WorldWideScience

Sample records for techniques plasma spatial

  1. [Plasma exchange in nephrology: Indications and technique].

    Science.gov (United States)

    Ridel, Christophe; Kissling, Sébastien; Mesnard, Laurent; Hertig, Alexandre; Rondeau, Éric

    2017-02-01

    Plasma exchange is a non-selective apheresis technique that can be performed by filtration or centrifugation allowing rapid purification of high molecular weight pathogens. An immunosuppressive treatment is generally associated to reduce the rebound effect of the purified substance. Substitution solutes such as human albumin and macromolecules are needed to compensate for plasma extraction. Compensation by viro-attenuated plasma is reserved solely for the treatment of thrombotic microangiopathies or when there is a risk of bleeding, because this product is very allergenic and expensive. The treatment goal for a plasma exchange session should be between one and one and one-half times the patient's plasma volume estimated at 40 mL/kg body weight. The anticoagulation is best ensured by the citrate. Complications of plasma exchange are quite rare according to the French hemapheresis registry. The level of evidence of efficacy of plasma exchange in nephrology varies from one pathology to another. Main indications of plasma exchange in nephrology are Goodpasture syndrome, antineutrophil cytoplasmic antibody vasculitis when plasma creatinine is greater than 500 μmol/L, and thrombotic microangiopathies. During renal transplantation, plasma exchange may be proposed in the context of human leukocyte antigen (HLA) desensitization protocols or ABO-incompatible graft. After renal transplantation, plasma exchange is indicated as part of the treatment of acute humoral rejection or recurrent focal segmental glomerulosclerosis on the graft. Plasma exchanges are also proposed in the management of cryoglobulinemia or polyarteritis nodosa. Hemodialysis with membranes of very high permeability tends to replace plasma exchange for myeloma nephropathy. The benefit from plasma exchange has not been formally demonstrated for the treatment of severe lupus or antiphospholipid antibody syndrome. There is no indication of plasma exchange in the treatment of scleroderma or nephrogenic

  2. Influence of plasma density and plasma sheath dynamics on the ion implantation by plasma immersion technique

    OpenAIRE

    Ensinger, Wolfgang

    1996-01-01

    Influence of plasma density and plasma sheath dynamics on the ion implantation by plasma immersion technique / B. Rauschenbach ... - In: Nuclear instruments and methods in physics research. B. 113. 1996. S. 266-269

  3. Cathodic Cage Plasma Nitriding: An Innovative Technique

    OpenAIRE

    Sousa,R.R.M.; de Araújo, F. O.; J. A. P. da Costa; Brandim,A.S.; R. A. de Brito; C. Alves

    2012-01-01

    Cylindrical samples of AISI 1020, AISI 316, and AISI 420 steels, with different heights, were simultaneously treated by a new technique of ionic nitriding, entitled cathodic cage plasma nitriding (CCPN), in order to evaluate the efficiency of this technique to produce nitrided layers with better properties compared with those obtained using conventional ionic nitriding technique. This method is able to eliminate the edge effect in the samples, promoting a better uniformity of temperature, and...

  4. Plasma filtering techniques for nuclear waste remediation

    Energy Technology Data Exchange (ETDEWEB)

    Gueroult, Renaud, E-mail: rgueroul@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ 08540 (United States); Hobbs, David T. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Fisch, Nathaniel J. [Princeton Plasma Physics Laboratory, Princeton, NJ 08540 (United States)

    2015-10-30

    Highlights: • A detailed economic study on plasma mass filtering techniques is presented. • Comparison with chemical techniques shows similar costs for solid-waste pretreatment. • Significant savings potential is identified through superior waste minimization. - Abstract: Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste.

  5. Application of nonlinear dynamic techniques to high pressure plasma jets

    Science.gov (United States)

    Ghorui, S.; Das, A. K.

    2010-02-01

    Arcs and arc plasmas have been known and used for welding, cutting, chemical synthesis and multitude of other industrial applications for more than hundred years. Though a copious source of heat, light and active species, plasma arc is inherently unstable, turbulent and difficult to control. During recent years, primarily driven by the need of new and energy efficient materials processing, various research groups around the world have been studying new and innovative ways of looking at the issues related to arc dynamics, arc stabilization, species non equilibrium, flow and heat transfer in a stabilized arc plasma device. In this context, experimental determination of nature of arc instabilities using tools of non-linear dynamics, theoretical model formulation, prediction of instability behavior under given operating conditions and possible control methods for the observed instabilities in arcs are reviewed. Space selective probing of the zones inside arc plasma devices without disturbing the system is probably the best way to identify the originating zone of instabilities inside such devices. Existence of extremely high temperature and inaccessibility to direct experimentations due to mechanical obstructions make this task extremely difficult. Probing instabilities in otherwise inaccessible inner regions of the torches, using binary gas mixture as plasma gas is a novel technique that primarily rests on a process known as demixing in arcs. Once a binary gas mixture enters the constricted plasma column, the demixing process sets in causing spatial variations for each of the constituent gases depending on the diffusion coefficients and the gradient of the existing temperature field. By varying concentrations of the constituent gases in the feeding line, it is possible to obtain spatial variations of the plasma composition in a desired manner, enabling spatial probing of the associated zones. Detailed compositional description of different zones inside the torch may be

  6. Diagnostics of nonlocal plasmas: advanced techniques

    Science.gov (United States)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  7. Chaotic synchronization in coupled spatially extended beam-plasma systems

    OpenAIRE

    Filatov, Roman A.; Hramov, Alexander E.; ALEXEY A. KORONOVSKII

    2006-01-01

    The appearance of the chaotic synchronization regimes has been discovered for the coupled spatially extended beam-plasma Pierce systems. The coupling was introduced only on the right bound of each subsystem. It has been shown that with coupling increase the spatially extended beam-plasma systems show the transition from asynchronous behavior to the phase synchronization and then to the complete synchronization regime. For the consideration of the chaotic synchronization we used the concept of...

  8. Effect of Energetic Ion on Spatial Distribution of Recombining Plasma

    Science.gov (United States)

    Okamoto, A.; Daibo, A.; Kitajima, S.; Kumagai, T.; Takahashi, H.; Takahashi, T.; Tsubota, S.

    Spatial distribution of electron density is considered. By using a one-dimensional recombining plasma model, effects of transient energetic ion flux are investigated. The time response of the system against the transient flux is dominated by the recombination frequency. The magnitude of modification of the spatial distribution is determined by the ratio between the ionization due to the energetic ion and the recombination of the bulk plasma.

  9. Cathodic Cage Plasma Nitriding: An Innovative Technique

    Directory of Open Access Journals (Sweden)

    R. R. M. de Sousa

    2012-01-01

    Full Text Available Cylindrical samples of AISI 1020, AISI 316, and AISI 420 steels, with different heights, were simultaneously treated by a new technique of ionic nitriding, entitled cathodic cage plasma nitriding (CCPN, in order to evaluate the efficiency of this technique to produce nitrided layers with better properties compared with those obtained using conventional ionic nitriding technique. This method is able to eliminate the edge effect in the samples, promoting a better uniformity of temperature, and consequently, a smaller variation of the thickness/height relation can be obtained. The compound layers were characterized by X-ray diffraction, optical microscopy, and microhardness test profile. The results were compared with the properties of samples obtained with the conventional nitriding, for the three steel types. It was verified that samples treated by CCPN process presented, at the same temperature, a better uniformity in the thickness and absence of the edge effect.

  10. Spatial control of processing plasmas in a multicusp plasma source equipped with a movable magnetic filter

    Energy Technology Data Exchange (ETDEWEB)

    Fukumasa, O.; Naitou, H.; Sakiyama, S. (Yamaguchi Univ., Yamaguchi (Japan))

    1991-12-20

    The plasma chemical vapor deposition (p-CVD) method has been used in the preparation of various sorts of thin films such as hydrogenated amorphous silicon films and hydrogenated amorphous carbon films, etc. and the application feasibility of a magnetically filtered multicusp plasma source has been studied. In this paper, it is confirmed that plasma parameters (H {sub 2} - ch {sub 4} or Ar-CH {sub 4} plasmas) are spatially well controlled by using both a movable magnetic filter and a plasma grid. Plasma parameters change sharply across the magnetic filter at any filter position and the whole plasma is divided clearly into the region of source plasma with high-energy electrons and the region of diffused plasma without high-energy electrons. Concerning the role of the magnetic filter which reflects preferentially high-energy electrons, a study is made through computer simulation. 7 refs., 9 figs.

  11. Quantitative single shot and spatially resolved plasma wakefield diagnostics

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Levy, Matthew C; Ratan, Naren; Sadler, James; Bingham, Robert; Burrows, Philip N; Trines, Raoul; Wing, Matthew; Norreys, Peter

    2015-01-01

    Diagnosing plasma conditions can give great advantages in optimizing plasma wakefield accelerator experiments. One possible method is that of photon acceleration. By propagating a laser probe pulse through a plasma wakefield and extracting the imposed frequency modulation, one can obtain an image of the density modulation of the wakefield. In order to diagnose the wakefield parameters at a chosen point in the plasma, the probe pulse crosses the plasma at oblique angles relative to the wakefield. In this paper, mathematical expressions relating the frequency modulation of the laser pulse and the wakefield density profile of the plasma for oblique crossing angles are derived. Multidimensional particle-in-cell simulation results presented in this paper confirm that the frequency modulation profiles and the density modulation profiles agree to within 10%. Limitations to the accuracy of the measurement are discussed in this paper. This technique opens new possibilities to quantitatively diagnose the plasma wakefie...

  12. Atmospheric pressure plasma enhanced spatial ALD of silver

    NARCIS (Netherlands)

    Van Den Bruele, F.J.; Smets, M.; Illiberi, A.; Creyghton, Y.; Buskens, P.; Roozeboom, F.; Poodt, P.

    2014-01-01

    The authors have investigated the growth of thin silver films using a unique combination of atmospheric process elements: spatial atomic layer deposition and an atmospheric pressure surface dielectric barrier discharge plasma source. Silver films were grown on top of Si substrates with good purity a

  13. Atmospheric pressure plasma enhanced spatial ALD of silver

    NARCIS (Netherlands)

    Van Den Bruele, F.J.; Smets, M.; Illiberi, A.; Creyghton, Y.; Buskens, P.; Roozeboom, F.; Poodt, P.

    2014-01-01

    The authors have investigated the growth of thin silver films using a unique combination of atmospheric process elements: spatial atomic layer deposition and an atmospheric pressure surface dielectric barrier discharge plasma source. Silver films were grown on top of Si substrates with good purity a

  14. Spatial dependence of plasma oscillations in Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Holst, Thorsten; Hansen, Jørn Bindslev

    1991-01-01

    We report on direct measurements of the plasma oscillations in Josephson tunnel junctions of various spatial dimensions. The effect of the spatial variation of the Cooper-pair phase difference (the Josephson phase) on the dynamics of the junction was investigated by application of a static magnetic...... field threading the tunneling barrier. We compare measurements where the plasma frequency was tuned either by applying a magnetic field or by raising the temperature. A crossover from short- to long-junction behavior of the functional dependence of the plasma oscillations was observed in the case...... of an applied magnetic field. Numerical simulations of the governing partial-differential sine-Gordon equation were performed and compared to the experimental results and a perturbation analysis. The theoretical results support the experiments and allow us to interpret the observed crossover as due...

  15. Version based spatial record management techniques for spatial database management system

    Institute of Scientific and Technical Information of China (English)

    KIM Ho-seok; KIM Hee-taek; KIM Myung-keun; BAE Hae-young

    2004-01-01

    The search operation of spatial data was a principal operation in existent spatial database management system, but the update operation of spatial data such as tracking are occurring frequently in the spatial database management system recently. So, necessity of concurrency improvement among transactions is increasing. In general database management system, many techniques have been studied to solve concurrency problem of transaction. Among them, multi-version algorithm does to minimize interference among transactions. However, to apply existent multi-version algorithm to improve concurrency of transaction to spatial database management system, the waste of storage happens because it must store entire version for spatial record even if only aspatial data of spatial record is changed. This paper has proposed the record management techniques to manage separating aspatial data version and spatial data version to decrease waste of storage for record version and improve concurrency among transactions.

  16. Spatial Domain Technique for Visible Watermarking

    Institute of Scientific and Technical Information of China (English)

    PeterAdjeiFordjour; 王朔中

    2003-01-01

    A new technique for embedding visible watermarks into a digital image is described in this paper, which uses statistical properties of each pixel and its immediate surrounding pixels in the host image, and also the statistical properties of the host image and that of the image to be embedded (watermark), as the pixels in the host image are replaced one by one by the pixels in the watermark image. The aim is to establish a relationship between pixels in the images that will make the embedded watermark robust and semitransparent, and to minimize errors caused by watermark addition and subtraction. Also, the original image can be completely reconstructed from the watermarked images.

  17. Plasma scattering of electromagnetic radiation theory and measurement techniques

    CERN Document Server

    Froula, Dustin H; Luhmann, Neville C Jr; Sheffield, John

    2011-01-01

    This work presents one of the most powerful methods of plasma diagnosis in exquisite detail to guide researchers in the theory and measurement techniques of light scattering in plasmas. Light scattering in plasmas is essential in the research and development of fusion energy, environmental solutions, and electronics.Referred to as the "Bible" by researchers the work encompasses fusion and industrial applications essential in plasma research. It is the only comprehensive resource specific to the plasma scattering technique. It provides a wide-range of experimental examples and discussion of the

  18. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Silver, E.H.; Clauser, J.F.; Carter, M.R.; Failor, B.H.; Foote, J.H.; Hornady, R.S.; James, R.A.; Lasnier, C.J.; Perkins, D.E.

    1986-08-29

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented.

  19. Ion-acoustic solitons in multispecies spatially inhomogeneous plasmas

    Indian Academy of Sciences (India)

    Tarsem Singh Gill; Harvinder Kaur; Nareshpal Singh Saini

    2006-06-01

    Ion-acoustic solitons are investigated in the spatially inhomogeneous plasma having electrons-positrons and ions. The soliton characteristics are described by Korteweg-de Vries equation which has an additional term. The density and temperature of different species play an important role for the amplitude and width of the solitons. Numerical calculations show only the possibility of compressive solitons. Further, analytical results predict that the peak amplitude of soliton decreases with the decrease of density gradient. Soliton characteristics like peak amplitude and width are substantially different from those based on KdV theory for homogeneous plasmas.

  20. Computation of the spectrum of spatial Lyapunov exponents for the spatially extended beam-plasma systems and electron-wave devices

    CERN Document Server

    Hramov, Alexander E; Maximenko, Vladimir A; Moskalenko, Olga I; 10.1063/1.4740063

    2013-01-01

    The spectrum of Lyapunov exponents is powerful tool for the analysis of the complex system dynamics. In the general framework of nonlinear dynamical systems a number of the numerical technics have been developed to obtain the spectrum of Lyapunov exponents for the complex temporal behavior of the systems with a few degree of freedom. Unfortunately, these methods can not apply directly to analysis of complex spatio-temporal dynamics in plasma devices which are characterized by the infinite phase space, since they are the spatially extended active media. In the present paper we propose the method for the calculation of the spectrum of the spatial Lyapunov exponents (SLEs) for the spatially extended beam-plasma systems. The calculation technique is applied to the analysis of chaotic spatio-temporal oscillations in three different beam-plasma model: (1) simple plasma Pierce diode, (2) coupled Pierce diodes, and (3) electron-wave system with backward electromagnetic wave. We find an excellent agreement between the...

  1. Simplex-in-Cell Technique for Collisionless Plasma Simulations

    CERN Document Server

    Kates-Harbeck, Julian; Zrake, Jonathan; Abel, Tom

    2015-01-01

    We extend the simplex-in-cell (SIC) technique recently introduced in the context of collisionless dark matter fluids (Abel et al. 2012; Hahn et al. 2012) to the case of collisionless plasmas. The six-dimensional phase space distribution function $f(\\mathbf x,\\mathbf v)$ is represented by an ensemble of three-dimensional manifolds, which we refer to as sheets. The electric potential field is obtained by solving the Poisson equation on a uniform mesh, where the charge density is evaluated by a spatial projection of the phase space sheets. The SIC representation of phase space density facilitates robust, high accuracy numerical evolution of the Vlasov-Poisson system using significantly fewer tracer particles than comparable particle-in-cell (PIC) approaches by reducing the numerical shot-noise associated with the latter. We introduce the SIC formulation and describe its implementation in a new code, which we validate using standard test problems including plasma oscillations, Landau damping, and two stream insta...

  2. Simplex-in-cell technique for collisionless plasma simulations

    Science.gov (United States)

    Kates-Harbeck, Julian; Totorica, Samuel; Zrake, Jonathan; Abel, Tom

    2016-01-01

    We extend the simplex-in-cell (SIC) technique recently introduced in the context of collisionless dark matter fluids [1,2] to the case of collisionless plasmas. The six-dimensional phase space distribution function f (x , v) is represented by an ensemble of three-dimensional manifolds, which we refer to as sheets. The electric potential field is obtained by solving the Poisson equation on a uniform mesh, where the charge density is evaluated by a spatial projection of the phase space sheets. The SIC representation of phase space density facilitates robust, high accuracy numerical evolution of the Vlasov-Poisson system using significantly fewer tracer particles than comparable particle-in-cell (PIC) approaches by reducing the numerical shot-noise associated with the latter. We introduce the SIC formulation and describe its implementation in a new code, which we validate using standard test problems including plasma oscillations, Landau damping, and two stream instabilities in one dimension. Merits of the new scheme are shown to include higher accuracy and faster convergence rates in the number of particles. We finally motivate and outline the efficient application of SIC to higher dimensional problems.

  3. Improved spatial resolution in PET scanners using sampling techniques

    Science.gov (United States)

    Surti, Suleman; Scheuermann, Ryan; Werner, Matthew E.; Karp, Joel S.

    2009-01-01

    Increased focus towards improved detector spatial resolution in PET has led to the use of smaller crystals in some form of light sharing detector design. In this work we evaluate two sampling techniques that can be applied during calibrations for pixelated detector designs in order to improve the reconstructed spatial resolution. The inter-crystal positioning technique utilizes sub-sampling in the crystal flood map to better sample the Compton scatter events in the detector. The Compton scatter rejection technique, on the other hand, rejects those events that are located further from individual crystal centers in the flood map. We performed Monte Carlo simulations followed by measurements on two whole-body scanners for point source data. The simulations and measurements were performed for scanners using scintillators with Zeff ranging from 46.9 to 63 for LaBr3 and LYSO, respectively. Our results show that near the center of the scanner, inter-crystal positioning technique leads to a gain of about 0.5-mm in reconstructed spatial resolution (FWHM) for both scanner designs. In a small animal LYSO scanner the resolution improves from 1.9-mm to 1.6-mm with the inter-crystal technique. The Compton scatter rejection technique shows higher gains in spatial resolution but at the cost of reduction in scanner sensitivity. The inter-crystal positioning technique represents a modest acquisition software modification for an improvement in spatial resolution, but at a cost of potentially longer data correction and reconstruction times. The Compton scatter rejection technique, while also requiring a modest acquisition software change with no increased data correction and reconstruction times, will be useful in applications where the scanner sensitivity is very high and larger improvements in spatial resolution are desirable. PMID:19779586

  4. Comparative analyses of plasma probe diagnostics techniques

    Energy Technology Data Exchange (ETDEWEB)

    Godyak, V. A. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts 02446 (United States); Alexandrovich, B. M. [Plasma Sensors, Brookline, Massachusetts 02446 (United States)

    2015-12-21

    The subject of this paper is a comparative analysis of the plasma parameters inferred from the classical Langmuir probe procedure, from different theories of the ion current to the probe, and from measured electron energy distribution function (EEDF) obtained by double differentiation of the probe characteristic. We concluded that the plasma parameters inferred from the classical Langmuir procedure can be subjected to significant inaccuracy due to the non-Maxwellian EEDF, uncertainty of locating the plasma potential, and the arbitrariness of the ion current approximation. The plasma densities derived from the ion part of the probe characteristics diverge by as much as an order of magnitude from the density calculated according to Langmuir procedure or calculated as corresponding integral of the measured EEDF. The electron temperature extracted from the ion part is always subjected to uncertainty. Such inaccuracy is attributed to modification of the EEDF for fast electrons due to inelastic electron collisions, and to deficiencies in the existing ion current theories; i.e., unrealistic assumptions about Maxwellian EEDFs, underestimation of the ion collisions and the ion ambipolar drift, and discounting deformation of the one-dimensional structure of the region perturbed by the probe. We concluded that EEDF measurement is the single reliable probe diagnostics for the basic research and industrial applications of highly non-equilibrium gas discharge plasmas. Examples of EEDF measurements point up importance of examining the probe current derivatives in real time and reiterate significance of the equipment technical characteristics, such as high energy resolution and wide dynamic range.

  5. Spatially Confined Propagation of Intense Ultraviolet Radiation in Plasmas.

    Science.gov (United States)

    Shi, Xiaomei

    X-ray amplification requires a high energy deposition rate in a high aspect-ratio volume. High power lasers for x-ray laser pumping have become available with the development of the short pulse and high intensity laser technology capable of producing pulses with a peak power as high as 10^{12} watts. Short pulses of high intensity x-ray have been observed in laser -plasma interactions, which encurages many scientists actively pursuing the goal of constructing practical x-ray lasers. Our approach has concentrated on producing high aspect ratio x-ray amplifying medium by spatially confined propagation of high power laser pulse in plasmas. A high intensity laser beam induces nonlinear refractive index changes in plasma. In the case of subpicosecond ultrahigh power laser-plasma interaction, the dominant mechanisms responsible for the refractive index change in plasmas are: (1) the relativistic free electron mass increase due to the increase of electron oscillation velocity in the intense electromagnetic field of the laser pulses; and (2) displacement of free electrons out of the high intensity region of the laser beam by ponderomotive force. Both of the above effects lead to a refractive index change of the plasma, which in turn has a positive lensing effect on the beam. If the focusing effect is strong enough to overcome diffraction the beam will stay in a spatially confined mode of propagation. This confined propagation provides an effective method of concentrating energy. The field intensity associated with the confined propagation is so high that the highly excited medium with high aspect ratio suitable for x-ray amplification can be achieved. In this research we have successfully demonstrated spatially confined propagation of 500 GW subpicosecond laser pulse in laser induced plasma. The measured diameter of the propagation is less than 2 μm and the aspect ratio of the confined propagation is over 1000. The filed intensity associated with the propagation is

  6. Visualization techniques for spatial probability density function data

    Directory of Open Access Journals (Sweden)

    Udeepta D Bordoloi

    2006-01-01

    Full Text Available Novel visualization methods are presented for spatial probability density function data. These are spatial datasets, where each pixel is a random variable, and has multiple samples which are the results of experiments on that random variable. We use clustering as a means to reduce the information contained in these datasets; and present two different ways of interpreting and clustering the data. The clustering methods are used on two datasets, and the results are discussed with the help of visualization techniques designed for the spatial probability data.

  7. Plasma filtering techniques for nuclear waste remediation

    CERN Document Server

    Gueroult, Renaud; Fisch, Nathaniel J

    2015-01-01

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste.

  8. Plasma filtering techniques for nuclear waste remediation.

    Science.gov (United States)

    Gueroult, Renaud; Hobbs, David T; Fisch, Nathaniel J

    2015-10-30

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste.

  9. Influence of excited state spatial distributions on plasma diagnostics: Atmospheric pressure laser-induced He-H2 plasma

    Science.gov (United States)

    Monfared, Shabnam K.; Hüwel, Lutz

    2012-10-01

    Atmospheric pressure plasmas in helium-hydrogen mixtures with H2 molar concentrations ranging from 0.13% to 19.7% were investigated at times from 1 to 25 μs after formation by a Q-switched Nd:YAG laser. Spatially integrated electron density values are obtained using time resolved optical emission spectroscopic techniques. Depending on mixture concentration and delay time, electron densities vary from almost 1017 cm-3 to about 1014 cm-3. Helium based results agree reasonably well with each other, as do values extracted from the Hα and Hβ emission lines. However, in particular for delays up to about 7 μs and in mixtures with less than 1% hydrogen, large discrepancies are observed between results obtained from the two species. Differences decrease with increasing hydrogen partial pressure and/or increasing delay time. In mixtures with molecular hydrogen fraction of 7% or more, all methods yield electron densities that are in good agreement. These findings seemingly contradict the well-established idea that addition of small amounts of hydrogen for diagnostic purposes does not perturb the plasma. Using Abel inversion analysis of the experimental data and a semi-empirical numerical model, we demonstrate that the major part of the detected discrepancies can be traced to differences in the spatial distributions of excited helium and hydrogen neutrals. The model yields spatially resolved emission intensities and electron density profiles that are in qualitative agreement with experiment. For the test case of a 1% H2 mixture at 5 μs delay, our model suggests that high electron temperatures cause an elevated degree of ionization and thus a reduction of excited hydrogen concentration relative to that of helium near the plasma center. As a result, spatially integrated analysis of hydrogen emission lines leads to oversampling of the plasma perimeter and thus to lower electron density values compared to those obtained from helium lines.

  10. Spatial identification of the overionized plasma in W49B

    CERN Document Server

    Miceli, M; Decourchelle, A; Ballet, J; Reale, F

    2010-01-01

    Recent Suzaku X-ray observations of the ejecta-dominated supernova remnant W49B have shown that in the global spectrum there is a clear indication for the presence of overionized plasma whose physical origin is still under debate. In order to ascertain the physical origin of such a rapidly cooling plasma, we focus on the study of its spatial localization within the X-ray emitting ejecta. We confirm the presence of a saw-edged excess (interpreted as a strong radiative recombination continuum) in the global spectrum above 8 keV, emerging above the ionization-equilibrium model. We produce a hardness ratio map to determine where the plasma is overionized and we perform a spectral analysis of the regions with and without strong overionization. We find that the overionized plasma is localized in the center of the remnant and in its western jet, while it is not detected in the bright eastern jet, where the expansion of the ejecta is hampered by their interaction with a dense interstellar cloud. The location of overi...

  11. Study on spatial distribution of plasma parameters in a magnetized inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong, E-mail: kwhang@snu.ac.kr [Plasma Laboratory, Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Hyuk [Samsung Electronics Co., Banwol-dong, Hwaseong 445-701 (Korea, Republic of); Park, Wanjae [Tokyo Electron Miyagi Ltd., Taiwa-cho, Kurokawa-gun, Miyagi 981-3629 (Japan)

    2015-07-15

    Spatial distributions of various plasma parameters such as plasma density, electron temperature, and radical density in an inductively coupled plasma (ICP) and a magnetized inductively coupled plasma (M-ICP) were investigated and compared. Electron temperature in between the rf window and the substrate holder of M-ICP was higher than that of ICP, whereas the one just above the substrate holder of M-ICP was similar to that of ICP when a weak (<8 G) magnetic field was employed. As a result, radical densities in M-ICP were higher than those in ICP and the etch rate of oxide in M-ICP was faster than that in ICP without severe electron charging in 90 nm high aspect ratio contact hole etch.

  12. Positron plasma control techniques for the production of cold antihydrogen

    Science.gov (United States)

    Funakoshi, R.; Amoretti, M.; Bonomi, G.; Bowe, P. D.; Canali, C.; Carraro, C.; Cesar, C. L.; Charlton, M.; Doser, M.; Fontana, A.; Fujiwara, M. C.; Genova, P.; Hangst, J. S.; Hayano, R. S.; Jørgensen, L. V.; Kellerbauer, A.; Lagomarsino, V.; Landua, R.; Lodi Rizzini, E.; Macrì, M.; Madsen, N.; Manuzio, G.; Mitchard, D.; Montagna, P.; Posada, L. G. C.; Rotondi, A.; Testera, G.; Variola, A.; Venturelli, L.; van der Werf, D. P.; Yamazaki, Y.; Zurlo, N.

    2007-07-01

    An observation of a clear dependence of antihydrogen production on positron plasma shapes is reported. For this purpose a plasma control method has been developed combining the plasma rotating-wall technique with a mode diagnostic system. With the help of real-time and nondestructive observations, the rotating-wall parameters have been optimized. The positron plasma can be manipulated into a wide range of shapes (aspect ratio 6.5⩽α≲80 ) and densities (1.5×108⩽n≲7×109cm-3) within a short duration (25s) compatible with the ATHENA antihydrogen production cycle.

  13. Positron plasma control techniques for the production of cold antihydrogen

    CERN Document Server

    Funakoshi, R; Bonomi, G; Bowe, P D; Canali, C; Carraro, C; Cesar, C L; Charlton, M; Doser, M; Fontana, A; Fujiwara, M C; Genova, P; Hangst, J S; Hayano, R S; Jørgensen, L V; Kellerbauer, A G; Lagomarsino, V; Landua, R; Lodi-Rizzini, E; Macrì, M; Madsen, N; Manuzio, G; Mitchard, D; Montagna, P; Posada, L G C; Rotondi, A; Testera, G; Variola, A; Venturelli, L; Van der Werf, D P; Yamazaki, Y; Zurlo, N

    2007-01-01

    An observation of a clear dependence of antihydrogen production on positron plasma shapes is reported. For this purpose a plasma control method has been developed combining the plasma rotating-wall technique with a mode diagnostic system. With the help of real-time and nondestructive observations, the rotating-wall parameters have been optimized. The positron plasma can be manipulated into a wide range of shapes (aspect ratio 6.5≤α≲80) and densities (1.5×108≤n≲7×109 cm−3) within a short duration (25 s) compatible with the ATHENA antihydrogen production cycle.

  14. Plasma Technology as a New Preservation Technique

    Science.gov (United States)

    Rincón, R.; Calzada, M. D.

    The preliminary results of using the surface wave discharge at the atmospheric pressure on groups of lentils and sherry Fino wine samples are presented. In this research, the capability of active species and UV radiation from the plasma, has been assessed on preservation of food. Besides, the generation and emission of both excited molecules in a metastable state N2}(B3Π {g-> A3}Σ u{+) and the de-excitation of species NO(A2}Σ {+) producing UV radiation have been also studied.

  15. Spatial and frequency dependence of plasma currents in a 300 mm capacitively coupled plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Paul A [Sandia National Laboratories, MS 1423, PO Box 5800, Albuquerque, NM 87185-1423 (United States); Barnat, Edward V [Sandia National Laboratories, MS 1423, PO Box 5800, Albuquerque, NM 87185-1423 (United States); Hebner, Gregory A [Sandia National Laboratories, MS 1423, PO Box 5800, Albuquerque, NM 87185-1423 (United States); Paterson, Alex M [Applied Materials, Inc., 974 Arques Avenue, Sunnyvale, CA 94086 (United States); Holland, John P [Applied Materials, Inc., 974 Arques Avenue, Sunnyvale, CA 94086 (United States)

    2006-11-01

    There is much interest in scaling rf-excited capacitively coupled plasma reactors to larger sizes and to higher frequencies. As the size approaches operating wavelength, concerns arise about non-uniformity across the work piece, particularly in light of the well-documented slow-surface-wave phenomenon. We present measurements and calculations of spatial and frequency dependence of rf magnetic fields inside argon plasma in an industrially relevant, 300 mm plasma-processing chamber. The results show distinct differences in the spatial distributions and harmonic content of rf fields in the plasma at the three frequencies studied (13.56, 60 and 176 MHz). Evidence of a slow-wave structure was not apparent. The results suggest that interaction between the plasma and the rf excitation circuit may strongly influence the structures of these magnetic fields and that this interaction is frequency dependent. At the higher frequencies, wave propagation becomes extremely complex; it is controlled by the strong electrical nonlinearity of the sheath and is not explained simply by previous models.

  16. Beaming teaching application: recording techniques for spatial xylophone sound rendering

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Olesen, Søren Krarup;

    2012-01-01

    BEAMING is a telepresence research project aiming at providing a multimodal interaction between two or more participants located at distant locations. One of the BEAMING applications allows a distant teacher to give a xylophone playing lecture to the students. Therefore, rendering of the xylophone...... played at student's location is required at teacher's site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering. Directivity pattern of the xylophone was measured and spatial properties of the sound field created by a xylophone as a distributed sound...

  17. Atmospheric pressure plasma enhanced spatial ALD of silver

    Energy Technology Data Exchange (ETDEWEB)

    Bruele, Fieke J. van den, E-mail: Fieke.vandenBruele@tno.nl; Smets, Mireille; Illiberi, Andrea; Poodt, Paul [Holst Centre/TNO, High Tech Campus 31, 5656 AE Eindhoven (Netherlands); Creyghton, Yves [TNO, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Buskens, Pascal [TNO, Rondom 1, 5612 AP Eindhoven, The Netherlands and DWI Leibniz-Institut für Interaktive Materialien, Aachen (Germany); Roozeboom, Fred [TNO, High Tech Campus 21, 5656 AE Eindhoven, The Netherlands and Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

    2015-01-15

    The authors have investigated the growth of thin silver films using a unique combination of atmospheric process elements: spatial atomic layer deposition and an atmospheric pressure surface dielectric barrier discharge plasma source. Silver films were grown on top of Si substrates with good purity as revealed by resistivity values as low as 18 μΩ cm and C- and F-levels below detection limits of energy dispersive x-ray analysis. The growth of the silver films starts through the nucleation of islands that subsequently coalesce. The authors show that the surface island morphology is dependent on surface diffusion, which can be controlled by temperature within the deposition temperature range of 100–120 °C.

  18. DSPI system based on spatial carrier phase shifting technique

    Science.gov (United States)

    Wang, Yonghong; Li, Junrui; Sun, Jianfei; Yang, Lianxiang

    2013-10-01

    Digital Speckle Pattern Interferometry (DSPI) is an optical method for measuring small displacement and deformation. It allows whole field, non-contacting measurement of micro deformation. Traditional Temporal phase shifting has been used for quantitative analyses in DSPI. The technique requires the recording of at least three phase-shifted interferograms, which must be taken sequentially. This can lead to disturbances by thermal and mechanical fluctuations during the required recording time. In addition, fast object deformations cannot be detected. In this paper a DSPI system using Spatial Carrier Phase Shifting (SCPS) technique is introduced, which is useful for extracting quantitative displacement data from the system with only two interferograms. The sensitive direction of this system refers to the illumination direction and observation direction. The frequencies of the spatial carrier relates to the angle between reference light and observation direction. Fourier transform is adopted in the digital evaluation to filter out the frequencies links to the deformation of testing object. The phase is obtained from the complex matrix formed by inverse Fourier transform, and the phase difference and deformation are calculated subsequently. Comparing with conventional temporal phase shifting, the technique can achieve measuring the vibration and transient deformation of testing object. Experiment set-ups and results are presented in this paper, and the experiment results have shown the effectiveness and advantages of the SCPS technique.

  19. Reflectometry techniques for density profile measurements on fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Laviron, C. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Donne, A.J.H. [Associatie Euratom-FOM, Nieuwegein (Netherlands). FOM-Instituut voor Plasmafysica; Manso, M.E. [Instituto Superior Tecnico, Lisbon (Portugal). Lab. de Quimica Organica; Sanchez, J. [EURATOM-CIEMAT for Fusion Association, Madrid (Spain)

    1996-03-01

    Reflectometry applied to the measurement of density profiles on fusion plasmas has been subject to many recent developments. After a brief reminder of the principles of reflectometry, the theoretical accuracy of reflectometry measurements is discussed. The main difficulties limiting the performance, namely the plasma fluctuations and the quality of the transmission lines, are analysed. The different techniques used for reflectometry are then presented. The present status and achievements of actual implementations of these techniques are shown, with an analysis of their respective limitations and merits, as well as foreseen developments. (author). 70 refs.

  20. Feasibility of measuring density and temperature of laser produced plasmas using spectroscopic techniques.

    Energy Technology Data Exchange (ETDEWEB)

    Edens, Aaron D.

    2008-09-01

    A wide variety of experiments on the Z-Beamlet laser involve the creation of laser produced plasmas. Having a direct measurement of the density and temperature of these plasma would an extremely useful tool, as understanding how these quantities evolve in space and time gives insight into the causes of changes in other physical processes, such as x-ray generation and opacity. We propose to investigate the possibility of diagnosing the density and temperature of laser-produced plasma using temporally and spatially resolved spectroscopic techniques that are similar to ones that have been successfully fielded on other systems. Various researchers have measured the density and temperature of laboratory plasmas by looking at the width and intensity ratio of various characteristic lines in gases such as nitrogen and hydrogen, as well as in plasmas produced off of solid targets such as zinc. The plasma conditions produce two major measurable effects on the characteristic spectral lines of that plasma. The 1st is the Stark broadening of an individual line, which depends on the electron density of the plasma, with higher densities leading to broader lines. The second effect is a change in the ratio of various lines in the plasma corresponding to different ionization states. By looking at the ratio of these lines, we can gain some understanding of the plasma ionization state and consequently its temperature (and ion density when coupled with the broadening measurement). The hotter a plasma is, the higher greater the intensity of lines corresponding to higher ionization states. We would like to investigate fielding a system on the Z-Beamlet laser chamber to spectroscopically study laser produced plasmas from different material targets.

  1. Development of the dry decontamination technique using plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Soo; Seo, Yong Dae; Lee, Dong Uk; Jeon, Sang Hwan; Jung, Young Suk [Hanyang University, Seoul (Korea)

    2001-04-01

    In order to develop an advanced dry decontamination method, dry decontamination technique using gaseous plasma is studied. Scopes of the research are 1) literature survey and case studies of the international R and D activities and industrial application, 2) contaminant characteristics analysis, 3) feasibility and applicability study of the unit techniques, 4) process development study on the plasma decontamination, 5) plasma diagnostics and quantitative analysis by QMS and OES, and 6) design of (microwave) plasma torch system. The major research results are as belows. The maximum etching rate of UO{sub 2} is achieved to be 0.8 {mu}m/min. under 300 deg C, 150 W CF{sub 4}/O{sub 2}/N{sub 2} r.f. plasma maintaining the optimum ratio of CF{sub 4}/O{sub 2} of four, and that of Co and Mo is 0.06 {mu}m/min. and 1.9 {mu}m/min., respectively, under 380 deg C, 220 W CF{sub 4}/O{sub 2} r.f. plasma. The optimum process for the dry decontamination of TRU, CP, and or FP nuclides, therefore, requires the optimum gas composition above 350 deg C and 220W power. It is also demonstrated that this optimum process can be extrapolated to atmospheric high power torch system. In conclusion, if plasma power and temperature increases with maintaining the optimum gas composition, this dry decontamination techniques must be definitely effective and efficient. 17 refs., 62 figs., 4 tabs. (Author)

  2. Spatial Modeling of Geometallurgical Properties: Techniques and a Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, Jared L., E-mail: jdeutsch@ualberta.ca [University of Alberta, School of Mining and Petroleum Engineering, Department of Civil and Environmental Engineering (Canada); Palmer, Kevin [Teck Resources Limited (Canada); Deutsch, Clayton V.; Szymanski, Jozef [University of Alberta, School of Mining and Petroleum Engineering, Department of Civil and Environmental Engineering (Canada); Etsell, Thomas H. [University of Alberta, Department of Chemical and Materials Engineering (Canada)

    2016-06-15

    High-resolution spatial numerical models of metallurgical properties constrained by geological controls and more extensively by measured grade and geomechanical properties constitute an important part of geometallurgy. Geostatistical and other numerical techniques are adapted and developed to construct these high-resolution models accounting for all available data. Important issues that must be addressed include unequal sampling of the metallurgical properties versus grade assays, measurements at different scale, and complex nonlinear averaging of many metallurgical parameters. This paper establishes techniques to address each of these issues with the required implementation details and also demonstrates geometallurgical mineral deposit characterization for a copper–molybdenum deposit in South America. High-resolution models of grades and comminution indices are constructed, checked, and are rigorously validated. The workflow demonstrated in this case study is applicable to many other deposit types.

  3. Concerted spatial-frequency and polarization-phase filtering of laser images of polycrystalline networks of blood plasma smears

    Science.gov (United States)

    Ushenko, Yu A.

    2012-11-01

    The complex technique of concerted polarization-phase and spatial-frequency filtering of blood plasma laser images is suggested. The possibility of obtaining the coordinate distributions of phases of linearly and circularly birefringent protein networks of blood plasma separately is presented. The statistical (moments of the first to fourth orders) and scale self-similar (logarithmic dependences of power spectra) structure of phase maps of different types of birefringence of blood plasma of two groups of patients-healthy people (donors) and those suffering from rectal cancer-is investigated. The diagnostically sensitive parameters of a pathological change of the birefringence of blood plasma polycrystalline networks are determined. The effectiveness of this technique for detecting change in birefringence in the smears of other biological fluids in diagnosing the appearance of cholelithiasis (bile), operative differentiation of the acute and gangrenous appendicitis (exudate), and differentiation of inflammatory diseases of joints (synovial fluid) is shown.

  4. A Hybrid Method with Deviational Particles for Spatial Inhomogeneous Plasma

    CERN Document Server

    Yan, Bokai

    2015-01-01

    In this work we propose a Hybrid method with Deviational Particles (HDP) for a plasma modeled by the inhomogeneous Vlasov-Poisson-Landau system. We split the distribution into a Maxwellian part evolved by a grid based fluid solver and a deviation part simulated by numerical particles. These particles, named deviational particles, could be both positive and negative. We combine the Monte Carlo method proposed in \\cite{YC15}, a Particle in Cell method and a Macro-Micro decomposition method \\cite{BLM08} to design an efficient hybrid method. Furthermore, coarse particles are employed to accelerate the simulation. A particle resampling technique on both deviational particles and coarse particles is also investigated and improved. The efficiency is significantly improved compared to a PIC-MCC method, especially near the fluid regime.

  5. Flowing dusty plasma experiments: generation of flow and measurement techniques

    Science.gov (United States)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2016-12-01

    A variety of experimental techniques for the generation of subsonic/supersonic dust fluid flows and means of measuring such flow velocities are presented. The experiments have been carried out in a \\Pi -shaped dusty plasma experimental device with micron size kaolin/melamine formaldehyde particles embedded in a background of argon plasma created by a direct current glow discharge. A stationary dust cloud is formed over the cathode region by precisely balancing the pumping speed and gas flow rate. A flow of dust particles/fluid is generated by additional gas injection from a single or dual locations or by altering the dust confining potential. The flow velocity is then estimated by three different techniques, namely, by super particle identification code, particle image velocimetry analysis and the excitation of dust acoustic waves. The results obtained from these three different techniques along with their merits and demerits are discussed. An estimation of the neutral drag force responsible for the generation as well as the attenuation of the dust fluid flow is made. These techniques can be usefully employed in laboratory devices to investigate linear and non-linear collective excitations in a flowing dusty plasma.

  6. Recovering prehistoric woodworking skills using spatial analysis techniques

    Science.gov (United States)

    Kovács, K.; Hanke, K.

    2015-08-01

    Recovering of ancient woodworking skills can be achieved by the simultaneous documentation and analysis of the tangible evidences such as the geometry parameters of prehistoric hand tools or the fine morphological characteristics of well preserved wooden archaeological finds. During this study, altogether 10 different hand tool forms and over 60 hand tool impressions were investigated for the better understanding of the Bronze Age woodworking efficiency. Two archaeological experiments were also designed in this methodology and unknown prehistoric adzes could be reconstructed by the results of these studies and by the spatial analysis of the Bronze Age tool marks. Finally, the trimming efficiency of these objects were also implied and these woodworking skills could be quantified in the case of a Bronze Age wooden construction from Austria. The proposed GIS-based tool mark segmentation and comparison can offer an objective, user-independent technique for the related intangible heritage interpretations in the future.

  7. Extraction of the spatial distribution of electron temperature and density in Magnetized Liner Inertial Fusion implosion plasmas

    Science.gov (United States)

    Carpenter, Kyle; Mancini, Roberto

    2016-10-01

    We are testing polychromatic tomography to extract the spatial distribution of electron temperatures and densities in the cylindrical implosion plasmas created during MagLIF. Motivation for this technique stems from its successful application to spherical implosion core plasmas on Omega through the analysis of spatially resolved spectra (SRS) collected via pinhole imaging. In MagLIF, collections of SRS can be extracted from the images created by the slit imaging CRITR spectrometers. These spectra can be complemented with pinhole monochromatic images and spectra recorded with a spherical crystal spectrometer. One axially resolved and one radially resolved CRITR are field during MagLIF and information extracted from one of these SRS would be spatially integrated over a plane of finite thickness given by the spatial resolution of the instrument. In our method, we couple a model that creates synthetic sets of spectra, like those obtained from an experiment, with a Pareto genetic algorithm which searches in parameter space for the spatial distribution which best simultaneously and self-consistently fits the set of SRS/ Solutions obtained are used as the initial solution for a Levenberg-Marquadt minimization algorithm to provide a final ``fine-tuned'' solution. We are testing this method by creating synthetic ``experimental'' data and using the technique to search for the spatial distribution. The results of these feasibility studies will be discussed. The work is supported by a contract from Sandia National Laboratories.

  8. Relationship between the discharge mode and the spatial oxygen plasma distribution in a large size ferrite inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jun [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); R and D Center for PSK-INC Corporation, Hwaseong-si 445-170 (Korea, Republic of); Hwang, Hye Ju; Cho, Jeong Hee; Chae, Hee Sun [R and D Center for PSK-INC Corporation, Hwaseong-si 445-170 (Korea, Republic of); Kim, Dong Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-04-15

    The electrical characteristics and the spatial distribution of oxygen plasma according to the number of turns in ferrite inductively coupled plasmas (ferrite ICPs) are investigated. Through a new ICP model, which includes the capacitive coupling and the power loss of the ferrite material with the conventional ICP model, the variation of the oxygen discharge characteristics depending on the number of turns is simply understood by the electrical measurement, such as the antenna voltages and the currents. As the number of the turns increases, the capacitive coupling dominantly affects the spatial plasma distribution. This capacitive coupling results in a center focused density profile along the radial direction. In spite of the same discharge conditions (discharge chamber, neutral gas, and pressure), the spatial plasma distribution over 450 mm has drastic changes by increasing number of the turns. In addition, the effect of the negative species to the density profile is compared with the argon discharge characteristics at the same discharge configuration.

  9. Diagnostic techniques for measuring suprathermal electron dynamics in plasmas (invited).

    Science.gov (United States)

    Coda, S

    2008-10-01

    Plasmas, both in the laboratory and in space, are often not in thermodynamic equilibrium, and the plasma electron distribution function is accordingly non-Maxwellian. Suprathermal electron tails can be generated by external drives, such as rf waves and electric fields, or internal ones, such as instabilities and magnetic reconnection. The variety and importance of the phenomena in which suprathermal electrons play a significant role explains an enduring interest in diagnostic techniques to investigate their properties and dynamics. X-ray bremsstrahlung emission has been studied in hot magnetized plasmas for well over two decades, flanked progressively by electron-cyclotron emission in geometries favoring the high-energy end of the distribution function (high-field-side, vertical, oblique emission), by electron-cyclotron absorption, by spectroscopic techniques, and at lower temperatures, by Langmuir probes and electrostatic analyzers. Continuous progress in detector technology and in measurement and analysis techniques, increasingly sophisticated layouts (multichannel and tomographic systems, imaging geometries), and highly controlled suprathermal generation methods (e.g., perturbative rf modulation) have all been brought to bear in recent years on an increasingly detailed, although far from complete, understanding of suprathermal electron dynamics.

  10. A technique to reduce plasma armature formation voltage

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, K.A. (Science Applications International Corp., Shalimar, FL (US)); Littrell, D.M. (Air Force Armament Lab., Eglin AFB, FL (United States))

    1991-01-01

    The initiation of a plasma armature by foil vaporization in a railgun is often accompanied by a large, fast, voltage transient appearing on both the breech and muzzle of the gun. For a railgun driven by an inductor/opening switch power supply, this voltage transient becomes a concern during current commutation from the switch to the railgun. To lessen the requirements on the opening switch, techniques must be found to reduce the armature formation voltage. This paper presents the experimental results from railgun firings at AFATL's Electromagnetic Launcher Basic Research Facility (Site A-15, Eglin Air Force Base, Florida) using different shapes of initiation foils. These foils have been designed to vaporize into a plasma armature with reduced transient voltages. A design criteria was developed to ensure that all portions of the foil vaporize at slightly different times.

  11. Flowing dusty plasma experiments: Generation of flow and measurement techniques

    CERN Document Server

    Jaiswal, S; Sen, A

    2016-01-01

    A variety of experimental techniques for the generation of subsonic/supersonic dust fluid flows and means of measuring such flow velocities are presented. The experiments have been carried out in a $\\Pi-$shaped Dusty Plasma Experimental (DPEx) device with micron size kaolin/Melamine Formaldehyde (MF) particles embedded in a background of Argon plasma created by a direct current (DC) glow discharge. A stationary dust cloud is formed over the cathode region by precisely balancing the pumping speed and gas flow rate. A flow of dust particles/fluid is generated by additional gas injection from a single or dual locations or by altering the dust confining potential. The flow velocity is then estimated by three different techniques, namely, by super Particle Identification (sPIT) code, Particle Image Velocimetry (PIV) analysis and the excitation of Dust Acoustic Waves (DAWs). The results obtained from these three different techniques along with their merits and demerits are discussed. An estimation of the neutral dr...

  12. Spatially resolved spectroscopy of an atmospheric pressure microwave plasma jet used for surface treatment

    OpenAIRE

    Potočňáková Lucia; Hnilica Jaroslav; Kudrle Vít

    2014-01-01

    In this study, the variations of properties of a microwave plasma jet (surfatron) along the discharge axis have been investigated using optical emission spectroscopy. As the argon jet is not enclosed, the spatial distribution of individual species in effluent plasma is the result of rather complicated interplay between energy loss and gradual mixing with the air. Spatial 2D relative intensity profiles of atomic lines and molecular bands at 310 nm, 336 nm, 391 nm and 656 nm are presented in th...

  13. Spatial 3-D nonlinear calibration technique for PSD

    Science.gov (United States)

    Guo, Lifeng; Zhang, Guoxiong; Zheng, Qi; Gong, Qiang; Liu, Wenyao

    2006-11-01

    A 3-D nonlinear calibration technique for Position sensitive detector (PSD) in long distance laser collimating measurement is proposed. An automatic calibration system was developed to measure the nonlinearity of a 2-D PSD in 3-D space. It is mainly composed of a high accurate 2-D motorized translational stage, a high precision distance measuring device, and a computer-based data acquisition and control system. With the aid of the calibration system, the nonlinear characteristic of 2-D PSD is checked in a long collimating distance up to 78 meters. The calibration experiment was carried out for a series of distance, e.g. every 15 meters. The results showed that the nonlinearity of 2-D PSD is different evidently when the PSD element is at different distance from the laser head. One calculating method is defined to evaluate the nonlinear errors. The spatial 3-D mapping relationship between the actual displacements of the incident light and the coordinates of 2-D PSD outputs is established using a multilayer feedforward neural network.

  14. Study of laser-induced plasma shock waves by the probe beam deflection technique

    Institute of Scientific and Technical Information of China (English)

    Yan Qian; Jian Lu; Xiaowu Ni

    2009-01-01

    Laser probe beam deflection technique is used for the analysis of laser-induced plasma shock waves in air and distilled water.The temporal and spatial variations of the parameters on shock fronts are studied as funotions of focal lens position and laser energy.The influences of the characteristics of media are investigated on the well-designed experimental setup.It is found that the shock wave in distilled water attenuates to an acoustic wave faster than in air under the same laser energy.Good agreement is obtained between our experimental results and those attained with other techniques.This technique is versatile,economic,and simple to implement,being a pronmising diagnostic tool for pulsed laser processing.

  15. Review of Spatial Indexing Techniques for Large Urban Data Management

    DEFF Research Database (Denmark)

    Azri, Suhaibah; Ujang, Uznir; Anton, François

    Pressure on land development in urban areas causes progressive efforts in spatial planning and management. The physical expansion of urban areas to accommodate rural migration implies a massive impact to social, economical and political situations of major cities. Most of the models used...... in managing urban areas are moving towards sustainable urban development in order to fulfill current necessities while preserving the resources for future generations. However, in order to manage large amounts of urban spatial data, an efficient spatial data constellation method is needed. With the ease...... of three dimensional (3D) spatial data usage in urban areas as a new source of data input, practical spatial data indexing is necessary to improve data retrieval and management. Current two dimensional (2D) spatial indexing approaches seem not applicable to the current and future spatial developments...

  16. A laser-induced fluorescence measurement technique for obtaining neutral hydrogen densities in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yao, X.Z.; Yang, T.F.; Chang-Diaz, F.R. [Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    1995-09-01

    The resonance fluorescence of neutral hydrogen illuminated by {ital H}{sub {alpha}} radiation has been used as a technique for the spatially and temporally resolved density measurements of neutral hydrogen in high temperature plasmas, such as in the tokamak and magnetic mirror plasma fusion devices. The fluorescence signal, usually very weak and buried in the background of stray laser light and {ital H}{sub {alpha}} emission, is very difficult to extract and its measurements are inaccurate. This paper discusses the improvement of the signal extraction using two optical path laser-induced fluorescence (LIF) methods. One optical path carries the fluorescence signal and the background (the stray laser light and {ital H}{sub {alpha}} emission), whereas the other path carries only the background signal. By combining these two signals, a clean fluorescence signal can be isolated by subtracting out the background using a differential amplifier. The measurement is obtained instantaneously from these two signals which are taken simultaneously in one pulse rather than being extracted from two separate spectra taken in two sequential pulses (double pulses). This method, therefore, makes a significant improvement on the double pulse technique in terms of the accuracy of the measurement and the time resolution. Using this LIF technique the measurement of the neutral density profile in the exhaust of a tandem mirror plasma propulsion device is obtained and presented. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  17. Nano powders, components and coatings by plasma technique

    Science.gov (United States)

    McKechnie, Timothy N. (Inventor); Antony, Leo V. M. (Inventor); O'Dell, Scott (Inventor); Power, Chris (Inventor); Tabor, Terry (Inventor)

    2009-01-01

    Ultra fine and nanometer powders and a method of producing same are provided, preferably refractory metal and ceramic nanopowders. When certain precursors are injected into the plasma flame in a reactor chamber, the materials are heated, melted and vaporized and the chemical reaction is induced in the vapor phase. The vapor phase is quenched rapidly to solid phase to yield the ultra pure, ultra fine and nano product. With this technique, powders have been made 20 nanometers in size in a system capable of a bulk production rate of more than 10 lbs/hr. The process is particularly applicable to tungsten, molybdenum, rhenium, tungsten carbide, molybdenum carbide and other related materials.

  18. Developments in plasma enhanced spatial ALD for high throughput applications [3.04

    NARCIS (Netherlands)

    Creyghton, Y.; Illiberi, A.; Mione, M.; Boekel, W. van; Debernardi, N.; Seitz, M.; Bruele, F. van den; Poodt, P.; Roozeboom,F.

    2016-01-01

    Atomic layer deposition by means of spatial separation of reactive gases is emerging as an industrial manufacturing technology. Integration of non-thermal plasma in spatial ALD machines will further expand the process window towards lower operation temperatures and specific materials requiring radic

  19. Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution.

    Science.gov (United States)

    Laroche, G; Vallade, J; Bazinette, R; van Nijnatten, P; Hernandez, E; Hernandez, G; Massines, F

    2012-10-01

    This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm × 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45° beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

  20. Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Laroche, G. [Laboratoire d' Ingenierie de Surface, Centre de Recherche sur les Materiaux Avances, Departement de genie des mines, de la metallurgie et des materiaux, Universite Laval, 1065, avenue de la Medecine, Quebec G1V 0A6 (Canada); Centre de recherche du CHUQ, Hopital St Francois d' Assise, 10, rue de l' Espinay, local E0-165, Quebec G1L 3L5 (Canada); Vallade, J. [Laboratoire Procedes, Materiaux et Energie Solaire, PROMES, CNRS, Technosud, Rambla de la Thermodynamique, F-66100 Perpignan (France); Agence de l' environnement et de la Ma Latin-Small-Letter-Dotless-I -carettrise de l' Energie, 20, avenue du Gresille, BP 90406, F-49004 Angers Cedex 01 (France); Bazinette, R.; Hernandez, E.; Hernandez, G.; Massines, F. [Laboratoire Procedes, Materiaux et Energie Solaire, PROMES, CNRS, Technosud, Rambla de la Thermodynamique, F-66100 Perpignan (France); Nijnatten, P. van [OMT Solutions bv, High Tech Campus 9, 5656AE Eindhoven (Netherlands)

    2012-10-15

    This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm Multiplication-Sign 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45 Degree-Sign beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

  1. Spatial properties of a terahertz beam generated from a two-color air plasma

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Wang, Tianwu; Buron, Jonas Christian Due

    2013-01-01

    We present a spatial characterization of terahertz (THz) beams generated from a two-color air plasma under different conditions by measuring full 3D beam profiles using a commercial THz camera. We compare two THz beam profiles emitted from plasmas generated by 35 fs and 100 fs laser pulses......, and show that the spatial properties of the two THz beams do not change significantly. For the THz beam profile generated by the 35 fs pulse, the spatial effect of eliminating the lower frequencies is investigated by implementing two crossed polarizers working as a high-pass filter. We show...

  2. Image Interpolation Using Kriging Technique for Spatial Data

    OpenAIRE

    Jassim, Firas Ajil; Altaany, Fawzi Hasan

    2013-01-01

    Image interpolation has been used spaciously by customary interpolation techniques. Recently, Kriging technique has been widely implemented in simulation area and geostatistics for prediction. In this article, Kriging technique was used instead of the classical interpolation methods to predict the unknown points in the digital image array. The efficiency of the proposed technique was proven using the PSNR and compared with the traditional interpolation techniques. The results showed that Krig...

  3. Spatially-Structured Sharing Technique for Multimodal Problems

    Institute of Scientific and Technical Information of China (English)

    Grant Dick; Peter Whigham

    2008-01-01

    Spatially-structured populations are one approach to increasing genetic diversity in an evolutionary algorithm (EA). However, they are suscptible to convergence to a single peak in a multimodal fitness landscape. Niching methods, such as fitness sharing, allow an EA to maintain multiple solutions in a single population, however they have rarely been used in conjunction with spatially-structured populations. This paper introduces local sharing, a method that applies sharing to the overlapping demes of a spatially-structured population. The combination of these two methods succeeds in maintaining multiple solutions in problems that have previously proved difficult for sharing alone (and vice-versa).

  4. A polarization-based Thomson scattering technique for burning plasmas

    CERN Document Server

    Parke, E; Hartog, D J Den

    2013-01-01

    The traditional Thomson scattering diagnostic is based on measurement of the wavelength spectrum of scattered light, where electron temperature measurements are inferred from thermal broadening of the scattered laser light. At sufficiently high temperatures, especially those predicted for ITER and other burning plasmas, relativistic effects cause a change in the polarization state of the scattered photons. The resulting depolarization of the scattered light is temperature dependent and has been proposed elsewhere as a potential alternative to the traditional spectral decomposition technique. Following similar work, we analytically calculate the degree of polarization for incoherent Thomson scattering. For the first time, we obtain exact results valid for the full range of incident laser polarization states and electron temperatures. While previous work focused only on linear polarization, we show that circularly polarized incident light optimizes the degree of depolarization for a wide range of temperatures r...

  5. Parallel pic plasma simulation through particle decomposition techniques

    Energy Technology Data Exchange (ETDEWEB)

    Briguglio, S.; Vlad, G. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Energia; Di Martino, B. [Wien Univ. (Austria). Inst. for Software Tecnology and Parallel Systems]|[Naples, Univ. `Federico II` (Italy). Dipt. di Informatica e Sistemistica

    1998-02-01

    Particle-in-cell (PIC) codes are among the major candidates to yield a satisfactory description of the detail of kinetic effects, such as the resonant wave-particle interaction, relevant in determining the transport mechanism in magnetically confined plasmas. A significant improvement of the simulation performance of such codes con be expected from parallelization, e.g., by distributing the particle population among several parallel processors. Parallelization of a hybrid magnetohydrodynamic-gyrokinetic code has been accomplished within the High Performance Fortran (HPF) framework, and tested on the IBM SP2 parallel system, using a `particle decomposition` technique. The adopted technique requires a moderate effort in porting the code in parallel form and results in intrinsic load balancing and modest inter processor communication. The performance tests obtained confirm the hypothesis of high effectiveness of the strategy, if targeted towards moderately parallel architectures. Optimal use of resources is also discussed with reference to a specific physics problem. [Italiano] I codici Particle-in-cell (PIC) sono considerati tra i piu` promettenti candidati per ottenere una descrizione soddisfacente e dettagliata degli effetti cinetici, quali per esempio l`interazione risonante particella-onda, rilevanti nel determinare i meccanismi di trasporto che interessano il confinamento del plasma. Un significativo miglioramento delle prestazioni della simulazione puo` essere ottenuto distribuendo la popolazione di particelle tra diversi processori in parallelo. La parallelizzazione di un codice ibrido MHD-girocinetico e` stata effettuata, in ambiente HPF, utilizzando la tecnica di `decomposizione per particelle`, ed e` stata provata sul sistema parallelo IBM SP2. La tecnica adottata richiede uno sforzo moderato per la trasformazione del codice in versione parallela, permette un intrinseco bilanciamento tra i processori del carico di lavoro e necessita di una modesta

  6. A spatial compression technique for head-related transfer function interpolation and complexity estimation

    DEFF Research Database (Denmark)

    Shekarchi, Sayedali; Christensen-Dalsgaard, Jakob; Hallam, John

    2015-01-01

    datasets was evaluated quantitatively by defining an HRTF spatial complexity index, which considers the rate of change in HRTF power spectrum with respect to spatial position. The results indicate that the compression realized by the LP technique is largely independent of the number of spatial samples...

  7. Review of Spatial Indexing Techniques for Large Urban Data Management

    DEFF Research Database (Denmark)

    Azri, Suhaibah; Ujang, Uznir; Anton, François

    Pressure on land development in urban areas causes progressive efforts in spatial planning and management. The physical expansion of urban areas to accommodate rural migration implies a massive impact to social, economical and political situations of major cities. Most of the models used in manag......Pressure on land development in urban areas causes progressive efforts in spatial planning and management. The physical expansion of urban areas to accommodate rural migration implies a massive impact to social, economical and political situations of major cities. Most of the models used...

  8. Magnetic Resonance Microscopy Spatially Resolved NMR Techniques and Applications

    CERN Document Server

    Codd, Sarah

    2008-01-01

    This handbook and ready reference covers materials science applications as well as microfluidic, biomedical and dental applications and the monitoring of physicochemical processes. It includes the latest in hardware, methodology and applications of spatially resolved magnetic resonance, such as portable imaging and single-sided spectroscopy. For materials scientists, spectroscopists, chemists, physicists, and medicinal chemists.

  9. Spatial configuration of a plasma bunch formed under gyromagnetic resonance in a magnetic mirror trap

    Science.gov (United States)

    Andreev, V. V.; Novitskii, A. A.; Umnov, A. M.; Chuprov, D. V.

    2016-06-01

    The spatial configuration of a relativistic plasma bunch generated under the gyromagnetic autoresonance and confined in a magnetic mirror trap has been studied experimentally and numerically. The characteristics of bremsstrahlung generated by the plasma bunch from the gas and chamber walls were investigated using X-ray spectroscopy and radiometry, which made it possible to determine the localization of the bunch and analyze the dynamics of its confinement.

  10. Spatial distribution of low-energy plasma around comet 67P/CG from Rosetta measurements

    CERN Document Server

    Edberg, N J T; Odelstad, E; Henri, P; Lebreton, J -P; Gasc, S; Rubin, M; André, M; Gill, R; Johansson, E P G; Johansson, F; Vigren, E; Wahlund, J E; Carr, C M; Cupido, E; Glassmeier, K -H; Goldstein, R; Koenders, C; Mandt, K; Nemeth, Z; Nilsson, H; Richter, I; Wieser, G Stenberg; Szego, K; Volwerk, M

    2016-01-01

    We use measurements from the Rosetta plasma consortium (RPC) Langmuir probe (LAP) and mutual impedance probe (MIP) to study the spatial distribution of low-energy plasma in the near-nucleus coma of comet 67P/Churyumov-Gerasimenko. The spatial distribution is highly structured with the highest density in the summer hemisphere and above the region connecting the two main lobes of the comet, i.e. the neck region. There is a clear correlation with the neutral density and the plasma to neutral density ratio is found to be about 1-2x10^-6, at a cometocentric distance of 10 km and at 3.1 AU from the sun. A clear 6.2 h modulation of the plasma is seen as the neck is exposed twice per rotation. The electron density of the collisonless plasma within 260 km from the nucleus falls of with radial distance as about 1/r. The spatial structure indicates that local ionization of neutral gas is the dominant source of low-energy plasma around the comet.

  11. Electronically swept millimeter-wave interferometer for spatially resolved measurement of plasma electron density.

    Science.gov (United States)

    Howard, John; Oliver, David

    2006-12-01

    We report the development and initial implementation of what we believe to be a new rapid- spatial-scan millimeter-wave interferometer for plasma density measurements. The fast scan is effected by electronic frequency sweeping of a wideband (180-280 GHz) backward-wave oscillator whose output is focused onto a fixed blazed diffraction grating. The system, which augments the rotating-grating scanned multiview H-1 heliac interferometer, can sweep the plasma cross section in a period of less than 1 ms with a beam diameter in the plasma of 20 mm and phase noise of the order of 0.01 rad.

  12. Image Resolution Enhancement using DWT and Spatial Domain Interpolation Technique

    Directory of Open Access Journals (Sweden)

    Mrs. G. Padma Priya

    2016-02-01

    Full Text Available Image Resolution is one of the important quality metrics of images. Images with high resolution are required in many fields. In this paper, a new resolution enhancement technique is proposed based on the interpolation of four sub band images generated by Discrete Wavelet Transform (DWT and the original Low Resolution (LR input image. In this technique, the four sub band images generated by DWT and the input LR image are interpolated with scaling factor, α and then performed inverse DWT to obtain the intermediate High Resolution (HR Image. The difference between the intermediate HR image and the interpolated LR input image is added to the intermediate HR image to obtain final output HR Image. Lanczos interpolation is used in this technique. The proposed technique is tested on well known bench mark images. The quantitative and visual results shows the superiority of the proposed technique over the conventional and state of art image resolution enhancement techniques in wavelet domain using haar wavelet filter.

  13. Spatial heterodyne spectroscopy - A novel interferometric technique for the FUV

    Science.gov (United States)

    Harlander, J.; Roesler, F. L.; Chakrabarti, S.

    1990-01-01

    The optical principles associated with spatial heterodyne spectroscopy (SHS) are described and the results of proof-of-concept tests performed in both the visible and the UV spectral regions are presented. A specific all-reflecting SHS configuration now being developed for high-resolution planetary Lyman-alpha studies is discussed. The expected performance of SHS systems is compared to that of conventional instrumentation in two cases: Venusian Ly-alpha measurements at high resolution from a sounding rocket and the velocity-resolved survey of the diffuse FUV interstellar medium emission from a Small Explorer class satellite.

  14. Ionospheric Plasma Drift Analysis Technique Based On Ray Tracing

    Science.gov (United States)

    Ari, Gizem; Toker, Cenk

    2016-07-01

    Ionospheric drift measurements provide important information about the variability in the ionosphere, which can be used to quantify ionospheric disturbances caused by natural phenomena such as solar, geomagnetic, gravitational and seismic activities. One of the prominent ways for drift measurement depends on instrumentation based measurements, e.g. using an ionosonde. The drift estimation of an ionosonde depends on measuring the Doppler shift on the received signal, where the main cause of Doppler shift is the change in the length of the propagation path of the signal between the transmitter and the receiver. Unfortunately, ionosondes are expensive devices and their installation and maintenance require special care. Furthermore, the ionosonde network over the world or even Europe is not dense enough to obtain a global or continental drift map. In order to overcome the difficulties related to an ionosonde, we propose a technique to perform ionospheric drift estimation based on ray tracing. First, a two dimensional TEC map is constructed by using the IONOLAB-MAP tool which spatially interpolates the VTEC estimates obtained from the EUREF CORS network. Next, a three dimensional electron density profile is generated by inputting the TEC estimates to the IRI-2015 model. Eventually, a close-to-real situation electron density profile is obtained in which ray tracing can be performed. These profiles can be constructed periodically with a period of as low as 30 seconds. By processing two consequent snapshots together and calculating the propagation paths, we estimate the drift measurements over any coordinate of concern. We test our technique by comparing the results to the drift measurements taken at the DPS ionosonde at Pruhonice, Czech Republic. This study is supported by TUBITAK 115E915 and Joint TUBITAK 114E092 and AS CR14/001 projects.

  15. Comprehensive Flood Plain Studies Using Spatial Data Management Techniques.

    Science.gov (United States)

    1978-06-01

    and subbasin hydraulic length. The technique adopted is a modest extension and automation of the method developed for San Diego County (Franziniet al...land classified as 14 I ____.4_ natural vegetation under existing conditions is 272 acres while the total amount of landA classified as natural

  16. Longitudinal oscillations in a non-uniform spatially dispersive plasma

    Energy Technology Data Exchange (ETDEWEB)

    Calogeracos, Alex, E-mail: a.calogeracos@yahoo.co.uk

    2015-03-15

    Longitudinal oscillations of the electron fluid in the hydrodynamic model of a metal are examined with pressure effects taken into account. It is well-known that this entails spatial dispersion. The equilibrium electron number density is taken to be non-uniform and a non-self-adjoint fourth order differential equation obeyed by the electric potential is derived. A velocity potential necessary for the description of sound waves is introduced in the standard fashion and the generalized version of Bloch orthogonality appropriate to a non-uniform background is deduced. We observe a duality between electric and velocity potentials in the sense that the respective differential operators are adjoint to each other. The spectrum is calculated in the special case of an exponential profile for the equilibrium electron number density. The surface plasmons are connected with the analytic properties of the scattering amplitude in the complex plane. The phase shift at threshold is expressed in terms of the number of surface plasmon modes via an expression reminiscent of Levinson’s statement in quantum mechanics.

  17. A Novel Microwave Beam Steering Technique Using Plasma

    Science.gov (United States)

    Linardakis, Peter; Borg, Gerard G.; Harris, Jeffrey H.; Martin, Noel M.

    2002-10-01

    At frequencies above the plasma frequency, electromagnetic waves propagate through plasma with a wavelength longer than the free space wavelength. As a result, a plasma with a centrally peaked density profile can deflect rather than focus electromagnetic waves. We present a plasma device designed specifically to deflect a microwave beam as an alternative to conventional beam deflectors based on antenna arrays. A 22^rc deflection of Ka band microwave has been achieved using a laboratory plasma, with no detrimental effect on the beamwidth or side-lode level and structure. The use of a simple WKB model shows agreement and that the deflection can be increased with appropriate design. Results indicate the potential for increases in dynamic range, in power handling (for example from a gyrotron) and for the reduction of insertion losses over current beam steering systems. A ``plasma lens'' demonstrator device has also been designed to test practical performance aspects such as phase noise and to test optimization parameters.

  18. The spatial damping of magnetohydrodynamic waves in a flowing partially ionised prominence plasma

    CERN Document Server

    Carbonell, M; Oliver, R; Ballester, J L

    2010-01-01

    Solar prominences are partially ionised plasmas displaying flows and oscillations. These oscillations show time and spatial damping and, commonly, have been explained in terms of magnetohydrodynamic (MHD) waves. We study the spatial damping of linear non-adiabatic MHD waves in a flowing partially ionised plasma, having prominence-like physical properties. We consider single fluid equations for a partially ionised hydrogen plasma including in the energy equation optically thin radiation, thermal conduction by electrons and neutrals, and heating. Keeping the frequency real and fixed, we have solved the obtained dispersion relations for the complex wavenumber, k, and have analysed the behaviour of the damping length, wavelength and the ratio of the damping length to the wavelength, versus period, for Alfven, fast, slow and thermal waves.

  19. Spatial characteristics of Kα radiation from weakly relativistic laser plasmas

    Science.gov (United States)

    Eder, D. C.; Pretzler, G.; Fill, E.; Eidmann, K.; Saemann, A.

    The spatial dependence of Kα emission generated from laser-produced hot electrons is investigated experimentally and theoretically. In addition, the conversion efficiency of Kα production as a function of laser intensity is measured and compared with modeling results. We use the terawatt Ti:sapphire laser at MPQ and vary the peak intensity from 1015 to 1018 W/cm2 with a pulse duration of 200 fs. A solid Cu target is placed at various positions in the laser focus, which allows one to vary the intensity but keep the total energy on the target constant. When the target is near best focus, the FWHM of the Kα emission, measured using a knife-edge, is considerably larger than the FWHM of the laser intensity. In measuring the efficiency of Kα production using the fundamental wavelength of the laser, a clear maximum of Kα emission is observed at a position away from best focus, where the peak intensity is down by more than an order of magnitude from the value at best focus. When the second harmonic of the laser is used, the Kα emission is peaked near best focus. The Kα emission from layer targets is used to obtain an estimate of the temperature of the hot electrons. Modeling of Kα production, using a Monte Carlo electron/photon transport code, shows the relationship between incident electron energy and the emitted Kα emission. Efficient Kα generation from the low-intensity wings of the laser pulse contributes to the large spot size of the Kα emission. The lower electron temperatures that are expected for the second harmonic explain the differences in the location of maximum Kα emission for the two wavelengths. We discuss the use of Kα emission in photoionizing inner-shell electrons with the goal of achieving X-ray lasing at short wavelengths.

  20. Spatial profiles of electron density, electron temperature, average ionic charge, and EUV emission of laser-produced Sn plasmas for EUV lithography

    Science.gov (United States)

    Sato, Yuta; Tomita, Kentaro; Tsukiyama, Syoichi; Eguchi, Toshiaki; Uchino, Kiichiro; Kouge, Kouichiro; Tomuro, Hiroaki; Yanagida, Tatsuya; Wada, Yasunori; Kunishima, Masahito; Kodama, Takeshi; Mizoguchi, Hakaru

    2017-03-01

    Spatial profiles of the electron density (n e), electron temperature (T e), and average ionic charge (Z) of laser-produced Sn plasmas for EUV lithography, whose conversion efficiency (CE) is sufficiently high for practical use, were measured using a collective Thomson scattering (TS) technique. For plasma production, Sn droplets of 26 µm diameter were used as a fuel. First, a picosecond-pulsed laser was used to expand a Sn target. Next, a CO2 laser was used to generate plasmas. By changing the injection timing of the picosecond and CO2 lasers, three different types of plasmas were generated. The CEs of the three types of plasmas differed, and ranged from 2.8 to 4.0%. Regarding the different plasma conditions, the spatial profiles of n e, T e, and Z clearly differed. However, under all plasma conditions, intense EUV was only observed at a sufficiently high T e (> 25 eV) and in an adequate n e range [1024–(2 × 1025) m‑3]. These plasma parameters lie in the efficient-EUV light source range, as predicted by simulations.

  1. Temporal and Spatial Turbulent Spectra of MHD Plasma and an Observation of Variance Anisotropy

    CERN Document Server

    Schaffner, D A; Lukin, V S

    2014-01-01

    The nature of MHD turbulence is analyzed through both temporal and spatial magnetic fluctuation spectra. A magnetically turbulent plasma is produced in the MHD wind-tunnel configuration of the Swarthmore Spheromak Experiment (SSX). The power of magnetic fluctuations is projected into directions perpendicular and parallel to a local mean field; the ratio of these quantities shows the presence of variance anisotropy which varies as a function of frequency. Comparison amongst magnetic, velocity, and density spectra are also made, demonstrating that the energy of the turbulence observed is primarily seeded by magnetic fields created during plasma production. Direct spatial spectra are constructed using multi-channel diagnostics and are used to compare to frequency spectra converted to spatial scales using the Taylor Hypothesis. Evidence for the observation of dissipation due to ion inertial length scale physics is also discussed as well as the role laboratory experiment can play in understanding turbulence typica...

  2. Simulation techniques for spatially evolving instabilities in compressible flow over a flat plate

    NARCIS (Netherlands)

    Wasistho, B.; Geurts, B.J.; Kuerten, J.G.M.

    1997-01-01

    In this paper we present numerical techniques suitable for a direct numerical simulation in the spatial setting. We demonstrate the application to the simulation of compressible flat plate flow instabilities. We compare second and fourth order accurate spatial discretization schemes in combination w

  3. Calculation of the spatial resolution in two-photon absorption spectroscopy applied to plasma diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Lechuga, M. [Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, 47011-Valladolid (Spain); Laser Processing Group, Instituto de Óptica “Daza de Valdés,” CSIC, 28006-Madrid (Spain); Fuentes, L. M. [Departamento de Física Aplicada, Universidad de Valladolid, 47011-Valladolid (Spain); Grützmacher, K.; Pérez, C., E-mail: concha@opt.uva.es; Rosa, M. I. de la [Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, 47011-Valladolid (Spain)

    2014-10-07

    We report a detailed characterization of the spatial resolution provided by two-photon absorption spectroscopy suited for plasma diagnosis via the 1S-2S transition of atomic hydrogen for optogalvanic detection and laser induced fluorescence (LIF). A precise knowledge of the spatial resolution is crucial for a correct interpretation of measurements, if the plasma parameters to be analysed undergo strong spatial variations. The present study is based on a novel approach which provides a reliable and realistic determination of the spatial resolution. Measured irradiance distribution of laser beam waists in the overlap volume, provided by a high resolution UV camera, are employed to resolve coupled rate equations accounting for two-photon excitation, fluorescence decay and ionization. The resulting three-dimensional yield distributions reveal in detail the spatial resolution for optogalvanic and LIF detection and related saturation due to depletion. Two-photon absorption profiles broader than the Fourier transform-limited laser bandwidth are also incorporated in the calculations. The approach allows an accurate analysis of the spatial resolution present in recent and future measurements.

  4. Spatial and Excitation Variations for Different Applied Voltages in an Atmospheric Neon Plasma Jet

    Science.gov (United States)

    Yang, Lanlan; Tu, Yan; Yu, Yongbo; Hu, Dinglan; Zhang, Xiong

    2016-09-01

    A neon plasma jet was generated in air, driven by a 9 kHz sinusoidal power supply. The characteristics of the plasma plume and the optical spectra with plasma propagation for different applied voltages were investigated. By increasing the applied voltage, the plasma plume first increases and then retracts to become short and bulky. The shortened effect of Ne plasma plume (about 10 mm) for the further voltage increasing is more apparent than that of He (about 3 mm) and Ar (about 1 mm). Emission intensity of the N2 (337 nm) increases with the applied voltage, gradually substituting the emission intensity of Ne (702 nm and 585 nm) as the noticeable radiation. At the nozzle opening, the Ne (702 nm) emission dominates, while the Ne (585 nm) emission is most noticeable around the tip of the plasma plume. The spatial distribution of the three spectral lines indicates that Ne (702 nm) emission decreases dramatically with plasma propagation while Ne (585 nm) and N2 (337 nm) emissions reach their maxima at the middle of the plasma plume. The results indicate that the Ne (702 nm) emission is much more sensitive to the average electron temperature and the density of the high-energy electrons, so it changes greatly at the tube nozzle and little at the tip region as the voltage increases. The population of high-energy electrons, the average electron temperature, the collision with air molecules and the Penning effect between Ne metastables and air molecules may explain their different variations with plasma propagating and voltage increasing. supported by National Natural Science Fundation of China (No. 61271053), the Natural Science Foundation of Jiangsu Province of China (No. BK2012737), the Foundation for Excellent Youth Scholars of Southeast University, China

  5. Scaling up the DBSCAN Algorithm for Clustering Large Spatial Databases Based on Sampling Technique

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Clustering, in data mining, is a useful technique for discoveringinte resting data distributions and patterns in the underlying data, and has many app lication fields, such as statistical data analysis, pattern recognition, image p rocessing, and etc. We combine sampling technique with DBSCAN alg orithm to cluster large spatial databases, and two sampling-based DBSCAN (SDBSC A N) algorithms are developed. One algorithm introduces sampling technique inside DBSCAN, and the other uses sampling procedure outside DBSCAN. Experimental resul ts demonstrate that our algorithms are effective and efficient in clustering lar ge-scale spatial databases.

  6. Tomography of homogenized laser-induced plasma by Radon transform technique

    Science.gov (United States)

    Eschlböck-Fuchs, S.; Demidov, A.; Gornushkin, I. B.; Schmid, T.; Rössler, R.; Huber, N.; Panne, U.; Pedarnig, J. D.

    2016-09-01

    Tomography of a laser-induced plasma in air is performed by inverse Radon transform of angle-resolved plasma images. Plasmas were induced by single laser pulses (SP), double pulses (DP) in collinear geometry, and by a combination of single laser pulses with pulsed arc discharges (SP-AD). Images of plasmas on metallurgical steel slags were taken at delay times suitable for calibration-free laser-induced breakdown spectroscopy (CF-LIBS). Delays ranged from few microseconds for SP and DP up to tens of microseconds for SP-AD excitation. The white-light and the spectrally resolved emissivity ε(x,y,z) was reconstructed for the three plasma excitation schemes. The electron number density Ne(x,y,z) and plasma temperature Te(x,y,z) were determined from Mg and Mn emission lines in reconstructed spectra employing the Saha-Boltzmann plot method. The SP plasma revealed strongly inhomogeneous emissivity and plasma temperature. Re-excitation of plasma by a second laser pulse (DP) and by an arc discharge (SP-AD) homogenized the plasma and reduced the spatial variation of ε and Te. The homogenization of a plasma is a promising approach to increase the accuracy of calibration-free LIBS analysis of complex materials.

  7. Applicability of the molecular dynamics technique to a Coulomb plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, A.G.; Galeev, R.Kh.

    1993-09-01

    In the present work, we report the calculations of the local Lyapunov parameter which determines the nature of the motion for a system of n particles interacting according to Coulomb`s law. These calculations have been performed for the most probable states of a fully ionized plasma, and they were performed using a Microvax-3 computer with the NAG(FO2) program package for a plasma consisting of particles with the same mass and for a fully ionized hydrogen plasma. The particle coordinates were prescribed as a uniformly distributed set of random numbers obtained using the NAG(GO5) routine. Results for the Lyapunov parameter are presented, and it is shown that the values of the parameter increases sharply as a function of particle number up to n=100 and then saturate. This latter observation is attributed to shielding, related to Debye effects.

  8. GRAFT COPOLYMERIZATION OF ACRYLAMIDE ONTO POLYPROPYLENE FILMS BY PLASMA TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    WANG Shicai; YE Mu; LU Lizhen; CHEN Jie

    1988-01-01

    The graft copolymerization of acrylamide onto polypropylene (PP) film was carried out by using a capacitively coupled rf plasma apparatus with external plate electrodes. The relationship between the surface structure of the Ar plasma-treated PP films and the extent of grafting of acrylamide on the films was studied through observing the effects of discharge power and exposure time on the relative content of free-radical on the film surface. Meanwhile, the wettability and surface energy of the PP film were measured.

  9. Surface plasmon polaritons in a semi-bounded degenerate plasma: role of spatial dispersion and collisions

    CERN Document Server

    Tyshetskiy, Yuriy; Kompaneets, Roman; 10.1063/1.4764468

    2012-01-01

    Surface plasmon polaritons (SPPs) in a semi-bounded degenerate plasma (e.g., a metal) are studied using the quasiclassical mean-field kinetic model, taking into account the spatial dispersion of the plasma (due to quantum degeneracy of electrons) and electron-ion (electron-lattice, for metals) collisions. SPP dispersion and damping are obtained in both retarded ($\\omega/k_z\\sim c$) and non-retarded ($\\omega/k_z\\ll c$) regions, as well as in between. It is shown that the plasma spatial dispersion significantly affects the properties of SPPs, especially at short wavelengths (less than the collisionless skin depth, $\\lambda\\lesssim c/\\omega_{pe}$). Namely, the collisionless (Landau) damping of SPPs (due to spatial dispersion) is comparable to the purely collisional (Ohmic) damping (due to electron-lattice collisions) in a wide range of SPP wavelengths, e.g., from $\\lambda\\sim20$ nm to $\\lambda\\sim0.8$ nm for SPP in gold at T=293 K, and from $\\lambda\\sim400$ nm to $\\lambda\\sim0.7$ nm for SPPs in gold at T=100 K. ...

  10. Integral equation for electrostatic waves generated by a point source in a spatially homogeneous magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Podesta, John J. [Space Science Institute, Boulder, Colorado 80301 (United States)

    2012-08-15

    The electric field generated by a time varying point charge in a three-dimensional, unbounded, spatially homogeneous plasma with a uniform background magnetic field and a uniform (static) flow velocity is studied in the electrostatic approximation which is often valid in the near field. For plasmas characterized by Maxwell distribution functions with isotropic temperatures, the linearized Vlasov-Poisson equations may be formulated in terms of an equivalent integral equation in the time domain. The kernel of the integral equation has a relatively simple mathematical form consisting of elementary functions such as exponential and trigonometric functions (sines and cosines), and contains no infinite sums of Bessel functions. Consequently, the integral equation is amenable to numerical solutions and may be useful for the study of the impulse response of magnetized plasmas and, more generally, the response to arbitrary waveforms.

  11. Spatially Resolved Measurements of a Double Layer in an Argon Helicon Plasma

    Science.gov (United States)

    Aguirre, Evan; Siddiqui, Umair; McKee, John; Scime, Earl

    2015-11-01

    We report 2-dimensional, spatially resolved observations of a double layer in an expanding helicon plasma. These new measurements investigate the origins of previously observed multiple ion beam populations in the downstream plasma. We use Laser Induced Fluorescence (LIF) to measure the ion velocity distribution functions (IVDFs) of argon ions and neutrals both parallel and perpendicular to the background magnetic field and an rf-compensated Langmuir probe to determine the local plasma potential. These are the first multi-dimensional LIF measurements of ion acceleration in a current-free double layer and were obtained with a recently installed, internal scanning probe system in the HELIX-LEIA experimental facility. This work is supported by US National Science Foundation grant number PHY-1360278.

  12. [Analysis of Cr in soil by LIBS based on conical spatial confinement of plasma].

    Science.gov (United States)

    Lin, Yong-Zeng; Yao, Ming-Yin; Chen, Tian-Bing; Li, Wen-Bing; Zheng, Mei-Lan; Xu, Xue-Hong; Tu, Jian-Ping; Liu, Mu-Hua

    2013-11-01

    The present study is to improve the sensitivity of detection and reduce the limit of detection in detecting heavy metal of soil by laser induced breakdown spectroscopy (LIBS). The Cr element of national standard soil was regarded as the research object. In the experiment, a conical cavity with small diameter end of 20 mm and large diameter end of 45 mm respectively was installed below the focusing lens near the experiment sample to mainly confine the signal transmitted by plasma and to some extent to confine the plasma itself in the LIBS setup. In detecting Cr I 425.44 nm, the beast delay time gained from experiment is 1.3 micros, and the relative standard deviation is below 10%. Compared with the setup of non-spatial confinement, the spectral intensity of Cr in the soil sample was enhanced more than 7%. Calibration curve was established in the Cr concentration range from 60 to 400 microg x g(-1). Under the condition of spatial confinement, the liner regression coefficient and the limit of detection were 0.997 71 and 18.85 microg x g(-1) respectively, however, the regression coefficient and the limit of detection were 0.991 22 and 36.99 microg x g(-1) without spatial confinement. So, this shows that conical spatial confinement can/improve the sensitivity of detection and enhance the spectral intensity. And it is a good auxiliary function in detecting Cr in the soil by laser induced breakdown spectroscopy.

  13. Geostatistical characterization of the soil of Aguascalientes, México, by using spatial estimation techniques.

    Science.gov (United States)

    Magdaleno-Márquez, Ricardo; de la Luz Pérez-Rea, María; Castaño, Víctor M

    2016-01-01

    Four spatial estimation techniques available in commercial computational packages are evaluated and compared, namely: regularized splines interpolation, tension splines interpolation, inverse distance weighted interpolation, and ordinary Kriging estimation, in order to establish the best representation for the shallow stratigraphic configuration in the city of Aguascalientes, in Central Mexico. Data from 478 sample points along with the software ArcGIS (Environmental Systems Research Institute, Inc. (ESRI), ArcGIS, ver. 9.3, Redlands, California 2008) to calculate the spatial estimates. Each technique was evaluated based on the root mean square error, calculated from a validation between the generated estimates and measured data from 64 sample points which were not used in the spatial estimation process. The present study shows that, for the estimation of the hard-soil layer, ordinary Kriging offered the best performance among the evaluated techniques.

  14. Dynamics of the spatial electron density distribution of EUV-induced plasmas

    Science.gov (United States)

    van der Horst, R. M.; Beckers, J.; Osorio, E. A.; Banine, V. Y.

    2015-11-01

    We studied the temporal evolution of the electron density distribution in a low pressure pulsed plasma induced by high energy extreme ultraviolet (EUV) photons using microwave cavity resonance spectroscopy (MCRS). In principle, MCRS only provides space averaged information about the electron density. However, we demonstrate here the possibility to obtain spatial information by combining multiple resonant modes. It is shown that EUV-induced plasmas, albeit being a rather exotic plasma, can be explained by known plasma physical laws and processes. Two stages of plasma behaviour are observed: first the electron density distribution contracts, after which it expands. It is shown that the contraction is due to cooling of the electrons. The moment when the density distribution starts to expand is related to the inertia of the ions. After tens of microseconds, the electrons reached the wall of the cavity. The speed of this expansion is dependent on the gas pressure and can be divided into two regimes. It is shown that the acoustic dominated regime the expansion speed is independent of the gas pressure and that in the diffusion dominated regime the expansion depends reciprocal on the gas pressure.

  15. Advanced modeling techniques in application to plasma pulse treatment

    Science.gov (United States)

    Pashchenko, A. F.; Pashchenko, F. F.

    2016-06-01

    Different approaches considered for simulation of plasma pulse treatment process. The assumption of a significant non-linearity of processes in the treatment of oil wells has been confirmed. Method of functional transformations and fuzzy logic methods suggested for construction of a mathematical model. It is shown, that models, based on fuzzy logic are able to provide a satisfactory accuracy of simulation and prediction of non-linear processes observed.

  16. A plasma polymerization technique to overcome cerebrospinal fluid shunt infections.

    Science.gov (United States)

    Cökeliler, D; Caner, H; Zemek, J; Choukourov, A; Biederman, H; Mutlu, M

    2007-03-01

    Prosthetic devices, mainly shunts, are frequently used for temporary or permanent drainage of cerebrospinal fluid. The pathogenesis of shunt infection is a very important problem in modern medicine and generally this is characterized by staphylococcal adhesion to the cerebrospinal fluid shunt surfaces. In this paper, the prevention of the attachment of test microorganism Staphylococcus epidermidis on the cerebrospinal fluid shunt surfaces by 2-hydroxyethylmethacrylate (HEMA) precursor modification in the plasma polymerization system, is reported. Different plasma polymerization conditions (RF discharge power 10-20-30 W, exposure time 5-10-15 min) were employed during the surface modification. The surface chemistry and topology of unmodified and modified shunts was characterized by x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also, static contact angle measurements were performed to state the change of surface hydrophilicity. All samples were tested in vitro with Staphylococcus epidermidis. A plasma-polymerized HEMA film (PP HEMA) was found to be an alternative simple method to decrease the microorganism attachment and create bacterial anti-fouling surfaces. The attachment of the model microorganism Staphylococcus epidermidis on the shunt surface modified by PP HEMA at 20 W and 15 min was reduced 62.3% if compared to the unmodified control surface of the shunt.

  17. Power Efficient Plasma Technique for Rapid Water Sterilization

    Science.gov (United States)

    Hershcovitch, Ady

    2015-11-01

    Water especially good quality drinking water is a dwindling resource for significant segments of the world population. The BBC quoted this article (http://www.ft.com/cms/s/2/8e42bdc8-0838-11e4-9afc-00144feab7de.html) for a claim that water shortage is a bigger problem than climate change. One option for increasing the water supply is to recycle waste and polluted water by inexpensive, environmentally friendly methods. First steps involve filtrations while the last step is water disinfection. Presently disinfection is done chemically and/or UV radiation. Some chemicals cannot be used in large quantity due to residual toxicity, while UV disinfection systems consume a great deal electricity. Plasmas in water are very attractive for water sterilization due to UV radiation, ozone, etc. generation inside the water volume. Commercially available devices like NK-03 Blue Ballast System are used aboard ships for water purification. But, presently utilized plasmas: glow, pulsed arcs are not power efficient. Vortex stabilized plasmas, which are power efficient, can even degrade medications (antibiotics) advancing the state-of-the-art by orders of magnitude, especially when combined with electron beams. Disinfection scheme will be presented. Work supported by Contract No. DE-AC02-98CH1-886 with the US DOE.

  18. A plasma polymerization technique to overcome cerebrospinal fluid shunt infections

    Energy Technology Data Exchange (ETDEWEB)

    Coekeliler, D [Plasma Aided Bioengineering and Biotechnology Research Laboratory, Engineering Faculty, Hacettepe University, 06532, Ankara (Turkey); Caner, H [Department of Neurosurgery, School of Medicine, Baskent University, 06610, Ankara (Turkey); Zemek, J [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53, Prague, Czech Republic (Czech Republic); Choukourov, A [Department of Macromolecular Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Biederman, H [Department of Macromolecular Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Mutlu, M [Plasma Aided Bioengineering and Biotechnology Research Laboratory, Engineering Faculty, Hacettepe University, 06532, Ankara (Turkey)

    2007-03-01

    Prosthetic devices, mainly shunts, are frequently used for temporary or permanent drainage of cerebrospinal fluid. The pathogenesis of shunt infection is a very important problem in modern medicine and generally this is characterized by staphylococcal adhesion to the cerebrospinal fluid shunt surfaces. In this paper, the prevention of the attachment of test microorganism Staphylococcus epidermidis on the cerebrospinal fluid shunt surfaces by 2-hydroxyethylmethacrylate (HEMA) precursor modification in the plasma polymerization system, is reported. Different plasma polymerization conditions (RF discharge power 10-20-30 W, exposure time 5-10-15 min) were employed during the surface modification. The surface chemistry and topology of unmodified and modified shunts was characterized by x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also, static contact angle measurements were performed to state the change of surface hydrophilicity. All samples were tested in vitro with Staphylococcus epidermidis. A plasma-polymerized HEMA film (PP HEMA) was found to be an alternative simple method to decrease the microorganism attachment and create bacterial anti-fouling surfaces. The attachment of the model microorganism Staphylococcus epidermidis on the shunt surface modified by PP HEMA at 20 W and 15 min was reduced 62.3% if compared to the unmodified control surface of the shunt.

  19. Data Analysis Techniques for Resolving Nonlinear Processes in Plasmas : a Review

    OpenAIRE

    de Wit, T. Dudok

    1996-01-01

    The growing need for a better understanding of nonlinear processes in plasma physics has in the last decades stimulated the development of new and more advanced data analysis techniques. This review lists some of the basic properties one may wish to infer from a data set and then presents appropriate analysis techniques with some recent applications. The emphasis is put on the investigation of nonlinear wave phenomena and turbulence in space plasmas.

  20. Imaging of the magnetic field structure in megagauss plasmas by combining pulsed polarimetry with an optical Kerr effect shutter technique.

    Science.gov (United States)

    Smith, R J

    2010-10-01

    Pulsed polarimetry in combination with a high speed photographic technique based on the optical Kerr effect is described. The backscatter in a pulsed polarimeter is directed through a scattering cell and photographed using an ∼1 ps shutter, essentially freezing the intensity pattern. The image provides both the local electron density and magnetic field distributions along and transverse to the laser sightline. Submillimeter spatial resolution is possible for probing wavelengths in the visible due to the high densities and strong optical activity. Pulsed polarimetry is thereby extended to centimeter-sized plasmas with n(e)>10(19)-10(20) cm(-3) and B>20-100 T (MG) produced by multiterawatt, multimega-ampere electrical drivers, wire Z pinches, and liner imploded magnetized plasmas.

  1. Enhanced nonlinear iterative techniques applied to a non-equilibrium plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, D.A.; McHugh, P.R. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1996-12-31

    We study the application of enhanced nonlinear iterative methods to the steady-state solution of a system of two-dimensional convection-diffusion-reaction partial differential equations that describe the partially-ionized plasma flow in the boundary layer of a tokamak fusion reactor. This system of equations is characterized by multiple time and spatial scales, and contains highly anisotropic transport coefficients due to a strong imposed magnetic field. We use Newton`s method to linearize the nonlinear system of equations resulting from an implicit, finite volume discretization of the governing partial differential equations, on a staggered Cartesian mesh. The resulting linear systems are neither symmetric nor positive definite, and are poorly conditioned. Preconditioned Krylov iterative techniques are employed to solve these linear systems. We investigate both a modified and a matrix-free Newton-Krylov implementation, with the goal of reducing CPU cost associated with the numerical formation of the Jacobian. A combination of a damped iteration, one-way multigrid and a pseudo-transient continuation technique are used to enhance global nonlinear convergence and CPU efficiency. GMRES is employed as the Krylov method with Incomplete Lower-Upper(ILU) factorization preconditioning. The goal is to construct a combination of nonlinear and linear iterative techniques for this complex physical problem that optimizes trade-offs between robustness, CPU time, memory requirements, and code complexity. It is shown that a one-way multigrid implementation provides significant CPU savings for fine grid calculations. Performance comparisons of the modified Newton-Krylov and matrix-free Newton-Krylov algorithms will be presented.

  2. Experimental Study on Indoor Air Cleaning Technique of Nano-Titania Catalysis Under Plasma Discharge

    Institute of Scientific and Technical Information of China (English)

    GAO Deli; YANG Xuechang; ZHOU Fei; WU Yuhuang

    2008-01-01

    In this study, a new technique of air cleaning by plasma combined with catalyst was proposed, which consisted of electrostatic precipitation, volatile organic compounds (VOCs) decomposition and sterilization. A novel indoor air purifier based on this technique was adopted. The experimental results showed that formaldehyde decomposition by the plasma-catalyst hybrid system was more efficient than that by plasma only. Positive discharge was better than negative discharge in formaldehyde removal. Meanwhile, the outlet concentration of ozone byproduct was effectively reduced by the nano-titania catalyst.

  3. The value of remote sensing techniques in supporting effective extrapolation across multiple marine spatial scales.

    Science.gov (United States)

    Strong, James Asa; Elliott, Michael

    2017-03-15

    The reporting of ecological phenomena and environmental status routinely required point observations, collected with traditional sampling approaches to be extrapolated to larger reporting scales. This process encompasses difficulties that can quickly entrain significant errors. Remote sensing techniques offer insights and exceptional spatial coverage for observing the marine environment. This review provides guidance on (i) the structures and discontinuities inherent within the extrapolative process, (ii) how to extrapolate effectively across multiple spatial scales, and (iii) remote sensing techniques and data sets that can facilitate this process. This evaluation illustrates that remote sensing techniques are a critical component in extrapolation and likely to underpin the production of high-quality assessments of ecological phenomena and the regional reporting of environmental status. Ultimately, is it hoped that this guidance will aid the production of robust and consistent extrapolations that also make full use of the techniques and data sets that expedite this process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Sites of glucose transporter-4 vesicle fusion with the plasma membrane correlate spatially with microtubules.

    Directory of Open Access Journals (Sweden)

    Jennine M Dawicki-McKenna

    Full Text Available In adipocytes, vesicles containing glucose transporter-4 (GLUT4 redistribute from intracellular stores to the cell periphery in response to insulin stimulation. Vesicles then fuse with the plasma membrane, facilitating glucose transport into the cell. To gain insight into the details of microtubule involvement, we examined the spatial organization and dynamics of microtubules in relation to GLUT4 vesicle trafficking in living 3T3-L1 adipocytes using total internal reflection fluorescence (TIRF microscopy. Insulin stimulated an increase in microtubule density and curvature within the TIRF-illuminated region of the cell. The high degree of curvature and abrupt displacements of microtubules indicate that substantial forces act on microtubules. The time course of the microtubule density increase precedes that of the increase in intensity of fluorescently-tagged GLUT4 in this same region of the cell. In addition, portions of the microtubules are highly curved and are pulled closer to the cell cortex, as confirmed by Parallax microscopy. Microtubule disruption delayed and modestly reduced GLUT4 accumulation at the plasma membrane. Quantitative analysis revealed that fusions of GLUT4-containing vesicles with the plasma membrane, detected using insulin-regulated aminopeptidase with a pH-sensitive GFP tag (pHluorin, preferentially occur near microtubules. Interestingly, long-distance vesicle movement along microtubules visible at the cell surface prior to fusion does not appear to account for this proximity. We conclude that microtubules may be important in providing spatial information for GLUT4 vesicle fusion.

  5. Plasma-based ambient mass spectrometry techniques: The current status and future prospective.

    Science.gov (United States)

    Ding, Xuelu; Duan, Yixiang

    2015-01-01

    Plasma-based ambient mass spectrometry is emerging as a frontier technology for direct analysis of sample that employs low-energy plasma as the ionization reagent. The versatile sources of ambient mass spectrometry (MS) can be classified according to the plasma formation approaches; namely, corona discharge, glow discharge, dielectric barrier discharge, and microwave-induced discharge. These techniques allow pretreatment-free detection of samples, ranging from biological materials (e.g., flies, bacteria, plants, tissues, peptides, metabolites, and lipids) to pharmaceuticals, food-stuffs, polymers, chemical warfare reagents, and daily-use chemicals. In most cases, plasma-based ambient MS performs well as a qualitative tool and as an analyzer for semi-quantitation. Herein, we provide an overview of the key concepts, mechanisms, and applications of plasma-based ambient MS techniques, and discuss the challenges and outlook.

  6. Review of Geophysical Techniques to Define the Spatial Distribution of Subsurface Properties or Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Murray, Christopher J.; Last, George V.; Truex, Michael J.

    2005-08-22

    This is a letter report to Fluor Hanford, Inc. The purpose of this report is to summarize state-of-the-art, minimally intrusive geophysical techniques that can be used to clarify subsurface geology, structure, moisture, and chemical composition. The technology review focused on geophysical characterization techniques that provide two- or three-dimensional information about the spatial distribution of subsurface properties and/or contaminants.

  7. Assessing the reliability of the modified three-component spatial autocorrelation technique

    OpenAIRE

    Kohler, A.; M. Ohrnberger; Scherbaum, F.; Wathelet, M.; Cornou, Cécile

    2007-01-01

    Analysis of seismic ambient vibrations is becoming a widespread approach to estimate subsurface shear wave velocity profiles. However, the common restriction to vertical component wavefield data does not allow investigations of Love wave dispersion and the partitioning between Rayleigh and Love waves. In this study we extend the modified spatial autocorrelation technique (MSPAC) to three-component analysis (3c-MSPAC). By determination of Love wave dispersion curves, this technique provides ad...

  8. Plasma-Enhanced Atmospheric-Pressure Spatial ALD of Al2O3 and ZrO2

    NARCIS (Netherlands)

    Creyghton, Y.; Illiberi, A.; Mione, M.; Boekel, W. van; Debernardi, N.; Seitz, M.; Bruele, F. van den; Poodt, P.; Roozeboom,F.

    2016-01-01

    Non-thermal plasma sources are known to lower the operation temperatures and widen the process windows in thermal ALD of thin-film materials. In spatial ALD, novel plasma sources with exceptional dimensional and chemical stability are required to provide the flow geometries optimized for efficient t

  9. TESTING THE PERFORMANCE OF DIFFERENT SPATIAL INTERPOLATION TECHNIQUES ON MAPPING SHORT DATASERIES OF PRECIPITATION PROPRETIES

    Directory of Open Access Journals (Sweden)

    COJOCARU ŞTEFANA

    2014-03-01

    Full Text Available patial interpolation, in the context of spatial analysis, can be defined as the derivation of new data from already known information, a technique frequently used to predict and quantify spatial variation of a certain property or parameter. In this study we compared the performance of Inverse Distance Weighted (IDW, Ordinary Kriging and Natural Neighbor techniques, applied in spatial interpolation of precipitation parameters (pH, electrical conductivity and total dissolved solids. These techniques are often used when the area of interest is relatively small and the sampled locations are regularly spaced. The methods were tested on data collected in Iasi city (Romania between March – May 2013. Spatial modeling was performed on a small dataset, consisting of 7 sample locations and 13 different known values of each analyzed parameter. The precision of the techniques used is directly dependent on sample density as well as data variation, greater fluctuations in values between locations causing a decrease in the accuracy of the methods used. To validate the results and reveal the best method of interpolating rainfall characteristics, leave-one – out cross-validation approach was used. Comparing residues between the known values and the estimated values of pH, electrical conductivity and total dissolved solids, it was revealed that Natural Neighbor stands out as generating the smallest residues for pH and electrical conductivity, whereas IDW presents the smallest error in interpolating total dissolved solids (the parameter with the highest fluctuations in value.

  10. Single-step spatial rotation error separation technique for the ultraprecision measurement of surface profiles.

    Science.gov (United States)

    Hou, Maosheng; Qiu, Lirong; Zhao, Weiqian; Wang, Fan; Liu, Entao; Ji, Lin

    2014-01-20

    To improve the measurement accuracy of the profilometer for large optical surfaces, a new single-step spatial rotation error separation technique (SSEST) is proposed to separate the surface profile error and spindle spatial rotation error, and a novel SSEST-based system for surface profile measurement is developed. In the process of separation, two sets of measured results at the ith measurement circle are obtained before and after the rotation of error separation table, the surface profile error and spatial rotation error of spindle can be determined using discrete Fourier-transform and harmonic analysis. Theoretical analyses and experimental results indicate that SSEST can accurately separate spatial rotation error of spindle from the measured surface profile results within the range of 1-100 upr and improve the accuracy of surface profile measurements.

  11. Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

    Science.gov (United States)

    Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

    2014-02-01

    Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

  12. Solitary structures in a spatially nonuniform degenerate plasma in the presence of quantizing magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Masood, W. [COMSATS, Institute of Information Technology, Park Road, Chak Shahzad, Islamabad 44000 (Pakistan); National Center for Physics (NCP), Islamabad 44000 (Pakistan); Shaukat, Muzzamal I. [University of Engineering and Technology, Lahore (RCET Campus) 54000 (Pakistan); Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Shah, H. A. [Department of Physics, Forman Christian College, Lahore 54000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 44000 (Pakistan)

    2015-03-15

    In the present investigation, linear and nonlinear propagation of low frequency (ω≪Ω{sub ci}) electrostatic waves have been studied in a spatially inhomogeneous degenerate plasma with one dimensional electron trapping in the presence of a quantizing magnetic field and finite temperature effects. Using the drift approximation, formation of 1 and 2D drift ion solitary structures have been studied both for fully and partially degenerate plasmas. The theoretical results obtained have been analyzed numerically for the parameters typically found in white dwarfs for illustrative purpose. It is observed that the inclusion of Landau quantization significantly changes the expression of the electron number density of a dense degenerate plasma which affects the linear and nonlinear propagation of drift acoustic solitary waves in such a system. The present work may be beneficial to understand the propagation of drift solitary structures with weak transverse perturbation in a variety of physical situations, such as white dwarfs and laser-induced plasmas, where the quantum effects are expected to dominate.

  13. A fast spatial scanning combination emissive and mach probe for edge plasma diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Lehmer, R.D.; LaBombard, B.; Conn, R.W.

    1989-04-01

    A fast spatially scanning emissive and mach probe has been developed for the measurement of plasma profiles in the PISCES facility at UCLA. A pneumatic cylinder is used to drive a multiple tip probe along a 15cm stroke in less than 400msec, giving single shot profiles while limiting power deposition to the probe. A differentially pumped sliding O-ring seal allows the probe to be moved between shots to infer two and three dimensional profiles. The probe system has been used to investigate the plasma potential, density, and parallel mach number profiles of the presheath induced by a wall surface and scrape-off-layer profile modifications in biased limiter simulation experiments. Details of the hardware, data acquisition electronics, and tests of probe reliability are discussed. 30 refs., 24 figs.

  14. Gas Diffusion Barriers Prepared by Spatial Atmospheric Pressure Plasma Enhanced ALD.

    Science.gov (United States)

    Hoffmann, Lukas; Theirich, Detlef; Pack, Sven; Kocak, Firat; Schlamm, Daniel; Hasselmann, Tim; Fahl, Henry; Räupke, André; Gargouri, Hassan; Riedl, Thomas

    2017-02-01

    In this work, we report on aluminum oxide (Al2O3) gas permeation barriers prepared by spatial ALD (SALD) at atmospheric pressure. We compare the growth characteristics and layer properties using trimethylaluminum (TMA) in combination with an Ar/O2 remote atmospheric pressure plasma for different substrate velocities and different temperatures. The resulting Al2O3 films show ultralow water vapor transmission rates (WVTR) on the order of 10(-6) gm(-2)d(-1). In notable contrast, plasma based layers already show good barrier properties at low deposition temperatures (75 °C), while water based processes require a growth temperature above 100 °C to achieve equally low WVTRs. The activation energy for the water permeation mechanism was determined to be 62 kJ/mol.

  15. Multispectral image sharpening using wavelet transform techniques and spatial correlation of edges

    Science.gov (United States)

    Lemeshewsky, George P.; Schowengerdt, Robert A.

    2000-01-01

    Several reported image fusion or sharpening techniques are based on the discrete wavelet transform (DWT). The technique described here uses a pixel-based maximum selection rule to combine respective transform coefficients of lower spatial resolution near-infrared (NIR) and higher spatial resolution panchromatic (pan) imagery to produce a sharpened NIR image. Sharpening assumes a radiometric correlation between the spectral band images. However, there can be poor correlation, including edge contrast reversals (e.g., at soil-vegetation boundaries), between the fused images and, consequently, degraded performance. To improve sharpening, a local area-based correlation technique originally reported for edge comparison with image pyramid fusion is modified for application with the DWT process. Further improvements are obtained by using redundant, shift-invariant implementation of the DWT. Example images demonstrate the improvements in NIR image sharpening with higher resolution pan imagery.

  16. Plasma boronizing of Ti6AlV4 using solid precursors by double glow plasma alloying technique

    Institute of Scientific and Technical Information of China (English)

    QIN Lin; QU Jun-zhi; LIN Nai-ming; FAN Ai-lan; CHANG Da-qing; TANG Bin

    2006-01-01

    Solid state B-offerings (FeB compound) were used for plasma-assisted boronizing on Ti6Al4V alloy by double glow discharge plasma alloying technique (DGPSA). During all experiment processing there was no harmful and toxic. The thickness and morphology, phase formation, elements concentrations and wear properties of boride layers were examined by means of optical microscopy, Vickers microhardness, X-ray diffraction, glow discharge optical emission spectroscopy and Ball-disk wear tests. The results show that friction coefficient of boride alloying samples versus corundum ball is lower than that of Ti6Al4V samples, as well as wear rate. This indicates that plasma-assisted boronizing of Ti6Al4V alloy has a high potential for industrial applications under tribological conditions.

  17. Comparative proteomics evaluation of plasma exosome isolation techniques and assessment of the stability of exosomes in normal human blood plasma.

    Science.gov (United States)

    Kalra, Hina; Adda, Christopher G; Liem, Michael; Ang, Ching-Seng; Mechler, Adam; Simpson, Richard J; Hulett, Mark D; Mathivanan, Suresh

    2013-11-01

    Exosomes are nanovesicles released by a variety of cells and are detected in body fluids including blood. Recent studies have highlighted the critical application of exosomes as personalized targeted drug delivery vehicles and as reservoirs of disease biomarkers. While these research applications have created significant interest and can be translated into practice, the stability of exosomes needs to be assessed and exosome isolation protocols from blood plasma need to be optimized. To optimize methods to isolate exosomes from blood plasma, we performed a comparative evaluation of three exosome isolation techniques (differential centrifugation coupled with ultracentrifugation, epithelial cell adhesion molecule immunoaffinity pull-down, and OptiPrep(TM) density gradient separation) using normal human plasma. Based on MS, Western blotting and microscopy results, we found that the OptiPrep(TM) density gradient method was superior in isolating pure exosomal populations, devoid of highly abundant plasma proteins. In addition, we assessed the stability of exosomes in plasma over 90 days under various storage conditions. Western blotting analysis using the exosomal marker, TSG101, revealed that exosomes are stable for 90 days. Interestingly, in the context of cellular uptake, the isolated exosomes were able to fuse with target cells revealing that they were indeed biologically active.

  18. Investigation of the local thermodynamic equilibrium of laser-induced aluminum plasma by Thomson scattering technique

    Energy Technology Data Exchange (ETDEWEB)

    Mendys, A., E-mail: agata.mendys@uj.edu.pl [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland); Kański, M. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland); Farah-Sougueh, A. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland); GREMI — site de Bourges, Université d' Orléans, CNRS, rue Gaston Berger BP 4043, 18028 Bourges (France); Pellerin, S. [GREMI — site de Bourges, Université d' Orléans, CNRS, rue Gaston Berger BP 4043, 18028 Bourges (France); Pokrzywka, B. [Obserwatorium Astronomiczne na Suhorze, Uniwersytet Pedagogiczny, ul. Podchorażych 2, 30-084 Kraków (Poland); Dzierżęga, K. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland)

    2014-06-01

    A laser Thomson scattering method was applied to investigate the local Saha–Boltzmann equilibrium in aluminum laser-induced plasma. Plasma was created in ambient air using 4.5 ns pulses from a Nd:YAG laser at 532 nm, focused on an Al target. Spatially resolved measurements, performed for the time interval between 600 ns and 3 μs, show electron density and temperature to decrease from 3.4 × 10{sup 23} m{sup −3} to 0.5 × 10{sup 23} m{sup −3} and from 61,000 K to 13,000 K in the plasma core. The existence of local thermodynamic equilibria in the plasma was verified by comparing the rates of the collisional to radiative processes (the McWhirter criterion), as well as relaxation times and diffusion lengths of different plasma species, with the appropriate rate of electron density evolution and its gradients at given, experimentally determined, electron temperatures. We found these criteria to be much easier to satisfy for metallic plasma species than for nitrogen. The criteria are also easier to satisfy in the plasma core of higher electron density. - Highlights: • Laser Thomson scattering method was applied to investigate aluminum laser-induced plasma. • Spatio-temporal evolution of electron temperature and density was determined. • Three criteria for existence of local thermodynamic equilibrium were verified. • Criteria are much easier to satisfy for metallic plasma species than for nitrogen. • Criteria are easier to satisfy at earlier times and in the plasma core.

  19. Preionization Techniques in a kJ-Scale Dense Plasma Focus

    Science.gov (United States)

    Povilus, Alexander; Shaw, Brian; Chapman, Steve; Podpaly, Yuri; Cooper, Christopher; Falabella, Steve; Prasad, Rahul; Schmidt, Andrea

    2016-10-01

    A dense plasma focus (DPF) is a type of z-pinch device that uses a high current, coaxial plasma gun with an implosion phase to generate dense plasmas. These devices can accelerate a beam of ions to MeV-scale energies through strong electric fields generated by instabilities during the implosion of the plasma sheath. The formation of these instabilities, however, relies strongly on the history of the plasma sheath in the device, including the evolution of the gas breakdown in the device. In an effort to reduce variability in the performance of the device, we attempt to control the initial gas breakdown in the device by seeding the system with free charges before the main power pulse arrives. We report on the effectiveness of two techniques developed for a kJ-scale DPF at LLNL, a miniature primer spark gap and pulsed, 255nm LED illumination. Prepared by LLNL under Contract DE-AC52-07NA27344.

  20. Plasma-polymerized hexamethyldisilazane treated by nitrogen plasma immersion ion implantation technique

    Energy Technology Data Exchange (ETDEWEB)

    Honda, R Y; Mota, R P; Batocki, R G S; Santos, D C R; Nicoleti, T; Kostov, K G; Kayama, M E; Algatti, M A [Laboratorio de Plasma, Faculdade de Engenharia, UNESP, Av. Dr Ariberto Pereira da Cunha-333, 12516-410, Guaratingueta, SP (Brazil); Cruz, N C [Laboratorio de Plasmas Tecnologicos, Unidade Diferenciada, UNESP, Av. Tres de Marco-511, 18085-180, Sorocaba, SP (Brazil); Ruggiero, L, E-mail: honda@feg.unesp.b [Faculdade de Ciencias, UNESP, Av. Luis E. Carrijo Coube 14-1, 17033-360, Bauru, SP (Brazil)

    2009-05-01

    This paper describes the effect of nitrogen Plasma Immersion Ion Implantation (PIII) on chemical structure, refraction index and surface hardness of plasma-polymerized hexamethyldisilazane (PPHMDSN) thin films. Firstly, polymeric films were deposited at 13.56 MHz radiofrequency (RF) Plasma Enhanced Chemical Vapour Deposition (PECVD) and then, were treated by nitrogen PIII from 15 to 60 min. Fourier Transformed Infrared (FTIR) spectroscopy was employed to analyse the molecular structure of the samples, and it revealed that vibrations modes at 3350 cm{sup -1}, 2960 cm{sup -1}, 1650 cm{sup -1}, 1250 cm{sup -1} and 1050 cm{sup -1} were altered by nitrogen PIII. Visible-ultraviolet (vis-UV) spectroscopy was used to evaluate film refractive index and the results showed a slight increase from 1.6 to 1.8 following the implantation time. Nanoindentation revealed a surface hardness rise from 0.5 to 2.3 GPa as PIII treatment time increased. These results indicate nitrogen PIII is very promising in improving optical and mechanical properties of PPHMDSN films.

  1. Impact localization for a composite plate using the spatial focusing properties of advanced signal processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyunjo; Cho, Sungjong [Wonkwang Univ., Iksan (Korea, Republic of)

    2012-12-15

    A structural health monitoring technique for locating impact position in a composite plate is presented in this paper. The method employs a single sensor and spatial focusing properties of time reversal(TR) and inverse filtering(IF). We first examine the spatial focusing efficiency of both approaches at the impact position and its surroundings through impact experiments. The imaging results of impact localization show that the impact location can be accurately estimated in any position of the plate. Compared to existing techniques for locating impact or acoustic emission source, the proposed method has the benefits of using a single sensor and not requiring knowledge of anisotropic material properties and geometry of structures. Furthermore, it does not depend on a particular mode of dispersive Lamb waves that is frequently used in other ultrasonic testing of plate like structures.

  2. Mass spectrometry based imaging techniques for spatially resolved analysis of molecules

    Directory of Open Access Journals (Sweden)

    Andrea eMatros

    2013-04-01

    Full Text Available Higher plants are composed of a multitude of tissues with specific functions, reflected by distinct profiles for transcripts, proteins and metabolites. Comprehensive analysis of metabolites and proteins has advanced tremendously within recent years, and this progress has been driven by the rapid development of sophisticated mass spectrometrical techniques. In most of the current omics-studies, analysis is performed on whole organ or whole plant extracts, rendering to the loss of spatial information. Mass spectrometry based imaging (MSI techniques have opened a new avenue to obtain information on the spatial distribution of metabolites and of proteins. Pioneered in the field of medicine, the approaches are now applied to study the spatial profiles of molecules in plant systems. A range of different plant organs and tissues have been successfully analyzed by MSI, and patterns of various classes of metabolites from primary and secondary metabolism could be obtained. It can be envisaged that MSI approaches will substantially contribute to build spatially resolved biochemical networks.

  3. Portable (handheld) clinical device for quantitative spectroscopy of skin, utilizing spatial frequency domain reflectance techniques

    Science.gov (United States)

    Saager, Rolf B.; Dang, An N.; Huang, Samantha S.; Kelly, Kristen M.; Durkin, Anthony J.

    2017-09-01

    Spatial Frequency Domain Spectroscopy (SFDS) is a technique for quantifying in-vivo tissue optical properties. SFDS employs structured light patterns that are projected onto tissues using a spatial light modulator, such as a digital micromirror device. In combination with appropriate models of light propagation, this technique can be used to quantify tissue optical properties (absorption, μa, and scattering, μs', coefficients) and chromophore concentrations. Here we present a handheld implementation of an SFDS device that employs line (one dimensional) imaging. This instrument can measure 1088 spatial locations that span a 3 cm line as opposed to our original benchtop SFDS system that only collects a single 1 mm diameter spot. This imager, however, retains the spectral resolution (˜1 nm) and range (450-1000 nm) of our original benchtop SFDS device. In the context of homogeneous turbid media, we demonstrate that this new system matches the spectral response of our original system to within 1% across a typical range of spatial frequencies (0-0.35 mm-1). With the new form factor, the device has tremendously improved mobility and portability, allowing for greater ease of use in a clinical setting. A smaller size also enables access to different tissue locations, which increases the flexibility of the device. The design of this portable system not only enables SFDS to be used in clinical settings but also enables visualization of properties of layered tissues such as skin.

  4. Regional flood frequency analysis using spatial proximity and basin characteristics: Quantile regression vs. parameter regression technique

    Science.gov (United States)

    Ahn, Kuk-Hyun; Palmer, Richard

    2016-09-01

    Despite wide use of regression-based regional flood frequency analysis (RFFA) methods, the majority are based on either ordinary least squares (OLS) or generalized least squares (GLS). This paper proposes 'spatial proximity' based RFFA methods using the spatial lagged model (SLM) and spatial error model (SEM). The proposed methods are represented by two frameworks: the quantile regression technique (QRT) and parameter regression technique (PRT). The QRT develops prediction equations for flooding quantiles in average recurrence intervals (ARIs) of 2, 5, 10, 20, and 100 years whereas the PRT provides prediction of three parameters for the selected distribution. The proposed methods are tested using data incorporating 30 basin characteristics from 237 basins in Northeastern United States. Results show that generalized extreme value (GEV) distribution properly represents flood frequencies in the study gages. Also, basin area, stream network, and precipitation seasonality are found to be the most effective explanatory variables in prediction modeling by the QRT and PRT. 'Spatial proximity' based RFFA methods provide reliable flood quantile estimates compared to simpler methods. Compared to the QRT, the PRT may be recommended due to its accuracy and computational simplicity. The results presented in this paper may serve as one possible guidepost for hydrologists interested in flood analysis at ungaged sites.

  5. Suitability of the RGB Channels for a Pixel Manipulation in a Spatial Domain Data Hiding Techniques

    Directory of Open Access Journals (Sweden)

    Ante Poljicak

    2010-06-01

    Full Text Available The aim of this research was to determine which channel in rgb color space is the most suitable (regarding perceptibility for a pixel manipulation in a spatial domain data  hiding techniques. For this purpose three custom test targets were generated. The research also shows the behavior of two closely related colors in the ps (Print-Scan process. The results are interpreted using both a quantitative method (statistical comparison and a qualitative method (visual comparison.

  6. Suitability of the rgb Channels for a Pixel Manipulation in a Spatial Domain Data Hiding Techniques

    Directory of Open Access Journals (Sweden)

    Lidija Mandić

    2010-01-01

    Full Text Available The aim of this research was to determine which channel in rgb color space is the most suitable (regarding perceptibility for a pixel manipulation in a spatial domain data hiding techniques. For this purpose three custom test targets were generated. The research also shows the behavior of two closely related colors in the ps (Print-Scan process. The results are interpreted using both a quantitative method (statistical comparison and a qualitative method (visual comparison.

  7. Development of plasma assisted thermal vapor deposition technique for high-quality thin film

    Science.gov (United States)

    Lee, Kang-Il; Choi, Yong Sup; Park, Hyun Jae

    2016-12-01

    The novel technique of Plasma-Assisted Vapor Deposition (PAVD) is developed as a new deposition method for thin metal films. The PAVD technique yields a high-quality thin film without any heating of the substrate because evaporated particles acquire energy from plasma that is confined to the inside of the evaporation source. Experiments of silver thin film deposition have been carried out in conditions of pressure lower than 10-3 Pa. Pure silver plasma generation is verified by the measurement of the Ag-I peak using optical emission spectroscopy. A four point probe and a UV-VIS spectrophotometer are used to measure the electrical and optical properties of the silver film that is deposited by PAVD. For an ultra-thin silver film with a thickness of 6.5 nm, we obtain the result of high-performance silver film properties, including a sheet resistance 75%. The PAVD-film properties show a low sheet resistance of 30% and the same transmittance with conventional thermal evaporation film. In the PAVD source, highly energetic particles and UV from plasma do not reach the substrate because the plasma is completely shielded by the optimized nozzle of the crucible. This new PAVD technique could be a realistic solution to improve the qualities of transparent electrodes for organic light emission device fabrication without causing damage to the organic layers.

  8. Synthesis and Characterization of Nanofibrous Polyaniline Thin Film Prepared by Novel Atmospheric Pressure Plasma Polymerization Technique

    Directory of Open Access Journals (Sweden)

    Choon-Sang Park

    2016-01-01

    Full Text Available This work presents a study on the preparation of plasma-polymerized aniline (pPANI nanofibers and nanoparticles by an intense plasma cloud type atmospheric pressure plasma jets (iPC-APPJ device with a single bundle of three glass tubes. The nano size polymer was obtained at a sinusoidal wave with a peak value of 8 kV and a frequency of 26 kHz under ambient air. Discharge currents, photo-sensor amplifier, and optical emission spectrometer (OES techniques were used to analyze the plasma produced from the iPC-APPJ device. Field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, gas chromatography-mass spectrometry (GC-MS, and gel permeation chromatography (GPC techniques were used to analyze the pPANI. FE-SEM and TEM results show that pPANI has nanofibers, nanoparticles morphology, and polycrystalline characteristics. The FT-IR and GC-MS analysis show the characteristic polyaniline peaks with evidence that some quinone and benzene rings are broken by the discharge energy. GPC results show that pPANI has high molecular weight (Mw, about 533 kDa with 1.9 polydispersity index (PDI. This study contributes to a better understanding on the novel growth process and synthesis of uniform polyaniline nanofibers and nanoparticles with high molecular weights using the simple atmospheric pressure plasma polymerization technique.

  9. Dry-plasma-free chemical etch technique for variability reduction in multi-patterning (Conference Presentation)

    Science.gov (United States)

    Kal, Subhadeep; Mohanty, Nihar; Farrell, Richard A.; Franke, Elliott; Raley, Angelique; Thibaut, Sophie; Pereira, Cheryl; Pillai, Karthik; Ko, Akiteru; Mosden, Aelan; Biolsi, Peter

    2017-04-01

    Scaling beyond the 7nm technology node demands significant control over the variability down to a few angstroms, in order to achieve reasonable yield. For example, to meet the current scaling targets it is highly desirable to achieve sub 30nm pitch line/space features at back-end of the line (BEOL) or front end of line (FEOL); uniform and precise contact/hole patterning at middle of line (MOL). One of the quintessential requirements for such precise and possibly self-aligned patterning strategies is superior etch selectivity between the target films while other masks/films are exposed. The need to achieve high etch selectivity becomes more evident for unit process development at MOL and BEOL, as a result of low density films choices (compared to FEOL film choices) due to lower temperature budget. Low etch selectivity with conventional plasma and wet chemical etch techniques, causes significant gouging (un-intended etching of etch stop layer, as shown in Fig 1), high line edge roughness (LER)/line width roughness (LWR), non-uniformity, etc. In certain circumstances this may lead to added downstream process stochastics. Furthermore, conventional plasma etches may also have the added disadvantage of plasma VUV damage and corner rounding (Fig. 1). Finally, the above mentioned factors can potentially compromise edge placement error (EPE) and/or yield. Therefore a process flow enabled with extremely high selective etches inherent to film properties and/or etch chemistries is a significant advantage. To improve this etch selectivity for certain etch steps during a process flow, we have to implement alternate highly selective, plasma free techniques in conjunction with conventional plasma etches (Fig 2.). In this article, we will present our plasma free, chemical gas phase etch technique using chemistries that have high selectivity towards a spectrum of films owing to the reaction mechanism ( as shown Fig 1). Gas phase etches also help eliminate plasma damage to the

  10. Detection of Burn Area and Severity with MODIS Satellite Images and Spatial Autocorrelation Techniques

    Science.gov (United States)

    Kaya, S.; Kavzoglu, T.; Tonbul, H.

    2014-12-01

    Effects of forest fires and implications are one of the most important natural disasters all over the world. Statistical data observed that forest fires had a variable structure in the last century in Turkey, but correspondingly the population growth amount of forest fires and burn area increase widely in recent years. Depending on this, erosion, landslides, desertification and mass loss come into existence. In addition; after forest fires, renewal of forests and vegetation are very important for land management. Classic methods used for detection of burn area and severity requires a long and challenging process due to time and cost factors. Thanks to advanced techniques used in the field of Remote Sensing, burn area and severity can be determined with high detail and precision. The purpose of this study based on blending MODIS (Moderate Resolution Imaging Spectradiometer) satellite images and spatial autocorrelation techniques together, thus detect burn area and severity absolutely. In this context, spatial autocorrelation statistics like Moran's I and Get is-Ord Local Gi indexes were used to measure and analyze to burned area characteristics. Prefire and postfire satellite images were used to determine fire severity depending on spectral indexes corresponding to biomass loss and carbon emissivity intensities. Satellite images have used for identification of fire damages and risks in terms of fire management for a long time. This study was performed using prefire and postfire satellite images and spatial autocorrelation techniques to determining and analyzing forest fires in Antalya, Turkey region which serious fires occurred. In this context, this approach enables the characterization of distinctive texture of burned area and helps forecasting more precisely. Finally, it is observed that mapping of burned area and severity could be performed from local scale to national scale. Key Words: Spatial autocorrelation, MODIS, Fire, Burn Severity

  11. Spatially resolved optical-emission spectroscopy of a radio-frequency driven iodine plasma source

    Science.gov (United States)

    Dedrick, James; Doyle, Scott; Grondein, Pascaline; Aanesland, Ane

    2016-09-01

    Iodine is of interest for potential use as a propellant for spacecraft propulsion, and has become attractive as a replacement to xenon due to its similar mass and ionisation potential. Optical emission spectroscopy has been undertaken to characterise the emission from a low-pressure, radio-frequency driven inductively coupled plasma source operating in iodine with respect to axial distance across its transverse magnetic filter. The results are compared with axial profiles of the electron temperature and density for identical source conditions, and the spatial distribution of the emission intensity is observed to be closely correlated with the electron temperature. This work has been done within the LABEX Plas@Par project, and received financial state aid managed by the ``Agence Nationale de la Recherche'', as part of the ``Programme d'Investissements d'Avenir'' under the reference ANR-11-IDEX-0004-02.

  12. A Movable Mass Spectroscopy Sampling Apparatus for Measuring Spatial Distribution of Neutral Radicals in Silane Plasma

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao-Kui; LIN Kui-Xun; LIN Xuan-Ying; QIU Gui-Ming; ZHU Zu-Song

    2005-01-01

    @@ A movable mass spectroscopy gas sampling apparatus has been established and a straight-line fit ofsilane depletion fraction f is proposed.The spatial density distributions of SiHn (n = 0-3) radicals in silane radio frequency glow discharge have been measured by a mass spectrometer.The experimental results demonstrate that the densities of the neutral radicals have the peak value near the middle position of electrodes, and the densities of SiH2 and SiHs are higher than those of Si and SiH in silane plasma.This reveals that SiH2 and SiH3 may be the primary precursors in forming the a-Si:H film.

  13. A new method of measuring the spatial distribution of depletion fraction of silane plasma by mass spectrometer

    Institute of Scientific and Technical Information of China (English)

    Wang Zhao-Kui; Lin Kui-Xun; Lin Xuan-Ying; Qiu Gui-Ming; Zhu Zu-Song

    2005-01-01

    A newly established movable sampling apparatus of mass spectrometer is used to measure the spatial distribution of depletion fraction of silane plasma. A straight-line fit method of deducing the depletion fraction of silane is proposed.Theoretical analysis and test results demonstrate that the proposed new method is universal and more accurate than the existing one. There exist a largest peak near the middle of two electrodes and two peaks near the electrodes in the spatial distribution of silane depletion fraction, which are related to the distribution of electric field and the silane plasma sheaths.

  14. Tracer techniques for the assessment of material migration and surface modification of plasma-facing components

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, M., E-mail: rubel@kth.se [Department of Fusion Plasma Physics, Royal Institute of Technology, 100 44 Stockholm (Sweden); Weckmann, A.; Ström, P.; Petersson, P.; Garcia-Carrasco, A. [Department of Fusion Plasma Physics, Royal Institute of Technology, 100 44 Stockholm (Sweden); Brezinsek, S.; Coenen, J.; Kreter, A.; Möller, S.; Wienhold, P. [Institute of Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Wauters, T. [LPP-ERM/KMS, Association EURATOM-Belgian State, 1000 Brussels (Belgium); Fortuna-Zaleśna, E. [Faculty of Materials Science, Warsaw University of Technology, 02-507 Warsaw (Poland)

    2015-08-15

    Highlights: • Tracer techniques were used in the TEXTOR tokamak to determine high-Z metal migration and the retention of species used for plasma edge cooling or wall cleaning under different operation conditions. • Volatile molybdenum hexa-fluoride, nitrogen-15 and oxygen-18 were used as markers in tokamak or ion cyclotron wall conditioning discharges (ICWC). • The objective was to obtain qualitative and quantitative of a global and local deposition pattern and material mixing effects. • The deposition and retention was studied on plasma-facing components, collector probes and test limiters. • Optical spectroscopy and ex-situ analysis techniques were used to determine the plasma response to tracer injection and surface composition modification. - Abstract: Tracer techniques were used in the TEXTOR tokamak to determine high-Z metal migration and the deposition of species used for plasma edge cooling or wall conditioning under different types of operation conditions. Volatile molybdenum hexa-fluoride, nitrogen-15 and oxygen-18 were used as markers in tokamak or ion cyclotron wall conditioning discharges (ICWC). The objective was to obtain qualitative and quantitative of a global and local deposition pattern and material mixing effects. The deposition and retention was studied on plasma-facing components, collector probes and test limiters. Optical spectroscopy and ex-situ analysis techniques were used to determine the plasma response to tracer injection and the modification of surface composition. Molybdenum and light isotopes were detected on all types of limiters and short-term probes retrieved from the vessel showing that both helium and nitrogen are trapped following wall conditioning and edge cooling. Only small amounts below 1 × 10{sup 19} m{sup −2} of {sup 18}O were detected on surfaces treated by oxygen-assisted ICWC.

  15. Stable spatial Langmuir solitons as a model of long-lived atmospheric plasma structures

    CERN Document Server

    Dvornikov, Maxim

    2014-01-01

    I study stable spatial Langmuir solitons in plasma based on nonlinear radial oscillations of charged particles. I discuss two situations when a Langmuir soliton can be stable. In the former case the stability of solitons against the collapse is due to electron-electron interactions which result in the nonlocal terms in the nonlinear Schr\\"{o}dinger equation. In the latter situation I derive the new cubic-quintic nonlinear Schr\\"{o}dinger equation with accounts for the interaction of induced dipole moments of diatomic ions with a rapidly oscillating electric field and show that the collapse of Langmuir waves can be also arrested. In both cases I find the numerical solutions of the nonlinear Schr\\"{o}dinger equation and analyze their stability using the Vakhitov-Kolokolov criterion. I discuss the application of my results for the description of long-lived atmospheric plasma structures. I show that, using my model, one can explain the existence of atmospheric plasmoids in the upper ionosphere. It is also demonst...

  16. Spatial and temporal characteristics of a vacuum-arc rail-gun plasma

    Science.gov (United States)

    Roychowdhury, P.; Vijayan, T.; Iyengar, S. T.

    1997-08-01

    The dynamics of a vacuum-arc operated rail-gun plasma were numerically simulated for the undercritically damped regime and confirmed in experiments. Analytical solutions of arc current, its velocity, and position also showed good agreement with the results. The spatial development of the arc is shown here to follow a linear behavior, even though the propulsion velocity followed an exponential-step function due to the sinusoidal nature of the arc current. Peak arc current ˜100 kA, 15 μs period was propelled to ˜106 cm/s as indicated in time-of-flight measurements and simulations. The voltage signal induced on a B-dot probe by the dynamic sinusoidal arc was simulated, which compared well with the measured probe signal. A Gaussian current distribution inside the measured arc length ˜1-2 cm, was established by unfolding the B-dot probe signal. A peak magnetic field of the order 1-5 kG was also interpreted inside the arc. The emerging plasma contained ion current over tens of amperes in the pulse duration encompassing the arc envelope.

  17. Evaluating spatial- and temporal-oriented multi-dimensional visualization techniques

    Directory of Open Access Journals (Sweden)

    Chong Ho Yu

    2003-07-01

    Full Text Available Visualization tools are said to be helpful for researchers to unveil hidden patterns and..relationships among variables, and also for teachers to present abstract statistical concepts and..complicated data structures in a concrete manner. However, higher-dimension visualization..techniques can be confusing and even misleading, especially when human-instrument interface..and cognitive issues are under-applied. In this article, the efficacy of function-based, datadriven,..spatial-oriented, and temporal-oriented visualization techniques are discussed based..upon extensive review. Readers can find practical implications for both research and..instructional practices. For research purposes, the spatial-based graphs, such as Trellis displays..in S-Plus, are preferable over the temporal-based displays, such as the 3D animated plot in..SAS/Insight. For teaching purposes, the temporal-based displays, such as the 3D animation plot..in Maple, seem to have advantages over the spatial-based graphs, such as the 3D triangular..coordinate plot in SyStat.

  18. Remote sensing and spatial statistical techniques for modelling Ommatissus lybicus (Hemiptera: Tropiduchidae) habitat and population densities.

    Science.gov (United States)

    Al-Kindi, Khalifa M; Kwan, Paul; R Andrew, Nigel; Welch, Mitchell

    2017-01-01

    In order to understand the distribution and prevalence of Ommatissus lybicus (Hemiptera: Tropiduchidae) as well as analyse their current biographical patterns and predict their future spread, comprehensive and detailed information on the environmental, climatic, and agricultural practices are essential. The spatial analytical techniques such as Remote Sensing and Spatial Statistics Tools, can help detect and model spatial links and correlations between the presence, absence and density of O. lybicus in response to climatic, environmental, and human factors. The main objective of this paper is to review remote sensing and relevant analytical techniques that can be applied in mapping and modelling the habitat and population density of O. lybicus. An exhaustive search of related literature revealed that there are very limited studies linking location-based infestation levels of pests like the O. lybicus with climatic, environmental, and human practice related variables. This review also highlights the accumulated knowledge and addresses the gaps in this area of research. Furthermore, it makes recommendations for future studies, and gives suggestions on monitoring and surveillance methods in designing both local and regional level integrated pest management strategies of palm tree and other affected cultivated crops.

  19. Spatial and temporal air quality pattern recognition using environmetric techniques: a case study in Malaysia.

    Science.gov (United States)

    Syed Abdul Mutalib, Sharifah Norsukhairin; Juahir, Hafizan; Azid, Azman; Mohd Sharif, Sharifah; Latif, Mohd Talib; Aris, Ahmad Zaharin; Zain, Sharifuddin M; Dominick, Doreena

    2013-09-01

    The objective of this study is to identify spatial and temporal patterns in the air quality at three selected Malaysian air monitoring stations based on an eleven-year database (January 2000-December 2010). Four statistical methods, Discriminant Analysis (DA), Hierarchical Agglomerative Cluster Analysis (HACA), Principal Component Analysis (PCA) and Artificial Neural Networks (ANNs), were selected to analyze the datasets of five air quality parameters, namely: SO2, NO2, O3, CO and particulate matter with a diameter size of below 10 μm (PM10). The three selected air monitoring stations share the characteristic of being located in highly urbanized areas and are surrounded by a number of industries. The DA results show that spatial characterizations allow successful discrimination between the three stations, while HACA shows the temporal pattern from the monthly and yearly factor analysis which correlates with severe haze episodes that have happened in this country at certain periods of time. The PCA results show that the major source of air pollution is mostly due to the combustion of fossil fuel in motor vehicles and industrial activities. The spatial pattern recognition (S-ANN) results show a better prediction performance in discriminating between the regions, with an excellent percentage of correct classification compared to DA. This study presents the necessity and usefulness of environmetric techniques for the interpretation of large datasets aiming to obtain better information about air quality patterns based on spatial and temporal characterizations at the selected air monitoring stations.

  20. A spatial bootstrap technique for parameter estimation of rainfall annual maxima distribution

    Directory of Open Access Journals (Sweden)

    F. Uboldi

    2013-09-01

    Full Text Available Estimation of extreme event distributions and depth-duration-frequency (DDF curves is achieved at any target site by repeated sampling among all available raingauge data in the surrounding area. The estimate is computed over a gridded domain in Northern Italy, using precipitation time series from 1929 to 2011, including data from historical analog stations and from the present-day automatic observational network. The presented local regionalisation naturally overcomes traditional station-point methods, with their demand of long historical series and their sensitivity to very rare events occurring at very few stations, possibly causing unrealistic spatial gradients in DDF relations. At the same time, the presented approach allows for spatial dependence, necessary in a geographical domain such as Lombardy, complex for both its topography and its climatology. The bootstrap technique enables evaluating uncertainty maps for all estimated parameters and for rainfall depths at assigned return periods.

  1. Spatial Planning of Rural tourism with MAPPAC technique. Case study Khur and Biabanak County, (Iran

    Directory of Open Access Journals (Sweden)

    Hassan Ali Faraji Sabokbar

    2014-12-01

    Full Text Available Reviewing the concepts of space and tourism industry, tourism is in an old, deep, unbreakable bound with spatial and physical dimensions. In this way, the lack of systematic and scientific ranking process in spatial locating of rural tourism spots and also improper distribution of infrastructures are the critical deficiencies in this field. The research intends to introduce the hidden potentials and unique capabilities of Khur and Biabanak County, Iran. And prioritize their tourism spots. So tourism planners would be able to recognize proper space distribution. First, the weights of each criterion were calculated by a pairwise comparison questionnaire of AHP method, and MAPPAC technique was used for ranking. AHP was done in Expert Choice software and MAPPAC in MS Excel. Results showed that villages such as Bayaze, Jandagh, Mehrejan, Garmeh, and Iraj which are also older have a higher rank.

  2. Microwave techniques for electron density measurements in low pressure RF plasmas

    Science.gov (United States)

    Zheltukhin, Viktor; Gafarov, Ildar; Shemakhin, Alexander

    2016-09-01

    Results of the experimental studying of RF plasma jet at low pressure in the range of 10 - 300 Pa is presented. The electron density distribution both in inductive and in capacitive coupled RF discharges was measured at 1.76 MHz and 13.56 MHz consequently. We used three independent microwave diagnostic techniques such as free space (the ``two-frequency'' and ``on the cut-off signal'') and a resonator. It is found that the electron density in the RF plasma jets is by 1-2 orders of magnitude greater than in the decaying plasma jet, and by 1-2 orders of magnitude less than in the RF plasma torch. Thus the RF plasma jet is similar to the additional discharge between the electrodes or the coil and the vacuum chamber walls. As a consequence, the formation of the positive charge sheath near the specimen placed in plasma stream is observed. It is found that the maximum of ionization degree as well as more uniform electron density distribution across the stream is observed in the range of the gas flow rate Gg = 0 . 06 - 0 . 12 g/s and the discharge power Pd = 0 . 5 - 2 . 5 kW. The work was funded by RFBR, according to the research projects No. 16-31-60081 mol_a_dk.

  3. Application of plasma surface modification techniques to improve hemocompatibility of vascular grafts: A review.

    Science.gov (United States)

    Solouk, Atefeh; Cousins, Brian G; Mirzadeh, Hamid; Seifalian, Alexander M

    2011-01-01

    Surface modification using plasma processing can significantly change the chemical and physical characteristics of biomaterial surfaces. When used in combination with additional modification techniques such as direct chemical or biochemical methods, it can produce novel biomaterial surfaces, which are anticoagulant, bioactive, and biomimetic in nature. This article reviews recent advances in improving hemocompatibility of biomaterials by plasma surface modification (PSM). The focus of this review is on PSM of the most commonly used polymers for vascular prostheses such as expanded polytetrafluoroethylene (PTFE), polyethylene terephthalate (Dacron(®) ), and next generation of biomaterials, including polyhedral oligomeric silsesquioxane nanocomposite.

  4. Evaluation of spatial and temporal variations in marine sediments quality using multivariate statistical techniques.

    Science.gov (United States)

    Alvarez, Odalys Quevedo; Tagle, Margarita Edelia Villanueva; Pascual, Jorge L Gómez; Marín, Ma Teresa Larrea; Clemente, Ana Catalina Nuñez; Medina, Miriam Odette Cora; Palau, Raiza Rey; Alfonso, Mario Simeón Pomares

    2014-10-01

    Spatial and temporal variations of sediment quality in Matanzas Bay (Cuba) were studied by determining a total of 12 variables (Zn, Cu, Pb, As, Ni, Co, Al, Fe, Mn, V, CO₃²⁻, and total hydrocarbons (THC). Surface sediments were collected, annually, at eight stations during 2005-2008. Multivariate statistical techniques, such as principal component (PCA), cluster (CA), and lineal discriminant (LDA) analyses were applied for identification of the most significant variables influencing the environmental quality of sediments. Heavy metals (Zn, Cu, Pb, V, and As) and THC were the most significant species contributing to sediment quality variations during the sampling period. Concentrations of V and As were determined in sediments of this ecosystem for the first time. The variation of sediment environmental quality with the sampling period and the differentiation of samples in three groups along the bay were obtained. The usefulness of the multivariate statistical techniques employed for the environmental interpretation of a limited dataset was confirmed.

  5. Development of a novel plasma scanning technique for high-quality anodic bonding

    Science.gov (United States)

    Wu, Jim-Wei; Yang, Chii-Rong; Huang, Che-Yi

    2016-04-01

    Anodic bonding is a type of nonintermediate wafer bonding technique that has been widely used in microelectromechanical systems for sealing devices or assembling microstructures. However, the conventional anodic bonding method has a limitation. The specimens being bonded must typically be in contact with the anode and cathode electrodes during the bonding process. In general, the initial bonding position corresponds to the contact area of the two electrodes; subsequently, the bonded region gradually extends to cover the entire target region. Nevertheless, the traditional diffuse bonding method provides limited bonding efficiency in industrial applications. Therefore, this paper proposes a novel plasma bonding technique for 2D scanning anodic bonding. In this technique, the plasma is positioned to simultaneously heat and bond specimens. We conducted an experiment that entailed bonding 4-inch silicon/glass wafers by using N2 plasma. The results revealed that an almost bubble-free bonded interface and an average bonding strength exceeding 37 MPa were achieved for a bonding time of 15 min 53 s, bonding voltage of 2 kV, noncontact distance (between the cathode electrode and the bonding specimens) of 3 mm, variable raster scan path, scan speed of 3 mm s-1, and continuous scan steps of 2.5 mm in the x- and y-axes. A comprehensive series of experiments were performed to validate the bonding performance of the proposed technique.

  6. Modelling the potential spatial distribution of mosquito species using three different techniques.

    Science.gov (United States)

    Cianci, Daniela; Hartemink, Nienke; Ibáñez-Justicia, Adolfo

    2015-02-27

    Models for the spatial distribution of vector species are important tools in the assessment of the risk of establishment and subsequent spread of vector-borne diseases. The aims of this study are to define the environmental conditions suitable for several mosquito species through species distribution modelling techniques, and to compare the results produced with the different techniques. Three different modelling techniques, i.e., non-linear discriminant analysis, random forest and generalised linear model, were used to investigate the environmental suitability in the Netherlands for three indigenous mosquito species (Culiseta annulata, Anopheles claviger and Ochlerotatus punctor). Results obtained with the three statistical models were compared with regard to: (i) environmental suitability maps, (ii) environmental variables associated with occurrence, (iii) model evaluation. The models indicated that precipitation, temperature and population density were associated with the occurrence of Cs. annulata and An. claviger, whereas land surface temperature and vegetation indices were associated with the presence of Oc. punctor. The maps produced with the three different modelling techniques showed consistent spatial patterns for each species, but differences in the ranges of the predictions. Non-linear discriminant analysis had lower predictions than other methods. The model with the best classification skills for all the species was the random forest model, with specificity values ranging from 0.89 to 0.91, and sensitivity values ranging from 0.64 to 0.95. We mapped the environmental suitability for three mosquito species with three different modelling techniques. For each species, the maps showed consistent spatial patterns, but the level of predicted environmental suitability differed; NLDA gave lower predicted probabilities of presence than the other two methods. The variables selected as important in the models were in agreement with the existing knowledge about

  7. A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in radio frequency plasmas

    CERN Document Server

    Daksha, M; Schuengel, E; Korolov, I; Derzsi, A; Koepke, M; Donko, Z; Schulze, J

    2016-01-01

    A Computationally Assisted Spectroscopic Technique to measure secondary electron emission coefficients ($\\gamma$-CAST) in capacitively-coupled radio-frequency plasmas is proposed. This non-intrusive, sensitive diagnostic is based on a combination of Phase Resolved Optical Emission Spectroscopy and particle-based kinetic simulations. In such plasmas (under most conditions in electropositive gases) the spatio-temporally resolved electron-impact excitation/ionization rate features two distinct maxima adjacent to each electrode at different times within each RF period. While one maximum is the consequence of the energy gain of electrons due to sheath expansion, the second maximum is produced by secondary electrons accelerated towards the plasma bulk by the sheath electric field at the time of maximum voltage drop across the adjacent sheath. Due to these different excitation/ionization mechanisms, the ratio of the intensities of these maxima is very sensitive to the secondary electron emission coefficient $\\gamma$...

  8. Spatial Search Techniques for Mobile 3D Queries in Sensor Web Environments

    Directory of Open Access Journals (Sweden)

    James D. Carswell

    2013-03-01

    Full Text Available Developing mobile geo-information systems for sensor web applications involves technologies that can access linked geographical and semantically related Internet information. Additionally, in tomorrow’s Web 4.0 world, it is envisioned that trillions of inexpensive micro-sensors placed throughout the environment will also become available for discovery based on their unique geo-referenced IP address. Exploring these enormous volumes of disparate heterogeneous data on today’s location and orientation aware smartphones requires context-aware smart applications and services that can deal with “information overload”. 3DQ (Three Dimensional Query is our novel mobile spatial interaction (MSI prototype that acts as a next-generation base for human interaction within such geospatial sensor web environments/urban landscapes. It filters information using “Hidden Query Removal” functionality that intelligently refines the search space by calculating the geometry of a three dimensional visibility shape (Vista space at a user’s current location. This 3D shape then becomes the query “window” in a spatial database for retrieving information on only those objects visible within a user’s actual 3D field-of-view. 3DQ reduces information overload and serves to heighten situation awareness on constrained commercial off-the-shelf devices by providing visibility space searching as a mobile web service. The effects of variations in mobile spatial search techniques in terms of query speed vs. accuracy are evaluated and presented in this paper.

  9. REMOTE SENSING IMAGE CLASSIFICATION WITH GIS DATA BASED ON SPATIAL DATA MINING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Data mining techniques are used to discover knowledge from GIS database in order to improve remote sensing image classification.Two learning granularities are proposed for inductive learning from spatial data,one is spatial object granularity,the other is pixel granularity.We also present an approach to combine inductive learning with conventional image classification methods,which selects class probability of Bayes classification as learning attributes.A land use classification experiment is performed in the Beijing area using SPOT multi-spectral image and GIS data.Rules about spatial distribution patterns and shape features are discovered by C5.0 inductive learning algorithm and then the image is reclassified by deductive reasoning.Comparing with the result produced only by Bayes classification,the overall accuracy increased by 11% and the accuracy of some classes,such as garden and forest,increased by about 30%.The results indicate that inductive learning can resolve spectral confusion to a great extent.Combining Bayes method with inductive learning not only improves classification accuracy greatly,but also extends the classification by subdividing some classes with the discovered knowledge.

  10. Kinetic and Diagnostic Studies of Molecular Plasmas Using Laser Absorption Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Welzel, S [INP-Greifswald, 17489 Greifswald, Felix-Hausdorff-Str. 2 (Germany); Rousseau, A [Laboratoire de Physique et Technologie des Plasmas, Ecole Polytechnique, CNRS, 91128 Palaiseau (France); Davies, P B [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom); Roepcke, J [INP-Greifswald, 17489 Greifswald, Felix-Hausdorff-Str. 2 (Germany)

    2007-10-15

    Within the last decade mid infrared absorption spectroscopy between 3 and 20 {mu}m, known as Infrared Laser Absorption Spectroscopy (IRLAS) and based on tuneable semiconductor lasers, namely lead salt diode lasers, often called tuneable diode lasers (TDL), and quantum cascade lasers (QCL) has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has lead to further applications of IRLAS because most of these compounds and their decomposition products are infrared active. IRLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetics. Information about gas temperature and population densities can also be derived from IRLAS measurements. A variety of free radicals and molecular ions have been detected, especially using TDLs. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of QCLs offers an attractive new option for the monitoring and control of industrial plasma processes as well as for highly time-resolved studies on the kinetics of plasma processes. The aim of the present article is threefold: (i) to review recent achievements in our understanding of molecular phenomena in plasmas (ii) to report on selected studies of the spectroscopic properties and kinetic behaviour of radicals, and (iii) to describe the current status of advanced instrumentation for TDLAS in the mid infrared.

  11. Spatial Techniques to Visualize Acoustic Comfort along Cultural and Heritage Routes for a World Heritage City

    Directory of Open Access Journals (Sweden)

    Ni Sheng

    2015-07-01

    Full Text Available This paper proposes to visualize acoustic comfort along tourist routes. Route-based tourism is crucial to the sustainability of tourism development in historic areas. Applying the concept of route-based tourism to guide tourists rambling along cultural and heritage routes can relieve overcrowded condition at hot scenic spots and increase the overall carrying capacity of the city. However, acoustic comfort along tourist routes is rarely addressed in academic studies and decision-making. Taking Macao as an example, this paper has studied pedestrian exposure to traffic noise along the cultural and heritage routes. The study is based on a GIS-based traffic noise model system with a high spatial resolution down to individual buildings along both sides of the street. Results show that tourists suffer from excessive traffic noise at certain sites, which may have negative impact on the promotion of route-based tourism in the long run. In addition, it is found that urban growth affects urban form and street layout, which in turn affect traffic flow and acoustic comfort in urban area. The present study demonstrates spatial techniques to visualize acoustic comfort along tourist routes, and the techniques are foreseen to be used more frequently to support effective tourism planning in the future.

  12. Comparison of Two Spatial Optimization Techniques: A Framework to Solve Multiobjective Land Use Distribution Problems

    Science.gov (United States)

    Meyer, Burghard Christian; Lescot, Jean-Marie; Laplana, Ramon

    2009-02-01

    Two spatial optimization approaches, developed from the opposing perspectives of ecological economics and landscape planning and aimed at the definition of new distributions of farming systems and of land use elements, are compared and integrated into a general framework. The first approach, applied to a small river catchment in southwestern France, uses SWAT (Soil and Water Assessment Tool) and a weighted goal programming model in combination with a geographical information system (GIS) for the determination of optimal farming system patterns, based on selected objective functions to minimize deviations from the goals of reducing nitrogen and maintaining income. The second approach, demonstrated in a suburban landscape near Leipzig, Germany, defines a GIS-based predictive habitat model for the search of unfragmented regions suitable for hare populations ( Lepus europaeus), followed by compromise optimization with the aim of planning a new habitat structure distribution for the hare. The multifunctional problem is solved by the integration of the three landscape functions (“production of cereals,” “resistance to soil erosion by water,” and “landscape water retention”). Through the comparison, we propose a framework for the definition of optimal land use patterns based on optimization techniques. The framework includes the main aspects to solve land use distribution problems with the aim of finding the optimal or best land use decisions. It integrates indicators, goals of spatial developments and stakeholders, including weighting, and model tools for the prediction of objective functions and risk assessments. Methodological limits of the uncertainty of data and model outcomes are stressed. The framework clarifies the use of optimization techniques in spatial planning.

  13. Comparison of two spatial optimization techniques: a framework to solve multiobjective land use distribution problems.

    Science.gov (United States)

    Meyer, Burghard Christian; Lescot, Jean-Marie; Laplana, Ramon

    2009-02-01

    Two spatial optimization approaches, developed from the opposing perspectives of ecological economics and landscape planning and aimed at the definition of new distributions of farming systems and of land use elements, are compared and integrated into a general framework. The first approach, applied to a small river catchment in southwestern France, uses SWAT (Soil and Water Assessment Tool) and a weighted goal programming model in combination with a geographical information system (GIS) for the determination of optimal farming system patterns, based on selected objective functions to minimize deviations from the goals of reducing nitrogen and maintaining income. The second approach, demonstrated in a suburban landscape near Leipzig, Germany, defines a GIS-based predictive habitat model for the search of unfragmented regions suitable for hare populations (Lepus europaeus), followed by compromise optimization with the aim of planning a new habitat structure distribution for the hare. The multifunctional problem is solved by the integration of the three landscape functions ("production of cereals," "resistance to soil erosion by water," and "landscape water retention"). Through the comparison, we propose a framework for the definition of optimal land use patterns based on optimization techniques. The framework includes the main aspects to solve land use distribution problems with the aim of finding the optimal or best land use decisions. It integrates indicators, goals of spatial developments and stakeholders, including weighting, and model tools for the prediction of objective functions and risk assessments. Methodological limits of the uncertainty of data and model outcomes are stressed. The framework clarifies the use of optimization techniques in spatial planning.

  14. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, Raquel [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Todolí, José Luis, E-mail: jose.todoli@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Lienemann, Charles-Philippe [IFP Energies Nouvelles, Rond-point de l' échangeur de Solaize, BP 3, F-69360 Solaize (France); Mermet, Jean-Michel [Spectroscopy Forever, 01390 Tramoyes (France)

    2013-10-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described.

  15. A new application field of plasma spraying technique to environmental depollution

    Institute of Scientific and Technical Information of China (English)

    YE Fu-xing; A.Ohmori

    2004-01-01

    To expand the application of plasma spraying technique, TiO2 coatings were prepared using agglomerated anatase TiO2 powder to solve the environmental problems. The composition and photocatalytic activity of plasma sprayed TiO2 coatings were investigated systematically. The content of anatase TiO2 in the sprayed coatings was approximate to 7%- 15%, which was influenced by the melting state of TiO2 powder in plasma spraying process. The surface of sprayed coating was very rough and the arithmetical mean deviation of the surface profiles (Ra) was in the range of 5.7 - 8.8 μm. Under lower arc current, the surface of the coating became rougher. The anatase to rutile phase transformation temperature of agglomerated anatase TiO2 powder was approximate to 1 173 K. The TiO2 coating sprayed under the arc current of 400 A had good photocatalytic activity for the relative high content of anatase phase in it. It is concluded that the application of plasma spraying technique to environmental field has been developed.

  16. Spatial profiles of interelectrode electron density in direct current superposed dual-frequency capacitively coupled plasmas

    Science.gov (United States)

    Ohya, Yoshinobu; Ishikawa, Kenji; Komuro, Tatsuya; Yamaguchi, Tsuyoshi; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2017-04-01

    We present experimentally determined spatial profiles of the interelectrode electron density (n e) in dual-frequency capacitively coupled plasmas in which the negative direct current (dc) bias voltage (V dc) is superposed; in the experiment, 13 MHz (P low) was applied to the lower electrode and 60 MHz (P high) to the upper electrode. The bulk n e increased substantially with increases in the external power, P high, P low, and with increases in V dc. When P low was insufficient, the bulk n e decreased as the V dc bias increased. The bulk n e increased due to its dependence on V dc, especially for |V dc|  >  500 V. This may correspond to the sheath voltages (V s) of the lower electrode. The n e values in front of the upper electrode were coupled with the V dc: the V dc dependence first decreased and then increased. The dc currents (I dc) of the upper electrode were collected when a large P low was applied. The value of I dc at the threshold value of V dc  ≈  V s (e.g.  ‑500 V) increased with an increase in n e. When |V dc| exceeded the threshold, the spatial n e profile and the I dc dependence were changed relative to the electrical characteristics of the dc superposition; this led to a change in the location of the maximum n e, the width of the area of n e depletion in front of the electrodes, and a transition in the electron heating modes.

  17. Status of Plasma Physics Techniques for the Deposition of Tribological Coatings

    Science.gov (United States)

    Spalvins, T.

    1984-01-01

    The plasma physics deposition techniques of sputtering and ion-plating are reviewed. Their characteristics and potentials are discussed in terms of synthesis or deposition of tribological coatings. Since the glow discharge or plasma generated in the conventional sputtering and ion-plating techniques has a low ionization efficiency, rapid advances have been made in equipment design to further increase the ionization efficiency. The enhanced ionization favorably affects the nucleation and growth sequence of the coating. This leads to improved adherence and coherence, higher density, favorable morphological growth, and reduced internal stresses in the coatings. As a result, desirable coating characteristics can be precision tailored. Tribological coating characteristics of sputtered solid film lubricants such as MoS2, ion-plated soft gold and lead metallic films, and sputtered and ion-plated wear-resistant refractory compound films such as nitrides and carbides are discussed.

  18. Electrical properties of bilayer graphene synthesized using surface wave microwave plasma techniques at low temperature

    Science.gov (United States)

    Yamada, Takatoshi; Kato, Hiromitsu; Okigawa, Yuki; Ishihara, Masatou; Hasegawa, Masataka

    2017-01-01

    Bilayer graphene was synthesized at low temperature using surface wave microwave plasma techniques where poly(methyl metacrylate) (PMMA) and methane (CH4) were used as carbon sources. Temperature-dependent Hall effect measurements were carried out in a helium atmosphere. Sheet resistance, sheet carrier density and mobility showed weak temperature dependence for graphene from PMMA, and the highest carrier mobility is 740 cm2 V-1 s-1. For graphene from CH4, tunneling of the domain boundary limited carrier transport. The difference in average domain size was determined by Raman signal maps. In addition, residuals of PMMA were detected on graphene from PMMA. The low sheet resistances of graphene synthesized at a temperature of 280 °C using plasma techniques were explained by the PMMA related residuals rather than the domain sizes.

  19. Oxidation of Polyethylene: A Comparison of Plasma and Ultraviolet Ozone Processing Techniques

    Science.gov (United States)

    2009-01-01

    surface energy. We performed a series of wettability evaluations using the sessile drop method for four samples treated under He-O2, with 13% of...due to the advantages of low cost, corrosion resistance, and high strength to weight ratio. Although polymers offer many desirable attributes, the...Of the aforementioned methods, those based on atmospheric or low-pressure plasmas offer several advantages over other techniques with the most

  20. Studies on non-oxide coating on carbon fibers using plasma enhanced chemical vapor deposition technique

    Science.gov (United States)

    Patel, R. H.; Sharma, S.; Prajapati, K. K.; Vyas, M. M.; Batra, N. M.

    2016-05-01

    A new way of improving the oxidative behavior of carbon fibers coated with SiC through Plasma Enhanced Chemical Vapor Deposition technique. The complete study includes coating of SiC on glass slab and Stainless steel specimen as a starting test subjects but the major focus was to increase the oxidation temperature of carbon fibers by PECVD technique. This method uses relatively lower substrate temperature and guarantees better stoichiometry than other coating methods and hence the substrate shows higher resistance towards mechanical and thermal stresses along with increase in oxidation temperature.

  1. Spatial and Temporal Investigations of Laser Ablation Plasma Plume Density and Composition

    Science.gov (United States)

    Iratcabal, Jeremy; Bach, Bernhard; Beatty, Cuyler; Dutra, Eric; Darling, Timothy; Wiewior, Piotr; Covington, Aaron

    2016-10-01

    Laser ablation of solid targets with laser intensities of the order of 108-1011 W/cm2 provides a rich platform for investigating the density and composition of coexisting molecular, atomic, and ion species in the resulting plasma plume. Experiments measuring the spatial- and temporal-evolution of laser ablation plumes have been performed to simultaneously characterize the multiple parameters related to the energy and momentum partitioning of the incident laser energy as the ablation process occurs. The temperature, density, and relative populations of different molecular, atomic, and ion species can be determined by the simultaneous measurement of optical and charged particle spectroscopy, fast imaging cameras, and optical interferometric diagnostics. Additionally, background gas pressure, density, and species were carefully varied. A comparison of density measurements obtained with multiple interferometric, spectroscopic, and fast imaging diagnostics for a carbon ablation plume expanding into vacuum and into background gases with different Reynolds numbers will be presented. Atomic, molecular, and ion species population evolution will be presented as measured with optical and charged particle spectroscopy. This work was supported by the U.S. DOE NNSA Cooperative Agreement No. DE-NA0002075 and National Securities Technologies, LLC under Contract No. DE-AC52-06NA25946/subcontract No. 165819.

  2. High spatial resolution Hall sensor array for edge plasma magnetic field measurements

    Science.gov (United States)

    Liu, Yuhong; Maurer, David A.; Navratil, Gerald A.; Rivera, Nicholas

    2005-09-01

    A one-dimensional, high-spatial resolution, 20-element Hall sensor array has been developed to directly measure the edge plasma perpendicular magnetic field and its fluctuations as a function of radius with 4-mm resolution. The array employs new small-area, high-sensitivity indium antimonide (InSb) Hall probes in combination with a high-density seven-layer printed circuit board to provide for connections to supply Hall current, record the measured Hall voltage output signals, and mitigate inductive pickup. A combination of bench and in situ measurements is described that provides absolute calibration of the diagnostic array in the presence of a strong transverse magnetic field component that is approximately 1000 times greater than the perpendicular fluctuating field needed to be resolved by the diagnostic. The Hall probes calibrated using this method are capable of magnetic field measurements with a sensitivity of 7V/T over the frequency band from 0 to 20 kHz.

  3. Spatial control of plasma membrane domains: ROP GTPase-based symmetry breaking

    Science.gov (United States)

    Yang, Zhenbiao; Lavagi, Irene

    2013-01-01

    Breaking of the cell membrane symmetry to form polarized or localized domains/regions of the plasma membrane (PM) is a fundamental cellular process that occurs in essentially all cellular organisms, and is required for a wide variety of cellular functions/behaviors including cell morphogenesis, cell division and cell differentiation. In plants, the development of localized or polarized PM domains has been linked to a vast array of cellular and developmental processes such as polar cell expansion, asymmetric cell division, cell morphogenesis, the polarization of auxin transporters (and thus auxin polar transport), secondary cell wall patterning, cell type specification, and tissue pattern formation. Rho GTPases from plants (ROPs) are known to be involved in many of these processes. Here, we review the current knowledge on ROP involvement in breaking symmetry and propose that ROP-based self-organizing signaling may provide a common mechanism for the spatial control of PM domains required in various cellular and developmental processes in plants. PMID:23177207

  4. Mapping Tamarix: New techniques for field measurements, spatial modeling and remote sensing

    Science.gov (United States)

    Evangelista, Paul H.

    peak growing months. These studies demonstrate that new techniques can further our understanding of tamarisk's impacts on ecosystem processes, predict potential distribution and new invasions, and improve our ability to detect occurrence using remote sensing techniques. Collectively, the results of my studies may increase our ability to map tamarisk distributions and better quantify its impacts over multiple spatial and temporal scales.

  5. Spatial and Temporal characterization of plasma properties via emission spectroscopy in fusion materials testing device Proto-MPEX

    Science.gov (United States)

    Morean, Casey; Biewer, Theodore; Shaw, Guinevere; Beers, Josh; Ray, Holly

    2016-10-01

    The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma source, and is intended to study plasma-material interactions (PMI) in conditions similar to those found in future fusion reactors. A high-resolution McPherson Czerny-Turner visible range spectrometer has been utilized to study the behavior of ions in the plasma. Analysis of the spectral lines, D_beta, D_gamma, and D_delta yields valuable information regarding the temperature and density of plasma ions at various locations along Proto-MPEX. Spectroscopic temperature and density measurements are compared to double Langmuir probe measurements to determine plasma behavior as a function of radius. Temporal and spatial measurements along the length of Proto-MPEX are constructed and compared to a photomultiplier tube based diagnostic manufactured at ORNL to determine the plasma's axial behavior along Proto-MPEX. Relative emission of beta, gamma, and delta lines are used to assess recycling effects in the device. This work was supported by the U.S. D.O.E. contract DE-AC05-00OR22725.

  6. Comparison of Three Techniques to Monitor Bathymetric Evolution in a Spatially Extensive, Rapidly Changing Environment

    Science.gov (United States)

    Rutten, J.; Ruessink, G.

    2014-12-01

    The wide variety in spatial and temporal scales inherent to nearshore morphodynamics, together with site-specific environmental characteristics, complicate our current understanding and predictive capability of large (~ km)-scale, long-term (seasons-years) sediment transport patterns and morphologic evolution. The monitoring of this evolution at all relevant scales demands a smart combination of multiple techniques. Here, we compare depth estimates derived from operational optical (Argus video) and microwave (X-band radar) remote sensing with those from jet-ski echo-sounding in an approximately 2.5 km2 large region at the Sand Engine, a 20 Mm3 mega-nourishment at the Dutch coast. Using depth inversion techniques based on linear wave theory, frequent (hourly-daily) bathymetric maps were derived from instantaneous Argus video and X-band radar imagery. Jet-ski surveys were available every 2 to 3 months. Depth inversion on Argus imagery overestimates surveyed depths by up to 0.5 m in shallow water ( 5m) by up to 1 m. Averaged over the entire subtidal study area, the errors canceled in volumetric budget computations. Additionally, estimates of shoreline and subtidal sandbar positions were derived from Argus imagery and jet-ski surveys. Sandbar crest positions extracted from daily low-tide time-exposure Argus images reveal a persistent onshore offset of some 20 m, but do show the smaller temporal variability not visible from jet-ski surveys. Potential improvements to the applied depth-inversion technique will be discussed.

  7. JT-60U Thomson scattering system with multiple ruby laser and high spatial resolution for high electron temperature plasma measurement

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Hidetoshi; Naito, Osamu; Yamashita, Osamu; Kitamura, Shigeru; Hatae, Takaki; Nagashima, Akira [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1996-11-01

    This article describes the design and operation of a 60 spatial channel Thomson scattering system as of 1996 with multiple ruby lasers to measure the electron temperature T{sub e} and density n{sub e} profiles of the JT-60U plasmas. The wide spectral range (403-683 nm) of the spectrometer and newly developed two-dimensional detector (high repetition photodiode array) has enabled this system to measure the high electron temperature plasma (5 keV or more) formed at the plasma core during negative magnetic shear discharge with high precision and reliability. The high spatial resolution (8 mm) have provided the precise measurement of steep electron temperature and density gradients formed at the plasma edge and in the scrape-off layer during H-mode discharge. The multilaser operation with the minimum time interval of 2 ms has provided an essential tool for the transient phenomenon measurement like the formation process of edge transport barrier during L- to H-mode transition and internal transport barrier during discharge with negative magnetic shear, the relaxation process of pellet injected plasma and so on. Measurement examples of recent JT-60U T{sub e} and n{sub e} profiles are also presented. (author)

  8. Effects of anesthesia and blood sampling techniques on plasma metabolites and corticosterone in the rat.

    Science.gov (United States)

    Arnold, Myrtha; Langhans, Wolfgang

    2010-04-19

    Blood is routinely sampled from laboratory animals in biomedical research, and many of the commonly applied sampling techniques require anesthesia. Acute effects of many sampling and anesthesia procedures may confound the results, but those effects are incompletely characterized. We here compare the effects of four common anesthesia procedures (inhalation anesthesia with ether (EA) or isoflurane (IA) and intraperitoneal injection anesthesia with xylazin/ketamine (XKA) or medetomidine/midazolam/fentanyl (MMFA)) on plasma concentrations of glucose, lactate, non-esterified fatty acids (NEFAs), and corticosterone in blood obtained from a previously implanted jugular vein (JV) catheter with the effect of JV blood sampling from non-anesthetized, freely-moving rats (JV-NA). Also, we included in the comparison two other blood sampling procedures usually performed without anesthesia (NA), i.e., puncture of the saphenic vein (SV) and tail incision (TI). Whereas the control procedure (JV-NA) did not significantly affect any of the target parameters, plasma glucose increased from 14 (JV-IA) to 44 (JV-MMFA) % (all Ps=0.05 when compared with the control procedure) in all blood samples collected in anesthesia and was 12 and 14% lower (both Pssamples, respectively. Plasma lactate increased from 74 (JV-IA) to 226% (SV-NA) (all Pssampling and anesthesia procedures except for JV-XKA and JV-MMF. Plasma NEFAs increased to 52% (P0.05). Finally, only the JV-EA and the JV-MMFA procedures increased plasma corticosterone (+525 and +353%, respectively, both Pssampling procedures can have profound acute effects on plasma metabolite and hormone concentrations. This must be considered for the design and interpretation of blood sampling experiments in laboratory animals. (c) 2010. Published by Elsevier Inc.

  9. A rotating hot-wire technique for spatial sampling of disturbed and manipulated duct flows

    Science.gov (United States)

    Wark, C. E.; Nagib, H. M.; Jennings, M. J.

    1990-01-01

    A duct flow spatial sampling technique, in which an X-wire probe is rotated about the center of a cylindrical test section at a radius equal to one-half that of the test section in order to furnish nearly instantaneous multipoint measurements of the streamwise and azimuthal components, is presently evaluated in view of the control of flow disturbances downstream of various open inlet contractions. The effectiveness of a particular contraction in controlling ingested flow disturbances was ascertained by artificially introducing disturbances upstream of the contractions; control effectiveness if found to be strongly dependent on inlet contraction, with consequences for the reduction of passing-blade frequency noise during gas turbine engine ground testing.

  10. A rotating hot-wire technique for spatial sampling of disturbed and manipulated duct flows

    Science.gov (United States)

    Wark, C. E.; Nagib, H. M.; Jennings, M. J.

    1990-01-01

    A duct flow spatial sampling technique, in which an X-wire probe is rotated about the center of a cylindrical test section at a radius equal to one-half that of the test section in order to furnish nearly instantaneous multipoint measurements of the streamwise and azimuthal components, is presently evaluated in view of the control of flow disturbances downstream of various open inlet contractions. The effectiveness of a particular contraction in controlling ingested flow disturbances was ascertained by artificially introducing disturbances upstream of the contractions; control effectiveness if found to be strongly dependent on inlet contraction, with consequences for the reduction of passing-blade frequency noise during gas turbine engine ground testing.

  11. A rehabilitation training system with double-CCD camera and automatic spatial positioning technique

    Science.gov (United States)

    Lin, Chern-Sheng; Wei, Tzu-Chi; Lu, An-Tsung; Hung, San-Shan; Chen, Wei-Lung; Chang, Chia-Chang

    2011-03-01

    This study aimed to develop a computer game for machine vision integrated rehabilitation training system. The main function of the system is to allow users to conduct hand grasp-and-place movement through machine vision integration. Images are captured by a double-CCD camera, and then positioned on a large screen. After defining the right, left, upper, and lower boundaries of the captured images, an automatic spatial positioning technique is employed to obtain their correlation functions, and lookup tables are defined for cameras. This system can provide rehabilitation courses and games that allow users to exercise grasp-and-place movements, in order to improve their upper limb movement control, trigger trunk control, and balance training.

  12. The Run up Tsunami Modeling in Bengkulu using the Spatial Interpolation of Kriging Technique

    Directory of Open Access Journals (Sweden)

    Yulian Fauzi

    2014-12-01

    Full Text Available This research aims to design a tsunami hazard zone with the scenario of tsunami run-up height variation based on land use, slope and distance from the shoreline. The method used in this research is spatial modelling with GIS via Ordinary Kriging interpolation technique. Kriging interpolation method that is the best in this study is shown by Circular Kriging method with good semivariogram and RMSE values which are small compared to other RMSE kriging methods. The results shows that the area affected by the tsunami inundation run-up height, slope and land use. In the run-up to 30 meters, flooded areas are about 3,148.99 hectares or 20.7% of the total area of the city of Bengkulu.

  13. Approach dealing with transversely spatial profile of pump laser in Z-scan technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Wang, S Y; Zhao, P D; Wang, D Y; Liu, M; Zhang, Z D, E-mail: pdzhao@eyou.com, E-mail: pd_zhao@126.com [School of Science, Hebei University of Technology, 300130, Tianjin (China)

    2011-02-01

    The spatial pulse profile makes experimental values of Two-and three photon absorption (TPA and 3PA) coefficient deviate from its true value. We report an approach taking account of the influence of pump laser pulse profile on the nonlinear absorption coefficients (NAC) in Z-scan technique. We developed a new approach in which the factor (f factor) introduced to describe the influence coming from the spatial profile of laser on two and three photon absorption coefficient. The approximation of the approach is also estimated quantitatively. With Gaussian beams the numerically related results show that, compared with NAC based on the way dealing with the pulse in usual Z-scan, the relative differences of 2-photon and 3-photon absorption coefficients obtained based on the traditional one are less than 4.2% and 16.7%. The results suggest that the factor may become useful and simple parameters in dealing with the NAC deviation resulting from the pump laser pulse envelopes for the purpose of shortcutting the Z-scan datum process.

  14. Trade-offs between spatial and temporal resolutions in stochastic super-resolution microscopy techniques

    CERN Document Server

    Rupprecht, Jean-Francois; Tessier, Gilles

    2016-01-01

    Widefield stochastic microscopy techniques such as PALM or STORM rely on the progressive accumulation of a large number of frames, each containing a scarce number of super-resolved point images. We justify that the redundancy in the localization of detected events imposes a specific limit on the temporal resolution. Based on a theoretical model, we derive analytical predictions for the minimal time required to obtain a reliable image at a given spatial resolution, called image completion time. In contrast to standard assumptions, we find that the image completion time scales logarithmically with the ratio of the image size by the spatial resolution volume. We justify that this non-linear relation is the hallmark of a random coverage problem. We propose a method to estimate the risk that the image reconstruction is not complete, which we apply to an experimental data set. Our results provide a theoretical framework to quantify the pattern detection efficiency and to optimize the trade-off between image coverag...

  15. Landscape level assessment of critically endangered vegetation of Lakshadweep islands using geo-spatial techniques

    Indian Academy of Sciences (India)

    C Sudhakar Reddy; Bijan Debnath; P Hari Krishna; C S Jha

    2013-04-01

    The conservation of biodiversity is essential for human survival and quality of the environment. Lakshadweep islands are vulnerable to global change and the representing remnant natural vegetation. Landscape fragmentation, disturbance regimes and biological richness have been studied using geo-spatial techniques. Littoral vegetation is the only natural vegetation type of Lakshadweep islands. Altogether 59 patches of the littoral vegetation occupying an area of 137.2 ha were identified. 58.06% of the littoral vegetation patches belongs to the patch-size class of > 5 ha. The remnant natural vegetation surviving with patches of less than 20 ha size indicates severe anthropogenic pressure. The fragmentation of littoral vegetation habitat into smaller isolated patches poses one of the key threats to biodiversity and coastal environment. Phytosociological observations revealed distinct plant communities and presence of invasive species in littoral vegetation. The high disturbance areas accounted for 59.11% area of the total vegetation. The overall spatial distribution of biological richness (BR) in Lakshadweep shows maximum BR at low level (78%), followed by medium (19%), high (2%) and very high (1%). The study emphasizes the importance of conserving the remnant natural vegetation, which is critically endangered.

  16. PREFACE: IX International Conference on Modern Techniques of Plasma Diagnostics and their Application

    Science.gov (United States)

    Savjolov, A. S.; Dodulad, E. I.

    2016-01-01

    The IX Conference on ''Modern Techniques of Plasma Diagnosis and their Application'' was held on 5 - 7 November, 2014 at National Research Nuclear University MEPhI (NRNU MEPhI). The goal of the conference was an exchange of information on both high-temperature and low-temperature plasma diagnostics as well as deliberation and analysis of various diagnostic techniques and their applicability in science, industry, ecology, medicine and other fields. The Conference also provided young scientists from scientific centres and universities engaged in plasma diagnostics with an opportunity to attend the lectures given by the leading specialists in this field as well as present their own results and findings. The first workshop titled ''Modern problems of plasma diagnostics and their application for control of chemicals and the environment'' took place at Moscow Engineering and Physics Institute (MEPhI) in June 1998 with the support of the Section on Diagnostics of the Council of Russian Academic of Science on Plasma Physics and since then these forums have been held at MEPhI every two years. In 2008 the workshop was assigned a conference status. More than 150 specialists on plasma diagnostics and students took part in the last conference. They represented leading Russian scientific centres (such as Troitsk Institute of Innovative and Thermonuclear Research, National Research Centre ''Kurchatov Institute'', Russian Federal Nuclear Centre - All-Russian Scientific Research Institute of Experimental Physics and others) and universities from Belarus, Ukraine, Germany, USA, Belgium and Sweden. About 30 reports were made by young researchers, students and post-graduate students. All presentations during the conference were broadcasted online over the internet with viewers in Moscow, Prague, St. Petersburgh and other cities. The Conference was held within the framework of the Centre of Plasma, Laser Research and Technology supported by MEPhI Academic Excellence Project (Russian

  17. The role of spatial confinement for improvement of laser-induced Mg plasma parameters and growth of surface features

    Science.gov (United States)

    Hayat, Asma; Bashir, Shazia; Rafique, Muhammad Shahid; Ahmad, Riaz; Akram, Mahreen; Mahmood, Khaliq; Zaheer, Ali

    2017-08-01

    The role of spatial confinement for improvement of laser-induced Mg plasma parameters and growth of surface features is investigated by introducing a metallic blocker. Nd: YAG laser at various fluences ranging from 7 to 28 J cm-2 was employed as an irradiation source. All measurements were performed in the presence of Ar under different pressures. Confinement effects offered by metallic blocker are investigated by placing the blocker at different distances of 6, 8 and 10 mm from the target surface. It is revealed from laser-induced breakdown spectroscopy analysis that both plasma parameters, i.e., excitation temperature and electron number density initially increase with increasing laser fluence due to enhancement in energy deposition. With further increase in laser fluence, a decreasing trend followed by saturation is observed which is attributable to shielding effect and self-regulating regime. It is also observed that spatial confinement offered by metallic blocker is responsible for the significant enhancement of both electron temperature and electron number density of Mg plasma. This is true for all laser fluences and pressures of Ar. Maximum values of electron temperature and electron number density without blocker are 8335 K and 2.4 × 1016 cm-3, respectively, whereas these values are enhanced to 12,200 K and 4 × 1016 cm-3 in the presence of the blocker. The physical mechanisms responsible for the enhancement of Mg plasma parameters are plasma compression, confinement and pronounced collisional excitations due to reflection of shock waves. Scanning electron microscope analysis was performed to explore the surface morphology of laser-ablated Mg. It reveals the formation of cones, cavities and ripples. These features become more distinct and well defined in the presence of the blocker due to plasma confinement. The optimum combination of blocker distance, fluence and Ar pressure can identify the suitable conditions for defining the role of plasma parameters

  18. Influence of the initial parameters of the magnetic field and plasma on the spatial structure of the electric current and electron density in current sheets formed in helium

    Energy Technology Data Exchange (ETDEWEB)

    Ostrovskaya, G. V., E-mail: galya-ostr@mail.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Markov, V. S.; Frank, A. G., E-mail: annfrank@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2016-01-15

    The influence of the initial parameters of the magnetic field and plasma on the spatial structure of the electric current and electron density in current sheets formed in helium plasma in 2D and 3D magnetic configurations with X-type singular lines is studied by the methods of holographic interferometry and magnetic measurements. Significant differences in the structures of plasma and current sheets formed at close parameters of the initial plasma and similar configurations of the initial magnetic fields are revealed.

  19. Application of Geo-Spatial Techniques for Precise Demarcation of Village/Panchayat Boundaries

    Science.gov (United States)

    Rao, S. S.; Banu, V.; Tiwari, A.; Bahuguna, S.; Uniyal, S.; Chavan, S. B.; Murthy, M. V. R.; Arya, V. S.; Nagaraja, R.; Sharma, J. R.

    2014-11-01

    In order to achieve the overall progress of the country with active and effective participation of all sections of society, the 12th Five Year Plan (FYP) would bring Panchayats centre-stage and achieve the inclusive growth agenda through inclusive governance. The concept of 'democratic decentralization' in the form of a three-tier administration was introduced in the name of "Panchayat Raj". Horizontally, it is a network of village Panchayats. Vertically, it is an organic growth of Panchayats rising up to national level. The Ministry of Panchayati Raj has three broad agenda: Empowerment, Enablement and Accountability. Space based Information Support for Decentralized Planning (SIS-DP) is one of the initiatives taken by Govt. of India with ISRO/DOS for generation and dissemination of spatial information for planning at the grass root level. The boundary layer for villages across different states/district/block is available with line departments. Most of these data exist at a much generalized scale. These boundaries do not overlay exactly with that of ground realities and may not be suitable for accurate analysis in terms of area, shape, position, etc. To deal with this problem, a strategy is adopted, which makes use of High Resolution Satellite Imagery (HRSI) from Indian Remote sensing satellites and cadastral maps at 1:4000 scale integrated with GIS techniques to enhance the accuracy of geo-spatial depiction of Village/Panchayat boundaries. Cadastral maps are used to depict the boundaries of land parcels and other features at the village level. These maps are registered to ortho products of HRSI using Ground Control Points. The cadastral maps are precisely overlaid on ortho-rectified HRSI and each parcel vertex is tagged with the real-world geographical coordinates. Village boundaries are extracted from the geo-referenced village cadastral maps. These boundaries are fine-tuned by considering under lap and overlap of neighboring villages and a mosaic is generated at

  20. Thin Film Formation of Gallium Nitride Using Plasma-Sputter Deposition Technique

    Directory of Open Access Journals (Sweden)

    R. Flauta

    2003-06-01

    Full Text Available The formation of gallium nitride (GaN thin film using plasma-sputter deposition technique has beenconfirmed. The GaN film deposited on a glass substrate at an optimum plasma condition has shown x-raydiffraction (XRD peaks at angles corresponding to that of (002 and (101 reflections of GaN. The remainingmaterial on the sputtering target exhibited XRD reflections corresponding to that of bulk GaN powder. Toimprove the system’s base pressure, a new UHV compatible system is being developed to minimize theimpurities in residual gases during deposition. The sputtering target configuration was altered to allow themonitoring of target temperature using a molybdenum (Mo holder, which is more stable against Gaamalgam formation than stainless steel.

  1. An Efficient Pruning Technique for Mining Frequent Itemsets in Spatial Databases

    Directory of Open Access Journals (Sweden)

    G.Parthasarathy

    2016-07-01

    Full Text Available Frequent Itemset Mining is evaluating the rules and relationship within the data items are optimizing it, in the large spatial databases (for e.g. Images, Docs, AVI files etc.It is one of the major problems in DM (Data mining domain. Finding frequent item set in the large set is one of the computational complexities in mining. To improve the efficiency and performance of the mining frequent item set algorithm, the key term is to apply pruning techniques which reduces the search space and its complexity of the algorithm. Here we proposed a robust technique of pruning called SP pruning for uncertain data’s. Here our methodology is used to mine the data sources of uncertain data model. We have analyzed and implemented all well known algorithmic models for mining frequent item sets for both binaries and uncertain data’s. Our experimental results show that FPgrowth performance is high for binary data sets where our method performs at high rate of accuracy for uncertain data sets.

  2. Measuring 3-D location and shape parameters of cylinders by a spatial encoding technique

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.; Chia, T.L.; Ho, S.Y. (National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Inst. of Computer Science and Information Engineering)

    1994-10-01

    The authors are concerned with the problem of estimation of true cylinder radius, height, location, and orientation. The authors present mathematical models for measuring these location and shape parameters using a spatial encoding technique. A crucial step in the proposed method is to convert the estimation problem with complex curved stripe patterns to an equivalent, but simpler, estimation problem with line stripe patterns. The notions of silhouette edges and virtual plane are introduced. Various projective geometry techniques are applied to derive the cylinder location and shape parameters. The actual experiment apparatus is et up to employ the developed mathematical models to measure the cylinder geometric parameters. Description of the image-processing tasks for extracting perceived curved stripes and stripe endpoints is given. Sensitivity analysis and proper measures are taken to consider the effects of the uncertainties of stripe endpoints and silhouette edge locations on the measurement. Experiments have confirmed that their measurement method yields quite good results for different cylinders under various measurement environment conditions.

  3. High T(sub c) superconductors fabricated by plasma aerosol mist deposition technique

    Science.gov (United States)

    Wang, X. W.; Vuong, K. D.; Leone, A.; Shen, C. Q.; Williams, J.; Coy, M.

    1995-01-01

    We report new results on high T(sub c) superconductors fabricated by a plasma aerosol mist deposition technique, in atmospheric environment. Materials fabricated are YBaCuO, BiPbSrCaCuO, BaCaCuO precursor films for TlBaCaCuO, and other buffers such as YSZ. Depending on processing conditions, sizes of crystallites and/or particles are between dozens of nano-meters and several micrometers. Superconductive properties and other material characteristics can also be tailored.

  4. Synthesis and characterization of nano silicon and titanium nitride powders using atmospheric microwave plasma technique

    Indian Academy of Sciences (India)

    S Mahendra Kumar; K Murugan; S B Chandrasekhar; Neha Hebalkar; M Krishna; B S Satyanarayana; Giridhar Madras

    2012-05-01

    We have demonstrated a simple, scalable and inexpensive method based on microwave plasma for synthesizing 5 to 10 g/h of nanomaterials. Luminescent nano silicon particles were synthesized by homogenous nucleation of silicon vapour produced by the radial injection of silicon tetrachloride vapour and nano titanium nitride was synthesized by using liquid titanium tetrachloride as the precursor. The synthesized nano silicon and titanium nitride powders were characterized by XRD, XPS, TEM, SEM and BET. The characterization techniques indicated that the synthesized powders were indeed crystalline nanomaterials.

  5. Application of different techniques to obtain spatial estimates of debris flows erosion and deposition depths

    Science.gov (United States)

    Boreggio, Mauro; Gregoretti, Carlo; Degetto, Massimo; Bernard, Martino

    2016-04-01

    In Alpine regions, debris flows endanger settlements and human life. Danger mitigation strategies based on the preparation of hazard maps are necessary tools for the current land planning. To date, hazard maps are obtained by using one- or two-dimensional numerical models that are able to forecast the potential inundated areas, after careful calibration of those input parameters that directly affect the flow motion and its interaction with the ground surface (sediments entrainment or deposition). In principle, the reliability of these numerical models can be tested by flume experiments in laboratory using, for example, particles and water mixtures. However, for more realistic materials including coarse particles, the scaling effects are still difficult to account for. In some cases, where there are enough data (for example, point measures of flow depths and velocities or spatial estimation of erosion and deposition depths), these models can be tested against field observations. As it regards the spatial estimates of debris flows erosion and deposition depths, different approaches can be followed to obtain them, mainly depending on both the type and accuracy of the available initial data. In this work, we explain the methods that have been employed to obtain the maps of erosion and deposition depths for three occurred debris flows in the Dolomites area (North-Eastern Italian Alps). The three events are those occurred at Rio Lazer (Trento) on the 4th of November 1966, at Fiames (Belluno) on the 5th of July 2006 and at Rio Val Molinara (Trento) on the 15th of August 2010. For each case study, we present the available initial data and the related problems, the techniques that have been used to overcome them and finally the results obtained.

  6. A fast TDR-inversion technique for the reconstruction of spatial soil moisture content

    Directory of Open Access Journals (Sweden)

    S. Schlaeger

    2005-01-01

    Full Text Available Spatial moisture distribution in natural soil or other material is a valuably information for many applications. Standard measurement techniques give only mean or punctual results. Therefore a new inversion algorithm has been developed to derive moisture profiles along single TDR sensor-probes. The algorithm uses the full information content of TDR reflection data measured from one or both sides of an embedded probe. The system consisting of sensor probe and surrounded soil can be interpreted as a nonuniform transmission-line. The algorithm is based on the telegraph equations for nonuniform transmission-lines and an optimization approach to reconstruct the distribution of the capacitance and effective conductance along the transmission-line with high spatial resolution. The capacitance distribution can be converted into permittivity and water content by means of a capacitance model and dielectric mixing rules. Numerical investigations have been carried out to verify the accuracy of the inversion algorithm. Single- and double-sided time-domain reflection data were used to determine the capacitance and effective conductance profiles of lossless and lossy materials. The results show that single-sided reflection data are sufficient for lossless (or low-loss cases. In case of lossy material two independent reflection measurements are required to reconstruct a reliable capacitance profile. The inclusion of an additional effective conductivity profile leads to an improved capacitance profile. The algorithm converges very fast and yields a capacitance profile within a sufficiently short time. The additional transformation to the water content requires no significant calculation time.

  7. Peach maturity/quality assessment using hyperspectral imaging-based spatially resolved technique

    Science.gov (United States)

    Cen, Haiyan; Lu, Renfu; Mendoza, Fernando A.; Ariana, Diwan P.

    2011-06-01

    The objective of this research was to measure the absorption (μa) and reduced scattering coefficients (μs') of peaches, using a hyperspectral imaging-based spatially-resolved method, for their maturity/quality assessment. A newly developed optical property measuring instrument was used for acquiring hyperspectral reflectance images of 500 'Redstar' peaches. μa and μs' spectra for 515-1,000 nm were extracted from the spatially-resolved reflectance profiles using a diffusion model coupled with an inverse algorithm. The absorption spectra of peach fruit presented several absorption peaks around 525 nm for anthocyanin, 620 nm for chlorophyll-b, 675 nm for chlorophyll-a, and 970 nm for water, while μs' decreased consistently with the increase of wavelength for most of the tested samples. Both μa and μs' were correlated with peach firmness, soluble solids content (SSC), and skin and flesh color parameters. Better prediction results for partial least squares models were obtained using the combined values of μa and μs' (i.e., μa × μs' and μeff) than using μa or μs', where μeff = [3 μa (μa + μs')]1/2 is the effective attenuation coefficient. The results were further improved using least squares support vector machine models with values of the best correlation coefficient for firmness, SSC, skin lightness and flesh lightness being 0.749 (standard error of prediction or SEP = 17.39 N), 0.504 (SEP = 0.92 °Brix), 0.898 (SEP = 3.45), and 0.741 (SEP = 3.27), respectively. These results compared favorably to acoustic and impact firmness measurements with the correlation coefficient of 0.639 and 0.631, respectively. Hyperspectral imaging-based spatially-resolved technique is useful for measuring the optical properties of peach fruit, and it also has good potential for assessing fruit maturity/quality attributes.

  8. Spatial variation of eddy-diffusion coefficients in the turbulent plasma sheet during substorms

    Directory of Open Access Journals (Sweden)

    M. Stepanova

    2009-04-01

    Full Text Available Study of the plasma turbulence in the central plasma sheet was performed using the Interball-Tail satellite data. Fluctuations of the plasma bulk velocity in the plasma sheet were deduced from the measurements taken by the Corall instrument for different levels of geomagnetic activity and different locations inside the plasma sheet. The events that satisfied the following criteria were selected for analysis: number density 0.1–10 cm−3, ion temperature T≥0.3 keV, and average bulk velocity ≤100 km/s. It was found that the plasma sheet flow generally appears to be strongly turbulent, i.e. is dominated by fluctuations that are unpredictable. Corresponding eddy-diffusion coefficients in Y- and Z-direction in the GSM coordinate system were derived using the autocorrelation time and rms velocity. Statistical studies of variation of the eddy-diffusion coefficients with the location inside the plasma sheet showed a significant increase in these coefficients in the tailward direction. During substorms this dependence shows strong increase of eddy-diffusion in the central part of the plasma sheet at the distances of 10–30 Earth's radii. This effect is much stronger for Y-components of the eddy-diffusion coefficient, which could be related to the geometry of the plasma sheet, allowing more room for development of eddies in this direction.

  9. Surface modification by cold-plasma technique for dental implants—Bio-functionalization with binding pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Masao Yoshinari

    2011-08-01

    At the bone tissue/implant interface, a thin calcium phosphate coating and rapid heating with infrared radiation were effective in controlling the dissolution without cracking the coating. These thin calcium phosphate coatings may directly promote osteogenisis, but also enable immobilization and subsequent drug delivery system (DDS of bisphosphonates. Simvastatin is also an effective candidate that is reported to increase the expression of BMP-2. The thin-film of hexamethyldisiloxane (HMDSO was plasma-polymerized onto titanium, and then HMDSO surface was activated by O2-plasma treatment. A quartz crystal microbalance (QCM-D technique demonstrated that simvastatin was immobilized on the plasma-treated surfaces due to introduction of O2-functional groups. At the soft tissue/implant interface, multi-grooved surface topographies and utilizing the adhesive proteins such as fibronectin or laminin-5 may help in providing a biological seal around the implant. At the oral fluid/implant interface, an alumina coating, F+-implantation and immobilization of anti-microbial peptides were responsible for inhibiting the biofilm accumulation.

  10. A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in technological rf plasmas

    Science.gov (United States)

    Berger, Birk; Schulze, Julian; Daksha, Manaswi; Schuengel, Edmund; Koepke, Mark; Korolov, Ihor; Derzsi, Aranka; Donko, Zoltan

    2016-09-01

    A Computationally Assisted Spectroscopic Technique to measure secondary electron emission coefficients (y-CAST) in capacitive rf plasmas is proposed. This non-intrusive, sensitive diagnostic is based on a combination of Phase Resolved Optical Emission Spectroscopy and PIC simulations. Under most conditions in electropositive plasmas the spatio-temporally resolved electron-impact excitation rate features two distinct maxima adjacent to each electrode at different times within one rf period. One maximum is the consequence of an energy gain of the electrons due to sheath expansion. The second maximum is produced by electrons accelerated towards the plasma bulk by the sheath electric field at the time of maximum voltage drop across the sheath. Due to the different excitation mechanisms the ratio of the intensities of these maxima is very sensitive to y, which allows for its determination via comparing the experimentally measured excitation profiles with corresponding simulation data obtained with various y-coefficients. This diagnostic is tested here in a geometrically symmetric reactor, for stainless steel electrodes and argon gas. An effective secondary electron emission coefficient of y = 0.067+-0.010 is obtained, which is in excellent agreement with previous experimental results.

  11. A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in radio frequency plasmas

    Science.gov (United States)

    Daksha, M.; Berger, B.; Schuengel, E.; Korolov, I.; Derzsi, A.; Koepke, M.; Donkó, Z.; Schulze, J.

    2016-06-01

    A computationally assisted spectroscopic technique to measure secondary electron emission coefficients (γ-CAST) in capacitively-coupled radio-frequency plasmas is proposed. This non-intrusive, sensitive diagnostic is based on a combination of phase resolved optical emission spectroscopy and particle-based kinetic simulations. In such plasmas (under most conditions in electropositive gases) the spatio-temporally resolved electron-impact excitation/ionization rate features two distinct maxima adjacent to each electrode at different times within each RF period. While one maximum is the consequence of the energy gain of electrons due to sheath expansion, the second maximum is produced by secondary electrons accelerated towards the plasma bulk by the sheath electric field at the time of maximum voltage drop across the adjacent sheath. Due to these different excitation/ionization mechanisms, the ratio of the intensities of these maxima is very sensitive to the secondary electron emission coefficient γ. This sensitvity, in turn, allows γ to be determined by comparing experimental excitation profiles and simulation data obtained with various γ-coefficients. The diagnostic, tested here in a geometrically symmetric argon discharge, yields an effective secondary electron emission coefficient of γ =0.066+/- 0.01 for stainless steel electrodes.

  12. The Deflection Plate Analyzer: A Technique for Space Plasma Measurements Under Highly Disturbed Conditions

    Science.gov (United States)

    Wright, Kenneth H., Jr.; Dutton, Ken; Martinez, Nelson; Smith, Dennis; Stone, Nobie H.

    2004-01-01

    A technique has been developed to measure the characteristics of space plasmas under highly disturbed conditions; e.g., non-Maxwellian plasmas with strong drifting populations and plasmas contaminated by spacecraft outgassing. The present method is an extension of the capabilities of the Differential Ion Flux Probe (DIFP) to include a mass measurement that does not include either high voltage or contamination sensitive devices such as channeltron electron multipliers or microchannel plates. This reduces the complexity and expense of instrument fabrication, testing, and integration of flight hardware as compared to classical mass analyzers. The new instrument design is called the Deflection Plate Analyzer (DPA) and can deconvolve multiple ion streams and analyze each stream for ion flux intensity (density), velocity (including direction of motion), mass, and temperature (or energy distribution). The basic functionality of the DPA is discussed. The performance characteristics of a flight instrument as built for an electrodynamic tether mission, the Propulsive Small Expendable Deployer System (ProSEDS), and the instrument s role in measuring key experimental conditions are also discussed.

  13. An accurate automated technique for quasi-optics measurement of the microwave diagnostics for fusion plasma

    Science.gov (United States)

    Hu, Jianqiang; Liu, Ahdi; Zhou, Chu; Zhang, Xiaohui; Wang, Mingyuan; Zhang, Jin; Feng, Xi; Li, Hong; Xie, Jinlin; Liu, Wandong; Yu, Changxuan

    2017-08-01

    A new integrated technique for fast and accurate measurement of the quasi-optics, especially for the microwave/millimeter wave diagnostic systems of fusion plasma, has been developed. Using the LabVIEW-based comprehensive scanning system, we can realize not only automatic but also fast and accurate measurement, which will help to eliminate the effects of temperature drift and standing wave/multi-reflection. With the Matlab-based asymmetric two-dimensional Gaussian fitting method, all the desired parameters of the microwave beam can be obtained. This technique can be used in the design and testing of microwave diagnostic systems such as reflectometers and the electron cyclotron emission imaging diagnostic systems of the Experimental Advanced Superconducting Tokamak.

  14. Double-plasma enhanced carbon shield for spatial/interfacial controlled electrodes in lithium ion batteries via micro-sized silicon from wafer waste

    Science.gov (United States)

    Chen, Bing-Hong; Chuang, Shang-I.; Duh, Jenq-Gong

    2016-11-01

    Using spatial and interfacial control, the micro-sized silicon waste from wafer slurry could greatly increase its retention potential as a green resource for silicon-based anode in lithium ion batteries. Through step by step spatial and interfacial control for electrode, the cyclability of recycled waste gains potential performance from its original poor retention property. In the stages of spatial control, the electrode stabilizers of active, inactive and conductive additives were mixed into slurries for maintaining architecture and conductivity of electrode. In addition, a fusion electrode modification of interfacial control combines electrolyte additive, technique of double-plasma enhanced carbon shield (D-PECS) to convert the chemical bond states and to alter the formation of solid electrolyte interphases (SEIs) in the first cycle. The depth profiles of chemical composition from external into internal electrode illustrate that the fusion electrode modification not only forms a boundary to balance the interface between internal and external electrodes but also stabilizes the SEIs formation and soothe the expansion of micro-sized electrode. Through these effect approaches, the performance of micro-sized Si waste electrode can be boosted from its serious capacity degradation to potential retention (200 cycles, 1100 mAh/g) and better meet the requirements for facile and cost-effective in industrial production.

  15. Surface Modification of Graphene Oxides by Plasma Techniques and Their Application for Environmental Pollution Cleanup.

    Science.gov (United States)

    Wang, Xiangxue; Fan, Qiaohui; Chen, Zhongshan; Wang, Qi; Li, Jiaxing; Hobiny, Aatef; Alsaedi, Ahmed; Wang, Xiangke

    2016-02-01

    Graphene oxides (GOs) have come under intense multidisciplinary study because of their unique physicochemical properties and possible applications. The large amount of oxygen-containing functional groups on GOs leads to a high sorption capacity for the removal of various kinds of organic and inorganic pollutants from aqueous solutions in environmental pollution cleanup. However, the lack of selectivity results in difficulty in the selective removal of target pollutants from aqueous solutions in the presence of other coexisting pollutants. Herein, the surface grafting of GOs with special oxygen-containing functional groups using low-temperature plasma techniques and the application of the surface-modified GOs for the efficient removal of organic and inorganic pollutants in environmental pollution are reviewed. This paper gives an account of our research on the application of GO-based nanomaterials in environmental pollution cleanup, including: (1) the synthesis and surface grafting of functional groups on GOs, summarizing various types of low-temperature plasma techniques for the synthesis of graphene/GOs; and (2) the application of graphene/GOs and their composites for the efficient removal of organic and inorganic pollutants from aqueous solutions, including the interaction mechanism according to recently published results.

  16. Synthesis of Nanosized Titanium Oxide and Nitride Through Vacuum Arc Plasma Expansion Technique

    Science.gov (United States)

    Lepeshev, A. A.; Karpov, I. V.; Ushakov, A. V.; Fedorov, L. Yu.; Shaihadinov, A. A.

    2016-12-01

    Physical vapor deposition techniques such vacuum arc plasma deposition — which are very commonly used in thin film technology — appear to hold much promise for the synthesis of nanocrystalline thin films as well as nanoparticles. Monodisperse and spherical titanium oxide (TiO2) and nitride nanoparticles were produced at room temperature as a cluster beam in the gas phase using a cluster-deposition source. Using the basic principles of the gas condensation method, this study has developed vacuum arc nanoparticle synthesis system. We demonstrate that major process deposition parameter is the pressure in the plasma chamber. This is the major advantage of these techniques over thermal evaporation. Our method affords TiN powders with high specific surface areas exceeding 200m2g-1. TEM micrograph of TiO2 nanoparticles prepared at an oxygen pressure of 60Pa show an average particle size of 6nm. TiO2 nanoparticles prepared at an oxygen pressure of 70Pa were observed to not have a reduced average particle size.

  17. Spectral and spatial structure of extreme ultraviolet radiation in laser plasma-wall interactions

    NARCIS (Netherlands)

    Kuznetsov, A. S.; Stuik, R.; F. Bijkerk,; Shevelko, A. P.

    2012-01-01

    Intense extreme ultraviolet (XUV) radiation was observed during the interaction of low-temperature laser plasmas and wall materials. Laser plasmas with electron temperature T-e similar to 40 eV were created on massive solid targets (CF2 and Al) by an excimer KrF laser (248 nm/0.5 J/13 ns/1 Hz). The

  18. Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture

    Science.gov (United States)

    Rao, R. G. S.; Ulaby, F. T.

    1977-01-01

    The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures.

  19. Frequency and Spatial Domains Adaptive-based Enhancement Technique for Thermal Infrared Images

    Directory of Open Access Journals (Sweden)

    Debasis Chaudhuri

    2014-09-01

    Full Text Available Low contrast and noisy image limits the amount of information conveyed to the user. With the proliferation of digital imagery and computer interface between man-and-machine, it is now viable to consider digital enhancement in the image before presenting it to the user, thus increasing the information throughput. With better contrast, target detection and discrimination can be improved. The paper presents a sequence of filtering operations in frequency and spatial domains to improve the quality of the thermal infrared (IR images. Basically, two filters – homomorphic filter followed by adaptive Gaussian filter are applied to improve the quality of the thermal IR images. We have systematically evaluated the algorithm on a variety of images and carefully compared it with the techniques presented in the literature. We performed an evaluation of three filter banks such as homomorphic, Gaussian 5×5 and the proposed method, and we have seen that the proposed method yields optimal PSNR for all the thermal images. The results demonstrate that the proposed algorithm is efficient for enhancement of thermal IR images.Defence Science Journal, Vol. 64, No. 5, September 2014, pp.451-457, DOI:http://dx.doi.org/10.14429/dsj.64.6873

  20. Seismic Spatial Autocorrelation as a Technique to Track Changes in the Permafrost Active Layer

    Science.gov (United States)

    Abbott, R. E.

    2013-12-01

    We present preliminary results from an effort to continuously track freezing and thawing of the permafrost active layer using a small-aperture seismic array. The 7-element array of three-component posthole seismometers is installed on permafrost at Poker Flat Research Range, near Fairbanks, Alaska. The array is configured in two three-station circles with 75 and 25 meter radii that share a common center station. This configuration is designed to resolve omnidirectional, high-frequency seismic microtremor (i.e. ambient noise). Microtremor is continuously monitored and the data are processed using the spatial autocorrelation (SPAC) method. The resulting SPAC coefficients are then inverted for shear-wave velocity structure versus depth. Thawed active-layer soils have a much slower seismic velocity than frozen soils, allowing us to track the depth and intensity of thawing. Persistent monitoring on a permanent array would allow for a way to investigate year-to-year changes without costly site visits. Results from the seismic array will compared to, and correlated with, other measurement techniques, such as physical probing and remote sensing methods. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. Spatial analysis techniques applied to uranium prospecting in Chihuahua State, Mexico

    Science.gov (United States)

    Hinojosa de la Garza, Octavio R.; Montero Cabrera, María Elena; Sanín, Luz H.; Reyes Cortés, Manuel; Martínez Meyer, Enrique

    2014-07-01

    To estimate the distribution of uranium minerals in Chihuahua, the advanced statistical model "Maximun Entropy Method" (MaxEnt) was applied. A distinguishing feature of this method is that it can fit more complex models in case of small datasets (x and y data), as is the location of uranium ores in the State of Chihuahua. For georeferencing uranium ores, a database from the United States Geological Survey and workgroup of experts in Mexico was used. The main contribution of this paper is the proposal of maximum entropy techniques to obtain the mineral's potential distribution. For this model were used 24 environmental layers like topography, gravimetry, climate (worldclim), soil properties and others that were useful to project the uranium's distribution across the study area. For the validation of the places predicted by the model, comparisons were done with other research of the Mexican Service of Geological Survey, with direct exploration of specific areas and by talks with former exploration workers of the enterprise "Uranio de Mexico". Results. New uranium areas predicted by the model were validated, finding some relationship between the model predictions and geological faults. Conclusions. Modeling by spatial analysis provides additional information to the energy and mineral resources sectors.

  2. Experimental setup for temporally and spatially resolved ICCD imaging of (sub)nanosecond streamer plasma

    Science.gov (United States)

    Huiskamp, T.; Sengers, W.; Pemen, A. J. M.

    2016-12-01

    Streamer discharges are efficient non-thermal plasmas for air purification and can be generated in wire-cylinder electrode structures (the plasma reactor). When (sub)nanosecond high-voltage pulses are used to generate the plasma, components like a plasma reactor behave as transmission lines, where transmission times and reflections become important. We want to visually study the influence of these transmission-line effects on the streamer development in the reactor. Therefore, we need a unique experimental setup, which allows us to image the streamers with nanosecond time resolution over the entire length of the plasma reactor. This paper describes the setup we developed for this purpose. The setup consists of a large frame in which a specially designed plasma reactor can be mounted and imaged from below by an intensified charge-coupled device (ICCD) camera. This camera is mounted on a platform which can be moved by a stepper motor. A computer automates all the experiments and controls the camera movement, camera settings, and the nanosecond high-voltage pulse source we use for the experiments. With the automated setup, we can make ICCD images of the entire plasma reactor at different instances of time with nanosecond resolution (with a jitter of less than several hundreds of picoseconds). Consequently, parameters such as the streamer length and width can be calculated automatically.

  3. Spatial distribution of the electrical potential and ion concentration in the downstream area of atmospheric pressure remote plasma

    Directory of Open Access Journals (Sweden)

    M. V. Mishin

    2014-10-01

    Full Text Available This paper presents the results from an experimental study of the ion flux characteristics behind the remote plasma zone in a vertical tube reaction chamber for atmospheric pressure plasma enhanced chemical vapor deposition. Capacitively coupled radio frequency plasma was generated in pure He and gas mixtures: He–Ar, He–O2, He–TEOS. We previously used the reaction system He–TEOS for the synthesis of self-assembled structures of silicon dioxide nanoparticles. It is likely that the electrical parameters of the area, where nanoparticles have been transported from the synthesis zone to the substrate, play a significant role in the self-organization processes both in the vapor phase and on the substrate surface. The results from the spatial distribution of the electrical potential and ion concentration in the discharge downstream area measured by means of the external probe of original design and the special data processing method are demonstrated in this work. Positive and negatives ions with maximum concentrations of 106–107 cm−3 have been found at 10–80 mm distance behind the plasma zone. On the basis of the revealed distributions for different gas mixtures, the physical model of the observed phenomena is proposed. The model illustrates the capability of the virtual ion emitter formation behind the discharge gap and the presence of an extremum of the electrical potential at the distance of approximately 10−2–10−1 mm from the grounded electrode.

  4. A new in-situ technique for the determination of small scale spatial distribution of contact angles

    Science.gov (United States)

    Lamparter, Axel; Bachmann, Jörg; Woche, Susanne K.

    2010-05-01

    Water repellency is a common phenomenon in soils around the world. Its hydraulic impact reaches from decreased infiltration rates to preferential flow of water through the soil. The contact angle (CA), that forms at the three phase boundary solid-liquid-gas, has been established to quantify water repellency in soils. However, this CA is generally determined at a small amount of dry soil originating from homogenized samples. Thus, its spatial information is dependent on the size of the homogeneous sample. Information about the small scale spatial distribution of soil water repellency (SWR) cannot be obtained with this kind of sample preparation and thus the hydraulic relevance of the measured CA is questionable. Therefore we suggest a new sample preparation technique for measuring the spatial distribution of SWR of natural soils using the sessile drop method (SDM). Two horizontal and one vertical transects of about 1.2 m length have been measured on a sandy forest soil in northern Germany. The litter layer and vegetation, present at the site have been removed prior to the sampling. One side of a double sided adhesive tape has been pressed against the soil surface. This results in a mono-layer of sand grains attached to the tape that reflect the wetting properties in their original spatial surroundings. Using the Sessile Drop Method (SDM), CA have been measured on a straight line transect every 0.5 cm (Drop size 0.005 mL) in the laboratory with a contact angle microscope. Spatial differences in SWR can be measured at the research site. Results have been analyzed using spectral-analysis to reveal spatial correlations in SWR. Different spatial dependencies can be found in different depths of the soil. Results show that the new sampling technique is capable of detecting the spatial variability in natural soils. Thus, it might improve the hydraulic relevance of the small scale CA.

  5. Calibration of a thin metal foil for infrared imaging video bolometer to estimate the spatial variation of thermal diffusivity using a photo-thermal technique.

    Science.gov (United States)

    Pandya, Shwetang N; Peterson, Byron J; Sano, Ryuichi; Mukai, Kiyofumi; Drapiko, Evgeny A; Alekseyev, Andrey G; Akiyama, Tsuyoshi; Itomi, Muneji; Watanabe, Takashi

    2014-05-01

    A thin metal foil is used as a broad band radiation absorber for the InfraRed imaging Video Bolometer (IRVB), which is a vital diagnostic for studying three-dimensional radiation structures from high temperature plasmas in the Large Helical Device. The two-dimensional (2D) heat diffusion equation of the foil needs to be solved numerically to estimate the radiation falling on the foil through a pinhole geometry. The thermal, physical, and optical properties of the metal foil are among the inputs to the code besides the spatiotemporal variation of temperature, for reliable estimation of the exhaust power from the plasma illuminating the foil. The foil being very thin and of considerable size, non-uniformities in these properties need to be determined by suitable calibration procedures. The graphite spray used for increasing the surface emissivity also contributes to a change in the thermal properties. This paper discusses the application of the thermographic technique for determining the spatial variation of the effective in-plane thermal diffusivity of the thin metal foil and graphite composite. The paper also discusses the advantages of this technique in the light of limitations and drawbacks presented by other calibration techniques being practiced currently. The technique is initially applied to a material of known thickness and thermal properties for validation and finally to thin foils of gold and platinum both with two different thicknesses. It is observed that the effect of the graphite layer on the estimation of the thermal diffusivity becomes more pronounced for thinner foils and the measured values are approximately 2.5-3 times lower than the literature values. It is also observed that the percentage reduction in thermal diffusivity due to the coating is lower for high thermal diffusivity materials such as gold. This fact may also explain, albeit partially, the higher sensitivity of the platinum foil as compared to gold.

  6. Novel technique for spatially resolved imaging of molecular bond orientations using x-ray birefringence

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, John P., E-mail: john.sutter@diamond.ac.uk; Dolbnya, Igor P.; Collins, Stephen P. [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Harris, Kenneth D. M., E-mail: HarrisKDM@cardiff.ac.uk; Edwards-Gau, Gregory R.; Kariuki, Benson M. [School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT (United Kingdom); Palmer, Benjamin A. [Department of Structural Biology, Weizmann Institute of Science, 234 Herzl St., Rehovot 7610001 (Israel)

    2016-07-27

    Birefringence has been observed in anisotropic materials transmitting linearly polarized X-ray beams tuned close to an absorption edge of a specific element in the material. Synchrotron bending magnets provide X-ray beams of sufficiently high brightness and cross section for spatially resolved measurements of birefringence. The recently developed X-ray Birefringence Imaging (XBI) technique has been successfully applied for the first time using the versatile test beamline B16 at Diamond Light Source. Orientational distributions of the C–Br bonds of brominated “guest” molecules within crystalline “host” tunnel structures (in thiourea or urea inclusion compounds) have been studied using linearly polarized incident X-rays near the Br K-edge. Imaging of domain structures, changes in C–Br bond orientations associated with order-disorder phase transitions, and the effects of dynamic averaging of C–Br bond orientations have been demonstrated. The XBI setup uses a vertically deflecting high-resolution double-crystal monochromator upstream from the sample and a horizontally deflecting single-crystal polarization analyzer downstream, with a Bragg angle as close as possible to 45°. In this way, the ellipticity and rotation angle of the polarization of the beam transmitted through the sample is measured as in polarizing optical microscopy. The theoretical instrumental background calculated from the elliptical polarization of the bending-magnet X-rays, the imperfect polarization discrimination of the analyzer, and the correlation between vertical position and photon energy introduced by the monochromator agrees well with experimental observations. The background is calculated analytically because the region of X-ray phase space selected by this setup is sampled inefficiently by standard methods.

  7. Indentation strength of silicon nitride ceramics processed by spark plasma sintering technique

    Energy Technology Data Exchange (ETDEWEB)

    Azeggagh, N. [Université de Lyon, INSA-Lyon, LaMCoS CNRS UMR5259, F-69621 Villeurbanne (France); Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, F-69621 Villeurbanne (France); Tohoku University, 6-6-11, Aza-Aoba, Aramaki, Aobaku, Sendai 980-8579 (Japan); Joly-Pottuz, L., E-mail: lucile.joly-pottuz@insa-lyon.fr [Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, F-69621 Villeurbanne (France); Chevalier, J. [Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, F-69621 Villeurbanne (France); Omori, M.; Hashida, T. [Tohoku University, 6-6-11, Aza-Aoba, Aramaki, Aobaku, Sendai 980-8579 (Japan); Nélias, D. [Université de Lyon, INSA-Lyon, LaMCoS CNRS UMR5259, F-69621 Villeurbanne (France)

    2015-09-17

    We investigated the influence of the microstructure on the true stress–strain curve of silicon nitride based ceramics. The materials were processed by spark plasma sintering technique. Si{sub 3}N{sub 4} with fine, average and coarse microstructures were obtained. Load versus displacement curves (P–h) were obtained by means of instrumented indentation technique using diamond coni-spherical tip. The experimental data were coupled with a minimization method based on the Levenberg–Marquardt algorithm and the non-linear part of the mechanical response was identified. Based on the obtained stress–strain curves, rolling contact simulations were performed. In addition, the nature of Hertzian contact damage was examined in the material with coarse microstructure using diamond indenters of radii 0.2 and 1 mm. The surface damage was observed under optical microscopy while Focused Ion Beam Sectioning technique permitted to image the subsurface damage. An evident size effect was noticed: fracture consisting of classical ring cracks dominated at large scale while distributed microcracks beneath the indent dominated at small scale.

  8. Two approaches to plasma polarimetry: Angular variables technique and Stokes vector formalism

    Energy Technology Data Exchange (ETDEWEB)

    Bieg, Bohdan, E-mail: b.bieg@am.szczecin.pl [Maritime University of Szczecin, Szczecin (Poland); Chrzanowski, Janusz; Kravtsov, Yury A. [Maritime University of Szczecin, Szczecin (Poland); Murari, Andrea [Associazione EURATOM-ENEA, Padova (Italy); Orsitto, Francesco [Associazione EURATOM-ENEA, Frascati (Italy)

    2013-08-21

    The modern plasma polarimetry is based on Stokes vector formalism (SVF) suggested and developed in depth by Segre (see Ref. [1] and cited there references). Segre's equations describe evolution of the Stokes vector along the ray in the weakly inhomogeneous and weakly anisotropic plasma. Alternative approach – angular variables technique (AVT) – suggested by Czyż et al. [2] in distinction to SVF deals with angular parameters of the polarization ellipse. Equations for angular parameters drastically differ from the SVF equations; however, AVT and SVF equations happen to be equivalent to each other. This paper proves equivalence of the SVF and AVT and in the sometime reveals some practical distinctions between two approaches. Although all the results of SVF can be obtained in frame of the AVT and vice versa, in specific problems one of the methods can be more convenient. Generally, AVT may serve as a valuable compliment to traditional SVF, providing sometimes more simple an less laborious solution of polarimetric problems.

  9. The use of laser-induced plasma spectroscopy technique for the characterization of boiler tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, G. [Universidad de A Coruna, Departamento de Ingenieria Industrial II, E-15403 Ferrol (A Coruna) (Spain)], E-mail: gines@cdf.udc.es; Mateo, M.P.; Yanez, A. [Universidad de A Coruna, Departamento de Ingenieria Industrial II, E-15403 Ferrol (A Coruna) (Spain)

    2007-12-15

    The present work focuses on the characterization of boiler tube walls using laser-induced plasma spectroscopy technique with visual inspection by optical and scanning electron microscopy of the cross-sections of these tubes. In a watertube boiler, water runs through tubes that are surrounded by a heating source. As a result, the water is heated to very high temperatures, causing accumulation of deposits on the inside surfaces of the tubes. These deposits play an important role in the efficiency of the boiler tube because they produce a reduction of the boiler heat rate and an increase in the number of tube failures. The objectives are to determine the thickness and arrangement of deposits located on the highest heat area of the boiler and compare them with tube parts where the heat flux is lower. The major deposits found were copper and magnetite. These deposits come mainly from the boiler feedwater and from the reaction between iron and water, and they do not form on the tube walls at a uniform rate over time. Their amount depends on the areas where they are collected. A Nd:YAG laser operating at 355 nm has been used to perform laser-induced plasma spectra and depth profiles of the deposits.

  10. Non-thermal plasma as preparative technique to evaluate olive oil adulteration.

    Science.gov (United States)

    Van Durme, Jim; Vandamme, Jeroen

    2016-10-01

    In recent years adulteration of pure extra virgin olive oil (EVOO) with other types of vegetable oils has become an important issue. In this study, non-thermal plasma (NTP) is investigated as an innovative preparative analytical technique enabling classification of adulterated olive oil from an ascertained authentic batch of olive oil in a more sensitive manner. Non-thermal plasma discharges are a source of highly oxidative species such as singlet oxygen, and atomic oxygen. It was assumed that NTP-induced oxidation triggers unique lipid oxidation mechanisms depending on the specific composition of the oil matrix and minor constituents. In this work EVOO samples were adulterated with sunflower oil (1-3%) and submitted to NTP treatment. Results showed that while untreated samples could not be classified from the authentic olive oil reference, NTP treatments of 60min (Ar/O2 0.1%) on the oil batches resulted in the formation of a unique set of secondary volatile lipid oxidation products enabling classification of adulterated oil samples.

  11. A spatially variable power law tropospheric correction technique for InSAR data

    NARCIS (Netherlands)

    Bekaert, D.P.S.; Hooper, A.; Wright, T.J.

    2015-01-01

    Microwave signals traveling through the troposphere are subject to delays. These delays are mainly described by spatial and temporal variations in pressure, temperature, and relative humidity in the lower part of the troposphere, resulting in a spatially varying tropospheric signal in interferometri

  12. Comparison of two different plasma surface-modification techniques for the covalent immobilization of protein monolayers.

    Science.gov (United States)

    Cifuentes, Anna; Borrós, Salvador

    2013-06-04

    The immobilization of biologically active species is crucial for the fabrication of smart bioactive surfaces. For this purpose, plasma polymerization is frequently used to modify the surface nature without affecting the bulk properties of the material. Thus, it is possible to create materials with surface functional groups that can promote the anchoring of all kinds of biomolecules. Different methodologies in protein immobilization have been developed in recent years, although some drawbacks are still not solved, such as the difficulties that some procedures involve and/or the denaturalization of the protein due to the immobilization process. In this work, two different strategies to covalently attach bovine serum albumin (BSA) protein are developed. Both techniques are compared in order to understand how the nature of the surface modification affects the conformation of the protein upon immobilization.

  13. W/Cu composites produced by pulse plasma sintering technique (PPS)

    Energy Technology Data Exchange (ETDEWEB)

    Rosinski, M. [Association EURATOM-IPPLM, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Fortuna, E. [Association EURATOM-IPPLM, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)], E-mail: elaf@inmat.pw.edu.pl; Michalski, A.; Pakiela, Z.; Kurzydlowski, K.J. [Association EURATOM-IPPLM, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

    2007-10-15

    W-Cu composites of various compositions were produced using the pulse plasma sintering (PPS) technique which applies pulsed high electric discharges to heat the powders subjected to pressing. Because the arc discharges between the powder particles clean their surfaces and intensify diffusion processes, the sintering time is reduced to a few minutes. The powder preparation processes, milling, mixing and reduction before sintering, and the sintering conditions were optimized by undertaking detailed investigations of the microstructure of powders and composites. Room temperature tensile strength, using small samples, hardness and the coefficients of thermal expansion were measured. The results prove that by using the PPS method a high density material having 98% of the theoretical density can be fabricated. It has also been shown that the PPS device can be used to join the composite material to a tungsten plate.

  14. The MDF technique for the analysis of tokamak edge plasma fluctuations

    Science.gov (United States)

    Lafouti, M.; Ghoranneviss, M.; Meshkani, S.; Elahi, A. Salar; Elahi

    2014-02-01

    Tokamak edge plasma was analyzed by applying the multifractal detrend fluctuation analysis (MF-DFA) technique. This method has found wide application in the analysis of correlations and characterization of scaling behavior of the time-series data in physiology, finance, and natural sciences. The time evolution of the ion saturation current (Is ), the floating potential fluctuation (Vf ), the poloidal electric field (Ep ), and the radial particle flux (Γ r ) has been measured by using a set of Langmuir probes consisting of four tips on the probe head. The generalized Hurst exponents (h(q)), local fluctuation function (Fq(s)), the Rényi exponents (τ(q)) as well as the multifractal spectrum f(α h ) have been calculated by applying the MF-DFA method to Is , Vf , and the magnetohydrodynamic (MHD) fluctuation signal. Furthermore, we perform the shuffling and the phase randomization techniques to detect the sources of multifractality. The nonlinearity shape of τ(q) reveals a multifractal behavior of the time-series data. The results show that in the presence of biasing, Is , Vf , Ep , and Γ r reduce about 25%, 90%, 70%, and 50%, respectively, compared with the situation with no biasing. Also, they reduce about 15%, 90%, 35%, and 25%, respectively, after resonant helical magnetic field (RHF) application. In the presence of biasing or RHF, the amplitude of the power spectrum of Is , Vf , Γ r , and MHD activity reduce remarkably in all the ranges of frequency, while their h(q) increase. The values of h(q) have been restricted between 0.6 and 0.68. These results are evidence of the existence of long-range correlations in the plasma edge turbulence. They also show the self-similar nature of the plasma edge fluctuations. Biasing or RHF reduces the amount of Fq(s). The multifractal spectrum width of Is , Vf , and MHD fluctuation amplitude reduce about 60%, 70%, and 42%, respectively, by applying biasing. In the presence of RHF, their width reduces about 60%, 85%, and 75

  15. Spatially resolved simulation of a radio frequency driven micro atmospheric pressure plasma jet and its effluent

    CERN Document Server

    Hemke, Torben; Gebhardt, Markus; Brinkmann, Ralf Peter; Mussenbrock, Thomas

    2011-01-01

    Radio frequency driven plasma jets are frequently employed as efficient plasma sources for surface modification and other processes at atmospheric pressure. The \\textit{radio-frequency driven micro-scaled atmospheric pressure plasma jet} ($\\mu$APPJ) is a particular variant of that concept whose geometry allows direct optical access. In this work, the characteristics of a $\\mu$APPJ operated with a helium-oxygen mixture and its interaction with a helium environment are studied by numerical simulation. The density and temperature of the electrons, as well as the concentration of all reactive species are studied both in the jet itself and in its effluent. It is found that the effluent is essentially free of charge carriers but contains a substantial amount of activated oxygen (O, O$_3$ and O$_2(^1\\Delta)$).

  16. Temporal and spatial profiles of emission intensities in atmospheric pressure helium plasma jet driven by microsecond pulse: Experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruixue; Zhang, Cheng; Yan, Ping; Shao, Tao, E-mail: st@mail.iee.ac.cn [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Shen, Yuan [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Zhu, Weidong [Department of Applied Science and Technology, Saint Peter' s University, Jersey City, New Jersey 07306 (United States); Babaeva, Natalia Yu.; Naidis, George V. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation)

    2015-09-28

    A needle-circular electrode structure helium plasma jet driven by microsecond pulsed power is studied. Spatially resolved emission results show that the emission intensity of He(3{sup 3}S{sub 1}) line decreases monotonically along the axial direction, while those of N{sub 2}(C{sup 3}Π{sub u}), N{sub 2}{sup +}(B{sup 2}∑{sup +}{sub u}), and O(3p{sup 5}P) reach their maxima at 3 cm, 2.6 cm, and 1.4 cm, respectively. The plasma plume of the four species shows different characteristics: The N{sub 2} emission plume travels at a fast speed along the entire plasma jet; the N{sub 2}{sup +} emission plume is composed of a bright head and relatively weak tail and travels a shorter distance than the N{sub 2} emission plume; the He emission plume travels at a slower speed for only a very short distance; propagation of the O emission plume is not observed. Results of calculation of radiation fluxes emitted by positive streamers propagating along helium plasma jets are presented. It is shown, in agreement with the results of the present experiment and with other available experimental data, that the intensities of radiation of N{sub 2}(C{sup 3}Π{sub u}) molecules and He(3{sup 3}S{sub 1}) atoms vary with time (along the plasma jet) quite differently. The factors resulting in this difference are discussed.

  17. Spatially-resolved spectral image of a microwave-induced plasma with Okamoto-cavity for nitridation of steel substrate.

    Science.gov (United States)

    Sato, Shigeo; Arai, Yuuki; Wagatsuma, Kazuaki

    2014-01-01

    When a nitrogen microwave-induced plasma produced with an Okamoto-cavity was employed as a source for the nitridation of steel samples, the characteristics of the plasma were investigated by analyzing a spatially-resolved emission image of nitrogen excited species obtained with a two-dimensionally imaging spectrograph. Our previous study had reported on an excellent performance of the Okamoto-cavity microwave-induced plasma (MIP), enabling a nitrided layer having a several-micrometer-thickness to form on an iron substrate, even if the treatment is completed within 1 min, which is superior to a conventional plasma nitriding using low-pressure glow discharges requiring a prolonged treatment time. In this paper, the reason for this is discussed based on a spectrometric investigation. The emission images of band heads of nitrogen molecule and nitrogen molecule ion extended toward the axial/radial directions of the plasma at larger microwave powers supplied to the MIP, thus elevating the number density of the excited species of nitrogen, which would activate any chemical reaction on the iron substrate. However, a drastic increase in the growth rate of the nitrided layer when increasing the microwave power from 600 to 700 W, which had been observed in our previous study, could not be explained only from such a variation in the excited species of nitrogen. This result is probably because the growth process is dominantly controlled by thermal diffusion of nitrogen atom after it enters into the iron substrate, where the substrate temperature is the most important parameter concerning the mobility in the iron lattice. Therefore, the Okamoto-cavity MIP could contribute to a thermal source through radiative heating as well as a source of nitrogen excited species, especially in the growth process of the nitrided layer.

  18. A technique for evaluating the influence of spatial sampling on the determination of global mean total columnar ozone

    Science.gov (United States)

    Tolson, R. H.

    1981-01-01

    A technique is described for providing a means of evaluating the influence of spatial sampling on the determination of global mean total columnar ozone. A finite number of coefficients in the expansion are determined, and the truncated part of the expansion is shown to contribute an error to the estimate, which depends strongly on the spatial sampling and is relatively insensitive to data noise. First and second order statistics are derived for each term in a spherical harmonic expansion which represents the ozone field, and the statistics are used to estimate systematic and random errors in the estimates of total ozone.

  19. Detection of Plasma Fluctuations in White-light Images of the Outer Solar Corona: Investigation of the Spatial and Temporal Evolution

    Science.gov (United States)

    Telloni, D.; Ventura, R.; Romano, P.; Spadaro, D.; Antonucci, E.

    2013-04-01

    This work focuses on the first results from the identification and characterization of periodic plasma density fluctuations in the outer corona, observed in STEREO-A COR1 white-light image time series. A two-dimensional reconstruction of the spatial distribution and temporal evolution of the coronal fluctuation power has been performed over the whole plane of the sky, from 1.4 to 4.0 R ⊙. The adopted diagnostic tool is based on wavelet transforms. This technique, with respect to the standard Fourier analysis, has the advantage of localizing non-persistent fluctuating features and exploring variations of the relating wavelet power in both space and time. The map of the variance of the coronal brightness clearly outlines intermittent spatially coherent fluctuating features, localized along, or adjacent to, the strongest magnetic field lines. In most cases, they do not correspond to the visible coronal structures in the brightness maps. The results obtained provide a scenario in which the solar corona shows quasi-periodic, non-stationary density variations characterized by a wide range of temporal and spatial scales and strongly confined by the magnetic field topology. In addition, structures fluctuating with larger power are larger in size and evolve more slowly. The characteristic periodicities of the fluctuations are comparable to their lifetimes. This suggests that plasma fluctuations lasting only one or two wave periods and initially characterized by a single dominant periodicity either rapidly decay into a turbulent mixed flow via nonlinear interactions with other plasma modes, or they are damped by thermal conduction. The periodic non-stationary coronal fluctuations outlined by the closed field lines at low and mid latitudes might be associated with the existence of slow standing magneto-acoustic waves excited by the convective supergranular motion. The fluctuating ray-like structures observed along open field lines appear to be linked either to the

  20. Experimental investigations of the distribution of pulsed-plasma-generator radiation at its various spatial orientation and global anisotropy of space

    Energy Technology Data Exchange (ETDEWEB)

    Baurov, Yu.A.; Timofeev, I.B.; Chernikov, V.A.; Chalkin, S.F.; Konradov, A.A

    2003-05-26

    Results of experimental investigation of plasma luminous emittance (integrated with respect to time and quartz transmission band spectrum) of a pulsed plasma generator depending on its axis spatial position, are presented. It is shown that the spatial distribution of plasma radiant intensity is of clearly anisotropic character, that is, there exists a cone of the plasma generator axial directions in which the radiation of plasma reaches its peak. A possible explanation of the results obtained based on a hypothesis of global anisotropy of space caused by the existence of a cosmological vectorial potential A{sub g}, is given. It is shown that the vector A{sub g} has the following coordinates in the second equatorial coordinate system: right ascension {alpha}=293 deg. {+-}10 deg., declination {delta}=36 deg. {+-}10 deg. The experimental results are in accordance with those of the earlier experiments on determining the direction of A{sub g}.

  1. Elimination of sulphur odours at landfills by bioconversion and the corona discharge plasma technique.

    Science.gov (United States)

    Xia, Fangfang; Liu, Xin; Kang, Ying; He, Ruo; Wu, Zucheng

    2015-01-01

    Hydrogen sulphide (H2S) contributes a lot to odours at landfills, which is a threat to the environment and the health of the staff therein. To mitigate its emission, the bioconversion within landfill cover soils (LCSs) was introduced. H2S emission and concentration both in the field air above the landfill and in microcosm testing were surveyed. Results indicated that H2S emission and concentration in the landfill varied with landfill seasons and sites. There existed relationship between H2S concentration and fluxes spatially and temporally. To characterize and assess the spatial and temporal diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) in the LCSs, the terminal-restriction fragment length polymorphism technique was employed. Using the functional genes of dsrB and soxB, SOB, including Halothiobacillus, Rhodothalassium, Paracocccus, Allochromatium, and Thiobacillus, and SRB, including Desulfovibrio, Syntrophobacter, Desulfomonile and Desulfobacca, were identical and exhibited the dominant role in the LCSs. By employing an alternative available corona reactor, more than 90% removal efficiencies of sulphides were demonstrated, suggesting that the LCSs for eliminating odours in a lower concentration would be feasible.

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

    Science.gov (United States)

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

    2013-11-01

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

  3. Charge plasma technique based dopingless accumulation mode junctionless cylindrical surrounding gate MOSFET: analog performance improvement

    Science.gov (United States)

    Trivedi, Nitin; Kumar, Manoj; Haldar, Subhasis; Deswal, S. S.; Gupta, Mridula; Gupta, R. S.

    2017-09-01

    A charge plasma technique based dopingless (DL) accumulation mode (AM) junctionless (JL) cylindrical surrounding gate (CSG) MOSFET has been proposed and extensively investigated. Proposed device has no physical junction at source to channel and channel to drain interface. The complete silicon pillar has been considered as undoped. The high free electron density or induced N+ region is designed by keeping the work function of source/drain metal contacts lower than the work function of undoped silicon. Thus, its fabrication complexity is drastically reduced by curbing the requirement of high temperature doping techniques. The electrical/analog characteristics for the proposed device has been extensively investigated using the numerical simulation and are compared with conventional junctionless cylindrical surrounding gate (JL-CSG) MOSFET with identical dimensions. For the numerical simulation purpose ATLAS-3D device simulator is used. The results show that the proposed device is more short channel immune to conventional JL-CSG MOSFET and suitable for faster switching applications due to higher I ON/ I OFF ratio.

  4. Detection of plasma fluctuations in white-light images of the outer solar corona: investigation of the spatial and temporal evolution

    CERN Document Server

    Telloni, D; Romano, P; Spadaro, D; Antonucci, E

    2013-01-01

    This work focus on the first results on the identification and characterization of periodic plasma density fluctuations in the outer corona, observed in STEREO-A COR1 white-light image time series. A 2D reconstruction of the spatial distribution and temporal evolution of the coronal fluctuation power has been performed over the whole plane of the sky, from 1.4 to 4.0 solar radii. The adopted diagnostic tool is based on wavelet transforms. This technique, with respect to the standard Fourier analysis, has the advantage of localizing non-persistent fluctuating features and exploring the variations of the relating wavelet power in both space and time. The map of the variance of the coronal brightness clearly outlines intermittent, spatially coherent fluctuating features, localized along, or adjacent to, the strongest magnetic field lines. In most cases they do not correspond to the coronal structures visible in the brightness maps. The results obtained provide a scenario in which the solar corona shows quasi-per...

  5. Spatial mode structures of electrostatic drift waves in a collisional cylindrical helicon plasma

    DEFF Research Database (Denmark)

    Schröder, C.; Grulke, O.; Klinger, T.;

    2004-01-01

    In a cylindrical helicon plasma, mode structures of coherent drift waves are studied in the poloidal plane, the plane perpendicular to the ambient magnetic field. The mode structures rotate with a constant angular velocity in the direction of the electron diamagnetic drift and show significant...

  6. Temperature measurement of plasma-assisted flames: comparison between optical emission spectroscopy and 2-color laser induced fluorescence techniques

    KAUST Repository

    Lacoste, Deanna A.

    2015-03-30

    Accurate thermometry of highly reactive environments, such as plasma-assisted combustion, is challenging. With the help of conical laminar premixed methane-air flames, this study compares two thermometry techniques for the temperature determination in a combustion front enhanced by nanosecond repetitively pulsed (NRP) plasma discharges. Based on emission spectroscopic analysis, the results show that the rotational temperature of CH(A) gives a reasonable estimate for the adiabatic flame temperature, only for lean and stoichiometric conditions. The rotational temperature of N2(C) is found to significantly underestimate the flame temperature. The 2-color OH-PLIF technique gives correct values of the flame temperature.

  7. Spatially resolved measurements and diagnostics of digitally controlled rotating field pulsed plasma operated in helium at 20 kHz

    Science.gov (United States)

    Giersz, Jacek; Jankowski, Krzysztof; Reszke, Edward

    2017-04-01

    Using optical emission spectrometry, fundamental properties are investigated of a stable, planar atmospheric pressure micro discharge, several dozen microliters in volume, driven by a digitally controlled 20 kHz rotating microsecond pulsed power. The discharge is generated by rectangular wave pulses using helium as the working gas. At a low cost, the digitally controlled plasma source produces a highly symmetrical, non-stationary helium discharge maintained in open air within 5 electrodes positioned in the plane toward the center. It has been shown that the geometrical shapes of the momentary discharges, which occur between the electrodes, are not arc-like shaped, but rather have a diffusive character and the resulting plasma can become doughnut-like in shape. Rotational and vibrational temperatures from OH and N2 bands, excitation temperatures from He lines and ionization temperatures from Ca lines, as well as electron number densities from Hβ Stark broadening have been estimated along the plasma diameter using axial viewing. The results demonstrated that Texc (He) reaches stable value of 3800 K for selected plasma generation conditions (one anode and two cathodes commutation mode, cathode pulse width 8 microseconds, supplied power 200 W, helium gas flow 1 L·min- 1), while the Trot (OH) is considerably lower (1700 K). The electron number density has been evaluated to be (1.7-3.3) × 1014 cm- 3 and both Tion (Ca) and Tvib (N2) varied, throughout in the 4500-5100 K and 4000-4800 K ranges respectively, reaching its peak value near 2 mm off the plasma axis. Spatial measurements revealed symmetrical distribution of the plasma parameters, while the measurements of calcium and nitrogen ionic emission confirmed symmetrical doughnut shape of the discharge. Moreover, the processes running inside the discharge and their interaction with the surrounding atmosphere have been described in accordance to the recorded spectra. Spectroscopic observation has shown the existence of

  8. Spatial Color Indexing: An Efficient and Robust Technique for Content-Based Image Retrieval

    Directory of Open Access Journals (Sweden)

    Rachid Alaoui

    2009-01-01

    Full Text Available Problem statement: Color Histogram is admitted as a useful representation of features because it is a statistical result and possesses the merits of simplicity, robustness and efficiency. However, the main problem with color histogram indexing is that it doesn't take into account the spatial information. Previous researches have proved that the effectiveness of image retrieval increases when spatial feature of colors is included in image retrieval. Approach: This study examined the use of a computational geometry-based spatial color indexing methodology, there are two major contributions: (1 Color Spatial Entropy (CSE which introduce entropy to describe the spatial information of colors. (2 Color Hybrid Entropy (CHE witch introduce a description spatial on multiresolution images. Results: The experiment results showed that CSE and CHE is more better performance and efficiently and relevant result than those traditional CBIR method based on the local histograms. Conclusion: our new system was presented to strengthen the retrieval efficacy and remains more stable performance by transformations geometry in more CHE characterize quantitatively the compactness of the multiresolution images.

  9. Ultrafast single-shot imaging of laser-produced plasmas via spatial division and routing

    Science.gov (United States)

    Yeola, Sarang; Kuk, Donghoon; Kim, Ki-Yong

    2017-01-01

    We have developed a single-shot imaging camera, which can capture ultrafast events occurring on femtosecond and picosecond time scales. The working principle of this camera relies on spatial division and routing of femtosecond laser pulses. Here we have employed simple optics such as mirrors to produce multiple, time-delayed laser pulses and to project time-evolving images onto separate standard cameras. This spatial division and routing method has been tested with a femtosecond amplified laser in visualizing the evolution of laser-induced ionization in air and ablation in solids in single-shots. The number of frames is currently limited to 4 but can be increased further to N x N by using 3D printed optics for spatial division and routing. Work supported by the National Science Foundation (NSF) under Award No. 1351455.

  10. Assessing the spatial distribution of glyphosate-AMPA in an Argentinian farm field using a pedometric technique

    Science.gov (United States)

    Barbera, Agustin; Zamora, Martin; Domenech, Marisa; Vega-Becerra, Andres; Castro-Franco, Mauricio

    2017-04-01

    The cultivation of transgenic glyphosate-resistant crops has been the most rapidly adopted crop technology in Argentina since 1997. Thus, more than 180 million liters of the broad-spectrum herbicide glyphosate (N - phosphonomethylglicine) are applied every year. The intensive use of glyphosate combined with geomorphometrical characteristics of the Pampa region is a matter of environmental concern. An integral component of assessing the risk of soil contamination in farm fields is to describe the spatial distribution of the levels of contaminant agent. Application of pedometric techniques for this purpose has been scarcely demonstrated. These techniques could provide an estimate of the concentration at a given unsampled location, as well as the probability that concentration will exceed the critical threshold concentration. In this work, a pedometric technique for assessing the spatial distribution of glyphosate in farm fields was developed. A field located at INTA Barrow, Argentina (Lat: -38.322844, Lon: -60.25572) which has a great soil spatial variability, was divided by soil-specific zones using a pedometric technique. This was developed integrating INTA Soil Survey information and a digital elevation model (DEM) obtained from a DGPS. Firstly, 10 topographic indices derived from a DEM were computed in a Random Forest algorithm to obtain a classification model for soil map units (SMU). Secondly, a classification model was applied to those topographic indices but at a scale higher than 1:1000. Finally, a spatial principal component analysis and a clustering using Fuzzy K-means were used into each SMU. From this clustering, three soil-specific zones were determined which were also validated through apparent electrical conductivity (CEa) measurements. Three soil sample points were determined by zone. In each one, samples from 0-10, 10-20 and 20-40cm depth were taken. Glyphosate content and AMPA in each soil sample were analyzed using de UPLC-MS/MS ESI (+/-). Only

  11. Application of the thermal plasma technique in the treatment of stone surfaces; Aplicacion de la tecnica de plasmas termicos en el tratamiento de superficies petreas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez A, Z.I

    2000-07-01

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

  12. Exploring the Spatial Resolution of the Photothermal Beam Deflection Technique in the Infrared Region

    CERN Document Server

    Seidel, Wolfgang

    2004-01-01

    In photothermal beam deflection spectroscopy (PTBD) generating and detection of thermal waves occur generally in the sub-millimeter length scale. Therefore, PTBD provides spatial information about the surface of the sample and permits imaging and/or microspectrometry. Recent results of PTBD experiments are presented with a high spatial resolution which is near the diffraction limit of the infrared pump beam (CLIO-FEL). We investigated germanium substrates showing restricted O+-doped regions with an infrared absorption line at a wavelength around 11.6 microns. The spatial resolution was obtained by strongly focusing the probe beam (i.e. a HeNe laser) on a sufficiently small spot. The strong divergence makes it necessary to refocus the probe beam in front of the position detector. The influence of the focusing elements on spatial resolution and signal-to-noise ratio is discussed. In future studies we expect an enhanced spatial resolution due to an extreme focusing of the probe beam leading to a highly sensitive...

  13. Physical-Chemical Characterization of Nanodispersed Powders Produced by a Plasma-Chemical Technique

    Institute of Scientific and Technical Information of China (English)

    M. GEORGIEVA; G. VISSOKOV; Iv. GRANCHAROV

    2007-01-01

    This article presents a review on the physical-chemical properties and characteristics of plasma-chemically produced nanodispersed powders (NDP), such as metals, oxides, nitrides, carbides, and catalysts. The plasma-chemical preparation of the powders was carried out in thermal plasma (TP) created by means of high-current electric arcs, plasma jets, high-frequency (HF) discharges, etc. We also discuss certain properties and characteristics of the NDPs, which are determined largely by the conditions of preparation.

  14. Modeling the Plasma Flow in the Inner Heliosheath with a Spatially Varying Compression Ratio

    Science.gov (United States)

    Nicolaou, G.; Livadiotis, G.

    2017-03-01

    We examine a semi-analytical non-magnetic model of the termination shock location previously developed by Exarhos & Moussas. In their study, the plasma flow beyond the shock is considered incompressible and irrotational, thus the flow potential is analytically derived from the Laplace equation. Here we examine the characteristics of the downstream flow in the heliosheath in order to resolve several inconsistencies existing in the Exarhos & Moussas model. In particular, the model is modified in order to be consistent with the Rankine-Hugoniot jump conditions and the geometry of the termination shock. It is shown that a shock compression ratio varying along the latitude can lead to physically correct results. We describe the new model and present several simplified examples for a nearly spherical, strong termination shock. Under those simplifications, the upstream plasma is nearly adiabatic for large (˜100 AU) heliosheath thickness.

  15. Pseudo-3D PIC modeling of drift-induced spatial inhomogeneities in planar magnetron plasmas

    Science.gov (United States)

    Revel, A.; Minea, T.; Tsikata, S.

    2016-10-01

    A pseudo-3D modeling approach, based on a particle-in-cell (PIC)-Monte Carlo collisions algorithm, has been developed for the study of large- and short-scale organization of the plasma in a planar magnetron. This extension of conventional PIC modeling permits the observation of spontaneous organization of the magnetron plasma, under the influence of crossed electric and magnetic fields, into the well-known, large-scale regions of enhanced ionization and density known as spokes. The nature of complex three-dimensional electron trajectories around such structures, and non-uniform ionization within them, is revealed. This modeling provides direct numerical evidence for the existence of high-amplitude internal spoke electric fields, proposed in earlier works. A 3D phenomenological model, consistent with numerical results, is proposed. Electron density fluctuations in the megahertz range, with characteristics similar to the electron cyclotron drift instability experimentally identified in a recent Letter, are also found.

  16. Investigation of Vortex Structures in Gas-Discharge Nonneutral Electron Plasma: I. Experimental Technique

    CERN Document Server

    Kervalishvili, N A

    2015-01-01

    The nonperturbing experimental methods have been described, by means of which the solitary vortex structures in gas-discharge nonneutral electron plasma were detected and investigated. The comparison with the experimental methods used in devices with pure electron plasma was made. The problems of shielding the electrostatic perturbations in nonneutral plasmas were considered.

  17. Simultaneous iterative reconstruction technique software for spectral-spatial EPR imaging

    Science.gov (United States)

    Spitzbarth, Martin; Drescher, Malte

    2015-08-01

    Continuous wave electron paramagnetic resonance imaging (EPRI) experiments often suffer from low signal to noise ratio. The increase in spectrometer time required to acquire data of sufficient quality to allow further analysis can be counteracted in part by more processing effort during the image reconstruction step. We suggest a simultaneous iterative reconstruction algorithm (SIRT) for reconstruction of continuous wave EPRI experimental data as an alternative to the widely applied filtered back projection algorithm (FBP). We show experimental and numerical test data of 2d spatial images and spectral-spatial images. We find that for low signal to noise ratio and spectral-spatial images that are limited by the maximum magnetic field gradient strength SIRT is more suitable than FBP.

  18. Spatial Encoding Using a Code Division Technique for Fast Ultrasound Imaging

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2008-01-01

    This paper describes a method for spatial encoding in synthetic transmit aperture ultrasound imaging. This allows several ultrasonic sources to be active simultaneously. The method is based on transmitting pseudo-random sequences to spatially encode the transmitters. The data can be decoded after...... ultrasound scanner and compared to a synthetic transmit aperture ultrasound imaging scheme using a sinusoidal excitation. The performance of the proposed method was comparable to the reference with respect to axial and lateral resolution, but it displayed poorer contrast with sidelobe levels at ∼-40 d...

  19. Spatial and Temporal Analysis of Mexico City Subsidence by Means of Interferometric Techniques

    Science.gov (United States)

    Lopez-Quiroz, P.; Tupin, F.; Briole, P.; Doin, M.; Nicolas, J.

    2007-05-01

    In Mexico city, water over-consumption leads to subsidence. Before the Spanish conquest, the southern part of the Mexico Valley, an endoreic basin surrounded by mountains, was filled by a large lake. Flooding problems oblige conquerors to dry the lakes, which by now have almost completely disappeared and have been replaced by buildings. The simplified hydrogeologic structure of Mexico Valley includes a superficial 50 to 300 m thick lacustrine aquitard overlying a thicker aquifer made of alluvial deposits. The aquitard layer plays a crucial role in the subsidence process due to the very high compressibility of its clay deposits separated by a less compressible sand layer where the biggest buildings are anchored. The aquifer over-exploitation leads to a depression of its piezometric level, inducing water downwards flow in the clays, yielding compaction and subsidence (Rivera, 1990). In order to quantitatively link subsidence to water pumping, the Mexico city subsidence needs to be mapped and analyzed through space and time. It will help identify possible variations related with seasonal recharge, anchored and non anchored buildings, old and new pumping areas with varying clay compressibility through time due to consolidation (Rivera, 1990, Ortega-Guerrero et al., 1999). Radar interferometry (InSAR, Interferometric Synthetic Aperture Radar) has been successfully applied to map subsidence caused by water pumping (e. g., Amelung et al., 2000). It uses two repeated SAR acquisitions to obtain distance measurements. After geometrical corrections, the interferometric phase contains deformation information as well as residual orbital and topographic errors and atmospheric delays. A previous work using levelling, interferometry and GPS techniques over Mexico city showed that the location of the maximum subsidence rates (about 400 mm/yr) has changed and moved from the downtown area to the east of the city over a 50 years interval (Cabral-Cano et al., 2006). In this previous

  20. Plasma turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

  1. A comparison of spatial clustering and cluster detection techniques for childhood leukemia incidence in Ohio, 1996 – 2003

    Directory of Open Access Journals (Sweden)

    Wheeler David C

    2007-03-01

    Full Text Available Abstract Background Spatial cluster detection is an important tool in cancer surveillance to identify areas of elevated risk and to generate hypotheses about cancer etiology. There are many cluster detection methods used in spatial epidemiology to investigate suspicious groupings of cancer occurrences in regional count data and case-control data, where controls are sampled from the at-risk population. Numerous studies in the literature have focused on childhood leukemia because of its relatively large incidence among children compared with other malignant diseases and substantial public concern over elevated leukemia incidence. The main focus of this paper is an analysis of the spatial distribution of leukemia incidence among children from 0 to 14 years of age in Ohio from 1996–2003 using individual case data from the Ohio Cancer Incidence Surveillance System (OCISS. Specifically, we explore whether there is statistically significant global clustering and if there are statistically significant local clusters of individual leukemia cases in Ohio using numerous published methods of spatial cluster detection, including spatial point process summary methods, a nearest neighbor method, and a local rate scanning method. We use the K function, Cuzick and Edward's method, and the kernel intensity function to test for significant global clustering and the kernel intensity function and Kulldorff's spatial scan statistic in SaTScan to test for significant local clusters. Results We found some evidence, although inconclusive, of significant local clusters in childhood leukemia in Ohio, but no significant overall clustering. The findings from the local cluster detection analyses are not consistent for the different cluster detection techniques, where the spatial scan method in SaTScan does not find statistically significant local clusters, while the kernel intensity function method suggests statistically significant clusters in areas of central, southern

  2. Modelling the potential spatial distribution of mosquito species using three different techniques

    NARCIS (Netherlands)

    Cianci, D.; Hartemink, N.; Ibáñez-Justicia, A.

    2015-01-01

    Background: Models for the spatial distribution of vector species are important tools in the assessment of the risk of establishment and subsequent spread of vector-borne diseases. The aims of this study are to define the environmental conditions suitable for several mosquito species through species

  3. Laboratory evaluation techniques to investigate the spatial potential of repellents for push & pull mosquito control systems

    Science.gov (United States)

    A protocol has been developed for the indoor evaluation of candidate spatial repellents intended for use in push and pull systems. Single treatments (catnip oil, 1-methylpiperazine and homopiperazine) and a mixture of catnip oil and homopiperazine were tested with yellow-fever mosquitoes (Aedes aegy...

  4. Musical Applications and Design Techniques for the Gametrak Tethered Spatial Position Controller

    DEFF Research Database (Denmark)

    Freed, Adrian; Overholt, Daniel; Hansen, Anne-Marie

    2009-01-01

    tangible gaming interface that promotes inter-generational creative play and discovery . After introducing the peculiarities of the GameTrak and comparing it to related spatial position sensing systems we survey musical applications of the device. The short paper format cannot do justice to the depth...

  5. Modelling the potential spatial distribution of mosquito species using three different techniques

    NARCIS (Netherlands)

    Cianci, Daniela; Hartemink, Nienke; Ibáñez-Justicia, Adolfo

    2015-01-01

    BACKGROUND: Models for the spatial distribution of vector species are important tools in the assessment of the risk of establishment and subsequent spread of vector-borne diseases. The aims of this study are to define the environmental conditions suitable for several mosquito species through species

  6. Spatial pattern of soil and soybean crop: an assessment using digital mapping techniques

    Science.gov (United States)

    Castro Franco, Mauricio; Cordoba, Mariano; Costa, Jose Luis; Aparicio, Virginia; Domenech, Marisa

    2017-04-01

    The aim of this study was to analyze the relationships among spatial patterns of soil properties and soybean crop. The study was carried out in three provinces of Argentina: (i) Buenos Aires (BA), (ii) Entre Rios (ER) and (iii) Cordoba (COR). In each province, 2 agricultural fields were selected. Ancillary information related to soil forming factors in each field was gathered, for example apparent electrical conductivity (ECa), NDVI and yield maps. We used principal component spatial analysis (MULTISPATI-PCA) to delimit zones for soil type by field. To zonal validation, 4 sampling sites were located in which we collected soil samples, grain yield and soybean crop quality. Random Forest (RF) was used to determine the importance of soil properties over soybean crop properties. For comparing soil properties in each zone between fields, a mix lineal model and ANOVA were adjusted. Our results suggest that MULTISPATI-PCA was efficient to delimit zones for soil type. Relationships between soil properties and crop yield were examined and understood. However, it did not occur with crop quality patterns. Topography did not prove to be an accurate indicator of spatial pattern relations of soil properties and crop, whereas ECa, yield maps and NDVI proved to be effective indicators. Grains m-2 and NDVI were affected homogeneously and were showed spatial correspondence according to soil limitations. Percentage of protein did not show spatial correspondence with delimitated zones in saline soils, particularly in ER. In such fields, Om and pH were important for percentage of protein. It was evidenced that a direct relation exists between complex relationship of soil and crop properties and soil degradation.

  7. Wavelet-based spatial comparison technique for analysing and evaluating two-dimensional geophysical model fields

    Directory of Open Access Journals (Sweden)

    S. Saux Picart

    2011-11-01

    Full Text Available Complex numerical models of the Earth's environment, based around 3-D or 4-D time and space domains are routinely used for applications including climate predictions, weather forecasts, fishery management and environmental impact assessments. Quantitatively assessing the ability of these models to accurately reproduce geographical patterns at a range of spatial and temporal scales has always been a difficult problem to address. However, this is crucial if we are to rely on these models for decision making. Satellite data are potentially the only observational dataset able to cover the large spatial domains analysed by many types of geophysical models. Consequently optical wavelength satellite data is beginning to be used to evaluate model hindcast fields of terrestrial and marine environments. However, these satellite data invariably contain regions of occluded or missing data due to clouds, further complicating or impacting on any comparisons with the model. A methodology has recently been developed to evaluate precipitation forecasts using radar observations. It allows model skill to be evaluated at a range of spatial scales and rain intensities. Here we extend the original method to allow its generic application to a range of continuous and discontinuous geophysical data fields, and therefore allowing its use with optical satellite data. This is achieved through two major improvements to the original method: (i all thresholds are determined based on the statistical distribution of the input data, so no a priori knowledge about the model fields being analysed is required and (ii occluded data can be analysed without impacting on the metric results. The method can be used to assess a model's ability to simulate geographical patterns over a range of spatial scales. We illustrate how the method provides a compact and concise way of visualising the degree of agreement between spatial features in two datasets. The application of the new method, its

  8. Polyaniline (PANI) modified bentonite by plasma technique for U(VI) removal from aqueous solution

    Science.gov (United States)

    Liu, Xinghao; Cheng, Cheng; Xiao, Chengjian; Shao, Dadong; Xu, Zimu; Wang, Jiaquan; Hu, Shuheng; Li, Xiaolong; Wang, Weijuan

    2017-07-01

    Polyaniline (PANI) modified bentonite (PANI/bentonie) was synthesized by plasma induced polymerization of aniline on bentonite surface, and applied to uptake of uranium(VI) ions from aqueous solution. The as-synthesized PANI/bentonie was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Batch adsorption technique was utilized to investigate the adsorption of U(VI) on bentonite and PANI/bentonite. The adsorption of U(VI) (10 mg/L) on PANI/bentonite surface is fairly depend on solution pH, ionic strength, and temperature in solution. The modified PANI on PANI/bentonite surface significantly enhances its adsorption capability for U(VI). The presence of humic acid (HA) can sound enhance U(VI) adsorption on PANI/bentonite at pH 6.5. According to the thermodynamic parameters, the adsorption of U(VI) on PANI/bentonite surface is a spontaneous and endothermic process. The results highlight the application of PANI/bentonite composites as candidate material for the uptake of trace U(VI) from aqueous solution.

  9. Fusing Observations and Model Results for Creation of Enhanced Ozone Spatial Fields: Comparison of Three Techniques

    Science.gov (United States)

    This paper presents three simple techniques for fusing observations and numerical model predictions. The techniques rely on model/observation bias being considered either as error free, or containing some uncertainty, the latter mitigated with a Kalman filter approach or a spati...

  10. Dynamical and transport properties in plasmas including three-particle spatial correlations

    Science.gov (United States)

    Ababsa, Hakima; Meftah, Med Tayeb; Chohra, Thouria

    2017-03-01

    In this work, we study the two and triplet static correlation functions in plasma when the ions interact via the Debye screened potential and via the Deutsch screened potential. The latter takes into consideration the possible quantum effects at short distances. The ratio of the mean distance between two ions and the thermal De Broglie wavelength ri/λT gives the measure of these effects. Our investigation is developed in the conditions of weak coupling parameter (Γ <1 ). The pair and the triplet correlation functions are calculated numerically and compared to the correlation functions due to the Kirkwood superposition approximation (KSA). Some applications to the ion velocity auto-correlation function D(t) and the electric field auto-correlation function C(t) at an ion (assumed to be an impurity) and the diffusion coefficient D are calculated for the two kinds of potentials in different plasma conditions. The comparison with other results found in the literature shows a well satisfactory agreement, for the static as well as the dynamic properties.

  11. Investigation of local thermodynamic equilibrium of laser induced Al2O3-TiC plasma in argon by spatially resolved optical emission spectroscopy

    Science.gov (United States)

    Alnama, K.; Alkhawwam, A.; Jazmati, A. K.

    2016-06-01

    Plasma plume of Al2O3-TiC is generated by third harmonic Q-switched Nd:YAG nanosecond laser. It is characterized using Optical Emission Spectroscopy (OES) at different argon background gas pressures 10, 102, 103, 104 and 105 Pa. Spatial evolution of excitation and ionic temperatures is deduced from spectral data analysis. Temporal evolution of Ti I emission originated from different energy states is probed. The correlation between the temporal behavior and the spatial temperature evolution are investigated under LTE condition for the possibility to use the temporal profile of Ti I emission as an indicator for LTE validity in the plasma.

  12. Investigation of local thermodynamic equilibrium of laser induced Al2O3–TiC plasma in argon by spatially resolved optical emission spectroscopy

    Directory of Open Access Journals (Sweden)

    K. Alnama

    2016-06-01

    Full Text Available Plasma plume of Al2O3–TiC is generated by third harmonic Q-switched Nd:YAG nanosecond laser. It is characterized using Optical Emission Spectroscopy (OES at different argon background gas pressures 10, 102, 103, 104 and 105 Pa. Spatial evolution of excitation and ionic temperatures is deduced from spectral data analysis. Temporal evolution of Ti I emission originated from different energy states is probed. The correlation between the temporal behavior and the spatial temperature evolution are investigated under LTE condition for the possibility to use the temporal profile of Ti I emission as an indicator for LTE validity in the plasma.

  13. Real-time spatial frequency domain imaging by single snapshot multiple frequency demodulation technique

    Science.gov (United States)

    Cao, Zili; Lin, Weihao; Chen, Xinlin; Zeng, Bixin; Xu, Min

    2017-02-01

    We have presented a novel Single Snapshot Multiple Frequency Demodulation (SSMD) method enabling single snapshot wide field imaging of optical properties of turbid media in the Spatial Frequency Domain. SSMD makes use of the orthogonality of harmonic functions and extracts the modulation transfer function (MTF) at multiple modulation frequencies and of arbitrary orientations and amplitudes simultaneously from a single structured-illuminated image at once. SSMD not only increases significantly the data acquisition speed and reduces motion artifacts but also exhibits excellent noise suppression in imaging as well. The performance of SSMD-SFDI is demonstrated with experiments on both tissue mimicking phantoms and in vivo for recovering optical properties. SSMD is ideal in the implementation of a real-time spatial frequency domain imaging platform, which will open up SFDI for vast applications in, for example, mapping the optical properties of a dynamic turbid medium or monitoring fast temporal evolutions.

  14. Conductive Polymer Synthesis with Single-Crystallinity via a Novel Plasma Polymerization Technique for Gas Sensor Applications

    Directory of Open Access Journals (Sweden)

    Choon-Sang Park

    2016-09-01

    Full Text Available This study proposes a new nanostructured conductive polymer synthesis method that can grow the single-crystalline high-density plasma-polymerized nanoparticle structures by enhancing the sufficient nucleation and fragmentation of the pyrrole monomer using a novel atmospheric pressure plasma jet (APPJ technique. Transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, X-ray photoelectron spectroscopy (XPS, and field emission scanning electron microscopy (FE-SEM results show that the plasma-polymerized pyrrole (pPPy nanoparticles have a fast deposition rate of 0.93 µm·min−1 under a room-temperature process and have single-crystalline characteristics with porous properties. In addition, the single-crystalline high-density pPPy nanoparticle structures were successfully synthesized on the glass, plastic, and interdigitated gas sensor electrode substrates using a novel plasma polymerization technique at room temperature. To check the suitability of the active layer for the fabrication of electrochemical toxic gas sensors, the resistance variations of the pPPy nanoparticles grown on the interdigitated gas sensor electrodes were examined by doping with iodine. As a result, the proposed APPJ device could obtain the high-density and ultra-fast single-crystalline pPPy thin films for various gas sensor applications. This work will contribute to the design of highly sensitive gas sensors adopting the novel plasma-polymerized conductive polymer as new active layer.

  15. Lacunarity analysis: A general technique for the analysis of spatial patterns

    Energy Technology Data Exchange (ETDEWEB)

    Plotnick, R.E. [Department of Geological Sciences, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7059 (United States); Gardner, R.H. [University of Maryland, Appalachian Environmental Laboratory, Frostburg, Maryland 21532 (United States); Hargrove, W.W. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6038 (United States); Prestegaard, K. [Department of Geology, University of Maryland, College Park, Maryland 20742 (United States); Perlmutter, M. [Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

    1996-05-01

    Lacunarity analysis is a multiscaled method for describing patterns of spatial dispersion. It can be used with both binary and quantitative data in one, two, and three dimensions. Although originally developed for fractal objects, the method is more general and can be readily used to describe nonfractal and multifractal patterns. Lacunarity analysis is broadly applicable to many data sets used in the natural sciences; we illustrate its application to both geological and ecological data. {copyright} {ital 1996 The American Physical Society.}

  16. Spatial analysis of ambient gamma dose equivalent rate data by means of digital image processing techniques.

    Science.gov (United States)

    Szabó, Katalin Zsuzsanna; Jordan, Gyozo; Petrik, Attila; Horváth, Ákos; Szabó, Csaba

    2017-01-01

    A detailed ambient gamma dose equivalent rate mapping based on field measurements at ground level and at 1 m height was carried out at 142 sites in 80 × 90 km area in Pest County, Hungary. Detailed digital image processing analysis was carried out to identify and characterise spatial features such as outlying points, anomalous zones and linear edges in a smoothed TIN interpolated surface. The applied method proceeds from the simple shaded relief model and digital cross-sections to the more complex gradient magnitude and gradient direction maps, 2nd derivative profile curvature map, relief map and lineament density map. Each map is analysed for statistical characteristics and histogram-based image segmentation is used to delineate areas homogeneous with respect to the parameter values in these maps. Assessment of spatial anisotropy is implemented by 2D autocorrelogram and directional variogram analyses. The identified spatial features are related to underlying geological and tectonic conditions using GIS technology. Results show that detailed digital image processing is efficient in revealing the pattern present in field-measured ambient gamma dose equivalent rates and they are related to regional scale tectonic zones and surface sedimentary lithological conditions in the study area.

  17. Spatial Modeling of Rainfall Patterns over the Ebro River Basin Using Multifractality and Non-Parametric Statistical Techniques

    Directory of Open Access Journals (Sweden)

    José L. Valencia

    2015-11-01

    Full Text Available Rainfall, one of the most important climate variables, is commonly studied due to its great heterogeneity, which occasionally causes negative economic, social, and environmental consequences. Modeling the spatial distributions of rainfall patterns over watersheds has become a major challenge for water resources management. Multifractal analysis can be used to reproduce the scale invariance and intermittency of rainfall processes. To identify which factors are the most influential on the variability of multifractal parameters and, consequently, on the spatial distribution of rainfall patterns for different time scales in this study, universal multifractal (UM analysis—C1, α, and γs UM parameters—was combined with non-parametric statistical techniques that allow spatial-temporal comparisons of distributions by gradients. The proposed combined approach was applied to a daily rainfall dataset of 132 time-series from 1931 to 2009, homogeneously spatially-distributed across a 25 km × 25 km grid covering the Ebro River Basin. A homogeneous increase in C1 over the watershed and a decrease in α mainly in the western regions, were detected, suggesting an increase in the frequency of dry periods at different scales and an increase in the occurrence of rainfall process variability over the last decades.

  18. Development of a spectroscopic technique for simultaneous magnetic field, electron density, and temperature measurements in ICF-relevant plasmas

    Science.gov (United States)

    Dutra, E. C.; Koch, J. A.; Presura, R.; Angermeier, W. A.; Darling, T.; Haque, S.; Mancini, R. C.; Covington, A. M.

    2016-11-01

    Spectroscopic techniques in the visible range are often used in plasma experiments to measure B-field induced Zeeman splitting, electron densities via Stark broadening, and temperatures from Doppler broadening. However, when electron densities and temperatures are sufficiently high, the broadening of the Stark and Doppler components can dominate the emission spectra and obscure the Zeeman component. In this research, we are developing a time-resolved multi-axial technique for measuring the Zeeman, Stark, and Doppler broadened line emission of dense magnetized plasmas for Z-pinch and Dense Plasma Focus (DPF) accelerators. The line emission is used to calculate the electron densities, temperatures, and B-fields. In parallel, we are developing a line-shape modeling code that incorporates the broadening effects due to Stark, Doppler, and Zeeman effects for dense magnetized plasma. This manuscript presents the details of the experimental setup and line shape code, along with the results obtained from an Al iii doublet at the University of Nevada, Reno at Nevada Terawatt Facility. Future tests are planned to further evaluate the technique and modeling on other material wire array, gas puff, and DPF platforms.

  19. Analysis of Plasma-Sprayed Thermal Barrier Coatings With Homogeneous and Heterogeneous Bond Coats Under Spatially Uniform Cyclic Thermal Loading

    Science.gov (United States)

    Arnold, Steven M.; Pindera, Marek-Jerzy; Aboudi, Jacob

    2003-01-01

    This report summarizes the results of a numerical investigation into the spallation mechanism in plasma-sprayed thermal barrier coatings observed under spatially-uniform cyclic thermal loading. The analysis focuses on the evolution of local stress and inelastic strain fields in the vicinity of the rough top/bond coat interface during thermal cycling, and how these fields are influenced by the presence of an oxide film and spatially uniform and graded distributions of alumina particles in the metallic bond coat aimed at reducing the top/bond coat thermal expansion mismatch. The impact of these factors on the potential growth of a local horizontal delamination at the rough interface's crest is included. The analysis is conducted using the Higher-Order Theory for Functionally Graded Materials with creep/relaxation constituent modeling capabilities. For two-phase bond coat microstructures, both the actual and homogenized properties are employed in the analysis. The results reveal the important contributions of both the normal and shear stress components to the delamination growth potential in the presence of an oxide film, and suggest mixed-mode crack propagation. The use of bond coats with uniform or graded microstructures is shown to increase the potential for delamination growth by increasing the magnitude of the crack-tip shear stress component.

  20. Advanced demodulation technique for the extraction of tissue optical properties and structural orientation contrast in the spatial frequency domain

    Science.gov (United States)

    Nadeau, Kyle P.; Durkin, Anthony J.; Tromberg, Bruce J.

    2014-05-01

    We have developed a method for extracting spatial frequency information content from biological tissue, which is used to calculate tissue optical properties and determine tissue structural orientation. This demodulation method employs a two-dimensional Hilbert transform using a spiral phase function in Fourier space. The approach presented here allows for the determination of tissue optical properties using a single frame of data for each modulation frequency, increasing imaging speed by two to threefold versus conventional, three-phase spatial frequency domain imaging (SFDI). This new single-phase Hilbert transform approach recovers optical property and scattering orientation index values within 1% and 10% of three-phase SFDI, respectively. These results suggest that, using the Hilbert demodulation technique, SFDI data acquisition speed can be increased significantly while preserving data quality, which will help us move forward toward the implementation of a real-time SFDI platform.

  1. Study of atmospheric pressure weakly ionized plasma as surface compatibilization technique for improved plastic composites loaded with cellulose based fillers

    Science.gov (United States)

    Lekobou, William Pimakouon

    Atmospheric pressure plasmas have gained considerable interest from researchers recently for their unique prospective of engineering surfaces with plasma without the need of vacuum systems. They offer the advantage of low energy consumption, minimal capital cost and their simplicity as compared to conventional low pressure plasmas make them easy to upscale from laboratory to industry size. The present dissertation summarizes results of our attempt at applying atmospheric pressure weakly ionized plasma (APWIP) to the engineering of plastic composites filled with cellulose based substrates. An APWIP reactor was designed and built based on a multipoint-to-grounded ring and screen configurations. The carrier gas was argon and acetylene serves as the precursor molecule. The APWIP reactors showed capability of depositing plasma polymerized coating rich in carbon on substrates positioned within the electrode gap as well as downstream of the plasma discharge into the afterglow region. Our findings show that films grow by forming islands which for prolonged deposition time grow into thin films showing nodules, aggregates of nodules and microspheres. They also show chemical structure similar to films deposited from hydrocarbons with other conventional plasma techniques. The plasma polymerized deposits were used on substrates to modify their surface properties. Results show the surface of wood veneer and wood flour can be finely tuned from hydrophilic to hydrophobic. It was achieved by altering the topography of the surfaces along with their chemical composition. The wettability of wood veneer was investigated with contact angle measurements on capacitive drops and the capillary effect was utilized to assess surface properties of wood flour exposed to the discharges.

  2. Millimeter-Wave Quasi-Optical and Spatial Powder Combining Techniques

    Science.gov (United States)

    1992-08-01

    Radiating Elements and Spatial Power Combiners Using Notch Antennas* Julio A. Navarro. Yone-H-ut ShU. Mid ii 01,1a1c. t-r11,. 11 Abstrac-A G.unn device...tuning bandwidth. Both configurations exhibit soi-tedvcs.uhasheartr orwebn a verN clean and stable output signal. A theoretical circuit model soi...NcClear\\ ajnd Julio A. Navarro %Aas horn in Cordoba. Argen- Mr .A u mrfor marNs aluable discussions and tina (in Norsember 13. 19t-4 He receised theMr. . A

  3. Spatially-Resolved Characterization Techniques to Investigate Impact Damage in Ultra-High Performance Concretes

    Science.gov (United States)

    2013-04-01

    steps used a 50:50 mixture of ethylene glycol (C2H6O2) and ethanol (C2H6O) for a polishing lubricant . All steps used a force of 30 N per specimen for...spatially-correlated nano - indentation/SEM/EDX measurements reduces the validity of nanoindenta- tion for determining single-phase nanomechanical...influence of high strain-rate impact loadings on the nano - mechanical properties of UHPCs was determined. Significant degradation in both the elastic modulus

  4. Radioimmunoassay of arginine vasopressin in Rhesus Monkey plasma. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Hayward, J.N.; Pavasuthipaisit, K.; Perez-Lopez, F.R.; Sofroniew, M.V.

    1976-04-01

    Using a new antiserum and an enzymatic radioiodination of arginine vasopressin (AVP), we have developed a sensitive and specific radioimmunoassay for plasma AVP in the monkey. The sensitivity of the assay is 0.5 ..mu..U/ml, the cross reaction with oxytocin (OT), minimal. We used this assay to study the effects that variations in blood osmolality have in regulating AVP secretion in unanesthetized, chair-restrained, chamber-isolated, adult female rhesus monkeys. Under water ad lib conditions, plasma AVP and osmolality were relatively constant, averaging 1.7 +- 0.6 (SD) ..mu..U/ml and 298 +- 3 mosmol/kg, respectively. Water loading decreased plasma AVP and osmolality to 0.6 +- 0.2 ..mu..U/ml and 282 +- 6 mosmol/kg, respectively. When fluid restriction increased osmolality, plasma AVP rose progressively to twice the baseline after 1 day, and to 6 times the baseline after 3 days. The rise in plasma AVP was linearly correlated with the rise in osmolality (r = 0.93; P less than 0.001). Intravenous infusions of hypertonic saline produced significant rises in plasma osmolality and plasma AVP. There was a dose-related rise in plasma AVP that declined later at the expected rate with the infusion of physiological amounts of synthetic AVP.

  5. A coverslip-based technique for evaluating Staphylococcus aureus biofilm formation on human plasma

    Directory of Open Access Journals (Sweden)

    Jennifer N Walker

    2012-03-01

    Full Text Available The ability of the opportunistic pathogen, Staphylococcus aureus, to form biofilms is increasingly being viewed as an important contributor to chronic infections. In vitro methods for analyzing S. aureus biofilm formation have focused on bacterial attachment and accumulation on abiotic surfaces, such as in microtiter plate and flow cell assays. Microtiter plates provide a rapid measure of relative biomass levels, while flow cells have limited experimental throughput but are superior for confocal microscopy biofilm visualization. Although these assays have proven effective at identifying mechanisms involved in cell attachment and biofilm accumulation, the significance of these assays in vivo remains unclear. Studies have shown that when medical devices are implanted they are coated with host factors, such as matrix proteins, that facilitate S. aureus attachment and biofilm formation. To address the challenge of integrating existing biofilm assay features with a biotic surface, we have established an in vitro biofilm technique utilizing UV-sterilized coverslips coated with human plasma. The substratum more closely resembles the in vivo state and provides a platform for S. aureus to establish a robust biofilm. Importantly, these coverslips are amenable to confocal microscopy imaging to provide a visual reference of the biofilm growth stage, effectively merging the benefits of the microtiter and flow cell assays. We confirmed the approach using clinical S. aureus isolates and mutants with known biofilm phenotypes. Altogether, this new biofilm assay can be used to assess the function of S. aureus virulence factors associated with biofilm formation and for monitoring the efficacy of biofilm treatment modalities.

  6. A Cascaded Discharge Plasma-Adsorbent Technique for Engine Exhaust Treatment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A cascaded system of electrical discharges (non-thermal plasma) and adsorptionprocess was investigated for the removal of oxides of Nitrogen (NOx) and total hydrocarbons(THC) from an actual diesel engine exhaust. The non-thermal plasma and adsorption processeswere separately studied first and then the cascaded process was studied. In this study, differenttypes of adsorbents were used. The NOx removal efficiency was higher with plasma-associatedadsorption (cascaded) process compared to the individual processes and the removal efficiencywas found almost invariant in time. When associated by plasma, among the adsorbents studied,activated charcoal and MS-13X were more effective for NOx and THC removal respectively. Theexperiments were conducted at no load and at 50 % load conditions. The plasma reactor was keptat room temperature throughout the experiment, while the temperature of the adsorbent reactorwas varied. A relative comparison of adsorbents was discussed at the end.

  7. A Cascaded Discharge Plasma-Adsorbent Technique for Engine Exhaust Treatment

    Science.gov (United States)

    Rajanikanth, B. S.; Srinivasan, A. D.; Arya, Nandiny B.

    2003-06-01

    A cascaded system of electrical discharges (non-thermal plasma) and adsorption process was investigated for the removal of oxides of Nitrogen (NOx) and total hydrocarbons (THC) from an actual diesel engine exhaust. The non-thermal plasma and adsorption processes were separately studied first and then the cascaded process was studied. In this study, different types of adsorbents were used. The NOx removal efficiency was higher with plasma-associated adsorption (cascaded) process compared to the individual processes and the removal efficiency was found almost invariant in time. When associated by plasma, among the adsorbents studied, activated charcoal and MS-13X were more effective for NOx and THC removal respectively. The experiments were conducted at no load and at 50% load conditions. The plasma reactor was kept at room temperature throughout the experiment, while the temperature of the adsorbent reactor was varied. A relative comparison of adsorbents was discussed at the end.

  8. A technique to control cross-field diffusion of plasma across a transverse magnetic field

    Science.gov (United States)

    Hazarika, P.; Chakraborty, M.; Das, B. K.; Bandyopadhyay, M.

    2016-12-01

    A study to control charged particle transport across a transverse magnetic field (TMF), popularly known as the magnetic filter in a negative ion source, has been carried out in a double plasma device. In the experimental setup, the TMF placed between the two magnetic cages divides the whole plasma chamber into two distinct regions, viz., the source and the target on the basis of the plasma production and the corresponding electron temperature. The plasma produced in the source region by the filament discharge method diffuses into the target region through the TMF. Data are acquired by the Langmuir probe and are compared in different source configurations, in terms of external biasing applied to metallic plates inserted in the TMF plane but in the orthogonal direction. The effect of the direction of current between the two plates in either polarity of bias in the presence of TMF on the plasma parameters and the cross-field transport of charge particles are discussed.

  9. Spatial Modeling Techniques for Characterizing Geomaterials: Deterministic vs. Stochastic Modeling for Single-Variable and Multivariate Analyses%Spatial Modeling Techniques for Characterizing Geomaterials:Deterministic vs. Stochastic Modeling for Single-Variable and Multivariate Analyses

    Institute of Scientific and Technical Information of China (English)

    Katsuaki Koike

    2011-01-01

    Sample data in the Earth and environmental sciences are limited in quantity and sampling location and therefore, sophisticated spatial modeling techniques are indispensable for accurate imaging of complicated structures and properties of geomaterials. This paper presents several effective methods that are grouped into two categories depending on the nature of regionalized data used. Type I data originate from plural populations and type II data satisfy the prerequisite of stationarity and have distinct spatial correlations. For the type I data, three methods are shown to be effective and demonstrated to produce plausible results: (1) a spline-based method, (2) a combination of a spline-based method with a stochastic simulation, and (3) a neural network method. Geostatistics proves to be a powerful tool for type II data. Three new approaches of geostatistics are presented with case studies: an application to directional data such as fracture, multi-scale modeling that incorporates a scaling law,and space-time joint analysis for multivariate data. Methods for improving the contribution of such spatial modeling to Earth and environmental sciences are also discussed and future important problems to be solved are summarized.

  10. Using the SAL technique for spatial verification of cloud processes: A sensitivity analysis

    CERN Document Server

    Weniger, Michael

    2016-01-01

    The feature based spatial verification method SAL is applied to cloud data, i.e. two-dimensional spatial fields of total cloud cover and spectral radiance. Model output is obtained from the COSMO-DE forward operator SynSat and compared to SEVIRI satellite data. The aim of this study is twofold. First, to assess the applicability of SAL to this kind of data, and second, to analyze the role of external object identification algorithms (OIA) and the effects of observational uncertainties on the resulting scores. As a feature based method, SAL requires external OIA. A comparison of three different algorithms shows that the threshold level, which is a fundamental part of all studied algorithms, induces high sensitivity and unstable behavior of object dependent SAL scores (i.e. even very small changes in parameter values can lead to large changes in the resulting scores). An in-depth statistical analysis reveals significant effects on distributional quantities commonly used in the interpretation of SAL, e.g. median...

  11. A TEMPORAL AND SPATIAL ANALYSIS OF URBAN HEAT ISLAND IN BASIN CITY UTILIZING REMOTE SENSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    H.-T. Chang

    2016-06-01

    Full Text Available Urban Heat Island (UHI has been becoming a key factor in deteriorating the urban ecological environment. Spatial-temporal analysis on its prototype of basin city’s UHI and quantitatively evaluating effect from rapid urbanization will provide theoretical foundation for relieving UHI effect. Based on Landsat 8, ETM+ and TM images of Taipei basin areas from 1900 to 2015, this article has retrieved the land surface temperature (LST at summer solstice of each year, and then analysed spatial-temporal pattern and evolution characters of UHI in Taipei basin in this decade. The results showed that the expansion built district, UHI area constantly expanded from centre city to the suburb areas. The prototype of UHI in Taipei basin that showed in addition to higher temperatures in the centre city also were relatively high temperatures gathered boundaries surrounded by foot of mountains side. It calls “sinking heat island”. From 1900 to 2000, the higher UHI areas were different land use type change had obvious difference by public infrastructure works. And then, in next 15 years till 2015, building density of urban area has been increasing gradually. It has the trend that UHI flooding raises follow urban land use density. Hot spot of UHI in Taipei basin also has the same characteristics. The results suggest that anthropogenic heat release probably plays a significant role in the UHI effect, and must be considered in urban planning adaptation strategies.

  12. a Temporal and Spatial Analysis of Urban Heat Island in Basin City Utilizing Remote Sensing Techniques

    Science.gov (United States)

    Chang, Hsiao-Tung

    2016-06-01

    Urban Heat Island (UHI) has been becoming a key factor in deteriorating the urban ecological environment. Spatial-temporal analysis on its prototype of basin city's UHI and quantitatively evaluating effect from rapid urbanization will provide theoretical foundation for relieving UHI effect. Based on Landsat 8, ETM+ and TM images of Taipei basin areas from 1900 to 2015, this article has retrieved the land surface temperature (LST) at summer solstice of each year, and then analysed spatial-temporal pattern and evolution characters of UHI in Taipei basin in this decade. The results showed that the expansion built district, UHI area constantly expanded from centre city to the suburb areas. The prototype of UHI in Taipei basin that showed in addition to higher temperatures in the centre city also were relatively high temperatures gathered boundaries surrounded by foot of mountains side. It calls "sinking heat island". From 1900 to 2000, the higher UHI areas were different land use type change had obvious difference by public infrastructure works. And then, in next 15 years till 2015, building density of urban area has been increasing gradually. It has the trend that UHI flooding raises follow urban land use density. Hot spot of UHI in Taipei basin also has the same characteristics. The results suggest that anthropogenic heat release probably plays a significant role in the UHI effect, and must be considered in urban planning adaptation strategies.

  13. Synthesis of dynamic phase profile by the correlation technique for spatial control of optical beams in multiplexing and switching

    Science.gov (United States)

    Bugaychuk, Svitlana A.; Gnatovskyy, Vladimir O.; Sidorenko, Andrey V.; Pryadko, Igor I.; Negriyko, Anatoliy M.

    2015-11-01

    New approach for the correlation technique, which is based on multiple periodic structures to create a controllable angular spectrum, is proposed and investigated both theoretically and experimentally. The transformation of an initial laser beam occurs due to the actions of consecutive phase periodic structures, which may differ by their parameters. Then, after the Fourier transformation of a complex diffraction field, the output diffraction orders will be changed both by their intensities and by their spatial position. The controllable change of output angular spectrum is carried out by a simple control of the parameters of the periodic structures. We investigate several simple examples of such management.

  14. Experimental evaluation of a spatial resampling technique to improve the accuracy of pencil-beam dose calculation in proton therapy.

    Science.gov (United States)

    Egashira, Yusuke; Nishio, Teiji; Matsuura, Taeko; Kameoka, Satoru; Uesaka, Mitsuru

    2012-07-01

    In proton therapy, pencil-beam algorithms (PBAs) are the most widely used dose calculation methods. However, the PB calculations that employ one-dimensional density scaling neglect the effects of lateral density heterogeneity on the dose distributions, whereas some particles included in such pencil beams could overextend beyond the interface of the density heterogeneity. We have simplified a pencil-beam redefinition algorithm (PBRA), which was proposed for electron therapy, by a spatial resampling technique toward an application for proton therapy. The purpose of this study is to evaluate the calculation results of the spatial resampling technique in terms of lateral density heterogeneity by comparison with the dose distributions that were measured in heterogeneous slab phantoms. The pencil beams are characterized for multiple residual-range (i.e., proton energy) bins. To simplify the PBRA, the given pencil beams are resampled on one or two transport planes, in which smaller sub-beams that are parallel to each other are generated. We addressed the problem of lateral density heterogeneity comparing the calculation results to the dose distributions measured at different depths in heterogeneous slab phantoms using a two-dimensional detector. Two heterogeneity slab phantoms, namely, phantoms A and B, were designed for the measurements and calculations. In phantom A, the heterogeneity slab was placed close to the surface. On the other hand, in phantom B, it was placed close to the Bragg peak in the mono-energetic proton beam. In measurements, lateral dose profiles showed a dose reduction and increment in the vicinity ofx = 0 mm in both phantoms at depths z = 142 and 161 mm due to lateral particle disequilibrium. In phantom B, these dose reduction/increment effects were higher/lower, respectively, than those in phantom A. This is because a longer distance from the surface to the heterogeneous slab increases the strength of proton scattering. Sub-beams, which were

  15. Non-destructive techniques for biomonitoring of spatial, temporal, and demographic patterns of mercury bioaccumulation and maternal transfer in turtles.

    Science.gov (United States)

    Hopkins, Brittney C; Hepner, Mark J; Hopkins, William A

    2013-06-01

    Mercury (Hg) is a globally ubiquitous pollutant that has received much attention due to its toxicity to humans and wildlife. The development of non-destructive sampling techniques is a critical step for sustainable monitoring of Hg accumulation. We evaluated the efficacy of non-destructive sampling techniques and assessed spatial, temporal, and demographic factors that influence Hg bioaccumulation in turtles. We collected muscle, blood, nail, and eggs from snapping turtles (Chelydra serpentina) inhabiting an Hg contaminated river. As predicted, all Hg tissue concentrations strongly and positively correlated with each other. Additionally, we validated our mathematical models against two additional Hg contaminated locations and found that tissue relationships developed from the validation sites did not significantly differ from those generated from the original sampling site. The models provided herein will be useful for a wide array of systems where biomonitoring of Hg in turtles needs to be accomplished in a conservation-minded fashion.

  16. Spatial assessment of soil salinity in the Harran Plain using multiple kriging techniques.

    Science.gov (United States)

    Bilgili, Ali V

    2013-01-01

    The Harran Plain is located in the southeastern part of Turkey and has recently been developed for irrigation agriculture. It already faces soil salinity problems causing major yield losses. Management of the problem is hindered by the lack of information on the extent and geography of the salinization problem. A survey was carried out to delineate the spatial distribution of salt-affected areas by randomly selecting 140 locations that were sampled at two depths (0 to 30 and 30 to 60 cm) and analyzed for soil salinity variables: soil electrical conductivity (EC), soluble cations (Ca(2+,) Mg(2+), Na(+), and K(+)), soluble anions (SO (4) (2-) , Cl(-)), exchangeable Na(+) (me 100 g(-1)) and exchangeable sodium percentage. Terrain attributes (slope, topographical wetness index) were extracted from the digital elevation model of the study area. Variogram analyses after log transformation and ordinary kriging (OK) were applied to map spatial patterns of soil salinity variables. Multivariate geostatistical methods-regression kriging (RK) and kriging with external drift (KED)-were used using elevation and soil electrical conductivity data as covariates. Performances of the three estimation methods (OK, RK, and KED) were compared using independent validation samples randomly selected from the main dataset. Soils were categorized into salinity classes using disjunctive kriging (DK) and ArcGIS, and classification accuracy was tested using the kappa statistic. Results showed that soil salinity variables all have skewed distribution and are poorly correlated with terrain indices but have strong correlations among each other. Up to 65 % improvement was obtained in the estimations of soil salinity variables using hybrid methods over OK with the best estimations obtained with RK using EC(0-30) as covariate. DK-ArcGIS successfully classified soil samples into different salinity groups with overall accuracy of 75 % and kappa of 0.55 (p < 0.001).

  17. Parallel Comparison of N-Linked Glycopeptide Enrichment Techniques Reveals Extensive Glycoproteomic Analysis of Plasma Enabled by SAX-ERLIC.

    Science.gov (United States)

    Totten, Sarah M; Feasley, Christa L; Bermudez, Abel; Pitteri, Sharon J

    2017-03-03

    Protein glycosylation is of increasing interest due to its important roles in protein function and aberrant expression with disease. Characterizing protein glycosylation remains analytically challenging due to its low abundance, ion suppression issues, and microheterogeneity at glycosylation sites, especially in complex samples such as human plasma. In this study, the utility of three common N-linked glycopeptide enrichment techniques is compared using human plasma. By analysis on an LTQ-Orbitrap Elite mass spectrometer, electrostatic repulsion hydrophilic interaction liquid chromatography using strong anion exchange solid-phase extraction (SAX-ERLIC) provided the most extensive N-linked glycopeptide enrichment when compared with multilectin affinity chromatography (M-LAC) and Sepharose-HILIC enrichments. SAX-ERLIC enrichment yielded 191 unique glycoforms across 72 glycosylation sites from 48 glycoproteins, which is more than double that detected using other enrichment techniques. The greatest glycoform diversity was observed in SAX-ERLIC enrichment, with no apparent bias toward specific glycan types. SAX-ERLIC enrichments were additionally analyzed by an Orbitrap Fusion Lumos mass spectrometer to maximize glycopeptide identifications for a more comprehensive assessment of protein glycosylation. In these experiments, 829 unique glycoforms were identified across 208 glycosylation sites from 95 plasma glycoproteins, a significant improvement from the initial method comparison and one of the most extensive site-specific glycosylation analysis in immunodepleted human plasma to date. Data are available via ProteomeXchange with identifier PXD005655.

  18. X-ray spectroscopic technique for energetic electron transport studies in short-pulse laser/plasma interactions

    Energy Technology Data Exchange (ETDEWEB)

    Tutt, T.E.

    1994-12-01

    When a solid target is irradiated by a laser beam, the material is locally heated to a high temperature and a plasma forms. The interaction of the laser with plasma can produce energetic electrons. By observing the behavior of these {open_quotes}hot{close_quotes} electrons, we hope to obtain a better understanding of Laser/Plasma Interactions. In this work we employ a layered-fluorescer technique to study the transport, and therefore the energetics, of the electrons. The plasma forms on a thin foil of metallic Pd which is bonded to thin layer of metallic Sn. Electrons formed from the plasma penetrate first the Pd and then the Sn. In both layers the energetic electrons promote inner (K) shell ionization of the metallic atoms which leads to the emission of characteristic K{sub {alpha}} x-rays of the fluorescers. By recording the x-ray spectrum emitted by the two foils, we can estimate the energy-dependent range of the electrons and their numbers.

  19. Porous Silicon & Titanium Dioxide Coatings Prepared by Atmospheric Pressure Plasma Jet Chemical Vapour Deposition Technique-A Novel Coating Technology for Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    S. Bhatt

    2011-01-01

    Full Text Available Atmospheric Pressure Plasma Jet (APPJ is an alternative for wet processes used to make anti reflection coatings and smooth substrate surface for the PV module. It is also an attractive technique because of it’s high growth rate, low power consumption, lower cost and absence of high cost vacuum systems. This work deals with the deposition of silicon oxide from hexamethyldisiloxane (HMDSO thin films and titanium dioxide from tetraisopropyl ortho titanate using an atmospheric pressure plasma jet (APPJ system in open air conditions. A sinusoidal high voltage with a frequency between 19-23 kHz at power up to 1000 W was applied between two tubular electrodes separated by a dielectric material. The jet, characterized by Tg ~ 600-800 K, was mostly laminar (Re ~ 1200 at the nozzle exit and became partially turbulent along the jet axis (Re ~ 3300. The spatially resolved emission spectra showed OH, N2, N2+ and CN molecular bands and O, H, N, Cu and Cr lines as well as the NO2 chemiluminescence continuum (450-800 nm. Thin films with good uniformity on the substrate were obtained at high deposition rate, between 800 -1000 nm.s-1, and AFM results revealed that coatings are relatively smooth (Ra ~ 2 nm. The FTIR and SEM analyses were better used to monitor the chemical composition and the morphology of the films in function of the different experimental conditions.

  20. Determination of the species generated in atmospheric-pressure laser-induced plasmas by mass spectrometry techniques

    CERN Document Server

    Valle, F; Apiñaniz, J I; Carpentier, A V; Albaneda, M Sánchez; Roso, L; Raposo, C; Padilla, C; Conde, A Peralta

    2015-01-01

    We present temporal information obtained by mass spectrometry techniques about the evolution of plasmas generated by laser filamentation in air. The experimental setup used in this work allowed us to study not only the dynamics of the filament core but also of the energy reservoir that surrounds it. Furthermore, valuable insights about the chemistry of such systems like the photofragmentation and/or formation of molecules were obtained. The interpretation of the experimental results are supported by PIC (particle in cell) simulations.

  1. Spatial Dependence of DNA Damage in Bacteria due to Low-Temperature Plasma Application as Assessed at the Single Cell Level

    Science.gov (United States)

    Privat-Maldonado, Angela; O’Connell, Deborah; Welch, Emma; Vann, Roddy; van der Woude, Marjan W.

    2016-10-01

    Low temperature plasmas (LTPs) generate a cocktail of reactive nitrogen and oxygen species (RNOS) with bactericidal activity. The RNOS however are spatially unevenly distributed in the plasma. Here we test the hypothesis that this distribution will affect the mechanisms underpinning plasma bactericidal activity focussing on the level of DNA damage in situ. For the first time, a quantitative, single cell approach was applied to assess the level of DNA damage in bacteria as a function of the radial distance from the centre of the plasma jet. Salmonella enterica on a solid, dry surface was treated with two types of LTP: an atmospheric-pressure dielectric barrier discharge plasma jet (charged and neutral species) and a radio-frequency atmospheric-pressure plasma jet (neutral species). In both cases, there was an inverse correlation between the degree of DNA damage and the radial distance from the centre of the plasma, with the highest DNA damage occurring directly under the plasma. This trend was also observed with Staphylococcus aureus. LTP-generated UV radiation was eliminated as a contributing factor. Thus valuable mechanistic information can be obtained from assays on biological material, which can inform the development of LTP as a complementary or alternative therapy for (topical) bacterial infections.

  2. Temporal and spatial resolved SuperDARN line of sight velocity measurements corrected for plasma index of refraction using Bayesian inference

    Science.gov (United States)

    Spaleta, J.; Bristow, W. A.; Klein, J.

    2015-04-01

    Recent work by Gillies et al. (2012, 2009, 2010) has sought an explanation for the SuperDARN line-of-sight velocity underestimate of ionospheric plasma velocity. The reason for the underestimation is thought to be from the modification of the measured Doppler shift of the backscattered signal due to phase refractive index of the ionospheric plasma in the scattering region. Presented here is an analysis technique to estimate the plasma drift velocity, correcting for the index of the refraction of the scattering medium. The technique requires dual frequency SuperDARN observations and calculates velocity from the phase of the SuperDARN autocorrelation function (ACF). Both plasma velocity and plasma density are treated as independent unknowns, and self-consistent error estimates are generated for each. This new technique was employed at the McMurdo radar, resulting in estimates of plasma velocity on scales relevant to existing SuperDARN data products. The McMurdo dual frequency analysis also provides a new SuperDARN data product, an estimate for the plasma density in the ionospheric region derived wholly from SuperDARN backscatter.

  3. A Stochastic Technique for Error Correction and Spatial Downscaling of Global Gridded Precipitation Products

    Science.gov (United States)

    Seyyedi, H.; Kaheil, Y.; Anagnostou, E. N.; McCollum, J.; Beighley, E.

    2013-12-01

    Deriving flood maps requires an accurate characterization of precipitation variability at high spatio-temporal resolution. Most of the available global-scale gridded precipitation products are available at resolutions (e.g., 25 km) not directly applicable to flood modeling. An error correction and spatial downscaling method based on a two-dimensional satellite rainfall error model (SREM2D) is tested in this study based on a long-term (2001-2010) dataset. Specifically, the model is applied on two rainfall datasets: a satellite precipitation product (TRMM-3B42.V7 at 0.25 degree) and a global land-atmosphere re-analysis product (GLDAS-CLM at 1 degree), to produce error corrected rainfall ensembles at 0.05 degree spatial resolution. The NCEP hourly, 4-km resolution multi-sensor precipitation product (WSR-88D stage IV gauge-adjusted radar-rainfall product) is used as the reference rainfall dataset. The Hillslope River Routing (HRR) hydrologic model is forced with the downscaled ensemble rainfall data to produce an ensemble of runoff values. The Susquehanna River basin is the study area, consisting of 1000 sub-basins ranging from 39 to 67,000 square kilometers including complex terrain and high latitude locations. There are 437 significant storm events selected over the study area based on the 10-year database. The analysis performed is based on 60 percent of events in each season kept for model calibration and 40 percent for validation. The statistical analysis consists of two parts: (1) evaluation of error metrics (relative standard deviation and efficiency coefficient) to quantify improvements in rainfall and runoff simulations as function of basin size and storm severity, and (2) ensemble verification (exceedance probability and mean uncertainty ratio) of the rainfall and runoff ensembles to assess the accuracy of the ensemble-based uncertainty characterization. The study investigates how well the ensemble of downscaled and error-corrected rainfall data performs

  4. SHTV, as a technique for core calculation using spatial homogenization and temperature variation

    Energy Technology Data Exchange (ETDEWEB)

    Moghaddam, Nader Maleki, E-mail: nader.moghaddam@gmail.co [Department of Nuclear Engineering and Physics, Amir Kabir University of Technology (Tehran polytechnique), Hafez Street, Tehran (Iran, Islamic Republic of); Zahedinejad, Ehsan, E-mail: ehsanzahedinejad@gmail.co [Department of Energy Engineering, Sharif University of Technology, Azadi Street, Tehran (Iran, Islamic Republic of); Kashi, Samira, E-mail: smr.kashi@gmail.co [Department of Nuclear Engineering, Shahid Beheshti University, Evin Street, Tehran (Iran, Islamic Republic of); Davilu, Hadi, E-mail: Davilu@aut.ac.i [Department of Nuclear Engineering and Physics, Amir Kabir University of Technology (Tehran polytechnique), Hafez Street, Tehran (Iran, Islamic Republic of)

    2010-09-15

    The accuracy of static neutronic parameters in the nuclear reactors depends upon the determination of group constants of the diffusion equation in the desired geometry. Although several methods have been proposed for calculating these parameters, there is still the need for more reliable methods. In this paper a powerful and innovative method based on Spatial Homogenization and Temperature Variation (SHTV) of physical properties of a WWER-1000 nuclear reactor core for calculating the relative power distribution of Fuel Assemblies (FA) and the hot fuel rod, is presented. The method is based on replacing the heterogeneous lattices of materials with different properties by an equivalent homogeneous mixture of these material for determining the few group constants, while the effect of temperature variation in the fuel and coolant density along the axial core direction is considered. All calculations are performed using WIMS and CITATION codes. The obtained results are compared with the results of Final Safety Analysis Report (FSAR) prepared by the designer, and good agreement between the two results is shown.

  5. Spatial variation and source apportionment of water pollution in Qiantang River (China) using statistical techniques.

    Science.gov (United States)

    Huang, Fang; Wang, Xiaoquan; Lou, Liping; Zhou, Zhiqing; Wu, Jiaping

    2010-03-01

    Understanding the spatial distribution and apportioning the sources of water pollution are important in the study and efficient management of water resources. In this work, we considered data for 13 water quality variables collected during the year 2004 at 46 monitoring sites along the Qiantang River (China). Fuzzy comprehensive analysis categorized the data into three major pollution zones (low, moderate, and high) based on national quality standards for surface waters, China. Most sites classified as "low pollution zones" (LP) occurred in the main river channel, whereas those classified as "moderate and high pollution zones" (MP and HP, respectively) occurred in the tributaries. Factor analysis identified two potential pollution sources that explained 67% of the total variance in LP, two potential pollution sources that explained 73% of the total variance in MP, and three potential pollution sources that explained 80% of the total variance in HP. UNMIX was used to estimate contributions from identified pollution sources to each water quality variable and each monitoring site. Most water quality variables were influenced primarily by pollution due to industrial wastewater, agricultural activities and urban runoff. In LP, non-point source pollution such as agricultural runoff and urban runoff dominated; in MP and HP, mixed source pollution dominated. The pollution in the small tributaries was more serious than that in the main channel. These results provide information for developing better pollution control strategies for the Qiantang River.

  6. Gelatin-based laser direct-write technique for the precise spatial patterning of cells.

    Science.gov (United States)

    Schiele, Nathan R; Chrisey, Douglas B; Corr, David T

    2011-03-01

    Laser direct-writing provides a method to pattern living cells in vitro, to study various cell-cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research.

  7. Spatial structure and dispersion of drift mirror waves coupled with Alfvén waves in a 1-D inhomogeneous plasma

    Directory of Open Access Journals (Sweden)

    D. Yu. Klimushkin

    2006-09-01

    Full Text Available The paper employs the frame of a 1-D inhomogeneous model of space plasma,to examine the spatial structure and growth rate of drift mirror modes, often suggested for interpreting some oscillation types in space plasma. Owing to its coupling with the Alfvén mode, the drift mirror mode attains dispersion across magnetic shells (dependence of the frequency on the wave-vector's radial component, kr. The spatial structure of a mode confined across magnetic shells is studied. The scale of spatial localization of the wave is shown to be determined by the plasma inhomogeneity scale and by the azimuthal component of the wave vector. The wave propagates across magnetic shells, its amplitude modulated along the radial coordinate by the Gauss function. Coupling with the Alfvén mode strongly influences the growth rate of the drift mirror instability. The mirror mode can only exist in a narrow range of parameters. In the general case, the mode represents an Alfvén wave modified by plasma inhomogeneity.

  8. Near room-temperature direct encapsulation of organic photovoltaics by plasma-based deposition techniques

    Science.gov (United States)

    Perrotta, Alberto; Fuentes-Hernandez, Canek; Khan, Talha M.; Kippelen, Bernard; Creatore, Mariadriana; Graham, Samuel

    2017-01-01

    Plasma-assisted atomic layer deposition (ALD) is used for the deposition of environmental barriers directly onto organic photovoltaic devices (OPVs) at near room temperature (30 °C). To study the effect of the ALD process on the organic materials forming the device, the precursor diffusion and intermixing at the interface during the growth of different plasma-assisted ALD inorganic barriers (i.e. Al2O3 and TiO2) onto the organic photoactive layer (P3HT:ICBA) was investigated. Depth profile x-ray photoelectron spectroscopy was used to analyze the composition of the organic/inorganic interface to investigate the infiltration of the plasma-assisted ALD precursors into the photoactive layer as a function of the precursor dimension, the process temperature, and organic layer morphology. The free volume in the photoactive layer accessible to the ALD precursor was characterized by means of ellipsometric porosimetry (EP) and spectroscopic ellipsometry as a function of temperature. The organic layer is shown to exhibit free volume broadening at high temperatures, increasing the infiltration depth of the ALD precursor into the photoactive layer. Furthermore, based on previous investigations, the intrinsic permeation properties of the inorganic layers deposited by plasma-assisted ALD were predicted from the nano-porosity content as measured by EP and found to be in the 10-6 gm-2 d-1 range. Insight from our studies was used to design and fabricate multilayer barriers synthesized at near-room temperature by plasma-assisted ALD in combination with plasma-enhanced CVD onto organic photovoltaic (OPVs) devices. Encapsulated OPVs displayed shelf-lifetimes up to 1400 h at ambient conditions.

  9. Fabrication of copper-based anodes via atmosphoric plasma spraying techniques

    Science.gov (United States)

    Lu, Chun [Monroeville, PA

    2012-04-24

    A fuel electrode anode (18) for a solid oxide fuel cell is made by presenting a solid oxide fuel cell having an electrolyte surface (15), mixing copper powder with solid oxide electrolyte in a mixing step (24, 44) to provide a spray feedstock (30,50) which is fed into a plasma jet (32, 52) of a plasma torch to melt the spray feed stock and propel it onto an electrolyte surface (34, 54) where the spray feed stock flattens into lamellae layer upon solidification, where the layer (38, 59) is an anode coating with greater than 35 vol. % based on solids volume.

  10. A tropical cyclone dynamic initialization technique using high temporal and spatial density atmospheric motion vectors and airborne field campaign data

    Science.gov (United States)

    Hendricks, E. A.; Bell, M. M.; Elsberry, R. L.; Velden, C.

    2016-12-01

    A new tropical cyclone dynamic initialization technique is described and tested. The technique uses the triple-nested Coupled Ocean-Atmosphere Mesoscale Prediction System-Tropical Cyclones (COAMPS-TC) (with horizontal grid spacings of 45-,15-, and 5-km, respectively) in conjunction with the Spline Analysis at Mesoscale Utilizing Radar and Aircraft Instrumentation (SAMURAI). A proof-of-concept demonstration of this technique is given for Hurricane Joaquin from the Office of Naval Research (ONR) Tropical Cyclone Intensity (TCI) field program conducted in 2015. High spatial and temporal resolution atmospheric motion vectors (AMVs), dropwindsondes from the Yankee Environmental Systems High Definition Sounding System (HDSS), and surface wind speed retrievals from the Hurricane Imaging Radiometer (HIRAD) are ingested into SAMURAI to produce increments, which are then used by the COAMPS-TC dynamic initialization scheme to produce consistent dynamic and thermodynamically balanced fields. This high temporal resolution (order of 10-15 minutes) incremental dynamic initialization procedure has advantages over conventional methods in that a bogus vortex is not used, and existing asymmetries (including convective heating and upper and low level wind asymmetries) that exist in the TC are retained. The use of dynamic initialization also ensures improved vortex and environment balance, and consistency with the model physics. A preliminary verification of this new TC initialization scheme will be presented for the initialization and forecast of Hurricane Joaquin (2015).

  11. Spatial Distribution Analysis of Soil Properties in Varzaneh Region of Isfahan Using Image Processing Techniques

    Directory of Open Access Journals (Sweden)

    F. Mahmoodi

    2016-02-01

    Full Text Available Introduction: Use of remote sensing for soil assessment and monitoring started with the launch of the first Landsat satellite. Since then many other polar orbiting Earth-observation satellites such as the Landsat series, have been launched and their imagery have been used for a wide range of soil mapping. The broad swaths and regular revisit frequencies of these multispectral satellites mean that they can be used to rapidly detect changes in soil properties. Arid and semi-arid lands cover more than 70 percent of Iran and are very prone to desertification. Due to the broadness, remoteness, and harsh condition of these lands, soil studies using ground-based techniques appear to be limited. Remote sensing imagery with its cost and time-effectiveness has been suggested and used as an alternative approach for more than four decades. Flood irrigation is one of the most common techniques in Isfahan province in which 70% of water is lost through evaporation. This system has increased soil salinization and desert-like conditions in the region. For principled decision making on agricultural product management, combating desertification and its consequences and better use of production resources to achieve sustainable development; understanding and knowledge of the origin, amount and area of salinity, the percentage of calcite, gypsum and other mineral of soil in each region is essential. Therefore, this study aimed to map the physical and chemical characteristics of soils in Vazaneh region of Isfahan province, Iran. Materials and Methods : Varzaneh region with 75000 ha located in central Iran and lies between latitudes 3550234 N and 3594309 N and longitudes 626530 E to 658338 E. The climate in the study area is characterized by hot summers and cold winters. The mean daily maximum temperature ranges from 35°C in summer to approximately 17°C in winter and mean daily minimum temperature ranges from 5°C in summer to about -24.5°C in winter. The mean

  12. Spatial Domain based Image Enhancement Techniques for Scanned Electron Microscope-SEM-images

    Directory of Open Access Journals (Sweden)

    Rakhi Chanana

    2011-07-01

    Full Text Available The growing need for efficiently processing and analyzing the information contained in digital images is a continuous challenge in order to apply image processing. Digital images are captured from different imaging media elements like cameras, scanned electron microscopes etc. While going through the imaging process, Images get distorted in various forms resulting in extreme dark or light areas. All these things lead to the loss of information. The goal in each case is to extract useful information. In that case, Image processing extracts useful information by applying various image enhancement and algorithms. In this paper, we have discussed a practical implementation of various enhancement methods for Scanned Electron Microscope (SEM images and their experimental results. SEM images lead to very dark and light areas in an image. While imaging the information in the front scene is not only the source of information but some scenes on the dark side can also have the useful information. Before processing any further we require to enhance such images and one of the enhancement techniques i.e. Histogram Statistics comes out to be an ideal approach.

  13. Health impact assessment of particulate pollution in Tallinn using fine spatial resolution and modeling techniques

    Directory of Open Access Journals (Sweden)

    Kimmel Veljo

    2009-03-01

    Full Text Available Abstract Background Health impact assessments (HIA use information on exposure, baseline mortality/morbidity and exposure-response functions from epidemiological studies in order to quantify the health impacts of existing situations and/or alternative scenarios. The aim of this study was to improve HIA methods for air pollution studies in situations where exposures can be estimated using GIS with high spatial resolution and dispersion modeling approaches. Methods Tallinn was divided into 84 sections according to neighborhoods, with a total population of approx. 390 000 persons. Actual baseline rates for total mortality and hospitalization with cardiovascular and respiratory diagnosis were identified. The exposure to fine particles (PM2.5 from local emissions was defined as the modeled annual levels. The model validation and morbidity assessment were based on 2006 PM10 or PM2.5 levels at 3 monitoring stations. The exposure-response coefficients used were for total mortality 6.2% (95% CI 1.6–11% per 10 μg/m3 increase of annual mean PM2.5 concentration and for the assessment of respiratory and cardiovascular hospitalizations 1.14% (95% CI 0.62–1.67% and 0.73% (95% CI 0.47–0.93% per 10 μg/m3 increase of PM10. The direct costs related to morbidity were calculated according to hospital treatment expenses in 2005 and the cost of premature deaths using the concept of Value of Life Year (VOLY. Results The annual population-weighted-modeled exposure to locally emitted PM2.5 in Tallinn was 11.6 μg/m3. Our analysis showed that it corresponds to 296 (95% CI 76528 premature deaths resulting in 3859 (95% CI 10236636 Years of Life Lost (YLL per year. The average decrease in life-expectancy at birth per resident of Tallinn was estimated to be 0.64 (95% CI 0.17–1.10 years. While in the polluted city centre this may reach 1.17 years, in the least polluted neighborhoods it remains between 0.1 and 0.3 years. When dividing the YLL by the number of

  14. Characterization of solar cells. New techniques with high spatial resolution; Entwicklung neuer Verfahren zur raeumlich hochaufloesenden Charakterisierung von Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Schwalm, Michael

    2011-06-16

    Today's raising demand for energy relies to a degree of 85% on the consumption of fossil fuels. A change to regenerative forms of energy is an important and inevitable step in order to face the challenges of climate change and fading natural resources. Photovoltaic's (PV) plays a special role within the various forms of renewable energy since it converts sunlight, our most important and virtually endless energy source, directly into electricity. However, currently available PV-systems are still very expensive and, in combination with their relatively low performance, can hardly or cannot compete with conventional sources of energy from an economical point of view. One possibility to overcome this problem is the combination of highly efficient multi junction solar cells with cost-efficient concentrator optics that focus the incident sunlight to a small spot. The material system (GaIn)(NAs) is envisioned to play an important role in a future generation of multi junction solar cells for concentrator applications being a further development of existing device concepts. However, especially the carrier diffusion lengths in (GaIn)(NAs)-based solar cell layers are currently to low for the fabrication of highly efficient PV-structures. In this work, two novel techniques for the characterization of solar cells are developed and evaluated by experiments on test structures and numerical simulations. Both are based on the measurement of laser-induced currents. Spatially-resolved photocurrent spectroscopy (SRPS) allows a spatially-resolved determination of locally induced photocurrents at a fixed bias voltage while spatially-resolved IV-characteristics (SRIV) are measurements of local I-V-characteristics at a certain position. It is found that SRPS and SRIV allow for a reliable and meaningful characterization of solar cell prototypes with a high spatial resolution. Especially the local p-n-parameters of the sample become accessible. These are the short circuit current

  15. Hyperspectral imaging-based spatially-resolved technique for accurate measurement of the optical properties of horticultural products

    Science.gov (United States)

    Cen, Haiyan

    Hyperspectral imaging-based spatially-resolved technique is promising for determining the optical properties and quality attributes of horticultural and food products. However, considerable challenges still exist for accurate determination of spectral absorption and scattering properties from intact horticultural products. The objective of this research was, therefore, to develop and optimize hyperspectral imaging-based spatially-resolved technique for accurate measurement of the optical properties of horticultural products. Monte Carlo simulations and experiments for model samples of known optical properties were performed to optimize the inverse algorithm of a single-layer diffusion model and the optical designs, for extracting the absorption (micro a) and reduced scattering (micros') coefficients from spatially-resolved reflectance profiles. The logarithm and integral data transformation and the relative weighting methods were found to greatly improve the parameter estimation accuracy with the relative errors of 10.4%, 10.7%, and 11.4% for micro a, and 6.6%, 7.0%, and 7.1% for micros', respectively. More accurate measurements of optical properties were obtained when the light beam was of Gaussian type with the diameter of less than 1 mm, and the minimum and maximum source-detector distances were 1.5 mm and 10--20 transport mean free paths, respectively. An optical property measuring prototype was built, based on the optimization results, and evaluated for automatic measurement of absorption and reduced scattering coefficients for the wavelengths of 500--1,000 nm. The instrument was used to measure the optical properties, and assess quality/maturity, of 500 'Redstar' peaches and 1039 'Golden Delicious' (GD) and 1040 'Delicious' (RD) apples. A separate study was also conducted on confocal laser scanning and scanning electron microscopic image analysis and compression test of fruit tissue specimens to measure the structural and mechanical properties of 'Golden

  16. Distributed fiber Brillouin strain and temperature sensor with centimeter spatial resolution by coherent probe-pump technique

    Science.gov (United States)

    Zou, Lufan; Bao, Xiaoyi; Wan, Yidun; Ravet, Fabien; Chen, Liang

    2005-05-01

    We present a sensing principle of the distributed fiber Brillouin strain and temperature sensor by coherent probe-pump technique that offers a new method to achieve centimeter spatial resolution with high frequency resolution. A combination of continuous wave (cw) and pulse source as the probe (Stokes) beam and cw laser as the pump beam have resulted in stronger Brillouin interaction of Stokes and pump inside the pulse-length in the form of cw-pump and pulse-pump interactions. We find that the coherent portion inside the pulse-length of these two interactions due to the same phase has a very high Brillouin amplification. The Brillouin profile originating from the coherent interaction of pulse-pump with cw-pump results in high temperature and strain accuracy with centimeter resolution, which has been verified by successfully detecting 1.5 cm out-layer crack on an optical ground wire (OPGW) cable.

  17. MASTR: A Technique for Mosaic Mutant Analysis with Spatial and Temporal Control of Recombination Using Conditional Floxed Alleles in Mice

    Directory of Open Access Journals (Sweden)

    Zhimin Lao

    2012-08-01

    Full Text Available Mosaic mutant analysis, the study of cellular defects in scattered mutant cells in a wild-type environment, is a powerful approach for identifying critical functions of genes and has been applied extensively to invertebrate model organisms. A highly versatile technique has been developed in mouse: MASTR (mosaic mutant analysis with spatial and temporal control of recombination, which utilizes the increasing number of floxed alleles and simultaneously combines conditional gene mutagenesis and cell marking for fate analysis. A targeted allele (R26MASTR was engineered; the allele expresses a GFPcre fusion protein following FLP-mediated recombination, which serves the dual function of deleting floxed alleles and marking mutant cells with GFP. Within 24 hr of tamoxifen administration to R26MASTR mice carrying an inducible FlpoER transgene and a floxed allele, nearly all GFP-expressing cells have a mutant allele. The fate of single cells lacking FGF8 or SHH signaling in the developing hindbrain was analyzed using MASTR, and it was revealed that there is only a short time window when neural progenitors require FGFR1 for viability and that granule cell precursors differentiate rapidly when SMO is lost. MASTR is a powerful tool that provides cell-type-specific (spatial and temporal marking of mosaic mutant cells and is broadly applicable to developmental, cancer, and adult stem cell studies.

  18. A spatial model with pulsed releases to compare strategies for the sterile insect technique applied to the mosquito Aedes aegypti.

    Science.gov (United States)

    Oléron Evans, Thomas P; Bishop, Steven R

    2014-08-01

    We present a simple mathematical model to replicate the key features of the sterile insect technique (SIT) for controlling pest species, with particular reference to the mosquito Aedes aegypti, the main vector of dengue fever. The model differs from the majority of those studied previously in that it is simultaneously spatially explicit and involves pulsed, rather than continuous, sterile insect releases. The spatially uniform equilibria of the model are identified and analysed. Simulations are performed to analyse the impact of varying the number of release sites, the interval between pulsed releases and the overall volume of sterile insect releases on the effectiveness of SIT programmes. Results show that, given a fixed volume of available sterile insects, increasing the number of release sites and the frequency of releases increases the effectiveness of SIT programmes. It is also observed that programmes may become completely ineffective if the interval between pulsed releases is greater that a certain threshold value and that, beyond a certain point, increasing the overall volume of sterile insects released does not improve the effectiveness of SIT. It is also noted that insect dispersal drives a rapid recolonisation of areas in which the species has been eradicated and we argue that understanding the density dependent mortality of released insects is necessary to develop efficient, cost-effective SIT programmes.

  19. Spatio-Temporal Analysis of UHI using Geo-Spatial Techniques: A case study of Ahmedabad

    Science.gov (United States)

    Vyas, A.; Shastri, B.; Joshi, Y.

    2014-11-01

    vulnerabilities to human health, the marginal population affected largely as the natural environment is their only home or their main shelter. Furthermore elderly people also affected in greater amount as their weakening immunes system. Major effects of UHI on environment include: a) Air Quality, b) Energy consumption and c) Human health. To study the causes and effect of UHI of any urban area, the first step is to demarcate the spatial distribution of UHI and its intensity over different time period of the day as well as difference in the temperature of urban area with the surrounding rural areas. Secondly, study of land use land cover change in the area also helps in identifying causes of heat accumulation for particular region. After marking up of intensity, analysis of different zones for understanding the relationship between UHI and urban morphological features can be done which further became suggestive towards planning of urban center that mitigates the effect of UHI. Mainly two approaches are there to demarcate UHI study as: - Field data collection and observations - Remote sensing data analysis For a long period of time observations from interior of the city and outwards of it can analyze by a climatic methods, by observing many days as well as many times of a day continuously to analyze the daily variation law of the heat island effects. As the city is for its developmental approaches may cover an area of hundreds of square kilometers, the ground observation data is not able to provide enough detail about the urban heat island distribution characteristics. The most precise method is the Satellite Remote Sensing method. The UHI phenomenon can be analyzed by using the thermal infrared data obtained meteorological satellite sensing. The atmospheric attenuation can be corrected for the remote sensing data by use of meteorological soundings and ground observation data. Ideally the heat island effect over a city is not same for any other city. Satellite images from AVHRR

  20. [Determination of 10 sedative-hypnotics in human plasma using pulse splitless injection technique and gas chromatography-mass spectrometry].

    Science.gov (United States)

    Chang, Qing; Ma, Hongying; Wang, Fangjie; Ou, Honglian; Zou, Ming

    2011-11-01

    A simple, precise and sensitive gas chromatography-mass spectrometry (GC-MS) method coupled with pulse splitless injection technique was developed for the determination of 10 sedative-hypnotics (barbital, amobarbital, phenobarbital, oxazepam, diazepam, nitrazepam, clonazepam, estazolam, alprazolam, triazolam) in human plasma. The drugs spiked in plasma were extracted with ethyl acetate after alkalization with 0.1 mol/L NaOH solution. The organic solvent was evaporated under nitrogen stream, and the residues were redissolved by ethyl acetate. The separation was performed on an HP-5MS column (30 m x 250 microm x 0.25 microm). The analytes were determined and identified using selected ion monitoring (SIM) mode and scan mode, respectively. The internal standard method was used for the determination. The target analytes were well separated from each other on their SIM chromatograms and also on the total ion current (TIC) chromatograms. The blank extract from human plasma gave no peaks that interfered with all the analytes on the chromatogram. The calibration curves for 10 sedative-hypnotics showed excellent linearity. The correlation coefficients of all the drugs were higher than 0.9954. The recoveries of the drugs spiked in human plasma ranged from 92.28% to 111.7%, and the relative standard deviations (RSDs) of intra-day and inter-day determinations were from 4.09% to 14.26%. The detection limits ranged from 2 to 20 microg/L. The method is simple, reliable, rapid and sensitive for the determination and the quantification of 10 sedative-hypnotics in human plasma and seems to be useful in the practice of clinical toxicological cases.

  1. Toward the identification of communities with increased tobacco-associated cancer burden: Application of spatial modeling techniques

    Directory of Open Access Journals (Sweden)

    Noella A Dietz

    2011-01-01

    Full Text Available Introduction: Smoking-attributable risks for lung, esophageal, and head and neck (H/N cancers range from 54% to 90%. Identifying areas with higher than average cancer risk and smoking rates, then targeting those areas for intervention, is one approach to more rapidly lower the overall tobacco disease burden in a given state. Our research team used spatial modeling techniques to identify areas in Florida with higher than expected tobacco-associated cancer incidence clusters. Materials and Methods: Geocoded tobacco-associated incident cancer data from 1998 to 2002 from the Florida Cancer Data System were used. Tobacco-associated cancers included lung, esophageal, and H/N cancers. SaTScan was used to identify geographic areas that had statistically significant (P<0.10 excess age-adjusted rates of tobacco-associated cancers. The Poisson-based spatial scan statistic was used. Phi correlation coefficients were computed to examine associations among block groups with/without overlapping cancer clusters. The logistic regression was used to assess associations between county-level smoking prevalence rates and being diagnosed within versus outside a cancer cluster. Community-level smoking rates were obtained from the 2002 Florida Behavioral Risk Factor Surveillance System (BRFSS. Analyses were repeated using 2007 BRFSS to examine the consistency of associations. Results: Lung cancer clusters were geographically larger for both squamous cell and adenocarcinoma cases in Florida from 1998 to 2002, than esophageal or H/N clusters. There were very few squamous cell and adenocarcinoma esophageal cancer clusters. H/N cancer mapping showed some squamous cell and a very small amount of adenocarcinoma cancer clusters. Phi correlations were generally weak to moderate in strength. The odds of having an invasive lung cancer cluster increased by 12% per increase in the county-level smoking rate. Results were inconsistent for esophageal and H/N cancers, with some

  2. Spatially resolved Thomson scattering measurements of the transition from the collective to the non-collective regime in a laser-produced plasma

    Science.gov (United States)

    Schaeffer, D. B.; Constantin, C. G.; Bondarenko, A. S.; Everson, E. T.; Niemann, C.

    2016-11-01

    We present optical Thomson scattering results that image for the first time in a single measurement the spatial transition from collective to non-collective scattering. Data were taken in the Phoenix laser laboratory at the University of California, Los Angeles. The Raptor laser was used to ablate a carbon plasma, which was diagnosed with the frequency-doubled Phoenix laser serving as a Thomson scattering probe. Scattered light was collected from the laser plasma up to 10 cm from the target surface and up to 10 us after ablation, and imaged with high spatial and spectral resolutions. The results show a strong Thomson collective feature close to the target surface that smoothly transitions to a non-collective feature over several mm.

  3. Characteristics of heat-annealed silicon homojunction infrared photodetector fabricated by plasma-assisted technique

    Science.gov (United States)

    Hammadi, Oday A.

    2016-09-01

    In this work, the effect of thermal annealing on the characteristics of silicon homojunction photodetector was studied. This homojunction photodetector was fabricated by means of plasma-induced etching of p-type silicon substrate and plasma sputtering of n-type silicon target in vacuum. The electrical and spectral characteristics of this photodetector were determined and optimized before and after the annealing process. The maximum surface reflectance of 1.89% and 1.81%, the maximum responsivity of 0.495 A/W and 0.55 A/W, the ideality factor of 1.80 and 1.99, the maximum external quantum efficiency of 76% and 83.5%, and the built-in potential of 0.79 V and 0.72 V were obtained before and after annealing, respectively.

  4. Ion and X-ray techniques used for study of laser-produced plasmas

    Science.gov (United States)

    Wolowski, J.; Parys, P.; Rosinski, M.; Ryć, L.; Woryna, E.

    2015-04-01

    This review article describes apparatus for ion and X-ray diagnostics, which were used in experimental studies of laser-produced plasmas performed by the IPPLM's team in collaboration with other researchers at IPPLM and PALS Research Centre in Prague (the Czech Republic). The investigations of expanding laser-produced plasma properties in dependence on laser beam parameters were done by means of ion diagnostics devices: ion collectors (ICs), cylindrical ion energy analyzer (IEA) and the mass spectrograph of the Thomson type. At IPPLM, different types of detectors have been developed for measurement of X-ray emission. Properties of laser-produced beams of ions and X-ray radiation were analysed in the cooperative experiments performed with the use of a high-energy iodine laser PALS at the PALS Research Centre ASCR in the Czech Republic and the low-energy repetitive laser at IPPLM.

  5. The machinery at endoplasmic reticulum-plasma membrane contact sites contributes to spatial regulation of multiple Legionella effector proteins.

    Directory of Open Access Journals (Sweden)

    Andree Hubber

    2014-07-01

    Full Text Available The Dot/Icm system of the intracellular pathogen Legionella pneumophila has the capacity to deliver over 270 effector proteins into host cells during infection. Important questions remain as to spatial and temporal mechanisms used to regulate such a large array of virulence determinants after they have been delivered into host cells. Here we investigated several L. pneumophila effector proteins that contain a conserved phosphatidylinositol-4-phosphate (PI4P-binding domain first described in the effector DrrA (SidM. This PI4P binding domain was essential for the localization of effectors to the early L. pneumophila-containing vacuole (LCV, and DrrA-mediated recruitment of Rab1 to the LCV required PI4P-binding activity. It was found that the host cell machinery that regulates sites of contact between the plasma membrane (PM and the endoplasmic reticulum (ER modulates PI4P dynamics on the LCV to control localization of these effectors. Specifically, phosphatidylinositol-4-kinase IIIα (PI4KIIIα was important for generating a PI4P signature that enabled L. pneumophila effectors to localize to the PM-derived vacuole, and the ER-associated phosphatase Sac1 was involved in metabolizing the PI4P on the vacuole to promote the dissociation of effectors. A defect in L. pneumophila replication in macrophages deficient in PI4KIIIα was observed, highlighting that a PM-derived PI4P signature is critical for biogenesis of a vacuole that supports intracellular multiplication of L. pneumophila. These data indicate that PI4P metabolism by enzymes controlling PM-ER contact sites regulate the association of L. pneumophila effectors to coordinate early stages of vacuole biogenesis.

  6. Terapia de bioestimulación con plasma rico en plaquetas para el envejecimiento cutáneo Bioestimulation technique with rich plasma in platelets for skin aging

    Directory of Open Access Journals (Sweden)

    HM Escobar

    2012-03-01

    Full Text Available La bioestimulación con plasma rico en plaquetas es una técnica ambulatoria para la prevención y manejo del envejecimiento cutáneo, se basa en la fisiología de la piel y funciona muy bien sola o dentro de un plan terapéutico combinado. El derivado de sangre autóloga estimula la producción de colágeno, elastina y tejido epidérmico, lo que se traduce en piel más tersa, luminosa y de mejor calidad. Son mínimos los riesgos de formación de hematomas, infección, transmisión de enfermedades o reacciones alérgicas.Biostimulation with rich plasma in platelets is an outpatient technique for the prevention and management of skin aging, which is based on the physiology of the skin, and works very well alone or in a combined treatment plan. Own patient derivate blood stimulates production of collagen, elastin and skin tissue, resulting in a smoother skin, brighter and better quality. Risks of bruising, infection, disease transmission or allergic reactions are minimal.

  7. Synthesis and characterization of carbon fibers obtained through plasma techniques; Sintesis y caracterizacion de fibras de carbono obtenidas mediante tecnicas de plasma

    Energy Technology Data Exchange (ETDEWEB)

    Valdivia B, M

    2005-07-01

    The study of carbon, particularly the nano technology is a recent field, the one which has important implications in the science of new materials. It investigation is of great interest for industries producers of ceramic, metallurgy, electronic, energy storage, biomedicine, among others. The diverse application fields are a reason at national as international level, so that many works are focused in the production of nano fibers of carbon. The Thermal plasma applications laboratory (LAPT) of the National Institute of Nuclear Research (ININ), it is carrying out works about carbon nano technology. The present work has as purpose to carry out the synthesis and characterization of the carbon nano fibers which are obtained by electric arch of alternating current (CA) to high frequencies and by a plasma gun of non transferred arch, where are used hydrocarbons like benzene, methane, acetylene like carbon source and ferrocene, nickel, yttrium and cerium oxide like catalysts. For both techniques its were thought about a relationship among hydrocarbon-catalyst that it favored to the nano fibers production. The obtained product of each experiment outlined it was analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD), analysis with those were obtained pictures and diffraction graphs, which were observed to arrive to one conclusion on the operation conditions, same analysis with those were characterized the tests carried out according to the nano structures formation of carbon. (Author)

  8. The influence of heating rate on superconducting characteristics of MgB2 obtained by spark plasma sintering technique

    Science.gov (United States)

    Aldica, G.; Burdusel, M.; Popa, S.; Enculescu, M.; Pasuk, I.; Badica, P.

    2015-12-01

    Superconducting bulks of MgB2 were obtained by the Spark Plasma Sintering (SPS) technique. Different heating rates of 20, 100, 235, 355, and 475 °C/min were used. Samples have high density, above 95%. The onset critical temperature Tc, is about 38.8 K. There is an optimum heating rate of ∼100 °C/min to maximize the critical current density Jc0, the irreversibility field Hirr, the product (Jc0 x μ0Hirr), and to partially avoid formation of undesirable flux jumps at low temperatures. Significant microstructure differences were revealed for samples processed with low and high heating rates in respect to grain boundaries.

  9. The spatial distribution of temperature and oxygen deficiency in spark-plasma sintered superconducting Bi-based materials

    Energy Technology Data Exchange (ETDEWEB)

    Govea-Alcaide, E.; Pérez-Fernández, J.E. [Departamento de Ciencias Básicas, Facultad de Ciencias Técnicas, Universidad de Granma, Apdo. 21, P.O. Box 85100, Bayamo (Cuba); Machado, I.F. [Departamento de Engenharia Mecatrônica e Sistemas Mecânicos, Escola Politécnica, Universidade de São Paulo, 05508-900 São Paulo, SP (Brazil); Jardim, R.F., E-mail: rjardim@if.usp.br [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, SP (Brazil)

    2014-12-15

    Pre-reacted powders of (Bi–Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+δ} (Bi-2223) were consolidated by using the spark plasma sintering (SPS) technique under vacuum and at different consolidate temperatures T{sub D}. X-ray diffraction patterns revealed that the dominant phase in all SPS samples is the Bi-2223 phase, but traces of the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 10+x} (Bi-2212) phase were identified. We have found that the transport properties of SPS samples depend on their oxygen content because the SPS process is performed under vacuum. Simulations by using the finite element method (FEM) were performed for determining the actual temperature in which powders are consolidated. From these results we have inferred that SPS samples are oxygen deficient and such a deficiency is more marked near the grain boundaries, suggesting the occurrence of grains with core–shell morphology. We also argued that the width of the shell depends on the consolidation temperature, a feature corroborated by the FEM simulations.

  10. Spatial investigation of plasma emission from laminar diffusion methanol, ethanol, and n-propanol alcohol flames using LIBS method

    Science.gov (United States)

    Ghezelbash, Mahsa; Majd, Abdollah Eslami; Darbani, Seyyed Mohammad Reza; Mousavi, Seyyed Jabbar; Ghasemi, Ali; Tehrani, Masoud Kavosh

    2017-01-01

    Laser-induced breakdown spectroscopy (LIBS) technique is used to record some plasma emissions of different laminar diffusion methanol, ethanol, and n-propanol alcohol flames, to investigate the shapes, structures (i.e., reactants and products zones), kind, and quality of burning in different areas. For this purpose, molecular bands of CH, CH*, C2, CN, and CO as well as atomic and ionic lines of C, H, N, and O are identified, simultaneously. Experimental results indicate that the CN and C2 emissions have highest intensity in LIBS spectrum of n-propanol flame and the lowest in methanol. In addition, lowest content of CO pollution and better quality of burning process in n-propanol fuel flame toward ethanol and methanol are confirmed by comparison between their CO molecular band intensities. Moreover, variation of the signal intensity from these three flames with that from a known area of burner plate is compared. Our findings in this research advance the prior results in time-integrated LIBS combustion application and suggesting that LIBS can be used successfully with the CCD detector as a non-gated analytical tool, given its simple instrumentation needs, real-time capability applications of molecular detection in laminar diffusion flame samples, requirements.

  11. Surface Modification of a Titanium Alloy with a Phospholipid Polymer Prepared by a Plasma-Induced Grafting Technique to Improve Surface Thromboresistance

    OpenAIRE

    Ye, Sang Ho; Johnson, Carl A.; Woolley, Joshua R.; Oh, Heung-Il; Gamble, Lara J.; Ishihara, Kazuhiko; Wagner, William R.

    2009-01-01

    To improve the thromboresistance of a titanium alloy (TiAl6V4) surface which is currently utilized in several ventricular assist devices (VADs), a plasma-induced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) was carried out and poly(MPC) (PMPC) chains were covalently attached onto a TiAl6V4 surface by a plasma induced technique. Cleaned TiAl6V4 surfaces were pretreated with H2O-vapor-plasma and silanated with 3-methacryloylpropyltrimethoxysilane (MPS). Next, a plasma-...

  12. Atomic processes and equation of state of high Z plasmas for EUV sources and their effects on the spatial and temporal evolution of the plasmas

    Science.gov (United States)

    Sasaki, Akira; Sunahara, Atushi; Furukawa, Hiroyuki; Nishihara, Katsunobu; Nishikawa, Takeshi; Koike, Fumihiro

    2016-03-01

    Laser-produced plasma (LPP) extreme ultraviolet (EUV) light sources have been intensively investigated due to potential application to next-generation semiconductor technology. Current studies focus on the atomic processes and hydrodynamics of plasmas to develop shorter wavelength sources at λ = 6.x nm as well as to improve the conversion efficiency (CE) of λ = 13.5 nm sources. This paper examines the atomic processes of mid-z elements, which are potential candidates for λ = 6.x nm source using n=3-3 transitions. Furthermore, a method to calculate the hydrodynamics of the plasmas in terms of the initial interaction between a relatively weak prepulse laser is presented.

  13. Lasers techniques Improvement of classical accelerators by lasers. Laser accelerators with and without plasmas. Lasers accelerators in vacuum

    CERN Document Server

    Hora, Heinrich

    1991-01-01

    Of the unconventional accelerator techniques those including lasers are reported. After explaining the advances by lasers for classical accelerator techniques, as FELs and other methods for 100 GHz generation of GW pulses, a survey is given of far field and near field laser acceleration. Problems of the beat-wave accelerator are discussed and schemes for particle interaction in vacuum without plasma are elaborated. One scheme is the Boreham experiment and another is the acceleration of "standing" wave fields where charged particles are trapped in the intensity minima. Another scheme uses the relativistic acceleration by half waves where the now available petawatt-picosecond laser pulses should produce GeV electron pulses of high luminosity. Increase of these electron enrgies would need very large lasers in the future.

  14. The study of FTO surface texturing fabrication using Argon plasma etching technique for DSSC applications

    Science.gov (United States)

    Jayanti, Lindha; Kusumandari; Sujitno, Tjipto; Suryana, Risa

    2016-02-01

    This paper is aimed to investigate the fabrication of the fluorine-doped tin oxide (FTO) texturing by using Argon (Ar) plasma etching. The pressure and temperature of Ar gas during plasma etching were 1.6 mbar and 240-285oC, respectively. The plasma etching time was varied from 3 and 10 min. We also prepared without etching samples as reference. UV-Vis spectrophotometer showed that the transmittances of etching samples are higher than the without etching samples. The root mean square roughness (Rq) of etching samples are lower than the without etching samples. It is considered that the Ar ions bombardment can modify the FTO surfaces. However, the etching time does not significantly affect the FTO surfaces for 3 min and 10 min. The Rq of the without etching sample, the etching sample for 3 min, and the etching sample for 10 min are 11.697 nm, 9.859 nm, and 9.777 nm, respectively. These results are good agreement with the four point probe measurement that indicated that the sheet resistance (RS) for each the without sample, the etching sample for 3 min, and the etching sample for 10 min are 16.817 Ωsq, 16.067 Ω/sq, and 15.990 Ω/sq. In addition, the optical transmittance of the etching sample for 3 min and the etching sample for 10 min at wavelengths of 350 - 850 nm are almost similar. This is evidence that the etching time below 10 min cannot significantly change the morphology, optical and electrical properties.

  15. Iodine Determination by Microwave Plasma Torch Atomic Emission Spectrometer Coupled with Online Preconcentration Vapor Generation Technique

    Institute of Scientific and Technical Information of China (English)

    FEI Yan-qun; LUO Gui-min; FENG Guo-dong; CHEN Huan-wen; FEI Qiang; HUAN Yan-fu; JIN Qin-han

    2008-01-01

    This article focuses on iodine determination by microwave plasma torch atomic emission spectrometry (MPT-AES) coupled with online preconcentration vapor generation method.A new desolvation device,multistrand Nation dryer,was used as the substitute for condenser desolvation system.Some experimental conditions,such as preconcentration time,acidity of sample solution,rinsing solution acidity and dynamic linear range were investigated and optimized.The new desolvation system eliminates the problem of decreasing emission intensity of I(I) 206.238 nm line with the increase of working time on a conventional condenser desolvation system,thus greatly improving the reproducibility.

  16. Differentiating between spatial and temporal effects by applying modern data analyzing techniques to measured soil moisture data

    Science.gov (United States)

    Hohenbrink, Tobias L.; Lischeid, Gunnar; Schindler, Uwe

    2013-04-01

    Large data sets containing time series of soil hydrological variables exist due to extensive monitoring work in the last decades. The interplay of different processes and influencing factors cause spatial and temporal patterns which contribute to the total variance. That implies that monitoring data sets contain information about the most relevant processes. That information can be extracted using modern data analysis techniques. Our objectives were (i) to decompose the total variance of an example data set of measured soil moisture time series in independent components and (ii) relate them to specific influencing factors. Soil moisture had been measured at 12 plots in an Albeluvisol located in Müncheberg, northeastern Germany, between May 1st, 2008 and July 1st, 2011. Each plot was equipped with FDR probes in 7 depths between 30 cm and 300 cm. Six plots were cultivated with winter rye and silage maize (Crop Rotation System I) and the other six with silage maize, winter rye/millet, triticale/lucerne and lucerne (Crop Rotation System II). We applied a principal component analysis to the soil moisture data set. The first component described the mean behavior in time of all soil moisture time series. The second component reflected the impact of soil depth. Together they explained 80 % of the data set's total variance. An analysis of the first two components confirmed that measured plots showed similar signal damping extend in each depth. The fourth component revealed the impact of the two different crop rotation systems which explained about 4 % of the total variance and 13 % of the spatial variance of soil moisture data. That is only a minor fraction compared to small scale soil texture heterogeneity effects. Principal component analysis has proven to be a useful tool to extract less apparent signals.

  17. Land Use Changes Analysis for Kelantan Basin Using Spatial Matrix Technique “Patch Analyst” in Relation to Flood Disaster

    Directory of Open Access Journals (Sweden)

    Tuan Pah Rokiah Syed Hussain

    2011-09-01

    Full Text Available In the recent decade, there are many government efforts to develop rural area as a step to curb vast economic discrepancy status within community in the nation. This effort is in line with National Development Policy promoted by government shifting from New Economic Policy. Therefore, this study area also has impact done by development activities. The enormous economic developments have encourage growth in urbanization, tourism and recreation, public facilities, housing and so on. Furthermore, the area of cultivation land uses and foliages are becoming shrinking due to development growth, which is development needs to shift land use pattern hence denotes that human beings infuriate the environment to meet the life needs. In response to that, this research delves into the level of land use changes using the Geographic Information System (GIS and Spatial Analyst to determine the actual area or vicinity and what is the type of rigorous changes in land use. This issue can be seen all the way through the study outcome via spatial analysis technique adapted from Patch Density & Size Metrics (Mean Patch Size, Edge Metrics (Total Edge (TE, Edge Density (ED, Mean Perimeter-Area Ratio (Mpar and Shannons Diversity Index (SHDI. Results of the study show that, land use changes have occurred significantly in the study area for the period of 20 years, wher, all types of analysis verify that there is an increase in patch for every statistical test. The increase in patch is a picture of current land use changes, land use edge density and land use area in study area. Moreover, this study investigates the relationship between land use with rising flood disaster frequency and intensity variable which has always happened lately in Kelantan River Basin.

  18. Monitoring trace metals in urban aerosols from Buenos Aires city. Determination by plasma-based techniques.

    Science.gov (United States)

    Smichowski, Patricia; Gómez, Dario R; Dawidowski, Laura E; Giné, María Fernanda; Bellato, Ana Claudia Sánchez; Reich, Silvia L

    2004-04-01

    A study was undertaken, within the framework of a 3 years national project, to assess the content of 13 elements in airborne particulate matter collected in representative zones of the metropolitan area of Buenos Aires. The sampling strategy followed consisted in collecting simultaneously 67 samples of PM10 particulate matter in 9 sampling sites covering an area of about 30 km2 during one week. The collection was performed on ash-free fibre-glass filters using high volume samplers. A combination of aqua regia and perchloric acid was used for leaching metals from filters. Key elements, namely Al, Ca, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Sn, Zn and Zr, were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) at micro g g(-1) and ng g(-1) levels. Analyte concentration varied from 130 ng g(-1)(Mo) to over 30%(Ca). Multivariate statistical analysis was performed on the data set including the measured elemental compositions for the monitored period. The atmospheric concentration found for Pb confirms the decreasing levels of this element since the introduction of unleaded gasoline in 1995: 88 ng m(-3)(2001) gas imply low emissions of this element from combustion activities. To the best of our knowledge, S concentrations are reported for the first time for this city.

  19. Plasma etching and ashing: a technique for demonstrating internal structures of helminths using scanning electron microscopy.

    Science.gov (United States)

    Veltkamp, C J; Chubb, J C

    2006-03-01

    Plasma etching and ashing for demonstrating the three-dimensional ultrastructure of the internal organs of helminths is described. Adult worms of the cestode Caryophyllaeides fennica were dehydrated through an ethanol series, critical point dried (Polaron E3000) and sputter coated with 60% gold-palladium (Polaron E5100) and glued to a standard scanning electron microscope (SEM) stub positioned as required for ashing. After initial SEM viewing of worm surfaces for orientation, stubs were placed individually in the reactor chamber of a PT7150 plasma etching and ashing machine. Worms were exposed to a radio frequency (RF) potential in a low pressure (0.2 mbar) oxygen atmosphere at room temperature. The oxidation process was controlled by varying the times of exposure to the RF potential between 2 to 30 min, depending on the depth of surface tissue to be removed to expose target organs or tissues. After each exposure the oxidized layer was blown from the surface with compressed air, the specimen sputter-coated, and viewed by SEM. The procedure was repeated as necessary, to progressively expose successive layers. Fine details of organs, cells within, and cell contents were revealed. Ashing has the advantage of providing three dimensional images of the arrangement of organs that are impossible to visualize by any other procedure, for example facilitating testes counts in cestodes. Both freshly-fixed and long-term stored helminths can be ashed. Ashing times to obtain the desired results were determined by trial so that some duplicate material was needed.

  20. Thickness measurement approach for plasma sprayed coatings using ultrasonic testing technique

    Institute of Scientific and Technical Information of China (English)

    LIN Li; LI Xi-meng; XU Zhi-hui; LEI Ming-kai

    2004-01-01

    The special ultrasonic testing system has been developed for thickness measurement of plasma sprayed coatings. The ultrasonic immersion method was used to obtain stable coupling condition and avoid other disadvantages of contact method. Spherical acoustic lens were designed to focus ultrasonic beam so as to improve beam directivity and concentrate ultrasonic energy. To increase testing precision and avoid mussy wave signals, moderate pulse width and frequency of the transducer has been selected. The displacement of transducer in X-Y-Z directions was precisely manipulated by step-controlled system to insure the accuracy of focus length and repetition of measurement. Optimized testing conditions (with the transducer of center frequency of 10 MHz and crystal diameter of 8 mm, focus length of 9.5 mm, diameter of focal column of 0. 1 mm and length of focal column of 0.27 mm) were selected to determine the thickness between 285 -414 μm of ZrO2 coatings plasma sprayed on the nickel based superalloy. The frequency interval of the periodic extremums in ultrasonic power spectra decreases with increasing coating thickness. The ultrasonic results accord with those of metallographical method.

  1. Cell adhesion to plasma electrolytic oxidation (PEO) titania coatings, assessed using a centrifuging technique.

    Science.gov (United States)

    Robinson, H J; Markaki, A E; Collier, C A; Clyne, T W

    2011-11-01

    The adhesion of bovine chondrocytes and human osteoblasts to three titania-based coatings, formed by plasma electrolytic oxidation (PEO), was compared to that on uncoated Ti-6Al-4V substrates, and some comparisons were also made with plasma sprayed hydroxyapatite (HA) coatings. This was done using a centrifuge, with accelerations of up to 160,000 g, so as to induce buoyancy forces that created normal or shear stresses at the interface. It is shown that, on all surfaces, it was easier to remove cells under normal loading than under shear loading. Cell adhesion to the PEO coatings was stronger than that on Ti-6Al-4V and similar to that on HA. Cell proliferation rates were relatively high on one of the PEO coatings, which was virtually free of aluminium, but low on the other two, which contained significant levels of aluminium. It is concluded that the Al-free PEO coating offers promise for application to prosthetic implants.

  2. Phase stability in fMRI time series: effect of noise regression, off-resonance correction and spatial filtering techniques.

    Science.gov (United States)

    Hagberg, Gisela E; Bianciardi, Marta; Brainovich, Valentina; Cassara, Antonino Mario; Maraviglia, Bruno

    2012-02-15

    Although the majority of fMRI studies exploit magnitude changes only, there is an increasing interest regarding the potential additive information conveyed by the phase signal. This integrated part of the complex number furnished by the MR scanners can also be used for exploring direct detection of neuronal activity and for thermography. Few studies have explicitly addressed the issue of the available signal stability in the context of phase time-series, and therefore we explored the spatial pattern of frequency specific phase fluctuations, and evaluated the effect of physiological noise components (heart beat and respiration) on the phase signal. Three categories of retrospective noise reduction techniques were explored and the temporal signal stability was evaluated in terms of a physiologic noise model, for seven fMRI measurement protocols in eight healthy subjects at 3T, for segmented CSF, gray and white matter voxels. We confirmed that for most processing methods, an efficient use of the phase information is hampered by the fact that noise from physiological and instrumental sources contributes significantly more to the phase than to the magnitude instability. Noise regression based on the phase evolution of the central k-space point, RETROICOR, or an orthonormalized combination of these were able to reduce their impact, but without bringing phase stability down to levels expected from the magnitude signal. Similar results were obtained after targeted removal of scan-to-scan variations in the bulk magnetic field by the dynamic off-resonance in k-space (DORK) method and by the temporal off-resonance alignment of single-echo time series technique (TOAST). We found that spatial high-pass filtering was necessary, and in vivo a Gaussian filter width of 20mm was sufficient to suppress physiological noise and bring the phase fluctuations to magnitude levels. Stronger filters brought the fluctuations down to levels dictated by thermal noise contributions, and for 62

  3. Techniques For Injection Of Pre-Charaterized Dust Into The Scrape Off Layer Of Fusion Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Roquemore, A. L.; John, B.; Friesen, F.; Hartzfeld, K.; Mansfield, D. K.

    2011-07-21

    Introduction of micron-sized dust into the scrape-off layer (SOL) of a plasma has recently found many applications aimed primarily at determining dust behavior in future fusion reactors. The dust particles are typically composed of materials intrinsic to a fusion reactor. On DIII-D and TEXTOR carbon dust has been introduced into the SOL using a probe inserted from below into the divertor region. On NSTX, both Li and tungsten dust have been dropped from the top of the machine into the SOL throughout the duration of a discharge, by utilizing a vibrating piezoelectric based particle dropper. The original particle dropper was developed to inject passivated Li powder {approx} 40 {mu}m in diameter into the SOL to enhance plasma performance. A simplified version of the dropper was developed to introduce trace amounts of tungsten powder for only a few discharges, thus not requiring a large powder reservoir. The particles emit visible light from plasma interactions and can be tracked by either spectroscopic means or by fast frame rate visible cameras. This data can then be compared with dust transport codes such as DUSTT to make predictions of dust behavior in next-step devices such as ITER. For complete modeling results, it is desired to be able to inject pre-characterized dust particles in the SOL at various known poloidal locations, including near the vessel midplane. Purely mechanical methods of injecting particles are presently being studied using a modified piezoelectric-based powder dropper as a particle source and one of several piezo-based transducers to deflect the particles into the SOL. Vibrating piezo fans operating at 60 Hz with a deflection of {+-}2.5 cm can impart a significant horizontal boost in velocity. The highest injection velocities are expected from rotating paddle wheels capable of injecting particles at 10's of meters per second depending primarily on the rotation velocity and diameter of the wheel. Several injection concepts have been tested

  4. Surface modification of Polymers by plasma polymerization techniques for tissue engineering

    OpenAIRE

    Francesch de Castro, Laia

    2008-01-01

    El treball que es presenta en aquesta tesi pretén contribuir al camp de la ciència de superfícies biològiques, amb el desenvolupament de superfícies adaptades amb cadenes lateral reactives per tal de unir covalentment biomolècul·les d'interès a la superfície.La polimerització assistida per plasma del recobriments actius és un mètode atractiu per tal d'obtenir cadenes laterals reactives, mitjançant pel·lícules nanomètriques amb densitats de grups funcionals adaptats. Sota control de les condic...

  5. Determination of the Mechanical Properties of Plasma-Sprayed Hydroxyapatite Coatings Using the Knoop Indentation Technique

    Science.gov (United States)

    Hasan, Md. Fahad; Wang, James; Berndt, Christopher

    2015-06-01

    The microhardness and elastic modulus of plasma-sprayed hydroxyapatite coatings were evaluated using Knoop indentation on the cross section and on the top surface. The effects of indentation angle, testing direction, measurement location and applied load on the microhardness and elastic modulus were investigated. The variability and distribution of the microhardness and elastic modulus data were statistically analysed using the Weibull modulus distribution. The results indicate that the dependence of microhardness and elastic modulus on the indentation angle exhibits a parabolic shape. Dependence of the microhardness values on the indentation angle follows Pythagoras's theorem. The microhardness, Weibull modulus of microhardness and Weibull modulus of elastic modulus reach their maximum at the central position (175 µm) on the cross section of the coatings. The Weibull modulus of microhardness revealed similar values throughout the thickness, and the Weibull modulus of elastic modulus shows higher values on the top surface compared to the cross section.

  6. Spatial resolution in laser ablation inductively coupled plasma mass spectrometry; Resolucion espacial en la ablacion laser acoplada a la espectrometria de masas con fuente de plasm de acoplamiento inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Coedo, A. G.; Dorado, M. T.

    2010-07-01

    Laser ablation as sampling system in inductively coupled plasma mass spectrometry (LA-ICP-MS) offers the possibility to know the spatial distribution of elements present in a solid sample. By varying the position of the laser beam on the sample surface, the profile of the lateral distribution of elements is obtained and, with successive pulses fired on a fixed point, profile in depth is achieved. After optimization of operating parameters the technique has been applied to samples with different compositions in both surface and depth.With regard to the lateral resolution has been found that in a length similar to the crater diameter of the laser beam, the signals of the elements appear mixed, making difficult to accurately establish the interface. Regarding the resolution in depth is clearly established the influence of the natural abundance of the measured isotopes. (Author)

  7. Redox and speciation mapping of rock thin sections using high spatial resolution full-field imaging technique

    Science.gov (United States)

    de Andrade, V.; Susini, J.; Salomé, M.; Beraldin, O.; Heymes, T.; Lewin, E.

    2009-04-01

    Because of their complex genesis, natural rocks are the most often heterogeneous systems, with various scale-level heterogeneities for both chemistry and structure. In the last decade, the dramatic improvements of hyperspectral imaging techniques provided new tools for accurate material characterisation. Most of these micro- and nano- analytical techniques rely on scanning instruments, which offer high spatial resolution but suffer from long acquisition times imposing practical limits on the field of view. Conversely, full-field imaging techniques rely on a fast parallel acquisition but have limited resolution. Although soft X-ray full-field microscopes based on Fresnel zone plates are commonly used for high resolution imaging, its combination with spectroscopy is challenging and 2D chemical mapping still difficult. For harder X-rays, lensless X-ray microscope based on simple propagation geometry is easier and can be readily used for 2D spectro-microscopy. A full-field experimental setup was optimized at the ESRF-ID21 beamline to image iron redox and speciation distributions in rocks thin sections. The setup comprises a Si111 or Si220 (E = 0.4 eV) monochromator, a special sample stage and a sensitive camera associated with a brand new GGG:Eu light conversion scintillator and high magnification visible light optics. The pixel size ranges from 1.6 to 0.16 m according to the optic used. This instrument was used to analyse phyllosilicates and oxides of metamorphic sediments coming from the Aspromonte nappes-pile in Calabria. Iron chemical state distributions were derived - from images of 1000 Ã- 2000 Ã- 30 m3 rock thin sections - by subtraction of absorption images above and below the Fe K-edge. Using an automatic stitching reconstruction, a wide field image (4Ã-3 mm2 with a 1 m2 resolution for a total of about 12 millions pixels) of Fetotal elemental distribution was produced. Moreover, -XANES analyses (more than 1 million individual -XANES spectra) were performed

  8. 优质草莓立体无土设施栽培技术%Techniques of spatial and soilless cultivation for quafified strawberry

    Institute of Scientific and Technical Information of China (English)

    林金秀; 庄卫东; 郑金水; 张平泉

    2012-01-01

    引进台湾先进的立体草莓无土设施栽培技术,并进行改进与创新,提出与当地气候条件相配套的栽培管理技术。%The advanced techniques of spatial and soilless cultivation of strawberry from Taiwan were introduced, and then improved and innovated. This paper put forward the improved cultivation techniques according to the local climate conditions.

  9. Nanostructured silicon carbon thin films grown by plasma enhanced chemical vapour deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Coscia, U. [Dipartimento di Fisica, Università di Napoli “Federico II” Complesso Universitario MSA, via Cinthia, 80126 Napoli (Italy); CNISM Unita' di Napoli, Complesso Universitario MSA, via Cinthia, 80126 Napoli (Italy); Ambrosone, G., E-mail: ambrosone@na.infn.it [Dipartimento di Fisica, Università di Napoli “Federico II” Complesso Universitario MSA, via Cinthia, 80126 Napoli (Italy); SPIN-CNR, Complesso Universitario MSA, via Cinthia, 80126 Napoli (Italy); Basa, D.K. [Department of Physics, Utkal University, Bhubaneswar 751004 (India); Rigato, V. [INFN Laboratori Nazionali Legnaro, 35020 Legnaro (Padova) (Italy); Ferrero, S.; Virga, A. [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy)

    2013-09-30

    Nanostructured silicon carbon thin films, composed of Si nanocrystallites embedded in hydrogenated amorphous silicon carbon matrix, have been prepared by varying rf power in ultra high vacuum plasma enhanced chemical vapour deposition system using silane and methane gas mixtures diluted in hydrogen. In this paper we have studied the compositional, structural and electrical properties of these films as a function of rf power. It is shown that with increasing rf power the atomic densities of carbon and hydrogen increase while the atomic density of silicon decreases, resulting in a reduction in the mass density. Further, it is demonstrated that carbon is incorporated into amorphous matrix and it is mainly bonded to silicon. The study has also revealed that the crystalline volume fraction decreases with increase in rf power and that the films deposited with low rf power have a size distribution of large and small crystallites while the films deposited with relatively high power have only small crystallites. Finally, the enhanced transport properties of the nanostructured silicon carbon films, as compared to amorphous counterpart, have been attributed to the presence of Si nanocrystallites. - Highlights: • The mass density of silicon carbon films decreases from 2.3 to 2 g/cm{sup 3}. • Carbon is incorporated in the amorphous phase and it is mainly bonded to silicon. • Nanostructured silicon carbon films are deposited at rf power > 40 W. • Si nanocrystallites in amorphous silicon carbon enhance the electrical properties.

  10. Pressure dependent tailored attributes of silicon nanoneedles grown by VHF plasma technique

    Science.gov (United States)

    Mohammed, Yasir Hussein; Sakrani, Samsudi Bin; Rohani, Md Supar

    2016-06-01

    Gold (Au) catalysts assisted well-aligned silicon nanoneedles (SiNNs) are synthesized using very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The tailored morphology and the optical reflectance of such NNs are inspected as a function of varying reactor pressure (200-800 mTorr). FESEM images revealed the growth of high density SiNNs with diameter ranging from 45 to 600 nm and length as much as 5.66 ± 0.2 μm. Overall morphology of these NNs are found to be highly sensitive to the pressure variation, where appreciably aligned thinner NNs are achieved at 600 mTorr pressure. The presence of globule at the NNs tip authenticated their VLS mechanism mediated growth. The reactor pressure sensitivity of the aspect ratio, lattice parameters, Raman modes, and reflectance are demonstrated. XRD patterns manifested SiNNs cubic crystalline phase with preferred orientation along direction. The occurrence of NNs high crystallinity is further supported by the Raman and HRTEM data. The reflectance of SiNNs grown at 600 mTorr exhibited remarkable reduction (˜6.3%) than those obtained at other pressures. This reactor pressure dependent significant modification in the physical properties of synthesized SiNNs may be prospective for the development of optoelectronics.

  11. Highly zone-dependent synthesis of different carbon nanostructures using plasma-enhanced arc discharge technique

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajesh, E-mail: rajeshbhu1@gmail.com [Yonsei University, Department of Materials Science & Engineering (Korea, Republic of); Singh, Rajesh Kumar, E-mail: rksbhu@gmail.com [Banaras Hindu University, Department of Applied Physics, Indian Institute of Technology (India); Dubey, Pawan Kumar [University of Allahabad, Nanotechnology Application Centre (India); Yadav, Ram Manohar [Rice University, Department of Materials Science and Nano Engineering (United States); Singh, Dinesh Pratap [Universidad de Santiago de Chile, Departamento de Física (Chile); Tiwari, R. S.; Srivastava, O. N. [Banaras Hindu University, Department of Physics (India)

    2015-01-15

    Three kinds of carbon nanostructures, i.e., graphene nanoflakes (GNFs), multi walled carbon nanotubes (MWCNTs), and spherical carbon nanoparticles (SCNPs) were comparatively investigated in one run experiment. These carbon nanostructures are located at specific location inside the direct current plasma-assisted arc discharge chamber. These carbon nanomaterials have been successfully synthesized using graphite as arcing electrodes at 400 torr in helium (He) atmosphere. The SCNPs were found in the deposits formed on the cathode holder, in which highly curled graphitic structure are found in majority. The diameter varies from 20 to 60 nm and it also appears that these particles are self-assembled to each other. The MWCNTs with the diameter of 10–30 nm were obtained which were present inside the swelling portion of cathode deposited. These MWCNTs have 14–18 graphitic layers with 3.59 Å interlayer spacing. The GNFs have average lateral sizes of 1–5 μm and few of them are stacked layers and shows crumpled like structure. The GNFs are more stable at low temperature (low mass loss) but SCNPs have low mass loss at high temperature.

  12. Techniques for mass resolution improvement achieved by typical plasma mass analyzers: Modeling and simulations

    Science.gov (United States)

    Nicolaou, Georgios; Yamauchi, Masatoshi; Wieser, Martin; Barabash, Stas; Fedorov, Andrei

    2016-04-01

    Mass separation and particularly distinction between atomic ions and molecular ions are essential in understanding a wide range of plasma environments, with each consisted of different species with various properties. In this study we present the optimization results of light-weight (about 2 kg) magnetic mass analyzers with high g-factor for Rosetta (Ion Composition Analyser: ICA) and for Mars Express and Venus Express (Ion Mass Analyser: IMA). For the instrument's optimization we use SIMION, a 3D ion tracing software in which we can trace particle beams of several energies and directions, passing through the instrument's units. We first reproduced ICA and IMA results, which turned out to be different from simple models for low energy (< 100 eV). We then change the mechanical structure of several units of the instrument and we quantify the new mass resolution achieved with each change. Our goal is to find the optimal instrument's structure, which will allow us to achieve a proper mass resolution to distinguish atomic nitrogen from atomic oxygen for the purposes of a future magnetospheric mission.

  13. Wetting behaviour of carbon nitride nanostructures grown by plasma enhanced chemical vapour deposition technique

    Science.gov (United States)

    Ahmad Kamal, Shafarina Azlinda; Ritikos, Richard; Abdul Rahman, Saadah

    2015-02-01

    Tuning the wettability of various coating materials by simply controlling the deposition parameters is essential for various specific applications. In this work, carbon nitride (CNx) films were deposited on silicon (1 1 1) substrates using radio-frequency plasma enhanced chemical vapour deposition employing parallel plate electrode configuration. Effects of varying the electrode distance (DE) on the films' structure and bonding properties were investigated using Field emission scanning electron microscopy, Atomic force microscopy, Fourier transform infrared and X-ray photoemission spectroscopy. The wettability of the films was analyzed using water contact angle measurements. At high DE, the CNx films' surface was smooth and uniform. This changed into fibrous nanostructures when DE was decreased. Surface roughness of the films increased with this morphological transformation. Nitrogen incorporation increased with decrease in DE which manifested the increase in both relative intensities of Cdbnd N to Cdbnd C and Nsbnd H to Osbnd H bonds. sp2-C to sp3-C ratio increased as DE decreased due to greater deformation of sp2 bonded carbon at lower DE. The films' characteristics changed from hydrophilic to super-hydrophobic with the decrease in DE. Roughness ratio, surface porosity and surface energy calculated from contact angle measurements were strongly dependent on the morphology, surface roughness and bonding properties of the films.

  14. Green and Fast Laser Fusion Technique for Bulk Silicate Rock Analysis by Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Zhang, Chenxi; Hu, Zhaochu; Zhang, Wen; Liu, Yongsheng; Zong, Keqing; Li, Ming; Chen, Haihong; Hu, Shenghong

    2016-10-18

    Sample preparation of whole-rock powders is the major limitation for their accurate and precise elemental analysis by laser ablation inductively-coupled plasma mass spectrometry (ICPMS). In this study, a green, efficient, and simplified fusion technique using a high energy infrared laser was developed for major and trace elemental analysis. Fusion takes only tens of milliseconds for each sample. Compared to the pressed pellet sample preparation, the analytical precision of the developed laser fusion technique is higher by an order of magnitude for most elements in granodiorite GSP-2. Analytical results obtained for five USGS reference materials (ranging from mafic to intermediate to felsic) using the laser fusion technique generally agree with recommended values with discrepancies of less than 10% for most elements. However, high losses (20-70%) of highly volatile elements (Zn and Pb) and the transition metal Cu are observed. The achieved precision is within 5% for major elements and within 15% for most trace elements. Direct laser fusion of rock powders is a green and notably simple method to obtain homogeneous samples, which will significantly accelerate the application of laser ablation ICPMS for whole-rock sample analysis.

  15. Diagnosis of magnetic structures and intermittency in space-plasma turbulence using the technique of surrogate data.

    Science.gov (United States)

    Sahraoui, F

    2008-08-01

    Intermittency is usually identified in turbulent flows as non-Gaussian tails of the probability density functions (PDFs) of the turbulent field derivatives. Here we investigate the role of phase coherence among the Fourier modes in creating intermittency in magnetized space plasmas using the technique of surrogate data. We apply the technique to two examples: (i) synthetic data and (ii) magnetic field fluctuations recorded in the terrestrial magnetosheath by the Cluster spacecraft. We use a set of four series of data, one observed and three surrogate, and their PDFs and moments (q < or = 4) as discriminating statistics. We show that the technique allows for detecting coherent structures and estimating their scales. We show furthermore that the phases, but not the amplitudes, create the non-Gaussian tails of the PDFs. We show also that the surrogate data used cannot account for asymmetries of the PDFs of the observed data. This enables us to confirm a scenario of turbulent cascade of mirror structures proposed in previous publications, by showing the existence of an approximately constant energy flux in the inertial range.

  16. Determination of trimethylamine, trimethylamine N-oxide, and taurine in human plasma and urine by UHPLC-MS/MS technique.

    Science.gov (United States)

    Awwad, Hussain Mohamad; Geisel, Juergen; Obeid, Rima

    2016-12-01

    Trimethylamine-N-oxide (TMAO) is produced in the liver from trimethylamine (TMA) and is an important cellular osmolyte and potential atherogenic factor. Taurine is involved in cholesterol metabolism and also serves as a cellular osmolyte. Given their significant biological functions, the development of reliable measurement techniques is crucial to further study their role in health and disease METHODS: A new ultrahigh performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of TMA, TMAO, and taurine in plasma and urine. The method consisted of a deproteinization step using methanol/acetonitrile (15:85) that contained 0.2% formic acid and isotope-labeled internal standards. Samples were separated by centrifugation and injected into the UHPLC system. Quantification was conducted using a triple-quadrupole mass spectrometer detector with electrospray ionization interface in positive mode. The limits of detection ranged from 0.08 to 0.12μmol/L. The calibration curves were linear (r≥0.999) over the range examined (0.15-400μmol/L) for all compounds. The inter- and intra-day coefficients of variations were≤14.5% for TMA and ≤8% for TMAO and taurine. TMAO and taurine were found to be stable in EDTA plasma for at least 14 months at -70°C. Mean recoveries ranged from 95% to 109% and the relative matrix effects were≤4.0%. The method was applied to study physiological and pre-analytical factors in plasma and urine samples. The new UHPLC-MS/MS method has good accuracy, precision, and recovery. The assay combines simple sample processing with a short run time, making it well suited for high-throughput routine clinical or research purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. DEVELOPMENT OF AN AGAR LIFT-DNA/DNA HYBRIDIZATION TECHNIQUE FOR USE IN VISUALIZATION OF THE SPATIAL DISTRIBUTION OF EUBACTERIA ON SOIL SURFACES. (R825415)

    Science.gov (United States)

    AbstractWhile microbial growth is well-understood in pure culture systems, less is known about growth in intact soil systems. The objective of this work was to develop a technique to allow visualization of the two-dimensional spatial distribution of bacterial growth o...

  18. The influence of heating rate on superconducting characteristics of MgB{sub 2} obtained by spark plasma sintering technique

    Energy Technology Data Exchange (ETDEWEB)

    Aldica, G. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Burdusel, M. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Faculty of Materials Science and Engineering, University ’Politehnica’ of Bucharest, Splaiul Independentei 313, 060042 Bucharest (Romania); Popa, S.; Enculescu, M.; Pasuk, I. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Badica, P., E-mail: badica2003@yahoo.com [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania)

    2015-12-15

    Highlights: • MgB{sub 2} was obtained by ex-situ spark plasma sintering for different heating rates. • Heating rates were 20–475 °C/min: the optimum heating rate is ∼100 °C/min. • For 100 °C/min, J{sub c0}, H{sub irr} and (J{sub c0} x μ{sub 0}H{sub irr}) have maximum values. • For 100 °C/min, macro flux jumps are partially suppressed at 5 K. • Grain boundaries are modified depending on the heating rate. - Abstract: Superconducting bulks of MgB{sub 2} were obtained by the Spark Plasma Sintering (SPS) technique. Different heating rates of 20, 100, 235, 355, and 475 °C/min were used. Samples have high density, above 95%. The onset critical temperature T{sub c}, is about 38.8 K. There is an optimum heating rate of ∼100 °C/min to maximize the critical current density J{sub c0}, the irreversibility field H{sub irr}, the product (J{sub c0} x μ{sub 0}H{sub irr}), and to partially avoid formation of undesirable flux jumps at low temperatures. Significant microstructure differences were revealed for samples processed with low and high heating rates in respect to grain boundaries.

  19. Study of Titanizing the Surface of Copper Substrates by the Double Glow Discharge Plasma Surface Alloying Technique

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuefei; Chen Fei; Lü Junxia; Su Yongan; Xu Zhong

    2005-01-01

    This paper discusses a study in which Ti surface alloying has been performed on copper substrates by means of a double glow discharge plasma surface alloying technique. The micro-structure, the phase structure, the micro-hardness and the distribution of Ti concentration of alloying layer were investigated in detail by XRD, SEM and so on. The effect of process parameters on the alloying layer was studied. The experimental results show that a Ti solid solution with the precipitation Cu4Ti alloying layer has been formed on the copper surface. The thickness of the alloying layer is about 120μm and the surface titanium concentration gradually decreases from w (Ti) = 87% to w (Ti) = 4%. The micro-hardness of the alloying layer is between 300 HV ~ 800 HV. Source sputtering, surface absorption, ion bombarding and high temperature diffusion are the major factors that affect the alloying layer.

  20. Alternative Techniques for Injecting Massive Quantities of Gas for Plasma Disruption Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephen Kirk [ORNL; Meitner, Steven J [ORNL; Caughman, John B [ORNL; Commaux, Nicolas JC [ORNL; Fehling, Dan T [ORNL; Foust, Charles R [ORNL; Jernigan, Thomas C [ORNL; McGill, James M [ORNL; Parks, P. B. [General Atomics; Rasmussen, David A [ORNL

    2010-01-01

    Injection of massive quantities of noble gases or D2 has proven to be effective at mitigating some of the deleterious effects of disruptions in tokamaks. Two alternative methods that might offer some advantages over the present technique for massive gas injection are shattering massive pellets and employing closecoupled rupture disks. Laboratory testing has been carried out to evaluate their feasibility. For the study of massive pellets, a pipe gun pellet injector cooled with a cryogenic refrigerator was fitted with a relatively large barrel (16.5 mm bore), and D2 and Ne pellets were made and were accelerated to speeds of ~600 and 300 m/s, respectively. Based on the successful proof-of-principle testing with the injector and a special double-impact target to shatter pellets, a similar system has been prepared and installed on DIII-D, with preliminary experiments already carried out. To study the applicability of rupture disks for disruption mitigation, a simple test apparatus was assembled in the lab. Commercially available rupture disks of 1 in. nominal diameter were tested at conditions relevant for the application on tokamaks, including tests with Ar and He gases and rupture pressures of ~54 bar. Some technical and practical issues of implementing this technique on a tokamak are discussed.

  1. Complex polarization-phase and spatial-frequency selections of laser images of blood-plasma films in diagnostics of changes in their polycrystalline structure

    Science.gov (United States)

    Ushenko, Yu. A.; Angelskii, P. O.; Dubolazov, A. V.; Karachevtsev, A. O.; Sidor, M. I.; Mintser, O. P.; Oleinichenko, B. P.; Bizer, L. I.

    2013-10-01

    We present a theoretical formalism of correlation phase analysis of laser images of human blood plasma with spatial-frequency selection of manifestations of mechanisms of linear and circular birefringence of albumin and globulin polycrystalline networks. Comparative results of the measurement of coordinate distributions of the correlation parameter—the modulus of the degree of local correlation of amplitudes—of laser images of blood plasma taken from patients of three groups—healthy patients (donors), rheumatoid-arthritis patients, and breast-cancer patients—are presented. We investigate values and ranges of change of statistical (the first to fourth statistical moments), correlation (excess of autocorrelation functions), and fractal (slopes of approximating curves and dispersion of extrema of logarithmic dependences of power spectra) parameters of coordinate distributions of the degree of local correlation of amplitudes. Objective criteria for diagnostics of occurrence and differentiation of inflammatory and oncological states are determined.

  2. Use of indentation technique to measure elastic modulus of plasma-sprayed zirconia thermal barrier coating

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J.P.; Sutaria, M. [Argonne National Lab., IL (United States). Energy Technology Div.; Ferber, M. [Oak Ridge National Lab., TN (United States)

    1997-01-01

    Elastic modulus of an yttria partially stabilized zirconia (YSZ) thermal barrier coating (TBC) was evaluated with a Knoop indentation technique. The measured elastic modulus values for the coating ranged from 68.4 {+-} 22.6 GPa at an indentation load of 50 g to 35.7 {+-} 9.8 at an indentation load of 300 g. At higher loads, the elastic modulus values did not change significantly. This steady-state value of 35.7 GPa for ZrO{sub 2} TBC agreed well with literature values obtained by the Hertzian indentation method. Furthermore, the measured elastic modulus for the TBC is lower than that reported for bulk ZrO{sub 2} ({approx} 190 GPa). This difference is believed to be due to the presence of a significant amount of porosity and microcracks in the TBCs. Hardness was also measured.

  3. [Bacteriospermia in Assisted Reproductive Techniques: effects of bacteria on spermatozoa and seminal plasma, diagnosis and treatment].

    Science.gov (United States)

    Boitrelle, F; Robin, G; Lefebvre, C; Bailly, M; Selva, J; Courcol, R; Lornage, J; Albert, M

    2012-04-01

    The presence of bacteria in semen could induce impairment of sperm morphology, alteration of sperm function and mechanical or functional obstruction of the seminal tract. The term of bacteriospermia does not signify infection. Bacteriospermia and male accessory gland infection (MAGI) have indeed to be distinguished. They may lead both to male infertility but their diagnosis and treatment options differ. This review summarizes effects of bacteria and leucocytospermia on sperm parameters and functions. Then, indications, benefits and risks of treatment of bacteriospermia and MAGI, in assisted reproductive techniques (ART) will be discussed. For bacteria commonly observed in semen, this review aims at defining some thresholds above which a treatment is required. These thresholds were established according to literature, according to French microbiology society and in function of our usual practice. This review should help practitioners of reproductive medicine to take care of bacteriospermia in semen.

  4. Saturation of Alfvén modes in tokamak plasmas investigated by Hamiltonian mapping techniques

    Science.gov (United States)

    Briguglio, S.; Schneller, M.; Wang, X.; Di Troia, C.; Hayward-Schneider, T.; Fusco, V.; Vlad, G.; Fogaccia, G.

    2017-07-01

    Nonlinear dynamics of single toroidal number Alfvén eigenmodes destabilised by the the resonant interaction with fast ions is investigated, in tokamak equilibria, by means of Hamiltonian mapping techniques. The results obtained by two different simulation codes, XHMGC and HAGIS, are presented for n  =  2 Beta induced Alfvén eigenmodes and, respectively n  =  6 toroidal Alfvén eigenmodes. Simulations of the bump-on-tail instability performed by a 1-dimensional code, PIC1DP, are also analysed for comparison. As a general feature, modes saturate as the resonant-particle distribution function is flattened over the whole region where mode-particle power transfer can take place in the linear phase. Such region is limited by the narrowest of resonance width and mode width. In the former case, mode amplitude at saturation exhibits a quadratic scaling with the linear growth rate; in the latter case, the scaling is linear. These results are explained in terms of the approximate analytic solution of a nonlinear pendulum model. They are also used to prove that the radial width of the single poloidal harmonic sets an upper limit to the radial displacement of circulating fast ions produced by a single-toroidal-number gap mode in the large n limit, irrespectively of the possible existence of a large global mode structure formed by many harmonics.

  5. Spark Plasma Sintering As a Solid-State Recycling Technique: The Case of Aluminum Alloy Scrap Consolidation

    Directory of Open Access Journals (Sweden)

    Dimos Paraskevas

    2014-08-01

    Full Text Available Recently, “meltless” recycling techniques have been presented for the light metals category, targeting both energy and material savings by bypassing the final recycling step of remelting. In this context, the use of spark plasma sintering (SPS is proposed in this paper as a novel solid-state recycling technique. The objective is two-fold: (I to prove the technical feasibility of this approach; and (II to characterize the recycled samples. Aluminum (Al alloy scrap was selected to demonstrate the SPS effectiveness in producing fully-dense samples. For this purpose, Al alloy scrap in the form of machining chips was cold pre-compacted and sintered bellow the solidus temperature at 490 °C, under elevated pressure of 200 MPa. The dynamic scrap compaction, combined with electric current-based joule heating, achieved partial fracture of the stable surface oxides, desorption of the entrapped gases and activated the metallic surfaces, resulting in efficient solid-state chip welding eliminating residual porosity. The microhardness, the texture, the mechanical properties, the microstructure and the density of the recycled specimens have been investigated. An X-ray computed tomography (CT analysis confirmed the density measurements, revealing a void-less bulk material with homogeneously distributed intermetallic compounds and oxides. The oxide content of the chips incorporated within the recycled material slightly increases its elastic properties. Finally, a thermal distribution simulation of the process in different segments illustrates the improved energy efficiency of this approach.

  6. Effect of technique parameters on characteristics of hydrogen-free DLC films deposited by surface wave-sustained plasma

    Science.gov (United States)

    Xu, Junqi; Kousaka, Hiroyuki; Umehara, Noritsugu; Diao, Dongfeng

    2006-01-01

    Hydrogen-free diamond-like carbon (DLC) films were deposited by a new-type surface wave-sustained plasma physical vapor deposition (SWP-PVD) system under various technique conditions. Electron density was measured by a Langmuir probe, while the film thickness and hardness were characterized using a surface profilometer and a nanoindenter, respectively. Surface morphology was investigated by an atomic force microscope (AFM). It was found that the electron density and deposition rate increased following the increase in microwave power, target voltage, or gas pressure. The typical electron density and deposition rate were about 1.87-2.04×10 11 cm -3 and 1.61-14.32 nm/min respectively. AFM images indicated that the grains of films changes as the technique parameters vary. The optical constants, refractive index n and extinction coefficient k, were obtained using an optical ellipsometry. With the increase in microwave power from 150 to 270 W, the extinction coefficient of DLC films increased from 0.05 to 0.27 while the refractive index decreased from 2.31 to 2.18.

  7. Experiential Learning, Spatial Visualization and Metacognition: An Exercise with the “Blank Page” Technique for Learning Anatomy

    Directory of Open Access Journals (Sweden)

    Helen L. Naug

    2016-06-01

    Discussion: The blank page activity has merit in student engagement and facilitation of the learning of anatomy by broadening the scope of instruction to encompass multimodal learning preferences, metacognition and visual spatial thinking.

  8. Characterization of the Plasma Edge for Technique of Atomic Helium Beam in the CIEMAT Fusion Device; Caracterizacion del Borde del Plasma del Dispositivo de Fusion TJ-II del CIEMAT mediante el Diagnostico del Haz Supersonico de Helio

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo, A.

    2003-07-01

    In this report, the measurement of Electron Temperature and Density in the Boundary Plasma of TJ-II with a Supersonic Helium Beam Diagnostic and work devoted to the upgrading of this technique are described. Also, simulations of Laser Induced Fluorescence (LIF) studies of level populations of electronically excited He atoms are shown. This last technique is now being installed in the CIEMAT fusion device. (Author ) 36 refs.

  9. Simulations on the influence of the spatial distribution of source electrons on the plasma in a cusped-field thruster

    Science.gov (United States)

    Brandt, Tim; Trottenberg, Thomas; Groll, Rodion; Jansen, Frank; Hey, Franz Georg; Johann, Ulrich; Kersten, Holger; Braxmaier, Claus

    2015-06-01

    We present results from simulations on the influence of source electrons on the plasma properties in a magnetic cusps environment. Our simulations are based on the VSim/Vorpal particle-in-cell plasma simulation package. Magnetic cusps are a typical feature of High Efficiency Multistage Plasma Thrusters (HEMPTs). This research is part of an effort to downscale a HEMPT to thrust levels in the μN and sub- μN regime. The aim is to fulfill the requirements of upcoming formation flight satellites and probes. Those missions demand very precise attitude control. In order to get the necessary insight, the plasma of a section of the HEMPT discharge chamber is simulated with idealized boundary conditions. The results for such a section at two different distributions of source electrons are shown. A significant increase of the overall ion number is recognized for one of the distributions. Comparisons with published similar simulations are made. Factors that should be important for improvements of this thruster type are highlighted.

  10. Computation of electrical fields and currents in a plasma flowing in a spatial-periodic magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Gorodzha, L.V.; Krutilin, V.A.; Rashchepkin, A.P.

    1977-01-01

    Electrical processes in a plasma flow in an internal periodically changing magnetic field are studied analytically. The analysis was conducted on the basis of the Riemann boundary problem for automorphic functions. Consequently, evaluations were made of the energy characteristics of the hollow MHD generator with an alternating magnetic field and their relationship to the geometric dimensions of the channel was found.

  11. Influence of Topographic and Hydrographic Factors on the Spatial Distribution of Leptospirosis Disease in São Paulo County, Brazil: An Approach Using Geospatial Techniques and GIS Analysis

    Science.gov (United States)

    Ferreira, M. C.; Ferreira, M. F. M.

    2016-06-01

    Leptospirosis is a zoonosis caused by Leptospira genus bacteria. Rodents, especially Rattus norvegicus, are the most frequent hosts of this microorganism in the cities. The human transmission occurs by contact with urine, blood or tissues of the rodent and contacting water or mud contaminated by rodent urine. Spatial patterns of concentration of leptospirosis are related to the multiple environmental and socioeconomic factors, like housing near flooding areas, domestic garbage disposal sites and high-density of peoples living in slums located near river channels. We used geospatial techniques and geographical information system (GIS) to analysing spatial relationship between the distribution of leptospirosis cases and distance from rivers, river density in the census sector and terrain slope factors, in Sao Paulo County, Brazil. To test this methodology we used a sample of 183 geocoded leptospirosis cases confirmed in 2007, ASTER GDEM2 data, hydrography and census sectors shapefiles. Our results showed that GIS and geospatial analysis techniques improved the mapping of the disease and permitted identify the spatial pattern of association between location of cases and spatial distribution of the environmental variables analyzed. This study showed also that leptospirosis cases might be more related to the census sectors located on higher river density areas and households situated at shorter distances from rivers. In the other hand, it was not possible to assert that slope terrain contributes significantly to the location of leptospirosis cases.

  12. Spatial distribution of the electron component parameters in the nitrogen plasma of a low-pressure electrode microwave Discharge

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Yu. A., E-mail: lebedev@ips.ac.ru; Krashevskaya, G. V., E-mail: krashevskaya-gv@mail.ru; Gogoleva, M. A., E-mail: masha-g@list.ru [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation)

    2016-01-15

    Spatial distributions of charged particle concentration, electron temperature, and DC potential in an electrode microwave discharge in nitrogen at a pressure of 1 Torr have been measured using the double electric probe method. It has been shown that, near the electrode/antenna, the charged particle concentration exceeds a critical value. The concentration and heterogeneity of the discharge increase with increasing microwave power.

  13. Physicochemical characterization of titanium dioxide pigments using various techniques for size determination and asymmetric flow field flow fractionation hyphenated with inductively coupled plasma mass spectrometry

    NARCIS (Netherlands)

    Helsper, J.P.F.G.; Peters, R.J.B.; Bemmel, M.E.M. van; Rivera, Z.E.H.; Wagner, S.; Kammer, F. von der; Tromp, P.C.; Hofmann, T.; Weigel, S.

    2016-01-01

    Seven commercial titanium dioxide pigments and two other well-defined TiO2 materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (IC

  14. Advanced techniques for the storage and use of very large, heterogeneous spatial databases. The representation of geographic knowledge: Toward a universal framework. [relations (mathematics)

    Science.gov (United States)

    Peuquet, Donna J.

    1987-01-01

    A new approach to building geographic data models that is based on the fundamental characteristics of the data is presented. An overall theoretical framework for representing geographic data is proposed. An example of utilizing this framework in a Geographic Information System (GIS) context by combining artificial intelligence techniques with recent developments in spatial data processing techniques is given. Elements of data representation discussed include hierarchical structure, separation of locational and conceptual views, and the ability to store knowledge at variable levels of completeness and precision.

  15. Improving 3D spatial queries search: newfangled technique of space filling curves in 3D city modeling

    DEFF Research Database (Denmark)

    Uznir, U.; Anton, François; Suhaibah, A.

    2013-01-01

    web standards. However, these 3D city models consume much more storage compared to two dimensional (2D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access method......, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban objects...... modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert’s curve, preserves the Lebesgue measure and is Lipschitz...

  16. Data for spatial analysis of growth anomaly lesions on Montipora capitata coral colonies using 3D reconstruction techniques

    Directory of Open Access Journals (Sweden)

    John H.R. Burns

    2016-12-01

    Full Text Available Ten annotated 3D reconstructions of Montipora capitata coral colonies contain x,y,z coordinates for all growth anomaly (GA lesions affecting these corals. The 3D reconstructions are available as Virtual Reality Modeling Language (VRML files, and the GA lesions coordinates are in accompanying text files. The VRML models and GA lesion coordinates can be spatially analyzed using Matlab. Matlab scripts are provided for three spatial statistical procedures in order to assess clustering of the GA lesions across the coral colony surfaces in a 3D framework: Ripley׳s K, Moran׳s I, and the Kolmogorov–Smirnov test. Please see the research article, “Investigating the spatial distribution of Growth Anomalies affecting Montipora capitata corals in a 3-dimensional framework” (J.H.R. Burns, T. Alexandrov, E. Ovchinnikova, R.D. Gates, M. Takabayashi, 2016 [1], for further interpretation and discussion of the data.

  17. [XPS characterization of TiN layer on bearing steel surface treated by plasma immersion ion implantation and deposition technique].

    Science.gov (United States)

    Liu, Hong-xi; Jiang, Ye-hua; Zhan, Zhao-lin; Tang, Bao-yin

    2009-09-01

    Titanium nitride (TIN) hard protective films were fabricated on AISI52100 bearing steel surface employing plasma immersion ion implantation and deposition (PIIID) technique. The TiN films were characterized using a variety of test methods. Atomic force microscope (AFM) revealed that the titanium nitride film has extremely smooth surface, very high uniformity and efficiency of space filling over large areas. X-ray diffraction (XRD) result indicated that (200) crystal face of titanium nitride phase is the preferred orientation and three kinds of titanium components exist in the surface modified layer. Tailor fitting analysis of X-ray photoelectron spectroscopy (XPS) combined with Ar ion etching proved that Ti2p(1/2) and Ti2p(3/2) have two peaks in the titanium nitride film layer, respectively. It is shown that different chemical state exists in titanium compound. N(1s) bond energy of XPS has also three fitting peaks at 396.51, 397. 22 and 399.01 eV, corresponding to the nitrogen atom in TiNxOy, TiN and N--N, respectively. Combined with the XPS Tailor fitting analysis results of O(1s) bond energy, it was shown that there is a large amount of titanium nitride phase in addition to a small amount of simple substance nitrogen and oxide of titanium in the surface layer. The whole film system is made up of TiN, TiO2, N--N and Ti--O--N compound.

  18. Effect of active screen plasma nitriding pretreatment on wear behavior of TiN coating deposited by PACVD technique

    Energy Technology Data Exchange (ETDEWEB)

    Raoufi, M., E-mail: raoufi@iust.ac.ir [School of Metallurgical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Mirdamadi, Sh. [School of Metallurgical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Mahboubi, F. [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ahangarani, Sh. [Advanced Materials and Renewable Energies Dep., Iranian Research Organization for Science and Technology (Iran, Islamic Republic of); Mahdipoor, M.S. [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Elmkhah, H. [Department of Metallurgical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2012-08-01

    Titanium based alloys are used extensively for improving wear properties of different parts due to their high hardness contents. Titanium nitride (TiN) is among these coatings which can be deposited on surface using various techniques such as CVD, PVD and PACVD. Their weak interface with substrate is one major drawback which can increase the total wear in spite of favorite wear behavior of TiN. Disc shaped samples from AISI H13 (DIN 1.2344) steel were prepared in this study. Single TiN coating was deposited on some of them while others have experienced a TiN deposition by active screen plasma nitriding (ASPN). Hardness at the surface and depth of samples was measured through Vickers micro hardness test which revealed 1810 Hv hardness as the maximum values for a dual-layered ASPN-TiN. Pin-on-disc wear test was done in order to study the wear mechanism. In this regard, the wear behavior of samples was investigated against pins from 100Cr6 (Din 1.3505) bearing steel and tungsten carbide-cobalt (WC-Co) steel. It was evidenced that the dual-layer ASPN-TiN coating has shown the least weight loss with the best wearing behavior because of its high hardness values, stable interface and acceptable resistance against peeling during wearing period.

  19. Characterization of RF He-N2/Ar mixture plasma via Langmuir probe and optical emission spectroscopy techniques

    Science.gov (United States)

    Younus, Maria; Rehman, N. U.; Shafiq, M.; Hussain, S. S.; Zakaullah, M.; Zaka-ul-Islam, M.

    2016-08-01

    A Magnetic Pole Enhanced inductively coupled RF H e - N 2 / A r plasma is characterized using a Langmuir probe and optical emission spectroscopy (OES) techniques. The effect of helium mixing on electron density ( n e ) and temperature ( T e ) , electron energy probability functions (EEPFs), [ N ] atomic density, and N 2 dissociation is investigated. A Langmuir probe and a zero slope method based on trace rare gas-optical emission spectroscopy (TRG-OES) are employed to measure the electron temperature. It is noted that the electron temperature shows an increasing trend for both methods. However, the temperature measured by a zero slope method T e ( Z . S ) approaches the temperature measured by a Langmuir probe; T e ( L . P ) at 56% and above helium concentration in the discharge. "Advance actinometry" is employed to monitor the variation in [ N ] atomic density with helium concentration and gas pressure. It is noted that [ N ] atomic density increases at 56% and above helium in the discharge, which is consistent with the trend of electron temperature and EEPFs. A drastic enhancement in N 2 dissociation fraction D 1 determined by "advance actinometry" is noted at 56% and above helium concentration in the mixture due to modifications in different population and depopulation mechanisms. However, it is also noted that the dissociation fraction D 2 determined by intensity ratio method increases linearly with helium addition.

  20. Microstructure and Anticorrosion Property of AT13 Coatings Made by Combination of Nanoparticles Doping and Plasma Spraying Technique

    Institute of Scientific and Technical Information of China (English)

    LI Chun-fu; DAI Jia-lin; WANG Bin; ZHANG Ying; HE Tao-e; LUO Ping-ya

    2004-01-01

    Al2O3+13wt%TiO2 (AT13) particles were doped with 5%~30% nanoparticles and prefabricating powders were prepared by renewed granulation. AT13 coatings were prepared on the surface of steel 45# by air plasma spraying technique with the prefabricating powders. The microstructures of the AT13 prefabricating powders and the resulting coatings were investigated by SEM and EDS and XRD. The samples were undergone corrosion in the medium of 10% H2SO4 aqueous solution at temperature 80℃. The results indicate that the blistering time of coatings in the corrosive medium was increased with the increase of doped nanoparticle concentration while the time from blistering to spalling is independent of nanoparticle concentration. The results revealed that the structure of prefabricating powders was a twisted micrometer grade particle with dimension of 40-60μm, encapsulated by nanoparticles. The homogeneity of element distribution in coatings was improved and porosity was reduced. The phases of (Al2O3) 5.333 and orthorhombic Al2TiO5 were identified . The fracture analysis confirmed that there is a large amount of vermiculate whiskers with diameter of 10nm and length of 100~200 nm in coatings and the fracture type of coatings was the ductile trans-granular fracture.

  1. Microstructure and Anticorrosion Property of AT13 Coatings Made by Combination of Nanoparticles Doping and Plasma Spraying Technique

    Institute of Scientific and Technical Information of China (English)

    LIChun-fu; DAIJia-lin; WANGBin; ZHANGYing; HETao-e; LUOPing-ya

    2004-01-01

    Al2O3+ 13wt%TiO2 (AT13) particles were doped with 5%-30% nanoparticles and prefabricating powders were prepared by renewed granulation. AT13 coatings were prepared on the surface of steel 45# by air plasma spraying technique with the prefabricating powders. The microstructures of the AT13 prefabricating powders and the resulting coatings were investigated by SEM and EDS and XRD. The samples were undergone corrosion in the medium of 10% H2SO4 aqueous solution at temperature 80℃. The results indicate that the blistering time of coatings in the corrosive medium was increased with the increase of doped nanoparticle concentration while the time from blistering to spalling is independent of nanoparticle concentration.The results revealed that the structure of prefabricating powders was a twisted micrometer grade particle with dimension of 40-60μm, encapsulated by nanoparticles. The homogeneity of element distribution in coatings was improved and porosity was reduced. The phases of (Al2O3)5.333 and orthorhombic Al2TiO5 were identified. The fracture analysis confirmed that there is a large amount of vermiculate whiskers with diameter of 10nm and length of 100-200 nm in coatings and the fracture type of coatings was the ductile trans-granular fracture.

  2. Fabrication of Ni-Ti Alloy by Self-Propagating High-Temperature Synthesis and Spark Plasma Sintering Technique

    Science.gov (United States)

    Salvetr, Pavel; Kubatík, Tomáš František; Pignol, Damien; Novák, Pavel

    2017-04-01

    This work is focused on the possibilities of preparing Ni-Ti46 wt pct alloy by powder metallurgy methods. The self-propagating high-temperature synthesis (SHS) and combination of SHS reaction, milling, and spark plasma sintering consolidation (SPS) are explored. The aim of this work is the development of preparation method with the lowest amount of undesirable phases (mainly Ti2Ni phase). The SHS with high heating rate (approx. 200 and 300 K min-1) was applied. Because the SHS product is very porous, it was milled in vibratory disk milling and consolidated by SPS technique at temperatures of 1173 K, 1273 K, and 1373 K (900 °C, 1000 °C, and 1100 °C). The microstructures of samples prepared by SHS reaction and combination of SHS reaction, milling, and SPS consolidation are compared. The changes in microstructure with increasing temperature of SPS consolidation are observed. Mechanical properties are tested by hardness measurement. The way to reduce the amount of Ti2Ni phase in structure is leaching of powder in 35 pct hydrochloric acid before SPS consolidation.

  3. Bacteria Adherence Properties of Nitrogen-Doped TiO2 Coatings by Plasma Surface Alloying Technique

    Science.gov (United States)

    Wang, Hefeng; Tang, Bin; Li, Xiuyan; Fan, Ailan

    Titanium nitride coatings on 316L stainless steel (S. S) were obtained by plasma surface alloying technique. Nitrogen-doped titanium dioxide (TiO2-xNx) was synthesized by oxidative annealing the resulted TiNx coatings in air. The reference TiO2 samples were also prepared by oxidation of sputtered Ti coatings. The as-prepared coatings were characterized by X-ray diffraction, glow discharge optical emission spectrometer (GDOES), scanning electron microscopy, X-ray hotoelectron spectroscopy and UV-Vis spectrophotometry, respectively. The bacteria adherence property of the TiO2-xNx coatings on stainless steel on the oral bacteria Streptococcus Mutans was investigated and compared with that of stainless steel by fluorescence microscopy. The mechanism of the bacteria adherence was discussed. The results show that the TiO2-xNx coatings are composed of anatase crystalline structure. SEM measurement indicates a rough surface morphology with three-dimensional homogenous protuberances after annealing treatment. Optical properties reveal an extended tailing of the absorption edge toward the visible region due to nitrogen presence. The band gap of the N-doped sample is reduced from 2.29 eV to 1.90 eV compared with the pure TiO2 one. Because of the different roughness and microstructure, the TiO2-xNx coatings inhibit the bacteria adherence.

  4. Bacteria Adherence Properties of Nitrogen-Doped TiO2 Coatings by Plasma Surface Alloying Technique

    Institute of Scientific and Technical Information of China (English)

    WANG Hefeng; TANG Bin; LIN Naiming; LI Xiuyan; FAN Ailan; SHU Xuefeng

    2012-01-01

    In order to obtain a high-performance surface on 316L stainless steel (S.S) that can meet the requirements in medical material field environment,nitrogen-doped titanium dioxide (TiO2-xNx) was synthesized by oxidative annealing the resulted TiNx coatings in air.Titanium nitride coatings on 316L S.S were obtained by plasma surface alloying technique.The as-prepared coatings were characterized by X-ray diffraction,glow discharge optical emission spectrometer (GDOES),scanning electron microscopy and X-ray photoelectron spectroscopy,respectively.The bacteria adherence property of the TiO2-xNx coatings on S.S on the oral bacteria Streptococcus Mutans was investigated and compared with that of S.S by fluorescence microscopy.The mechanism of the bacteria adherence was discussed.The results show that the TiO2-xNx coatings are composed of anatase crystalline structure.SEM measurement indicates a rough surface morphology with three-dimensional homogenous protuberances after annealing treatment.Because of the photocatalysis and positive adhesion free energy,the TiO2-xNx coatings inhibit the bacteria adherence.

  5. Direct determination of impurities in high purity silicon carbide by inductively coupled plasma optical emission spectrometry using slurry nebulization technique.

    Science.gov (United States)

    Wang, Zheng; Qiu, Deren; Ni, Zheming; Tao, Guangyi; Yang, Pengyuan

    2006-09-08

    A novel method for the determination of Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni and Ti in high purity silicon carbide (SiC) using slurry introduction axial viewed inductively coupled plasma optical emission spectrometry (ICP-OES) was described. The various sizes of SiC slurry were dispersed by adding dispersant polyethylene imine (PEI). The stability of slurry was characterized by zeta potential measurement, SEM observation and signal stability testing. The optimal concentration of PEI was found to be 0.5 wt% for the SiC slurry. Analytical results of sub-mum size SiC by the slurry introduction were in good accordance with those by the alkaline fusion method which verified that determination could be calibrated by aqueous standards. For mum size SiC, results of most elements have a negative deviation and should be calibrated by the Certified Reference Material slurry. Owing to a rather low contamination in the sample preparation and stability of the slurry, the limits of detection (LODs), which are in the range of 40-2000 ng g(-1), superior to those of the conventional nebulization technique by ICP-OES or ICP-MS.

  6. Spatial Organization of the Cytoskeleton enhances Cargo Delivery to Specific Target Areas on the Plasma Membrane of Spherical Cells

    CERN Document Server

    Hafner, Anne E

    2016-01-01

    Intracellular transport is vital for the proper functioning and survival of a cell. Cargo (proteins, vesicles, organelles, etc.) is transferred from its place of creation to its target locations via molecular motor assisted transport along cytoskeletal filaments. The transport efficiency is strongly affected by the spatial organization of the cytoskeleton, which constitutes an inhomogeneous, complex network. In cells with a centrosome microtubules grow radially from the central microtubule organizing center towards the cell periphery whereas actin filaments form a dense meshwork, the actin cortex, underneath the cell membrane with a broad range of orientations. The emerging ballistic motion along filaments is frequently interrupted due to constricting intersection nodes or cycles of detachment and reattachment processes in the crowded cytoplasm. In order to investigate the efficiency of search strategies established by the cell's specific spatial organization of the cytoskeleton we formulate a random velocity...

  7. Volumetric measurements of a spatially growing dust acoustic wave

    Science.gov (United States)

    Williams, Jeremiah D.

    2012-11-01

    In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

  8. Volumetric measurements of a spatially growing dust acoustic wave

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jeremiah D. [Physics Department, Wittenberg University, Springfield, Ohio 45504 (United States)

    2012-11-15

    In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

  9. A technique for estimating spatial sampling errors in coarse-scale soil moisture estimates derived from point-scale observations

    Science.gov (United States)

    The validation of satellite surface soil moisture retrievals requires the spatial aggregation of point-scale ground soil moisture measurements up to coarse resolution satellite footprint scales (>10 km). In regions containing a limited number of ground measurements per satellite footprint, a large c...

  10. Mapping the hazard of extreme rainfall by peaks-over-threshold extreme value analysis and spatial regression techniques

    NARCIS (Netherlands)

    Beguería, S.; Vicente-Serrano, S.M.

    2006-01-01

    The occurrence of rainfalls of high magnitude constitutes a primary natural hazard in many parts of the world, and the elaboration of maps showing the hazard of extreme rainfalls has great theoretical and practical interest. In this work a procedure based on extreme value analysis and spatial

  11. Severe Hemolysis in a Patient With Erythrocytosis During Coupled Plasma Filtration Adsorption Therapy Was Prevented by Changing From Membrane-Based Technique to a Centrifuge-Based One.

    Science.gov (United States)

    Fan, Rong; Wu, Buyun; Kong, Ling; Gong, Dehua

    2016-01-01

    Coupled plasma filtration adsorption (CPFA) usually adopts membrane to separate plasma from blood. Here, we reported a case with erythrocytosis experienced severe hemolysis and membrane rupture during CPFA, which was avoided by changing from membrane-based technique to a centrifuge-based one. A 66-year-old man was to receive CPFA for severe hyperbilirubinemia (total bilirubin 922 μmol/L, direct bilirubin 638 μmol/L) caused by obstruction of biliary tract. He had erythrocytosis (hemoglobin 230 g/L, hematocrit 0.634) for years because of untreated tetralogy of Fallot. Severe hemolysis and membrane rupture occurred immediately after blood entering into the plasma separator even at a low flow rate (50 mL/min) and persisted after changing a new separator. Finally, centrifugal plasma separation technique was used for CPFA in this patient, and no hemolysis occurred. After 3 sessions of CPFA, total bilirubin level decreased to 199 μmol/L with an average decline by 35% per session. Thereafter, the patient received endoscopic biliary stent implantation, and total bilirubin level returned to nearly normal. Therefore, centrifugal-based plasma separation can also be used in CPFA and may be superior to a membrane-based one in patients with hyperviscosity.

  12. Innovative Plasma Disinfection Technique with the Reduced-pH Method and the Plasma-Treated Water (PTW) -Safety and Powerful Disinfection with Cryopreserved PTW-

    Science.gov (United States)

    Kitano, Katsuhisa; Ikawa, Satoshi; Nakashima, Yoichi; Tani, Atsushi; Yokoyama, Takashi; Ohshima, Tomoko

    2015-09-01

    Among the applications of the plasma disinfection to human body, plasma sterilization in liquid is crucial. We found that the plasma-treated water (PTW) has strong bactericidal activity under low pH condition and the half-lives of its activity depend on temperature. Lower temperature brings longer half-life and the bactericidal activity of PTW can be kept by cryopreservation. These physicochemical properties were in accordance with Arrhenius equation both in liquid and solid states. From the experimental results of ESR (Electron Spin Resonance) measurement of O2-in liquid against PTW with spin trapping method, half-lives of PTW were also in accordance with Arrhenius equation. It suggests that high concentration PTW as integrated value can be achieved by cooling of plasma apparatus. Pure PTW has disinfection power of 22 log reduction (B. subtilis). This corresponds to 65% H2O2, 14% hypochlorous acid and 0.33% peracetic acid, which are deadly poison for human. On the other hand, PTW is deactivated soon at body temperature. This indicates that toxicity to human body seems to be low. PTW, which is a sort of indirect plasma exposure, with pH and temperature controls could be applied for safety and powerful disinfection. MEXT (15H03583, 23340176, 25108505). NCCE (23-A-15).

  13. Spectroscopy of Very Hot Plasma in Non-flaring Parts of a Solar Limb Active Region: Spatial and Temporal Properties

    Science.gov (United States)

    Parenti, Susanna; del Zanna, Giulio; Petralia, Antonino; Reale, Fabio; Teriaca, Luca; Testa, Paola; Mason, Helen E.

    2017-09-01

    In this work we investigate the thermal structure of an off-limb active region (AR) in various non-flaring areas, as it provides key information on the way these structures are heated. In particular, we concentrate on the very hot component (> 3 {MK}) as it is a crucial element to distinguish between different heating mechanisms. We present an analysis using Fe and Ca emission lines from both the Solar Ultraviolet Measurement of Emitted Radiation (SUMER) on board the Solar and Heliospheric Observatory (SOHO) and the EUV Imaging Spectrometer (EIS) on board Hinode. A data set covering all ionization stages from Fe x to Fe xix has been used for the thermal analysis (both differential emission measure and emission measure, EM). Ca xiv is used for the SUMER-EIS radiometric cross calibration. We show that the very hot plasma is present and persistent almost everywhere in the core of the limb AR. The off-limb AR is clearly structured in Fe xviii. Almost everywhere, the EM analysis reveals plasma at 10 MK (visible in Fe xix emission), which is down to 0.1% of EM of the main 3 {MK} plasma. We estimate the power-law index of the hot tail of the EM to be between ‑8.5 and ‑4.4. However, the question about the possible existence of a small minor peak at around 10 {MK} remains open. The absence in some part of the AR of the Fe xix and Fe xxiii lines (which fall into our spectral range) enables us to determine an upper limit on the EM at these temperatures. Our results include a new Ca xiv 943.59 Å atomic model.

  14. Étude des techniques de spectrométrie de plasma pour l'analyse de matériaux à spectres optiques complexes : application aux terres rares et aux matériaux plastiques

    OpenAIRE

    Barbier, Sophie,

    2014-01-01

    The LIBS (Laser Induced Breakdown Spectroscopy) technique is an elemental analysis technique based on the use of the optical emission spectrum from a sample of laser ablation. Today, LIBS has not emerged as a technique of choice for the majority of applications, as is the case for inductive coupled plasma techniques. One of the main reasons for this is the difficulty in providing accurate quantitative measurements. So there is now a need to better understand and characterize plasmas and pheno...

  15. Direct asymmetry measurement of temperature and density spatial distributions in inertial confinement fusion plasmas from pinhole space-resolved spectra

    CERN Document Server

    Nagayama, T; Florido, R; Mayes, D; Tommasini, R; Koch, J A; Delettrez, J A; Regan, S P; Smalyuk, V A

    2014-01-01

    Two-dimensional space-resolved temperature and density images of an inertial confinement fusion (ICF) implosion core have been diagnosed for the first time. Argon-doped, direct-drive ICF experiments were performed at the Omega Laser Facility and a collection of two-dimensional space-resolved spectra were obtained from an array of gated, spectrally resolved pinhole images recorded by a multi-monochromatic x-ray imager. Detailed spectral analysis revealed asymmetries of the core not just in shape and size but in the temperature and density spatial distributions, thus characterizing the core with an unprecedented level of detail.

  16. Numerical Simulation of a Grinding Process Model for the Spatial Work-pieces: Development of Modeling Techniques

    Directory of Open Access Journals (Sweden)

    S. A. Voronov

    2015-01-01

    Full Text Available The article presents a literature review in simulation of grinding processes. It takes into consideration the statistical, energy based, and imitation approaches to simulation of grinding forces. Main stages of interaction between abrasive grains and machined surface are shown. The article describes main approaches to the geometry modeling of forming new surfaces when grinding. The review of approaches to the chip and pile up effect numerical modeling is shown. Advantages and disadvantages of grain-to-surface interaction by means of finite element method and molecular dynamics method are considered. The article points out that it is necessary to take into consideration the system dynamics and its effect on the finished surface. Structure of the complex imitation model of grinding process dynamics for flexible work-pieces with spatial surface geometry is proposed from the literature review. The proposed model of spatial grinding includes the model of work-piece dynamics, model of grinding wheel dynamics, phenomenological model of grinding forces based on 3D geometry modeling algorithm. Model gives the following results for spatial grinding process: vibration of machining part and grinding wheel, machined surface geometry, static deflection of the surface and grinding forces under various cutting conditions.

  17. Low-temperature oxidizing plasma surface modification and composite polymer thin-film fabrication techniques for tailoring the composition and behavior of polymer surfaces

    Science.gov (United States)

    Tompkins, Brendan D.

    This dissertation examines methods for modifying the composition and behavior of polymer material surfaces. This is accomplished using (1) low-temperature low-density oxidizing plasmas to etch and implant new functionality on polymers, and (2) plasma enhanced chemical vapor deposition (PECVD) techniques to fabricate composite polymer materials. Emphases are placed on the structure of modified polymer surfaces, the evolution of polymer surfaces after treatment, and the species responsible for modifying polymers during plasma processing. H2O vapor plasma modification of high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and 75A polyurethane (PU) was examined to further our understanding of polymer surface reorganization leading to hydrophobic recovery. Water contact angles (wCA) measurements showed that PP and PS were the most susceptible to hydrophobic recovery, while PC and HDPE were the most stable. X-ray photoelectron spectroscopy (XPS) revealed a significant quantity of polar functional groups on the surface of all treated polymer samples. Shifts in the C1s binding energies (BE) with sample age were measured on PP and PS, revealing that surface reorganization was responsible for hydrophobic recovery on these materials. Differential scanning calorimetry (DSC) was used to rule out the intrinsic thermal properties as the cause of reorganization and hydrophobic recovery on HDPE, LDPE, and PP. The different contributions that polymer cross-linking and chain scission mechanisms make to polymer aging effects are considered. The H2O plasma treatment technique was extended to the modification of 0.2 microm and 3.0 microm track-etched polycarbonate (PC-TE) and track-etched polyethylene terephthalate (PET-TE) membranes with the goal of permanently increasing the hydrophilicity of the membrane surfaces. Contact angle measurements on freshly treated and aged samples confirmed the wettability of the

  18. Slurry micro-sampling technique for use in argon-helium microwave induced plasma optical emission spectrometry.

    Science.gov (United States)

    Ślachciński, Mariusz

    2016-12-01

    The Flow Focusing Pneumatic Nebulizer (FFPN) working at low liquid flow rates was evaluated for the elemental analysis in slurried samples by argon-helium microwave induced plasma optical emission spectrometry (MIP-OES). The obtained results achieved were compared with commercially available V-groove Babington type nebulizer (VBPN). A univariate approach and the simplex optimization procedure were used to achieve optimized conditions and derive analytical figures of merit. Analytical performance of the micro nebulization system was characterized by a determination of the limits of detection (LODs), the precision (RSDs) and the wash-out times for Ba, Ca, Cd, Cu, Fe, Mg, Mn, Pb and Sr. The experimental concentration detection limits for simultaneous determination, calculated as the concentration giving a signal equal to three times of the standard deviation of the blank (LOD, 3σblank criterion, peak height) were 0.9, 0.2, 0.3, 0.2, 0.3, 0.1, 0.2, 0.4, 0.4 and 0.3ngmL(-1) for Ba, Ca, Cd, Cu, Fe, Mg, Mn, Pb and Sr, respectively. The method offers relatively good precision (RSD ranged from 5% to 8%) for micro-slurry sampling analysis. Analyses of the certified reference materials (NRCC DOLT-2, GBW 07302 and SRM 2710) were performed in order to determine the accuracy available with the presented nebulization systems. The measured contents of elements in the reference materials were in satisfactory agreement with the certified values. In addition, these elements were determined in two real samples. Slurry concentration up to 3% m/v (particles technique. An ultrasonic probe was used to homogenize the slurry in the polypropylene bottle just before its introduction into the nebulizer. The nebulizers exhibited no clogging problems. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. P-type ZnO films by phosphorus doping using plasma immersion ion-implantation technique

    Science.gov (United States)

    Nagar, S.; Chakrabarti, S.

    2013-03-01

    ZnO has been a subject of intense research in the optoelectronics community owing to its wide bandgap (3.3eV) and large exciton binding energy (60meV). However, difficulty in doping it p-type posts a hindrance in fabricating ZnO-based devices. In order to make p-type ZnO films, phosphorus implantation, using plasma immersion ion-implantation technique (2kV, 900W, 10μs pulse width) for 30 seconds, was performed on ZnO thin film deposited by RF Magnetron Sputtering (Sample A). The implanted samples were subsequently rapid thermal annealed at 700°C and 1000°C (Samples B and C) in oxygen environment for 30 seconds. Low temperature (8K) photoluminescence spectra reveal dominant donor-bound exciton (D°X) peak at 3.36eV for samples A and B. However, for Sample B the peaks around 3.31eV and 3.22eV corresponding to the free electron-acceptor (FA) and donor to acceptor pair peaks (DAP) are also observed. A dominant peak around 3.35eV, corresponding to acceptor bound exciton (A°X) peak, is detected for Sample C along with the presence of FA and DAP peaks around 3.31eV and 3.22eV. Moreover, the deep level peak around 2.5eV is higher for Sample B which may be due to implantation and acceptor related defects. However, for Sample C, the deep level peaks are very weak compared to the near band edge peaks confirming that these peaks are mainly due to intrinsic defects and not related to acceptors. These results clearly show us a promising way to achieve p-type ZnO films using phosphorus doping.

  20. Direct Measurements of the Spatial and Velocity Dependence of the Ion Density Fluctuation Spectrum of a Laboratory Plasma with Two Independent LIF Schemes

    Science.gov (United States)

    Mattingly, Sean; Berumen, Jorge; Chu, Feng; Hood, Ryan; Skiff, Fred

    2014-10-01

    By using two independently tunable lasers, each with its own collection optics and Ar II LIF transition scheme, we are able to investigate plasma ion density fluctuations as a function of not only spatial scales but also as a function of ion velocities as sampled on different points of a single Doppler-broadened spectral emission line. We do this by measuring the two point correlation C (x , v ,x' ,v' , τ) = t . With the current system, the two carriages determine x and x', while the velocities selected by each laser determine v and v'. Using the two lasers to make two point correlations in phase space demonstrates effects that are not fully understood. In this experiment, we explore the striking difference in correlations when, in the past, the particle orbits overlap in space versus when they do not overlap. This is performed on a small cylindrical laboratory plasma with n ~109 cm-3 , Te ~ 5 eV, Ti ~ 0 . 06 , and a 1 kG axial magnetic field. LIF is performed on ions at two locations aligned with the magnetic field line with a viewing volume comparable to the size of the Larmor radius. Results and interpretations from these experiments are presented and discussed. DOE Grant DE-FG02-99ER54543.

  1. Spatial organization of the cytoskeleton enhances cargo delivery to specific target areas on the plasma membrane of spherical cells

    Science.gov (United States)

    Hafner, Anne E.; Rieger, Heiko

    2016-12-01

    Intracellular transport is vital for the proper functioning and survival of a cell. Cargo (proteins, vesicles, organelles, etc) is transferred from its place of creation to its target locations via molecular motor assisted transport along cytoskeletal filaments. The transport efficiency is strongly affected by the spatial organization of the cytoskeleton, which constitutes an inhomogeneous, complex network. In cells with a centrosome microtubules grow radially from the central microtubule organizing center towards the cell periphery whereas actin filaments form a dense meshwork, the actin cortex, underneath the cell membrane with a broad range of orientations. The emerging ballistic motion along filaments is frequently interrupted due to constricting intersection nodes or cycles of detachment and reattachment processes in the crowded cytoplasm. In order to investigate the efficiency of search strategies established by the cell’s specific spatial organization of the cytoskeleton we formulate a random velocity model with intermittent arrest states. With extensive computer simulations we analyze the dependence of the mean first passage times for narrow escape problems on the structural characteristics of the cytoskeleton, the motor properties and the fraction of time spent in each state. We find that an inhomogeneous architecture with a small width of the actin cortex constitutes an efficient intracellular search strategy.

  2. Study on the interaction of plasma protein binding rate between edaravone and taurine in human plasma based on HPLC analysis coupled with ultrafiltration technique.

    Science.gov (United States)

    Tang, Dao-quan; Li, Yin-jie; Li, Zheng; Bian, Ting-ting; Chen, Kai; Zheng, Xiao-xiao; Yu, Yan-yan; Jiang, Shui-shi

    2015-08-01

    In this work, two high-performance liquid chromatography (HPLC) assays were developed and validated for the independent determination of edaravone and taurine using 3-methyl-1-p-tolyl-5-pyrazolone and L-glutamine as internal standards. In in vitro experiments, human plasma was separately spiked with a mixture of edaravone and taurine, edaravone or taurine alone. Plasma was precipitated with acetonitrile containing 0.1% formic acid. Ultrafiltration was employed to obtain the unbound ingredients of the two drugs. The factors that might influence the ultrafiltration effiency were elaborately optimized. Plasma supernatant and ultrafiltrate containing taurine were derivated with o-phthalaldehyde and ethanethiol in the presence of 40 mmol/L sodium borate buffer (pH 10.2) at room temperature within 1 min. Chromatographic separations were achieved on an InertSustain C18 column (250 × 4.6 mm, 5 µm). Isocratic 50 mmol/L ammonium acetate-acetonitrile and gradient 50 mmol/L sodium acetate (pH 5.3)-methanol were respectively selected as the mobile phase for the determination of edaravone and taurine. All of the validation data including linearity, extraction recovery, precision, accuracy and stability conformed to the requirements. Results showed that there were no significant alterations in the plasma protein binding rate of taurine and edaravone, implying that the proposed combination therapy was pharmacologically feasible. Copyright © 2014 John Wiley & Sons, Ltd.

  3. A comparison of inflection point and floating point emissive probe techniques for electric potential measurements in a Hall thruster plasma

    Science.gov (United States)

    Sheehan, J. P.; Raitses, Yevgeny; Hershkowitz, Noah; Fisch, Nathaniel

    2010-11-01

    Theory suggests that when increasing the electron emission of an emissive probe the floating potential will saturate ˜Te/e below the plasma potential. This can introduce significant errors in plasma potential measurements in Hall thrusters where Te> 10 eV. The method of determining the plasma potential from the inflection point of emissive IV traces in the limit of zero emission may give a more accurate measurement of the plasma potential. The two methods are compared in a Hall thruster where ne˜10^11 cm-3, Te˜20 eV, and ion flows are significant. The results can be generalized to other types of plasmas.

  4. Deposition of duplex Al 2O 3/aluminum coatings on steel using a combined technique of arc spraying and plasma electrolytic oxidation

    Science.gov (United States)

    Gu, Weichao; Shen, Dejiu; Wang, Yulin; Chen, Guangliang; Feng, Wenran; Zhang, Guling; Fan, Songhua; Liu, Chizi; Yang, Size

    2006-02-01

    Plasma electrolytic oxidation (PEO) is a cost-effective technique that can be used to prepare ceramic coatings on metals such as Ti, Al, Mg, Nb, etc., and their alloys, but this promising technique cannot be used to modify the surface properties of steels, which are the most widely used materials in engineering. In order to prepare metallurgically bonded ceramic coatings on steels, a combined technique of arc spraying and plasma electrolytic oxidation (PEO) was adopted. In this work, metallurgically bonded ceramic coatings on steels were obtained using this method. We firstly prepared aluminum coatings on steels by arc spraying, and then obtained the metallurgically bonded ceramic coatings on aluminum coatings by PEO. The characteristics of duplex coatings were analyzed by X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The corrosion and wear resistance of the ceramic coatings were also studied. The results show that, duplex Al 2O 3/aluminum coatings have been deposited on steel substrate after the combined treatment. The ceramic coatings are mainly composed of α-Al 2O 3, γ-Al 2O 3, θ-Al 2O 3 and some amorphous phase. The duplex coatings show favorable corrosion and wear resistance properties. The investigations indicate that the combination of arc spraying and plasma electrolytic oxidation proves a promising technique for surface modification of steels for protective purposes.

  5. Suitable Site Selection of Small Dams Using Geo-Spatial Technique: a Case Study of Dadu Tehsil, Sindh

    Science.gov (United States)

    Khalil, Zahid

    2016-07-01

    Decision making about identifying suitable sites for any project by considering different parameters, is difficult. Using GIS and Multi-Criteria Analysis (MCA) can make it easy for those projects. This technology has proved to be an efficient and adequate in acquiring the desired information. In this study, GIS and MCA were employed to identify the suitable sites for small dams in Dadu Tehsil, Sindh. The GIS software is used to create all the spatial parameters for the analysis. The parameters that derived are slope, drainage density, rainfall, land use / land cover, soil groups, Curve Number (CN) and runoff index with a spatial resolution of 30m. The data used for deriving above layers include 30 meter resolution SRTM DEM, Landsat 8 imagery, and rainfall from National Centre of Environment Prediction (NCEP) and soil data from World Harmonized Soil Data (WHSD). Land use/Land cover map is derived from Landsat 8 using supervised classification. Slope, drainage network and watershed are delineated by terrain processing of DEM. The Soil Conservation Services (SCS) method is implemented to estimate the surface runoff from the rainfall. Prior to this, SCS-CN grid is developed by integrating the soil and land use/land cover raster. These layers with some technical and ecological constraints are assigned weights on the basis of suitability criteria. The pair wise comparison method, also known as Analytical Hierarchy Process (AHP) is took into account as MCA for assigning weights on each decision element. All the parameters and group of parameters are integrated using weighted overlay in GIS environment to produce suitable sites for the Dams. The resultant layer is then classified into four classes namely, best suitable, suitable, moderate and less suitable. This study reveals a contribution to decision making about suitable sites analysis for small dams using geo-spatial data with minimal amount of ground data. This suitability maps can be helpful for water resource

  6. Dissolved methane and carbon dioxide fluxes in Subarctic and Arctic regions: Assessing measurement techniques and spatial gradients

    Science.gov (United States)

    Garcia-Tigreros Kodovska, Fenix; Sparrow, Katy J.; Yvon-Lewis, Shari A.; Paytan, Adina; Dimova, Natasha T.; Lecher, Alanna; Kessler, John D.

    2016-02-01

    Here we use a portable method to obtain high spatial resolution measurements of concentrations and calculate diffusive water-to-air fluxes of CH4 and CO2 from two Subarctic coastal regions (Kasitsna and Jakolof Bays) and an Arctic lake (Toolik Lake). The goals of this study are to determine distributions of these concentrations and fluxes to (1) critically evaluate the established protocols of collecting discrete water samples for these determinations, and to (2) provide a first-order extrapolation of the regional impacts of these diffusive atmospheric fluxes. Our measurements show that these environments are highly heterogeneous. Areas with the highest dissolved CH4 and CO2 concentrations were isolated, covering less than 21% of the total lake and bay areas, and significant errors can be introduced if the collection of discrete water samples does not adequately characterize these spatial distributions. A first order extrapolation of diffusive fluxes to all Arctic regions with similar characteristics as Toolik Lake suggests that these lakes are likely supplying 0.21 and 15.77 Tg of CH4 and CO2 to the atmosphere annually, respectively. Similarly, we found that the Subarctic Coastal Ocean is likely supplying 0.027 Tg of CH4 annually and is taking up roughly 524 Tg of CO2 per year. Although diffusive fluxes at Toolik Lake may not be as substantial when comparing against present seep ebullition and spring ice-out values, warming in the Arctic may result in the increase of methane discharge and methane emissions to the atmosphere. Thus further work is needed to understand this changing environment. This study suggests that high spatial resolution measurement protocols, similar to the one used here, should be incorporated into field campaigns to reduce regional uncertainty and refine global emission estimates.

  7. Preparation of starch stabilized silver nanoparticles with spatial self-phase modulation properties by laser ablation technique

    Energy Technology Data Exchange (ETDEWEB)

    Zamiri, Reza; Azmi, B.Z.; Sadrolhosseini, Amir R.; Husin, M.S.; Zaidan, A.W. [Universiti Putra Malaysia, Department of Physics, Faculty of Science, UPM Serdang, Selangor (Malaysia); Darroudi, Majid [Universiti Putra Malaysia, Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, UPM Serdang, Selangor (Malaysia); Mahdi, M.A. [Universiti Putra Malaysia, Wireless and Photonics Networks Research Center, Faculty of Engineering, UPM Serdang, Selangor (Malaysia)

    2011-01-15

    Silver nanoparticles inside the starch solution have been successfully fabricated by laser ablation of a silver plate immersed in starch solution. The ablation has been done using a Q-switched Nd:YAG laser at 10 Hz repetition rate. The starch solution allows for the formation of silver nanoparticles with uniform particle diameters and well dispersed. The ablation was performed at different time durations to study the influence of the laser ablation time on efficiency of particle formation and sizes. The Spatial Self-phase modulation phenomena which can determine the nonlinear optical property of the samples were also investigated for starch solutions containing silver nanoparticles. (orig.)

  8. Spatial Prediction of Soil Aggregate Stability and Aggregate-Associated Organic Carbon Content at the Catchment Scale Using Geostatistical Techniques

    Institute of Scientific and Technical Information of China (English)

    J.MOHAMMADI; M.H.MOTAGHIAN

    2011-01-01

    The association of organic carbon with secondary parzicles (aggregates) results in its storage and retention in soil. A study was carried out at a catchment covering about 92 km2 to predict spatial variability of soil water-stable aggregates (WSA), mean weight diameter (MWD) of aggregates and organic carbon (OC) content in macro- (> 2 mm), meso- (1-2 mm), and micro-aggregate (< 1 mm) fractions, using geostatistical methods. One hundred and eleven soil samples were c(o)llected at the 0-10 cm depth and fractionated into macro-, meso-, and micro-aggregates by wet sieving. The OC content was determined for each fraction. A greater percentage of water-stable aggregates was found for micro-aggregates, followed by meso-aggregates. Aggregate OC content was greatest in meso-aggregates (9 g kg-1), followed by micro-aggregates (7 g kg-1), while the least OC content was found in macro-aggregates (3 g kg-1). Although a significart effect (P = 0.000) of aggregate size on aggregate OC content was found, however, our findings did not support the model of aggregate hierarchy.Land use had a significant effect (P = 0.073) on aggregate OC content. The coefficients of variation (CVs) for OC contents associated with each aggregate fraction indicated macro-aggregates as the most variable (CV = 71%). Among the aggregate fractions, the micro-aggregate fraction had a lower CV value of 27%. The mean content of WSA ranged from 15% for macro-aggregates to 84% for micro-aggregates. Geostatistical analysis showed that the measured soil variables exhibited differences in their spatial patterns in both magnitude and space at each aggregate size fraction. The relative nugget variance for most aggregate-associated properties was lower than 45%. The range value for the variogram of water-stable aggregates was almost similar (about 3 km) for the three studied aggregate size classes. The range value for the variogram of aggregate-associated OC contents ranged from about 3 km for macro

  9. A temporally and spatially resolved electron density diagnostic method for the edge plasma based on Stark broadening

    Science.gov (United States)

    Zafar, A.; Martin, E. H.; Shannon, S. C.; Isler, R. C.; Caughman, J. B. O.

    2016-11-01

    An electron density diagnostic (≥1010 cm-3) capable of high temporal (ms) and spatial (mm) resolution is currently under development at Oak Ridge National Laboratory. The diagnostic is based on measuring the Stark broadened, Doppler-free spectral line profile of the n = 6-2 hydrogen Balmer series transition. The profile is then fit to a fully quantum mechanical model including the appropriate electric and magnetic field operators. The quasi-static approach used to calculate the Doppler-free spectral line profile is outlined here and the results from the model are presented for H-δ spectra for electron densities of 1010-1013 cm-3. The profile shows complex behavior due to the interaction between the magnetic substates of the atom.

  10. Spatial Surface PM2.5 Concentration Estimates for Wildfire Smoke Plumes in the Western U.S. Using Satellite Retrievals and Data Assimilation Techniques

    Science.gov (United States)

    Loria Salazar, S. M.; Holmes, H.

    2015-12-01

    Health effects studies of aerosol pollution have been extended spatially using data assimilation techniques that combine surface PM2.5 concentrations and Aerosol Optical Depth (AOD) from satellite retrievals. While most of these models were developed for the dark-vegetated eastern U.S. they are being used in the semi-arid western U.S. to remotely sense atmospheric aerosol concentrations. These models are helpful to understand the spatial variability of surface PM2.5concentrations in the western U.S. because of the sparse network of surface monitoring stations. However, the models developed for the eastern U.S. are not robust in the western U.S. due to different aerosol formation mechanisms, transport phenomena, and optical properties. This region is a challenge because of complex terrain, anthropogenic and biogenic emissions, secondary organic aerosol formation, smoke from wildfires, and low background aerosol concentrations. This research concentrates on the use and evaluation of satellite remote sensing to estimate surface PM2.5 concentrations from AOD satellite retrievals over California and Nevada during the summer months of 2012 and 2013. The aim of this investigation is to incorporate a spatial statistical model that uses AOD from AERONET as well as MODIS, surface PM2.5 concentrations, and land-use regression to characterize spatial surface PM2.5 concentrations. The land use regression model uses traditional inputs (e.g. meteorology, population density, terrain) and non-traditional variables (e.g. FIre Inventory from NCAR (FINN) emissions and MODIS albedo product) to account for variability related to smoke plume trajectories and land use. The results will be used in a spatially resolved health study to determine the association between wildfire smoke exposure and cardiorespiratory health endpoints. This relationship can be used with future projections of wildfire emissions related to climate change and droughts to quantify the expected health impact.

  11. The method of determining surface water erosion influence on agricultural valorization of soils with usage of geoprocessing techniques and spatial information systems

    Directory of Open Access Journals (Sweden)

    Prus Barbara

    2016-12-01

    Full Text Available The aim of the paper is to propose methodical solutions concerning synthetic agricultural analysis of production space which consists in combined (synthetic – in spatial and statistical contexts – analysis and evaluation of quality and farming utility of soils in connection with soils erosive risk level. The paper is aimed at presentation of methodology useful in such type of analyses as well as demonstration to what extent the areas of farming production space being subject to restrictive protection are exposed to destructive effect of surface water erosion. Own factor (HDSP.E was suggested, which is a high degree synthesis of soil protection in connection with degrees of surface water erosion risk. The proposed methodology was used for detailed spatial analyses performed for Tomice – the Małopolska rural commune (case study. The area model elaborated for the proposed methodology’s purpose faced with soils mechanical composition allowed to make a model of surface water erosion in five-grade scale. Synthetic evaluation (product of spatial objects on numerous thematic layers of quality and farming utility of soils and also zones of surface water erosion risk allowed to assign spatial distribution of HDSP.E factor (abbreviation of high degree of soil protection combined with erosion. The analyses enabled to determine proportional contribution of the most valuable resources of farming production space that are subject to soil erosion negative phenomenon. Geoprocessing techniques used for the analyses of environmental elements of farming production space were applied in the paper. The analysis of spatial distribution of researched phenomena was elaborated in Quantum GIS programme.

  12. Spatial analysis of time of flight-secondary ion mass spectrometric images by ordinary kriging and inverse distance weighted interpolation techniques.

    Science.gov (United States)

    Milillo, Tammy M; Gardella, Joseph A

    2008-07-01

    Ordinary kriging and inverse distance weighted (IDW) are two interpolation methods for spatial analysis of data and are commonly used to analyze macroscopic spatial data in the fields of remote sensing, geography, and geology. In this study, these two interpolation techniques were compared and used to analyze microscopic chemical images created from time of flight-secondary ion mass spectrometry images from a patterned polymer sample of fluorocarbon (C(x)F(y)) and poly(aminopropyl siloxane) (APS, a.k.a. siloxane). Data was eliminated from the original high-resolution data set by successive random removal, and the image file was interpolated and reconstructed with a random subset of points using both methods. The statistical validity of the reconstructed image was determined by both standard geographic information system (GIS) validation statistics and evaluating the resolution across an image boundary using ASTM depth and image resolution methodology. The results show that both ordinary kriging and IDW techniques can be used to accurately reconstruct an image using substantially fewer sample points than the original data set. Ordinary kriging performed better than the IDW technique, resulting in fewer errors in predicted intensities and greater retention of original image features. The size of the data set required for the most accurate reconstruction of the original image is directly related to the autocorrelation present within the data set. When 10% of the original siloxane data set was used for an ordinary kriging interpolation, the resulting image still retained the characteristic gridlike pattern. The C(x)F(y) data set exhibited stronger spatial correlation, resulting in reconstruction of the image with only 1% of the original data set. The removal of data points does result in a loss of image resolution; however, the resolution loss is not directly related to the percentage of sample points removed.

  13. Improvement of interfacial adhesion and nondestructive damage evaluation for plasma-treated PBO and Kevlar fibers/epoxy composites using micromechanical techniques and surface wettability.

    Science.gov (United States)

    Park, Joung-Man; Kim, Dae-Sik; Kim, Sung-Ryong

    2003-08-15

    Comparison of interfacial properties and microfailure mechanisms of oxygen-plasma treated poly(p-phenylene-2,6-benzobisoxazole (PBO, Zylon) and poly(p-phenylene terephthalamide) (PPTA, Kevlar) fibers/epoxy composites were investigated using a micromechanical technique and nondestructive acoustic emission (AE). The interfacial shear strength (IFSS) and work of adhesion, Wa, of PBO or Kevlar fiber/epoxy composites increased with oxygen-plasma treatment, due to induced hydrogen and covalent bondings at their interface. Plasma-treated Kevlar fiber showed the maximum critical surface tension and polar term, whereas the untreated PBO fiber showed the minimum values. The work of adhesion and the polar term were proportional to the IFSS directly for both PBO and Kevlar fibers. The microfibril fracture pattern of two plasma-treated fibers appeared obviously. Unlike in slow cooling, in rapid cooling, case kink band and kicking in PBO fiber appeared, whereas buckling in the Kevlar fiber was observed mainly due to compressive and residual stresses. Based on the propagation of microfibril failure toward the core region, the number of AE events for plasma-treated PBO and Kevlar fibers increased significantly compared to the untreated case. The results of nondestructive AE were consistent with microfailure modes.

  14. Thomson Scattering for Determining Electron Concentrations and Temperatures in an Inductively Coupled Plasma. 1. Assessment of the Technique for a Lo -Flow, Low-Power Plasma.

    Science.gov (United States)

    1988-02-15

    is the spectral density function which describes the frequency dependence of the scattering spectrum. If the electrons in the scattering volume are...stationary, no Doppler shift occurs and the spectral density function is 1 at (w=O (no frequency ,,diihit) and ;zero at all other frequencies. Of...electrons moving in a hot plasma. The spectral density function , which describes this Doppler- shifted spectrum, is very complicated and a description of it

  15. Experimental study of TJ-1 plasma using scattering and radiation emission techniques; Analisis experimental del plasma TJ-1 con tecnicas de scattering y emision de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, C.; Zurro, B.

    1987-07-01

    The Thomson scattering system of TJ-1 is described in detail. The radial profiles of Te and ne obtained in TJ-1 discharges are presented. This data make possible to deduce characteristic parameters of the plasma confinement in this machine, as energy confinement times, Zeff B. Using also radiation measurements (global and in the visible range) we obtained the particle confinement time and Zeff without non experimental assumptions. (Author) 52 refs.

  16. A novel technique for guided bone regeneration using platelet-rich plasma and osteogenic progenitor cells: Literature-based rationale and case report.

    Science.gov (United States)

    Kwon, TaeHyun; Grieco, Peter C; Levin, Liran; Intini, Giuseppe

    2016-03-01

    Achieving predictable guided bone regeneration in critical size defects for future endosseous dental implant therapy poses a great challenge to clinicians. A novel technique utilizing autogenous osteogenic progenitor cells, calcium sulfate activated platelet-rich plasma in addition to particulate allograft was successfully used to augment a severely deficient maxillary anterior edentulous ridge. After 6 months of healing, satisfactory radiographic and clinical bone gain was noted with significant increase in alveolar ridge width. Endosseous implants were placed and restored successfully. The techniques with underlying clinical and biologic rationales are presented and discussed in this report.

  17. Hard X-ray dose intensity and spatial distribution in a plasma focus device using thermoluminescence dosimeters

    Indian Academy of Sciences (India)

    A Kanani; M N Nasrabadi; B Shirani; I Jabbari

    2015-07-01

    In the present study, X-ray emission dose characteristics from a small Mather-type PF device in various pressures of argon as the operating gas were studied. The PF device was powered by a 12 F capacitor at 25 kV charging voltage. Time-integrated hard X-ray (HXR) emission was investigated using thermoluminescence dosimeters (TLDs). These detectors were calibrated with 60Co and 131Cs sources. Twenty-four dosimeters were placed at four different radial distances from the axis of the electrodes at the top of the anode to measure the dose spatial distribution at the top of the anode for different pressures (0.5–1.3 mbar). At each radius, six dosimeters were placed circularly with equal angular intervals on the inner surface of the device chamber. It was found that the optimum pressure for the highest yield of X-ray is 0.9 mbar. The maximum measured dose was 17 mGy per shot at the top of the anode and about 0.5 mGy per shot at 90° with respect to the anode axis. Furthermore, these results showed that the dose at each radius is symmetrical at 360° around the top of the anode, but X-ray distribution follows an anisotropical behaviour. A fast plastic scintillator was also used for time-resolved HXR detection, and a linear relation was observed between the amplitude of the scintillator-PMT signals and TLD responses.

  18. 皱大球蚧空间分布与抽样技术研究%Study on spatial distribution and sampling technique of Eulecanium kuwanai

    Institute of Scientific and Technical Information of China (English)

    刘军侠; 姜文虎; 崔松; 王银翠

    2011-01-01

    The purpose of this study about the spatial distribution pattern and sampling technique of Eulecanium kuwanai on the garden plants was to analyze the distribution of basic compositions, distribution type and distribution reasons. Result showed that a spatial aggregated distribution pattern of Eulecanium kuwanai, with the individual group as the basic component of spatial distribution pattern and with the individuals attracted to each other, indicating that the aggregation was due to the biological habits of insects along with their circumstances, which confirmed the theoretical sampling sample number and the sequential sampling table of Eulecanium huwanai and provided references for the prevention of scale insects.%研究了园林植物上皱大球蚧的空间分布型和抽样技术,分析了其分布的基本成分、分布类型和分布的原因.结果表明:皱大球蚧的分布属于聚集分布,分布的基本成分为个体群,且个体间相互吸引.皱大球蚧的聚集原因由昆虫本身的习性和环境共同引起,确定了皱大球蚧的理论抽样数和序贯抽样表,为皱大球蚧的防治提供参考.

  19. Evaluation of Different Change Detection Techniques in Forestry for Improvement of Spatial Objects Extraction Algorithms by Very High Resolution Remote Sensing Digital Imagery

    Science.gov (United States)

    Amiri, N.

    2013-09-01

    Earth observations which are being useable by spatial analysis ability play an important role in detecting, management and solving environmental problems such as climate changes, deforestation, disasters, land use, water resource and carbon cycle. Remote sensing technology in combination with geospatial information system (GIS) can render reliable information on vegetation cover. Satellite Remote sensed data and GIS for land cover/use with its changes is a key to many diverse applications such as Forestry. Change detection can be defined as the process of identifying differences in the state of an object or phenomenon by observing it at different times. The analysis of the spatial extent and temporal change of vegetation cover (Forest) by using remotely sensed data is critically importance to natural resource management sciences. The main aim of this review paper is to go through the different change detection methods and algorithms based on very high resolution remote sensing imagery data, evaluate the quality of the spatial individual crown cover extraction in forests with high density, analyse, compare the results by optimized performance of control data for the same objects to provide the improvement in technique for detection and improve the mathematical sides of the change detection algorithms for high dense forests regions with different boundaries.

  20. WE-G-17A-01: Improving Tracking Image Spatial Resolution for Onboard MR Image Guided Radiation Therapy Using the WHISKEE Technique

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Y; Mutic, S; Du, D; Green, O [Washington University School of Medicine, Saint Louis, MO (United States); Zeng, Q; Nana, R; Patrick, J; Shvartsman, S; Dempsey, J [ViewRay Incorporated, Oakwood Village, OH (United States)

    2014-06-15

    Purpose: To evaluate the feasibility of using the weighted hybrid iterative spiral k-space encoded estimation (WHISKEE) technique to improve spatial resolution of tracking images for onboard MR image guided radiation therapy (MR-IGRT). Methods: MR tracking images of abdomen and pelvis had been acquired from healthy volunteers using the ViewRay onboard MRIGRT system (ViewRay Inc. Oakwood Village, OH) at a spatial resolution of 2.0mm*2.0mm*5.0mm. The tracking MR images were acquired using the TrueFISP sequence. The temporal resolution had to be traded off to 2 frames per second (FPS) to achieve the 2.0mm in-plane spatial resolution. All MR images were imported into the MATLAB software. K-space data were synthesized through the Fourier Transform of the MR images. A mask was created to selected k-space points that corresponded to the under-sampled spiral k-space trajectory with an acceleration (or undersampling) factor of 3. The mask was applied to the fully sampled k-space data to synthesize the undersampled k-space data. The WHISKEE method was applied to the synthesized undersampled k-space data to reconstructed tracking MR images at 6 FPS. As a comparison, the undersampled k-space data were also reconstructed using the zero-padding technique. The reconstructed images were compared to the original image. The relatively reconstruction error was evaluated using the percentage of the norm of the differential image over the norm of the original image. Results: Compared to the zero-padding technique, the WHISKEE method was able to reconstruct MR images with better image quality. It significantly reduced the relative reconstruction error from 39.5% to 3.1% for the pelvis image and from 41.5% to 4.6% for the abdomen image at an acceleration factor of 3. Conclusion: We demonstrated that it was possible to use the WHISKEE method to expedite MR image acquisition for onboard MR-IGRT systems to achieve good spatial and temporal resolutions simultaneously. Y. Hu and O. green

  1. The control of plasma density profile in Tore Supra. Comparison of different fueling techniques; Controle du profil de densite dans le plasma de Tore Supra. Comparaison de differentes methodes d'alimentation en particules

    Energy Technology Data Exchange (ETDEWEB)

    Commaux, N

    2007-09-15

    The behaviour of a reactor-class plasma when fuelled using the existing techniques (gas puffing, supersonic molecular beam injection and pellet injection) is still very difficult to foresee. The present work has been initiated on Tore Supra in order to extrapolate the consequences of the different fuelling systems on ITER. Two main topics have been studied: the comparison of the plasma behaviour when fuelled using the different techniques at high Greenwald density fractions and the study of the homogenization following a pellet injection (main fuelling technique for ITER burning plasmas). The experiments at high Greenwald density fractions performed on Tore Supra showed that the plasma behaviour is very dependent on the fuelling method. The plasma energy confinement is following the scaling laws determined at low density when fuelled using pellet injection. which is better than for gas puffing and SMBI. both inducing a significant confinement loss. This behaviour is nor related to a transport modification: the ratio between effective diffusion and convection is similar to the pellet case. The difference between these shots is related only to the position of the matter source (at the edge for gas and close to the center for pellets). The study concerning the homogenization phenomena following a pellet injection aims mainly to study the {nabla}B-drift effect that expels the mater deposited by a pellet toward the low field side. A new phenomenon. which appears to be particularly important for the {nabla}B-drift during low field side injections. was then discovered: the influence of magnetic surfaces with an integer-valued safety factor (q). When the mater drifting toward low field side crosses an integer q surface. it experiences an important braking effect which stops the drift motion. It implies that the pellet material is mainly deposited on the last integer q surface crossed by the pellet during its injection. This study allows also to determine that the {nabla

  2. Discussing State-of-the-Art Spatial Visualization Techniques Applicable for the Epidemiological Surveillance Data on the Example of Campylobacter spp. in Raw Chicken Meat.

    Science.gov (United States)

    Plaza-Rodríguez, C; Appel, B; Kaesbohrer, A; Filter, M

    2016-08-01

    Within the European activities for the 'Monitoring and Collection of Information on Zoonoses', annually EFSA publishes a European report, including information related to the prevalence of Campylobacter spp. in Germany. Spatial epidemiology becomes here a fundamental tool for the generation of these reports, including the representation of prevalence as an essential element. Until now, choropleth maps are the default visualization technique applied in epidemiological monitoring and surveillance reports made by EFSA and German authorities. However, due to its limitations, it seems to be reasonable to explore alternative chart type. Four maps including choropleth, cartogram, graduated symbols and dot-density maps were created to visualize real-world sample data on the prevalence of Campylobacter spp. in raw chicken meat samples in Germany in 2011. In addition, adjacent and coincident maps were created to visualize also the associated uncertainty. As an outcome, we found that there is not a single data visualization technique that encompasses all the necessary features to visualize prevalence data alone or prevalence data together with their associated uncertainty. All the visualization techniques contemplated in this study demonstrated to have both advantages and disadvantages. To determine which visualization technique should be used for future reports, we recommend to create a dialogue between end-users and epidemiologists on the basis of sample data and charts. The final decision should also consider the knowledge and experience of end-users as well as the specific objective to be achieved with the charts.

  3. Dose reduction technique using a combination of a region of interest (ROI) material x-ray attenuator and spatially different temporal filtering for fluoroscopic interventions

    Science.gov (United States)

    Swetadri Vasan, S. N.; Panse, A.; Jain, A.; Sharma, P.; Ionita, Ciprian N.; Titus, A. H.; Cartwright, A. N.; Bednarek, D. R.; Rudin, S.

    2012-03-01

    We demonstrate a novel approach for achieving patient dose savings during image-guided neurovascular interventions, involving a combination of a material x-ray region of interest (ROI) attenuator and a spatially different ROI temporal filtering technique. The part of the image under the attenuator is reduced in dose but noisy and less bright due to fewer x-ray quanta reaching the detector, as compared to the non-attenuating (or less attenuating) region. First the brightness is equalized throughout the image by post processing and then a temporal filter with higher weights is applied to the high attenuating region to reduce the noise, at the cost of increased lag; however, in the regions where less attenuation is present, a lower temporal weight is needed and is applied to preserve temporal resolution. A simulation of the technique is first presented on an actual image sequence obtained from an endovascular image guided interventional (EIGI) procedure. Then the actual implementation of the technique with a physical ROI attenuator is presented. Quantitative analysis including noise analysis and integral dose calculations are presented to validate the proposed technique.

  4. 基于时空同现挖掘技术的FNRB-Tree%FNRB-Tree:Based on Spatial-temporal Co-occurrence Mining Technique

    Institute of Scientific and Technical Information of China (English)

    黄照鹤; 戴健

    2012-01-01

    FNR-Tree (Fixed Network R-Tree) is a spatial-temporal indexing tree which combines 2D R-Tree and ID R-Tree structure. However, with the increasing amount of spatial-temporal data, two inherent R-Tree problems become even more prominent; (1) update costly; (2) query costly. In this paper, we improve FNR-Tree with spatial-temporal co-occurrence mining technique and cluster parallel moving objects in the same road segment together in FNR-Tree to construct FNRB-Tree (Fixed Network R-Tree with Buckets). Experimental results show that in the case of a large mount spatial-temporal data, FNRB-Tree has two following advantages; (1) update efficiency improved; (2) better support for neighboring query.%FNR-Tree利用2D R-Tree和1D R-Tree的结构,很好地结合了时间和空间的索引.但是随着索引数据量的增多,R-Tree本身的两个问题凸显出来(1)更新效率不高;(2)查询效率不高.本文在考虑了移动对象的时空同现的模式基础上,提出了一种对FNR-Tree优化的索引树FNRB-Tree,对于相同时间具有相同子轨迹的移动对象进行了按照路段的索引合并,从而达到了对FNR-Tree进行批量更新的效果.实验结果表明,FNRB-Tree在大数据量的情况下,(1)更新效率进行了提高;(2)对于邻近查询的响应时间更短.

  5. 一种空间域的可见水印%Spatial Domain Technique for Visible Watermarking

    Institute of Scientific and Technical Information of China (English)

    Peter Adjei Fordjour; 王朔中

    2003-01-01

    A new technique for embedding visible watermarks into a digital image is described in this paper, which uses statisticalproperties of each pixel and its immediate surrounding pixels in the host image, and also the statistical properties of the host image andthat of the image to be embedded (watermark), as the pixels in the host image are replaced one by one by the pixels in the watermarkimage. The aim is to establish a relationship between pixels in the images that will make the embedded watermark robust and semi-transparent, and to minimize errors caused by watermark addition and subtraction. Also, the original image can be completely recon-structed from the watermarked images.

  6. Super-resolution imaging of C-type lectin spatial rearrangement within the dendritic cell plasma membrane at fungal microbe contact sites

    Directory of Open Access Journals (Sweden)

    Michelle S Itano

    2014-08-01

    Full Text Available Dendritic cells express DC-SIGN and CD206, C-type lectins (CTLs that bind a variety of pathogens and may facilitate pathogen uptake for subsequent antigen presentation. Both proteins form punctate membrane nanodomains (~80 nm on naïve cells. We analyzed the spatiotemporal distribution of CTLs following host-fungal particle contact using confocal microscopy and three distinct methods of cluster identification and measurement of receptor clusters in super-resolution datasets: DBSCAN, Pair Correlation and a custom implementation of the Getis spatial statistic. Quantitative analysis of confocal and super-resolution images demonstrated that CTL nanodomains become concentrated in the contact site relative to non-contact membrane after the first hour of exposure and established that this recruitment is sustained out to four hours. DC-SIGN nanodomains in fungal contact sites exhibit a 70% area increase and a 38% decrease in interdomain separation. Contact site CD206 nanodomains possess 90% greater area and 42% lower interdomain separation relative to non-contact regions. Contact site CTL clusters appear as disk-shaped domains of approximately 150-175 nm in diameter. The increase in length scale of CTL nanostructure in contact sites suggests that the smaller nanodomains on resting membranes may merge during fungal nanodomain structure, or that they become packed closely enough to achieve sub-resolution inter-domain edge separations of < 30 nm. This study provides evidence of local receptor spatial rearrangements on the nanoscale that occur in the plasma membrane upon pathogen binding and may direct important signaling interactions required to recognize and respond to the presence of a relatively large pathogen.

  7. Comparing the effectiveness of "plasma knife" tonsillectomy with two well-established tonsillectomy techniques: cold dissection and bipolar electrocautery. A prospective randomized study.

    Science.gov (United States)

    Sadikoglu, Fatih; Kurtaran, Hanifi; Ark, Nebil; Ugur, K Serife; Yilmaz, Turker; Gozdemir, Muhammed; Mutlu, Cemil; Aktas, Davut

    2009-09-01

    To evaluate the effectiveness of a new device "plasma knife" for tonsillectomy by comparing to two well-established tonsillectomy techniques: cold dissection, and bipolar electrocautery. A prospective, randomized study conducted on 110 patients undergoing tonsillectomy. Subjects were randomized to plasma knife (PKT), cold dissection (CDT) and bipolar electrocautery (BET) groups. Operative time, intraoperative blood loss and postoperative complications were recorded. Pain/discomfort level of patients and healing time of the tonsillar fossae were assessed postoperatively. Data were recorded and statistically analyzed. Operative time with plasma knife and bipolar electrocautery were associated with a significant decrease in operative time compared to cold dissection (pplasma knife, compared to cold dissection and bipolar electrocautery (pplasma knife compared to bipolar electrocautery but more postoperative pain was observed with both compared to CDT (pplasma knife and bipolar electrocautery, compared to cold dissection (pPlasma knife is a useful and safe device in tonsillectomy. Its use reduces intraoperative blood loss and provides a fast tonsillectomy with acceptable morbidity.

  8. A geodata warehouse: Using denormalisation techniques as a tool for delivering spatially enabled integrated geological information to geologists

    Science.gov (United States)

    Kingdon, Andrew; Nayembil, Martin L.; Richardson, Anne E.; Smith, A. Graham

    2016-11-01

    New requirements to understand geological properties in three dimensions have led to the development of PropBase, a data structure and delivery tools to deliver this. At the BGS, relational database management systems (RDBMS) has facilitated effective data management using normalised subject-based database designs with business rules in a centralised, vocabulary controlled, architecture. These have delivered effective data storage in a secure environment. However, isolated subject-oriented designs prevented efficient cross-domain querying of datasets. Additionally, the tools provided often did not enable effective data discovery as they struggled to resolve the complex underlying normalised structures providing poor data access speeds. Users developed bespoke access tools to structures they did not fully understand sometimes delivering them incorrect results. Therefore, BGS has developed PropBase, a generic denormalised data structure within an RDBMS to store property data, to facilitate rapid and standardised data discovery and access, incorporating 2D and 3D physical and chemical property data, with associated metadata. This includes scripts to populate and synchronise the layer with its data sources through structured input and transcription standards. A core component of the architecture includes, an optimised query object, to deliver geoscience information from a structure equivalent to a data warehouse. This enables optimised query performance to deliver data in multiple standardised formats using a web discovery tool. Semantic interoperability is enforced through vocabularies combined from all data sources facilitating searching of related terms. PropBase holds 28.1 million spatially enabled property data points from 10 source databases incorporating over 50 property data types with a vocabulary set that includes 557 property terms. By enabling property data searches across multiple databases PropBase has facilitated new scientific research, previously

  9. A novel fast and flexible technique of radical kinetic behaviour investigation based on pallet for plasma evaluation structure and numerical analysis

    Science.gov (United States)

    Malinowski, Arkadiusz; Takeuchi, Takuya; Chen, Shang; Suzuki, Toshiya; Ishikawa, Kenji; Sekine, Makoto; Hori, Masaru; Lukasiak, Lidia; Jakubowski, Andrzej

    2013-07-01

    This paper describes a new, fast, and case-independent technique for sticking coefficient (SC) estimation based on pallet for plasma evaluation (PAPE) structure and numerical analysis. Our approach does not require complicated structure, apparatus, or time-consuming measurements but offers high reliability of data and high flexibility. Thermal analysis is also possible. This technique has been successfully applied to estimation of very low value of SC of hydrogen radicals on chemically amplified ArF 193 nm photoresist (the main goal of this study). Upper bound of our technique has been determined by investigation of SC of fluorine radical on polysilicon (in elevated temperature). Sources of estimation error and ways of its reduction have been also discussed. Results of this study give an insight into the process kinetics, and not only they are helpful in better process understanding but additionally they may serve as parameters in a phenomenological model development for predictive modelling of etching for ultimate CMOS topography simulation.

  10. Single-molecule imaging technique to study the dynamic regulation of GPCR function at the plasma membrane

    NARCIS (Netherlands)

    Snaar-Jagalska, B.E.; Cambi, A.; Schmidt, T.; Keijzer, S. de

    2013-01-01

    The lateral diffusion of a G-protein-coupled receptor (GPCR) in the plasma membrane determines its interaction capabilities with downstream signaling molecules and critically modulates its function. Mechanisms that control GPCR mobility, like compartmentalization, enable a cell to fine-tune its

  11. Spatial and temporal variations of small-scale plasma turbulence parameters in the equatorial electrojet: HF and VHF radar observational results

    Directory of Open Access Journals (Sweden)

    G. Manju

    2005-06-01

    Full Text Available The spatial and temporal variations of various parameters associated with plasma wave turbulence in the equatorial electrojet (EEJ at the magnetic equatorial location of Trivandrum (8.5° N, 77° E; dip 0.5° N are studied for the first time, using co-located HF (18MHz and VHF (54.95MHz coherent backscatter radar observations (daytime in the altitude region of 95-110km, mostly on magnetically quiet days. The derived turbulence parameters are the mean electron density irregularity strength (δn/n, anomalous electron collision frequency (νe* and the corrected east-west electron drift velocity (Vey. The validity of the derived parameters is confirmed using radar data at two different frequencies and comparing with in-situ measurements. The behaviour of δn/n in relation to the backscattered power during weak and strong EEJ conditions is also examined to understand the growth and evolution of turbulence in the electrojet.

  12. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  13. Thomson scattering measurement of a shock in laser-produced counter-streaming plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Morita, T.; Kuramitsu, Y.; Moritaka, T. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Sakawa, Y.; Takabe, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan); Tomita, K.; Nakayama, K.; Inoue, K.; Uchino, K. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Ide, T.; Tsubouchi, K. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishio, K.; Ide, H.; Kuwada, M. [Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan)

    2013-09-15

    We report the first direct measurement of temporally and spatially resolved plasma temperatures at a shock as well as its spatial structure and propagation in laser-produced counter-streaming plasmas. Two shocks are formed in counter-streaming collisionless plasmas early in time, and they propagate opposite directions. This indicates the existence of counter-streaming collisionless flows to keep exciting the shocks, even though the collisional effects increase later in time. The shock images are observed with optical diagnostics, and the upstream and downstream plasma parameters of one of the shocks are measured using Thomson scattering technique.

  14. Characterization of Sintered and Sintered/Plasma-Nitrided Fe-1.5% Mo Alloy by SEM, X-Ray Diffraction and Electrochemical Techniques

    Directory of Open Access Journals (Sweden)

    Alves Neto José de Pinho

    2002-01-01

    Full Text Available Electrochemical experiments together with SEM and X-Ray techniques were carried out in order to evaluate the corrosion resistance, to analyze the surface condition and to characterize the nitride layer of the sintered and sintered/plasma-nitrided Fe-1.5% Mo alloy in Mg(NO32 0.5mol.L-1 solution (pH 7.0. The sintered/plasma-nitrided samples presented a higher corrosion resistance, indicating that the surface treatment improved the electrochemical properties of the sintered material. In addition, the nitride layer formed at 500 °C showed better corrosion resistance that the layers formed at higher temperatures. This difference can be ascribed to the nitrogen content in the nitride layer, which at 500°C is higher due to the formation of a phase rich in nitrogen (epsilon phase while at higher temperatures a phase poor in nitrogen (gamma' phase is formed.

  15. Spatially resolved measurement of the vibrational temperatures of the plasma in a DC-excited fast-axial-flow CO{sub 2} laser

    Energy Technology Data Exchange (ETDEWEB)

    Toebaert, D.; Desoppere, E. [Univ. of Gent (Belgium). Dept. of Applied Physics; Muys, P. [Radius Engineering NV, Gent (Belgium)

    1995-10-01

    Results of measurements of longitudinally-averaged vibrational and rotational temperatures of CO{sub 2} for different radial positions in the active medium of a fast-axial-flow, dc-excited CO{sub 2} laser are reported. The diagnostic technique which was implemented is high resolution absorption spectroscopy of the laser plasma, using a tunable diode laser (TDL). Two different gas inlet sections for the CO{sub 2} laser were tested: one with a single anode pin in front of a relatively large inlet nozzle, as still commonly used in industrial high-power lasers, and another with multiple anodes symmetrically spaced around the perimeter of the discharge tube, each in front of a small diameter inlet nozzle. It is shown that the latter design is capable of creating an essentially flat profile regarding rotational temperature T{sub R} and combined bending mode (T{sub 2}) and symmetric stretch mode (T{sub 1} {approx} T{sub 2}) temperature, while the asymmetric stretch temperature T{sub 3} exhibits a small central maximum. This type of gain pattern is considered to be beneficial for mode quality. The former, mostly used gas inlet design, fails to provide an adequate gain profile (i.e., flat or centered and symmetrical). The combination of the information provided by the spectroscopic technique and a previously developed theoretical model can prove to be a real design aid for developing compact, high-power, gaussian mode CO{sub 2} lasers for materials processing applications.

  16. Surface modification of a titanium alloy with a phospholipid polymer prepared by a plasma-induced grafting technique to improve surface thromboresistance.

    Science.gov (United States)

    Ye, Sang Ho; Johnson, Carl A; Woolley, Joshua R; Oh, Heung-Il; Gamble, Lara J; Ishihara, Kazuhiko; Wagner, William R

    2009-11-01

    To improve the thromboresistance of a titanium alloy (TiAl(6)V(4)) surface which is currently utilized in several ventricular assist devices (VADs), a plasma-induced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) was carried out and poly(MPC) (PMPC) chains were covalently attached onto a TiAl(6)V(4) surface by a plasma induced technique. Cleaned TiAl(6)V(4) surfaces were pretreated with H(2)O-vapor-plasma and silanated with 3-methacryloylpropyltrimethoxysilane (MPS). Next, a plasma-induced graft polymerization with MPC was performed after the surfaces were pretreated with Ar plasma. Surface compositions were verified by X-ray photoelectron spectroscopy (XPS). In vitro blood biocompatibility was evaluated by contacting the modified surfaces with ovine blood under continuous mixing. Bulk phase platelet activation was quantified by flow cytometric analysis, and surfaces were observed with scanning electron microscopy after blood contact. XPS data demonstrated successful modification of the TiAl(6)V(4) surfaces with PMPC as evidenced by increased N and P on modified surfaces. Platelet deposition was markedly reduced on the PMPC grafted surfaces and platelet activation in blood that contacted the PMPC-grafted samples was significantly reduced relative to the unmodified TiAl(6)V(4) and polystyrene control surfaces. Durability studies under continuously mixed water suggested no change in surface modification over a 1-month period. This modification strategy shows promise for further investigation as a means to reduce the thromboembolic risk associated with the metallic blood-contacting surfaces of VADs and other cardiovascular devices under development.

  17. Spatial Interpolation.

    NARCIS (Netherlands)

    Stein, A.

    1991-01-01

    The theory and practical application of techniques of statistical interpolation are studied in this thesis, and new developments in multivariate spatial interpolation and the design of sampling plans are discussed. Several applications to studies in soil science are presented.Sampling s

  18. A systematic comparison of different object-based classification techniques using high spatial resolution imagery in agricultural environments

    Science.gov (United States)

    Li, Manchun; Ma, Lei; Blaschke, Thomas; Cheng, Liang; Tiede, Dirk

    2016-07-01

    Geographic Object-Based Image Analysis (GEOBIA) is becoming more prevalent in remote sensing classification, especially for high-resolution imagery. Many supervised classification approaches are applied to objects rather than pixels, and several studies have been conducted to evaluate the performance of such supervised classification techniques in GEOBIA. However, these studies did not systematically investigate all relevant factors affecting the classification (segmentation scale, training set size, feature selection and mixed objects). In this study, statistical methods and visual inspection were used to compare these factors systematically in two agricultural case studies in China. The results indicate that Random Forest (RF) and Support Vector Machines (SVM) are highly suitable for GEOBIA classifications in agricultural areas and confirm the expected general tendency, namely that the overall accuracies decline with increasing segmentation scale. All other investigated methods except for RF and SVM are more prone to obtain a lower accuracy due to the broken objects at fine scales. In contrast to some previous studies, the RF classifiers yielded the best results and the k-nearest neighbor classifier were the worst results, in most cases. Likewise, the RF and Decision Tree classifiers are the most robust with or without feature selection. The results of training sample analyses indicated that the RF and adaboost. M1 possess a superior generalization capability, except when dealing with small training sample sizes. Furthermore, the classification accuracies were directly related to the homogeneity/heterogeneity of the segmented objects for all classifiers. Finally, it was suggested that RF should be considered in most cases for agricultural mapping.

  19. Urban vegetation cover extraction from hyperspectral imagery and geographic information system spatial analysis techniques: case of Athens, Greece

    Science.gov (United States)

    Petropoulos, George P.; Kalivas, Dionissios P.; Georgopoulou, Iro A.; Srivastava, Prashant K.

    2015-01-01

    The present study aimed at evaluating the performance of two different pixel-based classifiers [spectral angle mapper (SAM) and support vector machines (SVMs)] in discriminating different land-cover classes in a typical urban setting, focusing particularly on urban vegetation cover by utilizing hyperspectral (EO-1 Hyperion) data. As a case study, the city of Athens, Greece, was used. Validation of urban vegetation predictions was based on the error matrix statistics. Additionally, the final urban vegetation cover maps were compared at a municipality level against reference urban vegetation cover estimates derived from the digitization of very high-resolution imagery. To ensure consistency and comparability of the results, the same training and validation points dataset were used to compare the different classifiers. The results showed that SVMs outperformed SAM in terms of both classification and urban vegetation cover mapping with an overall accuracy of 86.53% and Kappa coefficient 0.823, whereas for SAM classification, the accuracy statistics obtained were 75.13% and 0.673, respectively. Our results confirmed the ability of both techniques, when combined with Hyperion imagery, to extract urban vegetation cover for the case of a densely populated city with complex urban features, such as Athens. Our findings offer significant information at the local scale as regards to the presence of open green spaces in the urban environment of Athens. Such information is vital for successful infrastructure development, urban landscape planning, and improvement of urban environment. More widely, this study also contributes significantly toward an objective assessment of Hyperion in detecting and mapping urban vegetation cover.

  20. Spatial and temporal dynamics of receptor for advanced glycation endproducts, integrins, and actin cytoskeleton as probed with fluorescence-based imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Syed, Aleem [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    Systematic spatial and temporal fluctuations are a fundamental part of any biological process. For example, lateral diffusion of membrane proteins is one of the key mechanisms in their cellular function. Lateral diffusion governs how membrane proteins interact with intracellular, transmembrane, and extracellular components to achieve their function. Herein, fluorescence-based techniques are used to elucidate the dynamics of receptor for advanced glycation end-products (RAGE) and integrin membrane proteins. RAGE is a transmembrane protein that is being used as a biomarker for various diseases. RAGE dependent signaling in numerous pathological conditions is well studied. However, RAGE lateral diffusion in the cell membrane is poorly understood. For this purpose, effect of cholesterol, cytoskeleton dynamics, and presence of ligand on RAGE lateral diffusion is investigated.

  1. Digital image multiplexing/demultiplexing method using spatial spectral diffusion and virtual phase conjugation technique for reduction of dynamic range consumption in holographic medium

    Science.gov (United States)

    Goto, Yuta; Okamoto, Atsushi; Takabayashi, Masanori; Ogawa, Kazuhisa; Tomita, Akihisa

    2017-09-01

    The recording density in holographic data storage (HDS) systems is determined by the dynamic range of the recording medium. If a hologram is recorded with a small exposure, the consumption amount of the dynamic range per hologram is reduced, and the recording density can be improved. In this report, we propose a digital image multiplexing/demultiplexing method using spatial spectral diffusion and a virtual phase conjugation technique to reduce the consumption amount of the dynamic range in a recording medium. In our method, multiple signals are simultaneously recorded in a medium by multiplexing those signals using a beam combiner before recording, unlike the general multiplexing method of HDS. Then, each original signal can be reproduced independently by utilizing the property of a random diffuser and a phase-conjugated light. In the simulation, we confirmed that our method can improve the recording density because the consumption of the dynamic range is reduced.

  2. Analysis of Geostatistical and Deterministic Techniques in the Spatial Variation of Groundwater Depth in the North-western part of Bangladesh

    Directory of Open Access Journals (Sweden)

    Ibrahim Hassan

    2016-06-01

    Full Text Available Various geostatistical and deterministic techniques were used to analyse the spatial variations of groundwater depths. Two different geostatistical methods of ordinary kriging and co-kriging with four semivariogram models, spherical, exponential, circular, Gaussian, and four deterministic methods which are inverse distance weighted (IDW, global polynomial interpolation (GPI, local Polynomial Interpolation (LPI, radial basis function (RBF were used for the estimation of groundwater depths. The study area is in the three Northwestern districts of Bangladesh. Groundwater depth data were recorded from 132 observation wells in the study area over a period of 6 years (2004 to 2009 was considered for the analysis. The spatial interpolation of groundwater depths was then performed using the best-fit model which is geostatistical model selected by comparing the observed RMSE values predicted by the geostatistical and deterministic models and the empirical semi-variogram models. Out of the four semi-variogram models, spherical semi-variogram with cokriging model was considered as the best fitted model for the study area. Result of sensitivity analysis conducted on the input parameters shows that inputs have a strong influence on groundwater levels and the statistical indicators of RMSE and ME suggest that the Co-kriging work best with percolation in predicting the average groundwater table of the study area.

  3. Generation and characterization of plasma channels in gas puff targets using soft X-ray radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Wachulak, P. W., E-mail: wachulak@gmail.com; Bartnik, A.; Jarocki, R.; Fok, T.; Węgrzyński, Ł.; Kostecki, J.; Szczurek, M.; Jabczyński, J.; Fiedorowicz, H. [Institute of Optoelectronics, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warsaw (Poland)

    2014-10-15

    We present our recent results of a formation and characterization of plasma channels in elongated krypton and xenon gas puff targets. The study of their formation and temporal expansion was carried out using a combination of a soft X-ray radiography (shadowgraphy) and pinhole camera imaging. Two high-energy short laser pulses were used to produce the channels. When a pumping laser pulse was shaped into a line focus, using cylindrical and spherical lenses, the channels were not produced because much smaller energy density was deposited in the gas puff target. However, when a point focus was obtained, using just a spherical lens, the plasma channels appeared. The channels were up to 9 mm in length, had a quite uniform density profile, and expanded in time with velocities of about 2 cm/μs.

  4. Characterizing Subcore Heterogeneity: A New Analytical Model and Technique to Observe the Spatial Variation of Transverse Dispersion

    Science.gov (United States)

    Boon, Maartje; Niu, Ben; Krevor, Sam

    2015-04-01

    of the NaI aqueous solution at steady state for the different Peclet numbers. The average transverse dispersion coefficient (Dt) was calculated from the change in variance of the transverse distance travelled by the NaI solution along the core. A Dt of 2.396e-04 cm2/min was obtained for Peclet nr 0.5 and a Dt of 4.771e-04 cm2/min for Peclet nr 2. These values coincide precisely with the Dt calculated from the pore scale modelling on Berea sandstone of Bijeljic and Blunt, 2007, and serves as a benchmark demonstrating the utility and repeatability of the technique. This new technique shows promise for use in characterising average transport characteristics and analysing the impacts of natural rock heterogeneity. Acknowledgement: This work was carried out as part of the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC). The authors gratefully acknowledge the funding of QCCSRC provided jointly by Qatar Petroleum, Shell, and the Qatar Science & Technology Park and for supporting the present project and the permission to present this research. References: 1. Blackwell, 1962 - Laboratory studies of microscopic dispersion phenomena. Society of Petroleum Engineers Journal 2, no.1:1-8 2. Bijeljic, B., and M. J. Blunt (2007), Pore-scale modeling of transverse dispersion in porous media, Water Resour. Res., 43, W12S11, doi:10.1029/2006WR005700. 3. Han, N.W., Bhakta, J and Carbonell, R.G., 1985 - Longitudinal and lateral dispersion in packed beds: Effect of column length and particle size distribution. AIChE Journal31, no.2:277-288. 4. Harleman, D.R., and R.R. Rumer. 1963. Longitudinal and lateral dispersion in an isotropic porous medium. Journal of Fluid Mechanics16, no. 2:385-394. 5. Hassinger, R.C. and Von Rosenberg, D.U., 1968 - A mathematical and experimental examination of transverse dispersion coefficients. Society of Petroleum Engineers Journal 8, no.1:195-204.

  5. Topographic gravity modeling for global Bouguer maps to degree 2160: Validation of spectral and spatial domain forward modeling techniques at the 10 microGal level

    Science.gov (United States)

    Hirt, Christian; Reußner, Elisabeth; Rexer, Moritz; Kuhn, Michael

    2016-09-01

    Over the past years, spectral techniques have become a standard to model Earth's global gravity field to 10 km scales, with the EGM2008 geopotential model being a prominent example. For some geophysical applications of EGM2008, particularly Bouguer gravity computation with spectral techniques, a topographic potential model of adequate resolution is required. However, current topographic potential models have not yet been successfully validated to degree 2160, and notable discrepancies between spectral modeling and Newtonian (numerical) integration well beyond the 10 mGal level have been reported. Here we accurately compute and validate gravity implied by a degree 2160 model of Earth's topographic masses. Our experiments are based on two key strategies, both of which require advanced computational resources. First, we construct a spectrally complete model of the gravity field which is generated by the degree 2160 Earth topography model. This involves expansion of the topographic potential to the 15th integer power of the topography and modeling of short-scale gravity signals to ultrahigh degree of 21,600, translating into unprecedented fine scales of 1 km. Second, we apply Newtonian integration in the space domain with high spatial resolution to reduce discretization errors. Our numerical study demonstrates excellent agreement (8 μGgal RMS) between gravity from both forward modeling techniques and provides insight into the convergence process associated with spectral modeling of gravity signals at very short scales (few km). As key conclusion, our work successfully validates the spectral domain forward modeling technique for degree 2160 topography and increases the confidence in new high-resolution global Bouguer gravity maps.

  6. The effects of venous cannulation technique and cardioplegia type on plasma potassium concentration and arterial blood pressure during cardiopulmonary bypass.

    LENUS (Irish Health Repository)

    Coleman, E T

    2012-02-03

    The cannulation method and cardioplegia solution used during cardiopulmonary bypass (CPB) may both influence plasma potassium concentrations ([K+]) and mean arterial blood pressure (MAP). Bi-caval or right atrial cannulation methods are routinely used in conjunction with crystalloid or blood cardioplegia. We investigated the influence of cannulation method and cardioplegia solutions on plasma [K+] and MAP during cardiopulmonary bypass. Sixty consecutive patients undergoing elective coronary artery bypass grafting (CABG) using CPB were studied. They were randomly divided into three groups of 20 patients. Patients in Group A underwent bi-caval venous cannulation and received crystalloid cardioplegia. Group B patients underwent right atrial cannulation and received crystalloid cardioplegia. Group C patients underwent right atrial cannulation and received blood cardioplegia. In each case. cardioplegia was administered antegrade via the aortic root. Plasma [K+], MAP. and hemoglobin concentration (Hb) were measured over an 8-min period following cardioplegia administration (pilot studies indicated pressure changes occuring post cardioplegia administration up to this time). The combination of bi-caval cannulation and crystalloid cardioplegia (Group A) was associated with the least increase in plasma [K+] and no decrease in MAP. The maximum [K+] for this Group was 4.2 mmol\\/L (4.6% increase). The minimum mean pressure was 57 mmHg (13.6% increase). Both right atrial cannulation groups (B and C) showed a large rise in plasma [K+] and a decrease in MAP. Group B maximum [K+] was 5.2 mmol\\/L (27.5% increase). Group C was also 5.2 mmol\\/L (26.0% increase). Group C showed the largest pressure decrease, the minimum mean pressure was 45 mmHg (21.3% decrease). The Group B minimum mean pressure was 45 mmHg (8.7% decrease). Our results show that patients undergoing CPB operations who are deemed to be at increased risk of suffering adverse effects from hypotensive episodes may

  7. Effects of Surface Modification of Nanodiamond Particles for Nucleation Enhancement during Its Film Growth by Microwave Plasma Jet Chemical Vapour Deposition Technique

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2014-01-01

    Full Text Available The seedings of the substrate with a suspension of nanodiamond particles (NDPs were widely used as nucleation seeds to enhance the growth of nanostructured diamond films. The formation of agglomerates in the suspension of NDPs, however, may have adverse impact on the initial growth period. Therefore, this paper was aimed at the surface modification of the NDPs to enhance the diamond nucleation for the growth of nanocrystalline diamond films which could be used in photovoltaic applications. Hydrogen plasma, thermal, and surfactant treatment techniques were employed to improve the dispersion characteristics of detonation nanodiamond particles in aqueous media. The seeding of silicon substrate was then carried out with an optimized spin-coating method. The results of both Fourier transform infrared spectroscopy and dynamic light scattering measurements demonstrated that plasma treated diamond nanoparticles possessed polar surface functional groups and attained high dispersion in methanol. The nanocrystalline diamond films deposited by microwave plasma jet chemical vapour deposition exhibited extremely fine grain and high smooth surfaces (~6.4 nm rms on the whole film. These results indeed open up a prospect of nanocrystalline diamond films in solar cell applications.

  8. Possibilities of LA-ICP-MS technique for the spatial elemental analysis of the recent fish scales: Line scan vs. depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hola, Marketa [Department of Chemistry, Masaryk University of Brno, Kamenice 5, 625 00 Brno (Czech Republic); Kalvoda, Jiri, E-mail: jkalvoda@centrum.cz [Department of Geological Sciences, Masaryk University of Brno, Kotlarska 2, 611 37 Brno (Czech Republic); Novakova, Hana [Department of Chemistry, Masaryk University of Brno, Kamenice 5, 625 00 Brno (Czech Republic); Skoda, Radek [Department of Geological Sciences, Masaryk University of Brno, Kotlarska 2, 611 37 Brno (Czech Republic); Kanicky, Viktor [Department of Chemistry, Masaryk University of Brno, Kamenice 5, 625 00 Brno (Czech Republic)

    2011-01-01

    LA-ICP-MS and solution based ICP-MS in combination with electron microprobe are presented as a method for the determination of the elemental spatial distribution in fish scales which represent an example of a heterogeneous layered bone structure. Two different LA-ICP-MS techniques were tested on recent common carp (Cyprinus carpio) scales: (a)A line scan through the whole fish scale perpendicular to the growth rings. The ablation crater of 55 {mu}m width and 50 {mu}m depth allowed analysis of the elemental distribution in the external layer. Suitable ablation conditions providing a deeper ablation crater gave average values from the external HAP layer and the collagen basal plate. (b)Depth profiling using spot analysis was tested in fish scales for the first time. Spot analysis allows information to be obtained about the depth profile of the elements at the selected position on the sample. The combination of all mentioned laser ablation techniques provides complete information about the elemental distribution in the fish scale samples. The results were compared with the solution based ICP-MS and EMP analyses. The fact that the results of depth profiling are in a good agreement both with EMP and PIXE results and, with the assumed ways of incorporation of the studied elements in the HAP structure, suggests a very good potential for this method.

  9. Microprobing the molecular spatial distribution and structural architecture of feed-type sorghum seed tissue (Sorghum Bicolor L.) using the synchrotron radiation infrared microspectroscopy technique.

    Science.gov (United States)

    Yu, Peiqiang

    2011-09-01

    Sorghum seed (Sorghum bicolor L.) has unique degradation and fermentation behaviours compared with other cereal grains such as wheat, barley and corn. This may be related to its cell and cell-wall architecture. The advanced synchrotron radiation infrared microspectroscopy (SR-IMS) technique enables the study of cell or living cell biochemistry within cellular dimensions. The objective of this study was to use the SR-IMS imaging technique to microprobe molecular spatial distribution and cell architecture of the sorghum seed tissue comprehensively. High-density mapping was carried out using SR-IMS on beamline U2B at the National Synchrotron Light Source (Brookhaven National Laboratory, NY, USA). Molecular images were systematically recorded from the outside to the inside of the seed tissue under various chemical functional groups and their ratios [peaks at ∼1725 (carbonyl C=O ester), 1650 (amide I), 1657 (protein secondary structure α-helix), 1628 (protein secondary structure β-sheet), 1550 (amide II), 1515 (aromatic compounds of lignin), 1428, 1371, 1245 (cellulosic compounds in plant seed tissue), 1025 (non-structural CHO, starch granules), 1246 (cellulosic material), 1160 (CHO), 1150 (CHO), 1080 (CHO), 930 (CHO), 860 (CHO), 3350 (OH and NH stretching), 2960 (CH(3) anti-symmetric), 2929 (CH(2) anti-symmetric), 2877 (CH(3) symmetric) and 2848 cm(-1) (CH(2) asymmetric)]. The relative protein secondary structure α-helix to β-sheet ratio image, protein amide I to starch granule ratio image, and anti-symmetric CH(3) to CH(2) ratio image were also investigated within the intact sorghum seed tissue. The results showed unique cell architecture, and the molecular spatial distribution and intensity in the sorghum seed tissue (which were analyzed through microprobe molecular imaging) were generated using SR-IMS. This imaging technique and methodology has high potential and could be used for scientists to develop specific cereal grain varieties with targeted food and

  10. Microprobing the Molecular Spatial Distribution and Structural Architecture of Feed-type Sorghum Seed Tissue (Sorghum Bicolor L.) using the Synchrotron Radiation Infrared Microspectroscopy Technique

    Energy Technology Data Exchange (ETDEWEB)

    P Yu

    2011-12-31

    Sorghum seed (Sorghum bicolor L.) has unique degradation and fermentation behaviours compared with other cereal grains such as wheat, barley and corn. This may be related to its cell and cell-wall architecture. The advanced synchrotron radiation infrared microspectroscopy (SR-IMS) technique enables the study of cell or living cell biochemistry within cellular dimensions. The objective of this study was to use the SR-IMS imaging technique to microprobe molecular spatial distribution and cell architecture of the sorghum seed tissue comprehensively. High-density mapping was carried out using SR-IMS on beamline U2B at the National Synchrotron Light Source (Brookhaven National Laboratory, NY, USA). Molecular images were systematically recorded from the outside to the inside of the seed tissue under various chemical functional groups and their ratios [peaks at {approx}1725 (carbonyl C=O ester), 1650 (amide I), 1657 (protein secondary structure {alpha}-helix), 1628 (protein secondary structure {beta}-sheet), 1550 (amide II), 1515 (aromatic compounds of lignin), 1428, 1371, 1245 (cellulosic compounds in plant seed tissue), 1025 (non-structural CHO, starch granules), 1246 (cellulosic material), 1160 (CHO), 1150 (CHO), 1080 (CHO), 930 (CHO), 860 (CHO), 3350 (OH and NH stretching), 2960 (CH{sub 3} anti-symmetric), 2929 (CH{sub 2} anti-symmetric), 2877 (CH{sub 3} symmetric) and 2848 cm{sup -1} (CH{sub 2} asymmetric)]. The relative protein secondary structure {alpha}-helix to {beta}-sheet ratio image, protein amide I to starch granule ratio image, and anti-symmetric CH{sub 3} to CH{sub 2} ratio image were also investigated within the intact sorghum seed tissue. The results showed unique cell architecture, and the molecular spatial distribution and intensity in the sorghum seed tissue (which were analyzed through microprobe molecular imaging) were generated using SR-IMS. This imaging technique and methodology has high potential and could be used for scientists to develop

  11. A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

    Energy Technology Data Exchange (ETDEWEB)

    Feister, S., E-mail: feister.7@osu.edu; Orban, C. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Nees, J. A. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Center for Ultra-Fast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Morrison, J. T. [Fellow, National Research Council, Washington, D.C. 20001 (United States); Frische, K. D. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Chowdhury, E. A. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Intense Energy Solutions, LLC., Plain City, Ohio 43064 (United States); Roquemore, W. M. [Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

    2014-11-15

    Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements

  12. The clinical value of enzyme-multiplied immunoassay technique monitoring the plasma concentrations of cyclosporine A a%The clinical value of enzyme-multiplied immunoassay technique monitoring the plasma concentrations of cyclosporine A aft

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hui Luo; wu-Jun Xue; Pu-Xun Tian; Xiao-Ming Ding; Hang Yan; He-Li Xiang; Yang Li

    2011-01-01

    The feasibility and the clinical value of the enzyme-multiplied immunoassay technique (EMIT) monitoring of blood concentrations of cyclosporine A (CsA) in patients treated with CsA were investigated after kidney transplantation. The validation method was

  13. Multirate Particle-in-Cell Time Integration Techniques of Vlasov-Maxwell Equations for Collisionless Kinetic Plasma Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guangye [Los Alamos National Laboratory; Chacon, Luis [Los Alamos National Laboratory; Knoll, Dana Alan [Los Alamos National Laboratory; Barnes, Daniel C [Coronado Consulting

    2015-07-31

    A multi-rate PIC formulation was developed that employs large timesteps for slow field evolution, and small (adaptive) timesteps for particle orbit integrations. Implementation is based on a JFNK solver with nonlinear elimination and moment preconditioning. The approach is free of numerical instabilities (ωpeΔt >>1, and Δx >> λD), and requires many fewer dofs (vs. explicit PIC) for comparable accuracy in challenging problems. Significant gains (vs. conventional explicit PIC) may be possible for large scale simulations. The paper is organized as follows: Vlasov-Maxwell Particle-in-cell (PIC) methods for plasmas; Explicit, semi-implicit, and implicit time integrations; Implicit PIC formulation (Jacobian-Free Newton-Krylov (JFNK) with nonlinear elimination allows different treatments of disparate scales, discrete conservation properties (energy, charge, canonical momentum, etc.)); Some numerical examples; and Summary.

  14. Intelligent Analysis of Samples by Semiquantitative Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) Technique: A Review.

    Science.gov (United States)

    Krzciuk, Karina

    2016-07-03

    Inductively coupled plasma-mass spectrometry (ICP-MS) is a popular and routine analytical method that has been used for determination of trace elements since the 1980s. It provides fast quantitative analysis and allows the determination of more than 70 elements with good accuracy and very low detection limits, but requires an intricate calibration procedure. In analyses of samples for which very low detection limits are not required a semiquantitative ICP-MS analysis mode can be used. This approach is more time- and cost-effective, and it uses a simple calibration procedure. This article presents a critical review of the semiquantitative (SQ) mode of ICP-MS and describes current and future applications of SQ analysis.

  15. Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique

    Science.gov (United States)

    The objective was to investigate the effect of intake prior to fasting on concentrations of metabolites and hormones, respiratory quotient (RQ) and fasting heat production (HP) using the washed rumen technique and to compare these values with those from the fed state. Six Holstein steers (360 ± 22 k...

  16. Time-resolved spatial distribution of plasma in the ablation of a Ba₀.₆Sr₀.₄TiO₃ target by 25 ns KrF ultraviolet laser

    Energy Technology Data Exchange (ETDEWEB)

    Lagrange, J. F.; Wolfman, J.; Motret, O. [Groupe de Recherche en Matériaux, microélectronique, Acoustique et Nanotechnologies (GREMAN) - UMR 7347 CNRS-CEA, Université François Rabelais de Tours, Faculté des Sciences and Techniques, Parc Grandmont - bât. E – 37200 Tours (France); Hermann, J. [Laboratoire Lasers, Plasmas et Procédés Photoniques (LP3), UMR 6182 CNRS, Aix-Marseille Université, 163 Avenue de Luminy, C. 917 - 13288 Marseille (France)

    2014-10-07

    We performed radially and longitudinally time-resolved plasma analysis during pulsed laser deposition of Ba₀.₆Sr₀.₄TiO₃ thin films. The plasma is shown to be optically thick and strongly non-uniform during the early expansion phase and the resonance line Ba II (455.4 nm) is strongly self-reversed during this time. Plasma temperature and electron density were obtained by comparing experimental emission spectra with the spectral radiance computed for a non-uniform plasma in local thermal equilibrium.

  17. Composition and spatial distribution of subtidal decapoda on the "Reef Coast", northeastern Brazil, evaluated through a low-impact visual census technique

    Directory of Open Access Journals (Sweden)

    Bruno W. Giraldes

    Full Text Available This study investigated the composition and spatial distribution of the sublittoral decapods on the reefs of Porto de Galinhas Beach, southern coast of Pernambuco, Brazil, through the Underwater Visual Census technique. Data were collected monthly, at night during full-moon tides in low tide periods from June 2004 to May 2005, using SCUBA diving and a visual census with a fixed belt transect (20 m long. Three sampling areas were defined: Confined Waters (low hydrodynamics with shallow sites (up to 2.5 m deep; Semi-open Water (3 to 6 m deep, influenced by waves and tidal currents (moderate hydrodynamics; and Open Water (7 to 10 m deep, in the breaker zone (high hydrodynamics. A total of 6,287 individuals of 34 species belonging to the infraorders Brachyura (19 species, Achelata and Anomura (5 species each, Caridea (3 species, and Stenopodidea and Astacidea (1 species each were collected. Two decapod assemblages were distinguished: in a habitat with low hydrodynamics and shallow (Confined water; and in a habitat with moderate to high hydrodynamics and depths of 3 to 10 m (Semi-open and Open water. At the sites with high hydrodynamics, i.e., the Open-water Area in the breaker zone, decapod diversity was significantly lower than in the other, protected areas on the reef bench. These results suggest that the distribution of subtidal decapods on coastal reefs is influenced by depth and exposure to water stress caused by waves and currents (hydrodynamics. The visual census technique with SCUBA proved to be suitable for ecological studies on subtidal decapods.

  18. Spatial assessment of Geo-environmental data by the integration of Remote Sensing and GIS techniques for Sitakund Region, Eastern foldbelt, Bangladesh.

    Science.gov (United States)

    Gazi, M. Y.; Rahman, M.; Islam, M. A.; Kabir, S. M. M.

    2016-12-01

    Techniques of remote sensing and geographic information systems (GIS) have been applied for the analysis and interpretation of the Geo-environmental assessment to Sitakund area, located within the administrative boundaries of the Chittagong district, Bangladesh. Landsat ETM+ image with a ground resolution of 30-meter and Digital Elevation Model (DEM) has been adopted in this study in order to produce a set of thematic maps. The diversity of the terrain characteristics had a major role in the diversity of recipes and types of soils that are based on the geological structure, also helped to diversity in land cover and use in the region. The geological situation has affected on the general landscape of the study area. The problem of research lies in the possibility of the estimating the techniques of remote sensing and geographic information systems in the evaluation of the natural data for the study area spatially as well as determine the appropriate in grades for the appearance of the ground and in line with the reality of the region. Software for remote sensing and geographic information systems were adopted in the analysis, classification and interpretation of the prepared thematic maps in order to get to the building of the Geo-environmental assessment map of the study area. Low risk geo-environmental land mostly covered area of Quaternary deposits especially with area of slope wash deposits carried by streams. Medium and high risk geo-environmental land distributed with area of other formation with the study area, mostly the high risk shows area of folds and faults. The study has assessed the suitability of lands for agricultural purpose and settlements in less vulnerable areas within this region.

  19. Plasma Processes : A simple and efficient levitation technique for noncontact coating of inertial confinement fusion targets

    Indian Academy of Sciences (India)

    K K Mishra; R K Khardekar; Rashmi Chouhan; R K Gupta

    2000-11-01

    A simple and very efficient gas jet levitation technique for levitating inertial confinement fusion (ICF) targets has been developed. A low velocity gas jet through diverging nozzle generates precisely controlled low Reynolds number flow pattern, capable of levitating polymer microballoons up to 2500 m diameter. Different shaped diverging nozzle are investigated, satisfactory levitation is achieved with simple conical shapes. With this setup microballoon can be levitated for hours with excellent stability, continuous rotation and at the desired height (reproducible with in less than 100 m). The height of stabilization depends upon cone angle of diverging nozzle and velocity of levitating gas. This technique is very robust and highly insensitive to external disturbances like nonuniform temperature fields and vibrations. This setup is very economical to fabricate, easy to operate and can be used efficiently in various spray coating application involving plastic and metallic layers on microballoons.

  20. Principle equivalence and practical difference between two approaches to plasma polarimetry: The Stokes vector formalism and the angular variables technique

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Yury A. [Maritime University, Szczecin (Poland); Bieg, Bohdan, E-mail: b.bieg@am.szczecin.pl [Maritime University, Szczecin (Poland); Chrzanowski, Janusz [Maritime University, Szczecin (Poland)

    2013-10-15

    In spite of well known different forms of the description of electromagnetic wave polarization state, up to now the evolution of the polarization state in weakly anisotropic media was described only by Stokes vector formalism (SVF) or quasi-istropic approximation (QIA). In this paper different approach is presented, based on angular variables technique (AVT): amplitude ratio and phase shift. It is shown that basic differential equations of angular variables technique can be derived directly from Stokes vector formalism. In turn Segre's equations of SVF are derived from the AVT equations, demonstrating the equivalence of the AVT and SVF formalisms. Also some practical distinctions between two approaches are pointed out. It is also shown that AVT explicitibly described interaction between Cotton–Mouton and Faraday effect.

  1. Study of HF-induced plasma turbulence by SEE and ISR technique during 2011 HAARP experimental campaign

    Science.gov (United States)

    Grach, Savely; Bernhardt, Paul; Sergeev, Evgeny; Shindin, Alexey; Broughton, Matt; Labelle, James; Bricinsky, Stanley; Mishin, Evgeny; Isham, Brett; Watkins, Brenton

    A concise review of the results of the 20 March - 4 April 2011 experimental campaign at the HAARP heating facility, Gakona, Alaska is presented. The campaign goals were to study the physical processes that determine the interaction of high-power HF radio waves with the F-region ionosphere. The stimulated electromagnetic emission (SEE) observational sites A/B/C were located along the magnetic meridian to the south of the HAARP facility at about 11/83/113 km distant. Site A (B) was nearly under the region during injections at vertical (Magnetic Zenith, MZ). Enhanced plasma line (PL) radar echoes were measured by the modular UHF incoherent scatter radar (MUIR) located at HAARP. Specially designed 'diagnostic' regimes of the pump wave radiation were used to account for the characteristic times of the excitation and fading of the plasma waves (Delta t_w ˜ 1-10 ms) and small-scale field-aligned irregularities (FAI, Delta t_{fai} ˜ 1-10 s). They include mainly (I) alternation low-duty cycles consisting of short (a few Delta t_w) pulses with long (Delta t_{fai}) pauses between them and high duty cycles, i.e. long injection pulses (≫ t_w) with a short pauses of 20-30 ms. The low-duty regime is aimed to study the excited Langmuir turbulence and at to specify the evolution of FAI and their scale-lengths related to different SEE spectral features. The main objective of the high-duty regime is to explore the excitation and fading of upper-hybrid and electron Bernstein plasma waves, with FAI fixed. (II) Concurrent injection of the pump wave f_0 in the regime I, and another wave at a frequency f_1≠q f_0 in the low duty cycle. Since these waves reflect/refract at different altitudes, the altitudinal distribution of FAI can be obtained. (III) Fast (within some seconds) sweeping the pump frequency about electron gyroharmonics s f_c (s=2,3,4) in order to determine the contribution of various nonlinear interaction processes to the excitation of the HF part of the pump

  2. Utility of spatially-resolved atmospheric pressure surface sampling and ionization techniques as alternatives to mass spectrometric imaging (MSI) in drug metabolism.

    Science.gov (United States)

    Blatherwick, Eleanor Q; Van Berkel, Gary J; Pickup, Kathryn; Johansson, Maria K; Beaudoin, Marie-Eve; Cole, Roderic O; Day, Jennifer M; Iverson, Suzanne; Wilson, Ian D; Scrivens, James H; Weston, Daniel J

    2011-08-01

    Tissue distribution studies of drug molecules play an essential role in the pharmaceutical industry and are commonly undertaken using quantitative whole body autoradiography (QWBA) methods. The growing need for complementary methods to address some scientific gaps around radiography methods has led to increased use of mass spectrometric imaging (MSI) technology over the last 5 to 10 years. More recently, the development of novel mass spectrometric techniques for ambient surface sampling has redefined what can be regarded as "fit-for-purpose" for MSI in a drug metabolism and disposition arena. Together with a review of these novel alternatives, this paper details the use of two liquid microjunction (LMJ)-based mass spectrometric surface sampling technologies. These approaches are used to provide qualitative determination of parent drug in rat liver tissue slices using liquid extraction surface analysis (LESA) and to assess the performance of a LMJ surface sampling probe (LMJ-SSP) interface for quantitative assessment of parent drug in brain, liver and muscle tissue slices. An assessment of the utility of these spatially-resolved sampling methods is given, showing interdependence between mass spectrometric and QWBA methods, in particular there emerges a reason to question typical MSI workflows for drug metabolism; suggesting the expedient use of profile or region analysis may be more appropriate, rather than generating time-intensive molecular images of the entire tissue section.

  3. Photon event distribution sampling: an image formation technique for scanning microscopes that permits tracking of sub-diffraction particles with high spatial and temporal resolutions.

    Science.gov (United States)

    Larkin, J D; Publicover, N G; Sutko, J L

    2011-01-01

    In photon event distribution sampling, an image formation technique for scanning microscopes, the maximum likelihood position of origin of each detected photon is acquired as a data set rather than binning photons in pixels. Subsequently, an intensity-related probability density function describing the uncertainty associated with the photon position measurement is applied to each position and individual photon intensity distributions are summed to form an image. Compared to pixel-based images, photon event distribution sampling images exhibit increased signal-to-noise and comparable spatial resolution. Photon event distribution sampling is superior to pixel-based image formation in recognizing the presence of structured (non-random) photon distributions at low photon counts and permits use of non-raster scanning patterns. A photon event distribution sampling based method for localizing single particles derived from a multi-variate normal distribution is more precise than statistical (Gaussian) fitting to pixel-based images. Using the multi-variate normal distribution method, non-raster scanning and a typical confocal microscope, localizations with 8 nm precision were achieved at 10 ms sampling rates with acquisition of ~200 photons per frame. Single nanometre precision was obtained with a greater number of photons per frame. In summary, photon event distribution sampling provides an efficient way to form images when low numbers of photons are involved and permits particle tracking with confocal point-scanning microscopes with nanometre precision deep within specimens. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  4. Utility of spatially-resolved atmospheric pressure surface sampling and ionization techniques as alternatives to mass spectrometric imaging (MSI) in drug metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Blatherwick, Eleanor Q. [University of Warwick, UK; Van Berkel, Gary J [ORNL; Pickup, Kathryn [AstraZeneca R& D Sweden; Johansson, Maria K. [AstraZeneca R& D Sweden; Beaudoin, Marie-Eve [AstraZeneca, USA; Cole, Roderic [ORNL; Day, Jennifer M. [AstraZeneca R& D, UK; Iverson, Suzanne [AstraZeneca R& D Sweden; Wilson, Ian D. [AstraZeneca R& D, UK; Scrivens, James H. [University of Warwick, UK; Weston, Daniel J. [AstraZeneca R& D, UK

    2011-01-01

    1. Tissue distribution studies of drug molecules play an essential role in the pharmaceutical industry and are commonly undertaken using quantitative whole body autoradiography (QWBA) methods. 2. The growing need for complementary methods to address some scientific gaps around radiography methods has led to increased use of mass spectrometric imaging (MSI) technology over the last 5 to 10 years. More recently, the development of novel mass spectrometric techniques for ambient surface sampling has redefined what can be regarded as fit-for-purpose for MSI in a drug metabolism and disposition arena. 3. Together with a review of these novel alternatives, this paper details the use of two liquid microjunction (LMJ)- based mass spectrometric surface sampling technologies. These approaches are used to provide qualitative determination of parent drug in rat liver tissue slices using liquid extraction surface analysis (LESA) and to assess the performance of a LMJ surface sampling probe (LMJ-SSP) interface for quantitative assessment of parent drug in brain, liver and muscle tissue slices. 4. An assessment of the utility of these spatially-resolved sampling methods is given, showing interdependence between mass spectrometric and QWBA methods, in particular there emerges a reason to question typical MSI workflows for drug metabolism; suggesting the expedient use of profile or region analysis may be more appropriate, rather than generating time-intensive molecular images of the entire tissue section.

  5. Vertical and bevel-structured SiC etching techniques incorporating different gas mixture plasmas for various microelectronic applications.

    Science.gov (United States)

    Sung, Ho-Kun; Qiang, Tian; Yao, Zhao; Li, Yang; Wu, Qun; Lee, Hee-Kwan; Park, Bum-Doo; Lim, Woong-Sun; Park, Kyung-Ho; Wang, Cong

    2017-06-20

    This study presents a detailed fabrication method, together with validation, discussion, and analysis, for state-of-the-art silicon carbide (SiC) etching of vertical and bevelled structures by using inductively coupled plasma reactive ion etching (ICP-RIE) for microelectronic applications. Applying different gas mixtures, a maximum bevel angle of 87° (almost vertical), large-angle bevels ranging from 40° to 80°, and small-angel bevels ranging from 7° to 17° were achieved separately using distinct gas mixtures at different ratios. We found that SF6 with additive O2 was effective for vertical etching, with a best etching rate of 3050 Å/min. As for the large-angle bevel structures, BCl3 + N2 gas mixtures show better characteristics, exhibiting a controllable and large etching angle range from 40° to 80° through the adjustment of the mixture ratio. Additionally, a Cl2 + O2 mixture at different ratios is applied to achieve a small-angel bevels ranging from 7° to 17°. A minimum bevel angel of approximately 7° was achieved under the specific volume of 2.4 sccm Cl2 and 3.6 sccm O2. These results can be used to improve performance in various microelectronic applications including MMIC via holes, PIN diodes, Schottky diodes, JFETs' bevel mesa, and avalanche photodiode fabrication.

  6. A new perspective on structural and morphological properties of carbon nanotubes synthesized by Plasma Enhanced Chemical Vapor Deposition technique

    Science.gov (United States)

    Salar Elahi, A.; Agah, K. Mikaili; Ghoranneviss, M.

    CNTs were produced on a silicon wafer by Plasma Enhanced Chemical Vapor Deposition (PECVD) using acetylene as a carbon source, cobalt as a catalyst and ammonia as a reactive gas. The DC-sputtering system was used to prepare cobalt thin films on Si substrates. A series of experiments was carried out to investigate the effects of reaction temperature and deposition time on the synthesis of the nanotubes. The deposition time was selected as 15 and 25 min for all growth temperatures. Energy Dispersive X-ray (EDX) measurements were used to investigate the elemental composition of the Co nanocatalyst deposited on Si substrates. Atomic Force Microscopy (AFM) was used to characterize the surface topography of the Co nanocatalyst deposited on Si substrates. The as-grown CNTs were characterized under Field Emission Scanning Electron Microscopy (FESEM) to study the morphological properties of CNTs. Also, the grown CNTs have been investigated by High Resolution Transmission Electron Microscopy (HRTEM) and Raman spectroscopy. The results demonstrated that increasing the temperature leads to increasing the diameter of CNTs.

  7. Corrosion behavior of amorphous/nanocrystalline Al-Cr-Fe film deposited by double glow plasmas technique

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In order to improve the corrosion resistance of AZ31 magnesium alloy,the amorphous/nanocrystal Al-Cr-Fe film has been successfully prepared on AZ31 magnesium alloy by double glow plasma tech-nology.The amorphous/nanocrystalline consists of two different regions,i.e.,an amorphous layer on outmost surface and an underlying lamellar nanocrystalline layer with a grain size of less than 10 nm.The corrosion behavior of amorphous/nanocrystalline Al-Cr-Fe film in 3.5% NaCl solution is investi-gated using an electrochemical polarization measurement.Compared with the AZ31 magnesium alloy,the amorphous/nanocrystalline Al-Cr-Fe film exhibits more positive corrosion potentials and lower corrosion current densities than that of AZ31 magnesium alloy.XPS measurement reveals that the passive film formed on the Al-Cr-Fe film after the anodic polarization tests is strongly enriched in Cr2O3,Fe2O3 and Al2O3 at outer surface of the film and in the inner layer consists of Cr2O3,FeO and Al2O3.

  8. A Novel Femtosecond-Gated, High-Resolution, Frequency-Shifted Shearing Interferometry Technique for Probing Pre-Plasma Expansion in Ultra-Intense Laser Experiments

    CERN Document Server

    Feister, S; Morrison, J T; Frische, K D; Orban, C; Chowdhury, E A; Roquemore, W M

    2014-01-01

    Ultra-intense laser-matter interaction experiments (>10$^{18}$ W/cm$^{2}$) with dense targets are highly sensitive to the effect of laser "noise" (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-femtosecond time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond p...

  9. Improved Bone Formation in Osteoporotic Rabbits with the Bone Morphogenetic Protein-2 (rhBMP-2 Coated Titanium Screws Which Were Coated By Using Plasma Polymerization Technique

    Directory of Open Access Journals (Sweden)

    Salih Gulsen

    2014-06-01

    Full Text Available Delaying of bone fusion in osteoporotic patients underwent spinal stabilization surgery leads to screw loosening, and this causes pseudoarticulation, mobility and fibrosis at vertebral segments. To prevent these complications, the screws coated with recombinant bone morphogenetic protein-2 (rhBMP-2 could be used. To verify this hypothesis, we coated 5 Titanium screws with rhBMP-2 using plasma polymerization method, and also used 10 uncoated screws for making comparison between coated and uncoated screws in different groups. And 15 skeletally mature white New Zealand female rabbits were assigned into three different groups: Group 1(N = 5: No osteoporosis induction and insertion of uncoated Titanium screw into right sacrum of each rabbit in group 1; group 2 (N = 5: Osteoporosis induction and insertion of uncoated Titanium screw into right sacrum of each rabbit in group 2; group 3 (N = 5 rhBMP-2 coated Titanium screw inserted into right sacrum of each rabbit in group 3. In summary, using of these coated screws provides new bone formation, but causes less fibrosis and less inflammation than uncoated screws at the interface between the coated screw and bone. Then the plasma polymerization technique provides controlled releasing of rhBMP-2 from the screw to the bone tissue in osteoporotic rabbits.

  10. Failure Behavior of Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings Under Three-Point Bending Test via Acoustic Emission Technique

    Science.gov (United States)

    Wang, L.; Ni, J. X.; Shao, F.; Yang, J. S.; Zhong, X. H.; Zhao, H. Y.; Liu, C. G.; Tao, S. Y.; Wang, Y.; Li, D. Y.

    2017-01-01

    In this paper, the failure behavior of plasma-sprayed yttria-stabilized zirconia thermal barrier coatings fabricated by atmospheric plasma spraying (APS-TBCs) under three-point bending (3PB) test has been characterized via acoustic emission (AE) technique. Linear positioning method has been adopted to monitor dynamic failure process of the APS-TBCs under 3PB test. The investigation results indicate that the variation of AE parameters (AE event counts, amplitudes and AE energy) corresponds well with the change of stress-strain curve of the loading processes. The failure mechanism was analyzed based on the characteristics of AE parameters. The distribution of frequency of crack propagation has been obtained. The AE signals came from two aspects: i.e., plastic deformation of substrates, initiation and propagation of the cracks in the coatings. The AE analysis combined with cross-sectional observation has indicated that many critical cracks initiate at the surface of the top-coat. And some main cracks tend to propagate toward the substrate/bond-coat interface. The actual failure mechanism of the APS-TBCs under 3PB test is attributed to the debonding of metallic coating from the substrates and the propagation of the horizontal crack along the substrate/bond-coat interface under the action of flexural moment.

  11. Criticality in Plasma Membranes

    Science.gov (United States)

    Machta, Benjamin; Papanikolaou, Stefanos; Sethna, James; Veatch, Sarah

    2011-03-01

    We are motivated by recent observations of micron-sized critical fluctuations in the 2d Ising Universality class in plasma membrane vesicles that are isolated from cortical cytoskeleton. We construct a minimal model of the plasma membrane's interaction with intact cytoskeleton which explains why large scale phase separation has not been observed in Vivo. In addition, we use analytical techniques from conformal field theory and numerical simulations to investigate the form of effective forces mediated by the membrane's proximity to criticality. We show that the range of this force is maximized near a critical point and we quantify its usefulness in mediating communication using techniques from information theory. Finally we use theoretical techniques from statistical physics in conjunction with Monte-Carlo simulations to understand how criticality can be used to increase the efficiency of membrane bound receptor mediated signaling. We expect that this sort of analysis will be broadly useful in understanding and quantifying the role of lipid ``rafts'' in a wide variety of membrane bound processes. Generally, we demonstrate that critical fluctuations provide a physical mechanism to organize and spatially segregate membrane components by providing channels for interaction over relatively large distances.

  12. Use of a parallel path nebulizer for capillary-based microseparation techniques coupled with an inductively coupled plasma mass spectrometer for speciation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Yanes, Enrique G. E-mail: yanes@bhnrc.usda.gov; Miller-Ihli, Nancy J. E-mail: miller-ihli@bhnrc.usda.gov

    2004-06-18

    A low flow, parallel path Mira Mist CE nebulizer designed for capillary electrophoresis (CE) was evaluated as a function of make-up solution flow rate, composition, and concentration, as well as the nebulizer gas flow rate. This research was conducted in support of a project related to the separation and quantification of cobalamin (vitamin B-12) species using microseparation techniques combined with inductively coupled plasma mass spectrometry (ICP-MS) detection. As such, Co signals were monitored during the nebulizer characterization process. Transient effects in the ICP were studied to evaluate the suitability of using gradients for microseparations and the benefit of using methanol for the make-up solution was demonstrated. Co signal response changed significantly as a function of changing methanol concentrations of the make-up solution and maximum signal enhancement was seen at 20% methanol with a 15 {mu}l/min flow rate. Evaluation of the effect of changing the nebulizer gas flow rates showed that argon flows from 0.8 to 1.2 l/min were equally effective. The Mira Mist CE parallel path nebulizer was then evaluated for interfacing capillary microseparation techniques including capillary electrophoresis (CE) and micro high performance liquid chromatography ({mu}HPLC) to inductively coupled plasma mass spectrometry (ICP-MS). A mixture of four cobalamin species standards (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5' deoxyadenosylcobalamin) and the corrinoid analogue cobinamide dicyanide were successfully separated using both CE-ICP-MS and {mu}HPLC-ICP-MS using the parallel path nebulizer with a make-up solution containing 20% methanol with a flow rate of 15 {mu}l/min.

  13. Use of a parallel path nebulizer for capillary-based microseparation techniques coupled with an inductively coupled plasma mass spectrometer for speciation measurements

    Science.gov (United States)

    Yanes, Enrique G.; Miller-Ihli, Nancy J.

    2004-06-01

    A low flow, parallel path Mira Mist CE nebulizer designed for capillary electrophoresis (CE) was evaluated as a function of make-up solution flow rate, composition, and concentration, as well as the nebulizer gas flow rate. This research was conducted in support of a project related to the separation and quantification of cobalamin (vitamin B-12) species using microseparation techniques combined with inductively coupled plasma mass spectrometry (ICP-MS) detection. As such, Co signals were monitored during the nebulizer characterization process. Transient effects in the ICP were studied to evaluate the suitability of using gradients for microseparations and the benefit of using methanol for the make-up solution was demonstrated. Co signal response changed significantly as a function of changing methanol concentrations of the make-up solution and maximum signal enhancement was seen at 20% methanol with a 15 μl/min flow rate. Evaluation of the effect of changing the nebulizer gas flow rates showed that argon flows from 0.8 to 1.2 l/min were equally effective. The Mira Mist CE parallel path nebulizer was then evaluated for interfacing capillary microseparation techniques including capillary electrophoresis (CE) and micro high performance liquid chromatography (μHPLC) to inductively coupled plasma mass spectrometry (ICP-MS). A mixture of four cobalamin species standards (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5' deoxyadenosylcobalamin) and the corrinoid analogue cobinamide dicyanide were successfully separated using both CE-ICP-MS and μHPLC-ICP-MS using the parallel path nebulizer with a make-up solution containing 20% methanol with a flow rate of 15 μl/min.

  14. Physicochemical characterization of titanium dioxide pigments using various techniques for size determination and asymmetric flow field flow fractionation hyphenated with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Helsper, Johannes P F G; Peters, Ruud J B; van Bemmel, Margaretha E M; Rivera, Zahira E Herrera; Wagner, Stephan; von der Kammer, Frank; Tromp, Peter C; Hofmann, Thilo; Weigel, Stefan

    2016-09-01

    Seven commercial titanium dioxide pigments and two other well-defined TiO2 materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (ICPMS) for chemical characterization. The aF4-ICPMS conditions were optimised and validated for linearity, limit of detection, recovery, repeatability and reproducibility, all indicating good performance. Multi-element detection with aF4-ICPMS showed that some commercial pigments contained zirconium co-eluting with titanium in aF4. The other two TiMs, NM103 and NM104, contained aluminium as integral part of the titanium peak eluting in aF4. The materials were characterised using various size determination techniques: retention time in aF4, aF4 hyphenated with multi-angle laser light spectrometry (MALS), single particle ICPMS (spICPMS), scanning electron microscopy (SEM) and particle tracking analysis (PTA). PTA appeared inappropriate. For the other techniques, size distribution patterns were quite similar, i.e. high polydispersity with diameters from 20 to >700 nm, a modal peak between 200 and 500 nm and a shoulder at 600 nm. Number-based size distribution techniques as spICPMS and SEM showed smaller modal diameters than aF4-UV, from which mass-based diameters are calculated. With aF4-MALS calculated, light-scattering-based "diameters of gyration" (Øg) are similar to hydrodynamic diameters (Øh) from aF4-UV analyses and diameters observed with SEM, but much larger than with spICPMS. A Øg/Øh ratio of about 1 indicates that the TiMs are oblate spheres or fractal aggregates. SEM observations confirm the latter structure. The rationale for differences in modal peak diameter is discussed.

  15. Application of a microwave-based desolvation system for multi-elemental analysis of wine by inductively coupled plasma based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Grindlay, Guillermo [Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, P.O. Box 99, 03080 Alicante (Spain)], E-mail: guillermo.grindlay@ua.es; Mora, Juan; Maestre, Salvador; Gras, Luis [Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, P.O. Box 99, 03080 Alicante (Spain)

    2008-11-23

    Elemental wine analysis is often required from a nutritional, toxicological, origin and authenticity point of view. Inductively coupled plasma based techniques are usually employed for this analysis because of their multi-elemental capabilities and good limits of detection. However, the accurate analysis of wine samples strongly depends on their matrix composition (i.e. salts, ethanol, organic acids) since they lead to both spectral and non-spectral interferences. To mitigate ethanol (up to 10% w/w) related matrix effects in inductively coupled plasma atomic emission spectrometry (ICP-AES), a microwave-based desolvation system (MWDS) can be successfully employed. This finding suggests that the MWDS could be employed for elemental wine analysis. The goal of this work is to evaluate the applicability of the MWDS for elemental wine analysis in ICP-AES and inductively coupled plasma mass spectrometry (ICP-MS). For the sake of comparison a conventional sample introduction system (i.e. pneumatic nebulizer attached to a spray chamber) was employed. Matrix effects, precision, accuracy and analysis throughput have been selected as comparison criteria. For ICP-AES measurements, wine samples can be directly analyzed without any sample treatment (i.e. sample dilution or digestion) using pure aqueous standards although internal standardization (IS) (i.e. Sc) is required. The behaviour of the MWDS operating with organic solutions in ICP-MS has been characterized for the first time. In this technique the MWDS has shown its efficiency to mitigate ethanol related matrix effects up to concentrations of 1% (w/w). Therefore, wine samples must be diluted to reduce the ethanol concentration up to this value. The results obtained have shown that the MWDS is a powerful device for the elemental analysis of wine samples in both ICP-AES and ICP-MS. In general, the MWDS has some attractive advantages for elemental wine analysis when compared to a conventional sample introduction system such

  16. Vibrational Spectroscopic Techniques for Analysis of Spatially Heterogeneous Materials%共振光谱技术在分析空间非均质物质上的应用

    Institute of Scientific and Technical Information of China (English)

    Eric; Y.Jiang; Forrest; J.; Weesener

    2005-01-01

    @@ This paper demonstrates three vibrational spectroscopic techniques andtheir applications in characterization of spatially heterogamous materials, namely step-scan phase modulation FTIR photoacoustic spectroscopy (S2φMPAS), visible (confocal) Raman microscopy (CRM) and FT-IR imaging. In addition, the applications of Raman spectroscopy in nanomaterials studies are also briefly discussed.

  17. Spatial Data Management

    CERN Document Server

    Mamoulis, Nikos

    2011-01-01

    Spatial database management deals with the storage, indexing, and querying of data with spatial features, such as location and geometric extent. Many applications require the efficient management of spatial data, including Geographic Information Systems, Computer Aided Design, and Location Based Services. The goal of this book is to provide the reader with an overview of spatial data management technology, with an emphasis on indexing and search techniques. It first introduces spatial data models and queries and discusses the main issues of extending a database system to support spatial data.

  18. High spatial resolution analysis of Pb and U isotopes for geochronology by laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS)

    National Research Council Canada - National Science Library

    Bühn, Bernhard; Pimentel, Márcio M; Matteini, Massimo; Dantas, Elton L

    2009-01-01

    ...), are widely used to decipher geological processes. A new method developed in the last couple of years, the laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS...

  19. Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique.

    Science.gov (United States)

    Kim, D H; McLeod, K R; Koontz, A F; Foote, A P; Klotz, J L; Harmon, D L

    2015-01-01

    The objective was to investigate the effect of intake before fasting on concentrations of metabolites and hormones, respiratory quotient (RQ) and fasting heat production (HP) using the washed rumen technique and to compare these values with those from the fed state. Six Holstein steers (360±22 kg) were maintained at 21°C and fed three different energy intakes within a replicated 3×3 Latin square design with 21-day periods. Steers were fed alfalfa cubes to provide 1.0, 1.5 and 2.0×NEm during 19 days of each experimental period. Steers were placed in individual metabolism stalls fitted with indirect calorimetry head-boxes on day 20 of each experimental period (FED steers) and fed their normal meal. On day 21 of each period the reticulorumen was emptied, washed and refilled with ruminal buffer (NaCl=96; NaHCO3=24; KHCO3=30; K2HPO4=2; CaCl2=1.5; MgCl2=1.5 mmol/kg of buffer) aerated with 75% N2 and 25% CO2 before introduction to the rumen (steers were not fed; WASHED steers). Each gas exchange was measured over 24 h. HP for 1.0, 1.5 and 2.0×NEm were 479, 597 and 714 kJ/daykg0.75 (s.e.m. =16), respectively. The plateau RQ was 0.756, 0.824 and 0.860 for the 1.0, 1.5 and 2.0×NEm intakes for the FED steers, respectively. After rumen washing, fasting HP was 331, 359 and 400 kJ/daykg0.75 (s.e.m.=13) for 1.0, 1.5, and 2.0×NEm intakes before fasting, respectively. The RQ for WASHED rumen steers was 0.717, 0.710 and 0.719, respectively. Cortisol and β-hydroxybutyrate concentrations in WASHED rumen steers did not exceed threshold levels for severe energy deficit and stress as can be induced from prolonged fasting. This study demonstrates that a fasting state can be emulated using the washed rumen technique, minimizing the time required as opposed to traditional fasting methodologies, without causing a severe energy deficit and stress.

  20. An ultra-clean technique for accurately analysing Pb isotopes and heavy metals at high spatial resolution in ice cores with sub-pg g(-1) Pb concentrations.

    Science.gov (United States)

    Burn, Laurie J; Rosman, Kevin J R; Candelone, Jean-Pierre; Vallelonga, Paul; Burton, Graeme R; Smith, Andrew M; Morgan, Vin I; Barbante, Carlo; Hong, Sungmin; Boutron, Claude F

    2009-02-23

    Measurements of Pb isotope ratios in ice containing sub-pg g(-1) concentrations are easily compromised by contamination, particularly where limited sample is available. Improved techniques are essential if Antarctic ice cores are to be analysed with sufficient spatial resolution to reveal seasonal variations due to climate. This was achieved here by using stainless steel chisels and saws and strict protocols in an ultra-clean cold room to decontaminate and section ice cores. Artificial ice cores, prepared from high purity water were used to develop and refine the procedures and quantify blanks. Ba and In, two other important elements present at pg g(-1) and fg g(-1) concentrations in Polar ice, were also measured. The final blank amounted to 0.2+/-0.2 pg of Pb with (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of 1.16+/-0.12 and 2.35+/-0.16, respectively, 1.5+/-0.4 pg of Ba and 0.6+/-2.0 fg of In, most of which probably originates from abrasion of the steel saws by the ice. The procedure was demonstrated on a Holocene Antarctic ice core section and was shown to contribute blanks of only approximately 5%, approximately 14% and approximately 0.8% to monthly resolved samples with respective Pb, Ba and In concentrations of 0.12 pg g(-1), 0.3 pg g(-1) and 2.3 fg g(-1). Uncertainties in the Pb isotopic ratio measurements were degraded by only approximately 0.2%.

  1. Compact collimated fiber optic array diagnostic for railgun plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tang, V; Solberg, J; Ferriera, T; Tully, L; Stephan, P

    2008-10-02

    We have developed and tested a compact collimated sixteen channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with {approx}mm spatial and sub-{micro}s temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore Fixed Hybrid Armature experiment are presented and compared with 1-D simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  2. Compact collimated fiber optic array diagnostic for railgun plasmas.

    Science.gov (United States)

    Tang, V; Solberg, J M; Ferriera, T J; Tully, L K; Stephan, P L

    2009-01-01

    We developed and tested a compact collimated 16 channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with approximately millimeter spatial and submicrosecond temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore fixed hybrid armature experiment are presented and compared with one-dimensional simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  3. Study of optoelectronic properties of thin film solar cell materials Cu2ZnSn(S,Se)4 using multiple correlative spatially-resolved spectroscopy techniques

    Science.gov (United States)

    Chen, Qiong

    Containing only earth abundant and environmental friendly elements, quaternary compounds Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe 4 (CZTSe) are considered as promising absorber materials for thin film solar cells. The best record efficiency for this type of thin film solar cell is now 12.6%. As a promising photovoltaic (PV) material, the electrical and optical properties of CZTS(Se) have not been well studied. In this work, an effort has been made to understand the optoelectronic and structural properties, in particular the spatial variations, of CZTS(Se) materials and devices by correlating multiple spatially resolved characterization techniques with sub-micron resolution. Micro-Raman (micro-Raman) spectroscopy was used to analyze the chemistry compositions in CZTS(Se) film; Micro-Photoluminescence (micro-PL) was used to determine the band gap and possible defects. Micro-Laser-Beam-Induced-Current (micro-LBIC) was used to examine the photo-response of CZTS(Se) solar cell in different illumination conditions. Micro-reflectance was used to estimate the reflectance loss. And Micro-I-V measurement was used to compare important electrical parameters from CZTS(Se) solar cells with different device structure or absorber compositions. Scanning electron microscopy and atomic force microscopy were used to characterize the surface morphology. Successfully integrating and correlating these techniques was first demonstrated during the course of this work in our laboratory, and this level of integration and correlation has been rare in the field of PV research. This effort is significant not only for this particular project and also for a wide range of research topics. Applying this approach, in conjunction with high-temperature and high-excitation-power optical spectroscopy, we have been able to reveal the microscopic scale variations among samples and devices that appeared to be very similar from macroscopic material and device characterizations, and thus serve as a very powerful tool

  4. Flow-injection technique for determination of uranium and thorium isotopes in urine by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Benkhedda, Karima; Epov, Vladimir N; Evans, R Douglas

    2005-04-01

    A sensitive and efficient flow-injection (FI) preconcentration and matrix-separation technique coupled to sector field ICP-mass spectrometry (SF-ICP-MS) has been developed and validated for simultaneous determination of ultra-low levels of uranium (U) and thorium (Th) in human urine. The method is based on selective retention of U and Th from a urine matrix, after microwave digestion, on an extraction chromatographic TRU resin, as an alternative to U/TEVA resin, and their subsequent elution with ammonium oxalate. Using a 10 mL sample, the limits of detection achieved for 238U and 232Th were 0.02 and 0.03 ng L(-1), respectively. The accuracy of the method was checked by spike-recovery measurements. Levels of U and Th in human urine were found to be in the ranges 1.86-5.50 and 0.176-2.35 ng L(-1), respectively, well in agreement with levels considered normal for non-occupationally exposed persons. The precision obtained for five replicate measurements of a urine sample was 2 and 3% for U and Th, respectively. The method also enables on-line measurements of the 235U/238U isotope ratios in urine. Precision of 0.82-1.04% (RSD) was obtained for 235U/238U at low ng L(-1) levels, using the FI transient signal approach.

  5. Development of the gas puff charge exchange recombination spectroscopy (GP-CXRS) technique for ion measurements in the plasma edge

    Energy Technology Data Exchange (ETDEWEB)

    Churchill, R. M.; Theiler, C.; Lipschultz, B. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Dux, R.; Pütterich, T.; Viezzer, E. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Collaboration: Alcator C-Mod Team; ASDEX Upgrade Team

    2013-09-15

    A novel charge-exchange recombination spectroscopy (CXRS) diagnostic method is presented, which uses a simple thermal gas puff for its donor neutral source, instead of the typical high-energy neutral beam. This diagnostic, named gas puff CXRS (GP-CXRS), is used to measure ion density, velocity, and temperature in the tokamak edge/pedestal region with excellent signal-background ratios, and has a number of advantages to conventional beam-based CXRS systems. Here we develop the physics basis for GP-CXRS, including the neutral transport, the charge-exchange process at low energies, and effects of energy-dependent rate coefficients on the measurements. The GP-CXRS hardware setup is described on two separate tokamaks, Alcator C-Mod and ASDEX Upgrade. Measured spectra and profiles are also presented. Profile comparisons of GP-CXRS and a beam based CXRS system show good agreement. Emphasis is given throughout to describing guiding principles for users interested in applying the GP-CXRS diagnostic technique.

  6. Novel bioimaging techniques of metals by laser ablation inductively coupled plasma mass spectrometry for diagnosis of fibrotic and cirrhotic liver disorders.

    Directory of Open Access Journals (Sweden)

    Pornwilard M-M

    Full Text Available BACKGROUND AND AIMS: Hereditary disorders associated with metal overload or unwanted toxic accumulation of heavy metals can lead to morbidity and mortality. Patients with hereditary hemochromatosis or Wilson disease for example may develop severe hepatic pathology including fibrosis, cirrhosis or hepatocellular carcinoma. While relevant disease genes are identified and genetic testing is applicable, liver biopsy in combination with metal detecting techniques such as energy-dispersive X-ray spectroscopy (EDX is still applied for accurate diagnosis of metals. Vice versa, several metals are needed in trace amounts for carrying out vital functions and their deficiency due to rapid growth, pregnancy, excessive blood loss, and insufficient nutritional or digestive uptake results in organic and systemic shortcomings. Established in situ techniques, such as EDX-ray spectroscopy, are not sensitive enough to analyze trace metal distribution and the quantification of metal images is difficult. METHODS: In this study, we developed a quantitative biometal imaging technique of human liver tissue by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS in order to compare the distribution of selected metals in cryo-sections of healthy and fibrotic/cirrhotic livers. RESULTS: Most of the metals are homogeneous distributed within the normal tissue, while they are redirected within fibrotic livers resulting in significant metal deposits. Moreover, total iron and copper concentrations in diseased liver were found about 3-5 times higher than in normal liver samples. CONCLUSIONS: Biometal imaging via LA-ICP-MS is a sensitive innovative diagnostic tool that will impact clinical practice in identification and evaluation of hepatic metal disorders and to detect subtle metal variations during ongoing hepatic fibrogenesis.

  7. A procedure for estimating the electron temperature and the departure of the LTE condition in a time-dependent, spatially homogeneous, optically thin plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bredice, F. [Centro de Investigaciones Opticas, La Plata (Argentina); Borges, F.O., E-mail: borges@if.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Fisica. Lab. de Plasma e Espectroscopia; Di Rocco, H.O. [Instituto de Fisica Arroyo Seco (IFAS), Universidad Nacional del Centro, Tandil (Argentina); Mercado, R.S. [Grupo de Espectroscopia Optica de Emision y Laser (GEOEL), Universidad del Atlantico, Barranquilla (Colombia); Villagran-Muniz, M. [Laboratorio de Fotofisica, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Palleschi, V. [Applied Laser Spectroscopy Laboratory, ICCOM-CNR, Pisa (Italy)

    2013-08-15

    We present a method to estimate the temperature of transient plasmas and their degree of departure from local thermodynamic equilibrium conditions. Our method is based on application of the Saha–Boltzmann equations on the temporal variation of the intensity of the spectral lines of the plasma, under the assumption that the plasmas at the different times when the spectra were obtained are in local thermodynamic equilibrium. The method requires no knowledge of the spectral efficiency of the spectrometer/detector, transition probabilities of the considered lines, or degeneracies of the upper and lower levels. Provided that the conditions of optically thin, homogeneous plasma in local thermodynamic equilibrium are satisfied, the accuracy of the procedure is limited only by the precision with which the line intensities and densities can be determined at two different temperatures. The procedure generates an equation describing the temporal evolution of the electron number density of transient plasmas under local thermodynamic equilibrium conditions. The method is applied to the analysis of two laser-induced breakdown spectra of cadmium at different temperatures. (author)

  8. Preliminary Report on the Spatial Distribution and Sampling Techniques of Phragmites communis in Wheat Fields%麦田芦苇空间分布型及抽样技术初报

    Institute of Scientific and Technical Information of China (English)

    刘楚彬; 章辉; 孟祥民; 耿军; 宋爱颖

    2013-01-01

    Spatial distribution and sampling techniques of Phragmites communis in wheat fields were studied.This weed has an aggregated spatial distribution with individual distribution group as basic components.Aggregation intensity increases with the increase of weed density.%对麦田中芦苇的空间分布型及抽样技术进行了调查,结果表明,芦苇的空间分布为聚集分布,分布的基本成分是个体群,且聚集强度随着杂草密度的增加而增强.

  9. 多层等离子体蚀刻技术的研究%Novel Technique for Multi-Partitioned Plasma Etching

    Institute of Scientific and Technical Information of China (English)

    于斌斌; 袁军堂; 汪振华; 薛志松; 黄云林

    2013-01-01

    A novel technique, tnulti-partitioned plasma etching, was developed to simultaneously etch GaN wafers with reactive ion beams in the multi-partitioned reactor. In the newly-developed technique, the vacuum chamber was divided into multiple partitions (three or more partitions) ,each of which acts as a separate plasma etching unit, with its own gas inlet,sample holder,and electrodes.The etching capacity was considerably scaled up.The photo-resist was dry etched with the lab-built,multi-partition etching setup.The impacts of the etching conditions,including the pressure,geometry of the partition, ratio of oxygen and argon flow rates, etc. on the etching rate were experimentally evaluated. The results show the average etching rate and uniformity can be up to 14.395 nm/min and 9.8% ,respectively,under the optimized condi-tions:a pressure of 40 Pa,a RF power of 600 W,an O2/Ar ratio of 1/2;a continuous etching time of 20 min in the three partitions with the bottom-up separations of 50,55 and 60 mm.%干法刻蚀现已成为微小高深宽比结构加工与微细图形制作的重要手段.提出了一种新的干法刻蚀技术一多层等离子体蚀刻,充分利用腔体的空间布局,布置多层电极,并采用分层送气装置输送放电气体,实现多层同时进行刻蚀,可成倍提高产能.采用该技术刻蚀光阻为例,从空间与时间两个角度分析了工艺参数对刻蚀速率与均匀性的影响规律与作用机理.实验结果表明,极板间距为50/55/60mm(由下向上),工作压力为40Pa,R[O2:Ar]为1/2,RF功率为600W时,整炉次刻蚀速率均值为14.395nm/min,均匀性为9.8%,此时工艺最为合理.

  10. Laser Induced Breakdown Spectroscopy compared with conventional plasma optical emission techniques for the analysis of metals - A review of applications and analytical performance

    Science.gov (United States)

    Bengtson, A.

    2017-08-01

    This review is focused on a comparison of LIBS with the two most common plasma Optical Emission Spectroscopy (OES) techniques for analysis of metals; spark OES and glow discharge (GD) OES. It is shown that these two techniques have only minor differences in analytical performance. An important part of the paper reviews a direct comparison of the analytical figures of merit for bulk analysis of steels using spark and LIBS sources. The comparison was carried out using one instrument with interchangeable sources, eliminating differences related to the optical system and detectors. It was found that the spark provides slightly better analytical figures of merit. The spark analysis is considerably faster, the simple design of the spark stand has enabled complete automation, both properties of great importance in the metallurgical industry for routine analysis. The analysis of non-metallic inclusions (NMI) with spark and LIBS is presented, in the case of the spark this has become known as Pulse Distribution Analysis (PDA). A very significant difference between the techniques is that the electrical spark typically evaporates 100 times more material than a single laser pulse, resulting in complete evaporation of an NMI present in the evaporated metal. The major advantage of LIBS is that it is localised with very good lateral resolution. The major advantages of spark is that it is much faster (can be done simultaneous with the bulk analysis) and easier to quantify. Compositional Depth Profiling (CDP) is compared for GD-OES and LIBS. It is shown that for applications where GD-OES is well suited, e.g. coated metallic sheet, GD-OES still performs slightly better than LIBS. Similar to the case of NMI analysis, the major advantage of LIBS is the great lateral resolution. This allows elemental surface mapping, as well as CDP of very small areas on μm scale. One further advantage of LIBS is that samples of almost any material, shape and size can be analysed, whereas GD-OES has

  11. Novel Prospects for Plasma Spray-Physical Vapor Deposition of Columnar Thermal Barrier Coatings

    Science.gov (United States)

    Anwaar, Aleem; Wei, Lianglinag; Guo, Qian; Zhang, Baopeng; Guo, Hongbo

    2017-09-01

    Plasma spray-physical vapor deposition (PS-PVD) is an emerging coating technique that can produce columnar thermal barrier coatings from vapor phase. Feedstock treatment at the start of its trajectory in the plasma torch nozzle is important for such vapor-phase deposition. This study describes the effects of the plasma composition (Ar/He) on the plasma characteristics, plasma-particle interaction, and particle dynamics at different points spatially distributed inside the plasma torch nozzle. The results of calculations show that increasing the fraction of argon in the plasma gas mixture enhances the momentum and heat flow between the plasma and injected feedstock. For the plasma gas combination of 45Ar/45He, the total enthalpy transferred to a representative powder particle inside the plasma torch nozzle is highest ( 9828 kJ/kg). Moreover, due to the properties of the plasma, the contribution of the cylindrical throat, i.e., from the feed injection point (FIP) to the start of divergence (SOD), to the total transferred energy is 69%. The carrier gas flow for different plasma gas mixtures was also investigated by optical emission spectroscopy (OES) measurements of zirconium emissions. Yttria-stabilized zirconia (YSZ) coating microstructures were produced when using selected plasma gas compositions and corresponding carrier gas flows; structural morphologies were found to be in good agreement with OES and theoretical predictions. Quasicolumnar microstructure was obtained with porosity of 15% when applying the plasma composition of 45Ar/45He.

  12. Collaborative study for establishment of a European Pharmacopoei Biological Reference Preparation (BRP) for B19 virus DNA testing of plasma pools by nucleic acid amplification technique.

    Science.gov (United States)

    Nübling, C M; Daas, A; Buchheit, K H

    2004-01-01

    The goal of the collaborative study was to calibrate the B19 DNA content of a candidate Biological Reference Preparation (BRP) that is intended to be used for the validation of the analytical procedure, as threshold control and/or as quantitative reference material in the Nucleic Acid Amplification Technique (NAT) test of plasma pools for detection of B19 contamination. The candidate BRP was calibrated against the 1st International Standard for B19 DNA NAT assays. According to the European Pharmacopoeia monograph Human anti-D immunoglobulin, the threshold control needs to have a titre of 10( 4) IU/ml of B19 virus DNA. The lyophilised candidate BRP was prepared from 0.5 ml aliquots of a plasma pool spiked with B19 virus. The B19 virus originated from a "B19 virus window phase" blood donation (anti-B19 negative, B19-DNA high titre positive) and was diluted in a plasma pool tested negative by both serological and NAT assays for Hepatitis B Virus, Hepatitis C Virus and Human Immunodeficiency Virus 1 to obtain a B19-DNA concentration level in the range of 10( 6) copies/ml. The residual water content of the lyophilised candidate BRP was determined as 0.98 +/- 0.65% (mean +/- relative standard deviation). Sixteen laboratories (Official Medicine Control Laboratories, manufacturers of plasma derivatives, NAT test laboratories and NAT kit manufacturers) from nine countries participated. Participants were requested to test the candidate BRP and the International Standard (99/800) in four independent test runs on different days using their in-house qualitative and/or quantitative NAT methods. Sixteen laboratories reported results. Thirteen laboratories reported results from qualitative assays and 5 laboratories reported results from quantitative assays. Two laboratories reported results from both types of assay. For the qualitative assays a weighted combined potency of 5.64 log( 10) IU/ml with 95 per cent confidence limits of +/- 0.17 log( 10) which corresponds to 67 to 150

  13. Effect of fish oil on lateral mobility of prostaglandin F2α (FP) receptors and spatial distribution of lipid microdomains in bovine luteal cell plasma membrane in vitro.

    Science.gov (United States)

    Plewes, M R; Burns, P D; Graham, P E; Hyslop, R M; Barisas, B G

    2017-01-01

    Lipid microdomains are ordered regions on the plasma membrane of cells, rich in cholesterol and sphingolipids, ranging in size from 10 to 200 nm in diameter. These lipid-ordered domains may serve as platforms to facilitate colocalization of intracellular signaling proteins during agonist-induced signal transduction. It is hypothesized that fish oil will disrupt the lipid microdomains, increasing spatial distribution of these lipid-ordered domains and lateral mobility of the prostaglandin (PG) F2α (FP) receptors in bovine luteal cells. The objectives of this study were to examine the effects of fish oil on (1) the spatial distribution of lipid microdomains, (2) lateral mobility of FP receptors, and (3) lateral mobility of FP receptors in the presence of PGF2α on the plasma membrane of bovine luteal cells in vitro. Bovine ovaries were obtained from a local abattoir and corpora lutea were digested using collagenase. In experiment 1, lipid microdomains were labeled using cholera toxin subunit B Alexa Fluor 555. Domains were detected as distinct patches on the plasma membrane of mixed luteal cells. Fish oil treatment decreased fluorescent intensity in a dose-dependent manner (P oil treatment on lateral mobility of FP receptors. Fish oil treatment increased microdiffusion and macrodiffusion coefficients of FP receptors as compared to control cells (P oil-treated cells (P oil treatment. Lateral mobility of receptors was decreased within 5 min following the addition of ligand for control cells (P oil-treated cells (P > 0.10). The data presented provide strong evidence that fish oil causes a disruption in lipid microdomains and affects lateral mobility of FP receptors in the absence and presence of PGF2α.

  14. Spatial planning

    OpenAIRE

    Dimitrov, Nikola; Koteski, Cane

    2016-01-01

    The professional book ,, Space planning "processed chapters on: space, concept and definition of space, space as a system, spatial economics, economic essence of space, space planning, social determinants of spatial planning, spatial planning as a process, factors development and elements in spatial planning, methodology, components and content of spatial planning stages and types of preparation of spatial planning, spatial planning and industrialization, industrialization, urbanization and s...

  15. Spatial planning

    OpenAIRE

    Dimitrov, Nikola; Koteski, Cane

    2016-01-01

    The professional book ,, Space planning "processed chapters on: space, concept and definition of space, space as a system, spatial economics, economic essence of space, space planning, social determinants of spatial planning, spatial planning as a process, factors development and elements in spatial planning, methodology, components and content of spatial planning stages and types of preparation of spatial planning, spatial planning and industrialization, industrialization, urbanization and s...

  16. Radiation properties and hydrodynamics evolution of highly charged ions in laser-produced silicon plasma.

    Science.gov (United States)

    Min, Qi; Su, Maogen; Cao, Shiquan; Sun, Duixiong; O'Sullivan, Gerry; Dong, Chenzhong

    2016-11-15

    We present a simplified radiation hydrodynamic model based on the fluid dynamic equations and the radiative transfer equation, which can be used to investigate the radiation properties and dynamics evolution of highly charged ions in a laser-produced plasma in vacuum. The outputs of the model consist of the evolution of the electron temperature, atom, and ion density, and the temporal and spatial evolution of various transient particles in plasma, as well as the simulated spectrum related to certain experimental conditions in a specified spectral window. In order to test the model and provide valuable experimental feedback, a series of EUV emission spectra of silicon plasmas have been measured using the spatio-temporally resolved laser produced plasma technique. The temporal and spatial evolution of the plasma is reliably reconstructed by using this model.

  17. Nonthermal plasma chemistry and physics

    CERN Document Server

    Meichsner, Jurgen; Schneider, Ralf; Wagner, Hans-Erich

    2013-01-01

    In addition to introducing the basics of plasma physics, Nonthermal Plasma Chemistry and Physics is a comprehensive presentation of recent developments in the rapidly growing field of nonthermal plasma chemistry. The book offers a detailed discussion of the fundamentals of plasma chemical reactions and modeling, nonthermal plasma sources, relevant diagnostic techniques, and selected applications.Elucidating interconnections and trends, the book focuses on basic principles and illustrations across a broad field of applications. Expert contributors address environmental aspects of plasma chemist

  18. Plasma diagnostics discharge parameters and chemistry

    CERN Document Server

    Auciello, Orlando

    1989-01-01

    Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

  19. Electron waves and resonances in bounded plasmas

    CERN Document Server

    Vandenplas, Paul E

    1968-01-01

    General theoretical methods and experimental techniques ; the uniform plasma slab-condenser system ; the hollow cylindrical plasma ; scattering of a plane electromagnetic wave by a plasma column in steady magnetic fields (cold plasma approximation) ; hot non-uniform plasma column ; metallic and dielectric resonance probes, plasma-dielectric coated antenna, general considerations.

  20. Mangrove vulnerability modelling in parts of Western Niger Delta, Nigeria using satellite images, GIS techniques and Spatial Multi-Criteria Analysis (SMCA).

    Science.gov (United States)

    Omo-Irabor, Omo O; Olobaniyi, Samuel B; Akunna, Joe; Venus, Valentijn; Maina, Joseph M; Paradzayi, Charles

    2011-07-01

    Mangroves are known for their global environmental and socioeconomic value. Despite their importance, mangrove like other ecosystems is now being threatened by natural and human-induced processes that damage them at alarming rates, thereby diminishing the limited number of existing mangrove vegetation. The development of a spatial vulnerability assessment model that takes into consideration environmental and socioeconomic criteria, in spatial and non-spatial formats has been attempted in this study. According to the model, 11 different input parameters are required in modelling mangrove vulnerability. These parameters and their effects on mangrove vulnerability were selected and weighted by experts in the related fields. Criteria identification and selection were mainly based on effects of environmental and socioeconomic changes associated with mangrove survival. The results obtained revealed the dominance of socioeconomic criteria such as population pressure and deforestation, with high vulnerability index of 0.75. The environmental criteria was broadly dispersed in the study area and represents vulnerability indices ranging from 0.00-0.75. This category reflects the greater influence of pollutant input from oil wells and pipelines and minimal contribution from climatic factors. This project has integrated spatial management framework for mangrove vulnerability assessment that utilises information technology in conjunction with expert knowledge and multi-criteria analysis to aid planners and policy/ decision makers in the protection of this very fragile ecosystem.

  1. Reliability of the two-point measurement of the spatial correlation length from Gaussian-shaped fluctuating signals in fusion-grade plasmas

    CERN Document Server

    Kim, Jaewook; Lampert, M; Ghim, Y -c

    2016-01-01

    A statistical method for the estimation of spatial correlation lengths of Gaussian-shaped fluctuating signals with two measurement points is examined to quantitatively evaluate its reliability (variance) and accuracy (bias error). The standard deviation of the correlation value is analytically derived for randomly distributed Gaussian shaped fluctuations satisfying stationarity and homogeneity, allowing us to evaluate, as a function of fluctuation-to-noise ratios, sizes of averaging time windows and ratios of the distance between the two measurement points to the true correlation length, the goodness of the two-point measurement for estimating the spatial correlation length. Analytic results are confirmed with numerically generated synthetic data and real experimental data obtained with the KSTAR beam emission spectroscopy diagnostic. Our results can be applied to Gaussian-shaped fluctuating signals where a correlation length must be measured with only two measurement points.

  2. Reliability of the two-point measurement of the spatial correlation length from Gaussian-shaped fluctuating signals in fusion-grade plasmas

    Science.gov (United States)

    Kim, Jaewook; Nam, Y. U.; Lampert, M.; Ghim, Y.-C.

    2016-10-01

    A statistical method for the estimation of the spatial correlation lengths of Gaussian-shaped fluctuating signals with two measurement points is examined to quantitatively evaluate its reliability (variance) and accuracy (bias error). The standard deviation of the correlation value is analytically derived for randomly distributed Gaussian shaped fluctuations satisfying stationarity and homogeneity, allowing us to evaluate, as a function of fluctuation-to-noise ratios, the sizes of averaging time windows and the ratios of the distance between the two measurement points to the true correlation length, and the goodness of the two-point measurement for estimating the spatial correlation length. Analytic results are confirmed with numerically generated synthetic data and real experimental data obtained with the KSTAR beam emission spectroscopy diagnostic. Our results can be applied to Gaussian-shaped fluctuating signals where a correlation length must be measured with only two measurement points.

  3. Elements of plasma technology

    CERN Document Server

    Wong, Chiow San

    2016-01-01

    This book presents some fundamental aspects of plasma technology that are important for beginners interested to start research in the area of plasma technology . These include the properties of plasma, methods of plasma generation and basic plasma diagnostic techniques. It also discusses several low cost plasma devices, including pulsed plasma sources such as plasma focus, pulsed capillary discharge, vacuum spark and exploding wire; as well as low temperature plasmas such as glow discharge and dielectric barrier discharge which the authors believe may have potential applications in industry. The treatments are experimental rather than theoretical, although some theoretical background is provided where appropriate. The principles of operation of these devices are also reviewed and discussed.

  4. Direct analysis of ultra-trace semiconductor gas by inductively coupled plasma mass spectrometry coupled with gas to particle conversion-gas exchange technique.

    Science.gov (United States)

    Ohata, Masaki; Sakurai, Hiromu; Nishiguchi, Kohei; Utani, Keisuke; Günther, Detlef

    2015-09-01

    An inductively coupled plasma mass spectrometry (ICPMS) coupled with gas to particle conversion-gas exchange technique was applied to the direct analysis of ultra-trace semiconductor gas in ambient air. The ultra-trace semiconductor gases such as arsine (AsH3) and phosphine (PH3) were converted to particles by reaction with ozone (O3) and ammonia (NH3) gases within a gas to particle conversion device (GPD). The converted particles were directly introduced and measured by ICPMS through a gas exchange device (GED), which could penetrate the particles as well as exchange to Ar from either non-reacted gases such as an air or remaining gases of O3 and NH3. The particle size distribution of converted particles was measured by scanning mobility particle sizer (SMPS) and the results supported the elucidation of particle agglomeration between the particle converted from semiconductor gas and the particle of ammonium nitrate (NH4NO3) which was produced as major particle in GPD. Stable time-resolved signals from AsH3 and PH3 in air were obtained by GPD-GED-ICPMS with continuous gas introduction; however, the slightly larger fluctuation, which could be due to the ionization fluctuation of particles in ICP, was observed compared to that of metal carbonyl gas in Ar introduced directly into ICPMS. The linear regression lines were obtained and the limits of detection (LODs) of 1.5 pL L(-1) and 2.4 nL L(-1) for AsH3 and PH3, respectively, were estimated. Since these LODs revealed sufficiently lower values than the measurement concentrations required from semiconductor industry such as 0.5 nL L(-1) and 30 nL L(-1) for AsH3 and PH3, respectively, the GPD-GED-ICPMS could be useful for direct and high sensitive analysis of ultra-trace semiconductor gas in air.

  5. Electrochemical behavior of TiAlSiN hard coatings synthesized by a multi-plasma immersion ion implantation and deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gengzhu [University of Science and Technology Liaoning, Anshan 114051 (China); Xie, Zhiwen, E-mail: xzw@cigit.ac.cn [University of Science and Technology Liaoning, Anshan 114051 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Chen, Tian [Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Chen, Zhenyu [Key Laboratory of Power Sources, Institute of Power Sources, Tianjin 300381 (China); Song, Xiaohang [Shanghai Aerospace Equipments Manufacturer, Shanghai 401122 (China); Gao, Xu; Yu, Xiaoguang; Song, Hua [University of Science and Technology Liaoning, Anshan 114051 (China)

    2015-06-01

    The TiAlSiN coatings are synthesized by a multi-plasma immersion ion implantation and deposition technique. The microstructure and the electrochemical behavior of the as-deposited coatings are investigated by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and electrochemical tests. These studies reveal that huge lattice distortions and dislocations emerge in the coating after introducing a small amount of Al component. These structural defects can facilitate the corrosion process of the TiAlN coating. The TiAlN coating exhibits a worse corrosion resistance performance than the TiN coating. The TiAlSiN coating has a two phase microstructure, nc-TiAlN/a-Si{sub 3}N{sub 4.} The grain size is greatly reduced after introducing Si component, whereas the portion of the a-Si{sub 3}N{sub 4} phase increases as the amount of Si increases in the coating. The reduced grain size and the increased percentage of the a-Si{sub 3}N{sub 4} phase in the TiAlSiN coatings enhance their ability in corrosion resistance. The TiAlSiN coating with a larger amount of Si shows better corrosion resistance performance. This research provides a comprehensive understanding of the relationship between the microstructure and the electrochemical behavior of the TiAlSiN hard coatings. - Highlights: • Microstructure and electrochemical behavior of TiAlSiN coatings are presented. • Al addition induces serious lattice distortions and dislocations. • Si incorporation induces an obvious grain refinement effect. • TiAlN coating shows a higher corrosion rate than the TiN coating. • TiAlSiN coating with higher Si content shows better corrosion resistance.

  6. Progress in spatial analysis methods and applications

    CERN Document Server

    Páez, Antonio; Buliung, Ron N; Dall'erba, Sandy

    2010-01-01

    This book brings together developments in spatial analysis techniques, including spatial statistics, econometrics, and spatial visualization, and applications to fields such as regional studies, transportation and land use, population and health.

  7. The Plasma Chemistry of Polymer Surfaces

    CERN Document Server

    Friedrich, Jö

    2012-01-01

    This book illustrates plasma properties, polymer characteristics, surface specifics, and how to purposefully combine plasma and polymer chemistry. In so doing, it covers plasma polymerization, surface functionalization, etching, crosslinking, and deposition of monotype functional-group-bearing plasma polymers. It explains different techniques and plasma types, such as pressure-pulsed, remote, low-wattage plasmas and plasma polymerization in liquids. Finally, among the numerous applications discussed are plasmas for chemical synthesis, industrial processes or the modification of membranes and p

  8. PCS: an Euler--Lagrange method for treating convection in pulsating stars using finite difference techniques in two spatial dimensions. [Finite difference method, time dependence

    Energy Technology Data Exchange (ETDEWEB)

    Deupree, R.G.

    1977-01-01

    Finite difference techniques were used to examine the coupling of radial pulsation and convection in stellar models having comparable time scales. Numerical procedures are emphasized, including diagnostics to help determine the range of free parameters.

  9. Development of low-energy x-ray fluorescence micro-distribution analysis using a laser plasma x-ray source and multilayer optics?

    NARCIS (Netherlands)

    Stuik, R.; Shmaenok, L. A.; Fledderus, H.; Andreev, S. S.; Shamov, E. A.; Zuev, S. Y.; Salashchenko, N. N.; F. Bijkerk,

    1999-01-01

    A new technique is presented for low-energy X-ray fluorescence micro-distribution analysis of low-Z elements at micrometer spatial resolutions. The technique is based on the use of a laser plasma X-ray source and spherically curved multilayer optics. A large collimator is used to focus the light fro

  10. Total oxidant-scavenging capacities of plasma from glycogen storage disease type Ia patients as measured by cyclic voltammetry, FRAP and luminescence techniques.

    Science.gov (United States)

    Koren, E; Lipkin, J; Klar, A; Hershkovitz, E; Ginsburg, I; Kohen, R

    2009-10-01

    It has been suggested that the very low incidence of atherosclerosis in glycogen storage disease type Ia (GSD Ia) subjects might be attributed to elevated levels of uric acid, one of the potent low molecular- weight antioxidants found in plasma. The present communication describes a use of two analytical methods-cyclic voltammetry and ferric reducing ability of plasma-and also two chemiluminescence methods to evaluate the total oxidant-scavenging capacities (TOSC) of plasma from GSD Ia patients. Our results verified the elevation of TOSC in GSD Ia patients and we propose the inclusion of luminescence and cyclic voltammetry assays as reliable methods for estimating TOSC in a variety of clinical disorders. Our findings with the cyclic voltammetry method add support to the assumption that the elevated uric acid levels might be the main contributor to plasma antioxidant capacity and possible protection against atherosclerosis.

  11. Applying spatial analysis techniques to assess the suitability of multipurpose uses of spring water in the Jiaosi Hot Spring Region, Taiwan

    Science.gov (United States)

    Jang, Cheng-Shin

    2016-04-01

    The Jiaosi Hot Spring Region is located in northeastern Taiwan and is rich in geothermal springs. The geothermal development of the Jiaosi Hot Spring Region dates back to the 18th century and currently, the spring water is processed for various uses, including irrigation, aquaculture, swimming, bathing, foot spas, and recreational tourism. Because of the proximity of the Jiaosi Hot Spring Region to the metropolitan area of Taipei City, the hot spring resources in this region attract millions of tourists annually. Recently, the Taiwan government is paying more attention to surveying the spring water temperatures in the Jiaosi Hot Spring Region because of the severe spring water overexploitation, causing a significant decline in spring water temperatures. Furthermore, the temperature of spring water is a reliable indicator for exploring the occurrence and evolution of springs and strongly affects hydrochemical reactions, components, and magnitudes. The multipurpose uses of spring water can be dictated by the temperature of the water. Therefore, accurately estimating the temperature distribution of the spring water is critical in the Jiaosi Hot Spring Region to facilitate the sustainable development and management of the multipurpose uses of the hot spring resources. To evaluate the suitability of spring water for these various uses, this study spatially characterized the spring water temperatures of the Jiaosi Hot Spring Region by using ordinary kriging (OK), sequential Gaussian simulation (SGS), and geographical information system (GIS). First, variogram analyses were used to determine the spatial variability of spring water temperatures. Next, OK and SGS were adopted to model the spatial distributions and uncertainty of the spring water temperatures. Finally, the land use (i.e., agriculture, dwelling, public land, and recreation) was determined and combined with the estimated distributions of the spring water temperatures using GIS. A suitable development strategy

  12. New-Measurement Techniques to Diagnose Charged Dust and Plasma Layers in the Near-Earth Space Environment Using Ground-Based Ionospheric Heating Facilities

    OpenAIRE

    Mahmoudian, Alireza

    2013-01-01

    Recently, experimental observations have shown that radar echoes from the irregularitysource region associated with mesospheric dusty space plasmas may be modulated by radio wave heating with ground-based ionospheric heating facilities. These experiments show great promise as a diagnostic for the associated dusty plasma in the Near-Earth Space Environment which is believed to have links to global change. This provides an alternative to more complicated and costly space-based observational app...

  13. Surface modification of Poly(tetrafluorethylene) magnetic stirring bars with plasma of hexamethyldisiloxane and its applications in the stir bar sorptive extraction technique

    OpenAIRE

    R. Baeza-Marrufo; P. Acereto-Escoffié; C. Carrera-Figueiras; D. Muñoz-Rodriguez; A. Ávila-Ortega; J. A. López-Barrera; J. Morales-Corona; Olayo-González, R.

    2012-01-01

    This paper explores the potential of plasma polymerization to modify the surface of stir bars for its use in Stir Bar Sorptive Extraction (SBSE). The modification of the poly(tetrafluoroethylene) surface of stir bars was done through plasma polymerization of hexamethyldisiloxane (30 min, 110 W and 1.4×10-1 Torr). The coating was characterized by contact angle, Fourier transform infrared spectroscopy, energy dispersive x-ray analysis and scanning electron microscopy. The modified stir bars wer...

  14. Quantification of Candesartan in Mouse Plasma by MALDI-TOFMS and in Tissue Sections by MALDI-Imaging Using the Stable-Isotope Dilution Technique.

    Science.gov (United States)

    Nakanishi, Toyofumi; Takai, Shinji; Jin, Denan; Takubo, Takayuki

    2013-01-01

    To determine the contents of candesartan in mouse plasma, and blood vessel and kidney sliced sections and also better understand its pharmacokinetics, we applied matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and MALDI-imaging mass spectrometry (IMS) with the selected reaction monitoring (SRM) mode using a labeled-internal standard. The results of fundamental examinations showed that the slope of the resulting curves of candesartan in the plasma from the equation was 0.91 and the y-intercept was 0.02. Both intra- and inter-day accuracies (n=10) and the precision of candesartan in the plasma by MALDI-TOFMS with the SRM mode were in the range of 3.4 to 17.3% and 93.2%, respectively. The detection limit of candesartan in spiked plasma was 0.2 nmol/L. IMS analysis enabled us to clarify distinct spacial time-distribution images in sliced mouse blood vessel and kidney sections although it still needed to improve a protocol of quantification. Typical pharmacokinetic patterns of candesartan were obtained in the plasma and sliced kidney sections, but those in the blood vessel sections gradually increased 24 h after administration. MALDI-TOFMS and IMS with the SRM mode are powerful tools to identify the spacial distribution and traceability of candesartan in sliced blood vessel and tissue sections as well as in the plasma.

  15. In situ ``artificial plasma'' calibration of tokamak magnetic sensors

    Science.gov (United States)

    Shiraki, D.; Levesque, J. P.; Bialek, J.; Byrne, P. J.; DeBono, B. A.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.; Rath, N.

    2013-06-01

    A unique in situ calibration technique has been used to spatially calibrate and characterize the extensive new magnetic diagnostic set and close-fitting conducting wall of the High Beta Tokamak-Extended Pulse (HBT-EP) experiment. A new set of 216 Mirnov coils has recently been installed inside the vacuum chamber of the device for high-resolution measurements of magnetohydrodynamic phenomena including the effects of eddy currents in the nearby conducting wall. The spatial positions of these sensors are calibrated by energizing several large in situ calibration coils in turn, and using measurements of the magnetic fields produced by the various coils to solve for each sensor's position. Since the calibration coils are built near the nominal location of the plasma current centroid, the technique is referred to as an "artificial plasma" calibration. The fitting procedure for the sensor positions is described, and results of the spatial calibration are compared with those based on metrology. The time response of the sensors is compared with the evolution of the artificial plasma current to deduce the eddy current contribution to each signal. This is compared with simulations using the VALEN electromagnetic code, and the modeled copper thickness profiles of the HBT-EP conducting wall are adjusted to better match experimental measurements of the eddy current decay. Finally, the multiple coils of the artificial plasma system are also used to directly calibrate a non-uniformly wound Fourier Rogowski coil on HBT-EP.

  16. SPATIAL STABILITY

    OpenAIRE

    Pascal Mossay

    2004-01-01

    We consider a continuous spatial economy consisting of pure exchange local economies. Agents are allowed to change their location over time as a response to spatial utility differentials. These spatial adjustments toward higher utility neighborhoods lead the spatial economy to converge to a spatially uniform allocation of resources, provided that the matrix of price effects is quasi-negative definite. Furthermore our model provides a real time interpretation of the tâtonnement story. Also, sp...

  17. In situ electromagnetic field