0596 MeV), spectrometric electronic chain, a 2x2'' NaI(Tl) detector and a measurements table , which allows the sample to move vertically. The hydraulic conductivity function was determined, applying the Sisson model , at 10 levels in the soil column and the results exhibit an increase of K(θ) with depth. (author)

Temporal characteristic analysis of laser-modulated pulsed X-ray source for space X-ray communication

Science.gov (United States)

Hang, Shuang; Liu, Yunpeng; Li, Huan; Tang, Xiaobin; Chen, Da

2018-04-01

X-ray communication (XCOM) is a new communication type and is expected to realize high-speed data transmission in some special communication scenarios, such as deep space communication and blackout communication. This study proposes a high-speed modulated X-ray source scheme based on the laser-to-X-ray conversion. The temporal characteristics of the essential components of the proposed laser-modulated pulsed X-ray source (LMPXS) were analyzed to evaluate its pulse emission performance. Results show that the LMPXS can provide a maximum modulation rate up to 100 Mbps which is expected to significantly improve the data rate of XCOM.

X-ray diffraction using the time structure of the SRS

International Nuclear Information System (INIS)

Tanner, B.K.

1983-01-01

The subject is discussed under the headings: introduction (advances in the techniques of X-ray topography; comparison with transmission electron microscopy); stroboscopic X-ray topography; stroboscopic X-ray topography of travelling surface acoustic waves; possible general diffraction experiments. (U.K.)

PROPRIEDADES PSICOMÉTRICAS DE INSTRUMENTOS DE MEDIDAS: BASES CONCEITUAIS E MÉTODOS DE AVALIAÇÃO–PARTE I

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Maria Elena Echevarría-Guanilo

2017-01-01

Full Text Available Objetivo: presentar y discutir bases conceptuales y métodos de evaluaciones que fundamentan importantes propiedades de instrumentos de medidas. En esta primera parte, se presentan y discute los conceptos de confiabilidad, responsividad e interpretabilidad, citados ejemplos de las principales formas de evaluación de esas propiedades. Método: estudio teórico basado en la literatura internacional y nacional y en los instrumentos Consensus-based Standards for the selection of health Measurement Instruments y Evaluating the Measurement of Patient-Reported Outcomes que contemplan conceptos de evaluación de instrumentos para la evaluación de los resultados de los pacientes. Resultados: en este enfoque, se puede percibir que todavía hay divergencias en algunas descripciones conceptuales. Sin embargo, los autores resaltan la importancia de la confiabilidad para evaluar el instrumento de medida. Se destaca la importancia del conocimiento del Modelo Conceptual, de las propiedades de medidas y de los diferentes métodos de evaluación para garantizar, principalmente en estudio de validación de instrumentos, resultados confiables y válidos. Conclusiones : se concluye que la discusión presentada sobre la confiabilidad, responsividad e interpretabilidad contribuye a los profesionales de la salud en el conocimiento teórico y sentido crítico en la elección de instrumentos y en la conducción de análisis sobre esas propiedades de medida.

Plan de negocios de la empresa Random; pantalones a medida

OpenAIRE

Marsal Josa, Armando

2017-01-01

Este trabajo trata de la realización del Plan de Negocio de Random, idea de negocio que consiste en una startup que diseña y vende pantalones tipo vaquero y chino a medida, pudiendo el comprador elegir, de entre una serie de detalles de motivos navajos ofrecidos por la marca, la forma de personalizarlos. Tendrán un precio asequible, intermedio entre las grandes marcas (Zara...) y las marcas tradicionales (Levi’s...). Se pretende dar salida a un producto artesanal y de calidad, aprovechando un...

Abdominoplastia y pexia de pubis: estandarización de medidas

OpenAIRE

O. Ballestas-Campo; A. Pomerane

2014-01-01

La abdominoplastia es el procedimiento de elección para corregir la flacidez abdominal, la lipodistrofia supra e infraumbilical y la diástasis de los rectos abdominales. Los nuevos métodos añaden liposucción para definir el contorno corporal. Presentamos una estandarización de medidas para lograr una cicatriz abdominal baja y pexia pubiana en casos de lipodistrofias tipo III y IV de Matarasso. Realizamos un estudio observacional, descriptivo y retrospectivo, evaluando las historias clínicas y...

X-ray fluorescence microtomography analyzing prostate tissues

International Nuclear Information System (INIS)

Pereira, Gabriela R.; Rocha, Henrique S.; Calza, Cristiane; Lopes, Ricardo T.

2009-01-01

The objective of this work is to determine the elemental distribution map in reference samples and prostate tissue samples using X-Ray Fluorescence Microtomography (XRFCT) in order to verify concentrations of certain elements correlated with characteristics observed by the transmission microtomography. The experiments were performed at the X-Ray Fluorescence Facility of the Brazilian Synchrotron Light Laboratory. A quasi-monochromatic beam produced by a multilayer monochromator was used as an incident beam. The transmission CT images were reconstructed using filtered-back-projection algorithm, and the XRFCT images were reconstructed using filtered-back-projection algorithm with absorption corrections. (author)

MEDIDAS DE NÚCLEO INFLACIONARIO PARA COSTA RICA

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Gabriela Saborío Muñoz

2003-07-01

Full Text Available En este documento se elaboran y evalúan medidas alternativas de núcleo inflacionario para Costa Rica. La idea fundamental contempla al núcleo inflacionario como un indicador de la tendencia subyacente de la inflación capaz de capturar el componente del cambio total de precios común a todos los bienes y servicios, cuya persistencia se mantendría en el mediano y largo plazo y que excluye los cambios en los precios relativos de estos. La medida de núcleo inflacionario seleccionada se contrasta con el Índice de Núcleo Inflacionario (INI, indicador de inflación subyacente actualmente utilizado por el Banco Central de Costa Rica (BCCR.El Índice Subyacente de Inflación (ISI, definido como una medida de núcleo inflacionario que excluye un 30,7% del peso total del Índice de Precios al Consumidor (IPC, refleja más fielmente la tendencia subyacente de la inflación y logra capturar el movimiento más permanente del nivel general de precios, aislando las variaciones en precios relativos. Además, el ISI es fácil de calcular e interpretar lo cual ayuda a incrementar la transparencia y credibilidad de la política monetaria. También es un indicador oportuno, aumentando su valor para los que formulan la política monetaria. Por último, el ISI supera algunas de las limitaciones del INI, como son la falta de un criterio estadístico para definir el punto de corte de los bienes y servicios a excluir y el alto porcentaje del peso total del IPC eliminado. AbstractThis paper builds and evaluates several alternative measures of core inflation for Costa Rica. The chosen measure of core inflation is contrasted with the core inflation index (INI, which is the indicator of underlying inflation used today by the Central Bank of Costa Rica (BCCR. The main idea is that core inflation is a good indicator of the underlying inflation and catches the part of overall price change common to all the goods and services that is expected to persist in the

Fundamentos e métodos de medidas de energia dinâmica no SPT

Directory of Open Access Journals (Sweden)

Antonio Belincanta

2000-05-01

Full Text Available Discutem-se neste trabalho os métodos disponíveis no Brasil e no exterior para a medida da energia transferida às hastes no SPT, apresentando-se inclusive registros típicos dos eventos dinâmicos correspondentes

Medida de la eficiencia ambiental en la industria cerámica española

Directory of Open Access Journals (Sweden)

Sala Garrido, Ramon

2008-01-01

Full Text Available En el trabajo de Färe, Grosskopf y Hernández-Sancho (2004 se propone un índice de eficiencia medioambiental, para medir el grado en el que las empresas generan outputs deseables al mismo tiempo que reducen su outputs no deseables. Este indicador consiste en una ratio entre una medida para outputs deseables y otra para no deseables. Cada uno de ellos está basado en el uso de las funciones distancia. El índice de los outputs deseables mide el éxito de una empresa k en aumentar estos outputs utilizando el mismo número de inputs y generando el mismo nivel de outputs no deseables. Esta medida de eficiencia medioambiental se ha aplicado a la industria de los pavimentos cerámicos sobre una muestra de empresas a las que se ha aplicado un test de Kruskal-Wallis para determinar la utilidad de este indicador.

Método del “Pulso Láser” para la medida de la difusividad térmica en materiales cerámicos

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García, E.

2001-08-01

Full Text Available Among the several techniques available to measure the thermal conductivity/ diffusivity, the laser flash method stands out for its low run time (less than 1 hour per temperature and the reduced sample size required. Nevertheless, the laser flash technique is not very accurate for porous materials due to laser transmission problems and the underestimation of the total sample thickness. The attaching to the porous sample of two thin foils of an opaque and high diffusivity material (Cu can solve these problems. This type of assembly was used to measure diffusivity in a porous alumina material. Data obtained are compared with theoretical models, wich predict effective thermal conductivity of the porous material from the thermal conductivity of the dense material, the amount of porosity and the type of microstructure.

Entre las distintas técnicas de medida de la conductividad/difusividad térmica de materiales, destaca la técnica del pulso láser por la rapidez de medida de la difusividad térmica y la facilidad de preparación de las muestras. Sin embargo, cuando se mide la difusividad térmica en materiales porosos, aparecen problemas relacionados con la transmisión del haz láser y la subestimacion del espesor de la muestra. En este trabajo, se propone un método para evitar estos problemas que consiste en formar un sistema tricapa Cu/material poroso/Cu. Este método se ha verificado experimentalmente utilizando materiales de alúmina densa y porosa. Los valores experimentales para la alúmina porosa se han explicado a partir de modelos que estiman la conductividad térmica efectiva de un material poroso en función de la conductividad del material denso, la porosidad y el tipo de microestructura.

Soil compaction: Evaluation of stress transmission and resulting soil structure

Science.gov (United States)

Naveed, Muhammad; Schjønning, Per; Keller, Thomas; Lamande, Mathieu

2016-04-01

Accurate estimation of stress transmission and resultant deformation in soil profiles is a prerequisite for the development of predictive models and decision support tools for preventing soil compaction. Numerous studies have been carried out on the effects of soil compaction, whilst relatively few studies have focused on the cause (mode of stress transmission in the soil). We have coupled both cause and effects together in the present study by carrying out partially confined compression tests on (1) wet aggregates, (2) air dry aggregates, and (3) intact soils to quantify stress transmission and compaction-resulted soil structure at the same time. Stress transmission was quantified using both X-ray CT and Tactilus sensor mat, and soil-pore structure was quantified using X-ray CT. Our results imply that stress transmission through soil highly depends on the magnitude of applied load and aggregate strength. As soon as the applied load is lower than the aggregate strength, the mode of stress transmission is discrete as stresses were mainly transmitted through chain of aggregates. With increasing applied load soil aggregates start deforming that transformed heterogeneous soil into homogenous, as a result stress transmission mode was shifted from discrete towards more like a continuum. Continuum-like stress transmission mode was better simulated with Boussinesq (1885) model based on theory of elasticity compared to discrete. The soil-pore structure was greatly affected by increasing applied stresses. Total porosity was reduced 5-16% and macroporosity 50-85% at 620 kPa applied stress for the intact soils. Similarly, significant changes in the morphological indices of the macropore space were also observed with increasing applied stresses.

Comparação e correlação entre automedida, medida casual e monitorização ambulatorial da pressão arterial

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Weimar Kunz Sebba Barroso de Souza

2011-08-01

Full Text Available FUNDAMENTO: A medida casual da pressão arterial (PA pelos profissionais de saúde está sujeita a uma grande variabilidade, sendo necessário buscar novos métodos que possam superar essa limitação. OBJETIVO: Comparar e avaliar a correlação entre os níveis de PA obtidos por meio da automedida da pressão arterial (AMPA com a medida casual e com a monitorização ambulatorial da pressão arterial (MAPA. MÉTODOS: Avaliamos hipertensos que realizaram as três metodologias de medida da PA com intervalo menor que 30 dias; as médias das pressões foram utilizadas para comparação e correlação. Foram empregados os aparelhos: OMRON 705 CP (medida casual, OMRON HEM 714 (AMPA e SPACELABS 9002 (MAPA. RESULTADOS: Foram avaliados 32 pacientes, 50,09% mulheres, idade média 59,7 (± 11,2 anos, média do IMC 26,04 (± 3,3 kg/m². Valores médios de pressão sistólica (PAS e pressão diastólica (PAD para a AMPA foram de 134 (± 15,71mmHg e 79,32 (± 12,38 mmHg. Na medida casual as médias da PAS e PAD foram, respectivamente, 140,84 (± 16,15mmHg e 85 (± 9,68 mmHg. Os valores médios da MAPA na vigília foram 130,47 (± 13,26 mmHg e 79,84 (± 9,82 mmHg para PAS e PAD, respectivamente. Na análise comparativa, a AMPA apresentou valores semelhantes aos da MAPA (p > 0,05 e diferentes da medida casual (p < 0,05. Na análise de correlação a AMPA foi superior à medida casual, considerando a MAPA como o padrão de referência nas medidas tensionais. CONCLUSÃO: A AMPA apresentou melhor comparação com a MAPA do que a medida casual e também se correlacionou melhor com a aquela, especialmente para a pressão diastólica, devendo ser considerada uma alternativa com baixo custo para o acompanhamento do paciente hipertenso.

Investigation of superthermal asymmetric electron distributions using electron cyclotron wave transmission in tokamaks

International Nuclear Information System (INIS)

Giruzzi, G.; Fidone, I.; Marcha, M.J.

1991-01-01

The asymmetric electron distribution generated during lower hybrid current drive has been computed using a 3-D Fokker-Planck code. The superthermal tail and the resulting current are generally a combination of two components streaming in opposite toroidal directions. An appropriate diagnostic method for experimental investigation of the two superthermal populations is wave transmission of two equivalent rays with equal and opposite values of the refractive index. These equivalent rays can be realized by launching the waves from symmetric positions with respect ot the equatorial plane at equal and opposite angles in the toroidal direction. Using an appropriate ray tracing code, the damping of the two rays is computed and it is shown that it results from electrons with opposite parallel velocities. The differential transmission is then a measure of the overall asymmetry of the electron momentum distribution. (author). 12 refs, 8 figs

Nuevo criterio de complejidad utilizando una medida de eficiencia

OpenAIRE

Munduate del Río, Arantza; Pérez Prados, Antonio; Cano Sevilla, Francisco J.

1995-01-01

Centrado en el campo de los árboles de decisión, este trabajo estudia la forma de selección de un árbol óptimo entre los posibles árbo1es obtenidos a partir del análisis de un conjunto de datos, utilizando para ello una cantidad criterio que combina linealmente dos medidas de la calidad de un árbol: el error de resustitución y la eficiencia. Analizando el efecto de un proceso de poda en la cantidad criterio se obtiene una sucesión finita de subárboles rnínimos óptimamente podados del árbol má...

A Scanning Transmission X-ray Microscopy Study of Cubic and Orthorhombic C3A and Their Hydration Products in the Presence of Gypsum

Directory of Open Access Journals (Sweden)

Vanessa Rheinheimer

2016-08-01

Full Text Available This paper shows the microstructural differences and phase characterization of pure phases and hydrated products of the cubic and orthorhombic (Na-doped polymorphs of tricalcium aluminate (C3A, which are commonly found in traditional Portland cements. Pure, anhydrous samples were characterized using scanning transmission X-ray microscopy (STXM, X-ray photoelectron spectroscopy (XPS and X-ray diffraction (XRD and demonstrated differences in the chemical and mineralogical composition as well as the morphology on a micro/nano-scale. C3A/gypsum blends with mass ratios of 0.2 and 1.9 were hydrated using a water/C3A ratio of 1.2, and the products obtained after three days were assessed using STXM. The hydration process and subsequent formation of calcium sulfate in the C3A/gypsum systems were identified through the changes in the LIII edge fine structure for Calcium. The results also show greater Ca LII binding energies between hydrated samples with different gypsum contents. Conversely, the hydrated samples from the cubic and orthorhombic C3A at the same amount of gypsum exhibited strong morphological differences but similar chemical environments.

Characterization of pigments applied on archaeological material from Chincha's Culture by x-rays fluorescence and transmission electronic microscopy

International Nuclear Information System (INIS)

Lopez M, Alcides; Olivera, Paula

2007-01-01

The elementary characterization of some pigments applied in the decoration of recipients used by our ancestors of the Chincha Culture by Energy dispersive X-ray fluorescence (EDXRF)method was allowed. Additionally, the morphological and crystalline characterization by Transmission Electronic Microscopy (TEM) method has been possible. The results have allowed identifying the presence of mercury sulphur (HgS) (cinnabar) in the red pigment on the 'mate'; the black and white pigments are constituted by materials of organic aspect; in the case the dark brown one they are constituted by organic matter and ferric oxide. This work also demonstrates that a portable EDXRF spectrometer is the most suitable for the study of pieces of our cultural patrimony, mainly of those that are difficult to transport from an archaeological place or museum to an analytic laboratory by reason of its dimensions and conservation conditions. (author)

Medidas de aislamiento en enfermedades transmisibles dentro del ámbito hospitalario

OpenAIRE

Villanueva Rábano, Raúl

2016-01-01

En el ámbito hospitalario, son un problema frecuente las infecciones nosocomiales, causadas por las enfermedades transmisibles que pasan de unos pacientes a otros. Estas infecciones son potencialmente prevenibles, a través de medidas de aislamiento llevadas a cabo por el personal sanitario y no sanitario encargado de atender al paciente. En este aspecto, el papel del personal de enfermería es de fundamental importancia dado que mantienen un estrecho contacto con el paciente como cuidadores pr...

X-ray metrology for ULSI structures

International Nuclear Information System (INIS)

Bowen, D. K.; Matney, K. M.; Wormington, M.

1998-01-01

Non-destructive X-ray metrological methods are discussed for application to both process development and process control of ULSI structures. X-ray methods can (a) detect the unacceptable levels of internal defects generated by RTA processes in large wafers, (b) accurately measure the thickness and roughness of layers between 1 and 1000 nm thick and (c) can monitor parameters such as crystallographic texture and the roughness of buried interfaces. In this paper we review transmission X-ray topography, thin film texture measurement, grazing-incidence X-ray reflectivity and high-resolution X-ray diffraction. We discuss in particular their suitability as on-line sensors for process control

Analysis of the dislocation content in a deformed Co-based superalloy by transmission electron microscopy and X-ray diffraction

International Nuclear Information System (INIS)

Breuer, D.; Klimanek, P.; Muehle, U.; Martin, U.

1997-01-01

The present paper compares the dislocation densities as determined in a Co-based superalloy (CoNi22Cr22W14) after creep and tensile deformation by Transmission Electron Microscopy (TEM) and X-ray profile analysis (XRD). After creep tests the dislocation densities obtained by both methods are in good agreement, which is the result of a nearly homogeneous dislocation distribution. The relationship between the dislocation density and the flow stress meets the Taylor equation. After tensile deformation the dislocation densities determined by TEM and XRD differ systematically from each other, but in both cases also a Taylor relationship can be obtained. The constant α of the dislocation interaction derived by TEM is much larger than in the creep tests and also than that of the XRD, which agrees well with the creep data. The difference between the TEM and the XRD results is the consequence of the dislocation cell structure much more developed in the tensile specimens, which leads to an underestimation of the dislocation density in TEM because of overweighting the cell interior. By fitting the Fourier coefficients of the X-ray diffraction line shapes with a bimodal distribution of the defect content (composite model), dislocation densities of the cell interior can be estimated that correspond well to the TEM data. (orig.)

Model of a catalytic injection in a riser by means of gamma ray transmission measurements

Energy Technology Data Exchange (ETDEWEB)

Moura, Alex E.; Brito, Macio F.P.; Dantas, Carlos C.; Melo, Silvio B., E-mail: alex.emoura@ufpe.br, E-mail: sbm@ufpe.br [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil); Barbosa, Enivaldo S., E-mail: Enivaldo.santos@ufcg.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia Mecanica; Lima, Emerson A.O., E-mail: eal@poli.br [Universidade de Pernambuco, Recife, PE (Brazil). Departamento de Matematica

2015-07-01

In Gas solid process involving a solid circulation through a closed loop the knowledge of the Solids Circulation Rate (SCR) is fundamental to control and improve the operation of a circulating fluidized bed system. A valve controls the circulation rate of solids in the riser of a fluid catalytic cracking unit. Initially, to control the catalyst injection in the riser, a rotary valve controlled and measured solid flow injection, but with a limited working time. Due to the fine powder catalyst abrasive action on the valve steel axis, this device stop work. A lab made valve were design to avoiding direct contact of the catalyst with mechanical moving parts in while control solid injection in riser, but do not measure the solid flow like the rotary valve. To control the lab made device a fixed pressure measurement at riser bottom is provided by control setup which corresponds to a given mass/time solid injection. In the present work, we proposed a method to evaluate the control valve based on a non-invasive technique. With gamma ray transmission measurements, in a cross section of the pipe, we developed a model that was used in the control system of the Cold Pilot Unit (CPU). Therefore, the interaction of the gamma ray with solid flow in riser should yield the necessary information for the process control system. A first model approximation consider the solid flow rate injection and solid velocity in riser as proposed in literature. In the CPU control system a Programmable Logic Controller-PLC keeps steady state processing the airflow, pressure profile and solid flow inputs. Additionally to preexisting PLC platform, some LabVIEW algorithms were implemented to achieve a good system performance operational condition. (author)

Model of a catalytic injection in a riser by means of gamma ray transmission measurements

International Nuclear Information System (INIS)

Moura, Alex E.; Brito, Macio F.P.; Dantas, Carlos C.; Melo, Silvio B.; Barbosa, Enivaldo S.; Lima, Emerson A.O.

2015-01-01

In Gas solid process involving a solid circulation through a closed loop the knowledge of the Solids Circulation Rate (SCR) is fundamental to control and improve the operation of a circulating fluidized bed system. A valve controls the circulation rate of solids in the riser of a fluid catalytic cracking unit. Initially, to control the catalyst injection in the riser, a rotary valve controlled and measured solid flow injection, but with a limited working time. Due to the fine powder catalyst abrasive action on the valve steel axis, this device stop work. A lab made valve were design to avoiding direct contact of the catalyst with mechanical moving parts in while control solid injection in riser, but do not measure the solid flow like the rotary valve. To control the lab made device a fixed pressure measurement at riser bottom is provided by control setup which corresponds to a given mass/time solid injection. In the present work, we proposed a method to evaluate the control valve based on a non-invasive technique. With gamma ray transmission measurements, in a cross section of the pipe, we developed a model that was used in the control system of the Cold Pilot Unit (CPU). Therefore, the interaction of the gamma ray with solid flow in riser should yield the necessary information for the process control system. A first model approximation consider the solid flow rate injection and solid velocity in riser as proposed in literature. In the CPU control system a Programmable Logic Controller-PLC keeps steady state processing the airflow, pressure profile and solid flow inputs. Additionally to preexisting PLC platform, some LabVIEW algorithms were implemented to achieve a good system performance operational condition. (author)

Real-time X-ray transmission microscopy for fundamental studies solidification: Al-Al2Au eutectic

International Nuclear Information System (INIS)

Curreri, Peter A.; Kaukler, William F.; Sen, Subhayu

1998-01-01

High resolution real-time X-ray Transmission Microscopy, XTM, has been applied to obtain information fundamental to solidification of optically opaque metallic systems. We have previously reported the measurement of the solute profile in the liquid, phase growth, and detailed solid-liquid interfacial morphology of aluminum based alloys with exposure times less than 2 seconds. Recent advances in XTM furnace design have provided an increase in real-time magnification (during solidification) for the XTM from 40X to 160X. The increased magnification has enabled for the first time the XTM imaging of real-time growth of fibers and particles with diameters of 5 μm. We have previously applied this system to study the kinetics of formation and morphological evolution of secondary fibers and particles in Al-Bi monotectic alloys. In this paper we present the preliminary results of the first real-time observations of fiber morphology evolution in optically opaque bulk metal sample of Aluminum-Gold eutectic alloy. These studies show that the XTM can be applied to study the fundamentals of eutectic and monotectic solidification. We are currently attempting to apply this technology in the fundamentals of solidification in microgravity

Portable pulsed X-ray digital radiographic system based on network transmission

International Nuclear Information System (INIS)

Tang Le; Li Yuanjing; Wang Yi; Cheng Jianping

2004-01-01

Network communication technology of TCP/IP protocol serves as application in pulse X-ray digital radiography system. The system radiographs synchronously with pulse X-ray and converts image signals to digital data, which are transmitted to computer for displaying and processing in network. The system composing structures are present and portable and other characteristics are introduced. (authors)

Effect of screening of immigrants on tuberculosis transmission

NARCIS (Netherlands)

Verver, S.; van Soolingen, D.; Borgdorff, M. W.

2002-01-01

SETTING: In The Netherlands all immigrants from highly endemic countries undergo obligatory entry screening by X-ray, followed by voluntary half-yearly screening for 2 years. OBJECTIVE: To estimate the contribution of screening of immigrants to reductions in tuberculosis transmission. DESIGN: All

Nano-fabrication of diffractive optics for soft X-ray and atom beam focusing

International Nuclear Information System (INIS)

Rehbein, S.

2002-01-01

Nano-structuring processes are described for manufacturing diffractive optics for the condenser-monochromator set-up of the transmission X-ray microscope (TXM) and for the scanning transmission X-ray microscope (STXM) at the BESSY II electron storage ring in Berlin. Furthermore, a process for manufacturing free-standing nickel zone plates for helium atom beam focusing experiments is presented. (author)

Adesão às medidas de precaução-padrão: relato de experiência Adhesión a las medidas de precaución padrón: relato de experiencia Adoption of standard precautions: a report

Directory of Open Access Journals (Sweden)

Maria Helena Baena de Moraes Lopes

1999-10-01

Full Text Available Durante 1993 e 1994 foi realizada reciclagem em Precauções-Padrão para os profissionais de enfermagem do Centro de Atenção Integral à Saúde da Mulher (CAISM. Em 1995 foi avaliada, por observação direta nos setores, a adesão a estas medidas, o uso adequado, a acessibilidade e disponibilidade de luvas e caixas para descarte de materiais pérfuro-cortantes. Registraram-se 60 observações e 232 procedimentos. Em 164 (71% destes houve adoção das medidas, não ocorrendo o mesmo em outros 68 (29%. Evidenciou-se a necessidade de enfatizar a lavagem de mãos e o não-reencape de agulhas.Durante el periodo de 1993 y 1994 se realizó la actualización en medidas de precaución patrón para los profisionales de enfermeria del Centro de Atención Integral a la Salud de la Mujer (CAISM. En 1995, se realizó una evaluación a través de la observación directa en los sectores; la adhesión a estas medidas, el uso adecuado y la disposición de guantes y cajas para descarte de materiales corto-punzantes. Se registraron 60 observaciones e 232 procedimientos, 164 de ellos (71% adoptaron el uso de las medidas y en 68 (29% esto no ocurrió. Es evidente la necesidad de dar énfasis al lavado de las manos y colocar de nuevo la camisa (tapa a las agujas.During 1993 and 1994, a recycling program on Standard Precautions was conducted for the nursing personnel at the Women's Health Centre (CAISM. In 1995, an evaluation was obtained through direct observation of these sectors regarding the adoption of these measures, the adequate use, access and availability of gloves and boxes for the disposal of perforating, sharp material. Sixty observations and 232 procedures were reported. One hundred sixty four procedures (71% adopted these measures and 68 procedures (29% did not. It was evident that the need to wash hands and not to use needles twice should be emphasized.

Phase space model for transmission of light beam

International Nuclear Information System (INIS)

Fu Shinian

1989-01-01

Based on Fermat's principle of ray optics, the Hamiltonian of an optical ray is derived by comparison with classical mechanics. A phase space model of light beam is proposed, assuming that the light beam, regarded as a group of rays, can be described by an ellipse in the μ-phase space. Therefore, the transmission of light beam is represented by the phase space matrix transformation. By means of this non-wave formulation, the same results are obtained as those from wave equation such as Kogelnik's ABCD law. As an example of the application on this model, the matching problem of optical cavity is solved

New Constraints on the Geometry and Kinematics of Matter Surrounding the Accretion Flow in X-Ray Binaries from Chandra High-energy Transmission Grating X-Ray Spectroscopy

Science.gov (United States)

Tzanavaris, P.; Yaqoob, T.

2018-03-01

The narrow, neutral Fe Kα fluorescence emission line in X-ray binaries (XRBs) is a powerful probe of the geometry, kinematics, and Fe abundance of matter around the accretion flow. In a recent study it has been claimed, using Chandra High-Energy Transmission Grating (HETG) spectra for a sample of XRBs, that the circumnuclear material is consistent with a solar-abundance, uniform, spherical distribution. It was also claimed that the Fe Kα line was unresolved in all cases by the HETG. However, these conclusions were based on ad hoc models that did not attempt to relate the global column density to the Fe Kα line emission. We revisit the sample and test a self-consistent model of a uniform, spherical X-ray reprocessor against HETG spectra from 56 observations of 14 Galactic XRBs. We find that the model is ruled out in 13/14 sources because a variable Fe abundance is required. In two sources a spherical distribution is viable, but with nonsolar Fe abundance. We also applied a solar-abundance Compton-thick reflection model, which can account for the spectra that are inconsistent with a spherical model, but spectra with a broader bandpass are required to better constrain model parameters. We also robustly measured the velocity width of the Fe Kα line and found FWHM values of up to ∼5000 km s‑1. Only in some spectra was the Fe Kα line unresolved by the HETG.

New Constraints on the Geometry and Kinematics of Matter Surrounding the Accretion Flow in X-Ray Binaries from Chandra High-Energy Transmission Grating X-Ray Spectroscopy

Science.gov (United States)

Tzanavaris, P.; Yaqoob, T.

2018-01-01

The narrow, neutral Fe Ka fluorescence emission line in X-ray binaries (XRBs) is a powerful probe of the geometry, kinematics, and Fe abundance of matter around the accretion flow. In a recent study it has been claimed, using Chandra High-Energy Transmission Grating (HETG) spectra for a sample of XRBs, that the circumnuclear material is consistent with a solar-abundance, uniform, spherical distribution. It was also claimed that the Fe Ka line was unresolved in all cases by the HETG. However, these conclusions were based on ad hoc models that did not attempt to relate the global column density to the Fe Ka line emission. We revisit the sample and test a self-consistent model of a uniform, spherical X-ray reprocessor against HETG spectra from 56 observations of 14 Galactic XRBs. We find that the model is ruled out in 13/14 sources because a variable Fe abundance is required. In two sources a spherical distribution is viable, but with nonsolar Fe abundance. We also applied a solar-abundance Compton-thick reflection model, which can account for the spectra that are inconsistent with a spherical model, but spectra with a broader bandpass are required to better constrain model parameters. We also robustly measured the velocity width of the Fe Ka line and found FWHM values of up to approx. 5000 km/s. Only in some spectra was the Fe Ka line unresolved by the HETG.

Transmission electron microscope studies of extraterrestrial materials

Science.gov (United States)

Keller, Lindsay P.

1995-01-01

Transmission Electron Microscopy, X-Ray spectrometry and electron-energy-loss spectroscopy are used to analyse carbon in interplanetary dust particles. Optical micrographs are shown depicting cross sections of the dust particles embedded in sulphur. Selected-area electron diffraction patterns are shown. Transmission Electron Microscope specimens of lunar soil were prepared using two methods: ion-milling and ultramicrotomy. A combination of high resolution TEM imaging and electron diffraction is used to characterize the opaque assemblages. The opaque assemblages analyzed in this study are dominated by ilmenite with lesser rutile and spinel exsolutions, and traces of Fe metal.

Detection of leaded-gasoline usage in catalyst-equipped vehicles: a gamma-ray transmission guage for measuring catalytic converter lead contamination

International Nuclear Information System (INIS)

Schneider, E.W.

1982-01-01

A gamma-ray transmission gauge has been developed for measuring the accumulation of lead inside the catalytic converters of vehicles operated on leaded gasoline. This nondestructive inspection system relates the amount of gamma radiation passing through the catalytic converter to the mass concentration of lead contained in the catalyst bed. Field studies have shown that vehicle usage of 200 L of leaded gasoline (0.34 g of Pb/L) can be detected at the 95% confidence level. Based on tests with one vehicle burning 1000 L of leaded gasoline, the accumulation rate of lead on the catalytic converter was relatively constant, accounting for 45% of the total lead consumed. Subsequent usage of unleaded gasoline resulted in no significant loss of lead from the catalytic converter

Soft X-ray multilayers and filters

CERN Document Server

Wang Zhan Shan; Tang Wei Xing; Qin Shuji; Zhou Bing; Chen Ling Ya

2002-01-01

The periodic and non-periodic multilayers were designed by using a random number to change each layer and a suitable merit function. Ion beam sputtering and magnetron sputtering were used to fabricate various multilayers and beam splitters in soft X-ray range. The characterization of multilayers by small angle X-ray diffraction, Auger electron spectroscopy, Rutherford back scattering spectroscopy and reflectivity illustrated the multilayers had good structures and smooth interlayers. The reflectivity and transmission of a beam splitter is about 5%. The fabrication and transmission properties of Ag, Zr were studied. The Rutherford back scattering spectroscopy and auger electron spectroscopy were used to investigate the contents and distributions of impurities and influence on qualities of filters. The attenuation coefficients were corrected by the data obtained by measurements

Relação da Importância dos Recursos Estratégicos com as Medidas de Desempenho em Empresas Brasileiras

Directory of Open Access Journals (Sweden)

Ilse Maria Beuren

2016-04-01

Full Text Available O estudo objetiva verificar se as medidas de desempenho são variáveis mediadoras entre a importância dos recursos estratégicos e a avaliação de desempenho em empresas brasileiras. De modo específico o estudo busca investigar a percepção dos gestores quanto à importância atribuída às medidas de desempenho tradicionais e não tradicionais e aos recursos estratégicos de capital humano, estrutural e físico em empresas brasileiras. O estudo pauta-se na pesquisa realizada por Widener (2006 em empresas norte americanas. Assim, um levantamento foi realizado junto aos gestores das empresas listadas na BM&FBovespa nos níveis 1 e 2 de Governança Corporativa. Na análise dos dados foi aplicada estatística descritiva e análise fatorial. Os resultados mostram que os gestores atribuem importância a várias medidas de desempenho, mas a estatística descritiva evidencia que a maior importância é atribuída às medidas de retorno e financeiras tradicionais. Dentre os recursos estratégicos, o capital humano desponta como o recurso mais importante para as empresas analisadas, seguido do capital estrutural e do capital físico. A partir das relações estabelecidas na pesquisa de base e aplicadas neste estudo, conclui-se que as medidas de desempenho são variáveis mediadoras entre a importância dos recursos estratégicos e o desempenho na percepção dos gestores.

Análise de desempenho de medidas estruturais e não estruturais de controle de inundações em uma bacia urbana

Directory of Open Access Journals (Sweden)

Thiago Galvão Tiradentes Decina

2016-03-01

Full Text Available RESUMO Este trabalho teve como objetivo analisar, por meio de simulações hidrológicas e hidráulicas, o desempenho de algumas medidas de controle de inundação, estruturais e não estruturais. Para tanto, os mapas e demais informações espaciais da bacia hidrográfica do Córrego do Gregório, em São Carlos (SP, foram digitalizadas com auxílio do software de geoprocessamento ArcGIS(r e imagens de satélite de alta resolução. Com base nessas informações, foram propostos cenários alternativos que incorporaram as medidas de controle. Através da utilização dos softwares HEC-HMS e HEC-RAS realizaram-se as modelações hidráulicas e hidrológicas, utilizando tempos de retorno de 25, 50 e 100 anos para a chuva de projeto. Com os resultados obtidos (hidrogramas de cheia e manchas de inundação referentes a cada tempo de retorno, foi possível analisar as medidas, comparando-se os diferentes cenários. Concluiu-se, para este caso, que os melhores resultados correspondem à associação das medidas estruturais e não estruturais. Contudo, também foi verificado que, mesmo com a concretização do cenário mais favorável, o problema das inundações não seria satisfatoriamente equacionado, o que revela a necessidade de se considerar outras medidas para minimizar os prejuízos decorrentes das inundações, tais como medidas de controle na fonte, seguros contra inundações e sistemas de alerta antecipados.

Synchrotron radiation calibration for soft X-ray detector

International Nuclear Information System (INIS)

Ning, Jiamin; Guo, Cun; Xu, Rongkun; Jiang, Shilun; Xu, Zeping; Chen, Jinchuan; Xia, Guangxin; Xue, Feibiao; Qin, Yi

2009-04-01

The calibration experiments were carried out to X-ray film, scintillator and transmission grating by employing the soft X-ray station at 3W1B beam-line in Beijing synchrotron Radiation Facility. The experiments presented the black intensity curve and energy response curve of soft X-ray film. And the experimental results can be used in diagnosis of X-ray radiation characterization of Z-pinch, such as in the measurement of soft X-ray Power Meter, grating spectrometer, pinhole camera and one-dimension imaging system which can ensure precision of Z-pinch results. (authors)

Study of variance and covariance terms in linear attenuation coefficient measurements of irregular samples through the two media method by gamma-ray transmission

International Nuclear Information System (INIS)

Kuramoto, R.Y.R.Renato Yoichi Ribeiro.; Appoloni, Carlos Roberto

2002-01-01

The two media method permits the application of Beer's law (Thesis (Master Degree), Universidade Estadual de Londrina, PR, Brazil, pp. 23) for the linear attenuation coefficient determination of irregular thickness samples by gamma-ray transmission. However, the use of this methodology introduces experimental complexity due to the great number of variables to be measured. As consequence of this complexity, the uncertainties associated with each of these variables may be correlated. In this paper, we examine the covariance terms in the uncertainty propagation, and quantify the correlation among the uncertainties of each of the variables in question

Preliminary experimental research to detect grease stain of petroleum pipeline by sup 1 sup 3 sup 7 Cs gamma-ray transmission method

CERN Document Server

Wang Shi Heng

2002-01-01

The experimental study on the detection of grease stain for petroleum pipeline in Karamay oil-field of Xinjiang is carried out by gamma-ray transmission method. Experimental provision consists of sup 1 sup 3 sup 7 Cs gamma radiator and NaI(Tl) scintillation detector. The response of grease stain thickness of petroleum pipeline in Karamay oil-field is ln(N sub 0 /N)=0.00548 d-0.0046, and the response of paraffin thickness is ln(N sub 0 /N)=0.00522d-0.0126. The result of experiment indicates that the response of grease stain thickness is more sensitive than the response of paraffin thickness

Nivel de conocimiento y aplicación de las medidas de bioseguridad del personal de enfermería

Directory of Open Access Journals (Sweden)

Luz Marina Bautista-Rodríguez

2013-12-01

Full Text Available Objetivo. Identificar el nivel de conocimiento y aplicación de las medidas de bioseguridad que tiene el personal de Enfermería. Materiales y Métodos. Se realizó investigación cuantitativa, de tipo descriptivo transversal, con una muestra de 96 personas pertenecientes. La información se recolectó a través de una encuesta y una lista de chequeo, la cual se analizó por medio de tabulaciones y representaciones gráficas. Resultados. El personal de Enfermería de la Clínica San José tiene un conocimiento regular en un 66% frente a las medidas de bioseguridad y un 70% de aplicación deficiente frente a estas. Conclusión. Se identificó que las principales medidas de bioseguridad, como métodos de barrera, eliminación adecuada del material contaminado, manejo adecuado de los elementos cortopunzante, lavado de manos no están siendo aplicadas correctamente por el personal de Enfermería de la institución, convirtiéndose estas situaciones en un factor de riesgo para el presentar un accidente laboral esta población.

Revisión de ideación, comportamiento suicida y medidas de evaluación psicológicas

Directory of Open Access Journals (Sweden)

Giselle Pianowski

2015-01-01

Full Text Available El presente estudio tuvo como objetivo una revisión en la base ScienceDirect de la literatura sobre ideación, comportamiento y medidas de evaluación del suicidio en los últimos años. Utilizamos las palabras suicide, ideation y scale, y para procesamiento, suicidal ideation, suicide ideation y rating scale, excluyendo estudios que no presentaban el suicidio como enfoque y no utilizaban medidas de evaluación, restringiéndose a 176 artículos. Los resultados revelaron una muestra preferentemente femenina, con edad económicamente activa y varios niveles de escolaridad. Sobre los objetivos, hubo prevalencia del enfoque del constructo y su relación con otras variables, resaltándose depresión, dolor crónico, desesperanza, pensamiento rumiante e histórico traumático, además del uso de substancias, apoyo familiar y social, condiciones socioeconómicas, sexualidad y otros. Se identificaron la Suicide Probability Scale, la Beck Scale for Suicide Ideation, y la Beck Depression Inventory Item, como medidas prioritarias en la evaluación de la ideación y/o comportamiento suicida.

X-ray-based attenuation correction for positron emission tomography/computed tomography scanners.

Science.gov (United States)

Kinahan, Paul E; Hasegawa, Bruce H; Beyer, Thomas

2003-07-01

A synergy of positron emission tomography (PET)/computed tomography (CT) scanners is the use of the CT data for x-ray-based attenuation correction of the PET emission data. Current methods of measuring transmission use positron sources, gamma-ray sources, or x-ray sources. Each of the types of transmission scans involves different trade-offs of noise versus bias, with positron transmission scans having the highest noise but lowest bias, whereas x-ray scans have negligible noise but the potential for increased quantitative errors. The use of x-ray-based attenuation correction, however, has other advantages, including a lack of bias introduced from post-injection transmission scanning, which is an important practical consideration for clinical scanners, as well as reduced scan times. The sensitivity of x-ray-based attenuation correction to artifacts and quantitative errors depends on the method of translating the CT image from the effective x-ray energy of approximately 70 keV to attenuation coefficients at the PET energy of 511 keV. These translation methods are usually based on segmentation and/or scaling techniques. Errors in the PET emission image arise from positional mismatches caused by patient motion or respiration differences between the PET and CT scans; incorrect calculation of attenuation coefficients for CT contrast agents or metallic implants; or keeping the patient's arms in the field of view, which leads to truncation and/or beam-hardening (or x-ray scatter) artifacts. Proper interpretation of PET emission images corrected for attenuation by using the CT image relies on an understanding of the potential artifacts. In cases where an artifact or bias is suspected, careful inspection of all three available images (CT and PET emission with and without attenuation correction) is recommended. Copyright 2003 Elsevier Inc. All rights reserved.

Shielding requirements for constant-potential diagnostic x-ray beams determined by a Monte Carlo calculation

International Nuclear Information System (INIS)

Simpkin, D.J.

1989-01-01

A Monte Carlo calculation has been performed to determine the transmission of broad constant-potential x-ray beams through Pb, concrete, gypsum wallboard, steel and plate glass. The EGS4 code system was used with a simple broad-beam geometric model to generate exposure transmission curves for published 70, 100, 120 and 140-kVcp x-ray spectra. These curves are compared to measured three-phase generated x-ray transmission data in the literature and found to be reasonable. For calculation ease the data are fit to an equation previously shown to describe such curves quite well. These calculated transmission data are then used to create three-phase shielding tables for Pb and concrete, as well as other materials not available in Report No. 49 of the NCRP

Shielding requirements for constant-potential diagnostic x-ray beams determined by a Monte Carlo calculation.

Science.gov (United States)

Simpkin, D J

1989-02-01

A Monte Carlo calculation has been performed to determine the transmission of broad constant-potential x-ray beams through Pb, concrete, gypsum wallboard, steel and plate glass. The EGS4 code system was used with a simple broad-beam geometric model to generate exposure transmission curves for published 70, 100, 120 and 140-kVcp x-ray spectra. These curves are compared to measured three-phase generated x-ray transmission data in the literature and found to be reasonable. For calculation ease the data are fit to an equation previously shown to describe such curves quite well. These calculated transmission data are then used to create three-phase shielding tables for Pb and concrete, as well as other materials not available in Report No. 49 of the NCRP.

Transmission diamond imaging detector

Energy Technology Data Exchange (ETDEWEB)

Smedley, John, E-mail: smedley@bnl.gov; Pinelli, Don; Gaoweia, Mengjia [Brookhaven National Laboratory, Upton, NY (United States); Muller, Erik; Ding, Wenxiang; Zhou, Tianyi [Stony Brook University, Stony Brook, NY (United States); Bohon, Jen [Case Center for Synchrotron Biosciences, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH (United States)

2016-07-27

Many modern synchrotron techniques are trending toward use of high flux beams and/or beams which require enhanced stability and precise understanding of beam position and intensity from the front end of the beamline all the way to the sample. For high flux beams, major challenges include heat load management in optics (including the vacuum windows) and a mechanism of real-time volumetric measurement of beam properties such as flux, position, and morphology. For beam stability in these environments, feedback from such measurements directly to control systems for optical elements or to sample positioning stages would be invaluable. To address these challenges, we are developing diamond-based instrumented vacuum windows with integrated volumetric x-ray intensity, beam profile and beam-position monitoring capabilities. A 50 µm thick single crystal diamond has been lithographically patterned to produce 60 µm pixels, creating a >1kilopixel free-standing transmission imaging detector. This device, coupled with a custom, FPGA-based readout, has been used to image both white and monochromatic x-ray beams and capture the last x-ray photons at the National Synchrotron Light Source (NSLS). This technology will form the basis for the instrumented end-station window of the x-ray footprinting beamline (XFP) at NSLS-II.

Aerogel as a Sample Collector and Sample Mount for Transmission XRD Analysis

Science.gov (United States)

Bish, D. L.; Vaniman, D. T.; Chipera, S. J.; Yen, A. S.; Jones, S. M.

2001-01-01

Silica aerogel can be used for dust collection and in situ X-ray analysis. Aerogels can be less absorbing than Be, and it is feasible to obtain X-ray transmission factors >50% using typical aerogels together with a 100-micrometer Be backing foil. Additional information is contained in the original extended abstract.

X-ray analysis and mapping by wavelength dispersive X-ray spectroscopy in an electron microscope

International Nuclear Information System (INIS)

Tanaka, Miyoko; Takeguchi, Masaki; Furuya, Kazuo

2008-01-01

A compact and easy-to-use wavelength dispersive X-ray spectrometer using a multi-capillary X-ray lens attached to a scanning (transmission) electron microscope has been tested for thin-film analysis. B-K spectra from thin-film boron compounds (B 4 C, h-BN, and B 2 O 3 ) samples showed prominent peak shifts and detailed structural differences. Mapping images of a thin W/Si double-layer sample resolved each element clearly. Additionally, a thin SiO 2 film grown on a Si substrate was imaged with O-K X-rays. Energy and spatial resolution of the system is also discussed

Hard-x-ray phase-difference microscopy with a low-brilliance laboratory x-ray source

International Nuclear Information System (INIS)

Kuwabara, Hiroaki; Yashiro, Wataru; Harasse, Sebastien; Momose, Atsushi; Mizutani, Haruo

2011-01-01

We have developed a hard-X-ray phase-imaging microscopy method using a low-brilliance X-ray source. The microscope consists of a sample, a Fresnel zone plate, a transmission grating, and a source grating creating an array of mutually incoherent X-ray sources. The microscope generates an image exhibiting twin features of the sample with opposite signs separated by a distance, which is processed to generate a phase image. The method is quantitative even for non-weak-phase objects that are difficult to be quantitatively examined by the widely used Zernike phase-contrast microscopy, and it has potentially broad applications in the material and biological science fields. (author)

Transmission Electron Microscopy Physics of Image Formation

CERN Document Server

Kohl, Helmut

2008-01-01

Transmission Electron Microscopy: Physics of Image Formation presents the theory of image and contrast formation, and the analytical modes in transmission electron microscopy. The principles of particle and wave optics of electrons are described. Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast. Also discussed are the kinematical and dynamical theories of electron diffraction and their applications for crystal-structure analysis and imaging of lattices and their defects. X-ray microanalysis and electron energy-loss spectroscopy are treated as analytical methods. Specimen damage and contamination by electron irradiation limits the resolution for biological and some inorganic specimens. This fifth edition includes discussion of recent progress, especially in the area of aberration correction and energy filtering; moreover, the topics introduced in the fourth edition have been updated. Transmission Electron Microscopy: Physics of Image Formation is written f...

Simulations of X-ray transmission through laser-produced plasmas

International Nuclear Information System (INIS)

Yan Jun; Qu Yizhi; Li Jiaming

1999-01-01

Using the detailed configuration accounting with the term structures treated by the unresolved transition array model, the authors present a method to calculate the transmission spectra for high-power laser-produced plasmas in local thermodynamic equilibrium. Based on the quantum defect theory, the UTA parameters with high principal quantum numbers can be conveniently calculated with much less computational efforts. This ensure us to handle a huge number of transition arrays from many configurations occurring in typical laser-produced middle-Z and high-Z plasmas

Medidas de selectividad y sensibilidad en un receptor de AM simplificado

OpenAIRE

Przylecki Siwek, Maciej

2011-01-01

Se describen las medidas de selectividad y sensibilidad de un receptor de AM simplificado que sólo dispone de una etapa detectora formada por antena de ferrita y un transistor BJT npn polarizado en zona no líneal actuando como un amplificador de clase B. La señal detectada se preamplifica y finalmente se lleva a un amplificador de audio de circuito integrado y al altavoz. Debido a la sencillez la selectividad es variable con la frecuencia de sintonía proporcionando a 392 KHz un...

A revelação de abuso sexual: as medidas adotadas pela rede de apoio

Directory of Open Access Journals (Sweden)

Luísa Fernanda Habigzang

Full Text Available O presente estudo identificou e analisou as medidas adotadas pela rede de apoio de crianças e adolescentes após a revelação de abuso sexual. Participaram 40 meninas, entre oito e 16 anos, vítimas de abuso sexual. As medidas de proteção adotadas pela rede foram mapeadas através de entrevista semi-estruturada. A revelação foi feita aos pais em 42,5% da amostra e 92,5% das pessoas acreditaram. O abrigamento ocorreu em 35% dos casos e o restante permaneceu com a família que afastou o agressor. A atitude de confiança da família na revelação e a denúncia da violência constituíram-se em um fator de proteção. Contudo, o alto índice de abrigamento e o não acompanhamento efetivo do afastamento do agressor representaram fatores de risco.

Comparación de las medidas del ángulo kappa realizadas mediante pupilometría y topografía corneal

OpenAIRE

Marcos Pérez, Mario

2016-01-01

El ojo no es un sistema óptico centrado, por ello surge la necesidad de definir ejes visuales. El ángulo kappa está formado entre el eje pupilar y la línea de mirada, es un parámetro mensurable y relevante a la hora de afrontar cirugía refractiva. El objetivo del trabajo es demostrar la intercambiabilidad de las medidas de kappa con los dispositivos Galilei G4 y Allegro Topolyzer. En la literatura no se encuentra un estudio similar, con lo que resulta conveniente. Para ello se realizan medida...

An evaluation of measurement uncertainties in the on-line measurement of coal ash content by gamma-ray transmission

International Nuclear Information System (INIS)

Wenzhong, Liu; Li, Kong; Tan, Qu; Jingjing, Cheng

2002-01-01

In this paper, a significant effect producing systematic errors in the on-line measurement using gamma-ray transmission is revealed. Ash content fluctuations or thickness changes lead to a permanent negative systematic error in the results of the measurements. To study uncertainties in the measurements applicable to time-independent ash content indicators and to investigate the characteristics of the radiation attenuation process, the behavior of the quantity in question is modeled with a stationary Gaussian distribution. A systematic error-producing effect has been found, and a quantitative correction is given to compensate for it. For some other quantities in question that vary in time, a linear model is used to discuss the systematic errors in the case of automated coal gangue separator. Results of experiments that demonstrate different systematic errors for different sampling intervals are presented. The reason for these errors is the nonlinearity of the relationship between the radiation intensity, on the one hand, and the sample thickness and mass attention, on the other

Classification of Multiple Types of Organic Carbon Composition in Atmospheric Particles by Scanning Transmission X-Ray Microscopy Analysis

Energy Technology Data Exchange (ETDEWEB)

Kilcoyne, Arthur L; Takahama, S.; Gilardoni, S.; Russell, L.M.; Kilcoyne, A.L.D.

2007-05-16

A scanning transmission X-ray microscope at the Lawrence Berkeley National Laboratory is used to measure organic functional group abundance and morphology of atmospheric aerosols. We present a summary of spectra, sizes, and shapes observed in 595 particles that were collected and analyzed between 2000 and 2006. These particles ranged between 0.1 and 12 mm and represent aerosols found in a large range of geographical areas, altitudes, and times. They include samples from seven different field campaigns: PELTI, ACE-ASIA, DYCOMS II, Princeton, MILAGRO (urban), MILAGRO (C-130), and INTEX-B. At least 14 different classes of organic particles show different types of spectroscopic signatures. Different particle types are found within the same region while the same particle types are also found in different geographical domains. Particles chemically resembling black carbon, humic-like aerosols, pine ultisol, and secondary or processed aerosol have been identified from functional group abundance and comparison of spectra with those published in the literature.

A comparative transmission electron microscopy, energy dispersive x-ray spectroscopy and spatially resolved micropillar compression study of the yttria partially stabilised zirconia - porcelain interface in dental prosthesis

Energy Technology Data Exchange (ETDEWEB)

Lunt, Alexander J.G., E-mail: alexander.lunt@chch.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom); Mohanty, Gaurav, E-mail: gaurav.mohanty@empa.ch [EMPA Materials Science & Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Ying, Siqi, E-mail: siqi.ying@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom); Dluhoš, Jiří, E-mail: jiri.dluhos@tescan.cz [TESCAN Brno, s.r.o., Libušina tř. 1, 623 00 Brno-Kohoutovice (Czech Republic); Sui, Tan, E-mail: tan.sui@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom); Neo, Tee K., E-mail: neophyte@singnet.com.sg [Specialist Dental Group, Mount Elizabeth Orchard, 3 Mount Elizabeth, #08-03/08-08/08-10, 228510 (Singapore); Michler, Johann, E-mail: johann.michler@empa.ch [EMPA Materials Science & Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Korsunsky, Alexander M., E-mail: alexander.korsunsky@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford, Oxfordshire OX1 3PJ (United Kingdom)

2015-12-01

Recent studies into the origins of failure of yttria partially stabilised zirconia–porcelain veneered prosthesis have revealed the importance of micro-to-nano scale characterisation of this interface zone. Current understanding suggests that the heat treatment, residual stresses and varying microstructure at this location may contribute to near-interface porcelain chipping. In this study the chemical, microstructural and mechanical property variation across the interfacial zone has been characterised at two differing length scales and using three independent techniques; energy dispersive X-ray spectroscopy, transmission electron microscopy and micropillar compression. Energy dispersive X-ray spectroscopy mapping of the near-interface region revealed, for the first time, that the diffusional lengths of twelve principal elements are limited to within 2–6 μm of the interface. This study also revealed that 0.2–2 μm diameter zirconia grains had become detached from the bulk and were embedded in the near-interface porcelain. Transmission electron microscopy analysis demonstrated the presence of nanoscale spherical features, indicative of tensile creep induced voiding, within the first 0.4–1.5 μm from the interface. Within zirconia, variations in grain size and atomistic structure were also observed within the 3 μm closest to the interface. Micropillar compression was performed over a 100 μm range on either side of the interface at the spatial resolution of 5 μm. This revealed an increase in zirconia and porcelain loading modulus at close proximities (< 5 μm) to the interface and a decrease in zirconia modulus at distances between 6 and 41 μm from this location. The combination of the three experimental techniques has revealed intricate details of the microstructural, chemical and consequently mechanical heterogeneities in the YPSZ–porcelain interface, and demonstrated that the length scales typically associated with this behaviour are approximately ± 5

Frameless image registration of X-ray CT and SPECT by volume matching

International Nuclear Information System (INIS)

Tanaka, Yuko; Kihara, Tomohiko; Yui, Nobuharu; Kinoshita, Fujimi; Kamimura, Yoshitsugu; Yamada, Yoshifumi.

1998-01-01

Image registration of functional (SPECT) and morphological (X-ray CT/MRI) images is studied in order to improve the accuracy and the quantity of the image diagnosis. We have developed a new frameless registration method of X-ray CT and SPECT image using transmission CT image acquired for absorption correction of SPECT images. This is the automated registration method and calculates the transformation matrix between the two coordinate systems of image data by the optimization method. This registration method is based on the similar physical property of X-ray CT and transmission CT image. The three-dimensional overlap of the bone region is used for image matching. We verified by a phantom test that it can provide a good result of within two millimeters error. We also evaluated visually the accuracy of the registration method by the application study of SPECT, X-ray CT, and transmission CT head images. This method can be carried out accurately without any frames. We expect this registration method becomes an efficient tool to improve image diagnosis and medical treatment. (author)

Advanced Nanoscale Characterization of Cement Based Materials Using X-Ray Synchrotron Radiation: A Review

KAUST Repository

Chae, Sejung R.

2013-05-22

We report various synchrotron radiation laboratory based techniques used to characterize cement based materials in nanometer scale. High resolution X-ray transmission imaging combined with a rotational axis allows for rendering of samples in three dimensions revealing volumetric details. Scanning transmission X-ray microscope combines high spatial resolution imaging with high spectral resolution of the incident beam to reveal X-ray absorption near edge structure variations in the material nanostructure. Microdiffraction scans the surface of a sample to map its high order reflection or crystallographic variations with a micron-sized incident beam. High pressure X-ray diffraction measures compressibility of pure phase materials. Unique results of studies using the above tools are discussed-a study of pores, connectivity, and morphology of a 2,000 year old concrete using nanotomography; detection of localized and varying silicate chain depolymerization in Al-substituted tobermorite, and quantification of monosulfate distribution in tricalcium aluminate hydration using scanning transmission X-ray microscopy; detection and mapping of hydration products in high volume fly ash paste using microdiffraction; and determination of mechanical properties of various AFm phases using high pressure X-ray diffraction. © 2013 The Author(s).

As creches e pré-escolas e as doenças transmissíveis Infectious diseases and daycare and preschool education

Directory of Open Access Journals (Sweden)

Maria M. M. Nesti

2007-08-01

Full Text Available OBJETIVO: Descrever o aumento do risco para aquisição de doenças infecciosas associado ao cuidado da criança fora do domicílio e a efetividade das medidas de controle para a prevenção da transmissão de doenças nas creches e pré-escolas. FONTES DE DADOS: Revisão das bases de dados MEDLINE, LILACS e Cochrane Library, através dos descritores creches, infecção, controle de infecção e doenças infecciosas, focalizada em estudos que comparam o risco de doença infecciosa em crianças cuidadas dentro e fora de casa, associam o risco às características do cuidado fora de casa e avaliam a efetividade de medidas de prevenção. SÍNTESE DE DADOS: As crianças cuidadas em creches ou pré-escolas apresentam risco de adquirir infecções aumentado em até duas a três vezes, com impacto na saúde individual e na disseminação das doenças à comunidade. O risco está associado, entre outros fatores, às características das creches, e medidas de prevenção simples são efetivas para diminuir a transmissão de doenças. Entre estas, recomenda-se: lavagem apropriada das mãos após exposição; utilização de precauções padrão; rotina padronizada para troca e descarte de fraldas usadas, localização e limpeza da área de troca, limpeza e desinfecção de áreas contaminadas; uso de lenços descartáveis para assoar o nariz; funcionários e área exclusivos para a manipulação de alimentos; notificação das doenças infecciosas; treinamento de funcionários e orientação dos pais. CONCLUSÕES: Diante da utilização crescente de creches e pré-escolas e da associação com risco aumentado de adquirir infecções, medidas de controle são imprescindíveis para a prevenção e controle das doenças transmissíveis.OBJECTIVE: To describe the increased risk of acquiring infectious diseases associated with out-of-home childcare and the effectiveness of measures for the control and prevention of diseases transmission at daycare and

Medidas de actuación para la prevención de la toxiinfección alimentaria

Directory of Open Access Journals (Sweden)

María Ascensión Maestre Naranjo

2008-09-01

Full Text Available La toxiinfección alimentaria manifestada en forma de brotes tiene gran importancia desde el punto de vista epidemiológico. Tras analizar su etiología se instauran las medidas preventivas y de seguridad en todos los procesos de manipulación de alimentos, así como las medidas de prevención para los trabajadores manipuladores de alimentos. Se insiste de forma especial en la información y formación que deben recibir estos trabajadores, para concienciar y fomentar su responsabilidad y educación en las medidas higiénico sanitarias que favorecen su desarrollo. En caso de producirse el brote se marcan las pautas a seguir para su notificación, por la gran importancia legal y epidemiológica que comporta.The alimentary toxiinfección manifested in form of buds has great importance from the epidemic point of view. After analyzing their etiología the preventive measures they are established and of security in all the processes of manipulation of foods, as well as the measures of prevention for the hard-working manipulators of foods. It is insisted in a special way in the information and formation that these workers should receive, to make aware and to foment their responsibility and education in the hygienic sanitary measures that favor their development. In the event of taking place the bud the rules they are marked to continue for their notification, for the legal and epidemic great importance that behaves.

As Inundações e Memória Social: Algumas Medidas De Prevenção ...

African Journals Online (AJOL)

As Inundações e Memória Social: Algumas Medidas De Prevenção e Controlo da Biodegradação Dos Documentos e Arquivos (Floods and Social Memory: Some Measures for the Protection and Control of Biodegradation in Records and Archives)

21 CFR 1020.30 - Diagnostic x-ray systems and their major components.

Science.gov (United States)

2010-04-01

... computer processing of x-ray transmission data. Control panel means that part of the x-ray control upon... section, linear interpolation or extrapolation may be made. Positive means 2 shall be provided to ensure...

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

Directory of Open Access Journals (Sweden)

Peter Guttmann

2015-02-01

Full Text Available Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM as well as full-field transmission X-ray microscopes (TXM allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples.

Overview of nanoscale NEXAFS performed with soft X-ray microscopes.

Science.gov (United States)

Guttmann, Peter; Bittencourt, Carla

2015-01-01

Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples.

Laboratory source based full-field x-ray microscopy at 9 keV

Energy Technology Data Exchange (ETDEWEB)

Fella, C.; Balles, A.; Wiest, W. [Lehrstuhl für Röntgenmikroskopie, Julius-Maximilians-Universität, 97074 Würzburg (Germany); Zabler, S.; Hanke, R. [Lehrstuhl für Röntgenmikroskopie, Julius-Maximilians-Universität, 97074 Würzburg (Germany); Fraunhofer Development Center X-Ray Technology (EZRT), Flugplatzstrasse 75, 90768 Fürth (Germany)

2016-01-28

In the past decade, hard x-ray transmission microscopy experienced tremendous developments. With the avail-ability of efficient Fresnel zone plates, even set-ups utilizing laboratory sources were developed [1]. In order to improve the performance of these x-ray microscopes, novel approaches to fabricate optical elements [2] and brighter x-ray tubes [3] are promising candidates. We are currently building a laboratory transmission x-ray microscope for 9.25 keV, using an electron impact liquid-metal-jet anode source. Up to now, the further elements of our setup are: a polycapillary condenser, a tungsten zone plate, and a scintillator which is optically coupled to a CMOS camera. However, further variations in terms of optical elements are intended. Here we present the current status of our work, as well as first experimental results.

Regulación de las medidas tecnológicas en el derecho comparado. Especial referencia al caso de Estados Unidos, Reino Unido y Australia

Directory of Open Access Journals (Sweden)

Juan Sebastián Sereno Restrepo

2009-11-01

Full Text Available En algunas normas europeas y en precedentes judiciales estadounidenses se encuentran los primeros antecedentes de tutela jurídica a medidas tecnológicas de protección. Sin embargo, sólo a partir de 1996, con del Tratado ompi de Derecho de Autor, se encuentra una consagración expresa de las medidas tecnológicas de protección. La amplia formulación adoptada en el tratado ha sido desarrollada por las legislaciones de los países signatarios de él. En cuanto a la definición, se encuentran los siguientes elementos: producto, dispositivo, componente; aplicación de la medida sobre un bien inmaterial sujeto al régimen de copyright (derecho de autor; la especial finalidad de prevenir o inhibir la infracción al copyright o controlar el acceso; la efectividad; la aplicación de la medida por un sujeto cualificado. La legitimación para el ejercicio del derecho, las modalidades de infracción, las consecuencias civiles y penales y las eximentes de responsabilidad han sido también objeto de tratamiento normativo. Este artículo desarrolla el significado de los complejos elementos enunciados, con ayuda de la jurisprudencia y la doctrina, en tres secciones: estudio de la función práctica de las medias tecnológicas y su historia legislativa; definición de medida y condiciones para su protección; modalidades de infracción y eximentes de responsabilidad

Regulación de las medidas tecnológicas en el derecho comparado. Especial referencia al caso de Estados Unidos, Reino Unido y Australia

Directory of Open Access Journals (Sweden)

Juan Sebastián Sereno Restrepo

2009-11-01

Full Text Available En algunas normas europeas y en precedentes judiciales estadounidenses se encuentran los primeros antecedentes de tutela jurídica a medidas tecnológicas de protección. Sin embargo, sólo a partir de 1996, con del Tratado ompi de Derecho de Autor, se encuentra una consagración expresa de las medidas tecnológicas de protección. La amplia formulación adoptada en el tratado ha sido desarrollada por las legislaciones de los países signatarios de él. En cuanto a la definición, se encuentran los siguientes elementos: producto, dispositivo, componente; aplicación de la medida sobre un bien inmaterial sujeto al régimen de copyright (derecho de autor; la especial finalidad de prevenir o inhibir la infracción al copyright o controlar el acceso; la efectividad; la aplicación de la medida por un sujeto cualificado. La legitimación para el ejercicio del derecho, las modalidades de infracción, las consecuencias civiles y penales y las eximentes de responsabilidad han sido también objeto de tratamiento normativo. Este artículo desarrolla el significado de los complejos elementos enunciados, con ayuda de la jurisprudencia y la doctrina, en tres secciones: estudio de la función práctica de las medias tecnológicas y su historia legislativa; definición de medida y condiciones para su protección; modalidades de infracción y eximentes de responsabilidad.

Transmission dose estimation algorithm for in vivo dosimetry

International Nuclear Information System (INIS)

Yun, Hyong Geun; Shin, Kyo Chul; Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan; Lee, Hyoung Koo

2002-01-01

Measurement of transmission dose is useful for in vivo dosimetry of QA purpose. The objective of this study is to develope an algorithm for estimation of tumor dose using measured transmission dose for open radiation field. Transmission dose was measured with various field size (FS), phantom thickness (Tp), and phantom chamber distance (PCD) with an acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. Using measured data and regression analysis, an algorithm was developed for estimation of expected reading of transmission dose. Accuracy of the algorithm was tested with flat solid phantom with various settings. The algorithm consisted of quadratic function of log(A/P) (where A/P is area-perimeter ratio) and tertiary function of PCD. The algorithm could estimate dose with very high accuracy for open square field, with errors within ±0.5%. For elongated radiation field, the errors were limited to ±1.0%. The developed algorithm can accurately estimate the transmission dose in open radiation fields with various treatment settings

Transmission dose estimation algorithm for in vivo dosimetry

Energy Technology Data Exchange (ETDEWEB)

Yun, Hyong Geun; Shin, Kyo Chul [Dankook Univ., Seoul (Korea, Republic of); Huh, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan [Seoul National Univ., Seoul (Korea, Republic of); Lee, Hyoung Koo [Catholic Univ., Seoul (Korea, Republic of)

2002-07-01

Measurement of transmission dose is useful for in vivo dosimetry of QA purpose. The objective of this study is to develope an algorithm for estimation of tumor dose using measured transmission dose for open radiation field. Transmission dose was measured with various field size (FS), phantom thickness (Tp), and phantom chamber distance (PCD) with an acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. Using measured data and regression analysis, an algorithm was developed for estimation of expected reading of transmission dose. Accuracy of the algorithm was tested with flat solid phantom with various settings. The algorithm consisted of quadratic function of log(A/P) (where A/P is area-perimeter ratio) and tertiary function of PCD. The algorithm could estimate dose with very high accuracy for open square field, with errors within {+-}0.5%. For elongated radiation field, the errors were limited to {+-}1.0%. The developed algorithm can accurately estimate the transmission dose in open radiation fields with various treatment settings.

Localization of lead within leaf cells of Rhytidiadelphus squarrosus (Hedw. ) Warnst. by means of transmission electron microscopy and X-ray microanalysis

Energy Technology Data Exchange (ETDEWEB)

Ophus, E M; Gullvag, B M

1974-01-01

Results of ultrastructural studies and transmission electron microscope microanalysis of leaves of the bryophyte Rhytidiadelphus squarrosus collected from a park in Trondheim are presented. The lead content of these leaves primarily derives from motor traffic exhaust gases. A fine structural examination of the leaf cells revealed that detectable amounts of lead had entered the cytoplasm and could be recognized as electron-dense precipitates localized inside the plasma membrane, within vesicles or vacuoles, chloroplasts, mitochondria, microbodies and plasmodesmata. Control material, fixed only in glutaraledhyde and not post-stained, showed that these precipitates must be due to metallic elements having great electron-scattering properties. TEM-X-ray microanalysis indicated the definite presence of lead and phosphorus within both the nuclear and chloroplast inclusions. The possible presence of some other metals is also discussed.

Thin film soft X-ray absorption filters

International Nuclear Information System (INIS)

Stattin, H.

1992-11-01

This report discusses the composition, reparation and performance of soft x-ray transmission filters for a water window soft x-ray microscope. Unbacked thin films of aluminum, silver and vanadium/aluminum were made by evaporation on a substrate from which they were released. Measured transmittances agree reasonably well with calculations. The report also includes some related theory and discussions about film preparation methods, film contamination and evaluation methods. 33 refs

Preferencias de estados de salud y medidas de utilidad = Preferences of states of health and measurements of utility

Directory of Open Access Journals (Sweden)

Yepes-Nuñez, Juan José

2011-12-01

Full Text Available La medición de los valores del estado de salud, preferencias y utilidad calcula el valor o la conveniencia de un estado de salud contra un instrumento externo; son medidas genéricas de la calidad de vida relacionada con la salud (CVRS y resumen el valor de esta en un solo número entre 0 (cero y 1 (uno. Las medidas de preferencias de estados de salud y de utilidad difieren de las medidas generales y específicas obtenidas mediante cuestionarios de CVRS en áreas importantes. Primero, calculan las predilecciones de los individuos por alternativas. Segundo, proveen un resultado completo de la CVRS. Tercero, ofrecen una unidad común de análisis. Existen dos métodos para la medición de las utilidades, uno directo y otro indirecto, que se conocen también como utilidades multiatributo o sistemas de clasificación de estados de salud. El proceso directo de medición consiste en un agregado de descripciones que un entrevistador presenta a los encuestados. Para las mediciones indirectas se aplican solamente cuestionarios. El objetivo principal de este artículo es describir los principales métodos de valoración de utilidades, con el fin de dar a conocer los desenlaces que actualmente se utilizan tanto en estudios de CVRS como en evaluaciones económicas.

Development of X-ray excitable luminescent probes for scanning X-ray microscopy

International Nuclear Information System (INIS)

Moronne, M.M.

1999-01-01

Transmission soft X-ray microscopy is now capable of achieving resolutions that are typically 5 times better than the best-visible light microscopes. With expected improvements in zone plate optics, an additional factor of two may be realized within the next few years. Despite the high resolution now available with X-ray microscopes and the high X-ray contrast provided by biological molecules in the soft X-ray region (λ=2-5 nm), molecular probes for localizing specific biological targets have been lacking. To circumvent this problem, X-ray excitable molecular probes are needed that can target unique biological features. In this paper we report our initial results on the development of lanthanide-based fluorescent probes for biological labeling. Using scanning luminescence X-ray microscopy (SLXM, Jacobsen et al., J. Microscopy 172 (1993) 121-129), we show that lanthanide organo-polychelate complexes are sufficiently bright and radiation resistant to be the basis of a new class of X-ray excitable molecular probes capable of providing at least a fivefold improvement in resolution over visible light microscopy. Lanthanide probes, able to bind 80-100 metal ions per molecule, were found to give strong luminescent signals with X-ray doses exceeding 10 8 Gy, and were used to label actin stress fibers and in vitro preparations of polymerized tubulin. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Infrared Radiography: Modeling X-ray Imaging without Harmful Radiation

Science.gov (United States)

Zietz, Otto; Mylott, Elliot; Widenhorn, Ralf

2015-01-01

Planar x-ray imaging is a ubiquitous diagnostic tool and is routinely performed to diagnose conditions as varied as bone fractures and pneumonia. The underlying principle is that the varying attenuation coefficients of air, water, tissue, bone, or metal implants within the body result in non-uniform transmission of x-ray radiation. Through the…

Tasa de reincidencia de la delincuencia juvenil de Extremadura. Medidas privativas de libertad Tasa de reincidencia de la delincuencia juvenil de Extremadura. Medidas privativas de libertad

Directory of Open Access Journals (Sweden)

Felipe Núñez Izquierdo

2012-04-01

Full Text Available Después de más de 10 años de entrada en vigor de la Ley Orgánica 5/2000, de 12 de enero, de Responsabilidad Penal del Menor, se hace imprescindible realizar un estudio sobre la reincidencia juvenil en Extremadura, para conocer el impacto de dicho precepto. No cabe duda que uno de los problemas que más alarma social genera en la población es la delincuencia cometida por los menores con responsabilidad penal. Inicialmente se hace un repaso a la literatura criminológica actual sobre la reincidencia, programas de prevención, tratamiento a menores delincuentes y la evaluación de la eficacia de dichos programas. En el presente trabajo, siguiendo la metodología de otros estudios nacionales como el de Catalunya, analizamos la reincidencia de la delincuencia juvenil en Extremadura, concretamente de las medidas privativas de libertad. Se analizan los expedientes judiciales cerrados de aquellos jóvenes que hubieran finalizado una medida de este tipo en el año 2007 y se realiza el seguimiento de los mismos hasta el año 2010. En el año 2007, 115 jóvenes cumplieron o estaban cumpliendo una medida privativa de libertad en un Centro de Menores o Permanencia Fin de Semana, de los cuales 63 (57 varones y 7 mujeres resultaron pertenecer a la muestra final objeto de análisis. Los resultados obtenidos revelan que la tasa de reincidencia es del 52,4%, similar a la de otras Comunidades Autónomas, como País Vasco o Catalunya, e inferior a la de Asturias. Otro dato relevante es que un 41,9% de los menores objeto de estudio presentaban antecedentes, por lo que se refleja un comienzo en carreras delictivas acorde con los estudios existentes. La presente investigación ayuda a conocer la eficacia de los diferentes programas que se aplican a los menores delincuentes que cumplen medidas de internamiento, así como también hace una crítica de ésta al situarla con una elevada tasa de reincidencia.After more than 10 years of the entry into force of the

La desigualdad económica medida a través de las curvas de Lorenz || Economic inequality measurement through Lorenz curves

Directory of Open Access Journals (Sweden)

Núñez Velázquez, José Javier

2006-12-01

Full Text Available En el presente trabajo se analiza la influencia de las curvas de Lorenz, el Principio de Transferencias y las relaciones de mayoración entre vectores de renta sobre las medidas de desigualdad. De esta forma, se pasa revista al desarrollo histórico que ha permitido diseñar el conjunto actual de axiomas o propiedades deseables para que una medida de desigualdad se comporte razonablemente. Además, se analiza la problemática de la ordenación en desigualdad de los vectores de renta. Ante la imposibilidad de selección de una única medida de desigualdad, se presenta la construcción de un indicador sintético dinámico construido a partir de una batería de índicessimples de desigualdad, compatibles con el criterio de dominación de Lorenz. Finalmente, se incluye como ilustración el estudio de la evolución de la desigualdad y el nivel de vida en los países de la Unión Europea, durante el período 1993-1999.

X-ray computed tomography imaging method which is immune to beam hardening effect

International Nuclear Information System (INIS)

Kanno, Ikuo; Uesaka, Akio; Nomiya, Seiichiro; Onabe, Hideaki

2009-01-01

For the easy treatment of cancers, early finding of them is an important theme of study. X-ray transmission measurement and computed tomography (CT) are powerful tools for finding cancers. The x-ray CT shows cross sectional view of human body and is able to detect small cancers such as 1 cm in diameter. The CT, however, gives very high dose exposure to human body: some 10 to 1000 times higher dose exposure than the chest radiography. It is not possible to have medical health check using CT frequently, in view of both individual and public accumulated dose exposures. The authors have been working on the reduction of dose exposure in x-ray transmission measurements in case of detecting iodine contrast media, which concentrates in cancers. In our method, energy information of x-rays is employed: in conventional x-ray transmission measurements, x-rays are measured as current and the energy of each x-ray is ignored. The numbers of x-ray events, φ 1 and φ 2 , of which energies are lower and higher than the one of iodine K-edge, respectively, are used for the estimation of iodine thickness in cancers. Moreover, high energy x-rays, which are not sensitive to the absorption by iodine, are cut by a filter made of higher atomic number material than iodine. We call this method filtered x-ray energy subtraction (FIX-ES) method. This FIX-ES method was shown twice as sensitive to iodine than current measurement method. With the choice of filter thickness, minimum dose exposure in FIX-ES is 30% of that when white x-rays are employed. In the study described above, we concentrated on the observation of cancer part. In this study, a cancer phantom in normal tissue is observed by FIX-ES method. The results are compared with the ones obtained by current measurement method. (author)

First tests of a Medipix-1 pixel detector for X-ray dynamic defectoscopy

CERN Document Server

Vavrik, D; Visschers, J; Pospísil, S; Ponchut, C; Zemankova, J

2002-01-01

Recent theoretical damage material models describe the dynamic development of voids and microcracks in materials under plastic deformation. For these models, experimental verification is needed. We propose direct and non-destructive observation of the propagation of material damage by measuring changes in transmission of X-rays penetrating a stressed material, using a photon-counting X-ray imager. The present contribution aims to demonstrate the applicability of silicon and gallium-arsenide devices for X-ray transmission measurements with a specimen of high-ductile aluminium alloy under study. The first experiments to determine the resolution and the sensitivity of the proposed method with the Medipix-1 pixel detector are presented.

Medidas de calidad aplicadas a los levantamientos topográficos en Colombia

OpenAIRE

Sabogal Lemus, Carlos Augusto

2016-01-01

Este trabajo documenta la investigación “Medidas de calidad aplicadas a los levantamientos topográficos en Colombia”; la propuesta metodológica de este documento, tiene como objetivo principal la realización de la evaluación de calidad de un conjunto de datos levantados en campo, para lo cual es necesario revisar los antecedentes de la topografía en Colombia, así como los diferentes sistemas de referencia que gobiernan la cartografía del país -- Previo a realizar una evaluación de calidad, se...

Pensamiento constructivo como medida de inteligencia emocional en patología dual

OpenAIRE

Albalat Alcaraz, Caridad; Fernández Ros, Encarnación; López García, Juan José

2014-01-01

Introducción: El objetivo de este estudio es comparar el pensamiento constructivo, una medida de inteligencia emocional, entre una muestra clínica de pacientes adultos diagnosticados de patología dual y una muestra no clínica. Método: Mediante un diseño de investigación comparativo, una muestra no clínica de 835 sujetos se comparó con una muestra de 180 sujetos diagnosticados de patología dual: 78 con trastornos clínicos o del Eje I y102 con trastornos de la personalidad o del ...

Medidas de indices de refração de cristais liquidos esmecticos

OpenAIRE

Kroin, Teodosio

1980-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro de Ciencias Fisicas e Matematicas Mostramos que os cristais líquidos biaxiais podem ter seus índices de refração principais medidos pelo método de Abbe, desde que convenientemente alinhados. Apresentam-se as medidas dos índices de refração das diferentes mesofases e da fase isotrópica do cristal líquido uni-axial 4-butoxibenzilideno-4'- aminoacetofenona em função da temperatura e para três comprimentos de onda. As medi...

Simuliidae and the transmission and control of human Onchocerciasis in Latin America

Directory of Open Access Journals (Sweden)

A. J. Shelley

1991-09-01

Full Text Available Factors that affect the propensity of a simuliid species to act as a host to Onchocerca volvulus and to naturally transmit this filarial worm in nature are discussed. Presence or absence of a cibarial armature is believed to be a major factor that has been previously overlooked and this is considered in relation to the choice of control methods currently advocated for onchocerciasis. The current epidemiological studies, transmission dynamics and relevant control measures are discussed for each onchocerciasis focus in Latin America.Neste trabalho são discutidos os fatores que interferem na suscetibilidade de espécies de simulídeos atuarem como hospedeiros do Onchocerca volvulus e de transmitir a filária em condições naturais. Acredita-se que a presença ou não da armadura do cibário pode ser um fator central, que anteriormente foi subestimado. Este aspecto é discutido em relação às opções em voga de métodos de controle na oncocercose. São também discutidos os estudos epidemiológicos correntes, a dinâmica de transmissão e principais medidas de controle para cada foco de oncocercose na América Latina.

Evaluación del desarrollo testicular y medidas morfométricas en ovinos de pelo colombiano

Directory of Open Access Journals (Sweden)

Amado Espitia-Pacheco

2018-01-01

Full Text Available Las medidas corporales en ovinos son útiles como indicador de tipo y función, permiten mejorar la selección. Se conocen estudios biométricos en ovinos que, relacionan la importancia de estas medidas con algunas variables productivas. El objetivo del presente estudio fue evaluar el desarrollo testicular y su relación con los parámetros morfométricos en ovinos de pelo colombiano, en el municipio de Sampués, Sucre, Colombia. Se utilizaron doce ovinos machos (destetados nacidos entre febrero y abril del 2014, sobre los cuales se tomaron las siguientes medidas: circunferencia escrotal (CE, peso corporal (PC, altura a la grupa (AG, alzada a la cruz (AC y longitud testicular derecha e izquierda (LTD y LTI, cada veintiocho días hasta los doce meses de edad. Para CE se efectuó análisis de regresión múltiple (RM del PC; AG; AC; LT. Para describir la variación del LT, el modelo incluyó solo las variables PC; AG; AC. El grado de asociación entre las variables estudiadas, se realizó por medio de correlación Pearson. La circunferencia escrotal mostró una correlación alta con los parámetros morfométricos evaluados. Dentro del análisis de RM, el PC influyó en la variable CE (p<0,05, mientras que las demás variables no influyeron significativamente. Según el coeficiente de regresión asociado a la medición, por cada kg de incremento en PC, hubo un correspondiente aumento de 0,09 cm en la CE.

Physics of x-ray computed tomography

International Nuclear Information System (INIS)

Akutagawa, W.M.; Huth, G.C.

1976-01-01

Sections are included on theoretical limits of x-ray computed tomography and the relationship of these limits to human organ imaging and specific disease diagnosis; potential of x-ray computed tomography in detection of small calcified particles in early breast cancer detection; early lung cancer measurement and detection; advanced materials for ionizing radiation detection; positron system with circular ring transaxial tomographic camera; contrast mechanism of transmission scanner and algorithms; and status of design on a 200 keV scanning proton microprobe

Transmission electron microscopy physics of image formation and microanalysis

CERN Document Server

Reimer, Ludwig

1993-01-01

"Transmission Electron Microscopy" presents the theory of image and contrastformation, and the analytical modes in transmission electron microscopy Theprinciples of particle and wave optics of electrons are described Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast Also analysed are the kinetical and dynamical theories of electron diffraction and their applications for crystal-structure determination and imaging of lattices and their defects X-ray microanalysis and electron energy-loss spectroscopy are treated as analytical methods The third edition includes a brief discussionof Schottky emission guns, some clarification of minor details, and references to the recent literature

Transmission X-Ray Microscopy of the Galvanostatic Growth of Lead Sulfate on Lead: Impact of Lignosulfonate

International Nuclear Information System (INIS)

Knehr, K.W.; Eng, Christopher; Wang, Jun; West, Alan C.

2015-01-01

The galvanostatic growth of PbSO 4 on Pb in H 2 SO 4 was studied using scanning electron microscopy and in situ transmission X-ray microscopy (TXM). Images from the TXM are used to investigate the effects of sodium lignosulfonate on the PbSO 4 formation and the initial growth of the PbSO 4 crystals. Sodium lignosulfonate is shown to retard, on average, the growth of the PbSO 4 crystals, yielding a film with smaller crystals and higher crystal densities. In addition, results from experiments with and without sodium lignosulfonate indicate an increase in the nucleation rate of the PbSO 4 crystals when the oxidation current is applied, which was attributed to an increase in the supersaturation of the electrolyte. Furthermore, an analysis of the growth rates of individual, large crystals showed an initial rapid growth which declined as the PbSO 4 surface coverage increased. It was concluded that the increase in PbSO 4 provides additional sites for precipitation and reduces the precipitation rate on the existing crystals. Finally, the potential-time transient at the beginning of oxidation is suggested to result from the relaxation of a supersaturated solution and the development of a PbSO 4 film with increasing resistance

Transmission Electron Microscopy and Diffractometry of Materials

CERN Document Server

Fultz, Brent

2013-01-01

This book explains concepts of transmission electron microscopy (TEM) and x-ray diffractometry (XRD) that are important for the characterization of materials. The fourth edition adds important new techniques of TEM such as electron tomography, nanobeam diffraction, and geometric phase analysis. A new chapter on neutron scattering completes the trio of x-ray, electron and neutron diffraction. All chapters were updated and revised for clarity. The book explains the fundamentals of how waves and wavefunctions interact with atoms in solids, and the similarities and differences of using x-rays, electrons, or neutrons for diffraction measurements. Diffraction effects of crystalline order, defects, and disorder in materials are explained in detail. Both practical and theoretical issues are covered. The book can be used in an introductory-level or advanced-level course, since sections are identified by difficulty. Each chapter includes a set of problems to illustrate principles, and the extensive Appendix includes la...

La variable latente calidad medida a través del modelo de Rasch.

Directory of Open Access Journals (Sweden)

Guerrero, Mª M.

1997-01-01

Full Text Available La obtención de aceites de oliva de calidad requiere unos cuidados especiales en todas y cada una de las sucesivas fases de elaboración de los mismos, es una cadena que comienza en el olivo y termina en el consumo. Condición indispensable para ello es conocer las características organolépticas del aceite (a fin de potenciar sus atributos y eliminar, en la medida de los posible, sus defectos, y la influencia del proceso de elaboración en las mismas. El control y medida de estos caracteres se hará mediante las catas, realizadas por expertos catadores utilizando para ello las fichas de cata del Consejo Oleícola Internacional. El modelo de Rasch, que emplearemos para obtener la evaluación sensorial de los aceites de oliva virgen, nos permitirá no sólo dar una calificación organoléptica global al aceite (que ya podemos realizar sin necesidad de aplicar ningún método, siguiendo la metodología de valoración del Consejo Oleícola Internacional, sino también clasificar y medir los factores sensoriales que intervienen en la calidad, lo que nos permitirá realizar las acciones oportunas encaminadas a obtener aceites de oliva de cualidades óptimas.

Obtenção de medidas de imagens adquiridas em estereomiscroscópio e escaner de mesa = Measures obtained from images acquired by a stereomicroscope and a desktop scanner

Directory of Open Access Journals (Sweden)

Larentis, Naiara Leites

2014-01-01

Full Text Available Objetivo: Esse estudo teve por objetivo comparar medidas obtidas de imagens de secções dentárias adquiridas em estereomiscrópio e escâner de mesa, assim como determinar se existem diferenças entre os dois métodos. Métodos: Cinquenta dentes humanos extraídos foram seccionados no sentido mésio-distal. Cada secção foi fotografada em estereomicroscópio e digitalizada em escâner de mesa com resolução de 230 dpi. O programa Photoshop foi utilizado para obter medidas verticais e horizontais das imagens de cada secção dentárias, adquiridas por ambos os métodos. Foram repetidas as medidas em 20% das amostras, selecionadas randomicamente. Resultados: As medidas iniciais e as repetidas apresentaram correlação positiva e o teste t para amostras pareadas não revelou diferença significativa (a=5% entre elas. A média das medidas e os devios-padrão foram: horizontal, estereomicroscópio 8,89 mm±4,30 mm e escâner 8,89 mm±4,52 mm; vertical, estereomicroscópio 4,42 mm±2,19 mm e escâner 4,43 mm±2,19 mm. Os resultados do teste t para amostras pareadas (a=5% não mostrou nenhuma diferença significativa entre os dois métodos para as medidas horizontais (p=0,685 e verticais (p=0,299. Conclusão: O escâner de mesa pode ser usado substituindo o estereomicroscópio na aquisição de imagens de secções dentárias para a obtenção de medidas verticais e horizontais

Size effect in X-ray and electron diffraction patterns from hydroxyapatite particles

International Nuclear Information System (INIS)

Suvorova, E.I.; Buffat, P.-A.

2001-01-01

High-resolution transmission electron microscopy (HRTEM), electron microdiffraction, and X-ray diffraction were used to study hydroxyapatite specimens with particle sizes from a few nanometers to several hundreds of nanometers. Diffuse scattering (without clear reflections in transmission diffraction patterns) or strongly broadened peaks in X-ray diffraction patterns are characteristic for agglomerated hydroxyapatite nanocrystals. However, HRTEM and microdiffraction showed that this cannot be considered as an indication of the amorphous state of the matter but rather as the demonstration of size effect and the morphological and structural features of hydroxyapatite nanocrystals

Force transmissibility versus displacement transmissibility

Science.gov (United States)

Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

2014-10-01

It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

Plant trial of a fast neutron and gamma-ray transmission gauge for the on-belt determination of moisture in lump coke

International Nuclear Information System (INIS)

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

1990-01-01

A fast neutron and γ-ray transmission (FNGT) gauge has been used to determine the moisture content of lump coke on the conveyor belt supplying the No. 3 blast furnace at the BHP Newcastle Steelworks. The gauge was operated on-line over the period June 1988-March 1989. Gauge moisture was compared with laboratory moisture, based on 30 increment composite samples taken from the belt, and with moisture determined by a second FNGT gauge on one of the hoppers feeding the conveyor belt. The r.m.s. difference between conveyor gauge moisture and laboratory moisture was 0.24 wt% during the calibration period for two hopper flow on the belt, which is normal plant condition. The accuracy of the conveyor belt gauge was maintained to within 0.37 wt% moisture over the full period of the plant trial. (author)

Depth profiling: RBS versus energy-dispersive X-ray imaging using scanning transmission electron microscopy

International Nuclear Information System (INIS)

Markwitz, Andreas

2000-01-01

Rutherford backscattering spectrometry (RBS) is known to be one of the techniques ideal for analysis of thin films. Elemental concentrations of matrix components and impurities can be investigated as well as depth profiles of almost each element of the periodic table. Best of all, RBS has both a high sensitivity and a high depth resolution, and is a non-destructive analysis technique that does not require specific sample preparation. Solid-state samples are mounted without preparation inside a high-vacuum analysis chamber. However, depth-related interpretation of elemental depth profiles requires the material density of the specimen and stopping power values to be taken into consideration. In many cases, these parameters can be estimated with sufficient precision. However, the assumed density can be inaccurate for depth scales in the nanometer range. For example, in the case of Ge nanoclusters in 500 nm thick SiO 2 layers, uncertainty is related to the actual position of a very thin Ge nanocluster band. Energy-dispersive X-ray emission (EDX) spectroscopy, using a high-resolution scanning transmission electron microscope (STEM) can assist in removing this uncertainty. By preparing a thin section of the specimen, EDX can be used to identify the position of the Ge nanocluster band very precisely, by correlating the Ge profile with the depth profiles of silicon and oxygen. However, extraction of the concentration profiles from STEM-EDX spectra is in general not straightforward. Therefore, a combination of the two very different analysis techniques is often the best and only successful way to extract high-resolution concentration profiles

Synchrotron-based transmission x-ray microscopy for improved extraction in shale during hydraulic fracturing

Science.gov (United States)

Kiss, Andrew M.; Jew, Adam D.; Joe-Wong, Claresta; Maher, Kate M.; Liu, Yijin; Brown, Gordon E.; Bargar, John

2015-09-01

Engineering topics which span a range of length and time scales present a unique challenge to researchers. Hydraulic fracturing (fracking) of oil shales is one of these challenges and provides an opportunity to use multiple research tools to thoroughly investigate a topic. Currently, the extraction efficiency from the shale is low but can be improved by carefully studying the processes at the micro- and nano-scale. Fracking fluid induces chemical changes in the shale which can have significant effects on the microstructure morphology, permeability, and chemical composition. These phenomena occur at different length and time scales which require different instrumentation to properly study. Using synchrotron-based techniques such as fluorescence tomography provide high sensitivity elemental mapping and an in situ micro-tomography system records morphological changes with time. In addition, the transmission X-ray microscope (TXM) at the Stanford Synchrotron Radiation Lightsource (SSRL) beamline 6-2 is utilized to collect a nano-scale three-dimensional representation of the sample morphology with elemental and chemical sensitivity. We present the study of a simplified model system, in which pyrite and quartz particles are mixed and exposed to oxidizing solution, to establish the basic understanding of the more complex geology-relevant oxidation reaction. The spatial distribution of the production of the oxidation reaction, ferrihydrite, is retrieved via full-field XANES tomography showing the reaction pathway. Further correlation between the high resolution TXM data and the high sensitivity micro-probe data provides insight into potential morphology changes which can decrease permeability and limit hydrocarbon recovery.

Structure-Property Relationships in Aluminum-Copper alloys using Transmission X-Ray Microscopy (TXM) and Micromechanical Testing

Science.gov (United States)

Kaira, Chandrashekara Shashank

that effect, in situ tests were conducted at the synchrotron (Advanced Photon Source) using Transmission X-Ray Microscopy as well as in a scanning electron microscope (SEM) to study real-time damage evolution in such alloys. Findings of precipitate size-dependent transition in deformation behavior from these tests have inspired a novel resilient aluminum alloy design.

A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements

Energy Technology Data Exchange (ETDEWEB)

Seidler, G. T., E-mail: seidler@uw.edu; Mortensen, D. R.; Remesnik, A. J.; Pacold, J. I.; Ball, N. A.; Barry, N.; Styczinski, M.; Hoidn, O. R. [Physics Department, University of Washington, Seattle, Washington 98195-1560 (United States)

2014-11-15

We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low power x-ray (bremsstrahlung) tube source, a spherically bent crystal analyzer, and an energy-resolving solid-state detector. This relatively inexpensive, introductory level instrument achieves 1-eV energy resolution for photon energies of ∼5 keV to ∼10 keV while also demonstrating a net efficiency previously seen only in laboratory monochromators having much coarser energy resolution. Despite the use of only a compact, air-cooled 10 W x-ray tube, we find count rates for nonresonant x-ray emission spectroscopy comparable to those achieved at monochromatized spectroscopy beamlines at synchrotron light sources. For x-ray absorption near edge structure, the monochromatized flux is small (due to the use of a low-powered x-ray generator) but still useful for routine transmission-mode studies of concentrated samples. These results indicate that upgrading to a standard commercial high-power line-focused x-ray tube or rotating anode x-ray generator would result in monochromatized fluxes of order 10{sup 6}–10{sup 7} photons/s with no loss in energy resolution. This work establishes core technical capabilities for a rejuvenation of laboratory-based hard x-ray spectroscopies that could have special relevance for contemporary research on catalytic or electrical energy storage systems using transition-metal, lanthanide, or noble-metal active species.

A low power x-ray tube for use in energy dispersive x-ray fluorescence analysis

International Nuclear Information System (INIS)

Kataria, S.K.; Govil, Rekha; Lal, M.

1980-01-01

A low power X-ray tube with thin molybdenum transmission target for use in energy dispersive X-ray fluorescence (ENDXRF) element analysis has been indigenously built, along with its power supply. The X-ray tube has been in operation since August 1979, and it has been operated upto maximum target voltage of 35 KV and tube current upto 200 μA which is more than sufficient for trace element analysis. This X-ray tube has been used alongwith the indigenously built Si(Li) detector X-ray spectrometer with an energy resolution of 200 eV at 5.9 Kev MnKsub(α) X-ray peak for ENDXRF analysis. A simple procedure of calibration has been developed for thin samples based on the cellulose diluted, thin multielement standard pellets. Analytical sensitivities of the order of a few p.p.m. have been obtained with the experimental setup for elements with 20 < = Z < = 38 and 60 < = Z < = 90. A number of X-ray spectra for samples of environmental, biological, agricultural, industrial and metallurgical interest are presented to demonstrate the salient features of the experimental sep up. (auth.)

Influência da resolução e da distância da câmera nas medidas feitas pelo software de avaliação postural (sapo

Directory of Open Access Journals (Sweden)

Yomara Lima Mota

2011-10-01

Full Text Available O erro na medida de um sistema de avaliação da postura está relacionado com a digitalização, a resolução da câmera, a distância da câmera em relação ao voluntário estudado, entre outros. Estes erros somam-se no procedimento metodológico e muitos deles não são possíveis evitar, porém devem ser conhecidos e quantificados. OBJETIVO: Quantificar o erro na medida realizada pelo SAPO (Software para avaliação postural em diferentes situações experimentais. MÉTODOS: Foram realizadas 16 fotos de um manequim de 1,40m articulado nos planos anterior, posterior, lateral direita e lateral esquerda com câmeras de 3,2 e 12,0 megapixels, posicionadas a 3,0m e a 5,0m de distância do manequim. Para a quantificação do erro, foram calculadas as diferenças das medidas obtidas por meio do SAPO com as medidas feitas diretamente no manequim. Apenas um avaliador realizou o registro das imagens, porém a digitalização no software dos pontos demarcados no manequim foi realizada por três digitalizadores, sendo dois inexperientes e um experiente. RESULTADOS: Os valores médios das medidas horizontais, verticais, angulares e de distância são próximos de zero, embora algumas variáveis angulares apresentem valores maiores, como nas medidas de ângulo Q direito e esquerdo. A câmera com resolução de 3,2 megapixels posicionada a 3m apresentou o menor erro. CONCLUSÃO: O SAPO é um método acurado para uso clínico; são necessários estudos para verificar a influência do plano de posicionamento do voluntário em relação à câmera, o efeito do reposicionamento e da palpação nas medidas oferecidas pelo software.

Método para obtenção de medidas antropométricas utilizando um digitalizador 3D de baixo custo

OpenAIRE

Clariana Fischer Bendler; Fábio Gonçalves Teixeira

2016-01-01

O objetivo é desenvolver um método para obtenção de medidas antropométricas através de um digitalizador 3D de baixo custo. A metodologia da pesquisa consiste em seis etapas: pesquisa bibliográfica, coleta e análise dos dados antropométricos pelo método direto e o desenvolvimento do método indireto de obtenção de medidas antropométricas, comparação e análise dos dados obtidos, discussão dos resultados e a finalização. O processo de digitalização utilizado está baseado em um dispositivo de baix...

Optimized fabrication protocols of microfluidic devices for X-ray analysis

KAUST Repository

Catalano, Rossella

2014-07-01

Microfluidics combined with X-ray scattering techniques allows probing conformational changes or assembly processes of biological materials. Our aim was to develop a highly X-ray transparent microfluidic cell for detecting small variations of X-ray scattering involved in such processes. We describe the fabrication of a polyimide microfluidic device based on a simple, reliable and inexpensive lamination process. The implemented microstructured features result in windows with optimized X-ray transmission. The microfluidic device was characterized by X-ray microbeam scattering at the ID13 beamline of the European Synchrotron Radiation Facility. © 2014 Elsevier B.V. All rights reserved.

Impactos de medidas “antidumping” adotadas pelos EUA sobre o setor siderúrgico de Minas Gerais e o restante do Brasil

Directory of Open Access Journals (Sweden)

Vinícius de Azevedo Couto Firme

2012-11-01

Full Text Available Analisar o impacto de medidas antidumping aplicadas pelos Estados Unidos sobre exportações do setor siderúrgico de Minas Gerais, para o período entre 1999 e 2002, foi o objetivo deste trabalho. Os resultados mostraram que tal medida teve efeitos estatisticamente significativos sobre a redução no fluxo de comércio. Na análise da integração dos resultados econométricos com a abordagem de matrizes inter-regionais de insumo-produto, foi possível concluir que o setor mais afetado, no que se refere à produção, seria a siderurgia mineira, em que o impacto representou mais de 75% do total, no período em análise. Com relação ao emprego, o impacto sobre a siderurgia de Minas Gerais corresponde, em média, a mais de 50% do total de vagas que seriam criadas, caso nenhuma medida antidumping tivesse sido adotada; e a siderurgia do restante do país seria responsável por mais de 16% dos postos de trabalho criados no período.

Construcción de un equipo de medida de fotosíntesis neta y transpiración para plantas individuales

Directory of Open Access Journals (Sweden)

Anundo Polanía

2010-01-01

Full Text Available Se construyó un equipo de medida de fotosíntesis neta y transpiración para plantas individuales jóvenes de sistema abierto. La parte aérea de la planta se introdujo en una cámara transparente con un sistema de entrada y salida de aire. Esta tenía un control de temperatura y ventilación y estaba iluminada por varias bombillas cuya distancia a la cámara era graduable.Un analizador de gases infrarrojo midió la diferencia de concentración de CO2 entre la entrada y la salida de la cámara. La humedad del aire era registrada por unhigrómetro de punto de rocío. La concentración de CO2 y H2O en el aire que entraba a la cámara era controlada usando trampas selectivas y saturadores de vapor de agua. Con el equipo se hicieron medidas de ratas de fotosíntesis neta y transpiración en plantas de maíz. La precisión y la reproducibilidad de las medidas obtenidas con el equipo permiten su utilización para estudios del mismo tipo en otrasespecies.

The color of X-rays Spectral X-ray computed tomography using energy sensitive pixel detectors

CERN Document Server

Schioppa, Enrico Junior

Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray fluorescence. The charge transport properties of the sensor are characterized using a high energy beam of charged particles at the Super Proton Synchrotron (SPS) at the European Center for Nuclear Research (CERN). Monochromatic X-rays at the European Synchrotron Radiation Facility (ESRF) are used to determined the energy response function. These data are used to implement a physics-based CT projection operator that accounts for the transmission of the source spectrum through the sample and detector effects. Based on this projection operator, an iterative spectral CT reconstruction algorithm is developed by extending an Ordered Subset Expectation Maximization (OSEM) method. Subsequently, a maximum likelihood based algo...

Nanometer-scale, quantitative composition mappings of InGaN layers from a combination of scanning transmission electron microscopy and energy dispersive x-ray spectroscopy

International Nuclear Information System (INIS)

Pantzas, K; Voss, P L; Ougazzaden, A; Patriarche, G; Largeau, L; Mauguin, O; Troadec, D; Gautier, S; Moudakir, T; Suresh, S

2012-01-01

Using elastic scattering theory we show that a small set of energy dispersive x-ray spectroscopy (EDX) measurements is sufficient to experimentally evaluate the scattering function of electrons in high-angle annular dark field scanning transmission microscopy (HAADF-STEM). We then demonstrate how to use this function to transform qualitative HAADF-STEM images of InGaN layers into precise, quantitative chemical maps of the indium composition. The maps obtained in this way combine the resolution of HAADF-STEM and the chemical precision of EDX. We illustrate the potential of such chemical maps by using them to investigate nanometer-scale fluctuations in the indium composition and their impact on the growth of epitaxial InGaN layers. (paper)

Effects of an ultraviolet-visible rays translation film on growth of leaf or root vegetables

International Nuclear Information System (INIS)

Hamamoto, H.; Ueno, K.; Yamazaki, K.

2008-01-01

A new film that absorbs ultraviolet radiation (UV) and fluoresces red light was tested as a rain shelter for the cultivation of turnip (Brassica rapa L.), spinach (Spinacia oleracea L.), and Welsh onion (Allium fistulosum L.). The effect of this UV-visible ray translation film on various growth parameters (height, fresh and dry weight, leaf area and leaf sheath diameter) was compared with those under normal clear film, new UV-cut film, and used UV-cut film respectively. The transmissivity of UV was about 70% for the normal clear film, about 20% for the UV-visible ray translation film and used UV-cut film, and about 10% for the new UV-cut film. The transmissivity of photosynthetically active radiation (PAR) was about 90% for the normal clear film and the new UV-cut film, and about 80% for the used UV-cut film, while the mean transmissivity of PAR was about 80% for the UV-visible ray translation film, with about 60% transmissivity of blue radiation and over 90% of red radiation. The UV-visible ray translation film did not promote the growth of turnip roots but did significantly promote the growth of spinaches and Welsh onions compared with the normal clear film. The UV-visible ray translation film cover promoted the growth of spinaches and Welsh onions to a similar or greater extent compared to the new UV-cut film and also to a greater extent compared to the used UV-cut film

La ciudad ante el contagio: medidas políticas y administrativas dictadas en la epidemia de fiebre amarilla de 1804 en Alicante

Directory of Open Access Journals (Sweden)

Pascual Artiaga, Mercedes

2002-06-01

Full Text Available Since 1800 the yellow fever started producing epidemic incidents in the Iberian Peninsula. In this article the measures that were established by the different sanitary assemblies implied in the control of the epìdemic outbreak that affected the city of Alicante in 1804 are shown and analysed. The study of this case in Alicante has allowed to put in context this analysis in the framework of what happened in other places during this and other epidemies. It is proved the coexistence of traditional measures of prevention and of new ones. The political and sanitary speech focused on assuring the isolation of the population affected in order to avoid the spreading of this disease and to extend it as long as possible, as a quarantee for the surrounding cities.

el artículo se presentan y analizan las medidas que instauraron las diversas Juntas de Sanidad implicadas en el control del brote epidémico que afectó a la ciudad de Alicante en 1804. El estudio del caso alicantino ha permitido contextualizar dicho análisis en el marco de lo sucedido en otras localidades durante ésta y otras epidemias. Se constata la coexistencia de medidas tradicionales de prevención y de nuevas medidas. Las medidas administrativas y sanitarias se centraron en asegurar el aislamiento de la población afectada para evitar la extensión de la enfermedad y prolongarlo el mayor tiempo posible, como una garantía para las localidades vecinas.

SERVIÇO SOCIAL, MEDIDAS SOCIOEDUCATIVAS E O ADOLESCENTE INFRATOR NO LIBERDADE ASSISTIDA

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Cristiano Costa Carvalho

2013-10-01

Full Text Available RESUMO: A temática dos adolescentes em conflito com a Lei é uma questão que merece uma atenção especial, pois é significativa ao longo da trajetória pela conquista da mudança de paradigma na legislação em relação ao enfrentamento desta expressão da questão social, e porque mesmo diante desta mudança, as medidas em meio aberto são as que têm sido menos aplicadas. Deste modo, esta pesquisa permitiu conhecer e problematizar a atuação do profissional de Serviço Social dentro da política de atendimento aos adolescentes em conflito com a Lei e em destaque a medida socioeducativa no programa de Liberdade Assistida, devido a sua característica educativa que preserva o convívio social, familiar e comunitária.  O processo de preparação desta pesquisa consistiu em entrevistas semi-estruturadas, estudos bibliográficos, documentais, e acervos digitais. Foi analisado o potencial da atuação profissional em consonância com as diretrizes previstas pelo Estatuto da Criança e do Adolescente, Lei que garante aos mesmos um atendimento especial, e reconhece que são sujeitos em processo de formação. PALAVRAS-CHAVE: adolescentes, ato infracional, medidas socioeducativas ABSTRACT: The topic of minors in conflict with the Law is an issue that deserves special attention due to its representativeness in the course of attaining a paradigm shift in the legislation related to this social matter, and because even before this change takes place, it is the open regime measures that have been less applied. This research has therefore helped identify and discuss the role of the Social Worker in the assistance policy for juveniles in conflict with the Law, highlighting the socio-educational measure of the probation program “Liberdade Assistida”, which, due to its educational nature, preserves the social, family and community life. The process of preparing this research consisted of semi-structured interviews, bibliographical and documentary

Study of light transmission through optical fiber-to-fiber connector assemblies

International Nuclear Information System (INIS)

Chung, M.; Gutowski, M.; Adams, M.; Solomon, J.

1998-01-01

Optical fiber-to-fiber connectors are now being used widely in particle tracking detectors. We describe the properties of the connectors, their production, and measurements of the light transmission through the gap of the connector assembly. We studied light transmission for various types of connectors illuminated by several different light sources. The light transmission was found to be dependent on the angular distribution of the light rays passing through a connector assembly. Two arrangements were studied, a point source and a diffuse source. A green LED with a diffuser is believed to best reproduce the angular distributions of light in the real detector applications. We also studied the transmission as a function of the index of refraction of the optical couplants. The light transmission depends on the index of refraction of an optical couplant placed in the gap, and improves as it approaches the index of refraction of the fiber core. Light transmissions of 80%∼88% were obtained without any optical couplant in the connector gap and transmissions of 89%∼99% with various optical couplants. A Monte Carlo study using measured light distributions from a fiber end produced a reasonable agreement with the transmission measurements made on a connector assembly

Study of light transmission through optical fiber-to-fiber connector assemblies

International Nuclear Information System (INIS)

Chung, M.; Gutowski, M.; Adams, M.; Solomon, J.

1998-01-01

Optical fiber-to-fiber connectors are now being used widely in particle tracking detectors. We describe the properties of the connectors, their production, and measurements of the light transmission through the gap of the connector assembly. We studied light transmission for various types of connectors illuminated by several different light sources. The light transmission was found to be dependent on the angular distribution of the light rays passing through a connector assembly. Two arrangements were studied, a point source and a diffuse source. A green LED with a diffuser is believed to best reproduce the angular distributions of light in the real detector applications. We also studied the transmission as a function of the index of refraction of the optical couplants. The light transmission depends on the index of refraction of an optical couplant placed in the gap, and improves as it approaches the index of refraction of the fiber core. Light transmissions of 80%∼88% were obtained without any optical couplant in the connector gap and transmissions of 89%∼99% with various optical couplants. A Monte Carlo study using measured light distributions from a fiber end produced a reasonable agreement with the transmission measurements made on a connector assembly. copyright 1998 American Institute of Physics

Medidas de conservación y ordenación pesquera del jurel Trachurus murphyien el Perú

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Jorge Zuzunaga

2013-10-01

Full Text Available Las pesquerías peruanas como actividades realizadas sobre recursos naturales renovables son reguladas por un marco jurídico, cuyo objetivo es asegurar su conservación y uso sostenible. La Ley General de Pesca (DL N°. 25977 señala que para cada tipo de pesquería y según la situación del recurso explotado debe establecerse un sistema de ordenamiento que concilie el principio de sostenibilidad de los recursos pesqueros o conservación en el largo plazo, con la obtención de los mayores beneficios económicos y sociales. En el ordenamiento pesquero del jurel Trachurus murphyi, las medidas incluyen entre otras, el régimen de acceso constituido por las autorizaciones de incremento de flota y permisos de pesca, que se otorgan solo a los buques cuyas capturas son destinadas únicamente para el consumo humano directo, de acuerdo a lo dispuesto en el Reglamento de Ordenamiento Pesquero (DS N.° 011-2007-PRODUCE. La obligación de destinar los recursos sardina Sardinops sagax, jurel T. murphyiy caballa Scomber japonicus al consumo humano directo rige desde septiembre 2002 (DS N°. 001-2002-PRODUCE. Otras medidas vigentes restringen el tamaño mínimo de malla de las redes, prohíben la captura de ejemplares menores de 31 cm de longitud total, determinan el inicio y cierre de las temporadas de pesca, los límites de captura o cuotas anuales. Estas disposiciones son complementadas por medidas de seguimiento, control y vigilancia para la efectiva conservación y uso sostenido del recurso.

Modelización numérica y mejora del sistema de medida en una instalación experimental docente de golpe de ariete

OpenAIRE

Martínez Fernández, José Luis

2016-01-01

En el laboratorio del departamento de Ingeniería Térmica y de Fluidos se dispone de una instalación experimental de golpe de ariete en la que es conveniente revisar y mejorar el sistema de medida. Paralelamente se desarrollará un modelo numérico mediante el método de las características que reproduzca en mayor medida los fenómenos transitorios producidos. Ambos aspectos del trabajo deben converger y permitir enriquecer el contenido de las prácticas realizables en la instalación y la com...

Adesão às medidas preventivas de pneumonia associada à ventilação mecânica.

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Luany Caroline Adamovicz Bork

2015-01-01

Full Text Available Justificativa e Objetivos: Ressaltando a relevância da adoção de medidas preventivas de infecção para a realização de uma assistência livre de danos emergiu a necessidade de observar como a equipe de saúde aplica o bundle. Objetivou-se verificar a adesão de medidas preventivas de pneumonia pelos profissionais de saúde, da Unidade de Terapia Intensiva geral adulta de um hospital público, Ponta Grossa-PR. Métodos: Pesquisa transversal, de abordagem quantitativa, prospectiva e observacional, realizada no período de abril a julho de 2013. A amostra constituiu-se de 33 pacientes que estavam em ventilação mecânica, totalizando o registro de 1522 momentos de aplicações das medidas preventivas de pneumonia associada à ventilação mecânica (PAVM. Resultados: Dos 33 pacientes, 13 desenvolveram pneumonia, a média de idade foi de 59,72 anos e a prevalência foi do gênero feminino (44,44%. Verificou-se que os profissionais de saúde atenderam a cabeceira elevada dos leitos em média 69,80%, assim como aderiram à interrupção da sedação em média 66,66%, realizaram a higiene oral com clorexidina 94,61%, mantiveram o cuff do tubo orotraqueal (entre 20 e 25 mmH20 64,44%, adequaram o filtro de nebulizador para ficar dentro da validade 89,50% e em 93,4% das observações deixaram os circuitos livre de condensados. Analisou-se que o valor médio de dias passados em ventilação mecânica dos pacientes que adquiriram infecção foi de 15,85 (DP = 8,65 dias. Conclusão: Revela-se que quando a equipe aplica todas as medidas preventivas ao paciente sob ventilação mecânica há redução do risco de adquirir infecção no trato respiratório. DESCRITORES: Terapia intensiva; Pneumonia associada à ventilação mecânica; Infecção hospitalar; Equipe de assistência ao paciente.

The economic emergency: an insufficient solution La emergencia económica: una medida inconclusa

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Lorente Luis

1997-06-01

Full Text Available There are many reasons for the Colombian recession that began in 1995, but the disagreement between fiscal and monetary authorities is an outstanding one. Monetary measures against inflation promoted high interest rates, made real investment more risky, rocketed the exchange rate, attracted foreign capital and elevated public debt costs.
Emergency measures announced early in the year were insufficient because the problem comes from old and needs long range measures. Balanced budget is a valid target, but along the economic cycle and not in each fiscal year. Reduction of public expenses or public debt must be applied in periods of growth and not when taxes go down because a recession has begun. Monetary policy must allow for anti-cyclical measures and can do it effectively by controlling the volume. of credit accessible to the Government, or to finance private construction of public works, or to those that will buy the facilities and services that get privatized.La fase recesiva de la economía colombiana que comenzó en 1995 tiene varias causas, en especial, el desacuerdo entre políticas fiscales y monetarias. Las medidas antiinflacionarias elevaron las tasas de interés y dificultaron la inversión, y provocaron la revaluación de la moneda, la promoción de la entrada masiva de capital externo y del encarecimiento del servicio de la deuda pública. Las medidas de emergencia anunciadas a comienzos de 1995 no fueron suficientes: se necesita una política con objetivos de largo plazo. Hay que buscar un balance fiscal a lo largo del ciclo económico y no en cada año fiscal; la contracción del gasto público debe aplicarse en las fases de auge económico y no cuando caen los recaudos porque ya comenzó una recesión. La política monetaria debe permitir medidas anticíclicas y puede contribuir a ellas si regula el volumen de crédito accesible al Estado, a sus contratistas y a quienes adquieren prvatizaciones.

Medidas de control de tuberculosis en una institución de salud de Bogotá D.C

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Alba I. Muñoz-Sánchez

2016-02-01

Full Text Available Resumen Objetivo: evaluar la implementación de medidas de control, de tipo administrativo, ambiental y de protección respiratoria, de la infección de tuberculosis en un hospital de III nivel de atención en la ciudad de Bogotá D.C. Metodología: estudio de tipo descriptivo, transversal. Para la recolección de datos se aplicó una herramienta de autorreporte a 158 trabajadores de la salud del hospital, se realizó una entrevista estructurada al responsable del programa institucional de control de tuberculosis y una visita de observación de un experto en salud y seguridad laboral a las diferentes áreas de trabajo, para indagar por la implementación de medidas de control de infección de tuberculosis en la institución. Resultados: el responsable del programa institucional de control de tuberculosis y 158 trabajadores de la salud del hospital objeto de estudio reportaron una deficiente implementación de medidas de control de tuberculosis, de tipo administrativo, ambiental y de protección respiratoria en la institución, lo cual fue corroborado por el experto. Conclusiones: la deficiente implementación de medidas de control de infección de tuberculosis en instituciones de la salud, y algunas condiciones de trabajo presentes pueden favorecer la exposición ocupacional de los trabajadores de la salud al Mycobacterium Tuberculosis. Abstract Objective: to evaluate the implementation of tuberculosis infection control measures in administrative, environmental and respiratory protection equipment in a third level hospital in Bogota D.C. Methodology: a descriptive, cross-sectional study. Data were collected through a self-reporting instrument applied on 158 health care workers. The chief officer of the institutional program for tuberculosis control participated in a structured interview. In addition, an expert in occupational health and safety conducted an observational visit to the different workplaces in order to inquire on the implementation

Induced magnetic anisotropy in Si-free nanocrystalline soft magnetic materials: A transmission x-ray diffraction study

International Nuclear Information System (INIS)

Parsons, R.; Suzuki, K.; Yanai, T.; Kishimoto, H.; Kato, A.; Ohnuma, M.

2015-01-01

In order to better understand the origin of field-induced anisotropy (K u ) in Si-free nanocrystalline soft magnetic alloys, the lattice spacing of the bcc-Fe phase in nanocrystalline Fe 94−x Nb 6 B x (x = 10, 12, 14) alloys annealed under an applied magnetic field has been investigated by X-ray diffraction in transmission geometry (t-XRD) with the diffraction vector parallel and perpendicular to the field direction. The saturation magnetostriction (λ s ) of nanocrystalline Fe 94−x Nb 6 B x was found to increase linearly with the volume fraction of the residual amorphous phase and is well described by taking into account the volume-weighted average of two local λ s values for the bcc-Fe nanocrystallites (−5 ± 2 ppm) and the residual amorphous matrix (+8 ± 2 ppm). The lattice distortion required to produce the measured K u values (∼100 J/m 3 ) was estimated via the inverse magnetostrictive effect using the measured λ s values and was compared to the lattice spacing estimations made by t-XRD. The lattice strain required to produce K u under the magnetoelastic model was not observed by the t-XRD experiments and so the findings of this study suggest that the origin of magnetic field induced K u cannot be explained through the magnetoelastic effect

Catalysts at work: From integral to spatially resolved X-ray absorption spectroscopy

DEFF Research Database (Denmark)

Grunwaldt, Jan-Dierk; Kimmerle, B.; Baiker, A.

2009-01-01

available techniques, X-ray absorption spectroscopy (XAS) is a well-suited tool for this purpose as the different selected examples highlight. Two different techniques, scanning and full-field X-ray microscopy/tomography, are described and compared. At first, the tomographic structure of impregnated alumina...... pellets is presented using full-field transmission microtomography and compared to the results obtained with a scanning X-ray microbeam technique to analyse the catalyst bed inside a catalytic quartz glass reactor. On the other hand, by using XAS in scanning microtomography, the structure...... metal-based catalysts. In order to obtain spectroscopic information on the spatial variation of the oxidation state of the catalyst inside the reactor XAS spectra were recorded by scanning with a micro-focussed beam along the catalyst bed. Alternatively, full-field transmission imaging was used...

The single reflection regime of X-rays travelling into a monocapillary

International Nuclear Information System (INIS)

Dabagov, S.B.; Marcelli, A.

1999-01-01

In this manuscript an analysis of the transmission of x-rays through a single monocapillary under the single reflection regime is presented and discussed. Because ray tracing does not allow to explain the experimental data, a first qualitative interpretation of the observed behavior is given in the framework of the wave theory

Medidas socioeducativas em meio aberto em Guaíba: entre pressupostos e significados

OpenAIRE

Jacques, Luciana Gomes de Lima

2015-01-01

No presente estudo, do tipo descritivo e exploratório, de natureza qualitativa, fundamentado no método dialético-crítico, discorre-se sobre os aspectos de proximidade e de distanciamento entre os pressupostos da socioeducação no Sistema Único de Assistência Social (SUAS) e no Sistema Nacional Socioeducativo (SINASE), e analisam-se os significados atribuídos às Medidas Socioeducativas em Meio Aberto (MSE-MA) pelos sujeitos que a protagonizam e/ou que participaram de seu processo de municipaliz...

A novel solution to the gated x-ray detector gain droop problem

International Nuclear Information System (INIS)

Oertel, J. A.; Archuleta, T. N.

2014-01-01

Microchannel plate (MCP), microstrip transmission line based, gated x-ray detectors used at the premier ICF laser facilities have a drop in gain as a function of mircostrip length that can be greater than 50% over 40 mm. These losses are due to ohmic losses in a microstrip coating that is less than the optimum electrical skin depth. The electrical skin depth for a copper transmission line at 3 GHz is 1.2 μm while the standard microstrip coating thickness is roughly half a single skin depth. Simply increasing the copper coating thickness would begin filling the MCP pores and limit the number of secondary electrons created in the MCP. The current coating thickness represents a compromise between gain and ohmic loss. We suggest a novel solution to the loss problem by overcoating the copper transmission line with five electrical skin depths (∼6 μm) of Beryllium. Beryllium is reasonably transparent to x-rays above 800 eV and would improve the carrier current on the transmission line. The net result should be an optically flat photocathode response with almost no measurable loss in voltage along the transmission line

A new Scanning Transmission X-ray Microscope at the ALS for operation up to 2500eV

International Nuclear Information System (INIS)

Kilcoyne, David; Ade, Harald; Attwood, David; Hitchcock, Adam; McKean, Pat; Mitchell, Gary; Monteiro, Paulo; Tyliszczak, Tolek; Warwick, Tony

2010-01-01

We report on the design and construction of a higher energy Scanning Transmission X-ray Microscope on a new bend magnet beam line at the Advanced Light Source. Previously we have operated such an instrument on a bend magnet for C, N and O 1s NEXAFS spectroscopy. The new instrument will have similar performance at higher energies up to and including the S 1s edge at 2472eV. A new microscope configuration is planned. A more open geometry will allow a fluorescence detector to count emitted photons from the front surface of the sample. There will be a capability for zone plate scanning in addition to the more conventional sample scanning mode. This will add the capability for imaging a massive sample at high resolution over a limited field of view, so that heavy reaction cells may be used to study processes in-situ, exploiting the longer photon attenuation length and the longer zone plate working distances available at higher photon energy. The energy range will extend down to include the C1s edge at 300eV, to allow high energy NEXAFS microscopic studies to correlate with the imaging of organics in the same sample region of interest.

Self-compensating x-ray or γ-ray thickness gauge

International Nuclear Information System (INIS)

Allport, J.J.

1977-01-01

A gauge is described for determining the mass per unit area, or alternatively the thickness of sheet material by measuring the attenuation, as well as backscatter, of an x-ray beam or the like, while continuously taking into account deviations and changes in localized material composition, insofar as these have an effect on the transmission coefficient of the beam. Electrical signals representing these deviations are combined with calibration data for given material nominal properties, i.e., nominal composition. The resultant and output signal represents the mass per unit area or thickness

Microstructural changes in CdSe-coated ZnO nanowires evaluated by in situ annealing in transmission electron microscopy and x-ray diffraction

International Nuclear Information System (INIS)

Majidi, Hasti; Baxter, Jason B; Winkler, Christopher R; Taheri, Mitra L

2012-01-01

We report on the crystallite growth and phase change of electrodeposited CdSe coatings on ZnO nanowires during annealing. Both in situ transmission electron microscopy (TEM) and x-ray diffraction (XRD) reveal that the nanocrystal size increases from ∼3 to ∼10 nm upon annealing at 350 °C for 1 h and then to more than 30 nm during another 1 h at 400 °C, exhibiting two distinct growth regimes. Nanocrystal growth occurs together with a structural change from zinc blende to wurtzite. The structural transition begins at 350 °C, which results in the formation of stacking faults. Increased crystallite size, comparable to the coating thickness, can improve charge separation in extremely thin absorber solar cells. We demonstrate a nearly two-fold improvement in power conversion efficiency upon annealing. (paper)

Microstructural changes in CdSe-coated ZnO nanowires evaluated by in situ annealing in transmission electron microscopy and x-ray diffraction

Science.gov (United States)

Majidi, Hasti; Winkler, Christopher R.; Taheri, Mitra L.; Baxter, Jason B.

2012-07-01

We report on the crystallite growth and phase change of electrodeposited CdSe coatings on ZnO nanowires during annealing. Both in situ transmission electron microscopy (TEM) and x-ray diffraction (XRD) reveal that the nanocrystal size increases from ˜3 to ˜10 nm upon annealing at 350 °C for 1 h and then to more than 30 nm during another 1 h at 400 °C, exhibiting two distinct growth regimes. Nanocrystal growth occurs together with a structural change from zinc blende to wurtzite. The structural transition begins at 350 °C, which results in the formation of stacking faults. Increased crystallite size, comparable to the coating thickness, can improve charge separation in extremely thin absorber solar cells. We demonstrate a nearly two-fold improvement in power conversion efficiency upon annealing.

Habilidades auditivas e medidas da imitância acústica em crianças de 4 a 6 anos de idade

OpenAIRE

Toscano,Rafaela Della Giacoma Prado; Anastasio,Adriana Ribeiro Tavares

2012-01-01

OBJETIVO: avaliar o desempenho em habilidades auditivas e as condições de orelha média de crianças de 4 a 6 anos de idade. MÉTODO: foram aplicados os testes de detecção sonora (audiômetro pediátrico em 20dBNA), a Avaliação Simplificada do Processamento Auditivo (ASPA) e as medidas de imitância acústica (handtymp com tom de 226Hz) em 61 crianças com média de idade de 5,65 anos. Para comparar os resultados das provas de habilidades auditivas e das medidas da imitância acústica foi aplicado o te...

Medida de Segurança: a violação do direito à saúde a partir do conceito de periculosidade

OpenAIRE

Valéria Rondon Rossi

2015-01-01

A relação dos fenômenos da loucura e criminalidade foi um ponto estratégico para a constituição da medicina mental – psiquiatria e para a constituição de instituições de controle, punição e regeneração. No Brasil, a resposta penal aos crimes dos loucos infratores é a medida de segurança, instituto que se anuncia como despenalizante e voltado ao tratamento em saúde. No entanto, vigora o sistema da periculosidade como parâmetro para imposição e suspensão da medida de segurança, o que faz com qu...

Los riesgos de la tecnología. Medidas tecnológicas de protección: el caso de los DVD

Directory of Open Access Journals (Sweden)

Jhonny Antonio Pabón Cadavid

2008-11-01

Full Text Available Conceptos como el de sociedad red y sociedad del riesgo revelan una serie de transformaciones que están sucediendo a nivel social, político, económico, cultural y jurídico. Las medidas tecnológicas de protección de los contenidos protegidos por el derecho de autor y la tutela legal que se les ha otorgado son un icono de las problemáticas del derecho en este nuevo escenario de la sociedad red y sociedad del riesgo. Se estudia en el presente artículo siete procesos relacionados con las mtp y los dvd-Video; jurisprudencias de Estados Unidos, Francia, Noruega y Finlandia, que nos permiten observar las múltiples implicaciones relacionadas de este tema con derecho del consumo, derecho de la competencia, libertad de expresión, acceso a la cultura, secretos comerciales, relaciones contractuales y propiedad intelectual. La jurisprudencia y el desarrollo del mercado de las medidas tecnológicas de protección demuestran que existe un desequilibrio entre los riesgos que intentan contener, los cuales son de interés exclusivo de la industria tecnológica y de contenidos, y los riesgos que la implementación de estas medidas producen en intereses colectivos, como la eficiencia del mercado y la innovación.

Understanding X-ray cargo imaging

International Nuclear Information System (INIS)

Chen Gongyin

2005-01-01

Cargo imaging is the field of imaging large objects, usually cargo containers, trains, trucks or boats. Transmission imaging with photons, especially X-rays of up to 9 MV is the dominant current technique, providing compelling details of the contents of objects this large. This paper discusses the physics aspects of a good X-ray cargo imaging system. The basic performance requirements, such as penetration, contrast and resolution and the components of a cargo imaging system are introduced. The imaging process is divided in this paper into three stages: forming information (probing the object), recording information and presenting information (image display). Their impact on performance is analyzed

O perfil dos adolescentes que cumprem medida socioeducativa de prestação de serviços à comunidade em Maringá - PR

Directory of Open Access Journals (Sweden)

José Lopes Silva

2011-07-01

Full Text Available Este artigo resulta da pesquisa sobre adolescentes em conflito com a lei e o cumprimento da medida sócio educativa de Prestação de Serviços a Comunidade no município de Maringá – PR. Trata-se de uma pesquisa documental qualitativa, cujo objetivo foi o de construir uma breve reflexão sobre a a infância e juventude para compreensão do envolvimento do adolescente em atos infracionais. A pesquisa foi realizada no Centro de Referência Sócio Educativo - CRSE, órgão executor das medidas sócio educativas de Prestação de Serviços a Comunidade e Liberdade Assistida, no município de Maringá- PR. A pesquisa ocorreu em duas etapas: a revisão de literatura sobre os temas criança e adolescente e adolescente em conflito com a lei. A segunda ocorreu por meio da consulta ao banco de dados do CRSE; do registro dos prontuários dos adolescentes que cumprem a referida medida, bem como os instrumentos utilizados pelos profissionais do CRSE nos atendimentos realizados. A pesquisa foi desenvolvida no período de julho a novembro de 2010. Foi possível identificar o perfil do adolescente em cumprimento de medida sócio educativa de PSC no CRSE. Esta identificação nos deu a dimensão da situação econômica e social do adolescente e família atendidos pela equipe do programa.

Estudo comparativo das medidas manual e digital da fenda palpebral A comparative study of the manual and digital measurements of the palpebral fissure

Directory of Open Access Journals (Sweden)

Tânia Pereira Nunes

2005-12-01

Full Text Available OBJETIVO: Comparar a medida manual do comprimento vertical da fenda palpebral e sua medida obtida por meio de processamento computadorizado de imagens de indivíduos sem alterações palpebrais. MÉTODOS: Foram analisadas 102 fendas palpebrais de 51 indivíduos normais. A faixa etária variou entre 17 e 84 anos, sendo 25 (49% do sexo masculino e 26 (51% do sexo feminino. RESULTADOS: Não houve diferença estatisticamente significativa entre as medidas manuais da fenda palpebral e as obtidas por meio de processamento computadorizado de imagens. Também não se observou diferença entre ambos os sexos e a faixa etária. CONCLUSÕES: Os resultados obtidos com estes dois métodos podem ser comparados entre si devida à equivalência estatística das medidas.PURPOSE: To compare the measurement of the palpebral fissure done either manually and by computer analysis of image of individuals without lid alterations. METHODS: One hundred two palpebral fissures from 51 normal subjects have been analyzed. The patients' age ranged from 17 to 84 years, with 25 (49% males and 26 (51% females. RESULTS: There was no statistically significant difference between the measurements done either manually or by computer analysis of images, neither, when we grouped the patients by sex or age. Also we did not observe difference between males and females, and regarding age. CONCLUSIONS: The results obtained by both methods are comparable and reliable due to the statistical equivalence of the obtained measurements.

X-ray technique and technology development trends

International Nuclear Information System (INIS)

Vlasov, P.V.; Chikirdin, Eh.G.

1994-01-01

Application of new types of x-ray devices for diagnosis of diseases was described. Modern roentgenological devices (Rentgen-60) were supplied by remote handling unit with the help of roentgen television. Roentgen television is based on transmission of image from the output of the screen of amplifier of x-ray image on the input of transmitting television camera. Scanning of input image accurred inside the camera, analog videosignal was amplified and reproduced on the display. The prospects of development of such roentgen equipment was emphasized

Transmission imaging with a coded source

International Nuclear Information System (INIS)

Stoner, W.W.; Sage, J.P.; Braun, M.; Wilson, D.T.; Barrett, H.H.

1976-01-01

The conventional approach to transmission imaging is to use a rotating anode x-ray tube, which provides the small, brilliant x-ray source needed to cast sharp images of acceptable intensity. Stationary anode sources, although inherently less brilliant, are more compatible with the use of large area anodes, and so they can be made more powerful than rotating anode sources. Spatial modulation of the source distribution provides a way to introduce detailed structure in the transmission images cast by large area sources, and this permits the recovery of high resolution images, in spite of the source diameter. The spatial modulation is deliberately chosen to optimize recovery of image structure; the modulation pattern is therefore called a ''code.'' A variety of codes may be used; the essential mathematical property is that the code possess a sharply peaked autocorrelation function, because this property permits the decoding of the raw image cast by th coded source. Random point arrays, non-redundant point arrays, and the Fresnel zone pattern are examples of suitable codes. This paper is restricted to the case of the Fresnel zone pattern code, which has the unique additional property of generating raw images analogous to Fresnel holograms. Because the spatial frequency of these raw images are extremely coarse compared with actual holograms, a photoreduction step onto a holographic plate is necessary before the decoded image may be displayed with the aid of coherent illumination

Biological effect of ultrasoft x-ray, 1

International Nuclear Information System (INIS)

Narita, Noboru

1985-01-01

Biological effect on Escherichia coli by ultrasoft X-ray have been studied by comparing with that by uv light (2537 A) and by soft X-ray (40 kVp, 5 mA). Ultrasoft X-ray is aluminium characteristic X-ray (about 1.5 keV) produced by low energy electron collision on aluminium foil target and is obtained from Lea-type transmission target discharge tube. Escherichia coli used here are AB1157, AB1886 (uvrA6), JC1569 (recA), AB2470 (recB) and AB2480 (uvr rec) for inactivation experiment and WP2, WP2uvrA, WP2pKM101 and WP2uvrApKM101 for mutation induction experiment. These strains are all irradiated in buffer. Results obtained are summerized as follows : (i) inactivation by ultrasoft X-ray is located between ones by uv light and by soft X-ray, or ultrasoft X-ray gives a lethal damage that uvrA6 gene seems to contribute, and (ii) ultrasoft X-ray does not show the remarkable mutation induction like that induced by low dose irradiation of uv light or soft X-ray. (author)

ARTEAM - Advanced ray tracing with earth atmospheric models

NARCIS (Netherlands)

Kunz, G.J.; Moerman, M.M.; Eijk, A.M.J. van

2002-01-01

The Advanced Ray Tracing with Earth Atmospheric Models (ARTEAM) aims at a description of the electro-optical propagation environment in the marine atmospheric surface layer. For given meteorological conditions, the model evaluates height- and range-resolved transmission losses, refraction and

Medidas que puede tomar para prevenir el cáncer (Steps You Can Take to Prevent Cancer)

Centers for Disease Control (CDC) Podcasts

2012-02-02

Este podcast habla de las principales medidas que las personas pueden tomar para reducir su riesgo de contraer cáncer.  Created: 2/2/2012 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 3/13/2012.

Simulation and application of micro X-ray fluorescence based on an ellipsoidal capillary

Science.gov (United States)

Yang, Jing; Li, Yude; Wang, Xingyi; Zhang, Xiaoyun; Lin, Xiaoyan

2017-06-01

A micro X-ray fluorescence setup was presented, based on an ellipsoidal capillary and a traditional laboratorial X-ray source. Using Ray-tracing principle, we have simulated the transmission path of X-ray beam in the ellipsoidal capillary and designed the optimal parameters of the ellipsoidal capillary for the micro X-ray fluorescence setup. We demonstrate that ellipsoidal capillary is well suited as condenser for the micro X-ray fluorescence based on traditional laboratorial X-ray source. Furthermore, we obtain the 2D mapping image of the leaf blade sample by using the ellipsoidal capillary we designed.

GRITO DE SOCORRO: TENHO MEDO DE MORRER - A VIOLÊNCIA DOMÉSTICA E O USO DA MEDIDA PROTETIVA

Directory of Open Access Journals (Sweden)

Elizangêla Silva Paiva

2018-03-01

Full Text Available O presente artigo trata-se da Lei 11.340/06, mais conhecida como Lei Maria da Penha. Tem-se o objetivo de demonstrar a importância da lei citada. Para a realização de tal estudo, foram analisadas obras bibliográficas. Apresentando conceitos trazidos por Dias (2007, Mirabetti (2000, Souza (2009, entre outros; busca-se desenvolver o entendimento sobre as formas de violência dos casos onde a referida lei poderá ser aplicada. Seguindo esta linha de raciocínio, apresentam-se as soluções sustentadas pela lei Maria da Penha, analisando-se o contexto do caso concreto para aplicar-se uma medida eficaz. Ao estudarem-se estas medidas, nota-se a existência de vários casos aos quais não se verifica a eficácia da sansão imposta; neste diapasão, tem-se um breve estudo apresentando as principais causas que podem justificar a origem desta questão.

Observation of dislocations in crystals using X-ray and electron transmission

International Nuclear Information System (INIS)

Morlevat, J.P.

1965-10-01

Two approaches of the dynamical theory of diffraction (EWALD's and AUTHIER's) are recalled briefly. In the light of these theories, one then considers what information concerning the dislocations existing in a crystal can be obtained by X-Ray as well as electron diffraction. (author) [fr

A generalized transmission method for gamma-efficiency determinations in soil samples

International Nuclear Information System (INIS)

Bolivar, J.P.; Garcia-Tenorio, R.; Garcia-Leon, M.

1994-01-01

In this paper, a generalization of the γ-ray transmission method which is useful for measurements on soil samples, for example, is presented. The correction factor, f, is given, which is a function of the apparent density of the soil and the γ-ray energy. With this method, the need for individual determinations of f, for each energy and apparent soil density is avoided. Although the method has been developed for soils, the general philosophy can be applied to other sample matrices, such as water or vegetables for example. (author)

Development of a segmented gamma ray scanning system

International Nuclear Information System (INIS)

Zhu Rongbao; Tan Yajun; Yuan Xiaoxin

1994-01-01

A segmented gamma ray scanning system is developed for the purposes of non-destructive assay of the contents of uranium, plutonium or fission products existing in packed low density or medium density nuclear residuals, scrapes or wastes. The near field three-dimensional model for computing CF(AT) is used for cylindrical sample and container, the system developed consists of a transmission source wheel, a rotatable scanning plate, a beam shutter, and annular shielding body, stepping motors and control system, HPGe detector, nuclear electronics and computer. The full scale scanning of samples, spectrum accumulation and data reduction could be fulfilled automatically according to preset standard procedures. The radioisotopes of 169 Yb and 75 Se and used as the transmission sources for assaying 235 U and potential 239 Pu respectively. The calibration experiments using 1 liter solution sample of 192 Ir and 235 U is performed. The standard deviations were obtained for 192 Ir γ rays of 295 keV, 308 keV and 316 keV are +- 0.41%, +- 0.29% and +-0.42% respectively. The standard divination for 235 U 185 keV γ ray is +- 0.62%

Determination of ash content of coal by mass absorption coefficient measurements at two X-ray energies

International Nuclear Information System (INIS)

Fookes, R.A.; Gravitis, V.L.; Watt, J.S.

1977-01-01

A method for determining the ash content of coal is proposed. It involves measurements proportional to mass absorption coefficients of coal at two X-ray energies. These measurements can be made using X-ray transmission or scatter techniques. Calculations based on transmission of narrow beams of X-rays have shown that ash can be determined to about 1wt%(1 sigma) in coal of widely varying ash content and composition. Experimentally, ash content was determined to 0.67wt% by transmission techniques and 1.0wt% by backscatter techniques in coal samples from the Bulli seam, NSW, Australia, having ash in the range 11-34wt%. For samples with a much wider range of coal composition (7-53wt% ash and 0-25wt% iron in the ash), ash content was determined by backscatter measurements to 1.62wt%. The method produced ash determinations at least as accurate as those produced by the established technique which compensates for variation in iron content of the ash by X-ray fluorescence analysis for iron. Compared with the established technique, it has the advantage of averaging analysis over much larger volumes of coal, but the disadvantage that much more precise measurements of X-ray intensities are required. (author)

El tecnoestrés: un estudio del desarrollo de diferentes instrumentos de medida

OpenAIRE

Ventura, Mercedes; Llorens Gumbau, Susana; Salanova Soria, Marisa

2005-01-01

Onzenes Jornades de Foment de la Investigació de la FCHS (Any 2005-2006) El uso de las Tecnologías de la Información y la Comunicación (TICs) como herramienta de trabajo está teniendo un gran impacto en el mundo laboral. A pesar de que en si misma la tecnología es ‘neutra’ también puede generar consecuencias negativas en los usuarios de TIC quienes pueden sufrir el llamado ‘tecnoestrés’. El concepto y por tanto, la medida de este fenómeno han sufrido diferentes variaciones a lo la...

Elemental mapping in scanning transmission electron microscopy

International Nuclear Information System (INIS)

Allen, L J; D'Alfonso, A J; Lugg, N R; Findlay, S D; LeBeau, J M; Stemmer, S

2010-01-01

We discuss atomic resolution chemical mapping in scanning transmission electron microscopy (STEM) based on core-loss electron energy loss spectroscopy (EELS) and also on energy dispersive X-ray (EDX) imaging. Chemical mapping using EELS can yield counterintuitive results which, however, can be understood using first principles calculations. Experimental chemical maps based on EDX bear out the thesis that such maps are always likely to be directly interpretable. This can be explained in terms of the local nature of the effective optical potential for ionization under those imaging conditions. This is followed by an excursion into the complementary technique of elemental mapping using energy-filtered transmission electron microscopy (EFTEM) in a conventional transmission electron microscope. We will then consider the widely used technique of Z-contrast or high-angle annular dark field (HAADF) imaging, which is based on phonon excitation, where it has recently been shown that intensity variations can be placed on an absolute scale by normalizing the measured intensities to the incident beam. Results, showing excellent agreement between theory and experiment to within a few percent, are shown for Z-contrast imaging from a sample of PbWO 4 .

Transmissão vertical do HIV: situação encontrada em uma maternidade de Teresina Transmisión vertical del HIV: situación encontrada en una maternidade de Teresina Vertical transmission of HIV: situation found in a maternity of Teresina

Directory of Open Access Journals (Sweden)

Liliam Mendes de Araújo

2007-08-01

Full Text Available Oaumento dos casos de AIDS em mulheres evidencia um progressivo aumento da transmissão vertical do HIV, no Brasil e no Piauí. Considerando a relevância do tema o presente estudo teve como objetivo analisar as condições da implementação das normas e medidas recomendadas pelo Ministério da Saúde para prevenir a transmissão vertical do HIV em uma maternidade de Teresina - PI. O caminho teórico-metodológico compreendeu o estudo da dinâmica organizacional e dos seus atores, por meio de abordagem qualitativa. Para obtenção dos dados foram realizadas 17 entrevistas semi-estruturadas. Os resultados mostraram que as recomendações do Ministério da Saúde não foram atendidas na sua totalidade evidenciando a precariedade da assistência prestada para o binômio mãe/filho.El aumento de los casos de AIDS en mujeres, evidencia un progresivo aumento de la transmisión vertical de lo HIV en el Brasil, e en el Piauí. Considerando la relevancia del tema, el presente estudio tuve como objetivo analizar las condiciones de la implementación de las reglas y medidas recomendadas por el Ministerio de la Salud para prevenir la transmisión vertical del HIV en una maternidad de Teresina-PI. El camino teórico-metodológico comprendió el estudio de la dinámica organizacional y de sus actores, a través del abordaje cualitativa.. Para la obtención de los datos fueran realizados 17 entrevistas medio-estructuradas. Los resultados mostraran que las recomendaciones del Ministerio de la Salud non fueran atendidas en la suya totalidad, evidenciando la precariedad de la asistencia prestada, para el binomio madre / hijo.The increase of the number of cases of AIDS among women reveals a progressive increase of the vertical transmission of HIV in Brazil, as well as in Piauí. Considering the relevance of the subject, this study had as objective to analyze the conditions of the implementation of the rules and measures recommended by the Ministry of Health to

X-ray spectromicroscopy studies of protein-polymer Interactions

International Nuclear Information System (INIS)

Hitchcock, A.P.; Tyliszczak, T.; Heng, Y.M.; Cornelius, R.; Brash, J.L.; Ade, H.; Anders, S.; Scholl, A.; Nolting, F.

2000-01-01

Identification of the sites of protein binding on laterally heterogeneous polymer surfaces can help understand mechanisms of bio-passivation, which in turn has practical impact on developing improved polymers for medical uses, such as blood contact applications. We have used scanning X-ray transmission microscopy and photoelectron emission microscopy to explore the sensitivity of these X-ray microscopies to detection of human serum albumin adsorbed onto the surface of two different polyurethane polymers. Both techniques appear capable of the requisite monolayer sensitivity

X-ray tube transformer

International Nuclear Information System (INIS)

1980-01-01

An X-ray generator is described which comprises a transmission line transformer including an electrical conductor with a cavity and a second electrical conductor including helical windings disposed along a longitudinal axis within the cavity of the first conductor. The windings have a pitch which varies per unit length along the axis. There is dielectric material in the cavity for insulation and to couple electromagnetically the two conductors in response to an electric current flowing through the conductors, which have an impedance between them; this varies with distance along the axis of the helix of the second conductor. An X-ray tube is disposed along the longitudinal axis within the cavity, for radiating X-rays. The invention increases the voltage of applied voltage pulses at the remote tube-head with a transformer formed by using a spiral delay line geometry to give a tapered-impedance coaxial high voltage multiplier for pulse voltage operation. This transformer is smaller and lighter than previous designs for the same high peak voltage and power ratings. This is important because the penetration capabilities of Flash X-ray equipment increase with voltage, particularly in heavy materials such as steel. (U.K.)

3D non-destructive fluorescent X-ray computed tomography (FXCT) with a CdTe array

Energy Technology Data Exchange (ETDEWEB)

Yoon, Chang Yeon; Lee, Won Ho; Kim, Young Hak [Dept. of Bio-convergence Engineering, Korea University Graduate School, Seoul (Korea, Republic of)

2015-10-15

In our research, the material was exposed to an X-ray and not only the conventional transmission image but also 3D images based on the information of characteristic X-ray detected by a 2D CdTe planar detector array were reconstructed. Since atoms have their own characteristic X-ray energy, our system was able to discriminate materials of even a same density if the materials were composed of different atomic numbers. We applied FXCT to distinguish various unknown materials with similar densities. The materials with similar densities were clearly distinguished in the 3D reconstructed images based on the information of the detected characteristic X-ray, while they were not discriminated from each other in the images based on the information of the detected transmission X-ray. In the fused images consisting of 3D transmitted and characteristic X-ray images, all of the positions, densities and atomic numbers of materials enclosed in plastic phantom or pipe were clearly identified by analyzing energy, position and amount of detected radiation.

Parameters and design considerations for tomographic transmission scanners

International Nuclear Information System (INIS)

Pentlow, K.S.; Beattie, J.W.; Laughlin, J.S.

1976-01-01

The design of transverse axial transmission scanners for reconstruction tomography involves many interrelated parameters and conflicting requirements. We have investigated some of those parameters and their interactions and, where appropriate, attempted to optimize them. It is convenient to group the considerations under four headings: (1) Geometrical factors (basic configurations, rectilinear and fan geometry, moving detectors or static arrays, spatial response variations and field uniformity, and collimation); (2) Radiation energy and sources (Considerations here include transmission versus sensitivity, detector efficiency, collimator penetration, scattered radiation, patient dose, monochromatic versus polychromatic radiation and X-ray tubes versus radionuclide sources); (3) Detection systems (types of detector, detection modes and the rejection of scatter); and (4) Reconstruction mathematics and quantum noise. As a result of such considerations we have proposed a particular design which should have advantages in certain applications

The influence of x-ray energy on lung dose uniformity in total-body irradiation

International Nuclear Information System (INIS)

Ekstrand, Kenneth; Greven, Kathryn; Wu Qingrong

1997-01-01

Purpose: In this study we examine the influence of x-ray energy on the uniformity of the dose within the lung in total-body irradiation treatments in which partial transmission blocks are used to control the lung dose. Methods and Materials: A solid water phantom with a cork insert to simulate a lung was irradiated by x-rays with energies of either 6, 10, or 18 MV. The source to phantom distance was 3.9 meters. The cork insert was either 10 cm wide or 6 cm wide. Partial transmission blocks with transmission factors of 50% were placed anterior to the cork insert. The blocks were either 8 or 4 cm in width. Kodak XV-2 film was placed in the midline of the phantom to record the dose. Midplane dose profiles were measured with a densitometer. Results: For the 10 cm wide cork insert the uniformity of the dose over 80% of the block width varied from 6.6% for the 6 MV x-rays to 12.2% for the 18 MV x-rays. For the 6 cm wide cork insert the uniformity was comparable for all three x-ray energies, but for 18 MV the central dose increased by 9.4% compared to the 10 cm wide insert. Conclusion: Many factors must be considered in optimizing the dose for total-body irradiation. This study suggests that for AP/PA techniques lung dose uniformity is superior with 6 MV irradiation. The blanket recommendation that the highest x-ray energy be used in TBI is not valid for all situations

Induced magnetic anisotropy in Si-free nanocrystalline soft magnetic materials: A transmission x-ray diffraction study

Energy Technology Data Exchange (ETDEWEB)

Parsons, R., E-mail: rparsons01@gmail.com; Suzuki, K. [Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800 (Australia); Yanai, T. [Graduate School of Engineering, Nagasaki University, Nagasaki 852-8521 (Japan); Kishimoto, H.; Kato, A. [Toyota Motor Corporation, Mishuku, Susono, Shizuoka 410-1193 (Japan); Ohnuma, M. [Faculty and Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

2015-05-07

In order to better understand the origin of field-induced anisotropy (K{sub u}) in Si-free nanocrystalline soft magnetic alloys, the lattice spacing of the bcc-Fe phase in nanocrystalline Fe{sub 94−x}Nb{sub 6}B{sub x} (x = 10, 12, 14) alloys annealed under an applied magnetic field has been investigated by X-ray diffraction in transmission geometry (t-XRD) with the diffraction vector parallel and perpendicular to the field direction. The saturation magnetostriction (λ{sub s}) of nanocrystalline Fe{sub 94−x}Nb{sub 6}B{sub x} was found to increase linearly with the volume fraction of the residual amorphous phase and is well described by taking into account the volume-weighted average of two local λ{sub s} values for the bcc-Fe nanocrystallites (−5 ± 2 ppm) and the residual amorphous matrix (+8 ± 2 ppm). The lattice distortion required to produce the measured K{sub u} values (∼100 J/m{sup 3}) was estimated via the inverse magnetostrictive effect using the measured λ{sub s} values and was compared to the lattice spacing estimations made by t-XRD. The lattice strain required to produce K{sub u} under the magnetoelastic model was not observed by the t-XRD experiments and so the findings of this study suggest that the origin of magnetic field induced K{sub u} cannot be explained through the magnetoelastic effect.

A new high-speed X-ray beam chopper

International Nuclear Information System (INIS)

McPherson, A.; Wang, J.; Lee, P. L.; Mills, D. M.

1999-01-01

A new high-speed x-ray beam chopper using laser scanner technology has been developed and tested on the SRI-CAT sector 1 beamline at the Advanced Photon Source (APS) storage ring (1). As illustrated in figure 1, it is compact in size and has two sets of transmission windows: BK-7 glass for visible light transmission and 0.23-mm-thick Be for the transmission of x-rays. The rotor is made of aluminum and has a diameter of 50.8 mm. A 0.5-mm-wide and 2.29-mm-tall slit is cut through the center of the rotor. The circumference of the rotor has a coating of 1-mm-thick Ni, which gives an attenuation of 10 8 at 30 keV. Turning at nearly 80000 RPM, this beam chopper has an opening time window of 2450 ns, corresponding to 67% of the revolution time of the APS storage ring. The primary feature in selecting laser scanner technology to develop into an x-ray beam chopper was the high level of rotational speed control of the rotor that makes up the beam chopper element (2). By using an optical feedback circuit to sample the rotational speed four times each revolution, the jitter in the position of the transmission open time window is only 3 ns at the 3 standard deviation level. The APS storage ring orbital frequency, supplied by the control room, is divided down to provide the appropriate drive frequency for the beam chopper motor controller. By this means, both the storage ring and the beam chopper are operating off the same master clock. After a turn-on time of about 15 to 20 seconds, the rotational precision of the motor results in immediate phase locking to the temporal structure of the APS storage ring. By inserting a Stanford delay generator between the frequency divider and the beam chopper motor controller, the phase between the storage ring temporal structure and the beam chopper rotation can be adjusted to position the transmission time window of the beam chopper on any desired part of the storage ring fill pattern. If an asymmetric fill pattern is used in the APS storage

Through-transmission laser welding of glass fibre composite: Experimental light scattering identification

Science.gov (United States)

Cosson, Benoit; Asséko, André Chateau Akué; Dauphin, Myriam

2018-05-01

The purpose of this paper is to develop a cost-effective, efficient and quick to implement experimental optical method in order to predict the optical properties (extinction coefficient) of semi-transparent polymer composites. The extinction coefficient takes into account the effects due to the absorption and the scattering phenomena in a semi-transparent component during the laser processes, i.e. TTLW (through-transmission laser welding). The present method used a laser as light source and a reflex camera equipped with a macro lens as a measurement device and is based on the light transmission measurement through different thickness samples. The interaction between the incident laser beam and the semi-transparent composite is exanimated. The results are presented for the case of a semi-transparent composite reinforced with the unidirectional glass fiber (UD). A numerical method, ray tracing, is used to validate the experimental results. The ray tracing method is appropriate to characterize the light-scattering phenomenon in semi-transparent materials.

Discovery of x-rays and its impact on the development of physics

International Nuclear Information System (INIS)

Sirdeshmukh, D.B.

1996-01-01

Roentgen's discovery of x-rays is discussed. Roentgen's discovery was important not only for the property of transmission of x-rays, which immediately resulted in the new field of radiology, but also because it led to several experiments which had a great impact on the development of physics. Laue's discovery of x-ray diffraction in turn led to the development of x-ray crystallography and x-ray spectroscopy. The contributions of Barkla, Moseley and Siegbahn are discussed. The experiments of Duane and Hunt on continuous x-rays and Compton on scattering of x-rays lent support to the photon nature of radiation. In recent times, the line-widths of x-ray emission lines have given information about the band structure of solids. (author). 21 refs., 6 figs

Medidas compensatórias aplicáveis à questão da poluição hídrica de origem agrícola

OpenAIRE

Martini, Luiz Carlos Pittol

2000-01-01

Tese (doutorado) - Universidade Federal do Rio Grande do Sul, Instituto de Pesquisas Hidráulicas. Em uma estrutura de gestão que privilegia aspectos econômicos, avalia-se o uso de medidas compensatórias como alternativa para proteção das águas no meio rural. Essas medidas visam compensar os agricultores pelas perdas econômicas decorrentes de mudanças no sistema de produção quando se busca proteção dos mananciais hídricos. Como exemplo de caso, simula-se a aplicação das compensações na baci...

Structure and dynamics in liquid water from x-ray absorption spectroscopy

International Nuclear Information System (INIS)

Wernet, Philippe

2009-01-01

Oxygen K-edge x-ray absorption spectra of water are discussed. The spectra of gas-phase water, liquid water and ice illustrate the sensitivity of oxygen K-edge x-ray absorption spectroscopy to hydrogen bonding in water. Transmission mode spectra of amorphous and crystalline ice are compared to x-ray Raman spectra of ice. The good agreement consolidates the experimental spectrum of crystalline ice and represents an incentive for theoretical calculations of the oxygen K-edge absorption spectrum of crystalline ice. Time-resolved infrared-pump and x-ray absorption probe results are finally discussed in the light of this structural interpretation.

La educación tributaria como medida para incrementar la recaudación fiscal

OpenAIRE

Tapia, Monica; Gaona, Wilmer; Tumbaco, Pedro

2009-01-01

La presente tesis está basada en el análisis de la La Educación Tributaria como Medida para Incrementar la Recaudación Fiscal en Ecuador; la importancia de este tema es incrementar la base de contribuyentes, aumentando la Recaudación Fiscal que ayudará a desarrollar planes de inversión y una estabilidad tributaria. Dentro de este estudio es necesario un análisis completo de naturaleza teórica, donde se examinaría la actividad financiera del Estado, la importancia en lo económico, ...

Present status of research and development on X-ray microprobe

International Nuclear Information System (INIS)

Koike, Masaki; Suzuki, I.H.

1991-01-01

X-ray beam micro-analysis has advanced rapidly in these years in conjunction with the development of powerful X-ray sources. Among a variety of methods being attempted, the method using a collimated narrow beam has been important because of high brightness, and of usability in both regions of soft and hard X-rays. In the soft X-ray region, the focused beam is formed by a fresnel zone plate or a Schwaltzschild mirror assembly, and can be used for scanning transmission microscope or scanning photoelectron microscope. In the hard X-ray region, the beam is formed by grazing incidence mirrors, and can be used for X-ray fluorescence micro-analysis for obtaining elemental mapping. In this report, the recent progress on the soft X-ray scanning microscopy and the X-ray microprobe has been surveyed, together with the improvement on the related optical elements. (author) 84 refs

Stochastic Modeling of Direct Radiation Transmission in Particle-Laden Turbulent Flows

Science.gov (United States)

Banko, Andrew; Villafane, Laura; Kim, Ji Hoon; Esmaily Moghadam, Mahdi; Eaton, John K.

2017-11-01

Direct radiation transmission in turbulent flows laden with heavy particles plays a fundamental role in systems such as clouds, spray combustors, and particle-solar-receivers. Owing to their inertia, the particles preferentially concentrate and the resulting voids and clusters lead to deviations in mean transmission from the classical Beer-Lambert law for exponential extinction. Additionally, the transmission fluctuations can exceed those of Poissonian media by an order of magnitude, which implies a gross misprediction in transmission statistics if the correlations in particle positions are neglected. On the other hand, tracking millions of particles in a turbulence simulation can be prohibitively expensive. This work presents stochastic processes as computationally cheap reduced order models for the instantaneous particle number density field and radiation transmission therein. Results from the stochastic processes are compared to Monte Carlo Ray Tracing (MCRT) simulations using the particle positions obtained from the point-particle DNS of isotropic turbulence at a Taylor Reynolds number of 150. Accurate transmission statistics are predicted with respect to MCRT by matching the mean, variance, and correlation length of DNS number density fields. Funded by the U.S. Department of Energy under Grant No. DE-NA0002373-1 and the National Science Foundation under Grant No. DGE-114747.

An expert system for the conception of industrial gauges based on beta, gamma or X ray transmission (JANU)

International Nuclear Information System (INIS)

Tola, F.

2000-01-01

A knowledge based software (named JANU expert system) for radiogauges design mainly density, thickness, mass per unit area, level and two-phase flows gauges, was prepared recently. Its aim is to optimise the different components of a transmission gauge (radioactive source, detector, electronic device, collimators and shielding), taking into account parameters and constraints linked to the configuration (nature and composition of materials, presence of shields and walls, ...), as well as users requirements (accuracy, counting time, beam collimating, duration of tests, ...). The database includes characteristics of radionuclides and industrial sources, photon cross sections, build-up factors, specific dose constants, physical properties of elements, usual scintillation detectors and shielding materials. It allows the determination of the most suited emitter, as well as a precise characterisation of a given emitter, including required source activity, expected counting rates, dose rates, etc. It has been extended to X rays generators, voltage and current intensity replacing in this case the energy and activity of the source. Information supplied by JANU has been validated by applications developed during the past 30 years. Its choices have always revealed most judicious and in general, numerical results in good agreement with experiments. Thus, it has become an essential and reliable tool for gauge designers. (author)

Smectite flocculation structure modified by Al13 macro-molecules--as revealed by the transmission X-ray microscopy (TXM).

Science.gov (United States)

Zbik, Marek S; Martens, Wayde N; Frost, Ray L; Song, Yen-Fang; Chen, Yi-Ming; Chen, Jian-Hua

2010-05-01

The aggregate structure which occurs in aqueous smectitic suspensions is responsible for poor water clarification, difficulties in sludge dewatering and the unusual rheological behaviour of smectite rich soils. These macroscopic properties are dictated by the 3D structural arrangement of smectite finest fraction within flocculated aggregates. Here, we report results from a relatively new technique, transmission X-ray microscopy (TXM), which makes it possible to investigate the internal structure and 3D tomographic reconstruction of the smectite clay aggregates modified by Al(13) Keggin macro-molecule [Al(13)(O)(4)(OH)(24)(H(2)O)(12)](7+). Three different treatment methods were shown resulted in three different micro-structural environments of the resulting flocculation. In case of smectite sample prepared in Methods 1 and 3 particles fall into the primary minimum where Van der Waals forces act between FF oriented smectite flakes and aggregates become approach irreversible flocculation. In case of sample prepared using Method 2, particles contacting by edges (EE) and edge to face (EF) orientation fell into secondary minimum and weak flocculation resulted in severe gelation and formation of the micelle-like texture in fringe superstructure, which was first time observed in smectite based gel. Copyright 2010 Elsevier Inc. All rights reserved.

El prejuicio racial en Brasil: medidas comparativas O preconceito racial no Brasil: medidas comparativas Racial prejudice in Brazil: comparative measures

Directory of Open Access Journals (Sweden)

Ana Maria Lacerda Teixeira Pires

2010-04-01

Full Text Available El estudio trataba de medir las manifestaciones del prejuicio racial en una muestra de la población brasileña, utilizando las escalas de racismo moderno de McConahay, Hardee y Batts (1981 y la escala de racismo cordial de Turra y Venturi (1995 y Venturi (2003. Se aplicó los cuestionarios a un total de 101 estudiantes de diversas universidades en la región sur de Brasil. Los resultados muestran que las dos escalas difieren entre si respecto a captar las expresiones del prejuicio. Las personas declararon mayor racismo moderno que racismo cordial. También hemos estudiado las variables que influyen en el prejuicio racial declarado por los participantes. La variable género y orientación a la dominancia social son variables que predicen el racismo moderno en la muestra estudiada. Los participantes indicaron, en mayor medida, la manifestación del prejuicio racial de forma encubierta y lo hacen más abiertamente cuando hay la posibilidad del contacto personal y estrecho.O estudo avaliou as manifestações de preconceito racial em uma amostra da população brasileira, usando escalas de racismo moderno de McConahay, Hardee e Batts (1981, escala racismo cordial do Datafolha (1995 e Venturi, G. (2003. Os questionários foram aplicados a um total de 101 estudantes de várias universidades da região sul do Brasil. Os resultados mostram que as duas escalas diferem entre si sobre como capturar as expressões de preconceito. As pessoas relataram mais racismo moderno que racismo cordial. Estudamos também as variáveis que influenciam o preconceito racial declarado pelos participantes. As variáveis gênero e orientação à dominância social são preditores do racismo moderno na amostra estudada. Os participantes indicaram, em maior medida, a manifestação do preconceito racial dissimulado e o fazem mais abertamente quando existe a possibilidade do contato pessoal e estreito.This study measured the manifestations of racial prejudice in a sample of

Demonstration of iron and thorium in autopsy tissues by x-ray microanalysis

International Nuclear Information System (INIS)

Landas, S.; Turner, J.W.; Moore, K.C.; Mitros, F.A.

1984-01-01

We performed x-ray microanalysis of autopsy specimens using a scanning-transmission electron microscopy mode. Tissues were obtained at necropsy from a patient with history of angiography using thorium dioxide and from a patient with hemochromatosis. X-ray microanalysis confirmed the presence of thorium and iron in their respective tissues. Effects of staining reagents were examined

TiO2 Nanoparticles as a Soft X-ray Molecular Probe

Energy Technology Data Exchange (ETDEWEB)

Larabell, Carolyn; Ashcroft, Jared M.; Gu, Weiwei; Zhang, Tierui; Hughes, Steven M.; Hartman, Keith B.; Hofmann, Cristina; Kanaras, Antonios G.; Kilcoyne, David A.; Le Gros, Mark; Yin, Yadong; Alivisatos, A. Paul; Larabell, Carolyn A.

2007-06-30

With the emergence of soft x-ray techniques for imaging cells, there is a pressing need to develop protein localization probes that can be unambiguously identified within the region of x-ray spectrum used for imaging. TiO2 nanocrystal colloids, which have a strong absorption cross-section within the "water-window" region of x-rays, areideally suited as soft x-ray microscopy probes. To demonstrate their efficacy, TiO2-streptavidin nanoconjugates were prepared and subsequently labeled microtubules polymerized from biotinylated tubulin. The microtubules were imaged using scanning transmission x-ray microscopy (STXM), and the TiO2 nanoparticle tags were specifically identified using x-ray absorption near edge spectroscopy (XANES). These experiments demonstrate that TiO2 nanoparticles are potential probes for protein localization analyses using soft x-ray microscopy.

The extraction of gold nanoparticles from oat and wheat biomasses using sodium citrate and cetyltrimethylammonium bromide, studied by x-ray absorption spectroscopy, high-resolution transmission electron microscopy, and UV-visible spectroscopy

International Nuclear Information System (INIS)

Armendariz, Veronica; Parsons, Jason G; Lopez, Martha L; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L; Jose-Yacaman, Miguel

2009-01-01

Gold (Au) nanoparticles can be produced through the interaction of Au(III) ions with oat and wheat biomasses. This paper describes a procedure to recover gold nanoparticles from oat and wheat biomasses using cetyltrimethylammonium bromide or sodium citrate. Extracts were analyzed using UV-visible spectroscopy, high-resolution transmission electron microscopy (HRTEM), and x-ray absorption spectroscopy. The HRTEM data demonstrated that smaller nanoparticles are extracted first, followed by larger nanoparticles. In the fourth extraction, coating of chelating agents is visible on the extracted nanoparticles.

The extraction of gold nanoparticles from oat and wheat biomasses using sodium citrate and cetyltrimethylammonium bromide, studied by x-ray absorption spectroscopy, high-resolution transmission electron microscopy, and UV-visible spectroscopy.

Science.gov (United States)

Armendariz, Veronica; Parsons, Jason G; Lopez, Martha L; Peralta-Videa, Jose R; Jose-Yacaman, Miguel; Gardea-Torresdey, Jorge L

2009-03-11

Gold (Au) nanoparticles can be produced through the interaction of Au(III) ions with oat and wheat biomasses. This paper describes a procedure to recover gold nanoparticles from oat and wheat biomasses using cetyltrimethylammonium bromide or sodium citrate. Extracts were analyzed using UV-visible spectroscopy, high-resolution transmission electron microscopy (HRTEM), and x-ray absorption spectroscopy. The HRTEM data demonstrated that smaller nanoparticles are extracted first, followed by larger nanoparticles. In the fourth extraction, coating of chelating agents is visible on the extracted nanoparticles.

Air slab-correction for Γ-ray attenuation measurements

Science.gov (United States)

Mann, Kulwinder Singh

2017-12-01

Gamma (γ)-ray shielding behaviour (GSB) of a material can be ascertained from its linear attenuation coefficient (μ, cm-1). Narrow-beam transmission geometry is required for μ-measurement. In such measurements, a thin slab of the material has to insert between point-isotropic γ-ray source and detector assembly. The accuracy in measurements requires that sample's optical thickness (OT) remain below 0.5 mean free path (mfp). Sometimes it is very difficult to produce thin slab of sample (absorber), on the other hand for thick absorber, i.e. OT >0.5 mfp, the influence of the air displaced by it cannot be ignored during μ-measurements. Thus, for a thick sample, correction factor has been suggested which compensates the air present in the transmission geometry. The correction factor has been named as an air slab-correction (ASC). Six samples of low-Z engineering materials (cement-black, clay, red-mud, lime-stone, cement-white and plaster-of-paris) have been selected for investigating the effect of ASC on μ-measurements at three γ-ray energies (661.66, 1173.24, 1332.50 keV). The measurements have been made using point-isotropic γ-ray sources (Cs-137 and Co-60), NaI(Tl) detector and multi-channel-analyser coupled with a personal computer. Theoretical values of μ have been computed using a GRIC2-toolkit (standardized computer programme). Elemental compositions of the samples were measured with Wavelength Dispersive X-ray Fluorescence (WDXRF) analyser. Inter-comparison of measured and computed μ-values, suggested that the application of ASC helps in precise μ-measurement for thick samples of low-Z materials. Thus, this hitherto widely ignored ASC factor is recommended to use in similar γ-ray measurements.

Transmission properties of barite mortar using X-ray spectra measured with Cd Te detector

Energy Technology Data Exchange (ETDEWEB)

Santos, J. C.; Mariano, L.; Costa, P. R. [Universidade de Sao Paulo, Instituto de Fisica, Rua do Matao Travessa R. 187, Cidade Universitaria, 05508-090 Sao Paulo (Brazil); Tomal, A., E-mail: josilene@usp.br [Universidade Federal de Goias, Instituto de Fisica, Campus Samambaia, 74001-970 Goiania (Brazil)

2014-08-15

Current methods for calculating X-ray shielding barriers do not take into account spectral distribution of the beam transmitted by the protective material. This consideration is important in dose estimations for radiation workers and general public in diagnostic radiology facilities. The aim of the present study was to estimate barite mortar attenuation curves using X-ray spectra weighted by a workload distribution. These curves were described in units of ambient dose equivalent (H (10)), since it is the radiation quantity adopted by IAEA for dose assessment in medical environment. Attenuation curves were determined using the optimized model for shielding evaluation presented by Costa and Caldas (2002). Workload distribution presented by Simpkin (1996), measured primary spectra and mass attenuation coefficients of barite mortar were used as input data in this model. X-ray beams in diagnostic energy range were generated by an industrial X-ray tube with 3 mm of aluminum additional filtration. Primary experimental spectra were measured by a Cd Te detector and corrected by the response function of detector by means of a stripping procedure. Air kerma measurements were performed using an ionization chamber for normalization purpose of the spectra. The corrected spectra presented good agreement with spectra generated by a semi-empirical model. The variation of the ambient dose equivalent as a function of barite mortar thickness was calculated. Using these data, it was estimated the optimized thickness of protective barrier needed for shielding a particular area in an X-ray imaging facility. The results obtained for primary protective barriers exhibit qualitative agreement with those presented in literature. (Author)

Violencia de género en el ámbito universitario. Medidas para su superación.

Directory of Open Access Journals (Sweden)

Consol Aguilar Ródenas

2009-01-01

Full Text Available Este artículo expone parte de los resultados de la primera investigación sobre violencia de género en las universidades españolas. A partir de la revisión de investigaciones internacionales, mostramos que la violencia de género tiene una presencia importante en las universidades. Posteriormente, identificamos medidas para la prevención y superación de la violencia de género que ya se están desarrollando en algunas de las universidades de más prestigio internacional. Ambos aspectos son el punto de partida para el estudio de la violencia de género en las universidades españolas y para el diseño de medidas que contribuyan a su superación.---------------------------------------------------------------------This article contains some of the results from the first research on gender violence in Spanish universities. Based on a review of international research, we demonstrate that gender violence is prevalent in universities. Subsequently, we identify measures to prevent and overcome gender violence which are already being developed in some of the most prestigious international universities. Both of these aspects are the starting off point to study gender violence in Spanish universities and to design measures which contribute towards overcoming it.

La repetición máxima en el ejercicio de sentadilla: procedimientos de medida y factores determinantes

Directory of Open Access Journals (Sweden)

Inmaculada García Sánchez

2011-06-01

Full Text Available En la actualidad, investigadores y entrenadores utilizan la repetición máxima (1RM en el ejercicio de sentadilla como la medida más identificativa y representativa de la máxima fuerza muscular en el movimiento de extensión de cadera y rodilla. El presente trabajo de revisión tiene el propósito de describir los procedimientos utilizados en investigación para evaluar la 1RM en el ejercicio de sentadilla y analizar los factores determinantes de su rendimiento. Con muestras de sujetos entrenados, en la mayoría de estudios revisados se utilizan protocolos de medida muy similares. Además, la heterogeneidad de los resultados publicados en relación al rendimiento obtenido en la 1RM se debe fundamentalmente a diferencias relacionadas con la edad y sexo de los ejecutantes, la técnica de ejecución del ejercicio de sentadilla y/o el historial de entrenamiento de fuerza de la muestra seleccionada según práctica deportiva.

Futebol libertário: compromisso social na medida

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Fábio Silvestre Silva

Full Text Available Baseados na Constituição de 1988 e no Estatuto da Criança e do Adolescente, de 1990, o Centro de Defesa dos Direitos da Criança e do Adolescente de Interlagos (CEDECA Interlagos traz um relato de experiência de uma metodologia alternativa de acompanhamento de adolescentes inseridos em medidas socioeducativas em meio aberto na região da Capela do Socorro e Parelheiros. Essa proposta utiliza o futebol como meio que possibilita ao adolescente refletir sobre sua realidade e suas práticas cotidianas, reconhecendo suas possibilidades de se desenvolver como sujeito de direito e de se tornar protagonista no que diz respeito às ações que busquem sua promoção social e a construção e o exercício da cidadania ativa. É possível observar que, com esse tipo de linguagem, mais próximo do desejo desses jovens, os mesmos atribuem um novo sentido ao acompanhamento a que foram submetidos. Na lógica socioeducativa, procuram superar obstáculos no sentido de buscar cada vez mais seu protagonismo, sua autoria, para reafirmar o que o ato infracional revelou, que é a busca por ser sujeito.

Electromagnetic Computation and Visualization of Transmission Particle Model and Its Simulation Based on GPU

Directory of Open Access Journals (Sweden)

Yingnian Wu

2014-01-01

Full Text Available Electromagnetic calculation plays an important role in both military and civic fields. Some methods and models proposed for calculation of electromagnetic wave propagation in a large range bring heavy burden in CPU computation and also require huge amount of memory. Using the GPU to accelerate computation and visualization can reduce the computational burden on the CPU. Based on forward ray-tracing method, a transmission particle model (TPM for calculating electromagnetic field is presented to combine the particle method. The movement of a particle obeys the principle of the propagation of electromagnetic wave, and then the particle distribution density in space reflects the electromagnetic distribution status. The algorithm with particle transmission, movement, reflection, and diffraction is described in detail. Since the particles in TPM are completely independent, it is very suitable for the parallel computing based on GPU. Deduction verification of TPM with the electric dipole antenna as the transmission source is conducted to prove that the particle movement itself represents the variation of electromagnetic field intensity caused by diffusion. Finally, the simulation comparisons are made against the forward and backward ray-tracing methods. The simulation results verified the effectiveness of the proposed method.

Reflexiones sobre el problema del analfabetismo y propuesta de algunas medidas pedagógicas para combatirlo

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Maria José NAVARRO PERALES

2009-11-01

Full Text Available El analfabetismo es la consecuencia de la desigualdad e injusticia social. Combatirlo es una labor igualmente social. Las medidas deben ser tomadas por los gobiernos a través de instituciones de educación formal y no formal. La prevención y desaparición del analfabetismo, en todas sus modalidades y grados, debe realizarse desde el punto de vista del analfabeto y no contra él.

Uncertainty evaluation of fluid dynamic models and validation by gamma ray transmission measurements of the catalyst flow in a FCC cold pilot unity

International Nuclear Information System (INIS)

Teles, Francisco A.S.; Santos, Ebenezer F.; Dantas, Carlos C.; Melo, Silvio B.; Santos, Valdemir A. dos; Lima, Emerson A.O.

2013-01-01

In this paper, fluid dynamics of Fluid Catalytic Cracking (FCC) process is investigated by means of a Cold Flow Pilot Unit (CFPU) constructed in Plexiglas to visualize operational conditions. Axial and radial catalyst profiles were measured by gamma ray transmission in the riser of the CFPU. Standard uncertainty was evaluated in volumetric solid fraction measurements for several concentrations at a given point of axial profile. Monitoring of the pressure drop in riser shows a good agreement with measured standard uncertainty data. A further evaluation of the combined uncertainty was applied to volumetric solid fraction equation using gamma transmission data. Limit condition of catalyst concentration in riser was defined and simulation with random numbers provided by MATLAB software has tested uncertainty evaluation. The Guide to the expression of Uncertainty in Measurement (GUM) is based on the law of propagation of uncertainty and on the characterization of the quantities measured by means of either a Gaussian distribution or a t-distribution, which allows measurement uncertainty to be delimited by means of a confidence interval. A variety of supplements to GUM are being developed, which will progressively enter into effect. The first of these supplements [3] describes an alternative procedure for the calculation of uncertainties: the Monte Carlo Method (MCM).MCM is an alternative to GUM, since it performs a characterization of the quantities measured based on the random sampling of the probability distribution functions. This paper also explains the basic implementation of the MCM method in MATLAB. (author)

Uncertainty evaluation of fluid dynamic models and validation by gamma ray transmission measurements of the catalyst flow in a FCC cold pilot unity

Energy Technology Data Exchange (ETDEWEB)

Teles, Francisco A.S.; Santos, Ebenezer F.; Dantas, Carlos C., E-mail: francisco.teles@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Departamento de Energia Nuclear; Melo, Silvio B., E-mail: sbm@cin.ufpe.br [Universidade Federal de Pernambuco (CIN/UFPE), Recife, PE (Brazil). Centro de Informatica; Santos, Valdemir A. dos, E-mail: vas@unicap.br [Universidade Catolica de Pernambuco (UNICAP), Recife, PE (Brazil). Dept. de Quimica; Lima, Emerson A.O., E-mail: emathematics@gmail.com [Universidade de Pernambuco (POLI/UPE), Recife, PE (Brazil). Escola Politecnica

2013-07-01

In this paper, fluid dynamics of Fluid Catalytic Cracking (FCC) process is investigated by means of a Cold Flow Pilot Unit (CFPU) constructed in Plexiglas to visualize operational conditions. Axial and radial catalyst profiles were measured by gamma ray transmission in the riser of the CFPU. Standard uncertainty was evaluated in volumetric solid fraction measurements for several concentrations at a given point of axial profile. Monitoring of the pressure drop in riser shows a good agreement with measured standard uncertainty data. A further evaluation of the combined uncertainty was applied to volumetric solid fraction equation using gamma transmission data. Limit condition of catalyst concentration in riser was defined and simulation with random numbers provided by MATLAB software has tested uncertainty evaluation. The Guide to the expression of Uncertainty in Measurement (GUM) is based on the law of propagation of uncertainty and on the characterization of the quantities measured by means of either a Gaussian distribution or a t-distribution, which allows measurement uncertainty to be delimited by means of a confidence interval. A variety of supplements to GUM are being developed, which will progressively enter into effect. The first of these supplements [3] describes an alternative procedure for the calculation of uncertainties: the Monte Carlo Method (MCM).MCM is an alternative to GUM, since it performs a characterization of the quantities measured based on the random sampling of the probability distribution functions. This paper also explains the basic implementation of the MCM method in MATLAB. (author)

Position sensitive X-ray or X-ray detector and 3-D-tomography using same

International Nuclear Information System (INIS)

1975-01-01

A fan-shaped beam of penetrating radiation, such as X-ray or γ-ray radiation, is directed through a slice of the body to be analyzed into a position sensitive detector for deriving a shadowgraph of transmission or absorption of the penetrating radiation by the body. A number of such shadowgraphs are obtained for different angles of rotation of the fan-shaped beam relative to the center of the slice being analyzed. The detected fan beam shadowgraph data is reordered into shadowgraph data corresponding to sets of parallel paths of radiation through the body. The reordered parallel path shadowgraph data is then convoluted in accordance with a 3-D reconstruction method by convolution in a computer to derive a 3-D reconstructed tomograph of the body under analysis. In a preferred embodiment, the position sensitive detector comprises a multiwire detector wherein the wires are arrayed parallel to the direction of the divergent penetrating rays to be detected. A focussed grid collimator is interposed between the body and the position sensitive detector for collimating the penetrating rays to be detected. The source of penetrating radiation is preferably a monochromatic source

Evaluation of prevention and control measures for ventilator-associated pneumonia Evaluación de las medidas de prevención y control de neumonía asociada a ventilación mecánica Avaliação das medidas de prevenção e controle de pneumonia associada à ventilação mecânica

Directory of Open Access Journals (Sweden)

Leandra Terezinha Roncolato da Silva

2011-12-01

Full Text Available This study aimed to evaluate the quality of health care delivered in an Intensive Care Unit, concerning the use of pneumonia prevention and control measures in high-risk patients on mechanical ventilation. In this descriptive and exploratory research, 839 observations of patients under invasive ventilation care were carried out, between November 2009 and January 2010, using the Indicator of Evaluation of Adherence to Prevention and Control Measures in High-risk Patients (IRPR. Some isolated measures that compose the mentioned indicator reached rates close to 100%, but the general compliance rate with all prevention and control measures of ventilator-associated pneumonia was 26.94%. It is concluded that, although the evaluated practices are accomplished at the unit, systematic evaluations of the interventions is needed so as to permit the discussion and practice of other educational strategies by the health team.Este estudio objetivó evaluar la calidad de la asistencia a la salud prestada en una Unidad de Terapia Intensiva, en lo que se refiere al uso de medidas de prevención y control de neumonía en pacientes de alto riesgo sometidos a ventilación mecánica. Se trató de una investigación descriptiva exploratoria en la cual fueron realizadas 839 observaciones de pacientes en asistencia ventilatoria invasora, en el período de noviembre de 2009 a enero de 2010, utilizando el Indicador de Evaluación de la Adhesión a las Medidas de Prevención y Control de Neumonía en Pacientes de Alto Riesgo (IRPR. Algunas medidas aisladas que componen el Indicador alcanzaron índices próximos a 100%, sin embargo el índice de la conformidad general en todas las medidas de prevención y control de neumonía asociada a la ventilación mecánica correspondió a 26,94%. Se concluye que a pesar de que estas prácticas evaluadas estuviesen instituidas en la unidad, hay necesidad de realizar evaluaciones sistemáticas de las intervenciones para que otras

Study of x-ray medical mitigation with lead and aluminium shield

International Nuclear Information System (INIS)

Malheiros, Emiliane A.; Ramos, Roberto Paulo B.; Oliveira, Ezequias Fernandes

2016-01-01

In this work, lead and aluminum as shielding materials and their variations in the spectra emitted by the X-ray equipment through the use of a computer program that determines the photon fluence . The study of the primary beam for power spectra used in the practice of diagnostic radiology allows you to analyze data representative of the average transmission and fluency for the studied materials. So we seek to analyze the transmission curves of lead and aluminum, as well as its influence on the thickness of shielding and changing the radiation spectrum characteristics X in the transmission of photons. (author)

GENERAL ASPECTS OF BODY MEASURES, WEIGHT AND SCORE CONDITION FEMALE NELORE BREED (Bos taurus indicus ON THE PERIOD OF 12 MONTHS ESTUDIO DE MEDIDAS CORPORALES, PESO VIVO Y CONDICIÓN CORPORAL DE BOVINOS HEMBRAS DE LA RAZA NELORE (Bos taurus indicus POR 12 MESES ESTUDO DE MEDIDAS CORPORAIS, PESO VIVO E CONDIÇÃO CORPORAL DE FÊMEAS DA RAÇA NELORE (Bos taurus indicus AO LONGO DE 12 MESES

Directory of Open Access Journals (Sweden)

Arcádio de Los Reys Borjas

2008-04-01

Full Text Available Four hundred and eighty cattle were used to verify alterations and correlations among corporal measures in Nelore zebu herd with cows and heifers. Body weight and length, corporal condition, heart girth, withers height and hip measures were evaluated. Eight collections were accomplished along the months of October of 2002 and October of 2003. In heifers there was increase of the averages of corporal measures with significant difference (p <0,05 among collections only the heart girth was different (p <0,05 in cows. The relationship between the body weight and body condition with the time were quadratic parallel curves (p <0,001. There were correlations among lineal measures body with hip measures (p<0,001 except for heart girth with hip length. The correlations of body weight and body condition among body measures were significant (p<0,001 except body condition with hip length in cows. It could be concluded that there was a growing variation of the body measures in heifers in the experimental period. The body weight, the body condition and heart girth were related with different periods of the year that the evaluation was accomplished. In cows the variations along the year were of 14,79%, 31,53% and 6,74%, respectively. The isquiun – iliun external measures, as height and width were correlated with size measures and weight. The body weight and body condition in heifers behave in way similar to cows. Further researches in relationship among body measures, body weight and body condition with productive and reproductive aspect are necessary. Con el objetivo de verificar alteraciones y correlaciones entre medidas corporales en un rebaño bovino de vaquillonas y vacas de la raza Nelore. Evaluaron-se 487 hembras en peso vivo, condición corporal, perímetro toráxico, largura corporal, altura de la cruz y medidas da anca. Fueron realizadas ocho coletas a lo largo de los meses de octubre de 2002 y octubre de 2003. En las vaquillonas hubo un aumento de

Progress in x-ray microanalysis in the analytical electron microscope

International Nuclear Information System (INIS)

Williams, D.B.

1987-01-01

Analytical electron microscopes (AEM) consisting of x-ray energy dispersive spectrometers (EDS) interfaced to scanning transmission electron microscopes have been available for more than a decade. During that time, progress towards reaching the fundamental limits of the technique has been slow. The progress of x-ray microanalysis in AEM is examined in terms of x-ray detector technology; the EDS/AEM interface; accuracy of microanalysis; and spatial resolution and detectability limits. X-ray microanalysis in the AEM has substantial room for improvement in terms of the interface between the detector and the microscope. Advances in microscope design and software should permit 10nm resolution with detectability limits approaching 0.01wt percent. 16 refs., 2 figs., 1 tab

GALAXI: Gallium anode low-angle x-ray instrument

Directory of Open Access Journals (Sweden)

Emmanuel Kentzinger

2016-03-01

Full Text Available The high brilliance laboratory small angle X-ray scattering instrument GALAXI, which is operated by JCNS, Forschungszentrum Jülich, permits the investigation of chemical correlations in bulk materials or of structures deposited on a surface at nanometre and mesoscopic length scales. The instrument is capable to perform GISAXS experiments in reflection at grazing incidence as well as SAXS experiments in transmission geometry. The X-ray flux on sample is comparable or higher than the one obtained at a comparable beamline at a second generation synchrotron radiation source.

A program to calculate pulse transmission responses through transversely isotropic media

Science.gov (United States)

Li, Wei; Schmitt, Douglas R.; Zou, Changchun; Chen, Xiwei

2018-05-01

We provide a program (AOTI2D) to model responses of ultrasonic pulse transmission measurements through arbitrarily oriented transversely isotropic rocks. The program is built with the distributed point source method that treats the transducers as a series of point sources. The response of each point source is calculated according to the ray-tracing theory of elastic plane waves. The program could offer basic wave parameters including phase and group velocities, polarization, anisotropic reflection coefficients and directivity patterns, and model the wave fields, static wave beam, and the observed signals for pulse transmission measurements considering the material's elastic stiffnesses and orientations, sample dimensions, and the size and positions of the transmitters and the receivers. The program could be applied to exhibit the ultrasonic beam behaviors in anisotropic media, such as the skew and diffraction of ultrasonic beams, and analyze its effect on pulse transmission measurements. The program would be a useful tool to help design the experimental configuration and interpret the results of ultrasonic pulse transmission measurements through either isotropic or transversely isotropic rock samples.

Nanoscale X-Ray Microscopic Imaging of Mammalian Mineralized Tissue

OpenAIRE

Andrews, Joy C.; Almeida, Eduardo; van der Meulen, Marjolein C.H.; Alwood, Joshua S.; Lee, Chialing; Liu, Yijin; Chen, Jie; Meirer, Florian; Feser, Michael; Gelb, Jeff; Rudati, Juana; Tkachuk, Andrei; Yun, Wenbing; Pianetta, Piero

2010-01-01

A novel hard transmission X-ray microscope (TXM) at the Stanford Synchrotron Radiation Light-source operating from 5 to 15 keV X-ray energy with 14 to 30 µm2 field of view has been used for high-resolution (30–40 nm) imaging and density quantification of mineralized tissue. TXM is uniquely suited for imaging of internal cellular structures and networks in mammalian mineralized tissues using relatively thick (50 µm), untreated samples that preserve tissue micro- and nanostructure. To test this...

Toma de medidas usando fotografías digitales: Repaso experimental a procedimientos existentes, posibles fuentes de error, reproductividad del método y usos potenciales

OpenAIRE

Bustos-Pérez, Guillermo

2016-01-01

El uso de medios digitales para el análisis arqueológico está a la orden del día. Un ejemplo es el uso de fotografías digitales para la obtención de medidas en diferentes objetos. Se presenta aquí un repaso al procedimiento de medida de filos en lascas publicado por Eren et al., (2008), una experiencia de reproductividad del método, y una ampliación experimental de sus potenciales usos para el análisis de industria lítica. Los resultados muestran que se trata de un procedimient...

Adaptacao transcultural e confiabilidade de medidas de caracteristicas autorreferidas de vizinhanca no ELSA-Brasil

Directory of Open Access Journals (Sweden)

Simone M Santos

2013-06-01

Full Text Available OBJETIVO: Descrever o processo de adaptação de escalas de medida de características de vizinhança para o português brasileiro. MÉTODOS: As dimensões abordadas foram coesão social, ambiente propício para atividade física, disponibilidade de alimentos saudáveis, segurança em relação a crimes, violência percebida e vitimização. No processo de adaptação foram avaliados aspectos de equivalência entre as escalas originais e respectivas versões para o português. A confiabilidade teste-reteste foi avaliada em submostra de 261 participantes do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil que responderam ao mesmo questionário em dois momentos distintos em um intervalo de tempo de sete a 14 dias entre as duas aplicações. RESULTADOS: Os aspectos de equivalência avaliados mostraram-se adequados. O coeficiente de correlação intraclasse variou entre 0,83 (IC95% 0,78;0,87 para Coesão Social e 0,90 (IC95% 0,87;0,92 para Ambiente para Atividade Física. As escalas apresentaram consistência interna (alfa de Cronbach que variaram entre 0,60 e 0,84. CONCLUSÕES: As medidas autorreferidas de características de vizinhança tiveram reprodutibilidade muito boa e boa consistência interna. Os resultados sugerem que essas escalas podem ser utilizadas em estudos com população brasileira que apresente características similares àquelas do ELSA-Brasil.

A Three-Year Program of Micro- and Nano-System Technology Development for X-Ray Astronomy

Science.gov (United States)

Canizares, Claude R.

1997-01-01

For many years the work at MIT aimed at the development of new concepts and technologies for space experiments in high-energy astrophysics, but not explicitly supported by flight programs, has been supported. This work has yielded new devices and techniques for X-ray astronomy, primarily low-noise, deep-depletion charge-coupled devices (CCDS) for spectrally-resolved X-ray imaging, and high-performance transmission gratings for high-resolution X-ray spectroscopy. Among the most significant recent achievements have been the development by G. Ricker and associates of the X-ray CCD camera flying on ASCA, and currently in development for AXAF and Astro-E, and the development by C. Canizares and associates of thick, 200 nm-period transmission gratings employing the phenomenon of phase shifting for high-resolution X-ray spectroscopy up to energies of 8- 1 0 keV that is essential for the operation of the AXAF High Energy Transmission Grating Spectrometer (HETGS). Through the current SR&T grant, the latter technology is now being extended successfully to the fabrication of 100 nm-period transmission gratings, which have twice the dispersion of the AXAF gratings. We note that, among other outcomes, the modest investments of past SR&T Grants at MIT resulted in the development of the key technologies for fully one-half of the scientific instrumentation on AXAF. In addition, NASA flight programs that have benefited from previous SR&T support at MIT include the SAS 3 X-ray Observatory, which carried the first rotation modulation collimator, the Focal Plane Crystal Spectrometer (FPCS) on the Einstein Observatory, the CCD cameras on ASCA and planned for Astro-E, the High Energy Transient Experiment (HETE), the Solar EUV Monitor on the Solar and Heliospheric Observatory (SOHO), the Medium Energy Neutral Atom imager (MENA) on the Image for Magnetopause-to-aurora Global Exploration (IMAGE) mission, and the recently-approved Two Wide-Angle Imaging Neutral-atom Spectrometers (TWINS

Avaliação das medidas de oximetria de pulso em indivíduos sadios com esmalte de unha Evaluación de las medidas de oximetría de pulso en individuos sanos con esmalte de uña Evaluation of pulse oximetry measurements in healthy subjects with nail polish

Directory of Open Access Journals (Sweden)

Solange Diccini

2011-01-01

Full Text Available OBJETIVO: Avaliar as alterações nas medidas da oximetria de pulso em indivíduos sadios com esmaltes de unha. MÉTODOS: Estudo transversal com 80 voluntárias sadias. As cores de esmalte utilizadas para avaliar a saturação periférica de oxigênio (SpO2 foram: café com leite, café, chocolate, vermelho e ameixa. Estas cores foram distribuídas entre as unhas dos dedos da mão esquerda. Os dedos da mão direita foram os controles. RESULTADOS: As cores vermelha (p=0,047 e café (p=0,024 mostraram valores menores na SpO2 quando comparados ao controle. As outras cores não alteraram a medida da SpO2. CONCLUSÃO: As cores vermelha e café causaram redução na medida da SpO2, porém a relevância clínica deste achado é questionável, pois os valores estavam dentro do intervalo de normalidade.OBJETIVO: Evaluar las alteraciones en las medidas de la oximetría de pulso en individuos sanos con esmalte de uña. MÉTODOS: Estudio transversal realizado con 80 voluntarias sanas. Los colores de esmalte utilizados para evaluar la saturación periférica de oxígeno (SpO2 fueron: café con leche, café, chocolate, rojo y ciruela. Estos colores fueron distribuidos entre las uñas de los dedos de la mano izquierda. Los dedos de la mano derecha fueron los controles. RESULTADOS: Los colores rojo (p=0,047 y café (p=0,024 mostraron valores menores en la SpO2 cuando fueron comparados al control. Los otros colores no alteraron la medida del SpO2. CONCLUSIÓN: Los colores rojo y café causaron reducción en la medida del SpO2, sin embargo la relevancia clínica de este hallazgo es cuestionable, pues los valores estaban dentro del intervalo de normalidad.OBJECTIVE: To evaluate the changes in measurements of pulse oximetry in healthy individuals with nail polish. METHODS: Cross sectional study with 80 healthy volunteers. The colors of enamel used to assess oxygen saturation (SpO2 were: coffee with milk, coffee, chocolate, red and plum. These colors were

Detection methods of pulsed X-rays for transmission tomography with a linear accelerator

International Nuclear Information System (INIS)

Glasser, F.

1988-07-01

Appropriate detection methods are studied for the development of a high energy tomograph using a linear accelerator for nondestructive testing of bulky objects. The aim is the selection of detectors adapted to a pulsed X-ray source and with a good behavior under X-ray radiations of several MeV. Performance of semiconductors (HgI 2 , Cl doped CdTe, GaAs, Bi 12 Ge0 20 ) and a scintillator (Bi 4 Ge 3 0 12 ) are examined. A prototype tomograph gave images that show the validity of detectors for analysis of medium size equipment such as a concrete drum of 60 cm in diameter [fr

Primary investigation of a design for a dual energy gamma-ray transmission gauge to determine the ash content of coal on a conveyor belt

International Nuclear Information System (INIS)

Abedinzadeh, A.; Rahimi, H.; Rahimi, N.; Amini, A.; Naimpour, A.; Moafian, J.

1993-01-01

In order to design a dual energy γ-ray transmission gauge for measuring, on-line, the ash content of coal, an investigation was carried out to determine the relation between the theoretical mass absorption coefficient (μ-bar) and the % ash of coal in the Kerman District Coal Mines. Because coal, transported on a conveyor belt, may be a non-homogeneous mixture from one or more mines, it was decided to compare % ash in a mixture of coals from several mines with that from individual mines, the measurements being made whilst the coal was being transported on a conveyor belt. The investigation shows that the relation between the mass absorption coefficient and the % ash in a coal mixture from several mines cannot be used to assess, accurately, the value of μ-bar for coals from individual mines in this particular region. (author)

Materials testing by computerized tomography with neutrons and gamma-rays

Energy Technology Data Exchange (ETDEWEB)

El-Ghobary, A M; Bakkoush, F A; Megahid, R M [Reactor and Neutron Physics Department, Nuclear Research Center, A.E.A., Cairo (Egypt)

1997-12-31

The method of computerized tomography by fast neutrons and gamma-rays are used for inspecting and testing of materials by non-destructive technique. The transmission technique was applied using narrow collimated beams of reactor neutrons and gamma-ray. The neutron and gamma-rays transmitted through the object inspection were measured by means of a neutron gamma detector with Ne - 213 liquid organic scintillator. The undesired pulses of neutrons or gamma-rays are rejected from the transmitted beam by a discrimination technique based on the difference in the decay part of light pulse produced by recoil electrons or recoil protons. The transmitted neutrons or gamma-rays for different projections used to get the image of the section through the object investigated using the method of filtered back projection (FBP) algorithm. 8 figs.

Revealing the synergetic effects in Ni nanoparticle-carbon nanotube hybrids by scanning transmission X-ray microscopy and their application in the hydrolysis of ammonia borane.

Science.gov (United States)

Zhao, Guanqi; Zhong, Jun; Wang, Jian; Sham, Tsun-Kong; Sun, Xuhui; Lee, Shuit-Tong

2015-06-07

The hybrids of carbon nanotubes (CNTs) and the supported Ni nanoparticles (NPs) have been studied by scanning transmission X-ray microscopy (STXM) and tested by the hydrolysis reaction of ammonia borane (AB, NH3BH3). Data clearly showed the existence of a strong interaction between Ni NPs and thin CNTs (C-O-Ni bonds), which favored the tunable (buffer) electronic structure of Ni NPs facilitating the catalytic process. The hydrolysis process of AB confirmed the hypothesis that the hybrids with a strong interfacial interaction would show superior catalytic performance, while the hybrids with a weak interfacial interaction show poor performance. Our results provide a wealth of detailed information regarding the electronic structure of the NP-CNT hybrids and provide guidance towards the rational design of high-performance catalysts for energy applications.

Transmission electron microscopy physics of image formation and microanalysis

CERN Document Server

Reimer, Ludwig

1997-01-01

Transmission Electron Microscopy presents the theory of image and contrast formation, and the analytical modes in transmission electron microscopy. The principles of particle and wave optics of electrons are described. Electron-specimen interactions are discussed for evaluating the theory of scattering and phase contrast. Also discussed are the kinematical and dynamical theories of electron diffraction and their applications for crystal-structure analysis and imaging of lattices and their defects. X-ray micronanalysis and electron energy-loss spectroscopy are treated as analytical methods. Specimen damage and contamination by electron irradiation limits the resolution for biological and some inorganic specimens. This fourth edition includes discussion of recent progress, especially in the area of Schottky emission guns, convergent-beam electron diffraction, electron tomography, holography and the high resolution of crystal lattices.

Emission and transmission tomography systems to be developed for the future needs of Jules Horowitz material testing reactor

Energy Technology Data Exchange (ETDEWEB)

Kotiluoto, Petri [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland)], E-mail: petri.kotiluoto@vtt.fi; Wasastjerna, Frej; Kekki, Tommi [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland); Sipilae, Heikki; Banzuzi, Kukka [Oxford Instruments Analytical Oy, Nihtisillankuja 5, P.O.Box 85, FI-02631 Espoo (Finland); Kinnunen, Petri; Heikinheimo, Liisa [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland)

2009-08-01

The new 100 MW Jules Horowitz material testing reactor will be built in Cadarache, France. It will support, for instance, research on new types of innovative nuclear fuel. As a Finnish in-kind contribution, 3D emission and transmission tomography equipment will be delivered for both the reactor and the active component storage pool. The image reconstruction of activities inside the used nuclear fuel will be based on gamma spectrometry measurements. A new type of underwater digital X-ray linear detector array is under development for transmission imaging, based on GaAs and direct conversion of X-rays into an electrical signal. A shared collimator will be used for both emission and transmission measurements. Some preliminary design has been performed. For the current design, the expected gamma spectrometric response of a typical high-purity germanium detector has been simulated with MCNP for minimum and maximum source activities (specified by CEA) to be measured in future.

Progress in high-resolution x-ray holographic microscopy

International Nuclear Information System (INIS)

Jacobsen, C.; Kirz, J.; Howells, M.; McQuaid, K.; Rothman, S.; Feder, R.; Sayre, D.

1987-07-01

Among the various types of x-ray microscopes that have been demonstrated, the holographic microscope has had the largest gap between promise and performance. The difficulties of fabricating x-ray optical elements have led some to view holography as the most attractive method for obtaining the ultimate in high resolution x-ray micrographs; however, we know of no investigations prior to 1987 that clearly demonstrated submicron resolution in reconstructed images. Previous efforts suffered from problems such as limited resolution and dynamic range in the recording media, low coherent x-ray flux, and aberrations and diffraction limits in visible light reconstruction. We have addressed the recording limitations through the use of an undulator x-ray source and high-resolution photoresist recording media. For improved results in the readout and reconstruction steps, we have employed metal shadowing and transmission electron microscopy, along with numerical reconstruction techniques. We believe that this approach will allow holography to emerge as a practical method of high-resolution x-ray microscopy. 30 refs., 4 figs

Progress in high-resolution x-ray holographic microscopy

Energy Technology Data Exchange (ETDEWEB)

Jacobsen, C.; Kirz, J.; Howells, M.; McQuaid, K.; Rothman, S.; Feder, R.; Sayre, D.

1987-07-01

Among the various types of x-ray microscopes that have been demonstrated, the holographic microscope has had the largest gap between promise and performance. The difficulties of fabricating x-ray optical elements have led some to view holography as the most attractive method for obtaining the ultimate in high resolution x-ray micrographs; however, we know of no investigations prior to 1987 that clearly demonstrated submicron resolution in reconstructed images. Previous efforts suffered from problems such as limited resolution and dynamic range in the recording media, low coherent x-ray flux, and aberrations and diffraction limits in visible light reconstruction. We have addressed the recording limitations through the use of an undulator x-ray source and high-resolution photoresist recording media. For improved results in the readout and reconstruction steps, we have employed metal shadowing and transmission electron microscopy, along with numerical reconstruction techniques. We believe that this approach will allow holography to emerge as a practical method of high-resolution x-ray microscopy. 30 refs., 4 figs.

Absolute Soft X-ray Emission Measurements at the Nike Laser

Science.gov (United States)

Weaver, J.; Atkin, R.; Boyer, C.; Colombant, D.; Feldman, U.; Fielding, D.; Gardner, J.; Holland, G.; Klapisch, M.; Mostovych, A. N.; Obenscain, S.; Seely, J. F.

2002-11-01

Recent experiments at the Nike laser facility have demonstrated that, when a low intensity prepulse ( 2main laser intensity) is used to heat a thin Au or Pd coating on a planar CH target, the growth of non-uniformities due to laser imprint can be reduced from the growth observed for an uncoated CH target. The absolute radiation intensity in the soft x-ray region (0.1-1 keV) has a important role in the energy balance for layered targets. There is an ongoing effort to characterize the soft x-ray emission using an absolutely calibrated transmission grating spectrometer and filtered diode modules. Measurements of the angular distribution of the emission from unlayered solid targets (Au, Pd, CH) have recently been made using an array of moveable filtered diode modules. The data from the angular distribution studies will be presented. A new absolutely calibrated, time-resolving transmission grating spectrometer has been installed at the Nike. The new version has improved spectral resolution, selectable transmission filters, and the potential for simultaneous temporal, spatial, and spectral resolution. Preliminary data from the new spectrometer will be presented and future experiments will be briefly discussed. *Work was supported by DoE

X-ray tomography: Biological cells in 3-D at better than 50 nm resolution

International Nuclear Information System (INIS)

Larabell, C.; Le Gros, M.

2004-01-01

Full text: X-ray microscopy can be used to image whole, hydrated, specimens with a spatial resolution 5-10 times better than that obtained using visible light microscopy. X-ray imaging at photon energies below the K- absorption edge of oxygen, referred to as the water window, exploits the strong natural contrast for organic material embedded in a mostly water matrix. With a transmission X-ray microscope using Fresnel zone plate optics, specimens up to 10 microns thick can be examined. The highest X-ray transmission in hydrated samples is obtained at a wavelength of 2.4 nm but, due to the low numerical aperture of zone plate lenses operated in st order diffraction mode the structures resolved are much larger than the X-ray wavelength. Because of the low NA of X-ray lenses (NA=0.05), combined with the effect of polychromatic illumination and a wavelength dependant focal length, the effective depth of ld is large (6-10 microns). The experiments presented here were performed at the Advanced Light Source using the full ld transmission X-ray microscope, XM-1. This microscope employs a bend magnet X-ray source and zone plate condenser and objective lenses. The condenser zone plate acts as a monochromator and the X-ray images are recorded directly on a cooled, back-thinned 1024x1024 pixel CCD camera. The sample holder was a rotationally symmetric glass tube; the region containing the sample was 10 microns in diameter with a wall thickness of 200 nm. Live yeast cells were loaded into the tube, rapidly frozen by a blast of liquid nitrogen-cooled helium gas, and maintained at 140 deg C by a steady flow of cold helium. The image sequence spanned 180 deg and consisted of 45 images spaced by 4 deg. The images were aligned to a common axis and computed tomographic reconstruction was used to obtain the 3-D X-ray linear absorption coefficient. Volume rendering and animation of reconstructed data was performed using the 3-D program, Amira. Acquisition time for 90 images was 3 min

Gamma ray auto absorption correction evaluation methodology

International Nuclear Information System (INIS)

Gugiu, Daniela; Roth, Csaba; Ghinescu, Alecse

2010-01-01

Neutron activation analysis (NAA) is a well established nuclear technique, suited to investigate the microstructural or elemental composition and can be applied to studies of a large variety of samples. The work with large samples involves, beside the development of large irradiation devices with well know neutron field characteristics, the knowledge of perturbing phenomena and adequate evaluation of correction factors like: neutron self shielding, extended source correction, gamma ray auto absorption. The objective of the works presented in this paper is to validate an appropriate methodology for gamma ray auto absorption correction evaluation for large inhomogeneous samples. For this purpose a benchmark experiment has been defined - a simple gamma ray transmission experiment, easy to be reproduced. The gamma ray attenuation in pottery samples has been measured and computed using MCNP5 code. The results show a good agreement between the computed and measured values, proving that the proposed methodology is able to evaluate the correction factors. (authors)

Project of a photoelectron X-ray microscope on ACO storage ring

International Nuclear Information System (INIS)

Polack, F.; Lowenthal, S.

1983-01-01

A photoelectron X-ray microscope is described which is based on the principles of contact X-ray imaging and of image converters. An X-ray image is projected by a parallel X-ray beam on a thin transmission photocathode. The emitted electrons are accelerated and imaged at large magnification by an emission microscope. The instrument, which is presently under construction, is designed to provide high resolution. An electron velocity filter has been added to the usual cross-over aperture so as to reduce the spherochromatic aberration, and the cathode lens has been designed to reduce field curvature. Resolution and detection efficiency of Au and CsI cathodes are compared. The interest of the instrument for soft X-ray microscopy is briefly discussed. (orig.)

X-ray microbeams based on Kumakhov polycapillary optics and its ...

Indian Academy of Sciences (India)

because of the total external reflection of X-rays from the inner capillary walls .... of the area of apertures and walls, and losses on internal reflections. All these factors as a whole are considered in experimentally received transmission factor Tr.

Sputtered carbon as a corrosion barrier for x-ray detector windows

Energy Technology Data Exchange (ETDEWEB)

Rowley, Joseph; Pei, Lei; Davis, Robert C., E-mail: davis@byu.edu; Vanfleet, Richard R. [Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602 (United States); Liddiard, Steven; Harker, Mallorie; Abbott, Jonathan [Moxtek, Inc., 452 W 1260 N, Orem, Utah 84057 (United States)

2016-09-15

Sputtered amorphous carbon thin films were explored as corrosion resistant coatings on aluminum thin films to be incorporated into x-ray detector windows. The requirements for this application include high corrosion resistance, low intrinsic stress, high strains at failure, and high x-ray transmission. Low temperature sputtering was used because of its compatibility with the rest of the window fabrication process. Corrosion resistance was tested by exposure of carbon coated and uncoated Al thin films to humidity. Substrate curvature and bulge testing measurements were used to determine intrinsic stress and ultimate strain at failure. The composition and bonding of the carbon films were further characterized by electron energy loss spectroscopy, Raman spectroscopy, and carbon, hydrogen, and nitrogen elemental analyses. Samples had low compressive stress (down to.08 GPa), a high strain at failure (3%), and a low fraction of sp{sup 3} carbon–carbon bonds (less than 5%). The high breaking strain and excellent x-ray transmission of these sputtered carbon films indicate that they will work well as corrosion barriers in this application.

Grating-based X-ray phase contrast for biomedical imaging applications

International Nuclear Information System (INIS)

Pfeiffer, Franz; Willner, Marian; Chabior, Michael; Herzen, Julia; Helmholtz-Zentrum Geesthacht, Geesthacht; Auweter, Sigrid; Reiser, Maximilian; Bamberg, Fabian

2013-01-01

In this review article we describe the development of grating-based X-ray phase-contrast imaging, with particular emphasis on potential biomedical applications of the technology. We review the basics of image formation in grating-based phase-contrast and dark-field radiography and present some exemplary multimodal radiography results obtained with laboratory X-ray sources. Furthermore, we discuss the theoretical concepts to extend grating-based multimodal radiography to quantitative transmission, phase-contrast, and dark-field scattering computed tomography. (orig.)

Avaliação da inteligência emocional: a relação entre medidas de desempenho e de autorrelato

Directory of Open Access Journals (Sweden)

Ana Cristina Fontes Costa

Full Text Available Apresenta-se a adaptação e validação do Teste de Vocabulário Emocional (TVE ao contexto português, uma medida de desempenho de inteligência emocional, explorando as suas qualidades psicométricas e a validade de critério e convergente com uma medida de autorrelato, o Questionário de Competência Emocional - Revisto (QCE-R. O TVE, com 35 itens, desenvolvido por Takšic, Herambasic e Velemir (2003 no contexto croata, mede a capacidade para compreender emoções. A amostra incluiu 682 alunos do 10.º ano, entre 14 e 21 anos (M = 15,5; DP = 0,77 de diferentes cursos científico-humanísticos. Genericamente, o TVE revelou boas qualidades psicométricas, tendo-se correlacionado positivamente com o rendimento académico e evidenciado maior capacidade para o predizer do que o QCE-R, com o qual não estabeleceu qualquer associação.

An experimental study of transmission, reflection and scattering of sound in a free-jet flight simulation facility and comparison with theory

Science.gov (United States)

Ahuja, K. K.; Tester, B. J.; Tanna, H. K.; Searle, N.

1977-01-01

Acoustic time delays across a free-jet shear layer are measured and compared with predictions based on (1) ray paths refracted abruptly across a cylindrical vortex sheet and (2) ray paths traced through a more realistic diverging flow model. The close agreement between measurement and theory confirms that Snell's law provides an accurate prediction of wavefront refraction or angle changes across a diverging shear layer. Microphones are placed on calculated ray paths to determine the coherent transmission and internal reflection characteristics of the shear layer and also the scattering of sound by the shear-layer turbulence. The transmission data essentially verify the proposed, theoretical calibration factor which forms part of a computational procedure that is being developed to convert model jet data from a free-jet facility to inflight conditions.

A transparency model and its applications for simulation of reflector arrays and sound transmission (A)

DEFF Research Database (Denmark)

Christensen, Claus Lynge; Rindel, Jens Holger

2006-01-01

The paper describes a new method for simulating the frequency-dependent reflection and transmission of reflector arrays, and the frequency-dependent airborne sound insulation between rooms by means of a room acoustic computer model. The method makes use of a transparency method in the ray...... of the partition, and this is useful for the auralization of sound transmission through different building constructions. The acoustic properties like volume, reverberation time, and the area of the transmitting surfaces are included in the simulation....

Mapping metals incorporation of a whole single catalyst particle using element specific X-ray nanotomography

NARCIS (Netherlands)

Meirer, Florian; Morris, Darius T; Kalirai, Samanbir; Liu, Yijin; Andrews, Joy C; Weckhuysen, Bert M

2015-01-01

Full-field transmission X-ray microscopy has been used to determine the 3D structure of a whole individual fluid catalytic cracking (FCC) particle at high spatial resolution and in a fast, noninvasive manner, maintaining the full integrity of the particle. Using X-ray absorption mosaic imaging to

Medidas de biossegurança adotadas por profissionais atuantes em audiologia

Directory of Open Access Journals (Sweden)

Ana Paula Ferreira Rocha

2015-03-01

Full Text Available OBJETIVO: explicitar as práticas de biossegurança adotadas por fonoaudiólogos atuantes na área de Audiologia e relacioná-las com a educação continuada e o tempo de formação dos profissionais. MÉTODOS: participaram deste estudo 70 fonoaudiólogos atuantes na área de Audiologia, nos municípios de Belo Horizonte e Contagem. Foi aplicado um questionário sobre biossegurança em Audiologia, com base na Norma Regulamentadora 32, composto por 27 perguntas fechadas, abordando os aspectos de higienização das mãos, equipamentos de proteção individual e organização e higienização dos artigos e do ambiente. RESULTADOS: a maioria dos fonoaudiólogos relatou que adota as seguintes medidas de biossegurança: higienização das mãos antes dos atendimentos (71%, uso de jaleco com mangas longas (74% e abotoado (91%, cabelos presos (79%, unhas limpas e cortadas (91%, separação e desinfecção dos artigos usados (83% e organização do ambiente (97%. No entanto somente 40% dos profissionais referiram higienizar as mãos entre os atendimentos e 9% referiram o uso de luvas na realização da meatoscopia. Observou-se que a destinação dos artigos para desinfecção é uma prática mais rotineira para profissionais com especialização (p< 0,05. Os profissionais com maior tempo de formação aderiram melhor à prática de higienização das mãos. CONCLUSÃO: higienizar as mãos antes dos atendimentos, vestir-se corretamente, destinar os artigos para desinfecção e organizar o ambiente de trabalho são práticas de biossegurança adotadas pela maioria dos fonoaudiólogos. Fatores como tempo de formação e educação continuada influenciam de maneira positiva na adoção de corretas medidas de biossegurança.

3D membrane segmentation and quantification of intact thick cells using cryo soft X-ray transmission microscopy: A pilot study

Science.gov (United States)

Klementieva, Oxana; Werner, Stephan; Guttmann, Peter; Pratsch, Christoph; Cladera, Josep

2017-01-01

Structural analysis of biological membranes is important for understanding cell and sub-cellular organelle function as well as their interaction with the surrounding environment. Imaging of whole cells in three dimension at high spatial resolution remains a significant challenge, particularly for thick cells. Cryo-transmission soft X-ray microscopy (cryo-TXM) has recently gained popularity to image, in 3D, intact thick cells (∼10μm) with details of sub-cellular architecture and organization in near-native state. This paper reports a new tool to segment and quantify structural changes of biological membranes in 3D from cryo-TXM images by tracking an initial 2D contour along the third axis of the microscope, through a multi-scale ridge detection followed by an active contours-based model, with a subsequent refinement along the other two axes. A quantitative metric that assesses the grayscale profiles perpendicular to the membrane surfaces is introduced and shown to be linearly related to the membrane thickness. Our methodology has been validated on synthetic phantoms using realistic microscope properties and structure dimensions, as well as on real cryo-TXM data. Results demonstrate the validity of our algorithms for cryo-TXM data analysis. PMID:28376110

Investigation on diagnostic techniques of X-ray radiation characteristic from slit target

International Nuclear Information System (INIS)

Cheng Jinxiu; Miao Wenyong; Sun Kexu; Wang Hongbin; Cao Leifeng; Yang Jiamin; Chen Zhenglin

2001-01-01

On the Xingguang-II facility, X-ray transport process in a cavity target was simulated in a long cylindrical cavity with slits. High temporally and spatially resolved Microchannel Plate (MCP) gated X-ray picosecond frame camera and soft X-ray steak camera were used to investigate the temporal and spatial distribution of the soft X-ray emitted from the cavity wall through the slit. X-ray transport velocity, X-ray emission time and amount of intensity decay was obtained. X-ray CCD pinhole transmission grating spectrometer was used to investigate the spectrum change of the emitted X-ray versus its location. The change characteristic of the spectrum of X-ray absorbed and emitted again and again in transport was obtained. X-ray diodes and Dante spectrometer were used to measure X-ray flux and radiation temperature in the slit, the source and the transport end, respectively. The typical results in the experiment were given. A brief and essential analysis and discussion were made

Characteristics of soft X-ray lens

International Nuclear Information System (INIS)

Qin Yi

2007-12-01

A soft X-lens was devised with waveguide X-ray optics of total external reflection (TER). The lens consists of a stack of 1 387 TER waveguides with inner diameter of 0.45 mm and outer diameter of 0.60 mm. With the help of plasma sources of soft X-ray radiation, high density of pure soft X-ray radiation (without plasma expansion fragments) with broad-band spectral range can be obtained at the focus of the lens. As laser-plasma is considered, the radiation density of 1.3 x 10 5 W/cm 2 is obtained, the transmission coefficient is 18.6%, the ratio of the density at the focus with and without the lens is 1000 and the radiation capture is 28.9 degree. The density of 0.5 TW/cm 2 can be obtained as far as Qiang-Guang I facility is considered. (authors)

Un criterio robusto para la medida del margen –coeficiente– de seguridad

Directory of Open Access Journals (Sweden)

Cervera, J.

2010-06-01

Full Text Available This paper offers a brief analysis of the drawbacks that can be found with the usual partial security coefficients, as loads multipliers, when employed for the measurement of the distance to the collapse condition in such structures, as masonry arches, that have important anisotropies or lacks tensile strength. To deal with such difficulties the paper presents a simple and robust security criterium based on a contraction of the yield surface. That criterium, that performs identically in isotropic structures to those usually employed, can however deal consistently with situations where former criteria fail. The criterium is applied to sections with double symmetry under axial load and unsymmetrical bending, in materials with and without tension resistance. It is also applied to the prism stability problem, showing the advantages in the caracterization of such problems.

En este trabajo se analizan en primer lugar algunos inconvenientes de los habituales coeficientes parciales de seguridad —factores multiplicadores de las cargas— como medida del alejamiento a las condiciones de colapso en el caso de las estructuras con anisotropías importantes, como son especialmente aquellas sin resistencia a la tracción —los arcos de fábrica, como ejemplo paradigmático— Para superar dichas dificultades se propone un criterio sencillo y robusto basado en la contracción de la superficie límite, criterio que aporta una medida coincidente con la habitual para los casos isótropos, pero que permite medir igualmente de forma consistente el alejamiento a las condiciones del colapso para el resto de las situaciones. Se aplica finalmente el modelo a la determinación de los márgenes de seguridad en secciones de doble simetría sometidas a compresión esviada para materiales sin, y con resistencia a tracción, así como al problema de la estabilidad de un prisma frente al vuelco, mostrando las mejoras que aporta para caracterizar dichos problemas.

Magnetic x-ray dichroism in ultrathin epitaxial films

Energy Technology Data Exchange (ETDEWEB)

Tobin, J.G.; Goodman, K.W. [Lawrence Berkeley National Lab., CA (United States); Cummins, T.R. [Univ. of Missouri, Rolla, MO (United States)] [and others

1997-04-01

The authors have used Magnetic X-ray Linear Dichroism (MXLD) and Magnetic X-ray Circular Dichroism (MXCD) to study the magnetic properties of epitaxial overlayers in an elementally specific fashion. Both MXLD and MXCD Photoelectron Spectroscopy were performed in a high resolution mode at the Spectromicroscopy Facility of the ALS. Circular Polarization was obtained via the utilization of a novel phase retarder (soft x-ray quarter wave plate) based upon transmission through a multilayer film. The samples were low temperature Fe overlayers, magnetic alloy films of NiFe and CoNi, and Gd grown on Y. The authors results include a direct comparison of high resolution angle resolved Photoelectron Spectroscopy performed in MXLD and MXCD modes as well as structural studies with photoelectron diffraction.

Magnetic x-ray dichroism in ultrathin epitaxial films

International Nuclear Information System (INIS)

Tobin, J.G.; Goodman, K.W.; Cummins, T.R.

1997-01-01

The authors have used Magnetic X-ray Linear Dichroism (MXLD) and Magnetic X-ray Circular Dichroism (MXCD) to study the magnetic properties of epitaxial overlayers in an elementally specific fashion. Both MXLD and MXCD Photoelectron Spectroscopy were performed in a high resolution mode at the Spectromicroscopy Facility of the ALS. Circular Polarization was obtained via the utilization of a novel phase retarder (soft x-ray quarter wave plate) based upon transmission through a multilayer film. The samples were low temperature Fe overlayers, magnetic alloy films of NiFe and CoNi, and Gd grown on Y. The authors results include a direct comparison of high resolution angle resolved Photoelectron Spectroscopy performed in MXLD and MXCD modes as well as structural studies with photoelectron diffraction

Charge state mapping of mixed valent iron and manganese mineral particles using Scanning Transmission X-ray Microscopy (STXM)

International Nuclear Information System (INIS)

Pecher, K.; Nealson, K.; Kneedler, E.; Rothe, J.; Meigs, G.; Warwick, T.; Tonner, B.

2000-01-01

The interfaces between solid mineral particles and water play a crucial role in partitioning and chemical transformation of many inorganic as well as organic pollutants in environmental systems. Among environmentally significant minerals, mixed-valent oxides and hydroxides of iron (e.g. magnetite, green rusts) and manganese (hausmanite, birnessite) have been recognized as particularly strong sorbents for metal ions. In addition, minerals containing Fe(II) have recently been proven to be powerful reductants for a wide range of pollutants. Chemical properties of these minerals strongly depend on the distribution and availability of reactive sites and little is known quantitatively about the nature of these sites. We have investigated the bulk distribution of charge states of manganese (Mn (II, III, IV)) and iron (Fe(II, III)) in single particles of natural manganese nodules and synthetic green rusts using Scanning Transmission X-ray SpectroMicroscopy (STXM). Pixel resolved spectra (XANES) extracted from stacks of images taken at different wave lengths across the metal absorption edge were fitted to total electron yield (TEY) spectra of single valent reference compounds. Two dimensional maps of bulk charge state distributions clearly reveal domains of different oxidation states within single particles of Mn-nodules and green rust precipitates. Changes of oxidation states of iron were followed as a result of reductive transformation of an environmental contaminant (CCl 4 ) using green rust as the only reductant

Small passenger car transmission test-Chevrolet 200 transmission

Science.gov (United States)

Bujold, M. P.

1980-01-01

The small passenger car transmission was tested to supply electric vehicle manufacturers with technical information regarding the performance of commerically available transmissions which would enable them to design a more energy efficient vehicle. With this information the manufacturers could estimate vehicle driving range as well as speed and torque requirements for specific road load performance characteristics. A 1979 Chevrolet Model 200 automatic transmission was tested per a passenger car automatic transmission test code (SAE J651b) which required drive performance, coast performance, and no load test conditions. The transmission attained maximum efficiencies in the mid-eighty percent range for both drive performance tests and coast performance tests. Torque, speed and efficiency curves map the complete performance characteristics for Chevrolet Model 200 transmission.

Light propagation and transmission in hybrid-aligned nematic liquid crystal cells: Geometrical optics calculations

Science.gov (United States)

Mendoza, Carlos I.; Reyes, J. Adrian

2006-08-01

The authors present a geometrical approach to calculate the transmission of light in a hybrid-aligned nematic cell under the influence of an applied electric field. Using the framework of geometrical optics they present results for the ray tracing as well as the transmission of light as a function of the applied low frequency voltage. Dispersion effects are included through a wavelength dependent dielectric function. Their results for the transmittance as a function of the applied voltage show oscillations that are in good qualitative agreement with previously obtained experimental measurements.

Simulation and application of micro X-ray fluorescence based on an ellipsoidal capillary

Energy Technology Data Exchange (ETDEWEB)

Yang, Jing; Li, Yude; Wang, Xingyi; Zhang, Xiaoyun; Lin, Xiaoyan, E-mail: yangjing_928@126.com

2017-06-15

Highlights: • A micro X-ray fluorescence setup based on an ellipsoidal capillary was presented. • The optimal parameters of ellipsoidal capillary were designed. • The 2D mapping image of biological sample was obtained. - Abstract: A micro X-ray fluorescence setup was presented, based on an ellipsoidal capillary and a traditional laboratorial X-ray source. Using Ray-tracing principle, we have simulated the transmission path of X-ray beam in the ellipsoidal capillary and designed the optimal parameters of the ellipsoidal capillary for the micro X-ray fluorescence setup. We demonstrate that ellipsoidal capillary is well suited as condenser for the micro X-ray fluorescence based on traditional laboratorial X-ray source. Furthermore, we obtain the 2D mapping image of the leaf blade sample by using the ellipsoidal capillary we designed.

High-resolution X-ray television and high-resolution video recorders

International Nuclear Information System (INIS)

Haendle, J.; Horbaschek, H.; Alexandrescu, M.

1977-01-01

The improved transmission properties of the high-resolution X-ray television chain described here make it possible to transmit more information per television image. The resolution in the fluoroscopic image, which is visually determined, depends on the dose rate and the inertia of the television pick-up tube. This connection is discussed. In the last few years, video recorders have been increasingly used in X-ray diagnostics. The video recorder is a further quality-limiting element in X-ray television. The development of function patterns of high-resolution magnetic video recorders shows that this quality drop may be largely overcome. The influence of electrical band width and number of lines on the resolution in the X-ray television image stored is explained in more detail. (orig.) [de

Pulmonary emphysema diagnosis using a preclinical small-animal X-ray dark-field scanner

Energy Technology Data Exchange (ETDEWEB)

Yaroshenko, Andre; Bech, Martin; Tapfer, Arne; Velroyen, Astrid; Pfeiffer, Franz [Department of Physics, Technische Universitaet Muenchen (Germany); Meinel, Felix; Nikolaou, Konstantin; Reiser, Maximilian [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Muenchen (Germany); Bohla, Alexander; Yildirim, Ali Oender; Eickelberg, Oliver [Institute of Lung Biology and Disease, Helmholtz Zentrum Muenchen (Germany)

2013-07-01

Pulmonary emphysema is one of the leading causes of morbidity and mortality worldwide that is difficult to detect using conventional x-ray radiographic methods. For emphysematous lungs with enlarged distal airspaces, x-ray scattering decreases and transmission increases, as has been demonstrated by the proof-of-principle experiments with brilliant x-rays from a synchrotron source. Therefore, combination of the transmission and dark-field signals leads to a novel diagnostic approach for pulmonary emphysema. In this study, images of excised murine lungs with pulmonary emphysema and control lungs were acquired using a compact phase- and dark-field scanner with a polychromatic source and a cone-beam geometry. The data analysis revealed a clear distinction between the two groups in the per-pixel scatter plot. The main difference was observed in the angle of the distribution to the vertical. The presented study reveals the high potential of the approach for the pulmonary emphysema diagnosis.

INTERRAD - inductive terawatt X-ray generator (project)

Energy Technology Data Exchange (ETDEWEB)