WorldWideScience

Sample records for conventional field strength

  1. 7T MRI in focal epilepsy with unrevealing conventional field strength imaging.

    Science.gov (United States)

    De Ciantis, Alessio; Barba, Carmen; Tassi, Laura; Cosottini, Mirco; Tosetti, Michela; Costagli, Mauro; Bramerio, Manuela; Bartolini, Emanuele; Biagi, Laura; Cossu, Massimo; Pelliccia, Veronica; Symms, Mark R; Guerrini, Renzo

    2016-03-01

    To assess the diagnostic yield of 7T magnetic resonance imaging (MRI) in detecting and characterizing structural lesions in patients with intractable focal epilepsy and unrevealing conventional (1.5 or 3T) MRI. We conducted an observational clinical imaging study on 21 patients (17 adults and 4 children) with intractable focal epilepsy, exhibiting clinical and electroencephalographic features consistent with a single seizure-onset zone (SOZ) and unrevealing conventional MRI. Patients were enrolled at two tertiary epilepsy surgery centers and imaged at 7T, including whole brain (three-dimensional [3D] T1 -weighted [T1W] fast-spoiled gradient echo (FSPGR), 3D susceptibility-weighted angiography [SWAN], 3D fluid-attenuated inversion recovery [FLAIR]) and targeted imaging (2D T2*-weighted dual-echo gradient-recalled echo [GRE] and 2D gray-white matter tissue border enhancement [TBE] fast spin echo inversion recovery [FSE-IR]). MRI studies at 1.5 or 3T deemed unrevealing at the referral center were reviewed by three experts in epilepsy imaging. Reviewers were provided information regarding the suspected localization of the SOZ. The same team subsequently reviewed 7T images. Agreement in imaging interpretation was reached through consensus-based discussions based on visual identification of structural abnormalities and their likely correlation with clinical and electrographic data. 7T MRI revealed structural lesions in 6 (29%) of 21 patients. The diagnostic gain in detection was obtained using GRE and FLAIR images. Four of the six patients with abnormal 7T underwent epilepsy surgery. Histopathology revealed focal cortical dysplasia (FCD) in all. In the remaining 15 patients (71%), 7T MRI remained unrevealing; 4 of the patients underwent epilepsy surgery and histopathologic evaluation revealed gliosis. 7T MRI improves detection of epileptogenic FCD that is not visible at conventional field strengths. A dedicated protocol including whole brain FLAIR and GRE images at 7T

  2. Magnetic Field Strength Evaluation Yu. S. Yefimov

    Indian Academy of Sciences (India)

    physical task is to evaluate the strength and topology of magnetic field in blazars and related ... polarization, spectral index of radiation, ratio of apparent velocity of the motion of matter along .... A detailed analysis of the evaluation of physical.

  3. Conventional cable testing methods: strengths, weaknesses and possibilities

    International Nuclear Information System (INIS)

    Reynolds, P.H.

    1988-01-01

    The paper reviews the major conventional methods that can be used to test power plant cables. It assesses their usefulness in diagnosing the condition of the insulation of the cable and then proposes some possible directions for innovation. The methods examined are dc insulation resistance measurement, ac signal injection for continuous monitoring and fault location, and the ac measurement of capacitance and loss angle. Specific subjects considered are the effects of temperature, cable construction and installation, and the validity of insulation resistance or loss angle measurement. The innovative proposals refer to the use of automation in the measurement and of computer-based Expert Systems for the evaluation of the results

  4. Strength and deformation behaviors of veined marble specimens after vacuum heat treatment under conventional triaxial compression

    Science.gov (United States)

    Su, Haijian; Jing, Hongwen; Yin, Qian; Yu, Liyuan; Wang, Yingchao; Wu, Xingjie

    2017-10-01

    The mechanical behaviors of rocks affected by high temperature and stress are generally believed to be significant for the stability of certain projects involving rocks, such as nuclear waste storage and geothermal resource exploitation. In this paper, veined marble specimens were treated to high temperature treatment and then used in conventional triaxial compression tests to investigate the effect of temperature, confining pressure, and vein angle on strength and deformation behaviors. The results show that the strength and deformation parameters of the veined marble specimens changed with the temperature, presenting a critical temperature of 600 °C. The triaxial compression strength of a horizontal vein (β = 90°) is obviously larger than that of a vertical vein (β = 0°). The triaxial compression strength, elasticity modulus, and secant modulus have an approximately linear relation to the confining pressure. Finally, Mohr-Coulomb and Hoek-Brown criteria were respectively used to analyze the effect of confining pressure on triaxial compression strength.

  5. Energy flux determines magnetic field strength of planets and stars.

    Science.gov (United States)

    Christensen, Ulrich R; Holzwarth, Volkmar; Reiners, Ansgar

    2009-01-08

    The magnetic fields of Earth and Jupiter, along with those of rapidly rotating, low-mass stars, are generated by convection-driven dynamos that may operate similarly (the slowly rotating Sun generates its field through a different dynamo mechanism). The field strengths of planets and stars vary over three orders of magnitude, but the critical factor causing that variation has hitherto been unclear. Here we report an extension of a scaling law derived from geodynamo models to rapidly rotating stars that have strong density stratification. The unifying principle in the scaling law is that the energy flux available for generating the magnetic field sets the field strength. Our scaling law fits the observed field strengths of Earth, Jupiter, young contracting stars and rapidly rotating low-mass stars, despite vast differences in the physical conditions of the objects. We predict that the field strengths of rapidly rotating brown dwarfs and massive extrasolar planets are high enough to make them observable.

  6. Design, characterization, and application of fast, broadband, high-dynamic range, three-axis field strength probes

    NARCIS (Netherlands)

    Serra, Ramiro; Leferink, Frank Bernardus Johannes

    2013-01-01

    Conventional field strength sensors use different detection methods, each having advantages and disadvantages. Modern signals in, for instance, wireless communication systems and radars use very complex modulation. Other signals, such as the ones often measured in reverberation chambers with mode

  7. Design, characterization and application of fast, broadband, high-dynamic range, three-axis field strength probes

    NARCIS (Netherlands)

    Serra, R.; Leferink, F.B.J.

    2013-01-01

    Conventional field strength sensors use different detection methods, each having advantages and disadvantages. Modern signals in, for instance, wireless communication systems and radars use very complex modulation. Other signals, such as the ones often measured in reverberation chambers with mode

  8. Evaluation of bond strength of a conventional adhesive system in irradiated teeth

    Directory of Open Access Journals (Sweden)

    Emanuel Jordan de CARVALHO

    Full Text Available Abstract Introduction One of the most common treatments of head and neck cancer patients is radiotherapy, a treatment method which uses ionizing radiation beam and destroys tumor cells, minimizing damage to neighbor cells. Purpose To evaluate the bond strength of a conventional adhesive system in irradiated teeth. Method 24 third human molars, 12 of which were randomly exposed to radiation and prepared from the removal of occlusal enamel, then exposed to a flat dentine surface. The adhesive system Stae was applied according to the manufacturer’s instructions. Next, two 2 mm increments of resin were implemented. The samples were hemi sectioned specimens, originating shapped toothpick. To evaluate the bond strength, a micro tensile test was done with 500N load and speed of 0.5 mm/minute. Result There was no statistically significant difference between the bond strength of teeth which were or were not exposed to radiation and which used a conventional adhesive system. Conclusion Although the radiation doses applied may cause some alterations in microscopic range in dental tissues, it can be concluded that these alterations do not influence in the bond strength in dentin of irradiated teeth.

  9. A multileaf collimator field prescription preparation system for conventional radiotherapy

    International Nuclear Information System (INIS)

    Du, M.N.; Yu, C. X.; Symons, M.; Yan, D.; Taylor, R.; Matter, R.C.; Gustafson, G.; Martinez, A.; Wong, J.W.

    1995-01-01

    Purpose: The purpose of this work is to develop a prescription preparation system for efficient field shaping using a multileaf collimator that can be used in community settings as well as research institutions. The efficiency advantage of the computer-controlled multileaf collimator, over cerrobend blocks, to shape radiation fields has been shown in conformal treatments, which typically require complete volumetric computerized tomographic data for three-dimensional radiation treatment planning--a utility not readily available to the general community. As a result, most patients today are treated with conventional radiation therapy. Therefore, we believe that it is very important to fully use the same efficiency advantage of multileaf collimator as a block replacement in conventional practice. Methods and Material: The multileaf collimator prescription preparation system developed by us acquires prescription images from different sources, including film scanner and radiation treatment planning systems. The multileaf collimator angle and leaf positions are set from the desired field contour defined on the prescription image, by minimizing the area discrepancies. Interactive graphical tools include manual adjustment of collimator angle and leaf positions, and definition of portions of the field edges that require maximal conformation. Data files of the final leaf positions are transferred to the multileaf collimator controller via a dedicated communication link. Results: We have implemented the field prescription preparation system and a network model for integrating the multileaf collimator and other radiotherapy modalities for routine treatments. For routine plan evaluation, isodose contours measured with film in solid water phantom at prescription depth are overlaid on the prescription image. Preliminary study indicates that the efficiency advantage of the MLC over cerrobend blocks in conformal therapy also holds true for conventional treatments. Conclusion: Our

  10. Examining the global health arena: strengths and weaknesses of a convention approach to global health challenges.

    Science.gov (United States)

    Haffeld, Just Balstad; Siem, Harald; Røttingen, John-Arne

    2010-01-01

    The article comprises a conceptual framework to analyze the strengths and weaknesses of a global health convention. The analyses are inspired by Lawrence Gostin's suggested Framework Convention on Global Health. The analytical model takes a starting-point in events tentatively following a logic sequence: Input (global health funding), Processes (coordination, cooperation, accountability, allocation of aid), Output (definition of basic survival needs), Outcome (access to health services), and Impact (health for all). It then examines to what degree binding international regulations can create order in such a sequence of events. We conclude that a global health convention could be an appropriate instrument to deal with some of the problems of global health. We also show that some of the tasks preceding a convention approach might be to muster international support for supra-national health regulations, negotiate compromises between existing stakeholders in the global health arena, and to utilize WHO as a platform for further discussions on a global health convention. © 2010 American Society of Law, Medicine & Ethics, Inc.

  11. Pulsar Emission Geometry and Accelerating Field Strength

    Science.gov (United States)

    DeCesar, Megan E.; Harding, Alice K.; Miller, M. Coleman; Kalapotharakos, Constantinos; Parent, Damien

    2012-01-01

    The high-quality Fermi LAT observations of gamma-ray pulsars have opened a new window to understanding the generation mechanisms of high-energy emission from these systems, The high statistics allow for careful modeling of the light curve features as well as for phase resolved spectral modeling. We modeled the LAT light curves of the Vela and CTA I pulsars with simulated high-energy light curves generated from geometrical representations of the outer gap and slot gap emission models. within the vacuum retarded dipole and force-free fields. A Markov Chain Monte Carlo maximum likelihood method was used to explore the phase space of the magnetic inclination angle, viewing angle. maximum emission radius, and gap width. We also used the measured spectral cutoff energies to estimate the accelerating parallel electric field dependence on radius. under the assumptions that the high-energy emission is dominated by curvature radiation and the geometry (radius of emission and minimum radius of curvature of the magnetic field lines) is determined by the best fitting light curves for each model. We find that light curves from the vacuum field more closely match the observed light curves and multiwavelength constraints, and that the calculated parallel electric field can place additional constraints on the emission geometry

  12. Low-Budget Instrumentation of a Conventional Leg Press to Measure Reliable Isometric-Strength Capacity.

    Science.gov (United States)

    Baur, Heiner; Groppa, Alessia Severina; Limacher, Regula; Radlinger, Lorenz

    2016-02-02

    Maximum strength and rate of force development (RFD) are 2 important strength characteristics for everyday tasks and athletic performance. Measurements of both parameters must be reliable. Expensive isokinetic devices with isometric modes are often used. The possibility of cost-effective measurements in a practical setting would facilitate quality control. The purpose of this study was to assess the reliability of measurements of maximum isometric strength (Fmax) and RFD on a conventional leg press. Sixteen subjects (23 ± 2 y, 1.68 ± 0.05 m, 59 ± 5 kg) were tested twice within 1 session. After warm-up, subjects performed 2 times 5 trials eliciting maximum voluntary isometric contractions on an instrumented leg press (1- and 2-legged randomized). Fmax (N) and RFD (N/s) were extracted from force-time curves. Reliability was determined for Fmax and RFD by calculating the intraclass correlation coefficient (ICC), the test-retest variability (TRV), and the bias and limits of agreement. Reliability measures revealed good to excellent ICCs of .80-.93. TRV showed mean differences between measurement sessions of 0.4-6.9%. The systematic error was low compared with the absolute mean values (Fmax 5-6%, RFD 1-4%). The implementation of a force transducer into a conventional leg press provides a viable procedure to assess Fmax and RFD. Both performance parameters can be assessed with good to excellent reliability allowing quality control of interventions.

  13. Effects of conventional welding and laser welding on the tensile strength, ultimate tensile strength and surface characteristics of two cobalt-chromium alloys: a comparative study.

    Science.gov (United States)

    Madhan Kumar, Seenivasan; Sethumadhava, Jayesh Raghavendra; Anand Kumar, Vaidyanathan; Manita, Grover

    2012-06-01

    The purpose of this study was to evaluate the efficacy of laser welding and conventional welding on the tensile strength and ultimate tensile strength of the cobalt-chromium alloy. Samples were prepared with two commercially available cobalt-chromium alloys (Wironium plus and Diadur alloy). The samples were sectioned and the broken fragments were joined using Conventional and Laser welding techniques. The welded joints were subjected to tensile and ultimate tensile strength testing; and scanning electron microscope to evaluate the surface characteristics at the welded site. Both on laser welding as well as on conventional welding technique, Diadur alloy samples showed lesser values when tested for tensile and ultimate tensile strength when compared to Wironium alloy samples. Under the scanning electron microscope, the laser welded joints show uniform welding and continuous molt pool all over the surface with less porosity than the conventionally welded joints. Laser welding is an advantageous method of connecting or repairing cast metal prosthetic frameworks.

  14. Microchip Electrophoresis at Elevated Temperatures and High Separation Field Strengths

    Science.gov (United States)

    Mitra, Indranil; Marczak, Steven P.; Jacobson, Stephen C.

    2014-01-01

    We report free-solution microchip electrophoresis performed at elevated temperatures and high separation field strengths. We used microfluidic devices with 11-cm long separation channels to conduct separations at temperatures between 22 (ambient) and 45 °C and field strengths from 100 to 1000 V/cm. To evaluate separation performance, N-glycans were used as a model system and labeled with 8-aminopyrene-1,3,6-trisulfonic acid to impart charge for electrophoresis and render them fluorescent. Typically, increased diffusivity at higher temperatures leads to increased axial dispersion and poor separation performance; however, we demonstrate that sufficiently high separation field strengths can be used to offset the impact of increased diffusivity in order to maintain separation efficiency. Efficiencies for these free-solution separations are the same at temperatures of 25, 35, and 45 °C with separation field strengths ≥500 V/cm. PMID:24114979

  15. 47 CFR 18.305 - Field strength limits.

    Science.gov (United States)

    2010-10-01

    ...) Field strength limit (uV/m) Distance (meters) Any type unless otherwise specified (miscellaneous) Any...Any 2515 300300 Ultrasonic Below 490 kHz Below 500500 or more 2,400/F(kHz)2,400/F(kHz)× SQRT(power/500... kHzOn or above 90 kHz AnyAny 1,500300 430 430 1 Field strength may not exceed 10 μV/m at 1600 meters...

  16. Technical Note: Computation of Electric Field Strength Necessary for ...

    African Journals Online (AJOL)

    Obviously, electric field is established by this charge. The effects of this field on the objects lying within its vicinity depend on its intensity. In this paper, the electric field of 33kV overhead line is considered. The aim of the paper is to determine the maximum electric field strength or potential gradient, E of the 33kV overhead ...

  17. 47 CFR 73.184 - Groundwave field strength graphs.

    Science.gov (United States)

    2010-10-01

    ... copies of these tabulations call or write the Consumer Affairs Office, Federal Communications Commission... relative values of groundwave field strength over a plane earth as a function of the numerical distance p... earth weakens the field more rapidly than these plane earth curves would indicate. Thus, no attempt...

  18. Paris Convention on third party liability in the field of nuclear energy and Brussels Convention Supplementary to the Paris Convention

    International Nuclear Information System (INIS)

    1989-01-01

    This new bilingual (English and French) edition of the 1960 Paris Convention and 1963 Brussels Supplementary Convention incorporates the provisions of the Protocols which amended each of them on two occasions, in 1964 and 1982. The Expose des motifs to the Paris Convention, as revised in 1982 is also included in this pubication. (NEA) [fr

  19. Gravitational field strength and generalized Komar-integral

    International Nuclear Information System (INIS)

    Simon, W.

    1984-01-01

    We define a 'gravitational field strength' in theories of the Einstein-Cartan type admitting a Killing-vector. This field strength is a second rank, antisymmetric, divergence-free tensor, whose ('Komar-') integral over a closed 2-surface gives a physically meaningful quantity. We find conditions on the Lagrange-density of the theory which ensure the existence of such a tensor, and show that they are satisfied for N = 2-supergravity and for a special case of the bosonic sector of N = 4-supergravity. We discuss a possible application of the generalized Komar-integral in the theory of stationary black holes. We also consider the Kaluza-Klein-approach to the 'field-strength-problem', which turns out to be particularly rewarding in the application to black holes. (Author)

  20. Methodological aspects of functional neuroimaging at high field strength: a critical review

    International Nuclear Information System (INIS)

    Scheef, L.; Landsberg, M.W.; Boecker, H.

    2007-01-01

    The last few years have proven that high field magnetic resonance imaging (MRI) is superior in nearly every way to conventional equipment up to 1.5 tesla (T). Following the global success of 3T-scanners in research institutes and medical practices, a new generation of MRI devices with field strengths of 7T and higher is now on the horizon. The introduction of ultra high fields has brought MRI technology closer to the physical limitations and increasingly greater costs are required to achieve this goal. This article provides a critical overview of the advantages and problems of functional neuroimaging using ultra high field strengths. This review is principally limited to T2*-based functional imaging techniques not dependent on contrast agents. The main issues include the significance of high field technology with respect to SNR, CNR, resolution, and sequences, as well as artifacts, noise exposure, and SAR. Of great relevance is the discussion of parallel imaging, which will presumably determine the further development of high and ultra high field strengths. Finally, the importance of high field strengths for functional neuroimaging is explained by selected publications. (orig.)

  1. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    Science.gov (United States)

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices.

  2. Cyclotron Lines: From Magnetic Field Strength Estimators to ...

    Indian Academy of Sciences (India)

    Chandreyee Maitra

    2017-09-12

    Sep 12, 2017 ... context can provide, to build a complete picture for the physics of accretion and ... cesses which occur near the NS surface, where the ... CRSF) which is the focal point of discussion in this arti- .... first direct measurement of the magnetic field strength of .... The above model requires a gradient in the magnetic.

  3. Studies of solar magnetic fields. V. The true average field strengths near the poles

    Energy Technology Data Exchange (ETDEWEB)

    Howard, R [Hale Observatories, Pasadena, Calif. (USA)

    1977-05-01

    An estimate of the average magnetic field strength at the poles of the Sun from Mount Wilson measurements is made by comparing low latitude magnetic measurements in the same regions made near the center of the disk and near the limb. There is still some uncertainty because the orientation angle of the field lines in the meridional plane is unknown, but the most likely possibility is that the true average field strengths are about twice the measured values (0-2 G), with an absolute upper limit on the underestimation of the field strengths of about a factor 5. The measurements refer to latitudes below about 80/sup 0/.

  4. On generalization of electric field strength in longitudinally blown arcs

    OpenAIRE

    Yas'ko, O.I.; Esipchuk, A.M.; Qing, Z.; Schram, D.C.; Fauchais, P.

    1997-01-01

    Generalization of av. elec. field strength for different discharge conditions in longitudinally blown arcs is considered. Exptl. data for distinctive devices and different gases were used for phys. modeling. Anal. showed that heat transfer processes are responsible for I-E characteristic formation. Turbulent heat transfer is the most effective for atm. pressure discharges while convection plays the main role in vacuum arcs. A generalized I-E characteristic was obtained. [on SciFinder (R)

  5. High-energy behavior of field-strength interactions

    International Nuclear Information System (INIS)

    Levin, D.N.

    1976-01-01

    It is known that spontaneously broken gauge theories are the only renormalizable theories of massive spin-one particles with mass dimension less than or equal to 4. This paper describes a search for renormalizable interactions with higher mass dimension. Specifically, we examine the high-energy behavior of a class of models which involve field-strength interactions. Power counting shows that the high-energy behavior of these models is no worse than the naively estimated high-energy behavior of a gauge theory in the U gauge. Therefore, there may be a ''soft'' symmetry-breaking mechanism (for instance, a soft divergence of an antisymmetric tensor current) which enforces renormalizable high-energy behavior in the same way that spontaneously broken gauge invariance guarantees the renormalizability of gauge theories. This hope is supported by the existence of ''gauge theories'' of strings, which describe analogous interactions of strings and field strengths. Unfortunately, this idea is tarnished by explicit calculations in which renormalizability is imposed in the form of unitarity bounds. These unitarity bounds imply that all possible field-strength couplings must be zero and that the remaining interactions describe a spontaneously broken gauge theory. Thus this result supports an earlier conjecture that gauge theories are the only renormalizable theories of massive vector bosons

  6. Crystal growth vs. conventional acid etching: A comparative evaluation of etch patterns, penetration depths, and bond strengths

    Directory of Open Access Journals (Sweden)

    Devanna Raghu

    2008-01-01

    Full Text Available The present study was undertaken to investigate the effect on enamel surface, penetration depth, and bond strength produced by 37% phosphoric acid and 20% sulfated polyacrylic acid as etching agents for direct bonding. Eighty teeth were used to study the efficacy of the etching agents on the enamel surface, penetration depth, and tensile bond strength. It was determined from the present study that a 30 sec application of 20% sulfated polyacrylic acid produced comparable etching topography with that of 37% phosphoric acid applied for 30 sec. The 37% phosphoric acid dissolves enamel to a greater extent than does the 20% sulfated polyacrylic acid. Instron Universal testing machine was used to evaluate the bond strengths of the two etching agents. Twenty percent sulfated polyacrylic acid provided adequate tensile bond strength. It was ascertained that crystal growth can be an alternative to conventional phosphoric acid etching as it dissolves lesser enamel and provides adequate tensile bond strength.

  7. Assessing Precision in Conventional Field Measurements of Individual Tree Attributes

    Directory of Open Access Journals (Sweden)

    Ville Luoma

    2017-02-01

    Full Text Available Forest resource information has a hierarchical structure: individual tree attributes are summed at the plot level and then in turn, plot-level estimates are used to derive stand or large-area estimates of forest resources. Due to this hierarchy, it is imperative that individual tree attributes are measured with accuracy and precision. With the widespread use of different measurement tools, it is also important to understand the expected degree of precision associated with these measurements. The most prevalent tree attributes measured in the field are tree species, stem diameter-at-breast-height (dbh, and tree height. For dbh and height, the most commonly used measuring devices are calipers and clinometers, respectively. The aim of our study was to characterize the precision of individual tree dbh and height measurements in boreal forest conditions when using calipers and clinometers. The data consisted of 319 sample trees at a study area in Evo, southern Finland. The sample trees were measured independently by four trained mensurationists. The standard deviation in tree dbh and height measurements was 0.3 cm (1.5% and 0.5 m (2.9%, respectively. Precision was also assessed by tree species and tree size classes; however, there were no statistically significant differences between the mensurationists for dbh or height measurements. Our study offers insights into the expected precision of tree dbh and height as measured with the most commonly used devices. These results are important when using sample plot data in forest inventory applications, especially now, at a time when new tree attribute measurement techniques based on remote sensing are being developed and compared to the conventional caliper and clinometer measurements.

  8. Magnetic resonance imaging: effects of magnetic field strength

    International Nuclear Information System (INIS)

    Crooks, L.E.; Arakawa, M.; Hoenninger, J.; McCarten, B.; Watts, J.; Kaufman, L.

    1984-01-01

    Magnetic resonance images of the head, abdomen, and pelvis of normal adult men were obtained using varying magnetic field strength, and measurements of T1 and T2 relaxations and of signal-to-noise (SN) ratios were determined. For any one spin echo sequence, gray/white matter contrast decreases and muscle/fat contrast increases with field. SN levels rise rapidly up to 3.0 kgauss and then change more slowly, actually dropping for muscle. The optimum field for magnetic resonance imaging depends on tissue type, body part, and imaging sequence, so that it does not have a unique value. Magnetic resonance systems that operate in the 3.0-5.0 kgauss range achieve most or all of the gains that can be achieved by higher magnetic fields

  9. The influence of removing sizing on strength and stiffness of conventional and high modulus E-glass fibres

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2016-01-01

    Two types of E-glass fibres, a conventional and a high modulus where the last one in the following will be denoted as ECR-glass fibre, were investigated regarding density, diameter, stiffness and strength. The fibres were analysed as pristine and after sizing removal treatments. The sizing was re...

  10. Estimating the Magnetic Field Strength in Hot Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Rakesh K. [Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138 (United States); Thorngren, Daniel P., E-mail: rakesh_yadav@fas.harvard.edu [Department of Physics, University of California, Santa Cruz, CA (United States)

    2017-11-01

    A large fraction of known Jupiter-like exoplanets are inflated as compared to Jupiter. These “hot” Jupiters orbit close to their parent star and are bombarded with intense starlight. Many theories have been proposed to explain their radius inflation and several suggest that a small fraction of the incident starlight is injected into the planetary interior, which helps to puff up the planet. How will such energy injection affect the planetary dynamo? In this Letter, we estimate the surface magnetic field strength of hot Jupiters using scaling arguments that relate energy available in planetary interiors to the dynamo-generated magnetic fields. We find that if we take into account the energy injected in the planetary interior that is sufficient to inflate hot Jupiters to observed radii, then the resulting dynamo should be able generate magnetic fields that are more than an order of magnitude stronger than the Jovian values. Our analysis highlights the potential fundamental role of the stellar light in setting the field strength in hot Jupiters.

  11. Gluon field strength correlation functions within a constrained instanton model

    International Nuclear Information System (INIS)

    Dorokhov, A.E.; Esaibegyan, S.V.; Maximov, A.E.; Mikhailov, S.V.

    2000-01-01

    We suggest a constrained instanton (CI) solution in the physical QCD vacuum which is described by large-scale vacuum field fluctuations. This solution decays exponentially at large distances. It is stable only if the interaction of the instanton with the background vacuum field is small and additional constraints are introduced. The CI solution is explicitly constructed in the ansatz form, and the two-point vacuum correlator of the gluon field strengths is calculated in the framework of the effective instanton vacuum model. At small distances the results are qualitatively similar to the single instanton case; in particular, the D 1 invariant structure is small, which is in agreement with the lattice calculations. (orig.)

  12. Mapping the absolute electromagnetic field strength of individual field components inside a photonic crystal

    NARCIS (Netherlands)

    Denis, T.; Reijnders, B.; Lee, J.H.H.; Vos, Willem L.; Boller, Klaus J.; van der Slot, Petrus J.M.

    2013-01-01

    We present a method to map the absolute electromagnetic field strength inside photonic crystals. We demonstrate our method by applying it to map the electric field component Ez of a two-dimensional photonic crystal slab at microwave frequencies. The slab is placed between two mirrors to create a

  13. A rigorous assessment of tree height measurements obtained using airborne LIDAR and conventional field methods.

    Science.gov (United States)

    Hans-Erik Andersen; Stephen E. Reutebuch; Robert J. McGaughey

    2006-01-01

    Tree height is an important variable in forest inventory programs but is typically time-consuming and costly to measure in the field using conventional techniques. Airborne light detection and ranging (LIDAR) provides individual tree height measurements that are highly correlated with field-derived measurements, but the imprecision of conventional field techniques does...

  14. An in vitro study to compare the transverse strength of thermopressed and conventional compression-molded polymethylmethacrylate polymers.

    Science.gov (United States)

    Raut, Anjana; Rao, Polsani Laxman; Vikas, B V J; Ravindranath, T; Paradkar, Archana; Malakondaiah, G

    2013-01-01

    Acrylic resins have been in the center stage of Prosthodontics for more than half a century. The flexural fatigue failure of denture base materials is the primary mode of clinical failure. Hence there is a need for superior physical and mechanical properties. This in vitro study compared the transverse strength of specimens of thermopressed injection-molded and conventional compression-molded polymethylmethacrylate polymers and examined the morphology and microstructure of fractured acrylic specimens. The following denture base resins were examined: Brecrystal (Thermopressed injection-molded, modified polymethylmethacrylate) and Pyrax (compression molded, control group). Specimens of each material were tested according to the American Society for Testing and Materials standard D790-03 for flexural strength testing of reinforced plastics and subsequently examined under SEM. The data was analyzed with Student unpaired t test. Flexural strength of Brecrystal (82.08 ± 1.27 MPa) was significantly higher than Pyrax (72.76 ± 0.97 MPa). The tested denture base materials fulfilled the requirements regarding flexural strength (>65 MPa). The scanning electron microscopy image of Brecrystal revealed a ductile fracture with crazing. The fracture pattern of control group specimens exhibited poorly defined crystallographic planes with a high degree of disorganization. Flexural strength of Brecrystal was significantly higher than the control group. Brecrystal showed a higher mean transverse strength value of 82.08 ± 1.27 MPa and a more homogenous pattern at microscopic level. Based on flexural strength properties and handling characteristics, Brecrystal may prove to be an useful alternative to conventional denture base resins.

  15. An in vitro study to compare the transverse strength of thermopressed and conventional compression-molded polymethylmethacrylate polymers

    Directory of Open Access Journals (Sweden)

    Anjana Raut

    2013-01-01

    Full Text Available Statement of Problem: Acrylic resins have been in the center stage of Prosthodontics for more than half a century. The flexural fatigue failure of denture base materials is the primary mode of clinical failure. Hence there is a need for superior physical and mechanical properties. Purpose: This in vitro study compared the transverse strength of specimens of thermopressed injection-molded and conventional compression-molded polymethylmethacrylate polymers and examined the morphology and microstructure of fractured acrylic specimens. Materials and Methods: The following denture base resins were examined: Brecrystal (Thermopressed injection-molded, modified polymethylmethacrylate and Pyrax (compression molded, control group. Specimens of each material were tested according to the American Society for Testing and Materials standard D790-03 for flexural strength testing of reinforced plastics and subsequently examined under SEM. The data was analyzed with Student unpaired t test. Results: Flexural strength of Brecrystal (82.08 ± 1.27 MPa was significantly higher than Pyrax (72.76 ± 0.97 MPa. The tested denture base materials fulfilled the requirements regarding flexural strength (>65 MPa. The scanning electron microscopy image of Brecrystal revealed a ductile fracture with crazing. The fracture pattern of control group specimens exhibited poorly defined crystallographic planes with a high degree of disorganization. Conclusion: Flexural strength of Brecrystal was significantly higher than the control group. Brecrystal showed a higher mean transverse strength value of 82.08 ± 1.27 MPa and a more homogenous pattern at microscopic level. Based on flexural strength properties and handling characteristics, Brecrystal may prove to be an useful alternative to conventional denture base resins.

  16. Effects of eccentric-focused and conventional resistance training on strength and functional capacity of older adults.

    Science.gov (United States)

    Dias, Caroline Pieta; Toscan, Rafael; de Camargo, Mainara; Pereira, Evelyn Possobom; Griebler, Nathália; Baroni, Bruno Manfredini; Tiggemann, Carlos Leandro

    2015-10-01

    The aim of the study was to assess the effect of eccentric training using a constant load with longer exposure time at the eccentric phase on knee extensor muscle strength and functional capacity of elderly subjects in comparison with a conventional resistance training program. Twenty-six healthy elderly women (age = 67 ± 6 years) were randomly assigned to an eccentric-focused training group (ETG; n = 13) or a conventional training group (CTG; n = 13). Subjects underwent 12 weeks of resistance training twice a week. For the ETG, concentric and eccentric phases were performed using 1.5 and 4.5 s, respectively, while for CTG, each phase lasted 1.5 s. Maximum dynamic strength was assessed by the one-repetition maximum (1RM) test in the leg press and knee extension exercises, and for functional capacity, subjects performed specific tests (6-m walk test, timed up-and-go test, stair-climbing test, and chair-rising test). Both groups improved knee extension 1RM (24-26 %; p = 0.021), timed up-and-go test (11-16 %; p training volume and intensity does not promote different adaptations in strength or functional capacity compared to conventional resistance training in elderly woman.

  17. Weed seed predation in organic and conventional fields

    DEFF Research Database (Denmark)

    Navntoft, Søren; Wratten, S.D.; Kristensen, Kristian

    2009-01-01

    Enhanced biological control of weed seeds may improve sustainability of agricultural production. Biological control due to seed predation may be higher in organic fields because organic production generally supports more seed predators. To investigate such a difference, weed seed predation...... University and in two of the fields used for estimating seed predation. Recording of predators had therefore limited overlap with seed predation assays but was expected to give important information on key seed predators in the region. The mean seed removal rate was 17% in organic fields compared with 10...... edges. Overall, there was no consistent effect of distance from the field edge. Vegetation had a significant influence on the predation rates, with maximum rates at a medium-dense plant cover. Based on the video images, birds were the most important seed predators. The higher weed seed predation rate...

  18. The effect of changing the magnetic field strength on HiPIMS deposition rates

    International Nuclear Information System (INIS)

    Bradley, J W; Mishra, A; Kelly, P J

    2015-01-01

    The marked difference in behaviour between HiPIMS and conventional dc or pulsed-dc magnetron sputtering discharges with changing magnetic field strengths is demonstrated through measurements of deposition rate. To provide a comparison between techniques the same circular magnetron was operated in the three excitation modes at a fixed average power of 680 W and a pressure of 0.54 Pa in the non-reactive sputtering of titanium. The total magnetic field strength B at the cathode surface in the middle of the racetrack was varied from 195 to 380 G. DC and pulsed-dc discharges show the expected behaviour that deposition rates fall with decreasing B (here by ∼25–40%), however the opposite trend is observed in HiPIMS with deposition rates rising by a factor of 2 over the same decrease in B.These observations are understood from the stand point of the different composition and transport processes of the depositing metal flux between the techniques. In HiPIMS, this flux is largely ionic and slow post-ionized sputtered particles are subject to strong back attraction to the target by a retarding plasma potential structure ahead of them. The height of this potential barrier is known to increase with increasing B.From a simple phenomenological model of the sputtered particles fluxes, and using the measured deposition rates from the different techniques as inputs, the combined probabilities of ionization, α, and back attraction, β, of the metal species in HiPIMS has been calculated. There is a clear fall in αβ (from ∼0.9 to ∼0.7) with decreasing B-field strengths, we argue primarily due to a weakening of electrostatic ion back attraction, so leading to higher deposition rates. The results indicate that careful design of magnetron field strengths should be considered to optimise HiPIMS deposition rates. (paper)

  19. 3 telsa MRI: successful results with higher field strengths

    International Nuclear Information System (INIS)

    Schmitt, F.; Grosu, D.; Purdy, D.; Salem, K.; Scott, K.T.; Stoeckel, B.; Mohr, C.

    2004-01-01

    The recent development of 3Telsa MRI (3T MRI) has been fueled by the promise of increased signal-to-noise ratio (SNR). Many are excited about the opportunity to no only use the increased SNR for clearer images, but also the change to exchange it for better resolution or faster scans. These possibilities have caused a rapid increase in the market for 3T MRI, where the faster scanning tips an already advantageous economic outlook in favor of the user. As a result, the global market for 3T has grown from a research only market just a few years ago to an ever-increasing clinically oriented customer base. There are, however, significant obstacles to 3T MRI presented by the physics at higher field strength. For example the T1 relaxation times are prolongued with increasing magnet field strength. Further, the increased RF-energy deposition (ASR), the larger chemical shift and the stronger susceptibility effect have to be considered as challenges. It is critical that one looks at both the advantages and disadvantages of using 3T. While there are many issues to address and a number of different methods for doing so, to properly tackle each of these concerns will take time and effort on the part of researchers and clinicians. The optimization of 3T MRI scanning will have to be combined effort, though much work has already been done. The most active area of work to date has been in neuroimaging. Multiple applications have been explored in addition to clinical anatomical imaging, where resolutions is improved showing structure in the brain never before seen in human MRI

  20. Push-Out Bond Strength of Restorations with Bulk-Fill, Flow, and Conventional Resin Composites

    Directory of Open Access Journals (Sweden)

    Rodrigo Vieira Caixeta

    2015-01-01

    Full Text Available The aim of this study was to evaluate the bond strengths of composite restorations made with different filler amounts and resin composites that were photoactivated using a light-emitting diode (LED. Thirty bovine incisors were selected, and a conical cavity was prepared in the facial surface of each tooth. All preparations were etched with Scotchbond Etching Gel, the Adper Scotchbond Multipurpose Plus adhesive system was applied followed by photoactivation, and the cavities were filled with a single increment of Filtek Z350 XT, Filtek Z350 XT Flow, or bulk-fill X-tra fil resin composite (n = 10 followed by photoactivation. A push-out test to determine bond strength was conducted using a universal testing machine. Data (MPa were submitted to Student’s t-test at a 5% significance level. After the test, the fractured specimens were examined using an optical microscope under magnification (10x. Although all three composites demonstrated a high prevalence of adhesive failures, the bond strength values of the different resin composites photoactivated by LED showed that the X-tra fil resin composite had a lower bond strength than the Filtek Z350 XT and Filtek Z350 XT Flow resin composites.

  1. Decreased functional diversity and biological pest control in conventional compared to organic crop fields.

    Directory of Open Access Journals (Sweden)

    Jochen Krauss

    Full Text Available Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short

  2. Decreased functional diversity and biological pest control in conventional compared to organic crop fields.

    Science.gov (United States)

    Krauss, Jochen; Gallenberger, Iris; Steffan-Dewenter, Ingolf

    2011-01-01

    Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional) and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short-term effects on aphid

  3. Field size and centring for conventional X-ray equipment

    International Nuclear Information System (INIS)

    Klimpel, H.; Kreienfeld, H.; Overbeck, R.

    1989-01-01

    Since 1973, all X-ray equipment for medical applications in the Federal Republic of Germany has had to be examined according to the requirements of the German ''Rontgenverordnung'' before it is used on patients and after each essential modification of design or construction. These examinations are carried out by inspectors appointed by the authorities, e.g. TUV. The field size adjustment and the centring of the radiation beam in relation to the image reception area is checked, along with other tests. To increase quality assurance in X-ray diagnosis, since the mid-1980s X-ray equipment has also been subject to in-service inspections to an increasing extent. (author)

  4. Comparison of porcelain bond strength of different metal frameworks prepared by using conventional and recently introduced fabrication methods.

    Science.gov (United States)

    Kaleli, Necati; Saraç, Duygu

    2017-07-01

    Most studies evaluating dental laser sintering systems have focused on the marginal accuracy of the restorations. However, the bond strength at the metal-ceramic interface is another important factor that affects the survival of restorations, and currently, few studies focus on this aspect. The purpose of this in vitro study was to compare the porcelain bond strength of cobalt-chromium (Co-Cr) metal frameworks prepared by using the conventional lost-wax technique, milling, direct metal laser sintering (DMLS), and laser cusing, a direct process powder-bed system. A total of 96 metal frameworks (n=24 in each group) were prepared by using conventional lost-wax (group C), milling (group M), DMLS (group LS), and direct process powder-bed (group LC) methods according to International Organization for Standardization standard ISO 9693-1. After porcelain application, a 3-point bend test was applied to each specimen by using a universal testing machine. Data were statistically analyzed using 1-way ANOVA and Tukey honest significant difference tests (α=.05). Failure types at the metal-ceramic interfaces were examined using stereomicroscopy. Additionally, 1 specimen from each group was prepared for scanning electron microscopy analysis to evaluate the surface topography of metal frameworks. The mean bond strength was 38.08 ±3.82 MPa for group C, 39.29 ±3.51 MPa for group M, 40.73 ±3.58 MPa for group LS, and 41.24 ±3.75 MPa for group LC. Statistically significant differences were observed among the 4 groups (P=.016). All groups, except for LS, exhibited adhesive and mixed type bond failure. Both of the laser sintering methods were found to be successful in terms of metal-ceramic bond strength. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  5. A field like today's? The strength of the geomagnetic field 1.1 billion years ago

    Science.gov (United States)

    Sprain, Courtney J.; Swanson-Hysell, Nicholas L.; Fairchild, Luke M.; Gaastra, Kevin

    2018-06-01

    Palaeomagnetic data from ancient rocks are one of the few types of observational data that can be brought to bear on the long-term evolution of Earth's core. A recent compilation of palaeointensity estimates from throughout Earth history has been interpreted to indicate that Earth's magnetic field strength increased in the Mesoproterozoic (between 1.5 and 1.0 billion years ago), with this increase taken to mark the onset of inner core nucleation. However, much of the data within the Precambrian palaeointensity database are from Thellier-style experiments with non-ideal behaviour that manifests in results such as double-slope Arai plots. Choices made when interpreting these data may significantly change conclusions about long-term trends in the intensity of Earth's geomagnetic field. In this study, we present new palaeointensity results from volcanics of the ˜1.1-billion-year-old North American Midcontinent Rift. While most of the results exhibit non-ideal double-slope or sagging behaviour in Arai plots, some flows have more ideal single-slope behaviour leading to palaeointensity estimates that may be some of the best constraints on the strength of Earth's field for this time. Taken together, new and previously published palaeointensity data from the Midcontinent Rift yield a median field strength estimate of 56.0 ZAm2—very similar to the median for the past 300 Myr. These field strength estimates are distinctly higher than those for the preceding billion years (Ga) after excluding ca. 1.3 Ga data that may be biased by non-ideal behaviour—consistent with an increase in field strength in the late Mesoproterozoic. However, given that ˜90 per cent of palaeointensity estimates from 1.1 to 0.5 Ga come from the Midcontinent Rift, it is difficult to evaluate whether these high values relative to those estimated for the preceding billion years are the result of a stepwise, sustained increase in dipole moment. Regardless, palaeointensity estimates from the Midcontinent

  6. Effects of Short-Term Carbohydrate Restrictive and Conventional Hypoenergetic Diets and Resistance Training on Strength Gains and Muscle Thickness

    Directory of Open Access Journals (Sweden)

    Claudia M. Meirelles, Paulo S.C. Gomes

    2016-12-01

    Full Text Available Hypoenergetic diets and resistance training (RT have been suggested to be important components of weight loss strategy programs; however, there is little evidence as to the chronic effects of different macronutrient compositions on strength performance and muscle mass with RT. The purpose of this study was to compare the effects of carbohydrate restrictive (CRD and conventional (CONV diets combined with RT on strength performance and muscle thicknesses in overweight and obese participants already involved in RT programs. Twenty-one volunteers engaged in an eight-week progressive RT program three times per week were assigned to a CRD (< 30 g carbohydrate; n = 12; 30.7 ± 3.9 km·m-2 or a CONV (30% energy deficit; 55%, 15% and 30% energy from carbohydrate, protein and fat, respectively; n=9; 27.7±2.5 km·m-2. Method: At baseline and week 8, the participants underwent body composition assessment by anthropometry, measurement of muscle thickness by ultrasound, and three strength tests using isotonic equipment. Both groups had similar reductions in body mass and fat mass as well as maintenance of fat-free mass. Muscle strength increased 14 ± 6% in the CRD group (p = 0.005 and 19 ± 9% in the CONV group (p = 0.028, with no significant differences between the groups. No significant differences were detected in muscle thicknesses within or between the groups. In conclusion, hypoenergetic diets combined with RT led to significant increases in muscle strength and were capable of maintaining muscle thicknesses in the upper and lower limbs of overweight and obese participants, regardless of the carbohydrate content of the diets.

  7. Effects of magnetic field strength in the discharge channel on the performance of a multi-cusped field thruster

    Directory of Open Access Journals (Sweden)

    Peng Hu

    2016-09-01

    Full Text Available The performance characteristics of a Multi-cusped Field Thruster depending on the magnetic field strength in the discharge channel were investigated. Four thrusters with different outer diameters of the magnet rings were designed to change the magnetic field strength in the discharge channel. It is found that increasing the magnetic field strength could restrain the radial cross-field electron current and decrease the radial width of main ionization region, which gives rise to the reduction of propellant utilization and thruster performance. The test results in different anode voltage conditions indicate that both the thrust and anode efficiency are higher for the weaker magnetic field in the discharge channel.

  8. Fretting friction and wear characteristics of magnetorheological fluid under different magnetic field strengths

    International Nuclear Information System (INIS)

    Zhang, P.; Lee, K.H.; Lee, C.H.

    2017-01-01

    A magnetorheological fluid (MRF) performs differently under different magnetic field strength. This study examined the fretting friction and wear characteristics of MRFs under a range of magnetic field strengths and oscillation frequencies. The fretting friction and wear behaviors of MRF are investigated using a fretting friction and wear tester. The surfaces of specimen are examined by optical microscopy and 3D surface profilometer before and after the tests and wear surface profiles, the wear volume loss and wear coefficient for each magnetic field strength are evaluated. The results show that the friction and wear properties of MRF change according to the magnetic field strength and oscillation frequency. - Highlights: • Fretting friction and wear characteristics of MRF is examined. • The friction coefficients increased with increasing magnetic field strength. • The coefficient of friction decreased with increasing oscillation frequency. • Wear volume and coefficient become worse with increasing magnetic field strength.

  9. Influence of Porous Spherical-Shaped Hydroxyapatite on Mechanical Strength and Bioactive Function of Conventional Glass Ionomer Cement

    Directory of Open Access Journals (Sweden)

    Szu-Yu Chiu

    2017-01-01

    Full Text Available Glass-ionomer-cement (GIC is helpful in Minimal Intervention Dentistry because it releases fluoride ions and is highly biocompatible. The aim of this study is to investigate the mechanisms by which hydroxyapatite (HAp improves the mechanical strength and bioactive functioning of GIC when these materials are combined to make apatite ionomer cement (AIC. A conventional GIC powder was mixed with porous, spherical-HAp particles (HApS, crystalline HAp (HAp200 or one of two types of cellulose. The micro-compressive strengths of the additive particles were measured, and various specimens were evaluated with regard to their compressive strengths (CS, fluoride release concentrations (fluoride electrode and multi-element release concentrations. The AIC was found to release higher concentrations of fluoride (1.2 times and strontium ions (1.5 times compared to the control GIC. It was detected the more release of calcium originated from HApS than HAp200 in AIC. The CS of the AIC incorporating an optimum level of HAp was also significantly higher than that of the GIC. These results suggest that adding HAp can increase the release concentration of ions required for remineralization while maintaining the CS of the GIC. This effect does not result from a physical phenomenon, but rather from chemical reactions between the HAp and polyacrylic acid of GIC.

  10. Cognition and sensation in very high static magnetic fields: a randomized case-crossover study with different field strengths.

    Science.gov (United States)

    Heinrich, Angela; Szostek, Anne; Meyer, Patric; Nees, Frauke; Rauschenberg, Jaane; Gröbner, Jens; Gilles, Maria; Paslakis, Georgios; Deuschle, Michael; Semmler, Wolfhard; Flor, Herta

    2013-01-01

    To establish the extent to which representative cognitive functions in subjects undergoing magnetic resonance (MR) imaging are acutely impaired by static magnetic fields of varying field strengths. This study was approved by the local ethics committee, and informed consent was obtained from all subjects. In this single-blind case-crossover study, 41 healthy subjects underwent an extensive neuropsychologic examination while in MR units of differing field strengths (1.5, 3.0, and 7.0 T), including a mock imager with no magnetic field as a control condition. Subjects were blinded to field strength. Tests were performed while subjects were lying still in the MR unit and while the examination table was moved. The tests covered a representative set of cognitive functions, such as memory, eye-hand coordination, attention, reaction time, and visual discrimination. Subjective sensory perceptions were also assessed. Effects were analyzed with a repeated-measures analysis of variance; the within-subject factors were field strength (0, 1.5, 3.0, and 7.0 T) and state (static, dynamic). Static magnetic fields were not found to have a significant effect on cognitive function at any field strength. However, sensory perceptions did vary according to field strength. Dizziness, nystagmus, phosphenes, and head ringing were related to the strength of the static magnetic field. Static magnetic fields as high as 7.0 T did not have a significant effect on cognition. RSNA, 2012

  11. Microchip capillary gel electrophoresis using programmed field strength gradients for the ultra-fast analysis of genetically modified organisms in soybeans.

    Science.gov (United States)

    Kim, Yun-Jeong; Chae, Joon-Seok; Chang, Jun Keun; Kang, Seong Ho

    2005-08-12

    We have developed a novel method for the ultra-fast analysis of genetically modified organisms (GMOs) in soybeans by microchip capillary gel electrophoresis (MCGE) using programmed field strength gradients (PFSG) in a conventional glass double-T microchip. Under the programmed electric field strength and 0.3% poly(ethylene oxide) sieving matrix, the GMO in soybeans was analyzed within only 11 s of the microchip. The MCGE-PFSG method was a program that changes the electric field strength during GMO analysis, and was also applied to the ultra-fast analysis of PCR products. Compared to MCGE using a conventional and constantly applied electric field, the MCGE-PFSG analysis generated faster results without the loss of resolving power and reproducibility for specific DNA fragments (100- and 250-bp DNA) of GM-soybeans. The MCGE-PFSG technique may prove to be a new tool in the GMO analysis due to its speed, simplicity, and high efficiency.

  12. A Field Test for Upper Body Strength and Endurance.

    Science.gov (United States)

    Nelson, Jack K.; And Others

    1991-01-01

    Researchers studied the reliability of the modified push-up test in measuring upper body strength and endurance in elementary through college students. It also examined the accuracy of partner scoring. The test proved much easier to administer than the regular floor push-up. It was valid and reliable for all students and suitable for partner…

  13. Optical Field-Strength Polarization of Two-Mode Single-Photon States

    Science.gov (United States)

    Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

  14. FITTING HELICAL SNAKE AND ROTATOR FIELD STRENGTH MEASUREMENTS IN RHIC

    International Nuclear Information System (INIS)

    RANJBAR, V.; LUCCIO, A.U.; MACKAY, W.W.; TSOUPAS, N.

    2001-01-01

    We examined recent multi-pole measurements for the helical snakes and rotators in RHIC to generate a full field map. Since multi-pole measurements yield real field values for B, field components we developed a unique technique to evaluate the full fields using a traditional finite element analysis software [1]. From these measurements we employed SNIG [2] to generate orbit and Spin plots. From orbit values we generated a transfer matrix for the first snake

  15. Large-field image intensifiers versus conventional chest radiography: ROC study with simulated interstitial disease

    International Nuclear Information System (INIS)

    Winter, L.H.L.; Chakraborty, D.P.; Waes, P.F.G.M.

    1988-01-01

    Two image intensifier tubes have recently been introduced whose large imaging area makes them suitable for chest imaging (Phillips Pulmodiagnost TLX slit II and Siemens TX 57 large entrance field II). Both modalities present a 10 x 10-cm hard copy image to the radiologist. A receiver operating characteristic (ROC) curve study with simulated interstitial disease was performed to compare the image quality of these image intensifiers with conventional chest images. The relative ranking in terms of decreasing ROC areas was Siemens, conventional, and Philips. Compared with conventional imaging, none of the differences in ROC curve area were statistically significant at the 5% level

  16. Antibacterial activity, surface roughness, flexural strength, and solubility of conventional luting cements containing chlorhexidine diacetate/cetrimide mixtures.

    Science.gov (United States)

    Korkmaz, Fatih Mehmet; Tüzüner, Tamer; Baygin, Ozgul; Buruk, Celal Kurtulus; Durkan, Rukiye; Bagis, Bora

    2013-08-01

    The failure of fixed dental restorations is commonly associated with caries. The use of conventional luting cements containing antibacterial agents may overcome this problem. The purpose of this study was to evaluate the antibacterial activity (ABA), surface roughness (Ra), flexural strength (FS), and solubility (SL) patterns of the conventional dental luting cements zinc phosphate (ZP), zinc polycarboxylate (PC), and glass ionomer (GIC) after the addition of 5% chlorhexidine diacetate/cetrimide (CHX+CT). Antibacterial agents with a total concentration of 5% (2.5% CHX+2.5% CT) were added to antibacterial agent-free conventional luting cement powders (ZPC, PCC, and GICC) and designated as experimental groups (ZPE, PCE, and GICE). ABA against Streptococcus mutans (SM) and Lactobacillus casei (LB) was examined by using the agar diffusion test method. Ra, FS, and SL values were obtained after storage in distilled water at 37°C for 24 hours. The Kruskal-Wallis and Mann Whitney U with Bonferroni correction tests were used to test for agar diffusion (α=.05) and 2-way ANOVA and Fisher Least Significant Difference (LSD) test were used to measure Ra, FS, and SL (α=.05). The control groups exhibited limited ABA. With the exception of PCE>PCC on day 1 for SM, all experimental groups showed significantly greater and longer-lasting protection against SM and LB bacteria for up to 180 days than their controls (PZPE; P>.05, PCC>PCE; PGICC (P>.05) when compared with their individual controls. Control groups exhibited higher FS values than did the experimental groups (ZPC>ZPE; PPCE; PGICE; P>.05). The experimental groups exhibited higher solubilities than did their controls in the ZPC (P>.05) and GICC groups (P<.05) but were lower in PCC group (P<.05). Incorporating a 5% CHX+CT mixture into conventional dental luting cements and altering their Ra, FS, and SL values may provide greater antibacterial protection against SM and LB. Copyright © 2013 The Editorial Council of the

  17. A comparison of ground beetle assemblages (Coleoptera: Carabidae in conventionally and ecologically managed alfalfa fields

    Directory of Open Access Journals (Sweden)

    P. Kolařík

    2014-12-01

    Full Text Available From 2007-2011, the occurrence of ground beetles (Coleoptera: Carabidae was studied using emergence traps in two differently managed alfalfa fields in the Czech Republic - a conventional and an ecological production system. In total, 784 specimens of ground beetles representing 58 species were trapped in these two alfalfa fields in South Moravia. A slightly higher number of specimens were trapped in the conventionally managed than in the ecological alfalfa stand (404 vs 380, respectively. In the conventionally managed alfalfa stand, the number of species was also higher than in the ecological stand (45 vs 40, respectively. With the exception of 2007 and 2009, Simpson’s indices of diversity were higher in the conventional stand than in the ecological in all study years. Shannon’s index was higher in the conventional alfalfa field in 2008, 2009, and 2011. Regarding distribution, species classified into group E (i.e., those without special demands on the type and quality of their habitat dominated in both types of management throughout the experimental period. The incidence of species classified into group R (i.e., those with narrow ecological amplitude was very low; i.e., only four species. These ground beetle species are included in the Red List of Threatened Species of the Czech Republic, and all of them (i.e. Acupalpus suturalis, Calosoma auropunctatum, Cicindela germanica and Ophonus cribricollis are listed as vulnerable.

  18. DO WE STILL NEED A CONVENTION IN THE FIELD OF HARMONISATION OF THE INTERNATIONAL COMMERCIAL LAW?

    Directory of Open Access Journals (Sweden)

    A. Korzhevskaya

    2014-01-01

    Full Text Available The paper critically discusses the opinion of certain scholars that the use of multilateral treaties (conventions in the field of harmonisation of international commercial law has been in a state of steady decline. They believe that traditional treaty law has been gradually replaced in recent years by softer methods of making international law, such as the use of restatements and model laws. Some scholars even claim that treaty law is dead or dying. The work assesses whether this view has reasonable grounds, providing an overview of the most prominent hard law and soft law harmonising instruments and outlining issues relating to the success of conventions, their advantages, drawbacks and tensions arising in this area. The paper suggests that conventions remain necessary where the third party or public interest are at stake, however, further improvements are needed to make conventions more successful instruments in international commercial law.

  19. Atomic hydrogen storage. [cryotrapping and magnetic field strength

    Science.gov (United States)

    Woollam, J. A. (Inventor)

    1980-01-01

    Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules.

  20. Non-ionizing radiation exposure: electric field strength measurement ...

    African Journals Online (AJOL)

    In this research, the measured values are compared with the international standard recommended by ICNIRP then were also compared with previous study from several locations around Malaysia. The result shows an increase in the values of electromagnetic field radiation. The result of this study could be used for health ...

  1. Measuring Undrained Shear Strength using CPT and Field Vane

    DEFF Research Database (Denmark)

    Luke, Kirsten

    1992-01-01

    This paper presents the results of CPT's and Field Vane tests from two small test areas with different soils, Glacial Till and Yoldia Clay. An average of Nk = qt/cv for the Yoldia Clay is 7.7 with a standard deviation of 0.7. The average of Nk for the Glacial Till is 9.7 with a standard deviation...

  2. Spectral characterization of plastic scintillation detector response as a function of magnetic field strength

    Science.gov (United States)

    Simiele, E.; Kapsch, R.-P.; Ankerhold, U.; Culberson, W.; DeWerd, L.

    2018-04-01

    The purpose of this work was to characterize intensity and spectral response changes in a plastic scintillation detector (PSD) as a function of magnetic field strength. Spectra measurements as a function of magnetic field strength were performed using an optical spectrometer. The response of both a PSD and PMMA fiber were investigated to isolate the changes in response from the scintillator and the noise signal as a function of magnetic field strength. All irradiations were performed in water at a photon beam energy of 6 MV. Magnetic field strengths of (0, ±0.35, ±0.70, ±1.05, and  ±1.40) T were investigated. Four noise subtraction techniques were investigated to evaluate the impact on the resulting noise-subtracted scintillator response with magnetic field strength. The noise subtraction methods included direct spectral subtraction, the spectral method, and variants thereof. The PMMA fiber exhibited changes in response of up to 50% with magnetic field strength due to the directional light emission from \\breve{C} erenkov radiation. The PSD showed increases in response of up to 10% when not corrected for the noise signal, which agrees with previous investigations of scintillator response in magnetic fields. Decreases in the \\breve{C} erenkov light ratio with negative field strength were observed with a maximum change at  ‑1.40 T of 3.2% compared to 0 T. The change in the noise-subtracted PSD response as a function of magnetic field strength varied with the noise subtraction technique used. Even after noise subtraction, the PSD exhibited changes in response of up to 5.5% over the four noise subtraction methods investigated.

  3. Modelling and assessment of the electric field strength caused by mobile phone to the human head

    Directory of Open Access Journals (Sweden)

    Buckus Raimondas

    2016-01-01

    Full Text Available Background/Aim. Electromagnetic field exposure is the one of the most important physical agents that actively affects live organisms and environment. Active use of mobile phones influences the increase of electromagnetic field radiation. The aim of the study was to measure and assess the electric field strength caused by mobile phones to the human head. Methods. In this paper the software “COMSOL Multiphysics” was used to establish the electric field strength created by mobile phones around the head. Results. The second generation (2G Global System for Mobile (GSM phones that operate in the frequency band of 900 MHz and reach the power of 2 W have a stronger electric field than (2G GSM mobile phones that operate in the higher frequency band of 1,800 MHz and reach the power up to 1 W during conversation. The third generation of (3G UMTS smart phones that effectively use high (2,100 MHz radio frequency band emit the smallest electric field strength values during conversation. The highest electric field strength created by mobile phones is around the ear, i.e. the mobile phone location. The strength of mobile phone electric field on the phantom head decreases exponentially while moving sidewards from the center of the effect zone (the ear, and constitutes 1-12% of the artificial head’s surface. Conclusion. The highest electric field strength values of mobile phones are associated with their higher power, bigger specific energy absorption rate (SAR and lower frequency of mobile phone. The stronger electric field emitted by the more powerful mobile phones takes a higher percentage of the head surface. The highest electric field strength created by mobile phones is distributed over the user ear.

  4. Modelling and assessment of the electric field strength caused by mobile phone to the human head.

    Science.gov (United States)

    Buckus, Raimondas; Strukcinskiene, Birute; Raistenskis, Juozas; Stukas, Rimantas

    2016-06-01

    Electromagnetic field exposure is the one of the most important physical agents that actively affects live organisms and environment. Active use of mobile phones influences the increase of electromagnetic field radiation. The aim of the study was to measure and assess the electric field strength caused by mobile phones to the human head. In this paper the software "COMSOL Multiphysics" was used to establish the electric field strength created by mobile phones around the head. The second generation (2G) Global System for Mobile (GSM) phones that operate in the frequency band of 900 MHz and reach the power of 2 W have a stronger electric field than (2G) GSM mobile phones that operate in the higher frequency band of 1,800 MHz and reach the power up to 1 W during conversation. The third generation of (3G) UMTS smart phones that effectively use high (2,100 MHz) radio frequency band emit the smallest electric field strength values during conversation. The highest electric field strength created by mobile phones is around the ear, i.e. the mobile phone location. The strength of mobile phone electric field on the phantom head decreases exponentially while moving sidewards from the center of the effect zone (the ear), and constitutes 1-12% of the artificial head's surface. The highest electric field strength values of mobile phones are associated with their higher power, bigger specific energy absorption rate (SAR) and lower frequency of mobile phone. The stronger electric field emitted by the more powerful mobile phones takes a higher percentage of the head surface. The highest electric field strength created by mobile phones is distributed over the user's ear.

  5. Dual Liability for Nuclear Damage in Conventions and Finnish Legislation in the Field of Transport

    International Nuclear Information System (INIS)

    Manninen, J.

    1986-01-01

    The exception made in the 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy to the otherwise absolute channelling of liability in order to avoid conflicts with the then existing international agreements in the field of transport is briefly described. The dual liability created by this provision is studied, as well as the question whether and when the victim might prefer to base his claim on a transport agreement instead of the Paris Convention. The so-called nuclear clauses in the new agreements in the transport field are analysed. The problems caused by the absence of a nuclear clause in the Guatemala City and Montreal Protocols, amending the Warsaw Convention relating to international air carriage are noted. Finally the relationship between nuclear liability legislation and transport legislation in Finland, as well as the cases where a dual liability existed at the time of the ratification of the Paris Convention and the changes which have taken place since then are described. (NEA) [fr

  6. A Dosimetric Evaluation of Conventional Helmet Field Irradiation Versus Two-Field Intensity-Modulated Radiotherapy Technique

    International Nuclear Information System (INIS)

    Yu, James B.; Shiao, Stephen L.; Knisely, Jonathan

    2007-01-01

    Purpose: To compare dosimetric differences between conventional two-beam helmet field irradiation (external beam radiotherapy, EBRT) of the brain and a two-field intensity-modulated radiotherapy (IMRT) technique. Methods and Materials: Ten patients who received helmet field irradiation at our institution were selected for study. External beam radiotherapy portals were planned per usual practice. Intensity-modulated radiotherapy fields were created using the identical field angles as the EBRT portals. Each brain was fully contoured along with the spinal cord to the bottom of the C2 vertebral body. This volume was then expanded symmetrically by 0.5 cm to construct the planning target volume. An IMRT plan was constructed using uniform optimization constraints. For both techniques, the nominal prescribed dose was 3,000 cGy in 10 fractions of 300 cGy using 6-MV photons. Comparative dose-volume histograms were generated for each patient and analyzed. Results: Intensity-modulated radiotherapy improved dose uniformity over EBRT for whole brain radiotherapy. The mean percentage of brain receiving >105% of dose was reduced from 29.3% with EBRT to 0.03% with IMRT. The mean maximum dose was reduced from 3,378 cGy (113%) for EBRT to 3,162 cGy (105%) with IMRT. The mean percent volume receiving at least 98% of the prescribed dose was 99.5% for the conventional technique and 100% for IMRT. Conclusions: Intensity-modulated radiotherapy reduces dose inhomogeneity, particularly for the midline frontal lobe structures where hot spots occur with conventional two-field EBRT. More study needs to be done addressing the clinical implications of optimizing dose uniformity and its effect on long-term cognitive function in selected long-lived patients

  7. Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

    DEFF Research Database (Denmark)

    Jensen, Birgit; Knudsen, Inge-Marie Birkedal; Andersen, Birgitte

    2013-01-01

    The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... produced cyclopenol, cyclopenin, and viridicatin on the artificially infected berries, while Altemaria arborescens produced tenuazonic acid, Alternaria tenuissima produced altertoxin land altenuene, and Trichoderma spp. produced several peptaibols. In conclusion, native strawberry microbiotas are highly...

  8. Direct imaging of phase objects enables conventional deconvolution in bright field light microscopy.

    Directory of Open Access Journals (Sweden)

    Carmen Noemí Hernández Candia

    Full Text Available In transmitted optical microscopy, absorption structure and phase structure of the specimen determine the three-dimensional intensity distribution of the image. The elementary impulse responses of the bright field microscope therefore consist of separate absorptive and phase components, precluding general application of linear, conventional deconvolution processing methods to improve image contrast and resolution. However, conventional deconvolution can be applied in the case of pure phase (or pure absorptive objects if the corresponding phase (or absorptive impulse responses of the microscope are known. In this work, we present direct measurements of the phase point- and line-spread functions of a high-aperture microscope operating in transmitted bright field. Polystyrene nanoparticles and microtubules (biological polymer filaments serve as the pure phase point and line objects, respectively, that are imaged with high contrast and low noise using standard microscopy plus digital image processing. Our experimental results agree with a proposed model for the response functions, and confirm previous theoretical predictions. Finally, we use the measured phase point-spread function to apply conventional deconvolution on the bright field images of living, unstained bacteria, resulting in improved definition of cell boundaries and sub-cellular features. These developments demonstrate practical application of standard restoration methods to improve imaging of phase objects such as cells in transmitted light microscopy.

  9. Electric field strength determination in filamentary DBDs by CARS-based four-wave mixing

    Science.gov (United States)

    Boehm, Patrick; Kettlitz, Manfred; Brandenburg, Ronny; Hoeft, Hans; Czarnetzki, Uwe

    2016-09-01

    The electric field strength is a basic parameter of non-thermal plasmas. Therefore, a profound knowledge of the electric field distribution is crucial. In this contribution a four wave mixing technique based on Coherent Anti-Stokes Raman spectroscopy (CARS) is used to measure electric field strengths in filamentary dielectric barrier discharges (DBDs). The discharges are operated with a pulsed voltage in nitrogen at atmospheric pressure. Small amounts hydrogen (10 vol%) are admixed as tracer gas to evaluate the electric field strength in the 1 mm discharge gap. Absolute values of the electric field strength are determined by calibration of the CARS setup with high voltage amplitudes below the ignition threshold of the arrangement. Alteration of the electric field strength has been observed during the internal polarity reversal and the breakdown process. In this case the major advantage over emission based methods is that this technique can be used independently from emission, e.g. in the pre-phase and in between two consecutive, opposite discharge pulses where no emission occurs at all. This work was supported by the Deutsche Forschungsgemeinschaft, Forschergruppe FOR 1123 and Sonderforschungsbereich TRR 24 ``Fundamentals of complex plasmas''.

  10. Structural control of metamaterial oscillator strength and electric field enhancement at terahertz frequencies

    DEFF Research Database (Denmark)

    Keiser, G. R.; Seren, H. R.; Strikwerda, Andrew C.

    2014-01-01

    The design of artificial nonlinear materials requires control over internal resonant charge densities and local electric field distributions. We present a MM design with a structurally controllable oscillator strength and local electric field enhancement at terahertz frequencies. The MM consists...... of a split ring resonator (SRR) array stacked above an array of closed conducting rings. An in-plane, lateral shift of a half unit cell between the SRR and closed ring arrays results in an increase of the MM oscillator strength by a factor of 4 and a 40% change in the amplitude of the resonant electric field...

  11. Dependence of Brownian and Néel relaxation times on magnetic field strength

    International Nuclear Information System (INIS)

    Deissler, Robert J.; Wu, Yong; Martens, Michael A.

    2014-01-01

    Purpose: In magnetic particle imaging (MPI) and magnetic particle spectroscopy (MPS) the relaxation time of the magnetization in response to externally applied magnetic fields is determined by the Brownian and Néel relaxation mechanisms. Here the authors investigate the dependence of the relaxation times on the magnetic field strength and the implications for MPI and MPS. Methods: The Fokker–Planck equation with Brownian relaxation and the Fokker–Planck equation with Néel relaxation are solved numerically for a time-varying externally applied magnetic field, including a step-function, a sinusoidally varying, and a linearly ramped magnetic field. For magnetic fields that are applied as a step function, an eigenvalue approach is used to directly calculate both the Brownian and Néel relaxation times for a range of magnetic field strengths. For Néel relaxation, the eigenvalue calculations are compared to Brown's high-barrier approximation formula. Results: The relaxation times due to the Brownian or Néel mechanisms depend on the magnitude of the applied magnetic field. In particular, the Néel relaxation time is sensitive to the magnetic field strength, and varies by many orders of magnitude for nanoparticle properties and magnetic field strengths relevant for MPI and MPS. Therefore, the well-known zero-field relaxation times underestimate the actual relaxation times and, in particular, can underestimate the Néel relaxation time by many orders of magnitude. When only Néel relaxation is present—if the particles are embedded in a solid for instance—the authors found that there can be a strong magnetization response to a sinusoidal driving field, even if the period is much less than the zero-field relaxation time. For a ferrofluid in which both Brownian and Néel relaxation are present, only one relaxation mechanism may dominate depending on the magnetic field strength, the driving frequency (or ramp time), and the phase of the magnetization relative to the

  12. Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning

    International Nuclear Information System (INIS)

    Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S.

    2012-01-01

    External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

  13. Shear bond strength and debonding characteristics of metal and ceramic brackets bonded with conventional acid-etch and self-etch primer systems: An in-vivo study.

    Science.gov (United States)

    Mirzakouchaki, Behnam; Shirazi, Sajjad; Sharghi, Reza; Shirazi, Samaneh; Moghimi, Mahsan; Shahrbaf, Shirin

    2016-02-01

    Different in-vitro studies have reported various results regarding shear bond strength (SBS) of orthodontic brackets when SEP technique is compared to conventional system. This in-vivo study was designed to compare the effect of conventional acid-etching and self-etching primer adhesive (SEP) systems on SBS and debonding characteristics of metal and ceramic orthodontic brackets. 120 intact first maxillary and mandibular premolars of 30 orthodontic patients were selected and bonded with metal and ceramic brackets using conventional acid-etch or self-etch primer system. The bonded brackets were incorporated into the wire during the study period to simulate the real orthodontic treatment condition. The teeth were extracted and debonded after 30 days. The SBS, debonding characteristics and adhesive remnant indices (ARI) were determined in all groups. The mean SBS of metal brackets was 10.63±1.42 MPa in conventional and 9.38±1.53 MPa in SEP system, (P=0.004). No statistically significant difference was noted between conventional and SEP systems in ceramic brackets. The frequency of 1, 2 and 3 ARI scores and debonding within the adhesive were the most common among all groups. No statistically significant difference was observed regarding ARI or failure mode of debonded specimens in different brackets or bonding systems. The SBS of metal brackets bonded using conventional system was significantly higher than SEP system, although the SBS of SEP system was clinically acceptable. No significant difference was found between conventional and SEP systems used with ceramic brackets. Total SBS of metal brackets was significantly higher than ceramic brackets. Due to adequate SBS of SEP system in bonding the metal brackets, it can be used as an alternative for conventional system. Shear bond strength, Orthodontic brackets, Adhesive remnant index, self-etch.

  14. Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

    DEFF Research Database (Denmark)

    Jensen, Birgit; Knudsen, Inge M. B.; Andersen, Birgitte

    2013-01-01

    The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... was complex including potential plant pathogens, opportunistic human pathogens, plant disease biocontrol agents and mycotoxin producers. The latter group was dominated by Penicillium spp. and Aspergillus niger was also isolated. As expected, bacteria were the most abundant and diverse group of the strawberry...... microbiota followed by yeasts and filamentous fungi. No obvious correlation between grower practice and the strawberry microbiota was observed. Differences between microbiotas on strawberries from conventional systems with up to 10 fungicide spray treatments and organic production systems were insignificant...

  15. Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength.

    Science.gov (United States)

    Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W

    2008-02-21

    Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems.

  16. Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength

    International Nuclear Information System (INIS)

    Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W

    2008-01-01

    Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems

  17. Electrokinetic transport of aerobic microorganisms under low-strength electric fields.

    Science.gov (United States)

    Maillacheruvu, Krishnanand Y; Chinchoud, Preethi R

    2011-01-01

    To investigate the feasibility of utilizing low strength electric fields to transport commonly available mixed cultures such as those from an activated sludge process, bench scale batch reactor studies were conducted in sand and sandy loam soils. A readily biodegradable substrate, dextrose, was used to test the activity of the transported microorganisms. Electric field strengths of 7V, 10.5V, and 14V were used. Results from this investigation showed that an electric field strength of 0.46 Volts per cm was sufficient to transport activated sludge microorganisms across a sandy loam soil across a distance of about 8 cm in 72 h. More importantly, the electrokinetically transported microbial culture remained active and viable after the transport process and was biodegrade 44% of the dextrose in the soil medium. Electrokinetic treatment without microorganisms resulted in removal of 37% and the absence of any treatment yielded a removal of about 15%.

  18. Tensile and shear bond strength of hard and soft denture relining materials to the conventional heat cured acrylic denture base resin: An In-vitro study.

    Science.gov (United States)

    Lau, Mayank; Amarnath, G S; Muddugangadhar, B C; Swetha, M U; Das, Kopal Anshuraj Ashok Kumar

    2014-04-01

    The condition of the denture bearing tissues may be adversely affected by high stress concentration during function. Chairside Denture (Hard and Soft) reliners are used to distribute forces applied to soft tissues during function. Tensile and shear bond strength has been shown to be dependent on their chemical composition. A weak bond could harbor bacteria, promote staining and delamination of the lining material. To investigate tensile and shear bond strength of 4 different commercially available denture relining materials to conventional heat cured acrylic denture base resin. 4 mm sections in the middle of 160 Acrylic cylindrical specimens (20 mm x 8 mm) were removed, packed with test materials (Mollosil, G C Reline Soft, G C Reline Hard (Kooliner) and Ufi Gel Hard and polymerized. Specimens were divided into 8 groups of 20 each. Tensile and shear bond strength to the conventional heat cured acrylic denture base resin were examined by Instron Universal Tensile Testing Machine using the equation F=N/A (F-maximum force exerted on the specimen (Newton) and A-bonding area= 50.24 mm2). One-way ANOVA was used for multiple group comparisons followed by Bonferroni Test and Hsu's MCB for multiple pairwise comparisons to asses any significant differences between the groups. The highest mean Tensile bond strength value was obtained for Ufi Gel Hard (6.49+0.08 MPa) and lowest for G C Reline Soft (0.52+0.01 MPa). The highest mean Shear bond strength value was obtained for Ufi Gel Hard (16.19+0.1 MPa) and lowest for Mollosil (0.59+0.05 MPa). The Benferroni test showed a significant difference in the mean tensile bond strength and the mean shear bond strength when the two denture soft liners were compared as well as when the two denture hard liners were compared. Hsu's MCB implied that Ufi gel hard is better than its other closest competitors. The Tensile and Shear bond strength values of denture soft reliners were significantly lower than denture hard reliners. How to cite the

  19. Effect of conventional and experimental gingival retraction solutions on the tensile strength and inhibition of polymerization of four types of impression materials

    Directory of Open Access Journals (Sweden)

    Sérgio Sábio

    2008-08-01

    Full Text Available In the present study, two types of tests (tensile strength test and polymerization inhibition test were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic, a polyether (Impregum, a condensation silicone (Xantopren and a polyvinylsiloxane (Aquasil ,3; when polymerized in contact with of one conventional (Hemostop and two experimental (Vislin and Afrin gingival retraction solutions. For the tensile strength test, the impression materials were mixed and packed into a steel plate with perforations that had residues of the gingival retraction solutions. After polymerization, the specimens were tested in tensile strength in a universal testing machine. For the polymerization inhibition test, specimens were obtained after taking impressions from a matrix with perforations that contained 1 drop of the gingival retraction solutions. Two independent examiners decided on whether or not impression material remnants remained unpolymerized, indicating interference of the chemical solutions. Based on the analysis of the results of both tests, the following conclusions were reached: 1. The tensile strength of the polysulfide decreased after contact with Hemostop and Afrin. 2. None of the chemical solutions inhibited the polymerization of the polysulfide; 3. The polyether presented lower tensile strength after polymerization in contact with the three gingival retraction agents; 4. The polyether had its polymerization inhibited only by Hemostop; 5. None of the chemical solutions affected the tensile strength of the condensation silicone; 6. Only Hemostop inhibited the polymerization of the condensation silicone; 7. The polyvinylsiloxane specimens polymerized in contact with Hemostop had significantly lower tensile strength; 8. Neither of the chemical solutions (Afrin and Vislin affected the tensile strength of the polyvinylsiloxane and the condensation silicone; 9. Results of the tensile strength

  20. Coulomb field strength measurement by electro-optic spectral decoding system at the CALIFES beam line

    CERN Document Server

    Pan, R; Lefevre, T; Gillepsie, WA; CERN. Geneva. ATS Department

    2016-01-01

    Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding(EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

  1. Field-strength formulation of gauge theories. The Hamiltonian approach in the Abelian theory

    International Nuclear Information System (INIS)

    Mendel, E.; Durand, L.

    1984-01-01

    We develop a Hamiltonian approach to the field-strength or dual formation of the Abelian gauge theory in which the potential A/sup μ/ is eliminated as a dynamical variable. Our work is based on the covariant gauge x/sup μ/A/sub μ/(x) = 0 which allows a simple elimination of A/sup μ/ in terms of the field strengths F/sup munu/. We obtain complete results for the generating functional for the Green's functions of the theory, Z = Z[f,g], where f and g are nonlocal currents coupled to E and B, and illustrate some unfamiliar aspects of the new formalism

  2. Comparison of Shear Bond Strength of Orthodontic Brackets Bonded to Enamel Prepared By Er:YAG Laser and Conventional Acid-Etching

    Science.gov (United States)

    Hosseini, M.H.; Namvar, F.; Chalipa, J.; Saber, K.; Chiniforush, N.; Sarmadi, S.; Mirhashemi, A.H.

    2012-01-01

    Introduction: The purpose of this study was to compare shear bond strength (SBS) of orthodontic brackets bonded to enamel prepared by Er:YAG laser with two different powers and conventional acid-etching. Materials and Methods: Forty-five human premolars extracted for orthodontic purposes were randomly assigned to three groups based on conditioning method: Group 1- conventional etching with 37% phosphoric acid; Group 2- irradiation with Er:YAG laser at 1 W; and Group 3- irradiation with Er:YAG laser at 1.5 W. Metal brackets were bonded on prepared enamel using a light-cured composite. All groups were subjected to thermocycling process. Then, the specimens mounted in auto-cure acryle and shear bond strength were measured using a universal testing machine with a crosshead speed of 0.5 mm per second. After debonding, the amount of resin remaining on the teeth was determined using the adhesive remnant index (ARI) scored 1 to 5. One-way analysis of variance was used to compare shear bond strengths and the Kruskal-Wallis test was performed to evaluate differences in the ARI for different etching types. Results: The mean and standard deviation of conventional acid-etch group, 1W laser group and 1.5W laser group was 3.82 ± 1.16, 6.97 ± 3.64 and 6.93 ± 4.87, respectively. Conclusion: The mean SBS obtained with an Er:YAG laser operated at 1W or 1.5W is approximately similar to that of conventional etching. However, the high variability of values in bond strength of irradiated enamel should be considered to find the appropriate parameters for applying Er:YAG laser as a favorable alternative for surface conditioning. PMID:22924098

  3. Comparison of Shear Bond Strength of Orthodontic Brackets Bonded to Enamel Prepared By Er:YAG Laser and Conven-tional Acid-Etching

    Directory of Open Access Journals (Sweden)

    M.H. Hosseini

    2012-01-01

    Full Text Available Introduction: The purpose of this study was to compare shear bond strength (SBS of orthodontic brackets bonded to enamel prepared by Er:YAG laser with two different powers and conventional acid-etching.Materials and Methods: Forty-five human premolars extracted for orthodontic purposes were randomly assigned to three groups based on conditioning method: Group 1- conventional etching with 37% phosphoric acid; Group 2- irradiation with Er:YAG laser at 1 W; and Group 3- irradiation with Er:YAG laser at 1.5 W. Metal brackets were bonded on prepared enamel using a light-cured composite. All groups were subjected to thermocycling process. Then, the specimens mounted in auto-cure acryle and shear bond strength were measured using a universal testing machine with a crosshead speed of 0.5 mm per second. After debonding, the amount of resin remaining on the teeth was determined using the adhesive remnant index (ARI scored 1 to 5. One-way analysis of variance was used to compare shear bond strengths and the Kruskal-Wallis test was performed to evaluate differences in the ARI for different etching types.Results: The mean and standard deviation of conventional acid-etch group, 1W laser group and 1.5W laser group was 3.82 ± 1.16, 6.97 ± 3.64 and 6.93 ± 4.87, respectively.Conclusion: The mean SBS obtained with an Er:YAG laser operated at 1W or 1.5W is approximately similar to that of conventional etching. However, the high variability of values in bond strength of irradiated enamel should be considered to find the appropriate parameters for applying Er:YAG laser as a favorable alternative for surface conditioning.

  4. SU(N) instantons in the field strength approach to QCD

    International Nuclear Information System (INIS)

    Reinhardt, H.

    1994-01-01

    Field strength formulated Yang-Mills theory is confronted to the traditional formulation in terms of gauge fields. It is shown that both formulations yield the same semiclassics, in particular the same instanton physics. The field strength formulation is, however, superior at the tree level where it includes already a good deal of quantum fluctuations of the standard formulation. These quantum fluctuations break the scale invariance of classical QCD and give rise to an instanton interaction. The latter causes the instanton to condense and to form a homogeneous instanton solid. These instanton solids show up in the field strength approach as homogeneous (constant up to gauge transformations) vacuum solutions. A new class of SU(N) instantons is presented which are not embeddings of SU(N-1) instantons but have non-trivial SU(N) color structure and carry winding number n = N/(N 2 -1)/6. These novel instantons generate (after condensation) the lowest action homogeneous solutions of the field strength approach. (orig.)

  5. Carboxylated magnetic nanoparticles as MRI contrast agents: Relaxation measurements at different field strengths

    Energy Technology Data Exchange (ETDEWEB)

    Jedlovszky-Hajdu, Angela, E-mail: angela.hajdu@net.sote.hu [Laboratory of Nanochemistry, Department of Biophysics and Radiation Biology, Semmelweis University, Nagyvarad Sq 4, H-1089 Budapest (Hungary); Tombacz, Etelka, E-mail: tombacz@chem.u-szeged.hu [Department of Physical Chemistry and Material Science, University of Szeged, Aradi Vt. Sq 1, Szeged 6720 (Hungary); Banyai, Istvan, E-mail: banyai.istvan@science.unideb.hu [Department of Colloid and Environmental Chemistry, University of Debrecen (Hungary); Babos, Magor, E-mail: babosmagor@yahoo.com [Euromedic Diagnostics Szeged Ltd., Semmelweis St 6, Szeged 6720 (Hungary); Palko, Andras, E-mail: palko@radio.szote.u-szeged.hu [Faculty of Medicine, Department of Radiology, University of Szeged (Hungary)

    2012-09-15

    At the moment the biomedical applications of magnetic fluids are the subject of intensive scientific interest. In the present work, magnetite nanoparticles (MNPs) were synthesized and stabilized in aqueous medium with different carboxylic compounds (citric acid (CA), polyacrylic acid (PAA), and sodium oleate (NaOA)), in order to prepare well stabilized magnetic fluids (MFs). The magnetic nanoparticles can be used in the magnetic resonance imaging (MRI) as contrast agents. Magnetic resonance relaxation measurements of the above MFs were performed at different field strengths (i.e., 0.47, 1.5 and 9.4 T) to reveal the field strength dependence of their magnetic responses, and to compare them with that of ferucarbotran, a well-known superparamagnetic contrast agent. The measurements showed characteristic differences between the tested magnetic fluids stabilized by carboxylic compounds and ferucarbotran. It is worthy of note that our magnetic fluids have the highest r2 relaxivities at the field strength of 1.5 T, where the most of the MRI works in worldwide. - Highlights: Black-Right-Pointing-Pointer Magnetic resonance relaxation measurements were done at different field strengths. Black-Right-Pointing-Pointer Results show characteristic differences between the tested carboxylated MFs. Black-Right-Pointing-Pointer r1 and r2 relaxivities depend on the thickness of the protecting layer. Black-Right-Pointing-Pointer MFs have high r2/r1 ratios at each magnetic field.

  6. Isolated electrostatic structures observed throughout the Cluster orbit: relationship to magnetic field strength

    Directory of Open Access Journals (Sweden)

    J. S. Pickett

    2004-07-01

    Full Text Available Isolated electrostatic structures are observed throughout much of the 4RE by 19.6RE Cluster orbit. These structures are observed in the Wideband plasma wave instrument's waveform data as bipolar pulses (one positive and one negative peak in the electric field amplitude and tripolar pulses (two positive and one negative peak, or vice versa. These structures are observed at all of the boundary layers, in the solar wind and magnetosheath, and along auroral field lines at 4.5-6.5RE. Using the Wideband waveform data from the various Cluster spacecraft we have carried out a survey of the amplitudes and time durations of these structures and how these quantities vary with the local magnetic field strength. Such a survey has not been carried out before, and it reveals certain characteristics of solitary structures in a finite magnetic field, a topic still inadequately addressed by theories. We find that there is a broad range of electric field amplitudes at any specific magnetic field strength, and there is a general trend for the electric field amplitudes to increase as the strength of the magnetic field increases over a range of 5 to 500nT. We provide a possible explanation for this trend that relates to the structures being Bernstein-Greene-Kruskal mode solitary waves. There is no corresponding dependence of the duration of the structures on the magnetic field strength, although a plot of these two quantities reveals the unexpected result that with the exception of the magnetosheath, all of the time durations for all of the other regions are comparable, whereas the magnetosheath time durations clearly are in a different category of much smaller time duration. We speculate that this implies that the structures are much smaller in size. The distinctly different pulse durations for the magnetosheath pulses indicate the possibility that the pulses are generated by a mechanism which is different from the mechanism operating in other regions.

  7. Critical Magnetic Field Strengths for Unipolar Solar Coronal Plumes In Quiet Regions and Coronal Holes?

    Science.gov (United States)

    Avallone, Ellis; Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L.; Winebarger, Amy

    2017-01-01

    Coronal plumes are bright magnetic funnels that are found in quiet regions and coronal holes that extend high into the solar corona whose lifetimes can last from hours to days. The heating processes that make plumes bright involve the magnetic field at the base of the plume, but their intricacies remain mysterious. Raouafi et al. (2014) infer from observation that plume heating is a consequence of magnetic reconnection at the base, whereas Wang et al. (2016) infer that plume heating is a result of convergence of the magnetic flux at the plume's base, or base flux. Both papers suggest that the base flux in their plumes is of mixed polarity, but do not quantitatively measure the base flux or consider whether a critical magnetic field strength is required for plume production. To investigate the magnetic origins of plume heating, we track plume luminosity in the 171 Å wavelength as well as the abundance and strength of the base flux over the lifetimes of six unipolar coronal plumes. Of these, three are in coronal holes and three are in quiet regions. For this sample, we find that plume heating is triggered when convergence of the base flux surpasses a field strength of approximately 300 - 500 Gauss, and that the luminosity of both quiet region and coronal hole plumes respond similarly to the strength of the magnetic field in the base.

  8. Electrohydrodynamics in nanochannels coated by mixed polymer brushes: effects of electric field strength and solvent quality

    Science.gov (United States)

    Cao, Qianqian; Tian, Xiu; You, Hao

    2018-04-01

    We examine the electrohydrodynamics in mixed polymer brush-coated nanochannels and the conformational dynamics of grafted polymers using molecular dynamics simulations. Charged (A) and neutral polymers (B) are alternately grafted on the channel surfaces. The effects of the electric field strength and solvent quality are addressed in detail. The dependence of electroosmotic flow characteristics and polymer conformational behavior on the solvent quality is influenced due to the change of the electric field strength. The enhanced electric field induces a collapse of the neutral polymer chains which adopt a highly extended conformation along the flow direction. However, the thickness of the charged polymer layer is affected weakly by the electric field, and even a slight swelling is identified for the A-B attraction case, implying the conformational coupling between two polymer species. Furthermore, the charged polymer chains incline entirely towards the electric field direction oppositely to the flow direction. More importantly, unlike the neutral polymer chains, the shape factor of the charged polymer chains, which is used to describe the overall shape of polymer chains, is reduced significantly with increasing the electric field strength, corresponding to a more coiled structure.

  9. The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method.

    Science.gov (United States)

    Shahabi, Sima; Chiniforush, Nasim; Bahramian, Hoda; Monzavi, Abbas; Baghalian, Ali; Kharazifard, Mohammad Javad

    2013-01-01

    The purpose of this study was to evaluate the effect of Er:YAG and Er,Cr:YSGG laser on tensile bond strength of composite resin to dentine in comparison with bur-prepared cavities. Fifteen extracted caries-free human third molars were selected. The teeth were cut at a level below the occlusal pit and fissure plan and randomly divided into three groups. Five cavities were prepared by diamond bur, five cavities prepared by Er:YAG laser, and the other group prepared by Er,Cr:YSGG laser. Then, all the cavities were restored by composite resin. The teeth were sectioned longitudinally with Isomet and the specimens prepared in dumbbelled shape (n = 36). The samples were attached to special jigs, and the tensile bond strength of the three groups was measured by universal testing machine at a speed of 0.5 mm/min. The results of the three groups were analyzed with one-way ANOVA and Tamhane test. The means and standard deviations of tensile bond strength of bur-cut, Er:YAG laser-ablated, and Er,Cr:YSGG laser-ablated dentine were 5.04 ± 0.93, 13.37 ± 3.87, and 4.85 ± 0.93 MPa, respectively. There is little difference in tensile bond strength of composite resin in Er,Cr:YSGG lased-prepared cavities in comparison with bur-prepared cavities, but the Er:YAG laser group showed higher bond strength than the other groups.

  10. Comparison of shear bond strengths of conventional orthodontic composite and nano-ceramic restorative composite: an in vitro study.

    Science.gov (United States)

    Nagar, Namit; Vaz, Anna C

    2013-01-01

    To compare the shear bond strength of a nano-ceramic restorative composite Ceram-X Mono(TM♦), a restorative resin with the traditional orthodontic composite Transbond XT(TM†) and to evaluate the site of bond failure using Adhesive Remnant Index. Sixty extracted human premolars were divided into two groups of 30 each. Stainless steel brackets were bonded using Transbond XT(TM†) (Group I) and Ceram-X Mono(TM♦) (Group II) according to manufacturer's protocol. Shear bond strength was measured on Universal testing machine at crosshead speed of 1 mm/minute. Adhesive Remnant Index scores were assigned to debonded brackets of each group. Data was analyzed using unpaired 't' test and Chi square test. The mean shear bond strength of Group I (Transbond XT(TM†)) was 12.89 MPa ± 2.19 and that of Group II (Ceram-X Mono(TM)) was 7.29 MPa ± 1.76. Unpaired 't' test revealed statistically significant differences amongst the shear bond strength of the samples measured. Chi-square test revealed statistically insignificant differences amongst the ARI scores of the samples measured. Ceram-X Mono(TM♦) had a lesser mean shear bond strength when compared to Transbond XT(TM†) which was statistically significant difference. However, the mean shear bond of Ceram X Mono was within the clinically acceptable range for bonding. Ceram-X Mono(TM†) and Transbond XT(TM†) showed cohesive fracture of adhesive in 72.6% and 66.6% of the specimens, respectively.

  11. Comparison of shear bond strengths of conventional orthodontic composite and nano-ceramic restorative composite: An in vitro study

    Directory of Open Access Journals (Sweden)

    Namit Nagar

    2013-01-01

    Full Text Available Objectives: To compare the shear bond strength of a nano-ceramic restorative composite Ceram-X MonoTM♦, a restorative resin with the traditional orthodontic composite Transbond XTTM† and to evaluate the site of bond failure using Adhesive Remnant Index. Materials and Methods: Sixty extracted human premolars were divided into two groups of 30 each. Stainless steel brackets were bonded using Transbond XTTM† (Group I and Ceram-X MonoTM♦ (Group II according to manufacturer′s protocol. Shear bond strength was measured on Universal testing machine at crosshead speed of 1 mm/minute. Adhesive Remnant Index scores were assigned to debonded brackets of each group. Data was analyzed using unpaired ′t′ test and Chi square test. Results: The mean shear bond strength of Group I (Transbond XTTM† was 12.89 MPa ± 2.19 and that of Group II (Ceram-X MonoTM was 7.29 MPa ± 1.76. Unpaired ′t′ test revealed statistically significant differences amongst the shear bond strength of the samples measured. Chi-square test revealed statistically insignificant differences amongst the ARI scores of the samples measured. Conclusions: Ceram-X MonoTM♦ had a lesser mean shear bond strength when compared to Transbond XTTM† which was statistically significant difference. However, the mean shear bond of Ceram X Mono was within the clinically acceptable range for bonding. Ceram-X MonoTM† and Transbond XTTM† showed cohesive fracture of adhesive in 72.6% and 66.6% of the specimens, respectively.

  12. Effects of low frequency electromagnetic field on the as-cast microstructures and mechanical properties of superhigh strength aluminum alloy

    International Nuclear Information System (INIS)

    Zuo Yubo; Cui Jianzhong; Dong Jie; Yu Fuxiao

    2005-01-01

    A new superhigh strength Al-Zn-Mg-Cu alloy was made by low frequency electromagnetic casting (LFEC) and conventional direct chill (DC) casting, respectively. The effects of low frequency electromagnetic field on the as-cast microstructures and mechanical properties were investigated. The results show that under the low frequency electromagnetic field (25 Hz, 32 mT), the microstructures of LFEC ingot from the border to the center on the cross section are all fine equiaxed or nearly equiaxed grains. The grains are much finer and more uniform than that of DC ingot. It was found that magnetic flux density plays an important role on the microstructure formation of LFEC ingots. With increasing the magnetic flux density, grains become finer and more uniform. In the range of experimental parameters, the optimum magnetic flux density for LFEC process is found to be 32 mT. The mechanical tests show that for this new superhigh strength Al-Zn-Mg-Cu alloy, the as-cast mechanical properties of LFEC ingot are much higher than that of DC ingot

  13. An Invitro Comparative Evaluation of Compressive Strength and Antibacterial Activity of Conventional GIC and Hydroxyapatite Reinforced GIC in Different Storage Media.

    Science.gov (United States)

    Bali, Praveen; Prabhakar, Attiguppe Ramasetty; Basappa, Nadig

    2015-07-01

    GIC is the most commonly used restorative material in pediatric dentistry since it has got various advantages like fluoride release, anticariogenic property and chemical adhesion to tooth but a major disadvantage is its contraindication in posterior teeth because of poor mechanical properties. The purpose of this study is a modest attempt to explore the influence of the addition of 8% hydroxyapatite to conventional GIC on its compressive strength when immersed in different storage media and antibacterial activity. One hundred and twenty six pellets of the specific dimension of 6 x 4 mm were prepared and divided into 6 groups and were immersed in deionized water, artificial saliva, lactic acid solution respectively for three hours everyday over 30 days test period. The compressive strength was measured by using a universal testing machine (AG-50kNG) at cross head of 1mm(2)/min and strength was determined after 1 day, 7 days, 30 days respectively and the antibacterial activity evaluated against Streptococcus mutans strain in brain heart infusion broth using serial dilution method. Group wise comparisons were made by one-way ANOVA followed by post-hoc Tukey's test, Intergroup comparison was done with Mann-Whitney test. GIC±HAp showed significantly greater antibacterial activity against Streptococcus mutans when compared to GIC group. There was no statistically significant change in the compressive strength among the groups except for group 3 and group 6 when immersed in lactic acid had shown significant difference at the end of 24 hours. The addition of 8% hydroxyapatite to GIC showed marked increased in the antibacterial activity of the conventional GIC against caries initiating organism without much increase in the compressive strength of the GIC when immersed in the different storage media.

  14. H:q ratios and bilateral leg strength in college field and court sports players.

    Science.gov (United States)

    Cheung, Roy T H; Smith, Andrew W; Wong, Del P

    2012-06-01

    One of the key components in sports injury prevention is the identification of imbalances in leg muscle strength. However, different leg muscle characteristics may occur in large playing area (field) sports and small playing area (court) sports, which should be considered in regular injury prevention assessment. This study examined the isokinetic hamstrings-to-quadriceps (H:Q) ratio and bilateral leg strength balance in 40 male college (age: 23.4 ± 2.5 yrs) team sport players (field sport = 23, soccer players; court sport = 17, volleyball and basketball players). Five repetitions of maximal knee concentric flexion and concentric extension were performed on an isokinetic dynamometer at two speeds (slow: 60°·s(-1) and fast: 300°·s(-1)) with 3 minutes rest between tests. Both legs were measured in counterbalanced order with the dominant leg being determined as the leg used to kick a ball. The highest concentric peak torque values (Nm) of the hamstrings and quadriceps of each leg were analyzed after body mass normalization (Nm·kg(-1)). Court sport players showed significantly weaker dominant leg hamstrings muscles at both contraction speeds (P Sport-specific leg muscle strength was evident in college players from field and court sports. These results suggest the need for different muscle strength training and rehabilitation protocols for college players according to the musculature requirements in their respective sports.

  15. Impact of high strength electromagnetic fields generated by Tesla transformer on plant cell ultrastructure

    Directory of Open Access Journals (Sweden)

    Anna Rusakova

    2017-09-01

    Full Text Available Non-thermal effects of direct electric fields and alternating electromagnetic fields (EMF have been successfully used in a number of studies and applications in agriculture and biotechnology. Among different kinds of high strength EMF generators, the Tesla transformer (TT is known as a widely applied, low cost, and troubleproof device, which generates EMF in the range of 2–8 MHz. Despite of a number of developed and perspective applications of high strength EMFs in agriculture and biotechnology, the EMFs generated by TT, as well as the 1–50 MHz range of high strength EMF still remain unexplored in the fields of plant physiology, ultrastructure studies and biochemistry. In this work, we have shown that TT-EMFs (4 MHz induced fast stem and petiole bending, disappearance of cell organelles, vacuolar membranes, and increase of a non-photochemical chlorophyll fluorescence quenching in petioles. It is intriguing that such fatal effects can be evoked in plants by EMFs which are well known as harmless for man at the applied strength and frequency.

  16. Hypercapnic normalization of BOLD fMRI: comparison across field strengths and pulse sequences

    DEFF Research Database (Denmark)

    Cohen, Eric R.; Rostrup, Egill; Sidaros, Karam

    2004-01-01

    to be more accurately localized and quantified based on changes in venous blood oxygenation alone. The normalized BOLD signal induced by the motor task was consistent across different magnetic fields and pulse sequences, and corresponded well with cerebral blood flow measurements. Our data suggest...... size, as well as experimental, such as pulse sequence and static magnetic field strength (B(0)). Thus, it is difficult to compare task-induced fMRI signals across subjects, field strengths, and pulse sequences. This problem can be overcome by normalizing the neural activity-induced BOLD fMRI response...... for global stimulation, subjects breathed a 5% CO(2) gas mixture. Under all conditions, voxels containing primarily large veins and those containing primarily active tissue (i.e., capillaries and small veins) showed distinguishable behavior after hypercapnic normalization. This allowed functional activity...

  17. Biological effects of high strength electric fields. Second interim progress report, September 1976--March 1977

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.D.; Kaune, W.T.

    1977-05-01

    This report describes progress made on the Project during the period of September 9, 1976 to March 31, 1977 towards the determination of the biological effects of high strength electric fields on small laboratory animals. The efforts to date can be divided into five categories: (1) the design, construction, and testing of a prototype and special studies exposure system; (2) the design and construction of exposure systems for rats and mice; (3) dosimetry; (4) experiments to determine the maximum field strength which does not produce corona discharge, ozone formation, shocks to the animal, hair stimulation, or a behavioral preference by rats to avoid exposure to the field; and (5) preparations for the biological screening experiments.

  18. Development of high-mechanical strength electrical insulations for tokamak toroidal field coils

    International Nuclear Information System (INIS)

    Burke, C.

    1977-01-01

    The electrical insulation for the TF (Toroidal Field) coils is subjected to a high interlaminar shear, tensile and compressive stresses. Two candidate epoxy/glass fiber systems using prepreg and vacuum impregnation techniques were evaluated. Specimens were prepared and processed under controlled conditions to simulate specification manufacturing procedures. The strengths of the insulation were measured in interlaminar shear, tension, compression, and combined shear and compression statically. Shear modulus determinations were also made. Various techniques of surface treatments to increase bond strengths with three resin primers were tested

  19. Energetic fitness: Field metabolic rates assessed via 3D accelerometry complement conventional fitness metrics

    Science.gov (United States)

    Grémillet, David; Lescroël, Amelie; Ballard, Grant; Dugger, Katie M.; Massaro, Melanie; Porzig, Elizabeth L.; Ainley, David G.

    2018-01-01

    Evaluating the fitness of organisms is an essential step towards understanding their responses to environmental change. Connections between energy expenditure and fitness have been postulated for nearly a century. However, testing this premise among wild animals is constrained by difficulties in measuring energy expenditure while simultaneously monitoring conventional fitness metrics such as survival and reproductive output.We addressed this issue by exploring the functional links between field metabolic rate (FMR), body condition, sex, age and reproductive performance in a wild population.We deployed 3D accelerometers on 115 Adélie penguins Pygoscelis adeliae during four breeding seasons at one of the largest colonies of this species, Cape Crozier, on Ross Island, Antarctica. The demography of this population has been studied for the past 18 years. From accelerometry recordings, collected for birds of known age and breeding history, we determined the vector of the dynamic body acceleration (VeDBA) and used it as a proxy for FMR.This allowed us to demonstrate relationships among FMR, a breeding quality index (BQI) and body condition. Notably, we found a significant quadratic relationship between mean VeDBA during foraging and BQI for experienced breeders, and individuals in better body condition showed lower rates of energy expenditure.We conclude that using FMR as a fitness component complementary to more conventional fitness metrics will yield greater understanding of evolutionary and conservation physiology.

  20. Gene flow from GM glyphosate-tolerant to conventional soybeans under field conditions in Japan.

    Science.gov (United States)

    Yoshimura, Yasuyuki; Matsuo, Kazuhito; Yasuda, Koji

    2006-01-01

    Natural out-crossing rates were evaluated for conventional soybeans (Glycine max (L.) Merr.) cultivated adjacent to genetically modified (GM) glyphosate-tolerant soybeans under field conditions during a four-year period in Japan. A total of 107 846 progeny of 2772 plants harvested from conventional varieties were screened for glyphosate herbicide tolerance. The highest out-crossing rates, 0.19% in 2001 and 0.16% in 2002, were observed in adjacent rows 0.7 m from the pollen source. The highest rate in 2004 was 0.052%, which was observed at 2.1 m. No out-crossing was observed in the rows 10.5 m from the pollen source over the four-year period. The farthest distances between receptor and pollen source at which out-crossing was observed were 7 m in 2001, 2.8 m in 2002, and 3.5 m in 2004. The greatest airborne pollen density during the flowering period, determined by Durham pollen samplers located between the rows of each variety, was 0.368 grains.cm(-2).day(-1), with the average value at 0.18 grains.cm(-2).day(-1), indicating that the possibility of out-crossing by wind is minimal. Thrips species and predatory Hemiptera visited the soybean flowers more frequently during the four-year period than any other common pollinators, such as bees.

  1. Contribution of Field Strength Gradients to the Net Vertical Current of Active Regions

    Science.gov (United States)

    Vemareddy, P.

    2017-12-01

    We examined the contribution of field strength gradients for the degree of net vertical current (NVC) neutralization in active regions (ARs). We used photospheric vector magnetic field observations of AR 11158 obtained by Helioseismic and Magnetic Imager on board SDO and Hinode. The vertical component of the electric current is decomposed into twist and shear terms. The NVC exhibits systematic evolution owing to the presence of the sheared polarity inversion line between rotating and shearing magnetic regions. We found that the sign of shear current distribution is opposite in dominant pixels (60%–65%) to that of twist current distribution, and its time profile bears no systematic trend. This result indicates that the gradient of magnetic field strength contributes to an opposite signed, though smaller in magnitude, current to that contributed by the magnetic field direction in the vertical component of the current. Consequently, the net value of the shear current is negative in both polarity regions, which when added to the net twist current reduces the direct current value in the north (B z > 0) polarity, resulting in a higher degree of NVC neutralization. We conjecture that the observed opposite signs of shear and twist currents are an indication, according to Parker, that the direct volume currents of flux tubes are canceled by their return currents, which are contributed by field strength gradients. Furthermore, with the increase of spatial resolution, we found higher values of twist, shear current distributions. However, the resolution effect is more useful in resolving the field strength gradients, and therefore suggests more contribution from shear current for the degree of NVC neutralization.

  2. Effect of low transverse magnetic field on the confinement strength in a quasi-1D wire

    International Nuclear Information System (INIS)

    Kumar, Sanjeev; Thomas, K. J.; Smith, L. W.; Farrer, I.; Ritchie, D. A.; Jones, G. A. C.; Griffiths, J.; Pepper, M.

    2013-01-01

    Transport measurements in a quasi-one dimensional (1D) quantum wire are reported in the presence of low transverse magnetic field. Differential conductance shows weak quantised plateaus when the 2D electrons are squeezed electrostatically. Application of a small transverse magnetic field (0.2T) enhances the overall degree of quantisation due to the formation of magneto-electric subbands. The results show the role of magnetic field to fine tune the confinement strength in low density wires when interaction gives rise to double row formation

  3. CALCULATION METHOD OF ELECTRIC POWER LINES MAGNETIC FIELD STRENGTH BASED ON CYLINDRICAL SPATIAL HARMONICS

    Directory of Open Access Journals (Sweden)

    A.V. Erisov

    2016-05-01

    Full Text Available Purpose. Simplification of accounting ratio to determine the magnetic field strength of electric power lines, and assessment of their environmental safety. Methodology. Description of the transmission lines of the magnetic field by using techniques of spatial harmonic analysis in the cylindrical coordinate system is carried out. Results. For engineering calculations of electric power lines magnetic field with sufficient accuracy describes their first spatial harmonic magnetic field. Originality. Substantial simplification of the definition of the impact of the construction of transmission line poles on the value of its magnetic field and the bands of land alienation sizes. Practical value. The environmentally friendly projection electric power lines on the level of the magnetic field.

  4. Conventional radiotherapy of localized right side breast cancer after radical mastectomy: development of innovative “field in field” technique

    Directory of Open Access Journals (Sweden)

    Goran Marošević

    2011-12-01

    Full Text Available Introduction: The aim of this paper is to study the distribution of the therapy dosage applied by a modified conventionalfield in field” technique and compare it to the distribution of the dosage applied by the standard conventional technique.Methods: The study included ten patients with right side breast cancer, after they were exposed to radical mastectomy and chemotherapy. Radiotherapy dosage of TD 50 Gy in 25 fractions was applied to the anterolateral side of the right thoracic wall, with two opposite conventional tangential fields by the linear accelerator Elekta Synergy and the energy of 6 megavolts (MV. A delineation of the target volume (CTV – Clinical Target Volume was done within conventional fields. At the XiO system for planning we included additional fields within the existing conventional fields, which was the so called “field in field” technique. On the basis of CTV the Dose Volume  Histogram (DVH was calculated for conventional and “field in field” plans. VD90%, VD95%, VD107%, VD115%, CI and HI were calculated for both techniques. Means were pared with the paired Student's t-test. The results were considered significantly different if p<0.05.Results: VD90% and VD 95% were significantly higher for the “field in field” technique. Therefore, CI also favored the “field in field” technique (p=0.02. There was no difference in VD107% and VD115% between the compared groups. Consequently, there was no statistically significant difference in HI (1.13±0.03 vs.1.13±0.03, p=0.06.Conclusion: Conventional postoperative radiotherapy of localized right side breast cancer by “field in field” technique provides excellent coverage of the target volume by radiotherapy isodose.

  5. Evaluation of mechanical strength of the joints in JT-60 toroidal field coil conductors

    International Nuclear Information System (INIS)

    Nishio, Satoshi; Ohkubo, Monoru; Sasajima, Hiroshi

    1980-04-01

    Toroidal field (TF) coils of JT-60 produce a toroidal field of 45 kG at a plasma axis, they have an inner bore of 3.90 m and a weight of about 80 metric tons per coil. Eighteen TF coils are located around a torus axis at regular intervals. TF coil conductors are mostly jointed by high frequency induction brazing, the rest jointed by welding. In deciding the details of the jointing procedures, the conductor size and the requested mechanical strength are mainly taken into consideration. Described are non-destructive inspection methods for the brazed joints, strength evaluation, and the inspection criteria. Ultrasonic testing method is found to be the most effective in evaluation of mechanical properties of the brazed joints especially in terms of fatigue strength. In section 1, specifications of the TF coils are given. In section 2, the ultrasonic inspection method and the detectability of this apparatus are described in detail, the defects of known size are compared with the indication values and display figures. The apparatus developed for JT-60 is operated automatically also recording the inspectionresults. In section 3, mechanical strength of the brazed joints with initial defects is discussed on the basis of Fracture Mechanics theory and results of the fatigue crack growth test. The inspection criteria in accordance with the descriptions of section 2 and 3 are given in section 4. (author)

  6. Effects of solvent volatilization time on the bond strength of etch-and-rinse adhesive to dentin using conventional or deproteinization bonding techniques.

    Science.gov (United States)

    de Sousa Júnior, José Aginaldo; Carregosa Santana, Márcia Luciana; de Figueiredo, Fabricio Eneas Diniz; Faria-E-Silva, André Luis

    2015-08-01

    This study determined the effect of the air-stream application time and the bonding technique on the dentin bond strength of adhesives with different solvents. Furthermore, the content and volatilization rate of the solvents contained in the adhesives were also evaluated. Three adhesive systems with different solvents (Stae, SDI, acetone; XP Bond, Dentsply De Trey, butanol; Ambar, FGM, ethanol) were evaluated. The concentrations and evaporation rates of each adhesive were measured using an analytical balance. After acid-etching and rinsing, medium occlusal dentin surfaces of human molars were kept moist (conventional) or were treated with 10% sodium hypochlorite for deproteinization. After applying adhesives over the dentin, slight air-stream was applied for 10, 30 or 60 sec. Composite cylinders were built up and submitted to shear testing. The data were submitted to ANOVA and Tukey's test (α = 0.05). Stae showed the highest solvent content and Ambar the lowest. Acetone presented the highest evaporation rate, followed by butanol. Shear bond strengths were significantly affected only by the factors of 'adhesive' and 'bonding technique' (p Stae showed the lowest bond strength values (p < 0.05), while no significant difference was observed between XP Bond and Ambar. Despite the differences in content and evaporation rate of the solvents, the duration of air-stream application did not affect the bond strength to dentin irrespective of the bonding technique.

  7. Bright-field Nanoscopy: Visualizing Nano-structures with Localized Optical Contrast Using a Conventional Microscope.

    Science.gov (United States)

    Suran, Swathi; Bharadwaj, Krishna; Raghavan, Srinivasan; Varma, Manoj M

    2016-04-26

    Most methods for optical visualization beyond the diffraction limit rely on fluorescence emission by molecular tags. Here, we report a method for visualization of nanostructures down to a few nanometers using a conventional bright-field microscope without requiring additional molecular tags such as fluorophores. The technique, Bright-field Nanoscopy, is based on the strong thickness dependent color of ultra-thin germanium on an optically thick gold film. We demonstrate the visualization of grain boundaries in chemical vapour deposited single layer graphene and the detection of single 40 nm Ag nanoparticles. We estimate a size detection limit of about 2 nm using this technique. In addition to visualizing nano-structures, this technique can be used to probe fluid phenomena at the nanoscale, such as transport through 2D membranes. We estimated the water transport rate through a 1 nm thick polymer film using this technique, as an illustration. Further, the technique can also be extended to study the transport of specific ions in the solution. It is anticipated that this technique will find use in applications ranging from single-nanoparticles resolved sensing to studying nanoscale fluid-solid interface phenomena.

  8. Gauge-invariant scalar and field strength correlators in 3d

    CERN Document Server

    Laine, Mikko

    1998-01-01

    Gauge-invariant non-local scalar and field strength operators have been argued to have significance, e.g., as a way to determine the behaviour of the screened static potential at large distances, as order parameters for confinement, as input parameters in models of confinement, and as gauge-invariant definitions of light constituent masses in bound state systems. We measure such "correlators" in the 3d pure SU(2) and SU(2)+Higgs models on the lattice. We extract the corresponding mass parameters and discuss their scaling and physical interpretation. We find that the finite part of the MS-bar scheme mass measured from the field strength correlator is large, more than half the glueball mass. We also determine the non-perturbative contribution to the Debye mass in the 4d finite T SU(2) gauge theory with a method due to Arnold and Yaffe, finding $\\delta m_D\\approx 1.06(4)g^2T$.

  9. Isolated electrostatic structures observed throughout the Cluster orbit: relationship to magnetic field strength

    Directory of Open Access Journals (Sweden)

    J. S. Pickett

    2004-07-01

    Full Text Available Isolated electrostatic structures are observed throughout much of the 4RE by 19.6RE Cluster orbit. These structures are observed in the Wideband plasma wave instrument's waveform data as bipolar pulses (one positive and one negative peak in the electric field amplitude and tripolar pulses (two positive and one negative peak, or vice versa. These structures are observed at all of the boundary layers, in the solar wind and magnetosheath, and along auroral field lines at 4.5-6.5RE. Using the Wideband waveform data from the various Cluster spacecraft we have carried out a survey of the amplitudes and time durations of these structures and how these quantities vary with the local magnetic field strength. Such a survey has not been carried out before, and it reveals certain characteristics of solitary structures in a finite magnetic field, a topic still inadequately addressed by theories. We find that there is a broad range of electric field amplitudes at any specific magnetic field strength, and there is a general trend for the electric field amplitudes to increase as the strength of the magnetic field increases over a range of 5 to 500nT. We provide a possible explanation for this trend that relates to the structures being Bernstein-Greene-Kruskal mode solitary waves. There is no corresponding dependence of the duration of the structures on the magnetic field strength, although a plot of these two quantities reveals the unexpected result that with the exception of the magnetosheath, all of the time durations for all of the other regions are comparable, whereas the magnetosheath time durations clearly are in a different category of much smaller time duration. We speculate that this implies that the structures are much smaller in size. The distinctly different pulse durations for the magnetosheath pulses indicate the possibility that the pulses are generated by a mechanism which is different

  10. Field strength correlators in QCD: new fits to the lattice data

    International Nuclear Information System (INIS)

    Meggiolaro, E.

    1999-01-01

    We discuss the results obtained by fitting the lattice data of the gauge-invariant field strength correlators in QCD with some particular functions which are commonly used in the literature in some phenomenological approaches to high-energy hadron-hadron scattering. A comparison is done with the results obtained in the original fits to the lattice data. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. CONSTRAINING THE SOLAR CORONAL MAGNETIC FIELD STRENGTH USING SPLIT-BAND TYPE II RADIO BURST OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, P.; Ramesh, R.; Hariharan, K.; Kathiravan, C. [Indian Institute of Astrophysics, 2nd Block, Koramangala, Bangalore—560034 (India); Gopalswamy, N., E-mail: kishore@iiap.res.in [Code 671, Solar Physics Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)

    2016-11-20

    We report on low-frequency radio (85–35 MHz) spectral observations of four different type II radio bursts, which exhibited fundamental-harmonic emission and split-band structure. Each of the bursts was found to be closely associated with a whitelight coronal mass ejection (CME) close to the Sun. We estimated the coronal magnetic field strength from the split-band characteristics of the bursts, by assuming a model for the coronal electron density distribution. The choice of the model was constrained, based on the following criteria: (1) when the radio burst is observed simultaneously in the upper and lower bands of the fundamental component, the location of the plasma level corresponding to the frequency of the burst in the lower band should be consistent with the deprojected location of the leading edge (LE) of the associated CME; (2) the drift speed of the type II bursts derived from such a model should agree closely with the deprojected speed of the LE of the corresponding CMEs. With the above conditions, we find that: (1) the estimated field strengths are unique to each type II burst, and (2) the radial variation of the field strength in the different events indicate a pattern. It is steepest for the case where the heliocentric distance range over which the associated burst is observed is closest to the Sun, and vice versa.

  12. Optical field-strength polarization of two-mode single-photon states

    Energy Technology Data Exchange (ETDEWEB)

    Linares, J; Nistal, M C; Barral, D; Moreno, V, E-mail: suso.linares.beiras@usc.e [Optics Area, Department of Applied Physics, Faculty of Physics and School of Optics and Optometry, University of Santiago de Compostela, Campus Universitario Sur s/n, 15782-Santiago de Compostela, Galicia (Spain)

    2010-09-15

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

  13. Optical field-strength polarization of two-mode single-photon states

    International Nuclear Information System (INIS)

    Linares, J; Nistal, M C; Barral, D; Moreno, V

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

  14. Resolution Improvements in in Vivo1H NMR Spectra with Increased Magnetic Field Strength

    Science.gov (United States)

    Gruetter, Rolf; Weisdorf, Sally A.; Rajanayagan, Vasantham; Terpstra, Melissa; Merkle, Hellmut; Truwit, Charles L.; Garwood, Michael; Nyberg, Scott L.; Ugurbil, Kâmil

    1998-11-01

    The measurement of cerebral metabolites using highly homologous localization techniques and similar shimming methods was performed in the human brain at 1.5 and 4 T as well as in the dog and rat brain at 9.4 T. In rat brain, improved resolution was achieved by shimming all first- and second-order shim coils using a fully adiabatic FASTMAP sequence. The spectra showed a clear improvement in spectral resolution for all metabolite resonances with increased field strength. Changes in cerebral glutamine content were clearly observed at 4 T compared to 1.5 T in patients with hepatic encephalopathy. At 9.4 T, glutamine H4 at 2.46 ppm was fully resolved from glutamate H4 at 2.37 ppm, as was the potential resonance from γ-amino-butyric acid at 2.30 ppm and N-acetyl-aspartyl-glutamate at 2.05 ppm. Singlet linewidths were found to be as low as 6 Hz (0.015 ppm) at 9.4 T, indicating a substantial decrease in ppm linewidth with field strength. Furthermore, the methylene peak of creatine was partially resolved from phosphocreatine, indicating a close to 1:1 relationship in gray matter. We conclude that increasing the magnetic field strength increases spectral resolution also for1H NMR, which can lead to more than linear sensitivity gains.

  15. An Ensemble Learning for Predicting Breakdown Field Strength of Polyimide Nanocomposite Films

    Directory of Open Access Journals (Sweden)

    Hai Guo

    2015-01-01

    Full Text Available Using the method of Stochastic Gradient Boosting, ten SMO-SVR are constructed into a strong prediction model (SGBS model that is efficient in predicting the breakdown field strength. Adopting the method of in situ polymerization, thirty-two samples of nanocomposite films with different percentage compositions, components, and thicknesses are prepared. Then, the breakdown field strength is tested by using voltage test equipment. From the test results, the correlation coefficient (CC, the mean absolute error (MAE, the root mean squared error (RMSE, the relative absolute error (RAE, and the root relative squared error (RRSE are 0.9664, 14.2598, 19.684, 22.26%, and 25.01% with SGBS model. The result indicates that the predicted values fit well with the measured ones. Comparisons between models such as linear regression, BP, GRNN, SVR, and SMO-SVR have also been made under the same conditions. They show that CC of the SGBS model is higher than those of other models. Nevertheless, the MAE, RMSE, RAE, and RRSE of the SGBS model are lower than those of other models. This demonstrates that the SGBS model is better than other models in predicting the breakdown field strength of polyimide nanocomposite films.

  16. Functional BOLD MRI: comparison of different field strengths in a motor task

    International Nuclear Information System (INIS)

    Meindl, T.; Born, C.; Britsch, S.; Reiser, M.; Schoenberg, S.

    2008-01-01

    The purpose was to evaluate the benefit of an increased field strength for functional magnetic resonance imaging in a motor task. Six right-handed volunteers were scanned at 1.5 T and 3.0 T using a motor task. Each experiment consisted of two runs with four activation blocks, each with right- and left-hand tapping. Analysis was done using BrainVoyagerQX registered . Differences between both field strengths concerning signal to noise (SNR), blood oxygen level-dependent (BOLD) signal change, functional sensitivity and BOLD contrast to noise (CNR) were tested using a paired t test. Delineation of activations and artifacts were graded by two independent readers. Results were further validated by means of a phantom study. The sensorimotor and premotor cortex, the supplementary motor area, subcortical and cerebellar structures were activated at each field strength. Additional activations of the right premotor cortex and right superior temporal gyrus were found at 3.0 T. Signal-to-noise, percentage of BOLD signal change, BOLD CNR and functional sensitivity improved at 3.0 T by a factor of up to 2.4. Functional imaging at 3.0 T results in detection of additional activated areas, increased SNR, BOLD signal change, functional sensitivity and BOLD CNR. (orig.)

  17. Conventional Gymnasium vs. Geodesic Field House. A Comparative Study of High School Physical Education and Assembly Facilities.

    Science.gov (United States)

    Educational Facilities Labs., Inc., New York, NY.

    A description is presented of the design features of a high school's geodesic dome field house. Following consideration of various design features and criteria for the physical education facility, a comprehensive analysis is given of comparative costs of a geodesic dome field house and conventional gymnasium. On the basis of the study it would…

  18. Study of a permanent-magnet dipole with variable field strength and polarity

    International Nuclear Information System (INIS)

    Honma, Toshihiro

    1996-01-01

    A proto-type dipole magnet employing permanent-magnet rods has been designed and constructed. The magnet is able to change the magnetic field strength continuously as well as the polarity of the field direction by rotating the rods. The magnet has a special advantage of high-field production within a small open space available. The magnet of this type will be used for beam steering at an extraction channel for a planned negative-ion acceleration in our cyclotron. The first important objective at the exit channel is to steer the beam extracted from the cyclotron by some dipole magnet onto the optical axis of a new beam line to be constructed. This is not a trivial task because available open space is too small to install a coil-type magnet. One of the selections is to use a permanent-magnet dipole because such a magnet is expected to provide a very high field in a small space when compared with a coil-type magnet. A proto-type permanent-magnet dipole (PMD) with variable field strength and polarity has been designed and constructed for such a purpose. (J.P.N.)

  19. Magnetic field strength dependence of the magnetostriction of rare-earth iron garnets

    International Nuclear Information System (INIS)

    Zvezdin, A.K.; Levitin, R.Z.; Popov, A.I.; Silant'ev, V.I.

    1981-01-01

    The magnetostriction of holmium-yttrium iron garnets Hosub(x)Ysub(3-x)Fesub(5)Osub(12) (x=3 or 1.05) is measured in pulsed magnetic fields up to 200 kOe at 78 K. It is shown that the magnetostriction constants lambda 111 and lambda 100 of these ferrimagnets depends on the magnetic field strength. The magnetostriction constant of the iron garnet Ho 3 Fe 5 O 12 increases and of the iron garnet Hosub(1.05)Ysub(1.95)Fesub(5)Osub(12) decreases with increase of the field strength. The field dependences of the anisotropic magnetostriction constants lambda 111 and lambda 100 for Hosub(1.05)Ysub(1.95)Fesub(5)Osub(12) are fundamentally different. Thus lambda 111 depends quadratically on the total effective field Hsub(eff) whereas lambda 100 depends almost linearly on Hsub(eff). A theoretical analysis of the magneto-elastic interaction in rare-earth iron garnets is carried out [ru

  20. Magnetic field strength of a neutron-star-powered ultraluminous X-ray source

    Science.gov (United States)

    Brightman, M.; Harrison, F. A.; Fürst, F.; Middleton, M. J.; Walton, D. J.; Stern, D.; Fabian, A. C.; Heida, M.; Barret, D.; Bachetti, M.

    2018-04-01

    Ultraluminous X-ray sources (ULXs) are bright X-ray sources in nearby galaxies not associated with the central supermassive black hole. Their luminosities imply they are powered by either an extreme accretion rate onto a compact stellar remnant, or an intermediate mass ( 100-105M⊙) black hole1. Recently detected coherent pulsations coming from three bright ULXs2-5 demonstrate that some of these sources are powered by accretion onto a neutron star, implying accretion rates significantly in excess of the Eddington limit, a high degree of geometric beaming, or both. The physical challenges associated with the high implied accretion rates can be mitigated if the neutron star surface field is very high (1014 G)6, since this suppresses the electron scattering cross-section, reducing the radiation pressure that chokes off accretion for high luminosities. Surface magnetic field strengths can be determined through cyclotron resonance scattering features7,8 produced by the transition of charged particles between quantized Landau levels. Here, we present the detection at a significance of 3.8σ of an absorption line at 4.5 keV in the Chandra spectrum of a ULX in M51. This feature is likely to be a cyclotron resonance scattering feature produced by the strong magnetic field of a neutron star. Assuming scattering off electrons, the magnetic field strength is implied to be 1011 G, while protons would imply a magnetic field of B 1015 G.

  1. Misconception regarding conventional coupling of fields and particles in XFEL codes

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [Europeam XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [DESY Hamburg (Germany)

    2016-01-15

    Maxwell theory is usually treated in the laboratory frame under the standard time order, that is the usual light-signal clock synchronization. In contrast, particle tracking in the laboratory frame usually treats time as an independent variable. As a result, here we argue that the evolution of electron beams is usually treated according to the absolute time convention i.e. using a different time order defined by a non-standard clock synchronization procedure. This essential point has never received attention in the accelerator community. There are two possible ways of coupling fields and particles in this situation. The first, Lorentz's prerelativistic way, consists in a 'translation' of Maxwell's electrodynamics to the absolute time world-picture. The second, Einstein's way, consists in a 'translation' of particle tracking results to the electromagnetic world-picture, obeying the standard time order. Conventional particle tracking shows that the electron beam direction changes after a transverse kick, while the orientation of the microbunching phase front stays unvaried. Here we show that in the ultrarelativistic asymptotic v → c, the orientation of the planes of simultaneity, i.e. the orientation of the microbunching fronts, is always perpendicular to the electron beam velocity when the evolution of the modulated electron beam is treated under Einstein's time order. This effect allows for the production of coherent undulator radiation from a modulated electron beam in the kicked direction without suppression. We hold a recent FEL study at the LCLS as a direct experimental evidence that the microbunching wavefront indeed readjusts its direction after the electron beam is kicked by a large angle, limited only by the beamline aperture. In a previous paper we quantitatively described this result invoking the aberration of light effect, which corresponds to Lorentz's way of coupling fields and particles. The purpose of

  2. Misconception regarding conventional coupling of fields and particles in XFEL codes

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2016-01-01

    Maxwell theory is usually treated in the laboratory frame under the standard time order, that is the usual light-signal clock synchronization. In contrast, particle tracking in the laboratory frame usually treats time as an independent variable. As a result, here we argue that the evolution of electron beams is usually treated according to the absolute time convention i.e. using a different time order defined by a non-standard clock synchronization procedure. This essential point has never received attention in the accelerator community. There are two possible ways of coupling fields and particles in this situation. The first, Lorentz's prerelativistic way, consists in a 'translation' of Maxwell's electrodynamics to the absolute time world-picture. The second, Einstein's way, consists in a 'translation' of particle tracking results to the electromagnetic world-picture, obeying the standard time order. Conventional particle tracking shows that the electron beam direction changes after a transverse kick, while the orientation of the microbunching phase front stays unvaried. Here we show that in the ultrarelativistic asymptotic v → c, the orientation of the planes of simultaneity, i.e. the orientation of the microbunching fronts, is always perpendicular to the electron beam velocity when the evolution of the modulated electron beam is treated under Einstein's time order. This effect allows for the production of coherent undulator radiation from a modulated electron beam in the kicked direction without suppression. We hold a recent FEL study at the LCLS as a direct experimental evidence that the microbunching wavefront indeed readjusts its direction after the electron beam is kicked by a large angle, limited only by the beamline aperture. In a previous paper we quantitatively described this result invoking the aberration of light effect, which corresponds to Lorentz's way of coupling fields and particles. The purpose of

  3. Effects of solvent volatilization time on the bond strength of etch-and-rinse adhesive to dentin using conventional or deproteinization bonding techniques

    Directory of Open Access Journals (Sweden)

    José Aginaldo de Sousa Júnior

    2015-08-01

    Full Text Available Objectives This study determined the effect of the air-stream application time and the bonding technique on the dentin bond strength of adhesives with different solvents. Furthermore, the content and volatilization rate of the solvents contained in the adhesives were also evaluated. Materials and Methods Three adhesive systems with different solvents (Stae, SDI, acetone; XP Bond, Dentsply De Trey, butanol; Ambar, FGM, ethanol were evaluated. The concentrations and evaporation rates of each adhesive were measured using an analytical balance. After acid-etching and rinsing, medium occlusal dentin surfaces of human molars were kept moist (conventional or were treated with 10% sodium hypochlorite for deproteinization. After applying adhesives over the dentin, slight air-stream was applied for 10, 30 or 60 sec. Composite cylinders were built up and submitted to shear testing. The data were submitted to ANOVA and Tukey's test (α = 0.05. Results Stae showed the highest solvent content and Ambar the lowest. Acetone presented the highest evaporation rate, followed by butanol. Shear bond strengths were significantly affected only by the factors of 'adhesive' and 'bonding technique' (p < 0.05, while the factor 'duration of air-stream' was not significant. Deproteinization of dentin increased the bond strength (p < 0.05. Stae showed the lowest bond strength values (p < 0.05, while no significant difference was observed between XP Bond and Ambar. Conclusions Despite the differences in content and evaporation rate of the solvents, the duration of air-stream application did not affect the bond strength to dentin irrespective of the bonding technique.

  4. Characteristics of the TPE reversed-field pinch plasmas in conventional and improved confinement regimes

    International Nuclear Information System (INIS)

    Sakakita, H.; Asai, T.; Fiksel, G.; Yagi, Y.; Frassinetti, L.; Hayase, K.; Hirano, Y.; Kiyama, S.; Koguchi, H.; Shimada, T.; Innocente, P.; Spizzo, G.; Terranova, D.; Sato, Y.; Yoshikawa, M.

    2005-01-01

    We present the characteristics and experimental scaling laws of reversed-field pinch (RFP) plasmas, which are obtained from the recently established toroidal pinch experiment (TPE) database. The database contains information for approximately 1500 discharges consistently selected from four TPE RFP devices, and covers two decades of RFP experiments under conventional operating conditions at the National Institute of Advanced Industrial Science and Technology. We present the physics of the pulsed poloidal current drive (PPCD) discharges in the TPE-RX RFP device, and a comparison of the improved energy confinement time in PPCD, τ E P PCD , with τ E s caling as the reference scaling law (τ E s caling ∼ a 1.63 (I P 0.78 (I P /N) 0.33 Θ 2.97 ) in the TPE database, is attempted. The result shows that τ E P PCD agrees well with τ E s caling because of the strong pinch parameter dependence on the TPE scaling law. A potential improved confinement mode in the quasi-single-helicity (QSH) state is also investigated in TPE-RX, with respect to the operation conditions under which the QSH spontaneously appears in the core region, where a typical island structure is observed by means of soft Xray tomography. (author)

  5. Act No. 160 of 17 March 1979 containing regulations approving the Paris Convention of 29 July 1960 on Third Party Liability in the Field of Nuclear Energy and its Additional Protocol of 28 January 1964 as well as the Brussels Convention of 31 January 1963 supplementary to the Paris Convention and its Additional Protocol of 28 January 1964

    International Nuclear Information System (INIS)

    1979-01-01

    By this Act the Netherlands approved the 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy, as well as the Brussels Convention of 1963 Supplementary to that Convention. This Act came into force on 28 December 1979 thus bringing into force on that date the Paris Convention and the Brussels Supplementary Convention in the Netherlands. (NEA) [fr

  6. Energy Levels and Spectral Lines of Li Atoms in White Dwarf Strength Magnetic Fields

    Science.gov (United States)

    Zhao, L. B.

    2018-04-01

    A theoretical approach based on B-splines has been developed to calculate atomic structures and discrete spectra of Li atoms in a strong magnetic field typical of magnetic white dwarf stars. Energy levels are presented for 20 electronic states with the symmetries 20+, 20‑, 2(‑1)+, 2(‑1)‑, and 2(‑2)+. The magnetic field strengths involved range from 0 to 2350 MG. The wavelengths and oscillator strengths for the electric dipole transitions relevant to these magnetized atomic states are reported. The current results are compared to the limited theoretical data in the literature. A good agreement has been found for the lower energy levels, but a significant discrepancy is clearly visible for the higher energy levels. The existing discrepancies of the wavelengths and oscillator strengths are also discussed. Our investigation shows that the spectrum data of magnetized Li atoms previously published are obviously far from meeting requirements of analyzing discrete atomic spectra of magnetic white dwarfs with lithium atmospheres.

  7. The retro-cut process: precision reshaping of magnetic quadrupole lens profiles to improve field strength

    International Nuclear Information System (INIS)

    Szymanski, Roland; Jamieson, David N.; Rout, Bibhudutta; Brenn, Ruediger

    2005-01-01

    In the evolution of magnetic quadrupole lens technology for nuclear microprobe systems, the pole profile has seen several improvements that have led to increases in the pole tip field for a given lens current. In a design dating from prior to 1994 the magnetic field strength was compromised by pole tip extensions that allowed significant flux leakage away from the central bore of the lens. There are many similar lenses in use world wide and they have a weaker focusing action compared to more modern designs which omit the pole tip extensions. We demonstrate that these pre-1994 lenses can have a new profile cut into the pole tip using a precision wire cutting machine that does not require the lens to be dismantled and does not compromise the purity of the lens field. We present the results of applying this process to lenses 1 and 4 in the antisymmetric quadruplet nuclear microprobe system at the University of Freiburg. The grid shadow method was used to show lens quality was not compromised by the process and we find that the lens field strength for a given current is increased by 15% when used to focus 2 MeV H + ions in the antisymmetric quadruplet

  8. A surface acoustic wave electric field strength meter for environmental studies of HV transmission lines

    International Nuclear Information System (INIS)

    Grandolfo, M.; Ranghiasci, C.; Verona, E.

    1988-01-01

    In recent years, there has been a significant increase in concern over the health and safety aspects of high voltage transmission lines (HVTL). The majority of research has focused on effects directly or indirectly involved with the central nervous system, including physiological, ultrastructural, and biochemical alterations, changes in blood composition, behaviour, reproduction, and development. Several recent epidemiological reports have presented preliminary data suggesting an increase in the incidence of cancer among children and adults exposed to magnetic fields through living close to various types of electrical power lines or devices. With the increase in environmental concerns there has been a concomitant consideration of biological effects and health implications related to presently existing HVTL and those planned in the future. It was concluded that the electric and magnetic field strengths and the electrical discharges are the most important electrophysical factors. Thus, it has been deemed necessary to develop measuring means to determine the field strengths in areas surrounding electric installations, in particular at ground level. In the present paper an electric field meter, based on the use of a surface acoustic wave (SAW) delay line, is presented and the experimental results obtained are discussed

  9. Agro-environmental scheme for segetal plant conservation in Wallonia (Belgium: an assessment in conventional and organic fields

    Directory of Open Access Journals (Sweden)

    Lemoine, C.

    2018-01-01

    Full Text Available Description of the subject. Segetal plant species are highly threatened in arable land. They are an integral part of agricultural history and biodiversity in Western Europe. In Wallonia (southern Belgium, an agro-environmental scheme (AES has been adopted for their conservation. It consists of strips on a field margin, with at least 60% cereals in crop rotation, and proscribes spraying and fertilisation. Objectives. This paper assessed the impact of an AES on segetal species conservation. Method. In eight organic fields and six conventional fields, a vegetation survey was performed on an AES strip and on a control margin of each field. Evenness, richness, cover and species composition for both total and segetal species were compared between AES strips and their corresponding control margins. Also, a cover of pernicious weeds was considered to be a factor in the rejection of AES by farmers. Results. In conventional agriculture, species richness (total and segetal and cover (total and segetal were higher in the AES than in the respective control; however, pernicious weed cover was also enhanced. In organic fields, total species richness was higher and pernicious weed cover was lower in the AES than in the respective control. Total evenness was higher in organic than in conventional fields, due to the co-dominance of several species. Under the AES, species composition and abundance remained different between conventional and organic fields. In all cases, rare species were hardly found in our survey. Conclusions. AES promote plant diversity in both organic and conventional fields. Sowing AES strips with uncleaned seeds from well-preserved fields, or species introduction, are recommended to enhance rare species recovery.

  10. Field strength and dose dependence of contrast enhancement by gadolinium-based MR contrast agents

    International Nuclear Information System (INIS)

    Rinck, P.A.; Muller, R.N.

    1999-01-01

    The relaxivities r 1 and r 2 of magnetic resonance contrast agents and the T 1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R 1 = 1/T 1 and R 2 = 1/T 2 ) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields. (orig.)

  11. Weakening of flux-pinning strength for high-Tc superconductors in an alternating magnetic field

    International Nuclear Information System (INIS)

    Chen, Q.Y.

    1992-01-01

    This paper reports on the flux-pinning forces in high temperature superconductors which were found to be weakened in an ac field as the applied field strength or the frequency increases. In the weakly pinned regime, flux dynamics could be described with the concept of magnetic diffusion. Flux-motion-induced finite resistivity could lead to significant skin-effect which was reflected in the ac screening effectiveness. The frequency dependence of the relative local field within a superconducting hollow cylinder were used to deduce the flux-motion resistivity ρ. For superconducting YB 2 Cu 3 O 7 - x compounds at 77K it was found that ρ ∼(mu, Omega)-cm. The corresponding magnetic diffusion coefficient was ∼ 224 cm 2 /s. At 750 Hz the skin depth is around 1.54 mm as compared with the 2-mm sample wall thickness

  12. Enhanced accuracy of the microwave field strength measurement in a CW-EPR by pulsed modulation technique

    Science.gov (United States)

    Rakvin, B.; Carić, D.; Kveder, M.

    2018-02-01

    The microwave magnetic field strength, B1, in the cavity of a conventional continuous wave electron paramagnetic resonance, CW-EPR, spectrometer was measured by employing modulation sidebands, MS, in the EPR spectrum. MS spectrum in CW-EPR is produced by applying the modulation frequency, ωrf, which exceeds the linewidth, δB, given in frequency units. An amplitude-modulated CW-EPR, AM-CW-EPR, was selected as detection method. Theoretical description of AM-CW-EPR spectrum was modified by adding Bloch-Siegert-like shift obtained by taking into account the cumulative effect of the non-resonant interactions between the driving fields and the spin system. This approach enables to enhance the precision of B1 measurement. In order to increase the sensitivity of the method when saturation effects, due to higher intensity of B1, decrease the resolution of AM-CW-EPR spectrum, detection at the second harmonic of CW-EPR has been employed.

  13. Enhanced accuracy of the microwave field strength measurement in a CW-EPR by pulsed modulation technique.

    Science.gov (United States)

    Rakvin, B; Carić, D; Kveder, M

    2018-02-01

    The microwave magnetic field strength, B 1 , in the cavity of a conventional continuous wave electron paramagnetic resonance, CW-EPR, spectrometer was measured by employing modulation sidebands, MS, in the EPR spectrum. MS spectrum in CW-EPR is produced by applying the modulation frequency, ω rf , which exceeds the linewidth, δB, given in frequency units. An amplitude-modulated CW-EPR, AM-CW-EPR, was selected as detection method. Theoretical description of AM-CW-EPR spectrum was modified by adding Bloch-Siegert-like shift obtained by taking into account the cumulative effect of the non-resonant interactions between the driving fields and the spin system. This approach enables to enhance the precision of B 1 measurement. In order to increase the sensitivity of the method when saturation effects, due to higher intensity of B 1 , decrease the resolution of AM-CW-EPR spectrum, detection at the second harmonic of CW-EPR has been employed. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Magnetic-Field Dependence of Raman Coupling Strength in Ultracold "4"0K Atomic Fermi Gas

    International Nuclear Information System (INIS)

    Huang Liang-Hui; Wang Peng-Jun; Meng Zeng-Ming; Peng Peng; Chen Liang-Chao; Li Dong-Hao; Zhang Jing

    2016-01-01

    We experimentally demonstrate the relation of Raman coupling strength with the external bias magnetic field in degenerate Fermi gas of "4"0K atoms. Two Raman lasers couple two Zeeman energy levels, whose energy splitting depends on the external bias magnetic field. The Raman coupling strength is determined by measuring the Rabi oscillation frequency. The characteristics of the Rabi oscillation is to be damped after several periods due to Fermi atoms in different momentum states oscillating with different Rabi frequencies. The experimental results show that the Raman coupling strength will decrease as the external bias magnetic field increases, which is in good agreement with the theoretical prediction. (paper)

  15. Measuring Plasma Formation Field Strength and Current Loss in Pulsed Power Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Patel, Sonal G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Falcon, Ross Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Cartwright, Keith [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Kiefer, Mark L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Cuneo, Michael E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Maron, Yitzhak [Weizmann Inst. of Science, Rehovot (Israel)

    2017-11-01

    This LDRD investigated plasma formation, field strength, and current loss in pulsed power diodes. In particular the Self-Magnetic Pinch (SMP) e-beam diode was studied on the RITS-6 accelerator. Magnetic fields of a few Tesla and electric fields of several MV/cm were measured using visible spectroscopy techniques. The magnetic field measurements were then used to determine the current distribution in the diode. This distribution showed that significant beam current extends radially beyond the few millimeter x-ray focal spot diameter. Additionally, shielding of the magnetic field due to dense electrode surface plasmas was observed, quantified, and found to be consistent with the calculated Spitzer resistivity. In addition to the work on RITS, measurements were also made on the Z-machine looking to quantify plasmas within the power flow regions. Measurements were taken in the post-hole convolute and final feed gap regions on Z. Dopants were applied to power flow surfaces and measured spectroscopically. These measurements gave species and density/temperature estimates. Preliminary B-field measurements in the load region were attempted as well. Finally, simulation work using the EMPHASIS, electromagnetic particle in cell code, was conducted using the Z MITL conditions. The purpose of these simulations was to investigate several surface plasma generations models under Z conditions for comparison with experimental data.

  16. Control over Janus micromotors by the strength of a magnetic field

    Science.gov (United States)

    Baraban, Larysa; Makarov, Denys; Schmidt, Oliver G.; Cuniberti, Gianaurelio; Leiderer, Paul; Erbe, Artur

    2013-01-01

    For transportation of molecules or biological cells using artificial motors, the control over their motion, i.e. direction and speed of transfer, is important. Here, we demonstrate that modification of the velocity and orientation of a magnetic Janus particle can be efficiently controlled by tuning the strength of an applied homogeneous magnetic field. Interestingly, by keeping the same orientation of the magnetic field but changing its magnitude not only the velocity of capped particles can be altered but even their direction of motion can be reversed. We put forth a simple qualitative model, which allows us to explain this intriguing observation.For transportation of molecules or biological cells using artificial motors, the control over their motion, i.e. direction and speed of transfer, is important. Here, we demonstrate that modification of the velocity and orientation of a magnetic Janus particle can be efficiently controlled by tuning the strength of an applied homogeneous magnetic field. Interestingly, by keeping the same orientation of the magnetic field but changing its magnitude not only the velocity of capped particles can be altered but even their direction of motion can be reversed. We put forth a simple qualitative model, which allows us to explain this intriguing observation. Electronic supplementary information (ESI) available: Videos (1-3) describe the behavior of the magnetic Janus micromotors at different magnetic fields applied. The magnetic field is always applied along the positive direction of the y-axis. All the movies are recorded at the same frame rate of 21 images per second. Experiments were performed at 30 wt% of hydrogen peroxide in aqueous solution. Video 1 shows the motion of the Janus micromotors when a small magnetic field is applied (B = 0.2 mT). The particle is propelled in the direction ``opposite to the cap'' with a velocity of about 6 μm s-1. Video 2 displays the motion of the same Janus bead when an intermediately strong

  17. National surveys of radiofrequency field strengths from radio base stations in Africa

    Science.gov (United States)

    Joyner, Ken H.; Van Wyk, Marthinus J.; Rowley, Jack T.

    2014-01-01

    The authors analysed almost 260 000 measurement points from surveys of radiofrequency (RF) field strengths near radio base stations in seven African countries over two time frames from 2001 to 2003 and 2006 to 2012. The results of the national surveys were compared, chronological trends investigated and potential exposures compared by technology and with frequency modulation (FM) radio. The key findings from thes data are that irrespective of country, the year and mobile technology, RF fields at a ground level were only a small fraction of the international human RF exposure recommendations. Importantly, there has been no significant increase in typical measured levels since the introduction of 3G services. The mean levels in these African countries are similar to the reported levels for countries of Asia, Europe and North America using similar mobile technologies. The median level for the FM services in South Africa was comparable to the individual but generally lower than the combined mobile services. PMID:24044904

  18. High-field-strength MR imaging evaluation of stroke in the sickle cell population

    International Nuclear Information System (INIS)

    Bello, J.A.; Pavlakis, S.G.; Prohovnik, I.; Hilal, S.K.; De Vivo, D.C.

    1987-01-01

    Stroke is a well-known but understudied complication of sickle cell disease (SCD). The authors have studied the incidence and patterns of clinical and subclinical stroke in 73 SCD patients. The patients underwent formal neurologic evaluation and high-field strength, heavily T2-weighted axial cranial MR imaging (TR = 3,500 msec, TE = 80 msec). Eighteen of the 73 patients had clinical strokes, acute, nonconvulsive neurologic events with lateralizing neurological signs lasting 1 hour. All but two of these patients demonstrated focal MR imaging abnormalities. The remaining 55 patients were controls. Ten percent of them had focal MR imaging abnormalities suggesting subclinical stroke. A feature of the SCD population is the preponderance of strokes in the distal field and watershed distribution

  19. National surveys of radiofrequency field strengths from radio base stations in Africa

    International Nuclear Information System (INIS)

    Joyner, K. H.; Van Wyk, M. J.; Rowley, J. T.

    2014-01-01

    The authors analysed almost 260 000 measurement points from surveys of radiofrequency (RF) field strengths near radio base stations in seven African countries over two time frames from 2001 to 2003 and 2006 to 2012. The results of the national surveys were compared, chronological trends investigated and potential exposures compared by technology and with frequency modulation (FM) radio. The key findings from these data are that irrespective of country, the year and mobile technology, RF fields at a ground level were only a small fraction of the international human RF exposure recommendations. Importantly, there has been no significant increase in typical measured levels since the introduction of 3G services. The mean levels in these African countries are similar to the reported levels for countries of Asia, Europe and North America using similar mobile technologies. The median level for the FM services in South Africa was comparable to the individual but generally lower than the combined mobile services. (authors)

  20. Earth-strength magnetic field affects the rheotactic threshold of zebrafish swimming in shoals.

    Science.gov (United States)

    Cresci, Alessandro; De Rosa, Rosario; Putman, Nathan F; Agnisola, Claudio

    2017-02-01

    Rheotaxis, the unconditioned orienting response to water currents, is a main component of fish behavior. Rheotaxis is achieved using multiple sensory systems, including visual and tactile cues. Rheotactic orientation in open or low-visibility waters might also benefit from the stable frame of reference provided by the geomagnetic field, but this possibility has not been explored before. Zebrafish (Danio rerio) form shoals living in freshwater systems with low visibility, show a robust positive rheotaxis, and respond to geomagnetic fields. Here, we investigated whether a static magnetic field in the Earth-strength range influenced the rheotactic threshold of zebrafish in a swimming tunnel. The direction of the horizontal component of the magnetic field relative to water flow influenced the rheotactic threshold of fish as part of a shoal, but not of fish tested alone. Results obtained after disabling the lateral line of shoaling individuals with Co 2+ suggest that this organ system is involved in the observed magneto-rheotactic response. These findings constitute preliminary evidence that magnetic fields influence rheotaxis and suggest new avenues for further research. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Dynamics of Entanglement in Jaynes–Cummings Nodes with Nonidentical Qubit-Field Coupling Strengths

    Directory of Open Access Journals (Sweden)

    Li-Tuo Shen

    2017-07-01

    Full Text Available How to analytically deal with the general entanglement dynamics of separate Jaynes–Cummings nodes with continuous-variable fields is still an open question, and few analytical approaches can be used to solve their general entanglement dynamics. Entanglement dynamics between two separate Jaynes–Cummings nodes are examined in this article. Both vacuum state and coherent state in the initial fields are considered through the numerical and analytical methods. The gap between two nonidentical qubit-field coupling strengths shifts the revival period and changes the revival amplitude of two-qubit entanglement. For vacuum-state fields, the maximal entanglement is fully revived after a gap-dependence period, within which the entanglement nonsmoothly decreases to zero and partly recovers without exhibiting sudden death phenomenon. For strong coherent-state fields, the two-qubit entanglement decays exponentially as the evolution time increases, exhibiting sudden death phenomenon, and the increasing gap accelerates the revival period and amplitude decay of the entanglement, where the numerical and analytical results have an excellent coincidence.

  2. A feasibility study of high-strength Bi-2223 conductor for high-field solenoids

    Science.gov (United States)

    Godeke, A.; Abraimov, D. V.; Arroyo, E.; Barret, N.; Bird, M. D.; Francis, A.; Jaroszynski, J.; Kurteva, D. V.; Markiewicz, W. D.; Marks, E. L.; Marshall, W. S.; McRae, D. M.; Noyes, P. D.; Pereira, R. C. P.; Viouchkov, Y. L.; Walsh, R. P.; White, J. M.

    2017-03-01

    We performed a feasibility study on a high-strength Bi{}2-xPb x Sr2Ca2Cu3O{}10-x(Bi-2223) tape conductor for high-field solenoid applications. The investigated conductor, DI-BSCCO Type HT-XX, is a pre-production version of Type HT-NX, which has recently become available from Sumitomo Electric Industries. It is based on their DI-BSCCO Type H tape, but laminated with a high-strength Ni-alloy. We used stress-strain characterizations, single- and double-bend tests, easy- and hard-way bent coil-turns at various radii, straight and helical samples in up to 31.2 T background field, and small 20-turn coils in up to 17 T background field to systematically determine the electro-mechanical limits in magnet-relevant conditions. In longitudinal tensile tests at 77 K, we found critical stress- and strain-levels of 516 MPa and 0.57%, respectively. In three decidedly different experiments we detected an amplification of the allowable strain with a combination of pure bending and Lorentz loading to ≥slant 0.92 % (calculated elastically at the outer tape edge). This significant strain level, and the fact that it is multi-filamentary conductor and available in the reacted and insulated state, makes DI-BSCCO HT-NX highly suitable for very high-field solenoids, for which high current densities and therefore high loads are required to retain manageable magnet dimensions.

  3. Relativistic hadrodynamics with field-strength dependent coupling of the scalar fields in Hartree and Hartree-Fock approximation

    International Nuclear Information System (INIS)

    Lindner, J.

    1992-09-01

    In this thesis in the framework of our model of the field-strength dependent coupling the properties of infinitely extended, homogeneous, static, spin- and isospin-saturated nuclear matter are studied. Thereby we use the Hartree-Mean-Field and the Hartree-Fock approximation, whereby the influence of the antiparticle states in the Fermi sea is neglected. In chapter 2 the Lagrangian density basing to our model is fixed. Starting from the Walecka model we modify in the Lagrangian density the Linear coupling of the scalar field to the scalar density as follows g S φanti ψψ→g S f(φ) anti ψψ. In chapter 3 we fix three different functions f(φ). For these three cases and for the Walecka model with f(φ)=φ nuclear-matter calculations are performed. In chapter 4 for the Hartree-Fock calculations, but also very especially regarding the molecular-dynamics calculations, the properties of the Dirac spinors in the plane-wave representation are intensively studied. (orig.)

  4. Surface magnetic field strengths: New tests of magnetoconvective models of M dwarfs

    International Nuclear Information System (INIS)

    MacDonald, James; Mullan, D. J.

    2014-01-01

    Precision modeling of M dwarfs has become worthwhile in recent years due to the increasingly precise values of masses and radii which can be obtained from eclipsing binary studies. In a recent paper, Torres has identified four prime M dwarf pairs with the most precise empirical determinations of masses and radii. The measured radii are consistently larger than standard stellar models predict by several percent. These four systems potentially provide the most challenging tests of precision evolutionary models of cool dwarfs at the present time. We have previously modeled M dwarfs in the context of a criterion due to Gough and Tayler in which magnetic fields inhibit the onset of convection according to a physics-based prescription. In the present paper, we apply our magnetoconvective approach to the four prime systems in the Torres list. Going a step beyond what we have already modeled in CM Dra (one of the four Torres systems), we note that new constraints on magnetoconvective models of M dwarfs are now available from empirical estimates of magnetic field strengths on the surfaces of these stars. In the present paper, we consider how well our magnetoconvective models succeed when confronted with this new test of surface magnetic field strengths. Among the systems listed by Torres, we find that plausible magnetic models work well for CM Dra, YY Gem, and CU Cnc. (The fourth system in Torres's list does not yet have enough information to warrant magnetic modeling.) Our magnetoconvection models of CM Dra, YY Gem, and CU Cnc yield predictions of the magnetic fluxes on the stellar surface which are consistent with the observed correlation between magnetic flux and X-ray luminosity.

  5. Surface Magnetic Field Strengths: New Tests of Magnetoconvective Models of M Dwarfs

    Science.gov (United States)

    MacDonald, James; Mullan, D. J.

    2014-05-01

    Precision modeling of M dwarfs has become worthwhile in recent years due to the increasingly precise values of masses and radii which can be obtained from eclipsing binary studies. In a recent paper, Torres has identified four prime M dwarf pairs with the most precise empirical determinations of masses and radii. The measured radii are consistently larger than standard stellar models predict by several percent. These four systems potentially provide the most challenging tests of precision evolutionary models of cool dwarfs at the present time. We have previously modeled M dwarfs in the context of a criterion due to Gough & Tayler in which magnetic fields inhibit the onset of convection according to a physics-based prescription. In the present paper, we apply our magnetoconvective approach to the four prime systems in the Torres list. Going a step beyond what we have already modeled in CM Dra (one of the four Torres systems), we note that new constraints on magnetoconvective models of M dwarfs are now available from empirical estimates of magnetic field strengths on the surfaces of these stars. In the present paper, we consider how well our magnetoconvective models succeed when confronted with this new test of surface magnetic field strengths. Among the systems listed by Torres, we find that plausible magnetic models work well for CM Dra, YY Gem, and CU Cnc. (The fourth system in Torres's list does not yet have enough information to warrant magnetic modeling.) Our magnetoconvection models of CM Dra, YY Gem, and CU Cnc yield predictions of the magnetic fluxes on the stellar surface which are consistent with the observed correlation between magnetic flux and X-ray luminosity.

  6. High resolution separations of charge variants and disulfide isomers of monoclonal antibodies and antibody drug conjugates using ultra-high voltage capillary electrophoresis with high electric field strength.

    Science.gov (United States)

    Henley, W Hampton; He, Yan; Mellors, J Scott; Batz, Nicholas G; Ramsey, J Michael; Jorgenson, James W

    2017-11-10

    Ultra-high voltage capillary electrophoresis with high electric field strength has been applied to the separation of the charge variants, drug conjugates, and disulfide isomers of monoclonal antibodies. Samples composed of many closely related species are difficult to resolve and quantify using traditional analytical instrumentation. High performance instrumentation can often save considerable time and effort otherwise spent on extensive method development. Ideally, the resolution obtained for a given CE buffer system scales with the square root of the applied voltage. Currently available commercial CE instrumentation is limited to an applied voltage of approximately 30kV and a maximum electric field strength of 1kV/cm due to design limitations. The instrumentation described here is capable of safely applying potentials of at least 120kV with electric field strengths over 2000V/cm, potentially doubling the resolution of the best conventional CE buffer/capillary systems while decreasing analysis time in some applications. Separations of these complex mixtures using this new instrumentation demonstrate the potential of ultra-high voltage CE to identify the presence of previously unresolved components and to reduce analysis time for complex mixtures of antibody variants and drug conjugates. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. A multipurpose hybrid conventional/scanning near-field optical microscope for applications in materials science and biology

    International Nuclear Information System (INIS)

    Longo, G; Girasole, M; Pompeo, G; Generosi, R; Luce, M; Cricenti, A

    2010-01-01

    A hybrid conventional/scanning near-field optical microscope is presented. The instrument is obtained coupling an Olympus IX-70 inverted optical microscope with a SNOM head, to combine the versatility and ease of use of the conventional microscope with the high-resolution and three-dimensional reconstruction achieved by the SNOM. The head can be run in shear or tapping mode and is optimized to characterize soft, biological samples including living cells in physiological environment by including the SNOM in a cylindrical chamber that insulates it from external noise, while maintaining a controlled temperature and atmosphere

  8. Influence of Nd:YAG laser on the bond strength of self-etching and conventional adhesive systems to dental hard tissues.

    Science.gov (United States)

    Marimoto, A K; Cunha, L A; Yui, K C K; Huhtala, M F R L; Barcellos, D C; Prakki, A; Gonçalves, S E P

    2013-01-01

    The aim of this study was to investigate the influence of Nd:YAG laser on the shear bond strength to enamel and dentin of total and self-etch adhesives when the laser was applied over the adhesives, before they were photopolymerized, in an attempt to create a new bonding layer by dentin-adhesive melting. One-hundred twenty bovine incisors were ground to obtain flat surfaces. Specimens were divided into two substrate groups (n=60): substrate E (enamel) and substrate D (dentin). Each substrate group was subdivided into four groups (n=15), according to the surface treatment accomplished: X (Xeno III self-etching adhesive, control), XL (Xeno III + laser Nd:YAG irradiation at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental), S (acid etching + Single Bond conventional adhesive, Control), and SL (acid etching + Single Bond + laser Nd:YAG at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental). The bonding area was delimited with 3-mm-diameter adhesive tape for the bonding procedures. Cylinders of composite were fabricated on the bonding area using a Teflon matrix. The teeth were stored in water at 37°C/48 h and submitted to shear testing at a crosshead speed of 0.5 mm/min in a universal testing machine. Results were analyzed with three-way analysis of variance (ANOVA; substrate, adhesive, and treatment) and Tukey tests (α=0.05). ANOVA revealed significant differences for the substrate, adhesive system, and type of treatment: lased or unlased (penamel groups were X=20.2 ± 5.61, XL=23.6 ± 4.92, S=20.8 ± 4.55, SL=22.1 ± 5.14 and for the dentin groups were X=14.1 ± 7.51, XL=22.2 ± 6.45, S=11.2 ± 5.77, SL=15.9 ± 3.61. For dentin, Xeno III self-etch adhesive showed significantly higher shear bond strength compared with Single Bond total-etch adhesive; Nd:YAG laser irradiation showed significantly higher shear bond strength compared with control (unlased). Nd:YAG laser application prior to photopolymerization of adhesive systems

  9. Temperature field in the hot-top during casting a new super-high strength Al-Zn-Mg-Cu alloy by low frequency electromagnetic process

    Directory of Open Access Journals (Sweden)

    Yubo ZUO

    2005-08-01

    Full Text Available The billets of a new super-high strength Al-Zn-Mg-Cu alloy in 200 mm diameter were produced by the processed of low frequency electromagnetic casting (LFEC and conventional direct chill(DCcasting, respectively. The effects of low frequency electromagnetic field on temperature field of the melt in the hot-top were investigated by temperature thermocouples into the casting during the processes. The results show that during LFEC process the temperature field in the melt applying the hot-top is very uniform, which is helpful to reduce the difference of thermal gradients between the surface and the center, and then to reduce the thermal stress and to eliminate casting crack.

  10. Impact of Conventional and Integrated Management Systems on the Water-Soluble Vitamin Content in Potatoes, Field Beans, and Cereals.

    Science.gov (United States)

    Freitag, Sabine; Verrall, Susan R; Pont, Simon D A; McRae, Diane; Sungurtas, Julia A; Palau, Raphaëlle; Hawes, Cathy; Alexander, Colin J; Allwood, J William; Foito, Alexandre; Stewart, Derek; Shepherd, Louise V T

    2018-01-31

    The reduction of the environmental footprint of crop production without compromising crop yield and their nutritional value is a key goal for improving the sustainability of agriculture. In 2009, the Balruddery Farm Platform was established at The James Hutton Institute as a long-term experimental platform for cross-disciplinary research of crops using two agricultural ecosystems. Crops representative of UK agriculture were grown under conventional and integrated management systems and analyzed for their water-soluble vitamin content. Integrated management, when compared with the conventional system, had only minor effects on water-soluble vitamin content, where significantly higher differences were seen for the conventional management practice on the levels of thiamine in field beans (p water-soluble vitamin content of the crops analyzed here.

  11. Investigation of the radiation level and electromagnetic field strength in sample of Damascus schools

    International Nuclear Information System (INIS)

    Shweikani, R.; Abukassem, I.; Raja, G.; Algamdi, H.

    2009-12-01

    The aim of this work is to determine radon concentration and natural gamma dose rate, and to measure the electromagnetic fields (EMFs) level produced by electric power lines and also mobile phone base station inside some elementary and preparatory schools in old town during two terms (studding terms and summer break). Results showed that most of the obtained values were less than 200 Bq/m 3 the action levels, but there were some classrooms concentrations which are more than 200 Bq/m 3 . These high values may be due to building materials, radon concentration in the soil and poor ventilation. It has been noticed that radon concentrations during the second term (summer) were higher than the first term. This may be due to the poor ventilation as schools are closed during summer break. The results showed also decreasing in radon concentration with increasing height of the floor, and radon concentration in old schools is higher than modern ones. EMFs levels in ground and first floors were higher than second floor; the maximum detected values exceeded 50 V/m and 270 mA/m for electric and magnetic field strength respectively, and 0.5 μT for magnetic flux density. Mobile microwave radiation level was relatively low in all positions, and signal increases with floor height. Finally, no observable correlation between the measured electromagnetic fields and the radon concentration were established.

  12. Particle roughness in magnetorheology: effect on the strength of the field-induced structures

    International Nuclear Information System (INIS)

    Vereda, F; Segovia-Gutiérrez, J P; De Vicente, J; Hidalgo-Alvarez, R

    2015-01-01

    We report a study on the effect of particle roughness on the strength of the field-induced structures of magnetorheological (MR) fluids in the quasi-static regime. We prepared one set of MR fluids with carbonyl iron particles and another set with magnetite particles, and in both sets we had particles with different degrees of surface roughness. Small amplitude oscillatory shear (SAOS) magnetosweeps and steady shear (SS) tests were carried out on the suspensions to measure their elastic modulus (G′) and static yield stress (τ static ). Results for both the iron and the magnetite sets of suspensions were consistent: for the MR fluids prepared with rougher particles, G′ increased at smaller fields and τ static was ca. 20% larger than for the suspensions prepared with relatively smooth particles. In addition to the experimental study, we carried out finite element method calculations to assess the effect of particle roughness on the magnetic interaction between particles. These calculations showed that roughness can facilitate the magnetization of the particles, thus increasing the magnetic energy of the system for a given field, but that this effect depends on the concrete morphology of the surface. For our real systems, no major differences were observed between the magnetization cycles of the MR fluids prepared with particles with different degree of roughness, which implied that the effect of roughness on the measured G′ and τ static was due mainly to friction between the solid surfaces of adjacent particles. (paper)

  13. Impact of magnetic field strength and receiver coil in ocular MRI: a phantom and patient study.

    Science.gov (United States)

    Erb-Eigner, K; Warmuth, C; Taupitz, M; Willerding, G; Bertelmann, E; Asbach, P

    2013-09-01

    Generally, high-resolution MRI of the eye is performed with small loop surface coils. The purpose of this phantom and patient study was to investigate the influence of magnetic field strength and receiver coils on image quality in ocular MRI. The eyeball and the complex geometry of the facial bone were simulated by a skull phantom with swine eyes. MR images were acquired with two small loop surface coils with diameters of 4 cm and 7 cm and with a multi-channel head coil at 1.5 and 3 Tesla, respectively. Furthermore, MRI of the eye was performed prospectively in 20 patients at 1.5 Tesla (7 cm loop surface coil) and 3 Tesla (head coil). These images were analysed qualitatively and quantitatively and statistical significance was tested using the Wilcoxon-signed-rank test (a p-value of less than 0.05 was considered to indicate statistical significance). The analysis of the phantom images yielded the highest mean signal-to-noise ratio (SNR) at 3 Tesla with the use of the 4 cm loop surface coil. In the phantom experiment as well as in the patient studies the SNR was higher at 1.5 Tesla by applying the 7 cm surface coil than at 3 Tesla by applying the head coil. Concerning the delineation of anatomic structures no statistically significant differences were found. Our results show that the influence of small loop surface coils on image quality (expressed in SNR) in ocular MRI is higher than the influence of the magnetic field strength. The similar visibility of detailed anatomy leads to the conclusion that the image quality of ocular MRI at 3 Tesla remains acceptable by applying the head coil as a receiver coil. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Low-field-strength magnetic resonance imaging in the canine brain

    International Nuclear Information System (INIS)

    Esteve Ratsch, B.

    2000-06-01

    Magnetic resonance imaging (MRI; 0,23 T) of the canine brain was performed. Each scan plane was compared with corresponding anatomic sections. The best imaging planes to visualize various anatomic structures were determined. Low-field-strength MRI allowed the good definition of all relevant anatomic structures of the brain of 55 dogs with the exception of most cranial nerves. White matter could be best differentiated using proton-weighted images. On T1-weighted images the contrast of white matter was markedly limited in the living dogs in contrast to the examined canine specimens. The relative size of the lateral ventricle was defined as the ratio of the size of the lateral ventricle and the size of the half brain. The relative size of the lateral ventricle of Yorkshire Terrier dogs (5,35 %) was significantly (p 0,05) in the relative size of the lateral ventricles of healthy Yorkshire Terrier dogs (5,35 %) and Yorkshire Terrier dogs with neurological symptoms (7,06 %). Asymmetric lateral ventricles were very common in the examined dogs independently from body size, skull shape and neurological status. Occasionally the septum telencephali was not developed completely. 11 of 12 intracranial neoplasm could be delineated using low-field-strength MRI. Anatomic site, number of intracerebral lesions, limitation, shape and growth pattern, secondary brain lesions and development of peritumoral edema were described for each intracranial neoplasm as well as its signal intensity on T1- and T2-weighted images and contrast enhancement pattern. MRI did not allow an accurate diagnosis of tumor type, nevertheless skull shape (brachycephalic/dolichocephalic), anatomic site and number of intracerebral lesions facilitated a presumable diagnosis of the tumor type. (author)

  15. Effect of high-intensity pulsed electric fields processing and conventional heat treatment on orange-carrot juice carotenoids.

    Science.gov (United States)

    Torregrosa, Francisco; Cortés, Clara; Esteve, María J; Frígola, Ana

    2005-11-30

    Liquid chromatography (LC) was the method of choice for quantification of carotenoids (including geometrical isomers) to evaluate the effects of high-intensity pulsed electric field (HIPEF), a nonthermal preservation method, with different parameters (electric field intensities and treatment times), on an orange-carrot juice mixture (80:20, v/v). In parallel, a conventional heat treatment (98 degrees C, 21 s) was applied to the juice. HIPEF processing generally caused a significant increase in the concentrations of the carotenoids identified as treatment time increased. HIPEF treatment at 25 and 30 kV/cm provided a vitamin A concentration higher than that found in the pasteurized juice.

  16. Electric field strength in a silicon surface barrier detector with the presence of a dielectric plasma column

    International Nuclear Information System (INIS)

    Kanno, Ikuo

    1994-01-01

    The dynamic change of the electric field strength in a silicon surface barrier detector (SSBD) is studied. With the presence of a dielectric plasma column in the depletion layer of the SSBD, the electric field strength inside/outside the plasma column is suppressed/enhanced. As the length and the dielectric constant of the plasma column become shorter and smaller, the suppression and enhancement of the electric field strength become less. The electric field strength recovers the initial state, when the plasma column disappears. When the electrons and holes are inside/outside the dielectric plasma column, they have less/more electric potential than the one they have when there is no plasma column. During the movement of the electron/hole outside the plasma column to the positive/negative electrode, the enhanced electric field strength becomes smaller. Electron and hole pairs, which are the parts of the dielectric plasma column, arrive at positive and negative electrodes, having insufficient electric potential to induce the unit charge. This paper shows that the presence of a dielectric plasma column explains the main part of the residual defect in a SSBD. ((orig.))

  17. Relationships between field-based measures of strength and power and golf club head speed.

    Science.gov (United States)

    Read, Paul J; Lloyd, Rhodri S; De Ste Croix, Mark; Oliver, Jon L

    2013-10-01

    Increased golf club head speed (CHS) has been shown to result in greater driving distances and is also correlated with golf handicap. The purpose of this study was to investigate the relationships between field-based measures of strength and power and golf CHS with a secondary aim to determine the reliability of the selected tests. A correlation design was used to assess the following variables: anthropometrics, squat jump (SJ) height and squat jump peak power (SJPP), unilateral countermovement jump (CMJ) heights (right leg countermovement jump and left leg countermovement jump [LLCMJ]), bilateral CMJ heights, countermovement jump peak power (CMJPP), and medicine ball seated throw (MBST) and medicine ball rotational throw (MBRT). Fouty-eight male subjects participated in the study (age: 20.1 ± 3.2 years, height: 1.76 ± 0.07 m, mass: 72.8 ± 7.8 kg, handicap: 5.8 ± 2.2). Moderate significant correlations were reported between CHS and MBRT (r = 0.67; p golf athletes using the proposed battery of field tests. Additionally, movements that are more concentrically dominant in nature may display stronger relationships with CHS due to MBST and SJ displaying the highest explained variance after a stepwise linear regression.

  18. Levels of electric field strength within the immediate vicinity of FM radio stations in Accra, Ghana.

    Science.gov (United States)

    Azah, C K; Amoako, J K; Fletcher, J J

    2013-10-01

    Heightened awareness of the ever-expanding use of radiofrequency (RF) techniques and technology has led to mounting concerns from the general public and the scientific community regarding the possible health effects that may arise as a consequence of exposure to RF radiations and has drawn the attention of many researchers the world over. A survey of the RF electromagnetic radiation at public access points in the vicinity of 20 frequency-modulated (FM) radio stations has been made in Accra, Ghana. The fundamental object was to determine the levels of RF fields from FM broadcast antennae within 10-200 m radius about the foot of the FM base station and at a height of 1.5 m above the ground at selected locations. A spectrum analyser and a bi-conical antenna element sensitive and effective within the frequency band of 30-300 MHz were used. Results obtained indicated that the levels of electric field strength ranged from 5.4E-04 V m(-1) at FM station 'O' to 7.4E-08 V m(-1) at FM station 'D'. At a transmission frequency range of 88-108 MHz, the variation of power densities is from 2.5E-10 to 1.5E-17 Wm(-2). These values are very low and are far below the reference level set by the International Commission on Non-Ionizing Radiation Protection and therefore do not pose any known hazard to the inhabitants of Accra, Ghana. The electric field levels presented in this work are comparable with those reported from epidemiological studies conducted elsewhere.

  19. Effect of electric field on the oscillator strength and cross-section for intersubband transition in a semiconductor quantum ring

    International Nuclear Information System (INIS)

    Bhattacharyya, S; Das, N R

    2012-01-01

    In this paper, we study the oscillator strength and cross-section for intersubband optical transition in an n-type semiconductor quantum ring of cylindrical symmetry in the presence of an electric field perpendicular to the plane of the ring. The analysis is done considering Kane-type band non-parabolicity of the semiconductor and assuming that the polarization of the incident radiation is along the axis of the ring. The results show that the oscillator strength decreases and the transition energy increases with the electric field. The assumption of a parabolic band leads to an overestimation of the oscillator strength. The effects of the electric field, band non-parabolicity and relaxation time on absorption cross-section for intersubband transition in a semiconductor quantum ring are also shown. (paper)

  20. Detection of pesticides residues in water samples from organic and conventional paddy fields of Ledang, Johor, Malaysia

    Science.gov (United States)

    Abdullah, Md Pauzi; Othman, Mohamed Rozali; Ishak, Anizan; Nabhan, Khitam Jaber

    2016-11-01

    Pesticides have been used extensively by the farmers in Malaysia during the last few decades. Sixteen water samples, collected from paddy fields both organic and conventional, from Ledang, Johor, were analyzed to determine the occurrence and distribution of organochlorine (OCPs) and organophosphorus (OPPs) pesticide residues. GC-ECD instrument was used to identify and determine the concentrations of these pesticide residues. Pesticide residues were detected in conventional fields in the range about 0.036-0.508 µg/L higher than detected in organic fields about 0.015-0.428 µg/L. However the level of concentration of pesticide residues in water sample from both paddy fields are in the exceed limit for human consumption, according to European Economic Commission (EEC) (Directive 98/83/EC) at 0.1 µg/L for any pesticide or 0.5 µg/L for total pesticides. The results that the organic plot is still contaminated with pesticides although pesticides were not use at all in plot possibly from historical used as well as from airborne contamination.

  1. Waste rice seed in conventional and stripper-head harvested fields in California: Implications for wintering waterfowl

    Science.gov (United States)

    Fleskes, Joseph P.; Halstead, Brian J.; Casazza, Michael L.; Coates, Peter S.; Kohl, Jeffrey D.; Skalos, Daniel A.

    2012-01-01

    Waste rice seed is an important food for wintering waterfowl and current estimates of its availability are needed to determine the carrying capacity of rice fields and guide habitat conservation. We used a line-intercept method to estimate mass-density of rice seed remaining after harvest during 2010 in the Sacramento Valley (SACV) of California and compared results with estimates from previous studies in the SACV and Mississippi Alluvial Valley (MAV). Posterior mean (95% credible interval) estimates of total waste rice seed mass-density for the SACV in 2010 were 388 (336–449) kg/ha in conventionally harvested fields and 245 (198–307) kg/ha in stripper-head harvested fields; the 2010 mass-density is nearly identical to the mid-1980s estimate for conventionally harvested fields but 36% lower than the mid-1990s estimate for stripped fields. About 18% of SACV fields were stripper-head harvested in 2010 vs. 9–15% in the mid-1990s and 0% in the mid-1980s; but due to a 50% increase in planted rice area, total mass of waste rice seed in SACV remaining after harvest in 2010 was 43% greater than in the mid-1980s. However, total mass of seed-eating waterfowl also increased 82%, and the ratio of waste rice seed to seed-eating waterfowl mass was 21% smaller in 2010 than in the mid-1980s. Mass-densities of waste rice remaining after harvest in SACV fields are within the range reported for MAV fields. However, because there is a lag between harvest and waterfowl use in the MAV but not in the SACV, seed loss is greater in the MAV and estimated waste seed mass-density available to wintering waterfowl in SACV fields is about 5–30 times recent MAV estimates. Waste rice seed remains an abundant food source for waterfowl wintering in the SACV, but increased use of stripper-head harvesters would reduce this food. To provide accurate data on carrying capacities of rice fields necessary for conservation planning, trends in planted rice area, harvest method, and postharvest field

  2. Reliability of conventional crystal field models in f-electron systems

    Energy Technology Data Exchange (ETDEWEB)

    Gajek, Z. [Polska Akademia Nauk, Wroclaw (Poland). Inst. Niskich Temperatur i Badan Strukturalnych

    1995-03-15

    Crystal field models commonly applied to explain the electronic properties of solid f-electron compounds are discussed from the point of view of their inherent limitations and the false conclusions they may lead to. Both phenomenological and ab initio approximate models are considered. The discussion is based on generalized perturbation model calculations of the crystal field parameters for europium, uranium, plutonium and neptunium ions in various crystals. The results reveal the inadequacy of various electrostatic approaches and the correctness of models based on renormalization terms. ((orig.))

  3. Monoisocentric three-beam split field technique for conventional treatment in the head and neck cancer using asymmetrical collimators

    International Nuclear Information System (INIS)

    Sriram Prasath, S.; Prabagaran, C.; Sanyal, B.; Sarkar, B.

    2008-01-01

    The importance of treatment planning of head and neck malignancies arises from the necessity to achieve homogenous doses to localized target volume surrounded by normal structures, which can produce acute and long-term morbidity. In many radiotherapy departments, a commonly employed strategy is a 3-field technique. Bilateral parallel-opposed fields are matched to anterior lower neck field. When the target extends to the lower neck regions, abutment of upper and lower neck fields is required. Field matching represents a technical challenge for the Medical Physicist and Radiation Oncologist to treat multiple fields while avoiding their overlap on the spinal cord. The aim of this work is to review merits, limitations and recent approaches to optimize matchline dose in Monoisocentric technique in conventional treatment for head and neck cancers. Although the technique has many advantages, it is subjected to some systematic and random errors due to equipment and patient setup accuracies. To decrease the magnitude of matchline inhomogeneities, multi leaf collimator have been used. This method is viable and represents alternative approaches to the problem of field matching using the asymmetric jaws

  4. Proof-of-principle study of a small animal PET/field-cycled MRI combined system using conventional PMT technology

    International Nuclear Information System (INIS)

    Peng Hao; Handler, William B.; Scholl, Timothy J.; Simpson, P.J.; Chronik, Blaine A.

    2010-01-01

    There are currently several approaches to the development of combined PET/MRI systems, all of which need to address adverse interactions between the two systems. Of particular relevance to the majority of proposed PET/MRI systems is the effect that static and dynamic magnetic fields have on the performance of PET detection systems based on photomultiplier tubes (PMTs). In the work reported in this paper, performance of two conventional PMTs has been systematically investigated and characterized as a function of magnetic field exposure conditions. Detector gain, energy resolution, time resolution, and efficiency were measured for static field exposures between 0 and 6.3 mT. Additionally, the short-term recovery and long-term stability of gain and energy resolution were measured in the presence of repeatedly applied dynamic magnetic fields changing at 4 T/s. It was found that the detectors recovered normal operation within several milliseconds following the end of large pulsed magnetic fields. In addition, the repeated applications of large pulsed magnetic fields did not significantly affect detector stability. Based on these results, we implemented a proof-of-principle PET/field-cycled MRI (FCMRI) system for small animal imaging using commercial PMT-based PET detectors. The first PET images acquired within the PET/FCMRI system are presented. The image quality, in terms of spatial resolution, was compared between standalone PET and the PET/FCMRI system. Finally, the relevance of these results to various aspects of PET/MRI system design is discussed.

  5. Stereotactic radiosurgery photon field profile dosimetry using conventional dosimeters and polymer gel dosimetry. Analysis and inter-comparison

    Energy Technology Data Exchange (ETDEWEB)

    Pappas, E; Maris, T G; Zacharopoulou, F; Papadakis, A [Department of Medical Physics, Faculty of Medicine, University of Crete, 711 10 Stavrakia-Heraklion, Crete (Greece); Manolopoulos, S; Green, S [Queen Elizabeth Medical Centre, University Hospital Birmingham NHS Trust, Birmingham B15 2TH (United Kingdom); Wojnecki, C, E-mail: epappas@edu.med.uoc.gr

    2009-05-01

    Small photon fields are increasingly used in modern radiotherapy and especially in IMRT and SRS/SRT treatments. Accurate beam profile measurements of such beams are crucial for a precise and effective treatment. In this work four different dosimetric methods have been used for profile measurements of three small 6 MV circular fields having diameters of 7.5, 15.0 and 30.0 mm. A small sensitive volume air ion chamber, a diamond detector, a novel silicon-diode array and Vinyl-Pyrrolidone based polymer gel dosimetry. The results of this work reveal the well-known disadvantages and/or problems of the conventional dosimeters for this kind of measurements and support that polymer gel dosimetry may overcome these problems. Conclusively, it is estimated that polymer gels could play an important role towards the minimization of the total SRS/SRT treatment error that is related with small field profile measurements.

  6. Comparison of Miniaturized and Conventional Asymmetrical Flow Field-Flow Fractionation (AF4 Channels for Nanoparticle Separations

    Directory of Open Access Journals (Sweden)

    Zengchao You

    2017-03-01

    Full Text Available The performance of a miniaturized channel for the separation of polymer and metal nanoparticles (NP using Asymmetrical Flow Field-Flow Fractionation (AF4 was investigated and compared with a conventional AF4 system. To develop standard separation methods, experimental parameters like cross flow, gradient profile and injection time were varied and optimized. Corresponding chromatographic parameters were calculated and compared. Our results indicate that the chromatographic resolution in the miniaturized channel is lower, whereas significantly shorter analyses time and less solvent consumption were obtained. Moreover, the limit of detection (LOD and limit of quantification (LOQ obtained from hyphenation with a UV-detector are obviously lower than in a conventional channel, which makes the miniaturized channel interesting for trace analysis.

  7. Electric field strength and plasma delay in silicon surface barrier detector

    International Nuclear Information System (INIS)

    Kanno, I.; Inbe, T.; Kanazawa, S.; Kimura, I.

    1994-01-01

    The resistivity change of a silicon irradiated by high energy neutrons became an interest of study associated with the large scale accelerator projects . The increase of the resistivity of the silicon of a silicon surface barrier detector (SSBD) was studied as a function of neutron fluence. The plasma delay, which was an interesting but not favorite timing property of the SSBD, was reported being dependent on the resistivity of silicon . The neutron irradiation brings the change of timing property as well as the resistivity change on the SSBD. The resistivity dependence of the plasma delay should be studied for the purpose of high energy accelerator experiments. Some empirical formulae of the plasma delay were reported, however, there were no discussions on the physical meanings of the resistivity dependence of the plasma delay. The plasma delay in a SSBD is discussed in the light of electric field strength in the depletion layer of the SSBD. The explanation of the plasma delay is presented taking into account of the competing two electric forces. The resistivity of the silicon affects the plasma delay through the electric forces. 3 figs, 3 refs. (author)

  8. Assessment of short/long term electric field strength measurements for a pilot district

    Science.gov (United States)

    Kurnaz, Cetin; Yildiz, Dogan; Karagol, Serap

    2018-03-01

    The level of electromagnetic radiation (EMR) exposure increases day by day as natural consequences of technological developments. In recent years, the increasing use of cellular systems has made it necessary to measure and evaluate EMR originating from base stations. In this study, broadband and band selective electric field strength (E) measurements were taken at four different times in order to evaluate the change of short term E in Atakum district of Samsun, Turkey. The measurements were collected from 46 different locations using a SRM 3006 and a PMM 8053 EMR meter in a band from 100 kHz to 3 GHz, and the maximum E (Emax) and the average E (Eavg) were recorded. The highest values have been noticed in these measurements at 9.45 V/m and 17.53 V/m for Eavg and Emax respectively. Apart from these measurements, 24 hour long term E measurements were taken at a location where the highest value was observed and analyzed, to observe the change of Es during a day. At the end of the study, a tentative mathematical model that helps in computing the total E of the medium with 95% accuracy, was obtained.

  9. Dependence of streamer density on electric field strength on positive electrode

    Science.gov (United States)

    Koki, Nakamura; Takahumi, Okuyama; Wang, Douyan; Takao, N.; Hidenori, Akiyama; Kumamoto University Collaboration

    2015-09-01

    Pulsed streamer discharge plasma, a type of non-thermal plasma, is known as generation method of reactive radicals and ozone and treatment of exhausted gas. From our previous research, the distance between electrodes has been considered a very important parameter for applications using pulsed streamer discharge. However, how the distance between electrodes affects the pulsed discharge hasn't been clarified. In this research, the propagation process of pulsed streamer discharge in a wire-plate electrode was observed using an ICCD camera for 4 electrodes having different distance between electrodes. The distance between electrodes was changeable at 45 mm, 40 mm, 35 mm, and 30 mm. The results show that, when the distance between electrodes was shortened, applied voltage with a pulse duration of 100 ns decreased from 80 to 60.3 kV. Conversely, discharge current increased from 149 to 190 A. Streamer head velocity became faster. On the other hand, Streamer head density at onset time of streamer head propagation didn't change. This is considered due to the electric field strength of streamer head at that time, in result, it was about 14 kV/mm under each distance between electrodes.

  10. Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy

    Science.gov (United States)

    Shubitidze, Fridon; Kekalo, Katsiaryna; Stigliano, Robert; Baker, Ian

    2015-03-01

    Magnetic nanoparticles (MNPs), referred to as the Dartmouth MNPs, which exhibit high specific absorption rate at low applied field strength have been developed for hyperthermia therapy applications. The MNPs consist of small (2-5 nm) single crystals of gamma-Fe2O3 with saccharide chains implanted in their crystalline structure, forming 20-40 nm flower-like aggregates with a hydrodynamic diameter of 110-120 nm. The MNPs form stable (>12 months) colloidal solutions in water and exhibit no hysteresis under an applied quasistatic magnetic field, and produce a significant amount of heat at field strengths as low as 100 Oe at 99-164 kHz. The MNP heating mechanisms under an alternating magnetic field (AMF) are discussed and analyzed quantitatively based on (a) the calculated multi-scale MNP interactions obtained using a three dimensional numerical model called the method of auxiliary sources, (b) measured MNP frequency spectra, and (c) quantified MNP friction losses based on magneto-viscous theory. The frequency responses and hysteresis curves of the Dartmouth MNPs are measured and compared to the modeled data. The specific absorption rate of the particles is measured at various AMF strengths and frequencies, and compared to commercially available MNPs. The comparisons demonstrate the superior heating properties of the Dartmouth MNPs at low field strengths (therapy to deeper tumors that were previously non-viable targets, potentially enabling the treatment of some of the most difficult cancers, such as pancreatic and rectal cancers, without damaging normal tissue.

  11. Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs

    Science.gov (United States)

    Mechtensimer, Sara

    2017-01-01

    Septic systems can be a potential source of phosphorus (P) in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench) to shallow groundwater. Two new in-situ drainfields (6.1 m long by 0.61 m wide) with a 3.72 m2 infiltrative surface were constructed. The drip dispersal drainfield was constructed by placing 30.5 cm commercial sand on top of natural soil and the gravel trench drainfield was constructed by placing 30.5 cm of gravel on top of 30.5 cm commercial sand and natural soil. Suction cup lysimeters were installed in the drainfields (at 30.5, 61, 106.7 cm below infiltrative surface) and piezometers were installed in the groundwater (>300 cm below infiltrative surface) to capture P dynamics from the continuum of unsaturated to saturated zones in the septic systems. Septic tank effluent (STE), soil-water, and groundwater samples were collected for 64 events (May 2012–Dec 2013) at 2 to 3 days (n = 13), weekly (n = 29), biweekly (n = 17), and monthly (n = 5) intervals. One piezometer was installed up-gradient of the drainfields to monitor background groundwater (n = 15). Samples were analyzed for total P (TP), orthophosphate-P (PO4–P), and other–P (TP—PO4-P). The gravel trench drainfield removed significantly (p300 cm in the groundwater, both systems had similar TP reductions of >97%. After 18 months of STE application, there was no significant increase in groundwater TP concentrations in both systems. We conclude that both drainfield designs are effective at reducing P transport to shallow groundwater. PMID:28107505

  12. Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs.

    Directory of Open Access Journals (Sweden)

    Sara Mechtensimer

    Full Text Available Septic systems can be a potential source of phosphorus (P in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench to shallow groundwater. Two new in-situ drainfields (6.1 m long by 0.61 m wide with a 3.72 m2 infiltrative surface were constructed. The drip dispersal drainfield was constructed by placing 30.5 cm commercial sand on top of natural soil and the gravel trench drainfield was constructed by placing 30.5 cm of gravel on top of 30.5 cm commercial sand and natural soil. Suction cup lysimeters were installed in the drainfields (at 30.5, 61, 106.7 cm below infiltrative surface and piezometers were installed in the groundwater (>300 cm below infiltrative surface to capture P dynamics from the continuum of unsaturated to saturated zones in the septic systems. Septic tank effluent (STE, soil-water, and groundwater samples were collected for 64 events (May 2012-Dec 2013 at 2 to 3 days (n = 13, weekly (n = 29, biweekly (n = 17, and monthly (n = 5 intervals. One piezometer was installed up-gradient of the drainfields to monitor background groundwater (n = 15. Samples were analyzed for total P (TP, orthophosphate-P (PO4-P, and other-P (TP-PO4-P. The gravel trench drainfield removed significantly (p300 cm in the groundwater, both systems had similar TP reductions of >97%. After 18 months of STE application, there was no significant increase in groundwater TP concentrations in both systems. We conclude that both drainfield designs are effective at reducing P transport to shallow groundwater.

  13. Earthworms influenced by reduced tillage, conventional tillage and energy forest in Swedish agricultural field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagerloef, Jan (SLU, Department of Ecology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), Email: Jan.Lagerlof@ekol.slu.se; Paalsson, Olof; Arvidsson, Johan (SLU, Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    2012-03-15

    We compared earthworm density, depth distribution and species composition in three soil cultivation experiments including the treatments ploughless tillage and mouldboard ploughing. Sampling was done in September 2005 and for one experiment also in 1994. By yearly sampling 1995-2005, earthworms in an energy forest of Salix viminalis were compared with those in an adjacent arable field. Sampling method was digging of soil blocks and hand sorting and formalin sampling in one cultivation experiment. Both methods were used in the energy forest and arable land comparison. In two soil cultivation experiments, highest abundances or biomass were found in ploughless tillage. Earthworm density was higher in the upper 10 cm, especially in the ploughless tillage. Earthworm density was significantly higher in the energy forest than in the arable field. Formalin sampling revealed c. 36% of the earthworm numbers found by digging in the energy forest and gave almost no earthworms in the arable field. In all treatments with soil cultivation, species living and feeding in the rhizosphere and soil dominated. One such species, Allolobophora chlorotica, was more abundant under mouldboard ploughing than ploughless tillage. Lumbricus terrestris, browsing on the surface and producing deep vertical burrows, was more common in the ploughless tillage. Species living and feeding close to the soil surface were almost only found in the energy forest, which had not been soil cultivated since 1984. The findings support earlier studies pointing out possibilities to encourage earthworms by reduced soil cultivation. This is one of the first published studies that followed earthworm populations in an energy forest plantation during several years. Explanation of earthworm reactions to management and environmental impacts should be done with consideration of the ecology of species or species groups. Earthworm sampling by formalin must always be interpreted with caution and calibrated by digging and

  14. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Han, K.; Embury, J.D.

    1998-10-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications.

  15. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    International Nuclear Information System (INIS)

    Han, K.; Embury, J.D.

    1998-01-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications

  16. Controlling the transport of cations through permselective mesoporous alumina layers by manipulation of electric field and ionic strength

    NARCIS (Netherlands)

    Schmuhl, R.; Keizer, Klaas; van den Berg, Albert; ten Elshof, Johan E.; Blank, David H.A.

    2004-01-01

    The electric field-driven transport of ions through supported mesoporous γ-alumina membranes was investigated. The influence of ion concentration, ion valency, pH, ionic strength, and electrolyte composition on transport behavior was determined. The permselectivity of the membrane was found to be

  17. Determination of electric field strength and kinetic temperature in the cathode fall region of a hollow cathode discharge

    Energy Technology Data Exchange (ETDEWEB)

    De la Rosa, M I; Perez, C; Gruetzmacher, K [Universidad de Valladolid, Facultad de Ciencias, 47071 Valladolid (Spain); Gonzalo, A B; Del Val, J A, E-mail: delarosa@opt.uva.e [Universidad de Salamanca, Escuela Politecnica Superior, 05003 Avila (Spain)

    2010-05-01

    In this work, we demonstrate the high potential of two-photon excitation of the 1S -2S transition of atomic hydrogen followed by optogalvanic detection, for measuring under identical experimental conditions, the kinetic temperature and the electric field strength in the cathode sheath region of a hollow cathode discharge. The first obtained results for both parameters are discussed in this paper.

  18. The application of strength and power related field tests in older adults : criteria, current status and a future perspective

    NARCIS (Netherlands)

    Regterschot, G. Ruben H.; Morat, Tobias; Folkersma, Marjanne; Zijlstra, Wiebren

    2015-01-01

    Leg muscle strength (LMS) and leg muscle power (LMP) are determinants of aspects of functional status and important parameters for measuring intervention effects in older adults. Field tests are often used for the evaluation of LMS and LMP in older persons. However, criteria important for the

  19. Acute peripheral joint injury: cost and effectiveness of low-field-strength MR imaging--results of randomized controlled trial.

    NARCIS (Netherlands)

    Nikken, J.J.; Oei, E.H.; Ginai, A.Z.; Krestin, G.P.; Verhaar, J.A.N.; Vugt, A.B. van; Hunink, M.G.M.

    2005-01-01

    PURPOSE: To assess prospectively if a short imaging examination performed with low-field-strength dedicated magnetic resonance (MR) imaging in addition to radiography is effective and cost saving compared with the current diagnostic imaging strategy (radiography alone) in patients with recent acute

  20. Propellant perforation breakdown technique: non-conventional field applications in Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Almazna, Edgar; Feijoo, David; Folse, Kent C.; Campuzano, Alvaro [Halliburton Energy Services (Colombia). Completions and Reservoir Optimization

    2004-07-01

    Hocol Nimir operates the SF-136 oil well, located in southern Colombia. The area is characterized by complex geology and low permeability, low porosity reservoirs. In SF-136, the operator wanted to produce from the Tetuan fractured carbonates, a shallower limestone with low permeability (estimated 0.01-1.0 md) and porosity (estimated to be 2.2%) that produces through natural fractures. The operator was seeking an economical technology that could provide contact with these fractures. To meet operator needs, a propellant-assisted technique was suggested. This stimulation technique can optimize well productivity while maintaining stringent technical, health, safety and environmental standards. The alternative technologies used to further develop the Tetuan reserves attained operator goals and provided a new option for Columbia field development, especially in wells where the presence of natural fractures had been detected. Another Columbian case history that required an unusual stimulation technique in a gas field operated by Petro-Colombia will also be presented. The well, Opon-6, provided extreme challenges because of difficult well Rio oil and gas expo and conference 2004 conditions caused by collapse points in the casing. In this well, fracturing software was used to perform several simulations before the job was run to predict the approximate micro fracture lengths and to foresee any potential problems with the completion equipment during the operation. This was a special application for which special tools had to be designed to modify the propellant application for slick-line operations. The process eliminated electric line by initiating the propellant with a special electronic triggering device. The process also used memory production logging tools to help properly position propellant devices at selected depths. The methods developed to satisfy the operational challenges in these cases will be presented. This paper will discuss how implementing innovative

  1. Effect of temperature on the uniform field breakdown strength of electronegative gases

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Mathis, R.A.; Hunter, S.R.; Carter, J.G.

    1987-03-01

    In general, the electron attachment rate constant, k/sub a/ ( ,Υ), as a function of the mean electron energy and temperature Υ for electronegative gases which attach electrons nondissociatively decreases greatly with Υ from room temperature to Υ ≤ 600K, while that for electronegative gases which attach electrons dissociatively increases with increasing Υ. Based on recent studies in our laboratory on k/sub a/ ( ,Υ), we investigated the variation with Υ (∼295-575K) of the uniform field breakdown strength, (E/N)/sub lim/, for three classes of electronegative gases: (a) gases such as c-C 4 F 8 (and c-C 4 F 6 , 1-C 3 F 6 ) which attach strongly low-energy (≤ 1 eV) electrons nondissociatively and for which k/sub a/ ( ,Υ), decreases precipitously with Υ above ambient; (b) gases such as C 2 F 6 and CF 3 Cl which attach electrons exclusively dissociatively and whose k/sub a/ ( ,Υ) increases with Υ; and (c) gases such as C 3 F 8 and n-C 4 F 10 which attach electrons both nondissociatively and dissociatively over a common low-energy range and whose k/sub a/ ( ,Υ) first decreases and then increases with Υ above ambient. The (E/N)/sub lim/(Υ) has been found to decrease significantly with Υ for (a), to decrease slowly with Υ for (c), and to increase slightly with Υ for (b). These changes in (E/N)/sub lim/ follow those in k/sub a/ ( ,Υ). A similar behavior is expected for other electronegative gaseous dielectrics in the respective three groups

  2. MAGNETIC FIELD STRENGTH FLUCTUATIONS IN THE HELIOSHEATH: VOYAGER 1 OBSERVATIONS DURING 2009

    International Nuclear Information System (INIS)

    Burlaga, L. F.; Ness, N. F.

    2012-01-01

    We analyze the ''microscale fluctuations'' of the magnetic field strength B on a scale of several hours observed by Voyager1 (V1) in the heliosheath during 2009. The microscale fluctuations of B range from coherent to stochastic structures. The amplitude of microscale fluctuations of B during 1 day is measured by the standard deviation (SD) of 48 s averages of B. The distribution of the daily values of SD is lognormal. SD(t) from day of year (DOY) 1 to 331, 2009, is very intermittent. SD(t) has a 1/f or 'pink noise' spectrum on scales from 1 to 100 days, and it has a broad multifractal spectrum f(α) with 0.57 ≤ α ≤ 1.39. The time series of increments SD(t + τ) – SD(t) has a pink noise spectrum with α' = 0.88 ± 0.14 on scales from 1 to 100 days. The increments have a Tsallis (q-Gaussian) distribution on scales from 1 to 165 days, with an average q = 1.75 ± 0.12. The skewness S and kurtosis K have Gaussian and lognormal distributions, respectively. The largest spikes in K(t) and S(t) are often associated with a change in B across a data gap and with identifiable physical structures. The 'turbulence' observed by V1 during 2009 was weakly compressible on average but still very intermittent, highly variable, and highly compressible at times. The turbulence observed just behind the termination shock by Voyager 2 was twice as strong. These observations place strong constraints on any model of 'turbulence' in the heliosheath.

  3. Comparison of swirling strengths derived from two- and three-dimensional velocity fields in channel flow

    Science.gov (United States)

    Chen, Huai; Li, Danxun; Bai, Ruonan; Wang, Xingkui

    2018-05-01

    Swirling strength is an effective vortex indicator in wall turbulence, and it can be determined based on either two-dimensional (2D) or three-dimensional (3D) velocity fields, written as λci2D and λci3D, respectively. A comparison between λci2D and λci3D has been made in this paper in sliced XY, YZ, and XZ planes by using 3D DNS data of channel flow. The magnitude of λci2D in three orthogonal planes differs in the inner region, but the difference tends to diminish in the outer flow. The magnitude of λci3D exceeds each λci2D, and the square of λci3D is greater than the summation of squares of three λci2D. Extraction with λci2D in XY, YZ, and XZ planes yields different population densities and vortex sizes, i.e., in XZ plane, the vortices display the largest population density and the smallest size, and in XY and YZ planes the vortices are similar in size but fewer vortices are extracted in the XY plane in the inner layer. Vortex size increases inversely with the threshold used for growing the vortex region from background turbulence. When identical thresholds are used, the λci3D approach leads to a slightly smaller population density and a greater vortex radius than the λci2D approach. A threshold of 0.8 for the λci3D approach is approximately equivalent to a threshold of 1.5 for the λci2D approach.

  4. THE TECHNOLOGICAL AND EXPLOITATIVE FACTORS OF LOCAL INCREASE OF ELECTRIC FIELD STRENGTH IN THE POWER CABLE OF COAXIAL DESIGN

    Directory of Open Access Journals (Sweden)

    G. V. Bezprozvannych

    2016-12-01

    Full Text Available Introduction. Reliability of high voltage power cables in the process of long-term operation is largely due to the intensity of polymeric insulation aging. It is now established that the aging of polyethylene, which is the main material for the insulation of high voltage power cables, under the action of the electric field is determined primarily by the presence of structural heterogeneity arising both during cable production and during use. The cable is always there deviations from the ideal structure, which manifest in a deviation of diameters of conductors from nominal values; in the arrangement of the conductor and the insulation is not strictly coaxially and eccentrically; in elliptic (oval core and insulation; change in relative dielectric constant and thickness of insulation on cable length force the formation of low molecular weight products (including water in the flow at the manufacturing stage crosslinked polyethylene insulation and moisture during operation. Such defects are structural, technological and operational irregularities, which lead to a local change in the electric field. Purpose. Analysis of the influence of the eccentricity, elliptic and spherical inclusions in the electric field distribution in the power cable of a coaxial design with cross-linked polyethylene insulation, based on numerical simulation. Methodology. The bases of the numerical method of calculation of the electrical field strength are Fredholm integral equations of the first and second kind (method of secondary sources for an axially symmetric field. Analysis of the influence of irregularities, including water treeing, the shape of the sounding signal is made using the method of discrete resistive circuit inductance and capacitance of substitution with the initial conditions. Solving systems of linear algebraic equations nodal analysis performed by the sweep method. Results. The presence of the eccentricity and ellipticity in the construction of cable has

  5. Application of Quantitative MRI for Brain Tissue Segmentation at 1.5 T and 3.0 T Field Strengths

    Science.gov (United States)

    West, Janne; Blystad, Ida; Engström, Maria; Warntjes, Jan B. M.; Lundberg, Peter

    2013-01-01

    Background Brain tissue segmentation of white matter (WM), grey matter (GM), and cerebrospinal fluid (CSF) are important in neuroradiological applications. Quantitative Mri (qMRI) allows segmentation based on physical tissue properties, and the dependencies on MR scanner settings are removed. Brain tissue groups into clusters in the three dimensional space formed by the qMRI parameters R1, R2 and PD, and partial volume voxels are intermediate in this space. The qMRI parameters, however, depend on the main magnetic field strength. Therefore, longitudinal studies can be seriously limited by system upgrades. The aim of this work was to apply one recently described brain tissue segmentation method, based on qMRI, at both 1.5 T and 3.0 T field strengths, and to investigate similarities and differences. Methods In vivo qMRI measurements were performed on 10 healthy subjects using both 1.5 T and 3.0 T MR scanners. The brain tissue segmentation method was applied for both 1.5 T and 3.0 T and volumes of WM, GM, CSF and brain parenchymal fraction (BPF) were calculated on both field strengths. Repeatability was calculated for each scanner and a General Linear Model was used to examine the effect of field strength. Voxel-wise t-tests were also performed to evaluate regional differences. Results Statistically significant differences were found between 1.5 T and 3.0 T for WM, GM, CSF and BPF (p3.0 T. The mean differences between 1.5 T and 3.0 T were -66 mL WM, 40 mL GM, 29 mL CSF and -1.99% BPF. Voxel-wise t-tests revealed regional differences of WM and GM in deep brain structures, cerebellum and brain stem. Conclusions Most of the brain was identically classified at the two field strengths, although some regional differences were observed. PMID:24066153

  6. A fast parallel code for calculating energies and oscillator strengths of many-electron atoms at neutron star magnetic field strengths in adiabatic approximation

    Science.gov (United States)

    Engel, D.; Klews, M.; Wunner, G.

    2009-02-01

    We have developed a new method for the fast computation of wavelengths and oscillator strengths for medium-Z atoms and ions, up to iron, at neutron star magnetic field strengths. The method is a parallelized Hartree-Fock approach in adiabatic approximation based on finite-element and B-spline techniques. It turns out that typically 15-20 finite elements are sufficient to calculate energies to within a relative accuracy of 10-5 in 4 or 5 iteration steps using B-splines of 6th order, with parallelization speed-ups of 20 on a 26-processor machine. Results have been obtained for the energies of the ground states and excited levels and for the transition strengths of astrophysically relevant atoms and ions in the range Z=2…26 in different ionization stages. Catalogue identifier: AECC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3845 No. of bytes in distributed program, including test data, etc.: 27 989 Distribution format: tar.gz Programming language: MPI/Fortran 95 and Python Computer: Cluster of 1-26 HP Compaq dc5750 Operating system: Fedora 7 Has the code been vectorised or parallelized?: Yes RAM: 1 GByte Classification: 2.1 External routines: MPI/GFortran, LAPACK, PyLab/Matplotlib Nature of problem: Calculations of synthetic spectra [1] of strongly magnetized neutron stars are bedevilled by the lack of data for atoms in intense magnetic fields. While the behaviour of hydrogen and helium has been investigated in detail (see, e.g., [2]), complete and reliable data for heavier elements, in particular iron, are still missing. Since neutron stars are formed by the collapse of the iron cores of massive stars, it may be assumed that their atmospheres contain an iron plasma. Our objective is to fill the gap

  7. Evaluation and field verification of strength and structural improvement of chemically stabilized subgrade soil.

    Science.gov (United States)

    2008-07-01

    Often subgrade soils exhibit properties, particularly strength and/or volume change properties that limit their performance as a support element for pavements. : Typical problems include shrink-swell, settlement, collapse, erosion or simply insuffici...

  8. Transient-field strength measurements for 52Cr traversing Fe hosts at high velocity and polarization transfer mechanisms

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Doran, C.E.; Byrne, A.P.; Bolotin, H.H.; Dracoulis, G.D.

    1986-12-01

    Transient-field strengths were measured for 52 Cr ions traversing polarized Fe hosts at velocities up to 12v>=o (v>=o = c/137 = Bohr velocity). The results are compared with predictions of various transient field parametrizations and discussed in terms of possible mechanisms by which polarization might be transferred from the Fe host to inner vacancies of the moving Cr ions. The g-factor of the first 2 + state of 52 Cr was also measured by the transient field technique and found to be in accord with shell-model calculations

  9. ROLE OF MAGNETIC FIELD STRENGTH AND NUMERICAL RESOLUTION IN SIMULATIONS OF THE HEAT-FLUX-DRIVEN BUOYANCY INSTABILITY

    International Nuclear Information System (INIS)

    Avara, Mark J.; Reynolds, Christopher S.; Bogdanović, Tamara

    2013-01-01

    The role played by magnetic fields in the intracluster medium (ICM) of galaxy clusters is complex. The weakly collisional nature of the ICM leads to thermal conduction that is channeled along field lines. This anisotropic heat conduction profoundly changes the instabilities of the ICM atmosphere, with convective stabilities being driven by temperature gradients of either sign. Here, we employ the Athena magnetohydrodynamic code to investigate the local non-linear behavior of the heat-flux-driven buoyancy instability (HBI) relevant in the cores of cooling-core clusters where the temperature increases with radius. We study a grid of two-dimensional simulations that span a large range of initial magnetic field strengths and numerical resolutions. For very weak initial fields, we recover the previously known result that the HBI wraps the field in the horizontal direction, thereby shutting off the heat flux. However, we find that simulations that begin with intermediate initial field strengths have a qualitatively different behavior, forming HBI-stable filaments that resist field-line wrapping and enable sustained vertical conductive heat flux at a level of 10%-25% of the Spitzer value. While astrophysical conclusions regarding the role of conduction in cooling cores require detailed global models, our local study proves that systems dominated by the HBI do not necessarily quench the conductive heat flux

  10. CT ESP for Yme, Converting the Yme field offshore Norway from a conventional rig-operated field to CT-operated for workover and drilling applications

    Energy Technology Data Exchange (ETDEWEB)

    Baklid, A.; Apeland, O. J.; Teigen, A. S. [Statoil (Norway)

    1998-12-31

    Conventional tubing deployed electrical submersible pump (ESP) was the original choice as the artificial lift method for the Yme field offshore Norway. Several operational problems experienced over the past two years, such as formation damage, complicated and costly workovers and limited access to the reservoir, combined with revised field requirements and a reevaluation of artificial lift methods resulted in a change in completion philosophy. Following these reassessments coiled tubing ESPs utilizing internal power cable were installed and became the preferred method. This paper provides an assessment of the value of installing CT-ESP in a live well, and describes the system design for a true underbalanced CT-ESP installation. Well control and barrier philosophy during installation, production and workover mode is also evaluated. 2 refs., 3 tabs., 5 figs.

  11. Comparative UAV and Field Phenotyping to Assess Yield and Nitrogen Use Efficiency in Hybrid and Conventional Barley.

    Science.gov (United States)

    Kefauver, Shawn C; Vicente, Rubén; Vergara-Díaz, Omar; Fernandez-Gallego, Jose A; Kerfal, Samir; Lopez, Antonio; Melichar, James P E; Serret Molins, María D; Araus, José L

    2017-01-01

    With the commercialization and increasing availability of Unmanned Aerial Vehicles (UAVs) multiple rotor copters have expanded rapidly in plant phenotyping studies with their ability to provide clear, high resolution images. As such, the traditional bottleneck of plant phenotyping has shifted from data collection to data processing. Fortunately, the necessarily controlled and repetitive design of plant phenotyping allows for the development of semi-automatic computer processing tools that may sufficiently reduce the time spent in data extraction. Here we present a comparison of UAV and field based high throughput plant phenotyping (HTPP) using the free, open-source image analysis software FIJI (Fiji is just ImageJ) using RGB (conventional digital cameras), multispectral and thermal aerial imagery in combination with a matching suite of ground sensors in a study of two hybrids and one conventional barely variety with ten different nitrogen treatments, combining different fertilization levels and application schedules. A detailed correlation network for physiological traits and exploration of the data comparing between treatments and varieties provided insights into crop performance under different management scenarios. Multivariate regression models explained 77.8, 71.6, and 82.7% of the variance in yield from aerial, ground, and combined data sets, respectively.

  12. Comparative UAV and Field Phenotyping to Assess Yield and Nitrogen Use Efficiency in Hybrid and Conventional Barley

    Directory of Open Access Journals (Sweden)

    Shawn C. Kefauver

    2017-10-01

    Full Text Available With the commercialization and increasing availability of Unmanned Aerial Vehicles (UAVs multiple rotor copters have expanded rapidly in plant phenotyping studies with their ability to provide clear, high resolution images. As such, the traditional bottleneck of plant phenotyping has shifted from data collection to data processing. Fortunately, the necessarily controlled and repetitive design of plant phenotyping allows for the development of semi-automatic computer processing tools that may sufficiently reduce the time spent in data extraction. Here we present a comparison of UAV and field based high throughput plant phenotyping (HTPP using the free, open-source image analysis software FIJI (Fiji is just ImageJ using RGB (conventional digital cameras, multispectral and thermal aerial imagery in combination with a matching suite of ground sensors in a study of two hybrids and one conventional barely variety with ten different nitrogen treatments, combining different fertilization levels and application schedules. A detailed correlation network for physiological traits and exploration of the data comparing between treatments and varieties provided insights into crop performance under different management scenarios. Multivariate regression models explained 77.8, 71.6, and 82.7% of the variance in yield from aerial, ground, and combined data sets, respectively.

  13. High strength H2S resistant steels and alloys for oil field tubular products

    International Nuclear Information System (INIS)

    Straatmann, J.A.; Grobner, P.J.

    1976-01-01

    New sources of oil and natural gas are more frequently occurring at greater depths in hostile surface and underground environments. The materials utilized in drilling and completing the wells require higher strength along with improved resistance to corrosive/embrittling attack by contaminants present in the deep, high pressure-high temperature formations. Higher strength steels having yield strengths in excess of 690 MPa and possessing improved resistance to sulfide stress corrosion cracking (SSC) have been developed and are currently being evaluated by the oil industry. The research to develop these new steels combined modifications of chemical compositions, heat treatment and processing variables. For most severe SSC environments and deep wells, it was necessary to provide even better alloys for tubular materials. The successful solution to the problem was found with the utilization of nickel-base alloys. These materials are being evaluated in commercial applications

  14. Radiation Effect on Body Weight and Hematological Changes of Hybrid Mice by Conventional Fraction, Large Abdominal Field Irradiation

    International Nuclear Information System (INIS)

    Lee, Sung Heon; Shin, Sei One; Kim, Myung Se

    1985-01-01

    Radiation effect on mammals, especially on hematologic changes, has been studied since discovery of x-ray. Various experimental animals were tried for radiobiological studies. 72 hybrid mice with conventional fraction (5X/week), large abdominal field (2 x 3cm, from symphysis pubic to xyphoid process) were used. Body weight was declined gradually by increasing irradiation doses, nadir was about 29.7% in male ; 30.4% in female at 6000 rad irradiation group. Hemoglobin value was nearly normal throughout entire treatment. Significant dropping of WBC count was noted to 40-50% of pretreatment values by only 1000 rad irradiation. Change of differential count was interesting; lymphocyte proportion showed gradual reduction, instead of gradual increasing of segmented neutrophil. Those proportion were reversed after 6000 rad irradiation. Urinary protein tests showed + - +++, showing no correlation with dosage. Application. of our study in clinical combination therapy (radiation + chemotherapy) was discussed

  15. Comparative evaluation of tensile bond strength and microleakage of conventional glass ionomer cement, resin modified glass ionomer cement and compomer: An in vitro study.

    Science.gov (United States)

    Rekha, C Vishnu; Varma, Balagopal; Jayanthi

    2012-07-01

    The purpose of this study was to evaluate and compare the tensile bond strength and microleakage of Fuji IX GP, Fuji II LC, and compoglass and to compare bond strength with degree of microleakage exhibited by the same materials. Occlusal surfaces of 96 noncarious primary teeth were ground perpendicular to long axis of the tooth. Preparations were distributed into three groups consisting of Fuji IX GP, Fuji II LC and Compoglass. Specimens were tested for tensile bond strength by mounting them on Instron Universal Testing Machine. Ninety-six primary molars were treated with Fuji IX GP, Fuji II LC, and compoglass on box-only prepared proximal surface. Samples were thermocycled, stained with dye, sectioned, and scored for microleakage under stereomicroscope. ANOVA and Bonferrani correction test were done for comparisons. Pearson Chi-square test and regression analysis were done to assess the association between the parameters. Compoglass showed highest tensile strength and Fuji II LC showed least microleakage. There was a significant difference between the three groups in tensile strength and microleakage levels. The correlation between tensile strength and microleakage level in each group showed that there was a significant negative correlation only in Group 3. Fuji II LC and compoglass can be advocated in primary teeth because of their superior physical properties when compared with Fuji IX GP.

  16. Comparative evaluation of tensile bond strength and microleakage of conventional glass ionomer cement, resin modified glass ionomer cement and compomer: An in vitro study

    Directory of Open Access Journals (Sweden)

    C Vishnu Rekha

    2012-01-01

    Full Text Available Aim: The purpose of this study was to evaluate and compare the tensile bond strength and microleakage of Fuji IX GP, Fuji II LC, and compoglass and to compare bond strength with degree of microleakage exhibited by the same materials. Materials and Methods: Occlusal surfaces of 96 noncarious primary teeth were ground perpendicular to long axis of the tooth. Preparations were distributed into three groups consisting of Fuji IX GP, Fuji II LC and Compoglass. Specimens were tested for tensile bond strength by mounting them on Instron Universal Testing Machine. Ninety-six primary molars were treated with Fuji IX GP, Fuji II LC, and compoglass on box-only prepared proximal surface. Samples were thermocycled, stained with dye, sectioned, and scored for microleakage under stereomicroscope. ANOVA and Bonferrani correction test were done for comparisons. Pearson Chi-square test and regression analysis were done to assess the association between the parameters. Results: Compoglass showed highest tensile strength and Fuji II LC showed least microleakage. There was a significant difference between the three groups in tensile strength and microleakage levels. The correlation between tensile strength and microleakage level in each group showed that there was a significant negative correlation only in Group 3. Conclusion: Fuji II LC and compoglass can be advocated in primary teeth because of their superior physical properties when compared with Fuji IX GP.

  17. Kinetic parameters, collision rates, energy exchanges and transport coefficients of non-thermal electrons in premixed flames at sub-breakdown electric field strengths

    KAUST Repository

    Bisetti, Fabrizio; El Morsli, Mbark

    2014-01-01

    The effects of an electric field on the collision rates, energy exchanges and transport properties of electrons in premixed flames are investigated via solutions to the Boltzmann kinetic equation. The case of high electric field strength, which

  18. Relationship of magnetic field strength and brightness of fine-structure elements in the solar temperature minimum region

    Science.gov (United States)

    Cook, J. W.; Ewing, J. A.

    1990-01-01

    A quantitative relationship was determined between magnetic field strength (or magnetic flux) from photospheric magnetograph observations and the brightness temperature of solar fine-structure elements observed at 1600 A, where the predominant flux source is continuum emission from the solar temperature minimum region. A Kitt Peak magnetogram and spectroheliograph observations at 1600 A taken during a sounding rocket flight of the High Resolution Telescope and Spectrograph from December 11, 1987 were used. The statistical distributions of brightness temperature in the quiet sun at 1600 A, and absolute value of magnetic field strength in the same area were determined from these observations. Using a technique which obtains the best-fit relationship of a given functional form between these two histogram distributions, a quantitative relationship was determined between absolute value of magnetic field strength B and brightness temperature which is essentially linear from 10 to 150 G. An interpretation is suggested, in which a basal heating occurs generally, while brighter elements are produced in magnetic regions with temperature enhancements proportional to B.

  19. On the importance of body posture and skin modelling with respect to in situ electric field strengths in magnetic field exposure scenarios

    Science.gov (United States)

    Schmid, Gernot; Hirtl, Rene

    2016-06-01

    The reference levels and maximum permissible exposure values for magnetic fields that are currently used have been derived from basic restrictions under the assumption of upright standing body models in a standard posture, i.e. with arms laterally down and without contact with metallic objects. Moreover, if anatomical modelling of the body was used at all, the skin was represented as a single homogeneous tissue layer. In the present paper we addressed the possible impacts of posture and skin modelling in scenarios of exposure to a 50 Hz uniform magnetic field on the in situ electric field strength in peripheral tissues, which must be limited in order to avoid peripheral nerve stimulation. We considered different body postures including situations where body parts form large induction loops (e.g. clasped hands) with skin-to-skin and skin-to-metal contact spots and compared the results obtained with a homogeneous single-layer skin model to results obtained with a more realistic two-layer skin representation consisting of a low-conductivity stratum corneum layer on top of a combined layer for the cellular epidermis and dermis. Our results clearly indicated that postures with loops formed of body parts may lead to substantially higher maximum values of induced in situ electric field strengths than in the case of standard postures due to a highly concentrated current density and in situ electric field strength in the skin-to-skin and skin-to-metal contact regions. With a homogeneous single-layer skin, as is used for even the most recent anatomical body models in exposure assessment, the in situ electric field strength may exceed the basic restrictions in such situations, even when the reference levels and maximum permissible exposure values are not exceeded. However, when using the more realistic two-layer skin model the obtained in situ electric field strengths were substantially lower and no violations of the basic restrictions occurred, which can be explained by the

  20. Effect of the ionic strength of pulsed electric field treatment medium on the physicochemical and structural characteristics of lactoferrin.

    Science.gov (United States)

    Sui, Qian; Roginski, Hubert; Williams, Roderick P W; Wooster, Tim J; Versteeg, Cornelis; Wan, Jason

    2010-11-24

    Pulsed electric field (PEF) treatment (35 kV cm(-1) for 19.2 μs using bipolar 2 μs pulses) was conducted on bovine lactoferrin (LF; 0.4 mg mL(-1)) prepared in simulated milk ultrafiltrate (SMUF), at concentrations between 0.2× and 2× normal strength, with electrical conductivities ranging from 0.17 to 1.04 S m(-1). The physicochemical and structural characteristics (LF content by a spectrophotometric and an ELISA method, surface hydrophobicity, electrophoretic mobility, far-UV circular dichroism spectra, and tryptophan fluorescence) of LF dissolved in SMUF of all strengths tested were not changed after PEF treatment. The PEF treatment of LF in 0.2 strength SMUF did not cause the release of LF-bound ferric ion into the aqueous phase, with a concentration of LF-bound iron being the same as that of the untreated LF control (174 μg L(-1)). However, in treatment media with higher ionic strengths, ferric ion was released from the LF molecule into the aqueous phase. The concentration of LF-bound iron decreased from 174 μg L(-1) for the LF treated in 0.2 strength SMUF to 80 μg L(-1) for that treated in double-strength SMUF. The results suggest that the PEF-induced iron depletion of LF does not appear to cause an appreciable conformational change in LF molecules. PEF treatment could be developed as a novel physical way to produce iron-depleted LF, as an alternative to the existing chemical method.

  1. Polarized Line Formation in Arbitrary Strength Magnetic Fields Angle-averaged and Angle-dependent Partial Frequency Redistribution

    Energy Technology Data Exchange (ETDEWEB)

    Sampoorna, M.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, Bengaluru 560 034 (India); Stenflo, J. O., E-mail: sampoorna@iiap.res.in, E-mail: knn@iiap.res.in, E-mail: stenflo@astro.phys.ethz.ch [Institute of Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland)

    2017-08-01

    Magnetic fields in the solar atmosphere leave their fingerprints in the polarized spectrum of the Sun via the Hanle and Zeeman effects. While the Hanle and Zeeman effects dominate, respectively, in the weak and strong field regimes, both these effects jointly operate in the intermediate field strength regime. Therefore, it is necessary to solve the polarized line transfer equation, including the combined influence of Hanle and Zeeman effects. Furthermore, it is required to take into account the effects of partial frequency redistribution (PRD) in scattering when dealing with strong chromospheric lines with broad damping wings. In this paper, we present a numerical method to solve the problem of polarized PRD line formation in magnetic fields of arbitrary strength and orientation. This numerical method is based on the concept of operator perturbation. For our studies, we consider a two-level atom model without hyperfine structure and lower-level polarization. We compare the PRD idealization of angle-averaged Hanle–Zeeman redistribution matrices with the full treatment of angle-dependent PRD, to indicate when the idealized treatment is inadequate and what kind of polarization effects are specific to angle-dependent PRD. Because the angle-dependent treatment is presently computationally prohibitive when applied to realistic model atmospheres, we present the computed emergent Stokes profiles for a range of magnetic fields, with the assumption of an isothermal one-dimensional medium.

  2. Comparative Evaluation of Shear Bond Strength of Orthodontic Brackets using Laser Etching and Two Conventional Etching Techniques: An in vitro Study

    Directory of Open Access Journals (Sweden)

    Shilpa Chawla Jamenis

    2011-01-01

    Conclusion : These results indicate that the shear bond strength of all the three groups was clinically acceptable with no significant difference between them but more adhesive was left on enamel treated with acid and laser as compared to self-etch primer treated enamel.

  3. Small static electric field strength promotes aggregation-prone structures in amyloid-β(29-42)

    Science.gov (United States)

    Lu, Yan; Shi, Xiao-Feng; Salsbury, Freddie R.; Derreumaux, Philippe

    2017-04-01

    The formation of senile plaques in central neural system resulting from the aggregation of the amyloid β (Aβ) of 40 and 42 residues is one of the two hallmarks of Alzheimer's disease. Numerous experiments and computational studies have shown that the aggregation of Aβ peptides in vitro is very complex and depends on many factors such as pH, agitation, temperature, and peptide concentration. The impact of a static electric field (EF) on amyloid peptide aggregation has been much less studied, although EFs may have some applications to treat Parkinson's disease symptoms. Here, we study the influence of an EF strength of 20 mV/nm, present in the human brains, on the conformation of the Aβ29-42 dimer. Our 7 μs non-equilibrium atomistic simulations in aqueous solution show that this field-strength promotes substantially the formation of β-hairpins, believed to be a very important intermediate state during aggregation. This work also suggests that structural biology experiments conducted under appropriate EF strengths may help reduce the conformational heterogeneity of Aβ1-40/Aβ1-42 dimers and provide significant insights into their structures that may be disease-causing.

  4. Last three millennia Earth's Magnetic field strength in Mesoamerica and southern United States: Implications in geomagnetism and archaeology

    Science.gov (United States)

    Goguitchaichvili, Avto; Ruiz, Rafael García; Pavón-Carrasco, F. Javier; Contreras, Juan Julio Morales; Arechalde, Ana María Soler; Urrutia-Fucugauchi, Jaime

    2018-06-01

    Earth's Magnetic Field variation strength may provide crucial information to understand the geodynamo mechanism and elucidate the conditions on the physics of the Earth's deep interiors. Aimed to reveal the fine characteristics of the geomagnetic field during the last three millennia in Mesoamerica, we analyzed the available absolute geomagnetic intensities associated to absolute radiometric dating as well some ages provided by historical documents. This analysis is achieved using thermoremanent magnetization carried by volcanic lava flows and burned archaeological artefacts. A total of 106 selected intensities from Mesoamerica and other 100 from the southern part of the United States represent the main core of the dataset to construct the variation curve using both combined bootstrap method and temporal penalized B-spline methods. The obtained intensity paleosecular variation curve for Mesoamerica generally disagrees with the values predicted by the global geomagnetic field models. There is rather firm evidence of eastward drift when compared to similar reference curves in Western Europe, Asia and Pacific Ocean. The recent hypothesis about the relationship between the geomagnetic field strength and paleoclimate is also critically analyzed in the light of this new data compilation.

  5. A review of the safety implications of magnetic resonance imaging at field strengths of 3 Tesla and above

    International Nuclear Information System (INIS)

    Crook, Neil; Robinson, Leslie

    2009-01-01

    Rationale: Diagnostic imaging is being driven by technological developments particularly so in the field of Magnetic Resonance Imaging (MRI). Electromagnetic fields used to produce images are becoming much stronger and switched more rapidly and it is essential that safety advice remains appropriate and current. Using a systematic methodology, this review aims to identify the clinical safety implications in performing MRI at field strengths of 3 Tesla (T) and above and determine whether the current clinical safety guidelines are appropriate. Method: References were sourced from The Cochrane Library, Centre for Reviews and Dissemination Science Direct, PubMed and Google Scholar. Related websites searched included The British Institute of Radiology, Society of Radiographers, Royal College of Radiologists, The Institution of Engineering and Technology, IMRSER (Institute for Magnetic Resonance Safety, Education, and Research), MagNet (NHS PASA). References supplied in retrieved papers were also checked for potential relevance. The use of consistent search terminology and inclusion and exclusion criteria ensured quality and provided rigour to conclusions drawn. Conclusion: According to the literature retrieved, the current body of knowledge has allowed safety guidelines to be established for patient safety and these are both appropriate and valid at field strengths of 3 T.

  6. RIEGER-TYPE PERIODICITY DURING SOLAR CYCLES 14–24: ESTIMATION OF DYNAMO MAGNETIC FIELD STRENGTH IN THE SOLAR INTERIOR

    Energy Technology Data Exchange (ETDEWEB)

    Gurgenashvili, Eka; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil; Ramishvili, Giorgi; Shergelashvili, Bidzina [Abastumani Astrophysical Observatory at Ilia State University, Tbilisi, Georgia (United States); Oliver, Ramon; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain); Hanslmeier, Arnold [IGAM, Institute of Physics, University of Graz, Universitätsplatz 5, A-8010 Graz (Austria); Poedts, Stefaan, E-mail: teimuraz.zaqarashvili@uni-graz.at [Centre for Mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, B-3001, Leuven (Belgium)

    2016-07-20

    Solar activity undergoes a variation over timescales of several months known as Rieger-type periodicity, which usually occurs near maxima of sunspot cycles. An early analysis showed that the periodicity appears only in some cycles and is absent in other cycles. But the appearance/absence during different cycles has not been explained. We performed a wavelet analysis of sunspot data from the Greenwich Royal Observatory and the Royal Observatory of Belgium during cycles 14–24. We found that the Rieger-type periods occur in all cycles, but they are cycle dependent: shorter periods occur during stronger cycles. Our analysis revealed a periodicity of 185–195 days during the weak cycles 14–15 and 24 and a periodicity of 155–165 days during the stronger cycles 16–23. We derived the dispersion relation of the spherical harmonics of the magnetic Rossby waves in the presence of differential rotation and a toroidal magnetic field in the dynamo layer near the base of the convection zone. This showed that the harmonics of fast Rossby waves with m = 1 and n = 4, where m ( n ) indicates the toroidal (poloidal) wavenumbers, perfectly fit with the observed periodicity. The variation of the toroidal field strength from weaker to stronger cycles may lead to the different periods found in those cycles, which explains the observed enigmatic feature of the Rieger-type periodicity. Finally, we used the observed periodicity to estimate the dynamo field strength during cycles 14–24. Our estimations suggest a field strength of ∼40 kG for the stronger cycles and ∼20 kG for the weaker cycles.

  7. Diversity and abundance of Beauveria bassiana in soils, stink bugs and plant tissues of common bean from organic and conventional fields.

    Science.gov (United States)

    Ramos, Yordanys; Portal, Orelvis; Lysøe, Erik; Meyling, Nicolai V; Klingen, Ingeborg

    2017-11-01

    The aim of this study was to evaluate the natural occurrence of Beauveria spp. in soil, from infections in the stink bug Piezodorus guildinii, an important pest of common bean (Phaseolus vulgaris) and as endophytes in bean plant tissue. Twelve conventional and 12 organic common bean fields in the Villa Clara province, Cuba were sampled from September 2014 to April 2015. One hundred and fifty Beauveria isolates were obtained from soil samples, bean plant parts and stink bugs. The overall frequency of occurrence of Beauveria isolates in conventional fields (8.4%) was significantly lower than that in organic fields (23.6%). Beauveria were also obtained significantly more frequently from bean roots in organic fields (15.0%) compared to bean roots in conventional fields (3.3%). DNA sequencing of the intergenic Bloc region was performed for Beauveria species identification. All isolates where characterized as Beauveria bassiana (Balsamo-Crivelli) Vuillemin, and clustered with isolates of neotropical origin previously described as AFNEO_1. The Cuban B. bassiana isolates formed five clusters in the phylogeny. Isolates of two clusters originated from all four locations, organic and conventional fields, as well as soil, plants and stink bugs. Organic fields contained isolates of all five clusters while conventional fields only harbored isolates of the two most frequent ones. Mating type PCR assays revealed that mating type distribution was skewed, with MAT1/MAT2 proportion of 146/4, indicating limited potential for recombination. The present study is the first to report of B. bassiana as a naturally occurring endophyte in common bean. Further, it shows that B. bassiana occurs naturally in diverse environments of common bean fields, and constitutes a potential reservoir of natural enemies against pest insects particularly in organic fields. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The dependence of potential well formation on the magnetic field strength and electron injection current in a polywell device

    International Nuclear Information System (INIS)

    Cornish, S.; Gummersall, D.; Carr, M.; Khachan, J.

    2014-01-01

    A capacitive probe has been used to measure the plasma potential in a polywell device in order to observe the dependence of potential well formation on magnetic field strength, electron injection current, and polywell voltage bias. The effectiveness of the capacitive probe in a high energy electron plasma was determined by measuring the plasma potential of a planar diode with an axial magnetic field. The capacitive probe was translated along the axis of one of the field coils of the polywell, and the spatial profile of the potential well was measured. The confinement time of electrons in the polywell was estimated with a simple analytical model which used the experimentally observed potential well depths, as well as a simulation of the electron trajectories using particle orbit theory

  9. Analytical solutions of the Schroedinger equation for a two-dimensional exciton in magnetic field of arbitrary strength

    Energy Technology Data Exchange (ETDEWEB)

    Hoang-Do, Ngoc-Tram; Hoang, Van-Hung; Le, Van-Hoang [Department of Physics, Ho Chi Minh City University of Pedagogy, 280 An Duong Vuong Street, District 5, Ho Chi Minh City (Viet Nam)

    2013-05-15

    The Feranchuk-Komarov operator method is developed by combining with the Levi-Civita transformation in order to construct analytical solutions of the Schroedinger equation for a two-dimensional exciton in a uniform magnetic field of arbitrary strength. As a result, analytical expressions for the energy of the ground and excited states are obtained with a very high precision of up to four decimal places. Especially, the precision is uniformly stable for the whole range of the magnetic field. This advantage appears due to the consideration of the asymptotic behaviour of the wave-functions in strong magnetic field. The results could be used for various physical analyses and the method used here could also be applied to other atomic systems.

  10. Field Evidence Supporting Conventional Onion Curing Practices as a Strategy To Mitigate Escherichia coli Contamination from Irrigation Water.

    Science.gov (United States)

    Wright, Daniel; Feibert, Erik; Reitz, Stuart; Shock, Clint; Waite-Cusic, Joy

    2018-03-01

    The Produce Safety Rule of the U.S. Food Safety Modernization Act includes restrictions on the use of agricultural water of poor microbiological quality. Mitigation options for poor water quality include the application of an irrigation-to-harvest interval of onion production includes an extended irrigation-to-harvest interval (onion fields (randomized block design; n = 5) via drip tape on the final day of irrigation. Onions remained undisturbed for 7 days and were then lifted to the surface to cure for an additional 21 days before harvest. Water, onions, and soil were tested for presence of rifampin-resistant E. coli. One day after irrigation, 13.3% of onions (20 of 150) receiving the poorest quality water (3 log CFU/mL) tested positive for E. coli; this prevalence was reduced to 4% (6 of 150 onions) after 7 days. Regardless of inoculum level, E. coli was not detected on any onions beyond 15 days postirrigation. These results support conventional dry bulb onion curing practices as an effective strategy to mitigate microbiological concerns associated with poor quality irrigation water.

  11. Determining of the electric field strength using high frequency broadband measurements

    Directory of Open Access Journals (Sweden)

    Vulević Branislav D.

    2017-01-01

    Full Text Available Exposure of humans to electromagnetic fields of high frequency (above 100 kHz, i.e. radiofrequency radiation from the modern wireless systems, today inevitable is. The purpose of this paper is to highlight the importance of broadband measurements of the electric field of high frequency in order to fast and reliable assessment of human exposure. A practical method of ‘in situ’ measurement the electric field intensity which is related to the frequency range of 3 MHz to 18 GHz, is provided.

  12. Conventional compressive strength parallel to the grain and mechanical resistance of wood against pin penetration and microdrilling established by in-situ semidestructive devices

    Czech Academy of Sciences Publication Activity Database

    Kloiber, Michal; Drdácký, Miloš; Tippner, J.; Hrivnák, J.

    2015-01-01

    Roč. 48, č. 10 (2015), s. 3217-3229 ISSN 1359-5997 R&D Projects: GA MK(CZ) DF11P01OVV001; GA MŠk(CZ) LO1219 Keywords : compressive strength * density * in situ testing * non-destructive testing (NDT) * small size loading jack * wood Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 2.453, year: 2015 http://link.springer.com/article/10.1617/s11527-014-0392-6

  13. Tensile bond strength of different adhesive systems to primary dentin treated by Er:YAG laser and conventional high-speed drill

    Science.gov (United States)

    Marques, Barbara A.; Navarro, Ricardo S.; Silvestre, Fellipe D.; Pinheiro, Sergio L.; Freitas, Patricia M.; Imparato, Jose Carlos P.; Oda, Margareth

    2005-03-01

    The aim of this study was to evaluate the tensile strength of different adhesive systems to primary tooth dentin prepared by high-speed drill and Er:YAG laser (2.94μm). Buccal surfaces of 38 primary canines were ground and flattened with sand paper disks (#120-600 grit) and distributed into five groups (n=15): G1: diamond bur in high-speed drill (HD)+ 35% phosphoric acid (PA)+Single Bond (SB); G2: HD+self-etching One Up Bond F (OUB);G3: Er:YAG laser (KaVo 3- LELO-FOUSP)(4Hz, 80mJ, 25,72J/cm2) (L)+PA+SB, G4: L+SB, G5: L+OUB. The inverted truncated cone samples built with Z-100 composite resin after storage in water (37°C/24h) were submitted to tensile bond strength test on Mini Instron 4442 (0.5mm/min, 500N). The data were analyzed with ANOVA and Tukey Test (pHD+PA+SB and HD+OUB (p=0.000), L+SB showed higher values than L+PA+SB and L+OUB (p=0.0311). Er:YAG laser radiation promoted significant increase of bond strength of different adhesive systems evaluated in the dentin of primary teeth.

  14. CNR considerations for rapid real-time MRI tumor tracking in radiotherapy hybrid devices: Effects of B0 field strength

    International Nuclear Information System (INIS)

    Wachowicz, K.; De Zanche, N.; Yip, E.; Volotovskyy, V.; Fallone, B. G.

    2016-01-01

    Purpose: This work examines the subject of contrast-to-noise ratio (CNR), specifically between tumor and tissue background, and its dependence on the MRI field strength, B 0 . This examination is motivated by the recent interest and developments in MRI/radiotherapy hybrids where real-time imaging can be used to guide treatment beams. The ability to distinguish a tumor from background tissue is of primary importance in this field, and this work seeks to elucidate the complex relationship between the CNR and B 0 that is too often assumed to be purely linear. Methods: Experimentally based models of B 0 -dependant relaxation for various tumor and normal tissues from the literature were used in conjunction with signal equations for MR sequences suitable for rapid real-time imaging to develop field-dependent predictions for CNR. These CNR models were developed for liver, lung, breast, glioma, and kidney tumors for spoiled gradient-echo, balanced steady-state free precession (bSSFP), and single-shot half-Fourier fast spin echo sequences. Results: Due to the pattern in which the relaxation properties of tissues are found to vary over B 0 field (specifically the T 1 time), there was always an improved CNR at lower fields compared to linear dependency. Further, in some tumor sites, the CNR at lower fields was found to be comparable to, or sometimes higher than those at higher fields (i.e., bSSFP CNR for glioma, kidney, and liver tumors). Conclusions: In terms of CNR, lower B 0 fields have been shown to perform as well or better than higher fields for some tumor sites due to superior T 1 contrast. In other sites this effect was less pronounced, reversing the CNR advantage. This complex relationship between CNR and B 0 reveals both low and high magnetic fields as viable options for tumor tracking in MRI/radiotherapy hybrids.

  15. Controlled Aloin Release from Crosslinked Polyacrylamide Hydrogels: Effects of Mesh Size, Electric Field Strength and a Conductive Polymer

    Directory of Open Access Journals (Sweden)

    Anuvat Sirivat

    2013-10-01

    Full Text Available The aim of this paper is to investigate the effects of hydrogel mesh size, a conductive polymer, and electric field strength on controlled drug delivery phenomena using drug-loaded polyacrylamide hydrogels prepared at various crosslinking ratios both with and without a conductive polymer system. Poly(p-phenylene vinylene, PPV, as the model conductive polymer, was used to study its ability to control aloin released from aloin-doped poly(p-phenylene vinylene/polyacrylamide hydrogel (aloin-doped PPV/PAAM. In the passive release, the diffusion of aloin from five aloin-doped PPV/PAAM hydrogel systems each was delayed ranging from during the first three hours to during the first 14 h due to the ionic interaction between the anionic drug and PPV. After the delayed periods, aloin could diffuse continuously into the buffer solution through the PAAM matrix. The amount of aloin released from the aloin-doped PPV/PAAM rose with increasing electric field strength as a result of the three mechanisms: the expansion of PPV chains inside the hydrogel, iontophoresis, and the electroporation of the matrix pore size, combined. Furthermore, the conductive polymer and the electric field could be used in combination to regulate the amount of release drug to a desired level, to control the release rate, and to switch the drug delivery on/off.

  16. Determination of the electric field strength of filamentary DBDs by CARS-based four-wave mixing

    Science.gov (United States)

    Böhm, P.; Kettlitz, M.; Brandenburg, R.; Höft, H.; Czarnetzki, U.

    2016-10-01

    It is demonstrated that a four-wave mixing technique based on coherent anti-Stokes Raman spectroscopy (CARS) can determine the electric field strength of a pulsed-driven filamentary dielectric barrier discharge (DBD) of 1 mm gap, using hydrogen as a tracer medium in nitrogen at atmospheric pressure. The measurements are presented for a hydrogen admixture of 10%, but even 5% H2 admixture delivers sufficient infrared signals. The lasers do not affect the discharge by photoionization or by other radiation-induced processes. The absolute values of the electric field strength can be determined by the calibration of the CARS setup with high voltage amplitudes below the ignition threshold of the arrangement. This procedure also enables the determination of the applied breakdown voltage. The alteration of the electric field is observed during the internal polarity reversal and the breakdown process. One advantage of the CARS technique over emission-based methods is that it can be used independently of emission, e.g. in the pre-phase and in between two consecutive discharges, where no emission occurs at all.

  17. An experimental study on the effects of temperature and magnetic field strength on the magnetorheological fluid stability and MR effect.

    Science.gov (United States)

    Rabbani, Yahya; Ashtiani, Mahshid; Hashemabadi, Seyed Hassan

    2015-06-14

    In this study, the stability and rheological properties of a suspension of carbonyl iron microparticles (CIMs) in silicone oil were investigated within a temperature range of 10 to 85 °C. The effect of adding two hydrophobic (stearic and palmitic) acids on the stability and magnetorheological effect of a suspension of CIMs in silicone oil was studied. According to the results, for preparing a stable and efficient magnetorheological (MR) fluid, additives should be utilized. Therefore, 3 wt% of stearic acid was added to the MR fluid which led to an enhancement of the fluid stability over 92% at 25 °C. By investigating shear stress variation due to the changes in the shear rate for acid-based MR fluids, the maximum yield stress was obtained by fitting the Bingham plastic rheological model at high shear rates. Based on the existing correlations of yield stress and either temperature or magnetic field strength, a new model was fitted to the experimental data to monitor the simultaneous effect of magnetic field strength and temperature on the maximum yield stress. The results demonstrated that as the magnetic field intensified or the temperature decreased, the maximum yield stress increased dramatically. In addition, when the MR fluid reached its magnetic saturation, the viscosity of fluid depended only on the shear rate.

  18. Strength-limited magnetic field intensity of toroidal magnet systems fabricated or the base of layer-by-layer shrouded solenoids

    International Nuclear Information System (INIS)

    Litvinnko, Yu.A.

    1982-01-01

    The possibilities, as to the ultimate magnetic field strength, of tokamak magnet systems made on the base of layer-by-laeyer shrouded coils are considered numerically. The toroidal magnet system is considered which consists of N skewe, layer-by-layer shrouded, equistrong coils in the ideal torus approximation. The dependences of the ragnetic field strength on the internal- and external torus radii, pulse duration and aspect ratio for copper coils shrouded with fiberglass are calculated as an example. The analysis of the obtained results shows that using of the layer-by-layer shrouding scheme for toroidal solenoid coils leads to a considerable growth of the ultimate magnetic field strengths in a wide duration range. For example, the limiting field strength along the toroidal solenoid axis of the considered type inside the ''FT'' installation toroidal solenoid at equivalent field pulse duration of approximately 0.3 s reaches H 0 =1.3zx10 7 A/m

  19. International activities in HF sky-wave field-strength estimation (period 1956-1991

    Directory of Open Access Journals (Sweden)

    P. A. Bradley

    1998-06-01

    Full Text Available Methods for the determination of the strengths of radio signals reflected from the ionosphere and propagated to distant locations are required for service planning and circuit operation. Efforts are described following World War II to arrive at agreed procedures and some of the features of the various empirical prediction methods that have been formulated over the years are discussed. The problems are highlighted of determining a "best" method from among those available. Measurement data collected for this purpose are reviewed and attention is drawn to their limitations of accuracy and coverage. Even comparison of predicted and measured values is not straightforward, and the techniques that have been developed to do this are considered.

  20. Unitarity corrections and high field strengths in high energy hard collisions

    International Nuclear Information System (INIS)

    Kovchegov, Y.V.; Mueller, A.H.

    1997-01-01

    Unitarity corrections to the BFKL description of high energy hard scattering are viewed in large N c QCD in light-cone quantization. In a center of mass frame unitarity corrections to high energy hard scattering are manifestly perturbatively calculable and unrelated to questions of parton saturation. In a frame where one of the hadrons is initially at rest unitarity corrections are related to parton saturation effects and involve potential strengths A μ ∝1/g. In such a frame we describe the high energy scattering in terms of the expectation value of a Wilson loop. The large potentials A μ ∝1/g are shown to be pure gauge terms allowing perturbation theory to again describe unitarity corrections and parton saturation effects. Genuine nonperturbative effects only come in at energies well beyond those energies where unitarity constraints first become important. (orig.)

  1. Can Images Obtained With High Field Strength Magnetic Resonance Imaging Reduce Contouring Variability of the Prostate?

    International Nuclear Information System (INIS)

    Usmani, Nawaid; Sloboda, Ron; Kamal, Wafa; Ghosh, Sunita; Pervez, Nadeem; Pedersen, John; Yee, Don; Danielson, Brita; Murtha, Albert; Amanie, John; Monajemi, Tara

    2011-01-01

    Purpose: The objective of this study is to determine whether there is less contouring variability of the prostate using higher-strength magnetic resonance images (MRI) compared with standard MRI and computed tomography (CT). Methods and Materials: Forty patients treated with prostate brachytherapy were accrued to a prospective study that included the acquisition of 1.5-T MR and CT images at specified time points. A subset of 10 patients had additional 3.0-T MR images acquired at the same time as their 1.5-T MR scans. Images from each of these patients were contoured by 5 radiation oncologists, with a random subset of patients repeated to quantify intraobserver contouring variability. To minimize bias in contouring the prostate, the image sets were placed in folders in a random order with all identifiers removed from the images. Results: Although there was less interobserver contouring variability in the overall prostate volumes in 1.5-T MRI compared with 3.0-T MRI (p < 0.01), there was no significant differences in contouring variability in the different regions of the prostate between 1.5-T MRI and 3.0-T MRI. MRI demonstrated significantly less interobserver contouring variability in both 1.5-T and 3.0-T compared with CT in overall prostate volumes (p < 0.01, p = 0.01), with the greatest benefits being appreciated in the base of the prostate. Overall, there was less intraobserver contouring variability than interobserver contouring variability for all of the measurements analyzed. Conclusions: Use of 3.0-T MRI does not demonstrate a significant improvement in contouring variability compared with 1.5-T MRI, although both magnetic strengths demonstrated less contouring variability compared with CT.

  2. Glyphosate-tolerant soybeans remain compositionally equivalent to conventional soybeans (Glycine max L.) during three years of field testing.

    Science.gov (United States)

    McCann, Melinda C; Liu, Keshun; Trujillo, William A; Dobert, Raymond C

    2005-06-29

    Previous studies have shown that the composition of glyphosate-tolerant soybeans (GTS) and selected processed fractions was substantially equivalent to that of conventional soybeans over a wide range of analytes. This study was designed to determine if the composition of GTS remains substantially equivalent to conventional soybeans over the course of several years and when introduced into multiple genetic backgrounds. Soybean seed samples of both GTS and conventional varieties were harvested during 2000, 2001, and 2002 and analyzed for the levels of proximates, lectin, trypsin inhibitor, and isoflavones. The measured analytes are representative of the basic nutritional and biologically active components in soybeans. Results show a similar range of natural variability for the GTS soybeans as well as conventional soybeans. It was concluded that the composition of commercial GTS over the three years of breeding into multiple varieties remains equivalent to that of conventional soybeans.

  3. The value of conventional high-field MRI in MS in the light of the McDonald criteria: a literature review

    DEFF Research Database (Denmark)

    Larsen, Line Sofie Lunde; Larsson, H B W; Frederiksen, Jette Lautrup Battistini

    2010-01-01

    The diagnosis of MS is based on the revised McDonald criteria and is multidisciplinary. Both clinical and paraclinical measures are included. High-field magnetic resonance imaging (MRI) is becoming increasingly available and it is therefore necessary to clarify possible advantages of high-field MRI...... multiple sclerosis. Further larger studies of patients with clinically isolated syndromes are needed to settle the question of a diagnostic consequence of high-field imaging in MS. We suggest that the next revision of the McDonald diagnostic criteria include a recommendation of field strength....

  4. Predictivity strength of the spatial variability of phenanthrene sorption across two sandy loam fields

    DEFF Research Database (Denmark)

    Soares, Antonio; Paradelo Pérez, Marcos; Møldrup, Per

    2015-01-01

    Sorption is commonly suggested as the major process underlying the transport and fate of polycyclic aromatic hydrocarbons (PAHs) in soils. However, studies focusing in spatial variability at the field scale in particular are still scarce. In order to investigate the sorption of phenanthrene...

  5. Proton and multinuclear magnetic resonance spectroscopy in the human brain at ultra-high field strength: A review.

    Science.gov (United States)

    Henning, Anke

    2018-03-01

    Magnetic Resonance Spectroscopy (MRS) allows for a non-invasive and non-ionizing determination of in vivo tissue concentrations and metabolic turn-over rates of more than 20 metabolites and compounds in the central nervous system of humans. The aim of this review is to give a comprehensive overview about the advantages, challenges and advances of ultra-high field MRS with regard to methodological development, discoveries and applications from its beginnings around 15 years ago up to the current state. The review is limited to human brain and spinal cord application at field strength of 7T and 9.4T and includes all relevant nuclei ( 1 H, 31 P, 13 C). Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Magnetic field strength requirements to capture superparamagnetic nanoparticles within capillary flow

    International Nuclear Information System (INIS)

    Hallmark, B.; Darton, N. J.; James, T.; Agrawal, P.; Slater, N. K. H.

    2010-01-01

    This article reports the development of a model, with supporting experimental data, which can predict the magnitude of the magnetic flux required to capture superparamagnetic nanoparticles flowing through a plastic capillary micro array. The model takes into account the shape of the magnetic field, the magnetically induced aggregation of the nanoparticles and a criterion to determine whether nanoparticles are held at the capillary wall or not. It was found that the model gave a semi-quantitative match to experimental data showing that, once steered out of the core of the fluid flow, nanoparticles could be held at a capillary wall within a weaker region of magnetic field. This result may have implications for the design of magnets for use in magnetic directed therapy in addition to having implications concerning the design of nanoparticle dosage regimes.

  7. How well do force fields capture the strength of salt bridges in proteins?

    Directory of Open Access Journals (Sweden)

    Mustapha Carab Ahmed

    2018-06-01

    Full Text Available Salt bridges form between pairs of ionisable residues in close proximity and are important interactions in proteins. While salt bridges are known to be important both for protein stability, recognition and regulation, we still do not have fully accurate predictive models to assess the energetic contributions of salt bridges. Molecular dynamics simulation is one technique that may be used study the complex relationship between structure, solvation and energetics of salt bridges, but the accuracy of such simulations depends on the force field used. We have used NMR data on the B1 domain of protein G (GB1 to benchmark molecular dynamics simulations. Using enhanced sampling simulations, we calculated the free energy of forming a salt bridge for three possible lysine-carboxylate ionic interactions in GB1. The NMR experiments showed that these interactions are either not formed, or only very weakly formed, in solution. In contrast, we show that the stability of the salt bridges is overestimated, to different extents, in simulations of GB1 using seven out of eight commonly used combinations of fixed charge force fields and water models. We also find that the Amber ff15ipq force field gives rise to weaker salt bridges in good agreement with the NMR experiments. We conclude that many force fields appear to overstabilize these ionic interactions, and that further work may be needed to refine our ability to model quantitatively the stability of salt bridges through simulations. We also suggest that comparisons between NMR experiments and simulations will play a crucial role in furthering our understanding of this important interaction.

  8. Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning; Comparacao entre tecnica 3D convencional, field-in-field e compensacao eletronica para planejamento de manto

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S., E-mail: pm.lais@gmail.com [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)

    2012-12-15

    External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

  9. Local Electric Field Strength in a Hollow Cathode Determined by Stark Splitting of the 2S Level of Hydrogen Isotopes by Optogalvanic Spectroscopy

    International Nuclear Information System (INIS)

    Perez, C.; Rosa, M. I. de la; Gruetzmacher, K.; Fuentes, L. M.; Gonzalo, A. B.

    2008-01-01

    In this work we present Doppler-free two-photon optogalvanic spectroscopy as a tool to measure the electric field strength in the cathode fall region of a hollow cathode discharge via the Stark splitting of the 2S level of atomic deuterium. The strong electric field strength present in the hollow cathode is determined for various discharge conditions which allows studying the corresponding variations of the cathode fall, and its changes with discharge operation time.

  10. Fiber-Optic Magnetic-Field-Strength Measurement System for Lightning Detection

    Science.gov (United States)

    Gurecki, Jay; Scully, Robert; Davis, Allen; Kirkendall, Clay; Bucholtz, Frank

    2011-01-01

    A fiber-optic sensor system is designed to measure magnetic fields associated with a lightning stroke. Field vector magnitudes are detected and processed for multiple locations. Since physical limitations prevent the sensor elements from being located in close proximity to highly conductive materials such as aluminum, the copper wire sensor elements (3) are located inside a 4-cubic-in. (.66-cubic-cm) plastic housing sensor head and connected to a fiber-optic conversion module by shielded cabling, which is limited to the shortest length feasible. The signal path between the conversion module and the avionics unit which processes the signals are fiber optic, providing enhanced immunity from electromagnetic radiation incident in the vicinity of the measurements. The sensors are passive, lightweight, and much smaller than commercial B-dot sensors in the configuration which measures a three-dimensional magnetic field. The system is expandable, and provides a standard-format output signal for downstream processing. Inside of the sensor head, three small search coils, each having a few turns on a circular form, are mounted orthogonally inside the non-metallic housing. The fiber-optic conversion module comprises three interferometers, one for each search coil. Each interferometer has a high bandwidth optical phase modulator that impresses the signal received from its search coil onto its output. The output of each interferometer travels by fiber optic cable to the avionics unit, and the search coil signal is recovered by an optical phase demodulator. The output of each demodulator is fed to an analog-to-digital converter, whose sampling rate is determined by the maximum expected rate of rise and peak signal magnitude. The output of the digital processor is a faithful reproduction of the coil response to the incident magnetic field. This information is provided in a standard output format on a 50-ohm port that can be connected to any number of data collection and processing

  11. Radial distributions of magnetic field strength in the solar corona as derived from data on fast halo CMEs

    Science.gov (United States)

    Fainshtein, Victor; Egorov, Yaroslav

    2018-03-01

    In recent years, information about the distance between the body of rapid coronal mass ejection (CME) and the associated shock wave has been used to measure the magnetic field in the solar corona. In all cases, this technique allows us to find coronal magnetic field radial profiles B(R) applied to the directions almost perpendicular to the line of sight. We have determined radial distributions of magnetic field strength along the directions close to the Sun-Earth axis. For this purpose, using the "ice-cream cone" model and SOHO/LASCO data, we found 3D characteristics for fast halo coronal mass ejections (HCMEs) and for HCME-related shocks. With these data, we managed to obtain the B(R) distributions as far as ≈43 solar radii from the Sun's center, which is approximately twice as far as those in other studies based on LASCO data. We have concluded that to improve the accuracy of this method for finding the coronal magnetic field we should develop a technique for detecting CME sites moving in the slow and fast solar wind. We propose a technique for selecting CMEs whose central (paraxial) part actually moves in the slow wind.

  12. Radial distributions of magnetic field strength in the solar corona as derived from data on fast halo CMEs

    Directory of Open Access Journals (Sweden)

    Fainshtein V.G.

    2018-03-01

    Full Text Available In recent years, information about the distance between the body of rapid coronal mass ejection (CME and the associated shock wave has been used to measure the magnetic field in the solar corona. In all cases, this technique allows us to find coronal magnetic field radial profiles B(R applied to the directions almost perpendicular to the line of sight. We have determined radial distributions of magnetic field strength along the directions close to the Sun–Earth axis. For this purpose, using the “ice-cream cone” model and SOHO/LASCO data, we found 3D characteristics for fast halo coronal mass ejections (HCMEs and for HCME-related shocks. With these data we managed to obtain the B(R distributions as far as ≈43 solar radii from the Sun's center, which is approximately twice as far as those in other studies based on LASCO data. We have concluded that to improve the accuracy of this method for finding the coronal magnetic field we should develop a technique for detecting CME parts moving in the slow and fast solar wind. We propose a technique for selecting CMEs whose central (paraxial part actually moves in the slow wind.

  13. Complete genome sequence of the biofilm-forming Curtobacterium sp. strain BH-2-1-1, isolated from lettuce (Lactuca sativa) originating from a conventional field in Norway.

    Science.gov (United States)

    Dees, Merete Wiken; Brurberg, May Bente; Lysøe, Erik

    2016-12-01

    Here, we present the 3,795,952 bp complete genome sequence of the biofilm-forming Curtobacterium sp. strain BH-2-1-1, isolated from conventionally grown lettuce ( Lactuca sativa ) from a field in Vestfold, Norway. The nucleotide sequence of this genome was deposited into NCBI GenBank under the accession CP017580.

  14. The value of conventional high-field MRI in MS in the light of the McDonald criteria: a literature review.

    Science.gov (United States)

    Lunde Larsen, L S; Larsson, H B W; Frederiksen, J L

    2010-09-01

    The diagnosis of MS is based on the revised McDonald criteria and is multidisciplinary. Both clinical and paraclinical measures are included. High-field magnetic resonance imaging (MRI) is becoming increasingly available and it is therefore necessary to clarify possible advantages of high-field MRI in MS. The aim of this paper was to review MRI studies in MS where a direct comparison of MRI at high field with MRI at 1-1.5 tesla (T) had been performed. The studies evaluated were found by searching Pubmed with relevant terms including MeSH terms. The reviewed studies all found the conspicuity of lesions to be better at high field. Of the seven studies, six found more and bigger lesions at high-field MRI. In the present paper, the relevant MRI sequences are evaluated in detail. The detection of more lesions at high-field strength did not seem to lead to earlier diagnosis of clinically definite multiple sclerosis. Further larger studies of patients with clinically isolated syndromes are needed to settle the question of a diagnostic consequence of high-field imaging in MS. We suggest that the next revision of the McDonald diagnostic criteria include a recommendation of field strength.

  15. Microhardness, strength and strain field characterization of self-reacting friction stir and plug welds of dissimilar aluminum alloys

    Science.gov (United States)

    Horton, Karla Renee

    Friction stir welding (FSW) is a solid state welding process with potential advantages for aerospace and automotive industries dealing with light alloys. Self-reacting friction stir welding (SR-FSW) is one variation of the FSW process being developed at the National Aeronautics and Space Administration (NASA) for use in the fabrication of propellant tanks. Friction plug welding is used to seal the exit hole that remains in a circumferential SR-FSW. This work reports on material properties and strain patterns developed in a SR-FSW with a friction plug weld. Specifically, this study examines the behavior of a SR-FSW formed between an AA2014-T6 plate on the advancing side and an AA2219-T87 plate on the retreating side and a SR-FSW (AA2014-T6 to AA2219-T87) with a 2219-T87 plug weld. This study presents the results of a characterization of the micro-hardness, joint strength, and strain field characterization of SR-FSW and FPW joints tested at room temperature and cryogenic temperatures. The initial weld microstructure analysis showed a nugget region with fine grains and a displaced weld seam from the advancing side past the thermo-mechanical affected zone (TMAZ) into the nugget region. The displaced material shared the same hardness as the parent material. Dynamic recrystallization was observed in the SR-FSW zone and the displaced weld seam region. The welds revealed a fine grain structure in the SR-FSW zone with a sharp demarcation seen on the advancing side and fairly diffuse flow observed on the retreating side. The parent material hardness is 145 HV700g with a drop in hardness starting at the HAZ to 130 HV700g. The hardness further drops in the TMAZ to118 HV700g with an increase representing a dispersed interface of AA2014-T6 material to 135 HV700g. The hardness then drops significantly within the nugget region to 85 HV700g followed by an increase through the retreating side TMAZ into the HAZ to 135 HV 700g. There was a sharp increase in the hardness value within

  16. The intra-observer reproducibility of cardiovascular magnetic resonance myocardial feature tracking strain assessment is independent of field strength

    International Nuclear Information System (INIS)

    Schuster, Andreas; Morton, Geraint; Hussain, Shazia T.

    2013-01-01

    Background: Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a promising novel method for quantification of myocardial wall mechanics from standard steady-state free precession (SSFP) images. We sought to determine whether magnetic field strength affects the intra-observer reproducibility of CMR-FT strain analysis. Methods: We studied 2 groups, each consisting of 10 healthy subjects, at 1.5 T or 3 T Analysis was performed at baseline and after 4 weeks using dedicated CMR-FT prototype software (Tomtec, Germany) to analyze standard SSFP cine images. Right ventricular (RV) and left ventricular (LV) longitudinal strain (Ell RV and Ell LV ) and LV long-axis radial strain (Err LAX ) were derived from the 4-chamber cine, and LV short-axis circumferential and radial strains (Ecc SAX , Err SAX ) from the short-axis orientation. Strain parameters were assessed together with LV ejection fraction (EF) and volumes. Intra-observer reproducibility was determined by comparing the first and the second analysis in both groups. Results: In all volunteers resting strain parameters were successfully derived from the SSFP images. There was no difference in strain parameters, volumes and EF between field strengths (p > 0.05). In general Ecc SAX was the most reproducible strain parameter as determined by the coefficient of variation (CV) at 1.5 T (CV 13.3% and 46% global and segmental respectively) and 3 T (CV 17.2% and 31.1% global and segmental respectively). The least reproducible parameter was Ell RV (CV 1.5 T 28.7% and 53.2%; 3 T 43.5% and 63.3% global and segmental respectively). Conclusions: CMR-FT results are similar with reasonable intra-observer reproducibility in different groups of volunteers at 1.5 T and 3 T. CMR-FT is a promising novel technique and our data indicate that results might be transferable between field strengths. However there is a considerable amount of segmental variability indicating that further refinements are needed before CMR

  17. Convention on the establishment of a security control in the field of nuclear energy. Protocol on the tribunal established by the convention on the establishment of a security control in the field of nuclear energy

    International Nuclear Information System (INIS)

    1957-01-01

    The governments of Germany, Austria, Belgium, Denmark, France, Greece, Ireland, Iceland, Italy, Luxembourg, Norway, Netherlands, Portugal, United Kingdom, Sweden, Switzerland and Turkey, having resolved to promote the development of the production and uses of nuclear energy in the Member countries of the Organisation for European Economic Co-operation between these countries and the harmonisation of national measures; considering that the joint action undertaken to this end in the Organisation is intended to develop the European nuclear industry for purely peaceful ends and must not further any military purpose; considering that at its meeting of' 18 July, 1956, the Council of the Organisation decided to establish to this effect an international security control; considering that by a Decision dated this day the Council has established, within the Organisation, a European Nuclear Energy Agency with the task of pursuing the joint action undertaken; have agreed the present convention. The governments party to the Convention, desirous of determining in accordance with Article 12 of the Convention the organisation of the Tribunal established by the said Article and the status of its judges; have agreed upon the provisions which are annexed to the Convention

  18. Use of CT simulation for treatment of cervical cancer to assess the adequacy of lymph node coverage of conventional pelvic fields based on bony landmarks

    International Nuclear Information System (INIS)

    Finlay, Marisa H.; Ackerman, Ida; Tirona, Romeo G. B.Sc.; Hamilton, Paul; Barbera, Lisa; Thomas, Gillian

    2006-01-01

    Purpose: To assess the adequacy of nodal coverage of 'conventional' pelvic radiation fields for carcinoma of the cervix, with contoured pelvic vessels on simulation computed tomography (CT) as surrogates for lymph node location. Methods and Materials: Pelvic arteries were contoured on non-contrast-enhanced CT simulation images of 43 patients with cervix cancer, FIGO Stages I-III. Vessel contours were hidden, and conventional pelvic fields were outlined: (1) anterior/posterior fields (AP): superior border, L5-S1 interspace; inferior border, obturator foramina; lateral border, 2 centimeters lateral to pelvic brim. (2) Lateral fields (LAT): Anterior border, symphysis pubis; posterior border, S2-S3 interspace. Distances were measured between the following: (1) bifurcation of the common iliac artery and superior border (2) external iliac artery and lateral border of the AP field, and (3) external iliac artery and anterior border of the LAT field. The distances were considered as 'inadequate' if 20 mm. Results: Superiorly, 34 patients (79.1%) had inadequate coverage. On the AP, margins were generous in 19 (44.2%), but inadequate in 9 (20.9%). On the LAT, margins were inadequate in 30 (69.8%) patients. Overall, 41 (95.4%, CI, 84.2%-99.4%) patients had at least 1 inadequate margin, the majority located superiorly. Twenty-four (55.8%; CI, 39.9%-70.9%) patients had at least 1 generous margin, the majority located laterally on the AP field. Conclusion: Conventional pelvic fields based on bony landmarks do not provide optimal lymph node coverage in a substantial proportion of patients and may include excess normal tissue in some. CT simulation with vessel contouring as a surrogate for lymph node localization provides more precise and individualized field delineation

  19. Field of first magnetic flux entry and pinning strength of superconductors for rf application measured with muon spin rotation

    Science.gov (United States)

    Junginger, T.; Abidi, S. H.; Maffett, R. D.; Buck, T.; Dehn, M. H.; Gheidi, S.; Kiefl, R.; Kolb, P.; Storey, D.; Thoeng, E.; Wasserman, W.; Laxdal, R. E.

    2018-03-01

    The performance of superconducting radiofrequency (SRF) cavities used for particle accelerators depends on two characteristic material parameters: field of first flux entry Hentry and pinning strength. The former sets the limit for the maximum achievable accelerating gradient, while the latter determines how efficiently flux can be expelled related to the maximum achievable quality factor. In this paper, a method based on muon spin rotation (μ SR ) is developed to probe these parameters on samples. It combines measurements from two different spectrometers, one being specifically built for these studies and samples of different geometries. It is found that annealing at 1400 °C virtually eliminates all pinning. Such an annealed substrate is ideally suited to measure Hentry of layered superconductors, which might enable accelerating gradients beyond bulk niobium technology.

  20. Conventional resin cation exchangers versus EDI for CACE measurement in power plants. Feasibility and practical field results

    Energy Technology Data Exchange (ETDEWEB)

    Sigrist, Manuel [Swan Systeme AG, Hinwil (Switzerland)

    2017-10-15

    The conductivity measurement after a cation exchanger in power plants with steam turbines was introduced soon after 1950 by Larson and Lane. Due to the simple measuring principle, the sensitivity to ionic contaminations and to its high reliability, the conductivity measurement after a cation exchanger (CACE) has become the most commonly used online analytical method in power plants with steam generators. Swan has investigated electro deionisation (EDI) as substitution of the conventional cation exchange resin and has developed a new conductivity instrument using this principle. This paper provides a description of the conventional method for cation conductivity measurements as well as of the new AMI CACE using EDI method.

  1. Conventional resin cation exchangers versus EDI for CACE measurement in power plants. Feasibility and practical field results

    International Nuclear Information System (INIS)

    Sigrist, Manuel

    2017-01-01

    The conductivity measurement after a cation exchanger in power plants with steam turbines was introduced soon after 1950 by Larson and Lane. Due to the simple measuring principle, the sensitivity to ionic contaminations and to its high reliability, the conductivity measurement after a cation exchanger (CACE) has become the most commonly used online analytical method in power plants with steam generators. Swan has investigated electro deionisation (EDI) as substitution of the conventional cation exchange resin and has developed a new conductivity instrument using this principle. This paper provides a description of the conventional method for cation conductivity measurements as well as of the new AMI CACE using EDI method.

  2. Influence of magnetic field strength and image registration strategy on voxel-based morphometry in a study of Alzheimer's disease.

    Science.gov (United States)

    Marchewka, Artur; Kherif, Ferath; Krueger, Gunnar; Grabowska, Anna; Frackowiak, Richard; Draganski, Bogdan

    2014-05-01

    Multi-centre data repositories like the Alzheimer's Disease Neuroimaging Initiative (ADNI) offer a unique research platform, but pose questions concerning comparability of results when using a range of imaging protocols and data processing algorithms. The variability is mainly due to the non-quantitative character of the widely used structural T1-weighted magnetic resonance (MR) images. Although the stability of the main effect of Alzheimer's disease (AD) on brain structure across platforms and field strength has been addressed in previous studies using multi-site MR images, there are only sparse empirically-based recommendations for processing and analysis of pooled multi-centre structural MR data acquired at different magnetic field strengths (MFS). Aiming to minimise potential systematic bias when using ADNI data we investigate the specific contributions of spatial registration strategies and the impact of MFS on voxel-based morphometry in AD. We perform a whole-brain analysis within the framework of Statistical Parametric Mapping, testing for main effects of various diffeomorphic spatial registration strategies, of MFS and their interaction with disease status. Beyond the confirmation of medial temporal lobe volume loss in AD, we detect a significant impact of spatial registration strategy on estimation of AD related atrophy. Additionally, we report a significant effect of MFS on the assessment of brain anatomy (i) in the cerebellum, (ii) the precentral gyrus and (iii) the thalamus bilaterally, showing no interaction with the disease status. We provide empirical evidence in support of pooling data in multi-centre VBM studies irrespective of disease status or MFS. Copyright © 2013 Wiley Periodicals, Inc.

  3. Quantitative susceptibility mapping across two clinical field strengths: Contrast-to-noise ratio enhancement at 1.5T.

    Science.gov (United States)

    Ippoliti, Matteo; Adams, Lisa C; Winfried, Brenner; Hamm, Bernd; Spincemaille, Pascal; Wang, Yi; Makowski, Marcus R

    2018-04-16

    Quantitative susceptibility mapping (QSM) is an MRI postprocessing technique that allows quantification of the spatial distribution of tissue magnetic susceptibility in vivo. Contributing sources include iron, blood products, calcium, myelin, and lipid content. To evaluate the reproducibility and consistency of QSM across clinical field strengths of 1.5T and 3T and to optimize the contrast-to-noise ratio (CNR) at 1.5T through bandwidth tuning. Prospective. Sixteen healthy volunteers (10 men, 6 women; age range 24-37; mean age 27.8 ± 3.2 years). 1.5T and 3T systems from the same vendor. Four spoiled gradient echo (SPGR) sequences were designed with different acquisition bandwidths. QSM reconstruction was achieved through a nonlinear morphology-enabled dipole inversion (MEDI) algorithm employing L1 regularization. CNR was calculated in seven regions of interest (ROIs), while reproducibility and consistency of QSM measurements were evaluated through voxel-based and region-specific linear correlation analyses and Bland-Altman plots. Interclass correlation, Wilcoxon rank sum test, linear regression analysis, Bland-Altman analysis, Welch's t-test. CNR analysis showed a statistically significant (P limits of agreement from -18.7 to 25.8 ppb) in the ROI-based analysis, while the correlation was found to be good for the voxel-based analysis of averaged maps (R ≥ 0.90, widest limits of agreement from -9.3 to 9.1 ppb). CNR of QSM images reconstructed from 1.5T acquisitions can be enhanced through bandwidth tuning. MEDI-based QSM reconstruction demonstrated to be reproducible and consistent both across field strengths (1.5T and 3T) and bandwidth variation. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  4. Study of two novel large-field-of-view image intensifiers versus conventional chest radiography with use of FROC methods and simulated pulmonary nodules

    International Nuclear Information System (INIS)

    Winter, L.H.L.; Chakraborty, D.P.; Van Waes, P.F.G.M.; Puylaert, C.B.A.J.

    1989-01-01

    Two novel large-field-of-view image intensifier (LFOV 1.1) tubes have been introduced whose image area makes them suitable for chest imaging. Both modalities present a 100-mm hard-copy image to the radiologist. A pulmonary nodule performance experiment was done to compare the diagnostic accuracy of these tubes with conventional full-size chest images. The data were analyzed with the maximum-likelihood FROCFIT program. The relative ranking in terms of decreasing A1 values was TLX, Siemens 43-cm mode, conventional radiography, and Siemens 57-cm mode

  5. Electric field strength and focality in electroconvulsive therapy and magnetic seizure therapy: a finite element simulation study

    Science.gov (United States)

    Deng, Zhi-De; Lisanby, Sarah H.; Peterchev, Angel V.

    2011-02-01

    We present the first computational study comparing the electric field induced by various electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) paradigms. Four ECT electrode configurations (bilateral, bifrontal, right unilateral, and focal electrically administered seizure therapy) and three MST coil configurations (circular, cap, and double cone) were modeled. The model incorporated a modality-specific neural activation threshold. ECT (0.3 ms pulse width) and MST induced the maximum electric field of 2.1-2.5 V cm-1 and 1.1-2.2 V cm-1 in the brain, corresponding to 6.2-7.2 times and 1.2-2.3 times the neural activation threshold, respectively. The MST electric field is more confined to the superficial cortex compared to ECT. The brain volume stimulated was much larger with ECT (up to 100%) than with MST (up to 8.2%). MST with the double-cone coil was the most focal, and bilateral ECT was the least focal. Our results suggest a possible biophysical explanation of the reduced side effects of MST compared to ECT. Our results also indicate that the conventional ECT pulse amplitude (800-900 mA) is much higher than necessary for seizure induction. Reducing the ECT pulse amplitude should be explored as a potential means of diminishing side effects.

  6. 3 July 1985: Convention signed in Brussels on 31 January 1963, supplementary to the Paris Convention of 29 July 1960 on Third Party Liability in the Field of Nuclear Energy and Act approving the Protocols to amend the Paris Convention and the Brussels Supplementary Convention

    International Nuclear Information System (INIS)

    1985-01-01

    This Act refers to the Brussels Supplementary Convention approved by Belgium in 1966 and ratified on 20 August 1985 and approves ratification of the Protocols of 16 November 1982 to amend the Paris Convention and the Brussels Supplementary Convention respectively. The Protocols are reproduced in French, Dutch and German. (NEA) [fr

  7. Analysis of the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy

    Directory of Open Access Journals (Sweden)

    Song-Lin Wang

    2017-04-01

    Full Text Available Objective: To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy. Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42 and the three-dimensional conformal radiotherapy group (n=42 according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated. Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3 +,CD4 +, and CD4 +/CD8 + were significantly elevated, while CD8 + was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions: The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.

  8. Chemical shift-selective snapshot FLASH MR imaging in combination with inversion-recovery T1 contrast at different field strengths

    International Nuclear Information System (INIS)

    Matthaei, D.; Haase, A.; Henrich, D.; Duhmke, E.

    1991-01-01

    With fast MR imaging, chemical shift contract becomes available to the clinician in seconds. The purpose of this paper is to evaluate the combination of chemical shift selective (CHESS) MR imaging using the snapshot FLASH MR method with the inversion-recovery technique and to obtain information concerning the signal-to-noise and chemical shift with the presaturation method at different field strengths. Investigations with volunteers and experimental animals were done at 2 and 3 T (whole body) and in a 4.7-T animal image. For the inversion-recovery experiments, saturation was done before every snapshot FLASH image. With increasing field strength due to signal-to-noise and chemical shift advantages, the method performs better. Increasing T1 values are also important at high field strengths. The combined technique is useful only for T1 water images with fat saturation. It also allows fast quantification of T1 in water-containing organs and pathologic processes. At high field strengths, fast CHESS and T1 imaging promise fast quantitative information. This is a possible argument for clinical high-field-strength MR imagining along with MR spectroscopy

  9. The influence of magnetic field strength in ionization stage on ion transport between two stages of a double stage Hall thruster

    International Nuclear Information System (INIS)

    Yu Daren; Song Maojiang; Li Hong; Liu Hui; Han Ke

    2012-01-01

    It is futile for a double stage Hall thruster to design a special ionization stage if the ionized ions cannot enter the acceleration stage. Based on this viewpoint, the ion transport under different magnetic field strengths in the ionization stage is investigated, and the physical mechanisms affecting the ion transport are analyzed in this paper. With a combined experimental and particle-in-cell simulation study, it is found that the ion transport between two stages is chiefly affected by the potential well, the potential barrier, and the potential drop at the bottom of potential well. With the increase of magnetic field strength in the ionization stage, there is larger plasma density caused by larger potential well. Furthermore, the potential barrier near the intermediate electrode declines first and then rises up while the potential drop at the bottom of potential well rises up first and then declines as the magnetic field strength increases in the ionization stage. Consequently, both the ion current entering the acceleration stage and the total ion current ejected from the thruster rise up first and then decline as the magnetic field strength increases in the ionization stage. Therefore, there is an optimal magnetic field strength in the ionization stage to guide the ion transport between two stages.

  10. Simple and versatile modifications allowing time gated spectral acquisition, imaging and lifetime profiling on conventional wide-field microscopes

    International Nuclear Information System (INIS)

    Pal, Robert; Beeby, Andrew

    2014-01-01

    An inverted microscope has been adapted to allow time-gated imaging and spectroscopy to be carried out on samples containing responsive lanthanide probes. The adaptation employs readily available components, including a pulsed light source, time-gated camera, spectrometer and photon counting detector, allowing imaging, emission spectroscopy and lifetime measurements. Each component is controlled by a suite of software written in LabVIEW and is powered via conventional USB ports. (technical note)

  11. Signal-to-noise ratio, T2 , and T2* for hyperpolarized helium-3 MRI of the human lung at three magnetic field strengths.

    Science.gov (United States)

    Komlosi, Peter; Altes, Talissa A; Qing, Kun; Mooney, Karen E; Miller, G Wilson; Mata, Jaime F; de Lange, Eduard E; Tobias, William A; Cates, Gordon D; Mugler, John P

    2017-10-01

    To evaluate T 2 , T2*, and signal-to-noise ratio (SNR) for hyperpolarized helium-3 ( 3 He) MRI of the human lung at three magnetic field strengths ranging from 0.43T to 1.5T. Sixteen healthy volunteers were imaged using a commercial whole body scanner at 0.43T, 0.79T, and 1.5T. Whole-lung T 2 values were calculated from a Carr-Purcell-Meiboom-Gill spin-echo-train acquisition. T2* maps and SNR were determined from dual-echo and single-echo gradient-echo images, respectively. Mean whole-lung SNR values were normalized by ventilated lung volume and administered 3 He dose. As expected, T 2 and T2* values demonstrated a significant inverse relationship to field strength. Hyperpolarized 3 He images acquired at all three field strengths had comparable SNR values and thus appeared visually very similar. Nonetheless, the relatively small SNR differences among field strengths were statistically significant. Hyperpolarized 3 He images of the human lung with similar image quality were obtained at three field strengths ranging from 0.43T and 1.5T. The decrease in susceptibility effects at lower fields that are reflected in longer T 2 and T2* values may be advantageous for optimizing pulse sequences inherently sensitive to such effects. The three-fold increase in T2* at lower field strength would allow lower receiver bandwidths, providing a concomitant decrease in noise and relative increase in SNR. Magn Reson Med 78:1458-1463, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  12. Complete genome sequence of the biofilm-forming Microbacterium sp. strain BH-3-3-3, isolated from conventional field-grown lettuce (Lactuca sativa) in Norway.

    Science.gov (United States)

    Dees, Merete Wiken; Brurberg, May Bente; Lysøe, Erik

    2017-03-01

    The genus Microbacterium contains bacteria that are ubiquitously distributed in various environments and includes plant-associated bacteria that are able to colonize tissue of agricultural crop plants. Here, we report the 3,508,491 bp complete genome sequence of Microbacterium sp. strain BH-3-3-3, isolated from conventionally grown lettuce ( Lactuca sativa ) from a field in Vestfold, Norway. The nucleotide sequence of this genome was deposited into NCBI GenBank under the accession CP017674.

  13. Field-tested technology for gas compression: using high-speed induction motors to replace conventional solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Karina Velloso; Pradurat, Jean Francois [Institut National Polytechnique de Lorraine (INPL), Nancy (France). Converteam Rotating Machines Division

    2009-07-01

    Industry leaders are all concerned about rationalization of electric power use, increase of efficiency and flexibility, environmental impact, installations size and maintenance efforts diminution. The high-speed induction motors are a good solution when addressing these parameters. How this technology works and how using it can help pipelines operators meet growing operational and environmental challenges is the main subject of this paper, that also explain how it can be used to replace conventional solutions. As a conclusion the future opportunities of electric high-speed drive systems application in production, transport and storage for natural gas industry are going to be discussed. (author)

  14. Binocular neurons in parastriate cortex: interocular 'matching' of receptive field properties, eye dominance and strength of silent suppression.

    Directory of Open Access Journals (Sweden)

    Phillip A Romo

    Full Text Available Spike-responses of single binocular neurons were recorded from a distinct part of primary visual cortex, the parastriate cortex (cytoarchitectonic area 18 of anaesthetized and immobilized domestic cats. Functional identification of neurons was based on the ratios of phase-variant (F1 component to the mean firing rate (F0 of their spike-responses to optimized (orientation, direction, spatial and temporal frequencies and size sine-wave-luminance-modulated drifting grating patches presented separately via each eye. In over 95% of neurons, the interocular differences in the phase-sensitivities (differences in F1/F0 spike-response ratios were small (≤ 0.3 and in over 80% of neurons, the interocular differences in preferred orientations were ≤ 10°. The interocular correlations of the direction selectivity indices and optimal spatial frequencies, like those of the phase sensitivies and optimal orientations, were also strong (coefficients of correlation r ≥ 0.7005. By contrast, the interocular correlations of the optimal temporal frequencies, the diameters of summation areas of the excitatory responses and suppression indices were weak (coefficients of correlation r ≤ 0.4585. In cells with high eye dominance indices (HEDI cells, the mean magnitudes of suppressions evoked by stimulation of silent, extra-classical receptive fields via the non-dominant eyes, were significantly greater than those when the stimuli were presented via the dominant eyes. We argue that the well documented 'eye-origin specific' segregation of the lateral geniculate inputs underpinning distinct eye dominance columns in primary visual cortices of mammals with frontally positioned eyes (distinct eye dominance columns, combined with significant interocular differences in the strength of silent suppressive fields, putatively contribute to binocular stereoscopic vision.

  15. In vitro study of relationship between signal intensity and gadolinium-DTPA concentration at high magnetic field strength

    International Nuclear Information System (INIS)

    Shahbazi-Gahrouei, D.; Williams, M.; Allen, B.J.

    2001-01-01

    Although gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) has been used as a contrast material in MRI, it is known that the contrast enhancement effect is not uniform for high concentrations of Gd-DTPA. In order to evaluate the proper pulse sequences for dynamic MRI in aqueous solutions of Gd-DTPA, blood samples and melanoma cells, the signal intensity for several concentrations of Gd-DTPA were measured under inversion recovery T 1 -weighted) at high magnetic field strength (7.0 Tesla). For aqueous solutions of Gd-DTPA, signal intensity correlated linearly with the concentration of Gd-DTPA between 0 mmol/L and 4 mmol/L. Using blood and melanoma cells, signal intensity correlated non-linearly with the concentration of Gd-DTPA between 0 mmol/L and 1.5 mmol/L. For concentrations of more than 4 mmol/L in aqueous solutions of Gd-DTPA, 1 mmol/L in blood and 1.5 mmol/L in melanoma, signal intensity decreased with increased Gd-DTPA concentration. Copyright (2001) Blackwell Science Pty Ltd

  16. Quantitative diffusion tensor MR imaging of the brain: field strength related variance of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) scalars

    International Nuclear Information System (INIS)

    Huisman, Thierry A.G.M.; Loenneker, Thomas; Barta, Gerd; Bellemann, Matthias E.; Hennig, Juergen; Fischer, Joachim E.; Il'yasov, Kamil A.

    2006-01-01

    The objectives were to study the ''impact'' of the magnetic field strength on diffusion tensor imaging (DTI) metrics and also to determine whether magnetic-field-related differences in T2-relaxation times of brain tissue influence DTI measurements. DTI was performed on 12 healthy volunteers at 1.5 and 3.0 Tesla (within 2 h) using identical DTI scan parameters. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were measured at multiple gray and white matter locations. ADC and FA values were compared and analyzed for statistically significant differences. In addition, DTI measurements were performed at different echo times (TE) for both field strengths. ADC values for gray and white matter were statistically significantly lower at 3.0 Tesla compared with 1.5 Tesla (% change between -1.94% and -9.79%). FA values were statistically significantly higher at 3.0 Tesla compared with 1.5 Tesla (% change between +4.04 and 11.15%). ADC and FA values are not significantly different for TE=91 ms and TE=125 ms. Thus, ADC and FA values vary with the used field strength. Comparative clinical studies using ADC or FA values should consequently compare ADC or FA results with normative ADC or FA values that have been determined for the field strength used. (orig.)

  17. Variations in the phytochemical contents and antioxidant capacity of organically and conventionally grown Italian cauliflower (Brassica oleracea L. subsp. botrytis): results from a three-year field study.

    Science.gov (United States)

    Lo Scalzo, Roberto; Picchi, Valentina; Migliori, Carmela Anna; Campanelli, Gabriele; Leteo, Fabrizio; Ferrari, Valentino; Di Cesare, Luigi Francesco

    2013-10-30

    A three-year field study (2009-2011) was performed to evaluate phytochemicals and antioxidant capacities of two genotypes (HF1 Emeraude and the local variety, Velox) of green cauliflower grown under organic and conventional management. The conventional system increased yield, but had little effect on the dry matter, whereas the organic system increased the soluble solids. Phytochemicals and antioxidant capacity showed significant year-to-year variability. During the third year, the scarce rainfall determined a significant increase of total glucosinolates and a general decrease of antioxidants in all samples. Interestingly, in the same year organic plants were less affected by the unfavorable climatic conditions, as they increased ascorbic acid, polyphenols, and carotenoids with respect to conventional ones. The overall results for the three years showed that the two genotypes responded differently. Compared to the conventional system, Velox showed 24, 21, 13, 48, and 44% higher content of ascorbic acid, polyphenols, carotenoids, volatiles, and antioxidant capacity, respectively. In contrast, no significant increase in the phytochemicals or the antioxidant potential was found in organic Emeraude, with the exception of total volatiles (+41%). These findings suggest that organic cultivation may be highly effective for particular cauliflower genotypes.

  18. Responses of conventional and extended-range neutron detectors in mixed radiation fields around a 150-MeV electron LINAC

    International Nuclear Information System (INIS)

    Lin, Yu-Chi; Sheu, Rong-Jiun; Chen, Ang-Yu

    2015-01-01

    This study analyzed the responses of two types of neutron detector in mixed gamma-ray and neutron radiation fields around a 150-MeV electron linear accelerator (LINAC). The detectors were self-assembled, high efficiency, and designed in two configurations: (1) a conventional moderated-type neutron detector based on a large cylindrical He-3 proportional counter; and (2) an extended-range version with an embedded layer of lead in the moderator to increase the detector’s sensitivity to high-energy neutrons. Two sets of the detectors were used to measure neutrons at the downstream and lateral locations simultaneously, where the radiation fields differed considerably in intensities and spectra of gamma rays and neutrons. Analyzing the detector responses through a comparison between calculations and measurements indicated that not only neutrons but also high-energy gamma rays (>5 MeV) triggered the detectors because of photoneutrons produced in the detector materials. In the lateral direction, the contribution of photoneutrons to both detectors was negligible. Downstream of the LINAC, where high-energy photons were abundant, photoneutrons contributed approximately 6% of the response of the conventional neutron detector; however, almost 50% of the registered counts of the extended-range neutron detector were from photoneutrons because of the presence of the detector rather than the effect of the neutron field. Dose readings delivered by extended-range neutron detectors should be interpreted cautiously when used in radiation fields containing a mixture of neutrons and high-energy gamma rays

  19. Rigid body displacement fields of an in-plane-deformable curved beam based on conventional strain definition

    International Nuclear Information System (INIS)

    Moon, Won Joo; Min, Oak Key; Kim, Yong Woo

    1998-01-01

    To improve the convergence and the accuracy of a finite element, the finite element has to describe not only displacement and stress distributions in a static analysis but also rigid body displacements. In this paper, we consider the in-plane-deformable curved beam element to understand the descriptive capability of rigid body displacements of a finite element. We derive the rigid body displacement fields of a single finite element under various essential boundary conditions when the nodal displacements are caused by the rigid body displacement. We also examine the rigid body displacement fields of a quadratic curved beam element by employing the reduced minimization theory

  20. Long-term conventional and no-tillage effects on field hydrology and yields of a dryland crop rotation

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch, SM, tillage as a result of improved soil conditions and water conservation, but information on long-term tillage effects on field hydrology and sustained crop production are needed. Our objective ...

  1. Influences of Biodynamic and Conventional Farming Systems on Quality of Potato (Solanum Tuberosum L.) Crops: Results from Multivariate Analyses of Two Long-Term Field Trials in Sweden.

    Science.gov (United States)

    Kjellenberg, Lars; Granstedt, Artur

    2015-09-15

    The aim of this paper was to present results from two long term field experiments comparing potato samples from conventional farming systems with samples from biodynamic farming systems. The principal component analyses (PCA), consistently exhibited differences between potato samples from the two farming systems. According to the PCA, potato samples treated with inorganic fertilizers exhibited a variation positively related to amounts of crude protein, yield, cooking or tissue discoloration and extract decomposition. Potato samples treated according to biodynamic principles, with composted cow manure, were more positively related to traits such as Quality- and EAA-indices, dry matter content, taste quality, relative proportion of pure protein and biocrystallization value. Distinctions between years, crop rotation and cultivars used were sometimes more significant than differences between manuring systems. Grown after barley the potato crop exhibited better quality traits compared to when grown after ley in both the conventional and the biodynamic farming system.

  2. Influences of Biodynamic and Conventional Farming Systems on Quality of Potato (Solanum Tuberosum L. Crops: Results from Multivariate Analyses of Two Long-Term Field Trials in Sweden

    Directory of Open Access Journals (Sweden)

    Lars Kjellenberg

    2015-09-01

    Full Text Available The aim of this paper was to present results from two long term field experiments comparing potato samples from conventional farming systems with samples from biodynamic farming systems. The principal component analyses (PCA, consistently exhibited differences between potato samples from the two farming systems. According to the PCA, potato samples treated with inorganic fertilizers exhibited a variation positively related to amounts of crude protein, yield, cooking or tissue discoloration and extract decomposition. Potato samples treated according to biodynamic principles, with composted cow manure, were more positively related to traits such as Quality- and EAA-indices, dry matter content, taste quality, relative proportion of pure protein and biocrystallization value. Distinctions between years, crop rotation and cultivars used were sometimes more significant than differences between manuring systems. Grown after barley the potato crop exhibited better quality traits compared to when grown after ley in both the conventional and the biodynamic farming system.

  3. Act of 18 July 1966 on Third Party Liability in the Field of Nuclear Energy, establishing certain measures regarding implementation of the Paris Convention and its additional protocol

    International Nuclear Information System (INIS)

    1966-01-01

    This Act on nuclear third party liability lays down that certain Articles (definitions, liability, scope and amounts of liability, insurance) of the Convention on Third Party Liability in the Field of Nuclear Energy (Paris Convention) are immediately applicable in Belgium. It stipulates that a nuclear operator is recognised as such by the King when he furnishes proof that he has taken out insurance or other financial security to cover his liability under this Act, without prejudice to implementation of legal and regulatory provisions on protection of the population against the hazards of ionizing radiations. Finally, the operator of a nuclear installation must take out and maintain, for each installation, insurance approved by the appropriate authorities; if the State itself operates a nuclear installation, it has no obligation to take out insurance or other financial security. (NEA) [fr

  4. Effect of magnetic field strength on NMR-based metabonomic human urine data. Comparative study of 250, 400, 500, and 800 MHz

    DEFF Research Database (Denmark)

    Bertram, Hanne Christine; Malmendal, Anders; Petersen, Bent O.

    2007-01-01

    Metabonomic analysis of urine utilizing high-resolution NMR spectroscopy and chemometric techniques has proven valuable in characterizing the biochemical response to an intervention. To assess the effect of magnetic field strength on information contained in NMR-based metabonomic data sets, 1H NMR...

  5. Optimizing the Relaxivity of MRI Probes at High Magnetic Field Strengths With Binuclear GdIII Complexes

    Directory of Open Access Journals (Sweden)

    Loredana Leone

    2018-05-01

    Full Text Available The key criteria to optimize the relaxivity of a Gd(III contrast agent at high fields (defined as the region ≥ 1.5 T can be summarized as follows: (i the occurrence of a rotational correlation time τR in the range of ca. 0.2–0.5 ns; (ii the rate of water exchange is not critical, but a τM < 100 ns is preferred; (iii a relevant contribution from water molecules in the second sphere of hydration. In addition, the use of macrocycle-based systems ensures the formation of thermodynamically and kinetically stable Gd(III complexes. Binuclear Gd(III complexes could potentially meet these requirements. Their efficiency depends primarily on the degree of flexibility of the linker connecting the two monomeric units, the absence of local motions and the presence of contribution from the second sphere water molecules. With the aim to maximize relaxivity (per Gd over a wide range of magnetic field strengths, two binuclear Gd(III chelates derived from the well-known macrocyclic systems DOTA-monopropionamide and HPDO3A (Gd2L1 and Gd2L2, respectively were synthesized through a multistep synthesis. Chemical Exchange Saturation Transfer (CEST experiments carried out on Eu2L2 at different pH showed the occurrence of a CEST effect at acidic pH that disappears at neutral pH, associated with the deprotonation of the hydroxyl groups. Then, a complete 1H and 17O NMR relaxometric study was carried out in order to evaluate the parameters that govern the relaxivity associated with these complexes. The relaxivities of Gd2L1 and Gd2L2 (20 MHz, 298 K are 8.7 and 9.5 mM−1 s−1, respectively, +77% and +106% higher than the relaxivity values of the corresponding mononuclear GdDOTAMAP-En and GdHPDO3A complexes. A significant contribution of second sphere water molecules was accounted for the strong relaxivity enhancement of Gd2L2. MR phantom images of the dinuclear complexes compared to GdHPDO3A, recorded at 7 T, confirmed the superiority of Gd2L2. Finally, ab initio

  6. Grain yield losses in yellow-rusted durum wheat estimated using digital and conventional parameters under field conditions

    Directory of Open Access Journals (Sweden)

    Omar Vergara-Diaz

    2015-06-01

    Full Text Available The biotrophic fungus Puccinia striiformis f. sp. tritici is the causal agent of the yellow rust in wheat. Between the years 2010–2013 a new strain of this pathogen (Warrior/Ambition, against which the present cultivated wheat varieties have no resistance, appeared and spread rapidly. It threatens cereal production in most of Europe. The search for sources of resistance to this strain is proposed as the most efficient and safe solution to ensure high grain production. This will be helped by the development of high performance and low cost techniques for field phenotyping. In this study we analyzed vegetation indices in the Red, Green, Blue (RGB images of crop canopies under field conditions. We evaluated their accuracy in predicting grain yield and assessing disease severity in comparison to other field measurements including the Normalized Difference Vegetation Index (NDVI, leaf chlorophyll content, stomatal conductance, and canopy temperature. We also discuss yield components and agronomic parameters in relation to grain yield and disease severity. RGB-based indices proved to be accurate predictors of grain yield and grain yield losses associated with yellow rust (R2 = 0.581 and R2 = 0.536, respectively, far surpassing the predictive ability of NDVI (R2 = 0.118 and R2 = 0.128, respectively. In comparison to potential yield, we found the presence of disease to be correlated with reductions in the number of grains per spike, grains per square meter, kernel weight and harvest index. Grain yield losses in the presence of yellow rust were also greater in later heading varieties. The combination of RGB-based indices and days to heading together explained 70.9% of the variability in grain yield and 62.7% of the yield losses.

  7. An open, multi-vendor, multi-field-strength brain MR dataset and analysis of publicly available skull stripping methods agreement.

    Science.gov (United States)

    Souza, Roberto; Lucena, Oeslle; Garrafa, Julia; Gobbi, David; Saluzzi, Marina; Appenzeller, Simone; Rittner, Letícia; Frayne, Richard; Lotufo, Roberto

    2018-04-15

    This paper presents an open, multi-vendor, multi-field strength magnetic resonance (MR) T1-weighted volumetric brain imaging dataset, named Calgary-Campinas-359 (CC-359). The dataset is composed of images of older healthy adults (29-80 years) acquired on scanners from three vendors (Siemens, Philips and General Electric) at both 1.5 T and 3 T. CC-359 is comprised of 359 datasets, approximately 60 subjects per vendor and magnetic field strength. The dataset is approximately age and gender balanced, subject to the constraints of the available images. It provides consensus brain extraction masks for all volumes generated using supervised classification. Manual segmentation results for twelve randomly selected subjects performed by an expert are also provided. The CC-359 dataset allows investigation of 1) the influences of both vendor and magnetic field strength on quantitative analysis of brain MR; 2) parameter optimization for automatic segmentation methods; and potentially 3) machine learning classifiers with big data, specifically those based on deep learning methods, as these approaches require a large amount of data. To illustrate the utility of this dataset, we compared to the results of a supervised classifier, the results of eight publicly available skull stripping methods and one publicly available consensus algorithm. A linear mixed effects model analysis indicated that vendor (p-valuefield strength (p-value<0.001) have statistically significant impacts on skull stripping results. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Variation in the WWV, 15 MHz field strength received at Hiraiso during a low solar activity and the application of the result to radio disturbance warning services

    International Nuclear Information System (INIS)

    Ohshio, Mitsuo; Kidokoro, Tsuneichi

    1978-01-01

    Recurrent geomagnetic storms occur predominantly apparently during the period of low solar activity. Radio disturbance warning services are apt to be made in terms of geomagnetic disturbances in this period. This analysis has been made from the standpoint of making the electric field strength of a short wave (WWV, 15 MHz) circuit with a long distance received at Hiraiso, Japan correspond to not only geomagnetic disturbances, but also its absorption in the ionosphere. The electric field strength has been treated as a newly introduced daily mean value of time-integrated one in this paper. The result has been obtained from the analysis that about 2/3 of the daily electric field strength of the total cases treated were influenced by geomagnetic disturbances and that about 2/3 within the remaining about 1/3 proved to be influenced by the ionospheric absorption, ionospheric parameters such as f sub(min) and the phase of a VLF radio wave circuit being used. The strength has been considered to be influenced by the absorption also in case of being influenced by geomagnetic disturbances. The remaining about 1/9 of the total cases could not correspond to its cause. Some applications of the consideration have been made to practical problems. (author)

  9. Dose-response curve for blood exposed to gamma-neutron mixed field by conventional cytogenetic method

    International Nuclear Information System (INIS)

    Brandao, Jose Odinilson de C.; Souza, Priscilla L.G.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

    2009-01-01

    There is increasing concern about airline crew members (about one million worldwide) are exposed to measurable neutrons doses. Historically, cytogenetic biodosimetry assays have been based on quantifying asymmetrical chromosome alterations (dicentrics, centric rings and acentric fragments) in mytogen-stimulated T-lymphocytes in their first mitosis after radiation exposure. Increased levels of chromosome damage in peripheral blood lymphocytes are a sensitive indicator of radiation exposure and they are routinely exploited for assessing radiation absorbed dose after accidental or occupational exposure. Since radiological accidents are not common, not all nations feel that it is economically justified to maintain biodosimetry competence. However, dependable access to biological dosimetry capabilities is completely critical in event of an accident. In this paper the dose-response curve was measured for the induction of chromosomal alterations in peripheral blood lymphocytes after chronic exposure in vitro to neutron-gamma mixes field. Blood was obtained from one healthy donor and exposed to two neutron-gamma mixed field from sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The evaluated absorbed doses were 0.2 Gy; 1.0 Gy and 2.5 Gy. The dicentric chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphase figures were analyzed for the presence of dicentrics by two experienced scorers after painted by giemsa 5%. Our preliminary results showed a linear dependence between radiations absorbed dose and dicentric chromosomes frequencies. Dose-response curve described in this paper will contribute to the construction of calibration curve that will be used in our laboratory for biological dosimetry. (author)

  10. Dose-response curve for blood exposed to gamma-neutron mixed field by conventional cytogenetic method

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Jose Odinilson de C.; Souza, Priscilla L.G.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F., E-mail: jodinilson@cnen.gov.b, E-mail: fflima@cnen.gov.b, E-mail: jasantos@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Calixto, Merilane S.; Santos, Neide, E-mail: santos_neide@yahoo.com.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica

    2009-07-01

    There is increasing concern about airline crew members (about one million worldwide) are exposed to measurable neutrons doses. Historically, cytogenetic biodosimetry assays have been based on quantifying asymmetrical chromosome alterations (dicentrics, centric rings and acentric fragments) in mytogen-stimulated T-lymphocytes in their first mitosis after radiation exposure. Increased levels of chromosome damage in peripheral blood lymphocytes are a sensitive indicator of radiation exposure and they are routinely exploited for assessing radiation absorbed dose after accidental or occupational exposure. Since radiological accidents are not common, not all nations feel that it is economically justified to maintain biodosimetry competence. However, dependable access to biological dosimetry capabilities is completely critical in event of an accident. In this paper the dose-response curve was measured for the induction of chromosomal alterations in peripheral blood lymphocytes after chronic exposure in vitro to neutron-gamma mixes field. Blood was obtained from one healthy donor and exposed to two neutron-gamma mixed field from sources {sup 241}AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The evaluated absorbed doses were 0.2 Gy; 1.0 Gy and 2.5 Gy. The dicentric chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphase figures were analyzed for the presence of dicentrics by two experienced scorers after painted by giemsa 5%. Our preliminary results showed a linear dependence between radiations absorbed dose and dicentric chromosomes frequencies. Dose-response curve described in this paper will contribute to the construction of calibration curve that will be used in our laboratory for biological dosimetry. (author)

  11. Conventional four-field pelvic radiotherapy technique without computed tomography-treatment planning in cancer of the cervix: potential geographic miss and its impact on pelvic control

    International Nuclear Information System (INIS)

    Kim, Robert Y.; McGinnis, L. Scott; Spencer, Sharon A.; Meredith, Ruby F.; Jennelle, Richard L.S.; Salter, Merle M.

    1995-01-01

    Purpose: To evaluate the impact of inadequate margins on pelvic control using the conventional four-field pelvic portals without computed tomography (CT)-treatment planning. Methods and Materials: Between 1986 and 1991, 34 patients with invasive cancer of the cervix were eligible for outcome study of conventional four-field radiation therapy (10 Stage I, 16 Stage II, 8 Stage III). The eligibility for this study includes four-field pelvic technique, definitive radiation therapy, and diagnostic CT scan of the pelvis. For this study, an inadequate margin is arbitrarily defined as ≤ 1.0 cm of normal tissue around the CT-defined tumor volume. Results: All 34 patients had adequate margins for anterio-posterior/posterio-anterior portals. However, 19 patients had an inadequate margin at the posterior border (S2-S3 interspace) and/or custom-shaped rectal block for lateral pelvic portals. Two patients had inadequate margins at the anterior border (level of symphysis pubis) due to an enlarged uterus. With a median follow-up of 36 months, pelvic control for adequate margins and inadequate margins was 100% and 71% for Stage IB disease and 88% and 50% for Stage IIB disease, respectively. However, pelvic control for Stage IIIB disease was 50% for both groups. There was no difference in total dose to point A or point B between the two groups. Conclusion: Our preliminary data show higher local failure in patients with an inadequate margin. For four-field pelvic radiation therapy, we strongly recommend CT-treatment planning. Otherwise, anterio-posterior/posterio-anterior pelvic therapy is the most reliable treatment for cancer of the uterine cervix

  12. Diagnosis of initial changes in patients suffering from rheumatoid arthritis. A comparison between low-field magnetic resonance imaging, 3-phase bone scintigraphy and conventional X-ray

    International Nuclear Information System (INIS)

    Hoepfner, S.; Dresel, S.; Weiss, M.; Hahn, K.; Treitl, M.; Krolak, C.; Becker-Gaab, C.; Schattenkirchner, M.

    2002-01-01

    Besides conventional X-rays, in the diagnostic work up of initial changes in patients suffering from rheumatoid arthritis (RA), 3-phase bone scintigraphy (3P-Sz) is as well established as magnetic resonance imaging (MRI). The aim of this study was to compare the diagnostic value of the newly developed low field MRI with the proven methods X-rays and 3P-Sz. Methods: 65 patients (47f, 18m; 20-86 yrs) were studied on a one day protocol with 3P-Sz (550 MBq Tc-99m DPD), MRI and X-rays of the hands. Images were visually analysed by two blinded nuclear medicine physicians and radiologists and classified as a) RA-typical, b) inflammatory, non-RA-typical and c) non inflammatory changes. All methods were compared to 3P-Sz as golden standard. Results: In comparison to 3P-Sz, low field MRI presents with almost equal sensitivity and specificity in rheumatoid-typical and inflammatory changes. Conventional X-rays revealed in arthritis-typical changes as well as in inflammatory changes a significantly lower sensitivity and also a lower negative predictive value while specificity equals the one of MRI. Quantitative analysis of 3P-Sz using ROI-technique unveiled significantly higher values in patients with rheumatoid arthritis than in those with no inflammatory changes. Conclusion: MRI represents an equally sensitive method in the initial diagnosis of rheumatoid-typical and inflammatory changes in the region of the hands as compared to the 3P-Sz. Besides the basic diagnosis with conventional X-rays, 3P-Sz is still the recommended method of choice to evaluate the whole body when RA is suspected. Additionally, quantitative analysis of the 3P-Sz using the ROI technique in the region of the hands reveals statistically significant results and should therefore be taken into account in the assessment of inflammatory changes. (orig.) [de

  13. The role of hydrothermal processes in concentrating high-field strength elements in the Strange Lake peralkaline complex, northeastern Canada

    Science.gov (United States)

    Salvi, Stefano; Williams-Jones, Anthony E.

    1996-06-01

    The middle-Proterozoic peralkaline pluton at Strange Lake, Quebec/Labrador, comprises hypersolvus to subsolvus phases which are unusually enriched in Zr, Y, REEs, Nb, Be, and F, as exotic alkali and alkaline-earth silicate minerals. The highest concentrations of these elements are in subsolvus granite, which underwent intense low temperature (≤200°C) hydrothermal alteration involving hematization and the replacement of alkali high-field strength element (HFSE) minerals by calcic equivalents. This alteration is interpreted to have been caused by meteoric or formational waters. High temperature (≥ 350°C) alteration, attributed to orthomagmatic fluids, is evident in other parts of the subsolvus granite by the replacement of arfvedsonite by aegirine. Comparisons of the chemical compositions of fresh and altered rocks indicate that rocks subjected to high temperature alteration were chemically unaffected, except for depletion in Zr, Y, and HREEs. These elements were appreciably enriched in rocks that underwent low temperature alteration. Other elements affected by low temperature alteration include Ca and Mg, which were added and Na, which was removed. Available data on HFSE speciation in aqueous fluids and the chemistry of the pluton, suggest that the HFSEs were transported as fluoride complexes. If this was the case, the low temperature fluid could not have been responsible for HFSE transport, because the high concentration of Ca and low solubility of fluorite would have buffered F - activity to levels too low to permit significant complexation. We propose that HFSE mineralization and accompanying alteration were the result of mixing, in the apical parts of the pluton, of a F-rich, essentially Ca-free orthomagmatic fluid containing significant concentrations of HFSEs, with an externally derived meteoric-dominated fluid, enriched in Ca as a result of interaction with calc-silicate gneisses and gabbros. According to this interpretation, the latter fluid was

  14. Multi-site study of diffusion metric variability: effects of site, vendor, field strength, and echo time on regions-of-interest and histogram-bin analyses.

    Science.gov (United States)

    Helmer, K G; Chou, M-C; Preciado, R I; Gimi, B; Rollins, N K; Song, A; Turner, J; Mori, S

    2016-02-27

    It is now common for magnetic-resonance-imaging (MRI) based multi-site trials to include diffusion-weighted imaging (DWI) as part of the protocol. It is also common for these sites to possess MR scanners of different manufacturers, different software and hardware, and different software licenses. These differences mean that scanners may not be able to acquire data with the same number of gradient amplitude values and number of available gradient directions. Variability can also occur in achievable b-values and minimum echo times. The challenge of a multi-site study then, is to create a common protocol by understanding and then minimizing the effects of scanner variability and identifying reliable and accurate diffusion metrics. This study describes the effect of site, scanner vendor, field strength, and TE on two diffusion metrics: the first moment of the diffusion tensor field (mean diffusivity, MD), and the fractional anisotropy (FA) using two common analyses (region-of-interest and mean-bin value of whole brain histograms). The goal of the study was to identify sources of variability in diffusion-sensitized imaging and their influence on commonly reported metrics. The results demonstrate that the site, vendor, field strength, and echo time all contribute to variability in FA and MD, though to different extent. We conclude that characterization of the variability of DTI metrics due to site, vendor, field strength, and echo time is a worthwhile step in the construction of multi-center trials.

  15. Dumping convention

    International Nuclear Information System (INIS)

    Roche, P.

    1992-01-01

    Sea dumping of radioactive waste has, since 1983, been precluded under a moratorium established by the London Dumping Convention. Pressure from the nuclear industry to allow ocean dumping of nuclear waste is reported in this article. (author)

  16. Method to increase the transition temperature and for the critical magnetic field strength of the known intermetallic compounds of vanadium or niobium

    International Nuclear Information System (INIS)

    Winter, H.

    1977-01-01

    The invention deals with a method to raise the transition temperature and critical magnetic field strength of superconducting, intermetallic compounds of vanadium and niobium. For example, a niobium alloy with 4 wt.% Al in melted in vacuum electric arc and formed into a sheet of about 1 mm thick. Strips of this sheet are electrically heated up to 1,900 0 C for one hour in a high-vacuum oven. The strips are then annealed in evacuated quartz ampoules for 120 hours at 800 0 C. These strips have a transition temperature of 24 K and a critical magnetic field strength of 600 kg; the critical current density was 5 x 10 4 A/cm 2 . (HPOE) [de

  17. Scaling submillimeter single-cycle transients toward megavolts per centimeter field strength via optical rectification in the organic crystal OH1.

    Science.gov (United States)

    Ruchert, Clemens; Vicario, Carlo; Hauri, Christoph P

    2012-03-01

    We present the generation of high-power single-cycle terahertz (THz) pulses in the organic salt crystal 2-[3-(4-hydroxystyryl)-5.5-dimethylcyclohex-2-enylidene]malononitrile or OH1. Broadband THz radiation with a central frequency of 1.5 THz (λ(c)=200 μm) and high electric field strength of 440 kV/cm is produced by optical rectification driven by the signal of a powerful femtosecond optical parametric amplifier. A 1.5% pump to THz energy conversion efficiency is reported, and pulse energy stability better than 1% RMS is achieved. An approach toward the realization of higher field strength is discussed. © 2012 Optical Society of America

  18. Characteristics of structural loess strength and preliminary framework for joint strength formula

    OpenAIRE

    Rong-jian Li; Jun-ding Liu; Rui Yan; Wen Zheng; Sheng-jun Shao

    2014-01-01

    The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress (Kf line), and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests: the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural lo...

  19. Table of charged particle energies versus magnetic field strength x orbit radius (Bρ) for A = 1 to 7 (100< (Bρ) < 1200 kG.cm)

    International Nuclear Information System (INIS)

    Bianchi, L.

    1969-01-01

    A table of charged particle energies versus magnetic field strength x orbit radius (B ρ ) is presented. Particles p, d, t, 3 He ++ , 4 He + , 4 He ++ , 6 Li + , 6 Li ++ , 6 Li +++ , 7 Li + , 7 Li ++ , 7 Li +++ . Values of B ρ : 100 to 1200 kG.cm by steps of 0.5 kG.cm. Values of energies are given in keV. (author) [fr

  20. Influence of field strength, coil type and image resolution on assessment of synovitis by unenhanced MRI - a comparison with contrast-enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Eshed, Iris [The Sheba Medical Center, Department of Diagnostic Imaging, Tel Hashomer (Israel); Tel Aviv University, Sackler School of Medicine, Tel Aviv (Israel); Krabbe, Simon; Axelsen, Mette; Pedersen, Susanne Juhl [Copenhagen University Hospital Glostrup, Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Copenhagen (Denmark); Oestergaard, Mikkel [Copenhagen University Hospital Glostrup, Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Copenhagen (Denmark); Copenhagen University Hospital Gentofte, Department of Rheumatology/C, Copenhagen (Denmark); Boeyesen, Pernille [Diakonhjemmet Hospital, Department of Rheumatology, Oslo (Norway); Moeller, Jakob M. [Copenhagen University Hospital at Herlev, Department of Radiology, Copenhagen (Denmark); Therkildsen, Flemming [Metropolitan University College, Copenhagen (Denmark); Madsen, Ole Rintek [Copenhagen University Hospital Gentofte, Department of Rheumatology/C, Copenhagen (Denmark)

    2015-04-01

    To explore if the reliability of synovitis assessment by unenhanced MRI is influenced by different MRI field-strengths, coil types and image resolutions in RA patients. Forty-one RA patients and 12 healthy controls underwent hand MRI (wrist and 2{sup nd}-5{sup th} metacarpophalangeal joints) at 4 different field-strengths (0.23 T/0.6 T/1.5 T/3.0 T) on the same day. Seven protocols using a STIR sequence with different field-strengths, coils (flex coils/dedicated phased-array extremity coils) and resolution were applied and scored blindly for synovitis (OMERACT-RAMRIS method). A 1.5 T post-contrast T1-weighted sequence was used as gold standard reference. Fair-good agreement (ICC=0.38-0.72) between the standard reference and the different STIR protocols (best agreement with extremity coil and small voxel size at 1.5 T). The accuracy for presence/absence of synovitis was very high per person (0.80-1.0), and moderate-high per joint (0.63-0.85), whereas exact agreements on scores were moderate (0.50-0.66). The intrareader agreement (15 patients and 3 controls) on presence/absence of synovitis was very high (0.87-1.0). Unenhanced MRI using STIR sequence is only moderately reliable for assessing hand synovitis in RA, when contrast-enhanced MRI is considered the gold standard reference. Contrast injection, field strength and coil type influence synovitis assessment, and should be considered before performing MRI in clinical trials and practice. (orig.)

  1. Influence of field strength, coil type and image resolution on assessment of synovitis by unenhanced MRI - a comparison with contrast-enhanced MRI

    International Nuclear Information System (INIS)

    Eshed, Iris; Krabbe, Simon; Axelsen, Mette; Pedersen, Susanne Juhl; Oestergaard, Mikkel; Boeyesen, Pernille; Moeller, Jakob M.; Therkildsen, Flemming; Madsen, Ole Rintek

    2015-01-01

    To explore if the reliability of synovitis assessment by unenhanced MRI is influenced by different MRI field-strengths, coil types and image resolutions in RA patients. Forty-one RA patients and 12 healthy controls underwent hand MRI (wrist and 2 nd -5 th metacarpophalangeal joints) at 4 different field-strengths (0.23 T/0.6 T/1.5 T/3.0 T) on the same day. Seven protocols using a STIR sequence with different field-strengths, coils (flex coils/dedicated phased-array extremity coils) and resolution were applied and scored blindly for synovitis (OMERACT-RAMRIS method). A 1.5 T post-contrast T1-weighted sequence was used as gold standard reference. Fair-good agreement (ICC=0.38-0.72) between the standard reference and the different STIR protocols (best agreement with extremity coil and small voxel size at 1.5 T). The accuracy for presence/absence of synovitis was very high per person (0.80-1.0), and moderate-high per joint (0.63-0.85), whereas exact agreements on scores were moderate (0.50-0.66). The intrareader agreement (15 patients and 3 controls) on presence/absence of synovitis was very high (0.87-1.0). Unenhanced MRI using STIR sequence is only moderately reliable for assessing hand synovitis in RA, when contrast-enhanced MRI is considered the gold standard reference. Contrast injection, field strength and coil type influence synovitis assessment, and should be considered before performing MRI in clinical trials and practice. (orig.)

  2. Microbial inactivation and shelf life comparison of 'cold' hurdle processing with pulsed electric fields and microfiltration, and conventional thermal pasteurisation in skim milk.

    Science.gov (United States)

    Walkling-Ribeiro, M; Rodríguez-González, O; Jayaram, S; Griffiths, M W

    2011-01-05

    Thermal pasteurisation (TP) is the established food technology for commercial processing of milk. However, degradation of valuable nutrients in milk and its sensory characteristics occurs during TP due to substantial heat exposure. Pulsed electric fields (PEF) and microfiltration (MF) both represent emerging food processing technologies allowing gentle milk preservation at lower temperatures and shorter treatment times for similar, or better, microbial inactivation and shelf stability when applied in a hurdle approach compared to TP. Incubated raw milk was used as an inoculum for the enrichment of skim milk with native microorganisms before PEF, MF, and TP processing. Inoculated milk was PEF-processed at electric field strengths between 16 and 42 kV/cm for treatment times from 612 to 2105 μs; accounting for energy densities between 407 and 815 kJ/L, while MF was applied with a transmembrane flux of 660 L/h m². Milk was TP-treated at 75°C for 24 s. Comparing PEF, MF, and TP for the reduction of the native microbial load in milk led to a 4.6 log₁₀ CFU/mL reduction in count for TP, which was similar to 3.7 log₁₀ CFU/mL obtained by MF (P≥0.05), and more effective than the 2.5 log₁₀ CFU/mL inactivation achieved by PEF inactivation (at 815 kJ/L (Pfield strength, shorter treatment time, larger energy density, and rising temperature the efficacy of PEF/MF increased contrary to MF/PEF. Thus, PEF/MF represents a potential alternative for 'cold' pasteurisation of milk with improved quality. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect

    Directory of Open Access Journals (Sweden)

    Lennart Visser

    2017-11-01

    Full Text Available This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students (N = 54. The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23, the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks, the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.

  4. A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect.

    Science.gov (United States)

    Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A J

    2017-01-01

    This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students ( N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.

  5. Distribution of Flavonoids and Cyclohexenyl Chalcone Derivatives in Conventional Propagated and In Vitro-Derived Field-Grown Boesenbergia rotunda (L. Mansf.

    Directory of Open Access Journals (Sweden)

    Boon Chin Tan

    2015-01-01

    Full Text Available The distribution patterns of flavonoids and cyclohexenyl chalcone derivatives in conventional propagated (CP and in vitro-derived (CPA field-grown plants of an important medicinal ginger, Boesenbergia rotunda, are described. A total of eight compounds were extracted from six organs (rootlet, rhizome, shoot base, maroon stem, stalk, and leaf of the CP and CPA plants. Five major chromatographic peaks, namely, alpinetin, pinocembrin, pinostrobin, 4-hydroxypanduratin A, and panduratin A, were consistently observed by high performance liquid chromatography. Nonaerial organs had higher levels of flavonoids than the aerial ones for all types of samples. Among the compounds detected, pinostrobin and 4-hydroxypanduratin A were the most abundant flavonoid and cyclohexenyl chalcone derivative, respectively. The distribution and abundance of the bioactive compounds suggested that the shoot base could be more potentially useful for medicinal application than other organs of the plant and may be the site of storage or occurrence of biosynthetic enzymatic activities.

  6. Kinetic parameters, collision rates, energy exchanges and transport coefficients of non-thermal electrons in premixed flames at sub-breakdown electric field strengths

    KAUST Repository

    Bisetti, Fabrizio

    2014-01-02

    The effects of an electric field on the collision rates, energy exchanges and transport properties of electrons in premixed flames are investigated via solutions to the Boltzmann kinetic equation. The case of high electric field strength, which results in high-energy, non-thermal electrons, is analysed in detail at sub-breakdown conditions. The rates of inelastic collisions and the energy exchange between electrons and neutrals in the reaction zone of the flame are characterised quantitatively. The analysis includes attachment, ionisation, impact dissociation, and vibrational and electronic excitation processes. Our results suggest that Townsend breakdown occurs for E/N = 140 Td. Vibrational excitation is the dominant process up to breakdown, despite important rates of electronic excitation of CO, CO2 and N2 as well as impact dissociation of O2 being apparent from 50 Td onwards. Ohmic heating in the reaction zone is found to be negligible (less than 2% of peak heat release rate) up to breakdown field strengths for realistic electron densities equal to 1010 cm-3. The observed trends are largely independent of equivalence ratio. In the non-thermal regime, electron transport coefficients are insensitive to mixture composition and approximately constant across the flame, but are highly dependent on the electric field strength. In the thermal limit, kinetic parameters and transport coefficients vary substantially across the flame due to the spatially inhomogeneous concentration of water vapour. A practical approach for identifying the plasma regime (thermal versus non-thermal) in studies of electric field effects on flames is proposed. © 2014 Taylor & Francis.

  7. Abundance of Soil-Borne Entomopathogenic Fungi in Organic and Conventional Fields in the Midwestern USA with an Emphasis on the Effect of Herbicides and Fungicides on Fungal Persistence.

    Science.gov (United States)

    Clifton, Eric H; Jaronski, Stefan T; Hodgson, Erin W; Gassmann, Aaron J

    2015-01-01

    Entomopathogenic fungi (EPF) are widespread in agricultural fields and help suppress crop pests. These natural enemies may be hindered by certain agronomic practices associated with conventional agriculture including the use of pesticides. We tested whether the abundance of EPF differed between organic and conventional fields, and whether specific cropping practices and soil properties were correlated with their abundance. In one year of the survey, soil from organic fields and accompanying margins had significantly more EPF than conventional fields and accompanying margins. Regression analysis revealed that the percentage of silt and the application of organic fertilizer were positively correlated with EPF abundance; but nitrogen concentration, tillage, conventional fields, and margins of conventional fields were negatively correlated with EPF abundance. A greenhouse experiment in which fungicides and herbicides were applied to the soil surface showed no significant effect on EPF. Though organic fields were perceived to be more suitable environments for EPF, abiotic factors and cropping practices such as tillage may have greater impacts on the abundance of EPF. Also, fungicides and herbicides may not be as toxic to soil-borne EPF as originally thought.

  8. Abundance of Soil-Borne Entomopathogenic Fungi in Organic and Conventional Fields in the Midwestern USA with an Emphasis on the Effect of Herbicides and Fungicides on Fungal Persistence.

    Directory of Open Access Journals (Sweden)

    Eric H Clifton

    Full Text Available Entomopathogenic fungi (EPF are widespread in agricultural fields and help suppress crop pests. These natural enemies may be hindered by certain agronomic practices associated with conventional agriculture including the use of pesticides. We tested whether the abundance of EPF differed between organic and conventional fields, and whether specific cropping practices and soil properties were correlated with their abundance. In one year of the survey, soil from organic fields and accompanying margins had significantly more EPF than conventional fields and accompanying margins. Regression analysis revealed that the percentage of silt and the application of organic fertilizer were positively correlated with EPF abundance; but nitrogen concentration, tillage, conventional fields, and margins of conventional fields were negatively correlated with EPF abundance. A greenhouse experiment in which fungicides and herbicides were applied to the soil surface showed no significant effect on EPF. Though organic fields were perceived to be more suitable environments for EPF, abiotic factors and cropping practices such as tillage may have greater impacts on the abundance of EPF. Also, fungicides and herbicides may not be as toxic to soil-borne EPF as originally thought.

  9. Detailing magnetic field strength dependence and segmental artifact distribution of myocardial effective transverse relaxation rate at 1.5, 3.0, and 7.0 T.

    Science.gov (United States)

    Meloni, Antonella; Hezel, Fabian; Positano, Vincenzo; Keilberg, Petra; Pepe, Alessia; Lombardi, Massimo; Niendorf, Thoralf

    2014-06-01

    Realizing the challenges and opportunities of effective transverse relaxation rate (R2 *) mapping at high and ultrahigh fields, this work examines magnetic field strength (B0 ) dependence and segmental artifact distribution of myocardial R2 * at 1.5, 3.0, and 7.0 T. Healthy subjects were considered. Three short-axis views of the left ventricle were examined. R2 * was calculated for 16 standard myocardial segments. Global and mid-septum R2 * were determined. For each segment, an artifactual factor was estimated as the deviation of segmental from global R2 * value. The global artifactual factor was significantly enlarged at 7.0 T versus 1.5 T (P = 0.010) but not versus 3.0 T. At 7.0 T, the most severe susceptibility artifacts were detected in the inferior lateral wall. The mid-septum showed minor artifactual factors at 7.0 T, similar to those at 1.5 and 3.0 T. Mean R2 * increased linearly with the field strength, with larger changes for global heart R2 * values. At 7.0 T, segmental heart R2 * analysis is challenging due to macroscopic susceptibility artifacts induced by the heart-lung interface and the posterior vein. Myocardial R2 * depends linearly on the magnetic field strength. The increased R2 * sensitivity at 7.0 T might offer means for susceptibility-weighted and oxygenation level-dependent MR imaging of the myocardium. Copyright © 2013 Wiley Periodicals, Inc.

  10. Cooperative effect of random and time-periodic coupling strength on synchronization transitions in one-way coupled neural system: mean field approach.

    Science.gov (United States)

    Jiancheng, Shi; Min, Luo; Chusheng, Huang

    2017-08-01

    The cooperative effect of random coupling strength and time-periodic coupling strengh on synchronization transitions in one-way coupled neural system has been investigated by mean field approach. Results show that cooperative coupling strength (CCS) plays an active role for the enhancement of synchronization transitions. There exist an optimal frequency of CCS which makes the system display the best CCS-induced synchronization transitions, a critical frequency of CCS which can not further affect the CCS-induced synchronization transitions, and a critical amplitude of CCS which can not occur the CCS-induced synchronization transitions. Meanwhile, noise intensity plays a negative role for the CCS-induced synchronization transitions. Furthermore, it is found that the novel CCS amplitude-induced synchronization transitions and CCS frequency-induced synchronization transitions are found.

  11. Beyond the Debye length in high ionic strength solution: direct protein detection with field-effect transistors (FETs) in human serum.

    Science.gov (United States)

    Chu, Chia-Ho; Sarangadharan, Indu; Regmi, Abiral; Chen, Yen-Wen; Hsu, Chen-Pin; Chang, Wen-Hsin; Lee, Geng-Yen; Chyi, Jen-Inn; Chen, Chih-Chen; Shiesh, Shu-Chu; Lee, Gwo-Bin; Wang, Yu-Lin

    2017-07-12

    In this study, a new type of field-effect transistor (FET)-based biosensor is demonstrated to be able to overcome the problem of severe charge-screening effect caused by high ionic strength in solution and detect proteins in physiological environment. Antibody or aptamer-immobilized AlGaN/GaN high electron mobility transistors (HEMTs) are used to directly detect proteins, including HIV-1 RT, CEA, NT-proBNP and CRP, in 1X PBS (with 1%BSA) or human sera. The samples do not need any dilution or washing process to reduce the ionic strength. The sensor shows high sensitivity and the detection takes only 5 minutes. The designs of the sensor, the methodology of the measurement, and the working mechanism of the sensor are discussed and investigated. A theoretical model is proposed based on the finding of the experiments. This sensor is promising for point-of-care, home healthcare, and mobile diagnostic device.

  12. Magnetic resonance imaging of hindfoot involvement in patients with spondyloarthritides: Comparison of low-field and high-field strength units

    Energy Technology Data Exchange (ETDEWEB)

    Eshed, Iris; Althoff, Christian E. [Department of Radiology, Charite Medical School, Berlin (Germany); Feist, Eugen [Department of Rheumatology and Clinical Immunology, Charite Medical School, Berlin (Germany); Minden, Kirsten [Helios Clinics, 2nd Children' s Hospital Berlin-Buch, Rheumatology Unit, Berlin (Germany); German Rheumatology Research Center, Berlin (Germany); Schink, Tania [Department of Medical Biometry, Charite Medical School, Berlin (Germany); Hamm, Bernd [Department of Radiology, Charite Medical School, Berlin (Germany); Hermann, Kay-Geert A. [Department of Radiology, Charite Medical School, Berlin (Germany)], E-mail: kgh@charite.de

    2008-01-15

    Objective: To compare MRI evaluation of a painful hindfoot of patients with spondyloarthritides (SpA) on low-field (0.2 T) versus high-field (1.5 T) MRI. Materials and methods: Patients with SpA and hindfoot pain were randomly referred to either high-field or low-field MRI. Twenty-seven patients were evaluated (male/female: 17:10; mean age: 39 {+-} 1.4 years). Fifteen patients were examined by low-field and 12 by high-field MRI. Two patients (evaluated by high-field MRI) were excluded. Images were separately read by two radiologists who later reached a consensus. In each patient the prevalence of erosions, fluid, synovitis or bone marrow edema of the hindfoot joints, tendinosis or tenosynovitis of tendons, enthesitis of the plantar fascia and Achilles tendon and retrocalcaneal bursitis were recorded. Clinical and demographic parameters were comparable between both groups. Results: MRI evaluation of joints and tendons of the hindfoot revealed no significant differences in patients with SpA groups for all parameters. Analyzing all joints or tendons together, there was no statistically significant difference between the two groups. Conclusion: Low-field and high-field MRI provide comparable information for evaluation of inflammatory hindfoot involvement. Thus, low-field MRI can be considered as a reliable diagnostic tool for the detection of hindfoot abnormalities in SpA patients.

  13. Magnetic resonance imaging of hindfoot involvement in patients with spondyloarthritides: Comparison of low-field and high-field strength units

    International Nuclear Information System (INIS)

    Eshed, Iris; Althoff, Christian E.; Feist, Eugen; Minden, Kirsten; Schink, Tania; Hamm, Bernd; Hermann, Kay-Geert A.

    2008-01-01

    Objective: To compare MRI evaluation of a painful hindfoot of patients with spondyloarthritides (SpA) on low-field (0.2 T) versus high-field (1.5 T) MRI. Materials and methods: Patients with SpA and hindfoot pain were randomly referred to either high-field or low-field MRI. Twenty-seven patients were evaluated (male/female: 17:10; mean age: 39 ± 1.4 years). Fifteen patients were examined by low-field and 12 by high-field MRI. Two patients (evaluated by high-field MRI) were excluded. Images were separately read by two radiologists who later reached a consensus. In each patient the prevalence of erosions, fluid, synovitis or bone marrow edema of the hindfoot joints, tendinosis or tenosynovitis of tendons, enthesitis of the plantar fascia and Achilles tendon and retrocalcaneal bursitis were recorded. Clinical and demographic parameters were comparable between both groups. Results: MRI evaluation of joints and tendons of the hindfoot revealed no significant differences in patients with SpA groups for all parameters. Analyzing all joints or tendons together, there was no statistically significant difference between the two groups. Conclusion: Low-field and high-field MRI provide comparable information for evaluation of inflammatory hindfoot involvement. Thus, low-field MRI can be considered as a reliable diagnostic tool for the detection of hindfoot abnormalities in SpA patients

  14. Analytical solutions of the Schrödinger equation for a two-dimensional exciton in magnetic field of arbitrary strength

    International Nuclear Information System (INIS)

    Hoang-Do, Ngoc-Tram; Hoang, Van-Hung; Le, Van-Hoang

    2013-01-01

    The Feranchuk-Komarov operator method is developed by combining with the Levi-Civita transformation in order to construct analytical solutions of the Schrödinger equation for a two-dimensional exciton in a uniform magnetic field of arbitrary strength. As a result, analytical expressions for the energy of the ground and excited states are obtained with a very high precision of up to four decimal places. Especially, the precision is uniformly stable for the whole range of the magnetic field. This advantage appears due to the consideration of the asymptotic behaviour of the wave-functions in strong magnetic field. The results could be used for various physical analyses and the method used here could also be applied to other atomic systems.

  15. Government Decree No 24/84 approving accession to the Convention of 31 January 1963 Supplementary to the Paris Convention of 29 July 1960 on Third Party Liability in the Field of Nuclear Energy

    International Nuclear Information System (INIS)

    1984-01-01

    Portugal is a Contracting Party of the Paris Convention which establishes a special system of liability for the operator of nuclear installations in Contracting States: absolute liability and its limitation in amount and in time. The Brussels Supplementary Convention, to which Portugal will accede in accordance with this Decree of 24 April 1984, introduces an additional compensation in two further tiers, the first out of public funds from the country where the nuclear incident originates and the second, highest amount, out of public funds from all Contracting States in cases where damage exceeds the sum to be paid by the Contracting Party concerned. (NEA) [fr

  16. Protocol to amend the convention of 31st January 1963 supplementary to the Paris convention of 29th July 1960 on third party liability in the field of nuclear energy, as amended by the additional protocol of 28th January 1964, Paris, 16 November 1982

    International Nuclear Information System (INIS)

    1983-01-01

    This Protocol further amends the Convention of 31 January 1963 supplementary to the Paris Convention of 29 July 1960 on Third Party Liability in the Field of Nuclear Energy, concluded between the Federal Republic of Germany, Austria, Belgium, Denmark, Spain, Finland, France, Italy, Luxembourg, Norway, Netherlands, United Kingdom, Sweden and Switzerland, within the framework of the Organisation for Economic Co-operation and Development. (U.K.)

  17. Effects of high-field-strength MR imaging on the microcirculation in patients with sickle cell anemia

    International Nuclear Information System (INIS)

    Effmann, E.L.; Podolak, M.; Kinney, T.; Hedlund, L.

    1987-01-01

    Since deoxygenated sickled erythrocytes in vitro align in magnetic fields, the safety of MR imaging of patients with sickle cell anemia is questionable. To determine possible effects of high magnetic fields on blood flow in vivo, the authors used laser Doppler velocimetry to measure capillary blood flow from the forearm of five patients and three control subjects during exposure to a 1.5-T field. They found no significant differences (P<.15) between cutaneous blood flow measured outside and inside the magnet bore in either controls or patients not in crisis. While their results do not preclude the presence of effects in other capillary systems in sickle cell anemia patients in crisis, they do suggest that exposure to a 1.5-T field does not produce detectable flow changes in one microcirculatory bed

  18. The influence of electrical resistivity, magnetic field strength, boundary conditions, and injection conditions on the behavior of the magnetically injected plasma in the PBFA-II opening switch

    International Nuclear Information System (INIS)

    Watrous, J.J.; Frese, M.H.

    1993-01-01

    The Plasma Opening Switch used on PBFA-II uses a source plasma which is injected into the inter-electrode gap along the field lines of a modest-strength applied poloidal magnetic field. The distribution of this plasma within the gap plays an important role in the behavior of the switch. Knowledge of this distribution is critical for performing relevant switch calculations and for interpreting experimental data. In the work reported here, the influence on that distribution of the plasma electrical resistivity, the applied magnetic field strength, and the boundary and injection conditions have been investigated with the 2 1/2-dimensional magnetohydrodynamics simulation code, MACH2. The injected plasma has density in the 10 14 cm -3 range and temperature in the several eV range. In this parameter regime, the classical collision time scale is on the order of 10 ns, which, when compared to the 100 ns time scale of the inflowing plasma, means that the plasma is classically collisionless. However, mechanisms other than classical collisions are likely to contribute to electrical resistivity. The authors have investigated the effect of an anomalous resistivity which scales with the plasma frequency, varying the scaling from the electron plasma frequency to the ion plasma frequency. They will compare these results with results based on the assumption of an ideal plasma, and discuss other anomalous resistivity models

  19. Multi-site Study of Diffusion Metric Variability: Characterizing the Effects of Site, Vendor, Field Strength, and Echo Time using the Histogram Distance

    Science.gov (United States)

    Helmer, K. G.; Chou, M-C.; Preciado, R. I.; Gimi, B.; Rollins, N. K.; Song, A.; Turner, J.; Mori, S.

    2016-01-01

    MRI-based multi-site trials now routinely include some form of diffusion-weighted imaging (DWI) in their protocol. These studies can include data originating from scanners built by different vendors, each with their own set of unique protocol restrictions, including restrictions on the number of available gradient directions, whether an externally-generated list of gradient directions can be used, and restrictions on the echo time (TE). One challenge of multi-site studies is to create a common imaging protocol that will result in a reliable and accurate set of diffusion metrics. The present study describes the effect of site, scanner vendor, field strength, and TE on two common metrics: the first moment of the diffusion tensor field (mean diffusivity, MD), and the fractional anisotropy (FA). We have shown in earlier work that ROI metrics and the mean of MD and FA histograms are not sufficiently sensitive for use in site characterization. Here we use the distance between whole brain histograms of FA and MD to investigate within- and between-site effects. We concluded that the variability of DTI metrics due to site, vendor, field strength, and echo time could influence the results in multi-center trials and that histogram distance is sensitive metrics for each of these variables. PMID:27350723

  20. Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope

    Science.gov (United States)

    Watson, Fraser T.; Beck, Christian; Penn, Matthew J.; Tritschler, Alexandra; Pillet, Valentín Martinez; Livingston, William C.

    2015-11-01

    In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIRS) at the Dunn Solar Telescope. A synoptic observation program at the McMath-Pierce has measured umbral magnetic field strengths since 1998, and this data set has recently been compared with umbral magnetic field observations from SOHO/MDI and SDO/HMI. To further improve on the data from McMath-Pierce, we compared the data with measurements taken at the Dunn Solar Telescope with far greater spectral resolution than has been possible with space instrumentation. To minimise potential disruption to the study, concurrent umbral measurements were made so that the relationship between the two datasets can be most accurately characterised. We find that there is a strong agreement between the umbral magnetic field strengths recorded by each instrument, and we reduced the FIRS data in two different ways to successfully test this correlation further.

  1. Multi-site Study of Diffusion Metric Variability: Characterizing the Effects of Site, Vendor, Field Strength, and Echo Time using the Histogram Distance.

    Science.gov (United States)

    Helmer, K G; Chou, M-C; Preciado, R I; Gimi, B; Rollins, N K; Song, A; Turner, J; Mori, S

    2016-02-27

    MRI-based multi-site trials now routinely include some form of diffusion-weighted imaging (DWI) in their protocol. These studies can include data originating from scanners built by different vendors, each with their own set of unique protocol restrictions, including restrictions on the number of available gradient directions, whether an externally-generated list of gradient directions can be used, and restrictions on the echo time (TE). One challenge of multi-site studies is to create a common imaging protocol that will result in a reliable and accurate set of diffusion metrics. The present study describes the effect of site, scanner vendor, field strength, and TE on two common metrics: the first moment of the diffusion tensor field (mean diffusivity, MD), and the fractional anisotropy (FA). We have shown in earlier work that ROI metrics and the mean of MD and FA histograms are not sufficiently sensitive for use in site characterization. Here we use the distance between whole brain histograms of FA and MD to investigate within- and between-site effects. We concluded that the variability of DTI metrics due to site, vendor, field strength, and echo time could influence the results in multi-center trials and that histogram distance is sensitive metrics for each of these variables.

  2. Biological effects of high strength electric fields on small laboratory animals. Annual report, April 1977--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    Progress is reported on studies of the biological effects on mice and rats of exposure to 60-Hz electric fields. Results are reported on the effects of 30-day and 60-day exposures to 100 kV/m, 60-Hz electric fields on hematologic values, blood chemistry, and organ weights. With the possible exception of elevated blood platelet counts following 60-day exposures, there were no pathological changes observed in either mice or rats.

  3. ION KINETIC ENERGY CONSERVATION AND MAGNETIC FIELD STRENGTH CONSTANCY IN MULTI-FLUID SOLAR WIND ALFVÉNIC TURBULENCE

    Energy Technology Data Exchange (ETDEWEB)

    Matteini, L.; Horbury, T. S.; Schwartz, S. J. [The Blackett Laboratory, Imperial College London, SW7 2AZ (United Kingdom); Pantellini, F. [LESIA, Observatoire de Paris, CNRS, UPMC, Universit Paris-Diderot, 5 Place Jules Janssen, F-92195 Meudon (France); Velli, M. [Department of Earth, Planetary, and Space Sciences, UCLA, California (United States)

    2015-03-20

    We investigate the properties of plasma fluid motion in the large-amplitude, low-frequency fluctuations of highly Alfvénic fast solar wind. We show that protons locally conserve total kinetic energy when observed from an effective frame of reference comoving with the fluctuations. For typical properties of the fast wind, this frame can be reasonably identified by alpha particles which, due to their drift with respect to protons at about the Alfvén speed along the magnetic field, do not partake in the fluid low-frequency fluctuations. Using their velocity to transform the proton velocity into the frame of Alfvénic turbulence, we demonstrate that the resulting plasma motion is characterized by a constant absolute value of the velocity, zero electric fields, and aligned velocity and magnetic field vectors as expected for unidirectional Alfvénic fluctuations in equilibrium. We propose that this constraint, via the correlation between velocity and magnetic field in Alfvénic turbulence, is the origin of the observed constancy of the magnetic field; while the constant velocity corresponding to constant energy can only be observed in the frame of the fluctuations, the corresponding constant total magnetic field, invariant for Galilean transformations, remains the observational signature in the spacecraft frame of the constant total energy in the Alfvén turbulence frame.

  4. Influence of field strength, coil type and image resolution on assessment of synovitis by unenhanced MRI--a comparison with contrast-enhanced MRI

    DEFF Research Database (Denmark)

    Eshed, Iris; Krabbe, Simon; Østergaard, Mikkel

    2015-01-01

    post-contrast T1-weighted sequence was used as gold standard reference. RESULTS: Fair-good agreement (ICC=0.38--0.72) between the standard reference and the different STIR protocols (best agreement with extremity coil and small voxel size at 1.5 T). The accuracy for presence/absence of synovitis...... is only moderately reliable for assessing hand synovitis in RA, when contrast-enhanced MRI is considered the gold standard reference. Contrast injection, field strength and coil type influence synovitis assessment, and should be considered before performing MRI in clinical trials and practice. KEY POINTS...

  5. Proton density differences in signal characteristics of multiple sclerosis plaques versus white matter lesions of small vessel disease and vasculitis on high-field strength MR images

    International Nuclear Information System (INIS)

    Peyster, R.G.; Siegal, T.L.

    1990-01-01

    This paper determines if variations in signal intensity characteristics on multi-spin-echo images obtained with a high-field-strength magnet can be useful in differentiating demyelinating plaques of multiple sclerosis from other pathologic white matter processes due to small vessel disease and vasculities. Using the first of two multi-spin-echo images obtained with a General Electric 1.5-T magnet, the investigators compared signal intensity characteristics in 30 patients with a firm clinical diagnosis of multiple sclerosis versus a control group of 30 patients with a known clinical history of small-vessel disease and vasculitis are isodense to gray matter on proton-density images

  6. Reproducibility of MR-based liver fat quantification across field strength: Same-day comparison between 1.5T and 3T in obese subjects.

    Science.gov (United States)

    Artz, Nathan S; Haufe, William M; Hooker, Catherine A; Hamilton, Gavin; Wolfson, Tanya; Campos, Guilherme M; Gamst, Anthony C; Schwimmer, Jeffrey B; Sirlin, Claude B; Reeder, Scott B

    2015-09-01

    To examine the reproducibility of quantitative magnetic resonance (MR) methods to estimate hepatic proton density fat-fraction (PDFF) at different magnetic field strengths. This Health Insurance Portability and Accountability Act (HIPAA)-compliant study was approved by the Institutional Review Board. Following informed consent, 25 severely obese subjects (mean body mass index [BMI]: 45 ± 4, range: 38-53 kg/m(2) ) were scanned at 1.5T and 3T on the same day. Two confounder-corrected multiecho chemical shift-encoded gradient-echo-based imaging methods were acquired to estimate PDFF over the entire liver: 3D complex-based (MRI-C) and 2D magnitude-based (MRI-M) MRI. Single-voxel MR spectroscopy (MRS) was performed in the right liver lobe. Using linear regression, pairwise comparisons of estimated PDFF were made between methods (MRI-C, MRI-M, MRS) at each field strength and for each method across field strengths. 1.5T vs. 3T regression analyses for MRI-C, MRI-M, and MRS PDFF measurements yielded R(2) values of 0.99, 0.97, and 0.90, respectively. The best-fit line was near unity (slope(m) = 1, intercept(b) = 0), indicating excellent agreement for each case: MRI-C (m = 0.92 [0.87, 0.99], b = 1.4 [0.7, 1.8]); MRI-M (m = 1.0 [0.90, 1.08], b = -1.4 [-2.4, -0.5]); MRS (m = 0.98 [0.82, 1.15], b = 1.2 [-0.2, 3.0]). Comparing MRI-C and MRI-M yielded an R(2)  = 0.98 (m = 1.1 [1.02, 1.16], b = -1.8 [-2.8, -1.1]) at 1.5T, and R(2)  = 0.99 (m = 0.98 [0.93, 1.03], b = 1.2 [0.7, 1.7]) at 3T. This study demonstrates that PDFF estimation is reproducible across field strengths and across two confounder-corrected MR-based methods. © 2015 Wiley Periodicals, Inc.

  7. 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.

  8. The WHO Tobacco Convention: A New Dawn in the Implementation of International Health Instrument? Comment on "The Legal Strength of International Health Instruments - What It Brings to Global Health Governance?"

    Science.gov (United States)

    Durojaye, Ebenezer

    2017-07-05

    The Tobacco Convention was adopted by the World Health Organization (WHO) in 2003. Nikogosian and Kickbusch examine the five potential impacts of the Tobacco Convention and its Protocol on public health. These include the adoption of the Convention would seem to unlock the treaty-making powers of WHO; the impact of the Convention in the global health architecture has been phenomenal globally; the Convention has facilitated the adoption of further instruments to strengthen its implementation at the national level; the Convention has led to the adoption of appropriate legal framework to combat the use of tobacco at the national level and that the impact of the Convention would seem to go beyond public health but has also led to the adoption of the Protocol to Eliminate Illicit Trade in Tobacco. However, the article by Nikogosian and Kickbusch would seem to overlook some of the challenges that may militate against the effective implementation of international law, including the Tobacco Convention, at the national level. © 2018 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

  9. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: a truly hybrid x-ray/MR imaging system.

    Science.gov (United States)

    Fahrig, R; Wen, Z; Ganguly, A; DeCrescenzo, G; Rowlands, J A; Stevens, G M; Saunders, R F; Pelc, N J

    2005-06-01

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation.

  10. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: A truly hybrid x-ray/MR imaging system

    International Nuclear Information System (INIS)

    Fahrig, R.; Wen, Z.; Ganguly, A.; DeCrescenzo, G.; Rowlands, J.A.; Stevens, G.M.; Saunders, R.F.; Pelc, N.J.

    2005-01-01

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo TM flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP TM ) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation

  11. Study on Computerized Treatment Plan of Field-in-Field Intensity Modulated Radiation Therapy and Conventional Radiation Therapy according to PBC Algorithm and AAA on Breast Cancer Tangential Beam

    International Nuclear Information System (INIS)

    Yeom, Mi Suk; Bae, Seong Soo; Kim, Dae Sup; Back, Geum Mun

    2012-01-01

    Anisotropic Analytical Algorithm (AAA) provides more accurate dose calculation regarding impact on scatter and tissue inhomogeneity in comparison to Pencil Beam Convolution (PBC) algorithm. This study tries to analyze the difference of dose distribution according to PBC algorithm and dose calculation algorithm of AAA on breast cancer tangential plan. Computerized medical care plan using Eclipse treatment planning system (version 8.9, VARIAN, USA) has been established for the 10 breast cancer patients using 6 MV energy of Linac (CL-6EX, VARIAN, USA). After treatment plan of Conventional Radiation Therapy plan (Conventional plan) and Field-in-Field Intensity Modulated Radiation Therapy plan (FiF plan) using PBC algorithm has been established, MU has been fixed, implemented dose calculation after changing it to AAA, and compared and analyzed treatment plan using Dose Volume Histogram (DVH). Firstly, as a result of evaluating PBC algorithm of Conventional plan and the difference according to AAA, the average difference of CI value on target volume has been highly estimated by 0.295 on PBC algorithm and as a result of evaluating dose of lung, V 47 Gy and has been highly evaluated by 5.83% and 4.04% each, Mean dose, V 20 , V 5 , V 3 Gy has been highly evaluated 0.6%, 0.29%, 6.35%, 10.23% each on AAA. Secondly, in case of FiF plan, the average difference of CI value on target volume has been highly evaluated on PBC algorithm by 0.165, and dose on ipsilateral lung, V 47 , V 45 Gy, Mean dose has been highly evaluated 6.17%, 3.80%, 0.15% each on PBC algorithm, V 20 , V 5 , V 3 Gy has been highly evaluated 0.14%, 4.07%, 4.35% each on AAA. When calculating with AAA on breast cancer tangential plan, compared to PBC algorithm, Conformity on target volume of Conventional plan, FiF plan has been less evaluated by 0.295, 0.165 each. For the reason that dose of high dose region of ipsilateral lung has been showed little amount, and dose of low dose region has been showed much amount

  12. Ultra-high performance fiber-reinforced concrete (UHPFRC) for infrastructure rehabilitation Volume II : behavior of ultra-high strength concrete bridge deck panels compared to conventional stay-in-place deck panels

    Science.gov (United States)

    2017-08-01

    The remarkable features of ultra-high performance concrete (UHPC) have been reported. Its application in bridge construction has been an active research area in recent years, attributed to its higher compressive strength, higher ductility and reduced...

  13. Convention on the establishment of a security control in the field of nuclear energy. Protocol on the tribunal established by the convention on the establishment of a security control in the field of nuclear energy; Convention sur l'etablissement d'un controle de securite dans le domaine de l'energie nucleaire. Protocole relatif au tribunal cree par la Convention sur l'etablissement d'un controle de securite dans le domaine de l'energie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1957-12-20

    The governments of Germany, Austria, Belgium, Denmark, France, Greece, Ireland, Iceland, Italy, Luxembourg, Norway, Netherlands, Portugal, United Kingdom, Sweden, Switzerland and Turkey, having resolved to promote the development of the production and uses of nuclear energy in the Member countries of the Organisation for European Economic Co-operation between these countries and the harmonisation of national measures; considering that the joint action undertaken to this end in the Organisation is intended to develop the European nuclear industry for purely peaceful ends and must not further any military purpose; considering that at its meeting of' 18 July, 1956, the Council of the Organisation decided to establish to this effect an international security control; considering that by a Decision dated this day the Council has established, within the Organisation, a European Nuclear Energy Agency with the task of pursuing the joint action undertaken; have agreed the present convention. The governments party to the Convention, desirous of determining in accordance with Article 12 of the Convention the organisation of the Tribunal established by the said Article and the status of its judges; have agreed upon the provisions which are annexed to the Convention.

  14. Coulomb repulsion and correlation strength in LaFeAsO from density functional and dynamical mean-field theories

    Czech Academy of Sciences Publication Activity Database

    Anisimov, V.I.; Korotin, D. M.; Korotin, M. A.; Kozhevnikov, A, V.; Kuneš, Jan; Shorikov, A.O.; Skornyakov, S.L.; Streltsov, S. V.

    2009-01-01

    Roč. 21, č. 7 (2009), 075602/1-075602/7 ISSN 0953-8984 Institutional research plan: CEZ:AV0Z10100521 Keywords : iron pnictide * electronic correlations * dynamical mean-field theory Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.964, year: 2009

  15. The Effect of Shock Stress and Field Strength on Shock-Induced Depoling of Normally Poled PZT 95/5

    International Nuclear Information System (INIS)

    CHHABILDAS, LALIT C.; FURNISH, MICHAEL D.; MONTGOMERY, STEPHEN T.; SETCHELL, ROBERT E.

    1999-01-01

    Shock-induced depoling of the ferroelectric ceramic PZT 95/5 is utilized in a number of pulsed power devices. Several experimental and theoretical efforts are in progress in order to improve numerical simulations of these devices. In this study we have examined the shock response of normally poled PZT 95/5 under uniaxial strain conditions. On each experiment the current produced in an external circuit and the transmitted waveform at a window interface were recorded. The peak electrical field generated within the PZT sample was varied through the choice of external circuit resistance. Shock pressures were varied from 0.6 to 4.6 GPa, and peak electrical fields were varied from 0.2 to 37 kV/cm. For a 2.4 GPa shock and the lowest peak field, a nearly constant current governed simply by the remanent polarization and the shock velocity was recorded. Both decreasing the shock pressure and increasing the electrical field resulted in reduced current generation, indicating a retardation of the depoling kinetics

  16. Biological effects of high-strength electric fields on small laboratory animals. Interim report, March 1, 1978-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.D.; Anderson, L.E.; Kaune, W.T.

    1979-12-01

    Progress is described on a project assessing the biological effects of 60-Hz electric fields on small laboratory animals (rats and mice). The report includes sections on hematology and seram chemistry, immunology, pathology, metabolism, bone growth, endocrinology, cardiovascular function, neurophysiology, growth and development, and animal behavior. (ACR)

  17. Exact numerical solutions of the Schrödinger equation for a two-dimensional exciton in a constant magnetic field of arbitrary strength

    Energy Technology Data Exchange (ETDEWEB)

    Hoang-Do, Ngoc-Tram [Department of Physics, Ho Chi Minh City University of Pedagogy 280, An Duong Vuong Street, District 5, Ho Chi Minh City (Viet Nam); Pham, Dang-Lan [Institute for Computational Science and Technology, Quang Trung Software Town, District 12, Ho Chi Minh City (Viet Nam); Le, Van-Hoang, E-mail: hoanglv@hcmup.edu.vn [Department of Physics, Ho Chi Minh City University of Pedagogy 280, An Duong Vuong Street, District 5, Ho Chi Minh City (Viet Nam)

    2013-08-15

    Exact numerical solutions of the Schrödinger equation for a two-dimensional exciton in a constant magnetic field of arbitrary strength are obtained for not only the ground state but also high excited states. Toward this goal, the operator method is developed by combining with the Levi-Civita transformation which transforms the problem under investigation into that of a two-dimensional anharmonic oscillator. This development of the non-perturbation method is significant because it can be applied to other problems of two-dimensional atomic systems. The obtained energies and wave functions set a new record for their precision of up to 20 decimal places. Analyzing the obtained data we also find an interesting result that exact analytical solutions exist at some values of magnetic field intensity.

  18. Exact numerical solutions of the Schrödinger equation for a two-dimensional exciton in a constant magnetic field of arbitrary strength

    International Nuclear Information System (INIS)

    Hoang-Do, Ngoc-Tram; Pham, Dang-Lan; Le, Van-Hoang

    2013-01-01

    Exact numerical solutions of the Schrödinger equation for a two-dimensional exciton in a constant magnetic field of arbitrary strength are obtained for not only the ground state but also high excited states. Toward this goal, the operator method is developed by combining with the Levi-Civita transformation which transforms the problem under investigation into that of a two-dimensional anharmonic oscillator. This development of the non-perturbation method is significant because it can be applied to other problems of two-dimensional atomic systems. The obtained energies and wave functions set a new record for their precision of up to 20 decimal places. Analyzing the obtained data we also find an interesting result that exact analytical solutions exist at some values of magnetic field intensity

  19. Amplifiable DNA from Gram-negative and Gram-positive bacteria by a low strength pulsed electric field method

    Science.gov (United States)

    Vitzthum, Frank; Geiger, Georg; Bisswanger, Hans; Elkine, Bentsian; Brunner, Herwig; Bernhagen, Jürgen

    2000-01-01

    An efficient electric field-based procedure for cell disruption and DNA isolation is described. Isoosmotic suspensions of Gram-negative and Gram-positive bacteria were treated with pulsed electric fields of Pulses had an exponential decay waveform with a time constant of 3.4 µs. DNA yield was linearly dependent on time or pulse number, with several thousand pulses needed. Electrochemical side-effects and electrophoresis were minimal. The lysates contained non-fragmented DNA which was readily amplifiable by PCR. As the method was not limited to samples of high specific resistance, it should be applicable to physiological fluids and be useful for genomic and DNA diagnostic applications. PMID:10734214

  20. Influence of the Rashba and Dresselhaus spin-orbit interactions of equal strength on the electron states in the circular quantum dot in the presence of a magnetic field

    International Nuclear Information System (INIS)

    Kudryashov, V.V.; Baran, A.V.

    2012-01-01

    The solutions of the Schrodinger equation are obtained for an electron at a two-dimensional circular semiconductor quantum dot in the presence of both an external magnetic field and the Rashba and Dresselhaus spin-orbit interactions of equal strength. Confinement is simulated by a realistic potential well of finite depth. The dependence of energy levels on a magnetic field and a strength of spin-orbit interaction is presented. (authors)

  1. Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics

    DEFF Research Database (Denmark)

    Mie, Axel; Laursen, Kristian Holst; Åberg, K. Magnus

    2014-01-01

    The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, ...

  2. Randomized trial for superiority of high field strength intra-operative magnetic resonance imaging guided resection in pituitary surgery.

    Science.gov (United States)

    Tandon, Vivek; Raheja, Amol; Suri, Ashish; Chandra, P Sarat; Kale, Shashank S; Kumar, Rajinder; Garg, Ajay; Kalaivani, Mani; Pandey, Ravindra M; Sharma, Bhawani S

    2017-03-01

    Till date there are no randomized trials to suggest the superiority of intra-operative magnetic resonance imaging (IOMRI) guided trans-sphenoidal pituitary resection over two dimensional fluoroscopic (2D-F) guided resections. We conducted this trial to establish the superiority of IOMRI in pituitary surgery. Primary objective was to compare extent of tumor resection between the two study arms. It was a prospective, randomized, outcome assessor and statistician blinded, two arm (A: IOMRI, n=25 and B: 2D-F, n=25), parallel group clinical trial. 4 patients from IOMRI group cross-over to 2D-F group and were consequently analyzed in latter group, based on modified intent to treat method. A total of 50 patients were enrolled till completion of trial (n=25 in each study arm). Demographic profile and baseline parameters were comparable among the two arms (p>0.05) except for higher number of endoscopic procedures and experienced neurosurgeons (>10years) in arm B (p=0.02, 0.002 respectively). Extent of resection was similar in both study arms (A, 94.9% vs B, 93.6%; p=0.78), despite adjusting for experience of operating surgeon and use of microscope/endoscope for surgical resection. We observed that use of IOMRI helped optimize the extent of resection in 5/20 patients (25%) for pituitary tumor resection in-group A. Present study failed to observe superiorty of IOMRI over conventional 2D-F guided resection in pituitary macroadenoma surgery. By use of this technology, younger surgeons could validate their results intra-operatively and hence could increase EOR without causing any increase in complications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Dramatically enhanced electrical breakdown strength in cellulose nanopaper

    Directory of Open Access Journals (Sweden)

    Jianwen Huang

    2016-09-01

    Full Text Available Electrical breakdown behaviors of nanopaper prepared from nanofibrillated cellulose (NFC were investigated. Compared to conventional insulating paper made from micro softwood fibers, nanopaper has a dramatically enhanced breakdown strength. Breakdown field of nanopaper is 67.7 kV/mm, whereas that of conventional paper is only 20 kV/mm. Air voids in the surface of conventional paper are observed by scanning electron microscope (SEM. Further analyses using mercury intrusion show that pore diameter of conventional paper is around 1.7 μm, while that of nanopaper is below 3 nm. Specific pore size of nanopaper is determined to be approximately 2.8 nm by the gas adsorption technique. In addition, theoretical breakdown strengths of nanopaper and conventional paper are also calculated to evaluate the effect of pore size. It turns out that theoretical values agree well with experimental data, indicating that the improved strength in nanopaper is mainly attributed to the decreased pore size. Due to its outstanding breakdown strength, this study indicates the suitability of nanopaper for electrical insulation in ultra-high voltage convert transformers and other electrical devices.

  4. Mastitis diagnosis in dairy cows using PathoProof real-time polymerase chain reaction assay in comparison with conventional bacterial culture in a Northern German field study.

    Science.gov (United States)

    Spittel, Susanne; Hoedemaker, Martina

    2012-01-01

    In the following field study, the commercial PathoProof Mastitis PCR Assay, a real-time PCR for identifying eleven mastitis pathogens and the staphylococcal beta-lactamase gene, was compared with conventional bacterial culture. For this purpose, 681 udder quarter samples from 173 clinically healthy cows with varying somatic cell count from four dairy herds in the region of Osnabrück, Lower Saxony, Germany, were collected between July 2010 and February 2011 and subjected to PCR and bacterial culture. The frequency of positive pathogen signals was markedly higher with PCR compared with culture (70.6% vs. 32.2%). This was accompanied by a substantial higher percentage of multiple pathogen identifications and a lower percentage of single identifications in the PCR compared with bacterial culture. Using bacterial culture as gold standard, moderate to high sensitivities (76.9-100%) and specificities (63.3-98.7%) were calculated for six out of seven pathogens with sufficient detection numbers. For Enterococcus spp, the sensitivity was only 9.1%. When the PCR results of pooled udder quarter samples of the 173 cows were compared with the single udder quarter samples, in 72% of the cases, major pathogen DNA was either not found in both types of samples, or in the case of a positive pool sample, the respective pathogens were found in at least one udder quarter sample. With both methods, the most frequently detected mastitis pathogens were coryneform bacteria (PCR: Corynebacterium bovis), coagulase-negative staphylococci (CNS) and Staphylococcus (S.) aureus, followed by Arcanobacterium pyogenes/Peptoniphilus indolicus with PCR, and then with both methods, Streptococcus uberis. The staphylococcal beta-lactamase gene was found in 27.7% of the S. aureus and in 37.0% of the CNS identifications.

  5. Effect of stationary magnetic field strengths of 150 and 200 mT on reactive oxygen species production in soybean.

    Science.gov (United States)

    Shine, M B; Guruprasad, K N; Anand, Anjali

    2012-07-01

    Our previous investigation reported the beneficial effect of pre-sowing magnetic treatment for improving germination parameters and biomass accumulation in soybean. In this study, soybean seeds treated with static magnetic fields of 150 and 200 mT for 1 h were evaluated for reactive oxygen species (ROS) and activity of antioxidant enzymes. Superoxide and hydroxyl radicals were measured in embryos and hypocotyls of germinating seeds by electron paramagnetic resonance spectroscopy and kinetics of superoxide production; hydrogen peroxide and antioxidant activities were estimated spectrophotometrically. Magnetic field treatment resulted in enhanced production of ROS mediated by cell wall peroxidase while ascorbic acid content, superoxide dismutase and ascorbate peroxidase activity decreased in the hypocotyl of germinating seeds. An increase in the cytosolic peroxidase activity indicated that this antioxidant enzyme had a vital role in scavenging the increased H(2)O(2) produced in seedlings from the magnetically treated seeds. Hence, these studies contribute to our first report on the biochemical basis of enhanced germination and seedling growth in magnetically treated seeds of soybean in relation to increased production of ROS. Copyright © 2012 Wiley Periodicals, Inc.

  6. CNR considerations for rapid real-time MRI tumor tracking in radiotherapy hybrid devices: Effects of B{sub 0} field strength

    Energy Technology Data Exchange (ETDEWEB)

    Wachowicz, K., E-mail: keith.wachowicz@albertahealthservices.ca; De Zanche, N.; Yip, E. [Division of Medical Physics, Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Volotovskyy, V. [Cross Cancer Institute, Alberta Health Services, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada and Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

    2016-08-15

    Purpose: This work examines the subject of contrast-to-noise ratio (CNR), specifically between tumor and tissue background, and its dependence on the MRI field strength, B{sub 0}. This examination is motivated by the recent interest and developments in MRI/radiotherapy hybrids where real-time imaging can be used to guide treatment beams. The ability to distinguish a tumor from background tissue is of primary importance in this field, and this work seeks to elucidate the complex relationship between the CNR and B{sub 0} that is too often assumed to be purely linear. Methods: Experimentally based models of B{sub 0}-dependant relaxation for various tumor and normal tissues from the literature were used in conjunction with signal equations for MR sequences suitable for rapid real-time imaging to develop field-dependent predictions for CNR. These CNR models were developed for liver, lung, breast, glioma, and kidney tumors for spoiled gradient-echo, balanced steady-state free precession (bSSFP), and single-shot half-Fourier fast spin echo sequences. Results: Due to the pattern in which the relaxation properties of tissues are found to vary over B{sub 0} field (specifically the T{sub 1} time), there was always an improved CNR at lower fields compared to linear dependency. Further, in some tumor sites, the CNR at lower fields was found to be comparable to, or sometimes higher than those at higher fields (i.e., bSSFP CNR for glioma, kidney, and liver tumors). Conclusions: In terms of CNR, lower B{sub 0} fields have been shown to perform as well or better than higher fields for some tumor sites due to superior T{sub 1} contrast. In other sites this effect was less pronounced, reversing the CNR advantage. This complex relationship between CNR and B{sub 0} reveals both low and high magnetic fields as viable options for tumor tracking in MRI/radiotherapy hybrids.

  7. Optical absorption of carbon nanotube diodes: Strength of the electronic transitions and sensitivity to the electric field polarization

    Science.gov (United States)

    Mencarelli, Davide; Pierantoni, Luca; Rozzi, Tullio

    2008-03-01

    Aim of this work is to model electrostatically doped carbon nanotubes (CNT), which have recently proved to perform as ideal PN diodes, also showing photovoltaic properties. The new model is able to predict the optical absorption of semiconducting CNT as function of size and chirality. We justify theoretically, for the first time, the experimentally observed capability of CNTs to detect and select not only a well defined set of frequencies, as resulting from their discrete band structure, but also the polarization of the incident radiation. The analysis develops from an approach proposed in a recent contribution. The periodic structure of CNTs is formally modeled as a photonic crystal, that is characterized by means of numerical simulators. Longitudinal and transverse components of the electric field are shown to excite distinct interband transitions between well defined energy levels. Equivalently, for a given energy of the incident radiation, absorption may show polarization ratios strongly exceeding unity.

  8. Application of non-invasive low strength pulsed electric field to EGCG treatment synergistically enhanced the inhibition effect on PANC-1 cells.

    Science.gov (United States)

    Hsieh, Chih-Hsiung; Lu, Chueh-Hsuan; Chen, Wei-Ting; Ma, Bo-Lun; Chao, Chih-Yu

    2017-01-01

    Traditional therapies for pancreatic cancer are usually expensive and likely to cause side effects, and most patients have the risk of recurrence and suffering pain. Here, we investigated combination treatment of epigallocatechin-3-gallate (EGCG) and non-invasive low strength pulsed electric field (PEF) on the human pancreatic cell line PANC-1. Cells were cultured in various concentrations of EGCG and exposed to trains of PEF. The results showed that the low strength PEF alone or single treatment with low concentration of EGCG did not obviously affect the cell proliferation and migration in PANC-1. However, the EGCG-induced inhibitions of cell viability and migration ability in PANC-1 were dramatically enhanced by the further exposure of low strength PEF (60 V/cm). In particular, the same combination treatment caused less inhibition of cell viability in non-malignant HEK293 cells. We also found the combination treatment significantly decreased the ratio of Bcl-2/Bax protein and increased caspase activity in PANC-1 cells, resulting in the promotion of apoptotic responses, evidenced by chromatin condensation. The findings of the present study reveal the synergistic reactions in the combination treatment may severely disturb mitochondria, enhance the intrinsic pathway transduction, and effectively induce apoptosis; moreover, the migration and invasion of PANC-1 cancer cells were also significantly suppressed. Since normal cells are less sensitive to this combination treatment, and the non-invasive PEF could be modified to focus on a specific location, this treatment may serve as a promising method for anti-cancer therapy.

  9. A Comparison of an Acid Primer (Clearfil Liner Bond 2V with Other Conventional Etchants on the Shear Bond Strength and the Bracket—Adhesive Failure Mode: An ex vivo Study

    Directory of Open Access Journals (Sweden)

    Ashish Garg

    2013-01-01

    Results and conclusion: The results of the study indicated that acidic primer containing both the enamel etchant and primer have adequate bond strength with decreased residual adhesive left on the enamel surface after debonding, thereby maintaining a sound unblemished enamel surface after debonding orthodontic brackets and less chances of iatrogenic enamel fracture and crazing along with decreased chairside time.

  10. Yield and economic performance of organic and conventional cotton-based farming systems--results from a field trial in India.

    Science.gov (United States)

    Forster, Dionys; Andres, Christian; Verma, Rajeev; Zundel, Christine; Messmer, Monika M; Mäder, Paul

    2013-01-01

    The debate on the relative benefits of conventional and organic farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable farming practices on a large scale is of utmost importance. However, information concerning the performance of farming systems under organic and conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007-2010) of a farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without Bt cotton) management was investigated. We observed a significant yield gap between organic and conventional farming systems in the 1(st) crop cycle (cycle 1: 2007-2008) for cotton (-29%) and wheat (-27%), whereas in the 2(nd) crop cycle (cycle 2: 2009-2010) cotton and wheat yields were similar in all farming systems due to lower yields in the conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant) yields were marginally lower than conventional yields (-1% in cycle 1, -11% in cycle 2). Averaged across all crops, conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25%) due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11%) across the four harvest years compared to the conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of cotton and

  11. Yield and economic performance of organic and conventional cotton-based farming systems--results from a field trial in India.

    Directory of Open Access Journals (Sweden)

    Dionys Forster

    Full Text Available The debate on the relative benefits of conventional and organic farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable farming practices on a large scale is of utmost importance. However, information concerning the performance of farming systems under organic and conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007-2010 of a farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without Bt cotton management was investigated. We observed a significant yield gap between organic and conventional farming systems in the 1(st crop cycle (cycle 1: 2007-2008 for cotton (-29% and wheat (-27%, whereas in the 2(nd crop cycle (cycle 2: 2009-2010 cotton and wheat yields were similar in all farming systems due to lower yields in the conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant yields were marginally lower than conventional yields (-1% in cycle 1, -11% in cycle 2. Averaged across all crops, conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%, whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25% due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11% across the four harvest years compared to the conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of cotton

  12. Protocol to amend the convention on third party liability in the field of nuclear energy of 29th July 1960, as amended by the additional protocol of 28th January 1964, Paris, 16 November 1982

    International Nuclear Information System (INIS)

    1983-01-01

    This Protocol further amends the Convention on Third Party Liability in the Field of Nuclear Energy of 29 July 1960, concluded between the Federal Republic of Germany, Austria, Belgium, Denmark, Spain, Finland, France, Greece, Italy, Luxembourg, Norway, Netherlands, Portugal, United Kingdom, Sweden, Switzerland and Turkey within the framework of the Organisation for Economic Co-operation and Development. (U.K.)

  13. Polycyclic Aromatic Hydrocarbon Emission in Spitzer /IRS Maps. II. A Direct Link between Band Profiles and the Radiation Field Strength

    Energy Technology Data Exchange (ETDEWEB)

    Stock, D. J.; Peeters, E., E-mail: dstock84@gmail.com [Department of Physics and Astronomy, University of Western Ontario, London, ON, N6A 3K7 (Canada)

    2017-03-10

    We decompose the observed 7.7 μ m polycyclic aromatic hydrocarbon (PAH) emission complexes in a large sample of over 7000 mid-infrared spectra of the interstellar medium using spectral cubes observed with the Spitzer /IRS-SL instrument. In order to fit the 7.7 μ m PAH emission complex we invoke four Gaussian components, which are found to be very stable in terms of their peak positions and widths across all of our spectra, and subsequently define a decomposition with fixed parameters, which gives an acceptable fit for all the spectra. We see a strong environmental dependence on the interrelationships between our band fluxes—in the H ii regions all four components are intercorrelated, while in the reflection nebulae (RNs) the inner and outer pairs of bands correlate in the same manner as previously seen for NGC 2023. We show that this effect arises because the maps of RNs are dominated by emission from strongly irradiated photodissociation regions, while the much larger maps of H ii regions are dominated by emission from regions much more distant from the exciting stars, leading to subtly different spectral behavior. Further investigation of this dichotomy reveals that the ratio of two of these components (centered at 7.6 and 7.8 μ m) is linearly related to the UV-field intensity (log G {sub 0}). We find that this relationship does not hold for sources consisting of circumstellar material, which are known to have variable 7.7 μ m spectral profiles.

  14. Assessment of female ballet dancers' ankles in the en pointe position using high field strength magnetic resonance imaging.

    Science.gov (United States)

    Russell, Jeffrey A; Yoshioka, Hiroshi

    2016-08-01

    The en pointe position of the ankle in ballet is extreme. Previously, magnetic resonance imaging (MRI) of ballet dancers' ankles en pointe was confined to a low field, open MR device. To develop a reproducible ankle MRI protocol for ballet dancers en pointe and to assess the positions of the key structures in the dancers ankles. Six female ballet dancers participated; each was randomly assigned to stand en pointe while one of her feet and ankles was splinted with wooden rods affixed with straps or to begin with the ankle in neutral position. She lay in an MR scanner with the ankle inside a knee coil for en pointe imaging and inside an ankle/foot coil for neutral position imaging. Proton density weighted images with and without fat suppression and 3D water excitation gradient recalled echo images were obtained en pointe and in neutral position in sagittal, axial, and coronal planes. We compared the bones, cartilage, and soft tissues within and between positions. No difficulties using the protocol were encountered. En pointe the posterior articular surface of the tibial plafond was incongruent with the talar dome and rested on the posterior talus. The posterior edge of the plafond impinged Kager's fat pad. All participants exhibited one or more small ganglion cysts about the ankle and proximal foot, as well as fluid accumulation in the flexor and fibularis tendon sheaths. Our MRI protocol allows assessment of female ballet dancers' ankles in the extreme plantar flexion position in which the dancers perform. We consistently noted incongruence of the talocrural joint and convergence of the tibia, talus, and calcaneus posteriorly. This protocol may be useful for clinicians who evaluate dancers. © The Foundation Acta Radiologica 2015.

  15. T1 mapping of the myocardium: Intra-individual assessment of the effect of field strength, cardiac cycle and variation by myocardial region

    Directory of Open Access Journals (Sweden)

    Kawel Nadine

    2012-05-01

    Full Text Available Abstract Background Myocardial T1 relaxation time (T1 time and extracellular volume fraction (ECV are altered in the presence of myocardial fibrosis. The purpose of this study was to evaluate acquisition factors that may result in variation of measured T1 time and ECV including magnetic field strength, cardiac phase and myocardial region. Methods 31 study subjects were enrolled and underwent one cardiovascular MR exam at 1.5 T and two exams at 3 T, each on separate days. A Modified Look-Locker Inversion Recovery (MOLLI sequence was acquired before and 5, 10, 12, 20, 25 and 30 min after administration of 0.15 mmol/kg gadopentetate dimeglumine (Gd-DTPA; Magnevist at 1.5 T (exam 1. For exam 2, MOLLI sequences were acquired at 3 T both during diastole and systole, before and after administration of Gd-DTPA (0.15 mmol/kg Magnevist.Exam 3 was identical to exam 2 except gadobenate dimeglumine was administered (Gd-BOPTA; 0.1 mmol/kg Multihance. T1 times were measured in myocardium and blood. ECV was calculated by (ΔR1myocardium/ΔR1blood*(1-hematocrit. Results Before gadolinium, T1 times of myocardium and blood were significantly greater at 3 T versus 1.5 T (28% and 31% greater, respectively, p  Conclusion ECV is similar at field strengths of 1.5 T and 3 T. Due to minor variations in T1 time and ECV during the cardiac cycle and in different myocardial regions, T1 measurements should be obtained at the same cardiac phase and myocardial region in order to obtain consistent results.

  16. SU-E-T-590: Optimizing Magnetic Field Strengths with Matlab for An Ion-Optic System in Particle Therapy Consisting of Two Quadrupole Magnets for Subsequent Simulations with the Monte-Carlo Code FLUKA

    International Nuclear Information System (INIS)

    Baumann, K; Weber, U; Simeonov, Y; Zink, K

    2015-01-01

    Purpose: Aim of this study was to optimize the magnetic field strengths of two quadrupole magnets in a particle therapy facility in order to obtain a beam quality suitable for spot beam scanning. Methods: The particle transport through an ion-optic system of a particle therapy facility consisting of the beam tube, two quadrupole magnets and a beam monitor system was calculated with the help of Matlab by using matrices that solve the equation of motion of a charged particle in a magnetic field and field-free region, respectively. The magnetic field strengths were optimized in order to obtain a circular and thin beam spot at the iso-center of the therapy facility. These optimized field strengths were subsequently transferred to the Monte-Carlo code FLUKA and the transport of 80 MeV/u C12-ions through this ion-optic system was calculated by using a user-routine to implement magnetic fields. The fluence along the beam-axis and at the iso-center was evaluated. Results: The magnetic field strengths could be optimized by using Matlab and transferred to the Monte-Carlo code FLUKA. The implementation via a user-routine was successful. Analyzing the fluence-pattern along the beam-axis the characteristic focusing and de-focusing effects of the quadrupole magnets could be reproduced. Furthermore the beam spot at the iso-center was circular and significantly thinner compared to an unfocused beam. Conclusion: In this study a Matlab tool was developed to optimize magnetic field strengths for an ion-optic system consisting of two quadrupole magnets as part of a particle therapy facility. These magnetic field strengths could subsequently be transferred to and implemented in the Monte-Carlo code FLUKA to simulate the particle transport through this optimized ion-optic system

  17. Contrast visibility for indirect MR arthrography with different protein contents and agent relaxivities at different field strengths: An in vitro model

    International Nuclear Information System (INIS)

    Nouh, M.R.; Schweitzer, M.E.; Ragatte, Ravinder R.

    2011-01-01

    Objectives: Protein binding and relaxivity are major determinants of the relative effectiveness of an MR arthrographic contrast agent. We sought to evaluate the optimal concentrations of high and usual relaxivity agents in two different proteinous environments at variable field strength for two MR contrast agents of different relaxivities. Materials and methods: At 1.5, 3.0 and 7.0 T, gadobenate dimeglumine (Multihance) with high-relaxivity in proteinous environment and gadoteridol (Prohance) with more typical behavior were studied at 1.25, 2.5, 5, and 10 mmol in 1.7 g/dL and 3 g/dL albumin (mimicking protein content of normal and inflammatory synovial fluids, respectively) vs. pure normal saline, as a control. Analysis of image signal intensity (SI) and relaxivity values was done. Results: In our study a change in concentration had no significant effect on T1 SI. In contrast, nearly every change in concentration led to a significant change in T2 SI. In 1.25 mmol concentration, there was no effect on T1 SI of either protein concentrations while higher concentrations showed significant decreased SI in either protein carrier compared to saline. The SI of Gadoteridol was significantly higher (p < 0.0001) than that of gadobenate at each of 3 T and 7 T, but was significantly lower (p < 0.001) at 1.5 T in saline solution while this was not significant for either protein carrier. Both protein carriers had significant effect on T1 (p = 0.0124) and T2 (p = 0.0118) relaxivities. Also solution concentration significantly (p < 0.01) affected both T1 and T2 relaxivities. Field strength did not affect T1 relaxivity (p = 0.02511) while it significantly affected T2 relaxivity (p < 0.001). This was significant (p = 0.035) in case of gadoteridol at 3 T. Conclusion: 1.25 mmol concentration of both gadoteridol and gadobenate solutions yields the best diagnostic T1 SI specially in higher fields (3 T and 7 T) and avoid the deleterious effect of increasing concentration on T2 SI

  18. Development and application of multiple-quantum coherence techniques for in vivo sodium MRI at high and ultra-high field strengths

    International Nuclear Information System (INIS)

    Fiege, Daniel Pascal

    2014-01-01

    Sodium magnetic resonance imaging (MRI) can quantify directly and non-invasively tissue sodium concentration levels in vivo. Tissue sodium concentration levels are tightly regulated and have been shown to be directly linked to cell viability. The intracellular sodium concentration is an even more specific parameter. The triple-quantum filtering (TQF) technique for sodium MRI has been suggested to detect the intracellular sodium only. Despite their huge potential, only few studies with sodium MRI have been carried out because of the long acquisition times of sodium MRI techniques, their susceptibility to static field inhomogeneities and their limited signal-to-noise ratio compared to proton MRI. Three novel techniques that address these limitations are presented in this thesis: (a) a sodium MRI sequence that acquires simultaneously both tissue sodium concentration maps and TQF images, (b) a phase-rotation scheme that allows for the acquisition of static field inhomogeneity insensitive TQF images, and (c) the combination of the two aforementioned techniques with optimised parameters at the ultra-high fi eld strength of 9.4 T in vivo. The SISTINA sequence - simultaneous single-quantum and triple-quantum filtered imaging of 23 Na - is presented. The sequence is based on a TQF acquisition with a Cartesian readout and a three-pulse preparation. The delay between the first two pulses is used for an additional ultra-short echo time 3D radial readout. The method was implemented on a 4T scanner. It is validated in phantoms and in healthy volunteers that this additional readout does not interfere with the TQ preparation. The method is applied to three cases of brain tumours. The tissue sodium concentration maps and TQF images are presented and compared to 1 H MR and positron emission tomography images. The three-pulse TQF preparation is sensitive to static field inhomogeneities. This problem is caused by destructive interference of different coherence pathways. To address

  19. MRI of the knee: how do field strength and radiologist's experience influence diagnostic accuracy and interobserver correlation in assessing chondral and meniscal lesions and the integrity of the anterior cruciate ligament?

    International Nuclear Information System (INIS)

    Krampla, W.; Roesel, M.; Svoboda, K.; Nachbagauer, A.; Gschwantler, M.; Hruby, W.

    2009-01-01

    Accuracy of MRI reports is taken for granted. In this paper the inter-observer reliability in the interpretation of meniscal lesions, degree of chondropathy, and integrity of the ACL was analyzed while taking the radiologist's experience and field strength into account. Fifty-two MRI studies of knees were interpreted by 11 radiologists independently. Twenty-two were acquired on 1.0-T, 20 on 1.5-T, and 10 on 3.0-T systems. Four of the radiologists had more than 5 years and seven had 3 to 5 years of experience in interpreting MRI studies. The findings were compared with the intra-operative findings. Inter-observer variance, specificity, and sensitivity were evaluated for each field strength. Inter-observer correlation ranged between 0.370 for cartilage lesions and 0.597 for meniscal tears. Correlation values did not increase with experience or field strength. The number of false reports was dependent on the observer, but not on field strength. The rate of false interpretations was significantly higher for most criteria in the less experienced group. In conclusion, inter-observer correlation was low, although the diagnostic criteria were defined. The use of the classification scheme should be standardized by uniform training. Radiologist experience seems to be more important than field strength. (orig.)

  20. Influence of the Rashba and Dresselhaus spin-orbit interactions of equal strength on the electron states in the circular quantum ring in the presence of a magnetic field

    International Nuclear Information System (INIS)

    Kudryashov, V.V.; Baran, A.V.

    2012-01-01

    The solutions of the Schrodinger equation are obtained for an electron in the two-dimensional circular semiconductor quantum ring in the presence of both an external magnetic and the Rashba and Dresselhaus spin-orbit interactions of equal strength . Confinement is simulated by a realistic potential well of finite depth. The dependence of energy levels on the magnetic field, the strength of spin-orbit interaction, and the relative ring width is presented. (authors)

  1. Reduced field-of -view diffusion-weighted magnetic resonance imaging of the pancreas: Comparison with conventional single-shot echo-planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Jin; Lee, Jeong Min; Yoon, Jeong Hee; Jang, Jin Young; Kim, Sun Whe; Ryu, Ji Kon; Han, Joon Koo; Choi, Byung Ihn [Seoul National University Hospital, Seoul (Korea, Republic of); Kannengiesser, Stephan [Siemens Healthcare, Erlangen (Germany)

    2015-12-15

    To investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) diffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI. In this retrospective study, 2 readers independently performed qualitative analysis of full FOV DWI (FOV, 38 × 38 cm; b-value, 0 and 500 s/mm{sup 2}) and reduced FOV DWI (FOV, 28 × 8.5 cm; b-value, 0 and 400 s/mm{sup 2}). Both procedures were conducted with a two-dimensional spatially selective radiofrequency excitation pulse, in 102 patients with benign or malignant pancreatic diseases (mean size, 27.5 ± 14.4 mm). The study parameters included 1) anatomic structure visualization, 2) lesion conspicuity, 3) artifacts, 4) IQ score, and 5) subjective clinical utility for confirming or excluding initially considered differential diagnosis on conventional imaging. Another reader performed quantitative ADC measurements of focal pancreatic lesions and parenchyma. Wilcoxon signed-rank test was used to compare qualitative scores and ADCs between DWI sequences. Mann Whitney U-test was used to compare ADCs between the lesions and parenchyma. On qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm{sup 2} and 2.81 ± 0.64 at b = 400 s/mm{sup 2}), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm{sup 2} and 3.15 ± 0.79 at b = 400 s/mm{sup 2}), IQ score (8.51 ± 2.05 at b = 0 s/mm{sup 2} and 8.79 ± 1.60 at b = 400 s/mm{sup 2}), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm{sup 2} and 2.56 ± 0.47 at b = 500 s/mm{sup 2}; lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm{sup 2} and 2.89 ± 0.86 at b = 500 s/mm{sup 2}; IQ score, 7.13 ± 1.83 at b = 0 s/mm{sup 2} and 8.17 ± 1.31 at b = 500 s/mm{sup 2}; clinical utility, 3.14 ± 0.70) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm{sup 2} (full FOV DWI, 2.41 ± 0.63) (p

  2. Temperature dependent and applied field strength dependent magnetic study of cobalt nickel ferrite nano particles: Synthesized by an environmentally benign method

    Science.gov (United States)

    Sontu, Uday Bhasker; G, Narsinga Rao; Chou, F. C.; M, V. Ramana Reddy

    2018-04-01

    Spinel ferrites have come a long way in their versatile applications. The ever growing applications of these materials demand detailed study of material properties and environmental considerations in their synthesis. In this article, we report the effect of temperature and applied magnetic field strength on the magnetic behavior of the cobalt nickel ferrite nano powder samples. Basic structural properties of spinel ferrite nano particles, that are synthesized by an environmentally benign method of auto combustion, are characterized through XRD, TEM, RAMAN spectroscopy. Diffuse Reflectance Spectroscopy (DRS) is done to understand the nickel substitution effect on the optical properties of cobalt ferrite nano particles. Thermo magnetic studies using SQUID in the temperature range 5 K to 400 K and room temperature (300 K) VSM studies are performed on these samples. Fields of 0Oe (no applied field: ZF), 1 kOe (for ZFC and FC curves), 5 kOe (0.5 T), 50 kOe (5T) (for M-H loop study) are used to study the magnetic behavior of these nano particles. The XRD,TEM analysis suggest 40 nm crystallites that show changes in the cation distribution and phase changes in the spinel structure with nickel substitution. Raman micrographs support phase purity changes and cation redistributions with nickel substitution. Diffuse reflectance study on powder samples suggests two band gap values for nickel rich compounds. The Magnetic study of these sample nano particles show varied magnetic properties from that of hard magnetic, positive multi axial anisotropy and single-magnetic-domain structures at 5 K temperature to soft magnetic core shell like structures at 300 K temperature. Nickel substitution effect is non monotonous. Blocking temperature of all the samples is found to be higher than the values suggested in the literature.

  3. A Comparison of Soil microbial community structure, protozoa and nematodes in field plots of conventional and genetically modified maize expressing the Bacillus thuringiensis Cry1Ab toxin

    DEFF Research Database (Denmark)

    Griffiths, B. S.; Caul, S.; Thompson, J.

    2005-01-01

    Field trials were established at three European sites (Denmark, Eastern France, South-West France) of genetically modified maize (Zea mays L.) expressing the CryIAb Bacillus thuringiensis toxin (Bt), the near-isogenic non-Bt cultivar, another conventional maize cultivar and grass. Soil from Denmark......) and phospholipid fatty acid analysis (PLFA), and protozoa and nematodes in all samples. Individual differences within a site resulted from: greater nematode numbers under grass than maize on three occasions; different nematode populations under the conventional maize cultivars once; and two occasions when...... there was a reduced protozoan population under Bt maize compared to non-Bt maize. Microbial community structure within the sites only varied with grass compared to maize, with one occurrence of CLPP varying between maize cultivars (Bt versus a conventional cultivar). An overall comparison of Bt versus non-Bt maize...

  4. Functionalized Magnetic Resonance Contrast Agent Selectively Binds to Glycoprotein IIb/IIIa on Activated Human Platelets under Flow Conditions and Is Detectable at Clinically Relevant Field Strengths

    Directory of Open Access Journals (Sweden)

    Constantin von zur Mühlen

    2008-03-01

    Full Text Available Recent progress in molecular magnetic resonance imaging (MRI provides the opportunity to image cells and cellular receptors using microparticles of iron oxide (MPIOs. However, imaging targets on vessel walls remains challenging owing to the quantity of contrast agents delivered to areas of interest under shear stress conditions. We evaluated ex vivo binding characteristics of a functional MRI contrast agent to ligand-induced binding sites (LIBSs on activated glycoprotein IIb/IIIa receptors of human platelets, which were lining rupture-prone atherosclerotic plaques and could therefore facilitate detection of platelet-mediated pathology in atherothrombotic disease. MPIOs were conjugated to anti-LIBS single-chain antibodies (LIBS-MPIO or control antibodies (control MPIO. Ex vivo binding to human platelet-rich clots in a dose-dependent manner was confirmed on a 3 T clinical MRI scanner and by histology (p < .05 for LIBS-MPIO vs control MPIO. By using a flow chamber setup, significant binding of LIBS-MPIO to a platelet matrix was observed under venous and arterial flow conditions, but not for control MPIO (p < .001. A newly generated MRI contrast agent detects activated human platelets at clinically relevant magnetic field strengths and binds to platelets under venous and arterial flow conditions, conveying high payloads of contrast to specific molecular targets. This may provide the opportunity to identify vulnerable, rupture-prone atherosclerotic plaques via noninvasive MRI.

  5. Relationship Between Solidification Microstructure and Hot Cracking Susceptibility for Continuous Casting of Low-Carbon and High-Strength Low-Alloyed Steels: A Phase-Field Study

    Science.gov (United States)

    Böttger, B.; Apel, M.; Santillana, B.; Eskin, D. G.

    2013-08-01

    Hot cracking is one of the major defects in continuous casting of steels, frequently limiting the productivity. To understand the factors leading to this defect, microstructure formation is simulated for a low-carbon and two high-strength low-alloyed steels. 2D simulation of the initial stage of solidification is performed in a moving slice of the slab using proprietary multiphase-field software and taking into account all elements which are expected to have a relevant effect on the mechanical properties and structure formation during solidification. To account for the correct thermodynamic and kinetic properties of the multicomponent alloy grades, the simulation software is online coupled to commercial thermodynamic and mobility databases. A moving-frame boundary condition allows traveling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. From the simulation results, significant microstructure differences between the steel grades are quantitatively evaluated and correlated with their hot cracking behavior according to the Rappaz-Drezet-Gremaud (RDG) hot cracking criterion. The possible role of the microalloying elements in hot cracking, in particular of traces of Ti, is analyzed. With the assumption that TiN precipitates trigger coalescence of the primary dendrites, quantitative evaluation of the critical strain rates leads to a full agreement with the observed hot cracking behavior.

  6. The effect of magnetic field strength on the time evolution of high energy bremsstrahlung radiation created by an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ropponen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)], E-mail: tommi.ropponen@phys.jyu.fi; Tarvainen, O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Jones, P.; Peura, P.; Kalvas, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland); Suominen, P. [Prizztech Ltd/Magnet Technology Centre, Tiedepuisto 4, FI-28600 Pori (Finland); Koivisto, H.; Arje, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)

    2009-03-11

    An electron cyclotron resonance (ECR) ion source is one of the most used ion source types for high charge state heavy ion production. In ECR plasma the electrons are heated by radio frequency microwaves in order to provide ionization of neutral gases. As a consequence, ECR heating also generates very high electron energies (up to MeV region) which can produce a vast amount of bremsstrahlung radiation causing problems with radiation shielding and heating superconducting cryostat of an ECR ion source. To gain information about the time evolution of the electron energies in ECR plasma radial bremsstrahlung measurements were performed. JYFL 14 GHz ECR ion source was operated in pulsed mode and time evolution measurements were done with different axial magnetic field strengths with oxygen and argon plasmas. Bremsstrahlung data were analyzed with a time interval of 2 ms yielding information at unprecedented detail about the time evolution of high energy bremsstrahlung radiation from an ECR ion source. It was observed, for example, that reaching the steady state phase of the plasma bremsstrahlung requires several hundred milliseconds and the steady state time can be different with different gases.

  7. Comparative field evaluation of some newer versus conventional insecticides for the control of aphids (homoptera: aphididae) on oilseed rape (brassica napus l.)

    International Nuclear Information System (INIS)

    Sarwar, M.; Ahmad, N.; Bux, M.; Nasrullah, A.; Tofique, M.

    2011-01-01

    This study was designed to evaluate the effects of new insecticides like, Imidacloprid (Confidor 200 EC), Thiomethoxam (Actara 25 WG) and Acetamiprid (Megamos 20 SL) belonging to Nitroguanidine group along with conventional insecticides such as, Chlorpyrifos (Lorsban 40 EC) and Dimethoate (Systoate 40 EC) belonging to Organophosphate group against aphids' population on oilseed rape (Brassica napus L.). A perusal of data, based on the overall performance of the test compounds, reflected that newer insecticides were superior in reducing the population of aphids and yield enhancement as compared to conventional insecticides. The best results were achieved with the application of Imidacloprid by recording the lowest number of aphids (2.2 per plant) than obtained with Thiomethoxam and Acetamiprid (3.22 and 4.66, respectively). Other insecticides, viz., Chlorpyrifos and Dimethoate were also found to be effective in maintaining the aphids' population at lower levels per plant (16.2 and 17.5, respectively) over untreated control (227.7). Imidacloprid was responsible for increasing the grain yield to 3722.85 Kg per Hectare, approached by Thiomethoxam, Acetamiprid, Chlorpyrifos and Dimethoate as against unsprayed control (2980.0, 2542.85, 1542.85, 540.0 and 604.85 Kg per Hectare, respectively). Study indicated that selective use of newer insecticides would seem a reasonable strategy in aphids controlling and integration of such chemicals in insects' management package could help to reduce pest densities. (author)

  8. Diagnostic accuracy of contrast-enhanced spectral mammography in comparison to conventional full-field digital mammography in a population of women with dense breasts.

    Science.gov (United States)

    Mori, Miki; Akashi-Tanaka, Sadako; Suzuki, Satoko; Daniels, Murasaki Ikeda; Watanabe, Chie; Hirose, Masanori; Nakamura, Seigo

    2017-01-01

    Contrast-enhanced spectral mammography to compare clinical efficacy of contrast-enhanced spectral mammography (CESM) and conventional digital mammography (MMG) with histopathology as gold standard in dense breasts. A total of 143 breasts of 72 women who underwent CESM and MMG between 2011 and 2014 at Showa University Hospital were analyzed. 129 (90.2 %) of 143 breasts revealed dense breasts on MMG. 58 (40.6 %) of 143 breasts were diagnosed with breast cancer at histopathology. The remaining 85 breasts were diagnosed with benign findings after image assessments and/or core needle biopsy. CESM revealed 8 false-negative cases among 58 breast cancer cases (sensitivity 86.2 %) and 5 false-positive cases (specificity 94.1 %). Accuracy was 90.9 %. Conventional MMG was assessed true positive in 31 of 58 breast cancer cases (sensitivity 53.4 %) and false positive in 12 cases (specificity 85.9 %). Accuracy was 72.7 %. Sensitivity (p < 0.001), specificity (p = 0.016) and accuracy (p < 0.001) were significantly higher on CESM compared to MMG. MMG missed malignancy in 27 breasts. Of these, 25 were dense breasts. Of these 25, 20 (80.0 %) breasts were positive on CESM. These findings suggest that CESM offers superior clinical performance compared to MMG. Use of CESM may decrease false negatives especially for women with dense breasts.

  9. Condromalácia de patela: comparação entre os achados em aparelhos de RM de alto e baixo campo magnético Chondromalacia patellae: comparison of high-field strength versus low-field strength magnetic resonance imaging findings

    Directory of Open Access Journals (Sweden)

    Maxime Figueiredo de Oliveira Freire

    2006-06-01

    Full Text Available OBJETIVO: Comparar os aparelhos de ressonância magnética de baixo campo e de alto campo para estudo da cartilagem articular da patela. MATERIAIS E MÉTODOS: Foi realizado estudo usando as seqüências GRE 2D, GRE 3D, FSE T2 e STIR (baixo campo e TSE T2 SPIR. Cada seqüência foi analisada separadamente para o estudo da cartilagem, sem o conhecimento dos dados do paciente e do resultado das outras seqüências, sendo atribuído grau de lesão de 0 a 3 e descrita a sua localização. Os resultados de concordância e discordância foram analisados pelos testes de Kappa e McNemar. RESULTADOS: Na faceta medial houve baixas concordâncias e as discordâncias mostraram significativa superestimação. Na faceta lateral houve boas concordâncias e as discordâncias não foram significativas. No ápice houve boas concordâncias e as discordâncias mostraram significativa subestimação. CONCLUSÃO: A seqüência STIR teve a melhor concordância com a seqüência TSE T2 SPIR. Lesões de alto grau são mais bem caracterizadas pelas seqüências do aparelho de baixo campo. Áreas de aumento de sinal dificultam o estudo da cartilagem da faceta medial da patela no aparelho de baixo campo.OBJECTIVE: To compare the performance of low-field-strength and high-field-strength magnetic resonance imaging equipments for evaluation of the patella articular cartilage. MATERIALS AND METHODS: The study was developed using GRE 2D, GRE 3D, FSE T2, STIR sequences (low-field and TSE T2 SPIR sequence. Each sequence has been separately analyzed for evaluation of the cartilage without knowledge of other sequences results or any patients data; the lesion was assigned a grade from 0 to 3 and had its location defined. Agreement and disagreement results were analyzed by Kappa and McNemar tests. RESULTS: Medial facet has presented low agreement index and disagreements showed to be significantly overestimated. Lateral facet has presented a reasonable agreement index and disagreement

  10. Registration of 'Linkert' spring wheat with good straw strength and field resistance to the Ug99 family of stem rust races

    Science.gov (United States)

    Straw strength is one of the most important criteria for spring wheat cultivar selection in the north central U.S. ‘Linkert’ (PI 672164) hard red spring wheat was released by the University of Minnesota Agricultural Experiment Station in 2013 and has very good straw strength, high grain protein con...

  11. Paris convention - Decisions, recommendations, interpretations

    International Nuclear Information System (INIS)

    1990-01-01

    This booklet is published in a single edition in English and French. It contains decisions, recommendations and interpretations concerning the 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy adopted by the OECD Steering Committee and the OECD Council. All the instruments are set out according to the Article of the Convention to which they relate and explanatory notes are added where necessary [fr

  12. Magnetic resonance direct thrombus imaging at 3 T field strength in patients with lower limb deep vein thrombosis: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, S.A. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); O' Regan, D.P. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom)]. E-mail: declan.oregan@imperial.ac.uk; Gibson, D. [Imaging Department, Hammersmith Hospitals NHS Trust, London (United Kingdom); Cunningham, C. [Imaging Department, Hammersmith Hospitals NHS Trust, London (United Kingdom); Fitzpatrick, J. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); Allsop, J. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); Larkman, D.J. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); Hajnal, J.V. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom)

    2006-03-15

    AIM: To investigate the feasibility of imaging lower limb deep vein thrombosis using magnetic resonance imaging (MRI) at 3.0 T magnetic field strength with an optimized a T1 magnetization prepared rapid gradient echo technique (MP-RAGE) in patients with normal volunteers as controls. MATERIALS AND METHODS: Patients with deep vein thrombosis (n=4), thrombophlebitis (n=2) and healthy volunteers (n=9) were studied. MRI of the distal thigh and upper calf was performed at 3.0 T with MP-RAGE using two pre-pulses to suppress blood and fat (flip angle 15{sup o}, echo time 5 ms, and repetition time 10 ms). A qualitative analysis was performed for detection of thrombi and image quality. Contrast-to-noise ratios were determined in thrombosed and patent veins. RESULTS: Thrombi were clearly visible as high-signal intensity structures with good suppression of the anatomical background. A blinded reader accurately diagnosed 15 out of 16 cases. The contrast-to-noise ratio measurements showed a positive contrast of thrombus over background muscle 16.9 (SD 4.3, 95% CI: 12.5-21.3) and a negative contrast of the lumen to muscle in patent veins of normal volunteers -7.8 (SD 4.3, 95% CI: -11.1 to -4.5), with p=0.0015. CONCLUSION: Thrombi generate high signal intensity at 3.0 T allowing for their direct visualization if flowing blood, stationary blood and fat are sufficiently suppressed. This preliminary data supports the development of these techniques for other vascular applications.

  13. The value of conventional high-field MRI in MS in the light of the McDonald criteria: a literature review

    DEFF Research Database (Denmark)

    Larsen, Line Sofie Lunde; Larsson, H B W; Frederiksen, Jette Lautrup Battistini

    2010-01-01

    in MS. The aim of this paper was to review MRI studies in MS where a direct comparison of MRI at high field with MRI at 1-1.5 tesla (T) had been performed. The studies evaluated were found by searching Pubmed with relevant terms including MeSH terms. The reviewed studies all found the conspicuity...

  14. Protocol to amend the convention on third party liability in the field of nuclear energy of 29 July 1960, as amended by the additional protocol of 28 January 1964 and by the protocol of 16 November 1982

    International Nuclear Information System (INIS)

    Johnston, Donald; )

    2004-01-01

    The governments of Germany, Belgium, Denmark, Spain, Finland, France, Greece, Italy, Norway, Netherlands, Portugal, United Kingdom, Slovenia, Sweden, Switzerland and Turkey; considering that it is desirable to amend the Convention on Third Party Liability in the Field of Nuclear Energy, concluded at Paris on 29 July 1960 within the framework of the Organisation for European Economic Co-operation, now the Organisation for Economic Co-operation and Development, as amended by the Additional Protocol signed at Paris on 28 January 1964 and by the Protocol signed at Paris on 16 November 1982; have agreed that the Convention shall be amended again. This document presents the modifications given to the text in 6 different languages

  15. The European Convention on bioethics.

    Science.gov (United States)

    Byk, C

    1993-03-01

    Benefiting from a widely recognised experience of the field of bioethics, the Council of Europe which represents all the democratic countries of Europe, has embarked on the ambitious task of drafting a European Convention on bioethics. The purpose of this text is to set out fundamental values, such as respect for human dignity, free informed consent and non-commercialisation of the human body. In addition to this task, protocols will provide specific standards for the different fields concerned with the application of biomedical sciences. The convention and the first two protocols (human experiments and organ transplants) are due to be ready for signature by mid 1994.

  16. Revision of the Paris Convention and the Brussels Supplementary Convention

    International Nuclear Information System (INIS)

    Busekist, Otto von.

    1977-01-01

    The Paris Convention and the Brussels Supplementary Convention have in substance remained unchanged since their adoption in 1960 and 1963, respectively. During that period, nuclear industry and technology have developed considerably while the financial and monetary bases of the Conventions have been shattered. The amounts of liability and compensation have been eroded by inflation, and the gold-based unit of account in which these amounts are expressed has lost its original meaning after the abolition of the official gold price. The question of revising the Conventions, in particular of raising those amounts and of replacing the unit of account, is therefore being studied by the Group of Governmental Experts on Third party Liability in the Field of Nuclear Energy of the OECD Nuclear Energy Agency. (auth.) [fr

  17. Detection and characterization of silver nanoparticles in chicken meat by asymmetric flow field flow fractionation with detection by conventional or single particle ICP-MS

    DEFF Research Database (Denmark)

    Löschner, Katrin; Navratilova, Jana; Købler, Carsten

    2013-01-01

    of the AgNPs took place during the sample preparation stage. The digestate was injected into the asymmetric flow field flow fractionation (AF(4)) -ICP-MS system, which enabled fractionation of nanoparticles from the remaining meat matrix, and resulted in one large peak in the fractograms as well as two...... smaller peaks eluting close to the void volume. The recovery of silver contained in the large AgNP peak was around 80 %. Size determination of AgNPs in the meat matrix, based on external size calibration of the AF(4) channel, was hampered by non-ideal (early elution) behavior of the AgNPs. Single particle...

  18. Comparison of conventional and novel quadrupole drift tube magnets inspired by Klaus Halbach

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, B. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Quadrupole drift tube magnets for a heavy-ion linac provide a demanding application of magnet technology. A comparison is made of three different solutions to the problem of providing an adjustable high-field-strength quadrupole magnet in a small volume. A conventional tape-wound electromagnet quadrupole magnet (conventional) is compared with an adjustable permanent-magnet/iron quadrupole magnet (hybrid) and a laced permanent-magnet/iron/electromagnet (laced). Data is presented from magnets constructed for the SuperHILAC heavy-ion linear accelerator, and conclusions are drawn for various applications.

  19. Slow decay of magnetic fields in open Friedmann universes

    International Nuclear Information System (INIS)

    Barrow, John D.; Tsagas, Christos G.

    2008-01-01

    Magnetic fields in Friedmann universes can experience superadiabatic growth without departing from conventional electromagnetism. The reason is the relativistic coupling between vector fields and spacetime geometry, which slows down the decay of large-scale magnetic fields in open universes, compared to that seen in perfectly flat models. The result is a large relative gain in magnetic strength that can lead to astrophysically interesting B fields, even if our Universe is only marginally open today

  20. Attitude Strength.

    Science.gov (United States)

    Howe, Lauren C; Krosnick, Jon A

    2017-01-03

    Attitude strength has been the focus of a huge volume of research in psychology and related sciences for decades. The insights offered by this literature have tremendous value for understanding attitude functioning and structure and for the effective application of the attitude concept in applied settings. This is the first Annual Review of Psychology article on the topic, and it offers a review of theory and evidence regarding one of the most researched strength-related attitude features: attitude importance. Personal importance is attached to an attitude when the attitude is perceived to be relevant to self-interest, social identification with reference groups or reference individuals, and values. Attaching personal importance to an attitude causes crystallizing of attitudes (via enhanced resistance to change), effortful gathering and processing of relevant information, accumulation of a large store of well-organized relevant information in long-term memory, enhanced attitude extremity and accessibility, enhanced attitude impact on the regulation of interpersonal attraction, energizing of emotional reactions, and enhanced impact of attitudes on behavioral intentions and action. Thus, important attitudes are real and consequential psychological forces, and their study offers opportunities for addressing behavioral change.

  1. Characterization of hollow cathode fall field strength measured by Doppler-free two-photon optogalvanic spectroscopy via Stark splitting of the 2S level of hydrogen and deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C; De la Rosa, M I; Gruetzmacher, K, E-mail: concha@opt.uva.e [Universidad de Valladolid, Facultad de Ciencias, 47071 Valladolid (Spain)

    2010-05-01

    Doppler-free two-photon optogalvanic spectroscopy has been applied to measure the strong electric field strength and the cathode fall characteristics of hollow cathode discharges operated in hydrogen and deuterium via the Stark splitting of the 2S level of atomic hydrogen isotopes. In this paper we show similarities and differences in the tendencies of the cathode fall characteristics of hydrogen and deuterium in a wide range of identical discharge parameters.

  2. Characterization of hollow cathode fall field strength measured by Doppler-free two-photon optogalvanic spectroscopy via Stark splitting of the 2S level of hydrogen and deuterium

    International Nuclear Information System (INIS)

    Perez, C; De la Rosa, M I; Gruetzmacher, K

    2010-01-01

    Doppler-free two-photon optogalvanic spectroscopy has been applied to measure the strong electric field strength and the cathode fall characteristics of hollow cathode discharges operated in hydrogen and deuterium via the Stark splitting of the 2S level of atomic hydrogen isotopes. In this paper we show similarities and differences in the tendencies of the cathode fall characteristics of hydrogen and deuterium in a wide range of identical discharge parameters.

  3. Fatigue strength of field welded joints in I-section girders of thick flange plates with cope hole details; Sukarappu wo yusuru atsuita I gata danmen keta genba yosetsu tsugitebu no hiro kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Minami, K.; Miki, C.; Tateishi, K. [Tokyo Institute of Technology, Tokyo (Japan)

    1997-10-15

    Field welding an I-section girder forms details having scallop at the web, whereas the presence of the scallop causes shear deformation and localized stress concentration. Therefore the details in joints with low fatigue strength are ranked as class G in the fatigue design guideline published by JSSC. With special notice on the effect of shear, the present study has varied the phase by using multiple number of jacks; so loaded that the direction of the shear force will change; assumed field welding of a bridge constructed with a few number of main girders; and verified fatigue strength at thick flange plates. In addition, in order to improve the fatigue strength, elucidation was given on the effect of grinder finish at boxing welds. From these results, items to be considered were made clear when structural details are designed and fabricated, in which I-section girders having scallop are welded in fields. Furthermore, it was considered that stress in web plate jointing welding bead becomes relatively higher than local stress in boxing, which was indicated as a point requiring precaution. 8 refs., 20 figs., 2 tabs.

  4. Strength Training

    Science.gov (United States)

    ... is widespread in many sports — including football, swimming, biking, track and field, and baseball. But because many ... harder by doing aerobic exercise, such as running, biking, or swimming. Doctors recommend at least an hour ...

  5. The effect of steel slag as a coarse aggregate and Sinabung volcanic ash a filler on high strength concrete

    Science.gov (United States)

    Karolina, R.; Putra, A. L. A.

    2018-02-01

    The Development of concrete technology is continues to grow. The requisite for efficient constructions that are often viewed in terms of concrete mechanical behavior, application on the field, and cost estimation of implementation increasingly require engineers to optimize construction materials, especially for concrete materials. Various types of concrete have now been developed according to their needs, such as high strength concrete. On high strength concrete design, it is necessary to consider several factors that will affect the reach of the quality strength, Those are cement, water cement ratio (w/c), aggregates, and proper admixture. In the use of natural mineral, it is important for an engineer to keep an eye on the natural conditions that have been explored. So the selection of aggregates as possible is a material that is not causing nature destruction. On this experiment the use of steel slag from PT.Growth Sumatra Industry as a substitute of coarse and fine aggregate, and volcanic ash of mount Sinabung as microsilka in concrete mixture substituted to create high strength concrete that is harmless for the environment. The use of mount sinabung volcanic ash as microsilika coupled with the use of Master Glenium Sky 8614 superplasticizer. This experiment intend to compare high strength concrete based slag steel as the main constituent aggregates and high strength concrete with a conventional mixture. The research result for 28 days old concrete shows that conventional concrete compressive strength is 67.567 MPa, slag concrete 75.958 Mpa, conventional tensile strength 5.435 Mpa while slag concrete 5.053 Mpa, conventional concrete bending strength 44064.96 kgcm while concrete slag 51473.94 kgcm and modulus of conventional concrete fracture 124.978 kg / cm2 while slag concrete 145.956 kg / cm2. Both concrete slump values shows similar results due to the use of superplasticizer.

  6. Oxidative mobilization of cerium and uranium and enhanced release of "immobile" high field strength elements from igneous rocks in the presence of the biogenic siderophore desferrioxamine B

    Science.gov (United States)

    Kraemer, Dennis; Kopf, Sebastian; Bau, Michael

    2015-09-01

    Polyvalent trace elements such as the high field strength elements (HFSE) are commonly considered rather immobile during low-temperature water-rock interaction. Hence, they have become diagnostic tools that are widely applied in geochemical studies. We present results of batch leaching experiments focused on the mobilization of certain HFSE (Y, Zr, Hf, Th, U and rare earth elements) from mafic, intermediate and felsic igneous rocks in the presence and absence, respectively, of the siderophore desferrioxamine B (DFOB). Our data show that DFOB strongly enhances the mobility of these trace elements during low-temperature water-rock interaction. The presence of DFOB produces two distinct features in the Rare Earths and Yttrium (REY) patterns of leaching solutions, regardless of the mineralogical and chemical composition or the texture of the rock type studied. Bulk rock-normalized REY patterns of leaching solutions with DFOB show (i) a very distinct positive Ce anomaly and (ii) depletion of La and other light REY relative to the middle REY, with a concave downward pattern between La and Sm. These features are not observed in experiments with hydrochloric acid, acetic acid or deionized water. In DFOB-bearing leaching solutions Ce and U are decoupled from and selectively enriched relative to light REY and Th, respectively, due to oxidation to Ce(IV) and U(VI). Oxidation of Ce3+ and U4+ is promoted by the significantly higher stability of the Ce(IV) and U(VI) DFOB complexes as compared to the Ce(III) and U(IV) DFOB complexes. This is similar to the relationship between the Ce(IV)- and Ce(III)-pentacarbonate complexes that cause positive Ce anomalies in alkaline lakes. However, while formation of Ce(IV) carbonate complexes is confined to alkaline environments, Ce(IV) DFOB complexes may produce positive Ce anomalies even in mildly acidic and near-neutral natural waters. Siderophore-promoted dissolution processes also significantly enhance mobility of other 'immobile' HFSE

  7. Chemical Weapons Convention

    National Research Council Canada - National Science Library

    1997-01-01

    On April 29, 1997, the Convention on the Prohibition of the Development, Production, Stockpiling, and Use of Chemical Weapons and on Their Destruction, known as the Chemical Weapons Convention (CWC...

  8. The Hague Judgments Convention

    DEFF Research Database (Denmark)

    Nielsen, Peter Arnt

    2011-01-01

    The Hague Judgments Convention of 2005 is the first global convention on international jurisdiction and recognition and enforcement of judgments in civil and commercial matters. The author explains the political and legal background of the Convention, its content and certain crucial issues during...

  9. Gluebond strength of laser cut wood

    Science.gov (United States)

    Charles W. McMillin; Henry A. Huber

    1985-01-01

    The degree of strength loss when gluing laser cut wood as compared to conventionally sawn wood and the amount of additional surface treatment needed to improve bond quality were assessed under normal furniture plant operating conditions. The strength of laser cut oak glued with polyvinyl acetate adhesive was reduced to 75 percent of sawn joints and gum was reduced 43...

  10. Mn0.8Zn0.2Fe2O4 nanoparticulates spinel ferrites: An approach to enhance the antenna field strength for improved magnitude versus offset (MVO

    Directory of Open Access Journals (Sweden)

    Majid Niaz Akhtar

    2014-08-01

    Full Text Available Electromagnetic signals in deep reservoir are very weak so that it is difficult to predict about the presence of hydrocarbon in seabed logging (SBL environment. In the present work, Mn0.8Zn0.2Fe2O4 nanoferrites were prepared by a sol–gel technique at different sintering temperatures of 450 °C, 650 °C and 850 °C to increase the strength of electromagnetic (EM antenna. XRD, FESEM, Raman spectroscopy and HRTEM were used to analyze the phase, surface morphology and size of the nanoferrites. Magnetic properties of the nanoferrites were also measured using an impedance network analyzer. However, nanoferrites sintered at 850 °C with initial permeability of 200 and Q factor of 50 were used as magnetic feeders with the EM antenna. Lab scale experiments were performed to investigate the effect of magnetic field strength in scale tank. SPSS and MATLAB softwares were also used to confirm the oil presence in scale tank. It was observed that the magnitude of the EM waves for the antenna was increased up to 233%. Finally, the correlation values also show 208% increase in the magnetic field strength with the presence of the oil. Therefore, antenna with Mn0.8Zn0.2Fe2O4 nanoferrites based magnetic feeders can be used for deep water and deep target hydrocarbon exploration.

  11. Effect of electrical field strength applied by PEF processing and storage temperature on the outgrowth of yeasts and moulds naturally present in a fresh fruit smoothie

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Nederhoff, A.L.; Nierop Groot, M.N.; Boekel, van M.A.J.S.; Mastwijk, H.C.

    2016-01-01

    Pulsed electrical field (PEF) technology offers an alternative to thermal pasteurisation of high-acid fruit juices, by extending the shelf life of food products, while retaining its fresh taste and nutritional value. Substantial research has been performed on the effect of electrical field

  12. Quasisymmetry equations for conventional stellarators

    International Nuclear Information System (INIS)

    Pustovitov, V.D.

    1994-11-01

    General quasisymmetry condition, which demands the independence of B 2 on one of the angular Boozer coordinates, is reduced to two equations containing only geometrical characteristics and helical field of a stellarator. The analysis is performed for conventional stellarators with a planar circular axis using standard stellarator expansion. As a basis, the invariant quasisymmetry condition is used. The quasisymmetry equations for stellarators are obtained from this condition also in an invariant form. Simplified analogs of these equations are given for the case when averaged magnetic surfaces are circular shifted torii. It is shown that quasisymmetry condition can be satisfied, in principle, in a conventional stellarator by a proper choice of two satellite harmonics of the helical field in addition to the main harmonic. Besides, there appears a restriction on the shift of magnetic surfaces. Thus, in general, the problem is closely related with that of self-consistent description of a configuration. (author)

  13. Bond strength of masonry

    NARCIS (Netherlands)

    Pluijm, van der R.; Vermeltfoort, A.Th.

    1992-01-01

    Bond strength is not a well defined property of masonry. Normally three types of bond strength can be distinguished: - tensile bond strength, - shear (and torsional) bond strength, - flexural bond strength. In this contribution the behaviour and strength of masonry in deformation controlled uniaxial

  14. Dose-dependent ATP depletion and cancer cell death following calcium electroporation, relative effect of calcium concentration and electric field strength

    DEFF Research Database (Denmark)

    Hansen, Emilie Louise; Sozer, Esin Bengisu; Romeo, Stefania

    2015-01-01

    death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. METHODS: In three human cell lines--H69 (small-cell lung cancer), SW780 (bladder cancer), and U937 (leukaemia), viability...... was observed with fluorescence confocal microscopy of quinacrine-labelled U937 cells. RESULTS: Both H69 and SW780 cells showed dose-dependent (calcium concentration and electric field) decrease in intracellular ATP (p...-dependently reduced cell survival and intracellular ATP. Increasing extracellular calcium allows the use of a lower electric field. GENERAL SIGNIFICANCE: This study supports the use of calcium electroporation for treatment of cancer and possibly lowering the applied electric field in future trials....

  15. Effect of minimum strength of mirror magnetic field (Bmin) on production of highly charged heavy ions from RIKEN liquid-He-free super conducting electron-cyclotron resonance ion source (RAMSES)

    International Nuclear Information System (INIS)

    Arai, Hideyuki; Imanaka, Masashi; Lee, S.-M.Sang-Moo; Higurashi, Yoshihide; Nakagawa, Takahide; Kidera, Masanori; Kageyama, Tadashi; Kase, Masayuki; Yano, Yasushige; Aihara, Toshimitsu

    2002-01-01

    We measured the beam intensity of highly charged heavy ions (O, Ar and Kr ions) as a function of the minimum strength of mirror magnetic field (B min ) of the RIKEN liquid-He-free super conducting electron-cyclotron resonance ion source. In this experiment, we found that the optimum value of B min exists to maximize the beam intensity of highly charged heavy ions and the value was almost the same (∼0.49 T) for various charge state heavy ions

  16. Numerical assessment of conventional regulation effectiveness for ...

    African Journals Online (AJOL)

    ... depends on fire safety engineering that is provided, and which is generally established using smoke spread field and temperature distribution predictions. ... conventional regulation; ventilation strategies; smoke temperature; smoke barriers ...

  17. Performance evaluation of contrast-detail in full field digital mammography systems using ideal (Hotelling) observer vs. conventional automated analysis of CDMAM images for quality control of contrast-detail characteristics.

    Science.gov (United States)

    Delakis, Ioannis; Wise, Robert; Morris, Lauren; Kulama, Eugenia

    2015-11-01

    The purpose of this work was to evaluate the contrast-detail performance of full field digital mammography (FFDM) systems using ideal (Hotelling) observer Signal-to-Noise Ratio (SNR) methodology and ascertain whether it can be considered an alternative to the conventional, automated analysis of CDMAM phantom images. Five FFDM units currently used in the national breast screening programme were evaluated, which differed with respect to age, detector, Automatic Exposure Control (AEC) and target/filter combination. Contrast-detail performance was analysed using CDMAM and ideal observer SNR methodology. The ideal observer SNR was calculated for input signal originating from gold discs of varying thicknesses and diameters, and then used to estimate the threshold gold thickness for each diameter as per CDMAM analysis. The variability of both methods and the dependence of CDMAM analysis on phantom manufacturing discrepancies also investigated. Results from both CDMAM and ideal observer methodologies were informative differentiators of FFDM systems' contrast-detail performance, displaying comparable patterns with respect to the FFDM systems' type and age. CDMAM results suggested higher threshold gold thickness values compared with the ideal observer methodology, especially for small-diameter details, which can be attributed to the behaviour of the CDMAM phantom used in this study. In addition, ideal observer methodology results showed lower variability than CDMAM results. The Ideal observer SNR methodology can provide a useful metric of the FFDM systems' contrast detail characteristics and could be considered a surrogate for conventional, automated analysis of CDMAM images. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  18. Apparatus and procedure to characterize the surface quality of conductors by measuring the rate of cathode emission as a function of surface electric field strength

    Science.gov (United States)

    Mestayer, Mac; Christo, Steve; Taylor, Mark

    2014-10-21

    A device and method for characterizing quality of a conducting surface. The device including a gaseous ionizing chamber having centrally located inside the chamber a conducting sample to be tested to which a negative potential is applied, a plurality of anode or "sense" wires spaced regularly about the central test wire, a plurality of "field wires" at a negative potential are spaced regularly around the sense, and a plurality of "guard wires" at a positive potential are spaced regularly around the field wires in the chamber. The method utilizing the device to measure emission currents from the conductor.

  19. Strength and life under creeping

    International Nuclear Information System (INIS)

    Pospishil, B.

    1982-01-01

    Certain examples of the application of the Lepin modified creep model, which are of interest from technical viewpoint, are presented. Mathematical solution of the dependence of strength limit at elevated temperatures on creep characteristics is obtained. Tensile test at elevated temperatures is a particular case of creep or relaxation and both strength limit and conventional yield strength at elevated temperatures are completely determined by parameters of state equations during creep. The equation of fracture summing during creep is confirmed not only by the experiment data when stresses change sporadically, but also by good reflection of durability curve using the system of equations. The system presented on the basis of parameters of the equations obtained on any part of durability curve, permits to forecast the following parameters of creep: strain, strain rate, life time, strain in the process of fracture. Tensile test at elevated temperature is advisable as an addition when determining creep curves (time-strain curves) [ru

  20. Reduction of Polarization Field Strength in Fully Strained c-Plane InGaN/(In)GaN Multiple Quantum Wells Grown by MOCVD.

    Science.gov (United States)

    Zhang, Feng; Ikeda, Masao; Zhang, Shu-Ming; Liu, Jian-Ping; Tian, Ai-Qin; Wen, Peng-Yan; Cheng, Yang; Yang, Hui

    2016-12-01

    The polarization fields in c-plane InGaN/(In)GaN multiple quantum well (MQW) structures grown on sapphire substrate by metal-organic chemical vapor deposition are investigated in this paper. The indium composition in the quantum wells varies from 14.8 to 26.5% for different samples. The photoluminescence wavelengths are calculated theoretically by fully considering the related effects and compared with the measured wavelengths. It is found that when the indium content is lower than 17.3%, the measured wavelengths agree well with the theoretical values. However, when the indium content is higher than 17.3%, the measured ones are much shorter than the calculation results. This discrepancy is attributed to the reduced polarization field in the MQWs. For the MQWs with lower indium content, 100% theoretical polarization can be maintained, while, when the indium content is higher, the polarization field decreases significantly. The polarization field can be weakened down to 23% of the theoretical value when the indium content is 26.5%. Strain relaxation is excluded as the origin of the polarization reduction because there is no sign of lattice relaxation in the structures, judging by the X-ray diffraction reciprocal space mapping. The possible causes of the polarization reduction are discussed.

  1. Fatigue strength of repaired cracks in welded connections made of very high strength steels

    NARCIS (Netherlands)

    Akyel, A.

    2017-01-01

    For cyclically loaded structures, fatigue design becomes one of the important design criteria. The state of art shows that with modification of the conventional structural design methodology, the use of very high strength steels may have a positive effect on fatigue strength of welded connections.

  2. Convention on nuclear safety

    International Nuclear Information System (INIS)

    1994-01-01

    The Convention on Nuclear Safety was adopted on 17 June 1994 by Diplomatic Conference convened by the International Atomic Energy Agency at its Headquarters from 14 to 17 June 1994. The Convention will enter into force on the ninetieth day after the date of deposit with the Depository (the Agency's Director General) of the twenty-second instrument of ratification, acceptance or approval, including the instruments of seventeen States, having each at leas one nuclear installation which has achieved criticality in a reactor core. The text of the Convention as adopted is reproduced in the Annex hereto for the information of all Member States

  3. Gauge field copies

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

    1979-01-01

    The construction of field strength copies without any gauge constraint is discussed. Several examples are given, one of which is not only a field strength copy but also (at the same time) a 'current copy'. (author) [pt

  4. Evaluate electric field strengths in the vicinity of electric transmission systems of electric power; Avaliar intensidades de campo eletrico nas vizinhancas de sistemas de transmissao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, J.F.; Ulson, J.A.C.; Creppe, R.C.; Serni, P.J.A. [Universidade Estadual Paulista Julio de Mesquita Filho (FEB/UNESP), Bauru, SP (Brazil). Fac. de Engenharia. Dept. de Engenharia Eletrica], Emails: jfranc@feb.unesp.br, ulson@feb.unesp.br, creppe@feb.unesp.br, paulojas@feb.unesp.br

    2009-07-01

    The main purpose in this paper is to describe a methodology for the calculation of the profile of the electric field in the level soil and proximities originated by electric energy transmission systems real and in operation in the country. It is also commented the equation used and your computational implementation in order to agile and to optimize the studies. The results of simulations were just presented for the transmission system in the voltage class 500 kV for to simplify the understanding and space restriction in the article, although five others types of configurations have also been used in the complete study with very voltages and respective classes. The results were animating and very nearby of values well-known of electric field of other and publications traditional in the area. The graphic exits of software for better visual comprehension and understanding went in accomplished in the plan (2D) and in the space (3D). (author)

  5. A Novel Hysteresis Model of Magnetic Field Strength Determined by Magnetic Induction Intensity for Fe-3% Si Electrical Steel Applied in Cigarette Making Machines

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2016-01-01

    Full Text Available Hysteresis characteristics of grain-oriented electrical steel were studied through the hysteresis loop. Existing hysteresis fitting simulation methods were summarized, and new Fe-3% Si grain-oriented electrical steel hysteresis loop model was proposed. Undetermined coefficients of the magnetic field intensity and magnetic flux density were determined by both the fixed angle method and the least squares method, and the hysteresis loop model was validated with high fitting degree by experimental data.

  6. Minamata Convention on Mercury

    Science.gov (United States)

    On November 6, 2013 the United States signed the Minamata Convention on Mercury, a new multilateral environmental agreement that addresses specific human activities which are contributing to widespread mercury pollution

  7. Defect Detectability Improvement for Conventional Friction Stir Welds

    Science.gov (United States)

    Hill, Chris

    2013-01-01

    This research was conducted to evaluate the effects of defect detectability via phased array ultrasound technology in conventional friction stir welds by comparing conventionally prepped post weld surfaces to a machined surface finish. A machined surface is hypothesized to improve defect detectability and increase material strength.

  8. The evolution of hillslope strength following large earthquakes

    Science.gov (United States)

    Brain, Matthew; Rosser, Nick; Tunstall, Neil

    2017-04-01

    Earthquake-induced landslides play an important role in the evolution of mountain landscapes. Earthquake ground shaking triggers near-instantaneous landsliding, but has also been shown to weaken hillslopes, preconditioning them for failure during subsequent seismicity and/or precipitation events. The temporal evolution of hillslope strength during and following primary seismicity, and if and how this ultimately results in failure, is poorly constrained due to the rarity of high-magnitude earthquakes and limited availability of suitable field datasets. We present results obtained from novel geotechnical laboratory tests to better constrain the mechanisms that control strength evolution in Earth materials of differing rheology. We consider how the strength of hillslope materials responds to ground-shaking events of different magnitude and if and how this persists to influence landslide activity during interseismic periods. We demonstrate the role of stress path and stress history, strain rate and foreshock and aftershock sequences in controlling the evolution of hillslope strength and stability. Critically, we show how hillslopes can be strengthened rather than weakened in some settings, challenging conventional assumptions. On the basis of our laboratory data, we consider the implications for earthquake-induced geomorphic perturbations in mountain landscapes over multiple timescales and in different seismogenic settings.

  9. 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.

  10. The effect of electric field strength on electroplex emission at the interface of NPB/PBD organic light-emitting diodes

    Science.gov (United States)

    Zhao, De-Wei; Xu, Zheng; Zhang, Fu-Jun; Song, Shu-Fang; Zhao, Su-Ling; Wang, Yong; Yuan, Guang-Cai; Zhang, Yan-Fei; Xu, Hong-Hua

    2007-02-01

    Organic light-emitting diode (OLED) based on two kinds of blue emission materials N, N'-bis(1-naphthyl)- N, N'-diphenyl-l,l'-diphenyl-4,4'-diamine (NPB) and 2-(4-biphenylyl)-5(4- tert-butyl-phenyl)-1,3,4-oxadiazole (PBD) was fabricated. There is only one emission peak in photoluminescence (PL) spectrum which originates from NPB exciton emission. And the electroluminescence (EL) emission peaks have an apparent red-shift with the increase of driving voltage. The red-shift emission from exciplex emission could be ruled out. Thus, by the method of Gaussian fitting it should be ascribed to the overlap of exciton emission and electroplex emission which occurs at the interface between NPB and PBD. The formation of the electroplex emission under high electric field is analyzed.

  11. A general model to calculate the spin-lattice (T1) relaxation time of blood, accounting for haematocrit, oxygen saturation and magnetic field strength.

    Science.gov (United States)

    Hales, Patrick W; Kirkham, Fenella J; Clark, Christopher A

    2016-02-01

    Many MRI techniques require prior knowledge of the T1-relaxation time of blood (T1bl). An assumed/fixed value is often used; however, T1bl is sensitive to magnetic field (B0), haematocrit (Hct), and oxygen saturation (Y). We aimed to combine data from previous in vitro measurements into a mathematical model, to estimate T1bl as a function of B0, Hct, and Y. The model was shown to predict T1bl from in vivo studies with a good accuracy (± 87 ms). This model allows for improved estimation of T1bl between 1.5-7.0 T while accounting for variations in Hct and Y, leading to improved accuracy of MRI-derived perfusion measurements. © The Author(s) 2015.

  12. Climate change convention

    International Nuclear Information System (INIS)

    Russell, D.

    1992-01-01

    Principles that guide Canada's Green Plan with respect to global warming are outlined. These include respect for nature, meeting environmental goals in an economically beneficial manner, efficient use of resources, shared responsibilities, federal leadership, and informed decision making. The policy side of the international Framework Convention on Climate Change is then discussed and related to the Green Plan. The Convention has been signed by 154 nations and has the long-term objective of stabilizing anthropogenic greenhouse gas concentrations in the atmosphere at levels that prevent dangerous interference with the climate system. Some of the Convention's commitments toward achieving that objective are only applicable to the developed countries. Five general areas of commitment are emissions reductions, assistance to developing countries, reporting requirements, scientific and socioeconomic research, and education. The most controversial area is that of limiting emissions. The Convention has strong measures for public accountability and is open to future revisions. Canada's Green Plan represents one country's response to the Convention commitments, including a national goal to stabilize greenhouse gas emissions at the 1990 level by the year 2000

  13. The Strength Compass

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    In the Ph.D-project ͚Strengths-based Learning - Children͛s character strengths as a means to their learning potential͛ 750 Danish children have assessed ͚The Strength Compass͛ in order to identify their strengths and to create awareness of strengths. This was followed by a strengths......-based intervention program in order to explore the strengths. Finally different methods to apply the strength in everyday life at school were applied. The paper presentation will show the results for strengths display for children aged 6-16 in different categories: Different age groups: Are the same strengths...... present in both small children and youths? Gender: Do the results show differences between the two genders? Danish as a mother- tongue language: Do the results show any differences in the strengths display when considering different language and cultural backgrounds? Children with Special Needs: Do...

  14. Dentine bond strength of a composite resin polymerized with conventional light and argon laser Resistência de união à dentina de resina composta polimerizada com luz halógena e laser de argônio

    Directory of Open Access Journals (Sweden)

    Patricia Ramos Lloret

    2004-09-01

    Full Text Available The use of argon laser (488 nm has been suggested as a new alternative for polymerizing adhesive materials. This study aimed to evaluate the tensile bond strength of a microfilled composite (A110, 3M inserted by incremental technique (3 increments of 1 mm and by single increment (3 mm polymerized by argon laser for 10, 20 and 30 seconds and halogen light for 40 seconds. Eighty (8 groups of 10 teeth freshly extracted bovine teeth were stored in a freezer in distilled water for one week. The crowns were cross-sectioned from the roots. Pulpectomy was performed and the pulp chambers were sealed with wax. The buccal surfaces of the teeth were ground with wet sandpaper (grains: 120, 400, and 600 to expose the surface dentin, and the teeth were then included in acrylic resin. A metal device was used to fix each sample and a black propylene matrix25 (3 mm high with an internal millimetric delimitation was used to insert the material according to the groups studied. The polymerization intervals were of 10, 20 and 30 seconds for the laser polymerization and 40 seconds for the conventional polymerization. Tensile tests were performed by a Universal Testing Machine 4442 (Instron at a speed of 0.5 mm/min and 500 N load. According to the methodology used, the incremental technique increased bond strength values. There was no difference between the studied polymerization techniques when resin was filled in 3 increments.O uso do laser de argônio (488 nm tem sido sugerido como uma nova alternativa para polimerização de materiais adesivos. Este estudo tem o objetivo de avaliar a resistência adesiva de uma resina composta microparticulada (A110, 3M inserida pela técnica incremental (3 incrementos de 1 mm e de incremento único (3 mm polimerizada com laser de argônio por 10, 20 e 30 segundos e com luz halógena por 40 segundos. Oitenta (8 grupos com 10 dentes dentes bovinos recém-extraídos foram armazenados em geladeira, em água destilada, por uma semana

  15. BI-ground microstrip array coil vs. conventional microstrip array coil for mouse imaging at 7 tesla

    Science.gov (United States)

    Hernández, Ricardo; Terrones, M. A. López; Jakob, P. M.

    2012-10-01

    At high field strengths, the need for more efficient high frequency coils has grown. Since the radiation losses and the interaction between coil and sample increase proportionally to field strength, the quality factor (Q) and the sensitivity of the coil decrease as consequence of these negative effects. Since Zhang et al proposed in 2001 a new surface coil based on the microstrip transmission line for high frequency, different Tx-Rx phased arrays based on this concept have been already introduced in animal and whole body systems at high field strengths, each of them with different modifications in order to get better field homogeneity, SNR or isolation between coil elements in the array. All these arrays for animals systems have been built for rat imaging. One of these modifications is called BI-Ground Microstrip Array Coil (BIGMAC). The implementation of a smaller two-channel BIGMAC design for mouse imaging is studied and its performance compared to a two-channel conventional Microstrip array at 7 Tesla, the higher isolation by using BIGMAC elements in comparison with conventional Microstrip elements is shown in this work.

  16. Tritium and OSPAR convention

    International Nuclear Information System (INIS)

    2009-01-01

    The missions and the organisation of the OSPAR convention on protection of the NE Atlantic marine environment are given. The OSPAR strategy for the radioactive substances is stated. The results of work programme of the radioactive Substances committee are described and the consensus reached by contracting parties on the appropriate arrangements for this radionuclide is presented. (authors)

  17. Revised C++ coding conventions

    CERN Document Server

    Callot, O

    2001-01-01

    This document replaces the note LHCb 98-049 by Pavel Binko. After a few years of practice, some simplification and clarification of the rules was needed. As many more people have now some experience in writing C++ code, their opinion was also taken into account to get a commonly agreed set of conventions

  18. Global climate convention

    International Nuclear Information System (INIS)

    Simonis, U.E.

    1991-01-01

    The effort of negotiate a global convention on climate change is one of mankind's great endeavours - and a challenge to economists and development planners. The inherent linkages between climate and the habitability of the earth are increasingly well recognized, and a convention could help to ensure that conserving the environment and developing the economy in the future must go hand in hand. Due to growing environmental concern the United Nations General Assembly has set into motion an international negotiating process for a framework convention on climate change. One the major tasks in these negotiations is how to share the duties in reducing climate relevant gases, particularly carbon dioxide (CO 2 ), between the industrial and the developing countries. The results and proposals could be among the most far-reaching ever for socio-economic development, indeed for global security and survival itself. While the negotiations will be about climate and protection of the atmosphere, they will be on fundamental global changes in energy policies, forestry, transport, technology, and on development pathways with low greenhouse gas emissions. Some of these aspects of a climate convention, particularly the distributional options and consequences for the North-South relations, are addressed in this chapter. (orig.)

  19. Achievement report for fiscal 1999 on project for supporting the formation of energy/environmental technology verification project. International joint verification research project (Use of combined binary power generation systems at new geothermal fields on Mindoro Island, the Philippines, and comparison with conventional power generation systems); 1999 nendo Philippines koku Mindoro to no shinki chinetsutai ni okeru combined binary hatsuden hoshiki no tekiyo seika hokokusho. Conventional hatsuden hoshiki tono hikaku kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Concerning the Manito Lowlands geothermal field and the Montelago geothermal field where the systems are to be newly installed, the geothermal reservoir characteristics are assessed, and cost effectiveness is compared between different power generating systems. According to the investigations conducted into the two geothermal fields in the past, they are supposed to have geothermal potentials of the medium grade. Chemical analyses are conducted anew on this occasion into the hot spring water and fumarole gas, and the MT (magnetotelluric) method is implemented for the survey of reservoir distribution. It is now expected that approximately 20MWe will be exploited from each of the two geothermal fields. The power generation systems studied are the single flash type and double flash type for the conventional power generation system, and the cascade type, bottoming type, and two-phase binary type for the combined binary power generation system. As the result, it is concluded that the double flash type or two-phase binary type will be advantageous to the Manito Lowlands geothermal field, and the double flash type or bottoming type or two-phase binary type will be advantageous to the Montelago geothermal field. (NEDO)

  20. Convention on supplementary compensation for nuclear damage

    International Nuclear Information System (INIS)

    Chinese Nuclear Society, Beijing; U.S. Nuclear Energy Institute

    2000-01-01

    The Contracting parties recognize the importance of the measures provided in the Vienna Convention on Civil Liability for Nuclear Damage and the Paris Convention on Third party liability in the Field of Nuclear Energy as well as in national legislation on compensation for nuclear damage consistent with the principles of these conventions. The Contracting parties desire to establish a worldwide liability regime to supplement and enhance these measures with a view to increasing the amount of compensation for nuclear damage and encourage regional and global co-operation to promote a higher level of nuclear safety in accordance with the principle of international partnership and solidarity

  1. An ultra-high field strength MR image-guided robotic needle delivery system for in-bore small animal interventions.

    Science.gov (United States)

    Gravett, Matthew; Cepek, Jeremy; Fenster, Aaron

    2017-11-01

    The purpose of this study was to develop and validate an image-guided robotic needle delivery system for accurate and repeatable needle targeting procedures in mouse brains inside the 12 cm inner diameter gradient coil insert of a 9.4 T MR scanner. Many preclinical research techniques require the use of accurate needle deliveries to soft tissues, including brain tissue. Soft tissues are optimally visualized in MR images, which offer high-soft tissue contrast, as well as a range of unique imaging techniques, including functional, spectroscopy and thermal imaging, however, there are currently no solutions for delivering needles to small animal brains inside the bore of an ultra-high field MR scanner. This paper describes the mechatronic design, evaluation of MR compatibility, registration technique, mechanical calibration, the quantitative validation of the in-bore image-guided needle targeting accuracy and repeatability, and demonstrated the system's ability to deliver needles in situ. Our six degree-of-freedom, MR compatible, mechatronic system was designed to fit inside the bore of a 9.4 T MR scanner and is actuated using a combination of piezoelectric and hydraulic mechanisms. The MR compatibility and targeting accuracy of the needle delivery system are evaluated to ensure that the system is precisely calibrated to perform the needle targeting procedures. A semi-automated image registration is performed to link the robot coordinates to the MR coordinate system. Soft tissue targets can be accurately localized in MR images, followed by automatic alignment of the needle trajectory to the target. Intra-procedure visualization of the needle target location and the needle were confirmed through MR images after needle insertion. The effects of geometric distortions and signal noise were found to be below threshold that would have an impact on the accuracy of the system. The system was found to have negligible effect on the MR image signal noise and geometric distortion

  2. The strength compass

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    of agreement/disagreement. Also the child/teacher is asked whether the actual strength is important and if he or she has the possibilities to apply the strength in the school. In a PhDproject ‘Strengths-based Learning - Children’s Character Strengths as Means to their Learning Potential’ 750 Danish children......Individual paper presentation: The ‘Strength Compass’. The results of a PhDresearch project among schoolchildren (age 6-16) identifying VIAstrengths concerning age, gender, mother-tongue-langue and possible child psychiatric diagnosis. Strengths-based interventions in schools have a theoretical...... Psychological Publishing Company. ‘The Strength Compass’ is a computer/Ipad based qualitative tool to identify the strengths of a child by a self-survey or a teacher’s survey. It is designed as a visual analogue scale with a statement of the strength in which the child/teacher may declare the degree...

  3. Conventions and Institutional Logics

    DEFF Research Database (Denmark)

    Westenholz, Ann

    Two theoretical approaches – Conventions and Institutional Logics – are brought together and the similarities and differences between the two are explored. It is not the intention to combine the approaches, but I would like to open both ‘boxes’ and make them available to each other with the purpose...... of creating a space for dialog. Both approaches were developed in the mid-1980s as a reaction to rational-choice economic theory and collectivistic sociological theory. These two theories were oversimplifying social life as being founded either in actor-micro level analyses or in structure-macro level...... analyses. The theoretical quest of both Conventions and Institutional Logics has been to understand the increasing indeterminacy, uncertainty and ambiguity in people’s lives where a sense of reality, of value, of moral, of feelings is not fixed. Both approaches have created new theoretical insights...

  4. Manado Convention Centre (Megastructures)

    OpenAIRE

    Anggianto, Rio M; Rate, Johannes Van

    2013-01-01

    Proyek Manado Convention Center ini pada dasarnya merupakan wadah atau sarana komunikasi antara dua pihak dengan penerapkan berbagai metode komunikasi langsung tatap muka baik itu dari perorangan terhadap kelompok, kelompok terhadap kelompok atau kelompok terhadap masyarakat. Dan pada era kini hal ini menjadi suatu kebutuhan yang dianganggap penting. Kota Manado seringkali menjadi tuan rumah suatu konverensi dengan jumlah peserta yang tergolong besar karena cakupannya sampai manca negara....

  5. The conventional quark picture

    International Nuclear Information System (INIS)

    Dalitz, R.H.

    1976-01-01

    For baryons, mesons and deep inelastic phenomena the ideas and the problems of the conventional quark picture are pointed out. All observed baryons fit in three SU(3)-multiplets which cluster into larger SU(6)-multiplets. No mesons are known which have quantum numbers inconsistent with belonging to a SU(3) nonet or octet. The deep inelastic phenomena are described in terms of six structure functions of the proton. (BJ) [de

  6. Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic posts Efeito da carga cíclica na resistência de dentes tratados endodonticamente restaurados com pinos dentários convencionais e estéticos

    Directory of Open Access Journals (Sweden)

    Anuar Antônio Xible

    2006-08-01

    Full Text Available INTRODUCTION: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS AND METHODS: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost and glass-ceramic cores (IPS Empress Cosmopost; group 2 with fiber reinforced composite posts (FibreKor and group 3 with titanium posts (AZthec Anchor. Direct resin composite (Build It FR Resin Composite was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2. A resin cement/adhesive system (Cement It/Bond It Primer A+B was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests alpha=0.05. RESULTS: All groups had 100% survival rate after cyclic loading; fracture strength values (SD in N were: group 1 = 886.5(170.6, group 2 = 762.2(113.6 and group 3 = 768.9(72.9; there was no difference among groups (p=0.08; the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142. CONCLUSIONS: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite

  7. Electronic properties of quasi one-dimensional quantum wire models under equal coupling strength superpositions of Rashba and Dresselhaus spin-orbit interactions in the presence of an in-plane magnetic field

    International Nuclear Information System (INIS)

    Papp, E.; Micu, C.; Racolta, D.

    2013-01-01

    In this paper one deals with the theoretical derivation of energy bands and of related wavefunctions characterizing quasi 1D semiconductor heterostructures, such as InAs quantum wire models. Such models get characterized this time by equal coupling strength superpositions of Rashba and Dresselhaus spin-orbit interactions of dimensionless magnitude a under the influence of in-plane magnetic fields of magnitude B. We found that the orientations of the field can be selected by virtue of symmetry requirements. For this purpose one resorts to spin conservations, but alternative conditions providing sensible simplifications of the energy-band formula can be reasonably accounted for. Besides the wavenumber k relying on the 1D electron, one deals with the spin-like s=±1 factors in the front of the square root term of the energy. Having obtained the spinorial wavefunction, opens the way to the derivation of spin precession effects. For this purpose one resorts to the projections of the wavenumber operator on complementary spin states. Such projections are responsible for related displacements proceeding along the Ox-axis. This results in a 2D rotation matrix providing both the precession angle as well as the precession axis

  8. Test of QED at critical field strength

    Energy Technology Data Exchange (ETDEWEB)

    Bula, C. [Princeton Univ., NJ (United States)

    1997-01-01

    In a new experiment at the Final Focus Test Beam at SLAC, a low-emittance 46.6 GeV electron beam is brought into collisions with terawatt pulses of 1054 nm or 527 nm wavelength from a Nd:glass laser. Peak laser intensities of 10{sup 18} W/cm{sup 2} have been achieved corresponding to a value of 0.6 for the parameter {eta} = e{epsilon}/m{omega}{sub 0}c. In this case, an electron that crosses the center of the laser pulse has near-unit interaction probability. Results are presented for multiphoton Compton scattering in which an electron interacts with up to four laser photons, in agreement with theoretical calculations.

  9. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  10. Digitization of conventional radiographs

    International Nuclear Information System (INIS)

    Wenz, W.; Buitrago-Tellez, C.; Blum, U.; Hauenstein, K.H.; Gufler, H.; Meyer, E.; Ruediger, K.

    1992-01-01

    The diagnostic value of a digitization system for analogue films based on a charge-coupled-device (CCD) scanner with adjustable resolution of 2.5 or 5 lp/mm was assessed. Some 110 skeletal radiographs, 50 contrast studies, including 25 of patients with Crohn's disease, and 70 abdominal plain films before and after successful lithotripsy for renal stones were digitized. Receiver operating characteristic (ROC) studies showed improved detection of cortical and trabecular defects with contrast-optimized digitized films. Edge enhancement algorithms yielded no additional information. Inflammatory lesions of Crohn's disease were detected equally well by conventional films and digitized images. A statistically significant improvement (p [de

  11. Conventional RF system design

    International Nuclear Information System (INIS)

    Puglisi, M.

    1994-01-01

    The design of a conventional RF system is always complex and must fit the needs of the particular machine for which it is planned. It follows that many different design criteria should be considered and analyzed, thus exceeding the narrow limits of a lecture. For this reason only the fundamental components of an RF system, including the generators, are considered in this short seminar. The most common formulas are simply presented in the text, while their derivations are shown in the appendices to facilitate, if desired, a more advanced level of understanding. (orig.)

  12. Conventional magnets. Pt. 1

    International Nuclear Information System (INIS)

    Marks, N.

    1994-01-01

    The design and construction of conventional, steel-cored, direct-current magnets are discussed. Laplace's equation and the associated cylindrical harmonic solutions in two dimensions are established. The equations are used to define the ideal pole shapes and required excitation for dipole, quadrupole and sextupole magnets. Standard magnet geometries are then considered and criteria determining the coil design are presented. The use of codes for predicting flux density distributions and the iterative techniques used for pole face design are then discussed. This includes a description of the use of two-dimensional codes to generate suitable magnet end geometries. Finally, standard constructional techniques for cores and coils are described. (orig.)

  13. Estimation and comparison of tensile bond strengths at resin-dentin ...

    African Journals Online (AJOL)

    Nigerian Dental Journal ... Result: Etch-and-rinse adhesive Adper Single Bond 2 Total Etch® yielded high bond strength ... The self etch systems though convenient to use, do not match the bond strengths of conventional total etch systems.

  14. Suction pressure, yield strength and effective stress of partially saturated unbound granular pavement layers

    CSIR Research Space (South Africa)

    Theyse, HL

    2006-09-01

    Full Text Available to the ratio of the imposed stress over the shear strength of the material. Conventionally, the shear strength of the material was characterised with the Mohr-Coulomb shear strength parameters. This paper further develops a recent yield strength model...

  15. Conventional and anomalous quantum Rabi oscillations in graphene

    International Nuclear Information System (INIS)

    Khan, Enamullah; Kumar, Vipin; Kumar, Upendra; Setlur, Girish S.

    2014-01-01

    We study the non linear response of graphene in presence of quantum field in two different regimes. Far from resonance, using our new technique asymptotic rotating wave approximation (ARWA), we obtained that the matter field interaction leads to the slow oscillations like conventional Rabi oscillations observed in conventional semiconductors using well known rotating wave approximation (RWA). The Rabi frequency obtained in both the regimes

  16. Strengths-based Learning

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    -being. The Ph.D.-project in Strength-based learning took place in a Danish school with 750 pupils age 6-16 and a similar school was functioning as a control group. The presentation will focus on both the aware-explore-apply processes and the practical implications for the schools involved, and on measurable......Strength-based learning - Children͛s Character Strengths as Means to their Learning Potential͛ is a Ph.D.-project aiming to create a strength-based mindset in school settings and at the same time introducing strength-based interventions as specific tools to improve both learning and well...

  17. Treating locally advanced lung cancer with a 1.5T MR-Linac - Effects of the magnetic field and irradiation geometry on conventionally fractionated and isotoxic dose-escalated radiotherapy.

    Science.gov (United States)

    Bainbridge, Hannah E; Menten, Martin J; Fast, Martin F; Nill, Simeon; Oelfke, Uwe; McDonald, Fiona

    2017-11-01

    This study investigates the feasibility and potential benefits of radiotherapy with a 1.5T MR-Linac for locally advanced non-small cell lung cancer (LA NSCLC) patients. Ten patients with LA NSCLC were retrospectively re-planned six times: three treatment plans were created according to a protocol for conventionally fractionated radiotherapy and three treatment plans following guidelines for isotoxic target dose escalation. In each case, two plans were designed for the MR-Linac, either with standard (∼7mm) or reduced (∼3mm) planning target volume (PTV) margins, while one conventional linac plan was created with standard margins. Treatment plan quality was evaluated using dose-volume metrics or by quantifying dose escalation potential. All generated treatment plans fulfilled their respective planning constraints. For conventionally fractionated treatments, MR-Linac plans with standard margins had slightly increased skin dose when compared to conventional linac plans. Using reduced margins alleviated this issue and decreased exposure of several other organs-at-risk (OAR). Reduced margins also enabled increased isotoxic target dose escalation. It is feasible to generate treatment plans for LA NSCLC patients on a 1.5T MR-Linac. Margin reduction, facilitated by an envisioned MRI-guided workflow, enables increased OAR sparing and isotoxic target dose escalation for the respective treatment approaches. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Reducing Field Distortion in Magnetic Resonance Imaging

    Science.gov (United States)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2010-01-01

    A concept for a magnetic resonance imaging (MRI) system that would utilize a relatively weak magnetic field provides for several design features that differ significantly from the corresponding features of conventional MRI systems. Notable among these features are a magnetic-field configuration that reduces (relative to the conventional configuration) distortion and blurring of the image, the use of a superconducting quantum interference device (SQUID) magnetometer as the detector, and an imaging procedure suited for the unconventional field configuration and sensor. In a typical application of MRI, a radio-frequency pulse is used to excite precession of the magnetic moments of protons in an applied magnetic field, and the decaying precession is detected for a short time following the pulse. The precession occurs at a resonance frequency proportional to the strengths of the magnetic field and the proton magnetic moment. The magnetic field is configured to vary with position in a known way; hence, by virtue of the aforesaid proportionality, the resonance frequency varies with position in a known way. In other words, position is encoded as resonance frequency. MRI using magnetic fields weaker than those of conventional MRI offers several advantages, including cheaper and smaller equipment, greater compatibility with metallic objects, and higher image quality because of low susceptibility distortion and enhanced spin-lattice-relaxation- time contrast. SQUID MRI is being developed into a practical MRI method for applied magnetic flux densities of the order of only 100 T

  19. In vivo field-cycling relaxometry using an insert coil for magnetic field offset.

    Science.gov (United States)

    Pine, Kerrin J; Goldie, Fred; Lurie, David J

    2014-11-01

    The T(1) of tissue has a strong dependence on the measurement magnetic field strength. T(1) -dispersion could be a useful contrast parameter, but is unavailable to clinical MR systems which operate at fixed magnetic field strength. The purpose of this work was to implement a removable insert magnet coil for field-cycling T(1) -dispersion measurements on a vertical-field MRI scanner, by offsetting the static field over a volume of interest. An insert magnet coil was constructed for use with a whole-body sized 59 milli-Tesla (mT) vertical-field, permanent-magnet based imager. The coil has diameter 38 cm and thickness 6.1 cm and a homogeneous region (± 5%) of 5 cm DSV, offset by 5 cm from the coil surface. Surface radiofrequency (RF) coils were also constructed. The insert coil was used in conjunction with a surface RF coil and a volume-localized inversion-recovery pulse sequence to plot T(1) -dispersion in a human volunteer's forearm over a range of field strengths from 1 mT to 70 mT. T(1) -dispersion measurements were demonstrated on a fixed-field MRI scanner, using an insert coil. This demonstrates the feasibility of relaxation dispersion measurements on an otherwise conventional MR imager, facilitating the exploitation of T(1) -dispersion contrast for enhanced diagnosis. Copyright © 2013 Wiley Periodicals, Inc.

  20. Passive shimming of the fringe field of a superconducting magnet for ultra-low field hyperpolarized noble gas MRI.

    Science.gov (United States)

    Parra-Robles, Juan; Cross, Albert R; Santyr, Giles E

    2005-05-01

    Hyperpolarized noble gases (HNGs) provide exciting possibilities for MR imaging at ultra-low magnetic field strengths (superconductive magnets used in clinical MR imaging can provide a stable magnetic field for this purpose. In addition to offering the benefit of HNG MR imaging alongside conventional high field proton MRI, this approach offers the other useful advantage of providing different field strengths at different distances from the magnet. However, the extremely strong field gradients associated with the fringe field present a major challenge for imaging since impractically high active shim currents would be required to achieve the necessary homogeneity. In this work, a simple passive shimming method based on the placement of a small number of ferromagnetic pieces is proposed to reduce the fringe field inhomogeneities to a level that can be corrected using standard active shims. The method explicitly takes into account the strong variations of the field over the volume of the ferromagnetic pieces used to shim. The method is used to obtain spectra in the fringe field of a high-field (1.89 T) superconducting magnet from hyperpolarized 129Xe gas samples at two different ultra-low field strengths (8.5 and 17 mT). The linewidths of spectra measured from imaging phantoms (30 Hz) indicate a homogeneity sufficient for MRI of the rat lung.

  1. Strength of heat-resistant materials. Vynoslivost' zharoprochnykh materialov

    Energy Technology Data Exchange (ETDEWEB)

    Akimov, L M

    1977-01-01

    A presentation is made of the research results of the effect that metallurgical, technological, construction, and exploitation factors have on the durability of heat-resistant alloys, tested for mechanical, heat, and corrosion effects on metal in standard cylindrical and specially contoured samples under conventional conditions and conditional approaching operational ones. The causes of changes in fatigue strength of alloys are explained by the use of fractographic and metallographic analyses of fractures and structure. The book is intended for engineering--technical personnel at research institutes, and plant mechanical and metal studies laboratories in machine-building factories. The book may also be used by undergraduate and graduate students at institutions of higher learning specializing in the field of material studies and mechanical testing of steels and alloys. 176 references, 79 figures, 12 tables.

  2. Give Me Strength.

    Institute of Scientific and Technical Information of China (English)

    维拉

    1996-01-01

    Mort had an absolutely terrible day at the office.Everythingthat could go wrong did go wrong.As he walked home he could beheard muttering strange words to himself:“Oh,give me strength,give me strength.”Mort isn’t asking for the kind of strength thatbuilds strong muscles:he’s asking for the courage or ability to

  3. ESD and the Rio Conventions

    Science.gov (United States)

    Sarabhai, Kartikeya V.; Ravindranath, Shailaja; Schwarz, Rixa; Vyas, Purvi

    2012-01-01

    Chapter 36 of Agenda 21, a key document of the 1992 Earth Summit, emphasised reorienting education towards sustainable development. While two of the Rio conventions, the Convention on Biological Diversity (CBD) and the United Nations Framework Convention on Climate Change (UNFCCC), developed communication, education and public awareness (CEPA)…

  4. Collapse and Revival of an Atomic Beam Interacting with a Coherent State Light Field

    International Nuclear Information System (INIS)

    Ben, Li; Jing-Biao, Chen

    2009-01-01

    We report on the phenomena of the periodic spontaneous collapse and revival in the dynamics of an atomic beam interacting with a single-mode and coherent-state light field. Conventional collapse and revival by Eberly et al. [Phys. Rev. Lett. 44 (1980) 1323] are presented in the case of the evolution with time of the population inversion. Here, we study the evolution with coupling strength of population inversion. We define the collapse and revival coupling strengths as characteristic parameters to describe the above collapse and revival. Furthermore, we present the analytic formulas for the population inversion, the collapse and revival coupling strengths

  5. Decree No. 79-623 of 13 July 1979 publishing the Decision on the exclusion of certain categories of nuclear substances from the scope of the Convention of 29 July 1960 on Third Party Liability in the Field of Nuclear Energy and the Decision (with an annex) on the exclusion of small quantities of nuclear substances from the scope of the Convention of 29 July 1960 on Third Party Liability in the Field of Nuclear Energy, adopted on 27 October 1977

    International Nuclear Information System (INIS)

    1979-01-01

    This decree lays down that certain specified quantities and categories of nuclear substances are excluded from the nuclear operator's liability. This implements in France two Decisions taken by the NEA Steering Committee under the Paris Convention which enables the Committee to exclude from the operator's liability, nuclear installations, fuel or substances if the small extent of the risks involved so warrants. Both Decisions are reproduced in the Decree. (NEA) [fr

  6. Decision on the Exclusion of Small Quantities of Nuclear Substances outside a Nuclear Installation from the Application of the Convention on Third Party Liability in the Field of Nuclear Energy (This Decision was adopted at the 133. Session of the Steering Committee for Nuclear Energy held on 3-4 November 2016.)

    International Nuclear Information System (INIS)

    2017-01-01

    The steering committee, having regard to the Convention on Third Party Liability in the Field of Nuclear Energy of 29 July 1960, as amended by the Additional Protocol of 28 January 1964, by the Protocol of 16 November 1982 and by the Protocol of 12 February 2004, and, in particular, Article 1(b) thereof; considering that, by virtue of that Article, the Steering Committee may, if in its view the small extent of the risks involved so warrants, exclude any nuclear installation, nuclear fuel or nuclear substances from the application of the Paris Convention; considering that nuclear substances in transport or use outside a nuclear installation, within defined limits and under specifically prescribed conditions during transport, should, in view of the small extent of the risks involved, be excluded from the application of the Paris Convention; having regard to its Decision of 18 October 2007 on the Exclusion of Small Quantities of Nuclear Substances outside a Nuclear Installation from the Application of the Convention on Third Party Liability in the Field of Nuclear Energy of 29 July 1960 as amended; considering that the 2005 Edition of the Regulations for the Safe Transport of Radioactive Material of the International Atomic Energy Agency referred to in the Annex to the above-mentioned Decision, has been replaced by revised editions, the most recent of which is the 2012 Edition, which is used as the basis for corresponding national and international regulations in this field; considering the need for a decision the annex of which is in line with the 2012 Edition of those Regulations; decides: 1. Nuclear substances which are consigned by an operator to a recipient for use shall be excluded from the application of the Paris Convention for the period during which they are outside a nuclear installation provided that the consignment, when leaving a nuclear installation, complies with the provisions set forth in the Annex to this Decision and with other relevant

  7. Police Deprivation of Third Parties’ Liberty – A Field of Tension between National Police Law and the European Convention on Human Rights, as illustrated by Austin & Others v the United Kingdom

    Directory of Open Access Journals (Sweden)

    Steinar Fredriksen

    2015-07-01

    Full Text Available In Austin & Others v the United Kingdom The European Court of Human Rights came to the conclusion that the use of a police cordon, also known as “kettling”, where approximately 2000 people were forced to remain inside the cordon for up to eight hours, did not amount to deprivation of liberty under Article 5 (1 of the European Convention on Human Rights. This conclusion was reached by way of restrictive interpretation of the term “deprivation”. Previous case law establishes a set of criteria to be used when deciding if an infringement on the physical liberty to move from place to place constitutes a deprivation of this liberty, or merely a restriction upon it. These criteria were upheld in Austin, but were found to give room for taking into account the context and circumstances in which the police cordon was used. The previous view of the Court that the grounds justifying deprivations of liberty listed in Article 5 (1 (a-f are exhaustive, was also upheld. In this article the starting point is the close relationship between national police law regarding the maintenance of security and public order on one hand, and the principle of necessity on the other. It is emphasised that “necessity”-based norms in national police law can make police measures directed against innocent third parties legal, deprivations of liberty included, but that this possibility would have been absent in Article 5 (1 of the Convention without the aforementioned restrictive interpretation of the term “deprivation”. An attempt is made to show that this interpretation is in fact based on central elements of the principle of necessity. Furthermore, it is attempted to show that the restrictive interpretation can be seen as a reflection of the need acknowledged in national police law, as well as in other articles of the Convention, to direct police measures against innocent third parties.

  8. Diffusion Properties and 3D Architecture of Human Lower Leg Muscles Assessed with Ultra-High-Field-Strength Diffusion-Tensor MR Imaging and Tractography: Reproducibility and Sensitivity to Sex Difference and Intramuscular Variability.

    Science.gov (United States)

    Fouré, Alexandre; Ogier, Augustin C; Le Troter, Arnaud; Vilmen, Christophe; Feiweier, Thorsten; Guye, Maxime; Gondin, Julien; Besson, Pierre; Bendahan, David

    2018-05-01

    Purpose To demonstrate the reproducibility of the diffusion properties and three-dimensional structural organization measurements of the lower leg muscles by using diffusion-tensor imaging (DTI) assessed with ultra-high-field-strength (7.0-T) magnetic resonance (MR) imaging and tractography of skeletal muscle fibers. On the basis of robust statistical mapping analyses, this study also aimed at determining the sensitivity of the measurements to sex difference and intramuscular variability. Materials and Methods All examinations were performed with ethical review board approval; written informed consent was obtained from all volunteers. Reproducibility of diffusion tensor indexes assessment including eigenvalues, mean diffusivity, and fractional anisotropy (FA) as well as muscle volume and architecture (ie, fiber length and pennation angle) were characterized in lower leg muscles (n = 8). Intramuscular variability and sex differences were characterized in young healthy men and women (n = 10 in each group). Student t test, statistical parametric mapping, correlation coefficients (Spearman rho and Pearson product-moment) and coefficient of variation (CV) were used for statistical data analysis. Results High reproducibility of measurements (mean CV ± standard deviation, 4.6% ± 3.8) was determined in diffusion properties and architectural parameters. Significant sex differences were detected in FA (4.2% in women for the entire lower leg; P = .001) and muscle volume (21.7% in men for the entire lower leg; P = .008), whereas architecture parameters were almost identical across sex. Additional differences were found independently of sex in diffusion properties and architecture along several muscles of the lower leg. Conclusion The high-spatial-resolution DTI assessed with 7.0-T MR imaging allows a reproducible assessment of structural organization of superficial and deep muscles, giving indirect information on muscle function. © RSNA, 2018 Online supplemental material is

  9. A design method for two-layer beams consisting of normal and fibered high strength concrete

    International Nuclear Information System (INIS)

    Iskhakov, I.; Ribakov, Y.

    2007-01-01

    Two-layer fibered concrete beams can be analyzed using conventional methods for composite elements. The compressed zone of such beam section is made of high strength concrete (HSC), and the tensile one of normal strength concrete (NSC). The problems related to such type of beams are revealed and studied. An appropriate depth of each layer is prescribed. Compatibility conditions between HSC and NSC layers are found. It is based on the shear deformations equality on the layers border in a section with maximal depth of the compression zone. For the first time a rigorous definition of HSC is given using a comparative analysis of deformability and strength characteristics of different concrete classes. According to this definition, HSC has no download branch in the stress-strain diagram, the stress-strain function has minimum exponent, the ductility parameter is minimal and the concrete tensile strength remains constant with an increase in concrete compression strength. The application fields of two-layer concrete beams based on different static schemes and load conditions make known. It is known that the main disadvantage of HSCs is their low ductility. In order to overcome this problem, fibers are added to the HSC layer. Influence of different fiber volume ratios on structural ductility is discussed. An upper limit of the required fibers volume ratio is found based on compatibility equation of transverse tensile concrete deformations and deformations of fibers

  10. Anisotropic Concrete Compressive Strength

    DEFF Research Database (Denmark)

    Gustenhoff Hansen, Søren; Jørgensen, Henrik Brøner; Hoang, Linh Cao

    2017-01-01

    When the load carrying capacity of existing concrete structures is (re-)assessed it is often based on compressive strength of cores drilled out from the structure. Existing studies show that the core compressive strength is anisotropic; i.e. it depends on whether the cores are drilled parallel...

  11. High strength ferritic alloy

    International Nuclear Information System (INIS)

    1977-01-01

    A high strength ferritic steel is specified in which the major alloying elements are chromium and molybdenum, with smaller quantities of niobium, vanadium, silicon, manganese and carbon. The maximum swelling is specified for various irradiation conditions. Rupture strength is also specified. (U.K.)

  12. Photon strength functions

    International Nuclear Information System (INIS)

    Bergqvist, I.

    1976-01-01

    Methods for extracting photon strength functions are briefly discussed. We follow the Brink-Axel approach to relate the strength functions to the giant resonances observed in photonuclear work and summarize the available data on the E1, E2 and M1 resonances. Some experimental and theoretical problems are outlined. (author)

  13. Interviewing to Understand Strengths

    Science.gov (United States)

    Hass, Michael R.

    2018-01-01

    Interviewing clients about their strengths is an important part of developing a complete understanding of their lives and has several advantages over simply focusing on problems and pathology. Prerequisites for skillfully interviewing for strengths include the communication skills that emerge from a stance of not knowing, developing a vocabulary…

  14. Effects of gamma radiation induced forced formation of free radicals on the strength of concrete for use in nuclear power plants

    Directory of Open Access Journals (Sweden)

    Burnham Steven

    2017-01-01

    Full Text Available In this paper, we present a summary of preliminary experiments and numerical assessments of the effects of gamma radiation induced formation of free radicals in the curing stage of concrete on its characteristics. Substantial literature reports on the damaging effects of long-term and high-dose gamma and neutron exposure on concrete. However, we show that short-term exposure of concrete to gamma radiation can be beneficial in increasing its compressive strength. The effects of exposing to 630 MBq 137Cs the 56 cubes each made of 125 cm3 concrete during the first seven days of curing are compared to another 56 cubes cured by the conventional process. The average compressive strength of the gamma cured cubes is around 8.500 psi, while conventionally cured cubes show the lower average strength of around 6.700 psi. The microstructure of the gamma and conventionally cured concrete cubes is analyzed using a scanning electron microscope. The radiolysis within the microstructure of the concrete cubes is assessed with computational modeling based on Geant4. The production of free radicals from radiolysis is shown to increase with increasing source strength and increasing the time of exposure to gamma radiation. This research shows in general that curing concrete in gamma radiation field provides observable trends toward its increased strength.

  15. Imaging Shear Strength Along Subduction Faults

    Science.gov (United States)

    Bletery, Quentin; Thomas, Amanda M.; Rempel, Alan W.; Hardebeck, Jeanne L.

    2017-11-01

    Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.

  16. Imaging shear strength along subduction faults

    Science.gov (United States)

    Bletery, Quentin; Thomas, Amanda M.; Rempel, Alan W.; Hardebeck, Jeanne L.

    2017-01-01

    Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.

  17. Cosmology and convention

    Science.gov (United States)

    Merritt, David

    2017-02-01

    I argue that some important elements of the current cosmological model are 'conventionalist' in the sense defined by Karl Popper. These elements include dark matter and dark energy; both are auxiliary hypotheses that were invoked in response to observations that falsified the standard model as it existed at the time. The use of conventionalist stratagems in response to unexpected observations implies that the field of cosmology is in a state of 'degenerating problemshift' in the language of Imre Lakatos. I show that the 'concordance' argument, often put forward by cosmologists in support of the current paradigm, is weaker than the convergence arguments that were made in the past in support of the atomic theory of matter or the quantization of energy.

  18. Transfrontier nuclear civil liability without international conventions

    International Nuclear Information System (INIS)

    Dogauchi, M.

    1992-01-01

    Japan is not a contracting party of any international convention in the field of nuclear civil liability, and neither are other east Asian countries who have or will soon have nuclear plants. Therefore, the ordinary rules on private international law will play an important role in dealing with transfrontier nuclear civil liability. Above all, the problems on judicial jurisdiction and governing law are crucial points. With regard to the relations between the above countries and the countries whose legal systems are within the framework of Paris or Vienna Conventions, geographical scopes of these conventions are to be considered. There are two different parts in the international civil liability conventions: uniform civil liability law and mutual funds. As to the first, it is important that, even without the conventions, the basic structure of the nuclear civil liability laws in non-member countries are almost the same with those of members. In any event, considering that the establishment of a single international regime to cover all countries will be hardly possible, legal consequences under the private international law will be explored. (author)

  19. Compact Ignition Tokamak conventional facilities optimization

    International Nuclear Information System (INIS)

    Commander, J.C.; Spang, N.W.

    1987-01-01

    A high-field ignition machine with liquid-nitrogen-cooled copper coils, designated the Compact Ignition Tokamak (CIT), is proposed for the next phase of the United States magnetically confined fusion program. A team of national laboratory, university, and industrial participants completed the conceptual design for the CIT machine, support systems and conventional facilities. Following conceptual design, optimization studies were conducted with the goal of improving machine performance, support systems design, and conventional facilities configuration. This paper deals primarily with the conceptual design configuration of the CIT conventional facilities, the changes that evolved during optimization studies, and the revised changes resulting from functional and operational requirements (F and ORs). The CIT conventional facilities conceptual design is based on two premises: (1) satisfaction of the F and ORs developed in the CIT building and utilities requirements document, and (2) the assumption that the CIT project will be sited at the Princeton Plasma Physics Laboratory (PPPL) in order that maximum utilization can be made of existing Tokamak Fusion Test Reactor (TFTR) buildings and utilities. The optimization studies required reevaluation of the F and ORs and a second look at TFTR buildings and utilities. Some of the high-cost-impact optimization studies are discussed, including the evaluation criteria for a change from the conceptual design baseline configuration. The revised conventional facilities configuration are described and the estimated cost impact is summarized

  20. The Burning Plasma Experiment conventional facilities

    International Nuclear Information System (INIS)

    Commander, J.C.

    1991-01-01

    The Burning Program Plasma Experiment (BPX) is phased to start construction of conventional facilities in July 1994, in conjunction with the conclusion of the Tokamak Fusion Test Reactor (TFTR) project. This paper deals with the conceptual design of the BPX Conventional Facilities, for which Functional and Operational Requirements (F ampersand ORs) were developed. Existing TFTR buildings and utilities will be adapted and used to satisfy the BPX Project F ampersand ORs to the maximum extent possible. However, new conventional facilities will be required to support the BPX project. These facilities include: The BPX building; Site improvements and utilities; the Field Coil Power Conversion (FCPC) building; the TFTR modifications; the Motor Generation (MG) building; Liquid Nitrogen (LN 2 ) building; and the associated Instrumentation and Control (I ampersand C) systems. The BPX building will provide for safe and efficient shielding, housing, operation, handling, maintenance and decontamination of the BPX and its support systems. Site improvements and utilities will feature a utility tunnel which will provide a space for utility services--including pulse power duct banks and liquid nitrogen coolant lines. The FCPC building will house eight additional power supplied for the Toroidal Field (TF) coils. The MG building will house the two MG sets larger than the existing TFTR MG sets. This paper also addresses the conventional facility cost estimating methodology and the rationale for the construction schedule developed. 6 figs., 1 tab

  1. Proton moire fringes for diagnosing electromagnetic fields in opaque materials and plasmas

    International Nuclear Information System (INIS)

    Mackinnon, A.J.; Patel, P.K.; Price, D.W.; Hicks, D.; Romagnani, L.; Borghesi, M.

    2003-01-01

    High contrast proton moire fringes have been obtained in a laser-produced proton beam. Moire fringes with modulation of 20%-30% were observed in protons with energies in the range of 4-7 MeV. Monte Carlo simulations with simple test fields showed that shifts in the moire fringes can be used to give quantitative information on the strength of transient electromagnetic fields inside plasmas and materials that are opaque to conventional probing methods

  2. Field evaluation of piglet vaccination with a Mycoplasma hyopneumoniae bacterin as compared to a ready-to-use product including porcine circovirus 2 and M. hyopneumoniae in a conventional French farrow-to-finish farm.

    Science.gov (United States)

    Duivon, Didier; Corrégé, Isabelle; Hémonic, Anne; Rigaut, Martial; Roudaut, David; Jolie, Rika

    2018-01-01

    A controlled randomized trial was performed on a well-managed conventional French 180-sow farm. The trial compared the growth performances of piglets vaccinated at weaning (single shot) either with a commercial monovalent Mycoplasma hyopneumoniae bacterin vaccine or with a commercial bivalent vaccine (Porcilis® PCV M Hyo) against M. hyopneumoniae and porcine circovirus 2 (PCV2). The farm's porcine reproductive and respiratory syndrome status was stable, and most diseases (enzootic pneumonia, atrophic rhinitis, post-weaning multisystemic wasting syndrome) were controlled by routine vaccination. During the post-weaning phase, the growth performances of the piglets vaccinated with the bivalent vaccine were not significantly different from those vaccinated with the monovalent vaccine. However, during the fattening phase the group vaccinated with the bivalent vaccine had a significantly improved ADG (+34 g/d, p  = 0. 047), resulting in a 5-day earlier shipment to slaughter. The group also had a shorter and lower PCV2 load in serum during the fattening period, and an improved lung lesions score. In both groups, three pigs died during the peak PCV2 viraemia (16-23 weeks of age). Immunohistochemistry of the lymph nodes showed that in the group vaccinated with the bivalent vaccine, none of these pigs had PCV2-like lesions, while 2 out of the 3 from the other group did. Results suggest that the added PCV2 valence in the vaccination protocol helps countering the negative impact of subclinical PCV2 infection on growth. The calculated return on investment of the added PCV2 vaccine valence was €1.7 extra revenue per slaughtered pig (€ 39 additional revenue per sow and per year), despite the fact that the cost of the bivalent vaccine was higher than the monovalent M. hyopneumoniae vaccine. In this healthy conventional sow farm, the combined M. hyopneumoniae and PCV2 vaccination was efficacious, convenient to administer and profitable.

  3. Application of the Aarhus Convention

    Directory of Open Access Journals (Sweden)

    Tubić Bojan

    2011-01-01

    Full Text Available Convention on access to information, public participation in decision-making and access to justice in environmental matters (Aarhus Convention has been adopted in 1998 and entered into force three years later. It envisages three elements for strengthening democratic procedures in decision-making: access to information, public participation and access to justice. At the first meeting of the Member States the Aarhus Convention Compliance Committee was founded. The European Union is a party of the Convention and it has implemented the provisions in its legal order. After entering into force of the Convention, several Directives that regulate these issues in the EU have been enacted. Republic of Serbia has ratified the Convention in 2009 and it is currently in the process of its implementation by involving private subjects in decision-making on environmental issues.

  4. Understanding the conventional arms trade

    Science.gov (United States)

    Stohl, Rachel

    2017-11-01

    The global conventional arms trade is worth tens of billions of dollars every year and is engaged in by every country in the world. Yet, it is often difficult to control the legal trade in conventional arms and there is a thriving illicit market, willing to arm unscrupulous regimes and nefarious non-state actors. This chapter examines the international conventional arms trade, the range of tools that have been used to control it, and challenges to these international regimes.

  5. Comparison of Conventional and Semi-Conventional Management ...

    African Journals Online (AJOL)

    Comparison of Conventional and Semi-Conventional Management Systems on the Performance and Carcass Yield of Broiler Chickens. ... TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... Journal Home > Vol 20, No 1 (2018) >. Log in or ...

  6. Non-conventional rule of making a periodically varying different-pole magnetic field in low-power alternating current electrical machines with using ring coils in multiphase armature winding

    Science.gov (United States)

    Plastun, A. T.; Tikhonova, O. V.; Malygin, I. V.

    2018-02-01

    The paper presents methods of making a periodically varying different-pole magnetic field in low-power electrical machines. Authors consider classical designs of electrical machines and machines with ring windings in armature, structural features and calculated parameters of magnetic circuit for these machines.

  7. Utilization of inoculum of AM fungi produced on-farm for the production of Capsicum annuum: a summary of 7 years of field trials on a conventional vegetable farm

    Science.gov (United States)

    Utilization of arbuscular mycorrhizal [AM] fungus inoculum has been encouraged as a way for vegetable farmers to better utilize the AM symbiosis. On-farm systems can economically produce inoculum that has been shown to increase the yield of specific crops. We conducted seven years of field studies...

  8. Nuclear liability: Joint protocol relating to the application of the Vienna Convention and the Paris Convention, 1988

    International Nuclear Information System (INIS)

    1989-10-01

    The Joint Protocol Relating to the Application of the Vienna Convention and the Paris Convention was adopted by the Conference on the Relationship between the Paris Convention and the Vienna Convention, which met in Vienna, at the Headquarters of the International Atomic Energy Agency on 21 September 1988. The Joint Protocol establishes a link between the Paris Convention on Third Party Liability in the Field of Nuclear Energy of 1960 and the Vienna Convention on Civil Liability for Nuclear Damage of 1963. The Joint Protocol will extend to the States adhering to it the coverage of the two Conventions. It will also resolve potential conflicts of law, which could result from the simultaneous application of the two Conventions to the same nuclear accident. The Conference on the Relationship between the Paris Convention and the Vienna Convention was jointly organized by the International Atomic Energy Agency and the OECD Nuclear Energy Agency. This publication contains the text of the Final Act of the Conference in the six authentic languages, the Joint Protocol Relating to the Application of the Vienna Convention and the Paris Convention, also in the six authentic languages and an explanatory note, prepared by the IAEA and NEA Secretariats, providing background information on the content of the Joint Protocol

  9. Interactive Translation Prediction versus Conventional Post-editing in Practice

    DEFF Research Database (Denmark)

    Sanchis-Trilles, German; Alabau, Vicent; Buck, Christian

    2014-01-01

    We conducted a field trial in computer-assisted professional translation to compare Interactive Translation Prediction (ITP) against conventional post- editing (PE) of machine translation (MT) output. In contrast to the conventional PE set-up, where an MT system first produces a static translatio...

  10. Use of a Conventional Low Neck Field (LNF) and Intensity-Modulated Radiotherapy (IMRT): No Clinical Detriment of IMRT to an Anterior LNF During the Treatment of Head-and Neck-Cancer

    International Nuclear Information System (INIS)

    Turaka, Aruna; Li Tianyu; Nicolaou, Nicos; Lango, Miriam N.; Burtness, Barbara; Horwitz, Eric M.; Ridge, John A.; Feigenberg, Steven J.

    2011-01-01

    Purpose: To determine differences in clinical outcomes using intensity-modulated radiotherapy (IMRT) or a standard low neck field (LNF) to treat low neck. Methods and Materials: This is a retrospective, single-institution study. Ninety-one patients with squamous cell carcinoma of the head and neck were treated with curative intent. According to physician preference, some patients were treated with LNF (Planning Target Volume 3) field using a single anterior photon field matched to the IMRT field. Field junctions were not feathered. The endpoints were time to failure and use of a percutaneous endoscopic gastrostomy (PEG) tube (as a surrogate of laryngeal edema causing aspiration), and analysis was done with χ 2 and log-rank tests. Results: Median follow-up was 21 months (range, 2-89 months). Median age was 60 years. Thirty-seven patients (41%) were treated with LNF, 84% were Stage III or IV. A PEG tube was required in 30%, as opposed to 33% without the use of LNF. Node 2 or 3 neck disease was treated more commonly without LNF (38% vs. 24%, p = 0.009). Failures occurred in 12 patients (13%). Only 1 patient treated with LNF failed regionally, 4.5 cm above the match line. The 3-year disease-free survival rate was 87% and 79% with LNF and without LNF, respectively (p = 0.2), and the 3-year LR failure rate was 4% and 21%, respectively (p = 0.04). Conclusions: Using LNF to treat the low neck did not increase the risk of regional failure 'in early T and early N diseases' or decrease PEG tube requirements.

  11. The Density and Compressibility of BaCO3-SrCO3-CaCO3-K2CO3-Na2CO3-Li2CO3 Liquids: New Measurements and a Systematic Trend with Cation Field Strength

    Science.gov (United States)

    Hurt, S. M.; Lange, R. A.; Ai, Y.

    2015-12-01

    The volumetric properties of multi-component carbonate liquids are required to extend thermodynamic models that describe partial melting of the deep mantle (e.g. pMELTS; Ghiorso et al., 2003) to carbonate-bearing lithologies. Carbonate in the mantle is an important reservoir of carbon, which is released to the atmosphere as CO2 through volcanism, and thus contributes to the carbon cycle. Although MgCO3 is the most important carbonate component in the mantle, it is not possible to directly measure the 1-bar density and compressibility of MgCO3 liquid because, like other alkaline-earth carbonates, it decomposes at a temperature lower than its melting temperature. Despite this challenge, Liu and Lange (2003) and O'Leary et al. (2015) showed that the one bar molar volume, thermal expansion and compressibility of the CaCO3 liquid component could be obtained by measuring the density and sound speeds of stable liquids in the CaCO3-Li2CO3-Na2CO3-K2CO3 quaternary system at one bar. In this study, this same strategy is employed on SrCO3- and BaCO3-bearing alkali carbonate liquids. The density and sound speed of seven liquids in the SrCO3-Li2CO3-Na2CO3-K2CO3 quaternary and three liquids in the BaCO3-Li2CO3-Na2CO3-K2CO3 quaternary were measured from 739-1367K, with SrCO3 and BaCO3 concentrations ranging from 10-50 mol%. The density measurements were made using the double-bob Archimedean method and sound speeds were obtained with a frequency-sweep acoustic interferometer. The molar volume and sound speed measurements were used to calculate the isothermal compressibility of each liquid, and the results show the volumetric properties mix ideally with composition. The partial molar volume and compressibility of the SrCO3 and BaCO3 components are compared to those obtained for the CaCO3 component as a function of cation field strength. The results reveal a systematic trend that allows the partial molar volume and compressibility of the MgCO3 liquid component to be estimated.

  12. 47 CFR 27.55 - Power strength limits.

    Science.gov (United States)

    2010-10-01

    ... following bands, the predicted or measured median field strength at any location on the geographical border... predicted or measured median field strength at any location on the geographical border of a licensee's... antenna mounting structure. (c) Power flux density limit for stations operating in the 746-757 MHz, 758...

  13. Decision and Recommendation Concerning the Application of the Paris Convention on Third Party Liability in the Field of Nuclear Energy to Nuclear Installations for the Disposal of Certain Types of Low-level Radioactive Waste (This Decision and Recommendation was adopted at the 133. Session of the Steering Committee for Nuclear Energy held on 3-4 November 2016.)

    International Nuclear Information System (INIS)

    2017-01-01

    The steering committee, having regard to the Convention on Third Party Liability in the Field of Nuclear Energy of 29 July 1960, as amended by the Additional Protocol of 28 January 1964, by the Protocol of 16 November 1982 and by the Protocol of 12 February 2004, and in particular Article 1(b) thereof; Considering that, by virtue of that Article, the Steering Committee may, if in its view the small extent of the risks involved so warrants, exclude any nuclear installation, nuclear fuel or nuclear substances from the application of the Paris Convention; having regard to Article 8(b) and Article 10(b) of the Statute of the OECD Nuclear Energy Agency; considering that nuclear installations for the disposal of low-level radioactive waste are covered by the provisions of the Paris Convention; considering that it should be made possible for Contracting Parties to cease the application of the Paris Convention to a nuclear installation for the disposal of certain types of low-level radioactive waste where the risks involved are so limited; noting the attached Explanatory Note; decides that any Contracting Party may cease to apply the Paris Convention to a nuclear installation for the disposal of low-level radioactive waste, provided that the provisions set out in the Appendix to this Decision and Recommendation and any additional conditions which the Contracting Party may judge appropriate to establish are met; recommends that the Contracting Parties which make use of this option notify the other Contracting Parties, as well as the Nuclear Energy Agency; and recommends that the Nuclear Energy Agency, as appropriate, analyses periodically the experience gained by the Contracting Parties which use this option and reports back to all the Contracting Parties. (authors)

  14. Influence of adhesion promoters and curing-light sources on the shear bond strength of orthodontic brackets

    Directory of Open Access Journals (Sweden)

    Claudia Tavares Machado

    2012-01-01

    Conclusions: The conventional orthodontic adhesive presented higher bond strength than the nanofilled composite, although both materials interacted similarly to the teeth. The curing-light devices tested did not influence on bond strength of orthodontic brackets.

  15. Towards a Theory of Convention

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg

    2006-01-01

    Some thirty years ago Lewis published his Convention: A philosophical Study (Lewis 1969). Besides exciting the logical community by providing the seminal analysis work on common knowledge, it also laid the foundations for the formal approach to the study of social conventions by means of game the...

  16. Historical perspective: The pros and cons of conventional outcome measures in Parkinson's disease.

    Science.gov (United States)

    Lim, Shen-Yang; Tan, Ai Huey

    2018-01-01

    Conventional outcome measures (COMs) in Parkinson's disease (PD) refer to rating scales, questionnaires, patient diaries and clinically-based tests that do not require specialized equipment. It is timely at this juncture - as clinicians and researchers begin to grapple with the "invasion" of digital technologies - to review the strengths and weaknesses of these outcome measures. This paper discusses advances (including an enhanced understanding of PD itself, and the development of clinimetrics as a field) that have led to improvements in the COMs used in PD; their strengths and limitations; and factors to consider when selecting and using a measuring instrument. It is envisaged that in the future, a combination of COMs and technology-based objective measures will be utilized, with different methods having their own strengths and weaknesses. Judgement is required on the part of the clinician and researcher in terms of which instrument(s) are appropriate to use, depending on the particular clinical or research setting or question. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Performance of an Adjustable Strength Permanent Magnet Quadrupole

    CERN Document Server

    Gottschalk, Stephen C; Kangas, Kenneth; Spencer, Cherrill M; Volk, James T

    2005-01-01

    An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic centerline and field quality made using an air bearing rotating coil system. The magnetic centerline stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic centerline. Calibration procedures as well as centerline measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

  18. Non conventional energy sources and energy conservation

    International Nuclear Information System (INIS)

    Bueno M, F.

    1995-01-01

    Geographically speaking, Mexico is in an enviable position. Sun, water, biomass and geothermal fields main non conventional energy sources with commercial applications, are presents and in some cases plentiful in national territory. Moreover the coastal tidal power which is in research stage in several countries. Non conventional energy sources are an alternative which allow us to reduce the consumption of hydrocarbons or any other type of primary energetic, are not by oneself choices for the energy conservation, but energy replacements. At the beginning of this year, CONAE created the Direction of Non conventional Energy Sources, which main objective is to promote and impulse programs inclined towards the application of systems based in renewable energy sources. The research centers represent a technological and consultative support for the CONAE. They have an infrastructure developed along several years of continuous work. The non conventional energy sources will be a reality at the same time that their cost be equal or lower than the cost for the traditional generating systems. CONAE (National Commission for Energy Conservation). (Author)

  19. 4onse: four times open & non-conventional technology for sensing the environment

    Science.gov (United States)

    Cannata, Massimiliano; Ratnayake, Rangageewa; Antonovic, Milan; Strigaro, Daniele; Cardoso, Mirko; Hoffmann, Marcus

    2017-04-01

    The availability of complete, quality and dense monitoring hydro-meteorological data is essential to address a number of practical issues including, but not limited to, flood-water and urban drainage management, climate change impact assessment, early warning and risk management, now-casting and weather predictions. Thanks to the recent technological advances such as Internet Of Things, Big Data and Ubiquitous Internet, non-conventional monitoring systems based on open technologies and low cost sensors may represent a great opportunity either as a complement of authoritative monitoring network or as a vital source of information wherever existing monitoring networks are in decline or completely missing. Nevertheless, scientific literature on such a kind of open and non-conventional monitoring systems is still limited and often relates to prototype engineering and testing in rather limited case studies. For this reason the 4onse project aims at integrating existing open technologies in the field of Free & Open Source Software, Open Hardware, Open Data, and Open Standards and evaluate this kind of system in a real case (about 30 stations) for a medium period of 2 years to better scientifically understand strengths, criticalities and applicabilities in terms of data quality; system durability; management costs; performances; sustainability. The ultimate objective is to contribute in non-conventional monitoring systems adoption based on four open technologies.

  20. The nuclear liability conventions revised

    International Nuclear Information System (INIS)

    Reyners, P.

    2004-01-01

    The signature on 12 February 2004 of the Protocols amending respectively the 1960 Paris Convention and the 1963 Brussels Supplementary Convention was the second step of the process of modernisation of the international nuclear liability regime after the adoption in September 1997 of a Protocol revising the 1963 Vienna Convention and of a new Convention on Supplementary Compensation for Nuclear Damage. The common objective of the new instruments is to provide more funds to compensate a larger number of potential victims in respect of a broader range of damage. Another goal of the revision exercise was to maintain the compatibility between the Paris and Vienna based systems, a commitment enshrined in the 1988 Joint Protocol, as well as to ascertain that Paris/Brussels countries could also become a Party to the Convention on Supplementary Compensation. However, while generally consistent vis a vis the Joint Protocol, the provisions of the Paris and Vienna Conventions, as revised, differ on some significant aspects. Another remaining issue is whether the improved international nuclear liability regime will succeed in attracting in the future a larger number of countries, particularly outside Europe, and will so become truly universal. Therefore, the need for international co-operation to address these issues, to facilitate the adoption of new implementing legislation and to ensure that this special regime keeps abreast of economic and technological developments, is in no way diminished after the revision of the Conventions.(author)

  1. Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters.

    Science.gov (United States)

    Chowdhury, S; Maniar, A; Suganya, O M

    2015-11-01

    In this study, Wood Ash (WA) prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength) of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45) and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20%) including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM), strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper.

  2. Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters

    Directory of Open Access Journals (Sweden)

    S. Chowdhury

    2015-11-01

    Full Text Available In this study, Wood Ash (WA prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45 and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20% including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM, strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper.

  3. The evolution of development conventions

    Directory of Open Access Journals (Sweden)

    Fabio Stefano Erber

    2012-04-01

    Full Text Available This paper presents a conceptual view on development and its translation into development policies. It argues that society's perception of development is structured by conventions, which provide a view of the past, present and future and, at the same time, allows a certain hierarchy of problems and solutions to such problems. The prevalence of a specific convention depends on the international conditions faced by this society and on the distribution of economic and political power within that society. Therefore, in complex societies there is always a struggle for hegemony between competing development conventions.

  4. Strength of Fibrous Composites

    CERN Document Server

    Huang, Zheng-Ming

    2012-01-01

    "Strength of Fibrous Composites" addresses evaluation of the strength of a fibrous composite by using its constituent material properties and its fiber architecture parameters. Having gone through the book, a reader is able to predict the progressive failure behavior and ultimate strength of a fibrous laminate subjected to an arbitrary load condition in terms of the constituent fiber and matrix properties, as well as fiber geometric parameters. The book is useful to researchers and engineers working on design and analysis for composite materials. Dr. Zheng-Ming Huang is a professor at the School of Aerospace Engineering & Applied Mechanics, Tongji University, China. Mr. Ye-Xin Zhou is a PhD candidate at the Department of Mechanical Engineering, the University of Hong Kong, China.

  5. Effect of Mg and Si co-substitution on microstructure and strength of tricalcium phosphate ceramics.

    Science.gov (United States)

    García-Páez, Ismael H; Carrodeguas, Raúl García; De Aza, Antonio H; Baudín, Carmen; Pena, Pilar

    2014-02-01

    Magnesium and silicon co-doped tricalcium phosphate (TCP) ceramics with compositions corresponding to 0, 5 and 10wt% CaMg(SiO3)2 in the system Ca3(PO4)2-CaMg(SiO3)2 were obtained by conventional sintering of compacted mixtures of Ca3(PO4)2, MgO, SiO2 and CaCO3 powders at temperatures between 1100 and 1450°C. Microstructural analyses were performed by X-ray diffraction and field emission scanning electron microscopy with energy dispersive spectroscopy. Major phases in the obtained ceramics were β- or α+β-tricalcium phosphate containing Mg and Si in solid solution. Certain amounts of liquid were formed during sintering depending on composition and temperature. There were found significant differences in distributions of strength determined by the diametral compression of disc tests (DCDT). Failure strengths were controlled by microstructural defects associated with phase development. Mg and Si additions were found to be effective to improve densification and associated strength of TCP bioceramics due to the enhancement of sintering by the low viscosity liquids formed. The highest density and strength were obtained for the TCP ceramic containing 5wt% CaMg(SiO3)2 sintered at 1300°C. Cracking and porosity increased at higher temperatures due to grain growth and swelling. © 2013 Published by Elsevier Ltd.

  6. High strength alloys

    Science.gov (United States)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  7. Hand grip strength

    DEFF Research Database (Denmark)

    Frederiksen, Henrik; Gaist, David; Petersen, Hans Christian

    2002-01-01

    in life is a major problem in terms of prevalence, morbidity, functional limitations, and quality of life. It is therefore of interest to find a phenotype reflecting physical functioning which has a relatively high heritability and which can be measured in large samples. Hand grip strength is known......-55%). A powerful design to detect genes associated with a phenotype is obtained using the extreme discordant and concordant sib pairs, of whom 28 and 77 dizygotic twin pairs, respectively, were found in this study. Hence grip strength is a suitable phenotype for identifying genetic variants of importance to mid...

  8. An overview of strength training injuries: acute and chronic.

    Science.gov (United States)

    Lavallee, Mark E; Balam, Tucker

    2010-01-01

    This article introduces the history of strength training, explains the many different styles of strength training, and discusses common injuries specific to each style. Strength training is broken down into five disciplines: basic strength or resistance training, bodybuilding, power lifting, style-dependant strength sports (e.g., strongman competitions, Highland games, field events such as shot put, discus, hammer throw, and javelin), and Olympic-style weightlifting. Each style has its own principal injuries, both acute and chronic, related to the individual technique. Acute injuries should be further categorized as emergent or nonemergent. Specific age-related populations (i.e., the very young and the aging athlete) carry additional considerations.

  9. Evolutionary Games and Social Conventions

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg

    2007-01-01

    -defined metaphors of individual learning and social imitation processes, from which a revised theory of convention may be erected (see Sugden 2004, Binmore 1993 and Young 1998). This paper makes a general argument in support of the evolutionary turn in the theory of convention by a progressive exposition of its...... in Aumann (1976) and which, together with the assumptions of perfect rationality, came to be defining of classical game theory. However, classical game theory is currently undergoing severe crisis as a tool for exploring social phenomena; a crisis emerging from the problem of equilibrium selection around......Some thirty years ago Lewis published his Convention: A Philosophical Study (Lewis, 2002). This laid the foundation for a game-theoretic approach to social conventions, but became more famously known for its seminal analysis of common knowledge; the concept receiving its canonical analysis...

  10. High field MRI in the diagnosis of multiple sclerosis: high field-high yield?

    International Nuclear Information System (INIS)

    Wattjes, Mike P.; Barkhof, Frederik

    2009-01-01

    Following the approval of the U.S. Food and Drug Administration (FDA), high field magnetic resonance imaging (MRI) has been increasingly incorporated into the clinical setting. Especially in the field of neuroimaging, the number of high field MRI applications has been increased dramatically. Taking advantage on increased signal-to-noise ratio (SNR) and chemical shift, higher magnetic field strengths offer new perspectives particularly in brain imaging and also challenges in terms of several technical and physical consequences. Over the past few years, many applications of high field MRI in patients with suspected and definite multiple sclerosis (MS) have been reported including conventional and quantitative MRI methods. Conventional pulse sequences at 3 T offers higher lesion detection rates when compared to 1.5 T, particularly in anatomic regions which are important for the diagnosis of patients with MS. MR spectroscopy at 3 T is characterized by an improved spectral resolution due to increased chemical shift allowing a better quantification of metabolites. It detects significant axonal damage already in patients presenting with clinically isolated syndromes and can quantify metabolites of special interest such as glutamate which is technically difficult to quantify at lower field strengths. Furthermore, the higher susceptibility and SNR offer advantages in the field of functional MRI and diffusion tensor imaging. The recently introduced new generation of ultra-high field systems beyond 3 T allows scanning in submillimeter resolution and gives new insights into in vivo MS pathology on MRI. The objectives of this article are to review the current knowledge and level of evidence concerning the application of high field MRI in MS and to give some ideas of research perspectives in the future. (orig.)

  11. microRNA biosensors: Opportunities and challenges among conventional and commercially available techniques.

    Science.gov (United States)

    Kilic, Tugba; Erdem, Arzum; Ozsoz, Mehmet; Carrara, Sandro

    2018-01-15

    As being the most extensively studied, non-coding, evolutionary conserved, post-transcriptional gene regulators of genome, microRNAs (miRNAs) have taken great attention among various disciplines due to their important roles in biological processes and link with cancer. Due to their diagnostic value, there have been many conventional methods used in detection of miRNAs including northern blotting, quantitative real time PCR (qRT-PCR) and microarray technology besides novel techniques based on various nanotechnology approaches and molecular biology tools including miRNA biosensors. The aim of this review is to explain the importance of miRNAs in biomedical field with an emphasis on early cancer diagnosis by overviewing both research based and commercially available miRNA detection methods in the last decade considering their strengths and weakness with an emphasis on miRNA biosensors. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. An in vitro Evaluation of Shear Bond Strength of Adhesive Precoated Brackets

    Directory of Open Access Journals (Sweden)

    A S Sibi

    2014-01-01

    Full Text Available Newer materials have been introduced in the field of orthodontics to improve clinical efficacy as well as to simplify the technique. In an effort to reduce the time and steps to bond orthodontic attachments, adhesive precoated (APC brackets were introduced. In this study, an attempt is made to evaluate the shear bond strength (SBS and debonding behavior of APC brackets compared with uncoated ceramic brackets. A total of 60 human premolar teeth were divided into two groups of 30 each, bonded with APC ceramic brackets and uncoated ceramic brackets. Group I bonded with APC brackets as prescribed by the manufacturers and group II was bonded with conventional bonding using Turbobond. After bonding, sthe samples were kept in distilled water at 37°C for 24 hours and a universal testing mechine was used to apply an occlusal shear force at a speed of 0.5 mm/min. The shear bond strength of the groups was compared using Student t-test and the debonding behavior were compared using Mann-Whitney′s U test. Mean shear bond strength and standard deviation of the groups were group I - 9.09 ± 2.5 MPa and group II - 12.95 ± 2.81 MPa. There were significant differences in bond strength observed between the two groups. The debonding behavior showed an adhesive remnant index score of 0.90 ± 0.08 for group I and 1.10 ± 0.04 for group II, which indicates there is significant difference between each other. When considering the values required for optimum bond strength, APC brackets in this study showed adequate bond strength and could be used for routine clinical use.

  13. Probe tests microweld strength

    Science.gov (United States)

    1965-01-01

    Probe is developed to test strength of soldered, brazed or microwelded joints. It consists of a spring which may be adjusted to the desired test pressure by means of a threaded probe head, and an indicator lamp. Device may be used for electronic equipment testing.

  14. Improving the strength of additively manufactured objects via modified interior structure

    Science.gov (United States)

    Al, Can Mert; Yaman, Ulas

    2017-10-01

    Additive manufacturing (AM), in other words 3D printing, is becoming more common because of its crucial advantages such as geometric complexity, functional interior structures, etc. over traditional manufacturing methods. Especially, Fused Filament Fabrication (FFF) 3D printing technology is frequently used because of the fact that desktop variants of these types of printers are highly appropriate for different fields and are improving rapidly. In spite of the fact that there are significant advantages of AM, the strength of the parts fabricated with AM is still a major problem especially when plastic materials, such as Acrylonitrile butadiene styrene (ABS), Polylactic acid (PLA), Nylon, etc., are utilized. In this study, an alternative method is proposed in which the strength of AM fabricated parts is improved employing direct slicing approach. Traditional Computer Aided Manufacturing (CAM) software of 3D printers takes only the geometry as an input in triangular mesh form (stereolithography, STL file) generated by Computer Aided Design software. This file format includes data only about the outer boundaries of the geometry. Interior of the artifacts are manufactured with homogeneous infill patterns, such as diagonal, honeycomb, linear, etc. according to the paths generated in CAM software. The developed method within this study provides a way to fabricate parts with heterogeneous infill patterns by utilizing the stress field data obtained from a Finite Element Analysis software, such as ABAQUS. According to the performed tensile tests, the strength of the test specimen is improved by about 45% compared to the conventional way of 3D printing.

  15. The Galactic magnetic fields

    International Nuclear Information System (INIS)

    Han Jinlin

    2006-01-01

    A good progress has been made on studies of Galactic magnetic fields in last 10 years. I describe what we want to know about the Galactic magnetic fields, and then review we current knowledge about magnetic fields in the Galactic disk, the Galactic halo and the field strengths. I also listed many unsolved problems on this area

  16. Revision of the Paris and Brussels Conventions of Nuclear Liability

    International Nuclear Information System (INIS)

    Reyners, P.

    2002-01-01

    The Contracting Parties to the 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy and to the 1963 Brussels Convention Supplementary to the Paris Convention, have concluded this Spring four years of negotiation on the revision of these instruments. This exercise was itself started as a logical consequence of the adoption in 1997 of a revised Vienna Convention on Civil Liability for Nuclear Damage and of a Convention on Supplementary Compensation for Nuclear Damage. The Contracting Parties have concluded that the existing regime established by these Conventions remains viable and sound but that it also warrants improvements to ensure that greater financial security will be available to compensate a potentially larger number of victims in respect of a broader range of nuclear damage. A number of more technical amendments have also been agreed, in particular to ensure compatibility with other existing Conventions in this field. When the revised Paris and Brussels Conventions come into force, the total amount of funds available for compensation, provided by the liable nuclear operator and by the States concerned, will be 1.5 billion euros. (author)

  17. [Compressive and bend strength of experimental admixed high copper alloys].

    Science.gov (United States)

    Sourai, P; Paximada, H; Lagouvardos, P; Douvitsas, G

    1988-01-01

    Mixed alloys for dental amalgams have been used mainly in the form of admixed alloys, where eutectic spheres are blend with conventional flakes. In the present study the compressive strength, bend strength and microstructure of two high-copper alloys (Tytin, Ana-2000) is compared with three experimental alloys prepared of the two high copper by mixing them in proportions of 3:1, 1:1 and 1:3 by weight. The results revealed that experimental alloys inherited high early and final strength values without any significant change in their microstructure.

  18. Effects of etching time on enamel bond strengths.

    Science.gov (United States)

    Triolo, P T; Swift, E J; Mudgil, A; Levine, A

    1993-12-01

    This study evaluated the effects of etching time on bond strengths of composite to enamel. Proximal surfaces of extracted molars were etched with either a conventional etchant (35% phosphoric acid) or one of two dentin/enamel conditioners, 10% maleic acid (Scotchbond Multi-Purpose Etchant), or a solution of oxalic acid, aluminum nitrate, and glycine (Gluma 1 & 2 Conditioner). Each agent was applied for 15, 30, or 60 seconds. Specimens etched with 35% phosphoric acid had the highest mean bond strengths at each etching time. At the manufacturer's recommended application times, the other two agents gave significantly lower shear bond strengths than phosphoric acid.

  19. Novel versus conventional antipsychotic drugs.

    Science.gov (United States)

    Love, R C

    1996-01-01

    Novel antipsychotic agents differ from conventional ones in several key characteristics, including effectiveness, adverse reactions, and receptor-binding profile. Most of the newer agents have an affinity for the serotonin 5HT2 receptor that is at least 10 times greater than that for the dopamine D2 receptor. This increased affinity for the serotonin receptor may be responsible for another distinguishing characteristic of novel antipsychotic agents--decreased frequency of extrapyramidal side effects. These side effects, which include pseudoparkinsonism, acute dystonias, and akathisia, frequently are the reason for noncompliance with conventional drug therapy. The newer drugs are often effective in patients resistant to treatment with conventional agents. They also appear to reduce the negative symptoms of schizophrenia in many patients.

  20. Redox Buffer Strength

    Science.gov (United States)

    de Levie, Robert

    1999-04-01

    The proper functioning of enzymes in bodily fluids requires that the pH be maintained within rather narrow limits. The first line of defense against large pH fluctuations in such fluids is the passive control provided by the presence of pH buffers. The ability of pH buffers to stabilize the pH is indicated by the buffer value b introduced in 1922 by van Slyke. It is equally important for many enzymes that the redox potential is kept within a narrow range. In that case, stability of the potential is most readily achieved with a redox buffer. In this communication we define the redox buffer strength by analogy with acid-base buffer strength.

  1. The prospect of conventional disarmament

    International Nuclear Information System (INIS)

    Adeniji, O.

    1989-01-01

    The prospect of conventional disarmament in Europe holds out great consequences not only for the continent but also for the entire world. The arms race both in its nuclear and conventional aspects has been the single most important element of the destabilizing factors in international relations since 1945. Though initially borne out of the ideological division of Europe and the consequent quest for strategic military superiority, it soon developed a technological momentum of its own, becoming more the cause than the effect of the distrust in the relationship of the two alliances. The issue of conventional weapons was raised for negotiations side by side with that of nuclear weapons when the United Nations took up the question of disarmament in 1946. Due, however, to the unforeseen and most dangerous advance in nuclear weaponry, the fear engendered shifted all attention at the multilateral level to nuclear weapons. Except in Europe where the Mutual and Balanced Force Reduction Talks in Central Europe were initiated, conventional weapons disarmament did not attract multilateral attention again until the First Special Session of the United nations General Assembly Devoted to Disarmament in 1978. The Final Document of the Special Session did accord highest priority to negotiations on nuclear weapons. However, it also affirmed that side by side with negotiations on nuclear weapons, the limitation and gradual reduction of armed forces and conventional weapons should be resolutely pursued within the framework of general and complete disarmament. States with the largest military arsenals, it was stated, had a special responsibility in pursuing conventional armaments reduction. Underscoring the central role of Europe further, the Final Document postulated that the achievement of a more stable situation at a lower level of military potential would contribute toward strengthening of security in Europe and constitute a significant step toward international peace and security

  2. Corium crust strength measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439-4840 (United States)], E-mail: lomperski@anl.gov; Farmer, M.T. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439-4840 (United States)], E-mail: farmer@anl.gov

    2009-11-15

    Corium strength is of interest in the context of a severe reactor accident in which molten core material melts through the reactor vessel and collects on the containment basemat. Some accident management strategies involve pouring water over the melt to solidify it and halt corium/concrete interactions. The effectiveness of this method could be influenced by the strength of the corium crust at the interface between the melt and coolant. A strong, coherent crust anchored to the containment walls could allow the yet-molten corium to fall away from the crust as it erodes the basemat, thereby thermally decoupling the melt from the coolant and sharply reducing the cooling rate. This paper presents a diverse collection of measurements of the mechanical strength of corium. The data is based on load tests of corium samples in three different contexts: (1) small blocks cut from the debris of the large-scale MACE experiments, (2) 30 cm-diameter, 75 kg ingots produced by SSWICS quench tests, and (3) high temperature crusts loaded during large-scale corium/concrete interaction (CCI) tests. In every case the corium consisted of varying proportions of UO{sub 2}, ZrO{sub 2}, and the constituents of concrete to represent a LWR melt at different stages of a molten core/concrete interaction. The collection of data was used to assess the strength and stability of an anchored, plant-scale crust. The results indicate that such a crust is likely to be too weak to support itself above the melt. It is therefore improbable that an anchored crust configuration could persist and the melt become thermally decoupled from the water layer to restrict cooling and prolong an attack of the reactor cavity concrete.

  3. Conventional imaging in paediatric uroradiology

    International Nuclear Information System (INIS)

    Riccabona, M.; Lindbichler, F.; Sinzig, M.

    2002-01-01

    Objective: To briefly describe basic conventional imaging in paediatric uroradiology. Method: The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included. Result and conclusion: Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options

  4. Conventional imaging in paediatric uroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Riccabona, M. E-mail: michael.riccabona@kfunigraz.ac.at; Lindbichler, F.; Sinzig, M

    2002-08-01

    Objective: To briefly describe basic conventional imaging in paediatric uroradiology. Method: The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included. Result and conclusion: Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options.

  5. Conventional and unconventional political participation

    International Nuclear Information System (INIS)

    Opp, K.D.

    1985-01-01

    A non-recursive model is proposed and empirically tested with data of opponents of nuclear power. In explaining conventional and unconventional participation the theory of collective action is applied and modified in two respects: the perceived influence on the elimination of collective evils are taken into account; the selective incentives considered are non-material ones. These modifications proved to be valid: the collective good variables and non-material incentives were important determinants for the two forms of participation. Another result was that there is a reciprocal causal relationship between conventional and unconventional participation. (orig./PW) [de

  6. Strength capability while kneeling.

    Science.gov (United States)

    Haslegrave, C M; Tracy, M F; Corlett, E N

    1997-12-01

    Work sometimes has to be carried out kneeling, particularly where jobs are performed in confined spaces as is common for miners, aircraft baggage handlers and maintenance workers. In order to assess the risks in performing forceful tasks under such conditions, data is needed on strength capabilities of kneeling subjects. A study was undertaken to measure isometric strength in single-handed exertions for male subjects and to investigate the effects on this of task layout factors (direction of force exertion, reach distance, height of the workpiece and orientation relative to the subject's sagittal plane). The data has been tabulated to show the degree to which strength may be reduced in different situations and analysis of the task factors showed their influence to be complex with direction of exertion and reach distance having the greatest effect. The results also suggest that exertions are weaker when subjects are kneeling on two knees than when kneeling on one knee, although this needs to be confirmed by direct experimental comparison.

  7. A complementary conventional analysis for channelized reservoirs

    International Nuclear Information System (INIS)

    Escobar Freddy Humberto; Montealegre M, Matilde

    2007-01-01

    Many well pressure data coming from long and narrow reservoirs which result from either fluvial deposition of faulting connote be completely interpreted by conventional analysis since some flow regimes are not conventionally recognized yet in the oil literature. This narrow geometry allows for the simultaneous development of two linear flow regimes coming from each one of the lateral sides of the system towards the well. This has been called dual linear flow regime. If the well is off-centered with regards to the two lateral boundaries, then, and of the linear flow regimes vanishes and, than, two possibilities con be presented. Firstly, if the closer lateral boundary is close to flow the unique linear flow persists along the longer lateral boundary. It has been called single linear flow. Following this, either steady or pseudo-steady states will develop. Secondly, if a constant - pressure closer lateral boundary is dealt with, then parabolic flow develops along the longer lateral boundary. Steady state has to be developed once the disturbance reaches the farther boundary. This study presents new equations for conventional analysis for the dual linear, linear and parabolic flow regimes recently introduced to the oil literature. The equations were validated by applying them to field and simulated examples

  8. Spin resonance strength calculation through single particle tracking for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The strengths of spin resonances for the polarized-proton operation in the Relativistic Heavy Ion Collider are currently calculated with the code DEPOL, which numerically integrates through the ring based on an analytical approximate formula. In this article, we test a new way to calculate the spin resonance strengths by performing Fourier transformation to the actual transverse magnetic fields seen by a single particle traveling through the ring. Comparison of calculated spin resonance strengths is made between this method and DEPOL.

  9. Cosmic censorship and the strengths of singularities

    International Nuclear Information System (INIS)

    Newman, R.P.

    1986-01-01

    This paper considers the principal definitions concerning limiting curvature strength on geodesics, and on non-spacelike geodesics in particular. They are formulated in terms of focussing conditions. Two definitions suggest themselves, and these are given in terms of a concept of a generalized Jacobi field. An historical survey is presented on some important developments concerning examples of naked singularities. The historical context is recalled in which these models, and cosmic censorship in general, have arisen. It is the author's opinion that one can expect to obtain theoretical limitations on the strengths of any naked singularities which do occur

  10. Manufacturing of kevlar/polyester composite by resin transfer moulding using conventional and microwave heating

    International Nuclear Information System (INIS)

    Abdullah, I.

    2015-01-01

    Microwave heating was incorporated into the resin transfer moulding technique. Polytetrafluoroethylene (PTFE) mould was used to cure the composite panel. Through the use of microwave heating, the mechanical and physical properties of produced Kevlar fibre/polyester composites were compared to those manufactured by conventional resin transfer moulding. The flexural modulus and flexural strength of 6-ply conventionally cured composites was 45% and 9% higher than the flexural modulus and flexural strength of 6-ply microwaved cured composites, respectively. However, 19% increase in interlaminar shear strength (ILSS) and 2% increase in compressive strength was observed in 6-ply microwave cured composites. This enhancement in ILSS and compressive strength is attributed to the better interfacial bonding of polyester resin with Kevlar fibres in microwaved cured composite, which was also confirmed via electron microscopy scanning. Furthermore, the microwave cured composite yielded maximum void contents (3%). (author)

  11. Short-term Periodization Models: Effects on Strength and Speed-strength Performance.

    Science.gov (United States)

    Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena

    2015-10-01

    avoided because it does not provide an adequate training stimulus for gains in muscle cross-sectional area and strength performance. High-volume circuit strength training performed over 2 years negatively affected the development of the power output and maximal strength of the upper extremities in professional rugby players. Indeed, meta-analyses and results with weightlifters, American Football players, and throwers confirm the necessity of the habitual use of ≥80% 1 RM: (1) to improve maximal strength during the off-season and in-season in American Football, (2) to reach peak performance in maximal strength and vertical jump power during tapering in track-and-field, and (3) to produce hypertrophy and strength improvements in advanced athletes. The integration and extent of hypertrophy strength training in in-season conditioning depend on the duration of the contest period, the frequency of the contests, and the proportion of the conditioning program. Based on the literature, 72 h between hypertrophy strength training and strength-power training should be provided to allow for adequate regeneration times and therefore maximal stimulus intensities in training. This conclusion is only valid if the muscle is not trained otherwise during this regeneration phase. Thus, rotating hypertrophy and strength-power sessions in a microcycle during the season is a viable option. Comparative studies in competitive athletes who integrated strength training during pre-season conditioning confirm a tendency for gains in explosive strength and statistically significant improvements in medicine ball throw through SPP but not through daily undulating periodization. These findings indicate that to maximize the speed-strength in the short term (peaking), elite athletes should perform strength-power training twice per week. It is possible to perform a single strength-power session with the method of maximum explosive strength actions moving high-weight loads (90% 1 repetition maximum [RM]) at

  12. Diagnostic equivalence of conventional and fast spin echo magnetic resonance imaging of the anterior cruciate ligament of the knee

    International Nuclear Information System (INIS)

    Munk, P.L.; Hilborn, M.D.; Vellet, A.D.; University of Calgary, Calgary, Alberta,; Romano, C.C.; University of Calgary, Calgary, Alberta,

    1997-01-01

    Many techniques and pulse sequences have been devised for the assessment of the anterior cruciate ligament. The present study compares fast spin echo (FSE) imaging to conventional spin echo imaging at a field strength of 1.5 T in an effort to determine if these sequences are diagnostically equivalent. Where available, arthroscopy was also done. A total of 52 patients were imaged using both FSE and conventional spin echo sequences. Eight volunteers were used as controls. Arthroscopy was performed on 10 patients. The anterior cruciate ligament was assessed in a blinded fashion by three radiologists. The Kappa statistic was then used to determine the percentage agreement between FSE and conventional spin echo imaging. Fast spin echo sequencing demonstrated a sensitivity of 100%, a specificity of 94.8% and an accuracy of 96.3% when compared to arthroscopy. Conventional spin echo imaging and arthroscopy had a sensitivity of 100%, specificity of 84.6% and an accuracy of 88.9%. The remaining 34 patients who did not undergo arthroscopy were followed clinically because clinical and imaging findings were not suggestive of ACL tears. These demonstrated 72% agreement between FSE and conventional spin echo imaging using the Kappa statistic, with regards to calling ACL normal or having only a low-grade partial tear. Fast spin echo imaging produces images of the anterior cruciate ligament that have similar diagnostic accuracy to conventional spin echo images (P<0.05) within a much shorter scan time. These results however, require further validation in a larger group, preferably with arthroscopic correlation. (author)

  13. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

    The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current regula...

  14. Strengths only or strengths and relative weaknesses? A preliminary study.

    Science.gov (United States)

    Rust, Teri; Diessner, Rhett; Reade, Lindsay

    2009-10-01

    Does working on developing character strengths and relative character weaknesses cause lower life satisfaction than working on developing character strengths only? The present study provides a preliminary answer. After 76 college students completed the Values in Action Inventory of Strengths (C. Peterson & M. E. P. Seligman, 2004), the authors randomly assigned them to work on 2 character strengths or on 1 character strength and 1 relative weakness. Combined, these groups showed significant gains on the Satisfaction With Life Scale (E. Diener, R. A. Emmons, R. J. Larsen, & S. Griffin, 1985), compared with a 32-student no-treatment group. However, there was no significant difference in gain scores between the 2-strengths group and the 1-character-strength-and-1-relative-character-weakness group. The authors discuss how focusing on relative character weaknesses (along with strengths) does not diminish-and may assist in increasing-life satisfaction.

  15. The 'strength' of a system of differential equations

    International Nuclear Information System (INIS)

    Hoenselaers, C.

    1977-01-01

    A review of Einstein's concept of ''strength'' of a system of differential equations is given. As an example the strength of the Einstein-Maxwell equations for non-null Maxwell field is calculated and shown to be the same as for the pure vacuum Einstein equations. (auth.)

  16. Implementation of the Aarhus convention - A survey

    Directory of Open Access Journals (Sweden)

    Marina Malis Sazdovska

    2016-11-01

    Full Text Available Legislation on global and regional level in the field of environmental protection is characterized by the adoption of international conventions and agreements that attempt to regulate this matter legally. As an extremely important area, which exceeds the boundaries of nation-state and as a global environmental problem, the issues of environmental protection are a major concern to international organizations. It is directly linked to reducing the jurisdiction of the States and transfer of competences to international organizations and institutions in order to solve the problems in a global experience. In order to overcome the problems regarding the implementation of international documents, the creation of certain policies by international organizations and institutions is required to promote the idea of environmental protection as a basic mo$ o of the global world. Taking into account the recommendations of Brundtland Commission, humanity has a moral obligation to preserve natural resources for future generations. Main objective of this article is the presentation of research on the implementation of the Aarhus Convention and the proposal of measures for the creation of ideas and policies on improving access to information in the field. The research is done with the students from the faculty of Security which accessed the information in environmental matters.

  17. Strength and water absorption characteristics of cement-bonded ...

    African Journals Online (AJOL)

    Contrary to conventional practice, the boards were fabricated in the laboratory without external pressure application. The effects of calcium chloride (CaCl2) addition on the hardening time, appearance, bending and compressive strength, and water absorption properties of the boards were also investigated. The boards had ...

  18. Conventional and Non-Conventional Yeasts in Beer Production

    Directory of Open Access Journals (Sweden)

    Angela Capece

    2018-06-01

    Full Text Available The quality of beer relies on the activity of fermenting yeasts, not only for their good fermentation yield-efficiency, but also for their influence on beer aroma, since most of the aromatic compounds are intermediate metabolites and by-products of yeast metabolism. Beer production is a traditional process, in which Saccharomyces is the sole microbial component, and any deviation is considered a flaw. However, nowadays the brewing sector is faced with an increasing demand for innovative products, and it is diffusing the use of uncharacterized autochthonous starter cultures, spontaneous fermentation, or non-Saccharomyces starters, which leads to the production of distinctive and unusual products. Attempts to obtain products with more complex sensory characteristics have led one to prospect for non-conventional yeasts, i.e., non-Saccharomyces yeasts. These generally are characterized by low fermentation yields and are more sensitive to ethanol stress, but they provide a distinctive aroma and flavor. Furthermore, non-conventional yeasts can be used for the production of low-alcohol/non-alcoholic and light beers. This review aims to present the main findings about the role of traditional and non-conventional yeasts in brewing, demonstrating the wide choice of available yeasts, which represents a new biotechnological approach with which to target the characteristics of beer and to produce different or even totally new beer styles.

  19. Table 1. Summary of Field Testing and Measurement Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Key performance parameters measured during the field demonstration such as lining thickness, compressive strength, Flexural Strength, Modulus of Elasticity, bond...

  20. Compressive strength, flexural strength and water absorption of concrete containing palm oil kernel shell

    Science.gov (United States)

    Noor, Nurazuwa Md; Xiang-ONG, Jun; Noh, Hamidun Mohd; Hamid, Noor Azlina Abdul; Kuzaiman, Salsabila; Ali, Adiwijaya

    2017-11-01

    Effect of inclusion of palm oil kernel shell (PKS) and palm oil fibre (POF) in concrete was investigated on the compressive strength and flexural strength. In addition, investigation of palm oil kernel shell on concrete water absorption was also conducted. Total of 48 concrete cubes and 24 concrete prisms with the size of 100mm × 100mm × 100mm and 100mm × 100mm × 500mm were prepared, respectively. Four (4) series of concrete mix consists of coarse aggregate was replaced by 0%, 25%, 50% and 75% palm kernel shell and each series were divided into two (2) main group. The first group is without POF, while the second group was mixed with the 5cm length of 0.25% of the POF volume fraction. All specimen were tested after 7 and 28 days of water curing for a compression test, and flexural test at 28 days of curing period. Water absorption test was conducted on concrete cube age 28 days. The results showed that the replacement of PKS achieves lower compressive and flexural strength in comparison with conventional concrete. However, the 25% replacement of PKS concrete showed acceptable compressive strength which within the range of requirement for structural concrete. Meanwhile, the POF which should act as matrix reinforcement showed no enhancement in flexural strength due to the balling effect in concrete. As expected, water absorption was increasing with the increasing of PKS in the concrete cause by the porous characteristics of PKS