Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator

Energy Technology Data Exchange (ETDEWEB)

Ueno, Daisuke [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Watanabe, Mafumi [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Subramanian, Annamalai [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Tanaka, Hiroyuki [National Research Institute of Fisheries and Environment of Inland Sea (Japan); Fillmann, Gilberto [Fundacao Universidade Federal do Rio Grande (Brazil); Lam, Paul K.S. [Department of Biology and Chemistry, City University of Hong Kong, Hong Kong (China); Zheng, Gene J. [Department of Biology and Chemistry, City University of Hong Kong, Hong Kong (China); Muchtar, Muswerry [Research and Development Center for Oceanology, Indonesian Institute of Sciences (Indonesia); Razak, Hamidah [Research and Development Center for Oceanology, Indonesian Institute of Sciences (Indonesia); Prudente, Maricar [Science Education Department, De La Salle University (Philippines); Chung, Kyu-Hyuck [College of Pharmacy, Sungkyunkwan University (Korea, Republic of); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)]. E-mail: shinsuke@agr.ehime-u.ac.jp

2005-07-15

In order to elucidate the global distribution of dioxins and related compounds, such as PCDDs, PCDFs and coplanar PCBs, levels of these compounds were determined in the muscle of skipjack tuna (Katsuwonus pelamis) collected from the offshore waters and open seas near Japan, Taiwan, Philippines, Indonesia, Seychelles and Brazil, and the Japan Sea, the East China Sea, the South China Sea, the Indian Ocean and the North Pacific Ocean. PCDDs, PCDFs and coplanar PCBs were detected in almost all the specimens collected from all the locations surveyed, indicating widespread contamination by these compounds in the marine environment. Higher concentrations of dioxins and coplanar PCBs were detected in the samples from temperate Asian regions, plausibly due to larger usage and anthropogenic generation in highly industrialized countries around the East China Sea and the South China Sea, such as Japan, Korea, Taiwan, Hong Kong and coastal China. - Global pollution monitoring of PCDD/Fs and coplanar PCBs in offshore water and open sea were conducted using skipjack tuna as bioindicator.

Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator

International Nuclear Information System (INIS)

Ueno, Daisuke; Watanabe, Mafumi; Subramanian, Annamalai; Tanaka, Hiroyuki; Fillmann, Gilberto; Lam, Paul K.S.; Zheng, Gene J.; Muchtar, Muswerry; Razak, Hamidah; Prudente, Maricar; Chung, Kyu-Hyuck; Tanabe, Shinsuke

2005-01-01

In order to elucidate the global distribution of dioxins and related compounds, such as PCDDs, PCDFs and coplanar PCBs, levels of these compounds were determined in the muscle of skipjack tuna (Katsuwonus pelamis) collected from the offshore waters and open seas near Japan, Taiwan, Philippines, Indonesia, Seychelles and Brazil, and the Japan Sea, the East China Sea, the South China Sea, the Indian Ocean and the North Pacific Ocean. PCDDs, PCDFs and coplanar PCBs were detected in almost all the specimens collected from all the locations surveyed, indicating widespread contamination by these compounds in the marine environment. Higher concentrations of dioxins and coplanar PCBs were detected in the samples from temperate Asian regions, plausibly due to larger usage and anthropogenic generation in highly industrialized countries around the East China Sea and the South China Sea, such as Japan, Korea, Taiwan, Hong Kong and coastal China. - Global pollution monitoring of PCDD/Fs and coplanar PCBs in offshore water and open sea were conducted using skipjack tuna as bioindicator

3D printed biomimetic whisker-based sensor with co-planar capacitive sensing

NARCIS (Netherlands)

Delamare, John; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

2016-01-01

This paper describes the development of a whisker sensor for tactile purposes and which is fabricated by 3D printing. Read-out consists of a capacitive measurement of a co-planar capacitance which is affected by a dielectric that is driven into the electric field of the capacitance. The current

Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

Directory of Open Access Journals (Sweden)

J. Jilkova

2008-04-01

Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

LE «SOTTIGLIEZZE DI CERTA DIDATTICA SUPERLATIVA» DELLA GRAMMATICA ELEMENTARE: STORIA (ATTESTATA DEL METODO RAFFORZISTA (1814-1914

Directory of Open Access Journals (Sweden)

Michela Dota

2018-03-01

Full Text Available Il contributo ripercorre la storia e le peculiarità del metodo rafforzista, metodo glottodidattico per l’insegnamento della lettura e della scrittura. Il metodo, nato in Italia nel primo Ottocento, nell’epoca postunitaria era praticato nelle scuole elementari soprattutto dell’Italia meridionale, nonché nelle scuole reggimentali e in alcuni istituti per sordomuti. Le sue fondamenta, aberranti rispetto alla norma ortografica e ortoepica tradizionale, lo resero obiettivo di un tenace ostracismo da parte del Ministero dell’Istruzione pubblica, sostenuto per questa occasione da due tra i più eminenti glottologi dell’epoca: Graziadio Isaia Ascoli e Francesco Lorenzo Pullè. Il metodo finì per estinguersi nel secondo decennio del Novecento.   The history of the “metodo rafforzista” for teaching Italian (1814-1914 This article retraces the history and peculiarities of the “metodo rafforzista”, a language teaching method developed in Italy during the first part of 1800s. In the post-Unitarian period, it was used in elementary schools, especially in Southern Italy, and also in military schools and in some institutes for the Deaf and Dumb. Orthographic and orthoepic models proposed by the “metodo rafforzista” diverged from rules of traditional Italian grammar. The method, supported by Graziadio Isaia Ascoli and Francesco Lorenzo Pullè, two of the most distinguished Italian linguists at that time, was subsequently rejected by the Ministry of Public Education, and it vanished during the second half of 1900s.

Nanoscale constrictions in superconducting coplanar waveguide resonators

Energy Technology Data Exchange (ETDEWEB)

Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando, E-mail: fluis@unizar.es [Instituto de Ciencia de Materiales de Aragón, CSIC—Universidad de Zaragoza, 50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Sesé, Javier [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Atkinson, James; Barco, Enrique del [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Sánchez-Azqueta, Carlos [Dpto. de Ingeniería Electrónica y Telecomunicaciones, Universidad de Zaragoza, 50009 Zaragoza (Spain); Majer, Johannes [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna (Austria)

2014-10-20

We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.

Scienza e conoscenza: sul valore del metodo scientifico

Directory of Open Access Journals (Sweden)

Riccardo Luciano Appolloni

2014-05-01

Full Text Available L’antico problema di riconoscere una forma di conoscenza oggettivae fondata è ancora vivo; in questo scritto cercheremo di capire se la scienza moderna possa essere una forma di conoscenza tale e, quindi, privilegiata. A tal fine ci serviremo del pensiero di alcuni epistemologi e scienziati. In particolare, nel trattare il problema del valore epistemologico del metodo scientifico, non potremo esimerci dal fare i conti con l’anarchismo metodologico di Paul K. Feyerabend, verso il quale l’esito del presente articolo sarà fondamentalmente critico. A partire dai fecondi spunti di questo filosofo, tenteremo dapprima di analizzare i caratteri distintivi della scienza e del suo metodo rispetto ad altre forme di sapere; quindi, cercheremo di individuare alcuni limiti della conoscenza razionale.

LHC data and cosmic ray coplanarity at superhigh energies

Directory of Open Access Journals (Sweden)

Mukhamedshin R.A.

2017-01-01

Full Text Available A new phenomenological model FANSY 2.0 is designed, which makes it possible to simulate hadron interactions via traditional and coplanar generation of most energetic particles as well as to reproduce a lot of LHC (ALICE, ATLAS, CMS, TOTEM, LHCf data. Features of the model are compared with LHC data. Problems of coplanarity are considered and a testing experiment is proposed.

An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

Science.gov (United States)

Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

2016-04-01

To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

Energy flow analysis of out-of-plane vibration in coplanar coupled finite Mindlin plates

Directory of Open Access Journals (Sweden)

Young-Ho Park

2015-01-01

Full Text Available : In this paper, an Energy Flow Analysis (EFA for coplanar coupled Mindlin plates was performed to estimate their dynamic responses at high frequencies. Mindlin plate theory can consider the effects of shear distortion and rotatory inertia, which are very important at high frequencies. For EFA for coplanar coupled Mindlin plates, the wave transmission and reflection relationship for progressing out-of-plane waves (out-of-plane shear wave, bending dominant flexural wave, and shear dominant flexural wave in coplanar coupled Mindlin plates was newly derived. To verify the validity of the EFA results, numerical analyses were performed for various cases where coplanar coupled Mindlin plates are excited by a harmonic point force, and the energy flow solutions for coplanar coupled Mindlin plates were compared with the classical solutions in the various conditions.

Dynamics of dielectric barrier discharges in coplanar arrangements

International Nuclear Information System (INIS)

Gibalov, Valentin I; Pietsch, Gerhard J

2004-01-01

The development of a discharge channel in coplanar dielectric barrier arrangements is investigated numerically. Its behaviour in oxygen, like the spatial and temporal distributions of the field strength, charged and neutral particles and energy density, is described in detail. It is found that the streamer development is mainly determined by photoemission. A cathode layer appears near the position where the cathode directed streamer touches the dielectric surface. Secondary electron emission by ion collisions becomes significant and the parameters of the cathode layer are near those of a normal glow discharge. The charge transfer and energy release happen in the conductive channel of the discharge, which appears on the dielectric surface as a result of the cathode streamer development. The field strength in the conductive channel is nearly constant and about 70-100 Td in oxygen and air

Numerical and experimental modeling of liquid metal thin film flows in a quasi-coplanar magentic field

Energy Technology Data Exchange (ETDEWEB)

Morley, Neil B. [Univ. of California, Los Angeles, CA (United States)

1994-01-01

Liquid metal film protection of plasma-facing surfaces in fusion reactors is proposed in an effort to counter the adverse effects of high heat and particle fluxes from the burning plasma. Concerns still exist about establishing the required flow in presence of strong magnetic fields and plasma momentum flux typical of a reactor environment. In this work, the flow behavior of the film is examined under such conditions. Analysis of MHD equations as they apply to liquid metal flows with a free surface in the fully-developed limit was undertaken. Solution yields data for velocity profiles and uniform film heights vs key design parameters (channel size, magnetic field magnitude/orientation, channel slope, wall conductivity). These results are compared to previous models to determine accuracy of simplifying assumptions, in particular Hartmann averaging of films along {rvec B}. Effect of a plasma momentum flux on the thin films is also analyzed. The plasma momentum is strong enough in the cases examined to seriously upset the film, especially for lighter elements like Li. Ga performed much better and its possible use is bolstered by calculations. In an experiment in the MeGA-loop MHD facility, coplanar, wide film flow was found to be little affected by the magnetic field due to the elongated nature of the film. Both MHD drag and partial laminarization are observed, supporting the fully- developed film model predictions of the onset of MHD drag and duct flow estimations for flow laminarization.

Numerical and experimental modeling of liquid metal thin film flows in a quasi-coplanar magentic field

International Nuclear Information System (INIS)

Morley, N.B.

1994-01-01

Liquid metal film protection of plasma-facing surfaces in fusion reactors is proposed in an effort to counter the adverse effects of high heat and particle fluxes from the burning plasma. Concerns still exist about establishing the required flow in presence of strong magnetic fields and plasma momentum flux typical of a reactor environment. In this work, the flow behavior of the film is examined under such conditions. Analysis of MHD equations as they apply to liquid metal flows with a free surface in the fully-developed limit was undertaken. Solution yields data for velocity profiles and uniform film heights vs key design parameters (channel size, magnetic field magnitude/orientation, channel slope, wall conductivity). These results are compared to previous models to determine accuracy of simplifying assumptions, in particular Hartmann averaging of films along rvec B. Effect of a plasma momentum flux on the thin films is also analyzed. The plasma momentum is strong enough in the cases examined to seriously upset the film, especially for lighter elements like Li. Ga performed much better and its possible use is bolstered by calculations. In an experiment in the MeGA-loop MHD facility, coplanar, wide film flow was found to be little affected by the magnetic field due to the elongated nature of the film. Both MHD drag and partial laminarization are observed, supporting the fully- developed film model predictions of the onset of MHD drag and duct flow estimations for flow laminarization

MXene-on-Paper Coplanar Microsupercapacitors

KAUST Repository

Kurra, Narendra

2016-09-05

A simple and scalable direct laser machining process to fabricate MXene-on-paper coplanar microsupercapacitors is reported. Commercially available printing paper is employed as a platform in order to coat either hydrofluoric acid-etched or clay-like 2D Ti3C2 MXene sheets, followed by laser machining to fabricate thick-film MXene coplanar electrodes over a large area. The size, morphology, and conductivity of the 2D MXene sheets are found to strongly affect the electrochemical performance due to the efficiency of the ion-electron kinetics within the layered MXene sheets. The areal performance metrics of Ti3C2 MXene-on-paper microsupercapacitors show very competitive power-energy densities, comparable to the reported state-of-the-art paper-based microsupercapacitors. Various device architectures are fabricated using the MXene-on-paper electrodes and successfully demonstrated as a micropower source for light emitting diodes. The MXene-on-paper electrodes show promise for flexible on-paper energy storage devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimal Non-Coplanar Launch to Quick Rendezvous

National Research Council Canada - National Science Library

Sears, Gregory

1997-01-01

The purpose of this study was to determine the feasibility of launching a Delta Clipper-like vehicle on an optimal, non-coplanar trajectory to rendezvous with an earth orbiting object in one orbit or less...

Low loss superconducting titanium nitride coplanar waveguide resonators

International Nuclear Information System (INIS)

Vissers, M. R.; Gao, J.; Wisbey, D. S.; Hite, D. A.; Pappas, D. P.; Tsuei, C. C.; Corcoles, A. D.; Steffen, M.

2010-01-01

Thin films of TiN were sputter-deposited onto Si and sapphire wafers with and without SiN buffer layers. The films were fabricated into rf coplanar waveguide resonators, and internal quality factor measurements were taken at millikelvin temperatures in both the many photon and single photon limits, i.e., high and low electric field regimes, respectively. At high field, we found the highest internal quality factors (∼10 7 ) were measured for TiN with predominantly a (200)-TiN orientation. The (200)-TiN is favored for growth at high temperature on either bare Si or SiN buffer layers. However, growth on bare sapphire or Si(100) at low temperature resulted in primarily a (111)-TiN orientation. Ellipsometry and Auger measurements indicate that the (200)-TiN growth on the bare Si substrates is correlated with the formation of a thin, ≅2 nm, layer of SiN during the predeposition procedure. On these surfaces we found a significant increase of Q i for both high and low electric field regimes.

Quality factor of a transmission line coupled coplanar waveguide resonator

Energy Technology Data Exchange (ETDEWEB)

Besedin, Ilya [National University for Science and Technology (MISiS), Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Menushenkov, Alexey P. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

2018-12-15

We investigate analytically the coupling of a coplanar waveguide resonator to a coplanar waveguide feedline. Using a conformal mapping technique we obtain an expression for the characteristic mode impedances and coupling coefficients of an asymmetric multi-conductor transmission line. Leading order terms for the external quality factor and frequency shift are calculated. The obtained analytical results are relevant for designing circuit-QED quantum systems and frequency division multiplexing of superconducting bolometers, detectors and similar microwave-range multi-pixel devices. (orig.)

Influence of infrared stimulation on spectroscopy characteristics of co-planar grid CdZnTe detectors

International Nuclear Information System (INIS)

Fjodorov, V.; Ivanov, V.; Loutchanski, A.

2015-01-01

It was previously found that illumination with monochromatic infrared (IR) light with wavelengths close to the absorption edge of the CdZnTe exert significant positive influence on the spectrometric characteristics of quasi-hemispherical CdZnTe detectors at room temperature. In this paper, preliminary results of IR stimulation on the spectrometric characteristics of coplanar-grid CdZnTe detectors as well as results of further studies of planar and quasi-hemispherical detectors are presented. Coplanar-grid detectors of 10 mm x 10 mm x 10 mm from Redlen Technologies and commercial available IR LEDs with different wavelengths of 800-1000 nm were used in the experiments. Influence of intensity and direction of IR illumination on the detector's characteristics was studied. Analysis of signals shapes from the preamplifiers outputs at registration of alpha particles showed that IR illumination leads to a change in the shapes of these signals. This may indicate changes in electric fields distributions. An improvement in energy resolution at gamma-energy of 662 keV was observed with quasi-hemispherical and co-planar detectors at the certain levels of IR illumination intensity. The most noticeable effect of IR stimulation was observed with quasi-hemispherical detectors. It is due with optimization of charge collection conditions in the quasi-hemispherical detectors under IT stimulation. (authors)

A Numerical Study of Low-Thrust Limited Power Trajectories between Coplanar Circular Orbits in an Inverse-Square Force Field

Directory of Open Access Journals (Sweden)

Sandro da Silva Fernandes

2012-01-01

Full Text Available A numerical study of optimal low-thrust limited power trajectories for simple transfer (no rendezvous between circular coplanar orbits in an inverse-square force field is performed by two different classes of algorithms in optimization of trajectories. This study is carried out by means of a direct method based on gradient techniques and by an indirect method based on the second variation theory. The direct approach of the trajectory optimization problem combines the main positive characteristics of two well-known direct methods in optimization of trajectories: the steepest-descent (first-order gradient method and a direct second variation (second-order gradient method. On the other hand, the indirect approach of the trajectory optimization problem involves two different algorithms of the well-known neighboring extremals method. Several radius ratios and transfer durations are considered, and the fuel consumption is taken as the performance criterion. For small-amplitude transfers, the results are compared to the ones provided by a linear analytical theory.

Non-coplanar volumetric-modulated arc therapy (VMAT) for craniopharyngiomas reduces radiation doses to the bilateral hippocampus: a planning study comparing dynamic conformal arc therapy, coplanar VMAT, and non-coplanar VMAT

International Nuclear Information System (INIS)

Uto, Megumi; Mizowaki, Takashi; Ogura, Kengo; Hiraoka, Masahiro

2016-01-01

Recent studies suggest that radiation-induced injuries to the hippocampus play important roles in compromising neurocognitive functioning for patients with brain tumors and it could be important to spare the hippocampus using modern planning methods for patients with craniopharyngiomas. As bilateral hippocampus are located on the same level as the planning target volume (PTV) in patients with craniopharyngioma, it seems possible to reduce doses to hippocampus using non-coplanar beams. While the use of non-coplanar beams in volumetric-modulated arc therapy (VMAT) of malignant intracranial tumors has recently been reported, no dosimetric comparison has yet been made between VMAT using non-coplanar arcs (ncVMAT) and VMAT employing only coplanar arcs (coVMAT) among patients with craniopharyngiomas. We performed a planning study comparing dose distributions to the PTV, hippocampus, and other organs at risk (OAR) of dynamic conformal arc therapy (DCAT), coVMAT, and ncVMAT. DCAT, coVMAT, and ncVMAT plans were created for 10 patients with craniopharyngiomas. The prescription dose was 52.2 Gy in 29 fractions, and 99 % of each PTV was covered by 90 % of the prescribed dose. The maximum dose was held below 107 % of the prescribed dose. CoVMAT and ncVMAT plans were formulated to satisfy the following criteria: the doses to the hippocampus were minimized, and the doses to the OAR were similar to or lower than those of DCAT. The mean equivalent doses in 2-Gy fractions to 40 % of the volumes of the bilateral hippocampus [EQD 2 (40% hippos )] were 15.4/10.8/6.5 Gy for DCAT/coVMAT/ncVMAT, respectively. The EQD 2 (40% hippos ) for ncVMAT were <7.3 Gy, which is the threshold predicting cognitive impairment, as defined by Gondi et al.. The mean doses to normal brain tissue and the conformity indices were similar for the three plans, and the homogeneity indices were significantly better for coVMAT and ncVMAT compared with DCAT. NcVMAT is more appropriate than DCAT and coVMAT for

Observing electron spin resonance between 0.1 and 67 GHz at temperatures between 50 mK and 300 K using broadband metallic coplanar waveguides

Science.gov (United States)

Wiemann, Yvonne; Simmendinger, Julian; Clauss, Conrad; Bogani, Lapo; Bothner, Daniel; Koelle, Dieter; Kleiner, Reinhold; Dressel, Martin; Scheffler, Marc

2015-05-01

We describe a fully broadband approach for electron spin resonance (ESR) experiments, where it is possible to tune not only the magnetic field but also the frequency continuously over wide ranges. Here, a metallic coplanar transmission line acts as compact and versatile microwave probe that can easily be implemented in different cryogenic setups. We perform ESR measurements at frequencies between 0.1 and 67 GHz and at temperatures between 50 mK and room temperature. Three different types of samples (Cr3+ ions in ruby, organic radicals of the nitronyl-nitroxide family, and the doped semiconductor Si:P) represent different possible fields of application for the technique. We demonstrate that an extremely large phase space in temperature, magnetic field, and frequency for ESR measurements, substantially exceeding the range of conventional ESR setups, is accessible with metallic coplanar lines.

Dosimetric comparison between intensity-modulated with coplanar field and 3D conformal radiotherapy with noncoplanar field for postocular invasion tumor.

Science.gov (United States)

Wenyong, Tu; Lu, Liu; Jun, Zeng; Weidong, Yin; Yun, Li

2010-01-01

This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 degrees , 30-45 degrees , 240-270 degrees , and 310-335 degrees degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D(max) and D(min) dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed. 2010 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Dosimetric Comparison Between Intensity-Modulated with Coplanar Field and 3D Conformal Radiotherapy with Noncoplanar Field for Postocular Invasion Tumor

International Nuclear Information System (INIS)

Tu Wenyong; Liu Lu; Zeng Jun; Yin Weidong; Li Yun

2010-01-01

This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 deg., 30-45 deg., 240-270 deg., and 310-335 deg. degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D max and D min dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p < 0.001). Physical endpoints for target showed the mean target dose to be low in the CF IMRT plan, caused by a large target dose in homogeneity (p < 0.001). The impact of NCF 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed.

Coplanar-grid CdZnTe detector with three-dimensional position sensitivity

International Nuclear Information System (INIS)

Luke, P.N.; Amman, M.; Lee, J.S.; Yaver, H.

1998-06-01

A 3-dimensional position-sensitive coplanar-grid detector design for use with compound semiconductors is described. This detector design maintains the advantage of a coplanar-grid detector in which good energy resolution can be obtained from materials with poor charge transport. Position readout in two dimensions is accomplished using proximity-sensing electrodes adjacent to the electron-collecting grid electrode of the detector. Additionally, depth information is obtained by taking the ratio of the amplitudes of the collecting grid signal and the cathode signal. Experimental results from a prototype CdZnTe detector are presented

Coplanar Electrode Layout Optimized for Increased Sensitivity for Electrical Impedance Spectroscopy

DEFF Research Database (Denmark)

Clausen, Casper Hyttel; Skands, Gustav Erik; Bertelsen, Christian Vinther

2015-01-01

This work describes an improvement in the layout of coplanar electrodes for electrical impedance spectroscopy. We have developed, fabricated, and tested an improved electrode layout, which improves the sensitivity of an impedance flow cytometry chip. The improved chip was experimentally tested...... and compared to a chip with a conventional electrode layout. The improved chip was able to discriminate 0.5 mu m beads from 1 mu m as opposed to the conventional chip. Furthermore, finite element modeling was used to simulate the improvements in electrical field density and uniformity between the electrodes...... of the new electrode layout. Good agreement was observed between the model and the obtained experimental results....

A secondary, coplanar design Ni/MCM-41/Zn microbattery

Science.gov (United States)

Meskon, S. R.; Othman, R.; Ani, M. H.

2018-01-01

A secondary Ni/Zn microbattery (∼200 µm thick) has been developed in a coplanar electrode configuration. The cell is essentially of a circular shape (∼30 mm in diameter) consisting of a fine circular ring (cathode) and a circle (anode) split apart (~800 µm). Unlike the stacking cell architecture, coplanar configuration offers simple design, ease of fabrication and eventually cost saving. The use of MCM-41 mesoporous silica as the membrane separator cum electrolyte reservoir enables the successful implementation of coplanar configuration. The fabrication of Ni/Zn microbattery first begins with electrodeposition of zinc (Zn) and nickel hydroxide (Ni(OH)2) thin films onto patterned FR4 printed circuit board, followed by deposition of zinc oxide (ZnO) slurry onto the zinc active layer, and finally ends by multiple drop-coating procedures of MCM-41 from its precursor solution at ambient temperature. Once a potassium hydroxide (6 M KOH)/MCM-41 electrolyte-separator mixture is incorporated, the cell is sealed with an acrylic sheet and epoxy adhesive. The fabricated microbatteries were capable to sustain around 130 deep charge-discharge cycles. When rated at 0.1 mA, the energy density of the microbattery was around 3.82 Wh l-1 which is suitable for low rate applications and storage for micro energy harvesters such as piezoelectric generators.

Observing electron spin resonance between 0.1 and 67 GHz at temperatures between 50 mK and 300 K using broadband metallic coplanar waveguides

International Nuclear Information System (INIS)

Wiemann, Yvonne; Simmendinger, Julian; Clauss, Conrad; Bogani, Lapo; Dressel, Martin; Scheffler, Marc; Bothner, Daniel; Koelle, Dieter; Kleiner, Reinhold

2015-01-01

We describe a fully broadband approach for electron spin resonance (ESR) experiments, where it is possible to tune not only the magnetic field but also the frequency continuously over wide ranges. Here, a metallic coplanar transmission line acts as compact and versatile microwave probe that can easily be implemented in different cryogenic setups. We perform ESR measurements at frequencies between 0.1 and 67 GHz and at temperatures between 50 mK and room temperature. Three different types of samples (Cr 3+ ions in ruby, organic radicals of the nitronyl-nitroxide family, and the doped semiconductor Si:P) represent different possible fields of application for the technique. We demonstrate that an extremely large phase space in temperature, magnetic field, and frequency for ESR measurements, substantially exceeding the range of conventional ESR setups, is accessible with metallic coplanar lines

Observing electron spin resonance between 0.1 and 67 GHz at temperatures between 50 mK and 300 K using broadband metallic coplanar waveguides

Energy Technology Data Exchange (ETDEWEB)

Wiemann, Yvonne; Simmendinger, Julian; Clauss, Conrad; Bogani, Lapo; Dressel, Martin; Scheffler, Marc [1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany); Bothner, Daniel; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen (Germany)

2015-05-11

We describe a fully broadband approach for electron spin resonance (ESR) experiments, where it is possible to tune not only the magnetic field but also the frequency continuously over wide ranges. Here, a metallic coplanar transmission line acts as compact and versatile microwave probe that can easily be implemented in different cryogenic setups. We perform ESR measurements at frequencies between 0.1 and 67 GHz and at temperatures between 50 mK and room temperature. Three different types of samples (Cr{sup 3+} ions in ruby, organic radicals of the nitronyl-nitroxide family, and the doped semiconductor Si:P) represent different possible fields of application for the technique. We demonstrate that an extremely large phase space in temperature, magnetic field, and frequency for ESR measurements, substantially exceeding the range of conventional ESR setups, is accessible with metallic coplanar lines.

Coplanar Electrode Layout Optimized for Increased Sensitivity for Electrical Impedance Spectroscopy

Directory of Open Access Journals (Sweden)

Casper Hyttel Clausen

2014-12-01

Full Text Available This work describes an improvement in the layout of coplanar electrodes for electrical impedance spectroscopy. We have developed, fabricated, and tested an improved electrode layout, which improves the sensitivity of an impedance flow cytometry chip. The improved chip was experimentally tested and compared to a chip with a conventional electrode layout. The improved chip was able to discriminate 0.5 μm beads from 1 μm as opposed to the conventional chip. Furthermore, finite element modeling was used to simulate the improvements in electrical field density and uniformity between the electrodes of the new electrode layout. Good agreement was observed between the model and the obtained experimental results.

Optimized coplanar waveguide resonators for a superconductor–atom interface

Energy Technology Data Exchange (ETDEWEB)

Beck, M. A., E-mail: mabeck2@wisc.edu; Isaacs, J. A.; Booth, D.; Pritchard, J. D.; Saffman, M.; McDermott, R. [Department of Physics, University Of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)

2016-08-29

We describe the design and characterization of superconducting coplanar waveguide cavities tailored to facilitate strong coupling between superconducting quantum circuits and single trapped Rydberg atoms. For initial superconductor–atom experiments at 4.2 K, we show that resonator quality factors above 10{sup 4} can be readily achieved. Furthermore, we demonstrate that the incorporation of thick-film copper electrodes at a voltage antinode of the resonator provides a route to enhance the zero-point electric fields of the resonator in a trapping region that is 40 μm above the chip surface, thereby minimizing chip heating from scattered trap light. The combination of high resonator quality factor and strong electric dipole coupling between the resonator and the atom should make it possible to achieve the strong coupling limit of cavity quantum electrodynamics with this system.

Dynamic intensity-modulated non-coplanar arc radiotherapy (INCA) for head and neck cancer

International Nuclear Information System (INIS)

Krayenbuehl, Jerome; Davis, J. Bernard; Ciernik, I. Frank

2006-01-01

Background and purpose: To define the potential advantages of intensity-modulated radiotherapy (IMRT) applied using a non-coplanar dynamic arc technique for the treatment of head and neck cancer. Materials and methods: External beam radiotherapy (EBRT) was planned in ten patients with head and neck cancer using coplanar IMRT and non-coplanar arc techniques, termed intensity modulated non-coplanar arc EBRT (INCA). Planning target volumes (PTV1) of first order covered the gross tumor volume and surrounding clinical target volume treated with 68-70 Gy, whereas PTV2 covered the elective lymph nodes with 54-55 Gy using a simultaneous internal boost. Treatment plan comparison between IMRT and INCA was carried out using dose-volume histogram and 'equivalent uniform dose' (EUD). Results: INCA resulted in better dose coverage and homogeneity of the PTV1, PTV2, and reduced dose delivered to most of the organs at risk (OAR). For the parotid glands, a reduction of the mean dose of 2.9 (±2.0) Gy was observed (p 0.002), the mean dose to the larynx was reduced by 6.9 (±2.9) Gy (p 0.003), the oral mucosa by 2.4 (±1.1) Gy (p < 0.001), and the maximal dose to the spinal cord by 3.2 (±1.7) Gy (p = 0.004). The mean dose to the brain was increased by 3.0 (±1.4) Gy (p = 0.002) and the mean lung dose increased by 0.2 (±0.4) Gy (p = 0.87). The EUD suggested better avoidance of the OAR, except for the lung, and better coverage and dose uniformity were achieved with INCA compared to IMRT. Conclusion: Dose delivery accuracy with IMRT using a non-coplanar dynamic arc beam geometry potentially improves treatment of head and neck cancer

Double exchange model on triangular lattice: Non-coplanar spin configuration and phase transition near quarter filling

Energy Technology Data Exchange (ETDEWEB)

Zhang, G.P., E-mail: bugubird_zhang@hotmail.com [Department of Physics, Renmin University of China, Beijing 100872 (China); Zhang, Jian [3M Company, 3M Corporate Headquarters, 3M Center, St. Paul, MN 55144-1000 (United States); Zhang, Qi-Li [Data Center for High Energy Density Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Zhou, Jiang-Tao [College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Shangguan, M.H. [Department of Physics, Renmin University of China, Beijing 100872 (China)

2013-05-15

Unconventional anomalous Hall effect in frustrated pyrochlore oxides is originated from spin chirality of non-coplanar localized spins, which can also be induced by the competition between ferromagnetic (FM) double exchange interaction J{sub H} and antiferromagnetic superexchange interaction J{sub AF}. Here truncated polynomial expansion method and Monte Carlo simulation are adopted to investigate the above model on two-dimensional triangular lattice. We discuss the influence of the range of FM-type spin–spin correlation and strong electron–spin correlation on the truncation error of spin–spin correlation near quarter filling. Two peaks of the probability distribution of spin–spin correlation in non-coplanar spin configuration clearly show that non-coplanar spin configuration is an intermediate phase between FM and 120° spin phase. Near quarter filling, there is a phase transition from FM into non-coplanar and further into 120° spin phase when J{sub AF} continually increases. Finally the effect of temperature on the magnetic structure is discussed.

Development of gas ionization chambers with coplanar electrodes for alpha-ray spectrometry

International Nuclear Information System (INIS)

Iwasaki, Kenta; Tanaka, Naomichi; Murakami, Kohei; Hasebe, Nobuyuki; Kusano, Hiroki; Shibamura, Eido; Miyajima, Mitsuhiro

2016-01-01

A large-area alpha-ray spectrometer is required to measure the low level alpha emitters in environmental samples, which may be distributed in the vicinity of nuclear power plants. A gas ionization chamber with a coplanar electrode has attractive features such as with mechanical ruggedness, easy handling, easy fabrication of large electrode, and relatively well-known performance. We have investigated the performance of a gas ionization chamber with a coplanar electrode for alpha-ray spectrometry, particularly in the energy resolution. The present experiment shows that the energy resolution in the full width at half maximum (FWHM) is 129 keV (= 2.7%) for alpha-rays from Np with an energy of 4.78 MeV, 120 keV (= 2.2%) for those with 5.49 MeV from Am, and 109 keV (= 1.9%) for those with 5.81 MeV from Cm. It is found that the energy resolution obtained at the present experiment is dominated in the electronic noise caused by the large capacitance existed between the collecting anode (CA) and non-collecting anode (NCA) in the coplanar electrode. (author)

A comparison of dioxins, dibenzofurans and coplanar PCBs in uncooked and broiled ground beef, catfish and bacon.

Science.gov (United States)

Schecter, A; Dellarco, M; Päpke, O; Olson, J

1998-01-01

The primary source of dioxins (PCDDs), dibenzofurans (PCDFs) and coplanar PCBs for the general population is food, especially meat, fish, and dairy products. However, most data on the levels of these chemicals is from food in the raw or uncooked state. We report here the effect of one type of cooking (broiling) on the levels of PCDDs, PCDFs, and coplanar PCBs in ground beef (hamburger), bacon and catfish. Samples of hamburger, bacon, and catfish were broiled and compared to uncooked samples in order to measure changes in the amounts of dioxins in cooked food. The total amount of PCDD, PCDF, and coplanar PCB TEQ decreased by approximately 50% on average for each portion as a result of broiling the hamburger, bacon and catfish specimens. The mean concentration (pg TEQ/kg, wet weight) of PCDDs, PCDFs, and coplanar PCBs, however, remained the same in the hamburger, increased by 83% in the bacon, and decreased by 34% in the catfish. On average, the total measured concentration (pg/kg) of the congeners of PCDDs, PCDFs, and coplanar PCBs increased 14% in the hamburger, increased 29% in the bacon, and decreased 33% in the catfish.

Non-coplanar automatic beam orientation selection in cranial IMRT: a practical methodology

Energy Technology Data Exchange (ETDEWEB)

Llacer, Jorge [EC Engineering Consultants LLC, 130 Forest Hill Drive, Los Gatos, CA 95032 (United States); Li Sicong [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE 68198 (United States); Agazaryan, Nzhde; Solberg, Timothy D [Department of Radiation Oncology, University of California, Los Angeles, CA 90095 (United States); Promberger, Claus [BrainLAB AG, Kapellenstrasse 12, 85622 Feldkirchen (Germany)], E-mail: escalivat@jllacer.com, E-mail: sl1@unmc.edu, E-mail: NAgazaryan@mednet.ucla.edu, E-mail: claus.promberger@brainlab.com, E-mail: Timothy.Solberg@utsouthwestern.edu

2009-03-07

This paper proposes a method for automatic selection of beam orientations in non-coplanar cranial IMRT. Methods of computer vision, beam's eye view techniques and neural networks are used to define a new geometry-based methodology that leads to treatment plans for cranial lesions that are comparable in quality to those generated by experienced radiation physicists. The automatic beam selection (ABS) process can be carried out in clinically useful computation times, in 1 min or less for most cases. In the process of describing the ABS process, it is shown that the cranial beam orientation optimization problem is mathematically ill posed, with the expectation that a large number of solutions will lead to similar results. Nevertheless, there are better and worse solutions and we show that the proposed ABS process, by its design, has to lead to one of the better ones. We have carried out extensive tests with 14 patients with beam selection tasks ranging from the rather simple to quite complex. The ABS process has always yielded optimizations with results that are considered good for clinic use. Seven-beam coplanar optimizations for some of the patients have also been investigated. Comparisons with non-coplanar optimizations indicate in which cases the simpler coplanar plans can be used to advantage. Parameters used in the comparisons are dose-volume histograms, minimum and maximum PTV doses, equivalent uniform doses for the PTV and OARs, and treatment volume, conformity and normal tissue indices. It is felt that the current ABS methodology is ready for extensive clinical tests.

PCDDs, PCDFs, and coplanar PCBs in albatross from the North Pacific and Southern Oceans: levels, patterns, and toxicological implications.

Science.gov (United States)

Tanabe, Shinsuke; Watanabe, Mafumi; Minh, Tu Binh; Kunisue, Tatsuya; Nakanishi, Shigeyuki; Ono, Hitoshi; Tanaka, Hiroyuki

2004-01-15

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (coplanar PCBs) were determined in five albatross species collected from the North Pacific and Southern Oceans to assess the north-south differences in residue levels, accumulation patterns, and toxic potential. Black-footed and Laysan albatrosses from the North Pacific Ocean contained higher levels of PCDD/Fs and coplanar PCBs than albatrosses from the Southern Ocean, indicating that emission sources of these contaminants were predominant in the northern hemisphere. Residue levels in albatrosses from the remote North Pacific Ocean far from the point source of pollution were comparable to or higher than those in terrestrial and coastal birds from contaminated areas in developed nations, suggesting the specific exposure and accumulation of PCDD/Fs and coplanar PCBs in albatross. The long life span and ingestion of plastic resin pellets by albatrosses could be the plausible explanations for the elevated accumulation of persistent and lipophilic contaminants including PCDD/Fs and coplanar PCBs in these birds. Relative proportions of PCDFs and coplanar PCBs in albatross were higher than those observed in birds inhabiting terrestrial and coastal areas, suggesting that these toxic chemicals may have higher transportability by air and water than PCDDs. Congener patterns of PCDD/Fs in albatross showed less variability as compared to those in terrestrial species, indicating that contamination patterns of PCDD/Fs were similar within the open ocean environment. Contributions of PCDD/Fs to total TEQs in albatrosses from the open ocean were generally lower than those in terrestrial birds, suggesting different toxic potency of PCDD/Fs and coplanar PCBs on animals inhabiting open ocean and terrestrial environment. Whereas albatrosses from southern oceans retained lower TEQ concentrations, possible adverse effects of PCDD/Fs and coplanar PCBs

Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator

Energy Technology Data Exchange (ETDEWEB)

Ueno, D.; Watanabe, M.; Subraminian, A.N.; Tanabe, S. [Ehime Univ. (Japan); Tanaka, H. [National Research Inst. of Fisheries and Environment of Inland Sea (Japan); Fillmann, G. [Fundacao Univ. Federal do Rio Grande (Brazil); Lam, P.K.S.; Zheng, G.J. [City Univ. of Hong Kong (Hong Kong); Muchtar, M.; Razak, H. [Indonesian Inst. of Sciences (Indonesia); Prudente, M. [De La Salle Univ. (Philippines); Chung, K. [Sungkyunkwan Univ. (Korea)

2004-09-15

Worldwide contamination by dioxins and related compounds, such as polychlorinated dibenzop- dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) representing persistent organic pollutants (POPs) have been of great concern due to their persistency in the environment, highly bioaccumulative nature and adverse effects on wildlife and humans. Several studies on air samples and marine organisms from open seas suggested a long range transport of these compounds through atomosphere. Although several investigators have monitored dioxins pollution in localized areas, information on the global distribution of dioxins which can explain their atomospheric transport, behavior and fate are still limited. Skipjack tuna is primarily distributed from offshore waters to open seas in tropical and temperate regions almost all over the world such as the Pacific, Atlantic and Indian Oceans6. This species is an important commercial fish and its ecology and biology has been well studied. Moreover, suitability of skipjack tuna for global monitoring of organic pollutants (DDTs, HCHs PBDEs, organotins, etc.) has been established in our previous report, indicating that migration pattern, growth stage and sex of these animals have no or little effect on the variations of POPs residue levels in their bodies. Hence this species reflected POPs pollution levels in seawater when and where they were collected, caused by the rapid equilibrium partitioning between seawater and body lipid. These facts made skipjack tuna a suitable bioindicator for monitoring the contamination status of dioxins and related compounds. The objectives of this study are to elucidate the global distribution of dioxins (PCDD/Fs and coplanar PCBs) in offshore waters and open seas, and to understand the transport and behaviour of these chemicals using skipjack tuna as bioindicator.

Dynamical history of coplanar two-satellite systems

International Nuclear Information System (INIS)

Ruskol, E.L.; Nikolajeva, E.V.; Syzdykov, A.S.

1975-01-01

One of the possible early states of the Earth-Moon system was a system of several large satellites around the Earth. The dynamical evolution of coplanar three-body systems is studied; a planet (Earth) and two massive satellites (proto-moons) with geocentric orbits of slightly different radii. Such configurations may arise in multiple satellite systems receding from a planet due to tidal friction. The numerical integration of the equations of motion shows that initially circular Keplerian orbits are soon transformed into disturbed elliptic orbits which are intersecting. The life-time of such a coplanar system between two probable physical collisions of satellites is roughly from one day to one year for satellite systems with radii less than 20 R(Earth), and may reach 100 yr for three-dimensional systems. This time-scale is short in comparison with the duration of the removal of satellites due to tides raised on the planet, which is estimated as 10 6 -10 8 yr for the same orbital dimensions. Therefore, the life-time of a system of several proto-moons is mainly determined by their tidal interactions with the Earth. For conditions which we have considered, the most probable result of the evolution was coalescence of satellites as the consequence of the collisions. (Auth.)

Estudio numerico y experimental del proceso de soldeo MIG sobre la aleacion 6063--T5 utilizando el metodo de Taguchi

Science.gov (United States)

Meseguer Valdenebro, Jose Luis

improvement on mechanical properties in aluminum metal joint. Los procesos de soldadura por arco electrico representan unas de las tecnicas mas utilizadas en los procesos de fabricacion de componentes mecanicos en la industria moderna. Los procesos de soldeo por arco se han adaptado a las necesidades actuales, haciendose un modo de fabricacion flexible y versatil. Los resultados obtenidos numericamente en el proceso de soldadura son validados experimentalmente. Los principales metodos numericos mas empleados en la actualidad son tres, metodo por diferencias finitas, metodos por elementos finitos y metodo por volumenes finitos. El metodo numerico mas empleado para el modelado de uniones soldadas, es el metodo por elementos finitos, debido a que presenta una buena adaptacion a las condiciones geometricas y de contorno ademas de que existe una diversidad de programas comerciales que utilizan el metodo por elementos finitos como base de calculo. Este trabajo de investigacion presenta un estudio experimental de una union soldada mediante el proceso MIG de la aleacion de aluminio 6063-T5. El metodo numerico se valida experimentalmente aplicando el metodo de los elementos finitos con el programa de calculo ANSYS. Los resultados experimentales obtenidos son: las curvas de enfriamiento, el tiempo critico de enfriamiento t4/3, geometria del cordon, microdurezas obtenidas en la union soldada, zona afectada termicamente y metal base, dilucion del proceso, areas criticas intersecadas entre las curvas de enfriamiento y la curva TTP. Los resultados numericos son: las curvas del ciclo termico, que representan tanto el calentamiento hasta alcanzar la temperatura maxima y un posterior enfriamiento. Se calculan el tiempo critico de enfriamiento t4/3, el rendimiento termico y se representa la geometria del cordon obtenida experimentalmente. La zona afectada termicamente se obtiene diferenciando las zonas que se encuentran a diferentes temperaturas, las areas criticas intersecadas entre las

Triple differential cross-sections of Ne (2s2) in coplanar to perpendicular plane geometry

Science.gov (United States)

Chen, L. Q.; Khajuria, Y.; Chen, X. J.; Xu, K. Z.

2003-10-01

The distorted wave Born approximation (DWBA) with the spin averaged static exchange potential has been used to calculate the triple differential cross-sections (TDCSs) for Ne (2s^2) ionization by electron impact in coplanar to perpendicular plane symmetric geometry at 110.5 eV incident electron energy. The present theoretical results at gun angles Psi = 0^circ (coplanar symmetric geometry) and Psi = 90^circ (perpendicular plane geometry) are in satisfactory agreement with the available experimental data. A deep interference minimum appears in the TDCS in the coplanar symmetric geometry and a strong peak at scattering angle xi = 90^circ caused by the single collision mechanism has been observed in the perpendicular plane geometry. The TDCSs at the gun angles Psi = 30^circ, and Psi = 60^circ are predicted.

Coplanar UHF RFID tag antenna with U-shaped inductively coupled feed for metallic applications.

Directory of Open Access Journals (Sweden)

Karrar Naji Salman

Full Text Available In this paper, we present a novel compact, coplanar, tag antenna design for metallic objects. Electrically small antenna has designed for a UHF RFID (860-960 MHz based on a proximity-coupled feed through. Furthermore, two symmetrical Via-loaded coplanar grounds fed by a U-shaped inductively coupled feed through an embedded transmission line. This configuration results in an antenna with dimensions of 31 × 19.5 × 3.065 mm3 at 915 MHz, and the total gain for the antenna is 0.12 dBi. The Via-loaded coplanar and U-shaped inductively coupled feeds allow the antenna to provide flexible tuning in terms of antenna impedance. In addition, a figure of merit is applied for the proposed tag antenna, and the results are presented. The read range is measured to be 4.2 m, which is very close to simulated values. This antenna measurement shows very good agreement with simulations.

Coplanar stripline components for high frequency application

Science.gov (United States)

Goverdhanam, Kavita; Simons, Rainee N.; Dib, Nihad; Katehi, Linda P. B.

1996-01-01

In this paper, coplanar stripline discontinuities such as a slit, a right angle bend and a T-junction are characterized and their performance is parameterized with respect to frequency and geometry. Lumped equivalent circuits are presented for some of them. The element values are obtained from the measured discontinuity scattering (S) parameters. The experimental results are compared with theoretical data obtained using the Finite Difference Time Domain (FD-TD) technique for validation and show very good agreement.

PLATFORM DEFORMATION PHASE CORRECTION FOR THE AMiBA-13 COPLANAR INTERFEROMETER

Energy Technology Data Exchange (ETDEWEB)

Liao, Yu-Wei; Lin, Kai-Yang; Huang, Yau-De; Ho, Paul T. P.; Chen, Ming-Tang; Locutus Huang, Chih-Wei; Koch, Patrick M.; Nishioka, Hiroaki; Umetsu, Keiichi; Han, Chih-Chiang; Li, Chao-Te; Martin-Cocher, Pierre; Oshiro, Peter [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Proty Wu, Jiun-Huei; Cheng, Tai-An; Fu, Szu-Yuan; Wang, Fu-Cheng [Department of Physics, Institute of Astrophysics, and Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Liu, Guo-Chin [Department of Physics, Tamkang University, 251-37 Tamsui, New Taipei City, Taiwan (China); Molnar, Sandor M. [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Chang, Yu-Yen, E-mail: ywliao@asiaa.sinica.edu.tw, E-mail: jhpw@phys.ntu.edu.tw [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)

2013-05-20

We present a new way to solve the platform deformation problem of coplanar interferometers. The platform of a coplanar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modeled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with a given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50%-70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other coplanar telescopes but also to single-dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.

PLATFORM DEFORMATION PHASE CORRECTION FOR THE AMiBA-13 COPLANAR INTERFEROMETER

International Nuclear Information System (INIS)

Liao, Yu-Wei; Lin, Kai-Yang; Huang, Yau-De; Ho, Paul T. P.; Chen, Ming-Tang; Locutus Huang, Chih-Wei; Koch, Patrick M.; Nishioka, Hiroaki; Umetsu, Keiichi; Han, Chih-Chiang; Li, Chao-Te; Martin-Cocher, Pierre; Oshiro, Peter; Proty Wu, Jiun-Huei; Cheng, Tai-An; Fu, Szu-Yuan; Wang, Fu-Cheng; Liu, Guo-Chin; Molnar, Sandor M.; Chang, Yu-Yen

2013-01-01

We present a new way to solve the platform deformation problem of coplanar interferometers. The platform of a coplanar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modeled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with a given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50%-70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other coplanar telescopes but also to single-dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.

Platform Deformation Phase Correction for the AMiBA-13 Coplanar Interferometer

Science.gov (United States)

Liao, Yu-Wei; Lin, Kai-Yang; Huang, Yau-De; Proty Wu, Jiun-Huei; Ho, Paul T. P.; Chen, Ming-Tang; Locutus Huang, Chih-Wei; Koch, Patrick M.; Nishioka, Hiroaki; Cheng, Tai-An; Fu, Szu-Yuan; Liu, Guo-Chin; Molnar, Sandor M.; Umetsu, Keiichi; Wang, Fu-Cheng; Chang, Yu-Yen; Han, Chih-Chiang; Li, Chao-Te; Martin-Cocher, Pierre; Oshiro, Peter

2013-05-01

We present a new way to solve the platform deformation problem of coplanar interferometers. The platform of a coplanar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modeled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with a given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50%-70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other coplanar telescopes but also to single-dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.

Coplanar amorphous-indium-gallium-zinc-oxide thin film transistor with He plasma treated heavily doped layer

Energy Technology Data Exchange (ETDEWEB)

Jeong, Ho-young [Advanced Display Research Center, Department of Information Display, Kyung Hee University, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); LG Display R and D Center, 245 Lg-ro, Wollong-myeon, Paju-si, Gyeonggi-do 413-811 (Korea, Republic of); Lee, Bok-young; Lee, Young-jang; Lee, Jung-il; Yang, Myoung-su; Kang, In-byeong [LG Display R and D Center, 245 Lg-ro, Wollong-myeon, Paju-si, Gyeonggi-do 413-811 (Korea, Republic of); Mativenga, Mallory; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center, Department of Information Display, Kyung Hee University, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

2014-01-13

We report thermally stable coplanar amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with heavily doped n{sup +} a-IGZO source/drain regions. Doping is through He plasma treatment in which the resistivity of the a-IGZO decreases from 2.98 Ω cm to 2.79 × 10{sup −3} Ω cm after treatment, and then it increases to 7.92 × 10{sup −2} Ω cm after annealing at 300 °C. From the analysis of X-ray photoelectron spectroscopy, the concentration of oxygen vacancies in He plasma treated n{sup +}a-IGZO does not change much after thermal annealing at 300 °C, indicating thermally stable n{sup +} a-IGZO, even for TFTs with channel length L = 4 μm. Field-effect mobility of the coplanar a-IGZO TFTs with He plasma treatment changes from 10.7 to 9.2 cm{sup 2}/V s after annealing at 300 °C, but the performance of the a-IGZO TFT with Ar or H{sub 2} plasma treatment degrades significantly after 300 °C annealing.

Coplanar amorphous-indium-gallium-zinc-oxide thin film transistor with He plasma treated heavily doped layer

International Nuclear Information System (INIS)

Jeong, Ho-young; Lee, Bok-young; Lee, Young-jang; Lee, Jung-il; Yang, Myoung-su; Kang, In-byeong; Mativenga, Mallory; Jang, Jin

2014-01-01

We report thermally stable coplanar amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with heavily doped n + a-IGZO source/drain regions. Doping is through He plasma treatment in which the resistivity of the a-IGZO decreases from 2.98 Ω cm to 2.79 × 10 −3 Ω cm after treatment, and then it increases to 7.92 × 10 −2 Ω cm after annealing at 300 °C. From the analysis of X-ray photoelectron spectroscopy, the concentration of oxygen vacancies in He plasma treated n + a-IGZO does not change much after thermal annealing at 300 °C, indicating thermally stable n + a-IGZO, even for TFTs with channel length L = 4 μm. Field-effect mobility of the coplanar a-IGZO TFTs with He plasma treatment changes from 10.7 to 9.2 cm 2 /V s after annealing at 300 °C, but the performance of the a-IGZO TFT with Ar or H 2 plasma treatment degrades significantly after 300 °C annealing

Co-planar deformation and thermal propagation behavior in a bundle burst test

International Nuclear Information System (INIS)

Uetsuka, Hiroshi; Koizumi, Yasuo; Kawasaki, Satoru

1980-07-01

The probability of the suggested feedback mechanism which could lead to co-planar deformation in a bundle burst test was assessed by the data of test and the calculation based on simplified model. Following four points were evaluated. (1) The probability of local deformation during early heat up stage. (2) The relation between the characteristic of heater and the feedback mechanism. (3) Thermal propagation behavior between two adjacent rods during heat up stage. (4) The propagation of ballooning in a bundle. The probability of suggested feedback mechanism was denied in all the evaluation. The feedback mechanism suggested by Burman could not be a controlling mechanism in co-planar deformation in a bundle burst test. (author)

FANSY 1.0: a phenomenological model for simulation of coplanar particle generation in superhigh-energy hadron interactions

International Nuclear Information System (INIS)

Mukhamedshin, Rauf

2009-01-01

Simulations show that a phenomenon of coplanarity of most energetic subcores of γ-ray-hadron families found in mountain-based and stratospheric X-ray-emulsion chamber experiments requires to introduce a coplanar particle generation with large transverse momenta in hadron interactions at superhigh energies. Some physical mechanisms are considered. A phenomenological model, which makes it possible to simulate the coplanar particle generation, is presented. Different versions of this model are considered, their features are described and compared with those of models applied by the CORSIKA package. Cosmic-ray experimental data and simulated results are compared. Conclusion on features of hadron interactions at superhigh energies and some predictions with respect to LHC experiments are made. (orig.) 3

SU-F-BRB-10: A Statistical Voxel Based Normal Organ Dose Prediction Model for Coplanar and Non-Coplanar Prostate Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Tran, A; Yu, V; Nguyen, D; Woods, K; Low, D; Sheng, K [UCLA, Los Angeles, CA (United States)

2015-06-15

Purpose: Knowledge learned from previous plans can be used to guide future treatment planning. Existing knowledge-based treatment planning methods study the correlation between organ geometry and dose volume histogram (DVH), which is a lossy representation of the complete dose distribution. A statistical voxel dose learning (SVDL) model was developed that includes the complete dose volume information. Its accuracy of predicting volumetric-modulated arc therapy (VMAT) and non-coplanar 4π radiotherapy was quantified. SVDL provided more isotropic dose gradients and may improve knowledge-based planning. Methods: 12 prostate SBRT patients originally treated using two full-arc VMAT techniques were re-planned with 4π using 20 intensity-modulated non-coplanar fields to a prescription dose of 40 Gy. The bladder and rectum voxels were binned based on their distances to the PTV. The dose distribution in each bin was resampled by convolving to a Gaussian kernel, resulting in 1000 data points in each bin that predicted the statistical dose information of a voxel with unknown dose in a new patient without triaging information that may be collectively important to a particular patient. We used this method to predict the DVHs, mean and max doses in a leave-one-out cross validation (LOOCV) test and compared its performance against lossy estimators including mean, median, mode, Poisson and Rayleigh of the voxelized dose distributions. Results: SVDL predicted the bladder and rectum doses more accurately than other estimators, giving mean percentile errors ranging from 13.35–19.46%, 4.81–19.47%, 22.49–28.69%, 23.35–30.5%, 21.05–53.93% for predicting mean, max dose, V20, V35, and V40 respectively, to OARs in both planning techniques. The prediction errors were generally lower for 4π than VMAT. Conclusion: By employing all dose volume information in the SVDL model, the OAR doses were more accurately predicted. 4π plans are better suited for knowledge-based planning than

Osservazioni sul principio di legalità come idea e come metodo nell’esperienza giuridica della Chiesa

Directory of Open Access Journals (Sweden)

Beatrice Serra

2012-10-01

SOMMARIO: 1. Introduzione - 2. – La struttura essenziale del concetto di legalità e la sua realizzazione radicale nel diritto della Chiesa. - 3. L’idea di legalità come “regola che sta prima” nel ius commune e la sua coesistenza con un approccio empirico, essenzialmente giurisprudenziale e dottrinale, di costruzione del diritto. Il principio di legalità come metodo di produzione del diritto nel pensiero giuridico moderno- 4. Il legame storico-concettuale fra il principio di legalità e i Codici moderni - 5. Il Codex iuris canonici del 1917 e il principio di legalità come metodo di costruzione del ius ecclesiae in funzione della certezza del diritto - 6. (segueUlteriori riflessi della prima codificazione canonica sul principio di legalità.:

Josephson effect in Al/Bi{sub 2}Se{sub 3}/Al coplanar hybrid devices

Energy Technology Data Exchange (ETDEWEB)

Galletti, L., E-mail: luca.galletti@unina.it [Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, I-80126 Napoli (Italy); CNR-SPIN Napoli, Complesso Universitario di Monte Sant’Angelo, 80126 Napoli (Italy); Charpentier, S. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg (Sweden); Lucignano, P.; Massarotti, D. [Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, I-80126 Napoli (Italy); CNR-SPIN Napoli, Complesso Universitario di Monte Sant’Angelo, 80126 Napoli (Italy); Arpaia, R. [Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, I-80126 Napoli (Italy); Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg (Sweden); Tafuri, F. [CNR-SPIN Napoli, Complesso Universitario di Monte Sant’Angelo, 80126 Napoli (Italy); Dipartimento di Ingegneria Industriale e dell’Informazione, Seconda Università di Napoli, I-81031 Aversa (CE) (Italy); Bauch, T. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg (Sweden); Suzuki, Y. [University of Tsukuba, Institute of Materials Science, Tsukuba 305, Ibaraki (Japan); Tagliacozzo, A. [Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, I-80126 Napoli (Italy); Kadowaki, K. [University of Tsukuba, Institute of Materials Science, Tsukuba 305, Ibaraki (Japan); Lombardi, F. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg (Sweden)

2014-08-15

Highlights: • Superconducting proximity effect induced in Al/Bi{sub 2}Se{sub 3}/Al coplanar hybrid devices. • Comparative study of Al/Bi{sub 2}Se{sub 3} interfaces with various buffer layers. • Towards a Josephson super-current through the edge states of topological insulators. - Abstract: The edge states of Topological Insulators (TI) are protected against backscattering, thanks to the topological properties arising from their band structure. Coupling a TI to a superconductor (S) can induce unconventional effects, including the creation of Majorana bound states (MBS). The fabrication of coplanar hybrid devices is a fundamental step to pave the way to the understanding of proximity effects in topologically non-trivial systems, and to a large variety of experiments aimed at the possible detection of MBS. We discuss the feasibility and some relevant properties of Al–Bi{sub 2}Se{sub 3}–Al coplanar proximity devices. Special attention is devoted to the design of the junction, aimed at enhancing the coupling between the electrodes and the TI.

Analysis of a Segmented Annular Coplanar Capacitive Tilt Sensor with Increased Sensitivity.

Science.gov (United States)

Guo, Jiahao; Hu, Pengcheng; Tan, Jiubin

2016-01-21

An investigation of a segmented annular coplanar capacitor is presented. We focus on its theoretical model, and a mathematical expression of the capacitance value is derived by solving a Laplace equation with Hankel transform. The finite element method is employed to verify the analytical result. Different control parameters are discussed, and each contribution to the capacitance value of the capacitor is obtained. On this basis, we analyze and optimize the structure parameters of a segmented coplanar capacitive tilt sensor, and three models with different positions of the electrode gap are fabricated and tested. The experimental result shows that the model (whose electrode-gap position is 10 mm from the electrode center) realizes a high sensitivity: 0.129 pF/° with a non-linearity of design.

Coplanarity of two-proton emissions in 400 MeV/nucleon Ne + NaF, Pb reactions

International Nuclear Information System (INIS)

Tanihata, Isao.

1984-10-01

Two-proton coincidence spectra have been measured in a wide kinematical range for 20 Ne + NaF and 20 Ne + Pb collisions at 400 MeV/nucleon. Coplanar-type correlations show different feature between Ne + NaF and Ne + Pb target reactions. A strong in-plane correlation, which correspond to quasi-elastic scatterings (QES) of nucleons, was observed in wide angular range (15 to 90 0 ) in NaF target collisions. Angular distributions of QES were reproduced reasonably well by a single nucleon-nucleon scattering model. Enhancement of the QES at momentum transfer around t = 2 - 3m/sub π/, which is predicted as an indication of pionic instability, was not observed. In Ne + Pb collisions, an azimuthally asymmetric emission of particles with respect to the beam axis were implied by the anti-coplanar correlation. A new type of coplanar correlation between the emission angle and the momentum suggests a back-to-back emission of projectile and target nucleons. 8 references, 8 figures

Comparison of a new noncoplanar intensity-modulated radiation therapy technique for craniospinal irradiation with 3 coplanar techniques

DEFF Research Database (Denmark)

Hansen, Anders T; Lukacova, Slavka; Lassen-Ramshad, Yasmin A.

2015-01-01

When standard conformal x-ray technique for craniospinal irradiation is used, it is a challenge to achieve satisfactory dose coverage of the target including the area of the cribriform plate, while sparing organs at risk. We present a new intensity-modulated radiation therapy (IMRT), noncoplanar...... patient using the noncoplanar IMRT-based technique, a coplanar IMRT-based technique, and a coplanar volumetric-modulated arch therapy (VMAT) technique. Dosimetry data for all patients were compared with the corresponding data from the conventional treatment plans. The new noncoplanar IMRT technique...... substantially reduced the mean dose to organs at risk compared with the standard radiation technique. The 2 other coplanar techniques also reduced the mean dose to some of the critical organs. However, this reduction was not as substantial as the reduction obtained by the noncoplanar technique. Furthermore...

Three-Dimensional Non-Coplanar Conformal Radiotherapy Yields Better Results Than Traditional Beam Arrangements for Adjuvant Treatment of Gastric Cancer

International Nuclear Information System (INIS)

Soyfer, Viacheslav; Corn, Benjamin W.; Melamud, Alex B.S.; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

2007-01-01

Purpose: The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. Methods and Materials: A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field 'box' was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. Results: The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Conclusion: Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical

Three-dimensional non-coplanar conformal radiotherapy yields better results than traditional beam arrangements for adjuvant treatment of gastric cancer.

Science.gov (United States)

Soyfer, Viacheslav; Corn, Benjamin W; Melamud, Alex; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

2007-10-01

The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field "box" was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical practice.

Control of polymer-packing orientation in thin films through synthetic tailoring of backbone coplanarity

KAUST Repository

Chen, Mark S.

2013-10-22

Controlling solid-state order of π-conjugated polymers through macromolecular design is essential for achieving high electronic device performance; yet, it remains a challenge, especially with respect to polymer-packing orientation. Our work investigates the influence of backbone coplanarity on a polymer\\'s preference to pack face-on or edge-on relative to the substrate. Isoindigo-based polymers were synthesized with increasing planarity by systematically substituting thiophenes for phenyl rings in the acceptor comonomer. This increasing backbone coplanarity, supported by density functional theory (DFT) calculations of representative trimers, leads to the narrowing of polymer band gaps as characterized by ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy and cyclic voltammetry. Among the polymers studied, regiosymmetric II and TII polymers exhibited the highest hole mobilities in organic field-effect transistors (OFETs), while in organic photovoltaics (OPVs), TBII polymers that display intermediate levels of planarity provided the highest power conversion efficiencies. Upon thin-film analysis by atomic force microscropy (AFM) and grazing-incidence X-ray diffraction (GIXD), we discovered that polymer-packing orientation could be controlled by tuning polymer planarity and solubility. Highly soluble, planar polymers favor face-on orientation in thin films while the less soluble, nonplanar polymers favor an edge-on orientation. This study advances our fundamental understanding of how polymer structure influences nanostructural order and reveals a new synthetic strategy for the design of semiconducting materials with rationally engineered solid-state properties. © 2013 American Chemical Society.

SU-F-T-649: Dosimetric Evaluation of Non-Coplanar Arc Therapy Using a Novel Rotating Gamma Ray System

Energy Technology Data Exchange (ETDEWEB)

Eldib, A; Chibani, O; Jin, L; Fan, J; Veltchev, I; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Mora, G [Universidade de Lisboa, Codex, Lisboa (Portugal); Li, J [Cyber Medical Inc, Xian, Shaanxi (China)

2016-06-15

Purpose: Stereotactic intra and extra-cranial body radiation therapy has evolved with advances in treatment accuracy, effective radiation dose, and parameters necessary to maximize machine capabilities. Novel gamma systems with a ring type gantry were developed having the ability to perform oblique arcs. The aim of this study is to explore the dosimetric advantages of this new system. Methods: The rotating Gamma system is named CybeRay (Cyber Medical Corp., Xian, China). It has a treatment head of 16 cobalt-60 sources focused to the isocenter, which can rotate 360° on the ring gantry and swing 35° in the superior direction. Treatment plans were generated utilizing our in-house Monte Carlo treatment planning system. A cylindrical phantom was modeled with 2mm voxel size. Dose inside the cylindrical phantom was calculated for coplanar and non-coplanar arcs. Dosimetric differences between CybeRay cobalt beams and CyberKnife 6MV beams were compared in a lung phantom and for previously treated SBRT patients. Results: The full width at half maxima of cross profiles in the S-I direction for the coplanar setup matched the cone sizes, while for the non-coplanar setup, FWHM was larger by 2mm for a 10mm cone and about 5mm for larger cones. In the coronal and sagittal view, coplanar beams showed elliptical shaped isodose lines, while non-coplanar beams showed circular isodose lines. Thus proper selection of the oblique angle and cone size can aid optimal dose matching to the target volume. Comparing a single 5mm cone from CybeRay to that from CyberKnife showed similar penumbra in a lung phantom but CybeRay had significant lower doses beyond lung tissues. Comparable treatment plans were obtained with CybeRay as that from CyberKnife.ConclusionThe noncoplanar multiple source arrangement of CybeRay will be of great clinical benefits for stereotactic intra and extra-cranial radiation therapy.

Microscale adaptation of the potentiometric method with ion-selective electrode for the quantification of fluoride; Adaptacion a microescala del metodo potenciometrico con electrodo ion selectivo para la cuantificacion de fluoruro

Energy Technology Data Exchange (ETDEWEB)

Guevara Ruiz, Paulina; Ortiz Perez, Maria Deogracias [Laboratorio de Bioquimica, Facultad de de Medicina, Universidad Autonoma de San Luis Potosi, San Luis Potosi, San Luis Potosi, (Mexico)]. E-mail: mdortiz@uaslp.mx

2009-05-15

Similarly to other countries, ground water from Mexico is naturally polluted by fluoride. The main effects of fluoride at typical ground water concentrations are dental fluorosis, neurological deficits and reproductive disorders. In order to verify that the fluoride concentration is within the allowed guideline in Mexico (NOM 127 and 201), it is important to monitor fluoride levels in water and commercial beverages. The aim of this work is to develop a modification of the standard potentiometric method for fluoride determination in water, in order to reduce costs and amount of potentially toxic waste substances. Both methods were validated, the standard potentiometric method with the ion selective electrode and the microscale modification proposed in this paper. The methods were compared using statistic tests and graphics, followed by the comparison of 125 samples of commercial bottled water sold in the city of San Luis Potosi. Optimal results were obtained for the validation of both methods, and the microscale modification showed statistically identical results to those obtained with the standard method in all samples of bottled water. The microscale modification is a good alternative for fluoride assessment in water and beverages, and it represents a 95 % reduction of costs and chemical waste. [Spanish] En varios paises, incluido Mexico se presenta una contaminacion natural con fluoruro en agua subterranea; los principales efectos en la salud observados en poblacion expuesta a concentraciones mayores al valor permisible (que en Mexico es de 1.5 mg/L) son la fluorosis dental y esqueletica, asi como dano reproductivo y neurologico. En varios estados de la republica Mexicana, este problema es aun desconocido, de ahi la necesidad de evaluar las concentraciones de fluoruro en agua de consumo en varias comunidades. Asi, el objetivo de este trabajo es desarrollar un metodo a microescala para la determinacion de fluoruro en agua, que al reducir la cantidad de reactivo y

Non-coplanar polychlorinated biphenyls (PCBs) are direct agonists for the human pregnane-X receptor and constitutive androstane receptor, and activate target gene expression in a tissue-specific manner

International Nuclear Information System (INIS)

Al-Salman, Fadheela; Plant, Nick

2012-01-01

The polychlorinated biphenyl group possesses high environmental persistence, leading to bioaccumulation and a number of adverse effects in mammals. Whilst coplanar PCBs elicit their toxic effects through agonism of the aryl hydrocarbon receptor; however, non-coplanar PCBs are not ligands for AhR, but may be ligands for members of the nuclear receptor family of proteins. To better understand the biological actions of non-coplanar PCBs, we have undertaken a systematic analysis of their ability to activate PXR and CAR-mediated effects. Cells were exposed to a range of non-coplanar PCBs (99, 138, 153, 180 and 194), or the coplanar PCB77: Direct activation of PXR and CAR was measured using a mammalian receptor activation assay in human liver cells, with rifampicin and CITCO used as positive controls ligands for PXR and CAR, respectively; activation of target gene expression was examined using reporter gene plasmids for CYP3A4 and MDR1 transfected into liver, intestine and lung cell lines. Several of the non-coplanar PCBs directly activated PXR and CAR, whilst the coplanar PCB77 did not. Non-coplanar PCBs were also able to activate PXR/CAR target gene expression in a substitution- and tissue-specific manner. Non-coplanar PCBs act as direct activators for the nuclear receptors PXR and CAR, and are able to elicit transcriptional activation of target genes in a substitution- and tissue-dependent manner. Chronic activation of PXR/CAR is linked to adverse effects and must be included in any risk assessment of PCBs. -- Highlights: ► Several Non-coplanar PCBs are able to directly activate both PXR and CAR in vitro. ► PCB153 is the most potent direct activator of PXR and CAR nuclear receptors. ► Non-coplanar PCB activation of CYP3A4/MDR1 reporter genes is structure-dependent. ► Non-coplanar PCB activate CYP3A4/MDR1 reporter genes in a tissue-dependent. ► PCB153 is the most potent activator of PXR/CAR target gene in all tissues.

Ultra-Wideband Notched Characteristic Fed by Coplanar Waveguide

Directory of Open Access Journals (Sweden)

Rastanto Hadinegoro

2015-02-01

Full Text Available In this paper, a novel Ultra-Wide Band (UWB notch patch antenna with co-planar waveguide (CPW fed is presented. This antenna only used one layer and the patch antenna is constructed on the first layer and back to back with CPW fed and bottom part is ground plane. The width notch is used to achieve the UWB characteristic. The results shown that the impedance bandwidth is 1130 MHz (1.662–2.792 GHz or about 50.7% for VSWR <2.

Design and Analysis of an Abbé Free Coplanar Stage

Directory of Open Access Journals (Sweden)

Chung Tien-Tung

2017-01-01

Full Text Available Design and analysis of a new Abbé free coplanar xy stage are presented in this paper. The xy stage is formed as conventional xy stages which combine with two stacked up linear guides. The x-guide is on the bottom and the y-guide is on top of the x-guide. The travel range of this xy stage is 300mm × 300mm, which fits dimensions of 12-inch wafers. A special mechanism is designed such that the z-surface of the y-guide has the same height as the z-surface of x-guide, and the Abbé error and cumulative error of this coplanar stage can be reduced. The concept of symmetric structure design is also considered to eliminate the structural deformation due to driving force of two guides. For this long travel range precision stage, the finite element method (FEM is applied to analyze the structural deformation and vibration natural frequencies. The requirement of structural deformation due to self-weight load is limited to 1.5μm, and first natural frequency is limited to over 100 Hz.

Design and optimization of surface profilometer based on coplanar guide rail

Science.gov (United States)

Chen, Shuai; Dai, Yifan; Hu, Hao; Tie, Guipeng

2017-10-01

In order to implement the sub-micron precision measurement, a surface profilometer which based on the coplanar guide rail is designed. This profilometer adopts the open type air floating load and is driven by the magnetic force. As to achieve sub-micron accuracy, the flatness of granite guide working face and aerodynamic block are both processed to the micron level based on the homogenization of air flotation film theory. Permanent magnet which could reduce the influence of the driving disturbance to the measurement accuracy is used as the driving part. In this paper, the bearing capacity and the air floating stiffness of air floating block are both simulated and analyzed as to optimize the design parameters firstly. The layout and magnetic force of the magnet are also simulated. According to the simulation results, type selection and the position arrangement of the magnets are then confirmed. The test results on the experimental platform show that the surface profilometer based on coplanar guide rail possess the basis for realizing the submicron precision measurement.

Kidney-Sparing Methods for Extended-Field Intensity-Modulated Radiotherapy (EF-IMRT) in Cervical Carcinoma Treatment.

Science.gov (United States)

Kunogi, Hiroaki; Yamaguchi, Nanae; Terao, Yasuhisa; Sasai, Keisuke

2016-01-01

Coplanar extended-field intensity-modulated radiation therapy (EF-IMRT) targeting the whole-pelvic and para-aortic lymph nodes in patients with advanced cervical cancer results in impaired creatinine clearance. An improvement in renal function cannot be expected unless low-dose (approximately 10 Gy) kidney exposure is reduced. The dosimetric method should be considered during EF-IMRT planning to further reduce low-dose exposure to the kidneys. To assess the usefulness of non-coplanar EF-IMRT with kidney-avoiding beams to spare the kidneys during cervical carcinoma treatment in dosimetric analysis between non-coplanar and coplanar EF-IMRT, we compared the doses of the target organ and organs at risk, including the kidney, in 10 consecutive patients. To estimate the influence of EFRT on renal dysfunction, creatinine clearance values after treatment were also examined in 18 consecutive patients. Of these 18 patients, 10 patients who were included in the dosimetric analysis underwent extended field radiation therapy (EFRT) with concurrent chemotherapy, and eight patients underwent whole-pelvis radiation therapy with concurrent chemotherapy to treat cervical carcinoma between April 2012 and March 2015 at our institution. In the dosimetric analysis, non-coplanar EF-IMRT was effective at reducing low-dose (approximately 10 Gy) exposure to the kidneys, thus maintaining target coverage and sparing other organs at risk, such as the small bowel, rectum, and bladder, compared with coplanar EF-IMRT. Renal function in all 10 patients who underwent EFRT, including coplanar EF-IMRT (with kidney irradiation), was low after treatment, and differed significantly from that of the eight patients who underwent WPRT (no kidney irradiation) 6 months after the first day of treatment (P = 0.005). In conclusion, non-coplanar EF-IMRT should be considered in patients with advanced cervical cancer, particularly in patients with a long life expectancy or with pre-existing renal dysfunction.

Analysis of a Segmented Annular Coplanar Capacitive Tilt Sensor with Increased Sensitivity

Directory of Open Access Journals (Sweden)

Jiahao Guo

2016-01-01

Full Text Available An investigation of a segmented annular coplanar capacitor is presented. We focus on its theoretical model, and a mathematical expression of the capacitance value is derived by solving a Laplace equation with Hankel transform. The finite element method is employed to verify the analytical result. Different control parameters are discussed, and each contribution to the capacitance value of the capacitor is obtained. On this basis, we analyze and optimize the structure parameters of a segmented coplanar capacitive tilt sensor, and three models with different positions of the electrode gap are fabricated and tested. The experimental result shows that the model (whose electrode-gap position is 10 mm from the electrode center realizes a high sensitivity: 0.129 pF/° with a non-linearity of <0.4% FS (full scale of ±40°. This finding offers plenty of opportunities for various measurement requirements in addition to achieving an optimized structure in practical design.

Radiation dose in critical organs due to non-coplanar irradiation of the pituitary gland

International Nuclear Information System (INIS)

Schulte, R.W.M.; Rittmann, K.L.; Meinass, H.J.; Rennicke, P.

1996-01-01

In order to estimate the somatic and genetic risk associated with a non-coplanar linac-based radiation technique of the pituitary gland, systematic secondary-dose measurements in a phantom and sample measurements of the dose near critical organs of patients were performed. For measurements of the dose outside the primary radiation field an acrylic-PVC phantom was used which was irradiated with a single field (4x4 cm 2 ). Eight patients with pituitary tumors were treated isocentrically with a combination of sagittal and transverse rotational arcs. To measure the dose in critical organs, LiF thermoluminescence dosimeters (TLD) in chip form were placed onto 1 eyelid, the skin over the thyroid, and the patient's clothes covering the region of breasts and ovaries of female patients and the testicles of male patients. Measurements were performed for all patients during 1 sagittal irradiation and for the majority of patients during 1 transverse irradiation. The phantom measurements demonstrated that the secondary dose measured on the patients surface can be considered as a good approximation for the dose in adjacent organs. The median dose in critical organs for sagittal irradiation was in the range of 25.8 mGy (eyes) to 1.9 mGy (testicles), and for transverse irradiation in the range of 23.3 mGy (eyes) to 1.3 mGy (testicles). The ratio of median organ doses for sagittal and transverse irradiation was 2.1 for the thyroid gland, 1.1 for the eyes, and 1.5 for the other organs. The dose in critical organs due to non-coplanar irradiation of the pituitary gland is only a small fraction of the dose delivered to the reference point of the planning target volume. The risk of a radiation-induced tumor and a genetic consequence associated with these small doses is generally less than 1% and 0.1%, respectively. (orig./MG) [de

Reconsidering the advantages of the three-dimensional representation of the interferometric transform for imaging with non-coplanar baselines and wide fields of view

Science.gov (United States)

Smith, D. M. P.; Young, A.; Davidson, D. B.

2017-07-01

Radio telescopes with baselines that span thousands of kilometres and with fields of view that span tens of degrees have been recently deployed, such as the Low Frequency Array, and are currently being developed, such as the Square Kilometre Array. Additionally, there are proposals for space-based instruments with all-sky imaging capabilities, such as the Orbiting Low Frequency Array. Such telescopes produce observations with three-dimensional visibility distributions and curved image domains. In most work to date, the visibility distribution has been converted to a planar form to compute the brightness map using a two-dimensional Fourier transform. The celestial sphere is faceted in order to counter pixel distortion at wide angles, with each such facet requiring a unique planar form of the visibility distribution. Under the above conditions, the computational and storage complexities of this approach can become excessive. On the other hand, when using the direct Fourier transform approach, which maintains the three-dimensional shapes of the visibility distribution and celestial sphere, the non-coplanar visibility component requires no special attention. Furthermore, as the celestial samples are placed directly on the curved surface of the celestial sphere, pixel distortion at wide angles is avoided. In this paper, a number of examples illustrate that under these conditions (very long baselines and very wide fields of view) the costs of the direct Fourier transform may be comparable to (or even lower than) methods that utilise the two-dimensional fast Fourier transform.

DOLOČITEV POVRŠINSKE NAPETOSTI Z METODO KAPILARNEGA DVIGA DVOFAZNIH SISTEMOV

OpenAIRE

Kravanja, Gregor

2014-01-01

Namen magistrske naloge je bil postavitev merilne naprave in razvoj nove metode merjenja površinske napetosti s kapilarnim dvigom dvofaznih sistemov v okolici kritične točke. Za pridobitev natančnih in primerljivih meritev je bilo potrebno poznati natančni notranji premer tankih kapilar. Določili smo ga z metodo laserskega tipanja na nemški koordinatni merilni napravi ZEISS tipa UMC-850 s pomočjo merilne programske opreme CALYPSO 5.1.4. Za merjenje ravnotežne višine smo uporabili računalniški...

Limits of dose escalation in lung cancer: a dose-volume histogram analysis comparing coplanar and non-coplanar techniques

Energy Technology Data Exchange (ETDEWEB)

Derycke, S; Van Duyse, B; Schelfhout, J; De Neve, W

1995-12-01

To evaluate the feasibility of dose escalation in radiotherapy of inoperable lung cancer, a dose-volume histogram analysis was performed comparing standard coplanar (2D) with non-coplanar (3D) beam arrangements on a non-selected group of 20 patients planned by Sherouse`s GRATISTM 3D-planning system. Serial CT-scanning was performed and 2 Target Volumes (Tvs) were defined. Gross Tumor Volume (GTV) defined a high-dose Target Volume (TV-1). GTV plus location of node stations with > 10% probability of invasion (Minet et al.) defined an intermediate-dose Target Volume (TV-2). However, nodal regions which are incompatible with cure were excluded from TV-2. These are ATS-regions 1, 8, 9 and 14 all left and right as well as heterolateral regions. For 3D-planning, Beam`s Eye View selected (by an experienced planner) beam arrangements were optimised using Superdot, a method of target dose-gradient annihilation developed by Sherouse. A second 3D-planning was performed using 4 beam incidences with maximal angular separation. The linac`s isocenter for the optimal arrangement was located at the geometrical center of gravity of a tetraheder, the tetraheder`s comers being the consecutive positions of the virtual source. This ideal beam arrangement was approximated as close as possible, taking into account technical limitations (patient-couch-gantry collisions). Criteria for tolerance were met if no points inside the spinal cord exceeded 50 Gy and if at least 50% of the lung volume received less than 20Gy. If dose regions below 50 Gy were judged acceptable at TV-2, 2D- as well as 3D-plans allow safe escalation to 80 Gy at TV-1. When TV-2 needed to be encompassed by isodose surfaces exceeding 50Gy, 3D-plans were necessary to limit dose at the spinal cord below tolerance. For large TVs dose is limited by lung tolerance for 3D-plans. An analysis (including NTCP-TCP as cost functions) of rival 3D-plans is being performed.

55 CANCRI: A COPLANAR PLANETARY SYSTEM THAT IS LIKELY MISALIGNED WITH ITS STAR

International Nuclear Information System (INIS)

Kaib, Nathan A.; Duncan, Martin J.; Raymond, Sean N.

2011-01-01

Although the 55 Cnc system contains multiple, closely packed planets that are presumably in a coplanar configuration, we use numerical simulations to demonstrate that they are likely to be highly inclined to their parent star's spin axis. Due to perturbations from its distant binary companion, this planetary system precesses like a rigid body about its parent star. Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. Because only the projected separation of the binary is known, we study this effect statistically, assuming an isotropic distribution for wide binary orbits. We find that the most likely projected spin-orbit angle is ∼50°, with a ∼30% chance of a retrograde configuration. Transit observations of the innermost planet—55 Cnc e—may be used to verify these findings via the Rossiter-McLaughlin effect. 55 Cancri may thus represent a new class of planetary systems with well-ordered, coplanar orbits that are inclined with respect to the stellar equator.

Measuring the complex permittivity tensor of uniaxial biological materials with coplanar waveguide transmission line

Science.gov (United States)

A simple and accurate technique is described for measuring the uniaxial permittivity tensor of biological materials with a coplanar waveguide transmission-line configuration. Permittivity tensor results are presented for several chicken and beef fresh meat samples at 2.45 GHz....

Second-order Born effect in coplanar doubly symmetric (e,2e) collisions for sodium

Energy Technology Data Exchange (ETDEWEB)

Wang, Yang; Jiao, Liguang [Center for Theoretical Atomic and Molecular Physics, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China); Zhou, Yajun, E-mail: yajunzhou2003@yahoo.com.cn [Center for Theoretical Atomic and Molecular Physics, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China)

2012-06-18

The second-order distorted wave Born approximation (DWBA) method is employed to investigate the triple differential cross sections (TDCS) of coplanar doubly symmetric (e,2e) collisions for alkali target sodium at excess energies of 6–60 eV. Comparing with the first-order DWBA calculations, the inclusion of second-order Born term in the scattering amplitude improves the degree of agreement with experiments, especially for backward scattering region of TDCS. This indicates the present second-order Born term is capable to give a reasonable correction to DWBA model in studying coplanar symmetric (e,2e) problems in low and intermediate energy range. -- Highlights: ► We consider second-order Born effect in (e,2e) collisions for sodium. ► Our second-order term gives a correct description on the multi scattering process. ► Our second-order DWBA model improves the agreement between theory and experiment.

Evolution from the coplanar to the perpendicular plane geometry of helium (e,2e) differential cross sections symmetric in scattering angle and energy

International Nuclear Information System (INIS)

Murray, A.J.; Read, F.H.

1993-01-01

Experimentally determined differential cross sections are presented for the (e,2e) process in helium, in which the two outgoing electrons have the same energy and the same scattering angle with respect to the incident beam. At four incident energies from 20 to 50 eV above the ionization threshold the detection plane defined by the outgoing electrons was varied from being coplanar with the incident beam to being perpendicular to the beam. The differential cross section evolves from a two-peak structure in coplanar geometry to a three-peak structure in the perpendicular plane. At the lowest energy the forward-scattering coplanar peak is smaller than the backscatter peak, in contrast to the results at higher energies. A deep minimum is seen at an intermediate plane angle of 67.5 degree, this minimum being deepest at 40 eV above the ionization threshold. The results are normalized to an absolute scale using previous coplanar measurements as discussed in the text. The spectrometer used to collect these results is fully computer controlled and real-time computer optimized

Beam’s-eye-view imaging during non-coplanar lung SBRT

Energy Technology Data Exchange (ETDEWEB)

Yip, Stephen S. F., E-mail: syip@lroc.harvard.edu; Rottmann, Joerg; Berbeco, Ross I. [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States)

2015-12-15

Purpose: Beam’s-eye-view (BEV) imaging with an electronic portal imaging device (EPID) can be performed during lung stereotactic body radiation therapy (SBRT) to monitor the tumor location in real-time. Image quality for each patient and treatment field depends on several factors including the patient anatomy and the gantry and couch angles. The authors investigated the angular dependence of automatic tumor localization during non-coplanar lung SBRT delivery. Methods: All images were acquired at a frame rate of 12 Hz with an amorphous silicon EPID. A previously validated markerless lung tumor localization algorithm was employed with manual localization as the reference. From ten SBRT patients, 12 987 image frames of 123 image sequences acquired at 48 different gantry–couch rotations were analyzed. δ was defined by the position difference of the automatic and manual localization. Results: Regardless of the couch angle, the best tracking performance was found in image sequences with a gantry angle within 20° of 250° (δ = 1.40 mm). Image sequences acquired with gantry angles of 150°, 210°, and 350° also led to good tracking performances with δ = 1.77–2.00 mm. Overall, the couch angle was not correlated with the tracking results. Among all the gantry–couch combinations, image sequences acquired at (θ = 30°, ϕ = 330°), (θ = 210°, ϕ = 10°), and (θ = 250°, ϕ = 30°) led to the best tracking results with δ = 1.19–1.82 mm. The worst performing combinations were (θ = 90° and 230°, ϕ = 10°) and (θ = 270°, ϕ = 30°) with δ > 3.5 mm. However, 35% (17/48) of the gantry–couch rotations demonstrated substantial variability in tracking performances between patients. For example, the field angle (θ = 70°, ϕ = 10°) was acquired for five patients. While the tracking errors were ≤1.98 mm for three patients, poor performance was found for the other two patients with δ ≥ 2.18 mm, leading to average tracking error of 2.70 mm. Only one

A reverse method to estimate initial temperatures in geothermal reservoirs; Un metodo inverso para estimacion de la temperatura inicial de yacimientos geotermicos

Energy Technology Data Exchange (ETDEWEB)

Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx; Ramos Alcantara, Jose R. [Centro Nacional de Investigacion y Desarrollo Tecnologico, Departamento de Ingenieria Mecanica, Cuernavaca, Morelos (Mexico); Arellano Gomez, Victor M. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)

2010-01-15

A method is presented for estimating the initial temperature in geothermal-reservoir formations. The method is based on control theory where the measured temperatures or temperature logs are compared with corresponding simulated temperatures for different times with the well closed. The comparison is made using a control algorithm that makes changes to the originally assumed reservoir temperatures and performs iterations until the best fit between the temperature logs and the simulated temperatures is obtained. The simulation of fluid transport and heat in the well includes the processes of circulation and stop in the presence of circulation losses, modeled on macroscopic balances of momentum and energy. The transport processes in the formation regard the reservoir as an isotropic porous medium and fluid flow is described by Darcy's law. This model generates the fields of temperatures, pressures and speeds as a function of time and space. The method was tested with data from well LV-3 in Las Tres Virgenes geothermal field, Baja California Sur, Mexico. The estimated temperatures of the undisturbed formation-or initial temperatures-are compared within {+-}15 degrees Celsius with the measured temperatures, which is an acceptable outcome from an engineering point of view. [Spanish] Se presenta un metodo para la estimacion de la temperatura inicial en las formaciones de yacimientos geotermicos. El metodo se basa en la teoria de control donde las temperaturas medidas o registros de temperatura se comparan con las correspondientes temperaturas simuladas a diferentes tiempos con el pozo cerrado. La comparacion se hace usando un algoritmo de control el cual hace cambios a las temperaturas de yacimiento originalmente supuestas y realiza iteraciones hasta que se obtiene el mejor ajuste entre los registros de temperatura y las temperaturas simuladas. La simulacion del transporte de fluidos y calor en el pozo incluye los procesos de circulacion y paro en presencia de

Treatment planning for SBRT using automated field delivery: A case study

International Nuclear Information System (INIS)

Ritter, Timothy A.; Owen, Dawn; Brooks, Cassandra M.; Stenmark, Matthew H.

2015-01-01

Stereotactic body radiation therapy (SBRT) treatment planning and delivery can be accomplished using a variety of techniques that achieve highly conformal dose distributions. Herein, we describe a template-based automated treatment field approach that enables rapid delivery of more than 20 coplanar fields. A case study is presented to demonstrate how modest adaptations to traditional SBRT planning can be implemented to take clinical advantage of this technology. Treatment was planned for a left-sided lung lesion adjacent to the chest wall using 25 coplanar treatment fields spaced at 11° intervals. The plan spares the contralateral lung and is in compliance with the conformality standards set forth in Radiation Therapy and Oncology Group protocol 0915, and the dose tolerances found in the report of the American Association of Physicists in Medicine Task Group 101. Using a standard template, treatment planning was accomplished in less than 20 minutes, and each 10 Gy fraction was delivered in approximately 5.4 minutes. For those centers equipped with linear accelerators capable of automated treatment field delivery, the use of more than 20 coplanar fields is a viable SBRT planning approach and yields excellent conformality and quality combined with rapid planning and treatment delivery. Although the case study discusses a laterally located lung lesion, this technique can be applied to centrally located tumors with similar results

Coplanar strips for Josephson voltage standard circuits

International Nuclear Information System (INIS)

Schubert, M.; May, T.; Wende, G.; Fritzsch, L.; Meyer, H.-G.

2001-01-01

We present a microwave circuit for Josephson voltage standards. Here, the Josephson junctions are integrated in a microwave transmission line designed as coplanar strips (CPS). The new layout offers the possibility of achieving a higher scale of integration and to considerably simplify the fabrication technology. The characteristic impedance of the CPS is about 50 Ω, and this should be of interest for programmable Josephson voltage standard circuits with SNS or SINIS junctions. To demonstrate the function of the microwave circuit design, conventional 10 V Josephson voltage standard circuits with 17000 Nb/AlO x /Nb junctions were prepared and tested. Stable Shapiro steps at the 10 V level were generated. Furthermore, arrays of 1400 SINIS junctions in this microwave layout exhibited first-order Shapiro steps. Copyright 2001 American Institute of Physics

Ionisation differential cross section measurements for N2 at low incident energy in coplanar and non-coplanar geometries

International Nuclear Information System (INIS)

Sakaamini, Ahmad; Murray, Andrew James; Amami, Sadek; Madison, Don; Ning, Chuangang

2016-01-01

Ionisation triple differential cross sections have been determined experimentally and theoretically for the neutral molecule N 2 over a range of geometries from coplanar to the perpendicular plane. Data were obtained at incident electron energies ∼10 and ∼20 eV above the ionisation potential of the 3 σ g , 1 π u and 2 σ g states, using both equal and non-equal outgoing electron energies. The data were taken with the incident electron beam in the scattering plane ( ψ = 0°), at 45° to this plane and orthogonal to the plane ( ψ = 90°). The set of nine measured differential cross sections at a given energy were then inter-normalised to each other. The data are compared to new calculations using various distorted wave methods, and differences between theory and experiment are discussed. (paper)

Analytic computation of the quantum levels of a two-dimensional hydrogenic donor in the presence of a constant magnetic field of arbitrary strength

Energy Technology Data Exchange (ETDEWEB)

Villalba, Victor M.; Pino, Ramiro [Instituto Venezolano de Investigaciones Cientificas, Caracas (Venezuela)

2001-03-01

In this article we review different techniques for computing the energy spectrum of 2 D hydrogenic donors and two-electron quantum dots in the presence of a constant, magnetic field perpendicular to the plane of the electron. We compute the 1S, 2P- and 3D- energy levels via a scaled variational mixed-bases method. We compare our results with those obtained with the shifted 1/N method. [Spanish] En el presente articulo se exhiben distintos metodos para calcular el espectro de energia de donores hidrogenicos y puntos cuanticos con dos electrones en presencia de un campo magnetico constante perpendicular al plano del electron. Se calculan los niveles de energia 1S, 2P- y 3D- con ayuda del metodo variacional de bases mixtas con escalamiento. Comparamos nuestro resultados con los obtenidos con ayuda del metodo 1/N con corrimiento.

Vision Servo Motion Control and Error Analysis of a Coplanar XXY Stage for Image Alignment Motion

Directory of Open Access Journals (Sweden)

Hau-Wei Lee

2013-01-01

Full Text Available In recent years, as there is demand for smart mobile phones with touch panels, the alignment/compensation system of alignment stage with vision servo control has also increased. Due to the fact that the traditional stacked-type XYθ stage has cumulative errors of assembly and it is heavy, it has been gradually replaced by the coplanar stage characterized by three actuators on the same plane with three degrees of freedom. The simplest image alignment mode uses two cameras as the equipments for feedback control, and the work piece is placed on the working stage. The work piece is usually engraved/marked. After the cameras capture images and when the position of the mark in the camera is obtained by image processing, the mark can be moved to the designated position in the camera by moving the stage and using alignment algorithm. This study used a coplanar XXY stage with 1 μm positioning resolution. Due to the fact that the resolution of the camera is about 3.75 μm per pixel, thus a subpixel technology is used, and the linear and angular alignment repeatability of the alignment system can achieve 1 μm and 5 arcsec, respectively. The visual servo motion control for alignment motion is completed within 1 second using the coplanar XXY stage.

Torque calculation in the induction motor with the finite element method; Calculo del par en el motor de induccion con el metodo del elemento finito

Energy Technology Data Exchange (ETDEWEB)

Castillo Diaz, Ramon

2002-06-15

In this work the method of the finite element is applied to the bi-dimensional analysis of the induction motor in operation in steady state, excited by sine sources of laminar currents and sine sources of voltage. The analysis is focused mainly in the calculation of the electromagnetic torque. The topics of electromagnetic theory are covered and in an idealized model of the induction motor, analytically and numerically with the method of the finite element, in the variant method of Galerkin, the vectorial potential and the torque are calculated. The results obtained with the analytical and numerical methods are compared. Three formulations are developed to calculate the torque with the method of the finite element, using triangular elements of first order, based in the equation of force of Lorentz, the Maxwell tensor and the principle of the virtual work. Finally, a motor of induction of real characteristics is simulated, assuming it is connected to a three-phase voltage source. In this motor it is analyzed the convergence and the evolution in the results obtained of the torque with different discretions, and the torque-velocity performance curve is calculated. [Spanish] En este trabajo se aplica el metodo del elemento finito al analisis bidimensional del motor de induccion en operacion en estado estable, excitado por fuentes de corriente laminar senoidales y fuentes de voltaje senoidales. El analisis se enfoca principalmente en el calculo del par electromagnetico. Se tratan los topicos de teoria electromagnetica involucrados y en un modelo idealizado del motor de induccion, se calculan analitica y numericamente con el metodo del elemento finito, en la variante metodo de Galerkin, el potencial vectorial y el par. Se comparan resultados obtenidos con los metodos analiticos y numericos. Se desarrollan tres formulaciones para calcular el par con el metodo del elemento finito, utilizando elementos triangulares de primer orden, basadas en la ecuacion de fuerza de

Performance of CdZnTe coplanar-grid gamma-ray detectors

International Nuclear Information System (INIS)

Luke, P.N.; Eissler, E.E.

1995-11-01

CdZnTe crystals grown using the high-pressure Bridgman method exhibit many properties that are desirable for radiation detector fabrication, such as high resistivity, stable operation, relative ease of processing, and the availability of large volume crystals. However, as is common with other compound semi-conductor materials, currently available CdZnTe crystals have poor charge transport characteristics. This seriously the spectral performance of detectors, especially in gamma-ray detection. The coplanar-grid detection technique was recently developed to address such charge collection problems. This technique was first demonstrated using a 5 mm cube CdZnTe detector, and a dramatic improvement in spectral response has been achieved. These early results verified the effectiveness of this technique and suggested that large-volume gamma-ray detectors with high energy resolution can be realized. To further the development of such detectors, it is important to understand the various factors that affect detector performance. The purpose of this paper is to examine the effects of material properties on the spectral performance of CdZnTe coplanar-grid detectors. Theoretical spectral response is to show the level of performance that can be achieved given the typical carrier mobility-lifetime (μτ) properties of present-day materials. Nonuniformity in the charge transport properties of the material, which could limit the energy resolution of the detectors, has been studied experimentally and some of the results are presented here

SU-E-T-436: Fluence-Based Trajectory Optimization for Non-Coplanar VMAT

Energy Technology Data Exchange (ETDEWEB)

Smyth, G; Bamber, JC; Bedford, JL [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London (United Kingdom); Evans, PM [Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford (United Kingdom); Saran, FH; Mandeville, HC [The Royal Marsden NHS Foundation Trust, Sutton (United Kingdom)

2015-06-15

Purpose: To investigate a fluence-based trajectory optimization technique for non-coplanar VMAT for brain cancer. Methods: Single-arc non-coplanar VMAT trajectories were determined using a heuristic technique for five patients. Organ at risk (OAR) volume intersected during raytracing was minimized for two cases: absolute volume and the sum of relative volumes weighted by OAR importance. These trajectories and coplanar VMAT formed starting points for the fluence-based optimization method. Iterative least squares optimization was performed on control points 24° apart in gantry rotation. Optimization minimized the root-mean-square (RMS) deviation of PTV dose from the prescription (relative importance 100), maximum dose to the brainstem (10), optic chiasm (5), globes (5) and optic nerves (5), plus mean dose to the lenses (5), hippocampi (3), temporal lobes (2), cochleae (1) and brain excluding other regions of interest (1). Control point couch rotations were varied in steps of up to 10° and accepted if the cost function improved. Final treatment plans were optimized with the same objectives in an in-house planning system and evaluated using a composite metric - the sum of optimization metrics weighted by importance. Results: The composite metric decreased with fluence-based optimization in 14 of the 15 plans. In the remaining case its overall value, and the PTV and OAR components, were unchanged but the balance of OAR sparing differed. PTV RMS deviation was improved in 13 cases and unchanged in two. The OAR component was reduced in 13 plans. In one case the OAR component increased but the composite metric decreased - a 4 Gy increase in OAR metrics was balanced by a reduction in PTV RMS deviation from 2.8% to 2.6%. Conclusion: Fluence-based trajectory optimization improved plan quality as defined by the composite metric. While dose differences were case specific, fluence-based optimization improved both PTV and OAR dosimetry in 80% of cases.

Correlacion entre metodos de analisis de Zn disponible en cuatro ordenes de suelos de Costa Rica

Directory of Open Access Journals (Sweden)

Eloy Molina

2001-01-01

Full Text Available Se realizo una comparación entre métodos analisis del Zn disponible en 4 ordenes de sue- Analytilos de Costa Rica (Ultisoles, Vertisoles, Andisoles Inceptisoles, 25 de c/u, utilizando las siguientes soluciones extractoras: Olsen Modificado, Meh- lich 3, Morgan Modificado, DTPA y HC1. Las cantidades de Zn extrafdas dependieron de la natu- raleza qufmica de la solucion extractora. El HCl presento los contenidos mas altos de Zn en los chasuelos, excepto en Vertisoles. Las soluciones que hicontienen el agente quelante EDTA (Olsen Modi- ficado y Mehlich`3, extrajeron niveles interme- Modidios de Zn, en tanto que los metodos que contie- Den el quelato DTPA (Morgan Modificado y DT - PA, obtuvieron los valores mas bajos. Las corre- laciones de Zn extrafble entre los 5 metodos fue- signifirOD significativas en la mayona de los casos, tanto nivel de orden de suelos como en el conjunto de indivilos 100 suelos analizados. Los coeficientes de co- rrelacion mas altos, se presentaron entre Mehlich Morgan Modificado y DTPA. Las correlaciones Modifueron consistentes en los 4 ordenes, 10 que indica que estas soluciones poseen un amplio margen de adaptacion a diferentes tipos de suelo, siendo una caractenstica ventajosa para la selección de un metodo de analisis. El Olsen Modificado fue mas slighteficiente para la extraccion de Zn en suelos de pH ligeramente acido 0 neutro (Vertisoles e Inceptiso- les, que en suelos acidos (Ultisoles y Andisoles. EI HCI extrajo cantidades muy aItas de Zn que Moraparentementestan relacionadas con formas no disponibles para lag plantas. Se concluye que lag soluciones Mehlich 3, Morgan Modificado y DT - PA son semejantes en la forma de extraer Zn dispo- Dible, y podrian seT una altemativa para sustituir el metoda tradicional de Olsen Modificado utilizado en Costa Rica. Sin embargo,la eficiencia de ellas no puede seT establecida sino a traves de log estudios de correlacion contra rendimiento en invernadero y campo.

Design and study of a coplanar grid array CdZnTe detector for improved spatial resolution

International Nuclear Information System (INIS)

Ma, Yuedong; Xiao, Shali; Yang, Guoqiang; Zhang, Liuqiang

2014-01-01

Coplanar grid (CPG) CdZnTe detectors have been used as gamma-ray spectrometers for years. Comparing with pixelated CdZnTe detectors, CPG CdZnTe detectors have either no or poor spatial resolution, which directly limits its use in imaging applications. To address the issue, a 2×2 CPG array CdZnTe detector with dimensions of 7×7×5 mm 3 was fabricated. Each of the CPG pairs in the detector was moderately shrunk in size and precisely designed to improve the spatial resolution while maintaining good energy resolution, considering the charge loss at the surface between the strips of each CPG pairs. Preliminary measurements were demonstrated at an energy resolution of 2.7–3.9% for the four CPG pairs using 662 keV gamma rays and with a spatial resolution of 3.3 mm, which is the best spatial resolution ever achieved for CPG CdZnTe detectors. The results reveal that the CPG CdZnTe detector can also be applied to imaging applications at a substantially higher spatial resolution. - Highlights: • A novel structure of coplanar grid CdZnTe detector was designed to evaluate the possibility of applying the detector to gamma-ray imaging applications. • The best spatial resolution of coplanar grid CdZnTe detectors ever reported has been achieved, along with good spectroscopic performance. • Depth correction of the energy spectra using a new algorithm is presented

Conception and characterization of a virtual coplanar grid for a 11×11 pixelated CZT detector

Energy Technology Data Exchange (ETDEWEB)

Espagnet, Romain; Frezza, Andrea [Department of Physics, Engineering Physics and Optics and Cancer Research Center, Université Laval, Quebec city, QC, Canada G1R 0A6 (Canada); Martin, Jean-Pierre; Hamel, Louis-André [Department of Physics, Université de Montréal, C.P. 6128 Montréal QC, Canada H3C 3J7 (Canada); Després, Philippe, E-mail: philippe.despres@phy.ulaval.ca [Department of Physics, Engineering Physics and Optics and Cancer Research Center, Université Laval, Quebec city, QC, Canada G1R 0A6 (Canada); Department of Radiation Oncology and Research Center of CHU de Québec - Université Laval, Quebec city, QC Canada G1R 2J6 (Canada)

2017-07-11

Due to the low mobility of holes in CZT, commercially available detectors with a relatively large volume typically use a pixelated anode structure. They are mostly used in imaging applications and often require a dense electronic readout scheme. These large volume detectors are also interesting for high-sensitivity applications and a CZT-based blood gamma counter was developed from a 20×20×15 mm{sup 3} crystal available commercially and having a 11×11 pixelated readout scheme. A method is proposed here to reduce the number of channels required to use the crystal in a high-sensitivity counting application, dedicated to pharmacokinetic modelling in PET and SPECT. Inspired by a classic coplanar anode, an implementation of a virtual coplanar grid was done by connecting the 121 pixels of the detector to form intercalated bands. The layout, the front-end electronics and the characterization of the detector in this 2-channel anode geometry is presented. The coefficients required to compensate for electron trapping in CZT were determined experimentally to improve the performance. The resulting virtual coplanar detector has an intrinsic efficiency of 34% and an energy resolution of 8% at 662 keV. The detector's response was linear between 80 keV and 1372 keV. This suggests that large CZT crystals offer an excellent alternative to scintillation detectors for some applications, especially those where high-sensitivity and compactness are required.

Analysis of a Segmented Annular Coplanar Capacitive Tilt Sensor with Increased Sensitivity

OpenAIRE

Jiahao Guo; Pengcheng Hu; Jiubin Tan

2016-01-01

An investigation of a segmented annular coplanar capacitor is presented. We focus on its theoretical model, and a mathematical expression of the capacitance value is derived by solving a Laplace equation with Hankel transform. The finite element method is employed to verify the analytical result. Different control parameters are discussed, and each contribution to the capacitance value of the capacitor is obtained. On this basis, we analyze and optimize the structure parameters of a segmented...

Measurement of mortar permittivity during setting using a coplanar waveguide

International Nuclear Information System (INIS)

Juan-García, P; Torrents, J M

2010-01-01

A sensor based on a coplanar waveguide structure was designed to perform non-destructive tests for material characterization in which the measurement can be done only on one side of the sample. The measurements were compared with the impedance of a capacitor filled with the same material. The permittivity and insertion loss of the sensor showed valuable information about the setting process of a mortar slab during the first 28 days of the hardening process, and a good correlation between both measurements was obtained, so the proposed setup can be useful for structural surveillance and moisture detection in civil structures

Polychlorinated biphenyl residues in food and human milk: determination of co-planar and mono-ortho substituted congeners

International Nuclear Information System (INIS)

Boehm, V.; Schulte, E.; Thier, H.P.

1993-01-01

An analytical method is described for determining the residues of coplanar as well as mono-ortho substituted PCB congeners both exhibiting toxicological relevance, in foods of animal origin and in human milk. The unsophisticated procedure, convenient for routine analyses, includes the extraction of lipids, clean-up steps using liquid/liquid partition and column chromatography, fractionation of the congeners using HPLC on a special carbon column with an optimal gradient elution, and capillary column gas chromatography with electron capture or mass spectrometric detection. As preliminary results indicate, the low-chlorinated PCB technical products contribute more to the actual contamination of environment and foods than has been estimated so far. Obviously the co-planar congeners are accumulated during the food chain in a portion different from that found for the other congeners. (orig.)

Design and modeling of inductors, capacitors and coplanar waveguides at tens of GHz frequencies

CERN Document Server

Aryan, Naser Pour

2015-01-01

This book describes the basic principles of designing and modelling inductors, MIM capacitors and coplanar waveguides at frequencies of several tens of GHz. The author explains the design and modelling of key, passive elements, such as capacitors, inductors and transmission lines that enable high frequency MEMS operating at frequencies in the orders of tens of GHz.

Finite Ground Coplanar (FGC) Waveguide: Characteristics and Advantages Evaluated for Radiofrequency and Wireless Communication Circuits

Science.gov (United States)

Ponchak, George E.

1999-01-01

Researchers in NASA Lewis Research Center s Electron Device Technology Branch are developing transmission lines for radiofrequency and wireless circuits that are more efficient, smaller, and make lower cost circuits possible. Traditionally, radiofrequency and wireless circuits have employed a microstrip or coplanar waveguide to interconnect the various electrical elements that comprise a circuit. Although a coplanar waveguide (CPW) is widely viewed as better than a microstrip for most applications, it too has problems. To solve these problems, NASA Lewis and the University of Michigan developed a new version of a coplanar waveguide with electrically narrow ground planes. Through extensive numerical modeling and experimental measurements, we have characterized the propagation constant of the FGC waveguide, the lumped and distributed circuit elements integrated in the FGC waveguide, and the coupling between parallel transmission lines. Although the attenuation per unit length is higher for the FGC waveguide because of higher conductor loss, the attenuation is comparable when the ground plane width is twice the center conductor width as shown in the following graph. An upper limit to the line width is derived from observations that when the total line width is greater than ld/2, spurious resonances due to the parallel plate waveguide mode are established. Thus, the ground plane width must be less than ld/4 where ld is the wavelength in the dielectric. Since the center conductor width S is typically less than l/10 to maintain good transverse electromagnetic mode characteristics, it follows that a ground plane width of B = 2S would also be electrically narrow. Thus, we can now treat the ground strips of the FGC waveguide the same way that the center conductor is treated.

Method to allow the estimation of heat transfer coefficients in solar stills; Metodo para determinar coeficientes locales de transferencia de calor en destiladores solares

Energy Technology Data Exchange (ETDEWEB)

Rubio Cerda, Eduardo; Porta Gandara, Miguel A [CIBNOR, Mexico D.F (Mexico); Fernandez Zayas, Jose Luis [UNAM Mexico, D.F. (Mexico)

2000-07-01

This work reports an experimental method that allows to estimate the heat transfer coefficients in the neighborhood of walls or flat plates subject to convective transport phenomena. This method can be applied to a great variety of thermal systems since it is based on the knowledge of the border condition for the temperature at the surface of the plate, and the temperature profile that characterize the dimensionless coefficient of heat transfer in the fluid, according to its definition given by the Nusselt number. The approach of this work are the foundations of the method and the system that has been developed to apply it, that incorporates automatic acquisition equipment for continuos monitoring of the information and elements to control the parameters of interest. In addition, the experimental cavities on which the method will be evaluated are discussed, considering two different scales, as well as experiments in cavities filled with air, and with a mixture of air and steam water, as is the case for solar distillation. [Spanish] En este trabajo se presenta un metodo que permite determinar de manera experimental coeficientes de transferencia de calor por conveccion. Este metodo puede ser aplicado a una gran variedad de sistemas termicos ya que se fundamenta en el conocimiento de la condicion de frontera para la temperatura en la superficie de la placa, y del perfil de temperaturas que caracteriza el coeficiente adimensional de transferencia de calor en el fluido, de acuerdo a la definicion de este, dada por el numero de Nusselt. El trabajo que aqui se reporta esta enfocado a la fundamentacion del metodo y al equipamiento que se ha desarrollado para instrumentarlo, que incorpora equipos automaticos de adquisicion continua de informacion y elementos de control para los parametros de interes. Se presentan ademas, las cavidades experimentales sobre las que sera evaluado el metodo, que considera dos escalas diferentes, asi como experimentos en cavidades llenas de aire

Diagnostics of pre-breakdown light emission in a helium coplanar barrier discharge: the presence of neutral bremsstrahlung

Science.gov (United States)

Navrátil, Zdeněk; Morávek, Tomáš; Ráheľ, Jozef; Čech, Jan; Lalinský, Ondřej; Trunec, David

2017-05-01

Weak light emission (˜10-3 of active discharge signal; average count rate ˜ 1 photon s-1 nm-1) associated with surface charge relaxation during the dark phase of a helium diffuse coplanar barrier discharge was studied by optical emission spectroscopy, using a technique of phase-resolved single photon counting. The optical emission spectra of the dark phase contained luminescent bands of the dielectrics used (Al2O3, AlN) and spectral lines from the gas constituents (OH*, {{{N}}}2* , {{{N}}}2+* , He*, He{}2* , O*). During the charge relaxation event, a broad continuum appeared in the optical emission spectra, consisting of bremsstrahlung radiation and amplified luminescence of the dielectric barrier. The analysis presented suggests that the bremsstrahlung radiation originated from slow electrons colliding with neutral helium atoms. The fitting procedure we developed reproduced well the observed shape of the continuum. Moreover, it provided a method for the determination of electric field strength in the discharge during this particular phase. The electric field reached 1 kV cm-1 during the charge relaxation event.

Radical production efficiency and electrical characteristics of a coplanar barrier discharge built by multilayer ceramic technology

DEFF Research Database (Denmark)

Jõgi, Indrek; Erme, Kalev; Levoll, Erik

2017-01-01

The present study investigated the electrical characteristics and radical production efficiency of a coplanar barrier discharge (CBD) device manufactured by Kyocera by multilayer ceramic technology. The device consisted of a number of linear electrodes with electrode and gap widths of 0.75 mm...

The phase accumulation and antenna near field of microscopic propagating spin wave devices

Energy Technology Data Exchange (ETDEWEB)

Chang, Crosby S.; Kostylev, Mikhail, E-mail: mikhail.kostylev@uwa.edu.au; Ivanov, Eugene [School of Physics M013, The University of Western Australia, Crawley, WA 6009 (Australia); Ding, Junjia; Adeyeye, Adekunle O. [Department of Electrical and Computer Engineering, National University of Singapore, 117576 Singapore (Singapore)

2014-01-20

We studied phase accumulation by the highly non-reciprocal magnetostatic surface spin waves in thin Permalloy microstripes excited and received by microscopic coplanar antennae. We find that the experimentally measured characteristic length of the near field of the antenna is smaller than the total width of the coplanar. This is confirmed by our numerical simulations. Consequently, the distance over which the spin wave accumulates its phase while travelling between the input and output antennae coincides with the distance between the antennae symmetry axes with good accuracy.

The phase accumulation and antenna near field of microscopic propagating spin wave devices

International Nuclear Information System (INIS)

Chang, Crosby S.; Kostylev, Mikhail; Ivanov, Eugene; Ding, Junjia; Adeyeye, Adekunle O.

2014-01-01

We studied phase accumulation by the highly non-reciprocal magnetostatic surface spin waves in thin Permalloy microstripes excited and received by microscopic coplanar antennae. We find that the experimentally measured characteristic length of the near field of the antenna is smaller than the total width of the coplanar. This is confirmed by our numerical simulations. Consequently, the distance over which the spin wave accumulates its phase while travelling between the input and output antennae coincides with the distance between the antennae symmetry axes with good accuracy

Method of identifying the friction of rotors using the wavelet transform; Metodo para identificar el rozamiento de rotores utilizado la transformada wavelet

Energy Technology Data Exchange (ETDEWEB)

Jauregui Correa, Juan Carlos; Rubio Cerda, Eduardo; Gonzalez Brambila, Oscar [CIATEQ, A.C., Queretaro (Mexico)

2007-11-15

The modern processes of signal analysis that measure mechanical vibrations are based on the fast transform of Fourier (FFT), nevertheless, this method is not able to identify transient phenomena nor of nonlinear nature. Although many efforts have been made to try to identify these phenomena in the frequency spectra, it is not possible to correlate the spectra with the physical characteristics of this type of phenomena. Within these phenomena on the rubbing of a rotor against the housing or trunnion of a bearing, this phenomenon has a nonlinear behavior, as it is demonstrated in this paper. In the first part a method based on the of signal analysis type wavelets is presented and how this technique can be used to predict transient and nonlinear phenomena. Once defined the method, its application in the identification of the friction of rotors is demonstrated. With this, one demonstrates that the method presented in this paper allows to also identifying in real time the rubbing phenomenon and also that it can be used as an of analysis technique in the preventive maintenance systems. [Spanish] Los procesos modernos de analisis de senales que miden vibraciones mecanicas se basan en la transformada rapida de Fourier (FFT por sus siglas en ingles), sin embargo, este metodo no es capaz de identificar fenomenos transitorios ni de naturaleza no lineal. A pesar de que se han hecho muchos esfuerzos para tratar de identificar estos fenomenos en los espectros de frecuencia, no es posible correlacionar el espectro con las caracteristicas fisicas de este tipo de fenomenos. Dentro de estos fenomenos sobre el rozamiento de un rotor contra la carcasa o munon de una chumacera, este fenomeno tiene un comportamiento no lineal, como se demuestra en este trabajo. En la primera parte se presenta un metodo basado en el analisis de senales tipo wavelets y como esta tecnica puede utilizarse para predecir fenomenos transitorios y no lineales. Una vez definido el metodo, se demuestra su

Exposure to coplanar PCBs induces endothelial cell inflammation through epigenetic regulation of NF-κB subunit p65

Energy Technology Data Exchange (ETDEWEB)

Liu, Dandan; Perkins, Jordan T. [Superfund Research Center, University of Kentucky, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40536 (United States); Petriello, Michael C. [Superfund Research Center, University of Kentucky, Lexington, KY 40536 (United States); Graduate Center for Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Hennig, Bernhard, E-mail: bhennig@uky.edu [Superfund Research Center, University of Kentucky, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40536 (United States)

2015-12-15

Epigenetic modifications of DNA and histones alter cellular phenotypes without changing genetic codes. Alterations of epigenetic marks can be induced by exposure to environmental pollutants and may contribute to associated disease risks. Here we test the hypothesis that endothelial cell dysfunction induced by exposure to polychlorinated biphenyls (PCBs) is mediated in part though histone modifications. In this study, human vascular endothelial cells were exposed to physiologically relevant concentrations of several PCBs congeners (e.g., PCBs 77, 118, 126 and 153) followed by quantification of inflammatory gene expression and changes of histone methylation. Only exposure to coplanar PCBs 77 and 126 induced the expression of histone H3K9 trimethyl demethylase jumonji domain-containing protein 2B (JMJD2B) and nuclear factor-kappa B (NF-κB) subunit p65, activated NF-κB signaling as evidenced by nuclear translocation of p65, and up-regulated p65 target inflammatory genes, such as interleukin (IL)-6, C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and IL-1α/β. The increased accumulation of JMJD2B in the p65 promoter led to a depletion of H3K9me3 repression mark, which accounts for the observed up-regulation of p65 and associated inflammatory genes. JMJD2B gene knockdown confirmed a critical role for this histone demethylase in mediating PCB-induced inflammation of the vascular endothelium. Finally, it was determined, via chemical inhibition, that PCB-induced up-regulation of JMJD2B was estrogen receptor-alpha (ER-α) dependent. These data suggest that coplanar PCBs may exert endothelial cell toxicity through changes in histone modifications. - Highlights: • Coplanar PCBs significantly induced histone demethylase JMJD2B expression. • Coplanar PCBs activated NF-κB through p65 up-regulation and nuclear translocation. • Histone H3K4 and K9 modifications were mediated by ER-α/JMJD2B/MLL2 complex. �

Evaluation of mitogen-induced responses in marine mammal and human lymphocytes by in-vitro exposure of butyltins and non-ortho coplanar PCBs

International Nuclear Information System (INIS)

Nakata, H.; Sakakibara, A.; Kanoh, M.; Kudo, S.; Watanabe, H.; Nagai, N.; Miyazaki, N.; Asano, Y.; Tanabe, S.

2002-01-01

Butyltins may affect the immune response in marine mammals. - The effects of exposure to butyltin compounds (BTs: tributyltin; TBT, dibutyltin; DBT and monobutyltin; MBT) and non-ortho coplanar PCBs (IUPAC 77, 126 and 169) on marine mammals and human lymphocyte were evaluated. Peripheral blood mononuclear cells (PBMCs) isolated from Dall's porpoises (Phocoenoides dalli), bottlenose dolphins (Tursiops truncatus), a California sealion (Zalophus californianus), a larga seal (Phoca largha) and humans (Homo sapiens) were exposed at varying concentrations of BTs and coplanar PCBs. Concanavalin A (Con A)-stimulated mitogenesis found significantly suppressed (P<0.01) when the cells were exposed at 300 nM (89 ng/ml) of TBT and 330 nM of DBT (77 ng/ml), while MBT showed little cytotoxicity at treatment levels of up to 3600 nM (620 ng/ml). BTs concentrations in the liver of Dall's porpoises from Japanese coastal waters ranged between 81-450 ng/g for TBT and 200-1100 ng/g (wet wt.) for DBTs, which is greater than the cytotoxic levels registered in this study. In contrast, non-ortho coplanar PCBs did not suppress cell proliferation at concentrations of up to 30 nM (10 ng/ml). The residue levels of coplanar PCBs in the blubber of Dall's porpoises were 0.12-1.3 ng/g, which were one order of lower than those levels that do cell proliferation. When cells were exposed to a mixture of TBT/DBTand coplanar PCBs, the proliferation was significantly reduced to 33 nM DBT plus 34 nM CB-77 and 33 nM DBT plus 28 nM CB-169 mixtures, respectively. The investigations relating the contaminant-induced immunosuppression in marine mammals have been focused on persistent organochlorines such as PCBs, pesticides and dioxin compounds. However, this study suggested the possibility of BTs could also pose a serious threat to the immune functions in free-ranging marine mammals and humans

Evaluation of mitogen-induced responses in marine mammal and human lymphocytes by in-vitro exposure of butyltins and non-ortho coplanar PCBs

Energy Technology Data Exchange (ETDEWEB)

Nakata, H.; Sakakibara, A.; Kanoh, M.; Kudo, S.; Watanabe, H.; Nagai, N.; Miyazaki, N.; Asano, Y.; Tanabe, S

2002-12-01

Butyltins may affect the immune response in marine mammals. - The effects of exposure to butyltin compounds (BTs: tributyltin; TBT, dibutyltin; DBT and monobutyltin; MBT) and non-ortho coplanar PCBs (IUPAC 77, 126 and 169) on marine mammals and human lymphocyte were evaluated. Peripheral blood mononuclear cells (PBMCs) isolated from Dall's porpoises (Phocoenoides dalli), bottlenose dolphins (Tursiops truncatus), a California sealion (Zalophus californianus), a larga seal (Phoca largha) and humans (Homo sapiens) were exposed at varying concentrations of BTs and coplanar PCBs. Concanavalin A (Con A)-stimulated mitogenesis found significantly suppressed (P<0.01) when the cells were exposed at 300 nM (89 ng/ml) of TBT and 330 nM of DBT (77 ng/ml), while MBT showed little cytotoxicity at treatment levels of up to 3600 nM (620 ng/ml). BTs concentrations in the liver of Dall's porpoises from Japanese coastal waters ranged between 81-450 ng/g for TBT and 200-1100 ng/g (wet wt.) for DBTs, which is greater than the cytotoxic levels registered in this study. In contrast, non-ortho coplanar PCBs did not suppress cell proliferation at concentrations of up to 30 nM (10 ng/ml). The residue levels of coplanar PCBs in the blubber of Dall's porpoises were 0.12-1.3 ng/g, which were one order of lower than those levels that do cell proliferation. When cells were exposed to a mixture of TBT/DBTand coplanar PCBs, the proliferation was significantly reduced to 33 nM DBT plus 34 nM CB-77 and 33 nM DBT plus 28 nM CB-169 mixtures, respectively. The investigations relating the contaminant-induced immunosuppression in marine mammals have been focused on persistent organochlorines such as PCBs, pesticides and dioxin compounds. However, this study suggested the possibility of BTs could also pose a serious threat to the immune functions in free-ranging marine mammals and humans.

Low-temperature hydrogenation of diamond nanoparticles using diffuse coplanar surface barrier discharge at atmospheric pressure

Czech Academy of Sciences Publication Activity Database

Kromka, Alexander; Čech, J.; Kozak, Halyna; Artemenko, Anna; Ižák, Tibor; Čermák, Jan; Rezek, Bohuslav; Černák, M.

2015-01-01

Roč. 252, č. 11 (2015), s. 2602-2607 ISSN 0370-1972 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : atmospheric plasma * diamond nanoparticles * diffuse coplanar surface barrier discharge * FTIR * XPS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.522, year: 2015

Flow in potential cascades by means of the finite element method; Flujo en cascadas potenciales mediante el metodo del elemento finito

Energy Technology Data Exchange (ETDEWEB)

Sosa Cordero, Rodolfo; Fernandez Valencia, Gonzalo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1987-12-31

This article presents a mathematical model and its solution by means of the finite element method with approximate Garlekin formulation, for the flow analysis in a circular cascade, in a surface of revolution current of a turbo- machine, that can be axial, mixed or radial. To the revolution surface an agreed transformation is applied to obtain a plane, eliminating in this form one term in the equation succeeding in avoiding an iterative solution. Likewise, the finite element method allows to solve the equation in partial derivatives of the elliptical type in its quasi-harmonic form. Additionally, the method followed to introduce the contour conditions is presented; specially, the Kutta-Joukowsky conditions and the one of periodicity, which distinguishes this problem from the classical problems of ideal flows evaluated in the contour. [Espanol] En este articulo se presenta un modelo matematico y su solucion mediante el empleo del metodo del elemento finito con formulacion aproximada de Galerkin, para el analisis del flujo en una cascada circular, en una superficie de corriente de revolucion de una turbomaquina, que puede ser axial, mixta o radial. A la superficie de revolucion se le aplica una transformacion conforme para obtener un plano, eliminando de esta forma un termino en la ecuacion logrando evitar la solucion iterativa. Asimismo, el metodo del elemento finito permite resolver la ecuacion en derivadas parciales del tipo eliptico en su forma cuasiarmonica. Se presenta, ademas, el metodo seguido para introducir las condiciones de contorno; en especial, las condiciones de Kutta-Joukowsky y la de periodicidad, que distinguen a este problema de los problemas clasicos de flujos ideales valuados en el contorno.

Flow in potential cascades by means of the finite element method; Flujo en cascadas potenciales mediante el metodo del elemento finito

Energy Technology Data Exchange (ETDEWEB)

Sosa Cordero, Rodolfo; Fernandez Valencia, Gonzalo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1986-12-31

This article presents a mathematical model and its solution by means of the finite element method with approximate Garlekin formulation, for the flow analysis in a circular cascade, in a surface of revolution current of a turbo- machine, that can be axial, mixed or radial. To the revolution surface an agreed transformation is applied to obtain a plane, eliminating in this form one term in the equation succeeding in avoiding an iterative solution. Likewise, the finite element method allows to solve the equation in partial derivatives of the elliptical type in its quasi-harmonic form. Additionally, the method followed to introduce the contour conditions is presented; specially, the Kutta-Joukowsky conditions and the one of periodicity, which distinguishes this problem from the classical problems of ideal flows evaluated in the contour. [Espanol] En este articulo se presenta un modelo matematico y su solucion mediante el empleo del metodo del elemento finito con formulacion aproximada de Galerkin, para el analisis del flujo en una cascada circular, en una superficie de corriente de revolucion de una turbomaquina, que puede ser axial, mixta o radial. A la superficie de revolucion se le aplica una transformacion conforme para obtener un plano, eliminando de esta forma un termino en la ecuacion logrando evitar la solucion iterativa. Asimismo, el metodo del elemento finito permite resolver la ecuacion en derivadas parciales del tipo eliptico en su forma cuasiarmonica. Se presenta, ademas, el metodo seguido para introducir las condiciones de contorno; en especial, las condiciones de Kutta-Joukowsky y la de periodicidad, que distinguen a este problema de los problemas clasicos de flujos ideales valuados en el contorno.

Atomic processes in strong bichromatic elliptically polarized laser fields

Energy Technology Data Exchange (ETDEWEB)

Odžak, S., E-mail: senad.odzak@gmail.com; Hasović, E.; Gazibegović-Busuladžić, A.; Čerkić, A., E-mail: anercerkic@yahoo.com; Fetić, B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegovina); Kramo, A. [BHANSA, Aeronautical Meteorology Department, Kurta Schorka 36, 71000 Sarajevo (Bosnia and Herzegovina); Busuladžić, M. [Medical Faculty, University of Sarajevo, Čekaluša 90, 71000 Sarajevo (Bosnia and Herzegovina); Milošević, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegovina); Academy of Sciences and Arts of Bosnia and Herzegovina, Bistrik 7, 71000 Sarajevo (Bosnia and Herzegovina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

2016-03-25

Nonlinear quantum-mechanical phenomena in strong laser fields, such as high-order harmonic generation (HHG) and above-threshold ionization (ATI) are significantly modified if the applied laser field is bichromatic and/or elliptically polarized. Numerical results obtained within the strong-field approximation are presented for two special cases. We show results for HHG by plasma ablation in a bichromatic linearly polarized laser field. We also consider the ATI process in bicircular field which consists of two coplanar counter-rotating circularly polarized fields.

Fraction-variant beam orientation optimization for non-coplanar IMRT

Science.gov (United States)

O'Connor, Daniel; Yu, Victoria; Nguyen, Dan; Ruan, Dan; Sheng, Ke

2018-02-01

Conventional beam orientation optimization (BOO) algorithms for IMRT assume that the same set of beam angles is used for all treatment fractions. In this paper we present a BOO formulation based on group sparsity that simultaneously optimizes non-coplanar beam angles for all fractions, yielding a fraction-variant (FV) treatment plan. Beam angles are selected by solving a multi-fraction fluence map optimization problem involving 500-700 candidate beams per fraction, with an additional group sparsity term that encourages most candidate beams to be inactive. The optimization problem is solved using the fast iterative shrinkage-thresholding algorithm. Our FV BOO algorithm is used to create five-fraction treatment plans for digital phantom, prostate, and lung cases as well as a 30-fraction plan for a head and neck case. A homogeneous PTV dose coverage is maintained in all fractions. The treatment plans are compared with fraction-invariant plans that use a fixed set of beam angles for all fractions. The FV plans reduced OAR mean dose and D 2 values on average by 3.3% and 3.8% of the prescription dose, respectively. Notably, mean OAR dose was reduced by 14.3% of prescription dose (rectum), 11.6% (penile bulb), 10.7% (seminal vesicle), 5.5% (right femur), 3.5% (bladder), 4.0% (normal left lung), 15.5% (cochleas), and 5.2% (chiasm). D 2 was reduced by 14.9% of prescription dose (right femur), 8.2% (penile bulb), 12.7% (proximal bronchus), 4.1% (normal left lung), 15.2% (cochleas), 10.1% (orbits), 9.1% (chiasm), 8.7% (brainstem), and 7.1% (parotids). Meanwhile, PTV homogeneity defined as D 95/D 5 improved from .92 to .95 (digital phantom), from .95 to .98 (prostate case), and from .94 to .97 (lung case), and remained constant for the head and neck case. Moreover, the FV plans are dosimetrically similar to conventional plans that use twice as many beams per fraction. Thus, FV BOO offers the potential to reduce delivery time for non-coplanar IMRT.

Be discs in coplanar circular binaries: Phase-locked variations of emission lines

Science.gov (United States)

Panoglou, Despina; Faes, Daniel M.; Carciofi, Alex C.; Okazaki, Atsuo T.; Baade, Dietrich; Rivinius, Thomas; Borges Fernandes, Marcelo

2018-01-01

In this paper, we present the first results of radiative transfer calculations on decretion discs of binary Be stars. A smoothed particle hydrodynamics code computes the structure of Be discs in coplanar circular binary systems for a range of orbital and disc parameters. The resulting disc configuration consists of two spiral arms, and this can be given as input into a Monte Carlo code, which calculates the radiative transfer along the line of sight for various observational coordinates. Making use of the property of steady disc structure in coplanar circular binaries, observables are computed as functions of the orbital phase. Some orbital-phase series of line profiles are given for selected parameter sets under various viewing angles, to allow comparison with observations. Flat-topped profiles with and without superimposed multiple structures are reproduced, showing, for example, that triple-peaked profiles do not have to be necessarily associated with warped discs and misaligned binaries. It is demonstrated that binary tidal effects give rise to phase-locked variability of the violet-to-red (V/R) ratio of hydrogen emission lines. The V/R ratio exhibits two maxima per cycle; in certain cases those maxima are equal, leading to a clear new V/R cycle every half orbital period. This study opens a way to identifying binaries and to constraining the parameters of binary systems that exhibit phase-locked variations induced by tidal interaction with a companion star.

Numerical and Analytical Study of Optimal Low-Thrust Limited-Power Transfers between Close Circular Coplanar Orbits

Directory of Open Access Journals (Sweden)

Sandro da Silva Fernandes

2007-01-01

Full Text Available A numerical and analytical study of optimal low-thrust limited-power trajectories for simple transfer (no rendezvous between close circular coplanar orbits in an inverse-square force field is presented. The numerical study is carried out by means of an indirect approach of the optimization problem in which the two-point boundary value problem, obtained from the set of necessary conditions describing the optimal solutions, is solved through a neighboring extremal algorithm based on the solution of the linearized two-point boundary value problem through Riccati transformation. The analytical study is provided by a linear theory which is expressed in terms of nonsingular elements and is determined through the canonical transformation theory. The fuel consumption is taken as the performance criterion and the analysis is carried out considering various radius ratios and transfer durations. The results are compared to the ones provided by a numerical method based on gradient techniques.

Deep Ultraviolet Copper(I) Thiocyanate (CuSCN) Photodetectors Based on Coplanar Nanogap Electrodes Fabricated via Adhesion Lithography

KAUST Repository

Wyatt-Moon, Gwenhivir

2017-11-28

Adhesion lithography (a-Lith) is a versatile fabrication technique used to produce asymmetric coplanar electrodes separated by a <15 nm nanogap. Here, we use a-Lith to fabricate deep ultraviolet (DUV) photodetectors by combining coplanar asymmetric nanogap electrode architectures (Au/Al) with solution-processable wide-band-gap (3.5–3.9 eV) p-type semiconductor copper(I) thiocyanate (CuSCN). Because of the device’s unique architecture, the detectors exhibit high responsivity (≈79 A W–1) and photosensitivity (≈720) when illuminated with a DUV-range (λpeak = 280 nm) light-emitting diode at 220 μW cm–2. Interestingly, the photosensitivity of the photodetectors remains fairly high (≈7) even at illuminating intensities down to 0.2 μW cm–2. The scalability of the a-Lith process combined with the unique properties of CuSCN paves the way to new forms of inexpensive, yet high-performance, photodetectors that can be manufactured on arbitrary substrate materials including plastic.

Deep Ultraviolet Copper(I) Thiocyanate (CuSCN) Photodetectors Based on Coplanar Nanogap Electrodes Fabricated via Adhesion Lithography

KAUST Repository

Wyatt-Moon, Gwenhivir; Georgiadou, Dimitra G; Semple, James; Anthopoulos, Thomas D.

2017-01-01

Adhesion lithography (a-Lith) is a versatile fabrication technique used to produce asymmetric coplanar electrodes separated by a <15 nm nanogap. Here, we use a-Lith to fabricate deep ultraviolet (DUV) photodetectors by combining coplanar asymmetric nanogap electrode architectures (Au/Al) with solution-processable wide-band-gap (3.5–3.9 eV) p-type semiconductor copper(I) thiocyanate (CuSCN). Because of the device’s unique architecture, the detectors exhibit high responsivity (≈79 A W–1) and photosensitivity (≈720) when illuminated with a DUV-range (λpeak = 280 nm) light-emitting diode at 220 μW cm–2. Interestingly, the photosensitivity of the photodetectors remains fairly high (≈7) even at illuminating intensities down to 0.2 μW cm–2. The scalability of the a-Lith process combined with the unique properties of CuSCN paves the way to new forms of inexpensive, yet high-performance, photodetectors that can be manufactured on arbitrary substrate materials including plastic.

Neural Models for the Broadside-Coupled V-Shaped Microshield Coplanar Waveguides

Science.gov (United States)

Guney, K.; Yildiz, C.; Kaya, S.; Turkmen, M.

2006-09-01

This article presents a new approach based on multilayered perceptron neural networks (MLPNNs) to calculate the odd-and even-mode characteristic impedances and effective permittivities of the broadside-coupled V-shaped microshield coplanar waveguides (BC-VSMCPWs). Six learning algorithms, bayesian regulation (BR), Levenberg-Marquardt (LM), quasi-Newton (QN), scaled conjugate gradient (SCG), resilient propagation (RP), and conjugate gradient of Fletcher-Powell (CGF), are used to train the MLPNNs. The neural results are in very good agreement with the results reported elsewhere. When the performances of neural models are compared with each other, the best and worst results are obtained from the MLPNNs trained by the BR and CGF algorithms, respectively.

Validation of Hiriart equation to compute steam production by the lip pressure method; Validacion de la ecuacion de Hiriart para calculo de gasto de vapor por el metodo de presion de labio

Energy Technology Data Exchange (ETDEWEB)

Flores Armenta, Magaly [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

1996-09-01

Mainly in new geothermal wells, it is necessary to evaluate the production in a very fast, simple and not expensive way, to know the convenience to install surface equipment, such as silencers and separators, to drive the steam to the commercial gathering system. In practice, one of the most known methods is the lip pressure one, which requires a simple set of installations. The objective of this paper is to validate the steam flow rate calculated by the lip pressure method, with respect to the ASME method. The ASME method is known for its accuracy, and is done by measuring the steam and liquid after a high pressure separator, by an orifice plate of known diameter and a triangular weir. Results of the validation show up the feasibility of application of the lip pressure method by using a simple adjustment equation. Percentage of mistake results less than 1%, without any notable influence of the production enthalpy. That equation to be applied in a general case, is as follows: Q{nu} =(20642)(F*P*D{sup 2}/{radical}h-2000). For the particular case of the Los Azufres geothermal field, the equation is: Q{nu}= 810*P*D{sup 2} [Espanol] En los pozos geotermicos, principalmente en los nuevos, es necesario evaluar su produccion de manera rapida, sencilla y economica, para determinar la conveniencia de instalar equipo superficial, como separadores, silenciadores, etc., que permita la integracion del vapor al sistema comercial de generacion electrica. Para fines practicos uno de los metodos mas conocidos es el de presion de labio, que solo requiere un arreglo sencillo de instalaciones superficiales. En este documento se validan y ajustan los calculos de produccion de vapor por ese metodo de presion de labio, con respecto a las mediciones exactas efectuadas con el metodo ASME. Este ultimo es reconocido internacionalmente por su precision, y se lleva a cabo separando la mezcla obtenida en superficie en un recipiente a presion para medir el vapor a traves de una placa de orificio

Advantages and disadvantages of using non-coplanar techniques in radiotherapy of the abdomen formed 3D; Ventajas e inconvenientes del uso de tecnicas con coplanares en radiaoterpia 3D conformada de abdomen

Energy Technology Data Exchange (ETDEWEB)

Urena Llinares, A.; Castro Ramirez, I.; Iborra Oquendo, M. A; Quinones Rodriguez, L. A.; Angulo Pain, E.

2011-07-01

3D Radiotherapy locations abdomen, especially in pancreas and stomach cancers is often extremely difficult if we are to meet the dose constraints to organs at risk due to proximity and many of these (liver, kidneys, intestines, lungs, bone. ..). Of these, the most critical are the kidneys, which also present values of tolerance, in most cases difficult to meet. This is done in our hospital are using non-coplanar techniques performing well both as coating PTV dose to both kidneys.

Rectangular waveguide-to-coplanar waveguide transitions at U-band using e-plane probe and wire bonding

DEFF Research Database (Denmark)

Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy

2016-01-01

This paper presents rectangular waveguide-to-coplanar waveguide (CPW) transitions at U-band (40–60 GHz) using E-plane probe and wire bonding. The designs of CPWs based on quartz substrate with and without aluminum cover are explained. The single and double layer rectangular waveguide-to-CPW trans......This paper presents rectangular waveguide-to-coplanar waveguide (CPW) transitions at U-band (40–60 GHz) using E-plane probe and wire bonding. The designs of CPWs based on quartz substrate with and without aluminum cover are explained. The single and double layer rectangular waveguide......-to-CPW transitions using E-plane probe and wire bonding are designed. The proposed rectangular waveguide-to-CPW transition using wire bonding can provide 10 GHz bandwidth at U-band and does not require extra CPWs or connections between CPWs and chips. A single layer rectangular waveguide-to-CPW transition using E......-plane probe with aluminum package has been fabricated and measured to validate the proposed transitions. To the authors' best knowledge, this is the first time that a wire bonding is used as a probe for rectangular waveguide-to-CPW transition at U-band....

Oxidative stress and apoptosis of Carassius auratus lymphocytes induced by nonplanar (PCB153) and coplanar (PCB169) polychlorinated biphenyl congeners in vitro

Institute of Scientific and Technical Information of China (English)

ZHANG Jian-ying; ZHANG Hang-jun; NI Wan-min

2009-01-01

and the coplanar congener was more cytotoxic than nonplanar congener. This study suggests that cytotoxicity mechanisms of the PCB congeners on fish lymphocytes depend on their planarity and chemical structures.

Effect of electron transport properties on unipolar CdZnTe radiation detectors: LUND, SpectrumPlus, and Coplanar Grid

International Nuclear Information System (INIS)

James, Ralph B.

2000-01-01

Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd 0.9 Zn 0.1 Te (CZT) were performed for 137 Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumes were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices

Coplanar equal energy-sharing 64.6 eV e-He triple differential cross sections

International Nuclear Information System (INIS)

Bray, I.; Fursa, D. V.

1996-11-01

Electron impact ionization of the ground state of helium is measured and calculated for the case of 64.6 eV incident electrons with coplanar outgoing 20 eV electrons. Various geometries are considered: symmetric, fixed θ A and fixed θ B - θ A . The method of calculation is the convergent close-coupling theory. This theory is able to reproduce the angular profiles in essentially all of these geometries, yet it yields a constant factor of approximately two lower cross sections than experiment. 14 refs., 4 figs

SU-F-T-352: Development of a Knowledge Based Automatic Lung IMRT Planning Algorithm with Non-Coplanar Beams

International Nuclear Information System (INIS)

Zhu, W; Wu, Q; Yuan, L

2016-01-01

Purpose: To improve the robustness of a knowledge based automatic lung IMRT planning method and to further validate the reliability of this algorithm by utilizing for the planning of clinical cases with non-coplanar beams. Methods: A lung IMRT planning method which automatically determines both plan optimization objectives and beam configurations with non-coplanar beams has been reported previously. A beam efficiency index map is constructed to guide beam angle selection in this algorithm. This index takes into account both the dose contributions from individual beams and the combined effect of multiple beams which is represented by a beam separation score. We studied the effect of this beam separation score on plan quality and determined the optimal weight for this score.14 clinical plans were re-planned with the knowledge-based algorithm. Significant dosimetric metrics for the PTV and OARs in the automatic plans are compared with those in the clinical plans by the two-sample t-test. In addition, a composite dosimetric quality index was defined to obtain the relationship between the plan quality and the beam separation score. Results: On average, we observed more than 15% reduction on conformity index and homogeneity index for PTV and V_4_0, V_6_0 for heart while an 8% and 3% increase on V_5, V_2_0 for lungs, respectively. The variation curve of the composite index as a function of angle spread score shows that 0.6 is the best value for the weight of the beam separation score. Conclusion: Optimal value for beam angle spread score in automatic lung IMRT planning is obtained. With this value, model can result in statistically the “best” achievable plans. This method can potentially improve the quality and planning efficiency for IMRT plans with no-coplanar angles.

UHF coplanar-slot antenna for aircraft-to-satellite data communications

Science.gov (United States)

Myhre, R. W.

1979-01-01

The initiative for starting the Aircraft-to-Satellite Data Relay (ASDAR) Program came from a recognition that much of the world's weather originates in the data sparse area of the tropics which are primarily ocean. The ASDAR system consists of (1) a data acquisition and control unit to acquire, store and format these data; (2) a clock to time the data sampling and transmission periods; and (3) a transmitter and low-profile upper hemisphere coverage antenna to relay the formatted data via satellite to the National Weather Service ground stations, as shown schematically. The low-profile antenna is a conformal antenna based on the coplanar-slot approach. The antenna is circular polarized and has an on-axis gain of nearly 2.5 dB and a HPBW greater than 90 deg. The discussion covers antenna design, radiation characteristics, flight testing, and system performance.

Three-dimensional x-ray stereometry from paired coplanar images: a progress report.

Science.gov (United States)

Baumrind, S; Moffitt, F H; Curry, S

1983-10-01

More than fifty years ago, Broadbent reported the development of a three-dimensional cephalometric method which complexed information from pairs of x-ray images oriented in two planes at right angles to each other. Empirical problems have prevented the routine clinical use of this "biplanar" method, notwithstanding its obvious conceptual brilliance. The present article reports on recent work toward the development of an alternative method of three-dimensional cephalometry in which the two images of each x-ray pair are positioned in the same plane rather than being at right angles to each other. It is believed that this "coplanar" method avoids many of the technical problems that have limited the use of the Broadbent method.

Subsurface microbial ecology. Epi fluorescence direct counts; Ecologia microbica del sottosuolo: metodo di conta diretta in epifluorescenza

Energy Technology Data Exchange (ETDEWEB)

Barra Caracciolo, A.; Silvestri, C.; Creo, C.; Izzo, G. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

1998-07-01

To the aim of recognize the importance of microorganisms in affecting or even determining the fate of xenobiotics in the subsurface environment evaluating bacteria concentration in a subsurface ecosystem, the report discusses a soil sample treatment method which has been developed for epi fluorescence direct counting with DAPI. [Italian] Lo studio discute un metodo di trattamento del campione per la conta diretta in epifluorescenza con un marcatore selettivo per il DNA, il DAPI, al fine di quantificare la concentrazione batterica del sottosuolo e studiare il ruolo dei microrganismi nella biodegradazione delle molecole esogene, ancora poco indagato.

Planar self-aligned imprint lithography for coplanar plasmonic nanostructures fabrication

KAUST Repository

Wan, Weiwei

2014-03-01

Nanoimprint lithography (NIL) is a cost-efficient nanopatterning technology because of its promising advantages of high throughput and high resolution. However, accurate multilevel overlay capability of NIL required for integrated circuit manufacturing remains a challenge due to the high cost of achieving mechanical alignment precision. Although self-aligned imprint lithography was developed to avoid the need of alignment for the vertical layered structures, it has limited usage in the manufacture of the coplanar structures, such as integrated plasmonic devices. In this paper, we develop a new process of planar self-alignment imprint lithography (P-SAIL) to fabricate the metallic and dielectric structures on the same plane. P-SAIL transfers the multilevel imprint processes to a single-imprint process which offers higher efficiency and less cost than existing manufacturing methods. Such concept is demonstrated in an example of fabricating planar plasmonic structures consisting of different materials. © 2014 Springer-Verlag Berlin Heidelberg.

Flow measurement in a 170-MW hydraulic turbine using the Gibson method; Medicion del flujo de una turbina hidraulica de 170 MW utilizando el metodo Gibson

Energy Technology Data Exchange (ETDEWEB)

Urquiza, Gustavo [Universidad Autonoma del Estado de Morelos (Mexico); Adamkowski, Adam [The Szewalski Institute of Fluid-Flow Machinery (Poland); Kubiak, Janusz; Sierra, Fernando [Universidad Autonoma del Estado de Morelos (Mexico); Janicki, Waldemar [The Szewalski Institute of Fluid-Flow Machinery (Poland); Fernandez, J. Manuel [Comision Federal de Electricidad (Mexico)

2007-07-15

This paper describes the methodology applied for measuring water flow through a 170-MW hydraulic turbine. The flow rate was measured using the pressure-time method, also known as the Gibson method. This method uses the well-known water hammer phenomenon in pipelines; in turbine penstocks, for instance. The version of this method used here is based on measuring, during total stop of the water stream, the time-history of pressure change in one section of the turbine penstock and relate it to the pressure in the upper reservoir to which the penstock is connected. The volumetric flow rate is determined from the relevant integration of the measured temporary pressure rise. Flow measurement was possible this way because the influence of the penstock inlet was negligible as far as an error of the measurement is concerned. The length of the penstock was 300 m. Previous experience and a standard IEC-41-1991 were the criteria adopted and applied. A fast and efficient acquisition system, including a 16 bit card, was used. The flow rate was calculated using a computer program developed and tested on several cases. The results obtained with the Gibson method were used for calibration of the on-line flow measuring system based on the Winter-Kennedy method as one of the index methods. This method is very often used for continuous monitoring of the flow rate through hydraulic turbines, when the calibration has been done on site by using the results of measurements obtained by the absolute method. Having measured the flow rate and output power, the efficiency was calculated for any operating conditions. A curve showing the best operating conditions based on the highest efficiency is presented and discussed. The details of the instrumentation, its installation, and the results obtained are discussed in the paper. [Spanish] Este articulo describe la metodologia aplicada para la medicion del flujo en una turbina hidraulica de 170 MW. El flujo se midio utilizando el metodo de presion

A Reconfigurable Coplanar Waveguide Bowtie Antenna Using an Integrated Ferroelectric Thin-Film Varactor

Directory of Open Access Journals (Sweden)

K. C. Pan

2012-01-01

Full Text Available A novel printed antenna with a frequency reconfigurable feed network is presented. The antenna consists of a bowtie structure patch radiating element in the inner space of an annulus that is on a nongrounded substrate with a ferroelectric (FE Barium Strontium Titanate (BST thin film. The bowtie patch is fed by a coplanar waveguide (CPW transmission line that also includes a CPW-based BST shunt varactor. Reconfiguration of the compact 8 mm × 8 mm system has been demonstrated by shifting the antenna system’s operating frequency 500 MHz in the 7–9 GHz band by applying a DC voltage bias.

Factorized distorted wave approximation for the (e,2e) reaction on atoms : coplanar symmetric

International Nuclear Information System (INIS)

Fuss, I.; McCarthy, I.E.; Noble, C.J.; Weigold, E.

1977-02-01

The coplanar symmetric (e,2e) cross section has been studied in the intermediate energy region for the valence states of the inert gases He, Ar and Ne. Experimental measurements at 200, 400, 800, and 1200eV for He, and at 400, 800 and 1200eV for Ne and Ar, are compared with calculations based on the factorized half-off-shell distorted-wave impulse approximation. Calculations are carried out using partial wave expanded optical model wave functions which describe elastic scattering for the distorted waves, the eikonal approximation, and the plane wave approximation. (Author)

Channel-closing effects in strong-field ionization by a bicircular field

Science.gov (United States)

Milošević, D. B.; Becker, W.

2018-03-01

Channel-closing effects, such as threshold anomalies and resonantlike intensity-dependent enhancements in strong-field ionization by a bicircular laser field are analyzed. A bicircular field consists of two coplanar corotating or counter-rotating circularly polarized fields having different frequencies. For the total detachment rate of a negative ion by a bicircular field we observe threshold anomalies and explain them using the Wigner threshold law and energy and angular momentum conservation. For the corotating bicircular case, these effects are negligible, while for the counter-rotating case they are pronounced and their position depends on the magnetic quantum number of the initial state. For high-order above-threshold ionization of rare-gas atoms by a counter-rotating bicircular laser field we observe very pronounced intensity-dependent enhancements. We find all four types of threshold anomalies known from collision theory. Contrary to the case of linear polarization, channel-closing effects for a bicircular field are visible also in the cutoff region of the electron energy spectrum, which is explained using quantum-orbit theory.

The geometry of three-dimensional measurement from paired coplanar x-ray images.

Science.gov (United States)

Baumrind, S; Moffitt, F H; Curry, S

1983-10-01

This article outlines the geometric principles which underlie the process of making craniofacial measurements in three dimensions by combining information from pairs of coplanar x-ray images. The main focus is upon the rationale of the method rather than upon the computational details. We stress particularly the importance of having available accurate measurements as to the relative positions of the x-ray tubes and the film plane. The use of control arrays of radiopaque "points" whose projected images upon the film plane allow the retrospective calculation of the spatial relationship between the x-ray tubes and the film plane is explained. Finally, the question of correcting for movement of the subject between two films of an image pair is considered briefly.

Coplanar (e, 3e) differential cross-section of He atom

CERN Document Server

Choubisa, R; Sud, K K

2003-01-01

We present in this paper the results of our calculation of five-fold differential cross-section (FDCS) for (e, 3e) process on He atom in low momentum transfer and high electron impact energy in shake-off mechanism. The formalism has been developed in Born approximation using plane waves. Byron and Joachain as well as Le Sech and correlated BBK-type wave functions respectively for incident and scattered. bound and ejected electrons. The angular distribution of FDCS of our calculation is presented in various modes of coplanar geometry and comparison is made with the available experimental data. We observe that the present calculation is able to reproduce the trend of the experimental data. However, it differs in magnitude from the experiment. The present theory does not predict four-peak structure in summed mutual angle mode for lower excess ejected electron energies. We also discuss the importance of momentum transfer, post-collision interaction (PCI) and ion participation in the (e, 3e) process in constant th...

Advantages and disadvantages of using non-coplanar techniques in radiotherapy of the abdomen formed 3D

International Nuclear Information System (INIS)

Urena Llinares, A.; Castro Ramirez, I.; Iborra Oquendo, M. A; Quinones Rodriguez, L. A.; Angulo Pain, E.

2011-01-01

3D Radiotherapy locations abdomen, especially in pancreas and stomach cancers is often extremely difficult if we are to meet the dose constraints to organs at risk due to proximity and many of these (liver, kidneys, intestines, lungs, bone. ..). Of these, the most critical are the kidneys, which also present values of tolerance, in most cases difficult to meet. This is done in our hospital are using non-coplanar techniques performing well both as coating PTV dose to both kidneys.

The Comparative Accuracy of the 4 {pi} Liquid Scintillation Counting Method of Radioisotope Standardization; L'exactitude comparee de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des radioisotopes; Sravnitel'naya tochnost' 4 {pi} zhidkogo stsintillatsionnogo metoda podscheta standartiziruemykh radioizotopov; Exactitud del metodo de recuento con centelleador liquido 4 {pi} para normalizar radioisotopos, comparada con la de otros metodos

Energy Technology Data Exchange (ETDEWEB)

Steyn, J [National Physical Research Laboratory, Pretoria (South Africa)

1960-06-15

The accuracy of the 4 {pi} liquid scintillation counting method of standardizing {beta} emitters was compared to 4 l{pi} {beta}-{gamma} coincidence counting for the nuclides Co{sup 60}, I{sup 131} and Au{sup 198}. For P{sup 32} the liquid counting results were compared to 4 {pi} proportional counting. The efficiency of the liquid scintillation counting method was found to be energy dependent, dropping to about 97.5% for Co{sup 60} which was the lowest energy {beta} emitter investigated. (author) [French] La precision de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des emetteurs {beta} a ete comparee au comptage par coincidences 4 {pi} {beta}-{gamma} pour le So{sup 60}, le I{sup 131} et le Au{sup 198}. Dans le cas du P{sup 32}, les resultats du comptage au liquide ont ete compares a ceux du comptage 4 {pi} proportionnel. On a constate que le rendement de la methode de comptage a scintillateurs liquides variait en fonction de l'energie emise et qu'il descendait a environ 97.5% pour le Co{sup 60} qui, de tous les emetteurs {beta} etudies, emet l'energie la plus faible. (author) [Spanish] El autor compara la precision del metodo de recuento con centelleador iquido 4 {pi} para normalizar emisores {beta} con la del metodo de coincidencias {beta}-{gamma} 4 {pi}, para los siguientes nuclidos: So{sup 60}, I{sup 131} y Au{sup 198}. En el caso del P{sup 32}, confronta los resultados del primer metodo con los obtenidos mediante el recuento proporcional 4 {pi}. Comprueba que la eficacia del metodo de recuento con centelleador liquido depende de la energia y desciende al 97.5%, aproximadamente, para el Co{sup 60}, que fue el emisor {beta} mas debil que se investigo. (author) [Russian] Tochnost' 4 {pi} zhidkogo stsintillyatsionnog o metoda podscheta standartiziruemogo {beta}-izluchatelya sravnivalas' s 4 {pi} {beta}-{gamma} metodom podscheta na sovpadeniyakh dlya izotopov So{sup 60}, I{sup 131} i Au{sup 198}. Dlya R{sup 32} rezultaty zhidkogo

Numerical study of the influence of dielectric tube on propagation of atmospheric pressure plasma jet based on coplanar dielectric barrier discharge

Science.gov (United States)

Haixin, HU; Feng, HE; Ping, ZHU; Jiting, OUYANG

2018-05-01

A 2D fluid model was employed to simulate the influence of dielectric on the propagation of atmospheric pressure helium plasma jet based on coplanar dielectric barrier discharge (DBD). The spatio-temporal distributions of electron density, ionization rate, electrical field, spatial charge and the spatial structure were obtained for different dielectric tubes that limit the helium flow. The results show that the change of the relative permittivity of the dielectric tube where the plasma jet travels inside has no influence on the formation of DBD itself, but has great impact on the jet propagation. The velocity of the plasma jet changes drastically when the jet passes from a tube of higher permittivity to one of lower permittivity, resulting in an increase in jet length, ionization rate and electric field, as well as a change in the distribution of space charges and discharge states. The radius of the dielectric tube has a great influence on the ring-shaped or solid bullet structure. These results can well explain the behavior of the plasma jet from the dielectric tube into the ambient air and the hollow bullet in experiments.

Electromagnetic Modeling of Distributed-Source-Excitation of Coplanar Waveguides: Applications to Traveling-Wave Photomixers

Science.gov (United States)

Pasqualini, Davide; Neto, Andrea; Wyss, Rolf A.

2001-01-01

In this work an electromagnetic model and subsequent design is presented for a traveling-wave, coplanar waveguide (CPW) based source that will operate in the THz frequency regime. The radio frequency (RF) driving current is a result of photoexcitation of a thin GaAs membrane using two frequency-offset lasers. The GaAs film is grown by molecular-beam-epitaxy (MBE) and displays sub-ps carrier lifetimes which enable the material conductivity to be modulated at a very high rate. The RF current flows between electrodes deposited on the GaAs membrane which are biased with a DC voltage source. The electrodes form a CPW and are terminated with a double slot antenna that couples the power to a quasi-optical system. The membrane is suspended above a metallic reflector to launch all radiation in one direction. The theoretical investigation and consequent design is performed in two steps. The first step consists of a direct evaluation of the magnetic current distribution on an infinitely extended coplanar waveguide excited by an impressed electric current distributed over a finite area. The result of the analysis is the difference between the incident angle of the laser beams and the length of the excited area that maximizes the RF power coupled to the CPW. The optimal values for both parameters are found as functions of the CPW and membrane dimensions as well as the dielectric constants of the layers. In the second step, a design is presented of a double slot antenna that matches the CPW characteristic impedance and gives good overall performance. The design is presently being implemented and measurements will soon be available.

CIRCULARLY POLARIZED SLOTTED APERTURE ANTENNA WITH COPLANAR WAVEGUIDE FED FOR BROADBAND APPLICATIONS

Directory of Open Access Journals (Sweden)

B. T. P. MADHAV

2016-02-01

Full Text Available Coplanar waveguide fed circularly polarized microstrip patch antenna performance evaluation is presented in this paper. The broadband characteristics are attained by placing open end slot at the lower side of the antenna. The proposed design has the return loss of less than -10dB and VSWR<2 in the desired band of operation. A gain of 3dB to 4dB is attained in the desired band with good radiation characteristics and a suitable axial ratio of less than 3 dB is attained in the prescribed band of operation. Proposed antenna is fabricated on the FR4 substrate with dielectric constant of 4.4. Parametric analysis with change in substrate permittivity also performed and the optimized dimensions are presented in this work.

Initial temperature distribution in Los Humeros, Mexico, geothermal field; Distribucion de temperatura inicial en el campo geotermico de Los Humeros, Puebla

Energy Technology Data Exchange (ETDEWEB)

Garcia, A; Arellano, V; Aragon, A; Barragan, R.M; Izquierdo, G [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Pizano, A [Comision federal de Electricidad, Los Humeros, Puebla (Mexico)

2000-12-01

The initial formation temperatures surrounding 40 wells from the Los Humeros geothermal field are presented. These temperatures were estimated using the Horner and the sphere methods. A brief discussion on the applicability of each method is presented and previous applications are detailed. Then the more likely reservoir temperature of each well versus elevation is plotted based on the estimations about the main feed zone and the temperature of each well. The boiling with depth curve for pure water is also included. Two longitudinal and one traverse geological sections are presented to illustrate the field initial temperature distribution, the lithology and layers thickness, the basement topography and the wells traversed along each sections. Also, the main feed zones of the wells are indicated. Finally, the last series of measured temperature logs in well H-26 are produced by numerical simulation. This considers the well circulation losses and an assumed initial temperature profile. This profile iteratively modified until the computed profiles match the measured temperature profiles. The last assumed temperature profile is then considered as the best approximation to the undisturbed formation temperature around well H-26 and it is then compared with the stabilized temperatures obtained via the Horner and Sphere methods. [Spanish] Se presentan las temperaturas iniciales o estabilizadas de la formacion circundante a 40 pozos del campo geotermico Los Humeros, las cuales se estimaron mediante los metodos de Horner y el metodo de la esfera. Se presenta una discusion sobre la aplicacion de cada metodo y se detallan las aplicaciones previas del metodo de la esfera. Posteriormente y con base en las estimaciones de las principales zonas de aporte de cada pozo y sus correspondientes temperaturas se grafican las temperaturas mas probables de yacimiento para cada pozo contra la elevacion y se incluye en la misma grafica la curva de ebullicion del agua contra la elevacion. Se

TH-EF-BRB-05: 4pi Non-Coplanar IMRT Beam Angle Selection by Convex Optimization with Group Sparsity Penalty

International Nuclear Information System (INIS)

O’Connor, D; Nguyen, D; Voronenko, Y; Yin, W; Sheng, K

2016-01-01

Purpose: Integrated beam orientation and fluence map optimization is expected to be the foundation of robust automated planning but existing heuristic methods do not promise global optimality. We aim to develop a new method for beam angle selection in 4π non-coplanar IMRT systems based on solving (globally) a single convex optimization problem, and to demonstrate the effectiveness of the method by comparison with a state of the art column generation method for 4π beam angle selection. Methods: The beam angle selection problem is formulated as a large scale convex fluence map optimization problem with an additional group sparsity term that encourages most candidate beams to be inactive. The optimization problem is solved using an accelerated first-order method, the Fast Iterative Shrinkage-Thresholding Algorithm (FISTA). The beam angle selection and fluence map optimization algorithm is used to create non-coplanar 4π treatment plans for several cases (including head and neck, lung, and prostate cases) and the resulting treatment plans are compared with 4π treatment plans created using the column generation algorithm. Results: In our experiments the treatment plans created using the group sparsity method meet or exceed the dosimetric quality of plans created using the column generation algorithm, which was shown superior to clinical plans. Moreover, the group sparsity approach converges in about 3 minutes in these cases, as compared with runtimes of a few hours for the column generation method. Conclusion: This work demonstrates the first non-greedy approach to non-coplanar beam angle selection, based on convex optimization, for 4π IMRT systems. The method given here improves both treatment plan quality and runtime as compared with a state of the art column generation algorithm. When the group sparsity term is set to zero, we obtain an excellent method for fluence map optimization, useful when beam angles have already been selected. NIH R43CA183390, NIH R01CA

Coplanar capacitance sensors for detecting water intrusion in composite structures

International Nuclear Information System (INIS)

Nassr, Amr A; El-Dakhakhni, Wael W; Ahmed, Wael H

2008-01-01

Composite materials are becoming more affordable and widely used for retrofitting, rehabilitating and repairing reinforced concrete structures designed and constructed under older specifications. However, the mechanical properties and long-term durability of composite materials may degrade severely in the presence of water intrusion. This study presents a new non-destructive evaluation (NDE) technique for detecting the water intrusion in composite structures by evaluating the dielectric properties of different composite system constituent materials. The variation in the dielectric signatures was employed to design a coplanar capacitance sensor with high sensitivity to detect such defects. An analytical model was used to study the effect of the sensor geometry on the output signal and to optimize sensor design. A finite element model was developed to validate analytical results and to evaluate other sensor design-related parameters. Experimental testing of a concrete specimen wrapped with composite laminate and containing a series of pre-induced water intrusion defects was conducted in order to validate the concept of the new technique. Experimental data showed excellent agreement with the finite element model predictions and confirmed sensor performance

Possible Outcomes of Coplanar High-eccentricity Migration: Hot Jupiters, Close-in Super-Earths, and Counter-orbiting Planets

Energy Technology Data Exchange (ETDEWEB)

Xue, Yuxin; Masuda, Kento; Suto, Yasushi, E-mail: yuxin@utap.phys.s.u-tokyo.ac.jp [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan)

2017-02-01

We investigate the formation of close-in planets in near-coplanar eccentric hierarchical triple systems via the secular interaction between an inner planet and an outer perturber (Coplanar High-eccentricity Migration; CHEM). We generalize the previous work on the analytical condition for successful CHEM for point masses interacting only through gravity by taking into account the finite mass effect of the inner planet. We find that efficient CHEM requires that the systems should have m {sub 1}≪m {sub 0} and m {sub 1} ≪ m {sub 2}. In addition to the gravity for point masses, we examine the importance of the short-range forces, and provide an analytical estimate of the migration timescale. We perform a series of numerical simulations in CHEM for systems consisting of a Sun-like central star, giant gas inner planet, and planetary outer perturber, including the short-range forces and stellar and planetary dissipative tides. We find that most of such systems end up with a tidal disruption; a small fraction of the systems produce prograde hot Jupiters (HJs), but no retrograde HJ. In addition, we extend CHEM to super-Earth mass range, and show that the formation of close-in super-Earths in prograde orbits is also possible. Finally, we carry out CHEM simulation for the observed hierarchical triple and counter-orbiting HJ systems. We find that CHEM can explain a part of the former systems, but it is generally very difficult to reproduce counter-orbiting HJ systems.

Structural stability of coplanar 1T-2H superlattice MoS2 under high energy electron beam

Science.gov (United States)

Reshmi, S.; Akshaya, M. V.; Satpati, Biswarup; Basu, Palash Kumar; Bhattacharjee, K.

2018-05-01

Coplanar heterojunctions composed of van der Waals layered materials with different structural polymorphs have drawn immense interest recently due to low contact resistance and high carrier injection rate owing to low Schottky barrier height. Present research has largely focused on efficient exfoliation of these layered materials and their restacking to achieve better performances. We present here a microwave assisted easy, fast and efficient route to induce high concentration of metallic 1T phase in the original 2H matrix of exfoliated MoS2 layers and thus facilitating the formation of a 1T-2H coplanar superlattice phase. High resolution transmission electron microscopy (HRTEM) investigations reveal formation of highly crystalline 1T-2H hybridized structure with sharp interface and disclose the evidence of surface ripplocations within the same exfoliated layer of MoS2. In this work, the structural stability of 1T-2H superlattice phase during HRTEM measurements under an electron beam of energy 300 keV is reported. This structural stability could be either associated to the change in electronic configuration due to induction of the restacked hybridized phase with 1T- and 2H-regions or to the formation of the surface ripplocations. Surface ripplocations can act as an additional source of scattering centers to the electron beam and also it is possible that a pulse train of propagating ripplocations can sweep out the defects via interaction from specific areas of MoS2 sheets.

Spatial trends of co-planar contaminants in lobster digestive gland from the Gulf of St. Lawrence

Energy Technology Data Exchange (ETDEWEB)

Fairchild, W.L.; Arsenault, J.T.; Comeau, M. [Department of Fisheries and Oceans, Moncton, NB (Canada)

1997-05-01

A study on spatial trends of contaminants in Canadian marine biota was conducted between 1993 and 1995. Lobster digestive glands were sampled from eight locations on the Gulf of St. Lawrence near New Brunswick and Nova Scotia. A total of 15 gland samples were analysed for dioxin, furan and co-planar PCB congeners. The five highest concentrations measured (5.8-12 pg/g wet-weight) were from samples taken from within the barrier island of Miramichi Bay in New Brunswick. This is an area of municipal and industrial development where contamination levels in marine biota is a continuing local concern.

Plasma treatment of detonation and HPHT nanodiamonds in diffuse coplanar surface barrier discharge in H.sub.2./sub./N.sub.2./sub. flow

Czech Academy of Sciences Publication Activity Database

Jirásek, Vít; Čech, J.; Kozak, Halyna; Artemenko, Anna; Černák, M.; Kromka, Alexander

2016-01-01

Roč. 213, č. 10 (2016), s. 2680-2686 ISSN 1862-6300 R&D Projects: GA ČR(CZ) GA14-04790S Institutional support: RVO:68378271 Keywords : amination * diamond * diffuse coplanar surface barrier discharge * nanomaterials * surface functionalization Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.775, year: 2016

Noncoplanar magnetic fields at collisionless shocks: A test of a new approach

International Nuclear Information System (INIS)

Gosling, J.T.; Winske, D.; Thomsen, M.F.

1988-01-01

Within the foot and ramp of a fast mode collisionless shock the magnetic field rotates out of the plane of coplanarity defined by the upstream magnetic field and the shock normal. As previously noted (Goodrich and Scudder, 1984), the sense of this rotation is such as to reduce the cross-shock potential drop when measured in the deHoffman-Teller frame relative to that measured in the normal incidence frame. From a consideration of the requirement that there be zero current in the coplanarity plane downstream of the shock, Jones and Ellison (1987) have argued that the field rotation and potential drop difference are a consequence of unequal ion and electron masses, and have derived an expression for the spatial integral of the noncoplanar field component in terms of the electron current within the shock layer. Moreover, by assuming that the ion current within the shock layer is negligible compared to the electron current, they derive equations which predict the magnitude of both the field rotation and the potential drop difference in terms of upstream quantities and the field jump at the shock. We have tested their equations with ISEE 1 and 2 plasma and field measurements at the Earth's bow shock and by means of numerical simulations. We find substantial support for their suggestion that the field rotation and thus also the frame dependence of the potential drop are fundamentally a consequence of unequal ion and electron masses. Further, for subcritical shocks (low Mach number) one can neglect the ion current to predict both the sign and the magnitude of the field rotation and potential drop difference. However, at supercritical shocks (high Mach numbers) the ion current associated with reflected, gyrating ions cannot be neglected, and the final equations of Jones and Ellison seriously underestimate the magnitude of the field rotation and the potential drop difference at these shocks

Miniature Coplanar Implantable Antenna on Thin and Flexible Platform for Fully Wireless Intracranial Pressure Monitoring System

Directory of Open Access Journals (Sweden)

M. Waqas A. Khan

2017-01-01

Full Text Available Minimally invasive approach to intracranial pressure monitoring is desired for long-term diagnostics. The monitored pressure is transmitted outside the skull through an implant antenna. We present a new miniature (6 mm × 5 mm coplanar implant antenna and its integration on a sensor platform to establish a far-field data link for the sensor readout at distances of 0.5 to 1 meter. The implant antenna was developed using full-wave electromagnetic simulator and measured in a liquid phantom mimicking the dielectric properties of the human head. It achieved impedance reflection coefficient better than −10 dB from 2.38 GHz to 2.54 GHz which covers the targeted industrial, scientific, and medical band. Experiments resulted in an acceptable peak gain of approximately −23 dBi. The implant antenna was submerged in the liquid phantom and interfaced to a 0.5 mW voltage controlled oscillator. To verify the implant antenna performance as a part of the ICP monitoring system, we recorded the radiated signal strength using a spectrum analyzer. Using a half-wavelength dipole as the receiving antenna, we captured approximately −58.7 dBm signal at a distance of 1 m from the implant antenna which is well above for the reader with sensitivity of −80 dBm.

Atlas de aves: Un metodo para documentar distribucion y seguir poblaciones

Science.gov (United States)

Robbins, C.S.; Dowell, B.A.; Dawson, D.K.; Alvarez-Lopez, Humberto; Kattan, Gustavo; Murcia, Carolina

1988-01-01

Los Atlas de Aves son proyectos nacionales o regionalies para trazar en mapas la distribucion en reproduccion de cada especie de ave. Ese procedimiento se esta usando en Europa, Australia, Nueva Zelanda, Norteamerica, y partes de Africa. El tama?o de los cuadrados varia de medio grado de latitud y Iongitud hasta 5 x 5 km. El trabajo de campo de cada proyecto exige aproxlmadamente cinco a?os, pero los aficionados pueden llevar a cabo la mayor parte del trabajo. Es posible almacenar los resultados en un computador personal. Hay muchos beneficios: (I) se presenta la distribucion corriente de las aves de la nacion, del estado, o de la Iocalidad; (2) se desarrolla nueva informacion especialmente sobre especies raras o en peligro; (3) se descubren areas que tienen una avlfauna sobresaliente o habitats raros y ayuda a su proteccion, (4) se documentan cambios de dlstribucion; (5) se pueden usar para documentar cambios de poblacion, especialmente en los tropicos donde otros metodos son mas dificiles de usar porque hay muchas especies y no hay muchos observadores calificados en la identificacion de sonidos de las aves; (6) son proyectos buenos de investigacion para estudiantes graduados; (7) los turistas y los jefes de excursiones de historia natural pueden contribuir con muchas informaciones

SU-F-BRB-12: A Novel Haar Wavelet Based Approach to Deliver Non-Coplanar Intensity Modulated Radiotherapy Using Sparse Orthogonal Collimators

Energy Technology Data Exchange (ETDEWEB)

Nguyen, D; Ruan, D; Low, D; Sheng, K [Deparment of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States); O’Connor, D [Deparment of Mathematics, University of California Los Angeles, Los Angeles, CA (United States); Boucher, S [RadiaBeam Technologies, Santa Monica, CA (United States)

2015-06-15

Purpose: Existing efforts to replace complex multileaf collimator (MLC) by simple jaws for intensity modulated radiation therapy (IMRT) resulted in unacceptable compromise in plan quality and delivery efficiency. We introduce a novel fluence map segmentation method based on compressed sensing for plan delivery using a simplified sparse orthogonal collimator (SOC) on the 4π non-coplanar radiotherapy platform. Methods: 4π plans with varying prescription doses were first created by automatically selecting and optimizing 20 non-coplanar beams for 2 GBM, 2 head & neck, and 2 lung patients. To create deliverable 4π plans using SOC, which are two pairs of orthogonal collimators with 1 to 4 leaves in each collimator bank, a Haar Fluence Optimization (HFO) method was used to regulate the number of Haar wavelet coefficients while maximizing the dose fidelity to the ideal prescription. The plans were directly stratified utilizing the optimized Haar wavelet rectangular basis. A matching number of deliverable segments were stratified for the MLC-based plans. Results: Compared to the MLC-based 4π plans, the SOC-based 4π plans increased the average PTV dose homogeneity from 0.811 to 0.913. PTV D98 and D99 were improved by 3.53% and 5.60% of the corresponding prescription doses. The average mean and maximal OAR doses slightly increased by 0.57% and 2.57% of the prescription doses. The average number of segments ranged between 5 and 30 per beam. The collimator travel time to create the segments decreased with increasing leaf numbers in the SOC. The two and four leaf designs were 1.71 and 1.93 times more efficient, on average, than the single leaf design. Conclusion: The innovative dose domain optimization based on compressed sensing enables uncompromised 4π non-coplanar IMRT dose delivery using simple rectangular segments that are deliverable using a sparse orthogonal collimator, which only requires 8 to 16 leaves yet is unlimited in modulation resolution. This work is

Co-sputtered Mo/Re superconducting coplanar resonators compatible with carbon nanotube growth

Energy Technology Data Exchange (ETDEWEB)

Blien, Stefan; Stiller, Peter L.; Goetz, Karl; Vavra, Ondrej; Huber, Thomas; Mayer, Thomas; Strunk, Christoph; Huettel, Andreas K. [Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg (Germany)

2016-07-01

Carbon nanotubes are simultaneously prototypical single electron tunneling devices and nano-electromechanical resonators. In particular for ''ultraclean'' devices, where the nanotube is grown in a last fabrication step over pre-existing chip structures, highly regular quantum spectra and high mechanical quality factors emerge. Targeting optomechanical experiments, a coupling of these devices to on-chip superconducting coplanar waveguide resonators is highly desirable. The conditions for in-situ growth of carbon nanotubes over metal contacts are quite detrimental to most superconductors: the CVD growth process takes place in a hydrogen/methane atmosphere heated up to 900 {sup circle} C. We present data on transmission line resonators fabricated of a co-sputtered molybdenum rhenium alloy that withstand CVD and remain superconducting with critical temperatures up to 8K after growth. Resonant operation at cryogenic temperatures is demonstrated, and the behaviour is highly consistent with a combination of Mattis-Bardeen theory and two-level systems in the substrate.

Coplanar asymmetric angles and symmetric energy sharing triple differential cross sections for 200 eV electron-impact ionization of Ar (3p)

International Nuclear Information System (INIS)

Ozer, Zehra N; Varol, Onur; Yavuz, Murat; Dogan, Mevlut; Amami, Sadek; Madison, Don

2015-01-01

We have measured triple differential cross sections (TDCSs) for electron-impact ionization of the 3p shell of Ar at 200 eV incident electron energy. The experiments have been performed in coplanar asymmetric energy sharing geometry. The experimental results are compared with the theoretical models of three body distorted wave (3DW) and distorted wave Born approximation (DWBA). (paper)

iCycle: Integrated, multicriterial beam angle, and profile optimization for generation of coplanar and noncoplanar IMRT plans

International Nuclear Information System (INIS)

Breedveld, Sebastiaan; Storchi, Pascal R. M.; Voet, Peter W. J.; Heijmen, Ben J. M.

2012-01-01

Purpose: To introduce iCycle, a novel algorithm for integrated, multicriterial optimization of beam angles, and intensity modulated radiotherapy (IMRT) profiles. Methods: A multicriterial plan optimization with iCycle is based on a prescription called wish-list, containing hard constraints and objectives with ascribed priorities. Priorities are ordinal parameters used for relative importance ranking of the objectives. The higher an objective priority is, the higher the probability that the corresponding objective will be met. Beam directions are selected from an input set of candidate directions. Input sets can be restricted, e.g., to allow only generation of coplanar plans, or to avoid collisions between patient/couch and the gantry in a noncoplanar setup. Obtaining clinically feasible calculation times was an important design criterium for development of iCycle. This could be realized by sequentially adding beams to the treatment plan in an iterative procedure. Each iteration loop starts with selection of the optimal direction to be added. Then, a Pareto-optimal IMRT plan is generated for the (fixed) beam setup that includes all so far selected directions, using a previously published algorithm for multicriterial optimization of fluence profiles for a fixed beam arrangement Breedveld et al.[Phys. Med. Biol. 54, 7199-7209 (2009)]. To select the next direction, each not yet selected candidate direction is temporarily added to the plan and an optimization problem, derived from the Lagrangian obtained from the just performed optimization for establishing the Pareto-optimal plan, is solved. For each patient, a single one-beam, two-beam, three-beam, etc. Pareto-optimal plan is generated until addition of beams does no longer result in significant plan quality improvement. Plan generation with iCycle is fully automated. Results: Performance and characteristics of iCycle are demonstrated by generating plans for a maxillary sinus case, a cervical cancer patient, and a

A Ka-band low-noise amplifier with a coplanar waveguide (CPW) structure with 0.15-μm GaAs pHEMT technology

International Nuclear Information System (INIS)

Wu Chia-Song; Chang Chien-Huang; Liu Hsing-Chung; Lin Tah-Yeong; Wu Hsien-Ming

2010-01-01

This investigation explores a low-noise amplifier (LNA) with a coplanar waveguide (CPW) structure, in which a two-stage amplifier is associated with a cascade schematic circuit, implemented in 0.15-μm GaAs pseudomorphic high electron mobility transistor (pHEMT) technology in a Ka-band (26.5-40.0 GHz) microwave monolithic integrated circuit (MMIC). The experimental results demonstrate that the proposed LNA has a peak gain of 12.53 dB at 30 GHz and a minimum noise figure of 3.3 dB at 29.5 GHz, when biased at a V ds of 2 V and a V gs of -0.6 V with a drain current of 16 mA in the circuit. The results show that the millimeter-wave LNA with coplanar waveguide structure has a higher gain and wider bandwidth than a conventional circuit. Finally, the overall LNA characterization exhibits high gain and low noise, indicating that the LNA has a compact circuit and favorable RF characteristics. The strong RF character exhibited by the LNA circuit can be used in millimeter-wave circuit applications. (semiconductor integrated circuits)

Up-regulation of endothelial monocyte chemoattractant protein-1 by coplanar PCB77 is caveolin-1-dependent

International Nuclear Information System (INIS)

Majkova, Zuzana; Smart, Eric; Toborek, Michal; Hennig, Bernhard

2009-01-01

Atherosclerosis, the primary cause of heart disease and stroke is initiated in the vascular endothelium, and risk factors for its development include environmental exposure to persistent organic pollutants. Caveolae are membrane microdomains involved in regulation of many signaling pathways, and in particular in endothelial cells. We tested the hypothesis that intact caveolae are required for coplanar PCB77-induced up-regulation of monocyte chemoattractant protein-1 (MCP-1), an endothelium-derived chemokine that attracts monocytes into sub-endothelial space in early stages of the atherosclerosis development. Atherosclerosis-prone LDL-R -/- mice (control) or caveolin-1 -/- /LDL-R -/- mice were treated with PCB77. PCB77 induced aortic mRNA expression and plasma protein levels of MCP-1 in control, but not caveolin-1 -/- /LDL-R -/- mice. To study the mechanism of this effect, primary endothelial cells were used. PCB77 increased MCP-1 levels in endothelial cells in a time- and concentration-dependent manner. This effect was abolished by caveolin-1 silencing using siRNA. Also, MCP-1 up-regulation by PCB77 was prevented by inhibiting p38 and c-Jun N-terminal kinase (JNK), but not ERK1/2, suggesting regulatory functions via p38 and JNK MAPK pathways. Finally, pre-treatment of endothelial cells with the aryl hydrocarbon receptor (AhR) inhibitor α-naphthoflavone (α-NF) partially blocked MCP-1 up-regulation. Thus, our data demonstrate that coplanar PCB77 can induce MCP-1 expression by endothelial cells and that this effect is mediated by AhR, as well as p 38 and JNK MAPK pathways. Intact caveolae are required for these processes both in vivo and in vitro. This further supports a key role for caveolae in vascular inflammation induced by persistent organic pollutants.

The relative biological effectiveness of out-of-field dose

International Nuclear Information System (INIS)

Balderson, Michael; Koger, Brandon; Kirkby, Charles

2016-01-01

Purpose: using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. Materials and methods: using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. Results: spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. Conclusions: spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions. (paper)

Selection of coplanar or noncoplanar beams using three-dimensional optimization based on maximum beam separation and minimized nontarget irradiation

International Nuclear Information System (INIS)

Das, Shiva K.; Marks, Lawrence B.

1997-01-01

Purpose: The design of an appropriate set of multiple fixed fields to achieve a steep dose gradient at the tumor edge, with minimal normal tissue exposure, is a very difficult problem, since a virtually infinite number of possible beam orientations exists. In practice we have selected beams in an iterative and often time-consuming process. This work proposes an optimization method, based on geometric and dose elements, to effectively arrive at a set of beam orientations. Methods and Materials: Beams are selected by minimizing a goal function including an angle function (beam separation for steep dose gradient at target edge) and a length function (related to normal tissue dose volume histogram). The relative importance of these two factors may be adjusted depending on the clinic situation. The model is flexible and can include case specific practical anatomic and physical considerations. Results: In extremely simple situations, the goal function yields results consistent with well-known analytical solutions. When applied to more complex clinical situations, it provides clinically reasonable solutions similar to those empirically developed by the clinician. The optimization process takes approximately 25 min on a UNIX workstation. Conclusion: The optimization scheme provides a practical means for rapidly designing multiple field coplanar or noncoplanar treatments. It overcomes limitations in human three-dimensional visualization such as trying to visualize beam directions and keeping track of the hinge angle between beams while accounting for anatomic/machine constraints. In practice, it has been used as a starting point for physicians to make modifications, based on their clinical judgment

Omega-3 fatty acid oxidation products prevent vascular endothelial cell activation by coplanar polychlorinated biphenyls

International Nuclear Information System (INIS)

Majkova, Zuzana; Layne, Joseph; Sunkara, Manjula; Morris, Andrew J.; Toborek, Michal; Hennig, Bernhard

2011-01-01

Coplanar polychlorinated biphenyls (PCBs) may facilitate development of atherosclerosis by stimulating pro-inflammatory pathways in the vascular endothelium. Nutrition, including fish oil-derived long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA, 22:6ω-3), can reduce inflammation and thus the risk of atherosclerosis. We tested the hypothesis that cyclopentenone metabolites produced by oxidation of DHA can protect against PCB-induced endothelial cell dysfunction. Oxidized DHA (oxDHA) was prepared by incubation of the fatty acid with the free radical generator 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH). Cellular pretreatment with oxDHA prevented production of superoxide induced by PCB77, and subsequent activation of nuclear factor-κB (NF-κB). A 4 /J 4 -neuroprostanes (NPs) were identified and quantitated using HPLC ESI tandem mass spectrometry. Levels of these NPs were markedly increased after DHA oxidation with AAPH. The protective actions of oxDHA were reversed by treatment with sodium borohydride (NaBH 4 ), which concurrently abrogated A 4 /J 4 -NP formation. Up-regulation of monocyte chemoattractant protein-1 (MCP-1) by PCB77 was markedly reduced by oxDHA, but not by un-oxidized DHA. These protective effects were proportional to the abundance of A 4 /J 4 NPs in the oxidized DHA sample. Treatment of cells with oxidized eicosapentaenoic acid (EPA, 20:5ω-3) also reduced MCP-1 expression, but less than oxDHA. Treatment with DHA-derived cyclopentenones also increased DNA binding of NF-E2-related factor-2 (Nrf2) and downstream expression of NAD(P)H:quinone oxidoreductase (NQO1), similarly to the Nrf-2 activator sulforaphane. Furthermore, sulforaphane prevented PCB77-induced MCP-1 expression, suggesting that activation of Nrf-2 mediates the observed protection against PCB77 toxicity. Our data implicate A 4 /J 4 -NPs as mediators of omega-3 fatty acid-mediated protection against the endothelial toxicity of coplanar PCBs.

Cone beam CT imaging with limited angle of projections and prior knowledge for volumetric verification of non-coplanar beam radiation therapy: a proof of concept study

Science.gov (United States)

Meng, Bowen; Xing, Lei; Han, Bin; Koong, Albert; Chang, Daniel; Cheng, Jason; Li, Ruijiang

2013-11-01

Non-coplanar beams are important for treatment of both cranial and noncranial tumors. Treatment verification of such beams with couch rotation/kicks, however, is challenging, particularly for the application of cone beam CT (CBCT). In this situation, only limited and unconventional imaging angles are feasible to avoid collision between the gantry, couch, patient, and on-board imaging system. The purpose of this work is to develop a CBCT verification strategy for patients undergoing non-coplanar radiation therapy. We propose an image reconstruction scheme that integrates a prior image constrained compressed sensing (PICCS) technique with image registration. Planning CT or CBCT acquired at the neutral position is rotated and translated according to the nominal couch rotation/translation to serve as the initial prior image. Here, the nominal couch movement is chosen to have a rotational error of 5° and translational error of 8 mm from the ground truth in one or more axes or directions. The proposed reconstruction scheme alternates between two major steps. First, an image is reconstructed using the PICCS technique implemented with total-variation minimization and simultaneous algebraic reconstruction. Second, the rotational/translational setup errors are corrected and the prior image is updated by applying rigid image registration between the reconstructed image and the previous prior image. The PICCS algorithm and rigid image registration are alternated iteratively until the registration results fall below a predetermined threshold. The proposed reconstruction algorithm is evaluated with an anthropomorphic digital phantom and physical head phantom. The proposed algorithm provides useful volumetric images for patient setup using projections with an angular range as small as 60°. It reduced the translational setup errors from 8 mm to generally <1 mm and the rotational setup errors from 5° to <1°. Compared with the PICCS algorithm alone, the integration of rigid

Identification of an enhancer element of class Pi glutathione S-transferase gene required for expression by a co-planar polychlorinated biphenyl.

OpenAIRE

Matsumoto, M; Imagawa, M; Aoki, Y

1999-01-01

3,3',4,4',5-Pentachlorobiphenyl (PenCB), one of the most toxic co-planar polychlorinated biphenyl congeners, specifically induces class Pi glutathione S-transferase (GSTP1) as well as cytochrome P-450 1A1 in primary cultured rat liver parenchymal cells [Aoki, Matsumoto and Suzuki (1993) FEBS Lett. 333, 114-118]. However, the 5'-flanking sequence of the GSTP1 gene does not contain a xenobiotic responsive element, to which arylhydrocarbon receptor binds. Using a chloramphenicol acetyltransferas...

On the Coplanar Integrable Case of the Twice-Averaged Hill Problem with Central Body Oblateness

Science.gov (United States)

Vashkov'yak, M. A.

2018-01-01

The twice-averaged Hill problem with the oblateness of the central planet is considered in the case where its equatorial plane coincides with the plane of its orbital motion relative to the perturbing body. A qualitative study of this so-called coplanar integrable case was begun by Y. Kozai in 1963 and continued by M.L. Lidov and M.V. Yarskaya in 1974. However, no rigorous analytical solution of the problem can be obtained due to the complexity of the integrals. In this paper we obtain some quantitative evolution characteristics and propose an approximate constructive-analytical solution of the evolution system in the form of explicit time dependences of satellite orbit elements. The methodical accuracy has been estimated for several orbits of artificial lunar satellites by comparison with the numerical solution of the evolution system.

Application of the identification methods from Hilbert and Prony to the study of oscillatory phenomena in electrical power systems; Aplicacion de los metodos de identificacion de Hilbert y Prony al estudio de fenomenos oscilatorios en sistemas electricos de potencia

Energy Technology Data Exchange (ETDEWEB)

Andrade Soto, Manuel Antonio

2002-10-15

In the present thesis work the application of identification techniques is investigated based on methods of spectral analysis to the study of the instantaneous characteristics of signals obtained by means of digital simulation of the dynamic behavior of the power system. The study focuses on the perspectives developed from two different approaches of analysis: the use of lineal methods of spectral analysis and the use of methods of non-lineal analysis, based on the concept of an analytical signal. The developed tools are applied to the study of two phenomena of electromechanical origin of different characteristics in complex power systems. A comparison between the results obtained is performed for these techniques and the possibility of its application is discussed for the problem of on-line identification in power systems. [Spanish] En el presente trabajo de tesis se investiga la aplicacion de tecnicas de identificacion basadas en metodos de analisis espectral al estudio de las caracteristicas instantaneas de senales obtenidas mediante simulacion digital del comportamiento dinamico del sistema de potencia. El estudio se centra en las aproximaciones desarrolladas desde dos enfoques distintos de analisis: la utilizacion de metodos lineales de analisis espectral y la utilizacion de metodos de analisis no lineal, basados en el concepto de una senal analitica. Las herramientas desarrolladas se aplican al estudio de dos fenomenos de origen electromecanico de caracteristicas distintas en sistemas complejos de potencia. Se hace una comparacion entre los resultados obtenidos por estas tecnicas y se discute la posibilidad de su aplicacion al problema de identificacion en linea en sistemas de potencia.

Design and performance evaluation of a coplanar multimodality scanner for rodent imaging

Energy Technology Data Exchange (ETDEWEB)

Lage, E; Vaquero, J J; Sisniega, A; Tapias, G; Abella, M; Rodriguez-Ruano, A; Desco, M [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Espana, S [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense, Madrid (Spain); Ortuno, J E [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza (Spain); Udias, A [Departamento de Estadistica e Investigacion Operativa, Universidad Rey Juan Carlos, Fuenlabrada (Spain)], E-mail: elage@mce.hggm.es

2009-09-21

This work reports on the development and performance evaluation of the VrPET/CT, a new multimodality scanner with coplanar geometry for in vivo rodent imaging. The scanner design is based on a partial-ring PET system and a small-animal CT assembled on a rotatory gantry without axial displacement between the geometric centers of both fields of view (FOV). We report on the PET system performance based on the NEMA NU-4 protocol; the performance characteristics of the CT component are not included herein. The accuracy of inter-modality alignment and the imaging capability of the whole system are also evaluated on phantom and animal studies. Tangential spatial resolution of PET images ranged between 1.56 mm at the center of the FOV and 2.46 at a radial offset of 3.5 cm. The radial resolution varies from 1.48 mm to 1.88 mm, and the axial resolution from 2.34 mm to 3.38 mm for the same positions. The energy resolution was 16.5% on average for the entire system. The absolute coincidence sensitivity is 2.2% for a 100-700 keV energy window with a 3.8 ns coincident window. The scatter fraction values for the same settings were 11.45% for a mouse-sized phantom and 23.26% for a rat-sized phantom. The peak noise equivalent count rates were also evaluated for those phantoms obtaining 70.8 kcps at 0.66 MBq/cc and 31.5 kcps at 0.11 MBq/cc, respectively. The accuracy of inter-modality alignment is below half the PET resolution, and the image quality of biological specimens agrees with measured performance parameters. The assessment presented in this study shows that the VrPET/CT system is a good performance small-animal imager, while the cost derived from a partial ring detection system is substantially reduced as compared with a full-ring PET tomograph.

Novel method to improve power handling capability for coplanar waveguide high-temperature superconducting filter

Energy Technology Data Exchange (ETDEWEB)

Satoh, K; Koizumi, D; Narahashi, S [NTT DoCoMo, Inc., 3-5 Hikari-no-oka, 239-8536 Yokosuka (Japan)

2006-06-01

This paper proposes a novel method to improve the power handling capability of a coplanar waveguide (CPW) high-temperature superconducting (HTS) filter. The noteworthy point of the proposed method is that it is based on the concept that the power handling capability is improved by reducing the maximum current density of the filter. Numerical investigations confirm that a CPW HTS filter using 66-{omega} characteristic impedance resonators (66-{omega} CPW HTSF) reduces the maximum current density compared to that using conventional 50-{omega} resonators (50-{omega} CPW HTSF). We fabricated 5-GHz band four-pole Chevyshev CPW HTSFs based on the proposed and conventional methods. The fabricated 66-{omega} CPW HTSF exhibited the third-order intercept point (TOI) of + 61 dBm while the 50-{omega} CPW HTSF exhibited the TOI of + 54 dBm, both at 60 K. These results indicate the effectiveness of the proposed method.

Effect of magnetic field on noncollinear magnetism in classical bilinear-biquadratic Heisenberg model

Energy Technology Data Exchange (ETDEWEB)

Pasrija, Kanika, E-mail: kanikapasrija@iisermohali.ac.in; Kumar, Sanjeev, E-mail: sanjeev@iisermohali.ac.in [Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, S. A. S. Nagar, Manauli PO 140306 (India)

2016-05-06

We present a Monte Carlo simulation study of a bilinear-biquadratic Heisenberg model on a two-dimensional square lattice in the presence of an external magnetic field. The study is motivated by the relevance of this simple model to the non-collinear magnetism and the consequent ferroelectric behavior in the recently discovered high-temperature multiferroic, cupric oxide (CuO). We show that an external magnetic field stabilizes a non-coplanar magnetic phase, which is characterized by a finite ferromagnetic moment along the direction of the applied magnetic field and a spiral spin texture if projected in the plane perpendicular to the magnetic field. Real-space analysis highlights a coexistence of non-collinear regions with ferromagnetic clusters. The results are also supported by simple variational calculations.

TU-CD-304-05: 4Ï€ Non-Coplanar Radiotherapy: From Mathematical Modeling to Clinical Implementation

Energy Technology Data Exchange (ETDEWEB)

Yu, V; Nguyen, D; Tran, A; Ruan, D; Cao, M; Kaprealian, T; Kupelian, P; Low, D; Sheng, K [Department of Radiation Oncology, UCLA, Los Angeles, CA (United States)

2015-06-15

Purpose: To develop and clinically implement 4π radiotherapy, an inverse optimization platform that maximally utilizes non-coplanar intensity modulated radiotherapy (IMRT) beams to significantly improve critical organ sparing. Methods: A 3D scanner was used to digitize the human and phantom subject surfaces, which were positioned in the computer assisted design (CAD) model of a TrueBeam machine to create a virtual geometrical model, based on which, the feasible beam space was calculated for different tumor locations. Beamlets were computed for all feasible beams using convolution/superposition. A column generation algorithm was employed to optimize patient specific beam orientations and fluence maps. Optimal routing through all selected beams were calculated by a level set method. The resultant plans were converted to XML files and delivered to phantoms in the TrueBeam developer mode. Finally, 4π plans were recomputed in Eclipse and manually delivered to recurrent GBM patients. Results: Compared to IMRT utilizing manually selected beams and volumetric modulated arc therapy plans, markedly improved dosimetry was observed using 4π for the brain, head and neck, liver, lung, and prostate patients. The improvements were due to significantly improved conformality and reduced high dose spillage to organs mediolateral to the PTV. The virtual geometrical model was experimentally validated. Safety margins with 99.9% confidence in collision avoidance were included to the model based model accuracy estimates determined via 300 physical machine to phantom distance measurements. Automated delivery in the developer mode was completed in 10 minutes and collision free. Manual 4 π treatment on the GBM cases resulted in significant brainstem sparing and took 35–45 minutes including multiple images, which showed submillimeter cranial intrafractional motion. Conclusion: The mathematical modeling utilized in 4π is accurate to create and guide highly complex non-coplanar IMRT

L’utilizzo della ricostruzione nella comunicazione del patrimonio archeologico. L’approccio, il metodo, le finalità e alcuni spunti di discussione.

Directory of Open Access Journals (Sweden)

Elena Bacci

2010-05-01

In questo contributo si focalizza l’attenzione sulla ricostruzione grafica e virtuale del patrimonio e sulle sensazioni che la ricostruzione evoca nel fruitore del messaggio culturale. La ricostruzione si attua mediante la collaborazione tra archeologo e illustratore e costituisce un momento di verifica visiva dell’interpretazione archeologica e uno strumento di comunicazione del dato archeologico fruibile a più livelli. Ciò avviene grazie allo scambio costante di informazioni (dati scientifici e proposte di ricostruzione e il confronto che ne deriva determina i metodi e le fasi di avanzamento del progetto. Il metodo si basa sull’integrazione delle immagini 3D con il disegno tradizionale ed è finalizzato alla trasposizione del dato archeologico, in modo tale da garantire alla ricostruzione il duplice requisito di soddisfazione estetica e credibilità scientifica.

Journal Article: the National Dioxin Air Monitoring Network (Ndamn): Measurements of CDDs, CDFs and Coplanar PCBs at 15 Rural and 6 National Park Areas of the U.S.: June 1998-December 1999.

Science.gov (United States)

The U.S. EPA has established a National Dioxin Air Monitoring Network (NDAMN) to determine the temporal and geographical variability of atmospheric CDDs, CDFs and coplanar PCBs at rural and nonimpacted locations throughout the United States. Currently operating at 32 sampling st...

Evaluation of electromechanical coupling parameters of piezoelectric materials by using piezoelectric cantilever with coplanar electrode structure in quasi-stasis.

Science.gov (United States)

Zheng, Xuejun; Zhu, Yuankun; Liu, Xun; Liu, Jing; Zhang, Yong; Chen, Jianguo

2014-02-01

Based on Timoshenko beam theory, a principle model is proposed to establish the relationship between electric charge and excitation acceleration, and in quasi-stasis we apply the direct piezoelectric effect of multilayer cantilever with coplanar electrode structure to evaluate the piezoelectric strain coefficient d15 and electromechanical coupling coefficient k15. They are measured as 678 pC/N and 0.74 for the commercial piezoelectric ceramic lead zirconate titanate (PZT-51) bulk specimen and 656 pC/N and 0.63 for the lead magnesium niobate (PMN) bulk specimen, and they are in agreement with the calibration and simulation values. The maximum of relative errors is less than 4.2%, so the proposed method is reliable and convenient.

A review of calculation methods for fast and intermediate reactors; Expose des methodes pour le calcul de reacteurs a neutrons rapides et intermediaires; Obzor metodov rascheta reaktorov na promezhutochnykh i bystrykh nejtronakh; Estudio panoramico de los metodos de calculo de los reactores rapidos e intermedios

Energy Technology Data Exchange (ETDEWEB)

Marchuk, G I [Akademiya Nauk, Moskva, Union of Soviet Socialist Republics (Russian Federation)

1962-03-15

This paper discusses the development of methods for calculating intermediate and fast reactors. It deals with various approaches to the problems of physical calculation. The calculation of resonance effects is discussed. Consideration is given to multi-group systems of fundamental and conjugate equations, various applications of perturbation theory to the problems of physical reactor calculation, and numerical methods of solving fundamental and conjugate reactor equations, which approximate the method of spherical harmonics. The paper describes an application of the response method to the solution of critical-mass problems, and methods of calculating reactors with hydrogeneous moderators. The fundamental features of an effective one-group reactor model are described. (author) [French] L'auteur examine la mise au point de methodes pour le calcul de reacteurs a neutrons rapides et intermediaires . Il decrit diverses manieres d'aborder les problemes des calculs sur la physique des reacteurs, notamment le calcul des effets de resonance. Il s'attache particulierement aux points suivants: systemes d'equations fondamentales et conjuguees a plusieurs groupes; diverses applications de la theorie des perturbations aux problemes de calculs sur la physique des reacteurs; methodes numeriques pour resoudre les equations fondamentales et conjuguees, voisines de la methode des harmoniques spheriques. L'auteur decrit ensuite une maniere d'appliquer la methode de la reponse aux problemes de la masse critique ainsi que des methodes pour le calcul de reacteurs ralentis a l'hydrogene. Il decrit les caracteristique s fondamentale s d'un modele de reacteur a un groupe effectif. (author) [Spanish] El autor analiza el desarrollo de los metodos de calculo de los reactores nucleares que trabajan con neutrones rapidos y con neutrones intermedios. Examina diversos planteos de los problemas del calculo fisico. Indica la forma de tomar en cuenta los efectos de resonancia y menciona los sistemas

Kinetic equilibrium for an asymmetric tangential layer with rotation of the magnetic field

Science.gov (United States)

Belmont, Gérard; Dorville, Nicolas; Aunai, Nicolas; Rezeau, Laurence

2015-04-01

Finding kinetic equilibria for tangential current layers is a key issue for modeling plasma phenomena such as magnetic reconnection instabilities, for which theoretical and numerical studies have to start from steady-state current layers. Until 2012, all theoretical models -starting with the most famous "Harris" one- relied on distribution functions built as mono-valued functions of the trajectories invariants. For a coplanar anti-symmetric magnetic field and in absence of electric field, these models were only able to model symmetric variations of the plasma, so precluding any modeling of "magnetopause-like'' layers, which separate two plasmas of different densities and temperatures. Recently, the "BAS" model was presented (Belmont et al., 2012), where multi-valued functions were taken into account. This new tool is made necessary each time the magnetic field reversal occurs on scales larger than the particle Larmor radii, and therefore guaranties a logical transition with the MHD modeling of large scales. The BAS model so provides a new asymmetric equilibrium. It has been validated in a hybrid simulation by Aunai et al (2013), and more recently in a fully kinetic simulation as well. For this original equilibrium to be computed, the magnetic field had to stay coplanar inside the layer. We present here an important generalization, where the magnetic field rotates inside the layer (although restricted to a 180° rotation hitherto). The tangential layers so obtained are thus closer to those encountered at the real magnetopause. This will be necessary, in the future, for comparing directly the theoretical profiles with the experimental ones for the various physical parameters. As it was done previously, the equilibrium is presently tested with a hybrid simulation. Belmont, G.; Aunai, N.; Smets, R., Kinetic equilibrium for an asymmetric tangential layer, Physics of Plasmas, Volume 19, Issue 2, pp. 022108-022118-10, 2012 Aunai, N.; Belmont, G.; Smets, R., First

Strong-field ionization of linear molecules by a bicircular laser field: Symmetry considerations

Science.gov (United States)

Gazibegović-Busuladžić, A.; Busuladžić, M.; Hasović, E.; Becker, W.; Milošević, D. B.

2018-04-01

Using the improved molecular strong-field approximation, we investigate (high-order) above-threshold ionization [(H)ATI] of various linear polyatomic molecules by a two-color laser field of frequencies r ω and s ω (with integer numbers r and s ) having coplanar counter-rotating circularly polarized components (a so-called bicircular field). Reflection and rotational symmetries for molecules aligned in the laser-field polarization plane, analyzed for diatomic homonuclear molecules in Phys. Rev. A 95, 033411 (2017), 10.1103/PhysRevA.95.033411, are now considered for diatomic heteronuclear molecules and symmetric and asymmetric linear triatomic molecules. There are additional rotational symmetries for (H)ATI spectra of symmetric linear molecules compared to (H)ATI spectra of the asymmetric ones. It is shown that these symmetries manifest themselves differently for r +s odd and r +s even. For example, HATI spectra for symmetric molecules with r +s even obey inversion symmetry. For ATI spectra of linear molecules, reflection symmetry appears only for certain molecular orientation angles ±90∘-j r 180∘/(r +s ) (j integer). For symmetric linear molecules, reflection symmetry appears also for the angles -j r 180∘/(r +s ) . For perpendicular orientation of molecules with respect to the laser-field polarization plane, the HATI spectra are very similar to those of the atomic targets, i.e., both spectra are characterized by the same type of the (r +s )-fold symmetry.

Factors application of MW-mile method and participation in the allocation of charges by the drills use in electricity markets; Aplicacion de los factores de participacion y del metodo de MW-milla en la asignacion de cargos por uso de redes de transmision en mercados de electricidad

Energy Technology Data Exchange (ETDEWEB)

Alba-Gomez, L; Tovar-Hernandez, J. H; Gutierrez-Alcaraz, G [Instituto Tecnologico de Morelia, Michoacan (Mexico)]. E-mail: horaciotovar@mexico.com; ggutier@itmorelia.edu.mx

2007-04-15

Use of network allocation costs by shift factors and MW-Mile method is reported in this paper. Conventional shift factors are computed based on DC power flow. DC power flow requires to selecting a slack bus in order to avoid matrix singularity. Therefore, shift factors are slack bus dependent. In order to evade slack bus dependency, two approaches are considered. [Spanish] Este trabajo presenta la asignacion de costos por uso de red mediante la aplicacion de Factores de Participacion (FP) y el metodo de MW-Milla. Los FP clasicos son calculados a partir del modelo lineal de flujos de potencia para lo que se requiere de establecer un nodo de referencia a fin de eliminar la singularidad de la matriz de coeficientes. Por lo tanto, los FP son dependientes de la asignacion del nodo de referencia. Dos metodos alternativos para evitar la dependencia del nodo compensador en la obtencion de los factores de participacion son presentados.

Coplanar Waveguide Fed Compact Wide Circular-Slotted Antenna for Wi-Fi/WiMAX Applications

Directory of Open Access Journals (Sweden)

M. Samsuzzaman

2014-01-01

Full Text Available A coplanar waveguide (CPW fed printing and wide circular slotted, dual band antenna for Wi-Fi/WiMAX applications are presented. The antenna mainly encompasses a ground with a wide circular slot in the centre, a rectangular feeding strip, and two pairs of symmetric planar inverted L (SPIL strips connecting with the slotted ground. The tuning effects of the rectangular patch, ground size, and SPIL strips to the resonance and matching condition are examined by HFSS and the prototype is fabricated and measured. The simulation and experimental results show that the antenna has an impedance bandwidth with −10 dB reflection coefficients 600 MHz (3.26–3.86 GHz, lower band and 1040 MHz (5.02–6.26 GHz, upper band, which can cover both the Wi-Fi 5.2/5.5/5.8 GHz and WiMAX 3.3/3.5/3.7/5.8 GHz bands. Moreover, a stable omnidirectional radiation pattern and average peak gain for lower band 3.23 dB and upper band 5.93 dB have been achieved, respectively.

Journal Article: the National Dioxin Air Monitoring Network (Ndamn): Measurements of CDDs, CDFs, and Coplanar PCBs at 18 Rural, 8 National Parks, and 2 Suburban Areas of the U.S.: Results for the Year 2000.

Science.gov (United States)

In June, 1998, the U.S. EPA established the National Dioxin Air Monitoring Network (NDAMN). The primary goal of NDAMN is determine the temporal and geographical variability of atmospheric CDDs, CDFs, and coplanar PCBs at rural and nonimpacted locations throughout the United Stat...

A method for optimization of patient dose estimation in conventional radiology; Un metodo per l'ottimizzazione della stima della dose al paziente nella radiologia tradizionale

Energy Technology Data Exchange (ETDEWEB)

Tofani, A.; Del Corona, A. [Azienda Unita' Sanitaria Locale 6, Livorno (Italy). Unita' Ospedaliera di Fisica Sanitaria; Niespolo, A. [Azienda Ospedaliera Pisana, Pisa (Italy). Unita' Ospedaliera di Fisica Sanitaria

2000-05-01

found to depend on the average body surface, a parameter which takes into account both patient height and mass. Thus, determining the normalization factor for each projection and each view allows to estimate the absorbed dose under different geometrical conditions. The method has been verified by considering four of the most common X-ray procedures (chest AP, cervical spine LAT, lumbar spine AP and head LAT). The average error on dose estimation is about 13 %. In the very next future the method will be extended to all the projections and views of ICRP Report no. 34, and we plant to integrate the described algorithm in a computer program devoted to the automatic computation of patient dose. [Italian] Il metodo raccomandato dalla International Commission on Radiological Protection (ICRP) nel suo Report n. 34(1982) per il calcolo della dose al paziente negli esami di radiodiagnostica e' basato su dati dosimetrici tabulati ottenuti mediante simulazioni Monte Carlo su fantocci antropomorfi descritti da semplici funzioni matematiche. Nel caso del calcolo della dose per un paziente adulto, le limitazioni principali di questo metodo sono due: in primo luogo i parametri geometrici dell'esame - e in particolare la distanza fuoco-pellicola e il formato della pellicola- sono fissi, e questo rende problematico l'utilizzo dei dati dosimetrici nelle condizioni effettive in cui si e' svolto l'esame, che in genere non coincideranno con quelle standard ICRP. Inoltre quando le dimensioni e la massa del paziente differiscono sensibilmente da quelle del fantoccio utilizzato nelle simulazioni (il cosidetto uomo di riferimento, di altezza pari a 174 cm e massa di 70,9 Kg) il metodo ICRP puo' portare a errori considerevoli nella stima della dose. Lo scopo del presente lavoro e' quello di indicare una possibile via di uscita per superare queste limitazioni. L'algoritmo proposto in questo lavoro si basa sull'applicazione del metodo suggerito da Huda e

Gas geochemistry of Los Humeros geothermal field, Mexico; Geoquimica de gases del campo geotermico de Los Humeros, Puebla, Mexico

Energy Technology Data Exchange (ETDEWEB)

Barragan R, Rosa Maria; Arellano G, Victor M; Nieva G, David; Portugal M, Enrique; Garcia G, Alfonso; Aragon A, Alfonso [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Torres A, Ignasio S [Centro de Investigacion en Energia, Temixco, Morelos (Mexico); Tovar A, Rigoberto [Comision Federal de Electricidad, Los Humeros, Puebla (Mexico)

1999-12-01

Gas data of Los Humeros geothermal field were analyzed. A new method, which is based on the Fischer-Tropch reactions and on the combined pyrite-magnetite mineral equilibrium, was used. Reservoir temperature and reservoir excess steam were estimated for the starting stage of the field by using early data taken from producing wells at controlled conditions. The same parameters were also obtained for the present stage by using 1997 gas data. Reservoir temperatures ranged from 275 and 337 Celsius degrees and positive values for reservoir excess steam fractions were obtained for the starting stage. For well H-1 no excess steam was found since this well was fed by the shallower liquid-dominated reservoir. Results for 1997 showed lower scattering compared to early data and the possible occurrence of a heating process in the shallower stratum which could due to exploitation. [Spanish] En este articulo se presenta un analisis de datos de la fase gaseosa producida por pozos productores del campo geotermico de Los Humeros mediante un metodo que considera el equilibrio de la reaccion de Fischer-Tropsh y el equilibrio de minerales pirita-hematia y pirita-magnetita. Este metodo provee la temperatura del yacimiento y el exceso de vapor presente en la descarga total de los pozos. Los resultados se discuten tanto para el estado inicial del yacimiento utilizando los primeros datos de produccion en los que el flujo del pozo estuvo controlado y los obtenidos en 1997 que representan el estado actual del yacimiento. En el estado inicial se estimaron temperaturas de yacimiento de entre 275 y 337 grados Celsius y excesos de vapor positivos, con excepcion del pozo H-1 que se alimenta del estrato somero dominado por liquido. Los resultados obtenidos para 1997 muestran una dispersion menor y la probable ocurrencia de un proceso de calentamiento del estrato somero propiciado por la explotacion.

Cluster magnetic field observations of the bowshock: Orientation, motion and structure

Directory of Open Access Journals (Sweden)

T. S. Horbury

Full Text Available Four spacecraft Cluster magnetic field observations of the low quasi-perpendicular terrestrial bowshock are presented for the first time. Multiple quasi-perpendicular crossings on 25 December 2000 are analysed. By combining data from the four spacecraft, bowshock orientations and velocities can be calculated. It is shown that, even while in rapid motion, the bowshock normal direction remains remarkably constant, and that coplanarity estimates are accurate to, typically, around 20°. Magnetic field magnitude profiles are shown to be very well correlated between spacecraft although downstream waves with fluctuations perpendicular to the local field, while statistically similar at all four spacecraft, are poorly correlated on separation scales of several hundred km. Examples are shown of a number of bowshock phenomena, including non-standing fluctuations in the shock foot and the shock interacting with changing solar wind conditions.

Key words. Interplanetary physics (planetary bow shocks Space plasma physics (shock waves; waves and instabilities

Cluster magnetic field observations of the bowshock: Orientation, motion and structure

Directory of Open Access Journals (Sweden)

T. S. Horbury

2001-09-01

Full Text Available Four spacecraft Cluster magnetic field observations of the low quasi-perpendicular terrestrial bowshock are presented for the first time. Multiple quasi-perpendicular crossings on 25 December 2000 are analysed. By combining data from the four spacecraft, bowshock orientations and velocities can be calculated. It is shown that, even while in rapid motion, the bowshock normal direction remains remarkably constant, and that coplanarity estimates are accurate to, typically, around 20°. Magnetic field magnitude profiles are shown to be very well correlated between spacecraft although downstream waves with fluctuations perpendicular to the local field, while statistically similar at all four spacecraft, are poorly correlated on separation scales of several hundred km. Examples are shown of a number of bowshock phenomena, including non-standing fluctuations in the shock foot and the shock interacting with changing solar wind conditions.Key words. Interplanetary physics (planetary bow shocks Space plasma physics (shock waves; waves and instabilities

S,N-Heteroacene-Based Copolymers for Highly Efficient Organic Field Effect Transistors and Organic Solar Cells: Critical Impact of Aromatic Subunits in the Ladder π-System.

Science.gov (United States)

Chung, Chin-Lung; Chen, Hsieh-Chih; Yang, Yun-Siou; Tung, Wei-Yao; Chen, Jian-Wei; Chen, Wen-Chang; Wu, Chun-Guey; Wong, Ken-Tsung

2018-02-21

Three novel donor-acceptor alternating polymers containing ladder-type pentacyclic heteroacenes (PBo, PBi, and PT) are synthesized, characterized, and further applied to organic field effect transistors (OFETs) and polymer solar cells. Significant aspects of quinoidal characters, electrochemical properties, optical absorption, frontier orbitals, backbone coplanarity, molecular orientation, charge carrier mobilities, morphology discrepancies, and the corresponding device performances are notably different with various heteroarenes. PT exhibits a stronger quinoidal mesomeric structure, linear and coplanar conformation, smooth surface morphology, and better bimodal crystalline structures, which is beneficial to extend the π-conjugation and promotes charge transport via 3-D transport pathways and in consequence improves overall device performances. Organic photovoltaics based on the PT polymer achieve a power conversion efficiency of 6.04% along with a high short-circuit current density (J SC ) of 14.68 mA cm -2 , and a high hole mobility of 0.1 cm 2 V -1 s -1 is fulfilled in an OFET, which is superior to those of its counterparts, PBi and PBo.

Quantum incommensurate skyrmion crystals and commensurate to in-commensurate transitions in cold atoms and materials with spin-orbit couplings in a Zeeman field

Science.gov (United States)

Sun, Fadi; Ye, Jinwu; Liu, Wu-Ming

2017-08-01

In this work, we study strongly interacting spinor atoms in a lattice subject to a two dimensional (2d) anisotropic Rashba type of spin orbital coupling (SOC) and an Zeeman field. We find the interplay between the Zeeman field and the SOC provides a new platform to host rich and novel classes of quantum commensurate and in-commensurate phases, excitations and phase transitions. These commensurate phases include two collinear states at low and high Zeeman field, two co-planar canted states at mirror reflected SOC parameters respectively. Most importantly, there are non-coplanar incommensurate Skyrmion (IC-SkX) crystal phases surrounded by the four commensurate phases. New excitation spectra above all the five phases, especially on the IC-SKX phase are computed. Three different classes of quantum commensurate to in-commensurate transitions from the IC-SKX to its four neighboring commensurate phases are identified. Finite temperature behaviors and transitions are discussed. The critical temperatures of all the phases can be raised above that reachable by current cold atom cooling techniques simply by tuning the number of atoms N per site. In view of recent impressive experimental advances in generating 2d SOC for cold atoms in optical lattices, these new many-body phenomena can be explored in the current and near future cold atom experiments. Applications to various materials such as MnSi, {Fe}}0.5 {Co}}0.5Si, especially the complex incommensurate magnetic ordering in Li2IrO3 are given.

Survey of Pulsed Neutron Source Methods for Multiplying Media; Methodes des Neutrons Pulses Pour l'Etude des Milieux Multiplicateurs; Obzor metodov s ispol'zovaniem istochnikov impul'snykh nejtronov dlya razmnozhayushchej sredy; Estudio Panoramico de los Metodos de Empleo de Fuentes de Neutrons Pulsados en Medios Multiplicadores

Energy Technology Data Exchange (ETDEWEB)

Garelis, E. [General Electric Company, Vallecitos Atomic Laboratory, Pleasanton, CA (United States)

1965-10-15

-Small-L ). Il discute en outre l'emploi des methodes qui sont fondees sur la reponse a des impulsions pseudoaleatoires et utilisent une correlation entre l'entree et la sortie, pour la determination de la fonction de Green d'un milieu multiplicateur. H montre que les renseignements obtenus par ces methodes sont identiques a ceux fournis par les methodes de la source puisee a repetition, ce qui permet d'appliquer aux premieres les procedes qui ont ete mis au point pour les secondes. (author) [Spanish] En los ultimos afios ha habido dos tendencias principales acerca de la manera mas eficaz de medir la reactividad de parada, empleando fuentes de neutrones pulsados: la primera preconizaba el empleo de metodos tradicionales de medicion con fuentes neutronicas reiteradamente pulsadas, y la segunda propugnaba la aplicacion de metodos basados en una tecnica seudoaleatoria de respuesta a los impulsos, utilizando una correlacion entre los datos de entrada y los de salida. La informacion obtenida con una y otra tecnica es la misma; en teoria, ambos metodos sirven para determinar la funcion de respuesta. Se resefia el desarrollo de las tecnicas de empleo de fuentes de neutrones pulsados aplicadas a sistemas termicos con miras a medir la reactividad, desde los primeros intentos de Sjoestrand hasta el reciente metodo (k{beta}/ Script-Small-L ). Con el metodo usual de empleo de estas fuentes, la propiedad que se procuia determinar es la funcion de Green del conjunto subercritico empleado, es decir, la respuesta del reactor a una fuente de neutrones de funcion delta. El decrecimiento exponencial (e{sup {alpha}t}) de la funcion de Green proporciona una constante de decrecimiento de los neutrones instantaneos que es independiente del espacio. El autor examina los metodos para obtener el valor de la reactividad partiendo de la medida de a, como por ejemplo el metodo de la medicion de la criticidad por neutrones retardados a y el reciente metodo (k{beta}/ Script-Small-L ). Seguidamente examina el

Ka-Band, MEMS Switched Line Phase Shifters Implemented in Finite Ground Coplanar Waveguide

Science.gov (United States)

Scardelletti, Maximilian C.; Ponchak, George E.; Varaljay, Nicholas C.

2005-01-01

Ka-band MEMS switched line phase shifters implemented in finite ground coplanar waveguide are described in this paper. The phase shifters are constructed of single-pole double-throw (SPDT) switches with additional reference and phase offset transmission line lengths. The one- and two-bit phase shifters are fabricated on high resistivity (HR) silicon with a dielectric constant, Epsilon(sub T) = 11.7 and a substrate thickness, t = 500microns. The switching architectures integrated within the phase shifters consist of MEMS switches that are doubly anchored cantilever beam capacitive switches with additional high inductive sections (MEMS LC device). The SPDT switch is composed of a T-junction with a MEMS LC device at each output port. The one-bit phase shifter described in this paper has an insertion loss (IL) and return loss (RL) of 0.9 dB and 30 dB while the two-bit described has an IL and RL of 1.8 dB and 30 dB respectively. The one-bit phase shifter's designed offset phase is 22.5deg and actual measured phase shift is 21.8deg. The two-bit phase shifter's designed offset phase is 22.5deg, 45deg, and 67.5deg and the actual measured phase shifts are 21.4deg, 44.2deg, and 65.8deg, respectively.

Discrimination of alpha particles in CdZnTe detectors with coplanar grid for the COBRA experiment

Energy Technology Data Exchange (ETDEWEB)

Rebber, Henning [Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: COBRA-Collaboration

2016-07-01

The aim of the COBRA experiment is the search for neutrinoless double beta decay using CdZnTe semiconductor detectors. A background rate in the order of 10{sup -3} counts per keV, kg and year is intended in order to be sensitive to a half-life larger than 10{sup 26} years. Measurements from a demonstrator setup and Monte Carlo simulations indicate that a large background component is due to alpha particles. These generate charge clouds of only few μm in diameter in the detector, leading to characteristic pulse features. Parameter-based cut criteria were developed to discriminate alpha events by means of their pulse shapes. The cuts were tested on data from alpha and beta irradiation of a (1 x 1 x 1) cm{sup 3} CdZnTe detector with coplanar grid. The pulse shapes of all event signals were read out by FADCs with a sampling rate of 100 MHz. The signals were reproduced by a detector simulation which hence was used to study the cuts for energies up to 3 MeV and different detector regions.

Structures of Metalloporphyrin-Oligomer Multianions: Cofacial versus Coplanar Motifs as Resolved by Ion Mobility Spectrometry.

Science.gov (United States)

Brendle, Katrina; Schwarz, Ulrike; Jäger, Patrick; Weis, Patrick; Kappes, Manfred

2016-11-03

We have combined ion mobility mass spectrometry with quantum chemical calculations to investigate the gas-phase structures of multiply negatively charged oligomers of meso-tetra(4-sulfonatophenyl)metalloporphyrins comprising the divalent metal centers Zn II , Cu II , and Pd II . Sets of candidate structures were obtained by geometry optimizations based on calculations at both the semiempirical PM7 and density functional theory (DFT) levels. The corresponding theoretical cross sections were calculated with the projection approximation and also with the trajectory method. By comparing these collision cross sections with the respective experimental values we were able to assign oligomer structures up to the tetramer. In most cases the cross sections of the lowest energy isomers predicted by theory were found to agree with the measurements to within the experimental uncertainty (2%). Specifically, we find that for a given oligomer size the structures are independent of the metal center but depend strongly on the charge state. Oligomers in low charge states with a correspondingly larger number of sodium counterions tend to form stacked, cofacial structures reminiscent of H-aggregate motifs observed in solution. By contrast, in higher charge states, the stack opens to form coplanar structures.

Method for the depth corrected detection of ionizing events from a co-planar grids sensor

Science.gov (United States)

De Geronimo, Gianluigi [Syosset, NY; Bolotnikov, Aleksey E [South Setauket, NY; Carini, Gabriella [Port Jefferson, NY

2009-05-12

A method for the detection of ionizing events utilizing a co-planar grids sensor comprising a semiconductor substrate, cathode electrode, collecting grid and non-collecting grid. The semiconductor substrate is sensitive to ionizing radiation. A voltage less than 0 Volts is applied to the cathode electrode. A voltage greater than the voltage applied to the cathode is applied to the non-collecting grid. A voltage greater than the voltage applied to the non-collecting grid is applied to the collecting grid. The collecting grid and the non-collecting grid are summed and subtracted creating a sum and difference respectively. The difference and sum are divided creating a ratio. A gain coefficient factor for each depth (distance between the ionizing event and the collecting grid) is determined, whereby the difference between the collecting electrode and the non-collecting electrode multiplied by the corresponding gain coefficient is the depth corrected energy of an ionizing event. Therefore, the energy of each ionizing event is the difference between the collecting grid and the non-collecting grid multiplied by the corresponding gain coefficient. The depth of the ionizing event can also be determined from the ratio.

Design and construction of a broad-band electric field probe

International Nuclear Information System (INIS)

Bahrami, A.; Sohrabi, M.; Farvadin, D.

1996-01-01

The design of a broad-band electric field probe based on a resistive film diode antenna on RT/Duroid substrate to measure the electric RF/MW fields as constructed at the National Radiation Protection Department (NRPD) of the Atomic Energy Organization of Iran (AEOI) are described in this paper. A square law diode detector with a matching circuit and also low pass filter have been used to produce a dc current proportional to the square RF voltage across the resistive antenna gap. A double-strip coplanar waveguide has also been designed to transfer this dc current to an amplifier with an output signal showing the electric field intensity in one direction. By using three mutually orthogonal resistive antennas, an isotropic electric field probe was made. All parts of this probe have been completely modeled and solved by the MATLAB computer program to determine the optimum values of the elements of the probe. The frequency response of the probe has also been theoretically found to be flat in the range 0.8 to 3 GHz. It was found to be quite satisfactory compared with those of similar probes commercially available. The probe is being used routinely in practice. (author)

Analysis of a flip-chip bonded tunable high-temperature superconducting coplanar waveguide resonator using the conformal mapping technique

CERN Document Server

Misra, M; Murakami, H; Tonouchi, M

2003-01-01

We have studied the tuning properties of a high-temperature superconducting (HTS) half-wavelength coplanar waveguide (CPW) resonator operating at 5 GHz. The tuning schemes are based on flip-chip bonding of an electrically tunable ferroelectric (FE) thin film and a mechanically movable low-loss single crystal on top of the resonator. Using the conformal mapping method, closed-form analytical expressions have been derived for a flip-chip bonded conductor-backed and top-shielded CPW transmission line. The obtained expressions are used to analyse the volume effect of the FE thin film and the gap between the flip-chip and the CPW resonator on the tuning properties of the device. It has been found that large frequency modulation of the resonator produces impedance mismatch, which can considerably enhance the insertion loss of high-performance HTS microwave devices. Analysis also suggests that, for electrically tunable devices, flip-chip bonded FE thin films on HTS CPW devices provide a relatively higher performance...

Deformation bands and dislocation structures of [1-bar 5 5] coplanar double-slip-oriented copper single crystal under cyclic deformation

International Nuclear Information System (INIS)

Li, Y.; Li, S.X.; Li, G.Y.

2004-01-01

The features of surface morphology and dislocation structure of [1-bar 5 5] coplanar double-slip-oriented copper single crystal under cyclic deformation at a constant plastic shear strain amplitude of 2x10 -3 were studied using optical microscope (OP) and electron channelling contrast imaging (ECCI) in the scanning electron microscope (SEM). Experimental results show that there are two sets of the secondary type of deformation band (DBII) formed in the specimen. The geometry relationship of the two sets of deformation bands (DBs) and slip band (SB) are given. The habit planes of DBIIs are close to (1-bar 0 1) and (1-bar 1 0) plane, respectively. The surface dislocation structures in the specimen including vein, irregular dislocation cells and dislocation walls were also observed. The typical dislocation structure in DBII is the dislocation walls

Micromachined silicon cantilevers with integrated high-frequency magnetoimpedance sensors for simultaneous strain and magnetic field detection

Science.gov (United States)

Buettel, G.; Joppich, J.; Hartmann, U.

2017-12-01

Giant magnetoimpedance (GMI) measurements in the high-frequency regime utilizing a coplanar waveguide with an integrated Permalloy multilayer and micromachined on a silicon cantilever are reported. The fabrication process is described in detail. The aspect ratio of the magnetic multilayer in the magnetoresistive and magnetostrictive device was varied. Tensile strain and compressive strain were applied. Vector network analyzer measurements in the range from the skin effect to ferromagnetic resonance confirm the technological potential of GMI-based micro-electro-mechanical devices for strain and magnetic field sensing applications. The strain-impedance gauge factor was quantified by finite element strain calculations and reaches a maximum value of almost 200.

Foetal uptake of coplanar polychlorinated biphenyl (PCB) congeners in mice

International Nuclear Information System (INIS)

Darnerud, P.O.; Sinjari, T.; Joensson, C.J.

1996-01-01

Earlier studies have shown that the Ah-receptor binding polychlorinated biphenyl (PCB) congener 3,3',4,4'-tetrachlorobiphenyl (IUPAC number CB-77) accumulated as hydroxy and methylsulphone metabolites in late gestational mice foetuses. In the present paper the foetal accumulation potential in mice of other dioxin-like PCB congeners was studied: 3,3'4,4',4-pentachlorobiphenyl, 3,3'4,4'5,5'-hexachlorobiphenyl and 2,3,3',4,4'-pentachlorobiphenyl (IUPAC numbers CB-126, CB-169, CB-105, to some extent dioxin-like) were compared to results of CB-77 (all congeners 14 C-labelled and in equimolar doses (2.0 μmol/kg body wt.)). CB-77 resulted in the comparatively strongest foetal 14 C-accumulation, when measured in plasma or whole body homogenate four days after administration (day 17 of pregnancy); the plasma 14 C-values (calculated as pmol/g wet wt.) were 760, 130, 60 and 40 for CB-77, -126, 105 and -169, respectively, and the CB-77 derived radioactivity in the foetal compartment was 3.6% of administered dose (i.e. a considerable portion of the remaining maternal body radioactivity). Thin-layer chromatography (TLC) results, suggesting extensive CB-77 metabolism and foetal metabolite uptake, support earlier findings. The effects of CB-77 and CB-169 on foetal 7-ethoxyresorufin-O-deethylase (EROD) activities (day 17 of gestation; two days after 5 mg/kg body wt. dose (14.0-17.0 μmol/kg body wt.)) was about 20 times lower than of CB-126. In the dam, high radioactivity levels were observed int he liver and fat (highest concentrations found in CB-126 and CB-105, respectively). Strain comparison - foetal 14 C-uptake (four days after administration of CB-77) in C57BL mice was almost five times higher than in NMRI - may be correlated to earlier observed differences in EROD activities between these strains. The present results indicate that congener and strain differences exist regarding both foetal and maternal distribution patterns of coplanar PCB congeners and point out the

Constrained customization of non-coplanar beam orientations in radiotherapy of brain tumours

International Nuclear Information System (INIS)

Rowbottom, C.G.; Oldham, M.; Webb, S.

1999-01-01

A methodology for the constrained customization of non-coplanar beam orientations in radiotherapy treatment planning has been developed and tested on a cohort of five patients with tumours of the brain. The methodology employed a combination of single and multibeam cost functions to produce customized beam orientations. The single-beam cost function was used to reduce the search space for the multibeam cost function, which was minimized using a fast simulated annealing algorithm. The scheme aims to produce well-spaced, customized beam orientations for each patient that produce low dose to organs at risk (OARs). The customized plans were compared with standard plans containing the number and orientation of beams chosen by a human planner. The beam orientation constraint-customized plans employed the same number of treatment beams as the standard plan but with beam orientations chosen by the constrained-customization scheme. Improvements from beam orientation constraint-customization were studied in isolation by customizing the beam weights of both plans using a dose-based downhill simplex algorithm. The results show that beam orientation constraint-customization reduced the maximum dose to the orbits by an average of 18.8 (±3.8, 1SD)% and to the optic nerves by 11.4 (±4.8, 1SD)% with no degradation of the planning target volume (PTV) dose distribution. The mean doses, averaged over the patient cohort, were reduced by 4.2 (±1.1, 1SD)% and 12.4 (±3.1 1SD)% for the orbits and optic nerves respectively. In conclusion, the beam orientation constraint-customization can reduce the dose to OARs, for few-beam treatment plans, when compared with standard treatment plans developed by a human planner. (author)

Effects of the reconnection electric field on crescent electron distribution functions in asymmetric guide field reconnection

Science.gov (United States)

Bessho, N.; Chen, L. J.; Hesse, M.; Wang, S.

2017-12-01

In asymmetric reconnection with a guide field in the Earth's magnetopause, electron motion in the electron diffusion region (EDR) is largely affected by the guide field, the Hall electric field, and the reconnection electric field. The electron motion in the EDR is neither simple gyration around the guide field nor simple meandering motion across the current sheet. The combined meandering motion and gyration has essential effects on particle acceleration by the in-plane Hall electric field (existing only in the magnetospheric side) and the out-of-plane reconnection electric field. We analyze electron motion and crescent-shaped electron distribution functions in the EDR in asymmetric guide field reconnection, and perform 2-D particle-in-cell (PIC) simulations to elucidate the effect of reconnection electric field on electron distribution functions. Recently, we have analytically expressed the acceleration effect due to the reconnection electric field on electron crescent distribution functions in asymmetric reconnection without a guide field (Bessho et al., Phys. Plasmas, 24, 072903, 2017). We extend the theory to asymmetric guide field reconnection, and predict the crescent bulge in distribution functions. Assuming 1D approximation of field variations in the EDR, we derive the time period of oscillatory electron motion (meandering + gyration) in the EDR. The time period is expressed as a hybrid of the meandering period and the gyro period. Due to the guide field, electrons not only oscillate along crescent-shaped trajectories in the velocity plane perpendicular to the antiparallel magnetic fields, but also move along parabolic trajectories in the velocity plane coplanar with magnetic field. The trajectory in the velocity space gradually shifts to the acceleration direction by the reconnection electric field as multiple bounces continue. Due to the guide field, electron distributions for meandering particles are bounded by two paraboloids (or hyperboloids) in the

Identification of an enhancer element of class Pi glutathione S-transferase gene required for expression by a co-planar polychlorinated biphenyl.

Science.gov (United States)

Matsumoto, M; Imagawa, M; Aoki, Y

1999-01-01

3,3',4,4',5-Pentachlorobiphenyl (PenCB), one of the most toxic co-planar polychlorinated biphenyl congeners, specifically induces class Pi glutathione S-transferase (GSTP1) as well as cytochrome P-450 1A1 in primary cultured rat liver parenchymal cells [Aoki, Matsumoto and Suzuki (1993) FEBS Lett. 333, 114-118]. However, the 5'-flanking sequence of the GSTP1 gene does not contain a xenobiotic responsive element, to which arylhydrocarbon receptor binds. Using a chloramphenicol acetyltransferase assay we demonstrate here that the enhancer termed GSTP1 enhancer I (GPEI) is necessary for the stimulation by PenCB of GSTP1 gene expression in primary cultured rat liver parenchymal cells. GPEI is already known to contain a dyad of PMA responsive element-like elements oriented palindromically. It is suggested that a novel signal transduction pathway activated by PenCB contributes to the stimulation of GSTP1 expression. PMID:10051428

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.

The effect of cathode bias (field effect) on the surface leakage current of CdZnTe detectors

International Nuclear Information System (INIS)

Bolotnikov, A.E.; Hubert Chen, C.M.; Cook, W.R.; Harrison, F.A.; Kuvvetli, I.; Schindler, S.M.; Stahle, C.M.; Parker, B.H.

2003-01-01

Surface resistivity is an important parameter of multi-electrode CZT detectors such as coplanar-grid, strip, or pixel detectors. Low surface resistivity results in a high leakage current and affects the charge collection efficiency in the areas near contacts. Thus, it is always desirable to have the surface resistivity of the detector as high as possible. In the past the most significant efforts were concentrated to develop passivation techniques for CZT detectors. However, as we found, the field-effect caused by a bias applied on the cathode can significantly reduce the surface resistivity even though the detector surface was carefully passivated. In this paper we illustrate that the field-effect is a common feature of the CZT multi-electrode detectors, and discuss how to take advantage of this effect to improve the surface resistivity of CZT detectors

True coincidence-summing corrections for the coincident γ-rays measured with coplanar grid CdZnTe detectors

International Nuclear Information System (INIS)

Yuecel, H.; Solmaz, A.N.; Koese, E.; Bor, D.

2010-01-01

In this study, true coincidence-summing (TCS) correction factors have been measured for the sources 22 Na, 60 Co, 133 Ba and 152 Eu by use of three large volume coplanar grid CdZnTe (acronym: CZT) detectors. In case of a close-in detection geometry, two different TCS calculation algorithms were used to compute the required TCS correction factors. Both of the algorithms are based on the measured total-to-peak (TTP) ratio and full-energy peak (FEP) efficiency values that were obtained using almost 'single' energy and coincidence-free nuclides. The results for TCS correction factors obtained by two different algorithms were agreeable to each other. The obtained TCS factors were ranged from about 7% to 30.5% in a 2250 mm 3 CZT detector when a close counting geometry was used. For other two detectors with a volume of 1000 and 1687.5 mm 3 , the resulted TCS correction factors were relatively smaller and varied between about 0.1% and 20% at the close counting geometry condition. Therefore, the results indicate that there is a need for the estimation of TCS corrections in CZT detectors, especially when their crystal volumes are greater than 1 cm 3 and these detectors are used in the case of a close-in detection geometry.

In vitro reduction of coplanar PCB congeners by ABTS oxidases from the culture of Trametes versicolor

Energy Technology Data Exchange (ETDEWEB)

Sonoki, S. [High-Tech Research Center, Azabu Univ., Kanagawa (Japan); Sue, T.; Hisamatsu, S. [Graduate School of Environmental Health, Azabu Univ., Kanagawa (Japan); Nagasaka, H. [Inst. of Environmental Ecology, Shin-Nippon Meteorological and Oceanographical Consultant Co., Ltd., Shizuoka (Japan)

2004-09-15

In recent years, the environmental contamination by the harmful polluted chemicals becomes more serious. Among them, especially, the dioxins such as coplanar PCBs (Co-PCBs) and PCDDs are hard to be decomposed due to their stability and hydrophobic nature, leading to the world-wide contamination. To clean up the polluted environment, bioremediation using a microorganism is expected to solve the environmental pollution problem because of cost-effective alternative to the more established engineering method. There are some reports on the biodegradation of dioxins using various organisms, in which basidiomycetes, so-called white-rot fungi, have been extensively studied in the process of lignin degradation. As a result unique extracellular oxidative lignindegrading enzymes, such as lignin peroxidase, manganese-dependent peroxidase and laccase were supposed to be responsible for degrading dioxins. Overall many studies on biodegradation of dioxins or other chlorinated aromatic hydrocarbons have focused on using white-rot fungi; however, few reports referred to the metabolism of these environmental pollutants in the in vitro reaction by use of lignin-degrading enzymes produced by white-rot fungi. In this study, we reported the reduction of levels of Co-PCBs in the in vitro incubation with the fractions which had the oxidase activity toward 2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) in the culture fluid of white-rot fungus, Trametes versicolor.

Electric field measurements at subcritical, oblique bow shock crossings

International Nuclear Information System (INIS)

Wygant, J.R.; Bensadoun, M.; Mozer, F.S.

1987-01-01

Electric field measurements at oblique, subcritical bow shock crossings are presented from the ISEE 1 University of California, Berkeley, double-probe electric field experiment. The measurements averaged over the 3-s spin period of the spacecraft provide the first observations of the large-scale (100 km) laminar oscillations in the longitudinal component of the electric field associated with the whistler precursor which is characteristic of these dispersive shocks. The amplitude of the oscillations increases from ∼0.5 mV/m to a maximum of 6 mV/m across the magnetic ramp of the shock (directed along the shock normal). The calculated electric potential drops across the shocks varied from 340 to 550 volts, which is 40-60% of the observed loss of kinetic energy associated with the bulk flow of the ions. These measurements suggest that at these shocks the additional deceleration of incident ions is due to the Lorentz force. The contributions to the normal component of the large-scale electric field at the shock due to the parallel and perpendicular components (relative to the magnetic field) of the electric field are evaluated. It is shown that the perpendicular component of the electric field dominates, accounting for most of the cross-shock potential, but that there is a nonnegligible parallel component. This large-scale parallel component has a magnitude of 1-2 mV/m which sometimes results in a potential well for electrons with a depth of ∼150 eV. It is experimentally demonstrated that the dominance of the perpendicular over the parallel component of the electric field resulted in a correlation between the longitudinal component of the large-scale electric field and the fluctuations in the magnetic field component perpendicular to the coplanarity plane

Construction of the Tangent to a Cycloid Proposed by Wallis and Fermat

Directory of Open Access Journals (Sweden)

Loredana Biacino

2017-02-01

Full Text Available In this paper some methods used in the XVII century for the construction of the tangents to a cycloid in a point are exposed: the kinematical method employed by Roberval, the classical geometrical  method used by Wallis and the Fermat’s construction as a consequence of his tangents method. Le Costruzioni della Tangente alla Cicloide Proposte da Wallis e da Fermat In questo lavoro sono esposti vari metodi in uso nel ‘600 per la costruzione della tangente ad una cicloide in un suo punto: il metodo cinematico impiegato da Roberval, il metodo geometrico classico usato dal Wallis e la costruzione di Fermat come conseguenza del suo metodo delle tangenti. Parole Chiave: Cicloide, Tangente ad una curva, Metodo cinematico delle tangenti, Metodo delle tangenti di Fermat.

Magnon Hall effect without Dzyaloshinskii-Moriya interaction.

Science.gov (United States)

Owerre, S A

2017-01-25

Topological magnon bands and magnon Hall effect in insulating collinear ferromagnets are induced by the Dzyaloshinskii-Moriya interaction (DMI) even at zero magnetic field. In the geometrically frustrated star lattice, a coplanar/noncollinear [Formula: see text] magnetic ordering may be present due to spin frustration. This magnetic structure, however, does not exhibit topological magnon effects even with DMI in contrast to collinear ferromagnets. We show that a magnetic field applied perpendicular to the star plane induces a non-coplanar spin configuration with nonzero spin scalar chirality, which provides topological effects without the need of DMI. The non-coplanar spin texture originates from the topology of the spin configurations and does not need the presence of DMI or magnetic ordering, which suggests that this phenomenon may be present in the chiral spin liquid phases of frustrated magnetic systems. We propose that these anomalous topological magnon effects can be accessible in polymeric iron (III) acetate-a star-lattice antiferromagnet with both spin frustration and long-range magnetic ordering.

Accuracy of cranial coplanar beam therapy using an oblique, stereoscopic x-ray image guidance system

International Nuclear Information System (INIS)

Vinci, Justin P.; Hogstrom, Kenneth R.; Neck, Daniel W.

2008-01-01

A system for measuring two-dimensional (2D) dose distributions in orthogonal anatomical planes in the cranium was developed and used to evaluate the accuracy of coplanar conformal therapy using ExacTrac image guidance. Dose distributions were measured in the axial, sagittal, and coronal planes using a CIRS (Computerized Imaging Reference Systems, Inc.) anthropomorphic head phantom with a custom internal film cassette. Sections of radiographic Kodak EDR2 film were cut, processed, and digitized using custom templates. Spatial and dosimetric accuracy and precision of the film system were assessed. BrainScan planned a coplanar-beam treatment to conformally irradiate a 2-cm-diameterx2-cm-long cylindrical planning target volume. Prior to delivery, phantom misalignments were imposed in combinations of ±8 mm offsets in each of the principal directions. ExacTrac x-ray correction was applied until the phantom was within an acceptance criteria of 1 mm/1 deg. (first two measurement sets) or 0.4 mm/0.4 deg. (last two measurement sets). Measured dose distributions from film were registered to the treatment plan dose calculations and compared. Alignment errors, displacement between midpoints of planned and measured 70% isodose contours (Δc), and positional errors of the 80% isodose line were evaluated using 49 2D film measurements (98 profiles). Comparison of common, but independent measurements of Δc showed that systematic errors in the measurement technique were 0.2 mm or less along all three anatomical axes and that random error averaged (σ±σ σ ) 0.29±0.06 mm for the acceptance criteria of 1 mm/1 deg. and 0.15±0.02 mm for the acceptance criteria of 0.4 mm/0.4 deg. . The latter was consistent with independent estimates that showed the precision of the measurement system was 0.3 mm (2σ). Values of Δc were as great as 0.9, 0.3, and 1.0 mm along the P-A, R-L, and I-S axes, respectively. Variations in Δc along the P-A axis were correlated to misalignments between laser

Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

Science.gov (United States)

Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

2017-07-01

The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O2sbnd CF4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of Csbnd O, Osbnd Cdbnd O, Cdbnd O and sbnd NO2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

Some Non-Destructive Testing Methods Applicable to Sintered Materials; Quelques Methodes d'Essais Non Destructifs Applicables aux Materiaux Frittes; Nekotorye metody nedestruktivnykh ispytanii, primenimye k spechennym materialam; Algunos Metodos de Ensayo No Destructivo Aplicables a los Materiales Sinterizados

Energy Technology Data Exchange (ETDEWEB)

Labusca, Elena; Mirion, I.; Andreescu, N.; Alecu, M.; Biscoveanu, I. [Institut de Physique Atomique, Bucarest (Romania)

1965-10-15

solides frittes, a l'aide de la metallographie et de la microscopie electronique. Ces methodes mettent en evidence l'homogeneite de la structure, les dimensions et l'orientation des grains, la presence de defauts divers (inclusions, pores) et revolution meme du processus de frittage, y compris la formation des cristaux, la croissance granulaire, etc. Dans quelques cas, on peut combiner l'examen microscopique a des essais de microdurete. Cet examen de la structure microcristalline represente l'une des methodes principales de controle qualitatif des materiaux frittes, et ne peut etre remplace par aucun autre moyen d'investigation. 2. Controle du degre de consolidation, qui determine essentiellement la qualite des materiaux frittes. Ce controle est effectue par la mesure de quelques proprietes, telles que la conductibilite electrique et thermique, en correlation avec la densite, etant donne que la conductibilite des materiaux frittes est directement porportionnelle au degre de frittage. On a essaye aussi une methode adequate de controle de la porosite; on a obtenu des donnees experimentales interessantes, surtout au point de vue de la porosite libre, laquelle est susceptible aux inclusions gazeuses. Le memoire contient des donnees experimentales concernant l'application de ces methodes de controle a quelques materiaux frittes interessants pour la technologie nucleaire. (author) [Spanish] Teniendo en cuenta la estructura granular especifica de los materiales sinterizados, elaborados a partir de polvos, cuyo proceso de consolidacion se desarrolla en funcion del tratamiento de sinterizacion, los autores han estudiado algunos metodos para verificar el grado de sinterizacion y controlar ciertas propiedades. Entre los metodos no destructivos utilizados, se mencionan en la presente memoria: 1. Examen de la estructura cristalina de los solidos sinterizados por metalografia y microscopfa electronica. Estos metodos ponen de manifiesto el giado de homogeneidad estructural, la dimension

Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

Energy Technology Data Exchange (ETDEWEB)

McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

1966-02-15

Non-destructive methods for quantitative measurement of burn-up in nuclear reactor fuel elements are useful and desirable. The ideal method for fuel assay would be one that requires no special information about the neutron spectra, radiation history, or cooling time. The irradiated fuel element contains a record of the fuel burn-up. This record is in the form of radioactive and stable isotopes resulting from the fission process. Unfortunately, in the non-destructive as well as the destructive fuel assay methods, the neutron spectrum, irradiation history, and cooling period influence this record. Likewise, the lack of precise nuclear data, such as values of nuclear cross-sections, affects any calculations that can be made. Another difficulty in the non-destructive assay is the presence of high radiation fields which contribute to the ''noise'' background of the measurements. The development of useful and realistic standards is difficult. The non-destructive burn-up methods do serve a useful purpose especially when an approximate value of burn-up is required quickly and economically even though in the present state of the art they lack the desired precision and accuracy. Several non-destructive methods for determining burn-up have been used, are being evaluated, or have been proposed. Various types of spectrometers including the bent crystal, magnetic Compton, Compton coincidence, and scintillation have been used to analyse the gamma radiation from the radioactive material formed during the fission process. Other non-destructive methods include foil activation, neutron transmission, activation analysis, measurement of capture gamma rays, and the measurement of prompt and delayed neutrons. The basic principles of each of the above instruments and methods, their sensitivities and their limitations will be reviewed. Non-destructive methods using stable isotopes produced during the fission process are proposed. In the use of stable isotopes, detailed irradiation history

Uses and updating of the Benders method in the integer-mixed programming in the planning of the electric power systems expansion; Usos y actualizacion del metodo de Benders en la programacion entera-mixta y en la planeacion de la expansion de los sistemas electricos de potencia

Energy Technology Data Exchange (ETDEWEB)

De la Torre Vega, Eli

1997-04-01

of some potential improvements that the proposed method has. [Espanol] En el primer capitulo se presenta la deduccion de los cortes de Benders partiendo de las propiedades de la dualidad. Tambien se presentan las propiedades de los cortes de Benders asi como el algoritmo inicial de Benders para resolver cualquier problema de programacion lineal entera-mixta. En el segundo capitulo, se presenta el problema de la planeacion de la expansion de los medios de generacion y transmision en un sistema electrico de potencia, las distintas estructuras de la programacion matematica a que da lugar y como se puede adaptar el metodo de Benders a estas. En el tercer capitulo se presentan las aportaciones teoricas de este trabajo: a) Como inicializar el problema maestro para aprovechar la experiencia adquirida despues de haber resuelto un problema similar, de modo que se pueda resolver mas eficientemente, la sucesion de problemas de programacion lineal entero-mixtos que surgen al resolver el problema de la planeacion de la expansion de los medios de generacion y transmision en un sistema electrico de potencia. b) Como generar un problema maestro cuya solucion optima continua corresponda al optimo continuo del problema entero-mixto, de modo que la busqueda de soluciones enteras se realice en la vecindad del optimo continuo. c) Como generar una solucion entera, cercana al optimo continuo del problema entero-mixto, que tenga mucha probabilidad de ser factible, y que quizas sea la solucion optima entera, en un tiempo menor al que se requiere para resolverlo en forma exacta. Ademas, se presentan otras ideas que se le pueden incorporar al metodo de Benders. A fin de mostrar la efectividad de las ideas propuestas, en el capitulo 4 se presentan los resultados obtenidos al resolver varios problemas usando: 1. El metodo de Benders in actualizacion, 2. El metodo de Ramificacion y Acotamiento, 3. La actualizacion de Benders al agregar restricciones y 4. La actualizacion de Benders al considerar

Vinyl Flanked Difluorobenzothiadiazole-Dithiophene Conjugated Polymer for High Performance Organic Field-Effect Transistors.

Energy Technology Data Exchange (ETDEWEB)

Liang, Xianfeng; Sun, Wandong; Chen, Yanlin; Tan, Luxi; Cai, Zheng-Xu; Liu, Zitong; Wang, Lin; Li, Jing; Chen, Wei; Dong, Lichun

2018-02-21

Fluorine containing conjugated polymers have been widely applied in high performance organic solar cells, but their use in field-effect transistors is still quite limited. In this work, a conjugated polymer PTFBTV based on difluorobenzothiadiazole (DFBT) and dithiophene was synthesized, utilizing multiple vinylene as linkers. The polymer exhibits a relatively high hole mobility up to 2.0 cm(2) V-1 s(-1) compared with the reported DFBT-oligothiophene based polymers, yet its structural complexity is much simpler. The polymer thin film exhibits a typical 'face on' molecular orientation. A single crystal of its monomer revealed a non-covalent intramolecular contact between fluorine and the neighbouring proton, which strengthens the backbone co-planarity. Meanwhile an intermolecular F...F contact was also observed, which might cause rather scattered lamellar crystallinity for PTFBTV in the solid state.

Method and apparatus for balancing the magnetic field detecting loops of a cryogenic gradiometer using trimming coils and superconducting disks

International Nuclear Information System (INIS)

Lutes, C.L.

1982-01-01

An apparatus for and a method of measuring the difference in intensity between two coplanar magnetic field vector components at two different points in space. The device is comprised of two interconnected, relatively large, loop patterns of opposite, flux cancelling, winding sense. One or both loops include a trimming element that is itself formed of two interconnected, relatively small, loop patterns of opposite, flux cancelling, winding sense. The device is analyzed for imbalance between the two large loops and is then balanced by placing a balancing superconducting disk of the proper characteristic in or near one of the two small loops of the trimming element. The so-trimmed apparatus forms a gradiometer of substantially improved mensuration

Milk transfer and neonatal uptake of coplanar polychlorinated biphenyl (PCB) congeners in mice

Energy Technology Data Exchange (ETDEWEB)

Sinjari, T. [Uppsala Univ., Dept. of Pharmaceutical Biosciences, Div. of Toxicology, Uppsala (Sweden); Klasson-Wehler, W. [Stockholm Univ., Wallenberg Lb., Environmental Chemistry, Stockholm (Sweden); Oskarsson, A. [Swedish Univ. of Agricultural Science, Dept. of Food Hygiene, Uppsala (Sweden); Darnerud, P.O. [National Food Administration, Toxicology Div., uppsala (Sweden)

1996-03-01

The selective accumulation of 3,3`4,3`-tetrachlorobiphenyl metabolites in late gestational fetal blood and soft tissues in mice as a result of administration of different coplanar polychlorinated biphenyl (PCB) congeners, is reported elsewhere. The situation in the nursing neonate after maternal exposure to the same congeners is now studied: The {sup 14}C-labelled congeners 3,3`,4,4`-tetrachlorobiphenyl (IUPAC number CB-77), 3,3`,4,4`,5-pentachlorobiphenyl (IUPAC number CB-126), 3,3`4,4`5,5`-hexachlorobiphenyl (IUPAC number CB-169) (all three non-ortho congeners) and 2,3,3`,4,4`-pentachlorobiphenyl (IUPAC number CB-105) (mono-ortho congener) were injected intravenously in lactating mice at day 11 post partum. One day and four days later, milk and neonatal/maternal tissues and plasma radioactivity was monitored by liquid scintillation counting (dose: 2.0 {mu}mol (20-50 {mu}Ci)/kg body weight). In milk, CB-126, -169 and -105 showed higher levels (1450-2520 pmol/ml; one day after administration) than did CB-77 (580 pmol/ml), and in neonates, the relative whole-body levels of radioactivity were related to the levels seen in milk (probably the consequences of their metabolic persistence). The comparably high {sup 14}C-concentration found in neonatal liver (about 15,000 pmol/kg) after CB-126 administration and in plasma (880 pmol/ml) after CB-77 administration could be explained by binding to specific proteins. In general, neonatal mice had two to seven times higher plasma levels than those of their mothers. These results indicate that CB-126, -169 and -105 are transferred via milk to neonates in considerable quantity and are deposited in neonatal liver, whereas CB-77 is transferred in a comparably lower amount and accumulated in neonatal plasma. The lower {sup 14}C-levels in the NMRI mothers and offspring (about half of C57BL values in maternal and neonatal plasma), could possibly be explained by a differentiated metabolism of CB-77 in these two strains.

A Complete First-Order Analytical Solution for Optimal Low-Thrust Limited-Power Transfers Between Coplanar Orbits with Small Eccentricities

Science.gov (United States)

Da Silva Fernandes, Sandro; Das Chagas Carvalho, Francisco; Vilhena de Moraes, Rodolpho

The purpose of this work is to present a complete first order analytical solution, which includes short periodic terms, for the problem of optimal low-thrust limited power trajectories with large amplitude transfers (no rendezvous) between coplanar orbits with small eccentricities in Newtonian central gravity field. The study of these transfers is particularly interesting because the orbits found in practice often have a small eccentricity and the problem of transferring a vehicle from a low earth orbit to a high earth orbit is frequently found. Besides, the analysis has been motivated by the renewed interest in the use of low-thrust propulsion systems in space missions verified in the last two decades. Several researchers have obtained numerical and sometimes analytical solutions for a number of specific initial orbits and specific thrust profiles. Averaging methods are also used in such researches. Firstly, the optimization problem associated to the space transfer problem is formulated as a Mayer problem of optimal control with Cartesian elements - position and velocity vectors - as state variables. After applying the Pontryagin Maximum Principle, successive Mathieu transformations are performed and suitable sets of orbital elements are introduced. The short periodic terms are eliminated from the maximum Hamiltonian function through an infinitesimal canonical transformation built through Hori method - a perturbation canonical method based on Lie series. The new Hamiltonian function, which results from the infinitesimal canonical transformation, describes the extremal trajectories for long duration maneuvers. Closed-form analytical solutions are obtained for the new canonical system by solving the Hamilton-Jacobi equation through the separation of variables technique. By applying the transformation equations of the algorithm of Hori method, a first order analytical solution for the problem is obtained in non-singular orbital elements. For long duration maneuvers

Phase diagram of the Shastry-Sutherland Kondo lattice model with classical localized spins: a variational calculation study

Science.gov (United States)

Shahzad, Munir; Sengupta, Pinaki

2017-08-01

We study the Shastry-Sutherland Kondo lattice model with additional Dzyaloshinskii-Moriya (DM) interactions, exploring the possible magnetic phases in its multi-dimensional parameter space. Treating the local moments as classical spins and using a variational ansatz, we identify the parameter ranges over which various common magnetic orderings are potentially stabilized. Our results reveal that the competing interactions result in a heightened susceptibility towards a wide range of spin configurations including longitudinal ferromagnetic and antiferromagnetic order, coplanar flux configurations and most interestingly, multiple non-coplanar configurations including a novel canted-flux state as the different Hamiltonian parameters like electron density, interaction strengths and degree of frustration are varied. The non-coplanar and non-collinear magnetic ordering of localized spins behave like emergent electromagnetic fields and drive unusual transport and electronic phenomena.

Research on Wide-field Imaging Technologies for Low-frequency Radio Array

Science.gov (United States)

Lao, B. Q.; An, T.; Chen, X.; Wu, X. C.; Lu, Y.

2017-09-01

Wide-field imaging of low-frequency radio telescopes are subject to a number of difficult problems. One particularly pernicious problem is the non-coplanar baseline effect. It will lead to distortion of the final image when the phase of w direction called w-term is ignored. The image degradation effects are amplified for telescopes with the wide field of view. This paper summarizes and analyzes several w-term correction methods and their technical principles. Their advantages and disadvantages have been analyzed after comparing their computational cost and computational complexity. We conduct simulations with two of these methods, faceting and w-projection, based on the configuration of the first-phase Square Kilometre Array (SKA) low frequency array. The resulted images are also compared with the two-dimensional Fourier transform method. The results show that image quality and correctness derived from both faceting and w-projection are better than the two-dimensional Fourier transform method in wide-field imaging. The image quality and run time affected by the number of facets and w steps have been evaluated. The results indicate that the number of facets and w steps must be reasonable. Finally, we analyze the effect of data size on the run time of faceting and w-projection. The results show that faceting and w-projection need to be optimized before the massive amounts of data processing. The research of the present paper initiates the analysis of wide-field imaging techniques and their application in the existing and future low-frequency array, and fosters the application and promotion to much broader fields.

10 GHz Standing-Wave Coplanar Stripline on LiNbO3 Crystal for Radio to Optical-Wave Conversion

Science.gov (United States)

Darwis, F.; Wijayanto, Y. N.; Setiawan, A.; Mahmudin, D.; Rahman, A. N.; Daud, P.

2018-04-01

Recently, X-band radar systems are used widely for surveillance and navigation applications. Especially in archipelago or maritime country, the surveillance/navigation radar systems are required to monitoring critical areas and managing marine traffic. Accurate detection and fast analysis should be improved furthermore to provide security and safety condition. Therefore, several radar systems should be installed in many places to coverage the critical areas within radar networks. The radar network can be connected using optical fibers since it has extremely low propagation loss with optical-wave to carry-out the radar-wave. One important component in the scenario is a radio to optical-wave conversion component. In this paper, we report a 10 GHz radio to optical-wave conversion component using standing-wave coplanar stripline (CPS) on LiNbO3 optical crystal as the substrate. The standing-wave CPS electrodes with narrow slot are arranged in an array structure. An optical waveguide is located close to the narrow slot. The CPS electrodes were analysed using electromagnetic analysis software for 10 GHz operational frequency. Responses for slot width and electrode length variation are reported. As results, return loss of -14.580 dB and -19.517 dB are obtained for single and array CPS electrodes respectively. Optimization of the designed radio to optical-wave conversion devices was also done.

A Monte Carlo simulation for the field theory with quartic interaction

Energy Technology Data Exchange (ETDEWEB)

Santos, Sergio Mittmann dos [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio Grande do Sul (IFRS), Porto Alegre, RS (Brazil)

2011-07-01

Full text: In the work [1-S. M. Santos, B. E. J. Bodmann and A. T. Gomez, Um novo metodo computacional para a teoria de campos na rede: resultados preliminares, IV Escola do Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, 2002; and 2-S. M. Santos and B. E. J. Bodmann, Simulacao na rede de teorias de campos quanticos, XXVIII Congresso Nacional de Matematica Aplicada e Computacional (CNMAC), Sao Paulo, 2005], a computational method on the lattice was elaborated for the problem known as scalar field theory with quartic interaction (for instance, see: J. R. Klauder, Beyound conventional quantization, Cambridge: Cambridge University Press, 2000). This one introduced an algorithm, which allows the simulation of a given field theory and is independent of the lattice spacing, by redefining the fields and the parameters (the mass m and the coupling constant g). This kind of approach permits varying the dimension of the lattice without changing the computational complexity of the algorithm. A simulation was made using the Monte Carlo method, where the renormalized mass m{sub R}, the renormalized coupling constant g{sub R} and the two point correlation function were determined with success. In the present work, the genuine computational method is used for new simulations. Now, the Monte Carlo method is not used just for the simulation of the algorithm, like in [1, 2], but also for defining the adjust parameters (the mass and the coupling constant), introduced ad hoc in [1, 2]. This work presents the first simulations' outcomes, where best results that [1, 2] were determined, for the renormalized mass and the renormalized coupling constant. (author)

Research and Development Activities in Italy in the Field of Aerospace Structures and Materials,

Science.gov (United States)

1979-03-01

Aerotecnica, Missili e Spazio ” . An extensive historical and critical analysis of such long lasting research cannot be given here; the more recent results are...in the AGARD SMP Program on “ Critically Loaded Hole Technology ” carrying Out Falstaff spectrum fatigue tests on behalf of Italy ,~~ 7. The Un... Metodo degli Elementi Fi— niti — Prestampa n . 5 , IV °Congresso Nazionale A . I . D . A . A . ,M i l a — no ,1977 . 20. Cella Analisi di problein i

Development of an analytic method for arsenic's determination in lime and tortilla; Desarrollo de un metodo analitico para determinacion de arsenico en cal y tortilla

Energy Technology Data Exchange (ETDEWEB)

Huato Soberanis, Julio; Ogura, Tetsuya [Universidad Autonoma de Guadalajara, Guadalajara, Jalisco (Mexico)

1995-02-01

A spectrophotometric method to determine As in tortilla and lime has been optimized, modifying the AsH{sub 3} generator. The reaction between arsin (AsH{sub 3}){sub 4} and diethyldithiocarbamate of Ag (AgDDC); was followed spectrophotometrically. The conditions under which the As remains in the ash during the calcination of the tortillas were studied. It was found that when they were heated in a quartz tube with a careful control of the air flow and oxygen, as well as the heating temperature, the arsenic loss in minimized. [Spanish] Se ha optimizado el metodo para determinar As en la tortilla y cal mediante espectrometria en el visible del color producido en la reaccion entre Arsina (AsH{sub 3}){sub 4} y dietilditiocarbamato de plata (AgDDC); modificando el generador de AsH{sub 3}. Se han buscado las condiciones en las que el arsenico permanece en las cenizas de la calcinacion de las tortillas; encontrandose que las tortillas deben calentarse en un tubo de cuarzo con control del flujo de aire y oxigeno asi como de la temperatura de calentamiento.

Late morbidity profiles in prostate cancer patients treated to 79-84 Gy by a simple four-field coplanar beam arrangement

International Nuclear Information System (INIS)

Chism, Derek B.; Horwitz, Eric M.; Hanlon, Alexandra L.; Pinover, Wayne H.; Mitra, Raj K.; Hanks, Gerald E.

2003-01-01

Purpose: To describe the frequency and magnitude of late GI and GU morbidity in prostate cancer patients treated to high dose levels with a simple three-dimensional conformal technique. Methods and Materials: A total of 156 intermediate- and high-risk patients were treated between January 1, 1992 and February 28, 1999 with a simple four-field three-dimensional conformal technique to 79-84 Gy. All patients were treated with a four-field conformal technique; the prostate received 82 Gy and the seminal vesicles and periprostatic tissue 46 Gy. GI and GU toxicity was scored according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Morbidity Grading Scale and compared using Kaplan-Meier estimates. Results: The late Grade 2 GI complication rate was 9% and 38% at 3 years for patients treated with and without rectal blocking, respectively (p=0.0004). No Grade 3 late GI complications developed. The rate of Grade 2 late GU complications was 5%, 8%, and 12% at 12, 24, and 36 months, respectively. The Grade 3 late GU complication rate was 2% at 36 months. These differences were not statistically significant. Conclusion: The treatment method described is a simple four-field conformal technique that can be easily implemented in the general radiation community. A dose of 79-84 Gy can be safely delivered to the prostate, with a 9% rate of late Grade 2 GI, 12% rate of late Grade 2 GU, and 2% rate of late Grade 3 GU complications

A Portable Parallel Implementation of the U.S. Navy Layered Ocean Model

Science.gov (United States)

1995-01-01

Wallcraft, PhD (I.C. 1981) Planning Systems Inc. & P. R. Moore, PhD (Camb. 1971) IC Dept. Math. DR Moore 1° Encontro de Metodos Numericos...Kendall Square, Hypercube, D R Moore 1 ° Encontro de Metodos Numericos para Equacöes de Derivadas Parciais A. J. Wallcraft IC Mathematics...chips: Chips Machine DEC Alpha CrayT3D/E SUN Sparc Fujitsu AP1000 Intel 860 Paragon D R Moore 1° Encontro de Metodos Numericos para Equacöes

High-temperature superconducting coplanar-waveguide quarter-wavelength resonator with odd- and even-mode resonant frequencies for dual-band bandpass filter

Energy Technology Data Exchange (ETDEWEB)

Satoh, Kei; Takagi, Yuta; Narahashi, Shoichi [Research Laboratories, NTT DOCOMO, INC., 3-6 Hikari-no-oka Yokosuka, Kanagawa 239-8536 Japan (Japan); Nojima, Toshio, E-mail: satokei@nttdocomo.co.j [Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0814 Japan (Japan)

2010-06-01

This paper presents a high-temperature superconducting coplanar-waveguide quarter-wavelength resonator that has two different resonant modes for use in a dual-band bandpass filter (DBPF). An RF filter with multiple passbands such as the DBPF is a basic element that is expected to achieve broadband transmission by using separated frequency bands aggregately and simultaneously in future mobile communication systems. The proposed resonator has a folded center conductor and two open stubs that are aligned close to it. The odd- and even-mode resonant frequencies are configured using the space between the folded center conductor and the open stubs. It is easy to configure the odd- and even-mode coupling coefficients independently because the two resonant modes have different current density distributions. Consequently, a DBPF with two different bandwidths can be easily designed. This paper presents three design examples for a four-pole Chebyshev DBPF with different combinations of fractional bandwidths in order to investigate the validity of the proposed resonator. This paper also presents measured results of the DBPF based on the design examples from the standpoint of experimental investigation. The designed and measured frequency responses confirm that the proposed resonator is effective in achieving DBPFs not only with two of the same bandwidths but also with two different bandwidths.

Radical production efficiency and electrical characteristics of a coplanar barrier discharge built by multilayer ceramic technology

International Nuclear Information System (INIS)

Jõgi, Indrek; Erme, Kalev; Levoll, Erik; Stamate, Eugen

2017-01-01

The present study investigated the electrical characteristics and radical production efficiency of a coplanar barrier discharge (CBD) device manufactured by Kyocera by multilayer ceramic technology. The device consisted of a number of linear electrodes with electrode and gap widths of 0.75 mm, immersed into a ceramic dielectric barrier. A closed flow-through system necessary for the measurements was prepared by placing a quartz plate at a height of 3 mm from the ceramic barrier. The production of nitrogen radicals was determined from the removal of a trace amount of NO in pure N 2 gas, while the production of oxygen radicals was determined by ozone production in pure O 2 or synthetic air. The production efficiency of N and O radicals and NO oxidation in synthetic air was comparable with the efficiency of a volume barrier discharge device. The power density per unit of surface area of the CBD device was more than two times larger than that of a similar volume barrier discharge setup, which makes the CBD device a compact alternative for gas treatment. The production of ozone and different nitrogen oxides was also evaluated for the open system of the CBD which is usable for surface treatment. The ozone concentration of this system was nearly independent from the input power, while the concentration of nitrogen oxides increased with input power. The open system of the CBD was additionally tested for the treatment of a silicon surface. An increase of applied power decreased the time required to reduce the water contact angle below 10 degrees but also started to have an impact on the surface roughness. (paper)

Low-power-consumption and high-sensitivity NO2 micro gas sensors based on a co-planar micro-heater fabricated by using a CMOS-MEMS process

International Nuclear Information System (INIS)

Moon, S. E.; Lee, J. W.; Park, S. J.; Park, J.; Park, K. H.; Kim, J.

2010-01-01

Small-scale, low-power-consumption, and high-sensitivity NO 2 gas sensors based on ZnO nanorods are reported in this work. To activate the chemical absorption and desorption for NO 2 gas, we embedded co-planar micro-heater in a micro gas sensor, that was made by using a Complementary Metal-oxide-semiconductor compatible Microelectromechanical Systems(CMOS-MEMS) process. To acquire simple fabrication and low fabrication cost, we located the micro-heater and the sensing electrode in the same plane. High-quality single-crystalline ZnO nanorods were selectively grown by using photolithography and a hydrothermal method. Their structural properties were confirmed by using X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy microanalysis (EDAX), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The temperature-dependent current-voltage characteristics were measured to optimize the operating temperature of the fabricated devices as a chemical gas sensor. To test the possibility for use as chemical sensor, we measured the NO 2 gas response.

Micropatterned superconducting film circuitry for operation in hybrid quantum devices

International Nuclear Information System (INIS)

Bothner, Daniel

2013-01-01

This thesis discusses three aspects of the arduous way towards hybrid quantum systems consisting of superconducting circuits and ensembles of ultracold paramagnetic atoms. In the first part of the thesis, superconducting coplanar microwave resonators as used for quantum information processing with superconducting qubits are investigated in magnetic fields. In the second part of the thesis integrated atom chips are designed and fabricated, which offer the possibility to trap an ensemble of ultracold atoms close to a superconducting coplanar resonator on that chip. In the third and last part of the thesis, unconventional disordered and quasiperiodic arrangements of microfabricated holes (antidots) in superconducting films are patterned and investigated with respect to the impact of the arrangement on the superconductor transport properties in magnetic fields.

Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

International Nuclear Information System (INIS)

Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

2017-01-01

Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O_2−CF_4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO_2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

Precise magnetostatic field using the finite element method; Calculo de campos magnetostaticos com precisao utilizando o metodo dos elementos finitos

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Francisco Rogerio Teixeira do

2013-07-01

The main objective of this work is to simulate electromagnetic fields using the Finite Element Method. Even in the easiest case of electrostatic and magnetostatic numerical simulation some problems appear when the nodal finite element is used. It is difficult to model vector fields with scalar functions mainly in non-homogeneous materials. With the aim to solve these problems two types of techniques are tried: the adaptive remeshing using nodal elements and the edge finite element that ensure the continuity of tangential components. Some numerical analysis of simple electromagnetic problems with homogeneous and non-homogeneous materials are performed using first, the adaptive remeshing based in various error indicators and second, the numerical solution of waveguides using edge finite element. (author)

The MITRA as a solar and ionospheric instrument

Science.gov (United States)

Beeharry, G. K.

2015-12-01

The MITRA is an international/pan-African radioastronomy project which aims to do extremely wide field imaging with heterogeneous non coplanar arrays. It can be used for solar and ionospheric studies.

Impact of field number and beam angle on functional image-guided lung cancer radiotherapy planning

Science.gov (United States)

Tahir, Bilal A.; Bragg, Chris M.; Wild, Jim M.; Swinscoe, James A.; Lawless, Sarah E.; Hart, Kerry A.; Hatton, Matthew Q.; Ireland, Rob H.

2017-09-01

To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 magnetic resonance imaging (3He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment 3He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving  ⩾20 Gy (V20) were compared with plans that minimised 3He MRI defined functional lung receiving  ⩾20 Gy (fV20). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV20 and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV90). Incorporation of 3He MRI led to median reductions in fV20 of 1.3% (range: 0.2-9.3% p  =  0.04) and 0.2% (range: 0 to 4.1%; p  =  0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised 3He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.

Cross-validation of two commercial methods for volumetric high-resolution dose reconstruction on a phantom for non-coplanar VMAT beams

International Nuclear Information System (INIS)

Feygelman, Vladimir; Stambaugh, Cassandra; Opp, Daniel; Zhang, Geoffrey; Moros, Eduardo G.; Nelms, Benjamin E.

2014-01-01

Background and purpose: Delta 4 (ScandiDos AB, Uppsala, Sweden) and ArcCHECK with 3DVH software (Sun Nuclear Corp., Melbourne, FL, USA) are commercial quasi-three-dimensional diode dosimetry arrays capable of volumetric measurement-guided dose reconstruction. A method to reconstruct dose for non-coplanar VMAT beams with 3DVH is described. The Delta 4 3D dose reconstruction on its own phantom for VMAT delivery has not been thoroughly evaluated previously, and we do so by comparison with 3DVH. Materials and methods: Reconstructed volumetric doses for VMAT plans delivered with different table angles were compared between the Delta 4 and 3DVH using gamma analysis. Results: The average γ (2% local dose-error normalization/2mm) passing rate comparing the directly measured Delta 4 diode dose with 3DVH was 98.2 ± 1.6% (1SD). The average passing rate for the full volumetric comparison of the reconstructed doses on a homogeneous cylindrical phantom was 95.6 ± 1.5%. No dependence on the table angle was observed. Conclusions: Modified 3DVH algorithm is capable of 3D VMAT dose reconstruction on an arbitrary volume for the full range of table angles. Our comparison results between different dosimeters make a compelling case for the use of electronic arrays with high-resolution 3D dose reconstruction as primary means of evaluating spatial dose distributions during IMRT/VMAT verification

Generation, transmission, and detection of terahertz photons on an electrically driven single chip

Energy Technology Data Exchange (ETDEWEB)

Ikushima, Kenji; Ito, Atsushi; Okano, Shun [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588 (Japan)

2014-02-03

We demonstrate single photon counting of terahertz (THz) waves transmitted from a local THz point source through a coplanar two-wire waveguide on a GaAs/AlGaAs single heterostructure crystal. In the electrically driven all-in-one chip, quantum Hall edge transport is used to achieve a noiseless injection current for a monochromatic point source of THz fields. The local THz fields are coupled to a coplanar two-wire metal waveguide and transmitted over a macroscopic scale greater than the wavelength (38 μm in GaAs). THz waves propagating on the waveguide are counted as individual photons by a quantum-dot single-electron transistor on the same chip. Photon counting on integrated high-frequency circuits will open the possibilities for on-chip quantum optical experiments.

Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

Energy Technology Data Exchange (ETDEWEB)

Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Gong, Lijun [Research and Development Department, Guangzhou Fastprint Circuit Tech Co., Ltd., Guangzhou 510663 (China); He, Wei, E-mail: heweiz@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Research and Development Department, Guangdong Guanghua Sci-Tech Co., Ltd., Shantou 515000 (China)

2017-07-31

Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O{sub 2}−CF{sub 4} low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO{sub 2} by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

Photon and proton therapy planning comparison for malignant glioma based on CT, FDG-PET, DTI-MRI and fiber tracking

Energy Technology Data Exchange (ETDEWEB)

Munck af Rosenschoeld, Per; Engelholm, Silke; Ohlhues, Lars; Vogelius, Ivan; Engelholm, Svend Aage (Radiation Medicine Research Center, Dept. of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark)), e-mail: per.munck@rh.regionh.dk; Law, Ian (Dept. of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark))

2011-08-15

Purpose. The purpose of this study was to compare treatment plans generated using fixed beam Intensity Modulated photon Radiation Therapy (IMRT), inversely optimized arc therapy (RapidArc(R), RA) with spot-scanned Intensity Modulated Proton Therapy (IMPT) for high-grade glioma patients. Plans were compared with respect to target coverage and sparing of organs at risk (OARs), with special attention to the possibility of hippocampus sparing. Method. Fifteen consecutive patients diagnosed with grade III and IV glioma were selected for this study. The target and OARs were delineated based on computed tomography (CT), FDG-positron emission tomography (PET) and T1-, T2-weighted, and Diffusion Tensor Imaging (DTI) magnetic resonance imaging (MRI) and fiber-tracking. In this study, a 6 MV photon beam on a linear accelerator with a multileaf collimator (MLC) with 2.5 mm leaves and a spot-scanning proton therapy machine were used. Two RA fields, using both a coplanar (clinical standard) and a non-coplanar, setup was compared to the IMRT and IMPT techniques. Three and three to four non-coplanar fields where used in the spot-scanned IMPT and IMRT plans, respectively. The same set of planning dose-volume optimizer objective values were used for the four techniques. The highest planning priority was given to the brainstem (maximum 54 Gy) followed by the PTV (prescription 60 Gy); the hippocampi, eyes, inner ears, brain and chiasm were given lower priority. Doses were recorded for the plans to targets and OARs and compared to our clinical standard technique using the Wilcoxon signed rank test. Result. The PTV coverage was significantly more conform for IMPT than the coplanar RA technique, while RA plans tended to be more conform than the IMRT plans, as measured by the standard deviation of the PTV dose. In the cases where the tumor was confined in one cerebral hemisphere (eight patients), the non-coplanar RA and IMPT techniques yielded borderline significantly lower doses to the

Control Methods Used in the Department of Metallurgy for Structure and Fuel Elements; Methodes de Controle Utilisees au Departement de Metallurgie pour les Elements de Structure et les Elements Combustibles; Metody kontrolya struktury toplivnykh ehlementov v departamente metallurgii; Metodos de Control Utilizados en el Departamento de Metalurgia para los Elementos Estructurales y Combustibles

Energy Technology Data Exchange (ETDEWEB)

Destribats, Marie-Therese; Allain, C.; Prot, A.; Thome, P. [Centre d' Etudes Nucleaires de Saclay (France)

1965-09-15

reactores indujeron a utilizar y a perfeccionar numersos metodos no destructivos destinados a inspeccionar los distintos materiales que intervienen en la construccion de esos reactores; en particular radiografia y gamma- grafia, metodos ultrasonicos y empleo de corrientes de Foucault.. A continuacion se enumeran las operaciones de control llevadas a cabo durante la construccion de reactores pertenecientes a las familias EdF (grafito-gas) y EL 4 (agua pesada), y de elementos colaminados; se hace hincapie en ciertos aspectos caracteristicos de estos metodos, algunos de los cuales son ya bien conocidos. Familia EdF: metodos ultrasonicos para medir el espesor de las paredes de tubos de uranio o aleacion de uranio ; localizacion de las cavidades en esos tubos por gammagraffa; empleo de medios ultrasonicos para control de los tratamientos termicos a que se someten los tubos; empleo de procedimientos ultrasonicos para buscar fallas (inclusiones, grietas) en las palanquillas y barras con que se elaboran las vainas de Mg-Zr; control de la estanqueidad de los elementos mediante exudacion de helio. EL4: uso de metodos ultrasonicos y corrientes de Foucault para medir espesores de pared en tubos de Zircaloy, sean de fuerza o de guia; empleo de metodos ultrasonicos para inspeccionar tubos de fuerza de Zircaloy y vainas de acero inoxidable; radiografia al vacio de vainas de Be; control de la estanqueidad de barras huecas mediante exudacion de helio. Elementos colimados: medida del espesor de vainas mediante el empleo de corrientes de Foucault pulsadas; verificacion de la posicion del alma en tubos y placas mediante radiografia, recuento gamma y aplicacion de corrientes de Foucault pulsadas; control de la homogeneidad del combustible por recuento gamma; deteccion de defectos en barras de Zr-U mediante procedimientos ultrasonicos y gammagraficos; determinacion de las zonas despegadas en placas, empleando metodos ultrasonicos, corrientes de Foucault pulsadas y medicion de resistividad. Estos

The effect of cathode bias (field effect) on the surface leakage current of CdZnTe detectors

DEFF Research Database (Denmark)

Bolotnikov, A.E.; Chen, C.M.H.; Cook, W.R.

2003-01-01

Surface resistivity is an important parameter of multi-electrode CZT detectors such as coplanar-grid, strip, or pixel detectors. Low surface resistivity results in a high leakage current and affects the charge collection efficiency in the areas near contacts. Thus, it is always desirable to have ...

Intensity-Modulated Radiation Therapy with Noncoplanar Beams for Treatment of Prostate Cancer in Patients with Bilateral Hip Prosthesis-A Case Study

International Nuclear Information System (INIS)

Brooks, Chris; Cheung, Rex Min; Kudchadker, Rajat J.

2010-01-01

Megavoltage photon intensity-modulated radiation therapy (IMRT) is typically used in the treatment of prostate cancer at our institution. Approximately 1% to 2% of patients with prostate cancer have hip prostheses. The presence of the prosthesis usually complicates the planning process because of dose perturbation around the prosthesis, radiation attenuation through the prosthesis, and the introduction of computed tomography artifacts in the planning volume. In addition, hip prostheses are typically made of materials of high atomic number, which add uncertainty to the dosimetry of the prostate and critical organs in the planning volume. When the prosthesis is bilateral, treatment planning is further complicated because only a limited number of beam angles can be used to avoid the prostheses. In this case study, we will report the observed advantages of using noncoplanar beams in the delivery of IMRT to a prostate cancer patient with bilateral hip prostheses. The treatment was planned for 75.6 Gy using a 7-field coplanar approach and a noncoplanar arrangement, with all fields avoiding entrance though the prostheses. Our results indicate that, compared with the coplanar plan, the noncoplanar plan delivers the prescribed dose to the target with a slightly better conformality and sparing of rectal tissue versus the coplanar plan.

Documentation of COMRAD program (= Comprehensive System for Interactive Planning in Radiation Therapy)

International Nuclear Information System (INIS)

Pfister, G.; Friedlein, H.P.

1984-05-01

COMRAD is a radiotherapy planning program for calculating dose distribution in two- and three-dimensional patient geometries with coplanar or non-coplanar fields. The program was developed at the IBM Scientific Center Heidelberg and extended for applications in neutron therapy at the IKE by integration of the neutron dose formula and further specification options. These modifications were necessary for an accurate determination of inhomogeneities in neutron therapy and for neutron kerma calculations. Administrative data, e.g. patient name and number, date, doctor and physicist appear on all printed dose distributions. The treatment data comprise the therapy unit in use, specifications of the radiation field (radiation axis, source/skin distance, portal size, rotation parameters), dose specifications, and field specifications. The location and orientation of the planar cuts through the patient (windows) into which dose distributions shall be calculated can be set at will. The same applies to the density of the raster points at which dose values shall be computed. (orig./HP) [de

Simulation of molecular transitions using classical trajectories

Energy Technology Data Exchange (ETDEWEB)

Donoso, A.; Martens, C. C. [University of California, California (United States)

2001-03-01

In the present work, we describe the implementation of a semiclassical method to study physical-chemical processes in molecular systems where electronic state transitions and quantum coherence play a dominant role. The method is based on classical trajectory propagation on the underlying coupled electronic surfaces and is derived from the semiclassical limit of the quantum Liouville equation. Unlike previous classical trajectory-based methods, quantum electronic coherence are treated naturally within this approach as complex weighted trajectory ensembles propagating on the average electronic surfaces. The method is tested on a model problem consisting of one-dimensional motion on two crossing electronic surfaces. Excellent agreement is obtained when compared to the exact results obtained by wave packet propagation. The method is applied to model quantum wave packet interferometry, where two wave packets, differing only in a relative phase, collide in the region where the two electronic surfaces cross. The dependence of the resulting population transfer on the initial relative phase of the wave packets is perfectly captured by our classical trajectory method. Comparison with an alternative method, surface hopping, shows that our approach is appropriate for modelling quantum interference phenomena. [Spanish] En este trabajo se describe la implementacion de un metodo semiclasico para estudiar procesos fisicos-quimicos en sistemas moleculares donde las transiciones entre estados electronicos y las coherencias cuanticas juegan un papel predominante. El metodo se basa en la propagacion de trayectorias clasicas sobre las correspondientes superficies electronicas acopladas y se deriva a partir del limite semiclasico de la ecuacion cuantica de Liouville. A diferencia de metodos previos basados en trayectoria clasica, dentro de este esquema, las coherencias electronicas cuanticas son tratadas de manera natural como ensamble de trayectorias con pesos complejos, moviendose en

Avaliação dos métodos de amostragem para fauna perifítica em macrófitas na Reserva da Biosfera, Serra do Espinhaço, Estado de Minas Gerais, Brasil - DOI: 10.4025/actascibiolsci.v30i3.377 Evaluation of sampling methods for periphytic fauna in macrophytes at the Espinhaço Mountain Range Biosphere Reserve, Minas Gerais State, Brazil - DOI: 10.4025/actascibiolsci.v30i3.377

Directory of Open Access Journals (Sweden)

Cristiane Machado López

2008-10-01

Full Text Available Os métodos “Jarra”, “Remocao Manual” e “Draga de Eckman modificada” foram avaliados para amostrar a fauna perifitica associada a macrofitas aquaticas. Foram coletadas 63 amostras em cinco ambientes lenticos e tres loticos na reserva da biosfera da Serra do Espinhaco (Estado de Minas Gerais, Brasil. Os testes estatisticos Anova e Tukey foram feitos para riqueza de Protista, Rotifera e Crustacea, enquanto para a abundancia de Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada e Nematoda foram avaliados os percentuais. Os protozoarios e rotiferos representaram 80% da abundancia e riqueza da comunidade. Nos ecossistemas avaliados todos os metodos foram relevantes para Protista, por outro lado, o metodo da Jarra foi o mais adequado para a analise de Crustacea. Entre os metodos, a Draga foi menos indicada para os grupos de microinvertebrados nos ecossistemas aquaticos. Os metodos Remocao Manual e Draga foram apropriados para analisar Rotifera. A abundancia de Gastrotricha e Tardigrada demonstrou melhores resultados pelo metodo da Jarra e Nematoda pelo metodo da Draga. Os tres metodos sao apropriados para amostragem da fauna perifitica em ambos os sistemas aquaticos. Entretanto, e importante estar ciente de que para cada tipo de ecossistema a amostragem da comunidade faunistica requer um metodo especifico para obter a melhor performance.The methods “Jar”, “Manual Removal” and “modified Ekman`s Dredge” were evaluated for sampling periphyton fauna associated to aquatic macrophytes. Sixty three samples were collected from five lentic and three lotic water bodies at Espinhaço Mountain Range Biosphere Reserve (Minas Gerais, Brazil. ANOVA and Tukey statistical tests were performed for Protista, Rotifera and Crustacea richness, whilst Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada and Nematoda, abundance were evaluate by percentage. Amongst the three methods, Dregde is less indicated for different water bodies systems

Circuit QED with transmon qubits

Energy Technology Data Exchange (ETDEWEB)

Wulschner, Karl Friedrich; Puertas, Javier; Baust, Alexander; Eder, Peter; Fischer, Michael; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Xie, Edwar; Zhong, Ling; Deppe, Frank; Fedorov, Kirill; Marx, Achim; Menzel, Edwin; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Huebl, Hans [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Weides, Martin [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

2015-07-01

Superconducting quantum bits are basic building blocks for circuit QED systems. Applications in the fields of quantum computation and quantum simulation require long coherence times. We have fabricated and characterized superconducting transmon qubits which are designed to operate at a high ratio of Josephson energy and charging energy. Due to their low sensitivity to charge noise transmon qubits show good coherence properties. We couple transmon qubits to coplanar waveguide resonators and coplanar slotline resonators and characterize the devices at mK-temperatures. From the experimental data we derive the qubit-resonator coupling strength, the qubit relaxation time and calibrate the photon number in the resonator via Stark shifts.

Phase control effects in optical diffraction radiation from a slit

International Nuclear Information System (INIS)

Castellano, M.; Chiadroni, E.; Cianchi, A.

2010-01-01

Optical Diffraction Radiation (ODR) from a slit is becoming a real promising instrument for measuring the transverse beam size, or even the emittance of the very high brightness linacs driving SASE FELs or the future ILC which require non-intercepting diagnostic devices. But to correctly explain experimental data it is necessary to further develop the theory of this radiation emission. In this paper we discuss in particular the effects of a non-perfect coplanarity of the two halves of a slit, that introduces a phase difference in the field produced by the two half-planes. Such non-coplanarity can result from mechanical stress for instance.

A 40 GHz fully integrated circuit with a vector network analyzer and a coplanar-line-based detection area for circulating tumor cell analysis using 65 nm CMOS technology

Science.gov (United States)

Nakanishi, Taiki; Matsunaga, Maya; Kobayashi, Atsuki; Nakazato, Kazuo; Niitsu, Kiichi

2018-03-01

A 40-GHz fully integrated CMOS-based circuit for circulating tumor cells (CTC) analysis, consisting of an on-chip vector network analyzer (VNA) and a highly sensitive coplanar-line-based detection area is presented in this paper. In this work, we introduce a fully integrated architecture that eliminates unwanted parasitic effects. The proposed analyzer was designed using 65 nm CMOS technology, and SPICE and MWS simulations were used to validate its operation. The simulation confirmed that the proposed circuit can measure S-parameter shifts resulting from the addition of various types of tumor cells to the detection area, the data of which are provided in a previous study: the |S 21| values for HepG2, A549, and HEC-1-A cells are -0.683, -0.580, and -0.623 dB, respectively. Additionally, the measurement demonstrated an S-parameters reduction of -25.7% when a silicone resin was put on the circuit. Hence, the proposed system is expected to contribute to cancer diagnosis.

Comparative Study of the Methods Used for the Computer Resolution of Composite Gamma-Ray Spectra; Etude Comparative des Methodes Utilisees pour la Resolution de Spectres Gamma Complexes au Moyen d'un Ordinateur; Sravnitel'noe izuchenie metodov razresheniya sostavnykh gamma-spektrov pri pomoshchi schetno-reshayushchego ustrojstva; Estudio Comparativo de los Metodos Aplicados para Resolver Espectros Gamma Complejos Mediante Calculadoras

Energy Technology Data Exchange (ETDEWEB)

DeHaan, A. Jr.; Leventhal, L.; Benson, P. [Tracerlab, Richmond, CA (United States)

1965-10-15

'a resolution; 2. Resolution du pic sans elimination; 3. Etablissement d'un ensemble d'equ'ations lineaires simultanees du meme ordre que le nombre de radionucleides presents dans le melange et solution de ces equations; 4. Evaluation des concentrations non connues par la methode des moindres carres, classique ou ponderee; 5. Combinaison des methodes statistiques et des methodes des moindres carres utilisant la regression lineaire multiple progressive, en s'efforcant d'integrer des processus decisifs dans l'analyse. Pour chaque methode d'analyse appliquee a des melanges de radionucleides, les auteurs fournissent une estimation statistique des erreurs de mesure de la concentration des radionucleides. (author) [Spanish] La resolucion de mezclas complejas de emisores gamma se ha simplificado gracias al empleo de espectrometros gamma muy perfeccionados en asociacion con calculadoras numericas. En la actualidad, los laboratorios pueden en general disponer de estos instrumentos o tener facilmente acceso a ellos. En la memoria se examinan los metodos seguidos en el laboratorio de los autores para determinar la concentracion de cada radionuclido emisor gamma contenido en muestras de precipitaciones radiactivas, y se comparan los resultados obtenidos por los diferentes metodos matematicos aplicables a las muestras compuestas. Los datos proporcionados por las calculadoras se comparan con los resultados obtenidos por analisis radioquimico de la muestra. Se han analizado muestras binarias por los metodos mencionados, operacion que se extendio despues a las mezclas integradas por muchos componentes. Se ha elaborado un metodo de computo que normaliza los espectros gamma para reducir al mfnimo el efecto de la deriva del espectrometro a largo plazo, y representa el espectro segun un sistema de coordenadas, una de las cuales es la energia. Se han investigado los efectos de un 'fotopico imprevisto', de una componente de intensidad cero y de picos superpuestos en la resolucion segun los

Coligand-regulated assembly, fluorescence, and magnetic properties of Co(II) and Cd(II) complexes with a non-coplanar dicarboxylate

International Nuclear Information System (INIS)

Xin, Ling-Yun; Liu, Guang-Zhen; Ma, Lu-Fang; Wang, Li-Ya

2013-01-01

A non-coplanar dicarboxylate ndca (H 2 ndca=5-norbornene-2,3-dicarboxylic acid), combining with various dipyridyl-typed tectons, constructs six Cd(II)/Co(II) coordination polymers under hydrothermal conditions, namely [Co(ndca)(H 2 O)] n (1), ([Co(ndca)(bpe)(H 2 O)]·H 2 O) n (2), [Co(ndca)(bpa) 0.5 (H 2 O)] n (3), [Cd(ndca)(bpe)(H 2 O)] n (4), ([Cd(ndca)(bpa)(H 2 O)]·0.5H 2 O) n (5), and ([Cd(ndca)(bpp) (H 2 O)]·H 2 O) n (6) (bpe=1,2-di(4-pyridyl)ethylene, bpa=1,2-bi(4-pyridyl)ethane, and bpp=1,3-bis(4-pyridyl)propane). All these compounds contain various metal(II)–carboxylate motifs, including carboxylate binuclear (2, 4, 5), carboxylate chain (1, 6) and carboxylate layer (3), which are further extended by dipyridyl-typed coligands to afford a vast diversity of the structures with 2D pyknotic layers (1, 6), 2D open layer (5), 2D→3D interpenetrated networks (2,4), and 3D pillared-layer framework (3), respectively. In addition, fluorescent spectra of Cd(II) complexes and magnetic properties of Co(II) complexes are also given. - Graphical abstract: Six various cadmium(II)/cobalt(II)–organic frameworks were constructed by 5-norbornene-2,3-dicarboxylic acid and different bis(pyridine) rod-like tectons, and Cd (II) complexes exhibit blue–violet emissions, whereas Co (II) complexes show antiferromagnetic behaviours. Display Omitted

Initial thermal state of the Los Humeros, Puebla, Mexico, geothermal field; Estado termico inicial del campo geotermico de Los Humeros, Puebla, Mexico

Energy Technology Data Exchange (ETDEWEB)

Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx

2009-01-15

The initial temperatures field is presented for 40 wells in the Los Humeros geothermal reservoir, along with an elevation curve based on the formation temperature or the most probable reservoir temperature. Stabilized temperatures were estimated using the Radial Spherical Heat Flow method, chosen over the Horner method based on the numerical simulation of the circulation and stop processes of well H-26. In this well, the last temperature log series was reproduced, considering circulation losses. The temperatures were used to produce isothermal curves over three geological sections of the field, which represent the initial distribution of temperatures in the reservoir and show the thermal characteristics and the relationships among thermal anomalies and faults in the reservoir. The elevation curve plotted against the initial temperature of the formation was generated based on detection of the main feed zones at each well, which in turn was developed using detailed analyses of diverse information, such as temperature logs, circulation losses, lithology, well completion, and heat velocities. Based on the results, two groups of wells may be distinguished: one between 1000 and 1600 masl with temperatures from 290 to 330 degrees Celsius, and one between 900 and 0 masl with temperatures from 300 to 400 degrees Celsius. [Spanish] En este trabajo se presenta el campo de temperatura inicial del yacimiento geotermico de Los Humeros y una curva de elevacion contra la temperatura de formacion o temperatura mas probable del yacimiento, obtenida para 40 pozos del campo. Las temperaturas estabilizadas se estimaron mediante el metodo de Flujo de Calor Esferico Radial, y su eleccion sobre las temperaturas del metodo de Horner se soporta con simulacion numerica de los procesos de circulacion y paro del pozo H-26, en la cual la ultima serie de registros se reprodujo considerando perdidas de circulacion. Con estas temperaturas se generaron curvas isotermicas para tres secciones

Responsabilità giuridica e scienze sperimentali sul vivente

Directory of Open Access Journals (Sweden)

Patrick Nerhot

2017-12-01

Full Text Available SOMMARIO: 1. Il "vivente": inoperosità dei concetti della filosofia profana dei Lumi - 2. La ricerca-costruzione di una infinita-fine - 3. Le scienze "sperimentali" come la non distinzione tra "causa" e "effetto" - 4. La nuova questione di metodo posta al "vivente" - 5. La sfida di una etica come adeguazione tra etica e metodo.

Coligand-regulated assembly, fluorescence, and magnetic properties of Co(II) and Cd(II) complexes with a non-coplanar dicarboxylate

Energy Technology Data Exchange (ETDEWEB)

Xin, Ling-Yun [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Liu, Guang-Zhen, E-mail: gzliuly@126.com [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Ma, Lu-Fang [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Wang, Li-Ya [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang 473061 (China)

2013-10-15

A non-coplanar dicarboxylate ndca (H{sub 2}ndca=5-norbornene-2,3-dicarboxylic acid), combining with various dipyridyl-typed tectons, constructs six Cd(II)/Co(II) coordination polymers under hydrothermal conditions, namely [Co(ndca)(H{sub 2}O)]{sub n} (1), ([Co(ndca)(bpe)(H{sub 2}O)]·H{sub 2}O){sub n} (2), [Co(ndca)(bpa){sub 0.5}(H{sub 2}O)]{sub n} (3), [Cd(ndca)(bpe)(H{sub 2}O)]{sub n} (4), ([Cd(ndca)(bpa)(H{sub 2}O)]·0.5H{sub 2}O){sub n} (5), and ([Cd(ndca)(bpp) (H{sub 2}O)]·H{sub 2}O){sub n} (6) (bpe=1,2-di(4-pyridyl)ethylene, bpa=1,2-bi(4-pyridyl)ethane, and bpp=1,3-bis(4-pyridyl)propane). All these compounds contain various metal(II)–carboxylate motifs, including carboxylate binuclear (2, 4, 5), carboxylate chain (1, 6) and carboxylate layer (3), which are further extended by dipyridyl-typed coligands to afford a vast diversity of the structures with 2D pyknotic layers (1, 6), 2D open layer (5), 2D→3D interpenetrated networks (2,4), and 3D pillared-layer framework (3), respectively. In addition, fluorescent spectra of Cd(II) complexes and magnetic properties of Co(II) complexes are also given. - Graphical abstract: Six various cadmium(II)/cobalt(II)–organic frameworks were constructed by 5-norbornene-2,3-dicarboxylic acid and different bis(pyridine) rod-like tectons, and Cd (II) complexes exhibit blue–violet emissions, whereas Co (II) complexes show antiferromagnetic behaviours. Display Omitted.

Induction logging device

Science.gov (United States)

Koelle, A.R.; Landt, J.A.

An instrument is disclosed for mapping vertical conductive fractures in a resistive bedrock, magnetically inducing eddy currents by a pair of vertically oriented, mutually perpendicular, coplanar coils. The eddy currents drive magnetic fields which are picked up by a second, similar pair of coils.

Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in total scalp irradiation: a single institutional experience

International Nuclear Information System (INIS)

Ostheimer, Christian; Huebsch, Patrick; Janich, Martin; Gerlach, Reinhard; Vordermark, Dirk

2016-01-01

Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensity-modulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8% –88.4% in coplanar, 77.5%–88.2% in non-coplanar IMRT and 82.8%–90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue

Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in total scalp irradiation: a single institutional experience

Energy Technology Data Exchange (ETDEWEB)

Ostheimer, Christian; Huebsch, Patrick; Janich, Martin; Gerlach, Reinhard; Vordermark, Dirk [Dept. of Radiation Oncology, Faculty of Medicine, Martin Luther University Halle-Wittenberg, Halle (Germany)

2016-12-15

Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensity-modulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8% –88.4% in coplanar, 77.5%–88.2% in non-coplanar IMRT and 82.8%–90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.

Analysis of Radiation Field and Block Pattern for Optimal Size in Multileaf Collimator

International Nuclear Information System (INIS)

Ahn, Seoung Do; Yang, Kwang Mo; Yi, Byong Yong; Choi, Eun Kyong; Chang, Hye Sook

1994-01-01

The patterns of the conventional radiation treatment fields and their shielding blocks are analysed to determine the optimal dimension of the MultiLeaf Collimator (MLC) which is considered as an essential tool for conformal therapy. Total 1169 radiation fields from 303 patients (203 from Asan Medical center, 50 from Baek Hosp and 50 from Hanyang Univ. Hosp.) were analysed for this study. Weighted case selection treatment site (from The Korean Society of Therapeutic Radiology 1003). Ninety one percent of total fields have shielding blocks. Y axis is defined as leaf movement direction and it is assumed that MLC is installed on the cranial-caudal direction. The length of X axis were distributed from 4cm to 40cm (less than 21cm for 95% of cases), and Y axis from 5cm to 38cm (less than 22cm for 95% of cases). The shielding blocks extended to less than 6cm from center of the filed for 95% of the cases. Start length for ninety five percent of block is less than 10cm for X axis and 11cm for Y axis. Seventy six percent of shielding blocks could be placed by either X or Y axis direction, 7.9% only by Y axis, 5.1% only by X axis and it is reasonable to install MLC for Y direction. Ninety five percent of patients can be treated with coplanar rotation therapy without changing the collimator angle. Eleven percent of cases of cases were impossible to replace with MLC. Futher study of shielding should be larger than 21cm X 22cm. The MLC should be designed as a pair of 21 leaves with 1cm wide for an acceptable resolution and 17cm long to enable the leaf to overtravel at least 6cm from the treatment field center

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like coplanar polychlorinated biphenyls in mackerel obtained from the Japanese market, 1999-2003.

Science.gov (United States)

Nakatani, Tadashi; Yamano, Testuo

2017-09-01

This study analysed the concentrations and toxic-equivalent (TEQ) levels of dioxin congeners in mackerel commercially available in Japan in early 2000s. The content of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like coplanar polychlorinated biphenyls (DL-PCBs) was determined in 17 mackerel samples from different areas. TEQ levels in mackerel muscle were 0.78 pg TEQ g - 1 wet weight (wt) on average (range = 0.21-2.26 pg TEQ g - 1 wet wt) for PCDD/Fs (PCDDs plus PCDFs), 2.81 pg TEQ g - 1 wet wt on average (range = 1.02-8.5 pg TEQ g - 1 wet wt) for DL-PCBs, and 3.59 pg TEQ g - 1 wet wt on average (range = 1.24-10.8 pg g - 1 wet wt) for dioxins (PCDD/Fs plus DL-PCBs). The results revealed somewhat higher TEQ levels for dioxins compared with the other data for fish and shellfish in the Japanese market. TEQ levels were well correlated with mackerel body weight; the main contributors were tetra- and penta-CDD/Fs, some hexa-CDD/Fs, and all 12 DL-PCBs, which are known to have high bioaccumulation potential. In particular, PCB 126 was mostly responsible for the observed correlation of DL-PCB and dioxins-TEQ levels with mackerel body weight. The average daily intake of dioxins in terms of TEQ through mackerel consumption was estimated to be 4.81 pg TEQ/person/day, accounting for 7% of the total intake of dioxins-TEQ through fish and shellfish in Japan.

Evaluation of accuracy about 2D vs 3D real-time position management system based on couch rotation when non-coplanar respiratory gated radiation therapy

International Nuclear Information System (INIS)

Kwon, Kyung Tae; Kim, Jung Soo; Sim, Hyun Sun; Min, Jung Whan; Son, Soon Yong; Han, Dong Kyoon

2016-01-01

Because of non-coplanar therapy with couch rotation in respiratory gated radiation therapy, the recognition of marker movement due to the change in the distance between the infrared camera and the marker due to the rotation of the couch is called RPM (Real-time The purpose of this paper is to evaluate the accuracy of motion reflections (baseline changes) of 2D gating configuration (two dot marker block) and 3D gating configuration (six dot marker block). The motion was measured by varying the couch angle in the clockwise and counterclockwise directions by 10° in the 2D gating configuration. In the 3D gating configuration, the couch angle was changed by 10° in the clockwise direction and compared with the baseline at the reference 0°. The reference amplitude was 1.173 to 1.165, the couch angle at 20° was 1.132, and the couch angle at 1.0° was 1.083. At 350° counterclockwise, the reference amplitude was 1.168 to 1.157, the couch angle at 340° was 1.124, and the couch angle at 330° was 1.079. In this study, the phantom is used to quantitatively evaluate the value of the amplitude according to couch change

Evaluation of accuracy about 2D vs 3D real-time position management system based on couch rotation when non-coplanar respiratory gated radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kyung Tae; Kim, Jung Soo [Dongnam Health University, Suwon (Korea, Republic of); Sim, Hyun Sun [College of Health Sciences, Korea University, Seoul (Korea, Republic of); Min, Jung Whan [Shingu University College, Sungnam (Korea, Republic of); Son, Soon Yong [Wonkwang Health Science University, Iksan (Korea, Republic of); Han, Dong Kyoon [College of Health Sciences, EulJi University, Daejeon (Korea, Republic of)

2016-12-15

Because of non-coplanar therapy with couch rotation in respiratory gated radiation therapy, the recognition of marker movement due to the change in the distance between the infrared camera and the marker due to the rotation of the couch is called RPM (Real-time The purpose of this paper is to evaluate the accuracy of motion reflections (baseline changes) of 2D gating configuration (two dot marker block) and 3D gating configuration (six dot marker block). The motion was measured by varying the couch angle in the clockwise and counterclockwise directions by 10° in the 2D gating configuration. In the 3D gating configuration, the couch angle was changed by 10° in the clockwise direction and compared with the baseline at the reference 0°. The reference amplitude was 1.173 to 1.165, the couch angle at 20° was 1.132, and the couch angle at 1.0° was 1.083. At 350° counterclockwise, the reference amplitude was 1.168 to 1.157, the couch angle at 340° was 1.124, and the couch angle at 330° was 1.079. In this study, the phantom is used to quantitatively evaluate the value of the amplitude according to couch change.

Preparation of hydrotalcite compounds using ultrasound irradiation to capture CO{sub 2}; Preparacion de compuestos tipo hidrotalcita utilizando irradiacion de ultrasonido para la captura de CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Martinez, J.A.J.; Paredes, S.P.; Valenzuela, M.A.; Hernandez, M.L. [Instituto Politecnico Nacional, ESIQIE, Mexico, D.F. (Mexico)]. E-mail: sparedesc@ipn.com.mx

2009-09-15

Al-Mg hydrotalcite compounds (HTC) were prepared using co-precipitation, sol-gel and reconstruction of the structure with ultrasound-assisted irradiation. The interlaminar components for each method were nitrate, acetylacetonate ethoxide and metavanadate, respectively. Optimization of the synthesis was performed using x-ray diffraction. The effect of the different parameters on synthesis was studied, including pH, time and ultrasound irradiation power. In addition, for the reconstruction method, temperature and calcination time were evaluated. For all methods, ultrasound-assisted methods were found to be more efficient and economical than conventional methods reported (autoclave). They also have the advantage of being able to control properties such as crystallinity, porosity and the specific surface, which significantly depends on the preparation method, irradiation time and type of interlaminar component. These methods are intended to synthesize interlaminar anionic materials that are very scarce in nature with better properties than traditional adsorbents used for the capture of CO{sub 2}. [Spanish] Se prepararon compuestos tipo hidrotalcita Al-Mg por los metodos de: coprecipitacion, sol gel y reconstruccion de la estructura asistidos por irradiacion de ultrasonido. Los componentes interlaminares para cada metodo fueron respectivamente: nitrato, etoxido-acetilacetonato y metavanadato. La optimizacion de la sintesis, se efectuo mediante difraccion de rayos-X. Se estudio el efecto de diversos parametros en la sintesis: pH, tiempo y potencia de irradiacion de ultrasonido, ademas, para el metodo de reconstruccion se evaluaron la temperatura y el tiempo de calcinacion. En todos los casos se encontro que el empleo de metodos asistidos por ultrasonido resultan ser mas eficientes y economicos que los metodos convencionales reportados (autoclave), ademas tienen la ventaja, de poder controlar propiedades tales como: la cristalinidad, la porosidad y la superficie

Optimization of the coplanar interdigital capacitive sensor

Science.gov (United States)

Huang, Yunzhi; Zhan, Zheng; Bowler, Nicola

2017-02-01

Interdigital capacitive sensors are applied in nondestructive testing and material property characterization of low-conductivity materials. The sensor performance is typically described based on the penetration depth of the electric field into the sample material, the sensor signal strength and its sensitivity. These factors all depend on the geometry and material properties of the sensor and sample. In this paper, a detailed analysis is provided, through finite element simulations, of the ways in which the sensor's geometrical parameters affect its performance. The geometrical parameters include the number of digits forming the interdigital electrodes and the ratio of digit width to their separation. In addition, the influence of the presence or absence of a metal backplane on the sample is analyzed. Further, the effects of sensor substrate thickness and material on signal strength are studied. The results of the analysis show that it is necessary to take into account a trade-off between the desired sensitivity and penetration depth when designing the sensor. Parametric equations are presented to assist the sensor designer or nondestructive evaluation specialist in optimizing the design of a capacitive sensor.

Estimating the Permittivity of Rogers 4003C Substrate at Low Frequencies for Application in a Superdirective First-Order Probe for SNF Measurements

DEFF Research Database (Denmark)

Kim, Oleksiy S.

2016-01-01

The bulk permittivity of Rogers 4003C substrate is estimated in the lower UHF frequency band by comparing the simulated and measured return loss for a bandpass filter based on a coplanar waveguide and a capacitively loaded loop. The obtained value, which deviates from that specified by Rogers at ...... GHz, is subsequently utilized for accurate design of a new light-weight superdirective first-order probe for spherical near-field (SNF) antenna measurements at low frequencies.......The bulk permittivity of Rogers 4003C substrate is estimated in the lower UHF frequency band by comparing the simulated and measured return loss for a bandpass filter based on a coplanar waveguide and a capacitively loaded loop. The obtained value, which deviates from that specified by Rogers at 10...

Ultrafast pulse generation in photoconductive switches

DEFF Research Database (Denmark)

Keil, Ulrich Dieter Felix; Dykaar, D. R.

1996-01-01

Carrier and field dynamics in photoconductive switches are investigated by electrooptic sampling and voltage-dependent reflectivity measurements. We show that the nonuniform field distribution due to the two-dimensional nature of coplanar photoconductive switches, in combination with the large di...... difference in the mobilities of holes and electrons, determine the pronounced polarity dependence. Our measurements indicate that the pulse generation mechanism is a rapid voltage breakdown across the photoconductive switch and not a local field breakdown...

SU-F-T-646: SBRT Lung: Moving Beyond the 3D Conformal Paradigm with An Elekta VersaHD Accelerator

International Nuclear Information System (INIS)

Dalhart, A; Hyer, D; Allen, B; Flynn, R; Johnston, H

2016-01-01

Purpose: To develop a volumetric modulated arc therapy (VMAT) planning and delivery methodology for lung stereotactic body radiation therapy (SBRT) that addresses the unique geometric challenges presented when using an Elekta VersaHD linear accelerator. Methods: The Elekta VersaHD imaging panels are fixed at 160cm SID when deployed, limiting the ability to perform non-coplanar treatments due to collisions with the treatment table. The panels can be folded in a stored position for non-coplanar treatments, but in this configuration, longitudinal table travel is restricted by the space required for the folded panels. To overcome these design features, a non-coplanar VMAT technique was designed and evaluated for 6 patients that uses a superiorly placed isocenter near the apex of the lung. A coplanar VMAT technique with isocenter placement within the target was also assessed for each patient. Non-coplanar plans included three arcs, totalling 340° of arc angle, while coplanar plans included two arcs, totalling 280° of arc angle. Each technique avoided the contralateral lung and major overlap on patient skin. Corresponding 3DCRT plans were used as a baseline for each patient in evaluating VMAT plans. Results: Coplanar and noncoplanar VMAT plans yielded a high dose conformity index (CI) improvement of 6% and low dose CI improvements of 9% and 11%, respectively, over corresponding 3DCRT plans. While both VMAT techniques provided greater skin sparing compared to 3DCRT, the non-coplanar technique offered an improvement of 20% over the coplanar approach. Treatment time with for VMAT was ∼2.5 minutes compared to ∼10 minutes for 3DCRT. Conclusion: Two VMAT techniques were developed for lung SBRT that account for machine design limitations and provide greater dose conformity and normal tissue sparing than 3DCRT plans. The non-coplanar VMAT plans showed a marginal improvement over coplanar VMAT plans and may not warrant the additional complexity.

Field-induced magnetic phase transitions and correlated electronic states in the hexagonal RAgGE and RPtIn series

Energy Technology Data Exchange (ETDEWEB)

Morosan, Emilia [Iowa State Univ., Ames, IA (United States)

2005-01-01

The present work was initially motivated by the desire to continue the study of complex metamagnetism in relation to the crystal structure of various compounds; this study already included tetragonal compounds like HoNi₂B₂C (Canfield 1997b; Kalatsky 1998) and DyAgSb₂ (Myers 1999), in which the rare earths occupy unique tetragonal positions. We intended to find hexagonal systems suited for such a study, with complex metamagnetic properties, and the search for extremely anisotropic hexagonal compounds turned into a rewarding exploration. We identified and grew most of the heavy rare earth members of two isostructural series, RAgGe and RPtIn, both belonging to the hexagonal Fe₂P family of materials. In each of these series we found one compound, TmAgGe, and TbPtIn respectively, that was suitable for a simple study of angular dependent metamagnetism: they had three rare earth ions in the unit cell, positioned at a unique crystallographic site with orthorhombic point symmetry. The magnetization of both TmAgGe and TbPtIn was extremely anisotropic, with larger values for the in-plane orientation of the applied field than in the axial direction. Complex metamagnetic transitions existed for field within the ab-plane, and, similar to the case of the tetragonal compounds RNi₂B₂C and DyAgSb₂, they depended on the field orientation within the basal plane. We were thus able to develop a two-dimensional model, the three co-planar Ising-like systems model, which described well the angular dependence of the metamagnetic transitions in the TmAgGe and TbPtIn hexagonal compounds. Having three magnetic moments in the hexagonal unit cell, in orthorhombic point symmetry positions, added to the complexity of the analysis compared to the case of tetragonal compounds having one rare earth atom per unit cell, in tetragonal point symmetry. However, the three co-planar Ising-like systems model yielded complex, but

A microwave technique for electrical conductivity measurements in semiconductors; Un procedimiento en frecuencia de microondas para la medicion de la conductividad electrica en semiconductores

Energy Technology Data Exchange (ETDEWEB)

Ramirez, A; Zehe, A [Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Starostenko, O [Universidad de las Americas, Puebla, (Mexico); Perez, L [Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

2003-01-15

In the present paper a theoretical approach is given together with the description of the experimental technique for electrical conductivity measurements of semiconductors in frequency range of 10 GHz, corresponding to a wavelength of {lambda}= 3 cm. It is shown, that the sample conductivity, measured without the need of electrical contacts, Is practically identical with results obtained by direct current methods. The potential use of the method for dielectric measurements in samples of general shape is included in the discussion. Given that the local electrical field is known only in bodies of ellipsoidal shape, one has to apply approximation methods for sample shapes of practical relevance (cylinders, cubes, disks). Finally, the measuring range and corresponding errors are explained on the base of measurements realized with silicon samples. [Spanish] En el presente trabajo se desarrolla la teoria junto con la descripcion del arreglo experimental para la medicion de la conductividad electrica en muestras semiconductoras, utilizando un campo de microondas de {lambda}= 3 cm, correspondiente a una frecuencia n de 10 GHz. Se demuestra que la conductividad electrica medida sin la necesidad de contactos electricos es practicamente identica con resultados obtenidos por el metodo comun utilizando corriente directa (d.c.). Se incorpora en la discusion ademas el potencial del metodo para el estudio de propiedades dielectricas en muestras de geometria general. Dado que solamente en cuerpos con geometria elipsoidal se conoce bien el campo electrico local, y con esto el momento bipolar inducido, para muestras de geometrias mas practicas (cilindros, cubos, discos) se acude a metodos de aproximacion. Finalmente, se discute el rango de mediciones y errores, y se presentan mediciones concretas, utilizando muestras de silicio.

SU-F-T-590: Modeling PTV Dose Fall-Off for Cervical Cancer SBRT Treatment Planning Using VMAT and Step-And-Shoot IMRT

Energy Technology Data Exchange (ETDEWEB)

Delgado, A Brito; Cohen, D; Eng, T; Gutierrez, A [University of Texas Health Science Center San Antonio, San Antonio, TX (United States)

2016-06-15

Purpose: Due to the high dose per fraction in SBRT, dose conformity and dose fall-off are critical. In patients with cervical cancer, rapid dose fall-off is particularly important to limit dose to the nearby rectum, small bowel, and bladder. This study compares the target volume dose fall-off for two radiation delivery techniques, fixed-field IMRT & VMAT, using non-coplanar beam geometries. Further comparisons are made between 6 and 10MV photon beam energies. Methods: Eleven (n=11) patients were planned in Pinnacle3 v9.10 with a NovalisTx (HD120 MLC) machine model using 6 and 10 MV photons. The following three techniques were used: (1) IMRT (10 non-coplanar beams) (2) Dual, coplanar 360° VMAT arcs (4° spacing), and (3) Triple, non-coplanar VMAT arcs (1 full arc and dual partial arcs). All plans were normalized such that 98% of the PTV received at least 28Gy/4Fx. Dose was calculated using a 2.0mm isotropic dose grid. To assess dose fall-off, twenty concentric 2mm thick rings were created around the PTV. The maximum dose in each ring was recorded and the data was fitted to model dose fall-off. A separate analysis was performed by separating target volumes into small (0–50cc), medium (51–80cc), and large (81–110cc). Results: Triple, non-coplanar VMAT arcs showed the best dose fall-off for all patients evaluated. All fitted regressions had an R{sup 2}≥0.99. At 10mm from the PTV edge, 10 MV VMAT3-arc had an absolute improvement in dose fall-off of 3.8% and 6.9% over IMRT and VMAT2-arc, respectively. At 30mm, 10 MV VMAT3-arc had an absolute improvement of 12.0% and 7.0% over IMRT and VMAT2-arc, respectively. Faster dose fall-off was observed for small volumes as opposed to medium and large ones—9.6% at 20mm. Conclusion: Triple, non-coplanar VMAT arcs offer the sharpest dose fall-off for cervical SBRT plans. This improvement is most pronounced when treating smaller target volumes.

Development of an analytic outline for the aflatoxins analysis in grains and flours; Desarrollo de un esquema analitico para el analisis de aflatoxinas en granos y harinas

Energy Technology Data Exchange (ETDEWEB)

Sibaja Adams, Roxana

2000-07-01

The instrumental and analytic conditions were optimized for the aflatoxine determination B1, B2, 1 and G2 in corn and peanut byl iquid chromatography of high discharge following the analyzing method AOAC 994,08. Besides, it was defined a function for evaluating the dependence of the chromatographic discharge with the aflatoxine concentration. The analyzing method was validated, and four calibration curves were obtained for the aflatoxine B1, B2, G1 and G2, which turned to have a heterocedastico behavior. The applicability of this method was demonstrated, obtaining imagines of appropriate merit and comparable with those reported by the AOAC. Additionally, the applicability of the chromatographic method was demonstrated in fine layer for the presumptive analysis of aflatoxine, allowing both methods to propose an outline of reliable analysis of real samples. [Spanish] Se optimizaron las condiciones instrumentales y analiticas para la determinacion de aflatoxinas B1, B2, G1 y G2 en maiz y mani por Cromatografia liquida de alto desempeno siguiendo el metodo de analisis AOAC 994,08. Ademas, se definio una funcion para evaluar la dependencia del desempeno cromatografico con la concentracion de aflatoxinas.Se valido el metodo de analisis y se obtuvieron las cuatro curvas de calibracion para las aflatoxinas B1, B2, G1 y G2, las que resultaron tener un comportamiento heterocedastico. Se demostro la aplicabilidad del metodo, obteniendose figuras de merito adecuadas y comparables con las reportadas por el AOAC.Adicionalmente, se demostro la aplicabilidad del metodo de cromatografia en capa fina para el analisis presuntivo de aflatoxinas, permitiendo ambos metodos proponer un esquema de analisis confiable de muestras reales.

Dosimetric Comparison of Split Field and Fixed Jaw Techniques for Large IMRT Target Volumes in the Head and Neck

International Nuclear Information System (INIS)

Srivastava, Shiv P.; Das, Indra J.; Kumar, Arvind; Johnstone, Peter A.S.

2011-01-01

Some treatment planning systems (TPSs), when used for large-field (>14 cm) intensity-modulated radiation therapy (IMRT), create split fields that produce excessive multiple-leaf collimator segments, match-line dose inhomogeneity, and higher treatment times than nonsplit fields. A new method using a fixed-jaw technique (FJT) forces the jaw to stay at a fixed position during optimization and is proposed to reduce problems associated with split fields. Dosimetric comparisons between split-field technique (SFT) and FJT used for IMRT treatment is presented. Five patients with head and neck malignancies and regional target volumes were studied and compared with both techniques. Treatment planning was performed on an Eclipse TPS using beam data generated for Varian 2100C linear accelerator. A standard beam arrangement consisting of nine coplanar fields, equally spaced, was used in both techniques. Institutional dose-volume constraints used in head and neck cancer were kept the same for both techniques. The dosimetric coverage for the target volumes between SFT and FJT for head and neck IMRT plan is identical within ±1% up to 90% dose. Similarly, the organs at risk (OARs) have dose-volume coverage nearly identical for all patients. When the total monitor unit (MU) and segments were analyzed, SFT produces statistically significant higher segments (17.3 ± 6.3%) and higher MU (13.7 ± 4.4%) than the FJT. There is no match line in FJT and hence dose uniformity in the target volume is superior to the SFT. Dosimetrically, SFT and FJT are similar for dose-volume coverage; however, the FJT method provides better logistics, lower MU, shorter treatment time, and better dose uniformity. The number of segments and MU also has been correlated with the whole body radiation dose with long-term complications. Thus, FJT should be the preferred option over SFT for large target volumes.

Autoblocking dose-limiting normal structures within a radiation treatment field: 3-D computer optimization of 'unconventional' field arrangements

International Nuclear Information System (INIS)

Bates, Brian A.; Cullip, Timothy J.; Rosenman, Julian G.

1995-01-01

Purpose/Objective: To demonstrate that one can obtain a homogeneous dose distribution within a specified gross tumor volume (GTV) while severely limiting the dose to a structure surrounded by that tumor volume. We present three clinical examples below. Materials and Methods: Using planning CT scans from previously treated patients, we designed variety of radiation treatment plans in which the dose-critical normal structure was blocked, even if it meant blocking some of the tumor. To deal with the resulting dose inhomogeneities within the tumor, we introduced 3D compensation. Examples presented here include (1) blocking the spinal cord segment while treating an entire vertebral body, (2) blocking both kidneys while treating the entire peritoneal cavity, and (3) blocking one parotid gland while treating the oropharynx in its entirety along with regional nodes. A series of multiple planar and non-coplanar beam templates with automatic anatomic blocking and field shaping were designed for each scenario. Three-dimensional compensators were designed that gave the most homogeneous dose-distribution for the GTV. For each beam, rays were cast from the beam source through a 2D compensator grid and out through the tumor. The average tumor dose along each ray was then used to adjust the compensator thickness over successive iterations to achieve a uniform average dose. DVH calculations for the GTV, normal structures, and the 'auto-blocked' structure were made and used for inter-plan comparisons. Results: These optimized treatment plans successfully decreased dose to the dose-limiting structure while at the same time preserving or even improving the dose distribution to the tumor volume as compared to traditional treatment plans. Conclusion: The use of 3D compensation allows one to obtain dose distributions that are, theoretically, at least, far superior to those in common clinical use. Sensible beam templates, auto-blocking, auto-field shaping, and 3D compensators form a

Standardization of Schwarz-Christoffel transformation for engineering design of semiconductor and hybrid integrated-circuit elements

Science.gov (United States)

Yashin, A. A.

1985-04-01

A semiconductor or hybrid structure into a calculable two-dimensional region mapped by the Schwarz-Christoffel transformation and a universal algorithm can be constructed on the basis of Maxwell's electro-magnetic-thermal similarity principle for engineering design of integrated-circuit elements. The design procedure involves conformal mapping of the original region into a polygon and then the latter into a rectangle with uniform field distribution, where conductances and capacitances are calculated, using tabulated standard mapping functions. Subsequent synthesis of a device requires inverse conformal mapping. Devices adaptable as integrated-circuit elements are high-resistance film resistors with periodic serration, distributed-resistance film attenuators with high transformation ratio, coplanar microstrip lines, bipolar transistors, directional couplers with distributed coupling to microstrip lines for microwave bulk devices, and quasirregular smooth matching transitions from asymmetric to coplanar microstrip lines.

The situation of the wolf (Canis lupus in the area of the Regional Park of the Simbruini Mountains / La situazione del Lupo (Canis lupus nell'area del Parco Naturale Regionale dei Monti Simbruini

Directory of Open Access Journals (Sweden)

Paolo Verucci

1992-07-01

Full Text Available Abstract This work presents the results of a field research on the species Canis lupus in the Regional Park of the Simbruini Mountains. In relation to Wolf conservation, an investigation on feral and free-roving dogs was carried out. The method of snowtracking was used for Wolves and Feral dogs, the method of sighting was used for free-roving dogs. The research underlines the importance of the Simbruini Mountains for the protection of Wolf in central Apennines and the factors, at present, threatening its survival. Riassunto Nel presente lavoro vengono illustrati i risultati di una ricerca sul campo sulla specie Canis lupus nel Parco Naturale Regionale dei Monti Simbruini. In relazione agli aspetti riguardanti la conservazione del Lupo, è stata compiuta un'indagine sul fenomeno del randagismo canino. Per i lupi e i cani inselvatichiti è stato usato il metodo dello snowtracking, per le altre categorie di Cani è stato utilizzato il metodo dell'avvistamento. La ricerca ha messo in luce l'importanza dell'area dei Simbruini per la salvaguardia del Lupo nell'Appennino centrale e i fattori che, attualmente, ne minacciano la sopravvivenza.

The MLC tongue-and-groove effect on IMRT dose distributions

Energy Technology Data Exchange (ETDEWEB)

Deng Jun [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States). E-mail: jun@reyes.stanford.edu; Pawlicki, Todd; Chen Yan; Li Jinsheng; Jiang, Steve B.; Ma, C.-M. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)

2001-04-01

We have investigated the tongue-and-groove effect on the IMRT dose distributions for a Varian MLC. We have compared the dose distributions calculated using the intensity maps with and without the tongue-and-groove effect. Our results showed that, for one intensity-modulated treatment field, the maximum tongue-and-groove effect could be up to 10% of the maximum dose in the dose distributions. For an IMRT treatment with multiple gantry angles ({>=} 5), the difference between the dose distributions with and without the tongue-and-groove effect was hardly visible, less than 1.6% for the two typical clinical cases studied. After considering the patient setup errors, the dose distributions were smoothed with reduced and insignificant differences between plans with and without the tongue-and-groove effect. Therefore, for a multiple-field IMRT plan ({>=} 5), the tongue-and-groove effect on the IMRT dose distributions will be generally clinically insignificant due to the smearing effect of individual fields. The tongue-and-groove effect on an IMRT plan with small number of fields (<5) will vary depending on the number of fields in a plan (coplanar or non-coplanar), the MLC leaf sequences and the patient setup uncertainty, and may be significant (>5% of maximum dose) in some cases, especially when the patient setup uncertainty is small ({<=} 2 mm). (author)

Normal liver tissue sparing by intensity-modulated proton stereotactic body radiotherapy for solitary liver tumours

International Nuclear Information System (INIS)

Petersen, Joergen B. B.; Hansen, Anders T.; Lassen, Yasmin; Grau, Cai; Hoeyer, Morten; Muren, Ludvig P.

2011-01-01

Background. Stereotactic body radiotherapy (SBRT) is often the preferred treatment for the advanced liver tumours which owing to tumour distribution, size and multi-focality are out of range of surgical resection or radiofrequency ablation. However, only a minority of patients with liver tumours may be candidates for conventional SBRT because of the limited radiation tolerance of normal liver, intestine and other normal tissues. Due to the favourable depth-dose characteristics of protons, intensity-modulated proton therapy (IMPT) may be a superior alternative to photon-based SBRT. The purpose of this treatment planning study was therefore to investigate the potential sparing of normal liver by IMPT compared to photon-based intensity-modulated radiotherapy (IMRT) for solitary liver tumours. Material and methods. Ten patients with solitary liver metastasis treated at our institution with multi-field SBRT were retrospectively re-planned with IMRT and proton pencil beam scanning techniques. For the proton plans, two to three coplanar fields were used in contrast to five to six coplanar and non-coplanar photon fields. The same planning objectives were used for both techniques. A risk adapted dose prescription to the PTV surface of 12.5-16.75 Gy x 3 was used. Results. The spared liver volume for IMPT was higher compared to IMRT in all 10 patients. At the highest prescription dose level, the median liver volume receiving less than 15 Gy was 1411 cm 3 for IMPT and 955 cm 3 for IMRT (p D 15 Gy > 700 cm 3 constraint. For the D mean = 15 Gy constraint, nine of 10 cases could be treated at the highest dose level using IMPT whereas with IMRT, only two cases met this constraint at the highest dose level and six at the lowest dose level. Conclusion. A considerable sparing of normal liver tissue can be obtained using proton-based SBRT for solitary liver tumours

Sviluppo e validazione di un antigene-capture ELISA basato su anticorpi monoclonali specifici per Listeria monocytogenes negli alimenti

Directory of Open Access Journals (Sweden)

Rossella Lelli

2011-09-01

Full Text Available È stato standardizzato e validato un dosaggio immunoenzimatico capture ELISA per l’identificazione di Listeria monocytogenes negli alimenti. Il dosaggio è stato messo a punto analizzando campioni di prodotti carnei, ittici e lattiero-caseari, pasta di semola e di farina di grano. Il metodo è risultato specifico al 100% per Listeria spp., con limite di rivelazione di 6,6 × 10(3 cfu/ml. Il metodo L. monocytogenes capture ELISA è stato confrontato con il metodo ufficiale ISO 11290-1:1996 per l’isolamento e l’identificazione di L. monocytogenes in matrici alimentari ottenendo un indice di concordanza significativo. Il dosaggio è stato validato in base alle indicazioni della norma ISO 16140:2003 relativamente ai metodi di analisi qualitativi. Il dosaggio è risultato accurato, specifico, sensibile, selettivo, riproducibile e rapido da eseguire, consentendo nello screening degli alimenti la riduzione di tempi e costi dell’indagine microbiologica.

Capacitive Sensors for Feedback Control of Microfluidic Devices

Science.gov (United States)

Chen, J. Z.; Darhuber, A. A.; Troian, S. M.; Wagner, S.

2003-11-01

Automation of microfluidic devices based on thermocapillary flow [1] requires feedback control and detection techniques for monitoring the location, and ideally also composition and volume of liquid droplets. For this purpose we have developed a co-planar capacitance technique with a sensitivity of 0.07 pF at a frequency of 370 kHz. The variation in capacitance due to the presence of a droplet is monitored by the output frequency of an RC relaxation oscillator consisting of two inverters, one resistor and one capacitor. We discuss the performance of this coplanar sensor as a function of the electrode dimensions and geometry. These geometric variables determine the electric field penetration depth within the liquid, which in our studies ranged from 30 to 450 microns. Numerical solutions for the capacitance corresponding to the exact fabricated geometry agree very well with experimental data. An approximate analytic solution, which ignores fringe field effects, provides a simple but excellent guide for design development. [1] A. A. Darhuber et al., Appl. Phys. Lett. 82, 657 (2003).

Field theory methods applied for the study of superconductivity in one-dimensional systems; Metodos de teoria de campos no estudo da supercondutividade em sistemas unidimensionais

Energy Technology Data Exchange (ETDEWEB)

Martins, M J

1987-12-31

It is shown that the Froehlich`s hamiltonian in one spatial dimension is identical to that of an exactly solvable field Theory. The spectrum of the theory is computed. A critical coupling is found above which the system becomes unstable, indicating a superconducting transition. It is also proposed and investigated a renormalizable relativistic field theory model in two space-time dimensions, with quartic self-interaction among N species of fermions, which undergoes dynamical generation of a superconducting gap and is asymptotically free. A finite temperature is introduced and, for N -> {infinity} a critical value T{sub c} is found above which the gap vanishes. (author).

Influence of ortho-substitution homolog group on polychlorobiphenyl bioaccumulation factors and fugacity ratios in plankton and zebra mussels (Dreissena polymorpha)

Energy Technology Data Exchange (ETDEWEB)

Willman, E.J.; Manchester-Neesvig, J.B.; Agrell, C.; Armstrong, D.E.

1999-07-01

The accumulation of a set of non- and mono-ortho (coplanar) PCB congeners in aquatic ecosystems is of interest due to their dioxin-like toxicities. Chemical properties (octanol-water partition coefficients) suggest that the coplanar congeners may accumulate in organisms to a greater extent than homologs with greater ortho substitution. The authors analyzed a set of 65 PCB congeners with zero to four ortho-chlorines from seven homolog groups in water, suspended particulate matter, and zebra mussels from Green Bay, Wisconsin, USA, on four dates throughout the ice-free season. The suspended particulate matter was separated by size and characterized as phytoplankton or zooplankton using diagnostic carotenoid pigments and light microscopy. Median bioconcentration factors (BCFs) for accumulation from water by phytoplankton and bioaccumulation factors (BAFs) for accumulation from water plus food by zooplankton and zebra mussels ranged from 1 x 10{sup 4} to 1 x 10{sup 6} and were generally the greatest for the tetra- to heptachlorobiphenyls. The average coplanar congener BCFs and BAFs for accumulation from water by phytoplankton, zooplankton, and zebra mussels for the tri-, tetra-, and pentachlorobiphenyls were 54% larger than corresponding values for their homologs. Biomagnification factors (BMFs) of the tetra-, penta-, and hexachlorobiphenyls between zooplankton and zebra mussels and their food source, phytoplankton, typically ranged between 1 and 10, but the average coplanar congener BMFs were 25% less than values for their corresponding homologs. The tendency for coplanar congeners to accumulate to a lesser extent between trophic levels was not as large as their tendency to accumulate from water to a greater extent. Based on accumulation factors, the authors conclude that the dioxin-like tetra- and pentachlorobiphenyls generally accumulate in the phytoplankton, zooplankton, and zebra mussels of the Green Bay ecosystem to a greater extent than other congeners. Fugacity

Rapid Methods of Determining Internal Radioactive Contamination; Methodes Rapides Permettant d'Evaluer la Contamination Radioactive Interne; 0411 042b 0414 ; Metodos Rapidos para Determinar la Contaminacion Radiactiva Interna

Energy Technology Data Exchange (ETDEWEB)

Sedlet, J.; Fairman, W. D.; Robinson, J. J. [Industrial Hygiene and Safety Division, Argonne National Laboratory, Argonne, IL (United States)

1965-06-15

, il est possible de l'atteindre. Les emetteurs alpha et les emetteurs beta purs de faible energie presentent la plus grande difficulte du fait que les charges corporelles de ces nucleides doivent ordinairement etre evaluees par une analyse radiochimique du sang ou des excreta. Les auteurs decrivent les separations radiochimiques qui ont ete mises au point et appliquees au Laboratoire national d*Argonne pour doser rapidement ces emetteurs. Le memoire examine d'autre part certains problemes que pose l'obtention de charges corporelles a partir des taux d'excretion, peu apres l'absorption. Pendant ce laps de temps, l'excretion se modifie rapidement et, pour beaucoup de nucleides importants en l'occurrence, a un taux inconnu. Pour les taux d'absorption tres eleves ou tres bas, il n'est pas necessaire de connaitre immediatement la mesure precise des charges corporelles. Cependant, il existe pour chaque radionucleide une dose d'absorption intermediaire pour laquelle il faut pouvoir -determiner sans trop tarder la charge corporelle avec une precision relative, ce qui permet de decider ou non le traitement. Les auteurs examinent les proprietes et les facteurs qui rendent le dosage des elements osteotropes particulierement difficile dans les cas d'accident. (author) [Spanish] Los metodos aplicables en casos de accidente o en situaciones excepcionales tienen que ser suficientemente rapidos y sensibles para proporcionar resultados en plazos que faciliten el tratamiento eficaz de las personas sobreexpuestas. Los plazos disponibles dependeran, en parte, del numero de individuos irradiados. Si se logra obtener en pocas horas resultados utiles, se habra cumplido la funcion primaria de las mediciones rapidas de la carga corporal, que es la de contribuir en toda la medida de lo posible a reducir los danos debidos .a radionuclidos depositados internamente. Los metodos que se citan a continuacion pueden servir para evaluar la contaminacion interna en casos de accidente: recuento gamma y

Effects of in ovo exposure to PCBs (coplanar congener, kanechlor mixture, hydroxylated metabolite) on the developing cell-mediated immunity in chickens

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, J.; Matsuda, M.; Kawano, M.; Wakimoto, T. [Faculty of Agriculture, Ehime Univ., Matsuyama, Ehime (Japan); Kashima, Y. [Dept. of Hygiene, Yokohama City Univ. School of Medicine, Yokohama (Japan)

2004-09-15

Polychlorinated biphenyls (PCBs) are wide spread environmental contaminants and known to cause various adverse effects on health of human and wildlife. Immune system is one of the several targets for toxic effects of PCBs and its normal balance is often disrupted by the exposure of the compounds. For example, PCBs may induce immune suppression and result in increased susceptibility to bacterial and viral infections, or conversely, excessive immune enhancement may cause adverse outcomes including as autoimmune disease and anergy. Therefore immune function is regarded as one of an important endpoint in toxicological risk assessment. There are a number of studies shown that neonatal organisms perinatally exposed to polyhalogenated aromatic hydrocarbons (PHAHs) such as PCBs have severer effects on their immune system than adult. Dioxins and coplanar PCB congeners, structurally planar PHAHs are known to have high affinity for aryl hydrocarbon receptor (AhR). 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) have the strongest affinity among such compounds and these are considered to act on immune system through AhR. On the other hand, such as non-planar PCB congeners with low affinity for AhR, which are abundantly contained in commercial PCB preparations have non-additive (antagonistic) effects on immune function. Prenatal exposure of TCDD to rodent induced abnormal lymphoid development in the thymus and thymus-dependent immune functions were remarkably disturbed. Although several experimental studies in mammals have been carried out on the developmental immunotoxicity of PCBs, there are still limited information available on avian species. Thus in this study, prenatal exposure to low level of PCBs and the effects on the developing immune system were investigated with chicken as a model animal of avian species, especially it is focused on the cell-mediated immune function.

Noncoplanar VMAT for nasopharyngeal tumors: Plan quality versus treatment time

Energy Technology Data Exchange (ETDEWEB)

Wild, Esther, E-mail: e.wild@dkfz.de; Bangert, Mark [Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); Nill, Simeon [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG (United Kingdom); Oelfke, Uwe [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG, United Kingdom and Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany)

2015-05-15

Purpose: The authors investigated the potential of optimized noncoplanar irradiation trajectories for volumetric modulated arc therapy (VMAT) treatments of nasopharyngeal patients and studied the trade-off between treatment plan quality and delivery time in radiation therapy. Methods: For three nasopharyngeal patients, the authors generated treatment plans for nine different delivery scenarios using dedicated optimization methods. They compared these scenarios according to dose characteristics, number of beam directions, and estimated delivery times. In particular, the authors generated the following treatment plans: (1) a 4π plan, which is a not sequenced, fluence optimized plan that uses beam directions from approximately 1400 noncoplanar directions and marks a theoretical upper limit of the treatment plan quality, (2) a coplanar 2π plan with 72 coplanar beam directions as pendant to the noncoplanar 4π plan, (3) a coplanar VMAT plan, (4) a coplanar step and shoot (SnS) plan, (5) a beam angle optimized (BAO) coplanar SnS IMRT plan, (6) a noncoplanar BAO SnS plan, (7) a VMAT plan with rotated treatment couch, (8) a noncoplanar VMAT plan with an optimized great circle around the patient, and (9) a noncoplanar BAO VMAT plan with an arbitrary trajectory around the patient. Results: VMAT using optimized noncoplanar irradiation trajectories reduced the mean and maximum doses in organs at risk compared to coplanar VMAT plans by 19% on average while the target coverage remains constant. A coplanar BAO SnS plan was superior to coplanar SnS or VMAT; however, noncoplanar plans like a noncoplanar BAO SnS plan or noncoplanar VMAT yielded a better plan quality than the best coplanar 2π plan. The treatment plan quality of VMAT plans depended on the length of the trajectory. The delivery times of noncoplanar VMAT plans were estimated to be 6.5 min in average; 1.6 min longer than a coplanar plan but on average 2.8 min faster than a noncoplanar SnS plan with comparable

Noncoplanar VMAT for nasopharyngeal tumors: Plan quality versus treatment time

International Nuclear Information System (INIS)

Wild, Esther; Bangert, Mark; Nill, Simeon; Oelfke, Uwe

2015-01-01

Purpose: The authors investigated the potential of optimized noncoplanar irradiation trajectories for volumetric modulated arc therapy (VMAT) treatments of nasopharyngeal patients and studied the trade-off between treatment plan quality and delivery time in radiation therapy. Methods: For three nasopharyngeal patients, the authors generated treatment plans for nine different delivery scenarios using dedicated optimization methods. They compared these scenarios according to dose characteristics, number of beam directions, and estimated delivery times. In particular, the authors generated the following treatment plans: (1) a 4π plan, which is a not sequenced, fluence optimized plan that uses beam directions from approximately 1400 noncoplanar directions and marks a theoretical upper limit of the treatment plan quality, (2) a coplanar 2π plan with 72 coplanar beam directions as pendant to the noncoplanar 4π plan, (3) a coplanar VMAT plan, (4) a coplanar step and shoot (SnS) plan, (5) a beam angle optimized (BAO) coplanar SnS IMRT plan, (6) a noncoplanar BAO SnS plan, (7) a VMAT plan with rotated treatment couch, (8) a noncoplanar VMAT plan with an optimized great circle around the patient, and (9) a noncoplanar BAO VMAT plan with an arbitrary trajectory around the patient. Results: VMAT using optimized noncoplanar irradiation trajectories reduced the mean and maximum doses in organs at risk compared to coplanar VMAT plans by 19% on average while the target coverage remains constant. A coplanar BAO SnS plan was superior to coplanar SnS or VMAT; however, noncoplanar plans like a noncoplanar BAO SnS plan or noncoplanar VMAT yielded a better plan quality than the best coplanar 2π plan. The treatment plan quality of VMAT plans depended on the length of the trajectory. The delivery times of noncoplanar VMAT plans were estimated to be 6.5 min in average; 1.6 min longer than a coplanar plan but on average 2.8 min faster than a noncoplanar SnS plan with comparable

Reconocimiento automa?tico a trave?s de visio?n artificial, correlacio?n estadi?stica y Matlab aplicado a las matri?culas de vehi?culos

OpenAIRE

Barcia, Orlando

2014-01-01

Existen muchas investigaciones sobre el reconocimiento de caracteres e ima?genes utilizando diferentes me?todos tales como redes neuronales, me?todos estructurales, basados en la apariencia y otros (Pajares Martinsanz & De La Cruz Garci?a, 2008a). El problema es el reconocimiento automa?tico de caracteres en las placas o matri?culas de los vehi?culos del Ecuador. El trabajo innova en la aplicacio?n de las te?cnicas de visio?n artificial, adaptando el reconocimiento de las matri?culas de los v...

Fiber coupled ultrafast scanning tunneling microscope

DEFF Research Database (Denmark)

Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

1997-01-01

We report on a scanning tunneling microscope with a photoconductive gate in the tunneling current circuit. The tunneling tip is attached to a coplanar transmission line with an integrated photoconductive switch. The switch is illuminated through a fiber which is rigidly attached to the switch...... waveguide. The measurements show that the probe works as a transient voltage detector in contact and a capacitively coupled transient field detector in tunneling mode. We do not measure the transient voltage change in the ohmic tunneling current. In this sense, the spatial resolution for propagating...... substrate. By using a firmly attached fiber we achieve an excellent reproducibility and unconstrained positioning of the tip. We observe a transient signal with 2.9 ps pulse width in tunneling mode and 5 ps in contact mode. The instrument is applied to investigating the mode structure on a coplanar...

Automatic feathering of split fields for step-and-shoot intensity modulated radiation therapy

International Nuclear Information System (INIS)

Dogan, Nesrin; Leybovich, Leonid B; Sethi, Anil; Emami, Bahman

2003-01-01

Due to leaf travel range limitations of the Varian Dynamic Multileaf Collimator (DMLC) system, an IMRT field width exceeding 14.5 cm is split into two or more adjacent abutting sub-fields. The abutting sub-fields are then delivered as separate treatment fields. The accuracy of the delivery is very sensitive to multileaf positioning accuracy. The uncertainties in leaf and carriage positions cause errors in the delivered dose (e.g., hot or cold spots) along the match line of abutting sub-fields. The dose errors are proportional to the penumbra slope at the edge of each sub-field. To alleviate this problem, we developed techniques that feather the split line of IMRT fields. Feathering of the split line was achieved by dividing IMRT fields into several sub-groups with different split line positions. A Varian 21EX accelerator with an 80-leaf DLMC was used for IMRT delivery. Cylindrical targets with varying widths (>14.5 cm) were created to study the split line positions. Seven coplanar 6 MV fields were selected for planning using the NOMOS-CORVUS TM system. The isocentre of the fields was positioned at the centre of the target volume. Verification was done in a 30 x 30 x 30 cm 3 polystyrene phantom using film dosimetry. We investigated two techniques to move the split line from its original position or cause feathering of them: (1) varying the isocentre position along the target width and (2) introduction of a 'pseudo target' outside of the patient (phantom). The position of the 'pseudo target' was determined by analysing the divergence of IMRT fields. For target widths of 14-28 cm, IMRT fields were automatically split into two sub-fields, and the split line was positioned along the centre of the target by CORVUS. Measured dose distributions demonstrated that the dose to the critical structure was 10% higher than planned when the split line crossed through the centre of the target. Both methods of modifying the split line positions resulted in maximum shifts of ∼1 cm

IMRT for Image-Guided Single Vocal Cord Irradiation

Energy Technology Data Exchange (ETDEWEB)

Osman, Sarah O.S., E-mail: s.osman@erasmusmc.nl [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Astreinidou, Eleftheria; Boer, Hans C.J. de; Keskin-Cambay, Fatma; Breedveld, Sebastiaan; Voet, Peter; Al-Mamgani, Abrahim; Heijmen, Ben J.M.; Levendag, Peter C. [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

2012-02-01

Purpose: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques. Methods and Materials: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions. Results: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose {+-} standard deviation to the planning target volume was 67 {+-} 1 Gy. The contralateral vocal cord dose was reduced from 66 {+-} 1 Gy in the conventional plans to 39 {+-} 8 Gy and 36 {+-} 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk. Conclusions: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

IMRT for Image-Guided Single Vocal Cord Irradiation

International Nuclear Information System (INIS)

Osman, Sarah O.S.; Astreinidou, Eleftheria; Boer, Hans C.J. de; Keskin-Cambay, Fatma; Breedveld, Sebastiaan; Voet, Peter; Al-Mamgani, Abrahim; Heijmen, Ben J.M.; Levendag, Peter C.

2012-01-01

Purpose: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques. Methods and Materials: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions. Results: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose ± standard deviation to the planning target volume was 67 ± 1 Gy. The contralateral vocal cord dose was reduced from 66 ± 1 Gy in the conventional plans to 39 ± 8 Gy and 36 ± 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk. Conclusions: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

Esterification and hydrolysis of vitamin A in the liver of brook trout (Salvelinus fontinalis) and the influence of a coplanar polychlorinated biphenyl

International Nuclear Information System (INIS)

Ndayibagira, A.; Spear, P.A.

1999-01-01

Recent reports of extremely low retinoid stores in fish living in contaminated river systems prompted an initial investigation of the mechanisms of hepatic storage and mobilization in brook trout. Enzyme characterization in microsomes revealed a lecithin:retinol acyltransferase activity (LRAT) optimum in the alkaline range (pH 9.0; V max =0.6 nmol per mg prot. h -1 ; K m =10.2 μM) which is not known to occur in mammals, in addition to a secondary optimum at pH 6.5 typical of mammals. Acyl CoA:retinol acyltransferase (ARAT) kinetic parameters were quite different to those of mammals. The substrate affinity of trout ARAT (K m =1.6 μM) was approximately 22-fold greater than that of the rat while maximal velocity (V max =0.2 nmol per mg prot. h -1 ) was 18-fold less. Retinyl ester hydrolase activity (REH) was optimal under acid conditions (pH 4.2; V max =6.6 nmol per mg prot. h -1 ; K m =0.6 mM), was inhibited by a bile salt analogue and was greater in males than females. This REH was tentatively categorized as a bile salt-independent, acid retinyl ester hydrolase (BSI-AREH). REH was inhibited in a dose-dependent manner following in vivo exposure to a representative environmental contaminant the coplanar polychlorinated biphenyl (PCB), 3,3minutes or feet,4,4minutes or feet-tetrachlorobiphenyl (TCBP). Inhibition may be an indirect effect because enzyme activity was not affected by in vitro exposure of control microsomes. REH inhibition in the brook trout may affect the uptake of retinyl esters (REs) from chylomicron remnants as well as the mobilization of stored REs. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

A GENERAL ANALYTICAL APPROACH FOR PRESTRESSED AND NON-PRESTRESSED CONCRETE BEAM-COLUMNS REINFORCED WITH BONDED AND UNBONDED COMPOSITES: (I THEORY

Directory of Open Access Journals (Sweden)

J. A. RODRIGUEZ-GUTIÉRREZ

2011-01-01

Full Text Available Se propone un metodo de analisis que determina la respuesta a corto y largo plazo de vigas columnas de hormigon pretensado y no pretensado reforzado con cualquier combinacion de barras de FRP y/o placas, barras de acero, torones pretensados adheridos o no adheridos. El metodo de analisis propuesto incluye vigas y columnas revestidas con telas FRP y tubos de FRP rellenos de hormigon. Tambien se incluyen los efectos de la rigidez a traccion, fluencia y retraccion del hormigon y la relajacion de la armadura de acero pretensado. Se adoptan los modelos de Vecchio y Collins [1] y de Popovics [2, 3] en las relaciones esfuerzo-deformacion del hormigon a traccion y a compresion, respectivamente. Las relaciones esfuerzo-deformacion de los refuerzos de acero y de FRP se modelan mediante lineas rectas multiples (esto es, lineas poligonales. El metodo de las fibras (modificado es utilizado para calcular los diagramas momento-curvatura a diferentes niveles de la carga axial aplicada (es decir, las curvas M-P-¿Ö y el metodo de Gauss de integracion (para la suma de las contribuciones de los fibras paralelas al eje neutro para calcular las rotaciones laterales y deflexiones a lo largo de la luz de la viga-columna. La validez del modelo propuesto y las ecuaciones correspondientes se pusieron a prueba con datos experimentales disponibles en la literatura tecnica (vease la parte II de esta publicacion.

Double-Sampling Method for Carrying Out Quality Control of a Fabrication Process; Methode du Double Echantillonnage pour le Controle de la Qualite d'un Procede de Fabrication; Metod dvukh obraztsov dlya osushchestvleniya kontrolya za kachestvom v protsesse izgotovleniya; Metodo de Muestreo Doble para el Control de Calidad de un Proceso de Fabricacion

Energy Technology Data Exchange (ETDEWEB)

Cerrolaza, J. A.; Lago, A.; Montojo, Rosa M. [Junta de Energia Nuclear, Madrid (Spain)

1966-02-15

taille des echantillons et le degre de controle sont determines en fonction des risques inherents a la premiere et a la deuxieme condition. Bien que cette methode soit applicable, elle est fort peu pratique quand il s'agit de controler des pieces de reacteurs, car les echantillons qu'elle exige sont de dimensions excessives. Le memoire expose une methode analogue a celle de Cave mais qui consiste a etablir un double echantillonnage dans lequel la taille moyenne de l'echantillon est beaucoup plus reduite. (author) [Spanish] La fabricacion de componentes que han de ser empleados en reactores nucleares presenta dos caracteristicas fundamentales que condicionan el proceso: la exigencia de una calidad muy elevada que limita a valores muy bajos el porcentaje de piezas defectuosas admisibles, y el coste muy alto de cada uno de los componentes. Estas dos condiciones obligan a que el control durante la fabricacion posea una curva de operacion con potencia muy elevada, y, por otra parte, a que el numero de piezas destruidas en cada inspeccion sea un pequeno como se pueda, siempre que se cumpla la condicion anterior. Los metodos usuales de control, basados en fijar el riesgo de primera especie, no son aplicables, ya que en general su eficacia no es suficiente. Cave ha desarrollado un metodo en que, tanto el tamano de las muestras como los limites de control, se fijan en funcion de los riesgos de primera y segunda especie. Este metodo, si bien es aplicable, resulta poco practico en el control de componentes para reactores, ya que se necesitan muestras de un tamano excesivamente grande. En el presente trabajo se desarrolla un metodo semejante al de Cave, pero en el que se establece un muestreo doble, con lo que el tamano medio de la muestra es mucho mas reducido. (author) [Russian] Pri izgotovlenii komponentov dlja ispol'zovanija v reaktorah reshajushhee znachenie imejut dva osnovnyh faktora, a imenno: neobhodimost' obespechit' ochen' vysokoe kachestvo, dopuskajushhee lish' ochen

Lacunarity of geophysical well logs in the Cantarell oil field, Gulf of Mexico

Energy Technology Data Exchange (ETDEWEB)

Arizabalo, Ruben Dario [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Oleschko, Klavdia [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Juriquilla, Queretaro (Mexico); Korvin, Gabor [King Fahd University, Dhahran (Saudi Arabia); Lozada, Manuel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Castrejon, Ricardo [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Ronquillo, Gerardo [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

2006-04-15

Lacunarity and fractal variations in geophysical well logs are associated with stratigraphic and petrophysical properties of the naturally fractured Cantarell field in the Gulf of Mexico. Neutron porosity (NPHI), density (RHOB, DRHO, PEF), resistivity (LLD, LLS, MSFL), natural radioactivity (GR, CGR, URAN, POTA, THOR) and caliper (CALI) logs are studied. The resistivity logs yielded remarkably high lacunarity values, especially in the hydrocarbon source- and reservoir rocks. Lacunarity {delta} was found to depend on the resolution and radial depth of penetration of the logging method. It systematically increased in the following order: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD). [Spanish] En este trabajo fueron analizadas las variaciones fractales y de lagunaridad de los registros geofisicos de pozo, con el fin de asociarlos con las propiedades estratigraficas y petrofisicas del yacimiento naturalmente fracturado de Cantarell, en el Golfo de Mexico. Los registros considerados fueron: porosidad neutron (NPHI), densidad (RHOB, DRHO, PEF), resistividad (LLD, LLS, MSFL), radiactividad natural (GR, CGR, URAN, POTA, THOR) y caliper (CALI). Los registros de resistividad produjeron valores de lagunaridad notablemente altos, especialmente en las rocas generadoras y almacenadoras, a diferencia de los demas registros, cuya homogeneidad de traza implico una baja lagunaridad. Los resultados indican que la lagunaridad observada depende de la resolucion y profundidad radial de penetracion del metodo geofisico estudiado y aumenta sistematicamente en el siguiente orden: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD).

Plan Quality and Treatment Efficiency for Radiosurgery to Multiple Brain Metastases: Non-Coplanar RapidArc vs Gamma Knife

Directory of Open Access Journals (Sweden)

Haisong eLiu

2016-02-01

Full Text Available Objectives: This study compares the dosimetry and efficiency of two modern radiosurgery (SRS modalities for multiple brain metastases (Gamma Knife and LINAC-based RapidArc/volumetric modulated arc therapy, with a special focus on the comparison of low dose spread.Methods: Six patients with three or four small brain metastases were used in this study. The size of targets varied from 0.1 ~ 10.5 cc. SRS doses were prescribed according to size of lesions. SRS plans were made using both Gamma Knife® Perfexion and a single-isocenter, multiple non-coplanar RapidArc®. Dosimetric parameters analyzed included RTOG conformity index (CI, gradient index (GI, 12 Gy isodose volume (V12Gy for each target, and the dose spread (Dspread for each plan. Dspread reflects SRS plan’s capability of confining radiation to within the local vicinity of the lesion and to not spread out to the surrounding normal brain tissues. Each plan has a dose (Dspread, such that once dose decreases below Dspread (on total tissue DVH, isodose volume starts increasing dramatically. Dspread is defined as that dose when volume increase first exceeds 20 cc per 0.1 Gy dose decrease. Results: RapidArc SRS has smaller CI (1.19 ±0.14 vs. 1.50 ± 0.16, p<0.001 and larger GI (4.77 ± 1.49 vs. 3.65 ± 0.98, p <0.01. V12Gy results were comparable (2.73 ± 1.38 cc vs. 3.06 ± 2.20 cc, p = 0.58. Moderate to lower dose spread, V6, V4.5, and V3, were also equivalent. Gamma Knife plans achieved better very low dose spread (≤3 Gy and also had slightly smaller Dspread, 1.9 Gy vs 2.5 Gy. Total treatment time for Gamma Knife is estimated between 60~100 min. Gamma Knife treatments are between 3~5 times longer compared to RapidArc treatment techniques.Conclusion: Dosimetric parameters reflecting prescription dose conformality (CI, dose fall off (GI, radiation necrosis indicator (V12Gy, and dose spread (Dspread were compared between Gamma Knife SRS and RapidArc SRS for multi-mets. RapidArc plans have

UWB Sampler for Wireless Communications and Radar

National Research Council Canada - National Science Library

Han, Jeongwoo; Nguyen, Cam

2005-01-01

An ultra wideband (UWB) sampler, realized using step recovery and Schottky diodes on coplanar waveguide, coplanar strips and slotlines, has been developed for UWB wireless communications and radar systems...

Laser - assisted multiphoton ionization of ground state Li{sup +} by electron and positron impact

Energy Technology Data Exchange (ETDEWEB)

Deb, S Ghosh; Sinha, C, E-mail: srabanti.ghosh@gmail.co, E-mail: chand_sin@hotmail.co [Theoretical Physics Department, Indian Association for the Cultivation of Science, Kolkata - 700032 (India)

2009-11-01

The influence of the laser field on the dynamics of (e, 2e) process of Li{sup +} ion by electron / positron impact is studied for coplanar geometry with laser polarization parallel to the incident momentum. The laser dressed projectile wavefunctions are chosen as Coulomb Volkov (CV) while for ejected electron, modified CV is considered. The target dressing is constructed using the time dependent perturbation theory. Laser field suppresses the FF cross-sections significantly for single photon exchange while for multiple photon exchanges the cross-sections are enhanced. TDCS is quite sensitive with respect to the initial phase of the laser field.

Room temperature microwave-assisted recording on 500-Gbpsi-class perpendicular medium

Science.gov (United States)

Nozaki, Y.; Ishida, N.; Soeno, Y.; Sekiguchi, K.

2012-10-01

Microwave-assisted recording on a 500-Gbpsi-class perpendicular medium was experimentally demonstrated at room temperature. Magnetization reversal under a radio-frequency magnetic field was measured by an electrically shorted coplanar waveguide, which enabled us to evaluate the change in the medium's ferromagnetic resonance spectrum. A frequency-dependent reduction in the switching field was clearly observed in response to a microwave impulse 50 ns in duration. A significant reduction of up to 30% in the coercive field was achieved by applying a microwave impulse with an amplitude of 25 dBm and a frequency of 15 GHz.

Exploring the alignment of carbon nanotubes dispersed in a liquid crystal matrix using coplanar electrodes

International Nuclear Information System (INIS)

Volpati, D.; Massey, M. K.; Kotsialos, A.; Qaiser, F.; Pearson, C.; Tiburzi, G.; Zeze, D. A.; Petty, M. C.; Johnson, D. W.; Coleman, K. S.

2015-01-01

We report on the use of a liquid crystalline host medium to align single-walled carbon nanotubes in an electric field using an in-plane electrode configuration. Electron microscopy reveals that the nanotubes orient in the field with a resulting increase in the DC conductivity in the field direction. Current versus voltage measurements on the composite show a nonlinear behavior, which was modelled by using single-carrier space-charge injection. The possibility of manipulating the conductivity pathways in the same sample by applying the electrical field in different (in-plane) directions has also been demonstrated. Raman spectroscopy indicates that there is an interaction between the nanotubes and the host liquid crystal molecules that goes beyond that of simple physical mixing

Soluciones analiticas AL problema de jets con velocidad de eyeccion variable EN EL tiempo.

Science.gov (United States)

Canto, J.; Raga, A. C.; D'Alessio, P.

1998-11-01

Se presenta un nuevo metodo que permite resolver de manera exacta y analitica las ecuaciones que describen un jet hipersonico con velocidad de eyeccion variable en el tiempo. El metodo se basa en consideraciones sencillas de conservacion de momento para las superficies de trabajo que se forman en el interior del jet. Como ejemplo, se presentan soluciones para jets con variacion sinusoidal en la velocidad de eyeccion, y tambien para el caso de un incremento lineal en el tiempo. Estas soluciones analiticas tienen una clara aplicacion en la interpretacion de las observaciones de jets asociados a objetos Herbig-Haro.

Initiation of conformal radiotherapy with a multileaf-collimator - An approach to clinical routine

International Nuclear Information System (INIS)

Bannach, B.; Doll, Th.; Pape, H.; Schmitt, G.

1995-01-01

The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target Volume (PTV, ICRU 50) results in MLC-field-shaping concerning size, position and contour to PTV-projection in beams-eye-view (BEV). Field prescription with defined leaf positions of the MLC-setting for geometrical beam shaping is transferred from TPS via TCP/IP. Patient treatment with complex coplanar and non-coplanar field arrangements is performed with an automatic set-up for gantry and collimator angle position contolled by a verification system. Quality assurance for treatment set-up is gained with a mega-voltage imaging device (MVI / PHILIPS SRI 100). Actual treatment outcome and accurate dose delivery for conformal therapy is verified by intercomparison of geometrical field matching of MVI and digitally reconstructed radiographs (DRR) for each delivered beam in BEV

Josephson soliton oscillators in a superconducting thin film resonator

DEFF Research Database (Denmark)

Holm, J.; Mygind, Jesper; Pedersen, Niels Falsig

1993-01-01

Josephson soliton oscillators integrated in a resonator consisting of two closely spaced coplanar superconducting microstrips have been investigated experimentally. Pairs of long 1-D Josephson junctions with a current density of about 1000 A/cm2 were made using the Nb-AlOx-Nb trilayer technique....... Different modes of half-wave resonances in the thin-film structure impose different magnetic field configurations at the boundaries of the junctions. The DC I-V characteristic shows zero-field steps with a number of resonator-induced steps. These structures are compared to RF-induced steps generated...

Microwave and Millimeter Wave Properties of Vertically-Aligned Single Wall Carbon Nanotubes Films

Science.gov (United States)

Haddadi, K.; Tripon-Canseliet, C.; Hivin, Q.; Ducournau, G.; Teo, E.; Coquet, P.; Tay, B. K.; Lepilliet, S.; Avramovic, V.; Chazelas, J.; Decoster, D.

2016-05-01

We present the experimental determination of the complex permittivity of vertically aligned single wall carbon nanotubes (SWCNTs) films grown on quartz substrates in the microwave regime from 10 MHz up to 67 GHz, with the electrical field perpendicular to the main axis of the carbon nanotubes (CNTs), based on coplanar waveguide transmission line approach together with the measurement of the microwave impedance of top metalized vertically—aligned SWCNTs grown on conductive silicon substrates up to 26 GHz. From coplanar waveguide measurements, we obtain a real part of the permittivity almost equal to unity, which is interpreted in terms of low carbon atom density (3 × 1019 at/cm3) associated with a very low imaginary part of permittivity (vertically aligned CNTs bundle equivalent to a low resistance reveals a good conductivity (3 S/cm) parallel to the CNTs axis. From these two kinds of data, we experimentally demonstrate the tensor nature of the vertically grown CNTs bundles.

Broadband electron spin resonance from 500 MHz to 40 GHz using superconducting coplanar waveguides

Science.gov (United States)

Clauss, Conrad; Bothner, Daniel; Koelle, Dieter; Kleiner, Reinhold; Bogani, Lapo; Scheffler, Marc; Dressel, Martin

2013-04-01

We present non-conventional electron spin resonance (ESR) experiments based on microfabricated superconducting Nb thin film waveguides. A very broad frequency range, from 0.5 to 40 GHz, becomes accessible at low temperatures down to 1.6 K and in magnetic fields up to 1.4 T. This allows for an accurate inspection of the ESR absorption position in the frequency domain, in contrast to the more common observation as a function of magnetic field. We demonstrate the applicability of frequency-swept ESR on Cr3+ atoms in ruby as well as on organic radicals of the nitronyl-nitroxide family. Measurements between 1.6 and 30 K reveal a small frequency shift of the ESR and a resonance broadening below the critical temperature of Nb, which we both attribute to a modification of the magnetic field configuration due to the appearance of shielding supercurrents in the waveguide.

Methyl 4-(butyrylamino-5-methyl-2-nitrobenzoate

Directory of Open Access Journals (Sweden)

Cheng Yao

2008-04-01

Full Text Available The title compound, C13H16N2O5, is useful as an intermediate in the field of agrochemicals. Intramolecular C—H...O hydrogen bonds result in the formation of one six- and one five-membered nearly planar ring; the six-membered ring is also nearly coplanar with the adjacent benzene ring. In the crystal structure, intermolecular C—H...O hydrogen bonds link the molecules.

On the dynamics of non-stationary binary stellar systems

International Nuclear Information System (INIS)

Bekov, A. A.; Bejsekov, A.N.; Aldibaeva, L.T.

2005-01-01

The motion of test body in the external gravitational field of the binary stellar system with slowly variable some physical parameters of radiating components is considered on the base of restricted non-stationary photo-gravitational three and two bodies problem. The family of polar and coplanar solutions are obtained. These solutions give the possibility of the dynamical and structure interpretation of the binary young evolving stars and galaxies. (author)

Radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma: Dosimetric comparison and risk assessment of solid secondary cancer

Energy Technology Data Exchange (ETDEWEB)

Bae, Sun Hyun; Park, Hee Chul; Lim, Do Hoon [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Dong Wook [Dept. of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of); Kim, Mi Sook [Dept. of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Shin, Myung Hee [Dept. of Social and Preventive Medicine, Sungkyunkwan University School of Medicine, Suwon (Korea, Republic of)

2017-03-15

We compared the dosimetric parameters and the risk of solid secondary cancer from scattered doses among anterior-posterior/posterior-anterior parallel-opposed fields (AP/PA), anterior, posterior, right, and left lateral fields (4{sub f}ield), 3-dimensional conformal radiotherapy (3D-CRT) using noncoplanar beams, and intensity-modulated radiotherapy composed of 7 coplanar beams (IMRT{sub c}o) and 7 coplanar and noncoplanar beams (IMRT{sub n}on). We retrospectively generated 5 planning techniques for 5 patients with gastric MALToma. Homogeneity index (HI), conformity index (CI), and mean doses of the kidney and liver were calculated from the dose-volume histograms. Applied the Biological Effects of Ionizing Radiation VII report to scattered doses, the lifetime attributable risk (LAR) was calculated to estimate the risk of solid secondary cancer. The best value of CI was obtained with IMRT, although the HI varied among patients. The mean kidney dose was the highest with AP/PA, followed by 4{sub f}ield, 3D-CRT, IMRT{sub c}o, and IMRT{sub n}on. On the other hand, the mean liver dose was the highest with 4{sub f}ield and the lowest with AP/PA. Compared with 4{sub f}ield, the LAR for 3D-CRT decreased except the lungs, and the LAR for IMRT{sub c}o and IMRT{sub n}on increased except the lungs. However, the absolute differences were much lower than <1%. Tailored RT techniques seem to be beneficial because it could achieve adjacent organ sparing with very small and clinically irrelevant increase of secondary solid cancer risk compared to the conventional techniques.

Analytic techniques to quantify Tetrachlorohydroquinone and Chloranil; Tecnicas analiticas para cuantificar Tetraclorohidroquinona y Cloranilo

Energy Technology Data Exchange (ETDEWEB)

Castillo Escobedo, Ma. Teresa; Gutierrez de Gonzalez, Luz Ma; Gojon Zorrilla, Gabriel [Universidad Autonoma de Nuevo Leon, Monterrey, Nuevo Leon (Mexico)

1995-02-01

Tetrachlorohydroquinone (TCHQ) was determined by two methods: iodometry and cerimetry. Tritation with aqueous ceric ammonium sulphate using potentiometric end-point detection proved to be the method of choice on account of its coefficient of variation (CV=0.475%) and its excellent accuracy. Chloranil (TCQ) was quantified by titration with aqueous ascorbic acid in acetone-water-hexamethylene tetramine (HMT), the golden-yellow color of the TCQ-HMT complex disappearing at the end point. This method is accurate and has CV=0.396%. [Spanish] Se cuantifico la tetraclorohidroquinona (TCHQ) mediante una tecnica yodometrica y un metodo potenciometrico, basado en el uso de sulfato cerico amoniacal. Se concluyo que el metodo potenciometrico es el mejor, ya que tiene un coeficiente de variacion (CV) de 0.475%, y una exactitud muy aceptable. Se desarrollo un tecnica para cuantificar el Cloranilo (TCQ) por titulacion con Acido Ascorbico en presencia de Hexametilentetramina (HMT) en medio acetona-agua; el punto final se determino por la separacion del color amarillo oro del complejo TCQ-HMT. Esta tecnica presenta un coeficiente de variacion (CV) de 0.396% y una exactitud aceptable. Se realizaron pruebas de hipotesis para verificar la exactitud de los metodos elegidos.

Irreversible magnetic-field dependence of ferromagnetic resonance and inverse spin Hall effect voltage in CoFeB/Pt bilayer

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang-Il [Department of Materials Science and Engineering, Korea University, Seoul, 136-713 (Korea, Republic of); Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of); Seo, Min-Su [Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of); Choi, Yeon Suk, E-mail: ychoi@kbsi.re.kr [Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of); Park, Seung-Young, E-mail: parksy@kbsi.re.kr [Spin Engineering Physics Team, Division of Scientific Instrumentation, Korea Basic Science Institute, Daejeon, 305-806 (Korea, Republic of)

2017-01-01

Magnetic field (H) sweeping direction dependences of the mixed voltage V{sub mix} induced by the inverse-spin Hall effect(ISHE) and spin-rectified effect (SRE) in a CoFeB (5 nm)/Pt (10 nm) bilayer structure are investigated using the ferromagnetic resonance in the TE mode cavities and coplanar waveguide methods. Conventionally, the magnitude of ISHE voltage V{sub ISH} (symmetric) excluding the SRE (antisymmetric component) was unavoidably separated from the fitting curve of V{sub mix} (a sum of a symmetric and an antisymmetric part) for one direction of H-source. By studying the ratio of the two voltage parts with the bi-directional H sweeping, the optimized V{sub ISH} (no SRE condition) value which also include a well-defined spin Hall angle can be obtained via the linear response relation of ISHE and SRE components. - Highlights: • Hysteretic behavior of ferromagnetic resonance spectra in the CoFeB/Pt sample. • Hysteretic behavior of inverse-spin Hall effect voltage in the CoFeB/Pt sample. • Proportion of inverse spin-Hall effect voltage can be determined by the cavity mode. • The hysteretic behavior arise from the unsaturated magnetization limit. • The well-defined spin Hall angle which consider a hysteresis can be obtained.

ELENA MODENA, L'altrOrfeo. Considerazioni analitiche sulla vocalità, Roma, Aracne, 2009

Directory of Open Access Journals (Sweden)

Adriana Guarnieri

2012-11-01

Full Text Available Il volume propone un’indagine sulla vocalità ispirata al «metodo funzionale della voce» di Gisela Rohmert, didatta e fondatrice del Lichtenberger Institut für angewandte Stimmphysiologie, attivo in Germania dal 1982 . Da quell'esperienza – un metodo di pedagogia della voce fondato sullo studio della fisiologia vocale e del «fatto vocale» in quanto evento acustico e stimolo percettivo – Elena Modena ha derivato e illustra in questo libro una sua proposta di «analisi funzionale» della vocalità, storicamente considerata e rivolta, insieme, all’àmbito dell’emissione e a quello dell’ascolto.

CPW to CPS transition for feeding UWB antennas

DEFF Research Database (Denmark)

Butrym, Alexander; Pivnenko, Sergey

2004-01-01

The paper considers a transition (balun) from Coplanar Waveguide (CPW) to Coplanar Stripline (CPS) which is non-resonant and suitable for feeding UWB antennas such as Tapered Slot Antennas (Vivaldi antennas in particular), bow-tie antennas, and other. Some numerical and experimental results...

CPW to CPS transition for feeding UWB antennas

DEFF Research Database (Denmark)

Butrym, Alexander; Pivnenko, Sergey

2006-01-01

The paper considers a transition (balun) from Coplanar Waveguide (CPW) to Coplanar Stripline (CPS) which is non-resonant and suitable for feeding UWB antennas such as Tapered Slot Antennas (Vivaldi antennas, in particular), bow-tie antennas, and other. Some numerical and experimental results...

On the dynamics of non-stationary binary stellar system with non-isotropic mass flow

International Nuclear Information System (INIS)

Bekov, A.A.; Bejsekov, A.N.; Aldibaeva, L.T.

2006-01-01

The motion of test body in the external gravitational field of the binary stellar systems with slowly variable some physical parameters of radiating components is considered on the base of restricted nonstationary photo-gravitational three and two bodies problem with non-isotropic mass flow. The family of polar and coplanar solutions are obtained. The solutions give the possibility of the dynamical and structure interpretation of binary young evolving stars and galaxies. (author)

Determination of heat losses in the Cerro Prieto, Baja California, geothermal field steam transportation network based on the thermal insulation condition of the steam pipelines; Determinacion de perdidas de calor en la red de transporte de vapor del campo geotermico de Cerro Prieto, Baja California, con base en el estado fisico del aislamiento termico de vaporductos

Energy Technology Data Exchange (ETDEWEB)

Ovando Castelar, Rosember; Garcia Gutierrez, Alfonso; Martinez Estrella, Juan Ignacio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; Canchola Felix, Ismael; Jacobo Galvan, Paul; Miranda Herrera, Carlos; Mora Perez, Othon [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)

2011-07-15

In Cerro Prieto Geothermal Field (CPGF), the steam from producing wells is transported to power plants through a large and complex system of pipes thermally insulated with a 2 inches thick mineral wool or a fiber glass layer and an external aluminum or iron cover. The insulation material has been exposed to weather conditions during the field operation and has suffered density and thickness changes. In some cases the insulation has been lost completely, increasing heat transfer from the pipes to the environment. This paper analyzes the impact of the conditions of thermal insulation on heat losses in the CPGF steam-pipeline network. The heat losses are calculated by applying an iterative method to determine the surface temperature based on a heat balance calculated from the three basic mechanisms of heat transfer: conduction, convection, and radiation. Finally, using length and diameter data corresponding to the condition of the thermal insulation of each pipeline-and field operation data, the overall heat losses are quantified for steam lines throughout the pipeline network in the field. The results allow us to evaluate the magnitude of the heat losses in comparison with the overall energy losses occurring during steam transport from wells to the power plants. [Spanish] En el Campo Geotermico de Cerro Prieto (CGCP), BC, el transporte de vapor desde los pozos hasta las plantas generadoras de electricidad se lleva a cabo mediante un extenso y complejo sistema de tuberias que tipicamente se encuentran aisladas termicamente con una capa de 2 pulgadas de material aislante a base de lana mineral o fibra de vidrio, y una proteccion mecanica de aluminio o hierro galvanizado. Debido a la exposicion a las condiciones meteorologicas a traves del tiempo de operacion del campo, el aislamiento ha experimentado cambios en su densidad y espesor y en ocasiones se ha perdido por completo, lo cual repercute en una mayor transferencia de calor de las tuberias hacia el medio ambiente

SU-F-T-207: Does the Greater Flexibility of Pencil Beam Scanning Reduce the Need for a Proton Gantry?

Energy Technology Data Exchange (ETDEWEB)

Yan, S; Depauw, N; Flanz, J; Adams, J; Gorissen, BL; Shih, H; Bortfeld, T; Lu, H [Massachusetts General Hospital and Harvard Medical School, Department of Radiation Oncology, Boston, MA (United States)

2016-06-15

Purpose: Gantry-less proton treatment facility could lower the capital cost of proton therapy. This study investigates the dosimetric feasibility of using only coplanar pencil beam scanning (PBS) beams for those patients who had beam angles that would not have been deliverable without the gantry. Those coplanar beams are implemented on gantry-less horizontal beam-line with patients in sitting or standing positions. Methods: We have selected ten patients (seven head-and-neck, one thoracic, one abdominal and one pelvic case) with clinically delivered double scattering (DS) or PBS treatment plans with beam angles that were challenging to achieve without a gantry. After removing these beams angles, PBS plans were optimized for gantry-less intensity modulated proton therapy (IMPT) or single field optimization (SFO) with multi-criteria optimization (MCO). For head-and-neck patients who were treated by DS, we generated PBS plans with non-coplanar beams for comparison. Dose-volume-histograms (DVHs), target homogeneity index (HI), mean dose, D-2 and D-98 were reported. Robustness analysis was performed with ±2.5 mm setup errors and ±3.5% range uncertainties for three head-and-neck patients. Results: PBS-gantry-less plans provided more homogenous target coverage and significant improvements on organs-at-risk (OARs) sparing, compared to passive scattering treatments with a gantry. The PBS gantry-less treatments reduced the HI for target coverage by 1.3% to 47.2%, except for a suprasellar patient and a liver patient. The PBS-gantry-less plans reduced the D-mean of OARs by 3.6% to 67.4%. The PBS-gantry plans had similar target coverage and only marginal improvements on OAR sparing as compared to the PBS-gantry-less plans. These two PBS plans also had similar robustness relative to range uncertainties and setup errors. Conclusion: The gantry-less plans have with less mean dose to OARs and more homogeneous target coverage. Although the PBS-gantry plans have slightly improved

Determination of charge carrier mobility of hole transporting polytriarylamine-based diodes

International Nuclear Information System (INIS)

Barea, Eva M.; Garcia-Belmonte, Germa; Sommer, Michael; Huettner, Sven; Bolink, Henk J.; Thelakkat, Mukundan

2010-01-01

Hole transport properties of three different side chain poly(triarylamines) have been determined by means of the analysis of steady-state current-voltage characteristics using co-planar diode structures. The interpretation is based on space-charge limited models with field-dependent mobility. Mobilities between ∼ 10 -8 and 10 -6 cm 2 V -1 s -1 are obtained. The highest mobility is achieved for poly(tetraphenylbenzidine) devices and the lowest for poly(triphenylamine) devices. Electron-rich methoxy substituents increase the mobility of poly(triphenylamine)s. A comparison of the mobility values with those obtained using organic field-effect transistors is also given.

Cockpit Displays to Support Hazard Awareness in Free Flight

Science.gov (United States)

Wickens, Christopher D.; Carbonari, Ron; Merwin, Dave; Morphew, Ephimia; OBrien, Janelle V.

1997-01-01

Three experiments are described which each examine different aspects of the formatting and integration of cockpit displays of traffic information to support pilots in traffic avoidance planning. The first two experiments compared two-dimensional (coplanar) with three-dimensional (perspective) versions of a cockpit display of traffic information. In Experiment 1, 30 certified flight instructors flew a series of traffic conflict detection and avoidance maneuvers around an intruder aircraft, sometimes in the presence of a second intruder. The results revealed an advantage for the coplanar display, particularly when there was vertical intruder behavior. In Experiment 2, 17 instructors flew with the coplanar and perspective formats when weather information was either overlaid or displayed separately. Again performance was best with the coplanar display, particularly when the weather data were overlaid. The results of both experiments are also discussed in ten-ns of the traffic maneuver stereotypes exhibited by the pilots. Experiment 3 examined the benefits of the two different predictor elements used in the coplanar displays of Experiments 1 and 2. The study was carried out in a multitask context. These elements were both found to improve safety (reduce actual and predicted conflicts) and to reduce workload, although the different elements affected workload in different ways. Neither predictor element imposed a cost to concurrent task performance.

Valutazione dell'appropriatezza dei ricoveri in un Policlinico Universitario: analisi mediante l'uso comparativo dei sistemi di classificazione isogravitá APR-DRG e Disease Staging e del PRUO

Directory of Open Access Journals (Sweden)

M. Volpe

2003-05-01

Full Text Available

Obiettivi: valutare l’appropriatezza organizzativa dei ricoveri effettuati in un Policlinico Universitario attraverso la comparazione di due metodi, dei quali uno basato sui dati della scheda di dimissione ospedaliera ed utilizza, rispettivamente, i sistemi di classificazione iso-gravità APR-DRG e Disease Staging e l’altro sulla revisione delle cartelle cliniche mediante il PRUO.

Metodi: oggetto di analisi sono i ricoveri ordinari effettuati nell’anno 2001 ed afferenti ai DRG inclusi nella delibera della Giunta Regionale del Lazio 864/2002 che recepisce il D.P.C.M. 29/11/2001 sui livelli essenziali di assistenza.

Risultati: i risultati evidenziano che le due varianti del
metodo basato sulla SDO (metodo APPRO mostrano quote di ricoveri inappropriati sovrapponibili rispetto al complesso dei ricoveri oggetto di analisi, ma con differenze anche rilevanti tra APR-DRG e Disease Staging in relazione ai singoli DRG considerati, riconducibili ai diversi algoritmi di attribuzione del livello di severità utilizzati dai due sistemi. L’analisi campionaria effettuata con il metodo PRUO su casi afferenti ai DRG della DGR 864/2002 caratterizzati da livelli di severità minimi evidenzia una proporzione di ricoveri inappropriati superiore a quella determinata tramite i metodi basati sulla SDO. Tale differenza è verosimilmente dovuta al ruolo del valore delle soglie percentuali di accettabilità individuate dalla Regione Lazio per ciascun DRG: le quote di ricoveri che eccedono tali soglie sono considerate inappropriate.

Conclusioni: sulla base dei risultati ottenuti gli autori
descrivono gli interventi organizzativi adottati per ottimizzare il contesto di erogazione delle prestazioni
oggetto di analisi, discutono vantaggi e limiti dei metodi SDO-based e del metodo analitico PRUObased e ne propongono l�

WE-AB-209-12: Quasi Constrained Multi-Criteria Optimization for Automated Radiation Therapy Treatment Planning

Energy Technology Data Exchange (ETDEWEB)

Watkins, W.T.; Siebers, J.V. [University of Virginia, Charlottesville, VA (United States)

2016-06-15

Purpose: To introduce quasi-constrained Multi-Criteria Optimization (qcMCO) for unsupervised radiation therapy optimization which generates alternative patient-specific plans emphasizing dosimetric tradeoffs and conformance to clinical constraints for multiple delivery techniques. Methods: For N Organs At Risk (OARs) and M delivery techniques, qcMCO generates M(N+1) alternative treatment plans per patient. Objective weight variations for OARs and targets are used to generate alternative qcMCO plans. For 30 locally advanced lung cancer patients, qcMCO plans were generated for dosimetric tradeoffs to four OARs: each lung, heart, and esophagus (N=4) and 4 delivery techniques (simple 4-field arrangements, 9-field coplanar IMRT, 27-field non-coplanar IMRT, and non-coplanar Arc IMRT). Quasi-constrained objectives included target prescription isodose to 95% (PTV-D95), maximum PTV dose (PTV-Dmax)< 110% of prescription, and spinal cord Dmax<45 Gy. The algorithm’s ability to meet these constraints while simultaneously revealing dosimetric tradeoffs was investigated. Statistically significant dosimetric tradeoffs were defined such that the coefficient of determination between dosimetric indices which varied by at least 5 Gy between different plans was >0.8. Results: The qcMCO plans varied mean dose by >5 Gy to ipsilateral lung for 24/30 patients, contralateral lung for 29/30 patients, esophagus for 29/30 patients, and heart for 19/30 patients. In the 600 plans computed without human interaction, average PTV-D95=67.4±3.3 Gy, PTV-Dmax=79.2±5.3 Gy, and spinal cord Dmax was >45 Gy in 93 plans (>50 Gy in 2/600 plans). Statistically significant dosimetric tradeoffs were evident in 19/30 plans, including multiple tradeoffs of at least 5 Gy between multiple OARs in 7/30 cases. The most common statistically significant tradeoff was increasing PTV-Dmax to reduce OAR dose (15/30 patients). Conclusion: The qcMCO method can conform to quasi-constrained objectives while revealing

WE-AB-209-12: Quasi Constrained Multi-Criteria Optimization for Automated Radiation Therapy Treatment Planning

International Nuclear Information System (INIS)

Watkins, W.T.; Siebers, J.V.

2016-01-01

Purpose: To introduce quasi-constrained Multi-Criteria Optimization (qcMCO) for unsupervised radiation therapy optimization which generates alternative patient-specific plans emphasizing dosimetric tradeoffs and conformance to clinical constraints for multiple delivery techniques. Methods: For N Organs At Risk (OARs) and M delivery techniques, qcMCO generates M(N+1) alternative treatment plans per patient. Objective weight variations for OARs and targets are used to generate alternative qcMCO plans. For 30 locally advanced lung cancer patients, qcMCO plans were generated for dosimetric tradeoffs to four OARs: each lung, heart, and esophagus (N=4) and 4 delivery techniques (simple 4-field arrangements, 9-field coplanar IMRT, 27-field non-coplanar IMRT, and non-coplanar Arc IMRT). Quasi-constrained objectives included target prescription isodose to 95% (PTV-D95), maximum PTV dose (PTV-Dmax)< 110% of prescription, and spinal cord Dmax<45 Gy. The algorithm’s ability to meet these constraints while simultaneously revealing dosimetric tradeoffs was investigated. Statistically significant dosimetric tradeoffs were defined such that the coefficient of determination between dosimetric indices which varied by at least 5 Gy between different plans was >0.8. Results: The qcMCO plans varied mean dose by >5 Gy to ipsilateral lung for 24/30 patients, contralateral lung for 29/30 patients, esophagus for 29/30 patients, and heart for 19/30 patients. In the 600 plans computed without human interaction, average PTV-D95=67.4±3.3 Gy, PTV-Dmax=79.2±5.3 Gy, and spinal cord Dmax was >45 Gy in 93 plans (>50 Gy in 2/600 plans). Statistically significant dosimetric tradeoffs were evident in 19/30 plans, including multiple tradeoffs of at least 5 Gy between multiple OARs in 7/30 cases. The most common statistically significant tradeoff was increasing PTV-Dmax to reduce OAR dose (15/30 patients). Conclusion: The qcMCO method can conform to quasi-constrained objectives while revealing

The need of alkalinity determination in the characterization of rain; Necesidad de la determinacion de la alcalinidad en la caracterizacion de la lluvia

Energy Technology Data Exchange (ETDEWEB)

Pal Verma, Mahendra [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-01-01

In this paper is presented the alkalinity determination of the carbonic species in the rain waters by the Gran titration method. The alkalinity values obtained by this method in low electric conductivity waters are fairly reliable. Also, the existing studies on the characterization of acid rains, are discussed. [Espanol] En este trabajo se presenta la medicion de la alcalinidad y la determinacion de las especies carbonicas en las aguas de lluvia por el metodo de la titulacion de Gran. Los valores de alcalinidad obtenidos por este metodo en las aguas de baja conductividad electrica son bastante confiables. Asimismo, se discuten los estudios existentes sobre la caracterizacion de la lluvia acida en la republica mexicana.

A New Technique for Whole Craniospinal Irradiation (WCSI)

International Nuclear Information System (INIS)

Chang, Hye Sook

1991-01-01

To irradiate the entire neuroaxis, bilateral parallel opposed brain fields and direct posterior spinal field have been utilized and radiation dose at the junction between abutting fields has been extensilvely studied. And several workable methods were reported to achieve uniform dose at a desired depth at the junction between abutting fields whose central axis are coplanar. But the dose distribution at the junction of orthogonal fields has been a persistent problem in radiation oncology. Author describes a new method to solve the junction problem between abutting fields whose central axis are orthogonal. Author utilized split beam/collimator rotation or collimator/couch rotation to avoid hot or cold spots that may arise from beam divergence. Author achieved accurate and homogeneous dose distribution by matching the 50% isodose line at the junction between orthogonal central axis beam fields

White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

Science.gov (United States)

Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

2014-06-01

White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 104 ≤ Q ≤ 2 × 104 and the square root of spectral density of current noise referred to the SQUID input √SI = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers PMR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √SI is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of PMR) or the quantization noise due to the resolution of 300-K electronics (for large values of PMR). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit √SI ≤ 5 pA/√Hz, i.e., close to √SI of

White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

International Nuclear Information System (INIS)

Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

2014-01-01

White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 10 4  ≤ Q ≤ 2 × 10 4 and the square root of spectral density of current noise referred to the SQUID input √S I  = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S 21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers P MR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √S I is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of P MR ) or the quantization noise due to the resolution of 300-K electronics (for large values of P MR ). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit �

Co-sputtered MoRe as carbon nanotube growth-compatible superconductor

Energy Technology Data Exchange (ETDEWEB)

Goetz, Karl; Blien, Stefan; Stiller, Peter; Vavra, Ondrej; Mayer, Thomas; Huber, Thomas; Meier, Thomas; Kronseder, Matthias; Strunk, Christoph; Huettel, Andreas [Institute for Experimental and Applied Physics, University of Regensburg (Germany)

2016-07-01

Molybdenum rhenium alloys exhibit superconducting transition temperatures up to 15 K as well as high critical current densities. In addition, the thin films are stable under typical carbon nanotube CVD growth conditions, i.e., a hydrogen/methane atmosphere at 900 C, and form good contacts in nanotube overgrowth. This makes them predestined for experiments integrating ''ultraclean'' carbon nanotube devices into coplanar radiofrequency circuits, towards quantum nano-electromechanics and information processing. MoRe thin films are deposited via co-sputtering of two separate targets. The resulting thin film composition and its controllability is verified via XPS spectroscopy both before and after undergoing nanotube growth conditions. The effects of the high temperature process on surface oxides, carbon content, superconducting critical temperature, magnetic field, and current are characterized. Selecting an optimized alloy composition, we define coplanar waveguide resonators, demonstrating resonant behaviour after CVD at f ∼ 3.. 4 GHz and up to Q{sub i} ∼ 5000. Modelling device properties via Mattis-Bardeen theory combined with substrate two-level systems leads to good agreement with the data.

Proposed method for the hydraulic design of ski-jump energy dissipators in dam spillways considering the occurrence of scour holes downstream of the structure; Metodo propuesto para el diseno hidraulico de trampolines empleados como disipadores de energia en aliviaderos para presas, considerando la ocurrencia del cono de socavacion al pie del mismo

Energy Technology Data Exchange (ETDEWEB)

Pardo-Gomez, Rafael [Centro de Investigaciones Hidraulicas (Cuba)

2008-04-15

Ski-jump energy dissipators are widely used in hydraulic engineering because of their well-known effectiveness. Nevertheless, some uncertainty exits associated with the dimensions of the scour hole appearing downstream of the structure. This paper presents a new method for solving this problem. This method includes spillway stability checking as part of the design process and also stability checking of any other construction near the energy dissipation zone. [Spanish] Los disipadores de energia tipo trampolin tienen amplia utilizacion en la practica de la ingenieria hidraulica por su probada eficacia; sin embargo, su diseno esta sujeto a cierto grado de incertidumbre en cuanto a la prediccion de las dimensiones del cono de socavacion que habra de producirse aguas abajo de la estructura. En el presente trabajo se muestra un metodo novedoso, mediante el cual el autor soluciona el aspecto antes referido, toda vez que se incluye como parte del proceso de diseno la comprobacion de la estabilidad del propio aliviadero o de cualquier otra obra cercana a la zona de disipacion de energia.

Planning the expansion of electrical transmission networks with evolutionary programming; Planeacion de la expansion de redes de transmision electrica con programacion evolucionaria

Energy Technology Data Exchange (ETDEWEB)

Ceciliano Meza, Jose Luis

1997-12-31

In this work it is presented for the first time in the literature the solution of the problem of the planning the expansion of an electrical transmission network (PERTE) with the use of the Evolutionary Programming. The evolutionary programming is a stochastic method of optimization with similar characteristics to the generic algorithms, but different. During the development of this work it is shown what each one of these two heuristic methods of optimization consist of. Additionally, the main characteristics of other two heuristic methods known in the literature are described (Tabu Searching and Simulated Annealing). These two methods together with the genetic algorithms and decomposition of Benders have also been used to solve the problem of planning PERTE. The operation of the proposed algorithm of evolutionary programming was tested in two networks of electrical transmission. The first case of test is a system which is known in the literature. The second case is a representative system of the electrical transmission network of Central America. The results obtained improve all the results shown when applying different heuristic methods of optimization (genetic algorithms, simulated annealing and Tabu searching) to solve the same problem. [Espanol] En este trabajo se presenta por primera vez en la literatura, la solucion del problema de la planeacion de expansion de una red de transmision electrica (PERTE) con el uso de la Programacion Evolucionaria. La programacion evolucionaria es un metodo estocastico de optimizacion con caracteristicas similares a los algoritmos geneticos, pero diferente. Durante el desarrollo de este trabajo se muestra en que consiste cada uno de estos dos metodos heuristicos de optimizacion. Ademas, se describen las caracteristicas principales de otros dos metodos heuristicos conocidos en la literatura (busqueda Tabu y Recorrido Simulado). Estos dos metodos juntos con los algoritmos geneticos y descomposicion de Benders tambien han sido

MINIMUM BRACING STIFFNESS FOR MULTI-COLUMN SYSTEMS: THEORY

Directory of Open Access Journals (Sweden)

J. DARÍO ARISTIZÁBAL-OCHOA

2011-01-01

Full Text Available Se propone un metodo que determina la rigidez minima de arrostramiento requeridos por un sistema elastico de varias columnas para lograr condiciones de pandeo sin deriva entre pisos. Las ecuaciones que evaluan la rigidez minima requerida de los arrostramientos laterales y de torsion y la carga critica de pandeo ¡§arriostrada¡¨ correspondiente para cada columna del nivel de piso se obtienen utilizando las funciones de estabilidad modificadas. Se incluyen los siguientes efectos: 1 tipos de conexiones (rigidas, semirrigidas y simples, 2 la distribucion en planta de las columnas (es decir, la orientacion de la seccion transversal y la ubicacion del centro de gravedad de cada columna, 3 deformaciones por cortante a lo largo de cada columna mediante el metodo modificado propuesto por Haringx en 1948, y 4 distribucion de la carga axial entre las columnas (es decir, el patron de carga. Los efectos de las deformaciones axial y de torsion no estan incluidos. El metodo propuesto es aplicable a estructuras 2D y 3D con conexiones rigidas, semirigidas y simple. La formulacion se presenta en este documento se basa en un trabajo previo presentado por Aristizabal-Ochoa en 2007. Se demuestra que la rigidez minima de los arrostramientos laterales y de torsion requeridos por un sistema de varias columnas depende de: 1 la distribucion en planta las columnas; 2 la variacion en altura y propiedades de la seccion transversal de las columnas; 3las rigideces a flexion y a cortante de cada columna; 4 el patron de cargas en el sistema de columnas; 5 la falta de simetria (en el patron de carga, en la disposicion de las columnas, tamanos de las columnas, y sus alturas que hacen que el pandeo combinado de torsion y flexion lateral pueden reducir la capacidad de pandeo critico de la estructura en su conjunto; y 6 las condiciones de apoyo y restricciones en el extremo superior de las columnas. El metodo propuesto se limita a sistemas multi-columna con columnas elasticas y

Perinatal exposure to dioxins perturbs learning performance of the rat in a dose-specific fashion

Energy Technology Data Exchange (ETDEWEB)

Hojo, R.; Rieko, H.; Masaki, K.; Junzo, Y.; Chiharu, T. [National Inst. for Environmental Studies, Tsukuba (Japan)

2004-09-15

Dioxins (chlorinated dibenzo-p-dioxin congeners and related compounds including coplanar PCBs) are transferred transplacentally and lactationally from mothers to the developing brain of offspring. Maternal exposure to dioxins are suspected to cause adverse effects on the advanced brain function of offspring, because Previous studies indicate that the most toxic dioxin congener, 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD), affected the advanced brain function of rats, even when mothers had been exposed to a relatively low level of dioxins that would not affect themselves. In coplanar PCBs, which are dioxin-like, toxic equivalency factors (TEFs) are based on similar toxicity to TCDD and on a common mechanism of action, mediated by the aromatic hydrocarbon receptor (AhR). However, non-coplanar PCBs, which are considered to be non-dioxin-like PCBs, also show adverse effects on the learning and memory functions of offspring. In the present study, we hypothesize that coplanar PCBs have two types of toxicities, one is the similar to TCDD and the other is the specific toxicity of PCB itself. To address this hypothesis, effects of maternal exposure to one of the coplanar PCBs, 3,3',4,4',5-pentachlorobiphenyl (PCB126, 1997 WHO TEF = 0.1), on learning and behavioural performance of rats assessed by schedule-controlled operant behavior (SCOB) were examined and compared to TCDD.

Development of a chromatographic method for the study of the stability and compatibility of Mexican fuel oils; Desarrollo de un metodo cromatografico para el estudio de estabilidad y compatibilidad de combustoleos mexicanos

Energy Technology Data Exchange (ETDEWEB)

Blass Amador, Georgina; Panama Tirado, Luz Angelica [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1992-11-01

compatibility of fuel oil mixes. [Espanol] En Mexico, la mayoria de la energia electrica producida proviene del uso de combustibles residuales pesados conocidos como combustoleos los cuales han sufrido disminuciones en la calidad debido a una combinacion de factores, entre los que destaca el de los cambios en el proceso de refinacion. Es necesario desarrollar metodos que sean capaces de indicar la inestabilidad (formacion de sedimento o incremento en viscosidad durante el almacenamiento o calentamiento) o incompatibilidad (formacion de sedimento al mezclar dos o mas) de los combustoleos utilizados en las centrales termoelectricas. El objetivo de este trabajo fue el desarrollar una prueba alternativa para el estudio de la compatibilidad y/o estabilidad de combustoleos mexicanos empleando cromatografia de liquidos de alta resolucion (CLAR) y asi poder determinar aspectos estructurales del combustoleo que determinan su estabilidad. Dado que la formacion de sedimentos ocurre cuando el poder disolvente del combustible es inadecuado para mantener los asfaltenos en solucion, es importante conocer la medida del poder disolvente o aromaticidad del diluyente; asi pues, la primera parte de este trabajo se centro en la determinacion del perfil de compuestos aromaticos de los diluyentes de los combustoleos, la otra parte se dedico a la determinacion del perfil de distribucion de los pesos moleculares de los asfaltenos presentes en los combustoleos. Los perfiles de la fraccion aromatica, asi como los de distribucion de pesos moleculares se determinaron empleando cromatografia de liquidos, en la que se empleo una variedad de columnas y de disolventes. Se efectuo una combinacion de pruebas de rutina tales como contenido de asfaltenos, equivalencia de tolueno, viscosidad, etcetera con el fin de obtener correlaciones con el metodo cromatografico desarrollado. En este articulo se discute solo la seccion correspondiente a la obtencion del perfil de contenidos de aromaticos de los combustoleos. Se

Dosimetric comparison of intensity modulated radiotherapy techniques and standard wedged tangents for whole breast radiotherapy

International Nuclear Information System (INIS)

Fong, Andrew; Bromley, Regina; Beat, Mardi; Vien, Din; Dineley, Jude; Morgan, Graeme

2009-01-01

Full text: Prior to introducing intensity modulated radiotherapy (IMRT) for whole breast radiotherapy (WBRT) into our department we undertook a comparison of the dose parameters of several IMRT techniques and standard wedged tangents (SWT). Our aim was to improve the dose distribution to the breast and to decrease the dose to organs at risk (OAR): heart, lung and contralateral breast (Contra Br). Treatment plans for 20 women (10 right-sided and 10 left-sided) previously treated with SWT for WBRT were used to compare (a) SWT; (b) electronic compensators IMRT (E-IMRT); (c) tangential beam IMRT (T-IMRT); (d) coplanar multi-field IMRT (CP-IMRT); and (e) non-coplanar multi-field IMRT (NCP-IMRT). Plans for the breast were compared for (i) dose homogeneity (DH); (ii) conformity index (CI); (iii) mean dose; (iv) maximum dose; (v) minimum dose; and dose to OAR were calculated (vi) heart; (vii) lung and (viii) Contra Br. Compared with SWT, all plans except CP-IMRT gave improvement in at least two of the seven parameters evaluated. T-IMRT and NCP-IMRT resulted in significant improvement in all parameters except DH and both gave significant reduction in doses to OAR. As on initial evaluation NCP-IMRT is likely to be too time consuming to introduce on a large scale, T-IMRT is the preferred technique for WBRT for use in our department.

Asymmetric kinetic equilibria: Generalization of the BAS model for rotating magnetic profile and non-zero electric field

Science.gov (United States)

Dorville, Nicolas; Belmont, Gérard; Aunai, Nicolas; Dargent, Jérémy; Rezeau, Laurence

2015-09-01

Finding kinetic equilibria for non-collisional/collisionless tangential current layers is a key issue as well for their theoretical modeling as for our understanding of the processes that disturb them, such as tearing or Kelvin Helmholtz instabilities. The famous Harris equilibrium [E. Harris, Il Nuovo Cimento Ser. 10 23, 115-121 (1962)] assumes drifting Maxwellian distributions for ions and electrons, with constant temperatures and flow velocities; these assumptions lead to symmetric layers surrounded by vacuum. This strongly particular kind of layer is not suited for the general case: asymmetric boundaries between two media with different plasmas and different magnetic fields. The standard method for constructing more general kinetic equilibria consists in using Jeans theorem, which says that any function depending only on the Hamiltonian constants of motion is a solution to the steady Vlasov equation [P. J. Channell, Phys. Fluids (1958-1988) 19, 1541 (1976); M. Roth et al., Space Sci. Rev. 76, 251-317 (1996); and F. Mottez, Phys. Plasmas 10, 1541-1545 (2003)]. The inverse implication is however not true: when using the motion invariants as variables instead of the velocity components, the general stationary particle distributions keep on depending explicitly of the position, in addition to the implicit dependence introduced by these invariants. The standard approach therefore strongly restricts the class of solutions to the problem and probably does not select the most physically reasonable. The BAS (Belmont-Aunai-Smets) model [G. Belmont et al., Phys. Plasmas 19, 022108 (2012)] used for the first time the concept of particle accessibility to find new solutions: considering the case of a coplanar-antiparallel magnetic field configuration without electric field, asymmetric solutions could be found while the standard method can only lead to symmetric ones. These solutions were validated in a hybrid simulation [N. Aunai et al., Phys. Plasmas (1994-present) 20

Asymmetric kinetic equilibria: Generalization of the BAS model for rotating magnetic profile and non-zero electric field

International Nuclear Information System (INIS)

Dorville, Nicolas; Belmont, Gérard; Aunai, Nicolas; Dargent, Jérémy; Rezeau, Laurence

2015-01-01

Finding kinetic equilibria for non-collisional/collisionless tangential current layers is a key issue as well for their theoretical modeling as for our understanding of the processes that disturb them, such as tearing or Kelvin Helmholtz instabilities. The famous Harris equilibrium [E. Harris, Il Nuovo Cimento Ser. 10 23, 115–121 (1962)] assumes drifting Maxwellian distributions for ions and electrons, with constant temperatures and flow velocities; these assumptions lead to symmetric layers surrounded by vacuum. This strongly particular kind of layer is not suited for the general case: asymmetric boundaries between two media with different plasmas and different magnetic fields. The standard method for constructing more general kinetic equilibria consists in using Jeans theorem, which says that any function depending only on the Hamiltonian constants of motion is a solution to the steady Vlasov equation [P. J. Channell, Phys. Fluids (1958–1988) 19, 1541 (1976); M. Roth et al., Space Sci. Rev. 76, 251–317 (1996); and F. Mottez, Phys. Plasmas 10, 1541–1545 (2003)]. The inverse implication is however not true: when using the motion invariants as variables instead of the velocity components, the general stationary particle distributions keep on depending explicitly of the position, in addition to the implicit dependence introduced by these invariants. The standard approach therefore strongly restricts the class of solutions to the problem and probably does not select the most physically reasonable. The BAS (Belmont-Aunai-Smets) model [G. Belmont et al., Phys. Plasmas 19, 022108 (2012)] used for the first time the concept of particle accessibility to find new solutions: considering the case of a coplanar-antiparallel magnetic field configuration without electric field, asymmetric solutions could be found while the standard method can only lead to symmetric ones. These solutions were validated in a hybrid simulation [N. Aunai et al., Phys. Plasmas (1994-present

Preliminary report on electromagnetic model studies

Science.gov (United States)

Frischknecht, F.C.; Mangan, G.B.

1960-01-01

More than 70 resopnse curves for various models have been obtained using the slingram and turam electromagnetic methods. Results show that for the slingram method, horizontal co-planar coils are usually more sensitive than vertical, co-axial or vertical, co-planar coils. The shape of the anomaly usually is simpler for the vertical coils.

Determination of charge carrier mobility of hole transporting polytriarylamine-based diodes

Energy Technology Data Exchange (ETDEWEB)

Barea, Eva M. [Photovoltaic and Optoelectronic Devices Group, Departament de Fisica, Universitat Jaume I, 12071 Castello (Spain); Garcia-Belmonte, Germa, E-mail: garciag@uji.e [Photovoltaic and Optoelectronic Devices Group, Departament de Fisica, Universitat Jaume I, 12071 Castello (Spain); Sommer, Michael; Huettner, Sven [Applied Functional Polymers, Universitaet Bayreuth, 95440 Bayreuth (Germany); Bolink, Henk J. [Molecular Science Institute-Universitat de Valencia, Poligon La Coma s/n, 46980 Paterna, Valencia (Spain); Thelakkat, Mukundan, E-mail: mukundan.thelakkat@uni-bayreuth.d [Applied Functional Polymers, Universitaet Bayreuth, 95440 Bayreuth (Germany)

2010-04-02

Hole transport properties of three different side chain poly(triarylamines) have been determined by means of the analysis of steady-state current-voltage characteristics using co-planar diode structures. The interpretation is based on space-charge limited models with field-dependent mobility. Mobilities between {approx} 10{sup -8} and 10{sup -6} cm{sup 2} V{sup -1} s{sup -1} are obtained. The highest mobility is achieved for poly(tetraphenylbenzidine) devices and the lowest for poly(triphenylamine) devices. Electron-rich methoxy substituents increase the mobility of poly(triphenylamine)s. A comparison of the mobility values with those obtained using organic field-effect transistors is also given.

TH-EF-BRB-03: Significant Cord and Esophagus Dose Reduction by 4π Non-Coplanar Spine Stereotactic Body Radiation Therapy and Stereotactic Radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Yu, V; Tran, A; Nguyen, D; Woods, K; Cao, M; Kaprealian, T; Chin, R; Low, D; Sheng, K [UCLA, Los Angeles, CA (United States)

2016-06-15

Purpose: To demonstrate significant organ-at-risk (OAR) sparing achievable with 4π non-coplanar radiotherapy on spine SBRT and SRS patients. Methods: Twenty-five stereotactic spine cases previously treated with VMAT (n = 23) or IMRT (n = 2) were included in this study. A computer-aided-design model of a Linac with a 3D-scanned human surface was utilized to determine the feasible beam space throughout the 4π steradian and beam specific source-to-target-distances (STD) required for collision avoidance. 4π radiotherapy plans integrating beam orientation and fluence map optimization were then created using a column-generation algorithm. Twenty optimal beams were selected for each case. To evaluate the tradeoff between dosimetric benefit and treatment complexity, 4π plans including only isocentrically deliverable beams were also created. Beam angles of all standard and isocentric 4π plans were imported into Eclipse to recalculate the dose using the same calculation engine as the clinical plans for unbiased comparison. OAR and PTV dose statistics for the clinical, standard-4π, and isocentric-4π plans were compared. Results: Comparing standard-4π to clinical plans, particularly significant average percent reduction in the [mean, maximum] dose of the cord and esophagus of [41%, 21.7%], and [38.7%, 36.4%] was observed, along with global decrease in all other OAR dose statistics. The average cord volume receiving more than 50% prescription dose was substantially decreased by 76%. In addition, improved PTV coverage was demonstrated with a maximum dose reduction of 0.93% and 1.66% increase in homogeneity index (D95/D5). All isocentric-4π plans achieved dosimetric performance equivalent to that of the standard-4π plans with higher delivery complexity. Conclusion: 4π radiotherapy significantly improves stereotactic spine treatment dosimetry. With the substantial OAR dose sparing, PTV dose escalation is considerably safer. Isocentric-4π is sufficient to achieve the

Design and construction of a live insulator washing system for transformers; Diseno y construccion de un sistema de lavado en vivo para los aisladores de transformadores

Energy Technology Data Exchange (ETDEWEB)

Lizama-Camara, Y.A. [Universidad Veracruzana, Veracruz (Mexico)]. E-mail: yahir_lizama@ieee.org; Mendieta-Antunez, J.A.; Blanco-Brisset, E. [Industrias IEM, Tlalnepantla, Estado de Mexico (Mexico)]. E-mail: unamanu@hotmail.com; Olivares Galvan, J.C.; Escarela-Perez, R. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D.F. (Mexico)]. E-mails: jolivare_1999@yahoo.com; r.escarela@ieee.org

2012-04-15

Through the electrical industry history there have been developments of different cleaning methods to avoid the insulators flashover s due to pollution. This paper describes the principal cleaning methods applicable to transformers insulators, emphasizing the high pressure fixed-type live insulator washing method, which was applied for cleaning the insulators of 900 MVA transformer bank of the Laguna Verde power plant localized at the state of Veracruz in Mexico. We propose a transformer insulator cleaning methodology, which identifies the main variables to take into account (the voltage level of the transformers, the pollution level of the insulators, determination of the optimal wash time, the amount of water, the optimal pressure of water jet, the maximum conductivity of the water and the wind velocity), reference values are given for these variables. In addition, we present an economic cost analysis when applying a method of this kind in an electric substation. [Spanish] A lo largo de la historia de la industria electrica se han desarrollado diferentes metodos de limpieza para evitar las fallas de los aisladores de los transformadores debido a la contaminacion. Este articulo describe los principales metodos de limpieza aplicables a los aisladores de transformadores, enfatizando el sistema de lavado en vivo tipo fijo con agua a alta presion, metodo que fue aplicado para realizar la limpieza de los aisladores en el banco de transformadores de 900 MVA de la central electrica Laguna Verde, ubicada en el estado de Veracruz, en Mexico. Se propone una metodologia para la limpieza de los aisladores de transformadores, donde se identifican las principales variables a tomar en cuenta (el nivel de tension de los transformadores, nivel de contaminacion de los aisladores, determinacion del tiempo optimo de lavado, cantidad de precipitacion de agua, presion optima del chorro de agua, maxima conductividad del agua y las velocidades de los vientos) y se dan valores de

Fundamentos del metodo cientifico

Directory of Open Access Journals (Sweden)

Badii, M. H.

2004-01-01

Full Text Available El objetivo de esta obra no radica en realizar una búsqueda exhaustiva de la literatura en el tema, sino, sentar las bases del método científico, notando los aspectos filosóficos e éticos de la ciencia. Se presentan los conceptos y definiciones fundamentales relacionados con la metodología de la investigación científica. Se maneja el concepto de la toma de los datos válidos como un requisito básico en cualquier trabajo científico. Se pone a disposición del lector un modelo denominado el ECOEE que es una herramienta poderosa para establecer puntos de comparación e discusión entre los resultados de diferentes trabajos científicos. Finalmente, ofrece unas sugerencias de que hacer o no hacer en cuanto a realizar un trabajo de investigación.

Mathematics and history: history and analysis epistemology: from exhaustion method to defined integral

Directory of Open Access Journals (Sweden)

Mario Mandrone

2015-06-01

Full Text Available The creation of the calculation (differential, in the terminology of Leibniz, bending in that of Newton is the event that, in the second half of the seventeenth century, marked, in a sense, the transition from classical to modern mathematics. The aim of this work is a historical analysis of the rigor and epistemological question and the "metaphysics" of calculus that takes account of the methods of the ancient (eg. Of Archimedes' method of exhaustion, as well as interpretations of Leibniz and Newton and their successors. The problem of searching for a sure foundation on which to base the calculus, glimpsed by D'Alembert in the theory of limits and taken up by Lagrange to the theory of infinite series, and that the derivative functions, found in Cachy the pioneer of a new way to seek rigor in analysis. The Cauchy setting will be tightened by Weierstrass in the second half of the 800 with the definition of limit, with the epsilon-delta method, which in turn is based on definitions concerning the real numbers. In this sense we speak of "arithmetisation" analysis.         Matematica e storia: storia ed epistemologia dell’analisi: dal metodo  di esaustione  all’integrale  definito La creazione del calcolo (differenziale, nella terminologia leibniziana flessionale in quella di Newton è l’evento che, nella seconda metà del seicento, ha segnato, in un certo senso, il passaggio dalla matematica classica a quella moderna. Obiettivo del presente lavoro è una analisi storica ed epistemologica della questione del rigore e della “metafisica” del calcolo infinitesimale che tenga conto dei metodi degli antichi (ad es.  del metodo di esaustione di Archimede, nonché delle interpretazioni di Leibniz e Newton e dei loro successori. Il problema della ricerca di un fondamento sicuro su cui basare il calcolo infinitesimale, intravisto da D’Alembert nella teoria dei limiti e ripreso da Lagrange con la teoria delle serie infinite e quella delle

Development of sialons colloidally processed in aqueous medium

Science.gov (United States)

Pereira, Catarina Alexandra Goncalves

Desenvolveu-se um novo metodo de processamento coloidal em meio aquoso para consolidar cerâmicos de ?-Y-SiAlON, os quais foram sinterizados por prensagem isostatica a quente (HIP) e por spark plasma sintering (SPS). Preparou-se com sucesso uma suspensao aquosa de pos precursores de YSiAlON (Si3N4, Al2O3, Y2O3 e AlN), temporariamente estavel, usando Dolapix PC21 como dispersante, permitindo a fabricacao de pos granulados pela tecnica de aspersao-congelamento-liofilizacao e a consolidacao de corpos em verde por enchimento por barbotina. Avaliou-se o efeito do excesso de oxigenio introduzido pelo processamento aquoso no desenvolvimento microestrutural e nas propriedades mecânicas. Os corpos de Y-SiAlON consolidados por enchimento por barbotina e sinterizados por HIP a 1800ºC apresentaram microestruturas e propriedades mecânicas similares a corpos consolidados por prensagem a seco. Estes materiais exibiram densificacao completa, dureza Vickers maxima de 2003 e tenacidade a fractura (metodo SEVNB) maxima de 5.20 MPam1/2. Foi ainda possivel estabelecer uma relacao estreita entre o aumento do conteudo em oxigenio das amostras sinterizadas e a diminuicao da tenacidade a fractura. Na tentativa de melhorar a tenacidade a fractura dos materiais, procedeu-se a incorporacao nas suspensoes de sementes de Ca-?-SiAlON de geometria alongada produzidas por sintese por combustao, adicionadas como agentes de reforco. A sintese por combustao realizada em larga escala (cargas ate 1 kg) nao produziu efeitos negativos obvios nos produtos da reaccao. Investigara-se os efeitos da adicao de 5 % em peso de sementes nas propriedades mecânicas e no desenvolvimento microestrutural de amostras densificadas por HIP. Em comparacao com os materiais sem sementes, a tenacidade a fractura (metodo SEVNB) aumentou 13%, mas a dureza Vickers resultou 14,5% inferior. A sinterizacao por SPS permitiu obter densificacao completa a temperaturas tao baixas como 1600ºC a partir dos pos granulados de Y

Accessibilità e fruibilità del patrimonio architettonico: occasioni per una sostenibilità “sociale” del recupero

Directory of Open Access Journals (Sweden)

Alessandro Greco

2012-12-01

Full Text Available Il tema dell’accessibilità e della fruibilità del patrimonio storico – architettonico sta assumendo sempre più rilevanza nel contesto nazionale, e in quello europeo più in generale, anche per le importanti funzioni che normalmente vengono inserite in contenitori edilizi dall’elevato valore culturale e documentale, collocati spesso nel centro storico delle città oppure in aree di elevato pregio ambientale.Il contributo propone riflessioni di carattere generale sull’importanza “sociale” dell’accessibilità al patrimonio edilizio storico e offre spunti per un approccio alla progettazione dell’accessibilità secondo un metodo consapevole della complessità del tema, partecipato e multidisciplinare. Il testo si completa con l’illustrazione di due ricerche applicate (una alla scala urbana e una alla scala edilizia sviluppate secondo tale metodo.

Colorectal cancer: before and after PET-CT; Cancer colorrectal: antes y despues de PET-TC

Energy Technology Data Exchange (ETDEWEB)

San Roman, Jose [Hospital Italiano, Buenos Aires (Argentina). Servicio de Diagnostico por Imagenes

2008-07-01

The author makes reference to the fundamental and growing role of images in the detection, localization, staging and control in colorectal cancer therapy. He points out the main reasons why the combined method PET-CT has meant to a great progress in diagnostic imaging and compares its diagnostic capacity and cost-benefit with other methods. Also, he makes a brief review of some technical aspects. [Spanish] El autor senala el rol central y creciente de las imagenes para la deteccion, localizacion, estadificacion y control del tratamiento del CCR. Menciona las razones principales por las que el metodo combinado PET-TC ha significado un progreso mayor para el diagnostico por imagenes y compara su capacidad diagnostica y costo-beneficio con los metodos establecidos. Tambien hace un repaso breve de algunos aspectos tecnicos.

Solitary pulmonary nodule: radiologic features and diagnostic approach; Nodulo pulmonar solitario: caracteristicas radiologicas y abordaje diagnostico

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Cambronero, Luis Enrique

2012-07-01

A literature review is conducted on the solitary pulmonary nodule, to determine the diagnostic methods and specific characteristics. The diagnostic methods used have been: chest radiography, computed tomography, positron emission tomography and magnetic resonance imaging. The radiological features are defined: location, size, definition of contours or edges (margins), densitometric and attenuation characteristics, cavitation, air bronchogram, growth, doubling time, satellite nodules, nutrient vessels [Spanish] Una revision bibliografica es realizada sobre el nodulo pulmonar solitario, para determinar los metodos de diagnostico y caracteristicas especificas. Los metodos de diagnostico utilizados han sido: la radiografia de torax, tomografia computarizada, tomografia por emision de positrones y resonancia magnetica. Las caracteristicas radiologicas son definidas: localizacion, tamano, definicion de los bordes o contornos (margenes), caracteristicas densitometricas y de atenuacion, cavitacion, broncograma aereo, crecimiento, tiempo de duplicacion, nodulos satelite, vasos nutrientes.

Some considerations concerning volume-modulated arc therapy: a stepping stone towards a general theory

International Nuclear Information System (INIS)

Webb, S; McQuaid, D

2009-01-01

In this paper it is formally shown that the dynamic multileaf collimator (MLC) IMRT delivery technique remains valid if the MLC is supported on a 1D moving platform. It is also shown that, in such circumstances, it is always time preferable to deliver overlapping modulating fields as a single swept field rather than as separate fields. The most general formulism is presented and then related to simpler equations in limiting cases. The paper explains in detail how a 'small-arc approximation' can be invoked to relate the 1D linear theory to the MLC-on-moving-platform-(gantry) delivery technique involving rotation therapy and known as volume-modulated arc therapy (VMAT). It is explained how volume-modulated arc therapy delivered with open unmodulated fields and which can deliver conformal dose distributions can be interpreted as an IMRT delivery. The (Elekta adopted) term VMAT will be used in a generic sense to include a similar (Varian) method known as RapidArc. Approximate expressions are derived for the 'amount of modulation' possible in a VMAT delivery. This paper does not discuss the actual VMAT planning but gives an insight at a deep level into VMAT delivery. No universal theory of VMAT is known in the sense that there is no theory that can predict precisely the performance of a VMAT delivery in terms of the free parameters available (variable gantry speed, variable fluence-delivery rate, set of MLC shapes, MLC orientation, number of arcs, coplanarity versus non-coplanarity, etc). This is in stark contrast to the situation with several other IMRT delivery techniques where such theoretical analyses are known. In this paper we do not provide such a theory; the material presented is a stepping stone on the path towards this.

Digital multi-level laminography on the basis of a micro-focus device

International Nuclear Information System (INIS)

Schors, J.; Ewert, U.; Nockemann, C.; Bellon, C.

1993-01-01

The starting point for the work is the coplanar rotation laminography, as it has a spatial resolution higher by a factor of π. By using modern technique, particularly X-ray picture digitalisation and computerized reconstruction with powerful computers, one can shorten the measurement time and obtain a higher resolution of the pictures. The principle of classical coplanar rotation laminography is explained. (orig./DG) [de

Comparison of two sus clavicular irradiation techniques in the breast cancer

International Nuclear Information System (INIS)

Boukhelif, W.; Henni, M.; Abrous-Anane, S.; Maisonobe, J.A.; Klotz, S.; Leignel, D.; Dessard-Diana, B.; Giraud, P.; Durdux, C.; Housset, M.

2009-01-01

Purpose: to compare the irradiation of the sub clavicular area by a non coplanar beam with the irradiation by a classical beam in the breast cancer. Conclusion: In the breast cancer, the non coplanar irradiation of sub clavicular ganglions allows to better protect the lungs comparatively to the classical irradiation and that without modifying the coverage of the sub clavicular target volume. (N.C.)

Chimica-fisica primo anno

CERN Document Server

Bianchi, U; Volta, L

Termodinamica ; cenni sulla costituzione della materia ; il metodo statistico ; le statistiche di Boltzmann-Maxwell, Bose-Einstein e Fermi-Dirac ; studio termodinamico e statistico del gas perfetto e delle miscele gassose ; i solidi cristallini ; le reazioni chimiche.

The role of projectile interactions in triply differential cross sections for excitation-ionization of helium

Energy Technology Data Exchange (ETDEWEB)

Dey, R., E-mail: ritud@ipp.mpg.d [Max-Planck Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Roy, A.C. [School of Mathematical Sciences, Ramakrishna Mission Vivekananda University, Belur Math 711 202, West Bengal (India)

2011-02-01

We report triply differential cross section (TDCS) for the simultaneous excitation-ionization of helium by electron impact for both coplanar and non-coplanar geometry. In the coplanar case, calculations have been performed for an incident energy of 500 eV and low ejection energies (3 and 10 eV), whereas in the noncoplanar case we have considered impact energies in the range 1240-4260 eV for a symmetric geometry. The present calculation is based on the eikonal approximation due to Glauber. We have incorporated the effect of post-collision interaction in the Glauber approximation. A comparison is made of the present calculations with the results of other theoretical methods and recent experiments. The Glauber results are in reasonably good agreement with the experiment for small scattering angles.

An Appraisal of Analytical Methods for Plutonium and their Applications to the Analysis of Nuclear Materials; Evaluation des Methodes Analytiques de Dosage du Plutonium et de Leur Application a l'Analyse des Matieres Nucleaires; Otsenka analiticheskikh metodov opredeleniya plutoniya i ikh primenenie dlya analiza yadernykh materialov; Metodos Analiticos de Determinacion del Plutonio y su Empleo en el Analisis de Materiales Nucleares

Energy Technology Data Exchange (ETDEWEB)

Milner, G. W.C.; Phillips, G. [Atomic Energy Research Establishment, Harwell, Berks. (United Kingdom)

1966-02-15

respectifs de la dissolution dans des melanges d'acides mineraux courants et de la dissolution faisant appel a des procedes de fusion, avec des exemples a l'appui. Les auteurs decrivent aussi les procedes utilises et les resultats obtenus, pour l'analyse des alliages Pu-U, Pu-Ce-Co et Pu-U-Mo, des oxydes et carbures de Pu-U, et des cermets de carbure de Pu-U contenant Fe, Mo et Cr. Ces matieres sont l'aboutissement de recherches metallurgiques destinees a mettre au point des combustibles nucleaires. (author) [Spanish] Para determinar el contenido de plutonio de los materiales nucleares existen diversos metodos. Si se trata de cantidades del orden del miligramo se pueden emplear la espectrofotometria diferencial por el color del Pu (III), la gravimetria basada en el PuO2{sub ,} si recuento gamma y metodos de oxidorreduccion como las valoraciones potenciometricas o amperimetricas y la culombiometria de potencial controlado. Si se trata de microgramos son preferibles el recuento alfa, la dilucion isotopica o las tecnicas polarograficas. Teniendo en cuenta que unos metodos son mas adecuados que otros para ciertos tipos de muestra, el analista tiene que resolver un dificil problema de seleccion a fin de obtener ios mejores resultados posibles. Los autores exponen las ventajas y las limitaciones puestas de manifiesto por los anos de experiencia en la A.E.R.E. y formulan observaciones acerca de la exactitud y la precision de los metodos, su sensibilidad y otras cuestiones de especial interes. Como algunos de esos metodos exigen la separacion previa del plutonio, los autores estudian el empleo de las tecnicas de intercambio anionico y de cromatografia en fase inversa, y en particular su conveniencia para el analisis de muestras radiactivas. Examinan los muchos problemas que han surgido al analizar por estos metodos, aleaciones, productos ceramicos y cermets de plutonio en diversos sistemas que contenian uranio, torio, hierro, cromo, molibdeno, cerio y cobalto. La memoria trata

SU-E-T-106: Development of a Collision Prediction Algorithm for Determining Problematic Geometry for SBRT Treatments Using a Stereotactic Body Frame

Energy Technology Data Exchange (ETDEWEB)

Wagar, M; Friesen, S; Mannarino, E [Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States); Hacker, F [Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States); Harvard Medical School, Boston, MA (United States)

2014-06-01

Purpose: Collision between the gantry and the couch or patient during Radiotherapy is not a common concern for conventional RT (static fields or arc). With the increase in the application of stereotactic planning techniques to the body, collisions have become a greater concern. Non-coplanar beam geometry is desirable in stereotatic treatments in order to achieve sharp gradients and a high conformality. Non-coplanar geometry is less intuitive in the body and often requires an iterative process of planning and dry runs to guarantee deliverability. Methods: Purpose written software was developed in order to predict the likelihood of collision between the head of the gantry and the couch, patient or stereotatic body frame. Using the DICOM plan and structures set, exported by the treatment planning system, this software is able to predict the possibility of a collision. Given the plan's isocenter, treatment geometry and exterior contours, the software is able to determine if a particular beam/arc is clinically deliverable or if collision is imminent. Results: The software was tested on real world treatment plans with untreatable beam geometry. Both static non-coplanar and VMAT plans were tested. Of these, the collision prediction software could identify all as having potentially problematic geometry. Re-plans of the same cases were also tested and validated as deliverable. Conclusion: This software is capable of giving good initial indication of deliverability for treatment plans that utilize complex geometry (SBRT) or have lateral isocenters. This software is not intended to replace the standard pre-treatment QA dry run. The effectiveness is limited to those portions of the patient and immobilization devices that have been included in the simulation CT and contoured in the planning system. It will however aid the planner in reducing the iterations required to create complex treatment geometries necessary to achieve ideal conformality and organ sparing.

Data Evaluation Problems in the Pulsed Neutron Source Method; Problemes d'Evaluation des Donnees dans les Applications de la Methode de la Source Pulsee; Problemy otsenki dannykh pri primenenii metoda istochnika impul'snykh nejtronov; Problemas de Evaluacion de Datos en el Metodo de la Fuente de Neutrones Pulsados

Energy Technology Data Exchange (ETDEWEB)

Pal, L.; Bod, L.; Szatmary, Z. [Central Research Institute for Physics, Hungarian Academy of Sciences, Budapest (Hungary)

1965-08-15

moyen de transport dans de nombreuses matieres hydrogenees. (author) [Spanish] Desde hace mas de diez anos se viene empleando el metodo de los neutrones pulsados para determinar los parametros de difusion de los neutrones termicos. Este metodo ha resultado especialmente idoneo para el estudio de los moderadores hidrogenados. Los autores dan los resultados de las mediciones hechas en agua, benceno, tolueno, xileno, ciclohexano, n-hexano y difenilo, y examinan los metodos para evaluar con el minimo error los parametros de difusion de interes partiendo de los datos obtenidos en las mediciones. Se examina detenidamente, tanto en el plano teorico como en el experimental, el efecto de tiempo de vuelo que se manifiesta por razones tecnicas cuando se investigan moderadores a elevadas temperaturas, y que influye en el valor de la constante de desintegracion, y se exponen las condiciones geometricas en que se ha de operar para obtener resultados satisfactorios. Los autores determinan tambien el efecto que sobre la constante de desintegracion ejerce el tiempo muerto del detector neutronico y del amplificador, y demuestran que es despreciable cuando [i(t) {tau}]{sup 2} << 1, siendo i/t/dt el numero de neutrones detectados en el intervalo de tiempo/t, t + dt/, y {tau} el tiempo muerto. Se evaluo la constante de desintegracion empleando el metodo de la maxima probabilidad. Para determinar inequivocamente la funcion de probabilidad, se eligio un analizador multicanal que acumulaba como maximo una sola senal por ciclo de analisis y por canal. Se comprobo que la incorporacion del parametro caracteristico del fondo a la funcion de probabilidad tiene primordial importancia. Los parametros de la funcion de maxima probabilidad se evaluaron en una calculadora aplicando el metodo de iteracion de Newton. Cuando no se tiene debidamente en cuenta el fondo, este puede causar una mayor contaminacion aparente de armonicos, la cual, a su vez, puede interpretarse como un fondo aparente. Por ello es

Dioxin body burden of persons living near incinerators and sintering plants: results from Belgium; Evaluation de la charge corporelle en dioxines des riverains d'incinerateurs et de la siderurgie: resultats d'une etude realisee en Belgique

Energy Technology Data Exchange (ETDEWEB)

Fierens, S.; Bernard, A. [Universite Catholique de Louvain (UCL), Unite de Toxicologie Industrielle et de Medecine du Travail, Faculte de Medecine, Louvain-la-Neuve (Belgium); Focant, J.F.; Eppe, G.; Pauw, E. de [Liege Univ., Lab. de Spectrometrie de Masse (CART) (Belgium)

2005-01-15

The aim of this study was to evaluate the impact on local residents' exposure to dioxines and coplanar PCBs (polychlorinated biphenyls) of two municipal solid waste incinerators (MSWI), one in an industrial area and the other in a rural zone, and two sintering plants, all located in Wallonia (Belgium). In all, 142 volunteers subjects living around these facilities and 63 volunteer referents from an unpolluted rural area were recruited and compared. They completed a self-administered questionnaire that furnished information about dietary habits, smoking habits, anthropometric characteristics, residential history and health status. They also provided blood samples under fasting conditions so that the body burden of dioxines (17 PCDD/Fs congeners) and coplanar PCBs could be assessed. After adjustment for co-variates determined by multiple linear regression analysis, serum concentrations of dioxines and coplanar PCBs in subjects living in the vicinity of the MSWI in the industrial area and of the sintering plants were similar to those of referents. In contrast, subjects living in the vicinity of the rural MSWI had significantly higher serum levels of dioxines (geometric mean, 38 vs 24 pg TEQ/g fat, p{<=}0.0001) and coplanar PCBs (geometric mean, 10.8 vs 7.0 pg TEQ/g fat, p{<=}0.05). Age-adjusted dioxin levels in referents did not vary with local animal fat consumption, but dioxin concentrations in subjects living around the MSWIs correlated positively with their intake of local animal fat, with levels almost doubled in subjects with the highest intake. These results show that the dioxines and coplanar PCBs emitted by MSWIs can indeed accumulate in the body of residents who consume animal products of local origin. (authors)

Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

Science.gov (United States)

Smyth, Gregory; Bamber, Jeffrey C.; Evans, Philip M.; Bedford, James L.

2013-11-01

Non-coplanar radiation beams are often used in three-dimensional conformal and intensity modulated radiotherapy to reduce dose to organs at risk (OAR) by geometric avoidance. In volumetric modulated arc radiotherapy (VMAT) non-coplanar geometries are generally achieved by applying patient couch rotations to single or multiple full or partial arcs. This paper presents a trajectory optimization method for a non-coplanar technique, dynamic couch rotation during VMAT (DCR-VMAT), which combines ray tracing with a graph search algorithm. Four clinical test cases (partial breast, brain, prostate only, and prostate and pelvic nodes) were used to evaluate the potential OAR sparing for trajectory-optimized DCR-VMAT plans, compared with standard coplanar VMAT. In each case, ray tracing was performed and a cost map reflecting the number of OAR voxels intersected for each potential source position was generated. The least-cost path through the cost map, corresponding to an optimal DCR-VMAT trajectory, was determined using Dijkstra’s algorithm. Results show that trajectory optimization can reduce dose to specified OARs for plans otherwise comparable to conventional coplanar VMAT techniques. For the partial breast case, the mean heart dose was reduced by 53%. In the brain case, the maximum lens doses were reduced by 61% (left) and 77% (right) and the globes by 37% (left) and 40% (right). Bowel mean dose was reduced by 15% in the prostate only case. For the prostate and pelvic nodes case, the bowel V50 Gy and V60 Gy were reduced by 9% and 45% respectively. Future work will involve further development of the algorithm and assessment of its performance over a larger number of cases in site-specific cohorts.

Analysis of the nonlinear dynamic behavior of power systems using normal forms of superior order; Analisis del comportamiento dinamico no lineal de sistemas de potencia usando formas normales de orden superior

Energy Technology Data Exchange (ETDEWEB)

Marinez Carrillo, Irma

2003-08-01

This thesis investigates the application of parameter disturbance methods of analysis to the nonlinear dynamic systems theory, for the study of the stability of small signal of electric power systems. The work is centered in the determination of two fundamental aspects of interest in the study of the nonlinear dynamic behavior of the system: the characterization and quantification of the nonlinear interaction degree between the fundamental ways of oscillation of the system and the study of the ways with greater influence in the response of the system in the presence of small disturbances. With these objectives, a general mathematical model, based on the application of the expansion in series of power of the nonlinear model of the power system and the theory of normal forms of vector fields is proposed for the study of the dynamic behavior of the power system. The proposed tool generalizes the existing methods in the literature to consider effects of superior order in the dynamic model of the power system. Starting off of this representation, a methodology is proposed to obtain analytical solutions of loop back and the extension of the existing methods is investigated to identify and quantify the of interaction degree among the fundamental ways of oscillation of the system. The developed tool allows, from analytical expressions of loop backs, the development of analytical measures to evaluate the stress degree in the system, the interaction between the fundamental ways of oscillation and the determination of stability borders. The conceptual development of the proposed method in this thesis offers, on the other hand, a great flexibility to incorporate detailed models of the power system and the evaluation of diverse measures of the nonlinear modal interaction. Finally, the results are presented of the application of the method of analysis proposed for the study of the nonlinear dynamic behavior in a machine-infinite bus system considering different modeled degrees

Comportamiento de Laminaciones Coplanares y No Coplanares en Acero API5L X52 Simuladas mediante Elementos Finitos Behavior of Coplanar and Non-Coplanar Laminations in API5L X52 Steel Simulated by Finite Elements

OpenAIRE

Alberto Servin; Jorge L González; Alfredo Morales

2009-01-01

Se determina el comportamiento mecánico de laminaciones simples y escalonadas modeladas por elementos finitos en condiciones no lineales de esfuerzo-deformación, para comprender la secuencia de la interacción de los campos de esfuerzos en los extremos de la grietas. Se estableció una matriz de simulación variando la extensión circunferencial de las laminaciones, con espesor del tubo de 610mm de diámetro, con separación vertical y horizontal para el caso de laminaciones escalonadas. Se determi...

Journal of Rehabilitation Research and Development Progress Reports 1994, Volume 32, June 1995

Science.gov (United States)

1995-06-01

May 1993. La misura degli intervalli di attivazione muscolare durante il movimento: un metodo di detezione statistica, Bonato P, D’alessio T...Philadelphia, PA 19107; Division of Medical Sciences. Alfred I. dti Pont Institute, Wilmington, DP. 19803; Olsen Biochemistry Laboratories, South Dakota

Fiber optics for voltage and current measurement; Utilizacion de fibras opticas en la medicion de voltaje y corriente

Energy Technology Data Exchange (ETDEWEB)

Mendieta Jimenez, Francisco Javier; Santos Dominguez, Martin; Gutierrez Martinez, Celso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1988-12-31

This paper offers a brief revision of the techniques employed in the voltage and current measurement in power plants and mention is made also of its main limitations. Likewise the optical methods of transduction of the mentioned electrical variables indicating their advantages and difficulties for its implementation. Finally the activities developed at the Instituto de Investigaciones Elctricas (IIE) in this field are described. [Espanol] En este trabajo se ofrece una breve revision de las tecnicas utilizadas en la medicion de voltaje y corriente en plantas electricas y se mencionan sus principales limitaciones. Asimismo, se presentan los metodos opticos de transduccion de las variables electricas mencionadas, indicando sus ventajas y las dificultades para su realizacion. Finalmente, se describen las actividades que se desarrollan en el Instituto de Investigaciones Electricas (IIE) en este campo.

Optimization of stereotactically-guided conformal treatment planning of sellar and parasellar tumors, based on normal brain dose volume histograms

International Nuclear Information System (INIS)

Perks, Julian R.; Jalali, Rakesh; Cosgrove, Vivian P.; Adams, Elizabeth J.; Shepherd, Stephen F.; Warrington, Alan P.; Brada, Michael

1999-01-01

Purpose: To investigate the optimal treatment plan for stereo tactically-guided conformal radiotherapy (SCRT) of sellar and parasellar lesions, with respect to sparing normal brain tissue, in the context of routine treatment delivery, based on dose volume histogram analysis. Methods and Materials: Computed tomography (CT) data sets for 8 patients with sellar- and parasellar-based tumors (6 pituitary adenomas and 2 meningiomas) have been used in this study. Treatment plans were prepared for 3-coplanar and 3-, 4-, 6-, and 30-noncoplanar-field arrangements to obtain 95% isodose coverage of the planning target volume (PTV) for each plan. Conformal shaping was achieved by customized blocks generated with the beams eye view (BEV) facility. Dose volume histograms (DVH) were calculated for the normal brain (excluding the PTV), and comparisons made for normal tissue sparing for all treatment plans at ≥80%, ≥60%, and ≥40% of the prescribed dose. Results: The mean volume of normal brain receiving ≥80% and ≥60% of the prescribed dose decreased by 22.3% (range 14.8-35.1%, standard deviation σ = 7.5%) and 47.6% (range 25.8-69.1%, σ 13.2%), respectively, with a 4-field noncoplanar technique when compared with a conventional 3-field coplanar technique. Adding 2 further fields, from 4-noncoplanar to 6-noncoplanar fields reduced the mean normal brain volume receiving ≥80% of the prescribed dose by a further 4.1% (range -6.5-11.8%, σ = 6.4%), and the volume receiving ≥60% by 3.3% (range -5.5-12.2%, σ = 5.4%), neither of which were statistically significant. Each case must be considered individually however, as a wide range is seen in the volume spared when increasing the number of fields from 4 to 6. Comparing the 4- and 6-field noncoplanar techniques to a 30-field conformal field approach (simulating a dynamic arc plan) revealed near-equivalent normal tissue sparing. Conclusion: Four to six widely spaced, fixed-conformal fields provide the optimum class solution

A theoretical and experimental study of microshield circuits

Science.gov (United States)

Dib, Nihad I.; Drayton, Rhonda F.; Katehi, Linda P. B.

1993-05-01

The novel type of monolithic planar transmission line presently studied theoretically and experimentally operates without via-holes or ground-equalizing air bridges; it also radiates less than conventional coplanar waveguides and furnishes a wide range of impedances in virtue of its many design parameters. The space-domain integral equation method is used to analyze several discontinuities of the proposed line. It is shown that the proposed line discontinuities radiate less than the corresponding coplanar waveguide cases.

Valoracion economica ambiental de la calidad del aire por emisiones industriales en la ciudad de quevedo,ecuador

OpenAIRE

Espol; Cabrera Casillas, Elvis Antonio; Lozano Mendoza, Pedro Harrys

2017-01-01

El objetivo principal del estudio es realizar una valoracion economico ambiental por la mejora de la calidad del aire en quevedo, para esto se elaboro un escenario hipotètico utilizando el metodo de valoracion contingente en su formato dicotomico doble. Guayaquil CAMBIO CLIMATICO

Use and Analysis of Finite Element Methods for Problems of Solid Mechanics and Fracture

Science.gov (United States)

1993-01-19

improve global accuracy and convergence rates, specific activities such as mesh refinement may be undertaken local to the crack tips. A criticism ...Sciences, Centro Internacional de Metodos Numnericos en Ingenieria, Barcelona, 1992 11 1 |l!avacek, J Rosenberg, A E Beagles and J R Whiteman

Ultra-high-speed oscillographic techniques; Techniques d'oscillographie ultra-rapide; Metody sverkhskorostnoj ostsillografii; Metodos oscilograficos ultrarrapidos

Energy Technology Data Exchange (ETDEWEB)

Abercrombie, S; Elphick, B; Foster, H [Atomic Weapons Research Establishment, Aldermaston (United Kingdom)

1962-04-15

100 {Omega}; e) Des resistances de complement a large bande, destinees a l'extraction des signaux de declenchement de la base de temps; / ) Des bases de temps fournissant des signaux de l'ordre de quelques nanosecondes et comportant des dispositifs de declenchement et de suppression du faisceau; g) Un appareil de prise de vues a grande ouverture. En conclusion, le memoire examine certaines applications de l'electronique nucleaire. (author) [Spanish] Despues de un resumen historico de los metodos de utilizacion de oscilografos para senales transitorias de alta velocidad, los autores examinan sus limites de aplicacion practica. En la memoria se pasa revista a los tubos de rayos catodicos apropiados para estos oscilografos, tomando en cuenta especialmente los tipos de deflexion por onda progresiva. En la memoria se estudian los siguientes componentes de un oscilografo completo para senales transitorias: a) Un tubo de rayos catodicos con deflexion por onda progresiva con conexion coaxial balanceada y una anchura de banda de 2 GHz; b) Un transformador inversor de fase con una impedancia caracteristica de 100 y 50 {Omega} y una anchura de banda de 1,5 kHz a 1,5 GHz; c) Resistencias de terminacion coaxial para frecuencias del orden de los GHz; d) Condensadores de acoplamiento compensados para usarlos en lineas coaxiales con frecuencias comprendidas entre 5 kHz y 3 GHz y 100 {Omega} de impedancia caracteristica; e) Atenuadores resistivos de banda ancha, para la extraccion de senales de disparo de base de tiempos; f) Bases de tiempo del orden de los nanosegundos, con dispositivos disparadores y supresores ; g) Una camara de gran apertura. Finalmente, los autores examinan las aplicaciones de estos oscilografos en la electronica nuclear. (author) [Russian] Posle kratkogo opisaniya ostsillograficheskogo metoda izucheniya sverkhskorostnykh perekhodnykh izluchenij obsuzhdayutsya prakticheskie vozmozhnosti ehtogo apparata. Daetsya obzor podkhodyashchikh katodnykh ehlektronnykh lamp

Wideband Cavity Backed Spiral Antenna for Stepped Frequency Ground Penetrating Radar

DEFF Research Database (Denmark)

Thaysen, Jesper; Jakobsen, Kaj Bjarne; Lenler-Eriksen, Hans-Rudolph

2005-01-01

A 1.7 turn cavity backed coplanar waveguide to coplanar strip-fed logarithmic uniplanar spiral antenna is presented and compared to a 1.5 turn spiral antenna. The 1.7 turn spiral antenna has a wide beamwidth, are circular polarised and has a bandwidth with a return loss better than 6 dB in the fr......B in the frequency band from 0.25 GHz to 4.5 GHz (18:1). The antenna is useful for Ground Penetrating Radar (GPR)....

SU-E-P-40: Dosimetric Characteristics of Field Aperture Margin Design in Stereotactic Body Radiation Therapy (SBRT)

Energy Technology Data Exchange (ETDEWEB)

Zhu, J

2015-06-15

Purpose: To characterize the dosimetric effects of field aperture margin design in Stereotactic Body Radiation Therapy (SBRT). Methods: Three artificial spherical PTVs, with diameter of 10mm, 20mm and 30mm, were created on CT images of a human body thoracic phantom. Seven non-coplanar isocentric fields were used for treatment planning. For each PTV, treatment plans with margins 0mm, 1mm, 2mm and 3mm were planned. Dosimetric comparison among plans was done considering the following parameters: prescribed isodose line for target coverage, maximum dose, mean dose as well as dose spillages of V80, V50, and V20. Results: Corresponding to aperture margins of 0mm, 1mm,2m and 3mm used in the treatment planning, the percentage of isodose line chosen for dose prescription increases from 65% to 93% for 10mm PTV, 70% to 92% for 20mm PTV, and 75% to 92% for 30mm PTV. The maximum dose decrease accordingly from 155.7% to 109.5% for 10mm PTV, 145% to 111.6% for 20mm PTV, 137% to 112.2% for 30mm PTV. The mean dose decrease from 138.% to 104.4% for 10mm PTV, 122.8% to 106.1% for 20mm PTV, 121.3% to 106% for 30mm PTV. Dose spillages (mm3) increase (V80−2.6 to 4.02, V50−4.55 to 9.3, V20–87.86 to 101.71) for 10 mm PTV, (V80−6.78 to 9.89, V50–13.46 to 20.4, V20-119.16 to 219.1) for 20 mm PTV, (V80–22.01 to 28.59, V50–41.56 to 52.66, V20-532.71 to 551.84) for 30 mm PTV. Conclusion: In SBRT treatment planning, tight field aperture margin requires prescribing dose to lower isodose line that leading to higher dose inhomogeneity and higher mean dose to PTV. Loose margin allows prescribing dose to higher isodose line, therefore improves the dose homogeneity. However, it increases dose spillages. Clinician could try different margins according to the PTV size and location of surrounding critical organs to optimize the dose delivered to the patient.

Sizing an isolated wind-solar-fuel cell generation system based on the particle swarm optimization method; Dimensionamiento de un sistema de generacion aislado eolico-solar-celda de combustible basado en el metodo de optimizacion de enjambre de particulas

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Huerta, V; Ramirez-Arredondo, Juan M. [Universidad de Quintana Roo, Chetumal, Quintana Roo (Mexico)]. E-mail: vsanchez@gdl.cinvestav.mx; Arriaga-Hurtado, L. G. [CIDETEQ, Queretaro (Mexico)

2009-09-15

Sizing an electric energy system requires an analysis of investment, maintenance and operating costs. In the case of a generation system that uses renewable sources, optimal capacity becomes more complex compared to a conventional system, because of the randomness of renewable resources (wind, solar) and the still high costs of wind and photovoltage generator modules. This work presents the optimal sizing of a wind-solar-fuel cell generation system, minimizing the costs of the system while satisfying the energy demands of an isolated charge. The optimization method used is based on an evolutionary programming technique known as particle swarms (PSO-particle swarm optimization). The generation of energy with a hybrid system is discussed, based on the profile of insolation and wind availability at the site, with the objective of satisfying a specific electric demand. [Spanish] El dimensionamiento de un sistema de generacion de energia electrica requiere un analisis de los costos de inversion, mantenimiento y operacion. En el caso de un sistema de generacion que utiliza fuentes renovables la capacidad optima resulta mas compleja con respecto a un sistema convencional, debido a la aleatoriedad de los recursos renovables (eolico, solar), y a los aun altos costos de generadores eolicos y modulos fotovoltaicos. En este trabajo se presenta el dimensionamiento optimo de un sistema de generacion eolico-solar-celda de combustible minimizando los costos del sistema que satisfaga la energia demandada por una carga aislada. El metodo de optimizacion utilizado esta basado en una tecnica de programacion evolutiva conocida como enjambre de particulas (PSO por sus siglas en ingles: particle swarm optimization). Se plantea la generacion de energia del sistema hibrido con base a la insolacion y el perfil del viento disponible en sitio, con objeto de satisfacer una demanda electrica determinada.

The Application of Various Nondestructive Testing Methods to Fuel Elements of the Orgel Type; Application des Differentes Methodes d'Essais Non Destructifs aux Elements Combustibles du Type Orgel; Primenenie razlichnykh nedestruktivnykh metodov ispytanij k toplivnym ehlementam tipa ''orgel''; Aplicacion de Distintos Metodos de Ensayo No Destructivo a los Elementos Combustibles de Tipo Orgel

Energy Technology Data Exchange (ETDEWEB)

Bonnet, P.; Jansen, J. [EURATOM, C.C.R., Ispra (Italy)

1965-09-15

methode a un capteur montre quelles sont les limites d'utilisation de ces deux methodes. Defauts transversaux; La methode a un capteur appliquee a cette recherche fait l'objet d'une breve description. Entrainement mecanique: Le memoire fait etat d'un banc mecanique, type laboratoire, pour la recherche des criteres d'essais et d'un banc de passage des tubes, de type semi-industriel, pour l'examen en continu avec enregistrement des defauts. Les difficultes rencontrees et les moyens misenceuvrepoury remediersont evoques. c) Tests par radiographie. Cette methode fera l'objet d'un memoire special; seuls sont indiques les resultats obtenus sur tubes de force ou sur tubes de gaines. d) Test divers Les test finaux sur elements combustibles complets peuvent se resumer en deux parties. Tests d'etancheite au moyen du test a l'helium developpe par la SOGEV. Un dispositif permet d'examiner simultanement 4 ou 6 elements combustibles ou separement 2 ou 3. Tests classiques de radiographie; l'accent est mis plus particulierement sur l'etude des soudures; on donne la marge des conditions experimentales pour obtenir une bonne definition. En conclusion, les auteurs presentent un projet de chaine de controle semi-industrielle avec les differentes possibilites de traitements et essaient de degager une certaine philosophie des tests non destructifs appliques aux elements combustibles. (author) [Spanish] La memoria presenta los distintos metodos empleados para deteccion de fallas (de tipo dimensional o estructural) en vainas de elementos combustibles. Los autores describen, asimismo, los ensayos finales con elementos combustibles completos, en particular radiografia de las soldaduras y pruebas de estanqueidad. Este tema se ha tratado ya en forma parcial. El estudio de las caracteristicas dimensionales de las vainas lisas de SAP (producto de aluminio sinterizado) ha sido objeto de trabajos bastante avanzados. La memoria examina en particular los siguientes temas: 1. Medicion de diametros internos

Un universo comprensibile interazione tra scienza e teologia

CERN Document Server

Coyne, George V

2009-01-01

Perché il nostro mondo è comprensibile? La domanda sembra così banale, che solo pochi trovano il coraggio di porsela. In questo libro esploreremo le radici profonde del mistero della razionalità. L’indagine sulla razionalità del mondo cominciò duemilacinquecento anni or sono, quando un manipolo di audaci pensatori avviarono l’impresa di cercare di capire la Natura con la sola forza della ragione, rifiutando le comode e futili spiegazioni fornite da miti e leggende. Attraverso molte avventure filosofiche e teologiche, alla fine il concetto greco di razionalità pose le basi di un modo nuovo e rivoluzionario di pensare: quello del metodo scientifico, destinato a trasformare il mondo. Quando consideriamo i frutti più recenti dell’indagine sulla razionalità del mondo – la teoria della relatività, la meccanica quantistica, l’unificazione delle leggi fisiche, la gravitazione quantistica – viene da chiedersi: quali sono i limiti del metodo scientifico? Il principio fondamentale del pensiero razi...

Fabrication of coplanar HF analog devices

International Nuclear Information System (INIS)

Schulz, G.; Kratz, H.

1993-01-01

A thin film technology has to be built up, which allows the reliable and reproducible production of such devices. This technology has to fulfill some general requirements and many specific ones due to the difference of the devices. The general requirements concern the suitability of the technology for industrial production. That means, that the production processes should be reliable, they should allow a high trough-put, and up-scaling should be possible. Processes as passivation or cryo-packaging of the devices belong to this group of requirements as well. The technology for fabrication of the devices splits up into three well distinguishable techniques: deposition of thin films, control of the quality of the deposited layers and patterning of the device structures and contacts. (orig.)

A family of solutions with radiation reaction and retarded interactions for two charges in classical electrodynamics

International Nuclear Information System (INIS)

Rivera, R.; Villarroel, D.

2002-01-01

A family of solutions of the Lorentz-Dirac equation is constructed. It consists in the motion of two charges e 1 and e 2 of masses m 1 and m 2 in two coplanar and concentric circles of radii a and b. The charges rotate with constant angular velocity, and have an angular separation ψ. The radiation reaction forces and the retarded interactions between the charges are taken into account. The external electromagnetic field that allows the motion consists of a tangential time-independent electric field that takes a fixed value on each orbit, and a homogeneous time-independent magnetic field perpendicular to the plane of the motion. For all the solutions energy conservation is rigorously demonstrated by evaluating the energy radiated, with independence of the equation of motion, through the calculation of the instantaneous energy flux across a sphere of an infinitely large radius

Study of split-ring resonators for use on a pharmaceutical drug capsule for microwave activated drug release

DEFF Research Database (Denmark)

Jónasson, Sævar Þór; Jensen, Brian Sveistrup; Johansen, Tom Keinicke

2012-01-01

In this paper, a novel method for externally activating a pharmaceutical drug capsule by use of split-ring resonators (SRR) is introduced. To this end, the effect of the orientation of the SRRs on the ability to activate the capsules is examined. A coplanar waveguide is used to excite an identical...... pair of SRRs fabricated on a substrate, representing an enlarged lid for a pharmaceutical drug capsule. Orientations where the electric field component of a quasi-TEM wave lies across the gap of the SRRs provides the largest response. The optimal case is when the electric field component lies across...... the gap simultaneously with the magnetic field component normal to the SRRs. Furthermore, an analysis of the optimal conductivity and relative permittivity for enhanced temperature rise in the lid is performed. Conductivity of 0.09 S/m and relative permittivity of 12 shows the highest temperature rise....

Initial liquid metal magnetohydrodynamic thin film flow experiments in the MeGA-loop facility at UCLA

International Nuclear Information System (INIS)

Morley, N.B.; Gaizer, A.A.; Tillack, M.S.; Abdou, M.A.

1995-01-01

Free surface thin film flows of liquid metal were investigated experimentally in the presence of a coplanar magnetic field. This investigation was performed in a new magnetohydrodynamic (MHD) flow facility, the MeGA-loop, utilizing a low melting temperature lead-bismuth alloy as the working metal. Owing to the relatively low magnetic field produced by the present field coil system, the ordinary hydrodynamic and low MHD interaction regimes only were investigated. At the high flow speeds necessary for self cooling, the importance of a well designed and constructed channel becomes obvious. Partial MHD drag, increasing the film height, is observed as Haβ 2 becomes greater than unity. MHD laminarization of the turbulent film flows is observed when Haβ/Re>0.002, but fully laminar flow was not reached. Suggestions for facility upgrades to achieve greater MHD interaction are presented in the context of these initial results. (orig.)

Large density amplification measured on jets ejected from a magnetized plasma gun

OpenAIRE

Yun, Gunsu S.; You, Setthivoine; Bellan, Paul M.

2007-01-01

Observation of a large density amplification in the collimating plasma jet ejected from a coplanar coaxial plasma gun is reported. The jet velocity is ~30 km s^-1 and the electron density increases from ~10^20 to 10^(22–23) m^-3. In previous spheromak experiments, electron density of the order 10^(19–21) m^-3 had been measured in the flux conserver region, but no density measurement had been reported for the source gun region. The coplanar geometry of our electrodes permits direct observation...

Applied mathematics made simple

CERN Document Server

Murphy, Patrick

1982-01-01

Applied Mathematics: Made Simple provides an elementary study of the three main branches of classical applied mathematics: statics, hydrostatics, and dynamics. The book begins with discussion of the concepts of mechanics, parallel forces and rigid bodies, kinematics, motion with uniform acceleration in a straight line, and Newton's law of motion. Separate chapters cover vector algebra and coplanar motion, relative motion, projectiles, friction, and rigid bodies in equilibrium under the action of coplanar forces. The final chapters deal with machines and hydrostatics. The standard and conte

Approximate Riemann solver for the two-fluid plasma model

International Nuclear Information System (INIS)

Shumlak, U.; Loverich, J.

2003-01-01

An algorithm is presented for the simulation of plasma dynamics using the two-fluid plasma model. The two-fluid plasma model is more general than the magnetohydrodynamic (MHD) model often used for plasma dynamic simulations. The two-fluid equations are derived in divergence form and an approximate Riemann solver is developed to compute the fluxes of the electron and ion fluids at the computational cell interfaces and an upwind characteristic-based solver to compute the electromagnetic fields. The source terms that couple the fluids and fields are treated implicitly to relax the stiffness. The algorithm is validated with the coplanar Riemann problem, Langmuir plasma oscillations, and the electromagnetic shock problem that has been simulated with the MHD plasma model. A numerical dispersion relation is also presented that demonstrates agreement with analytical plasma waves

Spin wave propagation detected over 100 μm in half-metallic Heusler alloy Co2MnSi

Science.gov (United States)

Stückler, Tobias; Liu, Chuanpu; Yu, Haiming; Heimbach, Florian; Chen, Jilei; Hu, Junfeng; Tu, Sa; Alam, Md. Shah; Zhang, Jianyu; Zhang, Youguang; Farrell, Ian L.; Emeny, Chrissy; Granville, Simon; Liao, Zhi-Min; Yu, Dapeng; Zhao, Weisheng

2018-03-01

The field of magnon spintronics offers a charge current free way of information transportation by using spin waves (SWs). Compared to forward volume spin waves for example, Damon-Eshbach (DE) SWs need a relatively weak external magnetic field which is suitable for small spintronic devices. In this work we study DE SWs in Co2MnSi, a half-metallic Heusler alloy with significant potential for magnonics. Thin films have been produced by pulsed laser deposition. Integrated coplanar waveguide (CPW) antennas with different distances between emitter and detection antenna have been prepared on a Co2MnSi film. We used a vector network analyzer to measure spin wave reflection and transmission. We observe spin wave propagation up to 100 μm, a new record for half-metallic Heusler thin films.

Proceedings of the Ship Control Systems Symposium (9th) Held in Bethesda, Maryland on 10-14 September 1990. Theme: Automation in Surface Ship Control Systems, Today’s Applications and Future Trends. Volume 4

Science.gov (United States)

1990-09-14

and can be fused separately. The RTU’s low-power consumption makes them ideally suited for battery and solar powered applications. 3.5 Redundant...dei movimenti e delle sollecitazioni di una nave in mare tempestoso per mezzo del metodo dello spettro di energia e della teoria della

The Physical Oceanography of the Alboran Sea.

Science.gov (United States)

1987-03-01

relative vorticity was imposed, be critical . The vorticity mechanism proposed by however, the flow turned to the left. He suggested that Bryden and Stommel... Metodos y resultados. Inf. Teen. del Inc., Stroudsburg, Pennsylvania. I.E.O., Madrid, Spain (in press). Cheney, R. E. and R. A. Doblar (1982). Structure

A Methodology for Selection of a Satellite Servicing Architecture. Volume 3. Appendices.

Science.gov (United States)

1985-12-01

model transfers between inclined circu- lar orbits. If OSV time of flight becomes more critical . then a choice between the other two techniques is...ABSTRACT iContinue on ,viverse if necesary and identify by block, number) Title: A METODO ~LOGY FOR SELECION~ OF A SATELLITE SERVICING ARCHITEIR VOLUME

Parotid gland sparing radiotherapy technique using 3-D conformal radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Lim, Ji Hoon; Kim, Gwi Eon; Keum, Ki Chang; Suh, Chang Ok; Lee, Sang Wook; Park, Hee Chul; Cho, Jae Ho; Chang, Sei Kyung; Loh, Juhn Kyu

2000-01-01

Although using the high energy photon beam with conventional parallel-opposed beams radio-therapy for nasopgaryngeal carcinoma, radiation-induced xerostomia is a troublesome problem for patients. We conducted this study to explore a new parotid gland sparing technique in 3-D conformal radiotherapy (3-DCRT) in an effort to prevent the radiation-induced xerostomia. We performed three different planning for four clinically node-negative nasopharyngeal cancer patients with different location of tumor(intracranial extension, nasal cavity extension, oropharyngeal extension, parapharyngeal extension), and intercompared the plans. Total prescription dose was 70.2 Gy to the isocenter. For plan-A, 2-D parallel opposing fields, a conventional radiotherapy technique, were employed. For plan-B, 2-D parallel opposing fields were used up until 54 Gy and afterwards 3-D non-coplanar beams were used. For plan-C, the new technique, 54Gy was delivered by 3-D conformal 3-port beams (AP and both lateral ports with wedge compensator, shielding both superficial lobes of parotid glands at the AP beam using BEV) from the beginning of the treatment and early spinal cord block (at 36 Gy) was performed. And bilateral posterior necks were treated with electron after 36 Gy. After 54 Gy, non-coplanar beams were used for cone-down plan. We intercompared dose statistics (Dmax, Dmin, Dmean, D95, D05, V95, V05, Volume receiving 46 Gy) and dose volume histograms (DVH) of tumor and normal tissues and NTCP values of parotid glands for the above three plans. For all patients, the new technique (plan-C) was comparable or superior to the other plans in target volume isodose distribution and dose statistics and it has more homogenous target volume coverage. The new technique was most superior to the other plans in parotid glands sparing (volume receiving 46 Gy: 100, 98, 69% for each plan-A, B and C). And it showed the lowest NTCP value of parotid glands in all patients (range of NTCP; 96-100%, 79-99%, 51

Computer program for the calculation of stresses in rotary equipment discs; Programas de computo para el calculo de esfuerzos en discos de equipo rotatorio

Energy Technology Data Exchange (ETDEWEB)

Gutierrez Delgado, Wilson; Kubiak, Janusz; Serrano Romero, Luis Enrique [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1991-12-31

In the preliminary design and diagnosis of rotary machines is very common to utilize simple calculation methods for the mechanical and thermal stresses, dynamic and thermodynamic analysis and flow of fluids in this machines (Gutierrez et al., 1989). The analysis with these methods provides the necessary results for the project initial stage of the machine. Later on, more complex tools are employed to refine the design of some machine components. In the Gutierrez report et al., (1989) 34 programs were developed for the preliminary design and diagnosis of rotating equipment; in this article, one of them is presented in which a method for the analysis of mechanical and thermal stresses is applied in discs of uniform or variable thickness that are normally found in turbomachines and rotary equipment. [Espanol] En el diseno preliminar y diagnostico de maquinas rotatorias es muy comun emplear metodos de calculo sencillos para el analisis de esfuerzos mecanicos y termicos, analisis dinamico y termodinamico y de flujo de fluidos en estas maquinas (Gutierrez et al., 1989). El analisis con estos metodos proporcionan los resultados necesarios para la etapa del proyecto inicial de la maquina. Posteriormente, para refinar el diseno de algunos componentes de la maquina, se aplican las herramientas mas complejas. En el informe de Gutierrez et al., (1989) se desarrollan 34 programas para el diseno preliminar y diagnostico de equipo rotatorio; en este articulo, se presenta uno de ellos, en el que se emplea un metodo para el analisis de esfuerzos mecanicos y termicos en discos de espesor constante o variable que se encuentran comunmente en turbomaquinas y en equipos rotatorios.

Computer program for the calculation of stresses in rotary equipment discs; Programas de computo para el calculo de esfuerzos en discos de equipo rotatorio

Energy Technology Data Exchange (ETDEWEB)

Gutierrez Delgado, Wilson; Kubiak, Janusz; Serrano Romero, Luis Enrique [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

In the preliminary design and diagnosis of rotary machines is very common to utilize simple calculation methods for the mechanical and thermal stresses, dynamic and thermodynamic analysis and flow of fluids in this machines (Gutierrez et al., 1989). The analysis with these methods provides the necessary results for the project initial stage of the machine. Later on, more complex tools are employed to refine the design of some machine components. In the Gutierrez report et al., (1989) 34 programs were developed for the preliminary design and diagnosis of rotating equipment; in this article, one of them is presented in which a method for the analysis of mechanical and thermal stresses is applied in discs of uniform or variable thickness that are normally found in turbomachines and rotary equipment. [Espanol] En el diseno preliminar y diagnostico de maquinas rotatorias es muy comun emplear metodos de calculo sencillos para el analisis de esfuerzos mecanicos y termicos, analisis dinamico y termodinamico y de flujo de fluidos en estas maquinas (Gutierrez et al., 1989). El analisis con estos metodos proporcionan los resultados necesarios para la etapa del proyecto inicial de la maquina. Posteriormente, para refinar el diseno de algunos componentes de la maquina, se aplican las herramientas mas complejas. En el informe de Gutierrez et al., (1989) se desarrollan 34 programas para el diseno preliminar y diagnostico de equipo rotatorio; en este articulo, se presenta uno de ellos, en el que se emplea un metodo para el analisis de esfuerzos mecanicos y termicos en discos de espesor constante o variable que se encuentran comunmente en turbomaquinas y en equipos rotatorios.

An educational method for evaluating the resistance to the treatment in the diagnosis of dyscalculia

Directory of Open Access Journals (Sweden)

Giampaolo Chiappini

2016-04-01

Full Text Available In this paper a didactical method that has been proven effective for evaluating the “resistance to the treatment” of the student is presented. This parameter is essential for distinguishing the learning difficulties in mathematics from the learning disorder of dyscalculia. The method is based on GimmeFive, an application that has been designed to develop skills in mental calculation of multi-digit additions and subtractions. In this paper we present the results of two experiments conducted with groups of students respectively with learning difficulties in mathematics and dyscalculia. These experiments allowed to show the effectiveness of the didactical method in the evaluation of the resistance to the treatment and to discuss the features that make it adequate for the evaluation of the learning disorder. An educational method for evaluating the resistance to the treatment in the diagnosis of dyscalculiaIn questo lavoro viene presentato un metodo didattico che si è dimostrato efficace per valutare la resistenza al trattamento dello studente che è uno dei parametri fondamentali per distinguere la difficoltà di apprendimento in matematica dal disturbo di apprendimento noto come discalculia. Il metodo si basa sull’uso dell’applicazione GimmeFive che è stata progettata per sviluppare competenze nel calcolo mentale di addizioni e sottrazioni a più cifre. In questo lavoro vengono presentati risultati di due sperimentazioni condotte con gruppi di studenti rispettivamente con difficoltà di apprendimento e con diagnosi di discalculia. Queste sperimentazioni hanno consentito di mostrare l’efficacia del metodo didattico nella valutazione della resistenza al trattamento e di discutere le caratteristiche che lo rendono adeguato per la valutazione del disturbo di apprendimento.

Comparison of the in vitro effects of TCDD, PCB 126 and PCB 153 on thyroid-restricted gene expression and thyroid hormone secretion by the chicken thyroid gland.

Science.gov (United States)

Katarzyńska, Dorota; Hrabia, Anna; Kowalik, Kinga; Sechman, Andrzej

2015-03-01

The aim of this study was to compare the in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) and 2,2'4,4',5,5'-hexachlorobiphenyl (PCB153; non-coplanar PCB) on mRNA expression of thyroid-restricted genes, i.e. sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and thyroid hormone secretion from the thyroid gland of the laying chicken. Relative expression levels of NIS, TG and TPO genes and thyroxine (T4) and triiodothyronine (T3) secretion from the thyroidal explants were quantified by the real-time qPCR and RIA methods, respectively. In comparison with the control group, TCDD and PCB 126 significantly increased mRNA expression of TPO and TG genes. TCDD did not affect NIS mRNA levels, but PCB 126 decreased its expression. No effect of PCB 153 on the expression of these genes was observed. TCDD and PCB 126 significantly decreased T4 and T3 secretion. There was no significant effect of PCB 153 on these hormone secretions. In conclusion, the results obtained show that in comparison with non-coplanar PCB 153, TCDD and coplanar PCB 126 can directly affect thyroid hormone synthesis and secretion, and in consequence, they may disrupt the endocrine function of the thyroid gland of the laying chicken. Copyright © 2015 Elsevier B.V. All rights reserved.

Multiple mechanisms of PCB neurotoxicity

Energy Technology Data Exchange (ETDEWEB)

Carpenter, D.O.; Stoner, C.T.; Lawrence, D.A. [Univ. of New York, Albany, NY (United States)] [and others

1996-12-31

Polychlorinated biphenyls (PCBs) have been implicated in cancer, but many of the symptoms in humans exposed to PCBs are related to the nervous system and behavior. We demonstrated three different direct mechanisms whereby PCBs are neurotoxic in rats. By using flow cytometry, we demonstrated that the orthosubstituted PCB congener 2,4,4{prime}, but neither TCDD nor the coplanar PCB congener 3,4,5,3{prime},4{prime}, causes rapid death of cerebellar granule cells. The ortho-substituted congener 2,4,4{prime} reduced long-term potentiation, an indicator of cognitive potential, in hippocampal brain slices, but a similar effect was observed for the coplanar congener 3,4,3{prime},4{prime}, indicating that this effect may be caused by both ortho- and coplanar congeners by mechanisms presumably not mediated via the Ah receptor. It was previously shown that some ortho-substituted PCB congeners cause a reduction in levels of the neurotransmitter dopamine, and we present in vitro and in vivo evidence that this is due to reduction of synthesis of dopamine via inhibition of the enzyme tyrosine hydroxylase. Thus, PCBs have a variety of mechanisms of primary neurotoxicity, and neurotoxicity is a characteristic of ortho-substituted, non-dioxin-like congeners as well as some coplanar congeners. The relative contribution of each of these mechanisms to the loss of cognitive function in humans exposed to PCBs remains to be determined. 42 refs., 3 figs., 1 tab.

Correlating Charge Transport with Structure in Deconstructed Diketopyrrolopyrrole Oligomers: A Case Study of a Monomer in Field-Effect Transistors.

Science.gov (United States)

Pickett, Alec; Torkkeli, Mika; Mukhopadhyay, Tushita; Puttaraju, Boregowda; Laudari, Amrit; Lauritzen, Andreas E; Bikondoa, Oier; Kjelstrup-Hansen, Jakob; Knaapila, Matti; Patil, Satish; Guha, Suchismita

2018-06-13

Copolymers based on diketopyrrolopyrrole (DPP) cores have attracted a lot of attention because of their high p-type as well as n-type carrier mobilities in organic field-effect transistors (FETs) and high power conversion efficiencies in solar cell structures. We report the structural and charge transport properties of n-dialkyl side-chain-substituted thiophene DPP end-capped with a phenyl group (Ph-TDPP-Ph) monomer in FETs which were fabricated by vacuum deposition and solvent coating. Grazing-incidence X-ray diffraction (GIXRD) from bottom-gate, bottom-contact FET architectures was measured with and without biasing. Ph-TDPP-Ph reveals a polymorphic structure with π-conjugated stacking direction oriented in-plane. The unit cell comprises either one monomer with a = 20.89 Å, b = 13.02 Å, c = 5.85 Å, α = 101.4°, β = 90.6°, and γ = 94.7° for one phase (TR1) or two monomers with a = 24.92 Å, b = 25.59 Å, c = 5.42 Å, α = 80.3°, β = 83.5°, and γ = 111.8° for the second phase (TR2). The TR2 phase thus signals a shift from a coplanar to herringbone orientation of the molecules. The device performance is sensitive to the ratio of the two triclinic phases found in the film. Some of the best FET performances with p-type carrier mobilities of 0.1 cm 2 /V s and an on/off ratio of 10 6 are for films that comprise mainly the TR1 phase. GIXRD from in operando FETs demonstrates the crystalline stability of Ph-TDPP-Ph.

Exploring proton transfer in 1,2,3-triazole-triazolium dimer with ab initio method

Science.gov (United States)

Li, Ailin; Yan, Tianying; Shen, Panwen

Ab initio calculations are utilized to search for transition state structures for proton transfer in the 1,2,3-triazole-triazolium complexes on the basis of optimized dimers. The result suggests six transition state structures for single proton transfer in the complexes, most of which are coplanar. The energy barriers, between different stable and transition states structures with zero point energy (ZPE) corrections, show that proton transfer occurs at room temperature with coplanar configuration that has the lowest energy. The results clearly support that reorientation gives triazole flexibility for proton transfer.

Exploring proton transfer in 1,2,3-triazole-triazolium dimer with ab initio method

Energy Technology Data Exchange (ETDEWEB)

Li, Ailin; Yan, Tianying; Shen, Panwen [Department of Material Chemistry, Institute of New Energy Material Chemistry, Nankai University, Tianjin, 300071 (China)

2011-02-01

Ab initio calculations are utilized to search for transition state structures for proton transfer in the 1,2,3-triazole-triazolium complexes on the basis of optimized dimers. The result suggests six transition state structures for single proton transfer in the complexes, most of which are coplanar. The energy barriers, between different stable and transition states structures with zero point energy (ZPE) corrections, show that proton transfer occurs at room temperature with coplanar configuration that has the lowest energy. The results clearly support that reorientation gives triazole flexibility for proton transfer. (author)

Packaging of microwave integrated circuits operating beyond 100 GHz

Science.gov (United States)

Samoska, L.; Daniel, E.; Sokolov, V.; Sommerfeldt, S.; Bublitz, J.; Olson, K.; Gilbert, B.; Chow, D.

2002-01-01

Several methods of packaging high speed (75-330 GHz) InP HEMT MMIC devices are discussed. Coplanar wirebonding is presented with measured insertion loss of less than 0.5dB and return loss better than -17 dB from DC to 110 GHz. A motherboard/daughterboard packaging scheme is presented which supports minimum loss chains of MMICs using this coplanar wirebonding method. Split waveguide block packaging approaches are presented in G-band (140-220 GHz) with two types of MMIC-waveguide transitions: E-plane probe andantipodal finline.

Application of heating in dex in Los Humeros geothermal reservoir; Comportamiento de los indices de calentamiento en el yacimiento geotermico de los Humeros

Energy Technology Data Exchange (ETDEWEB)

Aragon, Alfonso; Arellano, Victor M; Izquierdo, Georgina; Garcia, Alfonso; Barragan, Rosa Maria; Verma, Mahendra P [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Pizano, Arturo [Comision Federal de Electricidad, Los Humeros (Mexico)

2000-12-01

Reservoir engineering uses several methodologies to evaluate reservoir information characteristics, which in one well vary with time during its production life. One of the methods widely used is the pressure analysis by stimulating the reservoir through cold water injection. For this case, the temperature is used as stimulating parameter and the resultant perturbation is analyzed for the formation intervals in order to determine reservoir permeability and thickness. This method requires a set of temperature logs taking a different stability time. The heating index is calculated from the temperature gradient with time. The index correlated with drilling parameters such as the circulation lost volume, lithology, drilling speed, et cetera. It is used identify interesting reservoir characteristics for production and injections purposes. The method is applied on wells: Br-2 from Broadlands, New Zealand; and H-11, H-31 and H-33 from Los Humeros, Mexico. The results indicate the usefulness of this method in evaluating geothermal reservoirs. [Spanish] La ingenieria de yacimientos dispone de diversas tecnicas para la evaluacion de las caracteristicas de los espesores de la formacion en un pozo, cuyo comportamiento cambia a largo de las diferentes etapas de su vida productiva. Uno de los metodos ampliamente utilizados es el comportamiento de la presion a traves de estimulos suministrados al yacimiento. Haciendo una analogia de la presion, para el caso de inyeccion de agua fria, se utiliza la temperatura como estimulo y se analizan los disturbios que esta provoca en algunas secciones de la formacion, a partir de lo cual es factible determinar intervalos permeables en el yacimiento. El metodo requiere de un par de perfiles de temperatura registrados a diferente tiempo de reposo del pozo. Con las diferencias de temperatura respecto al tiempo, se calcula el indice de calentamiento el cual se correlaciona con los parametros disponibles, contenidos durante la perforacion, como son

Use of Metallic Endosseous Implants as a Tooth Substitute

Science.gov (United States)

1975-11-25

metallic blades driven into the bone to become an anchor for prosthetic appliances. A complete critical review of the literature on dental implants was...Otto anni di practica col into metodo d’Infibulazione i:,otallica e-ndomn,,cel lare, rfrs;ultati e considerazioni, Riv. Ital. Sto::at. , January, I

MO-FG-CAMPUS-TeP2-05: Optimizing Stereotactic Radiosurgery Treatment of Multiple Brain Metastasis Lesions with Individualized Rotational Arc Trajectories

International Nuclear Information System (INIS)

Dong, P; Xing, L; Ma, L

2016-01-01

Purpose: Radiosurgery of multiple (n>4) brain metastasis lesions requires 3–4 noncoplanar VMAT arcs with excessively high monitor units and long delivery time. We investigated whether an improved optimization technique would decrease the needed arc numbers and increase the delivery efficiency, while improving or maintaining the plan quality. Methods: The proposed 4pi arc space optimization algorithm consists of two steps: automatic couch angle selection followed by aperture generation for each arc with optimized control points distribution. We use a greedy algorithm to select the couch angles. Starting from a single coplanar arc plan we search through the candidate noncoplanar arcs to pick a single noncoplanar arc that will bring the best plan quality when added into the existing treatment plan. Each time, only one additional noncoplanar arc is considered making the calculation time tractable. This process repeats itself until desired number of arc is reached. The technique is first evaluated in coplanar arc delivery scheme with testing cases and then applied to noncoplanar treatments of a case with 12 brain metastasis lesions. Results: Clinically acceptable plans are created within minutes. For the coplanar testing cases the algorithm yields singlearc plans with better dose distributions than that of two-arc VMAT, simultaneously with a 12–17% reduction in the delivery time and a 14–21% reduction in MUs. For the treatment of 12 brain mets while Paddick conformity indexes of the two plans were comparable the SCG-optimization with 2 arcs (1 noncoplanar and 1 coplanar) significantly improved the conventional VMAT with 3 arcs (2 noncoplanar and 1 coplanar). Specifically V16 V10 and V5 of the brain were reduced by 11%, 11% and 12% respectively. The beam delivery time was shortened by approximately 30%. Conclusion: The proposed 4pi arc space optimization technique promises to significantly reduce the brain toxicity while greatly improving the treatment efficiency.

MO-FG-CAMPUS-TeP2-05: Optimizing Stereotactic Radiosurgery Treatment of Multiple Brain Metastasis Lesions with Individualized Rotational Arc Trajectories

Energy Technology Data Exchange (ETDEWEB)

Dong, P; Xing, L [Stanford University School of Medicine, Stanford, CA (United States); Ma, L [UCSF Comprehensive Cancer Center, San Francisco, CA (United States)

2016-06-15

Purpose: Radiosurgery of multiple (n>4) brain metastasis lesions requires 3–4 noncoplanar VMAT arcs with excessively high monitor units and long delivery time. We investigated whether an improved optimization technique would decrease the needed arc numbers and increase the delivery efficiency, while improving or maintaining the plan quality. Methods: The proposed 4pi arc space optimization algorithm consists of two steps: automatic couch angle selection followed by aperture generation for each arc with optimized control points distribution. We use a greedy algorithm to select the couch angles. Starting from a single coplanar arc plan we search through the candidate noncoplanar arcs to pick a single noncoplanar arc that will bring the best plan quality when added into the existing treatment plan. Each time, only one additional noncoplanar arc is considered making the calculation time tractable. This process repeats itself until desired number of arc is reached. The technique is first evaluated in coplanar arc delivery scheme with testing cases and then applied to noncoplanar treatments of a case with 12 brain metastasis lesions. Results: Clinically acceptable plans are created within minutes. For the coplanar testing cases the algorithm yields singlearc plans with better dose distributions than that of two-arc VMAT, simultaneously with a 12–17% reduction in the delivery time and a 14–21% reduction in MUs. For the treatment of 12 brain mets while Paddick conformity indexes of the two plans were comparable the SCG-optimization with 2 arcs (1 noncoplanar and 1 coplanar) significantly improved the conventional VMAT with 3 arcs (2 noncoplanar and 1 coplanar). Specifically V16 V10 and V5 of the brain were reduced by 11%, 11% and 12% respectively. The beam delivery time was shortened by approximately 30%. Conclusion: The proposed 4pi arc space optimization technique promises to significantly reduce the brain toxicity while greatly improving the treatment efficiency.

Computer optimization of noncoplanar beam setups improves stereotactic treatment of liver tumors

International Nuclear Information System (INIS)

Pooter, Jacco A. de; Mendez Romero, Alejandra; Jansen, Wim; Storchi, Pascal; Woudstra, Evert; Levendag, Peter C.; Heijmen, Ben

2006-01-01

Purpose: To investigate whether computer-optimized fully noncoplanar beam setups may improve treatment plans for the stereotactic treatment of liver tumors. Methods: An algorithm for automated beam orientation and weight selection (Cycle) was extended for noncoplanar stereotactic treatments. For 8 liver patients previously treated in our clinic using a prescription isodose of 65%, Cycle was used to generate noncoplanar and coplanar plans with the highest achievable minimum planning target volume (PTV) dose for the clinically delivered isocenter and mean liver doses, while not violating the clinically applied hard planning constraints. The clinical and the optimized coplanar and noncoplanar plans were compared, with respect to D PTV,99% , the dose received by 99% of the PTV, the PTV generalized equivalent uniform dose (gEUD), and the compliance with the clinical constraints. Results: For each patient, the ratio between D PTV,99% and D isoc , and the gEUD -5 and gEUD -2 values of the optimized noncoplanar plan were higher than for the clinical plan with an average increase of respectively 18.8% (range, 7.8-24.0%), 6.4 Gy (range, 3.4-11.8 Gy), and 10.3 Gy (range, 6.7-12.5). D PTV,99% /D isoc , gEUD -5 , and gEUD -2 of the optimized noncoplanar plan was always higher than for the optimized coplanar plan with an average increase of, respectively, 4.5% (range, 0.2-9.7%), 2.7 Gy (range, 0.6-9.7 Gy), and 3.4 Gy (range, 0.6-9.9 Gy). All plans were within the imposed hard constraints. On average, the organs at risk were better spared with the optimized noncoplanar plan than with the optimized coplanar plan and the clinical plan. Conclusions: The use of automatically generated, fully noncoplanar beam setups results in plans that are favorable compared with coplanar techniques. Because of the automation, we found that the planning workload can be decreased from 1 to 2 days to 1 to 2 h

Identification and estimation ot carbohydrates using radioisotopic methods; Identification et dosage des hydrates de carbone a l'aide des radioisotopes; Identifikatsiya i opredelenie karbogidratov s pomoshch'yu radioizotopnykh metodov; Identificacion u valoracion de hidratos de carbono con ayuda de radioisotopos

Energy Technology Data Exchange (ETDEWEB)

Phillips, G O; Criddle, W J [Department of Chemistry, University College, Cardiff (United Kingdom)

1962-01-15

chromatogrammes sur bandes de papier; elle n'exige qu'une modification peu couteuse du materiel de comptage traditionnel. (author) [Spanish] Dado que los metodos analiticos clasicos no permiten obtener resultados satisfactorios, los autores han perfeccionado unos metodos de dilucion isotopica para identificar y valorar los productos que se forman en pequenas cantidades al exponer hidratos de carbono en solucion acuosa a las radiaciones gamma del {sup 60}Co. Las autorradiografias de cromatogramas sobre papel, obtenidos despues de irradiar soluciones de azucares marcados con {sup 14}C, revelan una considerable degradacion molecular. Gracias a un metodo de dilucion isotopica inverso basado en la adicion de portadores conocidos, y en la obtencion de derivados cristalizados de los fragmentos, los autores han podido determinar cuantitativamente los siguientes constituyentes. El metodo descrito por los autores permite distinguir entre estereoisomeros y valorar cada lino de ellos por separado. Asimismo puede utilizarse para resolver otros problemas de orden analitico que plantea la quimica de los hidratos de carbono. Los autores describen un nuevo metodo de exploracion y registro de la radiactividad a lo largo de las tiras de papel en las que se ha desarrollado el cromatograma. Este metodo solo requiere una modificacion poco onerosa del equipo de recuento corriente. (author) [Russian] Dlya identifikatsii i otsenki nebol'shikh kolichestv obrazovavshikhsya produktov pri obluchenii karbogidratov v vodnom rastvore gamma-aktivnym kobal'tom-60 byli razrabotany metody razbavleniya izotopov. Obychnye zhe analiticheskie metody okazalis' nedostatochnymi. Po obluchenii rastvorov S14-sakhar podgotovlennye avtoradiografii posle khromatografii na bumage ukazyvayut na znachitel'noe snizhenie. Ispol'zovanie protsedury obratnogo izotopnogo rastvora, svyazannoj s dobavkoj izvestnykh nositelej i preobrazovaniem oskolkov v derivaty kristallov, byli opredeleny kolichestvennye razmery sleduyushchikh

Improved Fourier-transform profilometry

International Nuclear Information System (INIS)

Mao Xianfu; Chen Wenjing; Su Xianyu

2007-01-01

An improved optical geometry of the projected-fringe profilometry technique, in which the exit pupil of the projecting lens and the entrance pupil of the imaging lens are neither at the same height above the reference plane nor coplanar, is discussed and used in Fourier-transform profilometry. Furthermore, an improved fringe-pattern description and phase-height mapping formula based on the improved geometrical generalization is deduced. Employing the new optical geometry, it is easier for us to obtain the full-field fringe by moving either the projector or the imaging device. Therefore the new method offers a flexible way to obtain reliable height distribution of a measured object

Computational Combination of the Optical Properties of Fenestration Layers at High Directional Resolution

Directory of Open Access Journals (Sweden)

Lars Oliver Grobe

2017-03-01

Full Text Available Complex fenestration systems typically comprise co-planar, clear and scattering layers. As there are many ways to combine layers in fenestration systems, a common approach in building simulation is to store optical properties separate for each layer. System properties are then computed employing a fast matrix formalism, often based on a directional basis devised by JHKlems comprising 145 incident and 145 outgoing directions. While this low directional resolution is found sufficient to predict illuminance and solar gains, it is too coarse to replicate the effects of directionality in the generation of imagery. For increased accuracy, a modification of the matrix formalism is proposed. The tensor-tree format of RADIANCE, employing an algorithm subdividing the hemisphere at variable resolutions, replaces the directional basis. The utilization of the tensor-tree with interfaces to simulation software allows sharing and re-use of data. The light scattering properties of two exemplary fenestration systems as computed employing the matrix formalism at variable resolution show good accordance with the results of ray-tracing. Computation times are reduced to 0.4% to 2.5% compared to ray-tracing through co-planar layers. Imagery computed employing the method illustrates the effect of directional resolution. The method is supposed to foster research in the field of daylighting, as well as applications in planning and design.

Diagnostics of pre-breakdown light emission in a helium coplanar barrier discharge: the presence of neutral bremsstrahlung

Czech Academy of Sciences Publication Activity Database

Navrátil, Z.; Morávek, T.; Ráhel’, J.; Čech, J.; Lalinský, Ondřej; Trunec, D.

2017-01-01

Roč. 26, č. 5 (2017), s. 1-10, č. článku 055025. ISSN 0963-0252 Institutional support: RVO:68081731 Keywords : dielectric barrier discharge * helium * single photon counting * bremsstrahlung * electric field * backward discharge * surface charge Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.302, year: 2016

A Comparison of Radioisotope Methods for River Flow Measurement; Comparaison de methodes radioisotopiques de mesure du debit des cours d'eau; Sravnenie radioizotopnykh metodov izmereniya rechnykh stokov; Comparacion de los metodos radioisotopicos para medir el caudal de los rios

Energy Technology Data Exchange (ETDEWEB)

Clayton, C. G.; Smith, D. B. [Wantage Research Laboratory Atomic Energy Research Establishment Wantage, Berks (United Kingdom)

1963-08-15

consequent d'aucune utilite comme indicateur dans la mesure du debit d'un cours d'eau s'il n'est pas employe avec un entraineur; mais avec un entraineur, on observe une amelioration marquee de l'exactitude des resultats. {sup 24}Na et {sup 82}Br n'ont accuse aucune adsorption a des distances bien superieures a celles qui sont necessaires pour assurer une brassage lateral; dans la riviere la plus lente, toutefois, on a note, a plus de 660 m du point d'injection, une certaine diminution de {sup 24}Na. Le memoire contient quelques observations sur la dispersion laterale et longitudinale qui, a une certain degre, influe sur l'application generale des methodes radioisotopiques a la mesure du debit des cours d'eau. Les auteurs parviennent a la conclusion que les trois methodes donnent des resultats satisfaisants. Ils preferent, en fin'de compte, la methode d'echantillonnage continue, car elle donne les resultats les plus exacts pour, la quantite minimum d'indicateur. (author) [Spanish] Los autores han empleado los procedimientos de dilucion, muestreo continuo y recuento total en un estudio comparativo de los metodos radioisotopicos de medicion de caudales fluviales en el arroyo Aylburton, en Gloucestershire, y en los rios Usway Burn y Alwin, en Northumberland. Se trata de tres tios de caracteristicas geologicas diferentes, cuyos caudales oscilan entre 2,5 1/s y 3 m{sup 3}/s. En todos los metodos de medicion de caudales que emplean indicadores, la distancia entre el punto en que se efectua la medicion y el punto en que se anade el indicador tiene que ser suficientemente grande para que se produzca una mezcla lateral completa. Por otra parte, no debe ser excesiva para evitar que la dipersion longitudinal supere cierto valor o que se pierda parte del indicador por adsorcion en el lecho fluvial. La dispersion depende de las caracteristicas hidraulicad de la corriente y es inherente al metodo. Por su parte, la adsorcion depende del indicador elegido y de las caracteristicas geologicas

Lo status di rifugiato religioso nelle fonti del diritto internazionale: le nuove frontiere delle libertà dello spirito

Directory of Open Access Journals (Sweden)

Daniele Ferrari

2017-11-01

Full Text Available SOMMARIO: 1. Libertà religiosa e protezione internazionale: note introduttive e di metodo - 2. La nozione di religione perseguitata - 3. I contenuti di tutela della libertà religiosa dei perseguitati - 4. Le condizioni di riconoscimento dello status di rifugiato religioso - 5. La procedura di valutazione delle domande - 6. Conclusioni.

Phase diagram and topological phases in the triangular lattice Kitaev-Hubbard model

Science.gov (United States)

Li, Kai; Yu, Shun-Li; Gu, Zhao-Long; Li, Jian-Xin

2016-09-01

We study the half-filled Hubbard model on a triangular lattice with spin-dependent Kitaev-like hopping. Using the variational cluster approach, we identify five phases: a metallic phase, a non-coplanar chiral magnetic order, a 120° magnetic order, a nonmagnetic insulator (NMI), and an interacting Chern insulator (CI) with a nonzero Chern number. The transition from CI to NMI is characterized by the change of the charge gap from an indirect band gap to a direct Mott gap. Based on the slave-rotor mean-field theory, the NMI phase is further suggested to be a gapless Mott insulator with a spinon Fermi surface or a fractionalized CI with nontrivial spinon topology, depending on the strength of the Kitaev-like hopping. Our work highlights the rising field in which interesting phases emerge from the interplay between band topology and Mott physics.

Switchable diode effect in oxygen vacancy-modulated SrTiO{sub 3} single crystal

Energy Technology Data Exchange (ETDEWEB)

Pan, Xinqiang; Shuai, Yao; Wu, Chuangui; Luo, Wenbo; Sun, Xiangyu; Zeng, Huizhong; Bai, Xiaoyuan; Gong, Chaoguan; Jian, Ke; Zhang, Wanli [University of Electronic Science and Technology of China, State Key Laboratory of Electronic Thin Films and Integrated Devices, Chengdu (China); Zhang, Lu; Guo, Hongliang [University of Electronic Science and Technology of China, The Center for Robotics, Chengdu (China); Tian, Benlang [26th Institute of China Electronics Technology Group Corporation, Chongqing (China)

2017-09-15

SrTiO{sub 3} (STO) single crystal wafer was annealed in vacuum, and co-planar metal-insulator-metal structure of Pt/Ti/STO/Ti/Pt were formed by sputtering Pt/Ti electrodes onto the surface of STO after annealing. The forming-free resistive switching behavior with self-compliance property was observed in the sample. The sample showed switchable diode effect, which is explained by a simple model that redistribution of oxygen vacancies (OVs) under the external electric field results in the formation of n-n{sup +} junction or n{sup +}-n junction (n donated n-type semiconductor; n{sup +} donated heavily doped n-type semiconductor). The self-compliance property is also interpreted by the formation of n-n{sup +}/n{sup +}-n junction caused by the migration of the OVs under the electric field. (orig.)

Water equivalent thickness of immobilization devices in proton therapy planning - Modelling at treatment planning and validation by measurements with a multi-layer ionization chamber.

Science.gov (United States)

Fellin, Francesco; Righetto, Roberto; Fava, Giovanni; Trevisan, Diego; Amelio, Dante; Farace, Paolo

2017-03-01

To investigate the range errors made in treatment planning due to the presence of the immobilization devices along the proton beam path. The measured water equivalent thickness (WET) of selected devices was measured by a high-energy spot and a multi-layer ionization chamber and compared with that predicted by treatment planning system (TPS). Two treatment couches, two thermoplastic masks (both un-stretched and stretched) and one headrest were selected. At TPS, every immobilization device was modelled as being part of the patient. The following parameters were assessed: CT acquisition protocol, dose-calculation grid-sizes (1.5 and 3.0mm) and beam-entrance with respect to the devices (coplanar and non-coplanar). Finally, the potential errors produced by a wrong manual separation between treatment couch and the CT table (not present during treatment) were investigated. In the thermoplastic mask, there was a clear effect due to beam entrance, a moderate effect due to the CT protocols and almost no effect due to TPS grid-size, with 1mm errors observed only when thick un-stretched portions were crossed by non-coplanar beams. In the treatment couches the WET errors were negligible (0.5mm with a 3.0mm grid-size. In the headrest, WET errors were negligible (0.2mm). With only one exception (un-stretched mask, non-coplanar beams), the WET of all the immobilization devices was properly modelled by the TPS. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

SUI CODICI UNIDIREZIONALI

Directory of Open Access Journals (Sweden)

Luca Tallini

1992-04-01

Full Text Available Oltre ad una breve descrizione della problematica sui codici Unidirezionali è qui data la dimostrazione di una congettura di S. Al-Bassan e B. Bose che interviene nella teoria dei suddetti autori, sulla costruzione di codici ottimali nella classe dei codici bilanciati che si ottengono con il metodo della complementazione di Knuth.

TEMPI DI TRAGITTO DELLE ONDE P* E SPESSORE DELLO STRATO DEL GRANITO NELL'ITALIA CENTRALE

Directory of Open Access Journals (Sweden)

L. Marcelli

1951-06-01

Full Text Available Proseguendo lo studio del terremoto del Gran Sasso d'Italia del5 settembre 1950 si rilevano alcune caratteristiche sismiche dell'Italiacentrale.Si determina la profondità ipocentrale con il metodo dell'angolodi emergenza. Indi si costruisce la dromocrona delle P* e si calcolalo spessore dello strato del granito relativamente alla zona.

100 GHz pulse waveform measurement based on electro-optic sampling

Science.gov (United States)

Feng, Zhigang; Zhao, Kejia; Yang, Zhijun; Miao, Jingyuan; Chen, He

2018-05-01

We present an ultrafast pulse waveform measurement system based on an electro-optic sampling technique at 1560 nm and prepare LiTaO3-based electro-optic modulators with a coplanar waveguide structure. The transmission and reflection characteristics of electrical pulses on a coplanar waveguide terminated with an open circuit and a resistor are investigated by analyzing the corresponding time-domain pulse waveforms. We measure the output electrical pulse waveform of a 100 GHz photodiode and the obtained rise times of the impulse and step responses are 2.5 and 3.4 ps, respectively.

THz Wave Propagation on Strip Lines: Devices, Properties, and Applications

Directory of Open Access Journals (Sweden)

Y. Kadoya

2008-06-01

Full Text Available We report the propagation characteristics of THz pulses on micro-strip-lines and coplanar strip-lines, in which low permittivity polymer materials are used as the dielectric layer or the substrate. As a result of the low attenuation and small dispersion in the devices, the spectral width up to 3 THz can be achieved even after the 1 mm propagation. Spectroscopic characterizations of liquid or powder specimens are demonstrated using the devices. We also show a possibility of realizing a very low attenuation using a quadrupole mode in three strip coplanar lines on the polymer substrate.

Investigations into the relationship between spheromak, solar, and astrophysical plasmas

International Nuclear Information System (INIS)

Bellan, P.M.; Hsu, S.C.; Hansen, J.F.; Tokman, M.; Pracko, S.E.; Romero-Talamas, C.A.

2003-01-01

Spheromaks offer the potential for a simple, low cost fusion reactor and involve physics similar to certain solar and astrophysical phenomena. A program to improve understanding of spheromaks by exploiting this relationship is underway using (i) a planar spheromak gun and (ii) a solar prominence simulator. These devices differ in symmetry but both involve spheromak technology whereby high-voltage is applied across electrodes linking a bias magnetic flux created by external coils. The planar spheromak gun consists of a co-planar disk and annulus linked by a poloidal bias field. Application of high voltage across the gap between disk and annulus drives a current along the bias field. If the current to flux ratio exceeds the inverse of the characteristic linear dimension, a spheromak is ejected. A distinct kink forms just below the ejection threshold. The solar simulation gun consists of two adjacent electromagnets which generate a 'horse-shoe' arched bias field. A current is driven along this arched field by a capacitor bank. The current channel first undergoes pinching, then writhes, and finally bulges outwards due to the hoop force. (author)

Métodos cromatográficos para determinar aminas biogênicas em alimentos de origem animal

Directory of Open Access Journals (Sweden)

César Aquiles Lázaro de la Torre

2013-12-01

Full Text Available Aminas biogenicas sao formadas como resultado da descarboxilacao de aminoacidos livres especificos. A analise desses metabolitos e de grande importancia na determinacao da qualidade e monitoramento de biogenicas como histamina e tiramina relacionadas com episodios de intoxicacao em humanos. A cromatografia e uma tecnica de separacao química usada para caracterizar aminas biogenicas. Variacoes da tecnica (cromatografia liquida, em camada delgada e gasosa tem sido amplamente usadas, porem a complexidade da matriz alimentar faz com que sejam realizadas mudancas nos processos de extracao, derivatizacao e deteccao em concordancia com cada grupo de alimento. A cromatografia liquida de alta eficiencia (CLAE e o metodo mais utilizado na determinacao de aminas biogenicas em alimentos. Contudo, devido a importancia das aminas biogenicas no controle da qualidade e a seguranca do consumidor, os pesquisadores tentam desenvolver novos metodos com o intuito de uma analise mais rapida e precisa para o controle de alimentos no mercado. O objetivo da revisao e apresentar algumas tecnicas cromatograficas aplicadas no monitoramento de aminas biogenicas em produtos de origem animal.

Il gradiente implicito nella verifica a fatica di giunzioni saldate sollecitate a fatica

Directory of Open Access Journals (Sweden)

R. Tovo

2009-07-01

Full Text Available L’incremento delle potenzialità di strumenti per la progettazione assistita (come modellatori solidi e strumenti per FEA in grado di gestire modelli molto complessi permette di ipotizzare lo sviluppo di strumenti numerici specifici per la previsione della resistenza a fatica delle giunzioni saldate. Tali strumenti potrebbero essere in grado di valutare l’influenza di geometria e carichi senza la necessità di elaborazioni successive, e spesso, del progettista (come nelle tensioni di Hot Spot. Il presente lavoro propone una metodologia di calcolo adatta alla previsione della vita a fatica di giunzioni saldate complesse. Un indice di resistenza è ottenuto innanzitutto risolvendo il problema tensionale completamente in modo numerico (agli elementi finiti. La previsione della resistenza a fatica, è calcolata facendo uso di un modello analitico basato sul gradiente implicito che assume come tensione efficace la tensione equivalente non locale derivante dalla tensione principale. Dapprima verrà tarato il metodo su prove sperimentali eseguite su giunzioni saldate a croce, successivamente il metodo verrà utilizzato per la verifica a fatica di giunzioni saldate più complesse a sviluppo tridimensionale.

La riscoperta della stereoscopia per la rappresentazione dello spazio architettonico

Directory of Open Access Journals (Sweden)

Simone Garagnani

2011-06-01

Full Text Available Il progressivo sviluppo dei metodi della rappresentazione grafica nel corso della storia è stato possibile in virtù della scoperta di strumenti e tecniche appartenenti al loro tempo: questo continuo progresso delle modalità di “raccontare” l’architettura è tuttora in corso di evoluzione, costituendo il fondamento di ogni strategia informativa e di comunicazione del progetto. Il sempre più pervasivo trattamento digitale dell’informazione, sia essa grafica che testuale, ha condotto ad una progressiva riscoperta di approcci tradizionali nella descrizione dello spazio costruito, declinandoli alle nuove tecnologie informatiche per amplificarne possibilità e valenze. È il caso della stereoscopia, diffuso metodo ottocentesco adottato in fotografia per rendere spaziale la percezione dell’immagine sfruttando la visione binoculare; oggi i modelli tridimensionali e le immagini digitali catturate da apposite fotocamere rendono l’approccio stereoscopico di immediato utilizzo anche per i profani della rappresentazione, semplificando e rendendo trasparenti i concetti di geometria proiettiva alla base del metodo. Questo contributo intende indagare le funzionalità, i vantaggi e le criticità della tecnologia stereoscopica immersiva nella moderna comunicazione del progetto d’architettura.

Physical fundaments of supersonic molecular beams; Fondamenti fisici dei fasci molecolari supersonici. Parte 7: Il getto libero supersonico

Energy Technology Data Exchange (ETDEWEB)

Tomassetti, G. [L' Aquila Univ., L' Aquila (Italy). Dipt. di Fisica; Sanna, G.

1999-07-01

The structure of the free jet emitted by a converging nozzle as obtained by the method of characteristics by Ashkenas and Sherman is described in details. In particular the dependence of the field variable by the distance from the nozzle is given. The transition from continuum to molecular free regime is then considered and the sudden freeze approximation is introduced. The processing of monoatomic and polyatomic gasses is also considered. [Italian] Le caratteristiche del campo di flusso in regime continuo di un getto libero supersonico ottenute col metodo delle caratteristiche da Askenas e Sherman sono messe in evidenza. In particolare le relazioni analitiche per i parametri di flusso in funzione della distanza dal nozzle sono riportate. Viene poi considerata la transazione al regime molecolare ed e' introdotta la sudden freeze approximation. Vengono anche considerate le situazioni di non equilibrio tra gradi di liberta' interni ed esterni.

Supersonic free jet, molecular free regime; Fondamenti fisici dei fasci molecolari supersonici. Parte 7. Il getto libero supersonico

Energy Technology Data Exchange (ETDEWEB)

Sanna, G. [ENEA, Centro Ricerche Frascati, Rome (Italy). Dipt. Innovazione; Tomassetti, G. [L' Aquila Univ., L' Aquila (Italy). Dipt. di Fisica

1999-07-01

The structure of the free jet emitted by a converging nozzle as obtained by the method of characteristics by Ashkenas e Sherman is described in details. In particular the dependence of the field variable by the distance from the nozzle is given. The transition from continuum to molecular free regime is then considered and the sudden freeze approximation is introduced. The processing of monoatomic and polyatomic gasses is also considered. [Italian] Le caratteristiche del campo di flusso in regime continuo di un getto libero supersonico ottenute col metodo delle caratteristiche da Ashekanas e Sherman sono messe in evidenza. In paricolare le relazioni analitiche per i parametri di flusso in funzione della distanza dal nozzle sono riportate. Viene poi considerata la transizione al regime molecolare ed e' introdotta la sudden freeze approximation. Vengono anche considerate le situazioni di non equilibrio tra gradi di liberta' interni ed esterni.

Impact of tumor attachment to the pleura measured by a pretreatment CT image on outcome of stage I NSCLC treated with stereotactic body radiotherapy

International Nuclear Information System (INIS)

Yamamoto, Takaya; Kadoya, Noriyuki; Shirata, Yuko; Koto, Masashi; Sato, Kiyokazu; Matsushita, Haruo; Sugawara, Toshiyuki; Umezawa, Rei; Kubozono, Masaki; Ishikawa, Yojiro; Kozumi, Maiko; Takahashi, Noriyoshi; Ito, Kengo; Katagiri, Yu; Takeda, Ken; Jingu, Keiichi

2015-01-01

Pleural invasion status is known to be a predictor of survival after pulmonary resection for non-small cell lung cancer. Our goal was to determine whether the length of tumor attachment to the pleura on a pretreatment CT image has prognostic value as an alternative to pleural invasion status for stage I non-small cell lung cancer treated with stereotactic body radiotherapy (SBRT). A total of 90 tumors in 87 patients (males: 68, females: 19) who received SBRT between March 2005 and September 2011 in our institution were reviewed. The median age of the patients was 78 years (range, 48-90 years). The median tumor diameter was 2.2 cm (range, 0.9-4.2 cm). The prescribed dose was typically 48 Gy in 4 fractions, 60 Gy in 8 fractions or 60 Gy in 15 fractions to the isocenter with 6 MV X-ray using 4 non-coplanar and 3 coplanar static beams. The lengths of attachment were measured using pretreatment CT images at the lung window. Cumulative incidence rates were calculated using Kaplan-Meier curves, and univariate and multivariate analyses for in-field tumor control, locoregional control (LRC), freedom from distant metastasis and freedom from progression (FFP) were performed using a Cox proportional hazards model. Of the 90 tumors, 42 tumors were attached to the pleura (median, 14.7 mm; range, 4.3-36.0 mm), 21 tumors had pleural indentation and 27 tumors had no attachment. The median follow-up period for survivors was 46.1 months. The 3-year in-field control, LRC, FFP and overall survival rates were 91.2%, 75.3%, 63.8% and 68.6%, respectively. SBRT dose and tumor diameter were independently significant predictors of in-field control (p = 0.02 and p = 0.04, respectively). Broad attachment to the pleura, the length being more than 14.7 mm, was a negative independent predictor of LRC and FFP (p = 0.02 and p = 0.01, respectively). Pleural attachment status on a pretreatment CT image might be an important predictor of LRC and FFP

Field transformations to multivalued fields

Energy Technology Data Exchange (ETDEWEB)

Kleinert, H [Institut fuer Theoretische Physik, Arnimallee 14, D-14195 Berlin (Germany)

2007-05-15

Changes of field variables may lead to multivalued fields which do not satisfy the Schwarz integrability conditions. Their quantum field theory needs special care as is shown in an application to the superfluid and superconducting phase transitions.

Variation on the magnetic field profiles of transmission lines for various surrounding conditions calculated by the finite element method; Variacion de los perfiles de campo magnetico en lineas de transmision en diversas condiciones del entorno calculadas mediante el metodo de elementos finitos

Energy Technology Data Exchange (ETDEWEB)

Ponta, Fernando; Ferreira, Fabiana

2001-07-01

This paper applies the finite element method for the calculation of line magnetic field transversal profile using own routine calculation. Using a real case, simulations were performed under various conditions gathering distortion elements, obtaining the field profile. By analysing these results conclusions are drawing related to the changes produced by the distortions on the magnetic field configuration and evaluations of the surrounding elements influence are evaluated.

Computer simulating for oil fields with artificial elevation method by electrical submersible pump; Simulacao computacional para pocos de petroleo com metodo de elevacao artificial por bombeio centrifugo submerso

Energy Technology Data Exchange (ETDEWEB)

Batista, Evellyne da Silva; Maitelli, Andre Laurindo [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Costa, Rutacio de Oliveira [PETROBRAS S.A., Natal, RN (Brazil). Unidade de Negocio RN/CE; Barbosa, Tiago de Souza [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia de Computacao

2008-07-01

The architecture heterogeneities and petrophysical properties of carbonate reservoirs result from a combination of platform morphology, related depositional environments, relative sea level changes and diagenetic events. The reservoir layering built for static and dynamic modelling purposes should reflect the key heterogeneities (depositional or diagenetic) which govern the fluid flow patterns. The layering needs to be adapted to the goal of the modelling, ranging from full field computations of hydrocarbon volumes, to sector-based fine-scale simulations to test the recovery improvement. This paper illustrates various reservoir layering types, including schemes dominated by depositional architecture, and those more driven by the diagenetic overprint. The examples include carbonate platform reservoirs from different stratigraphic settings (Tertiary, Cretaceous, Jurassic and Permian) and different regions (Europe, Africa and Middle East areas). This review shows how significant stratigraphic surfaces (such as sequence boundaries or maximum flooding) with their associated facies shifts, can be often considered as key markers to constrain the reservoir layering. Conversely, how diagenesis (dolomitization and karst development), resulting in units with particular poroperm characteristics, may significantly overprint the primary reservoir architecture by generating flow units which cross-cut depositional sequences. To demonstrate how diagenetic processes can create reservoir bodies with geometries that cross-cut the depositional fabric, different types of dolomitization and karst development are illustrated. (author)

Short communications

African Journals Online (AJOL)

1988-08-09

Aug 9, 1988 ... metodos de trabajo con el zooplancton marino, (ed.) Boltovsky, D. INIDEP Mar del Plata, Argentina. KUO. C.M., NASH, C.E. & SHEHADEH, Z.H. 1974. A ... The state of the gonads of the striped mullet (MugU cephalus) and the sharpnose mullet (Mugi/ saliens) leaving estuaries to spawn and their reaction to ...

Optimisation of radiotherapy for carcinoma of the parotid gland: a comparison of conventional, three-dimensional conformal, and intensity-modulated techniques

International Nuclear Information System (INIS)

Nutting, Christopher M.; Rowbottom, Carl G.; Cosgrove, Vivian P.; Henk, J. Michael; Dearnaley, David P.; Robinson, Martin H.; Conway, John; Webb, Steve

2001-01-01

Background and purpose: To compare external beam radiotherapy techniques for parotid gland tumours using conventional radiotherapy (RT), three-dimensional conformal radiotherapy (3DCRT), and intensity-modulated radiotherapy (IMRT). To optimise the IMRT techniques, and to produce an IMRT class solution. Materials and methods: The planning target volume (PTV), contra-lateral parotid gland, oral cavity, brain-stem, brain and cochlea were outlined on CT planning scans of six patients with parotid gland tumours. Optimised conventional RT and 3DCRT plans were created and compared with inverse-planned IMRT dose distributions using dose-volume histograms. The aim was to reduce the radiation dose to organs at risk and improve the PTV dose distribution. A beam-direction optimisation algorithm was used to improve the dose distribution of the IMRT plans, and a class solution for parotid gland IMRT was investigated. Results: 3DCRT plans produced an equivalent PTV irradiation and reduced the dose to the cochlea, oral cavity, brain, and other normal tissues compared with conventional RT. IMRT further reduced the radiation dose to the cochlea and oral cavity compared with 3DCRT. For nine- and seven-field IMRT techniques, there was an increase in low-dose radiation to non-target tissue and the contra-lateral parotid gland. IMRT plans produced using three to five optimised intensity-modulated beam directions maintained the advantages of the more complex IMRT plans, and reduced the contra-lateral parotid gland dose to acceptable levels. Three- and four-field non-coplanar beam arrangements increased the volume of brain irradiated, and increased PTV dose inhomogeneity. A four-field class solution consisting of paired ipsilateral coplanar anterior and posterior oblique beams (15, 45, 145 and 170 degree sign from the anterior plane) was developed which maintained the benefits without the complexity of individual patient optimisation. Conclusions: For patients with parotid gland tumours

Beyond dipolar regime in high-order plasmon mode bowtie antennas

Science.gov (United States)

Cuche, Aurélien; Viarbitskaya, Sviatlana; Kumar, Upkar; Sharma, Jadab; Arbouet, Arnaud; Girard, Christian; Dujardin, Erik

2017-03-01

Optical nanoantennas have shown their great potential for far-field to near-field coupling and for light confinement in subwavelength volumes. Here, we report on a multimodal configuration for bright and polarization-dependent bowtie antenna based on large and highly crystalline gold prisms. Each individual prism constituting an antenna arm sustains high order plasmon modes in the visible and near infrared range that allow for high field confinement and two-dimensional optical information propagation. We demonstrate by scanning two-photon luminescence (TPL) microscopy and numerical simulations based on the Green dyadic method that these bowtie antennas result in intense hot spots in different antenna locations as a function of the incident polarization. Finally, we quantify the local field enhancement above the antennas by computing the normalized total decay rate of a molecular system placed in the near field of the antenna gap as a function of the dipole orientation. We demonstrate the existence of a subtle relation between antenna geometry, polarization dependence and field enhancement. These new multimodal optical antennas are excellent far field to near field converter and they open the door for new strategies in the design of coplanar optical components for a wide range of applications including sensing, energy conversion or integrated information processing.

Relativistic electronic dressing in laser-assisted ionization of atomic hydrogen by electron impact

International Nuclear Information System (INIS)

Attaourti, Y.; Taj, S.

2004-01-01

Within the framework of the coplanar binary geometry where it is justified to use plane wave solutions for the study of the (e,2e) reaction and in the presence of a circularly polarized laser field, we introduce as a first step the Dirac-Volkov plane wave Born approximation 1 where we take into account only the relativistic dressing of the incident and scattered electrons. Then, we introduce the Dirac-Volkov plane wave Born approximation 2 where we take totally into account the relativistic dressing of the incident, scattered, and ejected electrons. We then compare the corresponding triple differential cross sections for laser-assisted ionization of atomic hydrogen by electron impact both for the nonrelativistic and the relativistic regime

Multiple spacecraft observations of interplanetary shocks: four spacecraft determination of shock normals

International Nuclear Information System (INIS)

Russell, C.T.; Mellott, M.M.; Smith, E.J.; King, J.H.

1983-01-01

ISEE 1,2,3 IMP8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for furture techniques. When the angle between upstream and downstream magnetic field is greater than 20, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, we recommend using overdetermined shock normal solutions whenever possible, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints

Il metodo storico nella critica testuale

OpenAIRE

Giangrande, Giusseppe

2008-01-01

Se ofrecen ejemplos de cómo es posible explicar por medio de un enfoque histórico pasajes controvertidos de autores griegos y latinos. Passages of Greek and Latin authors which many a critic cannot understand can often be explained by placing them in the proper historical perspective.

Probing the three-nucleon force using nucleon-deuteron breakup reactions

International Nuclear Information System (INIS)

Howell, C.R.; Lambert, J.M.; Witala, H.

1995-01-01

Results of our recent kinematically complete cross-section measurements of the space-star and coplanar-star configurations in n-d breakup at 13.0 MeV are reported. The experimental setup and details of the analysis are described. The new data for the space-star configuration are in good agreement with previous n-d data but differ significantly from both ''exact'' n-d calculations and p-d data. In contrast, the new coplanar-star data are in fair agreement with the calculations but are in gross disagreement with previous n-d data. The implications of these data for three-nucleon forces are discussed. (orig.)

Probing the three-nucleon force using nucleon-deuteron breakup reactions

Energy Technology Data Exchange (ETDEWEB)

Howell, C.R. [Duke Univ., Durham, NC (United States). Dept. of Physics; Setze, H.R. [Duke Univ., Durham, NC (United States). Dept. of Physics; Braun, R.T. [Duke Univ., Durham, NC (United States). Dept. of Physics; Gonzalez Trotter, D.E. [Duke Univ., Durham, NC (United States). Dept. of Physics; Hussein, A.H. [Duke Univ., Durham, NC (United States). Dept. of Physics; Roper, C.D. [Duke Univ., Durham, NC (United States). Dept. of Physics; Salinas, F. [Duke Univ., Durham, NC (United States). Dept. of Physics; Slaus, I. [Duke Univ., Durham, NC (United States). Dept. of Physics; Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics; Vlahovic, B. [Duke Univ., Durham, NC (United States). Dept. of Physics; Walter, R.L. [Duke Univ., Durham, NC (United States). Dept. of Physics; Mertens, G. [Tuebingen Univ. (Germany); Lambert, J.M. [Department of Physics, Georgetown University, Washington, DC 20057 (United States); Witala, H. [Institute of Physics, Jagellonian University, Reymonta 4, PL-30059 Cracow (Poland)

1995-05-01

Results of our recent kinematically complete cross-section measurements of the space-star and coplanar-star configurations in n-d breakup at 13.0 MeV are reported. The experimental setup and details of the analysis are described. The new data for the space-star configuration are in good agreement with previous n-d data but differ significantly from both ``exact`` n-d calculations and p-d data. In contrast, the new coplanar-star data are in fair agreement with the calculations but are in gross disagreement with previous n-d data. The implications of these data for three-nucleon forces are discussed. (orig.).

Flexible Polyhedral Surfaces with Two Flat Poses

Directory of Open Access Journals (Sweden)

Hellmuth Stachel

2015-05-01

Full Text Available We present three types of polyhedral surfaces, which are continuously flexible and have not only an initial pose, where all faces are coplanar, but pass during their self-motion through another pose with coplanar faces (“flat pose”. These surfaces are examples of so-called rigid origami, since we only admit exact flexions, i.e., each face remains rigid during the motion; only the dihedral angles vary. We analyze the geometry behind Miura-ori and address Kokotsakis’ example of a flexible tessellation with the particular case of a cyclic quadrangle. Finally, we recall Bricard’s octahedra of Type 3 and their relation to strophoids.

MEMS-based transmission lines for microwave applications

Science.gov (United States)

Wu, Qun; Fu, Jiahui; Gu, Xuemai; Shi, Huajuan; Lee, Jongchul

2003-04-01

This paper mainly presents a briefly review for recent progress in MEMS-based transmission lines for use in microwave and millimeterwave range. MEMS-based transmission lines including different transmission line structure such as membrane-supported microstrip line microstrip line, coplanar microshield transmission line, LIGA micromachined planar transmission line, micromachined waveguides and coplanar waveguide are discussed. MEMS-based transmission lines are characterized by low propagation loss, wide operation frequency band, low dispersion and high quality factor, in addition, the fabrication is compatible with traditional processing of integrated circuits (IC"s). The emergence of MEMS-based transmission lines provided a solution for miniaturizing microwave system and monolithic microwave integrated circuits.

Comparison of microelectrode sensing configurations for impedimetric cell monitoring

DEFF Research Database (Denmark)

Caviglia, Claudia; Heiskanen, Arto; Andresen, Thomas Lars

2012-01-01

interdigitated microelectrodes using a versatile custom-made monitoring platform including a 24-channel miniaturized potentiostat. As expected, characterization of bare microelectrodes in buffer and tracking experiments with HeLa cells over 16 hours demonstrate that the coplanar configuration provides a higher......A theoretical and experimental comparison between vertical and coplanar interdigitated sensing configurations for impedimetric cell growth tracking is presented. For the first time, these widely-adopted approaches are quantitatively compared on the same cell populations and on the same 10μm...... sensitivity to cell adhesion and spreading (Cell Index = 1.6 vs. 0.4) albeit at a higher frequency of maximum sensitivity (100kHz vs. 24 kHz)....

Classical trajectory Monte Carlo simulations of particle confinement using dual levitated coils

Directory of Open Access Journals (Sweden)

R. A. Lane

2014-07-01

Full Text Available The particle confinement properties of plasma confinement systems that employ dual levitated magnetic coils are investigated using classical trajectory Monte Carlo simulations. Two model systems are examined. In one, two identical current-carrying loops are coaxial and separated axially. In the second, two concentric and coplanar loops have different radii and carry equal currents. In both systems, a magnetic null circle is present between the current loops. Simulations are carried out for seven current loop separations for each system and at numerous values of magnetic field strength. Particle confinement is investigated at three locations between the loops at different distances from the magnetic null circle. Each simulated particle that did not escape the system exhibited one of four modes of confinement. Reduced results are given for both systems as the lowest magnetic field strength that exhibits complete confinement of all simulated particles for a particular loop separation.

Non-Destructive Testing Methods Applied to Multi-Finned SAP Tubing for Nuclear-Fuel Elements; Essais Non Destructifs de Gaines a Ailettes, en Poudre d'Aluminium Frittee, pour Elements Combustibles; Nedestruktivnye metody ispytaniya rebristykh trub iz spechennogo alyuminikiog'o poroshka dlya yadernykh toplivnykh ehlementov; Metodos de Ensayo No Destructivo Aplicados a Tubos de SAP con Aletas Multiples Destinados a Elementos Combustibles

Energy Technology Data Exchange (ETDEWEB)

Lund, S. A. [Danish Central Welding Institution, Copenhagen (Denmark); Knudsen, P. [Danish Atomic Energy Commission, Research Establishment, Risoe (Denmark)

1965-09-15

Energia Atomica de Dinamarca ha emprendido el estudio de un reactor de potencia con refrigerante organico y moderador de agua pesada. Los correspondientes elementos combustibles consisten en haces de 19 barras formadas por pastillas de dioxido de uranio sinterizado, encerradas en tubos de producto de aluminio sinterizado (SAP), de 2 m de longitud, provistos de aletas helicoidales. Para obtener condiciones optimas de transmision de calor y mantener la integridad del elemento combustible durante el funcionamiento del reactor, es necesario contar con tubos de muy alta calidad. Se citan dos ejemplos que ponen de manifiesto las estrechas tolerancias dimensionales adoptadas. Para asegurar una calidad adecuada de los tubos, se establecio un control de calidad muy estricto, basado en gran medida en la aplicacion de metodos no destructivos. Se describen en esta memoria las tecnicas desarrolladas para medir el espesor de pared y los diametros, y para descubrir defectos. La compleja seccion transversal, con 24 aletas, impide aplicar metodos ultrasonicos o de comentes de Foucault para medir el espesor de la pared. Por consiguiente, se desarrollo un calibre registrador de rayos beta, cuyo funcionamiento se basa en la atenuacion sufrida por la radiacion beta proveniente de una fuente de {sup 90}Sr colocada en el interior del tubo. Para el registro continuo del espesor de la pared del tubo con seccion transversal mas simple, de 12 aletas, se utiliza un metodo ultrasonico de resonancia por inmersion. Los diametros interno y externo (entre puntos de aletas) se registran de manera continua mediante calibres neumaticos rapidos. Las fallas se detectan mediante la tecnica de eco de impulsos ultrasonicos, y examinando los tubos con corrientes de Foucault. El metodo ultrasonico permite descubrir facilmente las fisuras transversales, pero hasta ahora ha sido imposible utilizarlo para la deteccion de defectos longitudinales. Por consiguiente, ademas del ensayo ultrasonico, se aplica el examen con

An electric field in a gravitational field

International Nuclear Information System (INIS)

Harpaz, Amos

2005-01-01

The behaviour of an electric field in a gravitational field is analysed. It is found that due to the mass (energy) of the electric field, it is subjected to gravity and it falls in the gravitational field. This fall curves the electric field, a stress force (a reaction force) is created, and the interaction of this reaction force with the static charge gives rise to the creation of radiation

Tripolar electric field Structure in guide field magnetic reconnection

Science.gov (United States)

Fu, Song; Huang, Shiyong; Zhou, Meng; Ni, Binbin; Deng, Xiaohua

2018-03-01

It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

Tripolar electric field Structure in guide field magnetic reconnection

Directory of Open Access Journals (Sweden)

S. Fu

2018-03-01

Full Text Available It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection. In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg. Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

Gauge fields in a torsion field

International Nuclear Information System (INIS)

Rosu, Ion

2004-01-01

In this paper we analyse the motion and the field equations in a non-null curvature and torsion space. In this 4-n dimensional space, the connection coefficients are γ bc a = 1/2S bc a + 1/2T bc a, where S bc a is the symmetrical part and T bc a are the components of the torsion tensor. We will consider that all the fields depend on x = x α , α = 1,2,3,4 and do not depend on y = y k , k=1,2,...,n. The factor S bc a depends on the components of the metric tensor g αβ (x) and on the gauge fields A ν s 0 (x) and the components of the torsion depend only on the gauge fields A ν s 0 (x). We take into consideration the particular case for which the geodesic equations coincide with the motion equations in the presence of the gravitational and the gauge fields. In this case the field equations are Einstein equations in a 4-n dimensional space. We show that both the geodesic equations and the field equations can be obtained from a variational principle. (author)

Commissioning and modification of the low temperature scanning polarization microscope (TTSPM) and imaging of the local magnetic flux density distribution in superconducting niobium samples

International Nuclear Information System (INIS)

Gruenzweig, Matthias Sebastian Peter

2014-01-01

possible to image the magnetization reversal process and thus the formation (or destruction) and the migration of an ''Interfacial Domain Wall'' (IDW) in such a Fe 1-x Tb x / vertical stroke Co/Pt vertical stroke n -heterostructure. Part II of the dissertation is about the magneto-optical imaging of superconducting Niobium coplanar microwave resonators as well as of a Niobium single crystal. By means of the magneto-optical images of the resonators, important findings about magnetic hysteresis effects in such coplanar microwave resonators could be achieved. It was also possible to confirm the results of transmission spectroscopy experiments on those coplanar resonators, which were performed in a previous dissertation of Daniel Bothner. Additionally, it was possible to show that initially inserted Abrikosov vortices can be almost completely removed from the coplanar resonators again by properly cycling the magnetic field. On the basis of magneto-optical images of a 2 mm thick Niobium single crystal, it was possible to observe dendritic avalanches in a superconducting bulk material for the first time. Here, the dendritic avalanches only appear in a very narrow temperature interval of about a tenth of a Kelvin below the critical temperature T c of the Niobium single crystal. Below this threshold temperature the magnetic flux penetrates nearly homogeneously into the single crystal. The observed dendritic avalanches in the bulk single crystal near T c have features which are identical to those seen in thin films at low temperatures caused by thermomagnetic instability. Therefore, one can conclude that the dendritic avalanches in the single crystal are formed in a thin superconducting layer at the surface of the single crystal, which can be formed under certain conditions near T c .

Propagation of 1-THz bandwidth electrical pulses on high Tc superconducting transmission lines

International Nuclear Information System (INIS)

Nuss, M.C.; Mankiewich, P.M.; Howard, R.E.; Harvey, T.E.; Brandle, C.D.; Straugh, B.L.; Smith, P.R.

1989-01-01

The new high temperature superconductors have triggered enormous interest not only because of the unique physics involved but also because of their technical potentials, such as the promise for propagation of extremely short electrical pulses. Superconducting band caps of --20TH z are predicted assuming BCS theory for the superconductor, making lossless propagation of electrical pulses as short as 50 fs possible. Despite microwave measurements at low frequencies of several gigahertz first studies at higher frequencies by Dykaar et al have shown distortion-free propagation of 100-GHz electrical pulses on YBa 2 Cu 3 O 3 (YBCO) lines for --5-mm propagation distance. Results were also reported for aluminum coplanar lines and a YBCO ground plane. The authors report on the propagation of 1-ps electrical pulses (1-THz bandwidth) on YBCO coplanar transmission lines defined on lanthanum gallate (LaGaO 3 ) as a substrate. On LaGaO 3 , YBCO grows highly oriented as on SrTiO 3 . However, unlike SrTiO 3 , LaGaO 3 has a much lower dielectric constant and small losses in the terahertz frequency range. Electrical pulses of --750-fs duration are generated in a radiation-damaged silicon-on-sapphire photoconductive switch integrated into a 20-μm coplanar stripline with 10-μm spacing and excited with 100-fs optical pulses from a CPM laser. An μ1-THz bandwidth electrical contact is made to the YBCO coplanar stripline defined on LaGaO 3 using a flip-chip geometry. They find that electrical pulses broaden only from 750 fs to 1 ps with little loss in amplitude on traveling through their flip-chip input and propagated electrical pulses are probed by electooptic sampling in two small LiTaO 3 crystals separated by 3 mm

Polychlorinated biphenyl-induced VCAM-1 expression is attenuated in aortic endothelial cells isolated from caveolin-1 deficient mice

International Nuclear Information System (INIS)

Han, Sung Gu; Eum, Sung Yong; Toborek, Michal; Smart, Eric; Hennig, Bernhard

2010-01-01

Exposure to environmental contaminants, such as polychlorinated biphenyls (PCBs), is a risk factor for the development of cardiovascular diseases such as atherosclerosis. Vascular cell adhesion molecule-1 (VCAM-1) is a critical mediator for adhesion and uptake of monocytes across the endothelium in the early stages of atherosclerosis development. The upregulation of VCAM-1 by PCBs may be dependent on functional membrane domains called caveolae. Caveolae are particularly abundant in endothelial cell membranes and involved in trafficking and signal transduction. The objective of this study was to investigate the role of caveolae in PCB-induced endothelial cell dysfunction. Primary mouse aortic endothelial cells (MAECs) isolated from caveolin-1-deficient mice and background C57BL/6 mice were treated with coplanar PCBs, such as PCB77 and PCB126. In addition, siRNA gene silencing technique was used to knockdown caveolin-1 in porcine vascular endothelial cells. In MAECs with functional caveolae, VCAM-1 protein levels were increased after exposure to both coplanar PCBs, whereas expression levels of VCAM-1 were not significantly altered in cells deficient of caveolin-1. Furthermore, PCB-induced monocyte adhesion was attenuated in caveolin-1-deficient MAECs. Similarly, siRNA silencing of caveolin-1 in porcine endothelial cells confirmed the caveolin-1-dependent VCAM-1 expression. Treatment of cells with PCB77 and PCB126 resulted in phosphorylation of extracellular signal-regulated kinase-1/2 (ERK1/2), and pharmacological inhibition of ERK1/2 diminished the observed PCB-induced increase in monocyte adhesion. These findings suggest that coplanar PCBs induce adhesion molecule expression, such as VCAM-1, in endothelial cells, and that this response is regulated by caveolin-1 and functional caveolae. Our data demonstrate a critical role of functional caveolae in the activation and dysfunction of endothelial cells by coplanar PCBs.

Gravitational potential energy of a disk-sphere pair of galaxies

International Nuclear Information System (INIS)

Ballabh, G.M.

1975-01-01

Algebraic expressions are obtained for the interaction potential energy of a pair of galaxies in which one is disk shaped and the other spherical. The density distribution in the disk galaxy is represented by a polynomial in ascending powers of the distance from the centre of the disk while the density distribution in the spherical galaxy is represented by the superposition of spherical polytropes of integral indices. The basic functions required for obtaining the interaction potential energy of a coplanar disk-sphere pair of galaxies are tabulated. The forces of attraction between a coplanar disk-sphere pair of galaxies are shown graphically for two density models of disk and spherical galaxies. An overlapping coplanar disk-sphere pair of galaxies attract just like two mass-points at a certain separation, rsub(c), of their centres. The force of attraction is less than that of two mass-points having masses equal to the masses of the two galaxies, if the separation of the centres is less than rsub(c), and greater if the separation is greater than rsub(c). For a typical coplanar disk-sphere pair of galaxies (the density of the disk is represented by Model II and of the sphere by a polytropic index n=4) of equal radii, the following is noted. At a separation of 0.79 R, R being the common radius of the two galaxies, the force of attraction between the pair is the same as if the entire mass of each galaxy is concentrated at its centre. The mass-point model for the two galaxies will overestimate the force of attraction by more than a factor of 10 if the separation is less than 0.36 R. For separation greater than the radii of the galaxies the mass-point model will underestimate the force but the departure in this case is less than 33%. (Auth.)

Body composition using deuterated water, index of insulin resistance and cortisol levels in Costa Rican school in the metropolitan area; Composicion corporal utilizando agua deuterada, indice de resistencia a la insulina y niveles de cortisol en escolares costarricenses del area metropolitana

Energy Technology Data Exchange (ETDEWEB)

Valverde Vindas, Allan Ignacio

2014-07-01

Body composition in the Costa Rican child population is evaluated and analyzed to determine the relationship with the index of insulin resistance and serum cortisol levels. 113 children in the metropolitan area were studied using deuterium isotope techniques as reference method for overweight and obesity. Morning cortisol levels were determined by immunoassay techniques (ELISA). The insulin resistance index of 113 Costa Rican boys and girls is obtained by the homeostatic method and the relationship between body composition with index of insulin resistance or levels of cortisol [Spanish] La composicion corporal en la poblacion infantil costarricense es evaluada y analizada para determinar la relacion con el indice de resistencia a la insulina y niveles de cortisol serico. 113 ninos y ninas del area metropolitana fueron estudiados utilizando tecnicas isotopicas de deuterio como metodo de referencia para sobrepeso y obesidad. Los niveles de cortisol matutino se han determinado mediante tecnicas inmunoensayo (ELISA). El indice resistencia a la insulina de 113 ninos y ninas costarricenses es obtenido mediante el metodo homeostatico asi como la relacion entre composicion corporal con indice de resistencia a la insulina o niveles de cortisol.

A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

Energy Technology Data Exchange (ETDEWEB)

Arya, S. P.; Mahajan, M. [Haryana, Kurukshetra Univ. (India). Dept. of Chemistry

1998-05-01

A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 {mu}g ml{sup -1}. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C. [Italiano] Si propone un rapido e semplice metodo spettrofotometrico per la determinazione dell`acido ascorbico. L`acido ascorbico riduce il ferro(III) a ferro(II) che forma con la dimetilgliossima, in presenza di piridina, un complesso colorato in rosso. L`assorbanza della soluzione risultante e` misurata a 514 nm e si ottiene una relazione lineare tra assorbanza e concentrazione dell`acido ascorbico fino a 14 {mu}g ml{sup -1}. Si sono condotti studi sugli interferenti usualmente associati all`acido ascorbico ed e` stata valutata l`applicabilita` del metodo all`analisi di preparati farmaceutici di vitamina C.

Learning on the fly with the analogical method

Directory of Open Access Journals (Sweden)

Zara Mehrnoosh

2016-04-01

Full Text Available Today in Italy 20-25% of students in primary school is reported to have difficulties with mathematical skills, although several researchers have noticed a man’s natural predisposition towards numbers. In the light of this high number of reports becomes therefore necessary to reconsider the didactic context to better support the natural evolution of numerical and mathematical cognition from early childhood. The following article presents the analogical method developed by Camillo Bortolato: non-conceptual didactic path focused on semantic process, subitizing and mental math. Apprendere al volo con il metodo analogicoAd oggi in Italia il 20-25% degli alunni nella scuola primaria viene segnalato per difficoltà nel calcolo, nonostante diversi ricercatori abbiano evidenziato una naturale predisposizione dell’uomo verso la numerosità. Alla luce di questo elevato numero di segnalazioni diviene necessario ripensare il contesto didattico per sostenere al meglio e fin dalla prima infanzia la naturale evoluzione della cognizione numerica e di calcolo. Nel seguente articolo viene presentato il metodo analogico di Camillo Bortolato, un percorso didattico non concettuale attento ai processi semantici, al ruolo del subitizing e del calcolo a mente.

Quantized fields in external field. Pt. 2

International Nuclear Information System (INIS)

Bellissard, J.

1976-01-01

The case of a charged scalar field is considered first. The existence of the corresponding Green's functions is proved. For weak fields, as well as pure electric or scalar external fields, the Bogoliubov S-operator is shown to be unitary, covariant, causal up-to-a-phase. These results are generalised to a class of higher spin quantized fields, 'nicely' coupled to external fields, which includes the Dirac theory, and in the case of minimal and magnetic dipole coupling, the spin one Petiau-Duffin-Kemmer theory. (orig.) [de

Wake fields and wake field acceleration

International Nuclear Information System (INIS)

Bane, K.L.F.; Wilson, P.B.; Weiland, T.

1984-12-01

In this lecture we introduce the concepts of wake fields and wake potentials, examine some basic properties of these functions, show how they can be calculated, and look briefly at a few important applications. One such application is wake field acceleration. The wake field accelerator is capable of producing the high gradients required for future very high energy e + e - linear colliders. The principles of wake field acceleration, and a brief description of experiments in progress in this area, are presented in the concluding section. 40 references, 27 figures

Jaws calibration method to get a homogeneous distribution of dose in the junction of hemi fields; Metodo de calibracion de mandibulas para conseguir una distribucion homogenea de dosis en la zona de union de hemicampos

Energy Technology Data Exchange (ETDEWEB)

Cenizo de Castro, E.; Garcia Pareja, S.; Moreno Saiz, C.; Hernandez Rodriguez, R.; Bodineau Gil, C.; Martin-Viera Cueto, J. A.

2011-07-01

Hemi fields treatments are widely used in radiotherapy. Because the tolerance established for the positioning of each jaw is 1 mm, may be cases of overlap or separation of up to 2 mm. This implies heterogeneity of doses up to 40% in the joint area. This paper presents an accurate method of calibration of the jaws so as to obtain homogeneous dose distributions when using this type of treatment. (Author)

Absolute triple differential cross section for electron-impact ionization of helium at 50 eV. Letter to the Editor

International Nuclear Information System (INIS)

Roeder, J.; Ehrhardt, H.; Bray, I.; Fursa, D.V.; McCarthy, I.E.

1995-01-01

A combined experimental and theoretical study of 50 eV electron-impact ionization of helium is presented. The absolute coplanar triple differential cross sections (TDCS) are measured for 4 eV and 10 eV slow electrons for fixed scattering angles; -20 deg, -25 deg, -30 deg and -35 deg of the fast electron. The convergent close-coupling (CCC) theory is used to calculate these and is found to be in good quantitative agreement with experiment for the 4 eV case, but lower than the measurement for the 10 eV case. The shape of the CCC theory shows good agreement with previous relative coplanar symmetric TDCS measurements. 11 refs., 4 figs

Geometry effects on the (e, 2e) cross section on ionic targets

International Nuclear Information System (INIS)

Khajuria, Y.

2005-01-01

The three body distorted wave Born approximation (DWBA) with spin averaged static exchange potential has been used to calculate the electron impact triple-differential cross section of Li + , Na + and K + ions in different geometries and kinematics. In coplanar geometry at high incident energy (≥ 500 eV) and scattering angle ∼10deg, both recoil and binary peaks in case of p-orbital electrons splits into two. The value of the binary to the recoil peak ratio for the specific value of the momentum transfer has been determined to understand the collision dynamics. In the non-coplanar geometry a strong interference resulting in a dip in triple differential cross section (TDCS) has been noticed. (author)

Methyl 5,7-dihydroxy-2,2,9-trimethyl-6,11-dioxo-6,11-dihydro-2H-anthra[2,3-b]pyran-8-carboxylate

Directory of Open Access Journals (Sweden)

Annelise Lobstein

2008-12-01

Full Text Available The title compound, C22H18O7, also known as laurentiquinone B, is a new anthraquinone which was isolated from Vismia laurentii, a Cameroonian medicinal plant. The asymmetric unit contains two independent molecules. Each of them contains four fused rings, three of which are coplanar and typical of anthracene, while the heterocyclic rings adopt envelope conformations. Intramolecular O—H...O hydrogen bonds result in the formation of two planar rings, which are also almost coplanar with the adjacent rings. In the crystal structure, intermolecular O—H...O and C—H...O hydrogen bonds link the molecules and a π–π contact is also present [centroid-centroid distance = 3.967 (3 Å].

Theoretical and experimental comparison of microelectrode sensing configurations for impedimetric cell monitoring

DEFF Research Database (Denmark)

Carminati, M.; Caviglia, Claudia; Heiskanen, Arto

2013-01-01

microelectrodes using a versatile custom-made monitoring platform including a 24-channel miniaturized potentiostat. The characterization of bare microelectrodes in buffer and tracking experiments with HeLa cells over 16 hours demonstrate that the coplanar configuration provides a higher sensitivity to cell......A theoretical and experimental comparison between vertical and coplanar interdigitated sensing configurations for impedimetric cell growth tracking is presented. These widely-adopted approaches are quantitatively compared on the same cell populations and on the same 10 μm interdigitated...... adhesion and spreading (Cell Index = 1.6 vs. 0.4) albeit at a higher frequency of maximum sensitivity (100 kHz vs. 24 kHz) shifting over time. © 2014 Taylor & Francis Group....

Productive fluid intervals in wells H-35 and H-39, Los Humeros geothermal field, Puebla (Mexico); Intervalos productores de fluidos en los pozos H-35 y H-39 del campo geotermico Los Humeros, Puebla, Mexico

Energy Technology Data Exchange (ETDEWEB)

Medina Martinez, Moises [Comision Federal de Electridad, Perote, Veracruz (Mexico)

2000-12-01

This paper presents the results of log interpretations using the percentage method to define the productive fluid intervals in wells H-35 and H-39. These were identified with pressure, temperature and flow rate (PTS) electronic logs, used for the first time in this field. The test were carried out with the well integrated to the electrical generation units. Well H-35 fed steam to Units 1, 4, 5 and 7 through a plate with a restriction orifice diameter of 50.8 mm (2 inches), a well head pressure of 45 bars and a mass flow rate of 40 t/h. Well H-39 fed steam to Unit 3 through plate with a restriction orifice diameter of 50.8 mm (2 inches), a well head pressure of 27 bars and a mass flow rate of 30 t/h. [Spanish] Se presenta la intervencion realizada por el metodo de porcentajes para definir los intervalos productores de fluidos en los pozos H-35 y H-39. El estudio se hizo a partir de datos obtenidos con una sonda electronica de presion, temperatura y velocidad de flujo (PTS), utilizada por primera vez en este campo. En ambos casos se realizaron las pruebas con el pozo integrado a las unidades de generacion electrica, el primero suministra vapor para las Unidades 1, 4, 5 y 7 a traves de una placa de orificio de restriccion de 50.8 mm (2 pulgadas) de diametro, con presion de cabezal de 45 bar manometricos y un gasto de mezcla de 40 t/h. El segundo alimenta a la Unidad 3, fluye por orificio de 50.8 mm (2 pulgadas) de diametro y produce 30 t/h de mezcla con una presion en la cabeza de 27 bar.

Multileaf collimator for radiotherapy machines

International Nuclear Information System (INIS)

Nunan, C.S.

1989-01-01

This patent describes an apparatus for radiotherapy treatment of a patient. It comprises: an electron linear accelerator means for generating x-rays at an x-ray source target; a set of four moveable jaws mounted on a jaw frame between the x-ray source target and the patient. The set of jaws defining a rectangular x-ray field; mounting means for mounting a leaf means on the jaw frame; the mounting means including a main leaf support frame; a pair of subframes, each of which is linearly movable mounted from the frame. The subframes being coplanar; a multiplicity of leaves of material substantially opaque to x-rays. The leaves provided with means to make them linearly movable relative to each subframe, each leaf being capable of extension beyond a field mid-line, the length of each leaf being shorter than half of a maximum field length capability of the jaws measured in the direction and plane of the leaves; leaf drive means; and computer control means for controlling the subframe drive means and the leaf drive means to provide a dynamically changing radiation field shape during the course of radiation treatment of the patient

Scaling control in superficial installations at the Las Tres Virgenes, geothermal field, BCS; Control de incrustacion en instalaciones superficiales del campo geotermico de Las Tres Virgenes, BCS

Energy Technology Data Exchange (ETDEWEB)

Tapia Salazar, Ruth [Comision Federal de Electricidad (Mexico)]. E-mail: ruth.tapia@cfe.gob.mx

2007-01-15

Silica scaling is one of the most important problems in the Las Tres Virgenes geothermal field. It affects not only the superficial installations, like brine injection pipelines, but also the injection wells where it reduces injection capacity. Separated brine passes from production wells to injection wells by means of steel pipelines 10 and 14 inches in diameter. The pipelines are affected by silica scaling that occurs when the two-phase fluid is discharged at atmospheric pressure and the separated brine is cooled and concentrated and then over saturated with amorphous silica. Even when the pipelines were cleaned periodically, it was necessary to implement a technique for prevent scaling. Two methods considered appropriate to the specific field conditions were studied, and finally the technique of modifying the brine pH was adopted. After over a year of using this technique in the general injection system, no mechanical cleaning of the pipelines has been necessary-and once cleaning was needed at least every third day. This represents an important improvement in the steam supply system. [Spanish] Uno de los problemas mas importantes en el campo geotermico de Las Tres Virgenes es la incrustacion por silice, la cual afecta no solo a instalaciones superficiales como lineas de inyeccion de salmuera, sino tambien a los pozos inyectores al reducir su capacidad de aceptacion. El agua producida por los pozos productores se conduce hasta los pozos inyectores por medio de tuberias de acero al carbon de 10 y 14 pulgadas de diametro, que se ven afectadas por la incrustacion de silice. La incrustacion ocurre debido a que cuando el fluido en dos fases es descargado a presion atmosferica, la salmuera separada, enfriada y concentrada, esta usualmente sobresaturada con respecto a la solubilidad de la silice amorfa. Aunque las tuberias se limpiaban mecanicamente, fue necesario seleccionar una tecnica para prevenir la incrustacion, para lo cual se estudiaron dos de los metodos que

Final Report for Grant of Properties of Magnetic Multilayer and Microstructures

National Research Council Canada - National Science Library

Camley, R

2002-01-01

...) Microwave Response of Microstructures Filters and Phase Shifters. Here we looked at exchange-spring systems, mictrostrip and coplanar notch filters and phase shifters using metallic ferromagnets. 3...

A field-sweep/field-lock system for superconducting magnets--Application to high-field EPR.

Science.gov (United States)

Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G

2006-12-01

We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of +/-0.4 T and a resolution of up to 10(-5) T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR.

A Field-Sweep/Field-Lock System for Superconducting Magnets-Application to High-Field EPR

Science.gov (United States)

Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G.

2007-01-01

We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H-NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of ± 0.4 T and a resolution of up to 10-5 T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR. PMID:17027306

The Resilience of Kepler Multi-systems to Stellar Obliquity

Science.gov (United States)

Spalding, Christopher; Marx, Noah W.; Batygin, Konstantin

2018-04-01

The Kepler mission and its successor K2 have brought forth a cascade of transiting planets. Many of these planetary systems exhibit multiple transiting members. However, a large fraction possesses only a single transiting planet. This high abundance of singles, dubbed the "Kepler Dichotomy," has been hypothesized to arise from significant mutual inclinations between orbits in multi-planet systems. Alternatively, the single-transiting population truly possesses no other planets in the system, but the true origin of the overabundance of single systems remains unresolved. In this work, we propose that planetary systems typically form with a coplanar, multiple-planetary architecture, but that quadrupolar gravitational perturbations from their rapidly-rotating host star subsequently disrupt this primordial coplanarity. We demonstrate that, given sufficient stellar obliquity, even systems beginning with 2 planetary constituents are susceptible to dynamical instability soon after planet formation, as a result of the stellar quadrupole moment. This mechanism stands as a widespread, yet poorly explored pathway toward planetary system instability. Moreover, by requiring that observed multi-systems remain coplanar on Gyr timescales, we are able to place upper limits on the stellar obliquity in systems such as K2-38 (obliquity < 20 degrees), where other methods of measuring spin-orbit misalignment are not currently available.

Carbon-ionogel supercapacitors for integrated microelectronics

Science.gov (United States)

Leung, Greg; Smith, Leland; Lau, Jonathan; Dunn, Bruce; Chui, Chi On

2016-01-01

To exceed the performance limits of dielectric capacitors in microelectronic circuit applications, we design and demonstrate on-chip coplanar electric double-layer capacitors (EDLCs), or supercapacitors, employing carbon-coated gold electrodes with ionogel electrolyte. The formation of carbon-coated microelectrodes is accomplished by solution processing and results in a ten-fold increase in EDLC capacitance compared to bare gold electrodes without carbon. At frequencies up to 10 Hz, an areal capacitance of 2.1 pF μm-2 is achieved for coplanar carbon-ionogel EDLCs with 10 μm electrode gaps and 0.14 mm2 electrode area. Our smallest devices, comprised of 5 μm electrode gaps and 80 μm2 of active electrode area, reach areal capacitance values of ˜0.3 pF μm-2 at frequencies up to 1 kHz, even without carbon. To our knowledge, these are the highest reported values to date for on-chip EDLCs with sub-mm2 areas. A physical EDLC model is developed through the use of computer-aided simulations for design exploration and optimization of coplanar EDLCs. Through modeling and comparison with experimental data, we highlight the importance of reducing the electrode gap and electrolyte resistance to achieve maximum performance from on-chip EDLCs.

A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan

Science.gov (United States)

YAMAMOTO, Kenya; KUDO, Mitsuhiro; ARITO, Heihachiro; OGAWA, Yasutaka; TAKATA, Tsutomu

2015-01-01

This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician’s interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects. PMID:26212412

OPTIMIZACIJA IN VALIDACIJA HPLC METODE ZA UGOTAVLJANJE VSEBNOSTI ARBUTINA V PRIPRAVKIH Z EKSTRAKTOM VEDNOZELENEGA GORNIKA (ARCTOSTAPHYLOS UVA-URSI L.)

OpenAIRE

Rajh, Eva

2010-01-01

Pripravki, ki vsebujejo ekstrakt ali učinkovino vednozelenega gornika, se zaradi vsebnosti arbutina, ki ima antiseptično delovanje, pogosto uporabljajo kot uroantiseptiki za samozdravljenje. Za namene zagotavljanja ustrezne kakovosti in pravilnega odmerjanja galenskega izdelka, ki so ga razvili v Javnem zdravstvenem zavodu Mariborskih lekarn Maribor, smo optimirali in validirali HPLC metodo, ki omogoča ugotavljanje vsebnosti arbutina v pripravkih, ki vsebujejo ekstrakt vednozelenega gorni...

Techniques for contact and contact with friction problems; Tecnicas para problemas de contacto y contacto con friccion

Energy Technology Data Exchange (ETDEWEB)

Velandia Arana, Gonzalo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

Different numerical techniques are presented based in the finite element method to obtain numerical solutions to contact and contact with friction problems between solid bodies, and compared between each other. [Espanol] Se presentan diferentes tecnicas numericas basadas en el metodo de elementos finitos para la obtencion de soluciones numericas de problemas de contacto y contacto con friccion entre cuerpos solidos, y se comparan entre si.

Techniques for contact and contact with friction problems; Tecnicas para problemas de contacto y contacto con friccion

Energy Technology Data Exchange (ETDEWEB)

Velandia Arana, Gonzalo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1989-12-31

Different numerical techniques are presented based in the finite element method to obtain numerical solutions to contact and contact with friction problems between solid bodies, and compared between each other. [Espanol] Se presentan diferentes tecnicas numericas basadas en el metodo de elementos finitos para la obtencion de soluciones numericas de problemas de contacto y contacto con friccion entre cuerpos solidos, y se comparan entre si.

International Conference on Chemical Kinetics: Program and Abstracts Held in Gaithersburg, Maryland on 17-19 June 1985.

Science.gov (United States)

1985-06-01

Salamanca Dpto. Fisica Teorica and University Complutense Dpto. Metodos Matematicos de la F1sica The authors show how the knowledge of (n-1) first...M. Dominguez. Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas Caracas 1010-A. Venezuela. The kinetics of the gas phase...Alexandra Rotinov, Rosa M. Domfnguez, and Ignacio Martin Centro de Qufmica, Instituto Venezolano de Investigaciones Cientificas (I.V.I.C.), Caracas

Reconocimiento geotécnico del terreno

OpenAIRE

Suriol Castellví, Josep; Lloret Morancho, Antonio; Josa Garcia-Tornel, Alejandro

2007-01-01

El presente texto trata de introducir al estudiante de Geotecnia a la problemática derivada del estudio del terreno como medio natural. Surge entonces la necesidad de transformar las propiedades del terreno en parámetros útiles al cálculo geotécnico. Los metodos de reconocimiento y los ensayos descritos tienen como objeto dar la solución a dicha problemática.

Matching tomographic IMRT fields with static photon fields

International Nuclear Information System (INIS)

Sethi, A.; Leybovich, L.; Dogan, N.; Emami, B.

2001-01-01

The matching of abutting radiation fields presents a challenging problem in radiation therapy. Due to sharp penumbra of linear accelerator beams, small (1-2 mm) errors in field positioning can lead to large (>30%) hot or cold spots in the abutment region. With head and neck immobilization devices (thermoplastic mask/aquaplast) an average setup error of 3 mm has been reported. Therefore hot or cold spots approaching 50% of the prescription dose may occur along the matchline. Although abutting radiation fields have been investigated for static fields, there is no reported study regarding matching of tomographic IMRT and static fields. Compared to static fields, the matching of tomographic IMRT fields with static fields is more complicated. Since IMRT and static fields are planned on separate treatment planning computers, the dose in the abutment region is not specified. In addition, commonly used techniques for matching fields, such as feathering of junctions, are not practical. We have developed a method that substantially reduces dose inhomogeneity in the abutment region. In this method, a 'buffer zone' around the matchline was created and was included as part of the target for both IMRT and static field plans. In both fields, a small dose gradient (≤3%/mm) in the buffer zone was created. In the IMRT plan, the buffer zone was divided into three sections with dose varying from 83% to 25% of prescription dose. The static field dose profile was modified using either a specially designed physical (hard) or a dynamic (soft) wedge. When these modified fields were matched, the combined dose in the abutment region varied by ≤10% in the presence of setup errors spanning 4 mm (±2 mm) when the hard wedge was used and 10 mm (±5 mm) with the soft wedge

Contactless measurement of alternating current conductance in quantum Hall structures

Energy Technology Data Exchange (ETDEWEB)

Drichko, I. L.; Diakonov, A. M.; Malysh, V. A.; Smirnov, I. Yu.; Ilyinskaya, N. D.; Usikova, A. A. [A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Galperin, Y. M. [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316 Oslo (Norway); A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Kummer, M.; Känel, H. von [Laboratorium für Festkörperphysik ETH Zürich, CH-8093 Zürich (Switzerland)

2014-10-21

We report a procedure to determine the frequency-dependent conductance of quantum Hall structures in a broad frequency domain. The procedure is based on the combination of two known probeless methods—acoustic spectroscopy and microwave spectroscopy. By using the acoustic spectroscopy, we study the low-frequency attenuation and phase shift of a surface acoustic wave in a piezoelectric crystal in the vicinity of the electron (hole) layer. The electronic contribution is resolved using its dependence on a transverse magnetic field. At high frequencies, we study the attenuation of an electromagnetic wave in a coplanar waveguide. To quantitatively calibrate these data, we use the fact that in the quantum-Hall-effect regime the conductance at the maxima of its magnetic field dependence is determined by extended states. Therefore, it should be frequency independent in a broad frequency domain. The procedure is verified by studies of a well-characterized p-SiGe/Ge/SiGe heterostructure.

Analysis of noncoplanar pressurized laminations in X2 steel pipes by non-linear finite element

Energy Technology Data Exchange (ETDEWEB)

Morales, Alfredo [Instituto Tecnologico de Puebla (Mexico). Dept. de Posgrado; Gonzalez, Jorge L.; Hallen, Jose M. [Instituto Politecnico Nacional (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE). Dept. de Ingenieria Metalurgica

2005-07-01

Hydrogen induced cracking is of great interest in the mechanical integrity assessment of sour gas pipelines. Multiple stepwise cracks with internal pressure called laminations are often observed in pipelines and their interaction and coalescence may significantly affect the residual strength of the pipes. In this work, the interacting fields of non coplanar pressurized laminations in the wall of a pipe under pressure are analyzed by non-lineal finite element, considering an isotropic hardening law and the real tensile properties of the X52 steel. The results are presented as the evolution of the stress fields in the interlaminar region as a function of the pressure inside the laminations. It is found that for two approaching stepwise laminations the critical pressure follows a hyperbolic type law, thus the effect of the lamination length is principal for greater lengths and for shorter lengths the effect is minimum. The critical pressure is defined as pressure inside the lamination that causes plastification of the interlaminar region. (author)

One-step generation of continuous-variable quadripartite cluster states in a circuit QED system

Science.gov (United States)

Yang, Zhi-peng; Li, Zhen; Ma, Sheng-li; Li, Fu-li

2017-07-01

We propose a dissipative scheme for one-step generation of continuous-variable quadripartite cluster states in a circuit QED setup consisting of four superconducting coplanar waveguide resonators and a gap-tunable superconducting flux qubit. With external driving fields to adjust the desired qubit-resonator and resonator-resonator interactions, we show that continuous-variable quadripartite cluster states of the four resonators can be generated with the assistance of energy relaxation of the qubit. By comparison with the previous proposals, the distinct advantage of our scheme is that only one step of quantum operation is needed to realize the quantum state engineering. This makes our scheme simpler and more feasible in experiment. Our result may have useful application for implementing quantum computation in solid-state circuit QED systems.

Analysis of the innovation needs of SME; Analisi della domanda di innovazione delle PMI

Energy Technology Data Exchange (ETDEWEB)

Sabattinin, A; Finelli, A; Rappini, R; Zacchiroli, R. [ENEA, Centro Richerche `E. Clementel`, Bologna (Italy)

1998-12-31

Within an EU financial support (Innovation Relay-Centre IRENE), was set up and tested a method to identify the innovation needs of SMEs. This method, based on firm visits and audits, has proved successful as it is possible to contact firms which find it difficult to approach research centres. These firms are left on their own towards innovation and they cannot evaluate the energetic and environmental implications of introducing a new process or carrying out a new product. The results obtained have highlighted that it is possible to realise a very interesting action of technological transfer starting from the requests for innovation and by means of direct contacts and relationships between firms and research centres. When the SMEs are directly involved they become aware of energetic and environmental problems and, in general, of the engagement that Italy undertook during the conference held in Kyoto. This method is particularly useful to the research centres to which firms can point out and transfer their needs. [Italiano] Nell`ambito di un finanziamento comunitario (Innovation Relay-Centre IRENE), e` stato messo a punto e testato un metodo per l`individuazione della domanda di innovzione delle PMI. Il metodo, basato su visite aziendali e audit, si e` dimostrato particolarmente efficace perche` permette di approcciare anche aziende che hanno grandi difficolta` ad avvicinarsi al mondo della ricerca. Queste imprese sono sole nei confronti dell`innovazione e non sono in grado di valutare quali possano essere le implicazioni, anche energetiche o ambientali, consguenti all`introduzzione di un nuovo processo o alla realizzazione di un nuovo prodotto. I risultati ottenuti hanno evidenziato che, partendo dalla domanda e attraverso il contatto diretto e il dialogo con le strutture di ricerca, e`possibile realizzare interventi di trasferimento tecnologico di grande interesse. Il coinvolgimento diretto permette altresi` di sensibilizzare le PMI sulle problematiche energetiche

Deep water invasions in oil fields of the gulf of Mexico: a challenge for the application of environmental isotopes; Invasiones de aguas profundas en yacimientos petroleros del golfo de Mexico: un reto para la aplicacion de isotopos ambientales

Energy Technology Data Exchange (ETDEWEB)

Birkle, Peter [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2001-07-01

It was verified the use of environmental isotopes as a useful method to improve the efficiency of the present exploitation in oil fields of the Gulf of Mexico. In general, the stable isotopes like deuterium, 18 O, 13 C, 37 Cl, 87 Sr and 34 S, support in questions on the origin of waters, its quality, the geochemistry evolution, recharge processes, interaction water-rock, origin of the salinity and contamination processes, whereas the radioactive isotopes (Tritium, 14 C, 36 I and 129 I) provide information on the time of circulation, the origin and the age of underground waters. Since year 1998, the Gerencia de Geotermia of the Instituto de Investigaciones Electricas is making investigation projects in the oil fields of the Actives of Production Luna, Pol-Chuc, Chilpilla-Colomo (all of them in the state of Tabasco) and Cactus-Sitio Grande (Chiapas) in the South Region of PEMEX Exploration and Production (PEP). As primary target of these studies hidrogeological models were developed on the migration and circulation of the fluids in the oil fields with the purpose of limiting the water invasion in producing wells and to increase the crude oil production. [Spanish] Se comprobo el uso de los isotopos ambientales como un metodo util para mejorar la eficiencia de la explotacion actual en yacimientos petroleros del golfo de Mexico. En general, los isotopos estables como deuterio, 18 O, 13 C, 37 Cl, 87 Sr y 34 S, apoyan en cuestiones sobre el origen de las aguas, su calidad, la evolucion geoquimica, procesos de recarga, interaccion agua-roca, origen de la salinidad y procesos de contaminacion, mientras que los isotopos radiactivos (Tritio, 14 C, 36 l Y 129 I) proporcionan informacion sobre el tiempo de circulacion, el origen y la edad de las aguas subterraneas. Desde el ano 1998, la Gerencia de Geotermia del Instituto de Investigaciones Electricas esta realizando proyectos de investigacion en los campos petroleros de los activos de Produccion Luna, Pol-Chuc, Chilpilla

Electromagnetic modeling of the rings of the squirrel cage of an induction motor; Modelado electromagnetico de los anillos de la jaula de ardilla de un motor de induccion

Energy Technology Data Exchange (ETDEWEB)

Limones Montoya, Juan Carlos

2004-03-15

An electromagnetic lineal model of a three-phase induction motor was developed in this thesis. The Finite element method in two dimensions was used. The model formulation takes into account the coupling with the stator wires and solid conductors of the rotor. In other words, the stator phases and squirrel-cage end-rings are considered in the model. The resulting set of electric-circuit and magnetic-field equations are solved simultaneously with the Incomplete Cholesky Bi-Conjugate Gradient Method using a matrix storage technique known as symmetric coordinate storage. The model was programmed in the C programming language. The magnetic field model is represented by the diffusion equation, which allows to compute the induced Eddy currents in the conducting material due to the sinusoidal stator excitation. The modelled induction motor has a rated power of 2.2 kW, 220 V, 9.6/11.0 A, 60 Hz and it can be operated at the speeds of 1750/1150 rpm. It is located in the Laboratorio de Propulsion at the Instituto Tecnologico de la Laguna. [Spanish] En este trabajo de tesis se desarrollo un modelo electromagnetico lineal de un motor de induccion trifasico utilizando el Metodo de Elemento Finito en dos dimensiones, en el cual se incluye la formulacion de sistemas acoplados para los conductores delgados y gruesos presentes en el estator y rotor respectivamente. Es decir, se incluyen en el modelo las fases de alimentacion y los anillos de cortocircuito del rotor de jaula de ardilla. Las ecuaciones electricas y magneticas derivadas del modelo se resuelven de manera acoplada con el Metodo del Gradiente BiConjugado con Precondicionamiento de Cholesky Incompleto empleando el sistema de Empaquetamiento de Coordenadas, cuyo codigo se desarrollo en el lenguaje de programacion C. En este modelo se resuelve la ecuacion de difusion, mediante la cual se determinan las corrientes de Eddy que se inducen en el material conductor debido a la presencia de fuentes de alimentacion senoidales. El

Field theories with subcanonical fields

International Nuclear Information System (INIS)

Bigi, I.I.Y.

1976-01-01

The properties of quantum field theories with spinor fields of dimension less than the canonical value of 3/2 are studied. As a starting point for the application of common perturbation theory we look for the linear version of these theories. A gange-interaction is introduced and with the aid of power counting the renormalizability of the theory is shown. It follows that in the case of a spinor-field with negative dimension renormalization can only be attained if the interaction has a further symmetry. By this symmetry the theory is determined in an unequivocal way. The gange-interaction introduced in the theory leads to a spontaneous breakdown of scale invariance whereby masses are produced. At the same time the spinor-field operators can now be separated in two orthogonal sections with opposite norm. It is proposed to use the section with negative (positive) norm to describe hadrons (leptons) respectively. (orig./WL) [de

Characterization of the K2-18 multi-planetary system with HARPS. A habitable zone super-Earth and discovery of a second, warm super-Earth on a non-coplanar orbit

Science.gov (United States)

Cloutier, R.; Astudillo-Defru, N.; Doyon, R.; Bonfils, X.; Almenara, J.-M.; Benneke, B.; Bouchy, F.; Delfosse, X.; Ehrenreich, D.; Forveille, T.; Lovis, C.; Mayor, M.; Menou, K.; Murgas, F.; Pepe, F.; Rowe, J.; Santos, N. C.; Udry, S.; Wünsche, A.

2017-12-01

Aims: The bright M2.5 dwarf K2-18 (Ms = 0.36 M⊙, Rs = 0.41 R⊙) at 34 pc is known to host a transiting super-Earth-sized planet orbiting within the star's habitable zone; K2-18b. Given the superlative nature of this system for studying an exoplanetary atmosphere receiving similar levels of insolation as the Earth, we aim to characterize the planet's mass which is required to interpret atmospheric properties and infer the planet's bulk composition. Methods: We have obtained precision radial velocity measurements with the HARPS spectrograph. We then coupled those measurements with the K2 photometry to jointly model the observed radial velocity variation with planetary signals and a correlated stellar activity model based on Gaussian process regression. Results: We measured the mass of K2-18b to be 8.0 ± 1.9M⊕ with a bulk density of 3.3 ± 1.2 g/cm3 which may correspond to a predominantly rocky planet with a significant gaseous envelope or an ocean planet with a water mass fraction ≳50%. We also find strong evidence for a second, warm super-Earth K2-18c (mp,csinic = 7.5 ± 1.3 M⊕) at approximately nine days with a semi-major axis 2.4 times smaller than the transiting K2-18b. After re-analyzing the available light curves of K2-18 we conclude that K2-18c is not detected in transit and therefore likely has an orbit that is non-coplanar with the orbit of K2-18b although only a small mutual inclination is required for K2-18c to miss a transiting configuration; | Δi| 1-2°. A suite of dynamical integrations are performed to numerically confirm the system's dynamical stability. By varying the simulated orbital eccentricities of the two planets, dynamical stability constraints are used as an additional prior on each planet's eccentricity posterior from which we constrain eb multi-planet systems around M dwarfs. The characterization of the density of K2-18b reveals that the planet likely has a thick gaseous envelope which, along with its proximity to the solar

Tripolar electric field Structure in guide field magnetic reconnection

OpenAIRE

S. Fu; S. Huang; M. Zhou; B. Ni; X. Deng

2018-01-01

It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplit...

High Performance Nano-Constituent Buffer Layer Thin Films to Enable Low Cost Integrated On-the-Move Communications Systems

National Research Council Canada - National Science Library

Cole, M. W; Nothwang, W. D; Hubbard, C; Ngo, E; Hirsch, S

2004-01-01

.... Utilizing a coplanar device design we successfully designed, fabricated, characterized, and optimized a high performance Ta2O5 thin film passive buffer layer on Si substrates, which will allow...

Gravitational Field Shielding by Scalar Field and Type II Superconductors

Directory of Open Access Journals (Sweden)

Zhang B. J.

2013-01-01

Full Text Available The gravitational field shielding by scalar field and type II superconductors are theoret- ically investigated. In accord with the well-developed five-dimensional fully covariant Kaluza-Klein theory with a scalar field, which unifies the Einsteinian general relativity and Maxwellian electromagnetic theory, the scalar field cannot only polarize the space as shown previously, but also flatten the space as indicated recently. The polariza- tion of space decreases the electromagnetic field by increasing the equivalent vacuum permittivity constant, while the flattening of space decreases the gravitational field by decreasing the equivalent gravitational constant. In other words, the scalar field can be also employed to shield the gravitational field. A strong scalar field significantly shield the gravitational field by largely decreasing the equivalent gravitational constant. According to the theory of gravitational field shielding by scalar field, the weight loss experimentally detected for a sample near a rotating ceramic disk at very low tempera- ture can be explained as the shielding of the Earth gravitational field by the Ginzburg- Landau scalar field, which is produced by the type II superconductors. The significant shielding of gravitational field by scalar field produced by superconductors may lead to a new spaceflight technology in future.

Design of interdigital spiral and concentric capacitive sensors for materials evaluation

Science.gov (United States)

Chen, Tianming; Bowler, Nicola

2013-01-01

This paper describes the design of two circular coplanar interdigital sensors with i) a spiral interdigital configuration and ii) a concentric interdigital configuration for the nondestructive evaluation of multilayered dielectric structures. A numerical model accounting for sensor geometry, test-piece geometry and real permittivity, and metal electrode thickness has been developed to calculate the capacitance of the sensors when in contact with a planar test-piece comprising up to four layers. Compared with a disk-and-ring coplanar capacitive sensor developed previously, the interdigital configurations are predicted to have higher signal-to-noise ratio and better accuracy in materials characterization. The disk-and-ring configuration, on the other hand, possesses advantages such as deeper penetration depth and better immunity to lift-off variations.

On vector fields having properties of Reeb fields

OpenAIRE

Hajduk, Boguslaw; Walczak, Rafal

2011-01-01

We study constructions of vector fields with properties which are characteristic to Reeb vector fields of contact forms. In particular, we prove that all closed oriented odd-dimensional manifold have geodesible vector fields.

Teoria della relatività ristretta

CERN Document Server

Ugarov, Vladimir Aleksandrovic

1982-01-01

Meccanica classica e principio di relatività ; postulati di Einstein, intervalo tra eventi, trasformazioni di Lorentz ; conseguenze della trasformazioni di Lorentz ; classificazione degli intervalli e principio di causalità, metodo del coefficiente k ; spazio-tempo quadridimensionale ; meccanica relativistica di una particella ; teoria di Maxwell in forma relativistica ; fenomeni ottici e teoria della relatività ristretta ; su alcuni "paradossi" della teoria della relatività ristretta ; supplementi ; eventi fondamentali della storia della TRR.

Módulos interactivos para el aprendizaje de la semántica.

OpenAIRE

Aquino Palacios, Ingrid

2012-01-01

Se proponen modulos interactivos para lograr el aprendizaje de la semantica en alumnos del V semestre de la Carrera de Lenguas, Literatura y Comunicacion de la Facultad de Educacion de la UNCP. Los metodos utilizados fueron el experimental y el bibliografico-documental. Los instrumentos utilizados fueron la prueba objetiva, prueba de ensayo y la prueba pedagogica. Se logró mejorar el aprendizaje de la semántica 

Bibliography of Books and Published Reports on Gas Turbines, Jet Propulsion, and Rocket Power Plants, January 1950 through December 1953

Science.gov (United States)

1953-12-01

75. Aeronautics In 1950. Engineer 191,67 and 100. Critical review of gas turbine progress in 1950. Engineer 191, 50. Gas turbines in 1950. Engineer 191...1952) ; Trans. ASME 75,121. A critical review of gas turbine progress, 1952. Engineer 195, 124. Aeronautics in 1952. Engineer 195, 24, 55 and 91...Physical fundamentals of jet propulsion. Forsch. Gebiete Ingenieurw. B19, Forschungaheft 437, p 5. 0. Santangelo, Metodo di calcolo delle

Technology and Power

Science.gov (United States)

2003-04-07

disappear and opponents will fight throughout the battlefield destroying critical points of command and control systems, logistical support and...with these problems. However, growth slumped to 3 percent in 2000. The Pakistani education sector is in a critical state of disarray. While substantial...Accessed 15 March 2003. Briones, Guillermo. Metodos y Técnicas de Investigación para las Ciencias Sociales, 3rd ed. Ciudad de México, México: Editorial

Grounding, Bonding, Shielding, and Lightning Bibliography 1972 to 1979

Science.gov (United States)

1981-02-01

Congress on Radiation Protection, May 3-5, 1972. For critical examination of incorporation in man besides the extensive medical evaluation it is...careful adherence to approved practices in critical areas. The ground- ing treatment is very brief, being limited to the most salient considera-1tions of...frequency are given. -58- - - I. Marongiu, " Metodo di Calcolo Semplificato della Resistenza di Terra di un Sistema di Dispersori Moiteplici Parallelo

Investigating the Mobility of Light Autonomous Tracked Vehicles using a High Performance Computing Simulation Capability

Science.gov (United States)

2012-08-01

of components and numerical outputs makes the results exceedingly difficult to in- terpret; consequently, rendering is a critical last step to the...output image and rendered indepen- dently. The REYES pipeline is illustrated in Fig. 13. Speed is another critical attribute of the render- ing...Methods and Applications, C. Bottasso, Ed. Springer, 2008, pp. 45–55. [33] TASORA, A., MANCONI, E., AND SILVESTRI, M. Un nuovo metodo del simplesso

On Jacobi-fields

International Nuclear Information System (INIS)

Bruening, E.

1981-01-01

The concept of a Jacobi-field is introduced as such a field for which the field-operators have the form of a generalized Jacobi-matrix with respect to the n-field-sector decomposition of the state-space. It is argued that the class of Jacobi-fields is of interest for relativistic quantum field theory for two reasons: (a) Jacobi-fields allow a direct association of particles (charges etc.) with fields. The concept of (generalized) creation- and annihilation-operators is thus available. (b) Jacobi-fields belong to that class of fields which can be characterized in terms of finitely many vacuum expectation values. A characterization of Jacobi-fields in terms of continuity and hermiticity properties of their system of vacuum expectation values is derived. Furthermore it is argued that all examples of relativistic quantum fields in a four-dimensional space-time are Jacobi-fields. This is evident for generalized free fields and Wick-powers of free fields, but is also true for a class of generalized Wick-powers of generalized free fields. (Auth.)

Field Science--the Nature and Utility of Scientific Fields.

Science.gov (United States)

Casadevall, Arturo; Fang, Ferric C

2015-09-08

Fields are the fundamental sociological units of science. Despite their importance, relatively little has been written about their emergence, composition, structure, and function in the scientific enterprise. This essay considers the nature of fields and their important role in maintaining information and providing normative standards for scientific work. We suggest that fields arise naturally as a consequence of increasing information and scientific specialization. New fields tend to emerge as research communities grow, which may reflect biologically determined optima for the size of human groups. The benefits of fields include the organization of scientists with similar interests into communities that collectively define the next important problems to pursue. In the discipline of microbiology, fields are often organized on the basis of phylogenetic differences between microorganisms being studied. Although fields are essential to the proper functioning of science, their emergence can restrict access by outsiders and sustain dogmas that hinder progress. We suggest mechanisms to improve the functioning of scientific fields and to promote interdisciplinary interaction between fields. Copyright © 2015 Casadevall and Fang.

Optimal field splitting for large intensity-modulated fields

International Nuclear Information System (INIS)

Kamath, Srijit; Sahni, Sartaj; Ranka, Sanjay; Li, Jonathan; Palta, Jatinder

2004-01-01

The multileaf travel range limitations on some linear accelerators require the splitting of a large intensity-modulated field into two or more adjacent abutting intensity-modulated subfields. The abutting subfields are then delivered as separate treatment fields. This workaround not only increases the treatment delivery time but it also increases the total monitor units (MU) delivered to the patient for a given prescribed dose. It is imperative that the cumulative intensity map of the subfields is exactly the same as the intensity map of the large field generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. In this work, we describe field splitting algorithms that split a large intensity-modulated field into two or more intensity-modulated subfields with and without feathering, with optimal MU efficiency while satisfying the hardware constraints. Compared to a field splitting technique (without feathering) used in a commercial planning system, our field splitting algorithm (without feathering) shows a decrease in total MU of up to 26% on clinical cases and up to 63% on synthetic cases

A general field-covariant formulation of quantum field theory

International Nuclear Information System (INIS)

Anselmi, Damiano

2013-01-01

In all nontrivial cases renormalization, as it is usually formulated, is not a change of integration variables in the functional integral, plus parameter redefinitions, but a set of replacements, of actions and/or field variables and parameters. Because of this, we cannot write simple identities relating bare and renormalized generating functionals, or generating functionals before and after nonlinear changes of field variables. In this paper we investigate this issue and work out a general field-covariant approach to quantum field theory, which allows us to treat all perturbative changes of field variables, including the relation between bare and renormalized fields, as true changes of variables in the functional integral, under which the functionals Z and W=lnZ behave as scalars. We investigate the relation between composite fields and changes of field variables, and we show that, if J are the sources coupled to the elementary fields, all changes of field variables can be expressed as J-dependent redefinitions of the sources L coupled to the composite fields. We also work out the relation between the renormalization of variable-changes and the renormalization of composite fields. Using our transformation rules it is possible to derive the renormalization of a theory in a new variable frame from the renormalization in the old variable frame, without having to calculate it anew. We define several approaches, useful for different purposes, in particular a linear approach where all variable changes are described as linear source redefinitions. We include a number of explicit examples. (orig.)

Two field formulation of closed string field theory

International Nuclear Information System (INIS)

Bogojevic, A.R.

1990-09-01

A formulation of closed string field theory is presented that is based on a two field action. It represents a generalization of Witten's Chern-Simons formulation of 3d gravity. The action contains only 3 string interactions and no string field truncations, unlike the previous non-polynomial action of Zwiebach. The two field action is found to follow from a purely cubic, background independent action similar to the one for open strings. (orig.)

Field Model: An Object-Oriented Data Model for Fields

Science.gov (United States)

Moran, Patrick J.

2001-01-01

We present an extensible, object-oriented data model designed for field data entitled Field Model (FM). FM objects can represent a wide variety of fields, including fields of arbitrary dimension and node type. FM can also handle time-series data. FM achieves generality through carefully selected topological primitives and through an implementation that leverages the potential of templated C++. FM supports fields where the nodes values are paired with any cell type. Thus FM can represent data where the field nodes are paired with the vertices ("vertex-centered" data), fields where the nodes are paired with the D-dimensional cells in R(sup D) (often called "cell-centered" data), as well as fields where nodes are paired with edges or other cell types. FM is designed to effectively handle very large data sets; in particular FM employs a demand-driven evaluation strategy that works especially well with large field data. Finally, the interfaces developed for FM have the potential to effectively abstract field data based on adaptive meshes. We present initial results with a triangular adaptive grid in R(sup 2) and discuss how the same design abstractions would work equally well with other adaptive-grid variations, including meshes in R(sup 3).

RESONANCE TRAPPING IN PROTOPLANETARY DISKS. I. COPLANAR SYSTEMS

International Nuclear Information System (INIS)

Lee, Aaron T.; Thommes, Edward W.; Rasio, Frederic A.

2009-01-01

Mean-motion resonances (MMRs) are likely to play an important role both during and after the lifetime of a protostellar gas disk. We study the dynamical evolution and stability of planetary systems containing two giant planets on circular orbits near a 2:1 resonance and closer. We find that by having the outer planet migrate inward, the two planets can capture into either the 2:1, 5:3, or 3:2 MMR. We use direct numerical integrations of ∼1000 systems in which the planets are initially locked into one of these resonances and allowed to evolve for up to ∼10 7 yr. We find that the final eccentricity distribution in systems which ultimately become unstable gives a good fit to observed exoplanets. Next, we integrate ∼500 two-planet systems in which the outer planet is driven to continuously migrate inward, resonantly capturing the inner planet; the systems are evolved until either instability sets in or the planets reach the star. We find that although the 5:3 resonance rapidly becomes unstable under migration, the 2:1 and 3:2 are very stable. Thus the lack of observed exoplanets in resonances closer than 2:1, if it continues to hold up, may be a primordial signature of the planet formation process.

Nonlinearity in superconducting titanium nitride coplanar waveguide resonators

International Nuclear Information System (INIS)

Neilinger, P.; Trgala, M.; Hrebikova, I.; Mikula, M.; Zahoran, M.; Truchly, M.; Grajcar, M.; Leporis, M.

2012-01-01

In this paper we present fabrication and characterization of superconducting CPW TiN resonator at 20 and 300 nm film thickness. Further we demonstrate strong nonlinearity in thin TiN resonators. (authors)

Il metodo mitico e i cattivi pensieri

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Elio Franzini

2012-05-01

Full Text Available Moving from a definition of his « mythical method», the essay aims to outline the so-called «Philosophy of Art» of Paul Valéry. It sketches a portrait of the French author as an authentic philosopher of phenomenology able to define in a non-abstract way what must be intended with «aesthetics».

Le narrazioni come metodo di indagine sociologica

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Rita Bichi

2012-04-01

Full Text Available L'incontro trentino ha dimostrato l'interesse crescente dei giovani sociologi per lo sviluppo dei metodi narrativi e la capacità che questi hanno di essere efficaci nell'analisi di svariati temi, dai racconti di malattia alle narrazioni identitarie, dallo studio di lavoro e organizzazioni a quello delle migrazioni, di genere e memoria. Tuttavia, l'interesse della sociologia italiana va visto in un quadro di sviluppo più ampio a livello europeo e americano dove, a partire dagli anni '90, l'intervento di alcuni autori come Lyotard, Bruner e Macintyre, ha sancito quella che alcuni autori hanno definito svolta narrativa. La sociologia, infatti, tende sempre più a valorizzare la narrazione come processo di conoscenza peculiare che è attivato costantemente nella vita quotidiana; la "rivoluzione" risiede nel fatto che la narrazione diventa oggetto della sociologia e la disciplina stessa valorizza il suo uso sia come strumento di indagine scientifica, sia come modo di conoscere che come modo di comunicare, rivendicando la legittimità scientifica all'ascolto della parola diretta degli individui coinvolti all'interno delle ricerche di stampo sociologico.

Trapped field recovery of bulk superconductor magnets by static field magnetization

Energy Technology Data Exchange (ETDEWEB)

Deng, Z., E-mail: zigang@kaiyodai.ac.jp [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan); Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M. [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan)

2011-11-15

A series of initial trapped fields after ZFC or FC magnetization are used to simulate the attenuated trapped field. It is possible and easy to recover the lost trapped field and regain the best trapped field performance as before. In the re-magnetization process, the initial magnetic flux inside the bulk magnets will help to recover the trapped field. The optimum recovery field is recommended to be 2.5 times the saturation field of the bulk at LN2 temperature. Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa{sub 2}Cu{sub 3}O{sub y} (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

Dosimetric Advantage of Intensity-Modulated Radiotherapy for Whole Ventricles in the Treatment of Localized Intracranial Germinoma

International Nuclear Information System (INIS)

Sakanaka, Katsuyuki; Mizowaki, Takashi; Hiraoka, Masahiro

2012-01-01

Purpose: To investigate the dosimetric advantage of intensity-modulated radiotherapy (IMRT) for whole ventricles (WV) in patients with a localized intracranial germinoma receiving induction chemotherapy. Methods and Materials: Data from 12 consecutive patients with localized intracranial germinomas who received induction chemotherapy and radiotherapy were used. Four-field coplanar three-dimensional conformal radiotherapy (3D-CRT) and seven-field coplanar IMRT plans were created. In both plans, 24 Gy was prescribed in 12 fractions for the planning target volume (PTV) involving WV and tumor bed. In IMRT planning, optimization was conducted to reduce the doses to the organs at risk (OARs) as much as possible, keeping the minimum dose equivalent to that of 3D-CRT. The 3D-CRT and IMRT plans were compared in terms of the dose–volume statistics for target coverage and the OARs. Results: IMRT significantly increased the percentage volume of the PTV receiving 24 Gy compared with 3D-CRT (93.5% vs. 84.8%; p = 0.007), while keeping target homogeneity equivalent to 3D-CRT (p = 0.869). The absolute percentage reduction in the irradiated volume of the normal brain receiving 100%, 75%, 50%, and 25% of 24 Gy ranged from 0.7% to 16.0% in IMRT compared with 3D-CRT (p < 0.001). No significant difference was observed in the volume of the normal brain receiving 10% and 5% of 24 Gy between IMRT and 3D-CRT. Conformation number was significantly improved in IMRT (p < 0.001). For other OARs, the mean dose to the cochlea was reduced significantly in IMRT by 22.3% of 24 Gy compared with 3D-CRT (p < 0.001). Conclusions: Compared with 3D-CRT, IMRT for WV improved the target coverage and reduced the irradiated volume of the normal brain in patients with intracranial germinomas receiving induction chemotherapy. IMRT for WV with induction chemotherapy could reduce the late side effects from cranial irradiation without compromising control of the tumor.

How fields vary.

Science.gov (United States)

Krause, Monika

2018-03-01

Field theorists have long insisted that research needs to pay attention to the particular properties of each field studied. But while much field-theoretical research is comparative, either explicitly or implicitly, scholars have only begun to develop the language for describing the dimensions along which fields can be similar to and different from each other. In this context, this paper articulates an agenda for the analysis of variable properties of fields. It discusses variation in the degree but also in the kind of field autonomy. It discusses different dimensions of variation in field structure: fields can be more or less contested, and more or less hierarchical. The structure of symbolic oppositions in a field may take different forms. Lastly, it analyses the dimensions of variation highlighted by research on fields on the sub- and transnational scale. Post-national analysis allows us to ask how fields relate to fields of the same kind on different scales, and how fields relate to fields on the same scale in other national contexts. It allows us to ask about the role resources from other scales play in structuring symbolic oppositions within fields. A more fine-tuned vocabulary for field variation can help us better describe particular fields and it is a precondition for generating hypotheses about the conditions under which we can expect to observe fields with specified characteristics. © London School of Economics and Political Science 2017.

Genealogy of the body and genealogical body

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Paola Cecchetti

2011-06-01

Full Text Available A partire da un quadro di Frida Kahlo intitolato I miei nonni, i miei genitori e io le due autrici indagano quel testo-immagine che sta all'origine dello stile di lettura del soggetto. Posto dinanzi alla stessa immagine, ciascuno ne fa una rappresentazione estremamente personale, un quadro delle proprie vicissitudini interne e dei legami transgenerazionali che lo hanno segnato. I momenti nei quali si articola la ricerca sono tre: la scrittura dell’occhio, il ricalco e il percorso della mano, il negativo e l’assenza.A essi segue poi lo psicodramma. Tale successione temporale abitua a vedere nell'immagine disegnata l'immagine negata, assente. L'esperienza sembra aver creato un nuovo metodo di indagine della psiche rispetto al transgenerazionale, metodo che intreccia il genogramma (di origini sistemico-relazionale e lo psicodramma analitico, e che viene chiamato “genodramma psicoanalitico”. Partendo da un dato clinico – l'esilità del legame che le nuove generazioni intrattengono con quelle che le precedono, sembra vogliano rinegoziare il contratto narcisistico che assegna al passato il posto dell'assenza. Il contributo si chiude con un interrogativo: “Alla ricerca di che cosa? Della presenza o, meglio, delle tracce lasciate nel soggetto dall'Altro che precede l'insediamento dell'Io”.

Efecto neutralizador del extracto acuoso de Dracontium loretense (JERGÓN SACHA sobre la actividad letal del veneno de Bothrops atrox

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Amanda Lovera

2006-07-01

Full Text Available Objetivo: Determinar la capacidad del extracto acuoso D. loretense (jergon sacha para neutralizar la actividad letal del veneno de la serpiente B. atrox. Materiales y metodos: Se realizo el screening fitoquimico del extracto acuoso del bulbo desecado de D. loretense, se calculo la dosis letal 50(DL50 para el extracto y el veneno de B. atrox. Luego se realizaron enfrentamientos de diferentes dosis de extracto y veneno inyectadas intraperitonealmente en ratones, previa incubacion, para calcular la dosis eficaz 50% (DE50 del extracto para neutralizar el efecto letal del veneno por el metodo de Probits. Resultados: El analisis fitoquimico del extracto permitio identificar compuestos fenolicos, taninos, saponinas, proteinas, terpenoides y esteroides. No sobrevivio ningun raton que recibio el veneno sin D. loretense, y no fallecio ninguno al que se le dio solo el extracto acuoso de D. loretense. Se determino la DE50 en 91,15 µg/raton del extracto para neutralizar 2DL50 del veneno. Se encontro que a mayor dosis del veneno de B.atrox se necesito menores dosis del extracto acuoso de D. loretense. Conclusiones: el extracto acuoso de D. loretense neutraliza la actividad letal de veneno de B. atrox. Es necesario realizar estudios que permitan identificar los metabolitos del extracto que tienen esta accion.

fields

Directory of Open Access Journals (Sweden)

Brad J. Arnold

2014-07-01

Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.